1 What has changed in GDB?
2 (Organized release by release)
4 *** Changes in GDB-4.17:
6 * New native configurations
8 Alpha Linux alpha*-*-linux*
9 Unixware 2.x i[3456]86-unixware2*
10 Irix 6.x mips*-sgi-irix6*
11 PowerPC Linux powerpc-*-linux*
12 PowerPC Solaris powerpcle-*-solaris*
13 Sparc Linux sparc-*-linux*
17 Argonaut Risc Chip (ARC) arc-*-*
18 Hitachi H8/300S h8300*-*-*
19 Matsushita MN10200 w/simulator mn10200-*-*
20 Matsushita MN10300 w/simulator mn10300-*-*
21 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
22 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
23 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
24 Mitsubishi D10V w/simulator d10v-*-*
25 Mitsubishi M32R/D w/simulator m32r-*-elf*
26 Tsqware Sparclet sparclet-*-*
27 NEC V850 w/simulator v850-*-*
29 * New debugging protocols
31 ARM with RDI protocol arm*-*-*
32 M68K with dBUG monitor m68*-*-{aout,coff,elf}
33 DDB and LSI variants of PMON protocol mips*-*-*
34 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
35 PowerPC with SDS protocol powerpc{,le}-*-eabi
36 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
40 All configurations can now understand and use the DWARF 2 debugging
41 format. The choice is automatic, if the symbol file contains DWARF 2
46 GDB now includes basic Java language support. This support is
47 only useful with Java compilers that produce native machine code.
49 * solib-absolute-prefix and solib-search-path
51 For SunOS and SVR4 shared libraries, you may now set the prefix for
52 loading absolute shared library symbol files, and the search path for
53 locating non-absolute shared library symbol files.
55 * Live range splitting
57 GDB can now effectively debug code for which GCC has performed live
58 range splitting as part of its optimization. See gdb/doc/LRS for
59 more details on the expected format of the stabs information.
63 GDB's support for the GNU Hurd, including thread debugging, has been
64 updated to work with current versions of the Hurd.
68 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
69 instruction set. ARM GDB automatically detects when Thumb
70 instructions are in use, and adjusts disassembly and backtracing
75 GDB's MIPS target configurations now handle the MIP16 16-bit
80 GDB now includes support for overlays; if an executable has been
81 linked such that multiple sections are based at the same address, GDB
82 will decide which section to use for symbolic info. You can choose to
83 control the decision manually, using overlay commands, or implement
84 additional target-side support and use "overlay load-target" to bring
85 in the overlay mapping. Do "help overlay" for more detail.
89 The command "info symbol <address>" displays information about
90 the symbol at the specified address.
94 The standard remote protocol now includes an extension that allows
95 asynchronous collection and display of trace data. This requires
96 extensive support in the target-side debugging stub. Tracing mode
97 includes a new interaction mode in GDB and new commands: see the
98 file tracepoint.c for more details.
102 Configurations for embedded MIPS now include a simulator contributed
103 by Cygnus Solutions. The simulator supports the instruction sets
104 of most MIPS variants.
108 Sparc configurations may now include the ERC32 simulator contributed
109 by the European Space Agency. The simulator is not built into
110 Sparc targets by default; configure with --enable-sim to include it.
114 For target configurations that may include multiple variants of a
115 basic architecture (such as MIPS and SH), you may now set the
116 architecture explicitly. "set arch" sets, "info arch" lists
117 the possible architectures.
119 *** Changes in GDB-4.16:
121 * New native configurations
123 Windows 95, x86 Windows NT i[345]86-*-cygwin32
124 M68K NetBSD m68k-*-netbsd*
125 PowerPC AIX 4.x powerpc-*-aix*
126 PowerPC MacOS powerpc-*-macos*
127 PowerPC Windows NT powerpcle-*-cygwin32
128 RS/6000 AIX 4.x rs6000-*-aix4*
132 ARM with RDP protocol arm-*-*
133 I960 with MON960 i960-*-coff
134 MIPS VxWorks mips*-*-vxworks*
135 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
136 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
138 Matra Sparclet sparclet-*-*
142 The powerpc-eabi configuration now includes the PSIM simulator,
143 contributed by Andrew Cagney, with assistance from Mike Meissner.
144 PSIM is a very elaborate model of the PowerPC, including not only
145 basic instruction set execution, but also details of execution unit
146 performance and I/O hardware. See sim/ppc/README for more details.
150 GDB now works with Solaris 2.5.
152 * Windows 95/NT native
154 GDB will now work as a native debugger on Windows 95 and Windows NT.
155 To build it from source, you must use the "gnu-win32" environment,
156 which uses a DLL to emulate enough of Unix to run the GNU tools.
157 Further information, binaries, and sources are available at
158 ftp.cygnus.com, under pub/gnu-win32.
160 * dont-repeat command
162 If a user-defined command includes the command `dont-repeat', then the
163 command will not be repeated if the user just types return. This is
164 useful if the command is time-consuming to run, so that accidental
165 extra keystrokes don't run the same command many times.
167 * Send break instead of ^C
169 The standard remote protocol now includes an option to send a break
170 rather than a ^C to the target in order to interrupt it. By default,
171 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
173 * Remote protocol timeout
175 The standard remote protocol includes a new variable `remotetimeout'
176 that allows you to set the number of seconds before GDB gives up trying
177 to read from the target. The default value is 2.
179 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
181 By default GDB will automatically keep track of objects as they are
182 loaded and unloaded by the dynamic linker. By using the command `set
183 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
184 when shared library events occur, thus allowing you to set breakpoints
185 in shared libraries which are explicitly loaded by the inferior.
187 Note this feature does not work on hpux8. On hpux9 you must link
188 /usr/lib/end.o into your program. This feature should work
189 automatically on hpux10.
191 * Irix 5.x hardware watchpoint support
193 Irix 5 configurations now support the use of hardware watchpoints.
195 * Mips protocol "SYN garbage limit"
197 When debugging a Mips target using the `target mips' protocol, you
198 may set the number of characters that GDB will ignore by setting
199 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
200 every character. The default value is 1050.
202 * Recording and replaying remote debug sessions
204 If you set `remotelogfile' to the name of a file, gdb will write to it
205 a recording of a remote debug session. This recording may then be
206 replayed back to gdb using "gdbreplay". See gdbserver/README for
207 details. This is useful when you have a problem with GDB while doing
208 remote debugging; you can make a recording of the session and send it
209 to someone else, who can then recreate the problem.
211 * Speedups for remote debugging
213 GDB includes speedups for downloading and stepping MIPS systems using
214 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
215 and more efficient S-record downloading.
217 * Memory use reductions and statistics collection
219 GDB now uses less memory and reports statistics about memory usage.
220 Try the `maint print statistics' command, for example.
222 *** Changes in GDB-4.15:
226 The symbol reader for AIX GDB now uses partial symbol tables. This
227 can greatly improve startup time, especially for large executables.
229 * Remote targets use caching
231 Remote targets now use a data cache to speed up communication with the
232 remote side. The data cache could lead to incorrect results because
233 it doesn't know about volatile variables, thus making it impossible to
234 debug targets which use memory mapped I/O devices. `set remotecache
235 off' turns the the data cache off.
237 * Remote targets may have threads
239 The standard remote protocol now includes support for multiple threads
240 in the target system, using new protocol commands 'H' and 'T'. See
241 gdb/remote.c for details.
245 If GDB is configured with `--enable-netrom', then it will include
246 support for the NetROM ROM emulator from XLNT Designs. The NetROM
247 acts as though it is a bank of ROM on the target board, but you can
248 write into it over the network. GDB's support consists only of
249 support for fast loading into the emulated ROM; to debug, you must use
250 another protocol, such as standard remote protocol. The usual
251 sequence is something like
253 target nrom <netrom-hostname>
255 target remote <netrom-hostname>:1235
259 GDB now includes support for the Apple Macintosh, as a host only. It
260 may be run as either an MPW tool or as a standalone application, and
261 it can debug through the serial port. All the usual GDB commands are
262 available, but to the target command, you must supply "serial" as the
263 device type instead of "/dev/ttyXX". See mpw-README in the main
264 directory for more information on how to build. The MPW configuration
265 scripts */mpw-config.in support only a few targets, and only the
266 mips-idt-ecoff target has been tested.
270 GDB configuration now uses autoconf. This is not user-visible,
271 but does simplify configuration and building.
275 GDB now supports hpux10.
277 *** Changes in GDB-4.14:
279 * New native configurations
281 x86 FreeBSD i[345]86-*-freebsd
282 x86 NetBSD i[345]86-*-netbsd
283 NS32k NetBSD ns32k-*-netbsd
284 Sparc NetBSD sparc-*-netbsd
288 A29K VxWorks a29k-*-vxworks
289 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
290 CPU32 EST-300 emulator m68*-*-est*
291 PowerPC ELF powerpc-*-elf
294 * Alpha OSF/1 support for procfs
296 GDB now supports procfs under OSF/1-2.x and higher, which makes it
297 possible to attach to running processes. As the mounting of the /proc
298 filesystem is optional on the Alpha, GDB automatically determines
299 the availability of /proc during startup. This can lead to problems
300 if /proc is unmounted after GDB has been started.
302 * Arguments to user-defined commands
304 User commands may accept up to 10 arguments separated by whitespace.
305 Arguments are accessed within the user command via $arg0..$arg9. A
308 print $arg0 + $arg1 + $arg2
310 To execute the command use:
313 Defines the command "adder" which prints the sum of its three arguments.
314 Note the arguments are text substitutions, so they may reference variables,
315 use complex expressions, or even perform inferior function calls.
317 * New `if' and `while' commands
319 This makes it possible to write more sophisticated user-defined
320 commands. Both commands take a single argument, which is the
321 expression to evaluate, and must be followed by the commands to
322 execute, one per line, if the expression is nonzero, the list being
323 terminated by the word `end'. The `if' command list may include an
324 `else' word, which causes the following commands to be executed only
325 if the expression is zero.
327 * Fortran source language mode
329 GDB now includes partial support for Fortran 77. It will recognize
330 Fortran programs and can evaluate a subset of Fortran expressions, but
331 variables and functions may not be handled correctly. GDB will work
332 with G77, but does not yet know much about symbols emitted by other
335 * Better HPUX support
337 Most debugging facilities now work on dynamic executables for HPPAs
338 running hpux9 or later. You can attach to running dynamically linked
339 processes, but by default the dynamic libraries will be read-only, so
340 for instance you won't be able to put breakpoints in them. To change
341 that behavior do the following before running the program:
347 This will cause the libraries to be mapped private and read-write.
348 To revert to the normal behavior, do this:
354 You cannot set breakpoints or examine data in the library until after
355 the library is loaded if the function/data symbols do not have
358 GDB can now also read debug symbols produced by the HP C compiler on
359 HPPAs (sorry, no C++, Fortran or 68k support).
361 * Target byte order now dynamically selectable
363 You can choose which byte order to use with a target system, via the
364 commands "set endian big" and "set endian little", and you can see the
365 current setting by using "show endian". You can also give the command
366 "set endian auto", in which case GDB will use the byte order
367 associated with the executable. Currently, only embedded MIPS
368 configurations support dynamic selection of target byte order.
370 * New DOS host serial code
372 This version uses DPMI interrupts to handle buffered I/O, so you
373 no longer need to run asynctsr when debugging boards connected to
376 *** Changes in GDB-4.13:
378 * New "complete" command
380 This lists all the possible completions for the rest of the line, if it
381 were to be given as a command itself. This is intended for use by emacs.
383 * Trailing space optional in prompt
385 "set prompt" no longer adds a space for you after the prompt you set. This
386 allows you to set a prompt which ends in a space or one that does not.
388 * Breakpoint hit counts
390 "info break" now displays a count of the number of times the breakpoint
391 has been hit. This is especially useful in conjunction with "ignore"; you
392 can ignore a large number of breakpoint hits, look at the breakpoint info
393 to see how many times the breakpoint was hit, then run again, ignoring one
394 less than that number, and this will get you quickly to the last hit of
397 * Ability to stop printing at NULL character
399 "set print null-stop" will cause GDB to stop printing the characters of
400 an array when the first NULL is encountered. This is useful when large
401 arrays actually contain only short strings.
403 * Shared library breakpoints
405 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
406 breakpoints in shared libraries before the executable is run.
408 * Hardware watchpoints
410 There is a new hardware breakpoint for the watch command for sparclite
411 targets. See gdb/sparclite/hw_breakpoint.note.
413 Hardware watchpoints are also now supported under Linux.
417 Annotations have been added. These are for use with graphical interfaces,
418 and are still experimental. Currently only gdba.el uses these.
420 * Improved Irix 5 support
422 GDB now works properly with Irix 5.2.
424 * Improved HPPA support
426 GDB now works properly with the latest GCC and GAS.
428 * New native configurations
430 Sequent PTX4 i[34]86-sequent-ptx4
431 HPPA running OSF/1 hppa*-*-osf*
432 Atari TT running SVR4 m68*-*-sysv4*
433 RS/6000 LynxOS rs6000-*-lynxos*
437 OS/9000 i[34]86-*-os9k
438 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
441 * Hitachi SH7000 and E7000-PC ICE support
443 There is now support for communicating with the Hitachi E7000-PC ICE.
444 This is available automatically when GDB is configured for the SH.
448 As usual, a variety of small fixes and improvements, both generic
449 and configuration-specific. See the ChangeLog for more detail.
451 *** Changes in GDB-4.12:
453 * Irix 5 is now supported
457 GDB-4.12 on the HPPA has a number of changes which make it unable
458 to debug the output from the currently released versions of GCC and
459 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
460 of GCC and GAS, versions of these tools designed to work with GDB-4.12
461 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
464 *** Changes in GDB-4.11:
466 * User visible changes:
470 The "set remotedebug" option is now consistent between the mips remote
471 target, remote targets using the gdb-specific protocol, UDI (AMD's
472 debug protocol for the 29k) and the 88k bug monitor. It is now an
473 integer specifying a debug level (normally 0 or 1, but 2 means more
474 debugging info for the mips target).
476 * DEC Alpha native support
478 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
479 debug info, but GDB works fairly well with the DEC compiler and should
480 work with a future GCC release. See the README file for a few
481 Alpha-specific notes.
483 * Preliminary thread implementation
485 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
487 * LynxOS native and target support for 386
489 This release has been hosted on LynxOS 2.2, and also can be configured
490 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
493 * Improvements in C++ mangling/demangling.
495 This release has much better g++ debugging, specifically in name
496 mangling/demangling, virtual function calls, print virtual table,
497 call methods, ...etc.
499 *** Changes in GDB-4.10:
501 * User visible changes:
503 Remote debugging using the GDB-specific (`target remote') protocol now
504 supports the `load' command. This is only useful if you have some
505 other way of getting the stub to the target system, and you can put it
506 somewhere in memory where it won't get clobbered by the download.
508 Filename completion now works.
510 When run under emacs mode, the "info line" command now causes the
511 arrow to point to the line specified. Also, "info line" prints
512 addresses in symbolic form (as well as hex).
514 All vxworks based targets now support a user settable option, called
515 vxworks-timeout. This option represents the number of seconds gdb
516 should wait for responses to rpc's. You might want to use this if
517 your vxworks target is, perhaps, a slow software simulator or happens
518 to be on the far side of a thin network line.
522 This release contains support for using a DEC alpha as a GDB host for
523 cross debugging. Native alpha debugging is not supported yet.
526 *** Changes in GDB-4.9:
530 This is the first GDB release which is accompanied by a matching testsuite.
531 The testsuite requires installation of dejagnu, which should be available
532 via ftp from most sites that carry GNU software.
536 'Cfront' style demangling has had its name changed to 'ARM' style, to
537 emphasize that it was written from the specifications in the C++ Annotated
538 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
539 disclaimers, it still generated too much confusion with users attempting to
540 use gdb with AT&T cfront.
544 GDB now uses a standard remote interface to a simulator library.
545 So far, the library contains simulators for the Zilog Z8001/2, the
546 Hitachi H8/300, H8/500 and Super-H.
548 * New targets supported
550 H8/300 simulator h8300-hitachi-hms or h8300hms
551 H8/500 simulator h8500-hitachi-hms or h8500hms
552 SH simulator sh-hitachi-hms or sh
553 Z8000 simulator z8k-zilog-none or z8ksim
554 IDT MIPS board over serial line mips-idt-ecoff
556 Cross-debugging to GO32 targets is supported. It requires a custom
557 version of the i386-stub.c module which is integrated with the
558 GO32 memory extender.
560 * New remote protocols
562 MIPS remote debugging protocol.
564 * New source languages supported
566 This version includes preliminary support for Chill, a Pascal like language
567 used by telecommunications companies. Chill support is also being integrated
568 into the GNU compiler, but we don't know when it will be publically available.
571 *** Changes in GDB-4.8:
573 * HP Precision Architecture supported
575 GDB now supports HP PA-RISC machines running HPUX. A preliminary
576 version of this support was available as a set of patches from the
577 University of Utah. GDB does not support debugging of programs
578 compiled with the HP compiler, because HP will not document their file
579 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
580 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
582 Many problems in the preliminary version have been fixed.
584 * Faster and better demangling
586 We have improved template demangling and fixed numerous bugs in the GNU style
587 demangler. It can now handle type modifiers such as `static' or `const'. Wide
588 character types (wchar_t) are now supported. Demangling of each symbol is now
589 only done once, and is cached when the symbol table for a file is read in.
590 This results in a small increase in memory usage for C programs, a moderate
591 increase in memory usage for C++ programs, and a fantastic speedup in
594 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
595 from the specifications in the Annotated Reference Manual, which AT&T's
596 compiler does not actually implement.
598 * G++ multiple inheritance compiler problem
600 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
601 inheritance lattices was reworked to properly discover ambiguities. We
602 recently found an example which causes this new algorithm to fail in a
603 very subtle way, producing bad debug information for those classes.
604 The file 'gcc.patch' (in this directory) can be applied to gcc to
605 circumvent the problem. A future GCC release will contain a complete
608 The previous G++ debug info problem (mentioned below for the gdb-4.7
609 release) is fixed in gcc version 2.3.2.
611 * Improved configure script
613 The `configure' script will now attempt to guess your system type if
614 you don't supply a host system type. The old scheme of supplying a
615 host system triplet is preferable over using this. All the magic is
616 done in the new `config.guess' script. Examine it for details.
618 We have also brought our configure script much more in line with the FSF's
619 version. It now supports the --with-xxx options. In particular,
620 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
621 The resulting GDB will not be able to read arbitrary object file formats --
622 only the format ``expected'' to be used on the configured target system.
623 We hope to make this the default in a future release.
625 * Documentation improvements
627 There's new internal documentation on how to modify GDB, and how to
628 produce clean changes to the code. We implore people to read it
629 before submitting changes.
631 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
632 M4 macros. The new texinfo.tex is provided in this release. Pre-built
633 `info' files are also provided. To build `info' files from scratch,
634 you will need the latest `makeinfo' release, which will be available in
635 a future texinfo-X.Y release.
637 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
638 We're not sure exactly which versions have this problem, but it has
639 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
640 or better. If that isn't possible, there is a patch in
641 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
646 GDB now supports array constants that can be used in expressions typed in by
647 the user. The syntax is `{element, element, ...}'. Ie: you can now type
648 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
651 The new directory `gdb/sparclite' contains a program that demonstrates
652 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
654 * New native hosts supported
656 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
657 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
659 * New targets supported
661 AMD 29k family via UDI a29k-amd-udi or udi29k
663 * New file formats supported
665 BFD now supports reading HP/PA-RISC executables (SOM file format?),
666 HPUX core files, and SCO 3.2v2 core files.
670 Attaching to processes now works again; thanks for the many bug reports.
672 We have also stomped on a bunch of core dumps caused by
673 printf_filtered("%s") problems.
675 We eliminated a copyright problem on the rpc and ptrace header files
676 for VxWorks, which was discovered at the last minute during the 4.7
677 release. You should now be able to build a VxWorks GDB.
679 You can now interrupt gdb while an attached process is running. This
680 will cause the attached process to stop, and give control back to GDB.
682 We fixed problems caused by using too many file descriptors
683 for reading symbols from object files and libraries. This was
684 especially a problem for programs that used many (~100) shared
687 The `step' command now only enters a subroutine if there is line number
688 information for the subroutine. Otherwise it acts like the `next'
689 command. Previously, `step' would enter subroutines if there was
690 any debugging information about the routine. This avoids problems
691 when using `cc -g1' on MIPS machines.
693 * Internal improvements
695 GDB's internal interfaces have been improved to make it easier to support
696 debugging of multiple languages in the future.
698 GDB now uses a common structure for symbol information internally.
699 Minimal symbols (derived from linkage symbols in object files), partial
700 symbols (from a quick scan of debug information), and full symbols
701 contain a common subset of information, making it easier to write
702 shared code that handles any of them.
704 * New command line options
706 We now accept --silent as an alias for --quiet.
710 The memory-mapped-malloc library is now licensed under the GNU Library
711 General Public License.
713 *** Changes in GDB-4.7:
715 * Host/native/target split
717 GDB has had some major internal surgery to untangle the support for
718 hosts and remote targets. Now, when you configure GDB for a remote
719 target, it will no longer load in all of the support for debugging
720 local programs on the host. When fully completed and tested, this will
721 ensure that arbitrary host/target combinations are possible.
723 The primary conceptual shift is to separate the non-portable code in
724 GDB into three categories. Host specific code is required any time GDB
725 is compiled on that host, regardless of the target. Target specific
726 code relates to the peculiarities of the target, but can be compiled on
727 any host. Native specific code is everything else: it can only be
728 built when the host and target are the same system. Child process
729 handling and core file support are two common `native' examples.
731 GDB's use of /proc for controlling Unix child processes is now cleaner.
732 It has been split out into a single module under the `target_ops' vector,
733 plus two native-dependent functions for each system that uses /proc.
735 * New hosts supported
737 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
738 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
739 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
741 * New targets supported
743 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
744 68030 and CPU32 m68030-*-*, m68332-*-*
746 * New native hosts supported
748 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
749 (386bsd is not well tested yet)
750 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
752 * New file formats supported
754 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
755 supports reading of `a.out.adobe' object files, which are an a.out
756 format extended with minimal information about multiple sections.
760 `show copying' is the same as the old `info copying'.
761 `show warranty' is the same as `info warrantee'.
762 These were renamed for consistency. The old commands continue to work.
764 `info handle' is a new alias for `info signals'.
766 You can now define pre-command hooks, which attach arbitrary command
767 scripts to any command. The commands in the hook will be executed
768 prior to the user's command. You can also create a hook which will be
769 executed whenever the program stops. See gdb.texinfo.
773 We now deal with Cfront style name mangling, and can even extract type
774 info from mangled symbols. GDB can automatically figure out which
775 symbol mangling style your C++ compiler uses.
777 Calling of methods and virtual functions has been improved as well.
781 The crash that occured when debugging Sun Ansi-C compiled binaries is
782 fixed. This was due to mishandling of the extra N_SO stabs output
785 We also finally got Ultrix 4.2 running in house, and fixed core file
786 support, with help from a dozen people on the net.
788 John M. Farrell discovered that the reason that single-stepping was so
789 slow on all of the Mips based platforms (primarily SGI and DEC) was
790 that we were trying to demangle and lookup a symbol used for internal
791 purposes on every instruction that was being stepped through. Changing
792 the name of that symbol so that it couldn't be mistaken for a C++
793 mangled symbol sped things up a great deal.
795 Rich Pixley sped up symbol lookups in general by getting much smarter
796 about when C++ symbol mangling is necessary. This should make symbol
797 completion (TAB on the command line) much faster. It's not as fast as
798 we'd like, but it's significantly faster than gdb-4.6.
802 A new user controllable variable 'call_scratch_address' can
803 specify the location of a scratch area to be used when GDB
804 calls a function in the target. This is necessary because the
805 usual method of putting the scratch area on the stack does not work
806 in systems that have separate instruction and data spaces.
808 We integrated changes to support the 29k UDI (Universal Debugger
809 Interface), but discovered at the last minute that we didn't have all
810 of the appropriate copyright paperwork. We are working with AMD to
811 resolve this, and hope to have it available soon.
815 We have sped up the remote serial line protocol, especially for targets
816 with lots of registers. It now supports a new `expedited status' ('T')
817 message which can be used in place of the existing 'S' status message.
818 This allows the remote stub to send only the registers that GDB
819 needs to make a quick decision about single-stepping or conditional
820 breakpoints, eliminating the need to fetch the entire register set for
821 each instruction being stepped through.
823 The GDB remote serial protocol now implements a write-through cache for
824 registers, only re-reading the registers if the target has run.
826 There is also a new remote serial stub for SPARC processors. You can
827 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
828 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
829 processor with a serial port.
833 Configure.in files have become much easier to read and modify. A new
834 `table driven' format makes it more obvious what configurations are
835 supported, and what files each one uses.
839 There is a new opcodes library which will eventually contain all of the
840 disassembly routines and opcode tables. At present, it only contains
841 Sparc and Z8000 routines. This will allow the assembler, debugger, and
842 disassembler (binutils/objdump) to share these routines.
844 The libiberty library is now copylefted under the GNU Library General
845 Public License. This allows more liberal use, and was done so libg++
846 can use it. This makes no difference to GDB, since the Library License
847 grants all the rights from the General Public License.
851 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
852 reference to the stabs symbol info used by the debugger. It is (as far
853 as we know) the only published document on this fascinating topic. We
854 encourage you to read it, compare it to the stabs information on your
855 system, and send improvements on the document in general (to
856 bug-gdb@prep.ai.mit.edu).
858 And, of course, many bugs have been fixed.
861 *** Changes in GDB-4.6:
863 * Better support for C++ function names
865 GDB now accepts as input the "demangled form" of C++ overloaded function
866 names and member function names, and can do command completion on such names
867 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
868 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
869 Make use of command completion, it is your friend.
871 GDB also now accepts a variety of C++ mangled symbol formats. They are
872 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
873 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
874 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
875 for the list of formats.
877 * G++ symbol mangling problem
879 Recent versions of gcc have a bug in how they emit debugging information for
880 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
881 directory) can be applied to gcc to fix the problem. Alternatively, if you
882 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
883 usual symptom is difficulty with setting breakpoints on methods. GDB complains
884 about the method being non-existent. (We believe that version 2.2.2 of GCC has
887 * New 'maintenance' command
889 All of the commands related to hacking GDB internals have been moved out of
890 the main command set, and now live behind the 'maintenance' command. This
891 can also be abbreviated as 'mt'. The following changes were made:
893 dump-me -> maintenance dump-me
894 info all-breakpoints -> maintenance info breakpoints
895 printmsyms -> maintenance print msyms
896 printobjfiles -> maintenance print objfiles
897 printpsyms -> maintenance print psymbols
898 printsyms -> maintenance print symbols
900 The following commands are new:
902 maintenance demangle Call internal GDB demangler routine to
903 demangle a C++ link name and prints the result.
904 maintenance print type Print a type chain for a given symbol
906 * Change to .gdbinit file processing
908 We now read the $HOME/.gdbinit file before processing the argv arguments
909 (e.g. reading symbol files or core files). This allows global parameters to
910 be set, which will apply during the symbol reading. The ./.gdbinit is still
911 read after argv processing.
913 * New hosts supported
915 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
917 Linux support i386-unknown-linux or linux
919 We are also including code to support the HP/PA running BSD and HPUX. This
920 is almost guaranteed not to work, as we didn't have time to test or build it
921 for this release. We are including it so that the more adventurous (or
922 masochistic) of you can play with it. We also had major problems with the
923 fact that the compiler that we got from HP doesn't support the -g option.
926 * New targets supported
928 Hitachi H8/300 h8300-hitachi-hms or h8300hms
930 * More smarts about finding #include files
932 GDB now remembers the compilation directory for all include files, and for
933 all files from which C is generated (like yacc and lex sources). This
934 greatly improves GDB's ability to find yacc/lex sources, and include files,
935 especially if you are debugging your program from a directory different from
936 the one that contains your sources.
938 We also fixed a bug which caused difficulty with listing and setting
939 breakpoints in include files which contain C code. (In the past, you had to
940 try twice in order to list an include file that you hadn't looked at before.)
942 * Interesting infernals change
944 GDB now deals with arbitrary numbers of sections, where the symbols for each
945 section must be relocated relative to that section's landing place in the
946 target's address space. This work was needed to support ELF with embedded
947 stabs used by Solaris-2.0.
949 * Bug fixes (of course!)
951 There have been loads of fixes for the following things:
952 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
953 i960, stabs, DOS(GO32), procfs, etc...
955 See the ChangeLog for details.
957 *** Changes in GDB-4.5:
959 * New machines supported (host and target)
961 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
963 SGI Irix-4.x mips-sgi-irix4 or iris4
967 GDB now uses a new memory manager called mmalloc, based on gmalloc.
968 Mmalloc is capable of handling mutiple heaps of memory. It is also
969 capable of saving a heap to a file, and then mapping it back in later.
970 This can be used to greatly speedup the startup of GDB by using a
971 pre-parsed symbol table which lives in a mmalloc managed heap. For
972 more details, please read mmalloc/mmalloc.texi.
976 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
977 'help info proc' for details.
979 * MIPS ecoff symbol table format
981 The code that reads MIPS symbol table format is now supported on all hosts.
982 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
985 * File name changes for MS-DOS
987 Many files in the config directories have been renamed to make it easier to
988 support GDB on MS-DOSe systems (which have very restrictive file name
989 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
990 environment) is close to working but has some remaining problems. Note
991 that debugging of DOS programs is not supported, due to limitations
992 in the ``operating system'', but it can be used to host cross-debugging.
994 * Cross byte order fixes
996 Many fixes have been made to support cross debugging of Sparc and MIPS
997 targets from hosts whose byte order differs.
999 * New -mapped and -readnow options
1001 If memory-mapped files are available on your system through the 'mmap'
1002 system call, you can use the -mapped option on the `file' or
1003 `symbol-file' commands to cause GDB to write the symbols from your
1004 program into a reusable file. If the program you are debugging is
1005 called `/path/fred', the mapped symbol file will be `./fred.syms'.
1006 Future GDB debugging sessions will notice the presence of this file,
1007 and will quickly map in symbol information from it, rather than reading
1008 the symbol table from the executable program. Using the '-mapped'
1009 option in a GDB `file' or `symbol-file' command has the same effect as
1010 starting GDB with the '-mapped' command-line option.
1012 You can cause GDB to read the entire symbol table immediately by using
1013 the '-readnow' option with any of the commands that load symbol table
1014 information (or on the GDB command line). This makes the command
1015 slower, but makes future operations faster.
1017 The -mapped and -readnow options are typically combined in order to
1018 build a `fred.syms' file that contains complete symbol information.
1019 A simple GDB invocation to do nothing but build a `.syms' file for future
1022 gdb -batch -nx -mapped -readnow programname
1024 The `.syms' file is specific to the host machine on which GDB is run.
1025 It holds an exact image of GDB's internal symbol table. It cannot be
1026 shared across multiple host platforms.
1028 * longjmp() handling
1030 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
1031 siglongjmp() without losing control. This feature has not yet been ported to
1032 all systems. It currently works on many 386 platforms, all MIPS-based
1033 platforms (SGI, DECstation, etc), and Sun3/4.
1037 Preliminary work has been put in to support the new Solaris OS from Sun. At
1038 this time, it can control and debug processes, but it is not capable of
1043 As always, many many bug fixes. The major areas were with g++, and mipsread.
1044 People using the MIPS-based platforms should experience fewer mysterious
1045 crashes and trashed symbol tables.
1047 *** Changes in GDB-4.4:
1049 * New machines supported (host and target)
1051 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
1053 BSD Reno on Vax vax-dec-bsd
1054 Ultrix on Vax vax-dec-ultrix
1056 * New machines supported (target)
1058 AMD 29000 embedded, using EBMON a29k-none-none
1062 GDB continues to improve its handling of C++. `References' work better.
1063 The demangler has also been improved, and now deals with symbols mangled as
1064 per the Annotated C++ Reference Guide.
1066 GDB also now handles `stabs' symbol information embedded in MIPS
1067 `ecoff' symbol tables. Since the ecoff format was not easily
1068 extensible to handle new languages such as C++, this appeared to be a
1069 good way to put C++ debugging info into MIPS binaries. This option
1070 will be supported in the GNU C compiler, version 2, when it is
1073 * New features for SVR4
1075 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
1076 shared libraries. Debugging dynamically linked programs should present
1077 only minor differences from debugging statically linked programs.
1079 The `info proc' command will print out information about any process
1080 on an SVR4 system (including the one you are debugging). At the moment,
1081 it prints the address mappings of the process.
1083 If you bring up GDB on another SVR4 system, please send mail to
1084 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
1086 * Better dynamic linking support in SunOS
1088 Reading symbols from shared libraries which contain debugging symbols
1089 now works properly. However, there remain issues such as automatic
1090 skipping of `transfer vector' code during function calls, which
1091 make it harder to debug code in a shared library, than to debug the
1092 same code linked statically.
1096 GDB is now using the latest `getopt' routines from the FSF. This
1097 version accepts the -- prefix for options with long names. GDB will
1098 continue to accept the old forms (-option and +option) as well.
1099 Various single letter abbreviations for options have been explicity
1100 added to the option table so that they won't get overshadowed in the
1101 future by other options that begin with the same letter.
1105 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
1106 Many assorted bugs have been handled. Many more remain to be handled.
1107 See the various ChangeLog files (primarily in gdb and bfd) for details.
1110 *** Changes in GDB-4.3:
1112 * New machines supported (host and target)
1114 Amiga 3000 running Amix m68k-cbm-svr4 or amix
1115 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
1116 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
1118 * Almost SCO Unix support
1120 We had hoped to support:
1121 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
1122 (except for core file support), but we discovered very late in the release
1123 that it has problems with process groups that render gdb unusable. Sorry
1124 about that. I encourage people to fix it and post the fixes.
1126 * Preliminary ELF and DWARF support
1128 GDB can read ELF object files on System V Release 4, and can handle
1129 debugging records for C, in DWARF format, in ELF files. This support
1130 is preliminary. If you bring up GDB on another SVR4 system, please
1131 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
1136 GDB now uses the latest `readline' library. One user-visible change
1137 is that two tabs will list possible command completions, which previously
1138 required typing M-? (meta-question mark, or ESC ?).
1142 The `stepi' bug that many of you noticed has been squashed.
1143 Many bugs in C++ have been handled. Many more remain to be handled.
1144 See the various ChangeLog files (primarily in gdb and bfd) for details.
1146 * State of the MIPS world (in case you wondered):
1148 GDB can understand the symbol tables emitted by the compilers
1149 supplied by most vendors of MIPS-based machines, including DEC. These
1150 symbol tables are in a format that essentially nobody else uses.
1152 Some versions of gcc come with an assembler post-processor called
1153 mips-tfile. This program is required if you want to do source-level
1154 debugging of gcc-compiled programs. I believe FSF does not ship
1155 mips-tfile with gcc version 1, but it will eventually come with gcc
1158 Debugging of g++ output remains a problem. g++ version 1.xx does not
1159 really support it at all. (If you're lucky, you should be able to get
1160 line numbers and stack traces to work, but no parameters or local
1161 variables.) With some work it should be possible to improve the
1164 When gcc version 2 is released, you will have somewhat better luck.
1165 However, even then you will get confusing results for inheritance and
1168 We will eventually provide full debugging of g++ output on
1169 DECstations. This will probably involve some kind of stabs-in-ecoff
1170 encapulation, but the details have not been worked out yet.
1173 *** Changes in GDB-4.2:
1175 * Improved configuration
1177 Only one copy of `configure' exists now, and it is not self-modifying.
1178 Porting BFD is simpler.
1182 The `step' and `next' commands now only stop at the first instruction
1183 of a source line. This prevents the multiple stops that used to occur
1184 in switch statements, for-loops, etc. `Step' continues to stop if a
1185 function that has debugging information is called within the line.
1189 Lots of small bugs fixed. More remain.
1191 * New host supported (not target)
1193 Intel 386 PC clone running Mach i386-none-mach
1196 *** Changes in GDB-4.1:
1198 * Multiple source language support
1200 GDB now has internal scaffolding to handle several source languages.
1201 It determines the type of each source file from its filename extension,
1202 and will switch expression parsing and number formatting to match the
1203 language of the function in the currently selected stack frame.
1204 You can also specifically set the language to be used, with
1205 `set language c' or `set language modula-2'.
1209 GDB now has preliminary support for the GNU Modula-2 compiler,
1210 currently under development at the State University of New York at
1211 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
1212 continue through the fall of 1991 and into 1992.
1214 Other Modula-2 compilers are currently not supported, and attempting to
1215 debug programs compiled with them will likely result in an error as the
1216 symbol table is read. Feel free to work on it, though!
1218 There are hooks in GDB for strict type checking and range checking,
1219 in the `Modula-2 philosophy', but they do not currently work.
1223 GDB can now write to executable and core files (e.g. patch
1224 a variable's value). You must turn this switch on, specify
1225 the file ("exec foo" or "core foo"), *then* modify it, e.g.
1226 by assigning a new value to a variable. Modifications take
1229 * Automatic SunOS shared library reading
1231 When you run your program, GDB automatically determines where its
1232 shared libraries (if any) have been loaded, and reads their symbols.
1233 The `share' command is no longer needed. This also works when
1234 examining core files.
1238 You can specify the number of lines that the `list' command shows.
1241 * New machines supported (host and target)
1243 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
1244 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
1245 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
1247 * New hosts supported (not targets)
1249 IBM RT/PC: romp-ibm-aix or rtpc
1251 * New targets supported (not hosts)
1253 AMD 29000 embedded with COFF a29k-none-coff
1254 AMD 29000 embedded with a.out a29k-none-aout
1255 Ultracomputer remote kernel debug a29k-nyu-kern
1257 * New remote interfaces
1263 *** Changes in GDB-4.0:
1267 Wide output is wrapped at good places to make the output more readable.
1269 Gdb now supports cross-debugging from a host machine of one type to a
1270 target machine of another type. Communication with the target system
1271 is over serial lines. The ``target'' command handles connecting to the
1272 remote system; the ``load'' command will download a program into the
1273 remote system. Serial stubs for the m68k and i386 are provided. Gdb
1274 also supports debugging of realtime processes running under VxWorks,
1275 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
1276 stub on the target system.
1278 New CPUs supported include the AMD 29000 and Intel 960.
1280 GDB now reads object files and symbol tables via a ``binary file''
1281 library, which allows a single copy of GDB to debug programs of multiple
1282 object file types such as a.out and coff.
1284 There is now a GDB reference card in "doc/refcard.tex". (Make targets
1285 refcard.dvi and refcard.ps are available to format it).
1288 * Control-Variable user interface simplified
1290 All variables that control the operation of the debugger can be set
1291 by the ``set'' command, and displayed by the ``show'' command.
1293 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
1294 ``Show prompt'' produces the response:
1295 Gdb's prompt is new-gdb=>.
1297 What follows are the NEW set commands. The command ``help set'' will
1298 print a complete list of old and new set commands. ``help set FOO''
1299 will give a longer description of the variable FOO. ``show'' will show
1300 all of the variable descriptions and their current settings.
1302 confirm on/off: Enables warning questions for operations that are
1303 hard to recover from, e.g. rerunning the program while
1304 it is already running. Default is ON.
1306 editing on/off: Enables EMACS style command line editing
1307 of input. Previous lines can be recalled with
1308 control-P, the current line can be edited with control-B,
1309 you can search for commands with control-R, etc.
1312 history filename NAME: NAME is where the gdb command history
1313 will be stored. The default is .gdb_history,
1314 or the value of the environment variable
1317 history size N: The size, in commands, of the command history. The
1318 default is 256, or the value of the environment variable
1321 history save on/off: If this value is set to ON, the history file will
1322 be saved after exiting gdb. If set to OFF, the
1323 file will not be saved. The default is OFF.
1325 history expansion on/off: If this value is set to ON, then csh-like
1326 history expansion will be performed on
1327 command line input. The default is OFF.
1329 radix N: Sets the default radix for input and output. It can be set
1330 to 8, 10, or 16. Note that the argument to "radix" is interpreted
1331 in the current radix, so "set radix 10" is always a no-op.
1333 height N: This integer value is the number of lines on a page. Default
1334 is 24, the current `stty rows'' setting, or the ``li#''
1335 setting from the termcap entry matching the environment
1338 width N: This integer value is the number of characters on a line.
1339 Default is 80, the current `stty cols'' setting, or the ``co#''
1340 setting from the termcap entry matching the environment
1343 Note: ``set screensize'' is obsolete. Use ``set height'' and
1344 ``set width'' instead.
1346 print address on/off: Print memory addresses in various command displays,
1347 such as stack traces and structure values. Gdb looks
1348 more ``symbolic'' if you turn this off; it looks more
1349 ``machine level'' with it on. Default is ON.
1351 print array on/off: Prettyprint arrays. New convenient format! Default
1354 print demangle on/off: Print C++ symbols in "source" form if on,
1357 print asm-demangle on/off: Same, for assembler level printouts
1360 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
1363 * Support for Epoch Environment.
1365 The epoch environment is a version of Emacs v18 with windowing. One
1366 new command, ``inspect'', is identical to ``print'', except that if you
1367 are running in the epoch environment, the value is printed in its own
1371 * Support for Shared Libraries
1373 GDB can now debug programs and core files that use SunOS shared libraries.
1374 Symbols from a shared library cannot be referenced
1375 before the shared library has been linked with the program (this
1376 happens after you type ``run'' and before the function main() is entered).
1377 At any time after this linking (including when examining core files
1378 from dynamically linked programs), gdb reads the symbols from each
1379 shared library when you type the ``sharedlibrary'' command.
1380 It can be abbreviated ``share''.
1382 sharedlibrary REGEXP: Load shared object library symbols for files
1383 matching a unix regular expression. No argument
1384 indicates to load symbols for all shared libraries.
1386 info sharedlibrary: Status of loaded shared libraries.
1391 A watchpoint stops execution of a program whenever the value of an
1392 expression changes. Checking for this slows down execution
1393 tremendously whenever you are in the scope of the expression, but is
1394 quite useful for catching tough ``bit-spreader'' or pointer misuse
1395 problems. Some machines such as the 386 have hardware for doing this
1396 more quickly, and future versions of gdb will use this hardware.
1398 watch EXP: Set a watchpoint (breakpoint) for an expression.
1400 info watchpoints: Information about your watchpoints.
1402 delete N: Deletes watchpoint number N (same as breakpoints).
1403 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
1404 enable N: Re-enables watchpoint number N (same as breakpoints).
1407 * C++ multiple inheritance
1409 When used with a GCC version 2 compiler, GDB supports multiple inheritance
1412 * C++ exception handling
1414 Gdb now supports limited C++ exception handling. Besides the existing
1415 ability to breakpoint on an exception handler, gdb can breakpoint on
1416 the raising of an exception (before the stack is peeled back to the
1419 catch FOO: If there is a FOO exception handler in the dynamic scope,
1420 set a breakpoint to catch exceptions which may be raised there.
1421 Multiple exceptions (``catch foo bar baz'') may be caught.
1423 info catch: Lists all exceptions which may be caught in the
1424 current stack frame.
1427 * Minor command changes
1429 The command ``call func (arg, arg, ...)'' now acts like the print
1430 command, except it does not print or save a value if the function's result
1431 is void. This is similar to dbx usage.
1433 The ``up'' and ``down'' commands now always print the frame they end up
1434 at; ``up-silently'' and `down-silently'' can be used in scripts to change
1435 frames without printing.
1437 * New directory command
1439 'dir' now adds directories to the FRONT of the source search path.
1440 The path starts off empty. Source files that contain debug information
1441 about the directory in which they were compiled can be found even
1442 with an empty path; Sun CC and GCC include this information. If GDB can't
1443 find your source file in the current directory, type "dir .".
1445 * Configuring GDB for compilation
1447 For normal use, type ``./configure host''. See README or gdb.texinfo
1450 GDB now handles cross debugging. If you are remotely debugging between
1451 two different machines, type ``./configure host -target=targ''.
1452 Host is the machine where GDB will run; targ is the machine
1453 where the program that you are debugging will run.