1 What has changed in GDB?
2 (Organized release by release)
4 *** Changes since GDB-4.18:
8 Motorola MCore mcore-*-*
9 x86 VxWorks i[3456]86-*-vxworks*
10 PowerPC VxWorks powerpc-*-vxworks*
11 TI TMS320C80 tic80-*-*
13 * OBSOLETE configurations
15 Altos 3068 m68*-altos-*
19 * Remote targets can connect to a sub-program
21 A popen(3) style serial-device has been added. This device starts a
22 sub-process (such as a stand-alone simulator) and then communicates
23 with that. The sub-program to run is specified using the syntax
24 ``|<program> <args>'' vis:
26 (gdb) set remotedebug 1
27 (gdb) target extended-remote |mn10300-elf-sim program-args
29 * MIPS 64 remote protocol
31 A long standing bug in the mips64 remote protocol where by GDB
32 expected certain 32 bit registers (ex SR) to be transfered as 32
33 instead of 64 bits has been fixed.
35 The command ``set remote-mips64-transfers-32bit-regs on'' has been
36 added to provide backward compatibility with older versions of GDB.
38 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
40 The command ``set remotebinarydownload'' command has been replaced by
41 ``set remote X-packet''. Other commands in ``set remote'' family
42 include ``set remote P-packet''.
44 *** Changes in GDB-4.18:
46 * New native configurations
48 HP-UX 10.20 hppa*-*-hpux10.20
49 HP-UX 11.x hppa*-*-hpux11.0*
50 M68K Linux m68*-*-linux*
54 Fujitsu FR30 fr30-*-elf*
55 Intel StrongARM strongarm-*-*
56 Mitsubishi D30V d30v-*-*
58 * OBSOLETE configurations
60 Gould PowerNode, NP1 np1-*-*, pn-*-*
62 Configurations that have been declared obsolete will be commented out,
63 but the code will be left in place. If there is no activity to revive
64 these configurations before the next release of GDB, the sources will
65 be permanently REMOVED.
69 As a compatibility experiment, GDB's source files buildsym.h and
70 buildsym.c have been converted to pure standard C, no longer
71 containing any K&R compatibility code. We believe that all systems in
72 use today either come with a standard C compiler, or have a GCC port
73 available. If this is not true, please report the affected
74 configuration to bug-gdb@gnu.org immediately. See the README file for
75 information about getting a standard C compiler if you don't have one
80 GDB now uses readline 2.2.
82 * set extension-language
84 You can now control the mapping between filename extensions and source
85 languages by using the `set extension-language' command. For instance,
86 you can ask GDB to treat .c files as C++ by saying
87 set extension-language .c c++
88 The command `info extensions' lists all of the recognized extensions
89 and their associated languages.
91 * Setting processor type for PowerPC and RS/6000
93 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
94 you can use the `set processor' command to specify what variant of the
95 PowerPC family you are debugging. The command
99 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
100 following PowerPC and RS6000 variants:
102 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
103 rs6000 IBM RS6000 ("POWER") architecture, user-level view
105 403GC IBM PowerPC 403GC
106 505 Motorola PowerPC 505
107 860 Motorola PowerPC 860 or 850
108 601 Motorola PowerPC 601
109 602 Motorola PowerPC 602
110 603 Motorola/IBM PowerPC 603 or 603e
111 604 Motorola PowerPC 604 or 604e
112 750 Motorola/IBM PowerPC 750 or 750
114 At the moment, this command just tells GDB what to name the
115 special-purpose processor registers. Since almost all the affected
116 registers are inaccessible to user-level programs, this command is
117 only useful for remote debugging in its present form.
121 Thanks to a major code donation from Hewlett-Packard, GDB now has much
122 more extensive support for HP-UX. Added features include shared
123 library support, kernel threads and hardware watchpoints for 11.00,
124 support for HP's ANSI C and C++ compilers, and a compatibility mode
125 for xdb and dbx commands.
129 HP's donation includes the new concept of catchpoints, which is a
130 generalization of the old catch command. On HP-UX, it is now possible
131 to catch exec, fork, and vfork, as well as library loading.
133 This means that the existing catch command has changed; its first
134 argument now specifies the type of catch to be set up. See the
135 output of "help catch" for a list of catchpoint types.
137 * Debugging across forks
139 On HP-UX, you can choose which process to debug when a fork() happens
144 HP has donated a curses-based terminal user interface (TUI). To get
145 it, build with --enable-tui. Although this can be enabled for any
146 configuration, at present it only works for native HP debugging.
148 * GDB remote protocol additions
150 A new protocol packet 'X' that writes binary data is now available.
151 Default behavior is to try 'X', then drop back to 'M' if the stub
152 fails to respond. The settable variable `remotebinarydownload'
153 allows explicit control over the use of 'X'.
155 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
156 full 64-bit address. The command
158 set remoteaddresssize 32
160 can be used to revert to the old behaviour. For existing remote stubs
161 the change should not be noticed, as the additional address information
164 In order to assist in debugging stubs, you may use the maintenance
165 command `packet' to send any text string to the stub. For instance,
167 maint packet heythere
169 sends the packet "$heythere#<checksum>". Note that it is very easy to
170 disrupt a debugging session by sending the wrong packet at the wrong
173 The compare-sections command allows you to compare section data on the
174 target to what is in the executable file without uploading or
175 downloading, by comparing CRC checksums.
177 * Tracing can collect general expressions
179 You may now collect general expressions at tracepoints. This requires
180 further additions to the target-side stub; see tracepoint.c and
181 doc/agentexpr.texi for further details.
183 * mask-address variable for Mips
185 For Mips targets, you may control the zeroing of the upper 32 bits of
186 a 64-bit address by entering `set mask-address on'. This is mainly
187 of interest to users of embedded R4xxx and R5xxx processors.
189 * Higher serial baud rates
191 GDB's serial code now allows you to specify baud rates 57600, 115200,
192 230400, and 460800 baud. (Note that your host system may not be able
193 to achieve all of these rates.)
197 The i960 configuration now includes an initial implementation of a
198 builtin simulator, contributed by Jim Wilson.
201 *** Changes in GDB-4.17:
203 * New native configurations
205 Alpha GNU/Linux alpha*-*-linux*
206 Unixware 2.x i[3456]86-unixware2*
207 Irix 6.x mips*-sgi-irix6*
208 PowerPC GNU/Linux powerpc-*-linux*
209 PowerPC Solaris powerpcle-*-solaris*
210 Sparc GNU/Linux sparc-*-linux*
211 Motorola sysV68 R3V7.1 m68k-motorola-sysv
215 Argonaut Risc Chip (ARC) arc-*-*
216 Hitachi H8/300S h8300*-*-*
217 Matsushita MN10200 w/simulator mn10200-*-*
218 Matsushita MN10300 w/simulator mn10300-*-*
219 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
220 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
221 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
222 Mitsubishi D10V w/simulator d10v-*-*
223 Mitsubishi M32R/D w/simulator m32r-*-elf*
224 Tsqware Sparclet sparclet-*-*
225 NEC V850 w/simulator v850-*-*
227 * New debugging protocols
229 ARM with RDI protocol arm*-*-*
230 M68K with dBUG monitor m68*-*-{aout,coff,elf}
231 DDB and LSI variants of PMON protocol mips*-*-*
232 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
233 PowerPC with SDS protocol powerpc{,le}-*-eabi
234 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
238 All configurations can now understand and use the DWARF 2 debugging
239 format. The choice is automatic, if the symbol file contains DWARF 2
244 GDB now includes basic Java language support. This support is
245 only useful with Java compilers that produce native machine code.
247 * solib-absolute-prefix and solib-search-path
249 For SunOS and SVR4 shared libraries, you may now set the prefix for
250 loading absolute shared library symbol files, and the search path for
251 locating non-absolute shared library symbol files.
253 * Live range splitting
255 GDB can now effectively debug code for which GCC has performed live
256 range splitting as part of its optimization. See gdb/doc/LRS for
257 more details on the expected format of the stabs information.
261 GDB's support for the GNU Hurd, including thread debugging, has been
262 updated to work with current versions of the Hurd.
266 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
267 instruction set. ARM GDB automatically detects when Thumb
268 instructions are in use, and adjusts disassembly and backtracing
273 GDB's MIPS target configurations now handle the MIP16 16-bit
278 GDB now includes support for overlays; if an executable has been
279 linked such that multiple sections are based at the same address, GDB
280 will decide which section to use for symbolic info. You can choose to
281 control the decision manually, using overlay commands, or implement
282 additional target-side support and use "overlay load-target" to bring
283 in the overlay mapping. Do "help overlay" for more detail.
287 The command "info symbol <address>" displays information about
288 the symbol at the specified address.
292 The standard remote protocol now includes an extension that allows
293 asynchronous collection and display of trace data. This requires
294 extensive support in the target-side debugging stub. Tracing mode
295 includes a new interaction mode in GDB and new commands: see the
296 file tracepoint.c for more details.
300 Configurations for embedded MIPS now include a simulator contributed
301 by Cygnus Solutions. The simulator supports the instruction sets
302 of most MIPS variants.
306 Sparc configurations may now include the ERC32 simulator contributed
307 by the European Space Agency. The simulator is not built into
308 Sparc targets by default; configure with --enable-sim to include it.
312 For target configurations that may include multiple variants of a
313 basic architecture (such as MIPS and SH), you may now set the
314 architecture explicitly. "set arch" sets, "info arch" lists
315 the possible architectures.
317 *** Changes in GDB-4.16:
319 * New native configurations
321 Windows 95, x86 Windows NT i[345]86-*-cygwin32
322 M68K NetBSD m68k-*-netbsd*
323 PowerPC AIX 4.x powerpc-*-aix*
324 PowerPC MacOS powerpc-*-macos*
325 PowerPC Windows NT powerpcle-*-cygwin32
326 RS/6000 AIX 4.x rs6000-*-aix4*
330 ARM with RDP protocol arm-*-*
331 I960 with MON960 i960-*-coff
332 MIPS VxWorks mips*-*-vxworks*
333 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
334 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
336 Matra Sparclet sparclet-*-*
340 The powerpc-eabi configuration now includes the PSIM simulator,
341 contributed by Andrew Cagney, with assistance from Mike Meissner.
342 PSIM is a very elaborate model of the PowerPC, including not only
343 basic instruction set execution, but also details of execution unit
344 performance and I/O hardware. See sim/ppc/README for more details.
348 GDB now works with Solaris 2.5.
350 * Windows 95/NT native
352 GDB will now work as a native debugger on Windows 95 and Windows NT.
353 To build it from source, you must use the "gnu-win32" environment,
354 which uses a DLL to emulate enough of Unix to run the GNU tools.
355 Further information, binaries, and sources are available at
356 ftp.cygnus.com, under pub/gnu-win32.
358 * dont-repeat command
360 If a user-defined command includes the command `dont-repeat', then the
361 command will not be repeated if the user just types return. This is
362 useful if the command is time-consuming to run, so that accidental
363 extra keystrokes don't run the same command many times.
365 * Send break instead of ^C
367 The standard remote protocol now includes an option to send a break
368 rather than a ^C to the target in order to interrupt it. By default,
369 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
371 * Remote protocol timeout
373 The standard remote protocol includes a new variable `remotetimeout'
374 that allows you to set the number of seconds before GDB gives up trying
375 to read from the target. The default value is 2.
377 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
379 By default GDB will automatically keep track of objects as they are
380 loaded and unloaded by the dynamic linker. By using the command `set
381 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
382 when shared library events occur, thus allowing you to set breakpoints
383 in shared libraries which are explicitly loaded by the inferior.
385 Note this feature does not work on hpux8. On hpux9 you must link
386 /usr/lib/end.o into your program. This feature should work
387 automatically on hpux10.
389 * Irix 5.x hardware watchpoint support
391 Irix 5 configurations now support the use of hardware watchpoints.
393 * Mips protocol "SYN garbage limit"
395 When debugging a Mips target using the `target mips' protocol, you
396 may set the number of characters that GDB will ignore by setting
397 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
398 every character. The default value is 1050.
400 * Recording and replaying remote debug sessions
402 If you set `remotelogfile' to the name of a file, gdb will write to it
403 a recording of a remote debug session. This recording may then be
404 replayed back to gdb using "gdbreplay". See gdbserver/README for
405 details. This is useful when you have a problem with GDB while doing
406 remote debugging; you can make a recording of the session and send it
407 to someone else, who can then recreate the problem.
409 * Speedups for remote debugging
411 GDB includes speedups for downloading and stepping MIPS systems using
412 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
413 and more efficient S-record downloading.
415 * Memory use reductions and statistics collection
417 GDB now uses less memory and reports statistics about memory usage.
418 Try the `maint print statistics' command, for example.
420 *** Changes in GDB-4.15:
424 The symbol reader for AIX GDB now uses partial symbol tables. This
425 can greatly improve startup time, especially for large executables.
427 * Remote targets use caching
429 Remote targets now use a data cache to speed up communication with the
430 remote side. The data cache could lead to incorrect results because
431 it doesn't know about volatile variables, thus making it impossible to
432 debug targets which use memory mapped I/O devices. `set remotecache
433 off' turns the the data cache off.
435 * Remote targets may have threads
437 The standard remote protocol now includes support for multiple threads
438 in the target system, using new protocol commands 'H' and 'T'. See
439 gdb/remote.c for details.
443 If GDB is configured with `--enable-netrom', then it will include
444 support for the NetROM ROM emulator from XLNT Designs. The NetROM
445 acts as though it is a bank of ROM on the target board, but you can
446 write into it over the network. GDB's support consists only of
447 support for fast loading into the emulated ROM; to debug, you must use
448 another protocol, such as standard remote protocol. The usual
449 sequence is something like
451 target nrom <netrom-hostname>
453 target remote <netrom-hostname>:1235
457 GDB now includes support for the Apple Macintosh, as a host only. It
458 may be run as either an MPW tool or as a standalone application, and
459 it can debug through the serial port. All the usual GDB commands are
460 available, but to the target command, you must supply "serial" as the
461 device type instead of "/dev/ttyXX". See mpw-README in the main
462 directory for more information on how to build. The MPW configuration
463 scripts */mpw-config.in support only a few targets, and only the
464 mips-idt-ecoff target has been tested.
468 GDB configuration now uses autoconf. This is not user-visible,
469 but does simplify configuration and building.
473 GDB now supports hpux10.
475 *** Changes in GDB-4.14:
477 * New native configurations
479 x86 FreeBSD i[345]86-*-freebsd
480 x86 NetBSD i[345]86-*-netbsd
481 NS32k NetBSD ns32k-*-netbsd
482 Sparc NetBSD sparc-*-netbsd
486 A29K VxWorks a29k-*-vxworks
487 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
488 CPU32 EST-300 emulator m68*-*-est*
489 PowerPC ELF powerpc-*-elf
492 * Alpha OSF/1 support for procfs
494 GDB now supports procfs under OSF/1-2.x and higher, which makes it
495 possible to attach to running processes. As the mounting of the /proc
496 filesystem is optional on the Alpha, GDB automatically determines
497 the availability of /proc during startup. This can lead to problems
498 if /proc is unmounted after GDB has been started.
500 * Arguments to user-defined commands
502 User commands may accept up to 10 arguments separated by whitespace.
503 Arguments are accessed within the user command via $arg0..$arg9. A
506 print $arg0 + $arg1 + $arg2
508 To execute the command use:
511 Defines the command "adder" which prints the sum of its three arguments.
512 Note the arguments are text substitutions, so they may reference variables,
513 use complex expressions, or even perform inferior function calls.
515 * New `if' and `while' commands
517 This makes it possible to write more sophisticated user-defined
518 commands. Both commands take a single argument, which is the
519 expression to evaluate, and must be followed by the commands to
520 execute, one per line, if the expression is nonzero, the list being
521 terminated by the word `end'. The `if' command list may include an
522 `else' word, which causes the following commands to be executed only
523 if the expression is zero.
525 * Fortran source language mode
527 GDB now includes partial support for Fortran 77. It will recognize
528 Fortran programs and can evaluate a subset of Fortran expressions, but
529 variables and functions may not be handled correctly. GDB will work
530 with G77, but does not yet know much about symbols emitted by other
533 * Better HPUX support
535 Most debugging facilities now work on dynamic executables for HPPAs
536 running hpux9 or later. You can attach to running dynamically linked
537 processes, but by default the dynamic libraries will be read-only, so
538 for instance you won't be able to put breakpoints in them. To change
539 that behavior do the following before running the program:
545 This will cause the libraries to be mapped private and read-write.
546 To revert to the normal behavior, do this:
552 You cannot set breakpoints or examine data in the library until after
553 the library is loaded if the function/data symbols do not have
556 GDB can now also read debug symbols produced by the HP C compiler on
557 HPPAs (sorry, no C++, Fortran or 68k support).
559 * Target byte order now dynamically selectable
561 You can choose which byte order to use with a target system, via the
562 commands "set endian big" and "set endian little", and you can see the
563 current setting by using "show endian". You can also give the command
564 "set endian auto", in which case GDB will use the byte order
565 associated with the executable. Currently, only embedded MIPS
566 configurations support dynamic selection of target byte order.
568 * New DOS host serial code
570 This version uses DPMI interrupts to handle buffered I/O, so you
571 no longer need to run asynctsr when debugging boards connected to
574 *** Changes in GDB-4.13:
576 * New "complete" command
578 This lists all the possible completions for the rest of the line, if it
579 were to be given as a command itself. This is intended for use by emacs.
581 * Trailing space optional in prompt
583 "set prompt" no longer adds a space for you after the prompt you set. This
584 allows you to set a prompt which ends in a space or one that does not.
586 * Breakpoint hit counts
588 "info break" now displays a count of the number of times the breakpoint
589 has been hit. This is especially useful in conjunction with "ignore"; you
590 can ignore a large number of breakpoint hits, look at the breakpoint info
591 to see how many times the breakpoint was hit, then run again, ignoring one
592 less than that number, and this will get you quickly to the last hit of
595 * Ability to stop printing at NULL character
597 "set print null-stop" will cause GDB to stop printing the characters of
598 an array when the first NULL is encountered. This is useful when large
599 arrays actually contain only short strings.
601 * Shared library breakpoints
603 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
604 breakpoints in shared libraries before the executable is run.
606 * Hardware watchpoints
608 There is a new hardware breakpoint for the watch command for sparclite
609 targets. See gdb/sparclite/hw_breakpoint.note.
611 Hardware watchpoints are also now supported under Linux.
615 Annotations have been added. These are for use with graphical interfaces,
616 and are still experimental. Currently only gdba.el uses these.
618 * Improved Irix 5 support
620 GDB now works properly with Irix 5.2.
622 * Improved HPPA support
624 GDB now works properly with the latest GCC and GAS.
626 * New native configurations
628 Sequent PTX4 i[34]86-sequent-ptx4
629 HPPA running OSF/1 hppa*-*-osf*
630 Atari TT running SVR4 m68*-*-sysv4*
631 RS/6000 LynxOS rs6000-*-lynxos*
635 OS/9000 i[34]86-*-os9k
636 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
639 * Hitachi SH7000 and E7000-PC ICE support
641 There is now support for communicating with the Hitachi E7000-PC ICE.
642 This is available automatically when GDB is configured for the SH.
646 As usual, a variety of small fixes and improvements, both generic
647 and configuration-specific. See the ChangeLog for more detail.
649 *** Changes in GDB-4.12:
651 * Irix 5 is now supported
655 GDB-4.12 on the HPPA has a number of changes which make it unable
656 to debug the output from the currently released versions of GCC and
657 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
658 of GCC and GAS, versions of these tools designed to work with GDB-4.12
659 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
662 *** Changes in GDB-4.11:
664 * User visible changes:
668 The "set remotedebug" option is now consistent between the mips remote
669 target, remote targets using the gdb-specific protocol, UDI (AMD's
670 debug protocol for the 29k) and the 88k bug monitor. It is now an
671 integer specifying a debug level (normally 0 or 1, but 2 means more
672 debugging info for the mips target).
674 * DEC Alpha native support
676 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
677 debug info, but GDB works fairly well with the DEC compiler and should
678 work with a future GCC release. See the README file for a few
679 Alpha-specific notes.
681 * Preliminary thread implementation
683 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
685 * LynxOS native and target support for 386
687 This release has been hosted on LynxOS 2.2, and also can be configured
688 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
691 * Improvements in C++ mangling/demangling.
693 This release has much better g++ debugging, specifically in name
694 mangling/demangling, virtual function calls, print virtual table,
695 call methods, ...etc.
697 *** Changes in GDB-4.10:
699 * User visible changes:
701 Remote debugging using the GDB-specific (`target remote') protocol now
702 supports the `load' command. This is only useful if you have some
703 other way of getting the stub to the target system, and you can put it
704 somewhere in memory where it won't get clobbered by the download.
706 Filename completion now works.
708 When run under emacs mode, the "info line" command now causes the
709 arrow to point to the line specified. Also, "info line" prints
710 addresses in symbolic form (as well as hex).
712 All vxworks based targets now support a user settable option, called
713 vxworks-timeout. This option represents the number of seconds gdb
714 should wait for responses to rpc's. You might want to use this if
715 your vxworks target is, perhaps, a slow software simulator or happens
716 to be on the far side of a thin network line.
720 This release contains support for using a DEC alpha as a GDB host for
721 cross debugging. Native alpha debugging is not supported yet.
724 *** Changes in GDB-4.9:
728 This is the first GDB release which is accompanied by a matching testsuite.
729 The testsuite requires installation of dejagnu, which should be available
730 via ftp from most sites that carry GNU software.
734 'Cfront' style demangling has had its name changed to 'ARM' style, to
735 emphasize that it was written from the specifications in the C++ Annotated
736 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
737 disclaimers, it still generated too much confusion with users attempting to
738 use gdb with AT&T cfront.
742 GDB now uses a standard remote interface to a simulator library.
743 So far, the library contains simulators for the Zilog Z8001/2, the
744 Hitachi H8/300, H8/500 and Super-H.
746 * New targets supported
748 H8/300 simulator h8300-hitachi-hms or h8300hms
749 H8/500 simulator h8500-hitachi-hms or h8500hms
750 SH simulator sh-hitachi-hms or sh
751 Z8000 simulator z8k-zilog-none or z8ksim
752 IDT MIPS board over serial line mips-idt-ecoff
754 Cross-debugging to GO32 targets is supported. It requires a custom
755 version of the i386-stub.c module which is integrated with the
756 GO32 memory extender.
758 * New remote protocols
760 MIPS remote debugging protocol.
762 * New source languages supported
764 This version includes preliminary support for Chill, a Pascal like language
765 used by telecommunications companies. Chill support is also being integrated
766 into the GNU compiler, but we don't know when it will be publically available.
769 *** Changes in GDB-4.8:
771 * HP Precision Architecture supported
773 GDB now supports HP PA-RISC machines running HPUX. A preliminary
774 version of this support was available as a set of patches from the
775 University of Utah. GDB does not support debugging of programs
776 compiled with the HP compiler, because HP will not document their file
777 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
778 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
780 Many problems in the preliminary version have been fixed.
782 * Faster and better demangling
784 We have improved template demangling and fixed numerous bugs in the GNU style
785 demangler. It can now handle type modifiers such as `static' or `const'. Wide
786 character types (wchar_t) are now supported. Demangling of each symbol is now
787 only done once, and is cached when the symbol table for a file is read in.
788 This results in a small increase in memory usage for C programs, a moderate
789 increase in memory usage for C++ programs, and a fantastic speedup in
792 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
793 from the specifications in the Annotated Reference Manual, which AT&T's
794 compiler does not actually implement.
796 * G++ multiple inheritance compiler problem
798 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
799 inheritance lattices was reworked to properly discover ambiguities. We
800 recently found an example which causes this new algorithm to fail in a
801 very subtle way, producing bad debug information for those classes.
802 The file 'gcc.patch' (in this directory) can be applied to gcc to
803 circumvent the problem. A future GCC release will contain a complete
806 The previous G++ debug info problem (mentioned below for the gdb-4.7
807 release) is fixed in gcc version 2.3.2.
809 * Improved configure script
811 The `configure' script will now attempt to guess your system type if
812 you don't supply a host system type. The old scheme of supplying a
813 host system triplet is preferable over using this. All the magic is
814 done in the new `config.guess' script. Examine it for details.
816 We have also brought our configure script much more in line with the FSF's
817 version. It now supports the --with-xxx options. In particular,
818 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
819 The resulting GDB will not be able to read arbitrary object file formats --
820 only the format ``expected'' to be used on the configured target system.
821 We hope to make this the default in a future release.
823 * Documentation improvements
825 There's new internal documentation on how to modify GDB, and how to
826 produce clean changes to the code. We implore people to read it
827 before submitting changes.
829 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
830 M4 macros. The new texinfo.tex is provided in this release. Pre-built
831 `info' files are also provided. To build `info' files from scratch,
832 you will need the latest `makeinfo' release, which will be available in
833 a future texinfo-X.Y release.
835 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
836 We're not sure exactly which versions have this problem, but it has
837 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
838 or better. If that isn't possible, there is a patch in
839 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
844 GDB now supports array constants that can be used in expressions typed in by
845 the user. The syntax is `{element, element, ...}'. Ie: you can now type
846 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
849 The new directory `gdb/sparclite' contains a program that demonstrates
850 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
852 * New native hosts supported
854 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
855 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
857 * New targets supported
859 AMD 29k family via UDI a29k-amd-udi or udi29k
861 * New file formats supported
863 BFD now supports reading HP/PA-RISC executables (SOM file format?),
864 HPUX core files, and SCO 3.2v2 core files.
868 Attaching to processes now works again; thanks for the many bug reports.
870 We have also stomped on a bunch of core dumps caused by
871 printf_filtered("%s") problems.
873 We eliminated a copyright problem on the rpc and ptrace header files
874 for VxWorks, which was discovered at the last minute during the 4.7
875 release. You should now be able to build a VxWorks GDB.
877 You can now interrupt gdb while an attached process is running. This
878 will cause the attached process to stop, and give control back to GDB.
880 We fixed problems caused by using too many file descriptors
881 for reading symbols from object files and libraries. This was
882 especially a problem for programs that used many (~100) shared
885 The `step' command now only enters a subroutine if there is line number
886 information for the subroutine. Otherwise it acts like the `next'
887 command. Previously, `step' would enter subroutines if there was
888 any debugging information about the routine. This avoids problems
889 when using `cc -g1' on MIPS machines.
891 * Internal improvements
893 GDB's internal interfaces have been improved to make it easier to support
894 debugging of multiple languages in the future.
896 GDB now uses a common structure for symbol information internally.
897 Minimal symbols (derived from linkage symbols in object files), partial
898 symbols (from a quick scan of debug information), and full symbols
899 contain a common subset of information, making it easier to write
900 shared code that handles any of them.
902 * New command line options
904 We now accept --silent as an alias for --quiet.
908 The memory-mapped-malloc library is now licensed under the GNU Library
909 General Public License.
911 *** Changes in GDB-4.7:
913 * Host/native/target split
915 GDB has had some major internal surgery to untangle the support for
916 hosts and remote targets. Now, when you configure GDB for a remote
917 target, it will no longer load in all of the support for debugging
918 local programs on the host. When fully completed and tested, this will
919 ensure that arbitrary host/target combinations are possible.
921 The primary conceptual shift is to separate the non-portable code in
922 GDB into three categories. Host specific code is required any time GDB
923 is compiled on that host, regardless of the target. Target specific
924 code relates to the peculiarities of the target, but can be compiled on
925 any host. Native specific code is everything else: it can only be
926 built when the host and target are the same system. Child process
927 handling and core file support are two common `native' examples.
929 GDB's use of /proc for controlling Unix child processes is now cleaner.
930 It has been split out into a single module under the `target_ops' vector,
931 plus two native-dependent functions for each system that uses /proc.
933 * New hosts supported
935 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
936 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
937 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
939 * New targets supported
941 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
942 68030 and CPU32 m68030-*-*, m68332-*-*
944 * New native hosts supported
946 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
947 (386bsd is not well tested yet)
948 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
950 * New file formats supported
952 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
953 supports reading of `a.out.adobe' object files, which are an a.out
954 format extended with minimal information about multiple sections.
958 `show copying' is the same as the old `info copying'.
959 `show warranty' is the same as `info warrantee'.
960 These were renamed for consistency. The old commands continue to work.
962 `info handle' is a new alias for `info signals'.
964 You can now define pre-command hooks, which attach arbitrary command
965 scripts to any command. The commands in the hook will be executed
966 prior to the user's command. You can also create a hook which will be
967 executed whenever the program stops. See gdb.texinfo.
971 We now deal with Cfront style name mangling, and can even extract type
972 info from mangled symbols. GDB can automatically figure out which
973 symbol mangling style your C++ compiler uses.
975 Calling of methods and virtual functions has been improved as well.
979 The crash that occured when debugging Sun Ansi-C compiled binaries is
980 fixed. This was due to mishandling of the extra N_SO stabs output
983 We also finally got Ultrix 4.2 running in house, and fixed core file
984 support, with help from a dozen people on the net.
986 John M. Farrell discovered that the reason that single-stepping was so
987 slow on all of the Mips based platforms (primarily SGI and DEC) was
988 that we were trying to demangle and lookup a symbol used for internal
989 purposes on every instruction that was being stepped through. Changing
990 the name of that symbol so that it couldn't be mistaken for a C++
991 mangled symbol sped things up a great deal.
993 Rich Pixley sped up symbol lookups in general by getting much smarter
994 about when C++ symbol mangling is necessary. This should make symbol
995 completion (TAB on the command line) much faster. It's not as fast as
996 we'd like, but it's significantly faster than gdb-4.6.
1000 A new user controllable variable 'call_scratch_address' can
1001 specify the location of a scratch area to be used when GDB
1002 calls a function in the target. This is necessary because the
1003 usual method of putting the scratch area on the stack does not work
1004 in systems that have separate instruction and data spaces.
1006 We integrated changes to support the 29k UDI (Universal Debugger
1007 Interface), but discovered at the last minute that we didn't have all
1008 of the appropriate copyright paperwork. We are working with AMD to
1009 resolve this, and hope to have it available soon.
1013 We have sped up the remote serial line protocol, especially for targets
1014 with lots of registers. It now supports a new `expedited status' ('T')
1015 message which can be used in place of the existing 'S' status message.
1016 This allows the remote stub to send only the registers that GDB
1017 needs to make a quick decision about single-stepping or conditional
1018 breakpoints, eliminating the need to fetch the entire register set for
1019 each instruction being stepped through.
1021 The GDB remote serial protocol now implements a write-through cache for
1022 registers, only re-reading the registers if the target has run.
1024 There is also a new remote serial stub for SPARC processors. You can
1025 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
1026 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
1027 processor with a serial port.
1031 Configure.in files have become much easier to read and modify. A new
1032 `table driven' format makes it more obvious what configurations are
1033 supported, and what files each one uses.
1037 There is a new opcodes library which will eventually contain all of the
1038 disassembly routines and opcode tables. At present, it only contains
1039 Sparc and Z8000 routines. This will allow the assembler, debugger, and
1040 disassembler (binutils/objdump) to share these routines.
1042 The libiberty library is now copylefted under the GNU Library General
1043 Public License. This allows more liberal use, and was done so libg++
1044 can use it. This makes no difference to GDB, since the Library License
1045 grants all the rights from the General Public License.
1049 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
1050 reference to the stabs symbol info used by the debugger. It is (as far
1051 as we know) the only published document on this fascinating topic. We
1052 encourage you to read it, compare it to the stabs information on your
1053 system, and send improvements on the document in general (to
1054 bug-gdb@prep.ai.mit.edu).
1056 And, of course, many bugs have been fixed.
1059 *** Changes in GDB-4.6:
1061 * Better support for C++ function names
1063 GDB now accepts as input the "demangled form" of C++ overloaded function
1064 names and member function names, and can do command completion on such names
1065 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
1066 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
1067 Make use of command completion, it is your friend.
1069 GDB also now accepts a variety of C++ mangled symbol formats. They are
1070 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
1071 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
1072 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
1073 for the list of formats.
1075 * G++ symbol mangling problem
1077 Recent versions of gcc have a bug in how they emit debugging information for
1078 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
1079 directory) can be applied to gcc to fix the problem. Alternatively, if you
1080 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
1081 usual symptom is difficulty with setting breakpoints on methods. GDB complains
1082 about the method being non-existent. (We believe that version 2.2.2 of GCC has
1085 * New 'maintenance' command
1087 All of the commands related to hacking GDB internals have been moved out of
1088 the main command set, and now live behind the 'maintenance' command. This
1089 can also be abbreviated as 'mt'. The following changes were made:
1091 dump-me -> maintenance dump-me
1092 info all-breakpoints -> maintenance info breakpoints
1093 printmsyms -> maintenance print msyms
1094 printobjfiles -> maintenance print objfiles
1095 printpsyms -> maintenance print psymbols
1096 printsyms -> maintenance print symbols
1098 The following commands are new:
1100 maintenance demangle Call internal GDB demangler routine to
1101 demangle a C++ link name and prints the result.
1102 maintenance print type Print a type chain for a given symbol
1104 * Change to .gdbinit file processing
1106 We now read the $HOME/.gdbinit file before processing the argv arguments
1107 (e.g. reading symbol files or core files). This allows global parameters to
1108 be set, which will apply during the symbol reading. The ./.gdbinit is still
1109 read after argv processing.
1111 * New hosts supported
1113 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
1115 Linux support i386-unknown-linux or linux
1117 We are also including code to support the HP/PA running BSD and HPUX. This
1118 is almost guaranteed not to work, as we didn't have time to test or build it
1119 for this release. We are including it so that the more adventurous (or
1120 masochistic) of you can play with it. We also had major problems with the
1121 fact that the compiler that we got from HP doesn't support the -g option.
1124 * New targets supported
1126 Hitachi H8/300 h8300-hitachi-hms or h8300hms
1128 * More smarts about finding #include files
1130 GDB now remembers the compilation directory for all include files, and for
1131 all files from which C is generated (like yacc and lex sources). This
1132 greatly improves GDB's ability to find yacc/lex sources, and include files,
1133 especially if you are debugging your program from a directory different from
1134 the one that contains your sources.
1136 We also fixed a bug which caused difficulty with listing and setting
1137 breakpoints in include files which contain C code. (In the past, you had to
1138 try twice in order to list an include file that you hadn't looked at before.)
1140 * Interesting infernals change
1142 GDB now deals with arbitrary numbers of sections, where the symbols for each
1143 section must be relocated relative to that section's landing place in the
1144 target's address space. This work was needed to support ELF with embedded
1145 stabs used by Solaris-2.0.
1147 * Bug fixes (of course!)
1149 There have been loads of fixes for the following things:
1150 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
1151 i960, stabs, DOS(GO32), procfs, etc...
1153 See the ChangeLog for details.
1155 *** Changes in GDB-4.5:
1157 * New machines supported (host and target)
1159 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
1161 SGI Irix-4.x mips-sgi-irix4 or iris4
1163 * New malloc package
1165 GDB now uses a new memory manager called mmalloc, based on gmalloc.
1166 Mmalloc is capable of handling mutiple heaps of memory. It is also
1167 capable of saving a heap to a file, and then mapping it back in later.
1168 This can be used to greatly speedup the startup of GDB by using a
1169 pre-parsed symbol table which lives in a mmalloc managed heap. For
1170 more details, please read mmalloc/mmalloc.texi.
1174 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
1175 'help info proc' for details.
1177 * MIPS ecoff symbol table format
1179 The code that reads MIPS symbol table format is now supported on all hosts.
1180 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
1183 * File name changes for MS-DOS
1185 Many files in the config directories have been renamed to make it easier to
1186 support GDB on MS-DOSe systems (which have very restrictive file name
1187 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
1188 environment) is close to working but has some remaining problems. Note
1189 that debugging of DOS programs is not supported, due to limitations
1190 in the ``operating system'', but it can be used to host cross-debugging.
1192 * Cross byte order fixes
1194 Many fixes have been made to support cross debugging of Sparc and MIPS
1195 targets from hosts whose byte order differs.
1197 * New -mapped and -readnow options
1199 If memory-mapped files are available on your system through the 'mmap'
1200 system call, you can use the -mapped option on the `file' or
1201 `symbol-file' commands to cause GDB to write the symbols from your
1202 program into a reusable file. If the program you are debugging is
1203 called `/path/fred', the mapped symbol file will be `./fred.syms'.
1204 Future GDB debugging sessions will notice the presence of this file,
1205 and will quickly map in symbol information from it, rather than reading
1206 the symbol table from the executable program. Using the '-mapped'
1207 option in a GDB `file' or `symbol-file' command has the same effect as
1208 starting GDB with the '-mapped' command-line option.
1210 You can cause GDB to read the entire symbol table immediately by using
1211 the '-readnow' option with any of the commands that load symbol table
1212 information (or on the GDB command line). This makes the command
1213 slower, but makes future operations faster.
1215 The -mapped and -readnow options are typically combined in order to
1216 build a `fred.syms' file that contains complete symbol information.
1217 A simple GDB invocation to do nothing but build a `.syms' file for future
1220 gdb -batch -nx -mapped -readnow programname
1222 The `.syms' file is specific to the host machine on which GDB is run.
1223 It holds an exact image of GDB's internal symbol table. It cannot be
1224 shared across multiple host platforms.
1226 * longjmp() handling
1228 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
1229 siglongjmp() without losing control. This feature has not yet been ported to
1230 all systems. It currently works on many 386 platforms, all MIPS-based
1231 platforms (SGI, DECstation, etc), and Sun3/4.
1235 Preliminary work has been put in to support the new Solaris OS from Sun. At
1236 this time, it can control and debug processes, but it is not capable of
1241 As always, many many bug fixes. The major areas were with g++, and mipsread.
1242 People using the MIPS-based platforms should experience fewer mysterious
1243 crashes and trashed symbol tables.
1245 *** Changes in GDB-4.4:
1247 * New machines supported (host and target)
1249 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
1251 BSD Reno on Vax vax-dec-bsd
1252 Ultrix on Vax vax-dec-ultrix
1254 * New machines supported (target)
1256 AMD 29000 embedded, using EBMON a29k-none-none
1260 GDB continues to improve its handling of C++. `References' work better.
1261 The demangler has also been improved, and now deals with symbols mangled as
1262 per the Annotated C++ Reference Guide.
1264 GDB also now handles `stabs' symbol information embedded in MIPS
1265 `ecoff' symbol tables. Since the ecoff format was not easily
1266 extensible to handle new languages such as C++, this appeared to be a
1267 good way to put C++ debugging info into MIPS binaries. This option
1268 will be supported in the GNU C compiler, version 2, when it is
1271 * New features for SVR4
1273 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
1274 shared libraries. Debugging dynamically linked programs should present
1275 only minor differences from debugging statically linked programs.
1277 The `info proc' command will print out information about any process
1278 on an SVR4 system (including the one you are debugging). At the moment,
1279 it prints the address mappings of the process.
1281 If you bring up GDB on another SVR4 system, please send mail to
1282 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
1284 * Better dynamic linking support in SunOS
1286 Reading symbols from shared libraries which contain debugging symbols
1287 now works properly. However, there remain issues such as automatic
1288 skipping of `transfer vector' code during function calls, which
1289 make it harder to debug code in a shared library, than to debug the
1290 same code linked statically.
1294 GDB is now using the latest `getopt' routines from the FSF. This
1295 version accepts the -- prefix for options with long names. GDB will
1296 continue to accept the old forms (-option and +option) as well.
1297 Various single letter abbreviations for options have been explicity
1298 added to the option table so that they won't get overshadowed in the
1299 future by other options that begin with the same letter.
1303 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
1304 Many assorted bugs have been handled. Many more remain to be handled.
1305 See the various ChangeLog files (primarily in gdb and bfd) for details.
1308 *** Changes in GDB-4.3:
1310 * New machines supported (host and target)
1312 Amiga 3000 running Amix m68k-cbm-svr4 or amix
1313 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
1314 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
1316 * Almost SCO Unix support
1318 We had hoped to support:
1319 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
1320 (except for core file support), but we discovered very late in the release
1321 that it has problems with process groups that render gdb unusable. Sorry
1322 about that. I encourage people to fix it and post the fixes.
1324 * Preliminary ELF and DWARF support
1326 GDB can read ELF object files on System V Release 4, and can handle
1327 debugging records for C, in DWARF format, in ELF files. This support
1328 is preliminary. If you bring up GDB on another SVR4 system, please
1329 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
1334 GDB now uses the latest `readline' library. One user-visible change
1335 is that two tabs will list possible command completions, which previously
1336 required typing M-? (meta-question mark, or ESC ?).
1340 The `stepi' bug that many of you noticed has been squashed.
1341 Many bugs in C++ have been handled. Many more remain to be handled.
1342 See the various ChangeLog files (primarily in gdb and bfd) for details.
1344 * State of the MIPS world (in case you wondered):
1346 GDB can understand the symbol tables emitted by the compilers
1347 supplied by most vendors of MIPS-based machines, including DEC. These
1348 symbol tables are in a format that essentially nobody else uses.
1350 Some versions of gcc come with an assembler post-processor called
1351 mips-tfile. This program is required if you want to do source-level
1352 debugging of gcc-compiled programs. I believe FSF does not ship
1353 mips-tfile with gcc version 1, but it will eventually come with gcc
1356 Debugging of g++ output remains a problem. g++ version 1.xx does not
1357 really support it at all. (If you're lucky, you should be able to get
1358 line numbers and stack traces to work, but no parameters or local
1359 variables.) With some work it should be possible to improve the
1362 When gcc version 2 is released, you will have somewhat better luck.
1363 However, even then you will get confusing results for inheritance and
1366 We will eventually provide full debugging of g++ output on
1367 DECstations. This will probably involve some kind of stabs-in-ecoff
1368 encapulation, but the details have not been worked out yet.
1371 *** Changes in GDB-4.2:
1373 * Improved configuration
1375 Only one copy of `configure' exists now, and it is not self-modifying.
1376 Porting BFD is simpler.
1380 The `step' and `next' commands now only stop at the first instruction
1381 of a source line. This prevents the multiple stops that used to occur
1382 in switch statements, for-loops, etc. `Step' continues to stop if a
1383 function that has debugging information is called within the line.
1387 Lots of small bugs fixed. More remain.
1389 * New host supported (not target)
1391 Intel 386 PC clone running Mach i386-none-mach
1394 *** Changes in GDB-4.1:
1396 * Multiple source language support
1398 GDB now has internal scaffolding to handle several source languages.
1399 It determines the type of each source file from its filename extension,
1400 and will switch expression parsing and number formatting to match the
1401 language of the function in the currently selected stack frame.
1402 You can also specifically set the language to be used, with
1403 `set language c' or `set language modula-2'.
1407 GDB now has preliminary support for the GNU Modula-2 compiler,
1408 currently under development at the State University of New York at
1409 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
1410 continue through the fall of 1991 and into 1992.
1412 Other Modula-2 compilers are currently not supported, and attempting to
1413 debug programs compiled with them will likely result in an error as the
1414 symbol table is read. Feel free to work on it, though!
1416 There are hooks in GDB for strict type checking and range checking,
1417 in the `Modula-2 philosophy', but they do not currently work.
1421 GDB can now write to executable and core files (e.g. patch
1422 a variable's value). You must turn this switch on, specify
1423 the file ("exec foo" or "core foo"), *then* modify it, e.g.
1424 by assigning a new value to a variable. Modifications take
1427 * Automatic SunOS shared library reading
1429 When you run your program, GDB automatically determines where its
1430 shared libraries (if any) have been loaded, and reads their symbols.
1431 The `share' command is no longer needed. This also works when
1432 examining core files.
1436 You can specify the number of lines that the `list' command shows.
1439 * New machines supported (host and target)
1441 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
1442 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
1443 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
1445 * New hosts supported (not targets)
1447 IBM RT/PC: romp-ibm-aix or rtpc
1449 * New targets supported (not hosts)
1451 AMD 29000 embedded with COFF a29k-none-coff
1452 AMD 29000 embedded with a.out a29k-none-aout
1453 Ultracomputer remote kernel debug a29k-nyu-kern
1455 * New remote interfaces
1461 *** Changes in GDB-4.0:
1465 Wide output is wrapped at good places to make the output more readable.
1467 Gdb now supports cross-debugging from a host machine of one type to a
1468 target machine of another type. Communication with the target system
1469 is over serial lines. The ``target'' command handles connecting to the
1470 remote system; the ``load'' command will download a program into the
1471 remote system. Serial stubs for the m68k and i386 are provided. Gdb
1472 also supports debugging of realtime processes running under VxWorks,
1473 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
1474 stub on the target system.
1476 New CPUs supported include the AMD 29000 and Intel 960.
1478 GDB now reads object files and symbol tables via a ``binary file''
1479 library, which allows a single copy of GDB to debug programs of multiple
1480 object file types such as a.out and coff.
1482 There is now a GDB reference card in "doc/refcard.tex". (Make targets
1483 refcard.dvi and refcard.ps are available to format it).
1486 * Control-Variable user interface simplified
1488 All variables that control the operation of the debugger can be set
1489 by the ``set'' command, and displayed by the ``show'' command.
1491 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
1492 ``Show prompt'' produces the response:
1493 Gdb's prompt is new-gdb=>.
1495 What follows are the NEW set commands. The command ``help set'' will
1496 print a complete list of old and new set commands. ``help set FOO''
1497 will give a longer description of the variable FOO. ``show'' will show
1498 all of the variable descriptions and their current settings.
1500 confirm on/off: Enables warning questions for operations that are
1501 hard to recover from, e.g. rerunning the program while
1502 it is already running. Default is ON.
1504 editing on/off: Enables EMACS style command line editing
1505 of input. Previous lines can be recalled with
1506 control-P, the current line can be edited with control-B,
1507 you can search for commands with control-R, etc.
1510 history filename NAME: NAME is where the gdb command history
1511 will be stored. The default is .gdb_history,
1512 or the value of the environment variable
1515 history size N: The size, in commands, of the command history. The
1516 default is 256, or the value of the environment variable
1519 history save on/off: If this value is set to ON, the history file will
1520 be saved after exiting gdb. If set to OFF, the
1521 file will not be saved. The default is OFF.
1523 history expansion on/off: If this value is set to ON, then csh-like
1524 history expansion will be performed on
1525 command line input. The default is OFF.
1527 radix N: Sets the default radix for input and output. It can be set
1528 to 8, 10, or 16. Note that the argument to "radix" is interpreted
1529 in the current radix, so "set radix 10" is always a no-op.
1531 height N: This integer value is the number of lines on a page. Default
1532 is 24, the current `stty rows'' setting, or the ``li#''
1533 setting from the termcap entry matching the environment
1536 width N: This integer value is the number of characters on a line.
1537 Default is 80, the current `stty cols'' setting, or the ``co#''
1538 setting from the termcap entry matching the environment
1541 Note: ``set screensize'' is obsolete. Use ``set height'' and
1542 ``set width'' instead.
1544 print address on/off: Print memory addresses in various command displays,
1545 such as stack traces and structure values. Gdb looks
1546 more ``symbolic'' if you turn this off; it looks more
1547 ``machine level'' with it on. Default is ON.
1549 print array on/off: Prettyprint arrays. New convenient format! Default
1552 print demangle on/off: Print C++ symbols in "source" form if on,
1555 print asm-demangle on/off: Same, for assembler level printouts
1558 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
1561 * Support for Epoch Environment.
1563 The epoch environment is a version of Emacs v18 with windowing. One
1564 new command, ``inspect'', is identical to ``print'', except that if you
1565 are running in the epoch environment, the value is printed in its own
1569 * Support for Shared Libraries
1571 GDB can now debug programs and core files that use SunOS shared libraries.
1572 Symbols from a shared library cannot be referenced
1573 before the shared library has been linked with the program (this
1574 happens after you type ``run'' and before the function main() is entered).
1575 At any time after this linking (including when examining core files
1576 from dynamically linked programs), gdb reads the symbols from each
1577 shared library when you type the ``sharedlibrary'' command.
1578 It can be abbreviated ``share''.
1580 sharedlibrary REGEXP: Load shared object library symbols for files
1581 matching a unix regular expression. No argument
1582 indicates to load symbols for all shared libraries.
1584 info sharedlibrary: Status of loaded shared libraries.
1589 A watchpoint stops execution of a program whenever the value of an
1590 expression changes. Checking for this slows down execution
1591 tremendously whenever you are in the scope of the expression, but is
1592 quite useful for catching tough ``bit-spreader'' or pointer misuse
1593 problems. Some machines such as the 386 have hardware for doing this
1594 more quickly, and future versions of gdb will use this hardware.
1596 watch EXP: Set a watchpoint (breakpoint) for an expression.
1598 info watchpoints: Information about your watchpoints.
1600 delete N: Deletes watchpoint number N (same as breakpoints).
1601 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
1602 enable N: Re-enables watchpoint number N (same as breakpoints).
1605 * C++ multiple inheritance
1607 When used with a GCC version 2 compiler, GDB supports multiple inheritance
1610 * C++ exception handling
1612 Gdb now supports limited C++ exception handling. Besides the existing
1613 ability to breakpoint on an exception handler, gdb can breakpoint on
1614 the raising of an exception (before the stack is peeled back to the
1617 catch FOO: If there is a FOO exception handler in the dynamic scope,
1618 set a breakpoint to catch exceptions which may be raised there.
1619 Multiple exceptions (``catch foo bar baz'') may be caught.
1621 info catch: Lists all exceptions which may be caught in the
1622 current stack frame.
1625 * Minor command changes
1627 The command ``call func (arg, arg, ...)'' now acts like the print
1628 command, except it does not print or save a value if the function's result
1629 is void. This is similar to dbx usage.
1631 The ``up'' and ``down'' commands now always print the frame they end up
1632 at; ``up-silently'' and `down-silently'' can be used in scripts to change
1633 frames without printing.
1635 * New directory command
1637 'dir' now adds directories to the FRONT of the source search path.
1638 The path starts off empty. Source files that contain debug information
1639 about the directory in which they were compiled can be found even
1640 with an empty path; Sun CC and GCC include this information. If GDB can't
1641 find your source file in the current directory, type "dir .".
1643 * Configuring GDB for compilation
1645 For normal use, type ``./configure host''. See README or gdb.texinfo
1648 GDB now handles cross debugging. If you are remotely debugging between
1649 two different machines, type ``./configure host -target=targ''.
1650 Host is the machine where GDB will run; targ is the machine
1651 where the program that you are debugging will run.