+1997-12-05 00:01 Ulrich Drepper <drepper@cygnus.com>
+
+ The kernel expects the arguments in a different order.
+ * sysdeps/unix/sysv/linux/i386/s_pread64.S: New file.
+ * sysdeps/unix/sysv/linux/i386/s_pwrite64.S: New file.
+
+ * FAQ.in: New file.
+ * gen-FAQ.pl: New file.
+ * Makefile (FAQ): Add rule to generate from FAQ.in.
+
+ * iconvdata/Makefile: Treat libJIS like the other modules.
+
+ * rt/librt.map: New file.
+
+ * sysdeps/wordsize-32/bits/environments.h: Add test for direct
+ inclusion.
+ * sysdeps/wordsize-64/bits/environments.h: Likewise. Correct
+ comment.
+
+1997-12-04 22:29 Ulrich Drepper <drepper@cygnus.com>
+
+ * sysdeps/unix/sysv/linux/rt_sigprocmask.c: Fix prototype.
+ * sysdeps/unix/sysv/linux/rt_sigsuspend.c: Likewise.
+ * sysdeps/unix/sysv/linux/rt_sigqueueinfo.c: Include <sys/types.h>.
+ Patches by Thorsten Kukuk <kukuk@weber.uni-paderborn.de>.
+
+1997-11-27 Andreas Jaeger <aj@arthur.rhein-neckar.de>
+
+ * string/bits/string2.h: Fix spellings.
+
+ * string/string.h: Fix spellings.
+
+1997-12-04 Andreas Jaeger <aj@arthur.rhein-neckar.de>
+
+ * sysdeps/unix/sysv/linux/i386/sigaction.c: Rename extern
+ declaration to __syscall_rt_sigaction.
+
+ * sysdeps/unix/sysv/linux/sigreturn.c: Remove inclusion of
+ non-existant <sigcontext.h>.
+
+1997-12-04 Andreas Jaeger <aj@arthur.rhein-neckar.de>
+
+ * sysdeps/generic/enbl-secure.c (__libc_init_secure): Correct
+ typo.
+
+1997-12-04 Andreas Jaeger <aj@arthur.rhein-neckar.de>
+
+ * sysdeps/wordsize-64/bits/environments.h: Correct spelling.
+
+ * Makeconfig (shared-thread-library): Correct spelling.
+
+ * sysdeps/unix/sysv/linux/sys/pci.h: Include <linux/pci.h> and not
+ <asm/pci.h>.
+
+1997-12-04 Andreas Jaeger <aj@arthur.rhein-neckar.de>
+
+ * sysdeps/unix/sysv/linux/bits/socket.h: Add AF_* and PF_
+ constants from Linux headers. Pointed out by
+ csmall@scooter.o.i.net. [PR libc/369]
+
+1997-12-04 10:21 Thorsten Kukuk <kukuk@vt.uni-paderborn.de>
+
+ * sunrpc/xcrypt.c: Fix lower/upper characters in optimized hexval.
+
+1997-12-04 00:06 Zack Weinberg <zack@rabi.phys.columbia.edu>
+
+ * configure.in: If --enable-add-ons is given without an
+ argument, set the addons list to all subdirs with a configure
+ script.
+
1997-12-03 23:50 Ulrich Drepper <drepper@cygnus.com>
* Makeconfig: Add shared-thread-library variable.
- Frequently Asked Question on GNU C Library
+ Frequently Asked Questions about the GNU C Library
-As every FAQ this one also tries to answer questions the user might have
-when using the package. Please make sure you read this before sending
-questions or bug reports to the maintainers.
+This document tries to answer questions a user might have when
+installing and using glibc. Please make sure you read this before
+sending questions or bug reports to the maintainers.
-The GNU C Library is very complex. The building process exploits the
-features available in tools generally available. But many things can
-only be done using GNU tools. Also the code is sometimes hard to
-understand because it has to be portable but on the other hand must be
-fast. But you need not understand the details to use GNU C Library.
-This will only be necessary if you intend to contribute or change it.
+The GNU C library is very complex. The installation process has not
+been completely automated; there are too many variables. You can do
+substantial damage to your system by installing the library
+incorrectly. Make sure you understand what you are undertaking before
+you begin.
If you have any questions you think should be answered in this document,
please let me know.
--drepper@cygnus.com
\f
-~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~
-[Q1] ``What systems does the GNU C Library run on?''
+~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~
+
+1. Compiling glibc
+
+1.1. What systems does the GNU C Library run on?
+1.2. What compiler do I need to build GNU libc?
+1.3. When I try to compile glibc I get only error messages.
+ What's wrong?
+1.4. Do I need a special linker or archiver?
+1.5. Do I need some more things to compile GNU C Library?
+1.6. When I run `nm -u libc.so' on the produced library I still
+ find unresolved symbols. Can this be ok?
+1.7. What are these `add-ons'?
+1.8. My XXX kernel emulates a floating-point coprocessor for me.
+ Should I enable --with-fp?
+1.9. When compiling GNU libc I get lots of errors saying functions
+ in glibc are duplicated in libgcc.
+1.10. What's the problem with configure --enable-omitfp?
+
+2. Installation and configuration issues
+
+2.1. Can I replace the libc on my Linux system with GNU libc?
+2.2. How do I configure GNU libc so that the essential libraries
+ like libc.so go into /lib and the other into /usr/lib?
+2.3. How should I avoid damaging my system when I install GNU libc?
+2.4. Do I need to use GNU CC to compile programs that will use the
+ GNU C Library?
+2.5. When linking with the new libc I get unresolved symbols
+ `crypt' and `setkey'. Why aren't these functions in the
+ libc anymore?
+2.6. When I use GNU libc on my Linux system by linking against
+ the libc.so which comes with glibc all I get is a core dump.
+2.7. Looking through the shared libc file I haven't found the
+ functions `stat', `lstat', `fstat', and `mknod' and while
+ linking on my Linux system I get error messages. How is
+ this supposed to work?
+2.8. How can I compile gcc 2.7.2.1 from the gcc source code using
+ glibc 2.x?
+2.9. The `gencat' utility cannot process the catalog sources which
+ were used on my Linux libc5 based system. Why?
+2.10. I have set up /etc/nis.conf, and the Linux libc 5 with NYS
+ works great. But the glibc NIS+ doesn't seem to work.
+2.11. After installing glibc name resolving doesn't work properly.
+2.12. I have /usr/include/net and /usr/include/scsi as symlinks
+ into my Linux source tree. Is that wrong?
+2.13. Programs like `logname', `top', `uptime' `users', `w' and
+ `who', show incorrect information about the (number of)
+ users on my system. Why?
+2.14. After upgrading to glibc 2.1 with symbol versioning I get
+ errors about undefined symbols. What went wrong?
+2.15. When I start the program XXX after upgrading the library
+ I get
+ XXX: Symbol `_sys_errlist' has different size in shared
+ object, consider re-linking
+ Why? What should I do?
+
+3. Source and binary incompatibilities, and what to do about them
+
+3.1. I expect GNU libc to be 100% source code compatible with
+ the old Linux based GNU libc. Why isn't it like this?
+3.2. Why does getlogin() always return NULL on my Linux box?
+3.3. Where are the DST_* constants found in <sys/time.h> on many
+ systems?
+3.4. The prototypes for `connect', `accept', `getsockopt',
+ `setsockopt', `getsockname', `getpeername', `send',
+ `sendto', and `recvfrom' are different in GNU libc from
+ any other system I saw. This is a bug, isn't it?
+3.5. On Linux I've got problems with the declarations in Linux
+ kernel headers.
+3.6. I don't include any kernel headers myself but the compiler
+ still complains about redeclarations of types in the kernel
+ headers.
+3.7. Why don't signals interrupt system calls anymore?
+3.8. I've got errors compiling code that uses certain string
+ functions. Why?
+
+4. Miscellaneous
+
+4.1. After I changed configure.in I get `Autoconf version X.Y.
+ or higher is required for this script'. What can I do?
+4.2. When I try to compile code which uses IPv6 headers and
+ definitions on my Linux 2.x.y system I am in trouble.
+ Nothing seems to work.
-[Q2] ``What compiler do I need to build GNU libc?''
-
-[Q3] ``When starting make I get only error messages.
- What's wrong?''
-
-[Q4] ``After I changed configure.in I get `Autoconf version X.Y.
- or higher is required for this script'. What can I do?''
-
-[Q5] ``Do I need a special linker or archiver?''
-
-[Q6] ``Do I need some more things to compile GNU C Library?''
-
-[Q7] ``When I run `nm -u libc.so' on the produced library I still
- find unresolved symbols? Can this be ok?''
-
-[Q8] ``Can I replace the libc on my Linux system with GNU libc?''
-
-[Q9] ``I expect GNU libc to be 100% source code compatible with
- the old Linux based GNU libc. Why isn't it like this?''
-
-[Q10] ``Why does getlogin() always return NULL on my Linux box?''
-
-[Q11] ``Where are the DST_* constants found in <sys/time.h> on many
- systems?''
-
-[Q12] ``The `gencat' utility cannot process the input which are
- successfully used on my Linux libc based system. Why?''
-
-[Q13] ``How do I configure GNU libc so that the essential libraries
- like libc.so go into /lib and the other into /usr/lib?''
-
-[Q14] ``When linking with the new libc I get unresolved symbols
- `crypt' and `setkey'. Why aren't these functions in the
- libc anymore?''
-
-[Q15] ``What are these `add-ons'?''
-
-[Q16] ``When I use GNU libc on my Linux system by linking against
- to libc.so which comes with glibc all I get is a core dump.''
-
-[Q17] ``Looking through the shared libc file I haven't found the
- functions `stat', `lstat', `fstat', and `mknod' and while
- linking on my Linux system I get error messages. How is
- this supposed to work?''
-
-[Q18] ``The prototypes for `connect', `accept', `getsockopt',
- `setsockopt', `getsockname', `getpeername', `send',
- `sendto', and `recvfrom' are different in GNU libc than
- on any other system I saw. This is a bug, isn't it?''
-
-[Q19] ``My XXX kernel emulates a floating-point coprocessor for me.
- Should I enable --with-fp?''
-
-[Q20] ``How can I compile gcc 2.7.2.1 from the gcc source code using
- glibc 2.x?
-
-[Q21] ``On Linux I've got problems with the declarations in Linux
- kernel headers.''
-
-[Q22] ``When I try to compile code which uses IPv6 header and
- definitions on my Linux 2.x.y system I am in trouble.
- Nothing seems to work.''
-
-[Q23] ``When compiling GNU libc I get lots of errors saying functions
- in glibc are duplicated in libgcc.''
-
-[Q24] ``I have set up /etc/nis.conf, and the Linux libc 5 with NYS
- works great. But the glibc NIS+ doesn't seem to work.''
-
-[Q25] ``After installing glibc name resolving doesn't work properly.''
-
-
-[Q26] ``I have /usr/include/net and /usr/include/scsi as symlinks
- into my Linux source tree. Is that wrong?''
-
-[Q27] ``Programs like `logname', `top', `uptime' `users', `w' and
- `who', show incorrect information about the (number of)
- users on my system. Why?''
-
-[Q28] ``After upgrading to a glibc 2.1 with symbol versioning I get
- errors about undefined symbols. What went wrong?''
-
-[Q29] ``I don't include any kernel header myself but still the
- compiler complains about type redeclarations of types in the
- kernel headers.''
-
-[Q30] ``When I start the program XXX after upgrading the library
- I get
- XXX: Symbol `_sys_errlist' has different size in shared object, consider re-linking
- Why? What to do?''
-
-[Q31] ``What's the problem with configure --enable-omitfp?''
+\f
+~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~
-[Q32] ``Why don't signals interrupt system calls anymore?''
+1. Compiling glibc
-[Q33] ``I've got errors compiling code that uses certain string
- functions. Why?''
-\f
-~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~
-[Q1] ``What systems does the GNU C Library run on?''
+1.1. What systems does the GNU C Library run on?
-[A1] {UD} This is difficult to answer. The file `README' lists the
-architectures GNU libc is known to run *at some time*. This does not
-mean that it still can be compiled and run on them in the moment.
+{UD} This is difficult to answer. The file `README' lists the
+architectures GNU libc was known to run on *at some time*. This does
+not mean that it still can be compiled and run on them now.
-The systems glibc is known to work on in the moment and most probably
-in the future are:
+The systems glibc is known to work on as of this release, and most
+probably in the future, are:
*-*-gnu GNU Hurd
i[3456]86-*-linux-gnu Linux-2.0 on Intel
sparc-*-linux-gnu Linux-2.0 on SPARC
sparc64-*-linux-gnu Linux-2.0 on UltraSPARC
-Other Linux platforms are also on the way to be supported but I need
-some success reports first.
+Ports to other Linux platforms are in development, and may in fact
+work already, but no one has sent us success reports for them.
+Currently no ports to other operating systems are underway, although a
+few people have expressed interest.
If you have a system not listed above (or in the `README' file) and
you are really interested in porting it, contact
<bug-glibc@prep.ai.mit.edu>
-~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~
-[Q2] ``What compiler do I need to build GNU libc?''
+1.2. What compiler do I need to build GNU libc?
-[A2] {UD} It is (almost) impossible to compile GNU C Library using a
-different compiler than GNU CC. A lot of extensions of GNU CC are
-used to increase the portability and speed.
+{UD} You must use GNU CC to compile GNU libc. A lot of extensions of
+GNU CC are used to increase portability and speed.
-But this does not mean you have to use GNU CC for using the GNU C
-Library. In fact you should be able to use the native C compiler
-because the success only depends on the binutils: the linker and
-archiver.
-
-The GNU CC is found like all other GNU packages on
+GNU CC is found, like all other GNU packages, on
ftp://prep.ai.mit.edu/pub/gnu
-or better one of the many mirror sites.
+and the many mirror sites. prep is always overloaded, so try to find
+a local mirror first.
You always should try to use the latest official release. Older
-versions might not have all the features GNU libc could use. It is
-known that on most platforms compilers earlier than 2.7.2.3 fail so
-at least use this version.
+versions may not have all the features GNU libc requires. On most
+supported platforms, 2.7.2.3 is the earliest version that works at all.
-~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~
-[Q3] ``When starting `make' I get only errors messages.
- What's wrong?''
+1.3. When I try to compile glibc I get only error messages.
+ What's wrong?
-[A3] {UD} You definitely need GNU make to translate GNU libc. No
+{UD} You definitely need GNU make to translate GNU libc. No
other make program has the needed functionality.
-Versions before 3.74 have bugs which prevent correct execution so you
-should upgrade to the latest version before starting the compilation.
-
-We recommend version GNU make version 3.75. Versions 3.76 and
-3.76.1 are known to have bugs which only show up in big projects like
-GNU libc.
+We recommend version GNU make version 3.75. Versions 3.76 and 3.76.1
+have bugs which appear when building big projects like GNU libc.
+Versions before 3.74 have bugs and/or are missing features.
-~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~
-[Q4] ``After I changed configure.in I get `Autoconf version X.Y.
- or higher is required for this script'. What can I do?''
+1.4. Do I need a special linker or archiver?
-[A4] {UD} You have to get the specified autoconf version (or a later)
-from your favourite mirror of prep.ai.mit.edu.
-
-
-~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~
-[Q5] ``Do I need a special linker or archiver?''
-
-[A5] {UD} If your native versions are not too buggy you can probably
-work with them. But GNU libc works best with GNU binutils.
+{UD} You may be able to use your system linker, but GNU libc works
+best with GNU binutils.
On systems where the native linker does not support weak symbols you
-will not get a really ISO C compliant C library. Generally speaking
+will not get a fully ISO C compliant C library. Generally speaking
you should use the GNU binutils if they provide at least the same
functionality as your system's tools.
-Always get the newest release of GNU binutils available.
-Older releases are known to have bugs that affect building the GNU C
-Library.
+Always get the newest release of GNU binutils available. Older
+releases are known to have bugs that prevent a successful compilation.
+{ZW} As of release 2.1 a linker supporting symbol versions is
+required. For Linux, get binutils-2.8.1.0.17 or later. Other systems
+may have native linker support, but it's moot right now, because glibc
+has not been ported to them.
-~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~
-[Q6] ``Do I need some more things to compile GNU C Library?''
-[A6] {UD} Yes, there are some more :-).
+1.5. Do I need some more things to compile GNU C Library?
-* GNU gettext; the GNU libc is internationalized and partly localized.
- For bringing the messages for the different languages in the needed
- form the tools from the GNU gettext package are necessary. See
- ftp://prep.ai.mit.edu/pub/gnu or better any mirror site.
+{UD} Yes, there are some more :-).
-* lots of diskspace (for i?86-linux this means, e.g., ~170MB; for ppc-linux
- even ~200MB).
+* GNU gettext. This package contains the tools needed to construct
+ `message catalog' files containing translated versions of system
+ messages. See ftp://prep.ai.mit.edu/pub/gnu or better any mirror
+ site. (We distribute compiled message catalogs, but they may not be
+ updated in patches.)
- You should avoid compiling on a NFS mounted device. This is very
- slow.
+* Some files depend on special tools. E.g., files ending in .gperf
+ need a `gperf' program. The GNU version (part of libg++) is known
+ to work while some vendor versions do not.
-* plenty of time (approx 1h for i?86-linux on i586@133 or 2.5h on
- i486@66 or 4.5h on i486@33), both for shared and static only).
- Multiply this by 1.5 or 2.0 if you build profiling and/or the highly
- optimized version as well. For Hurd systems times are much higher.
+ You should not need these tools unless you change the source files.
- For Atari Falcon (Motorola 68030 @ 16 Mhz, 14 Mb memory) James Troup
- <J.J.Troup@comp.brad.ac.uk> reports for a full build (shared, static,
- and profiled) a compile time of 45h34m.
+* When compiling for Linux, the header files of the Linux kernel must
+ be available to the compiler as <linux/*.h> and <asm/*.h>.
- For Atari TT030 (Motorola 68030 @ 32 Mhz, 34 Mb memory) (full build)
- a compile time of 22h48m.
+* lots of disk space (~170MB for i?86-linux; more for RISC platforms).
- If you have some more measurements let me know.
+* plenty of time. Compiling just the shared and static libraries for
+ i?86-linux takes approximately 1h on an i586@133, or 2.5h on
+ i486@66, or 4.5h on i486@33. Multiply this by 1.5 or 2.0 if you
+ build profiling and/or the highly optimized version as well. For
+ Hurd systems times are much higher.
-* When compiling for Linux:
+ You should avoid compiling in a NFS mounted filesystem. This is
+ very slow.
- + the header files of the Linux kernel must be available in the
- search path of the CPP as <linux/*.h> and <asm/*.h>.
+ James Troup <J.J.Troup@comp.brad.ac.uk> reports a compile time of
+ 45h34m for a full build (shared, static, and profiled) on
+ Atari Falcon (Motorola 68030 @ 16 Mhz, 14 Mb memory) and 22h48m
+ on Atari TT030 (Motorola 68030 @ 32 Mhz, 34 Mb memory)
-* Some files depend on special tools. E.g., files ending in .gperf
- need a `gperf' program. The GNU version (part of libg++) is known
- to work while some vendor versions do not.
+ If you have some more measurements let me know.
- You should not need these tools unless you change the source files.
-~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~
-[Q7] ``When I run `nm -u libc.so' on the produced library I still
- find unresolved symbols? Can this be ok?''
+1.6. When I run `nm -u libc.so' on the produced library I still
+ find unresolved symbols. Can this be ok?
-[A7] {UD} Yes, this is ok. There can be several kinds of unresolved
+{UD} Yes, this is ok. There can be several kinds of unresolved
symbols:
-* magic symbols automatically generated by the linker. Names are
- often like __start_* and __stop_*
+* magic symbols automatically generated by the linker. These have names
+ like __start_* and __stop_*
* symbols starting with _dl_* come from the dynamic linker
* symbols resolved by using libgcc.a
(__udivdi3, __umoddi3, or similar)
-* weak symbols, which need not be resolved at all
- (currently fabs among others; this gets resolved if the program
- is linked against libm, too.)
+* weak symbols, which need not be resolved at all (fabs for example)
Generally, you should make sure you find a real program which produces
errors while linking before deciding there is a problem.
-~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~
-[Q8] ``Can I replace the libc on my Linux system with GNU libc?''
-
-[A8] {UD} You cannot replace any existing libc for Linux with GNU
-libc. There are different versions of C libraries and you can run
-libcs with different major version independently.
-
-For Linux there are today two libc versions:
- libc-4 old a.out libc
- libc-5 current ELF libc
-
-GNU libc will have the major number 6 and therefore you can have this
-additionally installed. For more information consult documentation for
-shared library handling. The Makefiles of GNU libc will automatically
-generate the needed symbolic links which the linker will use.
+1.7. What are these `add-ons'?
+{UD} To avoid complications with export rules or external source
+code some optional parts of the libc are distributed as separate
+packages (e.g., the crypt package, see question 2.5).
-~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~
-[Q9] ``I expect GNU libc to be 100% source code compatible with
- the old Linux based GNU libc. Why isn't it like this?''
+To use these packages as part of GNU libc, just unpack the tarfiles in
+the libc source directory and tell the configuration script about them
+using the --enable-add-ons option. If you give just --enable-add-ons
+configure tries to find all the add-on packages in your source tree.
+This may not work. If it doesn't, or if you want to select only a
+subset of the add-ons, give a comma-separated list of the add-ons to
+enable:
-[A9] {DMT,UD} Not every extension in Linux libc's history was well
-thought-out. In fact it had a lot of problems with standards compliance
-and with cleanliness. With the introduction of a new version number these
-errors now can be corrected. Here is a list of the known source code
-incompatibilities:
+ configure --enable-add-ons=crypt,linuxthreads
-* _GNU_SOURCE: glibc does not automatically define _GNU_SOURCE. Thus,
- if a program depends on GNU extensions or some other non-standard
- functionality, it is necessary to compile it with C compiler option
- -D_GNU_SOURCE, or better, to put `#define _GNU_SOURCE' at the beginning
- of your source files, before any C library header files are included.
- This difference normally manifests itself in the form of missing
- prototypes and/or data type definitions. Thus, if you get such errors,
- the first thing you should do is try defining _GNU_SOURCE and see if
- that makes the problem go away.
+for example.
- For more information consult the file `NOTES' part of the GNU C
- library sources.
+Add-ons can add features (including entirely new shared libraries),
+override files, provide support for additional architectures, and
+just about anything else. The existing makefiles do most of the work;
+only some few stub rules must be written to get everything running.
-* reboot(): GNU libc sanitizes the interface of reboot() to be more
- compatible with the interface used on other OSes. In particular,
- reboot() as implemented in glibc takes just one argument. This argument
- corresponds to the third argument of the Linux reboot system call.
- That is, a call of the form reboot(a, b, c) needs to be changed into
- reboot(c).
- Beside this the header <sys/reboot.h> defines the needed constants
- for the argument. These RB_* constants should be used instead of the
- cryptic magic numbers.
-
-* swapon(): the interface of this function didn't changed, but the
- prototype is in a separate header file <sys/swap.h>. For the additional
- argument of swapon() you should use the SWAP_* constants from
- <linux/swap.h>, which get defined when <sys/swap.h> is included.
-
-* errno: If a program uses variable "errno", then it _must_ include header
- file <errno.h>. The old libc often (erroneously) declared this variable
- implicitly as a side-effect of including other libc header files. glibc
- is careful to avoid such namespace pollution, which, in turn, means that
- you really need to include the header files that you depend on. This
- difference normally manifests itself in the form of the compiler
- complaining about the references of the undeclared symbol "errno".
-* Linux-specific syscalls: All Linux system calls now have appropriate
- library wrappers and corresponding declarations in various header files.
- This is because the syscall() macro that was traditionally used to
- work around missing syscall wrappers are inherently non-portable and
- error-prone. The following tables lists all the new syscall stubs,
- the header-file declaring their interface and the system call name.
+1.8. My XXX kernel emulates a floating-point coprocessor for me.
+ Should I enable --with-fp?
- syscall name: wrapper name: declaring header file:
- ------------- ------------- ----------------------
- bdflush bdflush <sys/kdaemon.h>
- syslog ksyslog_ctl <sys/klog.h>
+{ZW} An emulated FPU is just as good as a real one, as far as the C
+library is concerned. You only need to say --without-fp if your
+machine has no way to execute floating-point instructions.
-* lpd: Older versions of lpd depend on a routine called _validuser().
- The library does not provide this function, but instead provides
- __ivaliduser() which has a slightly different interfaces. Simply
- upgrading to a newer lpd should fix this problem (e.g., the 4.4BSD
- lpd is known to be working).
+People who are interested in squeezing the last drop of performance
+out of their machine may wish to avoid the trap overhead, but this is
+far more trouble than it's worth: you then have to compile
+*everything* this way, including the compiler's internal libraries
+(libgcc.a for GNU C), because the calling conventions change.
-* resolver functions/BIND: like on many other systems the functions of
- the resolver library are not included in the libc itself. There is
- a separate library libresolv. If you find some symbols starting with
- `res_*' undefined simply add -lresolv to your call of the linker.
-* the `signal' function's behaviour corresponds to the BSD semantic and
- not the SysV semantic as it was in libc-5. The interface on all GNU
- systems shall be the same and BSD is the semantic of choice. To use
- the SysV behaviour simply use `sysv_signal', or define _XOPEN_SOURCE.
- See question 32 for details.
+1.9. When compiling GNU libc I get lots of errors saying functions
+ in glibc are duplicated in libgcc.
+{EY} This is *exactly* the same problem that I was having. The
+problem was due to the fact that configure didn't correctly detect
+that the linker flag --no-whole-archive was supported in my linker.
+In my case it was because I had run ./configure with bogus CFLAGS, and
+the test failed.
-~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~
-[Q10] ``Why does getlogin() always return NULL on my Linux box?''
+One thing that is particularly annoying about this problem is that
+once this is misdetected, running configure again won't fix it unless
+you first delete config.cache.
-[A10] {UD} The GNU C library has a format for the UTMP and WTMP file
-which differs from what your system currently has. It was extended to
-fulfill the needs of the next years when IPv6 is introduced. So the
-record size is different, fields might have a different position and
-so reading the files written by functions from the one library cannot
-be read by functions from the other library. Sorry, but this is what
-a major release is for. It's better to have a cut now than having no
-means to support the new techniques later.
+{UD} Starting with glibc-2.0.3 there should be a better test to avoid
+some problems of this kind. The setting of CFLAGS is checked at the
+very beginning and if it is not usable `configure' will bark.
-{MK} There is however a (partial) solution for this problem. Please
-take a look at the file `README.utmpd'.
+1.10. What's the problem with configure --enable-omitfp?
-~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~
-[Q11] ``Where are the DST_* constants found in <sys/time.h> on many
- systems?''
+{AJ} When --enable-omitfp is set the libraries are built without frame
+pointers. Some compilers produce buggy code for this model and
+therefore we don't advise using it at the moment.
-[A11] {UD} These constants come from the old BSD days and are not used
-today anymore (even the Linux based glibc does not implement the handling
-although the constants are defined).
+If you use --enable-omitfp, you're on your own. If you encounter
+problems with a library that was build this way, we advise you to
+rebuild the library without --enable-omitfp. If the problem vanishes
+consider tracking the problem down and report it as compiler failure.
-Instead GNU libc contains the zone database handling and compatibility
-code for POSIX TZ environment variable handling.
+Since a library build with --enable-omitfp is undebuggable on most
+systems, debuggable libraries are also built - you can use it by
+appending "_g" to the library names.
+The compilation of these extra libraries and the compiler optimizations
+slow down the build process and need more disk space.
-~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~
-[Q12] ``The `gencat' utility cannot process the input which are
- successfully used on my Linux libc based system. Why?''
+\f
+. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
-[A12] {UD} Unlike the author of the `gencat' program which is distributed
-with Linux libc I have read the underlying standards before writing the
-code. It is completely compatible with the specification given in
-X/Open Portability Guide.
+2. Installation and configuration issues
-To ease the transition from the Linux version some of the non-standard
-features are also present in the `gencat' program of GNU libc. This
-mainly includes the use of symbols for the message number and the automatic
-generation of header files which contain the needed #defines to map the
-symbols to integers.
+2.1. Can I replace the libc on my Linux system with GNU libc?
-Here is a simple SED script to convert at least some Linux specific
-catalog files to the XPG4 form:
+{UD} You cannot replace any existing libc for Linux with GNU
+libc. It is binary incompatible and therefore has a different major
+version. You can, however, install it alongside your existing libc.
------------------------------------------------------------------------
-# Change catalog source in Linux specific format to standard XPG format.
-# Ulrich Drepper <drepper@cygnus.com>, 1996.
-#
-/^\$ #/ {
- h
- s/\$ #\([^ ]*\).*/\1/
- x
- s/\$ #[^ ]* *\(.*\)/\$ \1/
-}
+For Linux there are three major libc versions:
+ libc-4 a.out libc
+ libc-5 original ELF libc
+ libc-6 GNU libc
-/^# / {
- s/^# \(.*\)/\1/
- G
- s/\(.*\)\n\(.*\)/\2 \1/
-}
------------------------------------------------------------------------
+You can have any combination of these three installed. For more
+information consult documentation for shared library handling. The
+Makefiles of GNU libc will automatically generate the needed symbolic
+links which the linker will use.
-~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~
-[Q13] ``How do I configure GNU libc so that the essential libraries
- like libc.so go into /lib and the other into /usr/lib?''
+2.2. How do I configure GNU libc so that the essential libraries
+ like libc.so go into /lib and the other into /usr/lib?
-[A13] {UD,AJ} Like all other GNU packages GNU libc is configured to
-use a base directory and install all files relative to this. If you
-intend to really use GNU libc on your system this base directory is
-/usr. I.e., you run
- configure --prefix=/usr <other_options>
+{UD,AJ} Like all other GNU packages GNU libc is designed to use a base
+directory and install all files relative to this. The default is
+/usr/local, because this is safe (it will not damage the system if
+installed there). If you wish to install GNU libc as the primary C
+library on your system, set the base directory to /usr (i.e. run
+configure --prefix=/usr <other_options>). Note that this can damage
+your system; see question 2.3 for details.
Some systems like Linux have a filesystem standard which makes a
difference between essential libraries and others. Essential
libraries are placed in /lib because this directory is required to be
located on the same disk partition as /. The /usr subtree might be
-found on another partition/disk.
+found on another partition/disk. If you configure for Linux with
+--prefix=/usr, then this will be done automatically.
-To install the essential libraries which come with GNU libc in /lib
-one must explicitly tell this (except on Linux, see below). Autoconf
-has no option for this so you have to use the file where all user
-supplied additional information should go in: `configparms' (see the
-`INSTALL' file). Therefore the `configparms' file should contain:
+To install the essential libraries which come with GNU libc in /lib on
+systems other than Linux one must explicitly request it. Autoconf has
+no option for this so you have to use a `configparms' file (see the
+`INSTALL' file for details). It should contain:
slibdir=/lib
sysconfdir=/etc
The first line specifies the directory for the essential libraries,
-the second line the directory for file which are by tradition placed
-in a directory named /etc.
+the second line the directory for system configuration files.
-No rule without an exception: If you configure for Linux with
---prefix=/usr, then slibdir and sysconfdir will automatically be
-defined as stated above.
+2.3. How should I avoid damaging my system when I install GNU libc?
-~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~
-[Q14] ``When linking with the new libc I get unresolved symbols
- `crypt' and `setkey'. Why aren't these functions in the
- libc anymore?''
+{ZW} If you wish to be cautious, do not configure with --prefix=/usr.
+If you don't specify a prefix, glibc will be installed in /usr/local,
+where it will probably not break anything. (If you wish to be
+certain, set the prefix to something like /usr/local/glibc2 which is
+not used for anything.)
-[A14] {UD} Remember the US restrictions of exporting cryptographic
-programs and source code. Until this law gets abolished we cannot
-ship the cryptographic function together with the libc.
+The dangers when installing glibc in /usr are twofold:
-But of course we provide the code and there is an very easy way to use
-this code. First get the extra package. People in the US may get it
-from the same place they got the GNU libc from. People outside the US
-should get the code from ftp://ftp.ifi.uio.no/pub/gnu, or another
-archive site outside the USA. The README explains how to install the
-sources.
+* glibc will overwrite the headers in /usr/include. Other C libraries
+ install a different but overlapping set of headers there, so the
+ effect will probably be that you can't compile anything. You need to
+ rename /usr/include out of the way first. (Do not throw it away; you
+ will then lose the ability to compile programs against your old libc.)
-If you already have the crypt code on your system the reason for the
-failure is probably that you failed to link with -lcrypt. The crypto
-functions are in a separate library to make it possible to export GNU
-libc binaries from the US.
+* None of your old libraries, static or shared, can be used with a
+ different C library major version. For shared libraries this is not a
+ problem, because the filenames are different and the dynamic linker
+ will enforce the restriction. But static libraries have no version
+ information. You have to evacuate all the static libraries in
+ /usr/lib to a safe location.
+The situation is rather similar to the move from a.out to ELF which
+long-time Linux users will remember.
-~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~
-[Q15] ``What are these `add-ons'?''
-[A15] {UD} To avoid complications with export rules or external source
-code some optional parts of the libc are distributed as separate
-packages (e.g., the crypt package, see Q14).
+2.4. Do I need to use GNU CC to compile programs that will use the
+ GNU C Library?
-To ease the use as part of GNU libc the installer just has to unpack
-the package and tell the configuration script about these additional
-subdirectories using the --enable-add-ons option. When you add the
-crypt add-on you just have to use
+{ZW} In theory, no; the linker does not care, and the headers are
+supposed to check for GNU CC before using its extensions to the C
+language.
- configure --enable-add-ons=crypt,XXX ...
+However, there are currently no ports of glibc to systems where
+another compiler is the default, so no one has tested the headers
+extensively against another compiler. You may therefore encounter
+difficulties. If you do, please report them as bugs.
-where XXX are possible other add-ons and ... means the rest of the
-normal option list.
+Also, in several places GNU extensions provide large benefits in code
+quality. For example, the library has hand-optimized, inline assembly
+versions of some string functions. These can only be used with GCC.
+See question 3.8 for details.
-You can use add-ons also to overwrite some files in glibc. The add-on
-system dependent subdirs are search first. It is also possible to add
-banner files (use a file named `Banner') or create shared libraries.
-Using add-ons has the big advantage that the makefiles of the GNU libc
-can be used. Only some few stub rules must be written to get
-everything running. Even handling of architecture dependent
-compilation is provided. The GNU libc's sysdeps/ directory shows how
-to use this feature.
+2.5. When linking with the new libc I get unresolved symbols
+ `crypt' and `setkey'. Why aren't these functions in the
+ libc anymore?
+{UD} The US places restrictions on exporting cryptographic programs
+and source code. Until this law gets abolished we cannot ship the
+cryptographic functions together with glibc.
-~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~
-[Q16] ``When I use GNU libc on my Linux system by linking against
- to libc.so which comes with glibc all I get is a core dump.''
+The functions are available, as an add-on (see question 1.7). People in the
+US may get it from the same place they got GNU libc from. People
+outside the US should get the code from ftp://ftp.ifi.uio.no/pub/gnu,
+or another archive site outside the USA. The README explains how to
+install the sources.
-[A16] {UD} It is not enough to simply link against the GNU libc
-library itself. The GNU C library comes with its own dynamic linker
-which really conforms to the ELF API standard. This dynamic linker
-must be used.
+If you already have the crypt code on your system the reason for the
+failure is probably that you did not link with -lcrypt. The crypto
+functions are in a separate library to make it possible to export GNU
+libc binaries from the US.
-Normally this is done by the compiler. The gcc will use
- -dynamic-linker /lib/ld-linux.so.1
+2.6. When I use GNU libc on my Linux system by linking against
+ the libc.so which comes with glibc all I get is a core dump.
-unless the user specifies her/himself a -dynamic-linker argument. But
-this is not the correct name for the GNU dynamic linker. The correct
-name is /lib/ld.so.1 which is the name specified in the SVr4 ABi.
+{UD} On Linux, gcc sets the dynamic linker to /lib/ld-linux.so.1
+unless the user specifies a -dynamic-linker argument. This is the
+name of the libc5 dynamic linker, which does not work with glibc.
+
+For casual use of GNU libc you can just specify
+ -dynamic-linker=/lib/ld-linux.so.2
+
+which is the glibc dynamic linker, on Linux systems. On other systems
+the name is /lib/ld.so.1.
To change your environment to use GNU libc for compiling you need to
change the `specs' file of your gcc. This file is normally found at
In this file you have to change a few things:
-- change `ld-linux.so.1' to `ld.so.1' (or to ld-linux.so.2, see below)
+- change `ld-linux.so.1' to `ld-linux.so.2'
- remove all expression `%{...:-lgmon}'; there is no libgmon in glibc
- fix a minor bug by changing %{pipe:-} to %|
-
-Things are getting a bit more complicated if you have GNU libc
-installed in some other place than /usr, i.e., if you do not want to
-use it instead of the old libc. In this case the needed startup files
-and libraries are not found in the regular places. So the specs file
-must tell the compiler and linker exactly what to use. Here is what
-the gcc-2.7.2 specs file should look like when GNU libc is installed at
-/usr:
+Here is what the gcc-2.7.2 specs file should look like when GNU libc
+is installed at /usr:
-----------------------------------------------------------------------
*asm:
-lgcc
*startfile:
-%{!shared: %{pg:gcrt1.o%s} %{!pg:%{p:gcrt1.o%s} %{!p:%{profile:gcrt1.o%s} %{!profile:crt1.o%s}}}} crti.o%s %{!shared:crtbegin.o%s} %{shared:crtbeginS.o%s}
+%{!shared: %{pg:gcrt1.o%s} %{!pg:%{p:gcrt1.o%s} %{!p:%{profile:gcrt1.o%s} %{!profile:crt1.o%s}}}} crti.o%s %{!shared:crtbegin.o%s} %{shared:crtbeginS.o%s}
*switches_need_spaces:
-----------------------------------------------------------------------
-The above is currently correct for ix86/Linux. Because of
-compatibility issues on this platform the dynamic linker must have
-a different name: ld-linux.so.2. So you have to replace
-
- %{!dynamic-linker:-dynamic-linker=/home/gnu/lib/ld-linux.so.2}
-by
- %{!dynamic-linker:-dynamic-linker=/home/gnu/lib/ld.so.1}
-
-in the above example specs file to make it work for other systems.
+Things get a bit more complicated if you have GNU libc installed in
+some other place than /usr, i.e., if you do not want to use it instead
+of the old libc. In this case the needed startup files and libraries
+are not found in the regular places. So the specs file must tell the
+compiler and linker exactly what to use.
Version 2.7.2.3 does and future versions of GCC will automatically
provide the correct specs.
-~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~
-[Q17] ``Looking through the shared libc file I haven't found the
- functions `stat', `lstat', `fstat', and `mknod' and while
- linking on my Linux system I get error messages. How is
- this supposed to work?''
+2.7. Looking through the shared libc file I haven't found the
+ functions `stat', `lstat', `fstat', and `mknod' and while
+ linking on my Linux system I get error messages. How is
+ this supposed to work?
-[A17] {RM} Believe it or not, stat and lstat (and fstat, and mknod)
+{RM} Believe it or not, stat and lstat (and fstat, and mknod)
are supposed to be undefined references in libc.so.6! Your problem is
probably a missing or incorrect /usr/lib/libc.so file; note that this
is a small text file now, not a symlink to libc.so.6. It should look
GROUP ( libc.so.6 ld-linux.so.2 libc.a )
-~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~
-[Q18] ``The prototypes for `connect', `accept', `getsockopt',
- `setsockopt', `getsockname', `getpeername', `send',
- `sendto', and `recvfrom' are different in GNU libc from
- any other system I saw. This is a bug, isn't it?''
+2.8. How can I compile gcc 2.7.2.1 from the gcc source code using
+ glibc 2.x?
-[A18] {UD} No, this is no bug. This version of the GNU libc already
-follows the Single Unix specifications (and I think the POSIX.1g
-draft which adopted the solution). The type for parameter describing
-a size is now `socklen_t', a new type.
+{AJ} There's only correct support for glibc 2.0.x in gcc 2.7.2.3
+or later. You should get at least gcc 2.7.2.3. All previous versions
+had problems with glibc support.
-~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~
-[Q19] ``My XXX kernel emulates a floating-point coprocessor for me.
- Should I enable --with-fp?''
+2.9. The `gencat' utility cannot process the catalog sources which
+ were used on my Linux libc5 based system. Why?
-[A19] {UD} As `configure --help' shows the default value is `yes' and
-this should not be changed unless the FPU instructions would be
-invalid. I.e., an emulated FPU is for the libc as good as a real one.
+{UD} The `gencat' utility provided with glibc complies to the XPG
+standard. The older Linux version did not obey the standard, so they
+are not compatible.
+To ease the transition from the Linux version some of the non-standard
+features are also present in the `gencat' program of GNU libc. This
+mainly includes the use of symbols for the message number and the automatic
+generation of header files which contain the needed #defines to map the
+symbols to integers.
-~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~
-[Q20] ``How can I compile gcc 2.7.2.1 from the gcc source code using
- glibc 2.x?
+Here is a simple SED script to convert at least some Linux specific
+catalog files to the XPG4 form:
-[A20] {AJ} There's only correct support for glibc 2.0.x in gcc 2.7.2.3
-or later. You should get at least gcc 2.7.2.3. All previous versions
-had problems with glibc support.
+-----------------------------------------------------------------------
+# Change catalog source in Linux specific format to standard XPG format.
+# Ulrich Drepper <drepper@cygnus.com>, 1996.
+#
+/^\$ #/ {
+ h
+ s/\$ #\([^ ]*\).*/\1/
+ x
+ s/\$ #[^ ]* *\(.*\)/\$ \1/
+}
+/^# / {
+ s/^# \(.*\)/\1/
+ G
+ s/\(.*\)\n\(.*\)/\2 \1/
+}
+-----------------------------------------------------------------------
-~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~
-[Q21] ``On Linux I've got problems with the declarations in Linux
- kernel headers.''
-[A21] {UD,AJ} On Linux, the use of kernel headers is reduced to a very
-minimum. Besides giving Linus the possibility to change the headers
-more freely it has another reason: user level programs now do not
-always use the same types like the kernel does.
+2.10. I have set up /etc/nis.conf, and the Linux libc 5 with NYS
+ works great. But the glibc NIS+ doesn't seem to work.
-I.e., the libc abstracts the use of types. E.g., the sigset_t type is
-in the kernel 32 or 64 bits wide. In glibc it is 1024 bits wide, in
-preparation for future development. The reasons are obvious: we don't
-want to have a new major release when the Linux kernel gets these
-functionality. Consult the headers for more information about the changes.
+{??} The glibc NIS+ implementation uses a /var/nis/NIS_COLD_START
+file for storing information about the NIS+ server and their public
+keys, because the nis.conf file does not contain all the necessary
+information. You have to copy a NIS_COLD_START file from a Solaris
+client (the NIS_COLD_START file is byte order independent) or generate
+it with nisinit from the nis-tools package (available at
+http://www-vt.uni-paderborn.de/~kukuk/linux/nisplus.html).
-Therefore you shouldn't include Linux kernel header files directly if
-glibc has defined a replacement. Otherwise you might get undefined
-results because of type conflicts.
+2.11. After installing glibc name resolving doesn't work properly.
-~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~
-[Q22] ``When I try to compile code which uses IPv6 header and
- definitions on my Linux 2.x.y system I am in trouble.
- Nothing seems to work.''
+{AJ} You probably should read the manual section describing
+nsswitch.conf (just type `info libc "NSS Configuration File"').
+The NSS configuration file is usually the culprit.
-[A22] {UD} The problem is that the IPv6 development still has not reached
-a point where it is stable. There are still lots of incompatible changes
-made and the libc headers have to follow.
-Currently (as of 970401) according to Philip Blundell <philb@gnu.ai.mit.edu>
-the required kernel version is 2.1.30.
+2.12. I have /usr/include/net and /usr/include/scsi as symlinks
+ into my Linux source tree. Is that wrong?
+{PB} This was necessary for libc5, but is not correct when using
+glibc. Including the kernel header files directly in user programs
+usually does not work (see question 3.5). glibc provides its own <net/*>
+and <scsi/*> header files to replace them, and you may have to remove
+any symlink that you have in place before you install glibc. However,
+/usr/include/asm and /usr/include/linux should remain as they were.
-~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~
-[Q23] ``When compiling GNU libc I get lots of errors saying functions
- in glibc are duplicated in libgcc.''
-[A23] {EY} This is *exactly* the same problem that I was having. The
-problem was due to the fact that the autoconfigure didn't correctly
-detect that linker flag --no-whole-archive was supported in my linker.
-In my case it was because I had run ./configure with bogus CFLAGS, and
-the test failed.
+2.13. Programs like `logname', `top', `uptime' `users', `w' and
+ `who', show incorrect information about the (number of)
+ users on my system. Why?
-One thing that is particularly annoying about this problem is that
-once this is misdetected, running configure again won't fix it unless
-you first delete config.cache.
+{MK} See question 3.2.
-{UD} Starting with glibc-2.0.3 there should be a better test to avoid
-some problems of this kind. The setting of CFLAGS is checked at the
-very beginning and if it is not usable `configure' will bark.
+2.14. After upgrading to glibc 2.1 with symbol versioning I get
+ errors about undefined symbols. What went wrong?
+{AJ} The problem is caused either by wrong program code or tools. In
+the versioned libc a lot of symbols are now local that were global
+symbols in previous versions. It seems that programs linked against
+older versions often accidentally used libc global variables --
+something that should not happen.
-~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~
-[Q24] ``I have set up /etc/nis.conf, and the Linux libc 5 with NYS
- works great. But the glibc NIS+ doesn't seem to work.''
+The only way to fix this is to recompile your program. Sorry, that's
+the price you might have to pay once for quite a number of advantages
+with symbol versioning.
-[A24] The glibc NIS+ implementation uses a /var/nis/NIS_COLD_START
-file for storing information about the NIS+ server and their public
-keys, because the nis.conf file do not contain all necessary
-information. You have to copy a NIS_COLD_START file from a Solaris
-client (the NIS_COLD_START file is byte order independend) or generate
-it new with nisinit from the nis-tools (look at
-http://www-vt.uni-paderborn.de/~kukuk/linux/nisplus.html).
+2.15. When I start the program XXX after upgrading the library
+ I get
+ XXX: Symbol `_sys_errlist' has different size in shared
+ object, consider re-linking
+ Why? What should I do?
-~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~
-[Q25] ``After installing glibc name resolving doesn't work properly.''
+{UD} As the message says, relink the binary. The problem is that
+a few symbols from the library can change in size and there is no way
+to avoid this. _sys_errlist is a good example. Occasionally there are
+new error numbers added to the kernel and this must be reflected at user
+level, breaking programs that refer to them directly.
-[A25] {AJ} You probable should read the manual section describing
-``nsswitch.conf'' (just type `info libc "NSS Configuration File"').
-The NSS configuration file is usually the culprit.
+Such symbols should normally not be used at all. There are mechanisms
+to avoid using them. In the case of _sys_errlist, there is the
+strerror() function which should _always_ be used instead. So the
+correct fix is to rewrite that part of the application.
+In some situations (especially when testing a new library release) it
+might be possible that a symbol changed size when that should not have
+happened. So in case of doubt report such a warning message as a
+problem.
-~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~
-[Q26] ``I have /usr/include/net and /usr/include/scsi as symlinks
- into my Linux source tree. Is that wrong?''
+\f
+. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
-[A26] {PB} This was necessary for libc5, but is not correct when using
-glibc. Including the kernel header files directly in user programs
-usually does not work (see Q21). glibc provides its own <net/*> and
-<scsi/*> header files to replace them, and you may have to remove any
-symlink that you have in place before you install glibc. However,
-/usr/include/asm and /usr/include/linux should remain as they were.
+3. Source and binary incompatibilities, and what to do about them
+3.1. I expect GNU libc to be 100% source code compatible with
+ the old Linux based GNU libc. Why isn't it like this?
-~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~
-[Q27] ``Programs like `logname', `top', `uptime' `users', `w' and
- `who', show incorrect information about the (number of)
- users on my system. Why?''
+{DMT,UD} Not every extension in Linux libc's history was well
+thought-out. In fact it had a lot of problems with standards compliance
+and with cleanliness. With the introduction of a new version number these
+errors can now be corrected. Here is a list of the known source code
+incompatibilities:
-[A27] {MK} See Q10.
+* _GNU_SOURCE: glibc does not make the GNU extensions available
+ automatically. If a program depends on GNU extensions or some
+ other non-standard functionality, it is necessary to compile it
+ with the C compiler option -D_GNU_SOURCE, or better, to put
+ `#define _GNU_SOURCE' at the beginning of your source files, before
+ any C library header files are included. This difference normally
+ manifests itself in the form of missing prototypes and/or data type
+ definitions. Thus, if you get such errors, the first thing you
+ should do is try defining _GNU_SOURCE and see if that makes the
+ problem go away.
+ For more information consult the file `NOTES' in the GNU C library
+ sources.
-~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~
-[Q28] ``After upgrading to a glibc 2.1 with symbol versioning I get
- errors about undefined symbols. What went wrong?''
+* reboot(): GNU libc sanitizes the interface of reboot() to be more
+ compatible with the interface used on other OSes. reboot() as
+ implemented in glibc takes just one argument. This argument
+ corresponds to the third argument of the Linux reboot system call.
+ That is, a call of the form reboot(a, b, c) needs to be changed into
+ reboot(c). Beside this the header <sys/reboot.h> defines the needed
+ constants for the argument. These RB_* constants should be used
+ instead of the cryptic magic numbers.
+
+* swapon(): the interface of this function didn't change, but the
+ prototype is in a separate header file <sys/swap.h>. This header
+ file also provides the SWAP_* constants defined by <linux/swap.h>;
+ you should use them for the second argument to swapon().
+
+* errno: If a program uses the variable "errno", then it _must_
+ include <errno.h>. The old libc often (erroneously) declared this
+ variable implicitly as a side-effect of including other libc header
+ files. glibc is careful to avoid such namespace pollution, which,
+ in turn, means that you really need to include the header files that
+ you depend on. This difference normally manifests itself in the
+ form of the compiler complaining about references to an undeclared
+ symbol "errno".
-[A28] {AJ} In a versioned libc a lot of symbols are now local that
-have been global symbols in previous versions. When defining a extern
-variable both in a user program and extern in the libc the links
-resolves this to only one reference - the one in the library. The
-problem is caused by either wrong program code or tools. In no case
-the global variables from libc should be used by any program. Since
-these reference are now local, you might see a message like:
+* Linux-specific syscalls: All Linux system calls now have appropriate
+ library wrappers and corresponding declarations in various header files.
+ This is because the syscall() macro that was traditionally used to
+ work around missing syscall wrappers are inherently non-portable and
+ error-prone. The following table lists all the new syscall stubs,
+ the header-file declaring their interface and the system call name.
-"msgfmt: error in loading shared libraries: : undefined symbol: _nl_domain_bindings"
+ syscall name: wrapper name: declaring header file:
+ ------------- ------------- ----------------------
+ bdflush bdflush <sys/kdaemon.h>
+ syslog ksyslog_ctl <sys/klog.h>
-The only way to fix this is to recompile your program. Sorry, that's
-the price you might have to pay once for quite a number of advantages
-with symbol versioning.
+* lpd: Older versions of lpd depend on a routine called _validuser().
+ The library does not provide this function, but instead provides
+ __ivaliduser() which has a slightly different interface. Simply
+ upgrading to a newer lpd should fix this problem (e.g., the 4.4BSD
+ lpd is known to be working).
+* resolver functions/BIND: like on many other systems the functions of
+ the resolver library are not included in libc itself. There is a
+ separate library libresolv. If you get undefined symbol errors for
+ symbols starting with `res_*' simply add -lresolv to your linker
+ command line.
-~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~
-[Q29] ``I don't include any kernel header myself but still the
- compiler complains about type redeclarations of types in the
- kernel headers.''
+* the `signal' function's behavior corresponds to the BSD semantic and
+ not the SysV semantic as it was in libc-5. The interface on all GNU
+ systems shall be the same and BSD is the semantic of choice. To use
+ the SysV behavior simply use `sysv_signal', or define _XOPEN_SOURCE.
+ See question 3.7 for details.
-[A29] {UD} The kernel headers before Linux 2.1.61 don't work correctly with
-glibc since they pollute the name space in a not acceptable way. Compiling
-C programs is possible in most cases but especially C++ programs have (due
-to the change of the name lookups for `struct's) problem. One prominent
-example is `struct fd_set'.
-There might be some more problems left but 2.1.61 fixes some of the known
-ones. See the BUGS file for other known problems.
+3.2. Why does getlogin() always return NULL on my Linux box?
+
+{UD} The GNU C library has a format for the UTMP and WTMP file which
+differs from what your system currently has. It was extended to
+fulfill the needs of the next years when IPv6 is introduced. The
+record size is different and some fields have different positions.
+The files written by functions from the one library cannot be read by
+functions from the other library. Sorry, but this is what a major
+release is for. It's better to have a cut now than having no means to
+support the new techniques later.
+{MK} There is however a (partial) solution for this problem. Please
+take a look at the file `README.utmpd'.
-~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~
-[Q30] ``When I start the program XXX after upgrading the library
- I get
- XXX: Symbol `_sys_errlist' has different size in shared object, consider re-linking
- Why? What to do?''
-[A30] {UD} As the message says, relink the binary. The problem is that
-very few symbols from the library can change in size and there is no way
-to avoid this. _sys_errlist is a good example. Occasionally there are
-new error numbers added to the kernel and this must be reflected at user
-level.
+3.3. Where are the DST_* constants found in <sys/time.h> on many
+ systems?
-But this does not mean all programs are doomed once such a change is
-necessary. Such symbols should normally not be used at all. There are
-mechanisms to avoid using them. In the case of _sys_errlist, there is the
-strerror() function which should _always_ be used instead. So the correct
-fix is to rewrite that part of the application.
+{UD} These constants come from the old BSD days and are not used
+anymore (libc5 does not actually implement the handling although the
+constants are defined).
-In some situations (especially when testing a new library release) it might
-be possible that such a symbol size change slipped in though it must not
-happen. So in case of doubt report such a warning message as a problem.
+Instead GNU libc contains zone database support and compatibility code
+for POSIX TZ environment variable handling.
-~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~
-[Q31] ``What's the problem with configure --enable-omitfp?''
+3.4. The prototypes for `connect', `accept', `getsockopt',
+ `setsockopt', `getsockname', `getpeername', `send',
+ `sendto', and `recvfrom' are different in GNU libc from
+ any other system I saw. This is a bug, isn't it?
-[A31] {AJ} When configuring with --enable-omitfp the libraries are build
-without frame pointers. Some compilers produce in this situation buggy
-code and therefore we don't advise using it at the moment.
+{UD} No, this is no bug. This version of GNU libc already follows the
+new Single Unix specifications (and I think the POSIX.1g draft which
+adopted the solution). The type for a parameter describing a size is
+now `socklen_t', a new type.
-If you use --enable-omitfp, you're on your own. If you encounter
-problems with a library that was build this way, I'll advise you to
-rebuild the library without --enable-omitfp. If the problem vanishes
-consider tracking the problem down and report it as compiler failure.
-Since a library build with --enable-omitfp is undebuggable, a
-debuggable library is also build - you can recognize it by the suffix
-"_g" to the library names.
+3.5. On Linux I've got problems with the declarations in Linux
+ kernel headers.
-The compilation of this extra libraries and the compiler optimizations
-slow down the build process and need more disk space.
+{UD,AJ} On Linux, the use of kernel headers is reduced to the minimum.
+This gives Linus the ability to change the headers more freely. Also,
+user programs are now insulated from changes in the size of kernel
+data structures.
+For example, the sigset_t type is 32 or 64 bits wide in the kernel.
+In glibc it is 1024 bits wide. This guarantees that when the kernel
+gets a bigger sigset_t (for POSIX.1e realtime support, say) user
+programs will not have to be recompiled. Consult the header files for
+more information about the changes.
+
+Therefore you shouldn't include Linux kernel header files directly if
+glibc has defined a replacement. Otherwise you might get undefined
+results because of type conflicts.
-~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~
-[Q32] ``Why don't signals interrupt system calls anymore?''
-[A32] {ZW} By default GNU libc uses the BSD semantics for signal(),
+3.6. I don't include any kernel headers myself but the compiler
+ still complains about redeclarations of types in the kernel
+ headers.
+
+{UD} The kernel headers before Linux 2.1.61 don't work correctly with
+glibc. Compiling C programs is possible in most cases but C++
+programs have (due to the change of the name lookups for `struct's)
+problems. One prominent example is `struct fd_set'.
+
+There might be some problems left but 2.1.61 fixes most of the known
+ones. See the BUGS file for other known problems.
+
+
+3.7. Why don't signals interrupt system calls anymore?
+
+{ZW} By default GNU libc uses the BSD semantics for signal(),
unlike Linux libc 5 which used System V semantics. This is partially
for compatibility with other systems and partially because the BSD
semantics tend to make programming with signals easier.
* A BSD signal is blocked during the execution of its handler. In other
words, a handler for SIGCHLD (for example) does not need to worry about
- being interrupted by another SIGCHLD. It may, however, be interrrupted
+ being interrupted by another SIGCHLD. It may, however, be interrupted
by other signals.
There is general consensus that for `casual' programming with signals, the
siginterrupt().
-~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~
-[Q33] ``I've got errors compiling code that uses certain string
- functions. Why?''
+3.8. I've got errors compiling code that uses certain string
+ functions. Why?
+
+{AJ} glibc 2.1 has special string functions that are faster
+than the normal library functions. Some of the functions are
+implemented as inline functions and others as macros.
-[A33] {AJ} glibc 2.1 has the much asked for optimized string
-functions that are faster than the normal library functions. Some of
-the functions are implemented as inline functions and others as
-macros.
The optimized string functions are only used when compiling with
-optimizations (-O1 or higher). The behaviour can be changed with two
+optimizations (-O1 or higher). The behavior can be changed with two
feature macros:
-* __NO_STRING_INLINES: Don't use string optimizations.
-* __USE_STRING_INLINES: Use also assembler inline functions (might
- increase code use dramatically).
+
+* __NO_STRING_INLINES: Don't do any string optimizations.
+* __USE_STRING_INLINES: Use assembly language inline functions (might
+ increase code size dramatically).
Since some of these string functions are now additionally defined as
-macros, code like "char *strncpy();" doesn't work anymore (and is even
-unneccessary since <string.h> has the necessary declarations). Either
+macros, code like "char *strncpy();" doesn't work anymore (and is
+unnecessary, since <string.h> has the necessary declarations). Either
change your code or define __NO_STRING_INLINES.
-{UD} Another problem in this area is that the gcc still has problems on
+{UD} Another problem in this area is that gcc still has problems on
machines with very few registers (e.g., ix86). The inline assembler
-code sometimes requires many/all registers and the register allocator
-cannot handle these situation in all cases.
+code can require almost all the registers and the register allocator
+cannot always handle this situation.
-If a function is also defined as a macro in the libc headers one can prevent
-the use of the macro easily. E.g., instead of
+One can disable the string optimizations selectively. Instead of writing
cp = strcpy (foo, "lkj");
cp = (strcpy) (foo, "lkj");
-Using this method one can avoid using the optimizations for selected
-function calls.
+This disables the optimization for that specific call.
+
+\f
+. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
+
+4. Miscellaneous
+
+4.1. After I changed configure.in I get `Autoconf version X.Y.
+ or higher is required for this script'. What can I do?
+
+{UD} You have to get the specified autoconf version (or a later one)
+from your favorite mirror of prep.ai.mit.edu.
+
+4.2. When I try to compile code which uses IPv6 headers and
+ definitions on my Linux 2.x.y system I am in trouble.
+ Nothing seems to work.
+
+{UD} The problem is that IPv6 development still has not reached a
+point where the headers are stable. There are still lots of
+incompatible changes made and the libc headers have to follow.
+
+Also, make sure you have a suitably recent kernel. As of the 970401
+snapshot, according to Philip Blundell <philb@gnu.ai.mit.edu>, the
+required kernel version is 2.1.30.
-~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~
\f
+~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~
+
Answers were given by:
{UD} Ulrich Drepper, <drepper@cygnus.com>
{DMT} David Mosberger-Tang, <davidm@AZStarNet.com>
{RM} Roland McGrath, <roland@gnu.org>
-{HJL} H.J. Lu, <hjl@gnu.org>
{AJ} Andreas Jaeger, <aj@arthur.rhein-neckar.de>
{EY} Eric Youngdale, <eric@andante.jic.com>
{PB} Phil Blundell, <Philip.Blundell@pobox.com>
{ZW} Zack Weinberg, <zack@rabi.phys.columbia.edu>
\f
Local Variables:
- mode:text
+ mode:outline
+ outline-regexp:"\\?"
End:
--- /dev/null
+ Frequently Asked Questions about the GNU C Library
+
+This document tries to answer questions a user might have when
+installing and using glibc. Please make sure you read this before
+sending questions or bug reports to the maintainers.
+
+The GNU C library is very complex. The installation process has not
+been completely automated; there are too many variables. You can do
+substantial damage to your system by installing the library
+incorrectly. Make sure you understand what you are undertaking before
+you begin.
+
+If you have any questions you think should be answered in this document,
+please let me know.
+
+ --drepper@cygnus.com
+\f
+? Compiling glibc
+
+?? What systems does the GNU C Library run on?
+
+{UD} This is difficult to answer. The file `README' lists the
+architectures GNU libc was known to run on *at some time*. This does
+not mean that it still can be compiled and run on them now.
+
+The systems glibc is known to work on as of this release, and most
+probably in the future, are:
+
+ *-*-gnu GNU Hurd
+ i[3456]86-*-linux-gnu Linux-2.0 on Intel
+ m68k-*-linux-gnu Linux-2.0 on Motorola 680x0
+ alpha-*-linux-gnu Linux-2.0 on DEC Alpha
+ powerpc-*-linux-gnu Linux and MkLinux on PowerPC systems
+ sparc-*-linux-gnu Linux-2.0 on SPARC
+ sparc64-*-linux-gnu Linux-2.0 on UltraSPARC
+
+Ports to other Linux platforms are in development, and may in fact
+work already, but no one has sent us success reports for them.
+Currently no ports to other operating systems are underway, although a
+few people have expressed interest.
+
+If you have a system not listed above (or in the `README' file) and
+you are really interested in porting it, contact
+
+ <bug-glibc@prep.ai.mit.edu>
+
+?? What compiler do I need to build GNU libc?
+
+{UD} You must use GNU CC to compile GNU libc. A lot of extensions of
+GNU CC are used to increase portability and speed.
+
+GNU CC is found, like all other GNU packages, on
+ ftp://prep.ai.mit.edu/pub/gnu
+and the many mirror sites. prep is always overloaded, so try to find
+a local mirror first.
+
+You always should try to use the latest official release. Older
+versions may not have all the features GNU libc requires. On most
+supported platforms, 2.7.2.3 is the earliest version that works at all.
+
+?? When I try to compile glibc I get only error messages.
+ What's wrong?
+
+{UD} You definitely need GNU make to translate GNU libc. No
+other make program has the needed functionality.
+
+We recommend version GNU make version 3.75. Versions 3.76 and 3.76.1
+have bugs which appear when building big projects like GNU libc.
+Versions before 3.74 have bugs and/or are missing features.
+
+?? Do I need a special linker or archiver?
+
+{UD} You may be able to use your system linker, but GNU libc works
+best with GNU binutils.
+
+On systems where the native linker does not support weak symbols you
+will not get a fully ISO C compliant C library. Generally speaking
+you should use the GNU binutils if they provide at least the same
+functionality as your system's tools.
+
+Always get the newest release of GNU binutils available. Older
+releases are known to have bugs that prevent a successful compilation.
+
+{ZW} As of release 2.1 a linker supporting symbol versions is
+required. For Linux, get binutils-2.8.1.0.17 or later. Other systems
+may have native linker support, but it's moot right now, because glibc
+has not been ported to them.
+
+?? Do I need some more things to compile GNU C Library?
+
+{UD} Yes, there are some more :-).
+
+* GNU gettext. This package contains the tools needed to construct
+ `message catalog' files containing translated versions of system
+ messages. See ftp://prep.ai.mit.edu/pub/gnu or better any mirror
+ site. (We distribute compiled message catalogs, but they may not be
+ updated in patches.)
+
+* Some files depend on special tools. E.g., files ending in .gperf
+ need a `gperf' program. The GNU version (part of libg++) is known
+ to work while some vendor versions do not.
+
+ You should not need these tools unless you change the source files.
+
+* When compiling for Linux, the header files of the Linux kernel must
+ be available to the compiler as <linux/*.h> and <asm/*.h>.
+
+* lots of disk space (~170MB for i?86-linux; more for RISC platforms).
+
+* plenty of time. Compiling just the shared and static libraries for
+ i?86-linux takes approximately 1h on an i586@133, or 2.5h on
+ i486@66, or 4.5h on i486@33. Multiply this by 1.5 or 2.0 if you
+ build profiling and/or the highly optimized version as well. For
+ Hurd systems times are much higher.
+
+ You should avoid compiling in a NFS mounted filesystem. This is
+ very slow.
+
+ James Troup <J.J.Troup@comp.brad.ac.uk> reports a compile time of
+ 45h34m for a full build (shared, static, and profiled) on
+ Atari Falcon (Motorola 68030 @ 16 Mhz, 14 Mb memory) and 22h48m
+ on Atari TT030 (Motorola 68030 @ 32 Mhz, 34 Mb memory)
+
+ If you have some more measurements let me know.
+
+?? When I run `nm -u libc.so' on the produced library I still
+ find unresolved symbols. Can this be ok?
+
+{UD} Yes, this is ok. There can be several kinds of unresolved
+symbols:
+
+* magic symbols automatically generated by the linker. These have names
+ like __start_* and __stop_*
+
+* symbols starting with _dl_* come from the dynamic linker
+
+* symbols resolved by using libgcc.a
+ (__udivdi3, __umoddi3, or similar)
+
+* weak symbols, which need not be resolved at all (fabs for example)
+
+Generally, you should make sure you find a real program which produces
+errors while linking before deciding there is a problem.
+
+??addon What are these `add-ons'?
+
+{UD} To avoid complications with export rules or external source
+code some optional parts of the libc are distributed as separate
+packages (e.g., the crypt package, see ?crypt).
+
+To use these packages as part of GNU libc, just unpack the tarfiles in
+the libc source directory and tell the configuration script about them
+using the --enable-add-ons option. If you give just --enable-add-ons
+configure tries to find all the add-on packages in your source tree.
+This may not work. If it doesn't, or if you want to select only a
+subset of the add-ons, give a comma-separated list of the add-ons to
+enable:
+
+ configure --enable-add-ons=crypt,linuxthreads
+
+for example.
+
+Add-ons can add features (including entirely new shared libraries),
+override files, provide support for additional architectures, and
+just about anything else. The existing makefiles do most of the work;
+only some few stub rules must be written to get everything running.
+
+?? My XXX kernel emulates a floating-point coprocessor for me.
+ Should I enable --with-fp?
+
+{ZW} An emulated FPU is just as good as a real one, as far as the C
+library is concerned. You only need to say --without-fp if your
+machine has no way to execute floating-point instructions.
+
+People who are interested in squeezing the last drop of performance
+out of their machine may wish to avoid the trap overhead, but this is
+far more trouble than it's worth: you then have to compile
+*everything* this way, including the compiler's internal libraries
+(libgcc.a for GNU C), because the calling conventions change.
+
+?? When compiling GNU libc I get lots of errors saying functions
+ in glibc are duplicated in libgcc.
+
+{EY} This is *exactly* the same problem that I was having. The
+problem was due to the fact that configure didn't correctly detect
+that the linker flag --no-whole-archive was supported in my linker.
+In my case it was because I had run ./configure with bogus CFLAGS, and
+the test failed.
+
+One thing that is particularly annoying about this problem is that
+once this is misdetected, running configure again won't fix it unless
+you first delete config.cache.
+
+{UD} Starting with glibc-2.0.3 there should be a better test to avoid
+some problems of this kind. The setting of CFLAGS is checked at the
+very beginning and if it is not usable `configure' will bark.
+
+?? What's the problem with configure --enable-omitfp?
+
+{AJ} When --enable-omitfp is set the libraries are built without frame
+pointers. Some compilers produce buggy code for this model and
+therefore we don't advise using it at the moment.
+
+If you use --enable-omitfp, you're on your own. If you encounter
+problems with a library that was build this way, we advise you to
+rebuild the library without --enable-omitfp. If the problem vanishes
+consider tracking the problem down and report it as compiler failure.
+
+Since a library build with --enable-omitfp is undebuggable on most
+systems, debuggable libraries are also built - you can use it by
+appending "_g" to the library names.
+
+The compilation of these extra libraries and the compiler optimizations
+slow down the build process and need more disk space.
+
+? Installation and configuration issues
+
+?? Can I replace the libc on my Linux system with GNU libc?
+
+{UD} You cannot replace any existing libc for Linux with GNU
+libc. It is binary incompatible and therefore has a different major
+version. You can, however, install it alongside your existing libc.
+
+For Linux there are three major libc versions:
+ libc-4 a.out libc
+ libc-5 original ELF libc
+ libc-6 GNU libc
+
+You can have any combination of these three installed. For more
+information consult documentation for shared library handling. The
+Makefiles of GNU libc will automatically generate the needed symbolic
+links which the linker will use.
+
+?? How do I configure GNU libc so that the essential libraries
+ like libc.so go into /lib and the other into /usr/lib?
+
+{UD,AJ} Like all other GNU packages GNU libc is designed to use a base
+directory and install all files relative to this. The default is
+/usr/local, because this is safe (it will not damage the system if
+installed there). If you wish to install GNU libc as the primary C
+library on your system, set the base directory to /usr (i.e. run
+configure --prefix=/usr <other_options>). Note that this can damage
+your system; see ?safety for details.
+
+Some systems like Linux have a filesystem standard which makes a
+difference between essential libraries and others. Essential
+libraries are placed in /lib because this directory is required to be
+located on the same disk partition as /. The /usr subtree might be
+found on another partition/disk. If you configure for Linux with
+--prefix=/usr, then this will be done automatically.
+
+To install the essential libraries which come with GNU libc in /lib on
+systems other than Linux one must explicitly request it. Autoconf has
+no option for this so you have to use a `configparms' file (see the
+`INSTALL' file for details). It should contain:
+
+slibdir=/lib
+sysconfdir=/etc
+
+The first line specifies the directory for the essential libraries,
+the second line the directory for system configuration files.
+
+??safety How should I avoid damaging my system when I install GNU libc?
+
+{ZW} If you wish to be cautious, do not configure with --prefix=/usr.
+If you don't specify a prefix, glibc will be installed in /usr/local,
+where it will probably not break anything. (If you wish to be
+certain, set the prefix to something like /usr/local/glibc2 which is
+not used for anything.)
+
+The dangers when installing glibc in /usr are twofold:
+
+* glibc will overwrite the headers in /usr/include. Other C libraries
+ install a different but overlapping set of headers there, so the
+ effect will probably be that you can't compile anything. You need to
+ rename /usr/include out of the way first. (Do not throw it away; you
+ will then lose the ability to compile programs against your old libc.)
+
+* None of your old libraries, static or shared, can be used with a
+ different C library major version. For shared libraries this is not a
+ problem, because the filenames are different and the dynamic linker
+ will enforce the restriction. But static libraries have no version
+ information. You have to evacuate all the static libraries in
+ /usr/lib to a safe location.
+
+The situation is rather similar to the move from a.out to ELF which
+long-time Linux users will remember.
+
+?? Do I need to use GNU CC to compile programs that will use the
+ GNU C Library?
+
+{ZW} In theory, no; the linker does not care, and the headers are
+supposed to check for GNU CC before using its extensions to the C
+language.
+
+However, there are currently no ports of glibc to systems where
+another compiler is the default, so no one has tested the headers
+extensively against another compiler. You may therefore encounter
+difficulties. If you do, please report them as bugs.
+
+Also, in several places GNU extensions provide large benefits in code
+quality. For example, the library has hand-optimized, inline assembly
+versions of some string functions. These can only be used with GCC.
+See ?string for details.
+
+??crypt When linking with the new libc I get unresolved symbols
+ `crypt' and `setkey'. Why aren't these functions in the
+ libc anymore?
+
+{UD} The US places restrictions on exporting cryptographic programs
+and source code. Until this law gets abolished we cannot ship the
+cryptographic functions together with glibc.
+
+The functions are available, as an add-on (see ?addon). People in the
+US may get it from the same place they got GNU libc from. People
+outside the US should get the code from ftp://ftp.ifi.uio.no/pub/gnu,
+or another archive site outside the USA. The README explains how to
+install the sources.
+
+If you already have the crypt code on your system the reason for the
+failure is probably that you did not link with -lcrypt. The crypto
+functions are in a separate library to make it possible to export GNU
+libc binaries from the US.
+
+?? When I use GNU libc on my Linux system by linking against
+ the libc.so which comes with glibc all I get is a core dump.
+
+{UD} On Linux, gcc sets the dynamic linker to /lib/ld-linux.so.1
+unless the user specifies a -dynamic-linker argument. This is the
+name of the libc5 dynamic linker, which does not work with glibc.
+
+For casual use of GNU libc you can just specify
+ -dynamic-linker=/lib/ld-linux.so.2
+
+which is the glibc dynamic linker, on Linux systems. On other systems
+the name is /lib/ld.so.1.
+
+To change your environment to use GNU libc for compiling you need to
+change the `specs' file of your gcc. This file is normally found at
+
+ /usr/lib/gcc-lib/<arch>/<version>/specs
+
+In this file you have to change a few things:
+
+- change `ld-linux.so.1' to `ld-linux.so.2'
+
+- remove all expression `%{...:-lgmon}'; there is no libgmon in glibc
+
+- fix a minor bug by changing %{pipe:-} to %|
+
+Here is what the gcc-2.7.2 specs file should look like when GNU libc
+is installed at /usr:
+
+-----------------------------------------------------------------------
+*asm:
+%{V} %{v:%{!V:-V}} %{Qy:} %{!Qn:-Qy} %{n} %{T} %{Ym,*} %{Yd,*} %{Wa,*:%*}
+
+*asm_final:
+%|
+
+*cpp:
+%{fPIC:-D__PIC__ -D__pic__} %{fpic:-D__PIC__ -D__pic__} %{!m386:-D__i486__} %{posix:-D_POSIX_SOURCE} %{pthread:-D_REENTRANT}
+
+*cc1:
+%{profile:-p}
+
+*cc1plus:
+
+
+*endfile:
+%{!shared:crtend.o%s} %{shared:crtendS.o%s} crtn.o%s
+
+*link:
+-m elf_i386 %{shared:-shared} %{!shared: %{!ibcs: %{!static: %{rdynamic:-export-dynamic} %{!dynamic-linker:-dynamic-linker /lib/ld-linux.so.2}} %{static:-static}}}
+
+*lib:
+%{!shared: %{pthread:-lpthread} %{profile:-lc_p} %{!profile: -lc}}
+
+*libgcc:
+-lgcc
+
+*startfile:
+%{!shared: %{pg:gcrt1.o%s} %{!pg:%{p:gcrt1.o%s} %{!p:%{profile:gcrt1.o%s} %{!profile:crt1.o%s}}}} crti.o%s %{!shared:crtbegin.o%s} %{shared:crtbeginS.o%s}
+
+*switches_need_spaces:
+
+
+*signed_char:
+%{funsigned-char:-D__CHAR_UNSIGNED__}
+
+*predefines:
+-D__ELF__ -Dunix -Di386 -Dlinux -Asystem(unix) -Asystem(posix) -Acpu(i386) -Amachine(i386)
+
+*cross_compile:
+0
+
+*multilib:
+. ;
+
+-----------------------------------------------------------------------
+
+Things get a bit more complicated if you have GNU libc installed in
+some other place than /usr, i.e., if you do not want to use it instead
+of the old libc. In this case the needed startup files and libraries
+are not found in the regular places. So the specs file must tell the
+compiler and linker exactly what to use.
+
+Version 2.7.2.3 does and future versions of GCC will automatically
+provide the correct specs.
+
+?? Looking through the shared libc file I haven't found the
+ functions `stat', `lstat', `fstat', and `mknod' and while
+ linking on my Linux system I get error messages. How is
+ this supposed to work?
+
+{RM} Believe it or not, stat and lstat (and fstat, and mknod)
+are supposed to be undefined references in libc.so.6! Your problem is
+probably a missing or incorrect /usr/lib/libc.so file; note that this
+is a small text file now, not a symlink to libc.so.6. It should look
+something like this:
+
+GROUP ( libc.so.6 ld.so.1 libc.a )
+
+or in ix86/Linux and alpha/Linux:
+
+GROUP ( libc.so.6 ld-linux.so.2 libc.a )
+
+?? How can I compile gcc 2.7.2.1 from the gcc source code using
+ glibc 2.x?
+
+{AJ} There's only correct support for glibc 2.0.x in gcc 2.7.2.3
+or later. You should get at least gcc 2.7.2.3. All previous versions
+had problems with glibc support.
+
+?? The `gencat' utility cannot process the catalog sources which
+ were used on my Linux libc5 based system. Why?
+
+{UD} The `gencat' utility provided with glibc complies to the XPG
+standard. The older Linux version did not obey the standard, so they
+are not compatible.
+
+To ease the transition from the Linux version some of the non-standard
+features are also present in the `gencat' program of GNU libc. This
+mainly includes the use of symbols for the message number and the automatic
+generation of header files which contain the needed #defines to map the
+symbols to integers.
+
+Here is a simple SED script to convert at least some Linux specific
+catalog files to the XPG4 form:
+
+-----------------------------------------------------------------------
+# Change catalog source in Linux specific format to standard XPG format.
+# Ulrich Drepper <drepper@cygnus.com>, 1996.
+#
+/^\$ #/ {
+ h
+ s/\$ #\([^ ]*\).*/\1/
+ x
+ s/\$ #[^ ]* *\(.*\)/\$ \1/
+}
+
+/^# / {
+ s/^# \(.*\)/\1/
+ G
+ s/\(.*\)\n\(.*\)/\2 \1/
+}
+-----------------------------------------------------------------------
+
+?? I have set up /etc/nis.conf, and the Linux libc 5 with NYS
+ works great. But the glibc NIS+ doesn't seem to work.
+
+{??} The glibc NIS+ implementation uses a /var/nis/NIS_COLD_START
+file for storing information about the NIS+ server and their public
+keys, because the nis.conf file does not contain all the necessary
+information. You have to copy a NIS_COLD_START file from a Solaris
+client (the NIS_COLD_START file is byte order independent) or generate
+it with nisinit from the nis-tools package (available at
+http://www-vt.uni-paderborn.de/~kukuk/linux/nisplus.html).
+
+?? After installing glibc name resolving doesn't work properly.
+
+{AJ} You probably should read the manual section describing
+nsswitch.conf (just type `info libc "NSS Configuration File"').
+The NSS configuration file is usually the culprit.
+
+?? I have /usr/include/net and /usr/include/scsi as symlinks
+ into my Linux source tree. Is that wrong?
+
+{PB} This was necessary for libc5, but is not correct when using
+glibc. Including the kernel header files directly in user programs
+usually does not work (see ?kerhdr). glibc provides its own <net/*>
+and <scsi/*> header files to replace them, and you may have to remove
+any symlink that you have in place before you install glibc. However,
+/usr/include/asm and /usr/include/linux should remain as they were.
+
+?? Programs like `logname', `top', `uptime' `users', `w' and
+ `who', show incorrect information about the (number of)
+ users on my system. Why?
+
+{MK} See ?getlog.
+
+?? After upgrading to glibc 2.1 with symbol versioning I get
+ errors about undefined symbols. What went wrong?
+
+{AJ} The problem is caused either by wrong program code or tools. In
+the versioned libc a lot of symbols are now local that were global
+symbols in previous versions. It seems that programs linked against
+older versions often accidentally used libc global variables --
+something that should not happen.
+
+The only way to fix this is to recompile your program. Sorry, that's
+the price you might have to pay once for quite a number of advantages
+with symbol versioning.
+
+?? When I start the program XXX after upgrading the library
+ I get
+ XXX: Symbol `_sys_errlist' has different size in shared
+ object, consider re-linking
+ Why? What should I do?
+
+{UD} As the message says, relink the binary. The problem is that
+a few symbols from the library can change in size and there is no way
+to avoid this. _sys_errlist is a good example. Occasionally there are
+new error numbers added to the kernel and this must be reflected at user
+level, breaking programs that refer to them directly.
+
+Such symbols should normally not be used at all. There are mechanisms
+to avoid using them. In the case of _sys_errlist, there is the
+strerror() function which should _always_ be used instead. So the
+correct fix is to rewrite that part of the application.
+
+In some situations (especially when testing a new library release) it
+might be possible that a symbol changed size when that should not have
+happened. So in case of doubt report such a warning message as a
+problem.
+
+? Source and binary incompatibilities, and what to do about them
+
+?? I expect GNU libc to be 100% source code compatible with
+ the old Linux based GNU libc. Why isn't it like this?
+
+{DMT,UD} Not every extension in Linux libc's history was well
+thought-out. In fact it had a lot of problems with standards compliance
+and with cleanliness. With the introduction of a new version number these
+errors can now be corrected. Here is a list of the known source code
+incompatibilities:
+
+* _GNU_SOURCE: glibc does not make the GNU extensions available
+ automatically. If a program depends on GNU extensions or some
+ other non-standard functionality, it is necessary to compile it
+ with the C compiler option -D_GNU_SOURCE, or better, to put
+ `#define _GNU_SOURCE' at the beginning of your source files, before
+ any C library header files are included. This difference normally
+ manifests itself in the form of missing prototypes and/or data type
+ definitions. Thus, if you get such errors, the first thing you
+ should do is try defining _GNU_SOURCE and see if that makes the
+ problem go away.
+
+ For more information consult the file `NOTES' in the GNU C library
+ sources.
+
+* reboot(): GNU libc sanitizes the interface of reboot() to be more
+ compatible with the interface used on other OSes. reboot() as
+ implemented in glibc takes just one argument. This argument
+ corresponds to the third argument of the Linux reboot system call.
+ That is, a call of the form reboot(a, b, c) needs to be changed into
+ reboot(c). Beside this the header <sys/reboot.h> defines the needed
+ constants for the argument. These RB_* constants should be used
+ instead of the cryptic magic numbers.
+
+* swapon(): the interface of this function didn't change, but the
+ prototype is in a separate header file <sys/swap.h>. This header
+ file also provides the SWAP_* constants defined by <linux/swap.h>;
+ you should use them for the second argument to swapon().
+
+* errno: If a program uses the variable "errno", then it _must_
+ include <errno.h>. The old libc often (erroneously) declared this
+ variable implicitly as a side-effect of including other libc header
+ files. glibc is careful to avoid such namespace pollution, which,
+ in turn, means that you really need to include the header files that
+ you depend on. This difference normally manifests itself in the
+ form of the compiler complaining about references to an undeclared
+ symbol "errno".
+
+* Linux-specific syscalls: All Linux system calls now have appropriate
+ library wrappers and corresponding declarations in various header files.
+ This is because the syscall() macro that was traditionally used to
+ work around missing syscall wrappers are inherently non-portable and
+ error-prone. The following table lists all the new syscall stubs,
+ the header-file declaring their interface and the system call name.
+
+ syscall name: wrapper name: declaring header file:
+ ------------- ------------- ----------------------
+ bdflush bdflush <sys/kdaemon.h>
+ syslog ksyslog_ctl <sys/klog.h>
+
+* lpd: Older versions of lpd depend on a routine called _validuser().
+ The library does not provide this function, but instead provides
+ __ivaliduser() which has a slightly different interface. Simply
+ upgrading to a newer lpd should fix this problem (e.g., the 4.4BSD
+ lpd is known to be working).
+
+* resolver functions/BIND: like on many other systems the functions of
+ the resolver library are not included in libc itself. There is a
+ separate library libresolv. If you get undefined symbol errors for
+ symbols starting with `res_*' simply add -lresolv to your linker
+ command line.
+
+* the `signal' function's behavior corresponds to the BSD semantic and
+ not the SysV semantic as it was in libc-5. The interface on all GNU
+ systems shall be the same and BSD is the semantic of choice. To use
+ the SysV behavior simply use `sysv_signal', or define _XOPEN_SOURCE.
+ See ?signal for details.
+
+??getlog Why does getlogin() always return NULL on my Linux box?
+
+{UD} The GNU C library has a format for the UTMP and WTMP file which
+differs from what your system currently has. It was extended to
+fulfill the needs of the next years when IPv6 is introduced. The
+record size is different and some fields have different positions.
+The files written by functions from the one library cannot be read by
+functions from the other library. Sorry, but this is what a major
+release is for. It's better to have a cut now than having no means to
+support the new techniques later.
+
+{MK} There is however a (partial) solution for this problem. Please
+take a look at the file `README.utmpd'.
+
+?? Where are the DST_* constants found in <sys/time.h> on many
+ systems?
+
+{UD} These constants come from the old BSD days and are not used
+anymore (libc5 does not actually implement the handling although the
+constants are defined).
+
+Instead GNU libc contains zone database support and compatibility code
+for POSIX TZ environment variable handling.
+
+?? The prototypes for `connect', `accept', `getsockopt',
+ `setsockopt', `getsockname', `getpeername', `send',
+ `sendto', and `recvfrom' are different in GNU libc from
+ any other system I saw. This is a bug, isn't it?
+
+{UD} No, this is no bug. This version of GNU libc already follows the
+new Single Unix specifications (and I think the POSIX.1g draft which
+adopted the solution). The type for a parameter describing a size is
+now `socklen_t', a new type.
+
+??kerhdr On Linux I've got problems with the declarations in Linux
+ kernel headers.
+
+{UD,AJ} On Linux, the use of kernel headers is reduced to the minimum.
+This gives Linus the ability to change the headers more freely. Also,
+user programs are now insulated from changes in the size of kernel
+data structures.
+
+For example, the sigset_t type is 32 or 64 bits wide in the kernel.
+In glibc it is 1024 bits wide. This guarantees that when the kernel
+gets a bigger sigset_t (for POSIX.1e realtime support, say) user
+programs will not have to be recompiled. Consult the header files for
+more information about the changes.
+
+Therefore you shouldn't include Linux kernel header files directly if
+glibc has defined a replacement. Otherwise you might get undefined
+results because of type conflicts.
+
+?? I don't include any kernel headers myself but the compiler
+ still complains about redeclarations of types in the kernel
+ headers.
+
+{UD} The kernel headers before Linux 2.1.61 don't work correctly with
+glibc. Compiling C programs is possible in most cases but C++
+programs have (due to the change of the name lookups for `struct's)
+problems. One prominent example is `struct fd_set'.
+
+There might be some problems left but 2.1.61 fixes most of the known
+ones. See the BUGS file for other known problems.
+
+??signal Why don't signals interrupt system calls anymore?
+
+{ZW} By default GNU libc uses the BSD semantics for signal(),
+unlike Linux libc 5 which used System V semantics. This is partially
+for compatibility with other systems and partially because the BSD
+semantics tend to make programming with signals easier.
+
+There are three differences:
+
+* BSD-style signals that occur in the middle of a system call do not
+ affect the system call; System V signals cause the system call to
+ fail and set errno to EINTR.
+
+* BSD signal handlers remain installed once triggered. System V signal
+ handlers work only once, so one must reinstall them each time.
+
+* A BSD signal is blocked during the execution of its handler. In other
+ words, a handler for SIGCHLD (for example) does not need to worry about
+ being interrupted by another SIGCHLD. It may, however, be interrupted
+ by other signals.
+
+There is general consensus that for `casual' programming with signals, the
+BSD semantics are preferable. You don't need to worry about system calls
+returning EINTR, and you don't need to worry about the race conditions
+associated with one-shot signal handlers.
+
+If you are porting an old program that relies on the old semantics, you can
+quickly fix the problem by changing signal() to sysv_signal() throughout.
+Alternatively, define _XOPEN_SOURCE before including <signal.h>.
+
+For new programs, the sigaction() function allows you to specify precisely
+how you want your signals to behave. All three differences listed above are
+individually switchable on a per-signal basis with this function.
+
+If all you want is for one specific signal to cause system calls to fail
+and return EINTR (for example, to implement a timeout) you can do this with
+siginterrupt().
+
+
+??string I've got errors compiling code that uses certain string
+ functions. Why?
+
+{AJ} glibc 2.1 has special string functions that are faster
+than the normal library functions. Some of the functions are
+implemented as inline functions and others as macros.
+
+The optimized string functions are only used when compiling with
+optimizations (-O1 or higher). The behavior can be changed with two
+feature macros:
+
+* __NO_STRING_INLINES: Don't do any string optimizations.
+* __USE_STRING_INLINES: Use assembly language inline functions (might
+ increase code size dramatically).
+
+Since some of these string functions are now additionally defined as
+macros, code like "char *strncpy();" doesn't work anymore (and is
+unnecessary, since <string.h> has the necessary declarations). Either
+change your code or define __NO_STRING_INLINES.
+
+{UD} Another problem in this area is that gcc still has problems on
+machines with very few registers (e.g., ix86). The inline assembler
+code can require almost all the registers and the register allocator
+cannot always handle this situation.
+
+One can disable the string optimizations selectively. Instead of writing
+
+ cp = strcpy (foo, "lkj");
+
+one can write
+
+ cp = (strcpy) (foo, "lkj");
+
+This disables the optimization for that specific call.
+
+? Miscellaneous
+
+?? After I changed configure.in I get `Autoconf version X.Y.
+ or higher is required for this script'. What can I do?
+
+{UD} You have to get the specified autoconf version (or a later one)
+from your favorite mirror of prep.ai.mit.edu.
+
+?? When I try to compile code which uses IPv6 headers and
+ definitions on my Linux 2.x.y system I am in trouble.
+ Nothing seems to work.
+
+{UD} The problem is that IPv6 development still has not reached a
+point where the headers are stable. There are still lots of
+incompatible changes made and the libc headers have to follow.
+
+Also, make sure you have a suitably recent kernel. As of the 970401
+snapshot, according to Philip Blundell <philb@gnu.ai.mit.edu>, the
+required kernel version is 2.1.30.
+
+\f
+Answers were given by:
+{UD} Ulrich Drepper, <drepper@cygnus.com>
+{DMT} David Mosberger-Tang, <davidm@AZStarNet.com>
+{RM} Roland McGrath, <roland@gnu.org>
+{AJ} Andreas Jaeger, <aj@arthur.rhein-neckar.de>
+{EY} Eric Youngdale, <eric@andante.jic.com>
+{PB} Phil Blundell, <Philip.Blundell@pobox.com>
+{MK} Mark Kettenis, <kettenis@phys.uva.nl>
+{ZW} Zack Weinberg, <zack@rabi.phys.columbia.edu>
+\f
+Local Variables:
+ mode:outline
+ outline-regexp:"\\?"
+End:
rtld-version-installed-name = ld-$(version).so
endif
-# The librt must contain be linked with the thread library. It least
+# The librt must be linked with the thread library, at least
# for now.
ifneq (,$(findstring linuxthreads,$(add-ons)))
shared-thread-library = $(common-objpfx)linuxthreads/libpthread.so
NOTES: manual/creature.texi; $(format-me)
manual/dir-add.texi manual/dir-add.info: FORCE
$(MAKE) $(PARALLELMFLAGS) -C $(@D) $(@F)
+FAQ: gen-FAQ.pl FAQ.in
+ $(PERL) $^ > $@.new && rm -f $@ && mv $@.new $@ && chmod a-w $@
FORCE:
rpm/%: subdir_distinfo
# Check whether --enable-add-ons or --disable-add-ons was given.
if test "${enable_add_ons+set}" = set; then
enableval="$enable_add_ons"
- add_ons=`echo "$enableval" | sed 's/,/ /g'`
+ case "$enableval" in
+ yes) add_ons=`echo $srcdir/*/configure | \
+ sed -e "s!$srcdir/!!g" -e 's!/configure!!g'`;;
+ *) add_ons=`echo "$enableval" | sed 's/,/ /g'`;;
+ esac
else
add_ons=
fi
+
ac_aux_dir=
for ac_dir in $srcdir $srcdir/.. $srcdir/../..; do
if test -f $ac_dir/install-sh; then
fi
echo $ac_n "checking host system type""... $ac_c" 1>&6
-echo "configure:756: checking host system type" >&5
+echo "configure:761: checking host system type" >&5
host_alias=$host
case "$host_alias" in
# This can take a while to compute.
sysdep_dir=$srcdir/sysdeps
echo $ac_n "checking sysdep dirs""... $ac_c" 1>&6
-echo "configure:875: checking sysdep dirs" >&5
+echo "configure:880: checking sysdep dirs" >&5
# Make sco3.2v4 become sco3.2.4 and sunos4.1.1_U1 become sunos4.1.1.U1.
os="`echo $os | sed 's/\([0-9A-Z]\)[v_]\([0-9A-Z]\)/\1.\2/g'`"
# SVR4 /usr/ucb/install, which tries to use the nonexistent group "staff"
# ./install, which can be erroneously created by make from ./install.sh.
echo $ac_n "checking for a BSD compatible install""... $ac_c" 1>&6
-echo "configure:1076: checking for a BSD compatible install" >&5
+echo "configure:1081: checking for a BSD compatible install" >&5
if test -z "$INSTALL"; then
if eval "test \"`echo '$''{'ac_cv_path_install'+set}'`\" = set"; then
echo $ac_n "(cached) $ac_c" 1>&6
INSTALL='\$(..)./install-sh -c'
fi
echo $ac_n "checking whether ln -s works""... $ac_c" 1>&6
-echo "configure:1130: checking whether ln -s works" >&5
+echo "configure:1135: checking whether ln -s works" >&5
if eval "test \"`echo '$''{'ac_cv_prog_LN_S'+set}'`\" = set"; then
echo $ac_n "(cached) $ac_c" 1>&6
else
# Extract the first word of "$ac_prog", so it can be a program name with args.
set dummy $ac_prog; ac_word=$2
echo $ac_n "checking for $ac_word""... $ac_c" 1>&6
-echo "configure:1155: checking for $ac_word" >&5
+echo "configure:1160: checking for $ac_word" >&5
if eval "test \"`echo '$''{'ac_cv_prog_MSGFMT'+set}'`\" = set"; then
echo $ac_n "(cached) $ac_c" 1>&6
else
# Extract the first word of "makeinfo", so it can be a program name with args.
set dummy makeinfo; ac_word=$2
echo $ac_n "checking for $ac_word""... $ac_c" 1>&6
-echo "configure:1187: checking for $ac_word" >&5
+echo "configure:1192: checking for $ac_word" >&5
if eval "test \"`echo '$''{'ac_cv_prog_MAKEINFO'+set}'`\" = set"; then
echo $ac_n "(cached) $ac_c" 1>&6
else
# Extract the first word of "gcc", so it can be a program name with args.
set dummy gcc; ac_word=$2
echo $ac_n "checking for $ac_word""... $ac_c" 1>&6
-echo "configure:1227: checking for $ac_word" >&5
+echo "configure:1232: checking for $ac_word" >&5
if eval "test \"`echo '$''{'ac_cv_prog_CC'+set}'`\" = set"; then
echo $ac_n "(cached) $ac_c" 1>&6
else
# Extract the first word of "cc", so it can be a program name with args.
set dummy cc; ac_word=$2
echo $ac_n "checking for $ac_word""... $ac_c" 1>&6
-echo "configure:1256: checking for $ac_word" >&5
+echo "configure:1261: checking for $ac_word" >&5
if eval "test \"`echo '$''{'ac_cv_prog_CC'+set}'`\" = set"; then
echo $ac_n "(cached) $ac_c" 1>&6
else
fi
echo $ac_n "checking whether the C compiler ($CC $CFLAGS $LDFLAGS) works""... $ac_c" 1>&6
-echo "configure:1304: checking whether the C compiler ($CC $CFLAGS $LDFLAGS) works" >&5
+echo "configure:1309: checking whether the C compiler ($CC $CFLAGS $LDFLAGS) works" >&5
ac_ext=c
# CFLAGS is not in ac_cpp because -g, -O, etc. are not valid cpp options.
cross_compiling=$ac_cv_prog_cc_cross
cat > conftest.$ac_ext <<EOF
-#line 1314 "configure"
+#line 1319 "configure"
#include "confdefs.h"
main(){return(0);}
EOF
-if { (eval echo configure:1318: \"$ac_link\") 1>&5; (eval $ac_link) 2>&5; } && test -s conftest; then
+if { (eval echo configure:1323: \"$ac_link\") 1>&5; (eval $ac_link) 2>&5; } && test -s conftest; then
ac_cv_prog_cc_works=yes
# If we can't run a trivial program, we are probably using a cross compiler.
if (./conftest; exit) 2>/dev/null; then
cross_linkable=yes
fi
echo $ac_n "checking whether the C compiler ($CC $CFLAGS $LDFLAGS) is a cross-compiler""... $ac_c" 1>&6
-echo "configure:1341: checking whether the C compiler ($CC $CFLAGS $LDFLAGS) is a cross-compiler" >&5
+echo "configure:1346: checking whether the C compiler ($CC $CFLAGS $LDFLAGS) is a cross-compiler" >&5
echo "$ac_t""$ac_cv_prog_cc_cross" 1>&6
cross_compiling=$ac_cv_prog_cc_cross
echo $ac_n "checking whether we are using GNU C""... $ac_c" 1>&6
-echo "configure:1347: checking whether we are using GNU C" >&5
+echo "configure:1352: checking whether we are using GNU C" >&5
if eval "test \"`echo '$''{'ac_cv_prog_gcc'+set}'`\" = set"; then
echo $ac_n "(cached) $ac_c" 1>&6
else
yes;
#endif
EOF
-if { ac_try='${CC-cc} -E conftest.c'; { (eval echo configure:1356: \"$ac_try\") 1>&5; (eval $ac_try) 2>&5; }; } | egrep yes >/dev/null 2>&1; then
+if { ac_try='${CC-cc} -E conftest.c'; { (eval echo configure:1361: \"$ac_try\") 1>&5; (eval $ac_try) 2>&5; }; } | egrep yes >/dev/null 2>&1; then
ac_cv_prog_gcc=yes
else
ac_cv_prog_gcc=no
yes;
#endif
EOF
- if { ac_try='${CC-cc} -E conftest.c'; { (eval echo configure:1373: \"$ac_try\") 1>&5; (eval $ac_try) 2>&5; }; } | egrep yes >/dev/null 2>&1; then
+ if { ac_try='${CC-cc} -E conftest.c'; { (eval echo configure:1378: \"$ac_try\") 1>&5; (eval $ac_try) 2>&5; }; } | egrep yes >/dev/null 2>&1; then
if test -z "$CFLAGS"; then
CFLAGS="-g -O2"
fi
fi
echo $ac_n "checking build system type""... $ac_c" 1>&6
-echo "configure:1385: checking build system type" >&5
+echo "configure:1390: checking build system type" >&5
build_alias=$build
case "$build_alias" in
# Extract the first word of "$ac_prog", so it can be a program name with args.
set dummy $ac_prog; ac_word=$2
echo $ac_n "checking for $ac_word""... $ac_c" 1>&6
-echo "configure:1408: checking for $ac_word" >&5
+echo "configure:1413: checking for $ac_word" >&5
if eval "test \"`echo '$''{'ac_cv_prog_BUILD_CC'+set}'`\" = set"; then
echo $ac_n "(cached) $ac_c" 1>&6
else
fi
echo $ac_n "checking how to run the C preprocessor""... $ac_c" 1>&6
-echo "configure:1439: checking how to run the C preprocessor" >&5
+echo "configure:1444: checking how to run the C preprocessor" >&5
# On Suns, sometimes $CPP names a directory.
if test -n "$CPP" && test -d "$CPP"; then
CPP=
# On the NeXT, cc -E runs the code through the compiler's parser,
# not just through cpp.
cat > conftest.$ac_ext <<EOF
-#line 1454 "configure"
+#line 1459 "configure"
#include "confdefs.h"
#include <assert.h>
Syntax Error
EOF
ac_try="$ac_cpp conftest.$ac_ext >/dev/null 2>conftest.out"
-{ (eval echo configure:1460: \"$ac_try\") 1>&5; (eval $ac_try) 2>&5; }
+{ (eval echo configure:1465: \"$ac_try\") 1>&5; (eval $ac_try) 2>&5; }
ac_err=`grep -v '^ *+' conftest.out`
if test -z "$ac_err"; then
:
rm -rf conftest*
CPP="${CC-cc} -E -traditional-cpp"
cat > conftest.$ac_ext <<EOF
-#line 1471 "configure"
+#line 1476 "configure"
#include "confdefs.h"
#include <assert.h>
Syntax Error
EOF
ac_try="$ac_cpp conftest.$ac_ext >/dev/null 2>conftest.out"
-{ (eval echo configure:1477: \"$ac_try\") 1>&5; (eval $ac_try) 2>&5; }
+{ (eval echo configure:1482: \"$ac_try\") 1>&5; (eval $ac_try) 2>&5; }
ac_err=`grep -v '^ *+' conftest.out`
if test -z "$ac_err"; then
:
# Determine whether we are using GNU binutils.
echo $ac_n "checking whether $AS is GNU as""... $ac_c" 1>&6
-echo "configure:1510: checking whether $AS is GNU as" >&5
+echo "configure:1515: checking whether $AS is GNU as" >&5
if eval "test \"`echo '$''{'libc_cv_prog_as_gnu'+set}'`\" = set"; then
echo $ac_n "(cached) $ac_c" 1>&6
else
gnu_as=$libc_cv_prog_as_gnu
echo $ac_n "checking whether $LD is GNU ld""... $ac_c" 1>&6
-echo "configure:1528: checking whether $LD is GNU ld" >&5
+echo "configure:1533: checking whether $LD is GNU ld" >&5
if eval "test \"`echo '$''{'libc_cv_prog_ld_gnu'+set}'`\" = set"; then
echo $ac_n "(cached) $ac_c" 1>&6
else
# Extract the first word of "${ac_tool_prefix}ar", so it can be a program name with args.
set dummy ${ac_tool_prefix}ar; ac_word=$2
echo $ac_n "checking for $ac_word""... $ac_c" 1>&6
-echo "configure:1552: checking for $ac_word" >&5
+echo "configure:1557: checking for $ac_word" >&5
if eval "test \"`echo '$''{'ac_cv_prog_AR'+set}'`\" = set"; then
echo $ac_n "(cached) $ac_c" 1>&6
else
# Extract the first word of "${ac_tool_prefix}ranlib", so it can be a program name with args.
set dummy ${ac_tool_prefix}ranlib; ac_word=$2
echo $ac_n "checking for $ac_word""... $ac_c" 1>&6
-echo "configure:1583: checking for $ac_word" >&5
+echo "configure:1588: checking for $ac_word" >&5
if eval "test \"`echo '$''{'ac_cv_prog_RANLIB'+set}'`\" = set"; then
echo $ac_n "(cached) $ac_c" 1>&6
else
# Extract the first word of "ranlib", so it can be a program name with args.
set dummy ranlib; ac_word=$2
echo $ac_n "checking for $ac_word""... $ac_c" 1>&6
-echo "configure:1614: checking for $ac_word" >&5
+echo "configure:1619: checking for $ac_word" >&5
if eval "test \"`echo '$''{'ac_cv_prog_RANLIB'+set}'`\" = set"; then
echo $ac_n "(cached) $ac_c" 1>&6
else
# Extract the first word of "bash", so it can be a program name with args.
set dummy bash; ac_word=$2
echo $ac_n "checking for $ac_word""... $ac_c" 1>&6
-echo "configure:1649: checking for $ac_word" >&5
+echo "configure:1654: checking for $ac_word" >&5
if eval "test \"`echo '$''{'ac_cv_path_BASH'+set}'`\" = set"; then
echo $ac_n "(cached) $ac_c" 1>&6
else
# Extract the first word of "ksh", so it can be a program name with args.
set dummy ksh; ac_word=$2
echo $ac_n "checking for $ac_word""... $ac_c" 1>&6
-echo "configure:1691: checking for $ac_word" >&5
+echo "configure:1696: checking for $ac_word" >&5
if eval "test \"`echo '$''{'ac_cv_path_KSH'+set}'`\" = set"; then
echo $ac_n "(cached) $ac_c" 1>&6
else
# Extract the first word of "$ac_prog", so it can be a program name with args.
set dummy $ac_prog; ac_word=$2
echo $ac_n "checking for $ac_word""... $ac_c" 1>&6
-echo "configure:1737: checking for $ac_word" >&5
+echo "configure:1742: checking for $ac_word" >&5
if eval "test \"`echo '$''{'ac_cv_path_PERL'+set}'`\" = set"; then
echo $ac_n "(cached) $ac_c" 1>&6
else
echo $ac_n "checking for signed size_t type""... $ac_c" 1>&6
-echo "configure:1772: checking for signed size_t type" >&5
+echo "configure:1777: checking for signed size_t type" >&5
if eval "test \"`echo '$''{'libc_cv_signed_size_t'+set}'`\" = set"; then
echo $ac_n "(cached) $ac_c" 1>&6
else
fi
echo $ac_n "checking for libc-friendly stddef.h""... $ac_c" 1>&6
-echo "configure:1796: checking for libc-friendly stddef.h" >&5
+echo "configure:1801: checking for libc-friendly stddef.h" >&5
if eval "test \"`echo '$''{'libc_cv_friendly_stddef'+set}'`\" = set"; then
echo $ac_n "(cached) $ac_c" 1>&6
else
cat > conftest.$ac_ext <<EOF
-#line 1801 "configure"
+#line 1806 "configure"
#include "confdefs.h"
#define __need_size_t
#define __need_wchar_t
if (&size == NULL || &wchar == NULL) abort ();
; return 0; }
EOF
-if { (eval echo configure:1816: \"$ac_compile\") 1>&5; (eval $ac_compile) 2>&5; }; then
+if { (eval echo configure:1821: \"$ac_compile\") 1>&5; (eval $ac_compile) 2>&5; }; then
rm -rf conftest*
libc_cv_friendly_stddef=yes
else
fi
echo $ac_n "checking whether we need to use -P to assemble .S files""... $ac_c" 1>&6
-echo "configure:1835: checking whether we need to use -P to assemble .S files" >&5
+echo "configure:1840: checking whether we need to use -P to assemble .S files" >&5
if eval "test \"`echo '$''{'libc_cv_need_minus_P'+set}'`\" = set"; then
echo $ac_n "(cached) $ac_c" 1>&6
else
# We must check this even if -pipe is not given here, because the user
# might do `make CFLAGS=-pipe'.
echo $ac_n "checking for gcc 2.7.x -pipe bug""... $ac_c" 1>&6
-echo "configure:1866: checking for gcc 2.7.x -pipe bug" >&5
+echo "configure:1871: checking for gcc 2.7.x -pipe bug" >&5
if eval "test \"`echo '$''{'libc_cv_gcc_pipe_bug'+set}'`\" = set"; then
echo $ac_n "(cached) $ac_c" 1>&6
else
fi
echo $ac_n "checking for assembler global-symbol directive""... $ac_c" 1>&6
-echo "configure:1895: checking for assembler global-symbol directive" >&5
+echo "configure:1900: checking for assembler global-symbol directive" >&5
if eval "test \"`echo '$''{'libc_cv_asm_global_directive'+set}'`\" = set"; then
echo $ac_n "(cached) $ac_c" 1>&6
else
fi
echo $ac_n "checking for .set assembler directive""... $ac_c" 1>&6
-echo "configure:1925: checking for .set assembler directive" >&5
+echo "configure:1930: checking for .set assembler directive" >&5
if eval "test \"`echo '$''{'libc_cv_asm_set_directive'+set}'`\" = set"; then
echo $ac_n "(cached) $ac_c" 1>&6
else
fi
echo $ac_n "checking for .symver assembler directive""... $ac_c" 1>&6
-echo "configure:1959: checking for .symver assembler directive" >&5
+echo "configure:1964: checking for .symver assembler directive" >&5
if eval "test \"`echo '$''{'libc_cv_asm_symver_directive'+set}'`\" = set"; then
echo $ac_n "(cached) $ac_c" 1>&6
else
echo "$ac_t""$libc_cv_asm_symver_directive" 1>&6
echo $ac_n "checking for ld --version-script""... $ac_c" 1>&6
-echo "configure:1978: checking for ld --version-script" >&5
+echo "configure:1983: checking for ld --version-script" >&5
if eval "test \"`echo '$''{'libc_cv_ld_version_script_option'+set}'`\" = set"; then
echo $ac_n "(cached) $ac_c" 1>&6
else
if { ac_try='${CC-cc} $CFLAGS -shared -o conftest.so conftest.o
-nostartfiles -nostdlib
-Wl,--version-script,conftest.map
- 1>&5'; { (eval echo configure:2001: \"$ac_try\") 1>&5; (eval $ac_try) 2>&5; }; };
+ 1>&5'; { (eval echo configure:2006: \"$ac_try\") 1>&5; (eval $ac_try) 2>&5; }; };
then
libc_cv_ld_version_script_option=yes
else
fi
if test $elf = yes; then
echo $ac_n "checking for .previous assembler directive""... $ac_c" 1>&6
-echo "configure:2039: checking for .previous assembler directive" >&5
+echo "configure:2044: checking for .previous assembler directive" >&5
if eval "test \"`echo '$''{'libc_cv_asm_previous_directive'+set}'`\" = set"; then
echo $ac_n "(cached) $ac_c" 1>&6
else
.section foo_section
.previous
EOF
- if { ac_try='${CC-cc} -c $CFLAGS conftest.s 1>&5'; { (eval echo configure:2047: \"$ac_try\") 1>&5; (eval $ac_try) 2>&5; }; }; then
+ if { ac_try='${CC-cc} -c $CFLAGS conftest.s 1>&5'; { (eval echo configure:2052: \"$ac_try\") 1>&5; (eval $ac_try) 2>&5; }; }; then
libc_cv_asm_previous_directive=yes
else
libc_cv_asm_previous_directive=no
else
echo $ac_n "checking for .popsection assembler directive""... $ac_c" 1>&6
-echo "configure:2063: checking for .popsection assembler directive" >&5
+echo "configure:2068: checking for .popsection assembler directive" >&5
if eval "test \"`echo '$''{'libc_cv_asm_popsection_directive'+set}'`\" = set"; then
echo $ac_n "(cached) $ac_c" 1>&6
else
.pushsection foo_section
.popsection
EOF
- if { ac_try='${CC-cc} -c $CFLAGS conftest.s 1>&5'; { (eval echo configure:2071: \"$ac_try\") 1>&5; (eval $ac_try) 2>&5; }; }; then
+ if { ac_try='${CC-cc} -c $CFLAGS conftest.s 1>&5'; { (eval echo configure:2076: \"$ac_try\") 1>&5; (eval $ac_try) 2>&5; }; }; then
libc_cv_asm_popsection_directive=yes
else
libc_cv_asm_popsection_directive=no
if test $elf != yes; then
echo $ac_n "checking for .init and .fini sections""... $ac_c" 1>&6
-echo "configure:2091: checking for .init and .fini sections" >&5
+echo "configure:2096: checking for .init and .fini sections" >&5
if eval "test \"`echo '$''{'libc_cv_have_initfini'+set}'`\" = set"; then
echo $ac_n "(cached) $ac_c" 1>&6
else
cat > conftest.$ac_ext <<EOF
-#line 2096 "configure"
+#line 2101 "configure"
#include "confdefs.h"
int main() {
asm (".text");
; return 0; }
EOF
-if { (eval echo configure:2105: \"$ac_compile\") 1>&5; (eval $ac_compile) 2>&5; }; then
+if { (eval echo configure:2110: \"$ac_compile\") 1>&5; (eval $ac_compile) 2>&5; }; then
rm -rf conftest*
libc_cv_have_initfini=yes
else
else
if test $ac_cv_prog_cc_works = yes; then
echo $ac_n "checking for _ prefix on C symbol names""... $ac_c" 1>&6
-echo "configure:2133: checking for _ prefix on C symbol names" >&5
+echo "configure:2138: checking for _ prefix on C symbol names" >&5
if eval "test \"`echo '$''{'libc_cv_asm_underscores'+set}'`\" = set"; then
echo $ac_n "(cached) $ac_c" 1>&6
else
cat > conftest.$ac_ext <<EOF
-#line 2138 "configure"
+#line 2143 "configure"
#include "confdefs.h"
asm ("_glibc_foobar:");
int main() {
glibc_foobar ();
; return 0; }
EOF
-if { (eval echo configure:2145: \"$ac_link\") 1>&5; (eval $ac_link) 2>&5; } && test -s conftest; then
+if { (eval echo configure:2150: \"$ac_link\") 1>&5; (eval $ac_link) 2>&5; } && test -s conftest; then
rm -rf conftest*
libc_cv_asm_underscores=yes
else
echo "$ac_t""$libc_cv_asm_underscores" 1>&6
else
echo $ac_n "checking for _ prefix on C symbol names""... $ac_c" 1>&6
-echo "configure:2160: checking for _ prefix on C symbol names" >&5
+echo "configure:2165: checking for _ prefix on C symbol names" >&5
if eval "test \"`echo '$''{'libc_cv_asm_underscores'+set}'`\" = set"; then
echo $ac_n "(cached) $ac_c" 1>&6
else
cat > conftest.$ac_ext <<EOF
-#line 2165 "configure"
+#line 2170 "configure"
#include "confdefs.h"
void underscore_test(void) {
return; }
EOF
-if { (eval echo configure:2170: \"$ac_compile\") 1>&5; (eval $ac_compile) 2>&5; }; then
+if { (eval echo configure:2175: \"$ac_compile\") 1>&5; (eval $ac_compile) 2>&5; }; then
if grep _underscore_test conftest* >/dev/null; then
rm -f conftest*
libc_cv_asm_underscores=yes
libc_cv_asm_weakext_directive=no
else
echo $ac_n "checking for assembler .weak directive""... $ac_c" 1>&6
-echo "configure:2203: checking for assembler .weak directive" >&5
+echo "configure:2208: checking for assembler .weak directive" >&5
if eval "test \"`echo '$''{'libc_cv_asm_weak_directive'+set}'`\" = set"; then
echo $ac_n "(cached) $ac_c" 1>&6
else
if test $libc_cv_asm_weak_directive = no; then
echo $ac_n "checking for assembler .weakext directive""... $ac_c" 1>&6
-echo "configure:2226: checking for assembler .weakext directive" >&5
+echo "configure:2231: checking for assembler .weakext directive" >&5
if eval "test \"`echo '$''{'libc_cv_asm_weakext_directive'+set}'`\" = set"; then
echo $ac_n "(cached) $ac_c" 1>&6
else
fi
echo $ac_n "checking for ld --no-whole-archive""... $ac_c" 1>&6
-echo "configure:2263: checking for ld --no-whole-archive" >&5
+echo "configure:2268: checking for ld --no-whole-archive" >&5
if eval "test \"`echo '$''{'libc_cv_ld_no_whole_archive'+set}'`\" = set"; then
echo $ac_n "(cached) $ac_c" 1>&6
else
EOF
if { ac_try='${CC-cc} $CFLAGS
-nostdlib -nostartfiles -Wl,--no-whole-archive
- -o conftest conftest.c 1>&5'; { (eval echo configure:2274: \"$ac_try\") 1>&5; (eval $ac_try) 2>&5; }; }; then
+ -o conftest conftest.c 1>&5'; { (eval echo configure:2279: \"$ac_try\") 1>&5; (eval $ac_try) 2>&5; }; }; then
libc_cv_ld_no_whole_archive=yes
else
libc_cv_ld_no_whole_archive=no
echo "$ac_t""$libc_cv_ld_no_whole_archive" 1>&6
echo $ac_n "checking for gcc -fno-exceptions""... $ac_c" 1>&6
-echo "configure:2285: checking for gcc -fno-exceptions" >&5
+echo "configure:2290: checking for gcc -fno-exceptions" >&5
if eval "test \"`echo '$''{'libc_cv_gcc_no_exceptions'+set}'`\" = set"; then
echo $ac_n "(cached) $ac_c" 1>&6
else
EOF
if { ac_try='${CC-cc} $CFLAGS
-nostdlib -nostartfiles -fno-exceptions
- -o conftest conftest.c 1>&5'; { (eval echo configure:2296: \"$ac_try\") 1>&5; (eval $ac_try) 2>&5; }; }; then
+ -o conftest conftest.c 1>&5'; { (eval echo configure:2301: \"$ac_try\") 1>&5; (eval $ac_try) 2>&5; }; }; then
libc_cv_gcc_no_exceptions=yes
else
libc_cv_gcc_no_exceptions=no
echo "$ac_t""$libc_cv_gcc_no_exceptions" 1>&6
echo $ac_n "checking for DWARF2 unwind info support""... $ac_c" 1>&6
-echo "configure:2307: checking for DWARF2 unwind info support" >&5
+echo "configure:2312: checking for DWARF2 unwind info support" >&5
if eval "test \"`echo '$''{'libc_cv_gcc_dwarf2_unwind_info'+set}'`\" = set"; then
echo $ac_n "(cached) $ac_c" 1>&6
else
cat > conftest.c <<EOF
-#line 2312 "configure"
+#line 2317 "configure"
static char __EH_FRAME_BEGIN__;
_start ()
{
EOF
if { ac_try='${CC-cc} $CFLAGS
-nostdlib -nostartfiles
- -o conftest conftest.c -lgcc >&5'; { (eval echo configure:2333: \"$ac_try\") 1>&5; (eval $ac_try) 2>&5; }; }; then
+ -o conftest conftest.c -lgcc >&5'; { (eval echo configure:2338: \"$ac_try\") 1>&5; (eval $ac_try) 2>&5; }; }; then
libc_cv_gcc_dwarf2_unwind_info=yes
else
libc_cv_gcc_dwarf2_unwind_info=no
fi
echo $ac_n "checking OS release for uname""... $ac_c" 1>&6
-echo "configure:2391: checking OS release for uname" >&5
+echo "configure:2396: checking OS release for uname" >&5
if eval "test \"`echo '$''{'libc_cv_uname_release'+set}'`\" = set"; then
echo $ac_n "(cached) $ac_c" 1>&6
else
uname_release="$libc_cv_uname_release"
echo $ac_n "checking OS version for uname""... $ac_c" 1>&6
-echo "configure:2413: checking OS version for uname" >&5
+echo "configure:2418: checking OS version for uname" >&5
if eval "test \"`echo '$''{'libc_cv_uname_version'+set}'`\" = set"; then
echo $ac_n "(cached) $ac_c" 1>&6
else
fi
echo $ac_n "checking stdio selection""... $ac_c" 1>&6
-echo "configure:2435: checking stdio selection" >&5
+echo "configure:2440: checking stdio selection" >&5
case $stdio in
libio) cat >> confdefs.h <<\EOF
echo "$ac_t""$stdio" 1>&6
echo $ac_n "checking ldap selection""... $ac_c" 1>&6
-echo "configure:2447: checking ldap selection" >&5
+echo "configure:2452: checking ldap selection" >&5
case $add_ons in
*ldap*)
fi
echo $ac_n "checking whether -fPIC is default""... $ac_c" 1>&6
-echo "configure:2497: checking whether -fPIC is default" >&5
+echo "configure:2502: checking whether -fPIC is default" >&5
if eval "test \"`echo '$''{'pic_default'+set}'`\" = set"; then
echo $ac_n "(cached) $ac_c" 1>&6
else
dnl Generic infrastructure for drop-in additions to libc.
AC_ARG_ENABLE(add-ons, dnl
[ --enable-add-ons=DIR1,DIR2... configure and build named extra directories],
- [add_ons=`echo "$enableval" | sed 's/,/ /g'`],
- [add_ons=])
+ [case "$enableval" in
+ yes) add_ons=`echo $srcdir/*/configure | \
+ sed -e "s!$srcdir/!!g" -e 's!/configure!!g'`;;
+ *) add_ons=`echo "$enableval" | sed 's/,/ /g'`;;
+ esac],
+ [add_ons=])
+
AC_CONFIG_SUBDIRS($add_ons)
add_ons_pfx=
if test x"$add_ons" != x; then
--- /dev/null
+#! /usr/local/bin/perl
+
+=pod
+This is a silly little program for generating the libc FAQ.
+
+The input format is:
+top boilerplate
+^L
+? section name (one line)
+?? question...
+...
+{ID} answer...
+...
+^L
+{ID} name <email@address>
+...
+
+which gets mapped to:
+
+top boilerplate
+^L
+1. section 1...
+1.1. q1.1
+1.2. q1.2
+...
+^L
+1. section 1...
+
+1.1. q1.1
+
+answer 1.1....
+
+
+^L
+Answers were provided by:
+...
+
+=cut
+
+# We slurp the whole file into a pair of assoc arrays indexed by
+# the 'section.question' number.
+%questions = ();
+%answers = ();
+$question = 0;
+
+# These arrays and counter keep track of the sections.
+@sectcount = ();
+@sections = ();
+$section = 0;
+
+# Cross reference list.
+%refs = ();
+
+# Separators.
+$sepmaj = "\f\n" . ('~ ' x 36) . "\n\n";
+$sepmin = "\f\n" . ('. ' x 36) . "\n\n";
+
+# Pass through the top boilerplate.
+while(<>)
+{
+ last if $_ eq "\f\n";
+ print;
+}
+
+# Now the body.
+while(<>)
+{
+ /\f/ && do
+ {
+ $sectcount[$section] = $question;
+ last;
+ };
+
+ s/^\?\s+// && do
+ {
+ chomp;
+ $sectcount[$section] = $question if $section > 0;
+ $section++;
+ $sections[$section] = $_;
+ $question = 0;
+ next;
+ };
+ s/^\?\?(\w*?)\s+// && do
+ {
+ $cur = \%questions;
+ $question++;
+ $questions{$section,$question} = $_;
+ $refs{$1} = "$section.$question" if $1 ne "";
+ next;
+ };
+ /^\{/ && do
+ {
+ $cur = \%answers;
+ $answers{$section,$question} .= $_;
+ next;
+ };
+
+ ${$cur}{$section,$question} .= $_;
+}
+
+# Now we have to clean up the newlines and deal with cross references.
+foreach(keys %questions) { $questions{$_} =~ s/\n+$//; }
+foreach(keys %answers)
+{
+ $answers{$_} =~ s/\n+$//;
+ $answers{$_} =~ s/(\s)\?(\w+)\b/$1 . "question " . ($refs{$2} or badref($2,$_), "!!$2")/eg;
+}
+
+# Now output the formatted FAQ.
+print $sepmaj;
+for($i = 1; $i <= $section; $i++)
+{
+ print "$i. $sections[$i]\n\n";
+ for($j = 1; $j <= $sectcount[$i]; $j++)
+ {
+ print "$i.$j.\t$questions{$i,$j}\n";
+ }
+ print "\n";
+}
+
+print $sepmaj;
+for($i = 1; $i <= $section; $i++)
+{
+ print "$i. $sections[$i]\n\n";
+ for($j = 1; $j <= $sectcount[$i]; $j++)
+ {
+ print "$i.$j.\t$questions{$i,$j}\n\n";
+ print $answers{$i,$j}, "\n\n";
+ print "\n" if $j < $sectcount[$i];
+ }
+ print $sepmin if $i < $section;
+}
+
+print $sepmaj;
+
+# Pass through the trailer.
+while(<>) { print; }
+
+sub badref
+{
+ my($ref,$quest) = @_;
+ $quest =~ s/$;/./;
+ print STDERR "Undefined reference to $ref in answer to Q$quest\n";
+}
modules := ISO8859-1 ISO8859-2 ISO8859-3 ISO8859-4 ISO8859-5 \
ISO8859-6 ISO8859-7 ISO8859-8 ISO8859-9 ISO8859-10 \
T.61 ISO_6937 SJIS KOI-8 KOI8-R LATIN-GREEK LATIN-GREEK-1 \
- HP-ROMAN8 EBCDIC-AT-DE EBCDIC-AT-DE-A EBCDIC-CA-FR
+ HP-ROMAN8 EBCDIC-AT-DE EBCDIC-AT-DE-A EBCDIC-CA-FR \
+ libJIS
modules.so := $(addsuffix .so, $(modules))
EBCDIC-AT-DE-routines := ebcdic-at-de
EBCDIC-AT-DE-A-routines := ebcdic-at-de-a
EBCDIC-CA-FR-routines := ebcdic-ca-fr
-
-extra-libs = libJIS
-extra-libs-others = $(extra-libs)
-
libJIS-routines := jis0201 jis0208 jis0212
-libJIS-inhibit-o := $(filter-out .os,$(object-suffixes))
distribute := 8bit-generic.c 8bit-gap.c gap.pl gaptab.pl \
iso8859-1.c iso8859-2.c iso8859-3.c iso8859-4.c iso8859-5.c \
--- /dev/null
+GLIBC_2.1 {
+ global:
+
+ # AIO functions.
+ aio_cancel; aio_cancel64; aio_error; aio_error64; aio_fsync; aio_fsync64;
+ aio_read; aio_read64; aio_return; aio_return64; aio_suspend; aio_suspend64;
+ aio_write; aio_write64; lio_listio; lio_listio64;
+
+ local:
+ *;
+};
#ifndef __NO_STRING_INLINES
/* Unlike the definitions in the header <bits/string.h> the
- definitions contained here are not optimizing down to assembler
- level. These optimizations are not always a good idea since this
+ definitions contained here are not optimized down to assembler
+ level. Those optimizations are not always a good idea since this
means the code size increases a lot. Instead the definitions here
- optimize some functions in a way which does not dramatically
- increase the code size and which does not use assembler. The main
+ optimize some functions in a way which do not dramatically
+ increase the code size and which do not use assembler. The main
trick is to use GNU CC's `__builtin_constant_p' function.
Every function XXX which has a defined version in
/* When using GNU CC we provide some optimized versions of selected
functions from this header. There are two kinds of optimizations:
- - machine-dependent optmizations, most probably using inline
- assembler code; these could be quite expensive since the code
- size could increase significantly.
+ - machine-dependent optimizations, most probably using inline
+ assembler code; these might be quite expensive since the code
+ size can increase significantly.
These optimizations are not used unless the symbol
__USE_STRING_INLINES
- is defined before including this header
+ is defined before including this header.
- machine-independent optimizations which do not increase the
code size significantly and which optimize mainly situations
where one or more arguments are compile-time constants.
These optimizations are used always when the compiler is
- taught to optimized.
+ taught to optimize.
One can inhibit all optimizations by defining __NO_STRING_INLINES. */
(c >= '0' && c <= '9' \
? c - '0' \
: ({ int upp = toupper (c); \
- upp >= 'a' && upp <= 'z' ? upp - 'a' + 10 : -1; }))
+ upp >= 'A' && upp <= 'Z' ? upp - 'A' + 10 : -1; }))
#else
static char hexval (char) internal_function;
#endif
void
__libc_init_secure (void)
{
- __libc_uid == __getuid ();
+ __libc_uid = __getuid ();
__libc_enable_secure = (__geteuid () != __libc_uid
|| __getegid () != __getgid ());
}
#define PF_AAL5 8 /* Reserved for Werner's ATM. */
#define PF_X25 9 /* Reserved for X.25 project. */
#define PF_INET6 10 /* IP version 6. */
-#define PF_MAX 12 /* For now.. */
+#define PF_ROSE 11 /* Amateur Radio X.25 PLP */
+#define PF_DECnet 12 /* Reserved for DECnet project */
+#define PF_NETBEUI 13 /* Reserved for 802.2LLC project*/
+#define PF_SECURITY 14 /* Security callback pseudo AF */
+#define pseudo_PF_KEY 15 /* PF_KEY key management API */
+#define PF_NETLINK 16
+#define PF_ROUTE PF_NETLINK /* Alias to emulate 4.4BSD */
+#define PF_PACKET 17 /* Packet family */
+#define PF_MAX 32 /* For now.. */
/* Address families. */
#define AF_UNSPEC PF_UNSPEC
#define AF_AAL5 PF_AAL5
#define AF_X25 PF_X25
#define AF_INET6 PF_INET6
+#define AF_ROSE PF_ROSE
+#define AF_DECnet PF_DECnet
+#define AF_NETBEUI PF_NETBEUI
+#define AF_SECURITY PF_SECURITY
+#define AF_KEY pseudo_PF_KEY
+#define AF_NETLINK PF_NETLINK
+#define AF_ROUTE PF_ROUTE
+#define AF_PACKET PF_PACKET
#define AF_MAX PF_MAX
/* Socket level values. Others are defined in the appropriate headers.
--- /dev/null
+/* pread64 syscall for Linux/ix86.
+ Copyright (C) 1997 Free Software Foundation, Inc.
+ This file is part of the GNU C Library.
+
+ The GNU C Library is free software; you can redistribute it and/or
+ modify it under the terms of the GNU Library General Public License as
+ published by the Free Software Foundation; either version 2 of the
+ License, or (at your option) any later version.
+
+ The GNU C Library is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ Library General Public License for more details.
+
+ You should have received a copy of the GNU Library General Public
+ License along with the GNU C Library; see the file COPYING.LIB. If not,
+ write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ Boston, MA 02111-1307, USA. */
+
+#include <sysdep.h>
+
+/* Please consult the file sysdeps/unix/sysv/linux/i386/sysdep.h for
+ more information about the value -4095 used below.*/
+
+ .text
+ENTRY (__syscall_pread64)
+
+ PUSHARGS_5 /* Save register contents. */
+
+ /* Load arguments. This is unfortunately a little bit of a problem
+ since the kernel expects the arguments in a different order. */
+ movl 0x20(%esp,1),%esi
+ movl 0x1c(%esp,1),%edi
+ movl 0x18(%esp,1),%edx
+ movl 0x14(%esp,1),%ecx
+ movl 0x10(%esp,1),%ebx
+ /* Load syscall number into %eax. */
+ movl $SYS_ify(pread), %eax
+ int $0x80 /* Do the system call. */
+ POPARGS_5 /* Restore register contents. */
+ cmpl $-4095, %eax /* Check %eax for error. */
+ jae syscall_error /* Jump to error handler if error. */
+ ret /* Return to caller. */
+
+PSEUDO_END (__syscall_pread64)
--- /dev/null
+/* pwrite64 syscall for Linux/ix86.
+ Copyright (C) 1997 Free Software Foundation, Inc.
+ This file is part of the GNU C Library.
+
+ The GNU C Library is free software; you can redistribute it and/or
+ modify it under the terms of the GNU Library General Public License as
+ published by the Free Software Foundation; either version 2 of the
+ License, or (at your option) any later version.
+
+ The GNU C Library is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ Library General Public License for more details.
+
+ You should have received a copy of the GNU Library General Public
+ License along with the GNU C Library; see the file COPYING.LIB. If not,
+ write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ Boston, MA 02111-1307, USA. */
+
+#include <sysdep.h>
+
+/* Please consult the file sysdeps/unix/sysv/linux/i386/sysdep.h for
+ more information about the value -4095 used below.*/
+
+ .text
+ENTRY (__syscall_pwrite64)
+
+ PUSHARGS_5 /* Save register contents. */
+
+ /* Load arguments. This is unfortunately a little bit of a problem
+ since the kernel expects the arguments in a different order. */
+ movl 0x20(%esp,1),%esi
+ movl 0x1c(%esp,1),%edi
+ movl 0x18(%esp,1),%edx
+ movl 0x14(%esp,1),%ecx
+ movl 0x10(%esp,1),%ebx
+ /* Load syscall number into %eax. */
+ movl $SYS_ify(pwrite), %eax
+ int $0x80 /* Do the system call. */
+ POPARGS_5 /* Restore register contents. */
+ cmpl $-4095, %eax /* Check %eax for error. */
+ jae syscall_error /* Jump to error handler if error. */
+ ret /* Return to caller. */
+
+PSEUDO_END (__syscall_pwrite64)
#include <kernel_sigaction.h>
-extern int __syscall_rt_signal (int, const struct sigaction *,
- struct sigaction *, size_t);
+extern int __syscall_rt_sigaction (int, const struct sigaction *,
+ struct sigaction *, size_t);
/* The variable is shared between all wrappers around signal handling
functions which have RT equivalents. It is defined in sigsuspend.c. */
#include <signal.h>
int
-__syscall_rt_sigprocmask (int how, const sigset *set, sigset_t *oset,
+__syscall_rt_sigprocmask (int how, const sigset_t *set, sigset_t *oset,
size_t setsize)
{
__set_errno (ENOSYS);
#include <errno.h>
#include <signal.h>
+#include <sys/types.h>
int
__syscall_rt_sigqueueinfo (pid_t pid, int sig, siginfo_t *uinfo)
#include <signal.h>
int
-__syscall_rt_sigsuspend (const sigset *set, size_t setsize)
+__syscall_rt_sigsuspend (const sigset_t *set, size_t setsize)
{
if (set == NULL)
{
#include <errno.h>
#include <signal.h>
-#include <sigcontext.h>
#include <unistd.h>
extern int __syscall_sigreturn (struct sigcontext *);
#define _SYS_PCI_H 1
/* We use the constants from the kernel. */
-#include <asm/pci.h>
+#include <linux/pci.h>
#endif /* sys/pci.h */
write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
Boston, MA 02111-1307, USA. */
-#ifndef _BITS_ENVIRONMENTS_H
-#define _BITS_ENVIRONMENTS_H 1
+#ifndef _UNISTD_H
+# error "Never include this file directly. Use <unistd.h> instead"
+#endif
/* By default we have 32-bit wide `int', `long int', pointers and `off_t'. */
#define _XBS5_ILP32_OFF32 1
/* We can never provide environments with 64-bit wide pointers. */
#define _XBS5_LP64_OFF64 -1
#define _XBS5_LPBIG_OFFBIG -1
-
-#endif /* bits/environments.h */
write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
Boston, MA 02111-1307, USA. */
-#ifndef _BITS_ENVIRONMENTS_H
-#define _BITS_ENVIRONMENTS_H 1
+#ifndef _UNISTD_H
+# error "Never include this file directly. Use <unistd.h> instead"
+#endif
-/* We can never provide environments with 64-bit wide pointers. */
+/* We can never provide environments with 32-bit wide pointers. */
#define _XBS5_ILP32_OFF32 -1
#define _XBS5_ILP32_OFFBIG -1
-/* By default we have 64-bit wide `int', `long int', pointers and `off_t'. */
+/* By default we have 64-bit wide `long int', pointers and `off_t'. */
#define _XBS5_LP64_OFF32 1
#define _XBS5_LPBIG_OFFBIG 1
-
-#endif /* bits/environments.h */
projects / platform / upstream / linaro-glibc.git / commitdiff