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*
12 M68K with dBUG monitor m68*-*-{aout,coff,elf}
14 *** Changes in GDB-4.16:
16 * New native configurations
18 Windows 95, x86 Windows NT i[345]86-*-cygwin32
19 M68K NetBSD m68k-*-netbsd*
20 PowerPC AIX 4.x powerpc-*-aix*
21 PowerPC MacOS powerpc-*-macos*
22 PowerPC Windows NT powerpcle-*-cygwin32
23 RS/6000 AIX 4.x rs6000-*-aix4*
27 ARM with RDP protocol arm-*-*
28 I960 with MON960 i960-*-coff
29 MIPS VxWorks mips*-*-vxworks*
30 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
31 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
33 Matra Sparclet sparclet-*-*
37 The powerpc-eabi configuration now includes the PSIM simulator,
38 contributed by Andrew Cagney, with assistance from Mike Meissner.
39 PSIM is a very elaborate model of the PowerPC, including not only
40 basic instruction set execution, but also details of execution unit
41 performance and I/O hardware. See sim/ppc/README for more details.
45 GDB now works with Solaris 2.5.
47 * Windows 95/NT native
49 GDB will now work as a native debugger on Windows 95 and Windows NT.
50 To build it from source, you must use the "gnu-win32" environment,
51 which uses a DLL to emulate enough of Unix to run the GNU tools.
52 Further information, binaries, and sources are available at
53 ftp.cygnus.com, under pub/gnu-win32.
57 If a user-defined command includes the command `dont-repeat', then the
58 command will not be repeated if the user just types return. This is
59 useful if the command is time-consuming to run, so that accidental
60 extra keystrokes don't run the same command many times.
62 * Send break instead of ^C
64 The standard remote protocol now includes an option to send a break
65 rather than a ^C to the target in order to interrupt it. By default,
66 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
68 * Remote protocol timeout
70 The standard remote protocol includes a new variable `remotetimeout'
71 that allows you to set the number of seconds before GDB gives up trying
72 to read from the target. The default value is 2.
74 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
76 By default GDB will automatically keep track of objects as they are
77 loaded and unloaded by the dynamic linker. By using the command `set
78 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
79 when shared library events occur, thus allowing you to set breakpoints
80 in shared libraries which are explicitly loaded by the inferior.
82 Note this feature does not work on hpux8. On hpux9 you must link
83 /usr/lib/end.o into your program. This feature should work
84 automatically on hpux10.
86 * Irix 5.x hardware watchpoint support
88 Irix 5 configurations now support the use of hardware watchpoints.
90 * Mips protocol "SYN garbage limit"
92 When debugging a Mips target using the `target mips' protocol, you
93 may set the number of characters that GDB will ignore by setting
94 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
95 every character. The default value is 1050.
97 * Recording and replaying remote debug sessions
99 If you set `remotelogfile' to the name of a file, gdb will write to it
100 a recording of a remote debug session. This recording may then be
101 replayed back to gdb using "gdbreplay". See gdbserver/README for
102 details. This is useful when you have a problem with GDB while doing
103 remote debugging; you can make a recording of the session and send it
104 to someone else, who can then recreate the problem.
106 * Speedups for remote debugging
108 GDB includes speedups for downloading and stepping MIPS systems using
109 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
110 and more efficient S-record downloading.
112 * Memory use reductions and statistics collection
114 GDB now uses less memory and reports statistics about memory usage.
115 Try the `maint print statistics' command, for example.
117 *** Changes in GDB-4.15:
121 The symbol reader for AIX GDB now uses partial symbol tables. This
122 can greatly improve startup time, especially for large executables.
124 * Remote targets use caching
126 Remote targets now use a data cache to speed up communication with the
127 remote side. The data cache could lead to incorrect results because
128 it doesn't know about volatile variables, thus making it impossible to
129 debug targets which use memory mapped I/O devices. `set remotecache
130 off' turns the the data cache off.
132 * Remote targets may have threads
134 The standard remote protocol now includes support for multiple threads
135 in the target system, using new protocol commands 'H' and 'T'. See
136 gdb/remote.c for details.
140 If GDB is configured with `--enable-netrom', then it will include
141 support for the NetROM ROM emulator from XLNT Designs. The NetROM
142 acts as though it is a bank of ROM on the target board, but you can
143 write into it over the network. GDB's support consists only of
144 support for fast loading into the emulated ROM; to debug, you must use
145 another protocol, such as standard remote protocol. The usual
146 sequence is something like
148 target nrom <netrom-hostname>
150 target remote <netrom-hostname>:1235
154 GDB now includes support for the Apple Macintosh, as a host only. It
155 may be run as either an MPW tool or as a standalone application, and
156 it can debug through the serial port. All the usual GDB commands are
157 available, but to the target command, you must supply "serial" as the
158 device type instead of "/dev/ttyXX". See mpw-README in the main
159 directory for more information on how to build. The MPW configuration
160 scripts */mpw-config.in support only a few targets, and only the
161 mips-idt-ecoff target has been tested.
165 GDB configuration now uses autoconf. This is not user-visible,
166 but does simplify configuration and building.
170 GDB now supports hpux10.
172 *** Changes in GDB-4.14:
174 * New native configurations
176 x86 FreeBSD i[345]86-*-freebsd
177 x86 NetBSD i[345]86-*-netbsd
178 NS32k NetBSD ns32k-*-netbsd
179 Sparc NetBSD sparc-*-netbsd
183 A29K VxWorks a29k-*-vxworks
184 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
185 CPU32 EST-300 emulator m68*-*-est*
186 PowerPC ELF powerpc-*-elf
189 * Alpha OSF/1 support for procfs
191 GDB now supports procfs under OSF/1-2.x and higher, which makes it
192 possible to attach to running processes. As the mounting of the /proc
193 filesystem is optional on the Alpha, GDB automatically determines
194 the availability of /proc during startup. This can lead to problems
195 if /proc is unmounted after GDB has been started.
197 * Arguments to user-defined commands
199 User commands may accept up to 10 arguments separated by whitespace.
200 Arguments are accessed within the user command via $arg0..$arg9. A
203 print $arg0 + $arg1 + $arg2
205 To execute the command use:
208 Defines the command "adder" which prints the sum of its three arguments.
209 Note the arguments are text substitutions, so they may reference variables,
210 use complex expressions, or even perform inferior function calls.
212 * New `if' and `while' commands
214 This makes it possible to write more sophisticated user-defined
215 commands. Both commands take a single argument, which is the
216 expression to evaluate, and must be followed by the commands to
217 execute, one per line, if the expression is nonzero, the list being
218 terminated by the word `end'. The `if' command list may include an
219 `else' word, which causes the following commands to be executed only
220 if the expression is zero.
222 * Fortran source language mode
224 GDB now includes partial support for Fortran 77. It will recognize
225 Fortran programs and can evaluate a subset of Fortran expressions, but
226 variables and functions may not be handled correctly. GDB will work
227 with G77, but does not yet know much about symbols emitted by other
230 * Better HPUX support
232 Most debugging facilities now work on dynamic executables for HPPAs
233 running hpux9 or later. You can attach to running dynamically linked
234 processes, but by default the dynamic libraries will be read-only, so
235 for instance you won't be able to put breakpoints in them. To change
236 that behavior do the following before running the program:
242 This will cause the libraries to be mapped private and read-write.
243 To revert to the normal behavior, do this:
249 You cannot set breakpoints or examine data in the library until after
250 the library is loaded if the function/data symbols do not have
253 GDB can now also read debug symbols produced by the HP C compiler on
254 HPPAs (sorry, no C++, Fortran or 68k support).
256 * Target byte order now dynamically selectable
258 You can choose which byte order to use with a target system, via the
259 commands "set endian big" and "set endian little", and you can see the
260 current setting by using "show endian". You can also give the command
261 "set endian auto", in which case GDB will use the byte order
262 associated with the executable. Currently, only embedded MIPS
263 configurations support dynamic selection of target byte order.
265 * New DOS host serial code
267 This version uses DPMI interrupts to handle buffered I/O, so you
268 no longer need to run asynctsr when debugging boards connected to
271 *** Changes in GDB-4.13:
273 * New "complete" command
275 This lists all the possible completions for the rest of the line, if it
276 were to be given as a command itself. This is intended for use by emacs.
278 * Trailing space optional in prompt
280 "set prompt" no longer adds a space for you after the prompt you set. This
281 allows you to set a prompt which ends in a space or one that does not.
283 * Breakpoint hit counts
285 "info break" now displays a count of the number of times the breakpoint
286 has been hit. This is especially useful in conjunction with "ignore"; you
287 can ignore a large number of breakpoint hits, look at the breakpoint info
288 to see how many times the breakpoint was hit, then run again, ignoring one
289 less than that number, and this will get you quickly to the last hit of
292 * Ability to stop printing at NULL character
294 "set print null-stop" will cause GDB to stop printing the characters of
295 an array when the first NULL is encountered. This is useful when large
296 arrays actually contain only short strings.
298 * Shared library breakpoints
300 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
301 breakpoints in shared libraries before the executable is run.
303 * Hardware watchpoints
305 There is a new hardware breakpoint for the watch command for sparclite
306 targets. See gdb/sparclite/hw_breakpoint.note.
308 Hardware watchpoints are also now supported under Linux.
312 Annotations have been added. These are for use with graphical interfaces,
313 and are still experimental. Currently only gdba.el uses these.
315 * Improved Irix 5 support
317 GDB now works properly with Irix 5.2.
319 * Improved HPPA support
321 GDB now works properly with the latest GCC and GAS.
323 * New native configurations
325 Sequent PTX4 i[34]86-sequent-ptx4
326 HPPA running OSF/1 hppa*-*-osf*
327 Atari TT running SVR4 m68*-*-sysv4*
328 RS/6000 LynxOS rs6000-*-lynxos*
332 OS/9000 i[34]86-*-os9k
333 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
336 * Hitachi SH7000 and E7000-PC ICE support
338 There is now support for communicating with the Hitachi E7000-PC ICE.
339 This is available automatically when GDB is configured for the SH.
343 As usual, a variety of small fixes and improvements, both generic
344 and configuration-specific. See the ChangeLog for more detail.
346 *** Changes in GDB-4.12:
348 * Irix 5 is now supported
352 GDB-4.12 on the HPPA has a number of changes which make it unable
353 to debug the output from the currently released versions of GCC and
354 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
355 of GCC and GAS, versions of these tools designed to work with GDB-4.12
356 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
359 *** Changes in GDB-4.11:
361 * User visible changes:
365 The "set remotedebug" option is now consistent between the mips remote
366 target, remote targets using the gdb-specific protocol, UDI (AMD's
367 debug protocol for the 29k) and the 88k bug monitor. It is now an
368 integer specifying a debug level (normally 0 or 1, but 2 means more
369 debugging info for the mips target).
371 * DEC Alpha native support
373 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
374 debug info, but GDB works fairly well with the DEC compiler and should
375 work with a future GCC release. See the README file for a few
376 Alpha-specific notes.
378 * Preliminary thread implementation
380 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
382 * LynxOS native and target support for 386
384 This release has been hosted on LynxOS 2.2, and also can be configured
385 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
388 * Improvements in C++ mangling/demangling.
390 This release has much better g++ debugging, specifically in name
391 mangling/demangling, virtual function calls, print virtual table,
392 call methods, ...etc.
394 *** Changes in GDB-4.10:
396 * User visible changes:
398 Remote debugging using the GDB-specific (`target remote') protocol now
399 supports the `load' command. This is only useful if you have some
400 other way of getting the stub to the target system, and you can put it
401 somewhere in memory where it won't get clobbered by the download.
403 Filename completion now works.
405 When run under emacs mode, the "info line" command now causes the
406 arrow to point to the line specified. Also, "info line" prints
407 addresses in symbolic form (as well as hex).
409 All vxworks based targets now support a user settable option, called
410 vxworks-timeout. This option represents the number of seconds gdb
411 should wait for responses to rpc's. You might want to use this if
412 your vxworks target is, perhaps, a slow software simulator or happens
413 to be on the far side of a thin network line.
417 This release contains support for using a DEC alpha as a GDB host for
418 cross debugging. Native alpha debugging is not supported yet.
421 *** Changes in GDB-4.9:
425 This is the first GDB release which is accompanied by a matching testsuite.
426 The testsuite requires installation of dejagnu, which should be available
427 via ftp from most sites that carry GNU software.
431 'Cfront' style demangling has had its name changed to 'ARM' style, to
432 emphasize that it was written from the specifications in the C++ Annotated
433 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
434 disclaimers, it still generated too much confusion with users attempting to
435 use gdb with AT&T cfront.
439 GDB now uses a standard remote interface to a simulator library.
440 So far, the library contains simulators for the Zilog Z8001/2, the
441 Hitachi H8/300, H8/500 and Super-H.
443 * New targets supported
445 H8/300 simulator h8300-hitachi-hms or h8300hms
446 H8/500 simulator h8500-hitachi-hms or h8500hms
447 SH simulator sh-hitachi-hms or sh
448 Z8000 simulator z8k-zilog-none or z8ksim
449 IDT MIPS board over serial line mips-idt-ecoff
451 Cross-debugging to GO32 targets is supported. It requires a custom
452 version of the i386-stub.c module which is integrated with the
453 GO32 memory extender.
455 * New remote protocols
457 MIPS remote debugging protocol.
459 * New source languages supported
461 This version includes preliminary support for Chill, a Pascal like language
462 used by telecommunications companies. Chill support is also being integrated
463 into the GNU compiler, but we don't know when it will be publically available.
466 *** Changes in GDB-4.8:
468 * HP Precision Architecture supported
470 GDB now supports HP PA-RISC machines running HPUX. A preliminary
471 version of this support was available as a set of patches from the
472 University of Utah. GDB does not support debugging of programs
473 compiled with the HP compiler, because HP will not document their file
474 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
475 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
477 Many problems in the preliminary version have been fixed.
479 * Faster and better demangling
481 We have improved template demangling and fixed numerous bugs in the GNU style
482 demangler. It can now handle type modifiers such as `static' or `const'. Wide
483 character types (wchar_t) are now supported. Demangling of each symbol is now
484 only done once, and is cached when the symbol table for a file is read in.
485 This results in a small increase in memory usage for C programs, a moderate
486 increase in memory usage for C++ programs, and a fantastic speedup in
489 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
490 from the specifications in the Annotated Reference Manual, which AT&T's
491 compiler does not actually implement.
493 * G++ multiple inheritance compiler problem
495 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
496 inheritance lattices was reworked to properly discover ambiguities. We
497 recently found an example which causes this new algorithm to fail in a
498 very subtle way, producing bad debug information for those classes.
499 The file 'gcc.patch' (in this directory) can be applied to gcc to
500 circumvent the problem. A future GCC release will contain a complete
503 The previous G++ debug info problem (mentioned below for the gdb-4.7
504 release) is fixed in gcc version 2.3.2.
506 * Improved configure script
508 The `configure' script will now attempt to guess your system type if
509 you don't supply a host system type. The old scheme of supplying a
510 host system triplet is preferable over using this. All the magic is
511 done in the new `config.guess' script. Examine it for details.
513 We have also brought our configure script much more in line with the FSF's
514 version. It now supports the --with-xxx options. In particular,
515 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
516 The resulting GDB will not be able to read arbitrary object file formats --
517 only the format ``expected'' to be used on the configured target system.
518 We hope to make this the default in a future release.
520 * Documentation improvements
522 There's new internal documentation on how to modify GDB, and how to
523 produce clean changes to the code. We implore people to read it
524 before submitting changes.
526 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
527 M4 macros. The new texinfo.tex is provided in this release. Pre-built
528 `info' files are also provided. To build `info' files from scratch,
529 you will need the latest `makeinfo' release, which will be available in
530 a future texinfo-X.Y release.
532 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
533 We're not sure exactly which versions have this problem, but it has
534 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
535 or better. If that isn't possible, there is a patch in
536 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
541 GDB now supports array constants that can be used in expressions typed in by
542 the user. The syntax is `{element, element, ...}'. Ie: you can now type
543 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
546 The new directory `gdb/sparclite' contains a program that demonstrates
547 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
549 * New native hosts supported
551 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
552 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
554 * New targets supported
556 AMD 29k family via UDI a29k-amd-udi or udi29k
558 * New file formats supported
560 BFD now supports reading HP/PA-RISC executables (SOM file format?),
561 HPUX core files, and SCO 3.2v2 core files.
565 Attaching to processes now works again; thanks for the many bug reports.
567 We have also stomped on a bunch of core dumps caused by
568 printf_filtered("%s") problems.
570 We eliminated a copyright problem on the rpc and ptrace header files
571 for VxWorks, which was discovered at the last minute during the 4.7
572 release. You should now be able to build a VxWorks GDB.
574 You can now interrupt gdb while an attached process is running. This
575 will cause the attached process to stop, and give control back to GDB.
577 We fixed problems caused by using too many file descriptors
578 for reading symbols from object files and libraries. This was
579 especially a problem for programs that used many (~100) shared
582 The `step' command now only enters a subroutine if there is line number
583 information for the subroutine. Otherwise it acts like the `next'
584 command. Previously, `step' would enter subroutines if there was
585 any debugging information about the routine. This avoids problems
586 when using `cc -g1' on MIPS machines.
588 * Internal improvements
590 GDB's internal interfaces have been improved to make it easier to support
591 debugging of multiple languages in the future.
593 GDB now uses a common structure for symbol information internally.
594 Minimal symbols (derived from linkage symbols in object files), partial
595 symbols (from a quick scan of debug information), and full symbols
596 contain a common subset of information, making it easier to write
597 shared code that handles any of them.
599 * New command line options
601 We now accept --silent as an alias for --quiet.
605 The memory-mapped-malloc library is now licensed under the GNU Library
606 General Public License.
608 *** Changes in GDB-4.7:
610 * Host/native/target split
612 GDB has had some major internal surgery to untangle the support for
613 hosts and remote targets. Now, when you configure GDB for a remote
614 target, it will no longer load in all of the support for debugging
615 local programs on the host. When fully completed and tested, this will
616 ensure that arbitrary host/target combinations are possible.
618 The primary conceptual shift is to separate the non-portable code in
619 GDB into three categories. Host specific code is required any time GDB
620 is compiled on that host, regardless of the target. Target specific
621 code relates to the peculiarities of the target, but can be compiled on
622 any host. Native specific code is everything else: it can only be
623 built when the host and target are the same system. Child process
624 handling and core file support are two common `native' examples.
626 GDB's use of /proc for controlling Unix child processes is now cleaner.
627 It has been split out into a single module under the `target_ops' vector,
628 plus two native-dependent functions for each system that uses /proc.
630 * New hosts supported
632 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
633 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
634 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
636 * New targets supported
638 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
639 68030 and CPU32 m68030-*-*, m68332-*-*
641 * New native hosts supported
643 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
644 (386bsd is not well tested yet)
645 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
647 * New file formats supported
649 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
650 supports reading of `a.out.adobe' object files, which are an a.out
651 format extended with minimal information about multiple sections.
655 `show copying' is the same as the old `info copying'.
656 `show warranty' is the same as `info warrantee'.
657 These were renamed for consistency. The old commands continue to work.
659 `info handle' is a new alias for `info signals'.
661 You can now define pre-command hooks, which attach arbitrary command
662 scripts to any command. The commands in the hook will be executed
663 prior to the user's command. You can also create a hook which will be
664 executed whenever the program stops. See gdb.texinfo.
668 We now deal with Cfront style name mangling, and can even extract type
669 info from mangled symbols. GDB can automatically figure out which
670 symbol mangling style your C++ compiler uses.
672 Calling of methods and virtual functions has been improved as well.
676 The crash that occured when debugging Sun Ansi-C compiled binaries is
677 fixed. This was due to mishandling of the extra N_SO stabs output
680 We also finally got Ultrix 4.2 running in house, and fixed core file
681 support, with help from a dozen people on the net.
683 John M. Farrell discovered that the reason that single-stepping was so
684 slow on all of the Mips based platforms (primarily SGI and DEC) was
685 that we were trying to demangle and lookup a symbol used for internal
686 purposes on every instruction that was being stepped through. Changing
687 the name of that symbol so that it couldn't be mistaken for a C++
688 mangled symbol sped things up a great deal.
690 Rich Pixley sped up symbol lookups in general by getting much smarter
691 about when C++ symbol mangling is necessary. This should make symbol
692 completion (TAB on the command line) much faster. It's not as fast as
693 we'd like, but it's significantly faster than gdb-4.6.
697 A new user controllable variable 'call_scratch_address' can
698 specify the location of a scratch area to be used when GDB
699 calls a function in the target. This is necessary because the
700 usual method of putting the scratch area on the stack does not work
701 in systems that have separate instruction and data spaces.
703 We integrated changes to support the 29k UDI (Universal Debugger
704 Interface), but discovered at the last minute that we didn't have all
705 of the appropriate copyright paperwork. We are working with AMD to
706 resolve this, and hope to have it available soon.
710 We have sped up the remote serial line protocol, especially for targets
711 with lots of registers. It now supports a new `expedited status' ('T')
712 message which can be used in place of the existing 'S' status message.
713 This allows the remote stub to send only the registers that GDB
714 needs to make a quick decision about single-stepping or conditional
715 breakpoints, eliminating the need to fetch the entire register set for
716 each instruction being stepped through.
718 The GDB remote serial protocol now implements a write-through cache for
719 registers, only re-reading the registers if the target has run.
721 There is also a new remote serial stub for SPARC processors. You can
722 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
723 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
724 processor with a serial port.
728 Configure.in files have become much easier to read and modify. A new
729 `table driven' format makes it more obvious what configurations are
730 supported, and what files each one uses.
734 There is a new opcodes library which will eventually contain all of the
735 disassembly routines and opcode tables. At present, it only contains
736 Sparc and Z8000 routines. This will allow the assembler, debugger, and
737 disassembler (binutils/objdump) to share these routines.
739 The libiberty library is now copylefted under the GNU Library General
740 Public License. This allows more liberal use, and was done so libg++
741 can use it. This makes no difference to GDB, since the Library License
742 grants all the rights from the General Public License.
746 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
747 reference to the stabs symbol info used by the debugger. It is (as far
748 as we know) the only published document on this fascinating topic. We
749 encourage you to read it, compare it to the stabs information on your
750 system, and send improvements on the document in general (to
751 bug-gdb@prep.ai.mit.edu).
753 And, of course, many bugs have been fixed.
756 *** Changes in GDB-4.6:
758 * Better support for C++ function names
760 GDB now accepts as input the "demangled form" of C++ overloaded function
761 names and member function names, and can do command completion on such names
762 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
763 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
764 Make use of command completion, it is your friend.
766 GDB also now accepts a variety of C++ mangled symbol formats. They are
767 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
768 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
769 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
770 for the list of formats.
772 * G++ symbol mangling problem
774 Recent versions of gcc have a bug in how they emit debugging information for
775 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
776 directory) can be applied to gcc to fix the problem. Alternatively, if you
777 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
778 usual symptom is difficulty with setting breakpoints on methods. GDB complains
779 about the method being non-existent. (We believe that version 2.2.2 of GCC has
782 * New 'maintenance' command
784 All of the commands related to hacking GDB internals have been moved out of
785 the main command set, and now live behind the 'maintenance' command. This
786 can also be abbreviated as 'mt'. The following changes were made:
788 dump-me -> maintenance dump-me
789 info all-breakpoints -> maintenance info breakpoints
790 printmsyms -> maintenance print msyms
791 printobjfiles -> maintenance print objfiles
792 printpsyms -> maintenance print psymbols
793 printsyms -> maintenance print symbols
795 The following commands are new:
797 maintenance demangle Call internal GDB demangler routine to
798 demangle a C++ link name and prints the result.
799 maintenance print type Print a type chain for a given symbol
801 * Change to .gdbinit file processing
803 We now read the $HOME/.gdbinit file before processing the argv arguments
804 (e.g. reading symbol files or core files). This allows global parameters to
805 be set, which will apply during the symbol reading. The ./.gdbinit is still
806 read after argv processing.
808 * New hosts supported
810 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
812 Linux support i386-unknown-linux or linux
814 We are also including code to support the HP/PA running BSD and HPUX. This
815 is almost guaranteed not to work, as we didn't have time to test or build it
816 for this release. We are including it so that the more adventurous (or
817 masochistic) of you can play with it. We also had major problems with the
818 fact that the compiler that we got from HP doesn't support the -g option.
821 * New targets supported
823 Hitachi H8/300 h8300-hitachi-hms or h8300hms
825 * More smarts about finding #include files
827 GDB now remembers the compilation directory for all include files, and for
828 all files from which C is generated (like yacc and lex sources). This
829 greatly improves GDB's ability to find yacc/lex sources, and include files,
830 especially if you are debugging your program from a directory different from
831 the one that contains your sources.
833 We also fixed a bug which caused difficulty with listing and setting
834 breakpoints in include files which contain C code. (In the past, you had to
835 try twice in order to list an include file that you hadn't looked at before.)
837 * Interesting infernals change
839 GDB now deals with arbitrary numbers of sections, where the symbols for each
840 section must be relocated relative to that section's landing place in the
841 target's address space. This work was needed to support ELF with embedded
842 stabs used by Solaris-2.0.
844 * Bug fixes (of course!)
846 There have been loads of fixes for the following things:
847 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
848 i960, stabs, DOS(GO32), procfs, etc...
850 See the ChangeLog for details.
852 *** Changes in GDB-4.5:
854 * New machines supported (host and target)
856 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
858 SGI Irix-4.x mips-sgi-irix4 or iris4
862 GDB now uses a new memory manager called mmalloc, based on gmalloc.
863 Mmalloc is capable of handling mutiple heaps of memory. It is also
864 capable of saving a heap to a file, and then mapping it back in later.
865 This can be used to greatly speedup the startup of GDB by using a
866 pre-parsed symbol table which lives in a mmalloc managed heap. For
867 more details, please read mmalloc/mmalloc.texi.
871 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
872 'help info proc' for details.
874 * MIPS ecoff symbol table format
876 The code that reads MIPS symbol table format is now supported on all hosts.
877 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
880 * File name changes for MS-DOS
882 Many files in the config directories have been renamed to make it easier to
883 support GDB on MS-DOSe systems (which have very restrictive file name
884 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
885 environment) is close to working but has some remaining problems. Note
886 that debugging of DOS programs is not supported, due to limitations
887 in the ``operating system'', but it can be used to host cross-debugging.
889 * Cross byte order fixes
891 Many fixes have been made to support cross debugging of Sparc and MIPS
892 targets from hosts whose byte order differs.
894 * New -mapped and -readnow options
896 If memory-mapped files are available on your system through the 'mmap'
897 system call, you can use the -mapped option on the `file' or
898 `symbol-file' commands to cause GDB to write the symbols from your
899 program into a reusable file. If the program you are debugging is
900 called `/path/fred', the mapped symbol file will be `./fred.syms'.
901 Future GDB debugging sessions will notice the presence of this file,
902 and will quickly map in symbol information from it, rather than reading
903 the symbol table from the executable program. Using the '-mapped'
904 option in a GDB `file' or `symbol-file' command has the same effect as
905 starting GDB with the '-mapped' command-line option.
907 You can cause GDB to read the entire symbol table immediately by using
908 the '-readnow' option with any of the commands that load symbol table
909 information (or on the GDB command line). This makes the command
910 slower, but makes future operations faster.
912 The -mapped and -readnow options are typically combined in order to
913 build a `fred.syms' file that contains complete symbol information.
914 A simple GDB invocation to do nothing but build a `.syms' file for future
917 gdb -batch -nx -mapped -readnow programname
919 The `.syms' file is specific to the host machine on which GDB is run.
920 It holds an exact image of GDB's internal symbol table. It cannot be
921 shared across multiple host platforms.
925 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
926 siglongjmp() without losing control. This feature has not yet been ported to
927 all systems. It currently works on many 386 platforms, all MIPS-based
928 platforms (SGI, DECstation, etc), and Sun3/4.
932 Preliminary work has been put in to support the new Solaris OS from Sun. At
933 this time, it can control and debug processes, but it is not capable of
938 As always, many many bug fixes. The major areas were with g++, and mipsread.
939 People using the MIPS-based platforms should experience fewer mysterious
940 crashes and trashed symbol tables.
942 *** Changes in GDB-4.4:
944 * New machines supported (host and target)
946 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
948 BSD Reno on Vax vax-dec-bsd
949 Ultrix on Vax vax-dec-ultrix
951 * New machines supported (target)
953 AMD 29000 embedded, using EBMON a29k-none-none
957 GDB continues to improve its handling of C++. `References' work better.
958 The demangler has also been improved, and now deals with symbols mangled as
959 per the Annotated C++ Reference Guide.
961 GDB also now handles `stabs' symbol information embedded in MIPS
962 `ecoff' symbol tables. Since the ecoff format was not easily
963 extensible to handle new languages such as C++, this appeared to be a
964 good way to put C++ debugging info into MIPS binaries. This option
965 will be supported in the GNU C compiler, version 2, when it is
968 * New features for SVR4
970 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
971 shared libraries. Debugging dynamically linked programs should present
972 only minor differences from debugging statically linked programs.
974 The `info proc' command will print out information about any process
975 on an SVR4 system (including the one you are debugging). At the moment,
976 it prints the address mappings of the process.
978 If you bring up GDB on another SVR4 system, please send mail to
979 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
981 * Better dynamic linking support in SunOS
983 Reading symbols from shared libraries which contain debugging symbols
984 now works properly. However, there remain issues such as automatic
985 skipping of `transfer vector' code during function calls, which
986 make it harder to debug code in a shared library, than to debug the
987 same code linked statically.
991 GDB is now using the latest `getopt' routines from the FSF. This
992 version accepts the -- prefix for options with long names. GDB will
993 continue to accept the old forms (-option and +option) as well.
994 Various single letter abbreviations for options have been explicity
995 added to the option table so that they won't get overshadowed in the
996 future by other options that begin with the same letter.
1000 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
1001 Many assorted bugs have been handled. Many more remain to be handled.
1002 See the various ChangeLog files (primarily in gdb and bfd) for details.
1005 *** Changes in GDB-4.3:
1007 * New machines supported (host and target)
1009 Amiga 3000 running Amix m68k-cbm-svr4 or amix
1010 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
1011 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
1013 * Almost SCO Unix support
1015 We had hoped to support:
1016 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
1017 (except for core file support), but we discovered very late in the release
1018 that it has problems with process groups that render gdb unusable. Sorry
1019 about that. I encourage people to fix it and post the fixes.
1021 * Preliminary ELF and DWARF support
1023 GDB can read ELF object files on System V Release 4, and can handle
1024 debugging records for C, in DWARF format, in ELF files. This support
1025 is preliminary. If you bring up GDB on another SVR4 system, please
1026 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
1031 GDB now uses the latest `readline' library. One user-visible change
1032 is that two tabs will list possible command completions, which previously
1033 required typing M-? (meta-question mark, or ESC ?).
1037 The `stepi' bug that many of you noticed has been squashed.
1038 Many bugs in C++ have been handled. Many more remain to be handled.
1039 See the various ChangeLog files (primarily in gdb and bfd) for details.
1041 * State of the MIPS world (in case you wondered):
1043 GDB can understand the symbol tables emitted by the compilers
1044 supplied by most vendors of MIPS-based machines, including DEC. These
1045 symbol tables are in a format that essentially nobody else uses.
1047 Some versions of gcc come with an assembler post-processor called
1048 mips-tfile. This program is required if you want to do source-level
1049 debugging of gcc-compiled programs. I believe FSF does not ship
1050 mips-tfile with gcc version 1, but it will eventually come with gcc
1053 Debugging of g++ output remains a problem. g++ version 1.xx does not
1054 really support it at all. (If you're lucky, you should be able to get
1055 line numbers and stack traces to work, but no parameters or local
1056 variables.) With some work it should be possible to improve the
1059 When gcc version 2 is released, you will have somewhat better luck.
1060 However, even then you will get confusing results for inheritance and
1063 We will eventually provide full debugging of g++ output on
1064 DECstations. This will probably involve some kind of stabs-in-ecoff
1065 encapulation, but the details have not been worked out yet.
1068 *** Changes in GDB-4.2:
1070 * Improved configuration
1072 Only one copy of `configure' exists now, and it is not self-modifying.
1073 Porting BFD is simpler.
1077 The `step' and `next' commands now only stop at the first instruction
1078 of a source line. This prevents the multiple stops that used to occur
1079 in switch statements, for-loops, etc. `Step' continues to stop if a
1080 function that has debugging information is called within the line.
1084 Lots of small bugs fixed. More remain.
1086 * New host supported (not target)
1088 Intel 386 PC clone running Mach i386-none-mach
1091 *** Changes in GDB-4.1:
1093 * Multiple source language support
1095 GDB now has internal scaffolding to handle several source languages.
1096 It determines the type of each source file from its filename extension,
1097 and will switch expression parsing and number formatting to match the
1098 language of the function in the currently selected stack frame.
1099 You can also specifically set the language to be used, with
1100 `set language c' or `set language modula-2'.
1104 GDB now has preliminary support for the GNU Modula-2 compiler,
1105 currently under development at the State University of New York at
1106 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
1107 continue through the fall of 1991 and into 1992.
1109 Other Modula-2 compilers are currently not supported, and attempting to
1110 debug programs compiled with them will likely result in an error as the
1111 symbol table is read. Feel free to work on it, though!
1113 There are hooks in GDB for strict type checking and range checking,
1114 in the `Modula-2 philosophy', but they do not currently work.
1118 GDB can now write to executable and core files (e.g. patch
1119 a variable's value). You must turn this switch on, specify
1120 the file ("exec foo" or "core foo"), *then* modify it, e.g.
1121 by assigning a new value to a variable. Modifications take
1124 * Automatic SunOS shared library reading
1126 When you run your program, GDB automatically determines where its
1127 shared libraries (if any) have been loaded, and reads their symbols.
1128 The `share' command is no longer needed. This also works when
1129 examining core files.
1133 You can specify the number of lines that the `list' command shows.
1136 * New machines supported (host and target)
1138 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
1139 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
1140 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
1142 * New hosts supported (not targets)
1144 IBM RT/PC: romp-ibm-aix or rtpc
1146 * New targets supported (not hosts)
1148 AMD 29000 embedded with COFF a29k-none-coff
1149 AMD 29000 embedded with a.out a29k-none-aout
1150 Ultracomputer remote kernel debug a29k-nyu-kern
1152 * New remote interfaces
1158 *** Changes in GDB-4.0:
1162 Wide output is wrapped at good places to make the output more readable.
1164 Gdb now supports cross-debugging from a host machine of one type to a
1165 target machine of another type. Communication with the target system
1166 is over serial lines. The ``target'' command handles connecting to the
1167 remote system; the ``load'' command will download a program into the
1168 remote system. Serial stubs for the m68k and i386 are provided. Gdb
1169 also supports debugging of realtime processes running under VxWorks,
1170 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
1171 stub on the target system.
1173 New CPUs supported include the AMD 29000 and Intel 960.
1175 GDB now reads object files and symbol tables via a ``binary file''
1176 library, which allows a single copy of GDB to debug programs of multiple
1177 object file types such as a.out and coff.
1179 There is now a GDB reference card in "doc/refcard.tex". (Make targets
1180 refcard.dvi and refcard.ps are available to format it).
1183 * Control-Variable user interface simplified
1185 All variables that control the operation of the debugger can be set
1186 by the ``set'' command, and displayed by the ``show'' command.
1188 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
1189 ``Show prompt'' produces the response:
1190 Gdb's prompt is new-gdb=>.
1192 What follows are the NEW set commands. The command ``help set'' will
1193 print a complete list of old and new set commands. ``help set FOO''
1194 will give a longer description of the variable FOO. ``show'' will show
1195 all of the variable descriptions and their current settings.
1197 confirm on/off: Enables warning questions for operations that are
1198 hard to recover from, e.g. rerunning the program while
1199 it is already running. Default is ON.
1201 editing on/off: Enables EMACS style command line editing
1202 of input. Previous lines can be recalled with
1203 control-P, the current line can be edited with control-B,
1204 you can search for commands with control-R, etc.
1207 history filename NAME: NAME is where the gdb command history
1208 will be stored. The default is .gdb_history,
1209 or the value of the environment variable
1212 history size N: The size, in commands, of the command history. The
1213 default is 256, or the value of the environment variable
1216 history save on/off: If this value is set to ON, the history file will
1217 be saved after exiting gdb. If set to OFF, the
1218 file will not be saved. The default is OFF.
1220 history expansion on/off: If this value is set to ON, then csh-like
1221 history expansion will be performed on
1222 command line input. The default is OFF.
1224 radix N: Sets the default radix for input and output. It can be set
1225 to 8, 10, or 16. Note that the argument to "radix" is interpreted
1226 in the current radix, so "set radix 10" is always a no-op.
1228 height N: This integer value is the number of lines on a page. Default
1229 is 24, the current `stty rows'' setting, or the ``li#''
1230 setting from the termcap entry matching the environment
1233 width N: This integer value is the number of characters on a line.
1234 Default is 80, the current `stty cols'' setting, or the ``co#''
1235 setting from the termcap entry matching the environment
1238 Note: ``set screensize'' is obsolete. Use ``set height'' and
1239 ``set width'' instead.
1241 print address on/off: Print memory addresses in various command displays,
1242 such as stack traces and structure values. Gdb looks
1243 more ``symbolic'' if you turn this off; it looks more
1244 ``machine level'' with it on. Default is ON.
1246 print array on/off: Prettyprint arrays. New convenient format! Default
1249 print demangle on/off: Print C++ symbols in "source" form if on,
1252 print asm-demangle on/off: Same, for assembler level printouts
1255 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
1258 * Support for Epoch Environment.
1260 The epoch environment is a version of Emacs v18 with windowing. One
1261 new command, ``inspect'', is identical to ``print'', except that if you
1262 are running in the epoch environment, the value is printed in its own
1266 * Support for Shared Libraries
1268 GDB can now debug programs and core files that use SunOS shared libraries.
1269 Symbols from a shared library cannot be referenced
1270 before the shared library has been linked with the program (this
1271 happens after you type ``run'' and before the function main() is entered).
1272 At any time after this linking (including when examining core files
1273 from dynamically linked programs), gdb reads the symbols from each
1274 shared library when you type the ``sharedlibrary'' command.
1275 It can be abbreviated ``share''.
1277 sharedlibrary REGEXP: Load shared object library symbols for files
1278 matching a unix regular expression. No argument
1279 indicates to load symbols for all shared libraries.
1281 info sharedlibrary: Status of loaded shared libraries.
1286 A watchpoint stops execution of a program whenever the value of an
1287 expression changes. Checking for this slows down execution
1288 tremendously whenever you are in the scope of the expression, but is
1289 quite useful for catching tough ``bit-spreader'' or pointer misuse
1290 problems. Some machines such as the 386 have hardware for doing this
1291 more quickly, and future versions of gdb will use this hardware.
1293 watch EXP: Set a watchpoint (breakpoint) for an expression.
1295 info watchpoints: Information about your watchpoints.
1297 delete N: Deletes watchpoint number N (same as breakpoints).
1298 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
1299 enable N: Re-enables watchpoint number N (same as breakpoints).
1302 * C++ multiple inheritance
1304 When used with a GCC version 2 compiler, GDB supports multiple inheritance
1307 * C++ exception handling
1309 Gdb now supports limited C++ exception handling. Besides the existing
1310 ability to breakpoint on an exception handler, gdb can breakpoint on
1311 the raising of an exception (before the stack is peeled back to the
1314 catch FOO: If there is a FOO exception handler in the dynamic scope,
1315 set a breakpoint to catch exceptions which may be raised there.
1316 Multiple exceptions (``catch foo bar baz'') may be caught.
1318 info catch: Lists all exceptions which may be caught in the
1319 current stack frame.
1322 * Minor command changes
1324 The command ``call func (arg, arg, ...)'' now acts like the print
1325 command, except it does not print or save a value if the function's result
1326 is void. This is similar to dbx usage.
1328 The ``up'' and ``down'' commands now always print the frame they end up
1329 at; ``up-silently'' and `down-silently'' can be used in scripts to change
1330 frames without printing.
1332 * New directory command
1334 'dir' now adds directories to the FRONT of the source search path.
1335 The path starts off empty. Source files that contain debug information
1336 about the directory in which they were compiled can be found even
1337 with an empty path; Sun CC and GCC include this information. If GDB can't
1338 find your source file in the current directory, type "dir .".
1340 * Configuring GDB for compilation
1342 For normal use, type ``./configure host''. See README or gdb.texinfo
1345 GDB now handles cross debugging. If you are remotely debugging between
1346 two different machines, type ``./configure host -target=targ''.
1347 Host is the machine where GDB will run; targ is the machine
1348 where the program that you are debugging will run.
projects / deliverable / binutils-gdb.git / blob