1 What has changed since GDB-3.5?
2 (Organized release by release)
4 *** Changes in GDB-4.11:
6 * User visible changes:
10 The "set remotedebug" option is now consistent between the mips remote
11 target, remote targets using the gdb-specific protocol, UDI (AMD's
12 debug protocol for the 29k) and the 88k bug monitor. It is now an
13 integer specifying a debug level (normally 0 or 1, but 2 means more
14 debugging info for the mips target).
16 * DEC Alpha native support
18 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
19 debug info, but GDB works fairly well with the DEC compiler and should
20 work with a future GCC release. See the README file for a few
23 * Preliminary thread implementation
25 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
27 * LynxOS native and target support for 386
29 This release has been hosted on LynxOS 2.2, and also can be configured
30 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
33 * Improvements in C++ mangling/demangling.
35 This release has much better g++ debugging, specifically in name
36 mangling/demangling, virtual function calls, print virtual table,
39 *** Changes in GDB-4.10:
41 * User visible changes:
43 Remote debugging using the GDB-specific (`target remote') protocol now
44 supports the `load' command. This is only useful if you have some
45 other way of getting the stub to the target system, and you can put it
46 somewhere in memory where it won't get clobbered by the download.
48 Filename completion now works.
50 When run under emacs mode, the "info line" command now causes the
51 arrow to point to the line specified. Also, "info line" prints
52 addresses in symbolic form (as well as hex).
54 All vxworks based targets now support a user settable option, called
55 vxworks-timeout. This option represents the number of seconds gdb
56 should wait for responses to rpc's. You might want to use this if
57 your vxworks target is, perhaps, a slow software simulator or happens
58 to be on the far side of a thin network line.
62 This release contains support for using a DEC alpha as a GDB host for
63 cross debugging. Native alpha debugging is not supported yet.
66 *** Changes in GDB-4.9:
70 This is the first GDB release which is accompanied by a matching testsuite.
71 The testsuite requires installation of dejagnu, which should be available
72 via ftp from most sites that carry GNU software.
76 'Cfront' style demangling has had its name changed to 'ARM' style, to
77 emphasize that it was written from the specifications in the C++ Annotated
78 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
79 disclaimers, it still generated too much confusion with users attempting to
80 use gdb with AT&T cfront.
84 GDB now uses a standard remote interface to a simulator library.
85 So far, the library contains simulators for the Zilog Z8001/2, the
86 Hitachi H8/300, H8/500 and Super-H.
88 * New targets supported
90 H8/300 simulator h8300-hitachi-hms or h8300hms
91 H8/500 simulator h8500-hitachi-hms or h8500hms
92 SH simulator sh-hitachi-hms or sh
93 Z8000 simulator z8k-zilog-none or z8ksim
94 IDT MIPS board over serial line mips-idt-ecoff
96 Cross-debugging to GO32 targets is supported. It requires a custom
97 version of the i386-stub.c module which is integrated with the
100 * New remote protocols
102 MIPS remote debugging protocol.
104 * New source languages supported
106 This version includes preliminary support for Chill, a Pascal like language
107 used by telecommunications companies. Chill support is also being integrated
108 into the GNU compiler, but we don't know when it will be publically available.
111 *** Changes in GDB-4.8:
113 * HP Precision Architecture supported
115 GDB now supports HP PA-RISC machines running HPUX. A preliminary
116 version of this support was available as a set of patches from the
117 University of Utah. GDB does not support debugging of programs
118 compiled with the HP compiler, because HP will not document their file
119 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
120 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
122 Many problems in the preliminary version have been fixed.
124 * Faster and better demangling
126 We have improved template demangling and fixed numerous bugs in the GNU style
127 demangler. It can now handle type modifiers such as `static' or `const'. Wide
128 character types (wchar_t) are now supported. Demangling of each symbol is now
129 only done once, and is cached when the symbol table for a file is read in.
130 This results in a small increase in memory usage for C programs, a moderate
131 increase in memory usage for C++ programs, and a fantastic speedup in
134 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
135 from the specifications in the Annotated Reference Manual, which AT&T's
136 compiler does not actually implement.
138 * G++ multiple inheritance compiler problem
140 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
141 inheritance lattices was reworked to properly discover ambiguities. We
142 recently found an example which causes this new algorithm to fail in a
143 very subtle way, producing bad debug information for those classes.
144 The file 'gcc.patch' (in this directory) can be applied to gcc to
145 circumvent the problem. A future GCC release will contain a complete
148 The previous G++ debug info problem (mentioned below for the gdb-4.7
149 release) is fixed in gcc version 2.3.2.
151 * Improved configure script
153 The `configure' script will now attempt to guess your system type if
154 you don't supply a host system type. The old scheme of supplying a
155 host system triplet is preferable over using this. All the magic is
156 done in the new `config.guess' script. Examine it for details.
158 We have also brought our configure script much more in line with the FSF's
159 version. It now supports the --with-xxx options. In particular,
160 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
161 The resulting GDB will not be able to read arbitrary object file formats --
162 only the format ``expected'' to be used on the configured target system.
163 We hope to make this the default in a future release.
165 * Documentation improvements
167 There's new internal documentation on how to modify GDB, and how to
168 produce clean changes to the code. We implore people to read it
169 before submitting changes.
171 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
172 M4 macros. The new texinfo.tex is provided in this release. Pre-built
173 `info' files are also provided. To build `info' files from scratch,
174 you will need the latest `makeinfo' release, which will be available in
175 a future texinfo-X.Y release.
177 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
178 We're not sure exactly which versions have this problem, but it has
179 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
180 or better. If that isn't possible, there is a patch in
181 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
186 GDB now supports array constants that can be used in expressions typed in by
187 the user. The syntax is `{element, element, ...}'. Ie: you can now type
188 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
191 The new directory `gdb/sparclite' contains a program that demonstrates
192 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
194 * New native hosts supported
196 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
197 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
199 * New targets supported
201 AMD 29k family via UDI a29k-amd-udi or udi29k
203 * New file formats supported
205 BFD now supports reading HP/PA-RISC executables (SOM file format?),
206 HPUX core files, and SCO 3.2v2 core files.
210 Attaching to processes now works again; thanks for the many bug reports.
212 We have also stomped on a bunch of core dumps caused by
213 printf_filtered("%s") problems.
215 We eliminated a copyright problem on the rpc and ptrace header files
216 for VxWorks, which was discovered at the last minute during the 4.7
217 release. You should now be able to build a VxWorks GDB.
219 You can now interrupt gdb while an attached process is running. This
220 will cause the attached process to stop, and give control back to GDB.
222 We fixed problems caused by using too many file descriptors
223 for reading symbols from object files and libraries. This was
224 especially a problem for programs that used many (~100) shared
227 The `step' command now only enters a subroutine if there is line number
228 information for the subroutine. Otherwise it acts like the `next'
229 command. Previously, `step' would enter subroutines if there was
230 any debugging information about the routine. This avoids problems
231 when using `cc -g1' on MIPS machines.
233 * Internal improvements
235 GDB's internal interfaces have been improved to make it easier to support
236 debugging of multiple languages in the future.
238 GDB now uses a common structure for symbol information internally.
239 Minimal symbols (derived from linkage symbols in object files), partial
240 symbols (from a quick scan of debug information), and full symbols
241 contain a common subset of information, making it easier to write
242 shared code that handles any of them.
244 * New command line options
246 We now accept --silent as an alias for --quiet.
250 The memory-mapped-malloc library is now licensed under the GNU Library
251 General Public License.
253 *** Changes in GDB-4.7:
255 * Host/native/target split
257 GDB has had some major internal surgery to untangle the support for
258 hosts and remote targets. Now, when you configure GDB for a remote
259 target, it will no longer load in all of the support for debugging
260 local programs on the host. When fully completed and tested, this will
261 ensure that arbitrary host/target combinations are possible.
263 The primary conceptual shift is to separate the non-portable code in
264 GDB into three categories. Host specific code is required any time GDB
265 is compiled on that host, regardless of the target. Target specific
266 code relates to the peculiarities of the target, but can be compiled on
267 any host. Native specific code is everything else: it can only be
268 built when the host and target are the same system. Child process
269 handling and core file support are two common `native' examples.
271 GDB's use of /proc for controlling Unix child processes is now cleaner.
272 It has been split out into a single module under the `target_ops' vector,
273 plus two native-dependent functions for each system that uses /proc.
275 * New hosts supported
277 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
278 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
279 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
281 * New targets supported
283 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
284 68030 and CPU32 m68030-*-*, m68332-*-*
286 * New native hosts supported
288 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
289 (386bsd is not well tested yet)
290 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
292 * New file formats supported
294 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
295 supports reading of `a.out.adobe' object files, which are an a.out
296 format extended with minimal information about multiple sections.
300 `show copying' is the same as the old `info copying'.
301 `show warranty' is the same as `info warrantee'.
302 These were renamed for consistency. The old commands continue to work.
304 `info handle' is a new alias for `info signals'.
306 You can now define pre-command hooks, which attach arbitrary command
307 scripts to any command. The commands in the hook will be executed
308 prior to the user's command. You can also create a hook which will be
309 executed whenever the program stops. See gdb.texinfo.
313 We now deal with Cfront style name mangling, and can even extract type
314 info from mangled symbols. GDB can automatically figure out which
315 symbol mangling style your C++ compiler uses.
317 Calling of methods and virtual functions has been improved as well.
321 The crash that occured when debugging Sun Ansi-C compiled binaries is
322 fixed. This was due to mishandling of the extra N_SO stabs output
325 We also finally got Ultrix 4.2 running in house, and fixed core file
326 support, with help from a dozen people on the net.
328 John M. Farrell discovered that the reason that single-stepping was so
329 slow on all of the Mips based platforms (primarily SGI and DEC) was
330 that we were trying to demangle and lookup a symbol used for internal
331 purposes on every instruction that was being stepped through. Changing
332 the name of that symbol so that it couldn't be mistaken for a C++
333 mangled symbol sped things up a great deal.
335 Rich Pixley sped up symbol lookups in general by getting much smarter
336 about when C++ symbol mangling is necessary. This should make symbol
337 completion (TAB on the command line) much faster. It's not as fast as
338 we'd like, but it's significantly faster than gdb-4.6.
342 A new user controllable variable 'call_scratch_address' can
343 specify the location of a scratch area to be used when GDB
344 calls a function in the target. This is necessary because the
345 usual method of putting the scratch area on the stack does not work
346 in systems that have separate instruction and data spaces.
348 We integrated changes to support the 29k UDI (Universal Debugger
349 Interface), but discovered at the last minute that we didn't have all
350 of the appropriate copyright paperwork. We are working with AMD to
351 resolve this, and hope to have it available soon.
355 We have sped up the remote serial line protocol, especially for targets
356 with lots of registers. It now supports a new `expedited status' ('T')
357 message which can be used in place of the existing 'S' status message.
358 This allows the remote stub to send only the registers that GDB
359 needs to make a quick decision about single-stepping or conditional
360 breakpoints, eliminating the need to fetch the entire register set for
361 each instruction being stepped through.
363 The GDB remote serial protocol now implements a write-through cache for
364 registers, only re-reading the registers if the target has run.
366 There is also a new remote serial stub for SPARC processors. You can
367 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
368 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
369 processor with a serial port.
373 Configure.in files have become much easier to read and modify. A new
374 `table driven' format makes it more obvious what configurations are
375 supported, and what files each one uses.
379 There is a new opcodes library which will eventually contain all of the
380 disassembly routines and opcode tables. At present, it only contains
381 Sparc and Z8000 routines. This will allow the assembler, debugger, and
382 disassembler (binutils/objdump) to share these routines.
384 The libiberty library is now copylefted under the GNU Library General
385 Public License. This allows more liberal use, and was done so libg++
386 can use it. This makes no difference to GDB, since the Library License
387 grants all the rights from the General Public License.
391 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
392 reference to the stabs symbol info used by the debugger. It is (as far
393 as we know) the only published document on this fascinating topic. We
394 encourage you to read it, compare it to the stabs information on your
395 system, and send improvements on the document in general (to
396 bug-gdb@prep.ai.mit.edu).
398 And, of course, many bugs have been fixed.
401 *** Changes in GDB-4.6:
403 * Better support for C++ function names
405 GDB now accepts as input the "demangled form" of C++ overloaded function
406 names and member function names, and can do command completion on such names
407 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
408 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
409 Make use of command completion, it is your friend.
411 GDB also now accepts a variety of C++ mangled symbol formats. They are
412 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
413 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
414 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
415 for the list of formats.
417 * G++ symbol mangling problem
419 Recent versions of gcc have a bug in how they emit debugging information for
420 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
421 directory) can be applied to gcc to fix the problem. Alternatively, if you
422 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
423 usual symptom is difficulty with setting breakpoints on methods. GDB complains
424 about the method being non-existent. (We believe that version 2.2.2 of GCC has
427 * New 'maintenance' command
429 All of the commands related to hacking GDB internals have been moved out of
430 the main command set, and now live behind the 'maintenance' command. This
431 can also be abbreviated as 'mt'. The following changes were made:
433 dump-me -> maintenance dump-me
434 info all-breakpoints -> maintenance info breakpoints
435 printmsyms -> maintenance print msyms
436 printobjfiles -> maintenance print objfiles
437 printpsyms -> maintenance print psymbols
438 printsyms -> maintenance print symbols
440 The following commands are new:
442 maintenance demangle Call internal GDB demangler routine to
443 demangle a C++ link name and prints the result.
444 maintenance print type Print a type chain for a given symbol
446 * Change to .gdbinit file processing
448 We now read the $HOME/.gdbinit file before processing the argv arguments
449 (e.g. reading symbol files or core files). This allows global parameters to
450 be set, which will apply during the symbol reading. The ./.gdbinit is still
451 read after argv processing.
453 * New hosts supported
455 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
457 Linux support i386-unknown-linux or linux
459 We are also including code to support the HP/PA running BSD and HPUX. This
460 is almost guaranteed not to work, as we didn't have time to test or build it
461 for this release. We are including it so that the more adventurous (or
462 masochistic) of you can play with it. We also had major problems with the
463 fact that the compiler that we got from HP doesn't support the -g option.
466 * New targets supported
468 Hitachi H8/300 h8300-hitachi-hms or h8300hms
470 * More smarts about finding #include files
472 GDB now remembers the compilation directory for all include files, and for
473 all files from which C is generated (like yacc and lex sources). This
474 greatly improves GDB's ability to find yacc/lex sources, and include files,
475 especially if you are debugging your program from a directory different from
476 the one that contains your sources.
478 We also fixed a bug which caused difficulty with listing and setting
479 breakpoints in include files which contain C code. (In the past, you had to
480 try twice in order to list an include file that you hadn't looked at before.)
482 * Interesting infernals change
484 GDB now deals with arbitrary numbers of sections, where the symbols for each
485 section must be relocated relative to that section's landing place in the
486 target's address space. This work was needed to support ELF with embedded
487 stabs used by Solaris-2.0.
489 * Bug fixes (of course!)
491 There have been loads of fixes for the following things:
492 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
493 i960, stabs, DOS(GO32), procfs, etc...
495 See the ChangeLog for details.
497 *** Changes in GDB-4.5:
499 * New machines supported (host and target)
501 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
503 SGI Irix-4.x mips-sgi-irix4 or iris4
507 GDB now uses a new memory manager called mmalloc, based on gmalloc.
508 Mmalloc is capable of handling mutiple heaps of memory. It is also
509 capable of saving a heap to a file, and then mapping it back in later.
510 This can be used to greatly speedup the startup of GDB by using a
511 pre-parsed symbol table which lives in a mmalloc managed heap. For
512 more details, please read mmalloc/mmalloc.texi.
516 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
517 'help info proc' for details.
519 * MIPS ecoff symbol table format
521 The code that reads MIPS symbol table format is now supported on all hosts.
522 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
525 * File name changes for MS-DOS
527 Many files in the config directories have been renamed to make it easier to
528 support GDB on MS-DOSe systems (which have very restrictive file name
529 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
530 environment) is close to working but has some remaining problems. Note
531 that debugging of DOS programs is not supported, due to limitations
532 in the ``operating system'', but it can be used to host cross-debugging.
534 * Cross byte order fixes
536 Many fixes have been made to support cross debugging of Sparc and MIPS
537 targets from hosts whose byte order differs.
539 * New -mapped and -readnow options
541 If memory-mapped files are available on your system through the 'mmap'
542 system call, you can use the -mapped option on the `file' or
543 `symbol-file' commands to cause GDB to write the symbols from your
544 program into a reusable file. If the program you are debugging is
545 called `/path/fred', the mapped symbol file will be `./fred.syms'.
546 Future GDB debugging sessions will notice the presence of this file,
547 and will quickly map in symbol information from it, rather than reading
548 the symbol table from the executable program. Using the '-mapped'
549 option in a GDB `file' or `symbol-file' command has the same effect as
550 starting GDB with the '-mapped' command-line option.
552 You can cause GDB to read the entire symbol table immediately by using
553 the '-readnow' option with any of the commands that load symbol table
554 information (or on the GDB command line). This makes the command
555 slower, but makes future operations faster.
557 The -mapped and -readnow options are typically combined in order to
558 build a `fred.syms' file that contains complete symbol information.
559 A simple GDB invocation to do nothing but build a `.syms' file for future
562 gdb -batch -nx -mapped -readnow programname
564 The `.syms' file is specific to the host machine on which GDB is run.
565 It holds an exact image of GDB's internal symbol table. It cannot be
566 shared across multiple host platforms.
570 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
571 siglongjmp() without losing control. This feature has not yet been ported to
572 all systems. It currently works on many 386 platforms, all MIPS-based
573 platforms (SGI, DECstation, etc), and Sun3/4.
577 Preliminary work has been put in to support the new Solaris OS from Sun. At
578 this time, it can control and debug processes, but it is not capable of
583 As always, many many bug fixes. The major areas were with g++, and mipsread.
584 People using the MIPS-based platforms should experience fewer mysterious
585 crashes and trashed symbol tables.
587 *** Changes in GDB-4.4:
589 * New machines supported (host and target)
591 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
593 BSD Reno on Vax vax-dec-bsd
594 Ultrix on Vax vax-dec-ultrix
596 * New machines supported (target)
598 AMD 29000 embedded, using EBMON a29k-none-none
602 GDB continues to improve its handling of C++. `References' work better.
603 The demangler has also been improved, and now deals with symbols mangled as
604 per the Annotated C++ Reference Guide.
606 GDB also now handles `stabs' symbol information embedded in MIPS
607 `ecoff' symbol tables. Since the ecoff format was not easily
608 extensible to handle new languages such as C++, this appeared to be a
609 good way to put C++ debugging info into MIPS binaries. This option
610 will be supported in the GNU C compiler, version 2, when it is
613 * New features for SVR4
615 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
616 shared libraries. Debugging dynamically linked programs should present
617 only minor differences from debugging statically linked programs.
619 The `info proc' command will print out information about any process
620 on an SVR4 system (including the one you are debugging). At the moment,
621 it prints the address mappings of the process.
623 If you bring up GDB on another SVR4 system, please send mail to
624 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
626 * Better dynamic linking support in SunOS
628 Reading symbols from shared libraries which contain debugging symbols
629 now works properly. However, there remain issues such as automatic
630 skipping of `transfer vector' code during function calls, which
631 make it harder to debug code in a shared library, than to debug the
632 same code linked statically.
636 GDB is now using the latest `getopt' routines from the FSF. This
637 version accepts the -- prefix for options with long names. GDB will
638 continue to accept the old forms (-option and +option) as well.
639 Various single letter abbreviations for options have been explicity
640 added to the option table so that they won't get overshadowed in the
641 future by other options that begin with the same letter.
645 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
646 Many assorted bugs have been handled. Many more remain to be handled.
647 See the various ChangeLog files (primarily in gdb and bfd) for details.
650 *** Changes in GDB-4.3:
652 * New machines supported (host and target)
654 Amiga 3000 running Amix m68k-cbm-svr4 or amix
655 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
656 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
658 * Almost SCO Unix support
660 We had hoped to support:
661 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
662 (except for core file support), but we discovered very late in the release
663 that it has problems with process groups that render gdb unusable. Sorry
664 about that. I encourage people to fix it and post the fixes.
666 * Preliminary ELF and DWARF support
668 GDB can read ELF object files on System V Release 4, and can handle
669 debugging records for C, in DWARF format, in ELF files. This support
670 is preliminary. If you bring up GDB on another SVR4 system, please
671 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
676 GDB now uses the latest `readline' library. One user-visible change
677 is that two tabs will list possible command completions, which previously
678 required typing M-? (meta-question mark, or ESC ?).
682 The `stepi' bug that many of you noticed has been squashed.
683 Many bugs in C++ have been handled. Many more remain to be handled.
684 See the various ChangeLog files (primarily in gdb and bfd) for details.
686 * State of the MIPS world (in case you wondered):
688 GDB can understand the symbol tables emitted by the compilers
689 supplied by most vendors of MIPS-based machines, including DEC. These
690 symbol tables are in a format that essentially nobody else uses.
692 Some versions of gcc come with an assembler post-processor called
693 mips-tfile. This program is required if you want to do source-level
694 debugging of gcc-compiled programs. I believe FSF does not ship
695 mips-tfile with gcc version 1, but it will eventually come with gcc
698 Debugging of g++ output remains a problem. g++ version 1.xx does not
699 really support it at all. (If you're lucky, you should be able to get
700 line numbers and stack traces to work, but no parameters or local
701 variables.) With some work it should be possible to improve the
704 When gcc version 2 is released, you will have somewhat better luck.
705 However, even then you will get confusing results for inheritance and
708 We will eventually provide full debugging of g++ output on
709 DECstations. This will probably involve some kind of stabs-in-ecoff
710 encapulation, but the details have not been worked out yet.
713 *** Changes in GDB-4.2:
715 * Improved configuration
717 Only one copy of `configure' exists now, and it is not self-modifying.
718 Porting BFD is simpler.
722 The `step' and `next' commands now only stop at the first instruction
723 of a source line. This prevents the multiple stops that used to occur
724 in switch statements, for-loops, etc. `Step' continues to stop if a
725 function that has debugging information is called within the line.
729 Lots of small bugs fixed. More remain.
731 * New host supported (not target)
733 Intel 386 PC clone running Mach i386-none-mach
736 *** Changes in GDB-4.1:
738 * Multiple source language support
740 GDB now has internal scaffolding to handle several source languages.
741 It determines the type of each source file from its filename extension,
742 and will switch expression parsing and number formatting to match the
743 language of the function in the currently selected stack frame.
744 You can also specifically set the language to be used, with
745 `set language c' or `set language modula-2'.
749 GDB now has preliminary support for the GNU Modula-2 compiler,
750 currently under development at the State University of New York at
751 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
752 continue through the fall of 1991 and into 1992.
754 Other Modula-2 compilers are currently not supported, and attempting to
755 debug programs compiled with them will likely result in an error as the
756 symbol table is read. Feel free to work on it, though!
758 There are hooks in GDB for strict type checking and range checking,
759 in the `Modula-2 philosophy', but they do not currently work.
763 GDB can now write to executable and core files (e.g. patch
764 a variable's value). You must turn this switch on, specify
765 the file ("exec foo" or "core foo"), *then* modify it, e.g.
766 by assigning a new value to a variable. Modifications take
769 * Automatic SunOS shared library reading
771 When you run your program, GDB automatically determines where its
772 shared libraries (if any) have been loaded, and reads their symbols.
773 The `share' command is no longer needed. This also works when
774 examining core files.
778 You can specify the number of lines that the `list' command shows.
781 * New machines supported (host and target)
783 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
784 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
785 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
787 * New hosts supported (not targets)
789 IBM RT/PC: romp-ibm-aix or rtpc
791 * New targets supported (not hosts)
793 AMD 29000 embedded with COFF a29k-none-coff
794 AMD 29000 embedded with a.out a29k-none-aout
795 Ultracomputer remote kernel debug a29k-nyu-kern
797 * New remote interfaces
803 *** Changes in GDB-4.0:
807 Wide output is wrapped at good places to make the output more readable.
809 Gdb now supports cross-debugging from a host machine of one type to a
810 target machine of another type. Communication with the target system
811 is over serial lines. The ``target'' command handles connecting to the
812 remote system; the ``load'' command will download a program into the
813 remote system. Serial stubs for the m68k and i386 are provided. Gdb
814 also supports debugging of realtime processes running under VxWorks,
815 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
816 stub on the target system.
818 New CPUs supported include the AMD 29000 and Intel 960.
820 GDB now reads object files and symbol tables via a ``binary file''
821 library, which allows a single copy of GDB to debug programs of multiple
822 object file types such as a.out and coff.
824 There is now a GDB reference card in "doc/refcard.tex". (Make targets
825 refcard.dvi and refcard.ps are available to format it).
828 * Control-Variable user interface simplified
830 All variables that control the operation of the debugger can be set
831 by the ``set'' command, and displayed by the ``show'' command.
833 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
834 ``Show prompt'' produces the response:
835 Gdb's prompt is new-gdb=>.
837 What follows are the NEW set commands. The command ``help set'' will
838 print a complete list of old and new set commands. ``help set FOO''
839 will give a longer description of the variable FOO. ``show'' will show
840 all of the variable descriptions and their current settings.
842 confirm on/off: Enables warning questions for operations that are
843 hard to recover from, e.g. rerunning the program while
844 it is already running. Default is ON.
846 editing on/off: Enables EMACS style command line editing
847 of input. Previous lines can be recalled with
848 control-P, the current line can be edited with control-B,
849 you can search for commands with control-R, etc.
852 history filename NAME: NAME is where the gdb command history
853 will be stored. The default is .gdb_history,
854 or the value of the environment variable
857 history size N: The size, in commands, of the command history. The
858 default is 256, or the value of the environment variable
861 history save on/off: If this value is set to ON, the history file will
862 be saved after exiting gdb. If set to OFF, the
863 file will not be saved. The default is OFF.
865 history expansion on/off: If this value is set to ON, then csh-like
866 history expansion will be performed on
867 command line input. The default is OFF.
869 radix N: Sets the default radix for input and output. It can be set
870 to 8, 10, or 16. Note that the argument to "radix" is interpreted
871 in the current radix, so "set radix 10" is always a no-op.
873 height N: This integer value is the number of lines on a page. Default
874 is 24, the current `stty rows'' setting, or the ``li#''
875 setting from the termcap entry matching the environment
878 width N: This integer value is the number of characters on a line.
879 Default is 80, the current `stty cols'' setting, or the ``co#''
880 setting from the termcap entry matching the environment
883 Note: ``set screensize'' is obsolete. Use ``set height'' and
884 ``set width'' instead.
886 print address on/off: Print memory addresses in various command displays,
887 such as stack traces and structure values. Gdb looks
888 more ``symbolic'' if you turn this off; it looks more
889 ``machine level'' with it on. Default is ON.
891 print array on/off: Prettyprint arrays. New convenient format! Default
894 print demangle on/off: Print C++ symbols in "source" form if on,
897 print asm-demangle on/off: Same, for assembler level printouts
900 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
903 * Support for Epoch Environment.
905 The epoch environment is a version of Emacs v18 with windowing. One
906 new command, ``inspect'', is identical to ``print'', except that if you
907 are running in the epoch environment, the value is printed in its own
911 * Support for Shared Libraries
913 GDB can now debug programs and core files that use SunOS shared libraries.
914 Symbols from a shared library cannot be referenced
915 before the shared library has been linked with the program (this
916 happens after you type ``run'' and before the function main() is entered).
917 At any time after this linking (including when examining core files
918 from dynamically linked programs), gdb reads the symbols from each
919 shared library when you type the ``sharedlibrary'' command.
920 It can be abbreviated ``share''.
922 sharedlibrary REGEXP: Load shared object library symbols for files
923 matching a unix regular expression. No argument
924 indicates to load symbols for all shared libraries.
926 info sharedlibrary: Status of loaded shared libraries.
931 A watchpoint stops execution of a program whenever the value of an
932 expression changes. Checking for this slows down execution
933 tremendously whenever you are in the scope of the expression, but is
934 quite useful for catching tough ``bit-spreader'' or pointer misuse
935 problems. Some machines such as the 386 have hardware for doing this
936 more quickly, and future versions of gdb will use this hardware.
938 watch EXP: Set a watchpoint (breakpoint) for an expression.
940 info watchpoints: Information about your watchpoints.
942 delete N: Deletes watchpoint number N (same as breakpoints).
943 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
944 enable N: Re-enables watchpoint number N (same as breakpoints).
947 * C++ multiple inheritance
949 When used with a GCC version 2 compiler, GDB supports multiple inheritance
952 * C++ exception handling
954 Gdb now supports limited C++ exception handling. Besides the existing
955 ability to breakpoint on an exception handler, gdb can breakpoint on
956 the raising of an exception (before the stack is peeled back to the
959 catch FOO: If there is a FOO exception handler in the dynamic scope,
960 set a breakpoint to catch exceptions which may be raised there.
961 Multiple exceptions (``catch foo bar baz'') may be caught.
963 info catch: Lists all exceptions which may be caught in the
967 * Minor command changes
969 The command ``call func (arg, arg, ...)'' now acts like the print
970 command, except it does not print or save a value if the function's result
971 is void. This is similar to dbx usage.
973 The ``up'' and ``down'' commands now always print the frame they end up
974 at; ``up-silently'' and `down-silently'' can be used in scripts to change
975 frames without printing.
977 * New directory command
979 'dir' now adds directories to the FRONT of the source search path.
980 The path starts off empty. Source files that contain debug information
981 about the directory in which they were compiled can be found even
982 with an empty path; Sun CC and GCC include this information. If GDB can't
983 find your source file in the current directory, type "dir .".
985 * Configuring GDB for compilation
987 For normal use, type ``./configure host''. See README or gdb.texinfo
990 GDB now handles cross debugging. If you are remotely debugging between
991 two different machines, type ``./configure host -target=targ''.
992 Host is the machine where GDB will run; targ is the machine
993 where the program that you are debugging will run.