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 *** Changes in GDB-4.13:
13 * New "complete" command
15 This lists all the possible completions for the rest of the line, if it
16 were to be given as a command itself. This is intended for use by emacs.
18 * Trailing space optional in prompt
20 "set prompt" no longer adds a space for you after the prompt you set. This
21 allows you to set a prompt which ends in a space or one that does not.
23 * Breakpoint hit counts
25 "info break" now displays a count of the number of times the breakpoint
26 has been hit. This is especially useful in conjunction with "ignore"; you
27 can ignore a large number of breakpoint hits, look at the breakpoint info
28 to see how many times the breakpoint was hit, then run again, ignoring one
29 less than that number, and this will get you quickly to the last hit of
32 * Ability to stop printing at NULL character
34 "set print null-stop" will cause GDB to stop printing the characters of
35 an array when the first NULL is encountered. This is useful when large
36 arrays actually contain only short strings.
38 * Shared library breakpoints
40 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
41 breakpoints in shared libraries before the executable is run.
43 * Hardware watchpoints
45 There is a new hardware breakpoint for the watch command for sparclite
46 targets. See gdb/sparclite/hw_breakpoint.note.
48 Hardware watchpoints are also now supported under Linux.
52 Annotations have been added. These are for use with graphical interfaces,
53 and are still experimental. Currently only gdba.el uses these.
55 * Improved Irix 5 support
57 GDB now works properly with Irix 5.2.
59 * Improved HPPA support
61 GDB now works properly with the latest GCC and GAS.
63 * New native configurations
65 Sequent PTX4 i[34]86-sequent-ptx4
66 HPPA running OSF/1 hppa*-*-osf*
67 Atari TT running SVR4 m68*-*-sysv4*
68 RS/6000 LynxOS rs6000-*-lynxos*
72 OS/9000 i[34]86-*-os9k
73 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
76 * Hitachi SH7000 and E7000-PC ICE support
78 There is now support for communicating with the Hitachi E7000-PC ICE.
79 This is available automatically when GDB is configured for the SH.
83 As usual, a variety of small fixes and improvements, both generic
84 and configuration-specific. See the ChangeLog for more detail.
86 *** Changes in GDB-4.12:
88 * Irix 5 is now supported
92 GDB-4.12 on the HPPA has a number of changes which make it unable
93 to debug the output from the currently released versions of GCC and
94 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
95 of GCC and GAS, versions of these tools designed to work with GDB-4.12
96 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
99 *** Changes in GDB-4.11:
101 * User visible changes:
105 The "set remotedebug" option is now consistent between the mips remote
106 target, remote targets using the gdb-specific protocol, UDI (AMD's
107 debug protocol for the 29k) and the 88k bug monitor. It is now an
108 integer specifying a debug level (normally 0 or 1, but 2 means more
109 debugging info for the mips target).
111 * DEC Alpha native support
113 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
114 debug info, but GDB works fairly well with the DEC compiler and should
115 work with a future GCC release. See the README file for a few
116 Alpha-specific notes.
118 * Preliminary thread implementation
120 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
122 * LynxOS native and target support for 386
124 This release has been hosted on LynxOS 2.2, and also can be configured
125 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
128 * Improvements in C++ mangling/demangling.
130 This release has much better g++ debugging, specifically in name
131 mangling/demangling, virtual function calls, print virtual table,
132 call methods, ...etc.
134 *** Changes in GDB-4.10:
136 * User visible changes:
138 Remote debugging using the GDB-specific (`target remote') protocol now
139 supports the `load' command. This is only useful if you have some
140 other way of getting the stub to the target system, and you can put it
141 somewhere in memory where it won't get clobbered by the download.
143 Filename completion now works.
145 When run under emacs mode, the "info line" command now causes the
146 arrow to point to the line specified. Also, "info line" prints
147 addresses in symbolic form (as well as hex).
149 All vxworks based targets now support a user settable option, called
150 vxworks-timeout. This option represents the number of seconds gdb
151 should wait for responses to rpc's. You might want to use this if
152 your vxworks target is, perhaps, a slow software simulator or happens
153 to be on the far side of a thin network line.
157 This release contains support for using a DEC alpha as a GDB host for
158 cross debugging. Native alpha debugging is not supported yet.
161 *** Changes in GDB-4.9:
165 This is the first GDB release which is accompanied by a matching testsuite.
166 The testsuite requires installation of dejagnu, which should be available
167 via ftp from most sites that carry GNU software.
171 'Cfront' style demangling has had its name changed to 'ARM' style, to
172 emphasize that it was written from the specifications in the C++ Annotated
173 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
174 disclaimers, it still generated too much confusion with users attempting to
175 use gdb with AT&T cfront.
179 GDB now uses a standard remote interface to a simulator library.
180 So far, the library contains simulators for the Zilog Z8001/2, the
181 Hitachi H8/300, H8/500 and Super-H.
183 * New targets supported
185 H8/300 simulator h8300-hitachi-hms or h8300hms
186 H8/500 simulator h8500-hitachi-hms or h8500hms
187 SH simulator sh-hitachi-hms or sh
188 Z8000 simulator z8k-zilog-none or z8ksim
189 IDT MIPS board over serial line mips-idt-ecoff
191 Cross-debugging to GO32 targets is supported. It requires a custom
192 version of the i386-stub.c module which is integrated with the
193 GO32 memory extender.
195 * New remote protocols
197 MIPS remote debugging protocol.
199 * New source languages supported
201 This version includes preliminary support for Chill, a Pascal like language
202 used by telecommunications companies. Chill support is also being integrated
203 into the GNU compiler, but we don't know when it will be publically available.
206 *** Changes in GDB-4.8:
208 * HP Precision Architecture supported
210 GDB now supports HP PA-RISC machines running HPUX. A preliminary
211 version of this support was available as a set of patches from the
212 University of Utah. GDB does not support debugging of programs
213 compiled with the HP compiler, because HP will not document their file
214 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
215 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
217 Many problems in the preliminary version have been fixed.
219 * Faster and better demangling
221 We have improved template demangling and fixed numerous bugs in the GNU style
222 demangler. It can now handle type modifiers such as `static' or `const'. Wide
223 character types (wchar_t) are now supported. Demangling of each symbol is now
224 only done once, and is cached when the symbol table for a file is read in.
225 This results in a small increase in memory usage for C programs, a moderate
226 increase in memory usage for C++ programs, and a fantastic speedup in
229 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
230 from the specifications in the Annotated Reference Manual, which AT&T's
231 compiler does not actually implement.
233 * G++ multiple inheritance compiler problem
235 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
236 inheritance lattices was reworked to properly discover ambiguities. We
237 recently found an example which causes this new algorithm to fail in a
238 very subtle way, producing bad debug information for those classes.
239 The file 'gcc.patch' (in this directory) can be applied to gcc to
240 circumvent the problem. A future GCC release will contain a complete
243 The previous G++ debug info problem (mentioned below for the gdb-4.7
244 release) is fixed in gcc version 2.3.2.
246 * Improved configure script
248 The `configure' script will now attempt to guess your system type if
249 you don't supply a host system type. The old scheme of supplying a
250 host system triplet is preferable over using this. All the magic is
251 done in the new `config.guess' script. Examine it for details.
253 We have also brought our configure script much more in line with the FSF's
254 version. It now supports the --with-xxx options. In particular,
255 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
256 The resulting GDB will not be able to read arbitrary object file formats --
257 only the format ``expected'' to be used on the configured target system.
258 We hope to make this the default in a future release.
260 * Documentation improvements
262 There's new internal documentation on how to modify GDB, and how to
263 produce clean changes to the code. We implore people to read it
264 before submitting changes.
266 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
267 M4 macros. The new texinfo.tex is provided in this release. Pre-built
268 `info' files are also provided. To build `info' files from scratch,
269 you will need the latest `makeinfo' release, which will be available in
270 a future texinfo-X.Y release.
272 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
273 We're not sure exactly which versions have this problem, but it has
274 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
275 or better. If that isn't possible, there is a patch in
276 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
281 GDB now supports array constants that can be used in expressions typed in by
282 the user. The syntax is `{element, element, ...}'. Ie: you can now type
283 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
286 The new directory `gdb/sparclite' contains a program that demonstrates
287 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
289 * New native hosts supported
291 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
292 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
294 * New targets supported
296 AMD 29k family via UDI a29k-amd-udi or udi29k
298 * New file formats supported
300 BFD now supports reading HP/PA-RISC executables (SOM file format?),
301 HPUX core files, and SCO 3.2v2 core files.
305 Attaching to processes now works again; thanks for the many bug reports.
307 We have also stomped on a bunch of core dumps caused by
308 printf_filtered("%s") problems.
310 We eliminated a copyright problem on the rpc and ptrace header files
311 for VxWorks, which was discovered at the last minute during the 4.7
312 release. You should now be able to build a VxWorks GDB.
314 You can now interrupt gdb while an attached process is running. This
315 will cause the attached process to stop, and give control back to GDB.
317 We fixed problems caused by using too many file descriptors
318 for reading symbols from object files and libraries. This was
319 especially a problem for programs that used many (~100) shared
322 The `step' command now only enters a subroutine if there is line number
323 information for the subroutine. Otherwise it acts like the `next'
324 command. Previously, `step' would enter subroutines if there was
325 any debugging information about the routine. This avoids problems
326 when using `cc -g1' on MIPS machines.
328 * Internal improvements
330 GDB's internal interfaces have been improved to make it easier to support
331 debugging of multiple languages in the future.
333 GDB now uses a common structure for symbol information internally.
334 Minimal symbols (derived from linkage symbols in object files), partial
335 symbols (from a quick scan of debug information), and full symbols
336 contain a common subset of information, making it easier to write
337 shared code that handles any of them.
339 * New command line options
341 We now accept --silent as an alias for --quiet.
345 The memory-mapped-malloc library is now licensed under the GNU Library
346 General Public License.
348 *** Changes in GDB-4.7:
350 * Host/native/target split
352 GDB has had some major internal surgery to untangle the support for
353 hosts and remote targets. Now, when you configure GDB for a remote
354 target, it will no longer load in all of the support for debugging
355 local programs on the host. When fully completed and tested, this will
356 ensure that arbitrary host/target combinations are possible.
358 The primary conceptual shift is to separate the non-portable code in
359 GDB into three categories. Host specific code is required any time GDB
360 is compiled on that host, regardless of the target. Target specific
361 code relates to the peculiarities of the target, but can be compiled on
362 any host. Native specific code is everything else: it can only be
363 built when the host and target are the same system. Child process
364 handling and core file support are two common `native' examples.
366 GDB's use of /proc for controlling Unix child processes is now cleaner.
367 It has been split out into a single module under the `target_ops' vector,
368 plus two native-dependent functions for each system that uses /proc.
370 * New hosts supported
372 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
373 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
374 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
376 * New targets supported
378 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
379 68030 and CPU32 m68030-*-*, m68332-*-*
381 * New native hosts supported
383 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
384 (386bsd is not well tested yet)
385 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
387 * New file formats supported
389 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
390 supports reading of `a.out.adobe' object files, which are an a.out
391 format extended with minimal information about multiple sections.
395 `show copying' is the same as the old `info copying'.
396 `show warranty' is the same as `info warrantee'.
397 These were renamed for consistency. The old commands continue to work.
399 `info handle' is a new alias for `info signals'.
401 You can now define pre-command hooks, which attach arbitrary command
402 scripts to any command. The commands in the hook will be executed
403 prior to the user's command. You can also create a hook which will be
404 executed whenever the program stops. See gdb.texinfo.
408 We now deal with Cfront style name mangling, and can even extract type
409 info from mangled symbols. GDB can automatically figure out which
410 symbol mangling style your C++ compiler uses.
412 Calling of methods and virtual functions has been improved as well.
416 The crash that occured when debugging Sun Ansi-C compiled binaries is
417 fixed. This was due to mishandling of the extra N_SO stabs output
420 We also finally got Ultrix 4.2 running in house, and fixed core file
421 support, with help from a dozen people on the net.
423 John M. Farrell discovered that the reason that single-stepping was so
424 slow on all of the Mips based platforms (primarily SGI and DEC) was
425 that we were trying to demangle and lookup a symbol used for internal
426 purposes on every instruction that was being stepped through. Changing
427 the name of that symbol so that it couldn't be mistaken for a C++
428 mangled symbol sped things up a great deal.
430 Rich Pixley sped up symbol lookups in general by getting much smarter
431 about when C++ symbol mangling is necessary. This should make symbol
432 completion (TAB on the command line) much faster. It's not as fast as
433 we'd like, but it's significantly faster than gdb-4.6.
437 A new user controllable variable 'call_scratch_address' can
438 specify the location of a scratch area to be used when GDB
439 calls a function in the target. This is necessary because the
440 usual method of putting the scratch area on the stack does not work
441 in systems that have separate instruction and data spaces.
443 We integrated changes to support the 29k UDI (Universal Debugger
444 Interface), but discovered at the last minute that we didn't have all
445 of the appropriate copyright paperwork. We are working with AMD to
446 resolve this, and hope to have it available soon.
450 We have sped up the remote serial line protocol, especially for targets
451 with lots of registers. It now supports a new `expedited status' ('T')
452 message which can be used in place of the existing 'S' status message.
453 This allows the remote stub to send only the registers that GDB
454 needs to make a quick decision about single-stepping or conditional
455 breakpoints, eliminating the need to fetch the entire register set for
456 each instruction being stepped through.
458 The GDB remote serial protocol now implements a write-through cache for
459 registers, only re-reading the registers if the target has run.
461 There is also a new remote serial stub for SPARC processors. You can
462 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
463 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
464 processor with a serial port.
468 Configure.in files have become much easier to read and modify. A new
469 `table driven' format makes it more obvious what configurations are
470 supported, and what files each one uses.
474 There is a new opcodes library which will eventually contain all of the
475 disassembly routines and opcode tables. At present, it only contains
476 Sparc and Z8000 routines. This will allow the assembler, debugger, and
477 disassembler (binutils/objdump) to share these routines.
479 The libiberty library is now copylefted under the GNU Library General
480 Public License. This allows more liberal use, and was done so libg++
481 can use it. This makes no difference to GDB, since the Library License
482 grants all the rights from the General Public License.
486 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
487 reference to the stabs symbol info used by the debugger. It is (as far
488 as we know) the only published document on this fascinating topic. We
489 encourage you to read it, compare it to the stabs information on your
490 system, and send improvements on the document in general (to
491 bug-gdb@prep.ai.mit.edu).
493 And, of course, many bugs have been fixed.
496 *** Changes in GDB-4.6:
498 * Better support for C++ function names
500 GDB now accepts as input the "demangled form" of C++ overloaded function
501 names and member function names, and can do command completion on such names
502 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
503 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
504 Make use of command completion, it is your friend.
506 GDB also now accepts a variety of C++ mangled symbol formats. They are
507 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
508 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
509 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
510 for the list of formats.
512 * G++ symbol mangling problem
514 Recent versions of gcc have a bug in how they emit debugging information for
515 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
516 directory) can be applied to gcc to fix the problem. Alternatively, if you
517 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
518 usual symptom is difficulty with setting breakpoints on methods. GDB complains
519 about the method being non-existent. (We believe that version 2.2.2 of GCC has
522 * New 'maintenance' command
524 All of the commands related to hacking GDB internals have been moved out of
525 the main command set, and now live behind the 'maintenance' command. This
526 can also be abbreviated as 'mt'. The following changes were made:
528 dump-me -> maintenance dump-me
529 info all-breakpoints -> maintenance info breakpoints
530 printmsyms -> maintenance print msyms
531 printobjfiles -> maintenance print objfiles
532 printpsyms -> maintenance print psymbols
533 printsyms -> maintenance print symbols
535 The following commands are new:
537 maintenance demangle Call internal GDB demangler routine to
538 demangle a C++ link name and prints the result.
539 maintenance print type Print a type chain for a given symbol
541 * Change to .gdbinit file processing
543 We now read the $HOME/.gdbinit file before processing the argv arguments
544 (e.g. reading symbol files or core files). This allows global parameters to
545 be set, which will apply during the symbol reading. The ./.gdbinit is still
546 read after argv processing.
548 * New hosts supported
550 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
552 Linux support i386-unknown-linux or linux
554 We are also including code to support the HP/PA running BSD and HPUX. This
555 is almost guaranteed not to work, as we didn't have time to test or build it
556 for this release. We are including it so that the more adventurous (or
557 masochistic) of you can play with it. We also had major problems with the
558 fact that the compiler that we got from HP doesn't support the -g option.
561 * New targets supported
563 Hitachi H8/300 h8300-hitachi-hms or h8300hms
565 * More smarts about finding #include files
567 GDB now remembers the compilation directory for all include files, and for
568 all files from which C is generated (like yacc and lex sources). This
569 greatly improves GDB's ability to find yacc/lex sources, and include files,
570 especially if you are debugging your program from a directory different from
571 the one that contains your sources.
573 We also fixed a bug which caused difficulty with listing and setting
574 breakpoints in include files which contain C code. (In the past, you had to
575 try twice in order to list an include file that you hadn't looked at before.)
577 * Interesting infernals change
579 GDB now deals with arbitrary numbers of sections, where the symbols for each
580 section must be relocated relative to that section's landing place in the
581 target's address space. This work was needed to support ELF with embedded
582 stabs used by Solaris-2.0.
584 * Bug fixes (of course!)
586 There have been loads of fixes for the following things:
587 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
588 i960, stabs, DOS(GO32), procfs, etc...
590 See the ChangeLog for details.
592 *** Changes in GDB-4.5:
594 * New machines supported (host and target)
596 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
598 SGI Irix-4.x mips-sgi-irix4 or iris4
602 GDB now uses a new memory manager called mmalloc, based on gmalloc.
603 Mmalloc is capable of handling mutiple heaps of memory. It is also
604 capable of saving a heap to a file, and then mapping it back in later.
605 This can be used to greatly speedup the startup of GDB by using a
606 pre-parsed symbol table which lives in a mmalloc managed heap. For
607 more details, please read mmalloc/mmalloc.texi.
611 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
612 'help info proc' for details.
614 * MIPS ecoff symbol table format
616 The code that reads MIPS symbol table format is now supported on all hosts.
617 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
620 * File name changes for MS-DOS
622 Many files in the config directories have been renamed to make it easier to
623 support GDB on MS-DOSe systems (which have very restrictive file name
624 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
625 environment) is close to working but has some remaining problems. Note
626 that debugging of DOS programs is not supported, due to limitations
627 in the ``operating system'', but it can be used to host cross-debugging.
629 * Cross byte order fixes
631 Many fixes have been made to support cross debugging of Sparc and MIPS
632 targets from hosts whose byte order differs.
634 * New -mapped and -readnow options
636 If memory-mapped files are available on your system through the 'mmap'
637 system call, you can use the -mapped option on the `file' or
638 `symbol-file' commands to cause GDB to write the symbols from your
639 program into a reusable file. If the program you are debugging is
640 called `/path/fred', the mapped symbol file will be `./fred.syms'.
641 Future GDB debugging sessions will notice the presence of this file,
642 and will quickly map in symbol information from it, rather than reading
643 the symbol table from the executable program. Using the '-mapped'
644 option in a GDB `file' or `symbol-file' command has the same effect as
645 starting GDB with the '-mapped' command-line option.
647 You can cause GDB to read the entire symbol table immediately by using
648 the '-readnow' option with any of the commands that load symbol table
649 information (or on the GDB command line). This makes the command
650 slower, but makes future operations faster.
652 The -mapped and -readnow options are typically combined in order to
653 build a `fred.syms' file that contains complete symbol information.
654 A simple GDB invocation to do nothing but build a `.syms' file for future
657 gdb -batch -nx -mapped -readnow programname
659 The `.syms' file is specific to the host machine on which GDB is run.
660 It holds an exact image of GDB's internal symbol table. It cannot be
661 shared across multiple host platforms.
665 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
666 siglongjmp() without losing control. This feature has not yet been ported to
667 all systems. It currently works on many 386 platforms, all MIPS-based
668 platforms (SGI, DECstation, etc), and Sun3/4.
672 Preliminary work has been put in to support the new Solaris OS from Sun. At
673 this time, it can control and debug processes, but it is not capable of
678 As always, many many bug fixes. The major areas were with g++, and mipsread.
679 People using the MIPS-based platforms should experience fewer mysterious
680 crashes and trashed symbol tables.
682 *** Changes in GDB-4.4:
684 * New machines supported (host and target)
686 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
688 BSD Reno on Vax vax-dec-bsd
689 Ultrix on Vax vax-dec-ultrix
691 * New machines supported (target)
693 AMD 29000 embedded, using EBMON a29k-none-none
697 GDB continues to improve its handling of C++. `References' work better.
698 The demangler has also been improved, and now deals with symbols mangled as
699 per the Annotated C++ Reference Guide.
701 GDB also now handles `stabs' symbol information embedded in MIPS
702 `ecoff' symbol tables. Since the ecoff format was not easily
703 extensible to handle new languages such as C++, this appeared to be a
704 good way to put C++ debugging info into MIPS binaries. This option
705 will be supported in the GNU C compiler, version 2, when it is
708 * New features for SVR4
710 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
711 shared libraries. Debugging dynamically linked programs should present
712 only minor differences from debugging statically linked programs.
714 The `info proc' command will print out information about any process
715 on an SVR4 system (including the one you are debugging). At the moment,
716 it prints the address mappings of the process.
718 If you bring up GDB on another SVR4 system, please send mail to
719 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
721 * Better dynamic linking support in SunOS
723 Reading symbols from shared libraries which contain debugging symbols
724 now works properly. However, there remain issues such as automatic
725 skipping of `transfer vector' code during function calls, which
726 make it harder to debug code in a shared library, than to debug the
727 same code linked statically.
731 GDB is now using the latest `getopt' routines from the FSF. This
732 version accepts the -- prefix for options with long names. GDB will
733 continue to accept the old forms (-option and +option) as well.
734 Various single letter abbreviations for options have been explicity
735 added to the option table so that they won't get overshadowed in the
736 future by other options that begin with the same letter.
740 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
741 Many assorted bugs have been handled. Many more remain to be handled.
742 See the various ChangeLog files (primarily in gdb and bfd) for details.
745 *** Changes in GDB-4.3:
747 * New machines supported (host and target)
749 Amiga 3000 running Amix m68k-cbm-svr4 or amix
750 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
751 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
753 * Almost SCO Unix support
755 We had hoped to support:
756 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
757 (except for core file support), but we discovered very late in the release
758 that it has problems with process groups that render gdb unusable. Sorry
759 about that. I encourage people to fix it and post the fixes.
761 * Preliminary ELF and DWARF support
763 GDB can read ELF object files on System V Release 4, and can handle
764 debugging records for C, in DWARF format, in ELF files. This support
765 is preliminary. If you bring up GDB on another SVR4 system, please
766 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
771 GDB now uses the latest `readline' library. One user-visible change
772 is that two tabs will list possible command completions, which previously
773 required typing M-? (meta-question mark, or ESC ?).
777 The `stepi' bug that many of you noticed has been squashed.
778 Many bugs in C++ have been handled. Many more remain to be handled.
779 See the various ChangeLog files (primarily in gdb and bfd) for details.
781 * State of the MIPS world (in case you wondered):
783 GDB can understand the symbol tables emitted by the compilers
784 supplied by most vendors of MIPS-based machines, including DEC. These
785 symbol tables are in a format that essentially nobody else uses.
787 Some versions of gcc come with an assembler post-processor called
788 mips-tfile. This program is required if you want to do source-level
789 debugging of gcc-compiled programs. I believe FSF does not ship
790 mips-tfile with gcc version 1, but it will eventually come with gcc
793 Debugging of g++ output remains a problem. g++ version 1.xx does not
794 really support it at all. (If you're lucky, you should be able to get
795 line numbers and stack traces to work, but no parameters or local
796 variables.) With some work it should be possible to improve the
799 When gcc version 2 is released, you will have somewhat better luck.
800 However, even then you will get confusing results for inheritance and
803 We will eventually provide full debugging of g++ output on
804 DECstations. This will probably involve some kind of stabs-in-ecoff
805 encapulation, but the details have not been worked out yet.
808 *** Changes in GDB-4.2:
810 * Improved configuration
812 Only one copy of `configure' exists now, and it is not self-modifying.
813 Porting BFD is simpler.
817 The `step' and `next' commands now only stop at the first instruction
818 of a source line. This prevents the multiple stops that used to occur
819 in switch statements, for-loops, etc. `Step' continues to stop if a
820 function that has debugging information is called within the line.
824 Lots of small bugs fixed. More remain.
826 * New host supported (not target)
828 Intel 386 PC clone running Mach i386-none-mach
831 *** Changes in GDB-4.1:
833 * Multiple source language support
835 GDB now has internal scaffolding to handle several source languages.
836 It determines the type of each source file from its filename extension,
837 and will switch expression parsing and number formatting to match the
838 language of the function in the currently selected stack frame.
839 You can also specifically set the language to be used, with
840 `set language c' or `set language modula-2'.
844 GDB now has preliminary support for the GNU Modula-2 compiler,
845 currently under development at the State University of New York at
846 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
847 continue through the fall of 1991 and into 1992.
849 Other Modula-2 compilers are currently not supported, and attempting to
850 debug programs compiled with them will likely result in an error as the
851 symbol table is read. Feel free to work on it, though!
853 There are hooks in GDB for strict type checking and range checking,
854 in the `Modula-2 philosophy', but they do not currently work.
858 GDB can now write to executable and core files (e.g. patch
859 a variable's value). You must turn this switch on, specify
860 the file ("exec foo" or "core foo"), *then* modify it, e.g.
861 by assigning a new value to a variable. Modifications take
864 * Automatic SunOS shared library reading
866 When you run your program, GDB automatically determines where its
867 shared libraries (if any) have been loaded, and reads their symbols.
868 The `share' command is no longer needed. This also works when
869 examining core files.
873 You can specify the number of lines that the `list' command shows.
876 * New machines supported (host and target)
878 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
879 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
880 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
882 * New hosts supported (not targets)
884 IBM RT/PC: romp-ibm-aix or rtpc
886 * New targets supported (not hosts)
888 AMD 29000 embedded with COFF a29k-none-coff
889 AMD 29000 embedded with a.out a29k-none-aout
890 Ultracomputer remote kernel debug a29k-nyu-kern
892 * New remote interfaces
898 *** Changes in GDB-4.0:
902 Wide output is wrapped at good places to make the output more readable.
904 Gdb now supports cross-debugging from a host machine of one type to a
905 target machine of another type. Communication with the target system
906 is over serial lines. The ``target'' command handles connecting to the
907 remote system; the ``load'' command will download a program into the
908 remote system. Serial stubs for the m68k and i386 are provided. Gdb
909 also supports debugging of realtime processes running under VxWorks,
910 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
911 stub on the target system.
913 New CPUs supported include the AMD 29000 and Intel 960.
915 GDB now reads object files and symbol tables via a ``binary file''
916 library, which allows a single copy of GDB to debug programs of multiple
917 object file types such as a.out and coff.
919 There is now a GDB reference card in "doc/refcard.tex". (Make targets
920 refcard.dvi and refcard.ps are available to format it).
923 * Control-Variable user interface simplified
925 All variables that control the operation of the debugger can be set
926 by the ``set'' command, and displayed by the ``show'' command.
928 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
929 ``Show prompt'' produces the response:
930 Gdb's prompt is new-gdb=>.
932 What follows are the NEW set commands. The command ``help set'' will
933 print a complete list of old and new set commands. ``help set FOO''
934 will give a longer description of the variable FOO. ``show'' will show
935 all of the variable descriptions and their current settings.
937 confirm on/off: Enables warning questions for operations that are
938 hard to recover from, e.g. rerunning the program while
939 it is already running. Default is ON.
941 editing on/off: Enables EMACS style command line editing
942 of input. Previous lines can be recalled with
943 control-P, the current line can be edited with control-B,
944 you can search for commands with control-R, etc.
947 history filename NAME: NAME is where the gdb command history
948 will be stored. The default is .gdb_history,
949 or the value of the environment variable
952 history size N: The size, in commands, of the command history. The
953 default is 256, or the value of the environment variable
956 history save on/off: If this value is set to ON, the history file will
957 be saved after exiting gdb. If set to OFF, the
958 file will not be saved. The default is OFF.
960 history expansion on/off: If this value is set to ON, then csh-like
961 history expansion will be performed on
962 command line input. The default is OFF.
964 radix N: Sets the default radix for input and output. It can be set
965 to 8, 10, or 16. Note that the argument to "radix" is interpreted
966 in the current radix, so "set radix 10" is always a no-op.
968 height N: This integer value is the number of lines on a page. Default
969 is 24, the current `stty rows'' setting, or the ``li#''
970 setting from the termcap entry matching the environment
973 width N: This integer value is the number of characters on a line.
974 Default is 80, the current `stty cols'' setting, or the ``co#''
975 setting from the termcap entry matching the environment
978 Note: ``set screensize'' is obsolete. Use ``set height'' and
979 ``set width'' instead.
981 print address on/off: Print memory addresses in various command displays,
982 such as stack traces and structure values. Gdb looks
983 more ``symbolic'' if you turn this off; it looks more
984 ``machine level'' with it on. Default is ON.
986 print array on/off: Prettyprint arrays. New convenient format! Default
989 print demangle on/off: Print C++ symbols in "source" form if on,
992 print asm-demangle on/off: Same, for assembler level printouts
995 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
998 * Support for Epoch Environment.
1000 The epoch environment is a version of Emacs v18 with windowing. One
1001 new command, ``inspect'', is identical to ``print'', except that if you
1002 are running in the epoch environment, the value is printed in its own
1006 * Support for Shared Libraries
1008 GDB can now debug programs and core files that use SunOS shared libraries.
1009 Symbols from a shared library cannot be referenced
1010 before the shared library has been linked with the program (this
1011 happens after you type ``run'' and before the function main() is entered).
1012 At any time after this linking (including when examining core files
1013 from dynamically linked programs), gdb reads the symbols from each
1014 shared library when you type the ``sharedlibrary'' command.
1015 It can be abbreviated ``share''.
1017 sharedlibrary REGEXP: Load shared object library symbols for files
1018 matching a unix regular expression. No argument
1019 indicates to load symbols for all shared libraries.
1021 info sharedlibrary: Status of loaded shared libraries.
1026 A watchpoint stops execution of a program whenever the value of an
1027 expression changes. Checking for this slows down execution
1028 tremendously whenever you are in the scope of the expression, but is
1029 quite useful for catching tough ``bit-spreader'' or pointer misuse
1030 problems. Some machines such as the 386 have hardware for doing this
1031 more quickly, and future versions of gdb will use this hardware.
1033 watch EXP: Set a watchpoint (breakpoint) for an expression.
1035 info watchpoints: Information about your watchpoints.
1037 delete N: Deletes watchpoint number N (same as breakpoints).
1038 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
1039 enable N: Re-enables watchpoint number N (same as breakpoints).
1042 * C++ multiple inheritance
1044 When used with a GCC version 2 compiler, GDB supports multiple inheritance
1047 * C++ exception handling
1049 Gdb now supports limited C++ exception handling. Besides the existing
1050 ability to breakpoint on an exception handler, gdb can breakpoint on
1051 the raising of an exception (before the stack is peeled back to the
1054 catch FOO: If there is a FOO exception handler in the dynamic scope,
1055 set a breakpoint to catch exceptions which may be raised there.
1056 Multiple exceptions (``catch foo bar baz'') may be caught.
1058 info catch: Lists all exceptions which may be caught in the
1059 current stack frame.
1062 * Minor command changes
1064 The command ``call func (arg, arg, ...)'' now acts like the print
1065 command, except it does not print or save a value if the function's result
1066 is void. This is similar to dbx usage.
1068 The ``up'' and ``down'' commands now always print the frame they end up
1069 at; ``up-silently'' and `down-silently'' can be used in scripts to change
1070 frames without printing.
1072 * New directory command
1074 'dir' now adds directories to the FRONT of the source search path.
1075 The path starts off empty. Source files that contain debug information
1076 about the directory in which they were compiled can be found even
1077 with an empty path; Sun CC and GCC include this information. If GDB can't
1078 find your source file in the current directory, type "dir .".
1080 * Configuring GDB for compilation
1082 For normal use, type ``./configure host''. See README or gdb.texinfo
1085 GDB now handles cross debugging. If you are remotely debugging between
1086 two different machines, type ``./configure host -target=targ''.
1087 Host is the machine where GDB will run; targ is the machine
1088 where the program that you are debugging will run.