1 What has changed in GDB?
2 (Organized release by release)
4 *** Changes since GDB-4.16:
6 * New native configurations
8 Alpha Linux alpha-*-linux*
10 *** Changes in GDB-4.16:
12 * New native configurations
14 Windows 95, x86 Windows NT i[345]86-*-cygwin32
15 M68K NetBSD m68k-*-netbsd*
16 PowerPC AIX 4.x powerpc-*-aix*
17 PowerPC MacOS powerpc-*-macos*
18 PowerPC Windows NT powerpcle-*-cygwin32
19 RS/6000 AIX 4.x rs6000-*-aix4*
23 ARM with RDP protocol arm-*-*
24 I960 with MON960 i960-*-coff
25 MIPS VxWorks mips*-*-vxworks*
26 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
27 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
29 Matra Sparclet sparclet-*-*
33 The powerpc-eabi configuration now includes the PSIM simulator,
34 contributed by Andrew Cagney, with assistance from Mike Meissner.
35 PSIM is a very elaborate model of the PowerPC, including not only
36 basic instruction set execution, but also details of execution unit
37 performance and I/O hardware. See sim/ppc/README for more details.
41 GDB now works with Solaris 2.5.
43 * Windows 95/NT native
45 GDB will now work as a native debugger on Windows 95 and Windows NT.
46 To build it from source, you must use the "gnu-win32" environment,
47 which uses a DLL to emulate enough of Unix to run the GNU tools.
48 Further information, binaries, and sources are available at
49 ftp.cygnus.com, under pub/gnu-win32.
53 If a user-defined command includes the command `dont-repeat', then the
54 command will not be repeated if the user just types return. This is
55 useful if the command is time-consuming to run, so that accidental
56 extra keystrokes don't run the same command many times.
58 * Send break instead of ^C
60 The standard remote protocol now includes an option to send a break
61 rather than a ^C to the target in order to interrupt it. By default,
62 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
64 * Remote protocol timeout
66 The standard remote protocol includes a new variable `remotetimeout'
67 that allows you to set the number of seconds before GDB gives up trying
68 to read from the target. The default value is 2.
70 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
72 By default GDB will automatically keep track of objects as they are
73 loaded and unloaded by the dynamic linker. By using the command `set
74 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
75 when shared library events occur, thus allowing you to set breakpoints
76 in shared libraries which are explicitly loaded by the inferior.
78 Note this feature does not work on hpux8. On hpux9 you must link
79 /usr/lib/end.o into your program. This feature should work
80 automatically on hpux10.
82 * Irix 5.x hardware watchpoint support
84 Irix 5 configurations now support the use of hardware watchpoints.
86 * Mips protocol "SYN garbage limit"
88 When debugging a Mips target using the `target mips' protocol, you
89 may set the number of characters that GDB will ignore by setting
90 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
91 every character. The default value is 1050.
93 * Recording and replaying remote debug sessions
95 If you set `remotelogfile' to the name of a file, gdb will write to it
96 a recording of a remote debug session. This recording may then be
97 replayed back to gdb using "gdbreplay". See gdbserver/README for
98 details. This is useful when you have a problem with GDB while doing
99 remote debugging; you can make a recording of the session and send it
100 to someone else, who can then recreate the problem.
102 * Speedups for remote debugging
104 GDB includes speedups for downloading and stepping MIPS systems using
105 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
106 and more efficient S-record downloading.
108 * Memory use reductions and statistics collection
110 GDB now uses less memory and reports statistics about memory usage.
111 Try the `maint print statistics' command, for example.
113 *** Changes in GDB-4.15:
117 The symbol reader for AIX GDB now uses partial symbol tables. This
118 can greatly improve startup time, especially for large executables.
120 * Remote targets use caching
122 Remote targets now use a data cache to speed up communication with the
123 remote side. The data cache could lead to incorrect results because
124 it doesn't know about volatile variables, thus making it impossible to
125 debug targets which use memory mapped I/O devices. `set remotecache
126 off' turns the the data cache off.
128 * Remote targets may have threads
130 The standard remote protocol now includes support for multiple threads
131 in the target system, using new protocol commands 'H' and 'T'. See
132 gdb/remote.c for details.
136 If GDB is configured with `--enable-netrom', then it will include
137 support for the NetROM ROM emulator from XLNT Designs. The NetROM
138 acts as though it is a bank of ROM on the target board, but you can
139 write into it over the network. GDB's support consists only of
140 support for fast loading into the emulated ROM; to debug, you must use
141 another protocol, such as standard remote protocol. The usual
142 sequence is something like
144 target nrom <netrom-hostname>
146 target remote <netrom-hostname>:1235
150 GDB now includes support for the Apple Macintosh, as a host only. It
151 may be run as either an MPW tool or as a standalone application, and
152 it can debug through the serial port. All the usual GDB commands are
153 available, but to the target command, you must supply "serial" as the
154 device type instead of "/dev/ttyXX". See mpw-README in the main
155 directory for more information on how to build. The MPW configuration
156 scripts */mpw-config.in support only a few targets, and only the
157 mips-idt-ecoff target has been tested.
161 GDB configuration now uses autoconf. This is not user-visible,
162 but does simplify configuration and building.
166 GDB now supports hpux10.
168 *** Changes in GDB-4.14:
170 * New native configurations
172 x86 FreeBSD i[345]86-*-freebsd
173 x86 NetBSD i[345]86-*-netbsd
174 NS32k NetBSD ns32k-*-netbsd
175 Sparc NetBSD sparc-*-netbsd
179 A29K VxWorks a29k-*-vxworks
180 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
181 CPU32 EST-300 emulator m68*-*-est*
182 PowerPC ELF powerpc-*-elf
185 * Alpha OSF/1 support for procfs
187 GDB now supports procfs under OSF/1-2.x and higher, which makes it
188 possible to attach to running processes. As the mounting of the /proc
189 filesystem is optional on the Alpha, GDB automatically determines
190 the availability of /proc during startup. This can lead to problems
191 if /proc is unmounted after GDB has been started.
193 * Arguments to user-defined commands
195 User commands may accept up to 10 arguments separated by whitespace.
196 Arguments are accessed within the user command via $arg0..$arg9. A
199 print $arg0 + $arg1 + $arg2
201 To execute the command use:
204 Defines the command "adder" which prints the sum of its three arguments.
205 Note the arguments are text substitutions, so they may reference variables,
206 use complex expressions, or even perform inferior function calls.
208 * New `if' and `while' commands
210 This makes it possible to write more sophisticated user-defined
211 commands. Both commands take a single argument, which is the
212 expression to evaluate, and must be followed by the commands to
213 execute, one per line, if the expression is nonzero, the list being
214 terminated by the word `end'. The `if' command list may include an
215 `else' word, which causes the following commands to be executed only
216 if the expression is zero.
218 * Fortran source language mode
220 GDB now includes partial support for Fortran 77. It will recognize
221 Fortran programs and can evaluate a subset of Fortran expressions, but
222 variables and functions may not be handled correctly. GDB will work
223 with G77, but does not yet know much about symbols emitted by other
226 * Better HPUX support
228 Most debugging facilities now work on dynamic executables for HPPAs
229 running hpux9 or later. You can attach to running dynamically linked
230 processes, but by default the dynamic libraries will be read-only, so
231 for instance you won't be able to put breakpoints in them. To change
232 that behavior do the following before running the program:
238 This will cause the libraries to be mapped private and read-write.
239 To revert to the normal behavior, do this:
245 You cannot set breakpoints or examine data in the library until after
246 the library is loaded if the function/data symbols do not have
249 GDB can now also read debug symbols produced by the HP C compiler on
250 HPPAs (sorry, no C++, Fortran or 68k support).
252 * Target byte order now dynamically selectable
254 You can choose which byte order to use with a target system, via the
255 commands "set endian big" and "set endian little", and you can see the
256 current setting by using "show endian". You can also give the command
257 "set endian auto", in which case GDB will use the byte order
258 associated with the executable. Currently, only embedded MIPS
259 configurations support dynamic selection of target byte order.
261 * New DOS host serial code
263 This version uses DPMI interrupts to handle buffered I/O, so you
264 no longer need to run asynctsr when debugging boards connected to
267 *** Changes in GDB-4.13:
269 * New "complete" command
271 This lists all the possible completions for the rest of the line, if it
272 were to be given as a command itself. This is intended for use by emacs.
274 * Trailing space optional in prompt
276 "set prompt" no longer adds a space for you after the prompt you set. This
277 allows you to set a prompt which ends in a space or one that does not.
279 * Breakpoint hit counts
281 "info break" now displays a count of the number of times the breakpoint
282 has been hit. This is especially useful in conjunction with "ignore"; you
283 can ignore a large number of breakpoint hits, look at the breakpoint info
284 to see how many times the breakpoint was hit, then run again, ignoring one
285 less than that number, and this will get you quickly to the last hit of
288 * Ability to stop printing at NULL character
290 "set print null-stop" will cause GDB to stop printing the characters of
291 an array when the first NULL is encountered. This is useful when large
292 arrays actually contain only short strings.
294 * Shared library breakpoints
296 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
297 breakpoints in shared libraries before the executable is run.
299 * Hardware watchpoints
301 There is a new hardware breakpoint for the watch command for sparclite
302 targets. See gdb/sparclite/hw_breakpoint.note.
304 Hardware watchpoints are also now supported under Linux.
308 Annotations have been added. These are for use with graphical interfaces,
309 and are still experimental. Currently only gdba.el uses these.
311 * Improved Irix 5 support
313 GDB now works properly with Irix 5.2.
315 * Improved HPPA support
317 GDB now works properly with the latest GCC and GAS.
319 * New native configurations
321 Sequent PTX4 i[34]86-sequent-ptx4
322 HPPA running OSF/1 hppa*-*-osf*
323 Atari TT running SVR4 m68*-*-sysv4*
324 RS/6000 LynxOS rs6000-*-lynxos*
328 OS/9000 i[34]86-*-os9k
329 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
332 * Hitachi SH7000 and E7000-PC ICE support
334 There is now support for communicating with the Hitachi E7000-PC ICE.
335 This is available automatically when GDB is configured for the SH.
339 As usual, a variety of small fixes and improvements, both generic
340 and configuration-specific. See the ChangeLog for more detail.
342 *** Changes in GDB-4.12:
344 * Irix 5 is now supported
348 GDB-4.12 on the HPPA has a number of changes which make it unable
349 to debug the output from the currently released versions of GCC and
350 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
351 of GCC and GAS, versions of these tools designed to work with GDB-4.12
352 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
355 *** Changes in GDB-4.11:
357 * User visible changes:
361 The "set remotedebug" option is now consistent between the mips remote
362 target, remote targets using the gdb-specific protocol, UDI (AMD's
363 debug protocol for the 29k) and the 88k bug monitor. It is now an
364 integer specifying a debug level (normally 0 or 1, but 2 means more
365 debugging info for the mips target).
367 * DEC Alpha native support
369 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
370 debug info, but GDB works fairly well with the DEC compiler and should
371 work with a future GCC release. See the README file for a few
372 Alpha-specific notes.
374 * Preliminary thread implementation
376 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
378 * LynxOS native and target support for 386
380 This release has been hosted on LynxOS 2.2, and also can be configured
381 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
384 * Improvements in C++ mangling/demangling.
386 This release has much better g++ debugging, specifically in name
387 mangling/demangling, virtual function calls, print virtual table,
388 call methods, ...etc.
390 *** Changes in GDB-4.10:
392 * User visible changes:
394 Remote debugging using the GDB-specific (`target remote') protocol now
395 supports the `load' command. This is only useful if you have some
396 other way of getting the stub to the target system, and you can put it
397 somewhere in memory where it won't get clobbered by the download.
399 Filename completion now works.
401 When run under emacs mode, the "info line" command now causes the
402 arrow to point to the line specified. Also, "info line" prints
403 addresses in symbolic form (as well as hex).
405 All vxworks based targets now support a user settable option, called
406 vxworks-timeout. This option represents the number of seconds gdb
407 should wait for responses to rpc's. You might want to use this if
408 your vxworks target is, perhaps, a slow software simulator or happens
409 to be on the far side of a thin network line.
413 This release contains support for using a DEC alpha as a GDB host for
414 cross debugging. Native alpha debugging is not supported yet.
417 *** Changes in GDB-4.9:
421 This is the first GDB release which is accompanied by a matching testsuite.
422 The testsuite requires installation of dejagnu, which should be available
423 via ftp from most sites that carry GNU software.
427 'Cfront' style demangling has had its name changed to 'ARM' style, to
428 emphasize that it was written from the specifications in the C++ Annotated
429 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
430 disclaimers, it still generated too much confusion with users attempting to
431 use gdb with AT&T cfront.
435 GDB now uses a standard remote interface to a simulator library.
436 So far, the library contains simulators for the Zilog Z8001/2, the
437 Hitachi H8/300, H8/500 and Super-H.
439 * New targets supported
441 H8/300 simulator h8300-hitachi-hms or h8300hms
442 H8/500 simulator h8500-hitachi-hms or h8500hms
443 SH simulator sh-hitachi-hms or sh
444 Z8000 simulator z8k-zilog-none or z8ksim
445 IDT MIPS board over serial line mips-idt-ecoff
447 Cross-debugging to GO32 targets is supported. It requires a custom
448 version of the i386-stub.c module which is integrated with the
449 GO32 memory extender.
451 * New remote protocols
453 MIPS remote debugging protocol.
455 * New source languages supported
457 This version includes preliminary support for Chill, a Pascal like language
458 used by telecommunications companies. Chill support is also being integrated
459 into the GNU compiler, but we don't know when it will be publically available.
462 *** Changes in GDB-4.8:
464 * HP Precision Architecture supported
466 GDB now supports HP PA-RISC machines running HPUX. A preliminary
467 version of this support was available as a set of patches from the
468 University of Utah. GDB does not support debugging of programs
469 compiled with the HP compiler, because HP will not document their file
470 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
471 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
473 Many problems in the preliminary version have been fixed.
475 * Faster and better demangling
477 We have improved template demangling and fixed numerous bugs in the GNU style
478 demangler. It can now handle type modifiers such as `static' or `const'. Wide
479 character types (wchar_t) are now supported. Demangling of each symbol is now
480 only done once, and is cached when the symbol table for a file is read in.
481 This results in a small increase in memory usage for C programs, a moderate
482 increase in memory usage for C++ programs, and a fantastic speedup in
485 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
486 from the specifications in the Annotated Reference Manual, which AT&T's
487 compiler does not actually implement.
489 * G++ multiple inheritance compiler problem
491 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
492 inheritance lattices was reworked to properly discover ambiguities. We
493 recently found an example which causes this new algorithm to fail in a
494 very subtle way, producing bad debug information for those classes.
495 The file 'gcc.patch' (in this directory) can be applied to gcc to
496 circumvent the problem. A future GCC release will contain a complete
499 The previous G++ debug info problem (mentioned below for the gdb-4.7
500 release) is fixed in gcc version 2.3.2.
502 * Improved configure script
504 The `configure' script will now attempt to guess your system type if
505 you don't supply a host system type. The old scheme of supplying a
506 host system triplet is preferable over using this. All the magic is
507 done in the new `config.guess' script. Examine it for details.
509 We have also brought our configure script much more in line with the FSF's
510 version. It now supports the --with-xxx options. In particular,
511 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
512 The resulting GDB will not be able to read arbitrary object file formats --
513 only the format ``expected'' to be used on the configured target system.
514 We hope to make this the default in a future release.
516 * Documentation improvements
518 There's new internal documentation on how to modify GDB, and how to
519 produce clean changes to the code. We implore people to read it
520 before submitting changes.
522 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
523 M4 macros. The new texinfo.tex is provided in this release. Pre-built
524 `info' files are also provided. To build `info' files from scratch,
525 you will need the latest `makeinfo' release, which will be available in
526 a future texinfo-X.Y release.
528 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
529 We're not sure exactly which versions have this problem, but it has
530 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
531 or better. If that isn't possible, there is a patch in
532 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
537 GDB now supports array constants that can be used in expressions typed in by
538 the user. The syntax is `{element, element, ...}'. Ie: you can now type
539 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
542 The new directory `gdb/sparclite' contains a program that demonstrates
543 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
545 * New native hosts supported
547 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
548 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
550 * New targets supported
552 AMD 29k family via UDI a29k-amd-udi or udi29k
554 * New file formats supported
556 BFD now supports reading HP/PA-RISC executables (SOM file format?),
557 HPUX core files, and SCO 3.2v2 core files.
561 Attaching to processes now works again; thanks for the many bug reports.
563 We have also stomped on a bunch of core dumps caused by
564 printf_filtered("%s") problems.
566 We eliminated a copyright problem on the rpc and ptrace header files
567 for VxWorks, which was discovered at the last minute during the 4.7
568 release. You should now be able to build a VxWorks GDB.
570 You can now interrupt gdb while an attached process is running. This
571 will cause the attached process to stop, and give control back to GDB.
573 We fixed problems caused by using too many file descriptors
574 for reading symbols from object files and libraries. This was
575 especially a problem for programs that used many (~100) shared
578 The `step' command now only enters a subroutine if there is line number
579 information for the subroutine. Otherwise it acts like the `next'
580 command. Previously, `step' would enter subroutines if there was
581 any debugging information about the routine. This avoids problems
582 when using `cc -g1' on MIPS machines.
584 * Internal improvements
586 GDB's internal interfaces have been improved to make it easier to support
587 debugging of multiple languages in the future.
589 GDB now uses a common structure for symbol information internally.
590 Minimal symbols (derived from linkage symbols in object files), partial
591 symbols (from a quick scan of debug information), and full symbols
592 contain a common subset of information, making it easier to write
593 shared code that handles any of them.
595 * New command line options
597 We now accept --silent as an alias for --quiet.
601 The memory-mapped-malloc library is now licensed under the GNU Library
602 General Public License.
604 *** Changes in GDB-4.7:
606 * Host/native/target split
608 GDB has had some major internal surgery to untangle the support for
609 hosts and remote targets. Now, when you configure GDB for a remote
610 target, it will no longer load in all of the support for debugging
611 local programs on the host. When fully completed and tested, this will
612 ensure that arbitrary host/target combinations are possible.
614 The primary conceptual shift is to separate the non-portable code in
615 GDB into three categories. Host specific code is required any time GDB
616 is compiled on that host, regardless of the target. Target specific
617 code relates to the peculiarities of the target, but can be compiled on
618 any host. Native specific code is everything else: it can only be
619 built when the host and target are the same system. Child process
620 handling and core file support are two common `native' examples.
622 GDB's use of /proc for controlling Unix child processes is now cleaner.
623 It has been split out into a single module under the `target_ops' vector,
624 plus two native-dependent functions for each system that uses /proc.
626 * New hosts supported
628 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
629 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
630 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
632 * New targets supported
634 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
635 68030 and CPU32 m68030-*-*, m68332-*-*
637 * New native hosts supported
639 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
640 (386bsd is not well tested yet)
641 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
643 * New file formats supported
645 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
646 supports reading of `a.out.adobe' object files, which are an a.out
647 format extended with minimal information about multiple sections.
651 `show copying' is the same as the old `info copying'.
652 `show warranty' is the same as `info warrantee'.
653 These were renamed for consistency. The old commands continue to work.
655 `info handle' is a new alias for `info signals'.
657 You can now define pre-command hooks, which attach arbitrary command
658 scripts to any command. The commands in the hook will be executed
659 prior to the user's command. You can also create a hook which will be
660 executed whenever the program stops. See gdb.texinfo.
664 We now deal with Cfront style name mangling, and can even extract type
665 info from mangled symbols. GDB can automatically figure out which
666 symbol mangling style your C++ compiler uses.
668 Calling of methods and virtual functions has been improved as well.
672 The crash that occured when debugging Sun Ansi-C compiled binaries is
673 fixed. This was due to mishandling of the extra N_SO stabs output
676 We also finally got Ultrix 4.2 running in house, and fixed core file
677 support, with help from a dozen people on the net.
679 John M. Farrell discovered that the reason that single-stepping was so
680 slow on all of the Mips based platforms (primarily SGI and DEC) was
681 that we were trying to demangle and lookup a symbol used for internal
682 purposes on every instruction that was being stepped through. Changing
683 the name of that symbol so that it couldn't be mistaken for a C++
684 mangled symbol sped things up a great deal.
686 Rich Pixley sped up symbol lookups in general by getting much smarter
687 about when C++ symbol mangling is necessary. This should make symbol
688 completion (TAB on the command line) much faster. It's not as fast as
689 we'd like, but it's significantly faster than gdb-4.6.
693 A new user controllable variable 'call_scratch_address' can
694 specify the location of a scratch area to be used when GDB
695 calls a function in the target. This is necessary because the
696 usual method of putting the scratch area on the stack does not work
697 in systems that have separate instruction and data spaces.
699 We integrated changes to support the 29k UDI (Universal Debugger
700 Interface), but discovered at the last minute that we didn't have all
701 of the appropriate copyright paperwork. We are working with AMD to
702 resolve this, and hope to have it available soon.
706 We have sped up the remote serial line protocol, especially for targets
707 with lots of registers. It now supports a new `expedited status' ('T')
708 message which can be used in place of the existing 'S' status message.
709 This allows the remote stub to send only the registers that GDB
710 needs to make a quick decision about single-stepping or conditional
711 breakpoints, eliminating the need to fetch the entire register set for
712 each instruction being stepped through.
714 The GDB remote serial protocol now implements a write-through cache for
715 registers, only re-reading the registers if the target has run.
717 There is also a new remote serial stub for SPARC processors. You can
718 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
719 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
720 processor with a serial port.
724 Configure.in files have become much easier to read and modify. A new
725 `table driven' format makes it more obvious what configurations are
726 supported, and what files each one uses.
730 There is a new opcodes library which will eventually contain all of the
731 disassembly routines and opcode tables. At present, it only contains
732 Sparc and Z8000 routines. This will allow the assembler, debugger, and
733 disassembler (binutils/objdump) to share these routines.
735 The libiberty library is now copylefted under the GNU Library General
736 Public License. This allows more liberal use, and was done so libg++
737 can use it. This makes no difference to GDB, since the Library License
738 grants all the rights from the General Public License.
742 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
743 reference to the stabs symbol info used by the debugger. It is (as far
744 as we know) the only published document on this fascinating topic. We
745 encourage you to read it, compare it to the stabs information on your
746 system, and send improvements on the document in general (to
747 bug-gdb@prep.ai.mit.edu).
749 And, of course, many bugs have been fixed.
752 *** Changes in GDB-4.6:
754 * Better support for C++ function names
756 GDB now accepts as input the "demangled form" of C++ overloaded function
757 names and member function names, and can do command completion on such names
758 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
759 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
760 Make use of command completion, it is your friend.
762 GDB also now accepts a variety of C++ mangled symbol formats. They are
763 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
764 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
765 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
766 for the list of formats.
768 * G++ symbol mangling problem
770 Recent versions of gcc have a bug in how they emit debugging information for
771 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
772 directory) can be applied to gcc to fix the problem. Alternatively, if you
773 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
774 usual symptom is difficulty with setting breakpoints on methods. GDB complains
775 about the method being non-existent. (We believe that version 2.2.2 of GCC has
778 * New 'maintenance' command
780 All of the commands related to hacking GDB internals have been moved out of
781 the main command set, and now live behind the 'maintenance' command. This
782 can also be abbreviated as 'mt'. The following changes were made:
784 dump-me -> maintenance dump-me
785 info all-breakpoints -> maintenance info breakpoints
786 printmsyms -> maintenance print msyms
787 printobjfiles -> maintenance print objfiles
788 printpsyms -> maintenance print psymbols
789 printsyms -> maintenance print symbols
791 The following commands are new:
793 maintenance demangle Call internal GDB demangler routine to
794 demangle a C++ link name and prints the result.
795 maintenance print type Print a type chain for a given symbol
797 * Change to .gdbinit file processing
799 We now read the $HOME/.gdbinit file before processing the argv arguments
800 (e.g. reading symbol files or core files). This allows global parameters to
801 be set, which will apply during the symbol reading. The ./.gdbinit is still
802 read after argv processing.
804 * New hosts supported
806 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
808 Linux support i386-unknown-linux or linux
810 We are also including code to support the HP/PA running BSD and HPUX. This
811 is almost guaranteed not to work, as we didn't have time to test or build it
812 for this release. We are including it so that the more adventurous (or
813 masochistic) of you can play with it. We also had major problems with the
814 fact that the compiler that we got from HP doesn't support the -g option.
817 * New targets supported
819 Hitachi H8/300 h8300-hitachi-hms or h8300hms
821 * More smarts about finding #include files
823 GDB now remembers the compilation directory for all include files, and for
824 all files from which C is generated (like yacc and lex sources). This
825 greatly improves GDB's ability to find yacc/lex sources, and include files,
826 especially if you are debugging your program from a directory different from
827 the one that contains your sources.
829 We also fixed a bug which caused difficulty with listing and setting
830 breakpoints in include files which contain C code. (In the past, you had to
831 try twice in order to list an include file that you hadn't looked at before.)
833 * Interesting infernals change
835 GDB now deals with arbitrary numbers of sections, where the symbols for each
836 section must be relocated relative to that section's landing place in the
837 target's address space. This work was needed to support ELF with embedded
838 stabs used by Solaris-2.0.
840 * Bug fixes (of course!)
842 There have been loads of fixes for the following things:
843 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
844 i960, stabs, DOS(GO32), procfs, etc...
846 See the ChangeLog for details.
848 *** Changes in GDB-4.5:
850 * New machines supported (host and target)
852 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
854 SGI Irix-4.x mips-sgi-irix4 or iris4
858 GDB now uses a new memory manager called mmalloc, based on gmalloc.
859 Mmalloc is capable of handling mutiple heaps of memory. It is also
860 capable of saving a heap to a file, and then mapping it back in later.
861 This can be used to greatly speedup the startup of GDB by using a
862 pre-parsed symbol table which lives in a mmalloc managed heap. For
863 more details, please read mmalloc/mmalloc.texi.
867 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
868 'help info proc' for details.
870 * MIPS ecoff symbol table format
872 The code that reads MIPS symbol table format is now supported on all hosts.
873 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
876 * File name changes for MS-DOS
878 Many files in the config directories have been renamed to make it easier to
879 support GDB on MS-DOSe systems (which have very restrictive file name
880 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
881 environment) is close to working but has some remaining problems. Note
882 that debugging of DOS programs is not supported, due to limitations
883 in the ``operating system'', but it can be used to host cross-debugging.
885 * Cross byte order fixes
887 Many fixes have been made to support cross debugging of Sparc and MIPS
888 targets from hosts whose byte order differs.
890 * New -mapped and -readnow options
892 If memory-mapped files are available on your system through the 'mmap'
893 system call, you can use the -mapped option on the `file' or
894 `symbol-file' commands to cause GDB to write the symbols from your
895 program into a reusable file. If the program you are debugging is
896 called `/path/fred', the mapped symbol file will be `./fred.syms'.
897 Future GDB debugging sessions will notice the presence of this file,
898 and will quickly map in symbol information from it, rather than reading
899 the symbol table from the executable program. Using the '-mapped'
900 option in a GDB `file' or `symbol-file' command has the same effect as
901 starting GDB with the '-mapped' command-line option.
903 You can cause GDB to read the entire symbol table immediately by using
904 the '-readnow' option with any of the commands that load symbol table
905 information (or on the GDB command line). This makes the command
906 slower, but makes future operations faster.
908 The -mapped and -readnow options are typically combined in order to
909 build a `fred.syms' file that contains complete symbol information.
910 A simple GDB invocation to do nothing but build a `.syms' file for future
913 gdb -batch -nx -mapped -readnow programname
915 The `.syms' file is specific to the host machine on which GDB is run.
916 It holds an exact image of GDB's internal symbol table. It cannot be
917 shared across multiple host platforms.
921 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
922 siglongjmp() without losing control. This feature has not yet been ported to
923 all systems. It currently works on many 386 platforms, all MIPS-based
924 platforms (SGI, DECstation, etc), and Sun3/4.
928 Preliminary work has been put in to support the new Solaris OS from Sun. At
929 this time, it can control and debug processes, but it is not capable of
934 As always, many many bug fixes. The major areas were with g++, and mipsread.
935 People using the MIPS-based platforms should experience fewer mysterious
936 crashes and trashed symbol tables.
938 *** Changes in GDB-4.4:
940 * New machines supported (host and target)
942 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
944 BSD Reno on Vax vax-dec-bsd
945 Ultrix on Vax vax-dec-ultrix
947 * New machines supported (target)
949 AMD 29000 embedded, using EBMON a29k-none-none
953 GDB continues to improve its handling of C++. `References' work better.
954 The demangler has also been improved, and now deals with symbols mangled as
955 per the Annotated C++ Reference Guide.
957 GDB also now handles `stabs' symbol information embedded in MIPS
958 `ecoff' symbol tables. Since the ecoff format was not easily
959 extensible to handle new languages such as C++, this appeared to be a
960 good way to put C++ debugging info into MIPS binaries. This option
961 will be supported in the GNU C compiler, version 2, when it is
964 * New features for SVR4
966 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
967 shared libraries. Debugging dynamically linked programs should present
968 only minor differences from debugging statically linked programs.
970 The `info proc' command will print out information about any process
971 on an SVR4 system (including the one you are debugging). At the moment,
972 it prints the address mappings of the process.
974 If you bring up GDB on another SVR4 system, please send mail to
975 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
977 * Better dynamic linking support in SunOS
979 Reading symbols from shared libraries which contain debugging symbols
980 now works properly. However, there remain issues such as automatic
981 skipping of `transfer vector' code during function calls, which
982 make it harder to debug code in a shared library, than to debug the
983 same code linked statically.
987 GDB is now using the latest `getopt' routines from the FSF. This
988 version accepts the -- prefix for options with long names. GDB will
989 continue to accept the old forms (-option and +option) as well.
990 Various single letter abbreviations for options have been explicity
991 added to the option table so that they won't get overshadowed in the
992 future by other options that begin with the same letter.
996 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
997 Many assorted bugs have been handled. Many more remain to be handled.
998 See the various ChangeLog files (primarily in gdb and bfd) for details.
1001 *** Changes in GDB-4.3:
1003 * New machines supported (host and target)
1005 Amiga 3000 running Amix m68k-cbm-svr4 or amix
1006 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
1007 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
1009 * Almost SCO Unix support
1011 We had hoped to support:
1012 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
1013 (except for core file support), but we discovered very late in the release
1014 that it has problems with process groups that render gdb unusable. Sorry
1015 about that. I encourage people to fix it and post the fixes.
1017 * Preliminary ELF and DWARF support
1019 GDB can read ELF object files on System V Release 4, and can handle
1020 debugging records for C, in DWARF format, in ELF files. This support
1021 is preliminary. If you bring up GDB on another SVR4 system, please
1022 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
1027 GDB now uses the latest `readline' library. One user-visible change
1028 is that two tabs will list possible command completions, which previously
1029 required typing M-? (meta-question mark, or ESC ?).
1033 The `stepi' bug that many of you noticed has been squashed.
1034 Many bugs in C++ have been handled. Many more remain to be handled.
1035 See the various ChangeLog files (primarily in gdb and bfd) for details.
1037 * State of the MIPS world (in case you wondered):
1039 GDB can understand the symbol tables emitted by the compilers
1040 supplied by most vendors of MIPS-based machines, including DEC. These
1041 symbol tables are in a format that essentially nobody else uses.
1043 Some versions of gcc come with an assembler post-processor called
1044 mips-tfile. This program is required if you want to do source-level
1045 debugging of gcc-compiled programs. I believe FSF does not ship
1046 mips-tfile with gcc version 1, but it will eventually come with gcc
1049 Debugging of g++ output remains a problem. g++ version 1.xx does not
1050 really support it at all. (If you're lucky, you should be able to get
1051 line numbers and stack traces to work, but no parameters or local
1052 variables.) With some work it should be possible to improve the
1055 When gcc version 2 is released, you will have somewhat better luck.
1056 However, even then you will get confusing results for inheritance and
1059 We will eventually provide full debugging of g++ output on
1060 DECstations. This will probably involve some kind of stabs-in-ecoff
1061 encapulation, but the details have not been worked out yet.
1064 *** Changes in GDB-4.2:
1066 * Improved configuration
1068 Only one copy of `configure' exists now, and it is not self-modifying.
1069 Porting BFD is simpler.
1073 The `step' and `next' commands now only stop at the first instruction
1074 of a source line. This prevents the multiple stops that used to occur
1075 in switch statements, for-loops, etc. `Step' continues to stop if a
1076 function that has debugging information is called within the line.
1080 Lots of small bugs fixed. More remain.
1082 * New host supported (not target)
1084 Intel 386 PC clone running Mach i386-none-mach
1087 *** Changes in GDB-4.1:
1089 * Multiple source language support
1091 GDB now has internal scaffolding to handle several source languages.
1092 It determines the type of each source file from its filename extension,
1093 and will switch expression parsing and number formatting to match the
1094 language of the function in the currently selected stack frame.
1095 You can also specifically set the language to be used, with
1096 `set language c' or `set language modula-2'.
1100 GDB now has preliminary support for the GNU Modula-2 compiler,
1101 currently under development at the State University of New York at
1102 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
1103 continue through the fall of 1991 and into 1992.
1105 Other Modula-2 compilers are currently not supported, and attempting to
1106 debug programs compiled with them will likely result in an error as the
1107 symbol table is read. Feel free to work on it, though!
1109 There are hooks in GDB for strict type checking and range checking,
1110 in the `Modula-2 philosophy', but they do not currently work.
1114 GDB can now write to executable and core files (e.g. patch
1115 a variable's value). You must turn this switch on, specify
1116 the file ("exec foo" or "core foo"), *then* modify it, e.g.
1117 by assigning a new value to a variable. Modifications take
1120 * Automatic SunOS shared library reading
1122 When you run your program, GDB automatically determines where its
1123 shared libraries (if any) have been loaded, and reads their symbols.
1124 The `share' command is no longer needed. This also works when
1125 examining core files.
1129 You can specify the number of lines that the `list' command shows.
1132 * New machines supported (host and target)
1134 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
1135 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
1136 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
1138 * New hosts supported (not targets)
1140 IBM RT/PC: romp-ibm-aix or rtpc
1142 * New targets supported (not hosts)
1144 AMD 29000 embedded with COFF a29k-none-coff
1145 AMD 29000 embedded with a.out a29k-none-aout
1146 Ultracomputer remote kernel debug a29k-nyu-kern
1148 * New remote interfaces
1154 *** Changes in GDB-4.0:
1158 Wide output is wrapped at good places to make the output more readable.
1160 Gdb now supports cross-debugging from a host machine of one type to a
1161 target machine of another type. Communication with the target system
1162 is over serial lines. The ``target'' command handles connecting to the
1163 remote system; the ``load'' command will download a program into the
1164 remote system. Serial stubs for the m68k and i386 are provided. Gdb
1165 also supports debugging of realtime processes running under VxWorks,
1166 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
1167 stub on the target system.
1169 New CPUs supported include the AMD 29000 and Intel 960.
1171 GDB now reads object files and symbol tables via a ``binary file''
1172 library, which allows a single copy of GDB to debug programs of multiple
1173 object file types such as a.out and coff.
1175 There is now a GDB reference card in "doc/refcard.tex". (Make targets
1176 refcard.dvi and refcard.ps are available to format it).
1179 * Control-Variable user interface simplified
1181 All variables that control the operation of the debugger can be set
1182 by the ``set'' command, and displayed by the ``show'' command.
1184 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
1185 ``Show prompt'' produces the response:
1186 Gdb's prompt is new-gdb=>.
1188 What follows are the NEW set commands. The command ``help set'' will
1189 print a complete list of old and new set commands. ``help set FOO''
1190 will give a longer description of the variable FOO. ``show'' will show
1191 all of the variable descriptions and their current settings.
1193 confirm on/off: Enables warning questions for operations that are
1194 hard to recover from, e.g. rerunning the program while
1195 it is already running. Default is ON.
1197 editing on/off: Enables EMACS style command line editing
1198 of input. Previous lines can be recalled with
1199 control-P, the current line can be edited with control-B,
1200 you can search for commands with control-R, etc.
1203 history filename NAME: NAME is where the gdb command history
1204 will be stored. The default is .gdb_history,
1205 or the value of the environment variable
1208 history size N: The size, in commands, of the command history. The
1209 default is 256, or the value of the environment variable
1212 history save on/off: If this value is set to ON, the history file will
1213 be saved after exiting gdb. If set to OFF, the
1214 file will not be saved. The default is OFF.
1216 history expansion on/off: If this value is set to ON, then csh-like
1217 history expansion will be performed on
1218 command line input. The default is OFF.
1220 radix N: Sets the default radix for input and output. It can be set
1221 to 8, 10, or 16. Note that the argument to "radix" is interpreted
1222 in the current radix, so "set radix 10" is always a no-op.
1224 height N: This integer value is the number of lines on a page. Default
1225 is 24, the current `stty rows'' setting, or the ``li#''
1226 setting from the termcap entry matching the environment
1229 width N: This integer value is the number of characters on a line.
1230 Default is 80, the current `stty cols'' setting, or the ``co#''
1231 setting from the termcap entry matching the environment
1234 Note: ``set screensize'' is obsolete. Use ``set height'' and
1235 ``set width'' instead.
1237 print address on/off: Print memory addresses in various command displays,
1238 such as stack traces and structure values. Gdb looks
1239 more ``symbolic'' if you turn this off; it looks more
1240 ``machine level'' with it on. Default is ON.
1242 print array on/off: Prettyprint arrays. New convenient format! Default
1245 print demangle on/off: Print C++ symbols in "source" form if on,
1248 print asm-demangle on/off: Same, for assembler level printouts
1251 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
1254 * Support for Epoch Environment.
1256 The epoch environment is a version of Emacs v18 with windowing. One
1257 new command, ``inspect'', is identical to ``print'', except that if you
1258 are running in the epoch environment, the value is printed in its own
1262 * Support for Shared Libraries
1264 GDB can now debug programs and core files that use SunOS shared libraries.
1265 Symbols from a shared library cannot be referenced
1266 before the shared library has been linked with the program (this
1267 happens after you type ``run'' and before the function main() is entered).
1268 At any time after this linking (including when examining core files
1269 from dynamically linked programs), gdb reads the symbols from each
1270 shared library when you type the ``sharedlibrary'' command.
1271 It can be abbreviated ``share''.
1273 sharedlibrary REGEXP: Load shared object library symbols for files
1274 matching a unix regular expression. No argument
1275 indicates to load symbols for all shared libraries.
1277 info sharedlibrary: Status of loaded shared libraries.
1282 A watchpoint stops execution of a program whenever the value of an
1283 expression changes. Checking for this slows down execution
1284 tremendously whenever you are in the scope of the expression, but is
1285 quite useful for catching tough ``bit-spreader'' or pointer misuse
1286 problems. Some machines such as the 386 have hardware for doing this
1287 more quickly, and future versions of gdb will use this hardware.
1289 watch EXP: Set a watchpoint (breakpoint) for an expression.
1291 info watchpoints: Information about your watchpoints.
1293 delete N: Deletes watchpoint number N (same as breakpoints).
1294 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
1295 enable N: Re-enables watchpoint number N (same as breakpoints).
1298 * C++ multiple inheritance
1300 When used with a GCC version 2 compiler, GDB supports multiple inheritance
1303 * C++ exception handling
1305 Gdb now supports limited C++ exception handling. Besides the existing
1306 ability to breakpoint on an exception handler, gdb can breakpoint on
1307 the raising of an exception (before the stack is peeled back to the
1310 catch FOO: If there is a FOO exception handler in the dynamic scope,
1311 set a breakpoint to catch exceptions which may be raised there.
1312 Multiple exceptions (``catch foo bar baz'') may be caught.
1314 info catch: Lists all exceptions which may be caught in the
1315 current stack frame.
1318 * Minor command changes
1320 The command ``call func (arg, arg, ...)'' now acts like the print
1321 command, except it does not print or save a value if the function's result
1322 is void. This is similar to dbx usage.
1324 The ``up'' and ``down'' commands now always print the frame they end up
1325 at; ``up-silently'' and `down-silently'' can be used in scripts to change
1326 frames without printing.
1328 * New directory command
1330 'dir' now adds directories to the FRONT of the source search path.
1331 The path starts off empty. Source files that contain debug information
1332 about the directory in which they were compiled can be found even
1333 with an empty path; Sun CC and GCC include this information. If GDB can't
1334 find your source file in the current directory, type "dir .".
1336 * Configuring GDB for compilation
1338 For normal use, type ``./configure host''. See README or gdb.texinfo
1341 GDB now handles cross debugging. If you are remotely debugging between
1342 two different machines, type ``./configure host -target=targ''.
1343 Host is the machine where GDB will run; targ is the machine
1344 where the program that you are debugging will run.
projects / deliverable / binutils-gdb.git / blob