1 What has changed since GDB-3.5?
2 (Organized release by release)
4 * New "if" and "while" commands. This makes it possible to write
5 somewhat more sophisticated user-defined commands.
7 * Most debugging facilities now work on dynamic executables for HPPAs
8 running hpux9 or later. See the GDB manual for the few minor problems
9 and potential workarounds.
11 * GDB can now read debug symbols produced by the HP C compiler on HPPAs
12 (sorry, no C++, Fortran or 68k support).
14 *** Changes in GDB-4.13:
16 * New "complete" command
18 This lists all the possible completions for the rest of the line, if it
19 were to be given as a command itself. This is intended for use by emacs.
21 * Trailing space optional in prompt
23 "set prompt" no longer adds a space for you after the prompt you set. This
24 allows you to set a prompt which ends in a space or one that does not.
26 * Breakpoint hit counts
28 "info break" now displays a count of the number of times the breakpoint
29 has been hit. This is especially useful in conjunction with "ignore"; you
30 can ignore a large number of breakpoint hits, look at the breakpoint info
31 to see how many times the breakpoint was hit, then run again, ignoring one
32 less than that number, and this will get you quickly to the last hit of
35 * Ability to stop printing at NULL character
37 "set print null-stop" will cause GDB to stop printing the characters of
38 an array when the first NULL is encountered. This is useful when large
39 arrays actually contain only short strings.
41 * Shared library breakpoints
43 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
44 breakpoints in shared libraries before the executable is run.
46 * Hardware watchpoints
48 There is a new hardware breakpoint for the watch command for sparclite
49 targets. See gdb/sparclite/hw_breakpoint.note.
51 Hardware watchpoints are also now supported under Linux.
55 Annotations have been added. These are for use with graphical interfaces,
56 and are still experimental. Currently only gdba.el uses these.
58 * Improved Irix 5 support
60 GDB now works properly with Irix 5.2.
62 * Improved HPPA support
64 GDB now works properly with the latest GCC and GAS.
66 * New native configurations
68 Sequent PTX4 i[34]86-sequent-ptx4
69 HPPA running OSF/1 hppa*-*-osf*
70 Atari TT running SVR4 m68*-*-sysv4*
71 RS/6000 LynxOS rs6000-*-lynxos*
75 OS/9000 i[34]86-*-os9k
76 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
79 * Hitachi SH7000 and E7000-PC ICE support
81 There is now support for communicating with the Hitachi E7000-PC ICE.
82 This is available automatically when GDB is configured for the SH.
86 As usual, a variety of small fixes and improvements, both generic
87 and configuration-specific. See the ChangeLog for more detail.
89 *** Changes in GDB-4.12:
91 * Irix 5 is now supported
95 GDB-4.12 on the HPPA has a number of changes which make it unable
96 to debug the output from the currently released versions of GCC and
97 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
98 of GCC and GAS, versions of these tools designed to work with GDB-4.12
99 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
102 *** Changes in GDB-4.11:
104 * User visible changes:
108 The "set remotedebug" option is now consistent between the mips remote
109 target, remote targets using the gdb-specific protocol, UDI (AMD's
110 debug protocol for the 29k) and the 88k bug monitor. It is now an
111 integer specifying a debug level (normally 0 or 1, but 2 means more
112 debugging info for the mips target).
114 * DEC Alpha native support
116 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
117 debug info, but GDB works fairly well with the DEC compiler and should
118 work with a future GCC release. See the README file for a few
119 Alpha-specific notes.
121 * Preliminary thread implementation
123 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
125 * LynxOS native and target support for 386
127 This release has been hosted on LynxOS 2.2, and also can be configured
128 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
131 * Improvements in C++ mangling/demangling.
133 This release has much better g++ debugging, specifically in name
134 mangling/demangling, virtual function calls, print virtual table,
135 call methods, ...etc.
137 *** Changes in GDB-4.10:
139 * User visible changes:
141 Remote debugging using the GDB-specific (`target remote') protocol now
142 supports the `load' command. This is only useful if you have some
143 other way of getting the stub to the target system, and you can put it
144 somewhere in memory where it won't get clobbered by the download.
146 Filename completion now works.
148 When run under emacs mode, the "info line" command now causes the
149 arrow to point to the line specified. Also, "info line" prints
150 addresses in symbolic form (as well as hex).
152 All vxworks based targets now support a user settable option, called
153 vxworks-timeout. This option represents the number of seconds gdb
154 should wait for responses to rpc's. You might want to use this if
155 your vxworks target is, perhaps, a slow software simulator or happens
156 to be on the far side of a thin network line.
160 This release contains support for using a DEC alpha as a GDB host for
161 cross debugging. Native alpha debugging is not supported yet.
164 *** Changes in GDB-4.9:
168 This is the first GDB release which is accompanied by a matching testsuite.
169 The testsuite requires installation of dejagnu, which should be available
170 via ftp from most sites that carry GNU software.
174 'Cfront' style demangling has had its name changed to 'ARM' style, to
175 emphasize that it was written from the specifications in the C++ Annotated
176 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
177 disclaimers, it still generated too much confusion with users attempting to
178 use gdb with AT&T cfront.
182 GDB now uses a standard remote interface to a simulator library.
183 So far, the library contains simulators for the Zilog Z8001/2, the
184 Hitachi H8/300, H8/500 and Super-H.
186 * New targets supported
188 H8/300 simulator h8300-hitachi-hms or h8300hms
189 H8/500 simulator h8500-hitachi-hms or h8500hms
190 SH simulator sh-hitachi-hms or sh
191 Z8000 simulator z8k-zilog-none or z8ksim
192 IDT MIPS board over serial line mips-idt-ecoff
194 Cross-debugging to GO32 targets is supported. It requires a custom
195 version of the i386-stub.c module which is integrated with the
196 GO32 memory extender.
198 * New remote protocols
200 MIPS remote debugging protocol.
202 * New source languages supported
204 This version includes preliminary support for Chill, a Pascal like language
205 used by telecommunications companies. Chill support is also being integrated
206 into the GNU compiler, but we don't know when it will be publically available.
209 *** Changes in GDB-4.8:
211 * HP Precision Architecture supported
213 GDB now supports HP PA-RISC machines running HPUX. A preliminary
214 version of this support was available as a set of patches from the
215 University of Utah. GDB does not support debugging of programs
216 compiled with the HP compiler, because HP will not document their file
217 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
218 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
220 Many problems in the preliminary version have been fixed.
222 * Faster and better demangling
224 We have improved template demangling and fixed numerous bugs in the GNU style
225 demangler. It can now handle type modifiers such as `static' or `const'. Wide
226 character types (wchar_t) are now supported. Demangling of each symbol is now
227 only done once, and is cached when the symbol table for a file is read in.
228 This results in a small increase in memory usage for C programs, a moderate
229 increase in memory usage for C++ programs, and a fantastic speedup in
232 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
233 from the specifications in the Annotated Reference Manual, which AT&T's
234 compiler does not actually implement.
236 * G++ multiple inheritance compiler problem
238 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
239 inheritance lattices was reworked to properly discover ambiguities. We
240 recently found an example which causes this new algorithm to fail in a
241 very subtle way, producing bad debug information for those classes.
242 The file 'gcc.patch' (in this directory) can be applied to gcc to
243 circumvent the problem. A future GCC release will contain a complete
246 The previous G++ debug info problem (mentioned below for the gdb-4.7
247 release) is fixed in gcc version 2.3.2.
249 * Improved configure script
251 The `configure' script will now attempt to guess your system type if
252 you don't supply a host system type. The old scheme of supplying a
253 host system triplet is preferable over using this. All the magic is
254 done in the new `config.guess' script. Examine it for details.
256 We have also brought our configure script much more in line with the FSF's
257 version. It now supports the --with-xxx options. In particular,
258 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
259 The resulting GDB will not be able to read arbitrary object file formats --
260 only the format ``expected'' to be used on the configured target system.
261 We hope to make this the default in a future release.
263 * Documentation improvements
265 There's new internal documentation on how to modify GDB, and how to
266 produce clean changes to the code. We implore people to read it
267 before submitting changes.
269 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
270 M4 macros. The new texinfo.tex is provided in this release. Pre-built
271 `info' files are also provided. To build `info' files from scratch,
272 you will need the latest `makeinfo' release, which will be available in
273 a future texinfo-X.Y release.
275 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
276 We're not sure exactly which versions have this problem, but it has
277 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
278 or better. If that isn't possible, there is a patch in
279 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
284 GDB now supports array constants that can be used in expressions typed in by
285 the user. The syntax is `{element, element, ...}'. Ie: you can now type
286 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
289 The new directory `gdb/sparclite' contains a program that demonstrates
290 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
292 * New native hosts supported
294 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
295 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
297 * New targets supported
299 AMD 29k family via UDI a29k-amd-udi or udi29k
301 * New file formats supported
303 BFD now supports reading HP/PA-RISC executables (SOM file format?),
304 HPUX core files, and SCO 3.2v2 core files.
308 Attaching to processes now works again; thanks for the many bug reports.
310 We have also stomped on a bunch of core dumps caused by
311 printf_filtered("%s") problems.
313 We eliminated a copyright problem on the rpc and ptrace header files
314 for VxWorks, which was discovered at the last minute during the 4.7
315 release. You should now be able to build a VxWorks GDB.
317 You can now interrupt gdb while an attached process is running. This
318 will cause the attached process to stop, and give control back to GDB.
320 We fixed problems caused by using too many file descriptors
321 for reading symbols from object files and libraries. This was
322 especially a problem for programs that used many (~100) shared
325 The `step' command now only enters a subroutine if there is line number
326 information for the subroutine. Otherwise it acts like the `next'
327 command. Previously, `step' would enter subroutines if there was
328 any debugging information about the routine. This avoids problems
329 when using `cc -g1' on MIPS machines.
331 * Internal improvements
333 GDB's internal interfaces have been improved to make it easier to support
334 debugging of multiple languages in the future.
336 GDB now uses a common structure for symbol information internally.
337 Minimal symbols (derived from linkage symbols in object files), partial
338 symbols (from a quick scan of debug information), and full symbols
339 contain a common subset of information, making it easier to write
340 shared code that handles any of them.
342 * New command line options
344 We now accept --silent as an alias for --quiet.
348 The memory-mapped-malloc library is now licensed under the GNU Library
349 General Public License.
351 *** Changes in GDB-4.7:
353 * Host/native/target split
355 GDB has had some major internal surgery to untangle the support for
356 hosts and remote targets. Now, when you configure GDB for a remote
357 target, it will no longer load in all of the support for debugging
358 local programs on the host. When fully completed and tested, this will
359 ensure that arbitrary host/target combinations are possible.
361 The primary conceptual shift is to separate the non-portable code in
362 GDB into three categories. Host specific code is required any time GDB
363 is compiled on that host, regardless of the target. Target specific
364 code relates to the peculiarities of the target, but can be compiled on
365 any host. Native specific code is everything else: it can only be
366 built when the host and target are the same system. Child process
367 handling and core file support are two common `native' examples.
369 GDB's use of /proc for controlling Unix child processes is now cleaner.
370 It has been split out into a single module under the `target_ops' vector,
371 plus two native-dependent functions for each system that uses /proc.
373 * New hosts supported
375 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
376 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
377 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
379 * New targets supported
381 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
382 68030 and CPU32 m68030-*-*, m68332-*-*
384 * New native hosts supported
386 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
387 (386bsd is not well tested yet)
388 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
390 * New file formats supported
392 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
393 supports reading of `a.out.adobe' object files, which are an a.out
394 format extended with minimal information about multiple sections.
398 `show copying' is the same as the old `info copying'.
399 `show warranty' is the same as `info warrantee'.
400 These were renamed for consistency. The old commands continue to work.
402 `info handle' is a new alias for `info signals'.
404 You can now define pre-command hooks, which attach arbitrary command
405 scripts to any command. The commands in the hook will be executed
406 prior to the user's command. You can also create a hook which will be
407 executed whenever the program stops. See gdb.texinfo.
411 We now deal with Cfront style name mangling, and can even extract type
412 info from mangled symbols. GDB can automatically figure out which
413 symbol mangling style your C++ compiler uses.
415 Calling of methods and virtual functions has been improved as well.
419 The crash that occured when debugging Sun Ansi-C compiled binaries is
420 fixed. This was due to mishandling of the extra N_SO stabs output
423 We also finally got Ultrix 4.2 running in house, and fixed core file
424 support, with help from a dozen people on the net.
426 John M. Farrell discovered that the reason that single-stepping was so
427 slow on all of the Mips based platforms (primarily SGI and DEC) was
428 that we were trying to demangle and lookup a symbol used for internal
429 purposes on every instruction that was being stepped through. Changing
430 the name of that symbol so that it couldn't be mistaken for a C++
431 mangled symbol sped things up a great deal.
433 Rich Pixley sped up symbol lookups in general by getting much smarter
434 about when C++ symbol mangling is necessary. This should make symbol
435 completion (TAB on the command line) much faster. It's not as fast as
436 we'd like, but it's significantly faster than gdb-4.6.
440 A new user controllable variable 'call_scratch_address' can
441 specify the location of a scratch area to be used when GDB
442 calls a function in the target. This is necessary because the
443 usual method of putting the scratch area on the stack does not work
444 in systems that have separate instruction and data spaces.
446 We integrated changes to support the 29k UDI (Universal Debugger
447 Interface), but discovered at the last minute that we didn't have all
448 of the appropriate copyright paperwork. We are working with AMD to
449 resolve this, and hope to have it available soon.
453 We have sped up the remote serial line protocol, especially for targets
454 with lots of registers. It now supports a new `expedited status' ('T')
455 message which can be used in place of the existing 'S' status message.
456 This allows the remote stub to send only the registers that GDB
457 needs to make a quick decision about single-stepping or conditional
458 breakpoints, eliminating the need to fetch the entire register set for
459 each instruction being stepped through.
461 The GDB remote serial protocol now implements a write-through cache for
462 registers, only re-reading the registers if the target has run.
464 There is also a new remote serial stub for SPARC processors. You can
465 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
466 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
467 processor with a serial port.
471 Configure.in files have become much easier to read and modify. A new
472 `table driven' format makes it more obvious what configurations are
473 supported, and what files each one uses.
477 There is a new opcodes library which will eventually contain all of the
478 disassembly routines and opcode tables. At present, it only contains
479 Sparc and Z8000 routines. This will allow the assembler, debugger, and
480 disassembler (binutils/objdump) to share these routines.
482 The libiberty library is now copylefted under the GNU Library General
483 Public License. This allows more liberal use, and was done so libg++
484 can use it. This makes no difference to GDB, since the Library License
485 grants all the rights from the General Public License.
489 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
490 reference to the stabs symbol info used by the debugger. It is (as far
491 as we know) the only published document on this fascinating topic. We
492 encourage you to read it, compare it to the stabs information on your
493 system, and send improvements on the document in general (to
494 bug-gdb@prep.ai.mit.edu).
496 And, of course, many bugs have been fixed.
499 *** Changes in GDB-4.6:
501 * Better support for C++ function names
503 GDB now accepts as input the "demangled form" of C++ overloaded function
504 names and member function names, and can do command completion on such names
505 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
506 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
507 Make use of command completion, it is your friend.
509 GDB also now accepts a variety of C++ mangled symbol formats. They are
510 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
511 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
512 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
513 for the list of formats.
515 * G++ symbol mangling problem
517 Recent versions of gcc have a bug in how they emit debugging information for
518 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
519 directory) can be applied to gcc to fix the problem. Alternatively, if you
520 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
521 usual symptom is difficulty with setting breakpoints on methods. GDB complains
522 about the method being non-existent. (We believe that version 2.2.2 of GCC has
525 * New 'maintenance' command
527 All of the commands related to hacking GDB internals have been moved out of
528 the main command set, and now live behind the 'maintenance' command. This
529 can also be abbreviated as 'mt'. The following changes were made:
531 dump-me -> maintenance dump-me
532 info all-breakpoints -> maintenance info breakpoints
533 printmsyms -> maintenance print msyms
534 printobjfiles -> maintenance print objfiles
535 printpsyms -> maintenance print psymbols
536 printsyms -> maintenance print symbols
538 The following commands are new:
540 maintenance demangle Call internal GDB demangler routine to
541 demangle a C++ link name and prints the result.
542 maintenance print type Print a type chain for a given symbol
544 * Change to .gdbinit file processing
546 We now read the $HOME/.gdbinit file before processing the argv arguments
547 (e.g. reading symbol files or core files). This allows global parameters to
548 be set, which will apply during the symbol reading. The ./.gdbinit is still
549 read after argv processing.
551 * New hosts supported
553 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
555 Linux support i386-unknown-linux or linux
557 We are also including code to support the HP/PA running BSD and HPUX. This
558 is almost guaranteed not to work, as we didn't have time to test or build it
559 for this release. We are including it so that the more adventurous (or
560 masochistic) of you can play with it. We also had major problems with the
561 fact that the compiler that we got from HP doesn't support the -g option.
564 * New targets supported
566 Hitachi H8/300 h8300-hitachi-hms or h8300hms
568 * More smarts about finding #include files
570 GDB now remembers the compilation directory for all include files, and for
571 all files from which C is generated (like yacc and lex sources). This
572 greatly improves GDB's ability to find yacc/lex sources, and include files,
573 especially if you are debugging your program from a directory different from
574 the one that contains your sources.
576 We also fixed a bug which caused difficulty with listing and setting
577 breakpoints in include files which contain C code. (In the past, you had to
578 try twice in order to list an include file that you hadn't looked at before.)
580 * Interesting infernals change
582 GDB now deals with arbitrary numbers of sections, where the symbols for each
583 section must be relocated relative to that section's landing place in the
584 target's address space. This work was needed to support ELF with embedded
585 stabs used by Solaris-2.0.
587 * Bug fixes (of course!)
589 There have been loads of fixes for the following things:
590 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
591 i960, stabs, DOS(GO32), procfs, etc...
593 See the ChangeLog for details.
595 *** Changes in GDB-4.5:
597 * New machines supported (host and target)
599 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
601 SGI Irix-4.x mips-sgi-irix4 or iris4
605 GDB now uses a new memory manager called mmalloc, based on gmalloc.
606 Mmalloc is capable of handling mutiple heaps of memory. It is also
607 capable of saving a heap to a file, and then mapping it back in later.
608 This can be used to greatly speedup the startup of GDB by using a
609 pre-parsed symbol table which lives in a mmalloc managed heap. For
610 more details, please read mmalloc/mmalloc.texi.
614 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
615 'help info proc' for details.
617 * MIPS ecoff symbol table format
619 The code that reads MIPS symbol table format is now supported on all hosts.
620 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
623 * File name changes for MS-DOS
625 Many files in the config directories have been renamed to make it easier to
626 support GDB on MS-DOSe systems (which have very restrictive file name
627 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
628 environment) is close to working but has some remaining problems. Note
629 that debugging of DOS programs is not supported, due to limitations
630 in the ``operating system'', but it can be used to host cross-debugging.
632 * Cross byte order fixes
634 Many fixes have been made to support cross debugging of Sparc and MIPS
635 targets from hosts whose byte order differs.
637 * New -mapped and -readnow options
639 If memory-mapped files are available on your system through the 'mmap'
640 system call, you can use the -mapped option on the `file' or
641 `symbol-file' commands to cause GDB to write the symbols from your
642 program into a reusable file. If the program you are debugging is
643 called `/path/fred', the mapped symbol file will be `./fred.syms'.
644 Future GDB debugging sessions will notice the presence of this file,
645 and will quickly map in symbol information from it, rather than reading
646 the symbol table from the executable program. Using the '-mapped'
647 option in a GDB `file' or `symbol-file' command has the same effect as
648 starting GDB with the '-mapped' command-line option.
650 You can cause GDB to read the entire symbol table immediately by using
651 the '-readnow' option with any of the commands that load symbol table
652 information (or on the GDB command line). This makes the command
653 slower, but makes future operations faster.
655 The -mapped and -readnow options are typically combined in order to
656 build a `fred.syms' file that contains complete symbol information.
657 A simple GDB invocation to do nothing but build a `.syms' file for future
660 gdb -batch -nx -mapped -readnow programname
662 The `.syms' file is specific to the host machine on which GDB is run.
663 It holds an exact image of GDB's internal symbol table. It cannot be
664 shared across multiple host platforms.
668 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
669 siglongjmp() without losing control. This feature has not yet been ported to
670 all systems. It currently works on many 386 platforms, all MIPS-based
671 platforms (SGI, DECstation, etc), and Sun3/4.
675 Preliminary work has been put in to support the new Solaris OS from Sun. At
676 this time, it can control and debug processes, but it is not capable of
681 As always, many many bug fixes. The major areas were with g++, and mipsread.
682 People using the MIPS-based platforms should experience fewer mysterious
683 crashes and trashed symbol tables.
685 *** Changes in GDB-4.4:
687 * New machines supported (host and target)
689 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
691 BSD Reno on Vax vax-dec-bsd
692 Ultrix on Vax vax-dec-ultrix
694 * New machines supported (target)
696 AMD 29000 embedded, using EBMON a29k-none-none
700 GDB continues to improve its handling of C++. `References' work better.
701 The demangler has also been improved, and now deals with symbols mangled as
702 per the Annotated C++ Reference Guide.
704 GDB also now handles `stabs' symbol information embedded in MIPS
705 `ecoff' symbol tables. Since the ecoff format was not easily
706 extensible to handle new languages such as C++, this appeared to be a
707 good way to put C++ debugging info into MIPS binaries. This option
708 will be supported in the GNU C compiler, version 2, when it is
711 * New features for SVR4
713 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
714 shared libraries. Debugging dynamically linked programs should present
715 only minor differences from debugging statically linked programs.
717 The `info proc' command will print out information about any process
718 on an SVR4 system (including the one you are debugging). At the moment,
719 it prints the address mappings of the process.
721 If you bring up GDB on another SVR4 system, please send mail to
722 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
724 * Better dynamic linking support in SunOS
726 Reading symbols from shared libraries which contain debugging symbols
727 now works properly. However, there remain issues such as automatic
728 skipping of `transfer vector' code during function calls, which
729 make it harder to debug code in a shared library, than to debug the
730 same code linked statically.
734 GDB is now using the latest `getopt' routines from the FSF. This
735 version accepts the -- prefix for options with long names. GDB will
736 continue to accept the old forms (-option and +option) as well.
737 Various single letter abbreviations for options have been explicity
738 added to the option table so that they won't get overshadowed in the
739 future by other options that begin with the same letter.
743 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
744 Many assorted bugs have been handled. Many more remain to be handled.
745 See the various ChangeLog files (primarily in gdb and bfd) for details.
748 *** Changes in GDB-4.3:
750 * New machines supported (host and target)
752 Amiga 3000 running Amix m68k-cbm-svr4 or amix
753 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
754 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
756 * Almost SCO Unix support
758 We had hoped to support:
759 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
760 (except for core file support), but we discovered very late in the release
761 that it has problems with process groups that render gdb unusable. Sorry
762 about that. I encourage people to fix it and post the fixes.
764 * Preliminary ELF and DWARF support
766 GDB can read ELF object files on System V Release 4, and can handle
767 debugging records for C, in DWARF format, in ELF files. This support
768 is preliminary. If you bring up GDB on another SVR4 system, please
769 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
774 GDB now uses the latest `readline' library. One user-visible change
775 is that two tabs will list possible command completions, which previously
776 required typing M-? (meta-question mark, or ESC ?).
780 The `stepi' bug that many of you noticed has been squashed.
781 Many bugs in C++ have been handled. Many more remain to be handled.
782 See the various ChangeLog files (primarily in gdb and bfd) for details.
784 * State of the MIPS world (in case you wondered):
786 GDB can understand the symbol tables emitted by the compilers
787 supplied by most vendors of MIPS-based machines, including DEC. These
788 symbol tables are in a format that essentially nobody else uses.
790 Some versions of gcc come with an assembler post-processor called
791 mips-tfile. This program is required if you want to do source-level
792 debugging of gcc-compiled programs. I believe FSF does not ship
793 mips-tfile with gcc version 1, but it will eventually come with gcc
796 Debugging of g++ output remains a problem. g++ version 1.xx does not
797 really support it at all. (If you're lucky, you should be able to get
798 line numbers and stack traces to work, but no parameters or local
799 variables.) With some work it should be possible to improve the
802 When gcc version 2 is released, you will have somewhat better luck.
803 However, even then you will get confusing results for inheritance and
806 We will eventually provide full debugging of g++ output on
807 DECstations. This will probably involve some kind of stabs-in-ecoff
808 encapulation, but the details have not been worked out yet.
811 *** Changes in GDB-4.2:
813 * Improved configuration
815 Only one copy of `configure' exists now, and it is not self-modifying.
816 Porting BFD is simpler.
820 The `step' and `next' commands now only stop at the first instruction
821 of a source line. This prevents the multiple stops that used to occur
822 in switch statements, for-loops, etc. `Step' continues to stop if a
823 function that has debugging information is called within the line.
827 Lots of small bugs fixed. More remain.
829 * New host supported (not target)
831 Intel 386 PC clone running Mach i386-none-mach
834 *** Changes in GDB-4.1:
836 * Multiple source language support
838 GDB now has internal scaffolding to handle several source languages.
839 It determines the type of each source file from its filename extension,
840 and will switch expression parsing and number formatting to match the
841 language of the function in the currently selected stack frame.
842 You can also specifically set the language to be used, with
843 `set language c' or `set language modula-2'.
847 GDB now has preliminary support for the GNU Modula-2 compiler,
848 currently under development at the State University of New York at
849 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
850 continue through the fall of 1991 and into 1992.
852 Other Modula-2 compilers are currently not supported, and attempting to
853 debug programs compiled with them will likely result in an error as the
854 symbol table is read. Feel free to work on it, though!
856 There are hooks in GDB for strict type checking and range checking,
857 in the `Modula-2 philosophy', but they do not currently work.
861 GDB can now write to executable and core files (e.g. patch
862 a variable's value). You must turn this switch on, specify
863 the file ("exec foo" or "core foo"), *then* modify it, e.g.
864 by assigning a new value to a variable. Modifications take
867 * Automatic SunOS shared library reading
869 When you run your program, GDB automatically determines where its
870 shared libraries (if any) have been loaded, and reads their symbols.
871 The `share' command is no longer needed. This also works when
872 examining core files.
876 You can specify the number of lines that the `list' command shows.
879 * New machines supported (host and target)
881 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
882 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
883 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
885 * New hosts supported (not targets)
887 IBM RT/PC: romp-ibm-aix or rtpc
889 * New targets supported (not hosts)
891 AMD 29000 embedded with COFF a29k-none-coff
892 AMD 29000 embedded with a.out a29k-none-aout
893 Ultracomputer remote kernel debug a29k-nyu-kern
895 * New remote interfaces
901 *** Changes in GDB-4.0:
905 Wide output is wrapped at good places to make the output more readable.
907 Gdb now supports cross-debugging from a host machine of one type to a
908 target machine of another type. Communication with the target system
909 is over serial lines. The ``target'' command handles connecting to the
910 remote system; the ``load'' command will download a program into the
911 remote system. Serial stubs for the m68k and i386 are provided. Gdb
912 also supports debugging of realtime processes running under VxWorks,
913 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
914 stub on the target system.
916 New CPUs supported include the AMD 29000 and Intel 960.
918 GDB now reads object files and symbol tables via a ``binary file''
919 library, which allows a single copy of GDB to debug programs of multiple
920 object file types such as a.out and coff.
922 There is now a GDB reference card in "doc/refcard.tex". (Make targets
923 refcard.dvi and refcard.ps are available to format it).
926 * Control-Variable user interface simplified
928 All variables that control the operation of the debugger can be set
929 by the ``set'' command, and displayed by the ``show'' command.
931 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
932 ``Show prompt'' produces the response:
933 Gdb's prompt is new-gdb=>.
935 What follows are the NEW set commands. The command ``help set'' will
936 print a complete list of old and new set commands. ``help set FOO''
937 will give a longer description of the variable FOO. ``show'' will show
938 all of the variable descriptions and their current settings.
940 confirm on/off: Enables warning questions for operations that are
941 hard to recover from, e.g. rerunning the program while
942 it is already running. Default is ON.
944 editing on/off: Enables EMACS style command line editing
945 of input. Previous lines can be recalled with
946 control-P, the current line can be edited with control-B,
947 you can search for commands with control-R, etc.
950 history filename NAME: NAME is where the gdb command history
951 will be stored. The default is .gdb_history,
952 or the value of the environment variable
955 history size N: The size, in commands, of the command history. The
956 default is 256, or the value of the environment variable
959 history save on/off: If this value is set to ON, the history file will
960 be saved after exiting gdb. If set to OFF, the
961 file will not be saved. The default is OFF.
963 history expansion on/off: If this value is set to ON, then csh-like
964 history expansion will be performed on
965 command line input. The default is OFF.
967 radix N: Sets the default radix for input and output. It can be set
968 to 8, 10, or 16. Note that the argument to "radix" is interpreted
969 in the current radix, so "set radix 10" is always a no-op.
971 height N: This integer value is the number of lines on a page. Default
972 is 24, the current `stty rows'' setting, or the ``li#''
973 setting from the termcap entry matching the environment
976 width N: This integer value is the number of characters on a line.
977 Default is 80, the current `stty cols'' setting, or the ``co#''
978 setting from the termcap entry matching the environment
981 Note: ``set screensize'' is obsolete. Use ``set height'' and
982 ``set width'' instead.
984 print address on/off: Print memory addresses in various command displays,
985 such as stack traces and structure values. Gdb looks
986 more ``symbolic'' if you turn this off; it looks more
987 ``machine level'' with it on. Default is ON.
989 print array on/off: Prettyprint arrays. New convenient format! Default
992 print demangle on/off: Print C++ symbols in "source" form if on,
995 print asm-demangle on/off: Same, for assembler level printouts
998 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
1001 * Support for Epoch Environment.
1003 The epoch environment is a version of Emacs v18 with windowing. One
1004 new command, ``inspect'', is identical to ``print'', except that if you
1005 are running in the epoch environment, the value is printed in its own
1009 * Support for Shared Libraries
1011 GDB can now debug programs and core files that use SunOS shared libraries.
1012 Symbols from a shared library cannot be referenced
1013 before the shared library has been linked with the program (this
1014 happens after you type ``run'' and before the function main() is entered).
1015 At any time after this linking (including when examining core files
1016 from dynamically linked programs), gdb reads the symbols from each
1017 shared library when you type the ``sharedlibrary'' command.
1018 It can be abbreviated ``share''.
1020 sharedlibrary REGEXP: Load shared object library symbols for files
1021 matching a unix regular expression. No argument
1022 indicates to load symbols for all shared libraries.
1024 info sharedlibrary: Status of loaded shared libraries.
1029 A watchpoint stops execution of a program whenever the value of an
1030 expression changes. Checking for this slows down execution
1031 tremendously whenever you are in the scope of the expression, but is
1032 quite useful for catching tough ``bit-spreader'' or pointer misuse
1033 problems. Some machines such as the 386 have hardware for doing this
1034 more quickly, and future versions of gdb will use this hardware.
1036 watch EXP: Set a watchpoint (breakpoint) for an expression.
1038 info watchpoints: Information about your watchpoints.
1040 delete N: Deletes watchpoint number N (same as breakpoints).
1041 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
1042 enable N: Re-enables watchpoint number N (same as breakpoints).
1045 * C++ multiple inheritance
1047 When used with a GCC version 2 compiler, GDB supports multiple inheritance
1050 * C++ exception handling
1052 Gdb now supports limited C++ exception handling. Besides the existing
1053 ability to breakpoint on an exception handler, gdb can breakpoint on
1054 the raising of an exception (before the stack is peeled back to the
1057 catch FOO: If there is a FOO exception handler in the dynamic scope,
1058 set a breakpoint to catch exceptions which may be raised there.
1059 Multiple exceptions (``catch foo bar baz'') may be caught.
1061 info catch: Lists all exceptions which may be caught in the
1062 current stack frame.
1065 * Minor command changes
1067 The command ``call func (arg, arg, ...)'' now acts like the print
1068 command, except it does not print or save a value if the function's result
1069 is void. This is similar to dbx usage.
1071 The ``up'' and ``down'' commands now always print the frame they end up
1072 at; ``up-silently'' and `down-silently'' can be used in scripts to change
1073 frames without printing.
1075 * New directory command
1077 'dir' now adds directories to the FRONT of the source search path.
1078 The path starts off empty. Source files that contain debug information
1079 about the directory in which they were compiled can be found even
1080 with an empty path; Sun CC and GCC include this information. If GDB can't
1081 find your source file in the current directory, type "dir .".
1083 * Configuring GDB for compilation
1085 For normal use, type ``./configure host''. See README or gdb.texinfo
1088 GDB now handles cross debugging. If you are remotely debugging between
1089 two different machines, type ``./configure host -target=targ''.
1090 Host is the machine where GDB will run; targ is the machine
1091 where the program that you are debugging will run.