1 What has changed since GDB-3.5?
2 (Organized release by release)
4 *** Changes in GDB-???:
6 * User visible changes:
8 Remote debugging using the GDB-specific (`target remote') protocol now
9 supports the `load' command. This is only useful if you have some
10 other way of getting the stub to the target system, and you can put it
11 somewhere in memory where it won't get clobbered by the download.
13 Filename completion now works.
15 When run under emacs mode, the "info line" command now causes the
16 arrow to point to the line specified. Also, "info line" prints
17 addresses in symbolic form (as well as hex).
19 All vxworks based targets now support a user settable option, called
20 vxworks-timeout. This option represents the number of seconds gdb
21 should wait for responses to rpc's. You might want to use this if
22 your vxworks target is, perhaps, a slow software simulator or happens
23 to be on the far side of a thin network line.
25 *** Changes in GDB-4.9:
29 This is the first GDB release which is accompanied by a matching testsuite.
30 The testsuite requires installation of dejagnu, which should be available
31 via ftp from most sites that carry GNU software.
35 'Cfront' style demangling has had its name changed to 'ARM' style, to
36 emphasize that it was written from the specifications in the C++ Annotated
37 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
38 disclaimers, it still generated too much confusion with users attempting to
39 use gdb with AT&T cfront.
43 GDB now uses a standard remote interface to a simulator library.
44 So far, the library contains simulators for the Zilog Z8001/2, the
45 Hitachi H8/300, H8/500 and Super-H.
47 * New targets supported
49 H8/300 simulator h8300-hitachi-hms or h8300hms
50 H8/500 simulator h8500-hitachi-hms or h8500hms
51 SH simulator sh-hitachi-hms or sh
52 Z8000 simulator z8k-zilog-none or z8ksim
53 IDT MIPS board over serial line mips-idt-ecoff
55 Cross-debugging to GO32 targets is supported. It requires a custom
56 version of the i386-stub.c module which is integrated with the
59 * New remote protocols
61 MIPS remote debugging protocol.
63 * New source languages supported
65 This version includes preliminary support for Chill, a Pascal like language
66 used by telecommunications companies. Chill support is also being integrated
67 into the GNU compiler, but we don't know when it will be publically available.
70 *** Changes in GDB-4.8:
72 * HP Precision Architecture supported
74 GDB now supports HP PA-RISC machines running HPUX. A preliminary
75 version of this support was available as a set of patches from the
76 University of Utah. GDB does not support debugging of programs
77 compiled with the HP compiler, because HP will not document their file
78 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
79 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
81 Many problems in the preliminary version have been fixed.
83 * Faster and better demangling
85 We have improved template demangling and fixed numerous bugs in the GNU style
86 demangler. It can now handle type modifiers such as `static' or `const'. Wide
87 character types (wchar_t) are now supported. Demangling of each symbol is now
88 only done once, and is cached when the symbol table for a file is read in.
89 This results in a small increase in memory usage for C programs, a moderate
90 increase in memory usage for C++ programs, and a fantastic speedup in
93 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
94 from the specifications in the Annotated Reference Manual, which AT&T's
95 compiler does not actually implement.
97 * G++ multiple inheritance compiler problem
99 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
100 inheritance lattices was reworked to properly discover ambiguities. We
101 recently found an example which causes this new algorithm to fail in a
102 very subtle way, producing bad debug information for those classes.
103 The file 'gcc.patch' (in this directory) can be applied to gcc to
104 circumvent the problem. A future GCC release will contain a complete
107 The previous G++ debug info problem (mentioned below for the gdb-4.7
108 release) is fixed in gcc version 2.3.2.
110 * Improved configure script
112 The `configure' script will now attempt to guess your system type if
113 you don't supply a host system type. The old scheme of supplying a
114 host system triplet is preferable over using this. All the magic is
115 done in the new `config.guess' script. Examine it for details.
117 We have also brought our configure script much more in line with the FSF's
118 version. It now supports the --with-xxx options. In particular,
119 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
120 The resulting GDB will not be able to read arbitrary object file formats --
121 only the format ``expected'' to be used on the configured target system.
122 We hope to make this the default in a future release.
124 * Documentation improvements
126 There's new internal documentation on how to modify GDB, and how to
127 produce clean changes to the code. We implore people to read it
128 before submitting changes.
130 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
131 M4 macros. The new texinfo.tex is provided in this release. Pre-built
132 `info' files are also provided. To build `info' files from scratch,
133 you will need the latest `makeinfo' release, which will be available in
134 a future texinfo-X.Y release.
136 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
137 We're not sure exactly which versions have this problem, but it has
138 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
139 or better. If that isn't possible, there is a patch in
140 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
145 GDB now supports array constants that can be used in expressions typed in by
146 the user. The syntax is `{element, element, ...}'. Ie: you can now type
147 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
150 The new directory `gdb/sparclite' contains a program that demonstrates
151 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
153 * New native hosts supported
155 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
156 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
158 * New targets supported
160 AMD 29k family via UDI a29k-amd-udi or udi29k
162 * New file formats supported
164 BFD now supports reading HP/PA-RISC executables (SOM file format?),
165 HPUX core files, and SCO 3.2v2 core files.
169 Attaching to processes now works again; thanks for the many bug reports.
171 We have also stomped on a bunch of core dumps caused by
172 printf_filtered("%s") problems.
174 We eliminated a copyright problem on the rpc and ptrace header files
175 for VxWorks, which was discovered at the last minute during the 4.7
176 release. You should now be able to build a VxWorks GDB.
178 You can now interrupt gdb while an attached process is running. This
179 will cause the attached process to stop, and give control back to GDB.
181 We fixed problems caused by using too many file descriptors
182 for reading symbols from object files and libraries. This was
183 especially a problem for programs that used many (~100) shared
186 The `step' command now only enters a subroutine if there is line number
187 information for the subroutine. Otherwise it acts like the `next'
188 command. Previously, `step' would enter subroutines if there was
189 any debugging information about the routine. This avoids problems
190 when using `cc -g1' on MIPS machines.
192 * Internal improvements
194 GDB's internal interfaces have been improved to make it easier to support
195 debugging of multiple languages in the future.
197 GDB now uses a common structure for symbol information internally.
198 Minimal symbols (derived from linkage symbols in object files), partial
199 symbols (from a quick scan of debug information), and full symbols
200 contain a common subset of information, making it easier to write
201 shared code that handles any of them.
203 * New command line options
205 We now accept --silent as an alias for --quiet.
209 The memory-mapped-malloc library is now licensed under the GNU Library
210 General Public License.
212 *** Changes in GDB-4.7:
214 * Host/native/target split
216 GDB has had some major internal surgery to untangle the support for
217 hosts and remote targets. Now, when you configure GDB for a remote
218 target, it will no longer load in all of the support for debugging
219 local programs on the host. When fully completed and tested, this will
220 ensure that arbitrary host/target combinations are possible.
222 The primary conceptual shift is to separate the non-portable code in
223 GDB into three categories. Host specific code is required any time GDB
224 is compiled on that host, regardless of the target. Target specific
225 code relates to the peculiarities of the target, but can be compiled on
226 any host. Native specific code is everything else: it can only be
227 built when the host and target are the same system. Child process
228 handling and core file support are two common `native' examples.
230 GDB's use of /proc for controlling Unix child processes is now cleaner.
231 It has been split out into a single module under the `target_ops' vector,
232 plus two native-dependent functions for each system that uses /proc.
234 * New hosts supported
236 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
237 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
238 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
240 * New targets supported
242 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
243 68030 and CPU32 m68030-*-*, m68332-*-*
245 * New native hosts supported
247 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
248 (386bsd is not well tested yet)
249 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
251 * New file formats supported
253 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
254 supports reading of `a.out.adobe' object files, which are an a.out
255 format extended with minimal information about multiple sections.
259 `show copying' is the same as the old `info copying'.
260 `show warranty' is the same as `info warrantee'.
261 These were renamed for consistency. The old commands continue to work.
263 `info handle' is a new alias for `info signals'.
265 You can now define pre-command hooks, which attach arbitrary command
266 scripts to any command. The commands in the hook will be executed
267 prior to the user's command. You can also create a hook which will be
268 executed whenever the program stops. See gdb.texinfo.
272 We now deal with Cfront style name mangling, and can even extract type
273 info from mangled symbols. GDB can automatically figure out which
274 symbol mangling style your C++ compiler uses.
276 Calling of methods and virtual functions has been improved as well.
280 The crash that occured when debugging Sun Ansi-C compiled binaries is
281 fixed. This was due to mishandling of the extra N_SO stabs output
284 We also finally got Ultrix 4.2 running in house, and fixed core file
285 support, with help from a dozen people on the net.
287 John M. Farrell discovered that the reason that single-stepping was so
288 slow on all of the Mips based platforms (primarily SGI and DEC) was
289 that we were trying to demangle and lookup a symbol used for internal
290 purposes on every instruction that was being stepped through. Changing
291 the name of that symbol so that it couldn't be mistaken for a C++
292 mangled symbol sped things up a great deal.
294 Rich Pixley sped up symbol lookups in general by getting much smarter
295 about when C++ symbol mangling is necessary. This should make symbol
296 completion (TAB on the command line) much faster. It's not as fast as
297 we'd like, but it's significantly faster than gdb-4.6.
301 A new user controllable variable 'call_scratch_address' can
302 specify the location of a scratch area to be used when GDB
303 calls a function in the target. This is necessary because the
304 usual method of putting the scratch area on the stack does not work
305 in systems that have separate instruction and data spaces.
307 We integrated changes to support the 29k UDI (Universal Debugger
308 Interface), but discovered at the last minute that we didn't have all
309 of the appropriate copyright paperwork. We are working with AMD to
310 resolve this, and hope to have it available soon.
314 We have sped up the remote serial line protocol, especially for targets
315 with lots of registers. It now supports a new `expedited status' ('T')
316 message which can be used in place of the existing 'S' status message.
317 This allows the remote stub to send only the registers that GDB
318 needs to make a quick decision about single-stepping or conditional
319 breakpoints, eliminating the need to fetch the entire register set for
320 each instruction being stepped through.
322 The GDB remote serial protocol now implements a write-through cache for
323 registers, only re-reading the registers if the target has run.
325 There is also a new remote serial stub for SPARC processors. You can
326 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
327 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
328 processor with a serial port.
332 Configure.in files have become much easier to read and modify. A new
333 `table driven' format makes it more obvious what configurations are
334 supported, and what files each one uses.
338 There is a new opcodes library which will eventually contain all of the
339 disassembly routines and opcode tables. At present, it only contains
340 Sparc and Z8000 routines. This will allow the assembler, debugger, and
341 disassembler (binutils/objdump) to share these routines.
343 The libiberty library is now copylefted under the GNU Library General
344 Public License. This allows more liberal use, and was done so libg++
345 can use it. This makes no difference to GDB, since the Library License
346 grants all the rights from the General Public License.
350 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
351 reference to the stabs symbol info used by the debugger. It is (as far
352 as we know) the only published document on this fascinating topic. We
353 encourage you to read it, compare it to the stabs information on your
354 system, and send improvements on the document in general (to
355 bug-gdb@prep.ai.mit.edu).
357 And, of course, many bugs have been fixed.
360 *** Changes in GDB-4.6:
362 * Better support for C++ function names
364 GDB now accepts as input the "demangled form" of C++ overloaded function
365 names and member function names, and can do command completion on such names
366 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
367 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
368 Make use of command completion, it is your friend.
370 GDB also now accepts a variety of C++ mangled symbol formats. They are
371 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
372 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
373 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
374 for the list of formats.
376 * G++ symbol mangling problem
378 Recent versions of gcc have a bug in how they emit debugging information for
379 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
380 directory) can be applied to gcc to fix the problem. Alternatively, if you
381 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
382 usual symptom is difficulty with setting breakpoints on methods. GDB complains
383 about the method being non-existent. (We believe that version 2.2.2 of GCC has
386 * New 'maintenance' command
388 All of the commands related to hacking GDB internals have been moved out of
389 the main command set, and now live behind the 'maintenance' command. This
390 can also be abbreviated as 'mt'. The following changes were made:
392 dump-me -> maintenance dump-me
393 info all-breakpoints -> maintenance info breakpoints
394 printmsyms -> maintenance print msyms
395 printobjfiles -> maintenance print objfiles
396 printpsyms -> maintenance print psymbols
397 printsyms -> maintenance print symbols
399 The following commands are new:
401 maintenance demangle Call internal GDB demangler routine to
402 demangle a C++ link name and prints the result.
403 maintenance print type Print a type chain for a given symbol
405 * Change to .gdbinit file processing
407 We now read the $HOME/.gdbinit file before processing the argv arguments
408 (e.g. reading symbol files or core files). This allows global parameters to
409 be set, which will apply during the symbol reading. The ./.gdbinit is still
410 read after argv processing.
412 * New hosts supported
414 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
416 Linux support i386-unknown-linux or linux
418 We are also including code to support the HP/PA running BSD and HPUX. This
419 is almost guaranteed not to work, as we didn't have time to test or build it
420 for this release. We are including it so that the more adventurous (or
421 masochistic) of you can play with it. We also had major problems with the
422 fact that the compiler that we got from HP doesn't support the -g option.
425 * New targets supported
427 Hitachi H8/300 h8300-hitachi-hms or h8300hms
429 * More smarts about finding #include files
431 GDB now remembers the compilation directory for all include files, and for
432 all files from which C is generated (like yacc and lex sources). This
433 greatly improves GDB's ability to find yacc/lex sources, and include files,
434 especially if you are debugging your program from a directory different from
435 the one that contains your sources.
437 We also fixed a bug which caused difficulty with listing and setting
438 breakpoints in include files which contain C code. (In the past, you had to
439 try twice in order to list an include file that you hadn't looked at before.)
441 * Interesting infernals change
443 GDB now deals with arbitrary numbers of sections, where the symbols for each
444 section must be relocated relative to that section's landing place in the
445 target's address space. This work was needed to support ELF with embedded
446 stabs used by Solaris-2.0.
448 * Bug fixes (of course!)
450 There have been loads of fixes for the following things:
451 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
452 i960, stabs, DOS(GO32), procfs, etc...
454 See the ChangeLog for details.
456 *** Changes in GDB-4.5:
458 * New machines supported (host and target)
460 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
462 SGI Irix-4.x mips-sgi-irix4 or iris4
466 GDB now uses a new memory manager called mmalloc, based on gmalloc.
467 Mmalloc is capable of handling mutiple heaps of memory. It is also
468 capable of saving a heap to a file, and then mapping it back in later.
469 This can be used to greatly speedup the startup of GDB by using a
470 pre-parsed symbol table which lives in a mmalloc managed heap. For
471 more details, please read mmalloc/mmalloc.texi.
475 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
476 'help info proc' for details.
478 * MIPS ecoff symbol table format
480 The code that reads MIPS symbol table format is now supported on all hosts.
481 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
484 * File name changes for MS-DOS
486 Many files in the config directories have been renamed to make it easier to
487 support GDB on MS-DOSe systems (which have very restrictive file name
488 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
489 environment) is close to working but has some remaining problems. Note
490 that debugging of DOS programs is not supported, due to limitations
491 in the ``operating system'', but it can be used to host cross-debugging.
493 * Cross byte order fixes
495 Many fixes have been made to support cross debugging of Sparc and MIPS
496 targets from hosts whose byte order differs.
498 * New -mapped and -readnow options
500 If memory-mapped files are available on your system through the 'mmap'
501 system call, you can use the -mapped option on the `file' or
502 `symbol-file' commands to cause GDB to write the symbols from your
503 program into a reusable file. If the program you are debugging is
504 called `/path/fred', the mapped symbol file will be `./fred.syms'.
505 Future GDB debugging sessions will notice the presence of this file,
506 and will quickly map in symbol information from it, rather than reading
507 the symbol table from the executable program. Using the '-mapped'
508 option in a GDB `file' or `symbol-file' command has the same effect as
509 starting GDB with the '-mapped' command-line option.
511 You can cause GDB to read the entire symbol table immediately by using
512 the '-readnow' option with any of the commands that load symbol table
513 information (or on the GDB command line). This makes the command
514 slower, but makes future operations faster.
516 The -mapped and -readnow options are typically combined in order to
517 build a `fred.syms' file that contains complete symbol information.
518 A simple GDB invocation to do nothing but build a `.syms' file for future
521 gdb -batch -nx -mapped -readnow programname
523 The `.syms' file is specific to the host machine on which GDB is run.
524 It holds an exact image of GDB's internal symbol table. It cannot be
525 shared across multiple host platforms.
529 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
530 siglongjmp() without losing control. This feature has not yet been ported to
531 all systems. It currently works on many 386 platforms, all MIPS-based
532 platforms (SGI, DECstation, etc), and Sun3/4.
536 Preliminary work has been put in to support the new Solaris OS from Sun. At
537 this time, it can control and debug processes, but it is not capable of
542 As always, many many bug fixes. The major areas were with g++, and mipsread.
543 People using the MIPS-based platforms should experience fewer mysterious
544 crashes and trashed symbol tables.
546 *** Changes in GDB-4.4:
548 * New machines supported (host and target)
550 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
552 BSD Reno on Vax vax-dec-bsd
553 Ultrix on Vax vax-dec-ultrix
555 * New machines supported (target)
557 AMD 29000 embedded, using EBMON a29k-none-none
561 GDB continues to improve its handling of C++. `References' work better.
562 The demangler has also been improved, and now deals with symbols mangled as
563 per the Annotated C++ Reference Guide.
565 GDB also now handles `stabs' symbol information embedded in MIPS
566 `ecoff' symbol tables. Since the ecoff format was not easily
567 extensible to handle new languages such as C++, this appeared to be a
568 good way to put C++ debugging info into MIPS binaries. This option
569 will be supported in the GNU C compiler, version 2, when it is
572 * New features for SVR4
574 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
575 shared libraries. Debugging dynamically linked programs should present
576 only minor differences from debugging statically linked programs.
578 The `info proc' command will print out information about any process
579 on an SVR4 system (including the one you are debugging). At the moment,
580 it prints the address mappings of the process.
582 If you bring up GDB on another SVR4 system, please send mail to
583 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
585 * Better dynamic linking support in SunOS
587 Reading symbols from shared libraries which contain debugging symbols
588 now works properly. However, there remain issues such as automatic
589 skipping of `transfer vector' code during function calls, which
590 make it harder to debug code in a shared library, than to debug the
591 same code linked statically.
595 GDB is now using the latest `getopt' routines from the FSF. This
596 version accepts the -- prefix for options with long names. GDB will
597 continue to accept the old forms (-option and +option) as well.
598 Various single letter abbreviations for options have been explicity
599 added to the option table so that they won't get overshadowed in the
600 future by other options that begin with the same letter.
604 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
605 Many assorted bugs have been handled. Many more remain to be handled.
606 See the various ChangeLog files (primarily in gdb and bfd) for details.
609 *** Changes in GDB-4.3:
611 * New machines supported (host and target)
613 Amiga 3000 running Amix m68k-cbm-svr4 or amix
614 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
615 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
617 * Almost SCO Unix support
619 We had hoped to support:
620 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
621 (except for core file support), but we discovered very late in the release
622 that it has problems with process groups that render gdb unusable. Sorry
623 about that. I encourage people to fix it and post the fixes.
625 * Preliminary ELF and DWARF support
627 GDB can read ELF object files on System V Release 4, and can handle
628 debugging records for C, in DWARF format, in ELF files. This support
629 is preliminary. If you bring up GDB on another SVR4 system, please
630 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
635 GDB now uses the latest `readline' library. One user-visible change
636 is that two tabs will list possible command completions, which previously
637 required typing M-? (meta-question mark, or ESC ?).
641 The `stepi' bug that many of you noticed has been squashed.
642 Many bugs in C++ have been handled. Many more remain to be handled.
643 See the various ChangeLog files (primarily in gdb and bfd) for details.
645 * State of the MIPS world (in case you wondered):
647 GDB can understand the symbol tables emitted by the compilers
648 supplied by most vendors of MIPS-based machines, including DEC. These
649 symbol tables are in a format that essentially nobody else uses.
651 Some versions of gcc come with an assembler post-processor called
652 mips-tfile. This program is required if you want to do source-level
653 debugging of gcc-compiled programs. I believe FSF does not ship
654 mips-tfile with gcc version 1, but it will eventually come with gcc
657 Debugging of g++ output remains a problem. g++ version 1.xx does not
658 really support it at all. (If you're lucky, you should be able to get
659 line numbers and stack traces to work, but no parameters or local
660 variables.) With some work it should be possible to improve the
663 When gcc version 2 is released, you will have somewhat better luck.
664 However, even then you will get confusing results for inheritance and
667 We will eventually provide full debugging of g++ output on
668 DECstations. This will probably involve some kind of stabs-in-ecoff
669 encapulation, but the details have not been worked out yet.
672 *** Changes in GDB-4.2:
674 * Improved configuration
676 Only one copy of `configure' exists now, and it is not self-modifying.
677 Porting BFD is simpler.
681 The `step' and `next' commands now only stop at the first instruction
682 of a source line. This prevents the multiple stops that used to occur
683 in switch statements, for-loops, etc. `Step' continues to stop if a
684 function that has debugging information is called within the line.
688 Lots of small bugs fixed. More remain.
690 * New host supported (not target)
692 Intel 386 PC clone running Mach i386-none-mach
695 *** Changes in GDB-4.1:
697 * Multiple source language support
699 GDB now has internal scaffolding to handle several source languages.
700 It determines the type of each source file from its filename extension,
701 and will switch expression parsing and number formatting to match the
702 language of the function in the currently selected stack frame.
703 You can also specifically set the language to be used, with
704 `set language c' or `set language modula-2'.
708 GDB now has preliminary support for the GNU Modula-2 compiler,
709 currently under development at the State University of New York at
710 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
711 continue through the fall of 1991 and into 1992.
713 Other Modula-2 compilers are currently not supported, and attempting to
714 debug programs compiled with them will likely result in an error as the
715 symbol table is read. Feel free to work on it, though!
717 There are hooks in GDB for strict type checking and range checking,
718 in the `Modula-2 philosophy', but they do not currently work.
722 GDB can now write to executable and core files (e.g. patch
723 a variable's value). You must turn this switch on, specify
724 the file ("exec foo" or "core foo"), *then* modify it, e.g.
725 by assigning a new value to a variable. Modifications take
728 * Automatic SunOS shared library reading
730 When you run your program, GDB automatically determines where its
731 shared libraries (if any) have been loaded, and reads their symbols.
732 The `share' command is no longer needed. This also works when
733 examining core files.
737 You can specify the number of lines that the `list' command shows.
740 * New machines supported (host and target)
742 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
743 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
744 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
746 * New hosts supported (not targets)
748 IBM RT/PC: romp-ibm-aix or rtpc
750 * New targets supported (not hosts)
752 AMD 29000 embedded with COFF a29k-none-coff
753 AMD 29000 embedded with a.out a29k-none-aout
754 Ultracomputer remote kernel debug a29k-nyu-kern
756 * New remote interfaces
762 *** Changes in GDB-4.0:
766 Wide output is wrapped at good places to make the output more readable.
768 Gdb now supports cross-debugging from a host machine of one type to a
769 target machine of another type. Communication with the target system
770 is over serial lines. The ``target'' command handles connecting to the
771 remote system; the ``load'' command will download a program into the
772 remote system. Serial stubs for the m68k and i386 are provided. Gdb
773 also supports debugging of realtime processes running under VxWorks,
774 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
775 stub on the target system.
777 New CPUs supported include the AMD 29000 and Intel 960.
779 GDB now reads object files and symbol tables via a ``binary file''
780 library, which allows a single copy of GDB to debug programs of multiple
781 object file types such as a.out and coff.
783 There is now a GDB reference card in "doc/refcard.tex". (Make targets
784 refcard.dvi and refcard.ps are available to format it).
787 * Control-Variable user interface simplified
789 All variables that control the operation of the debugger can be set
790 by the ``set'' command, and displayed by the ``show'' command.
792 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
793 ``Show prompt'' produces the response:
794 Gdb's prompt is new-gdb=>.
796 What follows are the NEW set commands. The command ``help set'' will
797 print a complete list of old and new set commands. ``help set FOO''
798 will give a longer description of the variable FOO. ``show'' will show
799 all of the variable descriptions and their current settings.
801 confirm on/off: Enables warning questions for operations that are
802 hard to recover from, e.g. rerunning the program while
803 it is already running. Default is ON.
805 editing on/off: Enables EMACS style command line editing
806 of input. Previous lines can be recalled with
807 control-P, the current line can be edited with control-B,
808 you can search for commands with control-R, etc.
811 history filename NAME: NAME is where the gdb command history
812 will be stored. The default is .gdb_history,
813 or the value of the environment variable
816 history size N: The size, in commands, of the command history. The
817 default is 256, or the value of the environment variable
820 history save on/off: If this value is set to ON, the history file will
821 be saved after exiting gdb. If set to OFF, the
822 file will not be saved. The default is OFF.
824 history expansion on/off: If this value is set to ON, then csh-like
825 history expansion will be performed on
826 command line input. The default is OFF.
828 radix N: Sets the default radix for input and output. It can be set
829 to 8, 10, or 16. Note that the argument to "radix" is interpreted
830 in the current radix, so "set radix 10" is always a no-op.
832 height N: This integer value is the number of lines on a page. Default
833 is 24, the current `stty rows'' setting, or the ``li#''
834 setting from the termcap entry matching the environment
837 width N: This integer value is the number of characters on a line.
838 Default is 80, the current `stty cols'' setting, or the ``co#''
839 setting from the termcap entry matching the environment
842 Note: ``set screensize'' is obsolete. Use ``set height'' and
843 ``set width'' instead.
845 print address on/off: Print memory addresses in various command displays,
846 such as stack traces and structure values. Gdb looks
847 more ``symbolic'' if you turn this off; it looks more
848 ``machine level'' with it on. Default is ON.
850 print array on/off: Prettyprint arrays. New convenient format! Default
853 print demangle on/off: Print C++ symbols in "source" form if on,
856 print asm-demangle on/off: Same, for assembler level printouts
859 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
862 * Support for Epoch Environment.
864 The epoch environment is a version of Emacs v18 with windowing. One
865 new command, ``inspect'', is identical to ``print'', except that if you
866 are running in the epoch environment, the value is printed in its own
870 * Support for Shared Libraries
872 GDB can now debug programs and core files that use SunOS shared libraries.
873 Symbols from a shared library cannot be referenced
874 before the shared library has been linked with the program (this
875 happens after you type ``run'' and before the function main() is entered).
876 At any time after this linking (including when examining core files
877 from dynamically linked programs), gdb reads the symbols from each
878 shared library when you type the ``sharedlibrary'' command.
879 It can be abbreviated ``share''.
881 sharedlibrary REGEXP: Load shared object library symbols for files
882 matching a unix regular expression. No argument
883 indicates to load symbols for all shared libraries.
885 info sharedlibrary: Status of loaded shared libraries.
890 A watchpoint stops execution of a program whenever the value of an
891 expression changes. Checking for this slows down execution
892 tremendously whenever you are in the scope of the expression, but is
893 quite useful for catching tough ``bit-spreader'' or pointer misuse
894 problems. Some machines such as the 386 have hardware for doing this
895 more quickly, and future versions of gdb will use this hardware.
897 watch EXP: Set a watchpoint (breakpoint) for an expression.
899 info watchpoints: Information about your watchpoints.
901 delete N: Deletes watchpoint number N (same as breakpoints).
902 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
903 enable N: Re-enables watchpoint number N (same as breakpoints).
906 * C++ multiple inheritance
908 When used with a GCC version 2 compiler, GDB supports multiple inheritance
911 * C++ exception handling
913 Gdb now supports limited C++ exception handling. Besides the existing
914 ability to breakpoint on an exception handler, gdb can breakpoint on
915 the raising of an exception (before the stack is peeled back to the
918 catch FOO: If there is a FOO exception handler in the dynamic scope,
919 set a breakpoint to catch exceptions which may be raised there.
920 Multiple exceptions (``catch foo bar baz'') may be caught.
922 info catch: Lists all exceptions which may be caught in the
926 * Minor command changes
928 The command ``call func (arg, arg, ...)'' now acts like the print
929 command, except it does not print or save a value if the function's result
930 is void. This is similar to dbx usage.
932 The ``up'' and ``down'' commands now always print the frame they end up
933 at; ``up-silently'' and `down-silently'' can be used in scripts to change
934 frames without printing.
936 * New directory command
938 'dir' now adds directories to the FRONT of the source search path.
939 The path starts off empty. Source files that contain debug information
940 about the directory in which they were compiled can be found even
941 with an empty path; Sun CC and GCC include this information. If GDB can't
942 find your source file in the current directory, type "dir .".
944 * Configuring GDB for compilation
946 For normal use, type ``./configure host''. See README or gdb.texinfo
949 GDB now handles cross debugging. If you are remotely debugging between
950 two different machines, type ``./configure host -target=targ''.
951 Host is the machine where GDB will run; targ is the machine
952 where the program that you are debugging will run.
projects / deliverable / binutils-gdb.git / blob