1 What has changed in GDB?
2 (Organized release by release)
4 *** Changes since GDB-4.15:
6 * Memory use reductions and statistics collection
8 We have begun to implement changes that reduce gdb's memory requirements
9 and to report statistics about memory usage. Try the "maint print statistics"
12 * New native configurations
14 Windows 95, Windows NT i[345]86-*-win32
18 ARM via RDP protocol arm-*-*
19 PowerPC via PPCBUG monitor powerpc{,le}-*-eabi*
20 PowerPC simulator powerpc{,le}-*-eabi if building with GCC
22 * Send break instead of ^C
24 The standard remote protocol now includes an option to send a break
25 rather than a ^C to the target in order to interrupt it. By default,
26 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
28 * Automatic tracking of dynamic object loading (HPUX and Solaris only at
31 By default GDB will automatically keep track of objects as they are
32 loaded and unloaded by the dynamic linker. By using the command
33 "set stop-on-solib-events 1" you can arrange for GDB to stop the
34 inferior when shared library events occur, thus allowing you to
35 set breakpoints in shared libraries which are explicitly loaded by
38 Note this feature does not work on hpux8. On hpux9 you must link
39 /usr/lib/end.o into your program. This feature should work automatically
42 * Recording and replaying remote debug sessions
44 If you set "remotelogfile" gdb will use that filename to make a
45 "recording" of a remote debug session which can be replayed back to
46 gdb using "gdbreplay". See gdbserver/README for details. This is
47 useful when you have a problem with gdb while doing remote debugging.
48 By making a recording of the session and sending it to the gdb
49 maintainers, it is possible to recreate your problem without access to
50 the remote hardware you are using.
52 *** Changes in GDB-4.15:
56 The symbol reader for AIX GDB now uses partial symbol tables. This
57 can greatly improve startup time, especially for large executables.
59 * Remote targets use caching
61 Remote targets now use a data cache to speed up communication with the
62 remote side. The data cache could lead to incorrect results because
63 it doesn't know about volatile variables, thus making it impossible to
64 debug targets which use memory mapped I/O devices. `set remotecache
65 off' turns the the data cache off.
67 * Remote targets may have threads
69 The standard remote protocol now includes support for multiple threads
70 in the target system, using new protocol commands 'H' and 'T'. See
71 gdb/remote.c for details.
75 If GDB is configured with `--enable-netrom', then it will include
76 support for the NetROM ROM emulator from XLNT Designs. The NetROM
77 acts as though it is a bank of ROM on the target board, but you can
78 write into it over the network. GDB's support consists only of
79 support for fast loading into the emulated ROM; to debug, you must use
80 another protocol, such as standard remote protocol. The usual
81 sequence is something like
83 target nrom <netrom-hostname>
85 target remote <netrom-hostname>:1235
89 GDB now includes support for the Apple Macintosh, as a host only. It
90 may be run as either an MPW tool or as a standalone application, and
91 it can debug through the serial port. All the usual GDB commands are
92 available, but to the target command, you must supply "serial" as the
93 device type instead of "/dev/ttyXX". See mpw-README in the main
94 directory for more information on how to build. The MPW configuration
95 scripts */mpw-config.in support only a few targets, and only the
96 mips-idt-ecoff target has been tested.
100 GDB configuration now uses autoconf. This is not user-visible,
101 but does simplify configuration and building.
105 GDB now supports hpux10.
107 *** Changes in GDB-4.14:
109 * New native configurations
111 x86 FreeBSD i[345]86-*-freebsd
112 x86 NetBSD i[345]86-*-netbsd
113 NS32k NetBSD ns32k-*-netbsd
114 Sparc NetBSD sparc-*-netbsd
118 A29K VxWorks a29k-*-vxworks
119 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
120 CPU32 EST-300 emulator m68*-*-est*
121 PowerPC ELF powerpc-*-elf
124 * Alpha OSF/1 support for procfs
126 GDB now supports procfs under OSF/1-2.x and higher, which makes it
127 possible to attach to running processes. As the mounting of the /proc
128 filesystem is optional on the Alpha, GDB automatically determines
129 the availability of /proc during startup. This can lead to problems
130 if /proc is unmounted after GDB has been started.
132 * Arguments to user-defined commands
134 User commands may accept up to 10 arguments separated by whitespace.
135 Arguments are accessed within the user command via $arg0..$arg9. A
138 print $arg0 + $arg1 + $arg2
140 To execute the command use:
143 Defines the command "adder" which prints the sum of its three arguments.
144 Note the arguments are text substitutions, so they may reference variables,
145 use complex expressions, or even perform inferior function calls.
147 * New `if' and `while' commands
149 This makes it possible to write more sophisticated user-defined
150 commands. Both commands take a single argument, which is the
151 expression to evaluate, and must be followed by the commands to
152 execute, one per line, if the expression is nonzero, the list being
153 terminated by the word `end'. The `if' command list may include an
154 `else' word, which causes the following commands to be executed only
155 if the expression is zero.
157 * Fortran source language mode
159 GDB now includes partial support for Fortran 77. It will recognize
160 Fortran programs and can evaluate a subset of Fortran expressions, but
161 variables and functions may not be handled correctly. GDB will work
162 with G77, but does not yet know much about symbols emitted by other
165 * Better HPUX support
167 Most debugging facilities now work on dynamic executables for HPPAs
168 running hpux9 or later. You can attach to running dynamically linked
169 processes, but by default the dynamic libraries will be read-only, so
170 for instance you won't be able to put breakpoints in them. To change
171 that behavior do the following before running the program:
177 This will cause the libraries to be mapped private and read-write.
178 To revert to the normal behavior, do this:
184 You cannot set breakpoints or examine data in the library until after
185 the library is loaded if the function/data symbols do not have
188 GDB can now also read debug symbols produced by the HP C compiler on
189 HPPAs (sorry, no C++, Fortran or 68k support).
191 * Target byte order now dynamically selectable
193 You can choose which byte order to use with a target system, via the
194 commands "set endian big" and "set endian little", and you can see the
195 current setting by using "show endian". You can also give the command
196 "set endian auto", in which case GDB will use the byte order
197 associated with the executable. Currently, only embedded MIPS
198 configurations support dynamic selection of target byte order.
200 * New DOS host serial code
202 This version uses DPMI interrupts to handle buffered I/O, so you
203 no longer need to run asynctsr when debugging boards connected to
206 *** Changes in GDB-4.13:
208 * New "complete" command
210 This lists all the possible completions for the rest of the line, if it
211 were to be given as a command itself. This is intended for use by emacs.
213 * Trailing space optional in prompt
215 "set prompt" no longer adds a space for you after the prompt you set. This
216 allows you to set a prompt which ends in a space or one that does not.
218 * Breakpoint hit counts
220 "info break" now displays a count of the number of times the breakpoint
221 has been hit. This is especially useful in conjunction with "ignore"; you
222 can ignore a large number of breakpoint hits, look at the breakpoint info
223 to see how many times the breakpoint was hit, then run again, ignoring one
224 less than that number, and this will get you quickly to the last hit of
227 * Ability to stop printing at NULL character
229 "set print null-stop" will cause GDB to stop printing the characters of
230 an array when the first NULL is encountered. This is useful when large
231 arrays actually contain only short strings.
233 * Shared library breakpoints
235 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
236 breakpoints in shared libraries before the executable is run.
238 * Hardware watchpoints
240 There is a new hardware breakpoint for the watch command for sparclite
241 targets. See gdb/sparclite/hw_breakpoint.note.
243 Hardware watchpoints are also now supported under Linux.
247 Annotations have been added. These are for use with graphical interfaces,
248 and are still experimental. Currently only gdba.el uses these.
250 * Improved Irix 5 support
252 GDB now works properly with Irix 5.2.
254 * Improved HPPA support
256 GDB now works properly with the latest GCC and GAS.
258 * New native configurations
260 Sequent PTX4 i[34]86-sequent-ptx4
261 HPPA running OSF/1 hppa*-*-osf*
262 Atari TT running SVR4 m68*-*-sysv4*
263 RS/6000 LynxOS rs6000-*-lynxos*
267 OS/9000 i[34]86-*-os9k
268 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
271 * Hitachi SH7000 and E7000-PC ICE support
273 There is now support for communicating with the Hitachi E7000-PC ICE.
274 This is available automatically when GDB is configured for the SH.
278 As usual, a variety of small fixes and improvements, both generic
279 and configuration-specific. See the ChangeLog for more detail.
281 *** Changes in GDB-4.12:
283 * Irix 5 is now supported
287 GDB-4.12 on the HPPA has a number of changes which make it unable
288 to debug the output from the currently released versions of GCC and
289 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
290 of GCC and GAS, versions of these tools designed to work with GDB-4.12
291 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
294 *** Changes in GDB-4.11:
296 * User visible changes:
300 The "set remotedebug" option is now consistent between the mips remote
301 target, remote targets using the gdb-specific protocol, UDI (AMD's
302 debug protocol for the 29k) and the 88k bug monitor. It is now an
303 integer specifying a debug level (normally 0 or 1, but 2 means more
304 debugging info for the mips target).
306 * DEC Alpha native support
308 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
309 debug info, but GDB works fairly well with the DEC compiler and should
310 work with a future GCC release. See the README file for a few
311 Alpha-specific notes.
313 * Preliminary thread implementation
315 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
317 * LynxOS native and target support for 386
319 This release has been hosted on LynxOS 2.2, and also can be configured
320 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
323 * Improvements in C++ mangling/demangling.
325 This release has much better g++ debugging, specifically in name
326 mangling/demangling, virtual function calls, print virtual table,
327 call methods, ...etc.
329 *** Changes in GDB-4.10:
331 * User visible changes:
333 Remote debugging using the GDB-specific (`target remote') protocol now
334 supports the `load' command. This is only useful if you have some
335 other way of getting the stub to the target system, and you can put it
336 somewhere in memory where it won't get clobbered by the download.
338 Filename completion now works.
340 When run under emacs mode, the "info line" command now causes the
341 arrow to point to the line specified. Also, "info line" prints
342 addresses in symbolic form (as well as hex).
344 All vxworks based targets now support a user settable option, called
345 vxworks-timeout. This option represents the number of seconds gdb
346 should wait for responses to rpc's. You might want to use this if
347 your vxworks target is, perhaps, a slow software simulator or happens
348 to be on the far side of a thin network line.
352 This release contains support for using a DEC alpha as a GDB host for
353 cross debugging. Native alpha debugging is not supported yet.
356 *** Changes in GDB-4.9:
360 This is the first GDB release which is accompanied by a matching testsuite.
361 The testsuite requires installation of dejagnu, which should be available
362 via ftp from most sites that carry GNU software.
366 'Cfront' style demangling has had its name changed to 'ARM' style, to
367 emphasize that it was written from the specifications in the C++ Annotated
368 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
369 disclaimers, it still generated too much confusion with users attempting to
370 use gdb with AT&T cfront.
374 GDB now uses a standard remote interface to a simulator library.
375 So far, the library contains simulators for the Zilog Z8001/2, the
376 Hitachi H8/300, H8/500 and Super-H.
378 * New targets supported
380 H8/300 simulator h8300-hitachi-hms or h8300hms
381 H8/500 simulator h8500-hitachi-hms or h8500hms
382 SH simulator sh-hitachi-hms or sh
383 Z8000 simulator z8k-zilog-none or z8ksim
384 IDT MIPS board over serial line mips-idt-ecoff
386 Cross-debugging to GO32 targets is supported. It requires a custom
387 version of the i386-stub.c module which is integrated with the
388 GO32 memory extender.
390 * New remote protocols
392 MIPS remote debugging protocol.
394 * New source languages supported
396 This version includes preliminary support for Chill, a Pascal like language
397 used by telecommunications companies. Chill support is also being integrated
398 into the GNU compiler, but we don't know when it will be publically available.
401 *** Changes in GDB-4.8:
403 * HP Precision Architecture supported
405 GDB now supports HP PA-RISC machines running HPUX. A preliminary
406 version of this support was available as a set of patches from the
407 University of Utah. GDB does not support debugging of programs
408 compiled with the HP compiler, because HP will not document their file
409 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
410 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
412 Many problems in the preliminary version have been fixed.
414 * Faster and better demangling
416 We have improved template demangling and fixed numerous bugs in the GNU style
417 demangler. It can now handle type modifiers such as `static' or `const'. Wide
418 character types (wchar_t) are now supported. Demangling of each symbol is now
419 only done once, and is cached when the symbol table for a file is read in.
420 This results in a small increase in memory usage for C programs, a moderate
421 increase in memory usage for C++ programs, and a fantastic speedup in
424 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
425 from the specifications in the Annotated Reference Manual, which AT&T's
426 compiler does not actually implement.
428 * G++ multiple inheritance compiler problem
430 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
431 inheritance lattices was reworked to properly discover ambiguities. We
432 recently found an example which causes this new algorithm to fail in a
433 very subtle way, producing bad debug information for those classes.
434 The file 'gcc.patch' (in this directory) can be applied to gcc to
435 circumvent the problem. A future GCC release will contain a complete
438 The previous G++ debug info problem (mentioned below for the gdb-4.7
439 release) is fixed in gcc version 2.3.2.
441 * Improved configure script
443 The `configure' script will now attempt to guess your system type if
444 you don't supply a host system type. The old scheme of supplying a
445 host system triplet is preferable over using this. All the magic is
446 done in the new `config.guess' script. Examine it for details.
448 We have also brought our configure script much more in line with the FSF's
449 version. It now supports the --with-xxx options. In particular,
450 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
451 The resulting GDB will not be able to read arbitrary object file formats --
452 only the format ``expected'' to be used on the configured target system.
453 We hope to make this the default in a future release.
455 * Documentation improvements
457 There's new internal documentation on how to modify GDB, and how to
458 produce clean changes to the code. We implore people to read it
459 before submitting changes.
461 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
462 M4 macros. The new texinfo.tex is provided in this release. Pre-built
463 `info' files are also provided. To build `info' files from scratch,
464 you will need the latest `makeinfo' release, which will be available in
465 a future texinfo-X.Y release.
467 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
468 We're not sure exactly which versions have this problem, but it has
469 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
470 or better. If that isn't possible, there is a patch in
471 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
476 GDB now supports array constants that can be used in expressions typed in by
477 the user. The syntax is `{element, element, ...}'. Ie: you can now type
478 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
481 The new directory `gdb/sparclite' contains a program that demonstrates
482 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
484 * New native hosts supported
486 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
487 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
489 * New targets supported
491 AMD 29k family via UDI a29k-amd-udi or udi29k
493 * New file formats supported
495 BFD now supports reading HP/PA-RISC executables (SOM file format?),
496 HPUX core files, and SCO 3.2v2 core files.
500 Attaching to processes now works again; thanks for the many bug reports.
502 We have also stomped on a bunch of core dumps caused by
503 printf_filtered("%s") problems.
505 We eliminated a copyright problem on the rpc and ptrace header files
506 for VxWorks, which was discovered at the last minute during the 4.7
507 release. You should now be able to build a VxWorks GDB.
509 You can now interrupt gdb while an attached process is running. This
510 will cause the attached process to stop, and give control back to GDB.
512 We fixed problems caused by using too many file descriptors
513 for reading symbols from object files and libraries. This was
514 especially a problem for programs that used many (~100) shared
517 The `step' command now only enters a subroutine if there is line number
518 information for the subroutine. Otherwise it acts like the `next'
519 command. Previously, `step' would enter subroutines if there was
520 any debugging information about the routine. This avoids problems
521 when using `cc -g1' on MIPS machines.
523 * Internal improvements
525 GDB's internal interfaces have been improved to make it easier to support
526 debugging of multiple languages in the future.
528 GDB now uses a common structure for symbol information internally.
529 Minimal symbols (derived from linkage symbols in object files), partial
530 symbols (from a quick scan of debug information), and full symbols
531 contain a common subset of information, making it easier to write
532 shared code that handles any of them.
534 * New command line options
536 We now accept --silent as an alias for --quiet.
540 The memory-mapped-malloc library is now licensed under the GNU Library
541 General Public License.
543 *** Changes in GDB-4.7:
545 * Host/native/target split
547 GDB has had some major internal surgery to untangle the support for
548 hosts and remote targets. Now, when you configure GDB for a remote
549 target, it will no longer load in all of the support for debugging
550 local programs on the host. When fully completed and tested, this will
551 ensure that arbitrary host/target combinations are possible.
553 The primary conceptual shift is to separate the non-portable code in
554 GDB into three categories. Host specific code is required any time GDB
555 is compiled on that host, regardless of the target. Target specific
556 code relates to the peculiarities of the target, but can be compiled on
557 any host. Native specific code is everything else: it can only be
558 built when the host and target are the same system. Child process
559 handling and core file support are two common `native' examples.
561 GDB's use of /proc for controlling Unix child processes is now cleaner.
562 It has been split out into a single module under the `target_ops' vector,
563 plus two native-dependent functions for each system that uses /proc.
565 * New hosts supported
567 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
568 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
569 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
571 * New targets supported
573 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
574 68030 and CPU32 m68030-*-*, m68332-*-*
576 * New native hosts supported
578 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
579 (386bsd is not well tested yet)
580 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
582 * New file formats supported
584 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
585 supports reading of `a.out.adobe' object files, which are an a.out
586 format extended with minimal information about multiple sections.
590 `show copying' is the same as the old `info copying'.
591 `show warranty' is the same as `info warrantee'.
592 These were renamed for consistency. The old commands continue to work.
594 `info handle' is a new alias for `info signals'.
596 You can now define pre-command hooks, which attach arbitrary command
597 scripts to any command. The commands in the hook will be executed
598 prior to the user's command. You can also create a hook which will be
599 executed whenever the program stops. See gdb.texinfo.
603 We now deal with Cfront style name mangling, and can even extract type
604 info from mangled symbols. GDB can automatically figure out which
605 symbol mangling style your C++ compiler uses.
607 Calling of methods and virtual functions has been improved as well.
611 The crash that occured when debugging Sun Ansi-C compiled binaries is
612 fixed. This was due to mishandling of the extra N_SO stabs output
615 We also finally got Ultrix 4.2 running in house, and fixed core file
616 support, with help from a dozen people on the net.
618 John M. Farrell discovered that the reason that single-stepping was so
619 slow on all of the Mips based platforms (primarily SGI and DEC) was
620 that we were trying to demangle and lookup a symbol used for internal
621 purposes on every instruction that was being stepped through. Changing
622 the name of that symbol so that it couldn't be mistaken for a C++
623 mangled symbol sped things up a great deal.
625 Rich Pixley sped up symbol lookups in general by getting much smarter
626 about when C++ symbol mangling is necessary. This should make symbol
627 completion (TAB on the command line) much faster. It's not as fast as
628 we'd like, but it's significantly faster than gdb-4.6.
632 A new user controllable variable 'call_scratch_address' can
633 specify the location of a scratch area to be used when GDB
634 calls a function in the target. This is necessary because the
635 usual method of putting the scratch area on the stack does not work
636 in systems that have separate instruction and data spaces.
638 We integrated changes to support the 29k UDI (Universal Debugger
639 Interface), but discovered at the last minute that we didn't have all
640 of the appropriate copyright paperwork. We are working with AMD to
641 resolve this, and hope to have it available soon.
645 We have sped up the remote serial line protocol, especially for targets
646 with lots of registers. It now supports a new `expedited status' ('T')
647 message which can be used in place of the existing 'S' status message.
648 This allows the remote stub to send only the registers that GDB
649 needs to make a quick decision about single-stepping or conditional
650 breakpoints, eliminating the need to fetch the entire register set for
651 each instruction being stepped through.
653 The GDB remote serial protocol now implements a write-through cache for
654 registers, only re-reading the registers if the target has run.
656 There is also a new remote serial stub for SPARC processors. You can
657 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
658 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
659 processor with a serial port.
663 Configure.in files have become much easier to read and modify. A new
664 `table driven' format makes it more obvious what configurations are
665 supported, and what files each one uses.
669 There is a new opcodes library which will eventually contain all of the
670 disassembly routines and opcode tables. At present, it only contains
671 Sparc and Z8000 routines. This will allow the assembler, debugger, and
672 disassembler (binutils/objdump) to share these routines.
674 The libiberty library is now copylefted under the GNU Library General
675 Public License. This allows more liberal use, and was done so libg++
676 can use it. This makes no difference to GDB, since the Library License
677 grants all the rights from the General Public License.
681 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
682 reference to the stabs symbol info used by the debugger. It is (as far
683 as we know) the only published document on this fascinating topic. We
684 encourage you to read it, compare it to the stabs information on your
685 system, and send improvements on the document in general (to
686 bug-gdb@prep.ai.mit.edu).
688 And, of course, many bugs have been fixed.
691 *** Changes in GDB-4.6:
693 * Better support for C++ function names
695 GDB now accepts as input the "demangled form" of C++ overloaded function
696 names and member function names, and can do command completion on such names
697 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
698 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
699 Make use of command completion, it is your friend.
701 GDB also now accepts a variety of C++ mangled symbol formats. They are
702 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
703 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
704 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
705 for the list of formats.
707 * G++ symbol mangling problem
709 Recent versions of gcc have a bug in how they emit debugging information for
710 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
711 directory) can be applied to gcc to fix the problem. Alternatively, if you
712 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
713 usual symptom is difficulty with setting breakpoints on methods. GDB complains
714 about the method being non-existent. (We believe that version 2.2.2 of GCC has
717 * New 'maintenance' command
719 All of the commands related to hacking GDB internals have been moved out of
720 the main command set, and now live behind the 'maintenance' command. This
721 can also be abbreviated as 'mt'. The following changes were made:
723 dump-me -> maintenance dump-me
724 info all-breakpoints -> maintenance info breakpoints
725 printmsyms -> maintenance print msyms
726 printobjfiles -> maintenance print objfiles
727 printpsyms -> maintenance print psymbols
728 printsyms -> maintenance print symbols
730 The following commands are new:
732 maintenance demangle Call internal GDB demangler routine to
733 demangle a C++ link name and prints the result.
734 maintenance print type Print a type chain for a given symbol
736 * Change to .gdbinit file processing
738 We now read the $HOME/.gdbinit file before processing the argv arguments
739 (e.g. reading symbol files or core files). This allows global parameters to
740 be set, which will apply during the symbol reading. The ./.gdbinit is still
741 read after argv processing.
743 * New hosts supported
745 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
747 Linux support i386-unknown-linux or linux
749 We are also including code to support the HP/PA running BSD and HPUX. This
750 is almost guaranteed not to work, as we didn't have time to test or build it
751 for this release. We are including it so that the more adventurous (or
752 masochistic) of you can play with it. We also had major problems with the
753 fact that the compiler that we got from HP doesn't support the -g option.
756 * New targets supported
758 Hitachi H8/300 h8300-hitachi-hms or h8300hms
760 * More smarts about finding #include files
762 GDB now remembers the compilation directory for all include files, and for
763 all files from which C is generated (like yacc and lex sources). This
764 greatly improves GDB's ability to find yacc/lex sources, and include files,
765 especially if you are debugging your program from a directory different from
766 the one that contains your sources.
768 We also fixed a bug which caused difficulty with listing and setting
769 breakpoints in include files which contain C code. (In the past, you had to
770 try twice in order to list an include file that you hadn't looked at before.)
772 * Interesting infernals change
774 GDB now deals with arbitrary numbers of sections, where the symbols for each
775 section must be relocated relative to that section's landing place in the
776 target's address space. This work was needed to support ELF with embedded
777 stabs used by Solaris-2.0.
779 * Bug fixes (of course!)
781 There have been loads of fixes for the following things:
782 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
783 i960, stabs, DOS(GO32), procfs, etc...
785 See the ChangeLog for details.
787 *** Changes in GDB-4.5:
789 * New machines supported (host and target)
791 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
793 SGI Irix-4.x mips-sgi-irix4 or iris4
797 GDB now uses a new memory manager called mmalloc, based on gmalloc.
798 Mmalloc is capable of handling mutiple heaps of memory. It is also
799 capable of saving a heap to a file, and then mapping it back in later.
800 This can be used to greatly speedup the startup of GDB by using a
801 pre-parsed symbol table which lives in a mmalloc managed heap. For
802 more details, please read mmalloc/mmalloc.texi.
806 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
807 'help info proc' for details.
809 * MIPS ecoff symbol table format
811 The code that reads MIPS symbol table format is now supported on all hosts.
812 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
815 * File name changes for MS-DOS
817 Many files in the config directories have been renamed to make it easier to
818 support GDB on MS-DOSe systems (which have very restrictive file name
819 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
820 environment) is close to working but has some remaining problems. Note
821 that debugging of DOS programs is not supported, due to limitations
822 in the ``operating system'', but it can be used to host cross-debugging.
824 * Cross byte order fixes
826 Many fixes have been made to support cross debugging of Sparc and MIPS
827 targets from hosts whose byte order differs.
829 * New -mapped and -readnow options
831 If memory-mapped files are available on your system through the 'mmap'
832 system call, you can use the -mapped option on the `file' or
833 `symbol-file' commands to cause GDB to write the symbols from your
834 program into a reusable file. If the program you are debugging is
835 called `/path/fred', the mapped symbol file will be `./fred.syms'.
836 Future GDB debugging sessions will notice the presence of this file,
837 and will quickly map in symbol information from it, rather than reading
838 the symbol table from the executable program. Using the '-mapped'
839 option in a GDB `file' or `symbol-file' command has the same effect as
840 starting GDB with the '-mapped' command-line option.
842 You can cause GDB to read the entire symbol table immediately by using
843 the '-readnow' option with any of the commands that load symbol table
844 information (or on the GDB command line). This makes the command
845 slower, but makes future operations faster.
847 The -mapped and -readnow options are typically combined in order to
848 build a `fred.syms' file that contains complete symbol information.
849 A simple GDB invocation to do nothing but build a `.syms' file for future
852 gdb -batch -nx -mapped -readnow programname
854 The `.syms' file is specific to the host machine on which GDB is run.
855 It holds an exact image of GDB's internal symbol table. It cannot be
856 shared across multiple host platforms.
860 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
861 siglongjmp() without losing control. This feature has not yet been ported to
862 all systems. It currently works on many 386 platforms, all MIPS-based
863 platforms (SGI, DECstation, etc), and Sun3/4.
867 Preliminary work has been put in to support the new Solaris OS from Sun. At
868 this time, it can control and debug processes, but it is not capable of
873 As always, many many bug fixes. The major areas were with g++, and mipsread.
874 People using the MIPS-based platforms should experience fewer mysterious
875 crashes and trashed symbol tables.
877 *** Changes in GDB-4.4:
879 * New machines supported (host and target)
881 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
883 BSD Reno on Vax vax-dec-bsd
884 Ultrix on Vax vax-dec-ultrix
886 * New machines supported (target)
888 AMD 29000 embedded, using EBMON a29k-none-none
892 GDB continues to improve its handling of C++. `References' work better.
893 The demangler has also been improved, and now deals with symbols mangled as
894 per the Annotated C++ Reference Guide.
896 GDB also now handles `stabs' symbol information embedded in MIPS
897 `ecoff' symbol tables. Since the ecoff format was not easily
898 extensible to handle new languages such as C++, this appeared to be a
899 good way to put C++ debugging info into MIPS binaries. This option
900 will be supported in the GNU C compiler, version 2, when it is
903 * New features for SVR4
905 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
906 shared libraries. Debugging dynamically linked programs should present
907 only minor differences from debugging statically linked programs.
909 The `info proc' command will print out information about any process
910 on an SVR4 system (including the one you are debugging). At the moment,
911 it prints the address mappings of the process.
913 If you bring up GDB on another SVR4 system, please send mail to
914 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
916 * Better dynamic linking support in SunOS
918 Reading symbols from shared libraries which contain debugging symbols
919 now works properly. However, there remain issues such as automatic
920 skipping of `transfer vector' code during function calls, which
921 make it harder to debug code in a shared library, than to debug the
922 same code linked statically.
926 GDB is now using the latest `getopt' routines from the FSF. This
927 version accepts the -- prefix for options with long names. GDB will
928 continue to accept the old forms (-option and +option) as well.
929 Various single letter abbreviations for options have been explicity
930 added to the option table so that they won't get overshadowed in the
931 future by other options that begin with the same letter.
935 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
936 Many assorted bugs have been handled. Many more remain to be handled.
937 See the various ChangeLog files (primarily in gdb and bfd) for details.
940 *** Changes in GDB-4.3:
942 * New machines supported (host and target)
944 Amiga 3000 running Amix m68k-cbm-svr4 or amix
945 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
946 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
948 * Almost SCO Unix support
950 We had hoped to support:
951 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
952 (except for core file support), but we discovered very late in the release
953 that it has problems with process groups that render gdb unusable. Sorry
954 about that. I encourage people to fix it and post the fixes.
956 * Preliminary ELF and DWARF support
958 GDB can read ELF object files on System V Release 4, and can handle
959 debugging records for C, in DWARF format, in ELF files. This support
960 is preliminary. If you bring up GDB on another SVR4 system, please
961 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
966 GDB now uses the latest `readline' library. One user-visible change
967 is that two tabs will list possible command completions, which previously
968 required typing M-? (meta-question mark, or ESC ?).
972 The `stepi' bug that many of you noticed has been squashed.
973 Many bugs in C++ have been handled. Many more remain to be handled.
974 See the various ChangeLog files (primarily in gdb and bfd) for details.
976 * State of the MIPS world (in case you wondered):
978 GDB can understand the symbol tables emitted by the compilers
979 supplied by most vendors of MIPS-based machines, including DEC. These
980 symbol tables are in a format that essentially nobody else uses.
982 Some versions of gcc come with an assembler post-processor called
983 mips-tfile. This program is required if you want to do source-level
984 debugging of gcc-compiled programs. I believe FSF does not ship
985 mips-tfile with gcc version 1, but it will eventually come with gcc
988 Debugging of g++ output remains a problem. g++ version 1.xx does not
989 really support it at all. (If you're lucky, you should be able to get
990 line numbers and stack traces to work, but no parameters or local
991 variables.) With some work it should be possible to improve the
994 When gcc version 2 is released, you will have somewhat better luck.
995 However, even then you will get confusing results for inheritance and
998 We will eventually provide full debugging of g++ output on
999 DECstations. This will probably involve some kind of stabs-in-ecoff
1000 encapulation, but the details have not been worked out yet.
1003 *** Changes in GDB-4.2:
1005 * Improved configuration
1007 Only one copy of `configure' exists now, and it is not self-modifying.
1008 Porting BFD is simpler.
1012 The `step' and `next' commands now only stop at the first instruction
1013 of a source line. This prevents the multiple stops that used to occur
1014 in switch statements, for-loops, etc. `Step' continues to stop if a
1015 function that has debugging information is called within the line.
1019 Lots of small bugs fixed. More remain.
1021 * New host supported (not target)
1023 Intel 386 PC clone running Mach i386-none-mach
1026 *** Changes in GDB-4.1:
1028 * Multiple source language support
1030 GDB now has internal scaffolding to handle several source languages.
1031 It determines the type of each source file from its filename extension,
1032 and will switch expression parsing and number formatting to match the
1033 language of the function in the currently selected stack frame.
1034 You can also specifically set the language to be used, with
1035 `set language c' or `set language modula-2'.
1039 GDB now has preliminary support for the GNU Modula-2 compiler,
1040 currently under development at the State University of New York at
1041 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
1042 continue through the fall of 1991 and into 1992.
1044 Other Modula-2 compilers are currently not supported, and attempting to
1045 debug programs compiled with them will likely result in an error as the
1046 symbol table is read. Feel free to work on it, though!
1048 There are hooks in GDB for strict type checking and range checking,
1049 in the `Modula-2 philosophy', but they do not currently work.
1053 GDB can now write to executable and core files (e.g. patch
1054 a variable's value). You must turn this switch on, specify
1055 the file ("exec foo" or "core foo"), *then* modify it, e.g.
1056 by assigning a new value to a variable. Modifications take
1059 * Automatic SunOS shared library reading
1061 When you run your program, GDB automatically determines where its
1062 shared libraries (if any) have been loaded, and reads their symbols.
1063 The `share' command is no longer needed. This also works when
1064 examining core files.
1068 You can specify the number of lines that the `list' command shows.
1071 * New machines supported (host and target)
1073 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
1074 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
1075 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
1077 * New hosts supported (not targets)
1079 IBM RT/PC: romp-ibm-aix or rtpc
1081 * New targets supported (not hosts)
1083 AMD 29000 embedded with COFF a29k-none-coff
1084 AMD 29000 embedded with a.out a29k-none-aout
1085 Ultracomputer remote kernel debug a29k-nyu-kern
1087 * New remote interfaces
1093 *** Changes in GDB-4.0:
1097 Wide output is wrapped at good places to make the output more readable.
1099 Gdb now supports cross-debugging from a host machine of one type to a
1100 target machine of another type. Communication with the target system
1101 is over serial lines. The ``target'' command handles connecting to the
1102 remote system; the ``load'' command will download a program into the
1103 remote system. Serial stubs for the m68k and i386 are provided. Gdb
1104 also supports debugging of realtime processes running under VxWorks,
1105 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
1106 stub on the target system.
1108 New CPUs supported include the AMD 29000 and Intel 960.
1110 GDB now reads object files and symbol tables via a ``binary file''
1111 library, which allows a single copy of GDB to debug programs of multiple
1112 object file types such as a.out and coff.
1114 There is now a GDB reference card in "doc/refcard.tex". (Make targets
1115 refcard.dvi and refcard.ps are available to format it).
1118 * Control-Variable user interface simplified
1120 All variables that control the operation of the debugger can be set
1121 by the ``set'' command, and displayed by the ``show'' command.
1123 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
1124 ``Show prompt'' produces the response:
1125 Gdb's prompt is new-gdb=>.
1127 What follows are the NEW set commands. The command ``help set'' will
1128 print a complete list of old and new set commands. ``help set FOO''
1129 will give a longer description of the variable FOO. ``show'' will show
1130 all of the variable descriptions and their current settings.
1132 confirm on/off: Enables warning questions for operations that are
1133 hard to recover from, e.g. rerunning the program while
1134 it is already running. Default is ON.
1136 editing on/off: Enables EMACS style command line editing
1137 of input. Previous lines can be recalled with
1138 control-P, the current line can be edited with control-B,
1139 you can search for commands with control-R, etc.
1142 history filename NAME: NAME is where the gdb command history
1143 will be stored. The default is .gdb_history,
1144 or the value of the environment variable
1147 history size N: The size, in commands, of the command history. The
1148 default is 256, or the value of the environment variable
1151 history save on/off: If this value is set to ON, the history file will
1152 be saved after exiting gdb. If set to OFF, the
1153 file will not be saved. The default is OFF.
1155 history expansion on/off: If this value is set to ON, then csh-like
1156 history expansion will be performed on
1157 command line input. The default is OFF.
1159 radix N: Sets the default radix for input and output. It can be set
1160 to 8, 10, or 16. Note that the argument to "radix" is interpreted
1161 in the current radix, so "set radix 10" is always a no-op.
1163 height N: This integer value is the number of lines on a page. Default
1164 is 24, the current `stty rows'' setting, or the ``li#''
1165 setting from the termcap entry matching the environment
1168 width N: This integer value is the number of characters on a line.
1169 Default is 80, the current `stty cols'' setting, or the ``co#''
1170 setting from the termcap entry matching the environment
1173 Note: ``set screensize'' is obsolete. Use ``set height'' and
1174 ``set width'' instead.
1176 print address on/off: Print memory addresses in various command displays,
1177 such as stack traces and structure values. Gdb looks
1178 more ``symbolic'' if you turn this off; it looks more
1179 ``machine level'' with it on. Default is ON.
1181 print array on/off: Prettyprint arrays. New convenient format! Default
1184 print demangle on/off: Print C++ symbols in "source" form if on,
1187 print asm-demangle on/off: Same, for assembler level printouts
1190 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
1193 * Support for Epoch Environment.
1195 The epoch environment is a version of Emacs v18 with windowing. One
1196 new command, ``inspect'', is identical to ``print'', except that if you
1197 are running in the epoch environment, the value is printed in its own
1201 * Support for Shared Libraries
1203 GDB can now debug programs and core files that use SunOS shared libraries.
1204 Symbols from a shared library cannot be referenced
1205 before the shared library has been linked with the program (this
1206 happens after you type ``run'' and before the function main() is entered).
1207 At any time after this linking (including when examining core files
1208 from dynamically linked programs), gdb reads the symbols from each
1209 shared library when you type the ``sharedlibrary'' command.
1210 It can be abbreviated ``share''.
1212 sharedlibrary REGEXP: Load shared object library symbols for files
1213 matching a unix regular expression. No argument
1214 indicates to load symbols for all shared libraries.
1216 info sharedlibrary: Status of loaded shared libraries.
1221 A watchpoint stops execution of a program whenever the value of an
1222 expression changes. Checking for this slows down execution
1223 tremendously whenever you are in the scope of the expression, but is
1224 quite useful for catching tough ``bit-spreader'' or pointer misuse
1225 problems. Some machines such as the 386 have hardware for doing this
1226 more quickly, and future versions of gdb will use this hardware.
1228 watch EXP: Set a watchpoint (breakpoint) for an expression.
1230 info watchpoints: Information about your watchpoints.
1232 delete N: Deletes watchpoint number N (same as breakpoints).
1233 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
1234 enable N: Re-enables watchpoint number N (same as breakpoints).
1237 * C++ multiple inheritance
1239 When used with a GCC version 2 compiler, GDB supports multiple inheritance
1242 * C++ exception handling
1244 Gdb now supports limited C++ exception handling. Besides the existing
1245 ability to breakpoint on an exception handler, gdb can breakpoint on
1246 the raising of an exception (before the stack is peeled back to the
1249 catch FOO: If there is a FOO exception handler in the dynamic scope,
1250 set a breakpoint to catch exceptions which may be raised there.
1251 Multiple exceptions (``catch foo bar baz'') may be caught.
1253 info catch: Lists all exceptions which may be caught in the
1254 current stack frame.
1257 * Minor command changes
1259 The command ``call func (arg, arg, ...)'' now acts like the print
1260 command, except it does not print or save a value if the function's result
1261 is void. This is similar to dbx usage.
1263 The ``up'' and ``down'' commands now always print the frame they end up
1264 at; ``up-silently'' and `down-silently'' can be used in scripts to change
1265 frames without printing.
1267 * New directory command
1269 'dir' now adds directories to the FRONT of the source search path.
1270 The path starts off empty. Source files that contain debug information
1271 about the directory in which they were compiled can be found even
1272 with an empty path; Sun CC and GCC include this information. If GDB can't
1273 find your source file in the current directory, type "dir .".
1275 * Configuring GDB for compilation
1277 For normal use, type ``./configure host''. See README or gdb.texinfo
1280 GDB now handles cross debugging. If you are remotely debugging between
1281 two different machines, type ``./configure host -target=targ''.
1282 Host is the machine where GDB will run; targ is the machine
1283 where the program that you are debugging will run.
projects / deliverable / binutils-gdb.git / blob