1 What has changed in GDB?
2 (Organized release by release)
4 *** Changes in GDB-4.14:
6 * New native configurations
8 x86 FreeBSD i[345]86-*-freebsd
9 x86 NetBSD i[345]86-*-netbsd
10 NS32k NetBSD ns32k-*-netbsd
11 Sparc NetBSD sparc-*-netbsd
15 A29K VxWorks a29k-*-vxworks
16 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
17 CPU32 EST-300 emulator m68*-*-est*
18 PowerPC ELF powerpc-*-elf
21 * Alpha OSF/1 support for procfs
23 GDB now supports procfs under OSF/1-2.x and higher, which makes it
24 possible to attach to running processes. As the mounting of the /proc
25 filesystem is optional on the Alpha, GDB automatically determines
26 the availability of /proc during startup. This can lead to problems
27 if /proc is unmounted after GDB has been started.
29 * Arguments to user-defined commands
31 User commands may accept up to 10 arguments separated by whitespace.
32 Arguments are accessed within the user command via $arg0..$arg9. A
35 print $arg0 + $arg1 + $arg2
37 To execute the command use:
40 Defines the command "adder" which prints the sum of its three arguments.
41 Note the arguments are text substitutions, so they may reference variables,
42 use complex expressions, or even perform inferior function calls.
44 * New `if' and `while' commands
46 This makes it possible to write more sophisticated user-defined
47 commands. Both commands take a single argument, which is the
48 expression to evaluate, and must be followed by the commands to
49 execute, one per line, if the expression is nonzero, the list being
50 terminated by the word `end'. The `if' command list may include an
51 `else' word, which causes the following commands to be executed only
52 if the expression is zero.
54 * Fortran source language mode
56 GDB now includes partial support for Fortran 77. It will recognize
57 Fortran programs and can evaluate a subset of Fortran expressions, but
58 variables and functions may not be handled correctly. GDB will work
59 with G77, but does not yet know much about symbols emitted by other
64 Most debugging facilities now work on dynamic executables for HPPAs
65 running hpux9 or later. You can attach to running dynamically linked
66 processes, but by default the dynamic libraries will be read-only, so
67 for instance you won't be able to put breakpoints in them. To change
68 that behavior do the following before running the program:
74 This will cause the libraries to be mapped private and read-write.
75 To revert to the normal behavior, do this:
81 You cannot set breakpoints or examine data in the library until after
82 the library is loaded if the function/data symbols do not have
85 GDB can now also read debug symbols produced by the HP C compiler on
86 HPPAs (sorry, no C++, Fortran or 68k support).
88 * Target byte order now dynamically selectable
90 You can choose which byte order to use with a target system, via the
91 commands "set endian big" and "set endian little", and you can see the
92 current setting by using "show endian". You can also give the command
93 "set endian auto", in which case GDB will use the byte order
94 associated with the executable. Currently, only embedded MIPS
95 configurations support dynamic selection of target byte order.
97 * New DOS host serial code
99 This version uses DPMI interrupts to handle buffered I/O, so you
100 no longer need to run asynctsr when debugging boards connected to
103 *** Changes in GDB-4.13:
105 * New "complete" command
107 This lists all the possible completions for the rest of the line, if it
108 were to be given as a command itself. This is intended for use by emacs.
110 * Trailing space optional in prompt
112 "set prompt" no longer adds a space for you after the prompt you set. This
113 allows you to set a prompt which ends in a space or one that does not.
115 * Breakpoint hit counts
117 "info break" now displays a count of the number of times the breakpoint
118 has been hit. This is especially useful in conjunction with "ignore"; you
119 can ignore a large number of breakpoint hits, look at the breakpoint info
120 to see how many times the breakpoint was hit, then run again, ignoring one
121 less than that number, and this will get you quickly to the last hit of
124 * Ability to stop printing at NULL character
126 "set print null-stop" will cause GDB to stop printing the characters of
127 an array when the first NULL is encountered. This is useful when large
128 arrays actually contain only short strings.
130 * Shared library breakpoints
132 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
133 breakpoints in shared libraries before the executable is run.
135 * Hardware watchpoints
137 There is a new hardware breakpoint for the watch command for sparclite
138 targets. See gdb/sparclite/hw_breakpoint.note.
140 Hardware watchpoints are also now supported under Linux.
144 Annotations have been added. These are for use with graphical interfaces,
145 and are still experimental. Currently only gdba.el uses these.
147 * Improved Irix 5 support
149 GDB now works properly with Irix 5.2.
151 * Improved HPPA support
153 GDB now works properly with the latest GCC and GAS.
155 * New native configurations
157 Sequent PTX4 i[34]86-sequent-ptx4
158 HPPA running OSF/1 hppa*-*-osf*
159 Atari TT running SVR4 m68*-*-sysv4*
160 RS/6000 LynxOS rs6000-*-lynxos*
164 OS/9000 i[34]86-*-os9k
165 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
168 * Hitachi SH7000 and E7000-PC ICE support
170 There is now support for communicating with the Hitachi E7000-PC ICE.
171 This is available automatically when GDB is configured for the SH.
175 As usual, a variety of small fixes and improvements, both generic
176 and configuration-specific. See the ChangeLog for more detail.
178 *** Changes in GDB-4.12:
180 * Irix 5 is now supported
184 GDB-4.12 on the HPPA has a number of changes which make it unable
185 to debug the output from the currently released versions of GCC and
186 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
187 of GCC and GAS, versions of these tools designed to work with GDB-4.12
188 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
191 *** Changes in GDB-4.11:
193 * User visible changes:
197 The "set remotedebug" option is now consistent between the mips remote
198 target, remote targets using the gdb-specific protocol, UDI (AMD's
199 debug protocol for the 29k) and the 88k bug monitor. It is now an
200 integer specifying a debug level (normally 0 or 1, but 2 means more
201 debugging info for the mips target).
203 * DEC Alpha native support
205 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
206 debug info, but GDB works fairly well with the DEC compiler and should
207 work with a future GCC release. See the README file for a few
208 Alpha-specific notes.
210 * Preliminary thread implementation
212 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
214 * LynxOS native and target support for 386
216 This release has been hosted on LynxOS 2.2, and also can be configured
217 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
220 * Improvements in C++ mangling/demangling.
222 This release has much better g++ debugging, specifically in name
223 mangling/demangling, virtual function calls, print virtual table,
224 call methods, ...etc.
226 *** Changes in GDB-4.10:
228 * User visible changes:
230 Remote debugging using the GDB-specific (`target remote') protocol now
231 supports the `load' command. This is only useful if you have some
232 other way of getting the stub to the target system, and you can put it
233 somewhere in memory where it won't get clobbered by the download.
235 Filename completion now works.
237 When run under emacs mode, the "info line" command now causes the
238 arrow to point to the line specified. Also, "info line" prints
239 addresses in symbolic form (as well as hex).
241 All vxworks based targets now support a user settable option, called
242 vxworks-timeout. This option represents the number of seconds gdb
243 should wait for responses to rpc's. You might want to use this if
244 your vxworks target is, perhaps, a slow software simulator or happens
245 to be on the far side of a thin network line.
249 This release contains support for using a DEC alpha as a GDB host for
250 cross debugging. Native alpha debugging is not supported yet.
253 *** Changes in GDB-4.9:
257 This is the first GDB release which is accompanied by a matching testsuite.
258 The testsuite requires installation of dejagnu, which should be available
259 via ftp from most sites that carry GNU software.
263 'Cfront' style demangling has had its name changed to 'ARM' style, to
264 emphasize that it was written from the specifications in the C++ Annotated
265 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
266 disclaimers, it still generated too much confusion with users attempting to
267 use gdb with AT&T cfront.
271 GDB now uses a standard remote interface to a simulator library.
272 So far, the library contains simulators for the Zilog Z8001/2, the
273 Hitachi H8/300, H8/500 and Super-H.
275 * New targets supported
277 H8/300 simulator h8300-hitachi-hms or h8300hms
278 H8/500 simulator h8500-hitachi-hms or h8500hms
279 SH simulator sh-hitachi-hms or sh
280 Z8000 simulator z8k-zilog-none or z8ksim
281 IDT MIPS board over serial line mips-idt-ecoff
283 Cross-debugging to GO32 targets is supported. It requires a custom
284 version of the i386-stub.c module which is integrated with the
285 GO32 memory extender.
287 * New remote protocols
289 MIPS remote debugging protocol.
291 * New source languages supported
293 This version includes preliminary support for Chill, a Pascal like language
294 used by telecommunications companies. Chill support is also being integrated
295 into the GNU compiler, but we don't know when it will be publically available.
298 *** Changes in GDB-4.8:
300 * HP Precision Architecture supported
302 GDB now supports HP PA-RISC machines running HPUX. A preliminary
303 version of this support was available as a set of patches from the
304 University of Utah. GDB does not support debugging of programs
305 compiled with the HP compiler, because HP will not document their file
306 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
307 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
309 Many problems in the preliminary version have been fixed.
311 * Faster and better demangling
313 We have improved template demangling and fixed numerous bugs in the GNU style
314 demangler. It can now handle type modifiers such as `static' or `const'. Wide
315 character types (wchar_t) are now supported. Demangling of each symbol is now
316 only done once, and is cached when the symbol table for a file is read in.
317 This results in a small increase in memory usage for C programs, a moderate
318 increase in memory usage for C++ programs, and a fantastic speedup in
321 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
322 from the specifications in the Annotated Reference Manual, which AT&T's
323 compiler does not actually implement.
325 * G++ multiple inheritance compiler problem
327 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
328 inheritance lattices was reworked to properly discover ambiguities. We
329 recently found an example which causes this new algorithm to fail in a
330 very subtle way, producing bad debug information for those classes.
331 The file 'gcc.patch' (in this directory) can be applied to gcc to
332 circumvent the problem. A future GCC release will contain a complete
335 The previous G++ debug info problem (mentioned below for the gdb-4.7
336 release) is fixed in gcc version 2.3.2.
338 * Improved configure script
340 The `configure' script will now attempt to guess your system type if
341 you don't supply a host system type. The old scheme of supplying a
342 host system triplet is preferable over using this. All the magic is
343 done in the new `config.guess' script. Examine it for details.
345 We have also brought our configure script much more in line with the FSF's
346 version. It now supports the --with-xxx options. In particular,
347 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
348 The resulting GDB will not be able to read arbitrary object file formats --
349 only the format ``expected'' to be used on the configured target system.
350 We hope to make this the default in a future release.
352 * Documentation improvements
354 There's new internal documentation on how to modify GDB, and how to
355 produce clean changes to the code. We implore people to read it
356 before submitting changes.
358 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
359 M4 macros. The new texinfo.tex is provided in this release. Pre-built
360 `info' files are also provided. To build `info' files from scratch,
361 you will need the latest `makeinfo' release, which will be available in
362 a future texinfo-X.Y release.
364 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
365 We're not sure exactly which versions have this problem, but it has
366 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
367 or better. If that isn't possible, there is a patch in
368 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
373 GDB now supports array constants that can be used in expressions typed in by
374 the user. The syntax is `{element, element, ...}'. Ie: you can now type
375 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
378 The new directory `gdb/sparclite' contains a program that demonstrates
379 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
381 * New native hosts supported
383 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
384 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
386 * New targets supported
388 AMD 29k family via UDI a29k-amd-udi or udi29k
390 * New file formats supported
392 BFD now supports reading HP/PA-RISC executables (SOM file format?),
393 HPUX core files, and SCO 3.2v2 core files.
397 Attaching to processes now works again; thanks for the many bug reports.
399 We have also stomped on a bunch of core dumps caused by
400 printf_filtered("%s") problems.
402 We eliminated a copyright problem on the rpc and ptrace header files
403 for VxWorks, which was discovered at the last minute during the 4.7
404 release. You should now be able to build a VxWorks GDB.
406 You can now interrupt gdb while an attached process is running. This
407 will cause the attached process to stop, and give control back to GDB.
409 We fixed problems caused by using too many file descriptors
410 for reading symbols from object files and libraries. This was
411 especially a problem for programs that used many (~100) shared
414 The `step' command now only enters a subroutine if there is line number
415 information for the subroutine. Otherwise it acts like the `next'
416 command. Previously, `step' would enter subroutines if there was
417 any debugging information about the routine. This avoids problems
418 when using `cc -g1' on MIPS machines.
420 * Internal improvements
422 GDB's internal interfaces have been improved to make it easier to support
423 debugging of multiple languages in the future.
425 GDB now uses a common structure for symbol information internally.
426 Minimal symbols (derived from linkage symbols in object files), partial
427 symbols (from a quick scan of debug information), and full symbols
428 contain a common subset of information, making it easier to write
429 shared code that handles any of them.
431 * New command line options
433 We now accept --silent as an alias for --quiet.
437 The memory-mapped-malloc library is now licensed under the GNU Library
438 General Public License.
440 *** Changes in GDB-4.7:
442 * Host/native/target split
444 GDB has had some major internal surgery to untangle the support for
445 hosts and remote targets. Now, when you configure GDB for a remote
446 target, it will no longer load in all of the support for debugging
447 local programs on the host. When fully completed and tested, this will
448 ensure that arbitrary host/target combinations are possible.
450 The primary conceptual shift is to separate the non-portable code in
451 GDB into three categories. Host specific code is required any time GDB
452 is compiled on that host, regardless of the target. Target specific
453 code relates to the peculiarities of the target, but can be compiled on
454 any host. Native specific code is everything else: it can only be
455 built when the host and target are the same system. Child process
456 handling and core file support are two common `native' examples.
458 GDB's use of /proc for controlling Unix child processes is now cleaner.
459 It has been split out into a single module under the `target_ops' vector,
460 plus two native-dependent functions for each system that uses /proc.
462 * New hosts supported
464 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
465 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
466 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
468 * New targets supported
470 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
471 68030 and CPU32 m68030-*-*, m68332-*-*
473 * New native hosts supported
475 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
476 (386bsd is not well tested yet)
477 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
479 * New file formats supported
481 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
482 supports reading of `a.out.adobe' object files, which are an a.out
483 format extended with minimal information about multiple sections.
487 `show copying' is the same as the old `info copying'.
488 `show warranty' is the same as `info warrantee'.
489 These were renamed for consistency. The old commands continue to work.
491 `info handle' is a new alias for `info signals'.
493 You can now define pre-command hooks, which attach arbitrary command
494 scripts to any command. The commands in the hook will be executed
495 prior to the user's command. You can also create a hook which will be
496 executed whenever the program stops. See gdb.texinfo.
500 We now deal with Cfront style name mangling, and can even extract type
501 info from mangled symbols. GDB can automatically figure out which
502 symbol mangling style your C++ compiler uses.
504 Calling of methods and virtual functions has been improved as well.
508 The crash that occured when debugging Sun Ansi-C compiled binaries is
509 fixed. This was due to mishandling of the extra N_SO stabs output
512 We also finally got Ultrix 4.2 running in house, and fixed core file
513 support, with help from a dozen people on the net.
515 John M. Farrell discovered that the reason that single-stepping was so
516 slow on all of the Mips based platforms (primarily SGI and DEC) was
517 that we were trying to demangle and lookup a symbol used for internal
518 purposes on every instruction that was being stepped through. Changing
519 the name of that symbol so that it couldn't be mistaken for a C++
520 mangled symbol sped things up a great deal.
522 Rich Pixley sped up symbol lookups in general by getting much smarter
523 about when C++ symbol mangling is necessary. This should make symbol
524 completion (TAB on the command line) much faster. It's not as fast as
525 we'd like, but it's significantly faster than gdb-4.6.
529 A new user controllable variable 'call_scratch_address' can
530 specify the location of a scratch area to be used when GDB
531 calls a function in the target. This is necessary because the
532 usual method of putting the scratch area on the stack does not work
533 in systems that have separate instruction and data spaces.
535 We integrated changes to support the 29k UDI (Universal Debugger
536 Interface), but discovered at the last minute that we didn't have all
537 of the appropriate copyright paperwork. We are working with AMD to
538 resolve this, and hope to have it available soon.
542 We have sped up the remote serial line protocol, especially for targets
543 with lots of registers. It now supports a new `expedited status' ('T')
544 message which can be used in place of the existing 'S' status message.
545 This allows the remote stub to send only the registers that GDB
546 needs to make a quick decision about single-stepping or conditional
547 breakpoints, eliminating the need to fetch the entire register set for
548 each instruction being stepped through.
550 The GDB remote serial protocol now implements a write-through cache for
551 registers, only re-reading the registers if the target has run.
553 There is also a new remote serial stub for SPARC processors. You can
554 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
555 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
556 processor with a serial port.
560 Configure.in files have become much easier to read and modify. A new
561 `table driven' format makes it more obvious what configurations are
562 supported, and what files each one uses.
566 There is a new opcodes library which will eventually contain all of the
567 disassembly routines and opcode tables. At present, it only contains
568 Sparc and Z8000 routines. This will allow the assembler, debugger, and
569 disassembler (binutils/objdump) to share these routines.
571 The libiberty library is now copylefted under the GNU Library General
572 Public License. This allows more liberal use, and was done so libg++
573 can use it. This makes no difference to GDB, since the Library License
574 grants all the rights from the General Public License.
578 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
579 reference to the stabs symbol info used by the debugger. It is (as far
580 as we know) the only published document on this fascinating topic. We
581 encourage you to read it, compare it to the stabs information on your
582 system, and send improvements on the document in general (to
583 bug-gdb@prep.ai.mit.edu).
585 And, of course, many bugs have been fixed.
588 *** Changes in GDB-4.6:
590 * Better support for C++ function names
592 GDB now accepts as input the "demangled form" of C++ overloaded function
593 names and member function names, and can do command completion on such names
594 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
595 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
596 Make use of command completion, it is your friend.
598 GDB also now accepts a variety of C++ mangled symbol formats. They are
599 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
600 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
601 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
602 for the list of formats.
604 * G++ symbol mangling problem
606 Recent versions of gcc have a bug in how they emit debugging information for
607 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
608 directory) can be applied to gcc to fix the problem. Alternatively, if you
609 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
610 usual symptom is difficulty with setting breakpoints on methods. GDB complains
611 about the method being non-existent. (We believe that version 2.2.2 of GCC has
614 * New 'maintenance' command
616 All of the commands related to hacking GDB internals have been moved out of
617 the main command set, and now live behind the 'maintenance' command. This
618 can also be abbreviated as 'mt'. The following changes were made:
620 dump-me -> maintenance dump-me
621 info all-breakpoints -> maintenance info breakpoints
622 printmsyms -> maintenance print msyms
623 printobjfiles -> maintenance print objfiles
624 printpsyms -> maintenance print psymbols
625 printsyms -> maintenance print symbols
627 The following commands are new:
629 maintenance demangle Call internal GDB demangler routine to
630 demangle a C++ link name and prints the result.
631 maintenance print type Print a type chain for a given symbol
633 * Change to .gdbinit file processing
635 We now read the $HOME/.gdbinit file before processing the argv arguments
636 (e.g. reading symbol files or core files). This allows global parameters to
637 be set, which will apply during the symbol reading. The ./.gdbinit is still
638 read after argv processing.
640 * New hosts supported
642 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
644 Linux support i386-unknown-linux or linux
646 We are also including code to support the HP/PA running BSD and HPUX. This
647 is almost guaranteed not to work, as we didn't have time to test or build it
648 for this release. We are including it so that the more adventurous (or
649 masochistic) of you can play with it. We also had major problems with the
650 fact that the compiler that we got from HP doesn't support the -g option.
653 * New targets supported
655 Hitachi H8/300 h8300-hitachi-hms or h8300hms
657 * More smarts about finding #include files
659 GDB now remembers the compilation directory for all include files, and for
660 all files from which C is generated (like yacc and lex sources). This
661 greatly improves GDB's ability to find yacc/lex sources, and include files,
662 especially if you are debugging your program from a directory different from
663 the one that contains your sources.
665 We also fixed a bug which caused difficulty with listing and setting
666 breakpoints in include files which contain C code. (In the past, you had to
667 try twice in order to list an include file that you hadn't looked at before.)
669 * Interesting infernals change
671 GDB now deals with arbitrary numbers of sections, where the symbols for each
672 section must be relocated relative to that section's landing place in the
673 target's address space. This work was needed to support ELF with embedded
674 stabs used by Solaris-2.0.
676 * Bug fixes (of course!)
678 There have been loads of fixes for the following things:
679 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
680 i960, stabs, DOS(GO32), procfs, etc...
682 See the ChangeLog for details.
684 *** Changes in GDB-4.5:
686 * New machines supported (host and target)
688 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
690 SGI Irix-4.x mips-sgi-irix4 or iris4
694 GDB now uses a new memory manager called mmalloc, based on gmalloc.
695 Mmalloc is capable of handling mutiple heaps of memory. It is also
696 capable of saving a heap to a file, and then mapping it back in later.
697 This can be used to greatly speedup the startup of GDB by using a
698 pre-parsed symbol table which lives in a mmalloc managed heap. For
699 more details, please read mmalloc/mmalloc.texi.
703 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
704 'help info proc' for details.
706 * MIPS ecoff symbol table format
708 The code that reads MIPS symbol table format is now supported on all hosts.
709 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
712 * File name changes for MS-DOS
714 Many files in the config directories have been renamed to make it easier to
715 support GDB on MS-DOSe systems (which have very restrictive file name
716 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
717 environment) is close to working but has some remaining problems. Note
718 that debugging of DOS programs is not supported, due to limitations
719 in the ``operating system'', but it can be used to host cross-debugging.
721 * Cross byte order fixes
723 Many fixes have been made to support cross debugging of Sparc and MIPS
724 targets from hosts whose byte order differs.
726 * New -mapped and -readnow options
728 If memory-mapped files are available on your system through the 'mmap'
729 system call, you can use the -mapped option on the `file' or
730 `symbol-file' commands to cause GDB to write the symbols from your
731 program into a reusable file. If the program you are debugging is
732 called `/path/fred', the mapped symbol file will be `./fred.syms'.
733 Future GDB debugging sessions will notice the presence of this file,
734 and will quickly map in symbol information from it, rather than reading
735 the symbol table from the executable program. Using the '-mapped'
736 option in a GDB `file' or `symbol-file' command has the same effect as
737 starting GDB with the '-mapped' command-line option.
739 You can cause GDB to read the entire symbol table immediately by using
740 the '-readnow' option with any of the commands that load symbol table
741 information (or on the GDB command line). This makes the command
742 slower, but makes future operations faster.
744 The -mapped and -readnow options are typically combined in order to
745 build a `fred.syms' file that contains complete symbol information.
746 A simple GDB invocation to do nothing but build a `.syms' file for future
749 gdb -batch -nx -mapped -readnow programname
751 The `.syms' file is specific to the host machine on which GDB is run.
752 It holds an exact image of GDB's internal symbol table. It cannot be
753 shared across multiple host platforms.
757 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
758 siglongjmp() without losing control. This feature has not yet been ported to
759 all systems. It currently works on many 386 platforms, all MIPS-based
760 platforms (SGI, DECstation, etc), and Sun3/4.
764 Preliminary work has been put in to support the new Solaris OS from Sun. At
765 this time, it can control and debug processes, but it is not capable of
770 As always, many many bug fixes. The major areas were with g++, and mipsread.
771 People using the MIPS-based platforms should experience fewer mysterious
772 crashes and trashed symbol tables.
774 *** Changes in GDB-4.4:
776 * New machines supported (host and target)
778 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
780 BSD Reno on Vax vax-dec-bsd
781 Ultrix on Vax vax-dec-ultrix
783 * New machines supported (target)
785 AMD 29000 embedded, using EBMON a29k-none-none
789 GDB continues to improve its handling of C++. `References' work better.
790 The demangler has also been improved, and now deals with symbols mangled as
791 per the Annotated C++ Reference Guide.
793 GDB also now handles `stabs' symbol information embedded in MIPS
794 `ecoff' symbol tables. Since the ecoff format was not easily
795 extensible to handle new languages such as C++, this appeared to be a
796 good way to put C++ debugging info into MIPS binaries. This option
797 will be supported in the GNU C compiler, version 2, when it is
800 * New features for SVR4
802 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
803 shared libraries. Debugging dynamically linked programs should present
804 only minor differences from debugging statically linked programs.
806 The `info proc' command will print out information about any process
807 on an SVR4 system (including the one you are debugging). At the moment,
808 it prints the address mappings of the process.
810 If you bring up GDB on another SVR4 system, please send mail to
811 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
813 * Better dynamic linking support in SunOS
815 Reading symbols from shared libraries which contain debugging symbols
816 now works properly. However, there remain issues such as automatic
817 skipping of `transfer vector' code during function calls, which
818 make it harder to debug code in a shared library, than to debug the
819 same code linked statically.
823 GDB is now using the latest `getopt' routines from the FSF. This
824 version accepts the -- prefix for options with long names. GDB will
825 continue to accept the old forms (-option and +option) as well.
826 Various single letter abbreviations for options have been explicity
827 added to the option table so that they won't get overshadowed in the
828 future by other options that begin with the same letter.
832 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
833 Many assorted bugs have been handled. Many more remain to be handled.
834 See the various ChangeLog files (primarily in gdb and bfd) for details.
837 *** Changes in GDB-4.3:
839 * New machines supported (host and target)
841 Amiga 3000 running Amix m68k-cbm-svr4 or amix
842 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
843 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
845 * Almost SCO Unix support
847 We had hoped to support:
848 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
849 (except for core file support), but we discovered very late in the release
850 that it has problems with process groups that render gdb unusable. Sorry
851 about that. I encourage people to fix it and post the fixes.
853 * Preliminary ELF and DWARF support
855 GDB can read ELF object files on System V Release 4, and can handle
856 debugging records for C, in DWARF format, in ELF files. This support
857 is preliminary. If you bring up GDB on another SVR4 system, please
858 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
863 GDB now uses the latest `readline' library. One user-visible change
864 is that two tabs will list possible command completions, which previously
865 required typing M-? (meta-question mark, or ESC ?).
869 The `stepi' bug that many of you noticed has been squashed.
870 Many bugs in C++ have been handled. Many more remain to be handled.
871 See the various ChangeLog files (primarily in gdb and bfd) for details.
873 * State of the MIPS world (in case you wondered):
875 GDB can understand the symbol tables emitted by the compilers
876 supplied by most vendors of MIPS-based machines, including DEC. These
877 symbol tables are in a format that essentially nobody else uses.
879 Some versions of gcc come with an assembler post-processor called
880 mips-tfile. This program is required if you want to do source-level
881 debugging of gcc-compiled programs. I believe FSF does not ship
882 mips-tfile with gcc version 1, but it will eventually come with gcc
885 Debugging of g++ output remains a problem. g++ version 1.xx does not
886 really support it at all. (If you're lucky, you should be able to get
887 line numbers and stack traces to work, but no parameters or local
888 variables.) With some work it should be possible to improve the
891 When gcc version 2 is released, you will have somewhat better luck.
892 However, even then you will get confusing results for inheritance and
895 We will eventually provide full debugging of g++ output on
896 DECstations. This will probably involve some kind of stabs-in-ecoff
897 encapulation, but the details have not been worked out yet.
900 *** Changes in GDB-4.2:
902 * Improved configuration
904 Only one copy of `configure' exists now, and it is not self-modifying.
905 Porting BFD is simpler.
909 The `step' and `next' commands now only stop at the first instruction
910 of a source line. This prevents the multiple stops that used to occur
911 in switch statements, for-loops, etc. `Step' continues to stop if a
912 function that has debugging information is called within the line.
916 Lots of small bugs fixed. More remain.
918 * New host supported (not target)
920 Intel 386 PC clone running Mach i386-none-mach
923 *** Changes in GDB-4.1:
925 * Multiple source language support
927 GDB now has internal scaffolding to handle several source languages.
928 It determines the type of each source file from its filename extension,
929 and will switch expression parsing and number formatting to match the
930 language of the function in the currently selected stack frame.
931 You can also specifically set the language to be used, with
932 `set language c' or `set language modula-2'.
936 GDB now has preliminary support for the GNU Modula-2 compiler,
937 currently under development at the State University of New York at
938 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
939 continue through the fall of 1991 and into 1992.
941 Other Modula-2 compilers are currently not supported, and attempting to
942 debug programs compiled with them will likely result in an error as the
943 symbol table is read. Feel free to work on it, though!
945 There are hooks in GDB for strict type checking and range checking,
946 in the `Modula-2 philosophy', but they do not currently work.
950 GDB can now write to executable and core files (e.g. patch
951 a variable's value). You must turn this switch on, specify
952 the file ("exec foo" or "core foo"), *then* modify it, e.g.
953 by assigning a new value to a variable. Modifications take
956 * Automatic SunOS shared library reading
958 When you run your program, GDB automatically determines where its
959 shared libraries (if any) have been loaded, and reads their symbols.
960 The `share' command is no longer needed. This also works when
961 examining core files.
965 You can specify the number of lines that the `list' command shows.
968 * New machines supported (host and target)
970 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
971 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
972 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
974 * New hosts supported (not targets)
976 IBM RT/PC: romp-ibm-aix or rtpc
978 * New targets supported (not hosts)
980 AMD 29000 embedded with COFF a29k-none-coff
981 AMD 29000 embedded with a.out a29k-none-aout
982 Ultracomputer remote kernel debug a29k-nyu-kern
984 * New remote interfaces
990 *** Changes in GDB-4.0:
994 Wide output is wrapped at good places to make the output more readable.
996 Gdb now supports cross-debugging from a host machine of one type to a
997 target machine of another type. Communication with the target system
998 is over serial lines. The ``target'' command handles connecting to the
999 remote system; the ``load'' command will download a program into the
1000 remote system. Serial stubs for the m68k and i386 are provided. Gdb
1001 also supports debugging of realtime processes running under VxWorks,
1002 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
1003 stub on the target system.
1005 New CPUs supported include the AMD 29000 and Intel 960.
1007 GDB now reads object files and symbol tables via a ``binary file''
1008 library, which allows a single copy of GDB to debug programs of multiple
1009 object file types such as a.out and coff.
1011 There is now a GDB reference card in "doc/refcard.tex". (Make targets
1012 refcard.dvi and refcard.ps are available to format it).
1015 * Control-Variable user interface simplified
1017 All variables that control the operation of the debugger can be set
1018 by the ``set'' command, and displayed by the ``show'' command.
1020 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
1021 ``Show prompt'' produces the response:
1022 Gdb's prompt is new-gdb=>.
1024 What follows are the NEW set commands. The command ``help set'' will
1025 print a complete list of old and new set commands. ``help set FOO''
1026 will give a longer description of the variable FOO. ``show'' will show
1027 all of the variable descriptions and their current settings.
1029 confirm on/off: Enables warning questions for operations that are
1030 hard to recover from, e.g. rerunning the program while
1031 it is already running. Default is ON.
1033 editing on/off: Enables EMACS style command line editing
1034 of input. Previous lines can be recalled with
1035 control-P, the current line can be edited with control-B,
1036 you can search for commands with control-R, etc.
1039 history filename NAME: NAME is where the gdb command history
1040 will be stored. The default is .gdb_history,
1041 or the value of the environment variable
1044 history size N: The size, in commands, of the command history. The
1045 default is 256, or the value of the environment variable
1048 history save on/off: If this value is set to ON, the history file will
1049 be saved after exiting gdb. If set to OFF, the
1050 file will not be saved. The default is OFF.
1052 history expansion on/off: If this value is set to ON, then csh-like
1053 history expansion will be performed on
1054 command line input. The default is OFF.
1056 radix N: Sets the default radix for input and output. It can be set
1057 to 8, 10, or 16. Note that the argument to "radix" is interpreted
1058 in the current radix, so "set radix 10" is always a no-op.
1060 height N: This integer value is the number of lines on a page. Default
1061 is 24, the current `stty rows'' setting, or the ``li#''
1062 setting from the termcap entry matching the environment
1065 width N: This integer value is the number of characters on a line.
1066 Default is 80, the current `stty cols'' setting, or the ``co#''
1067 setting from the termcap entry matching the environment
1070 Note: ``set screensize'' is obsolete. Use ``set height'' and
1071 ``set width'' instead.
1073 print address on/off: Print memory addresses in various command displays,
1074 such as stack traces and structure values. Gdb looks
1075 more ``symbolic'' if you turn this off; it looks more
1076 ``machine level'' with it on. Default is ON.
1078 print array on/off: Prettyprint arrays. New convenient format! Default
1081 print demangle on/off: Print C++ symbols in "source" form if on,
1084 print asm-demangle on/off: Same, for assembler level printouts
1087 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
1090 * Support for Epoch Environment.
1092 The epoch environment is a version of Emacs v18 with windowing. One
1093 new command, ``inspect'', is identical to ``print'', except that if you
1094 are running in the epoch environment, the value is printed in its own
1098 * Support for Shared Libraries
1100 GDB can now debug programs and core files that use SunOS shared libraries.
1101 Symbols from a shared library cannot be referenced
1102 before the shared library has been linked with the program (this
1103 happens after you type ``run'' and before the function main() is entered).
1104 At any time after this linking (including when examining core files
1105 from dynamically linked programs), gdb reads the symbols from each
1106 shared library when you type the ``sharedlibrary'' command.
1107 It can be abbreviated ``share''.
1109 sharedlibrary REGEXP: Load shared object library symbols for files
1110 matching a unix regular expression. No argument
1111 indicates to load symbols for all shared libraries.
1113 info sharedlibrary: Status of loaded shared libraries.
1118 A watchpoint stops execution of a program whenever the value of an
1119 expression changes. Checking for this slows down execution
1120 tremendously whenever you are in the scope of the expression, but is
1121 quite useful for catching tough ``bit-spreader'' or pointer misuse
1122 problems. Some machines such as the 386 have hardware for doing this
1123 more quickly, and future versions of gdb will use this hardware.
1125 watch EXP: Set a watchpoint (breakpoint) for an expression.
1127 info watchpoints: Information about your watchpoints.
1129 delete N: Deletes watchpoint number N (same as breakpoints).
1130 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
1131 enable N: Re-enables watchpoint number N (same as breakpoints).
1134 * C++ multiple inheritance
1136 When used with a GCC version 2 compiler, GDB supports multiple inheritance
1139 * C++ exception handling
1141 Gdb now supports limited C++ exception handling. Besides the existing
1142 ability to breakpoint on an exception handler, gdb can breakpoint on
1143 the raising of an exception (before the stack is peeled back to the
1146 catch FOO: If there is a FOO exception handler in the dynamic scope,
1147 set a breakpoint to catch exceptions which may be raised there.
1148 Multiple exceptions (``catch foo bar baz'') may be caught.
1150 info catch: Lists all exceptions which may be caught in the
1151 current stack frame.
1154 * Minor command changes
1156 The command ``call func (arg, arg, ...)'' now acts like the print
1157 command, except it does not print or save a value if the function's result
1158 is void. This is similar to dbx usage.
1160 The ``up'' and ``down'' commands now always print the frame they end up
1161 at; ``up-silently'' and `down-silently'' can be used in scripts to change
1162 frames without printing.
1164 * New directory command
1166 'dir' now adds directories to the FRONT of the source search path.
1167 The path starts off empty. Source files that contain debug information
1168 about the directory in which they were compiled can be found even
1169 with an empty path; Sun CC and GCC include this information. If GDB can't
1170 find your source file in the current directory, type "dir .".
1172 * Configuring GDB for compilation
1174 For normal use, type ``./configure host''. See README or gdb.texinfo
1177 GDB now handles cross debugging. If you are remotely debugging between
1178 two different machines, type ``./configure host -target=targ''.
1179 Host is the machine where GDB will run; targ is the machine
1180 where the program that you are debugging will run.
projects / deliverable / binutils-gdb.git / blob