1 What has changed in GDB?
2 (Organized release by release)
4 *** Changes since GDB-4.15:
6 * New native configurations
8 Windows 95, Windows NT i[345]86-*-win32
12 ARM via RDP protocol arm-*-*
13 PowerPC via PPCBUG monitor powerpc{,le}-*-eabi*
14 PowerPC simulator powerpc{,le}-*-eabi if building with GCC
16 * Send break instead of ^C
18 The standard remote protocol now includes an option to send a break
19 rather than a ^C to the target in order to interrupt it. By default,
20 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
22 *** Changes in GDB-4.15:
26 The symbol reader for AIX GDB now uses partial symbol tables. This
27 can greatly improve startup time, especially for large executables.
29 * Remote targets use caching
31 Remote targets now use a data cache to speed up communication with the
32 remote side. The data cache could lead to incorrect results because
33 it doesn't know about volatile variables, thus making it impossible to
34 debug targets which use memory mapped I/O devices. `set remotecache
35 off' turns the the data cache off.
37 * Remote targets may have threads
39 The standard remote protocol now includes support for multiple threads
40 in the target system, using new protocol commands 'H' and 'T'. See
41 gdb/remote.c for details.
45 If GDB is configured with `--enable-netrom', then it will include
46 support for the NetROM ROM emulator from XLNT Designs. The NetROM
47 acts as though it is a bank of ROM on the target board, but you can
48 write into it over the network. GDB's support consists only of
49 support for fast loading into the emulated ROM; to debug, you must use
50 another protocol, such as standard remote protocol. The usual
51 sequence is something like
53 target nrom <netrom-hostname>
55 target remote <netrom-hostname>:1235
59 GDB now includes support for the Apple Macintosh, as a host only. It
60 may be run as either an MPW tool or as a standalone application, and
61 it can debug through the serial port. All the usual GDB commands are
62 available, but to the target command, you must supply "serial" as the
63 device type instead of "/dev/ttyXX". See mpw-README in the main
64 directory for more information on how to build. The MPW configuration
65 scripts */mpw-config.in support only a few targets, and only the
66 mips-idt-ecoff target has been tested.
70 GDB configuration now uses autoconf. This is not user-visible,
71 but does simplify configuration and building.
75 GDB now supports hpux10.
77 *** Changes in GDB-4.14:
79 * New native configurations
81 x86 FreeBSD i[345]86-*-freebsd
82 x86 NetBSD i[345]86-*-netbsd
83 NS32k NetBSD ns32k-*-netbsd
84 Sparc NetBSD sparc-*-netbsd
88 A29K VxWorks a29k-*-vxworks
89 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
90 CPU32 EST-300 emulator m68*-*-est*
91 PowerPC ELF powerpc-*-elf
94 * Alpha OSF/1 support for procfs
96 GDB now supports procfs under OSF/1-2.x and higher, which makes it
97 possible to attach to running processes. As the mounting of the /proc
98 filesystem is optional on the Alpha, GDB automatically determines
99 the availability of /proc during startup. This can lead to problems
100 if /proc is unmounted after GDB has been started.
102 * Arguments to user-defined commands
104 User commands may accept up to 10 arguments separated by whitespace.
105 Arguments are accessed within the user command via $arg0..$arg9. A
108 print $arg0 + $arg1 + $arg2
110 To execute the command use:
113 Defines the command "adder" which prints the sum of its three arguments.
114 Note the arguments are text substitutions, so they may reference variables,
115 use complex expressions, or even perform inferior function calls.
117 * New `if' and `while' commands
119 This makes it possible to write more sophisticated user-defined
120 commands. Both commands take a single argument, which is the
121 expression to evaluate, and must be followed by the commands to
122 execute, one per line, if the expression is nonzero, the list being
123 terminated by the word `end'. The `if' command list may include an
124 `else' word, which causes the following commands to be executed only
125 if the expression is zero.
127 * Fortran source language mode
129 GDB now includes partial support for Fortran 77. It will recognize
130 Fortran programs and can evaluate a subset of Fortran expressions, but
131 variables and functions may not be handled correctly. GDB will work
132 with G77, but does not yet know much about symbols emitted by other
135 * Better HPUX support
137 Most debugging facilities now work on dynamic executables for HPPAs
138 running hpux9 or later. You can attach to running dynamically linked
139 processes, but by default the dynamic libraries will be read-only, so
140 for instance you won't be able to put breakpoints in them. To change
141 that behavior do the following before running the program:
147 This will cause the libraries to be mapped private and read-write.
148 To revert to the normal behavior, do this:
154 You cannot set breakpoints or examine data in the library until after
155 the library is loaded if the function/data symbols do not have
158 GDB can now also read debug symbols produced by the HP C compiler on
159 HPPAs (sorry, no C++, Fortran or 68k support).
161 * Target byte order now dynamically selectable
163 You can choose which byte order to use with a target system, via the
164 commands "set endian big" and "set endian little", and you can see the
165 current setting by using "show endian". You can also give the command
166 "set endian auto", in which case GDB will use the byte order
167 associated with the executable. Currently, only embedded MIPS
168 configurations support dynamic selection of target byte order.
170 * New DOS host serial code
172 This version uses DPMI interrupts to handle buffered I/O, so you
173 no longer need to run asynctsr when debugging boards connected to
176 *** Changes in GDB-4.13:
178 * New "complete" command
180 This lists all the possible completions for the rest of the line, if it
181 were to be given as a command itself. This is intended for use by emacs.
183 * Trailing space optional in prompt
185 "set prompt" no longer adds a space for you after the prompt you set. This
186 allows you to set a prompt which ends in a space or one that does not.
188 * Breakpoint hit counts
190 "info break" now displays a count of the number of times the breakpoint
191 has been hit. This is especially useful in conjunction with "ignore"; you
192 can ignore a large number of breakpoint hits, look at the breakpoint info
193 to see how many times the breakpoint was hit, then run again, ignoring one
194 less than that number, and this will get you quickly to the last hit of
197 * Ability to stop printing at NULL character
199 "set print null-stop" will cause GDB to stop printing the characters of
200 an array when the first NULL is encountered. This is useful when large
201 arrays actually contain only short strings.
203 * Shared library breakpoints
205 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
206 breakpoints in shared libraries before the executable is run.
208 * Hardware watchpoints
210 There is a new hardware breakpoint for the watch command for sparclite
211 targets. See gdb/sparclite/hw_breakpoint.note.
213 Hardware watchpoints are also now supported under Linux.
217 Annotations have been added. These are for use with graphical interfaces,
218 and are still experimental. Currently only gdba.el uses these.
220 * Improved Irix 5 support
222 GDB now works properly with Irix 5.2.
224 * Improved HPPA support
226 GDB now works properly with the latest GCC and GAS.
228 * New native configurations
230 Sequent PTX4 i[34]86-sequent-ptx4
231 HPPA running OSF/1 hppa*-*-osf*
232 Atari TT running SVR4 m68*-*-sysv4*
233 RS/6000 LynxOS rs6000-*-lynxos*
237 OS/9000 i[34]86-*-os9k
238 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
241 * Hitachi SH7000 and E7000-PC ICE support
243 There is now support for communicating with the Hitachi E7000-PC ICE.
244 This is available automatically when GDB is configured for the SH.
248 As usual, a variety of small fixes and improvements, both generic
249 and configuration-specific. See the ChangeLog for more detail.
251 *** Changes in GDB-4.12:
253 * Irix 5 is now supported
257 GDB-4.12 on the HPPA has a number of changes which make it unable
258 to debug the output from the currently released versions of GCC and
259 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
260 of GCC and GAS, versions of these tools designed to work with GDB-4.12
261 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
264 *** Changes in GDB-4.11:
266 * User visible changes:
270 The "set remotedebug" option is now consistent between the mips remote
271 target, remote targets using the gdb-specific protocol, UDI (AMD's
272 debug protocol for the 29k) and the 88k bug monitor. It is now an
273 integer specifying a debug level (normally 0 or 1, but 2 means more
274 debugging info for the mips target).
276 * DEC Alpha native support
278 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
279 debug info, but GDB works fairly well with the DEC compiler and should
280 work with a future GCC release. See the README file for a few
281 Alpha-specific notes.
283 * Preliminary thread implementation
285 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
287 * LynxOS native and target support for 386
289 This release has been hosted on LynxOS 2.2, and also can be configured
290 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
293 * Improvements in C++ mangling/demangling.
295 This release has much better g++ debugging, specifically in name
296 mangling/demangling, virtual function calls, print virtual table,
297 call methods, ...etc.
299 *** Changes in GDB-4.10:
301 * User visible changes:
303 Remote debugging using the GDB-specific (`target remote') protocol now
304 supports the `load' command. This is only useful if you have some
305 other way of getting the stub to the target system, and you can put it
306 somewhere in memory where it won't get clobbered by the download.
308 Filename completion now works.
310 When run under emacs mode, the "info line" command now causes the
311 arrow to point to the line specified. Also, "info line" prints
312 addresses in symbolic form (as well as hex).
314 All vxworks based targets now support a user settable option, called
315 vxworks-timeout. This option represents the number of seconds gdb
316 should wait for responses to rpc's. You might want to use this if
317 your vxworks target is, perhaps, a slow software simulator or happens
318 to be on the far side of a thin network line.
322 This release contains support for using a DEC alpha as a GDB host for
323 cross debugging. Native alpha debugging is not supported yet.
326 *** Changes in GDB-4.9:
330 This is the first GDB release which is accompanied by a matching testsuite.
331 The testsuite requires installation of dejagnu, which should be available
332 via ftp from most sites that carry GNU software.
336 'Cfront' style demangling has had its name changed to 'ARM' style, to
337 emphasize that it was written from the specifications in the C++ Annotated
338 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
339 disclaimers, it still generated too much confusion with users attempting to
340 use gdb with AT&T cfront.
344 GDB now uses a standard remote interface to a simulator library.
345 So far, the library contains simulators for the Zilog Z8001/2, the
346 Hitachi H8/300, H8/500 and Super-H.
348 * New targets supported
350 H8/300 simulator h8300-hitachi-hms or h8300hms
351 H8/500 simulator h8500-hitachi-hms or h8500hms
352 SH simulator sh-hitachi-hms or sh
353 Z8000 simulator z8k-zilog-none or z8ksim
354 IDT MIPS board over serial line mips-idt-ecoff
356 Cross-debugging to GO32 targets is supported. It requires a custom
357 version of the i386-stub.c module which is integrated with the
358 GO32 memory extender.
360 * New remote protocols
362 MIPS remote debugging protocol.
364 * New source languages supported
366 This version includes preliminary support for Chill, a Pascal like language
367 used by telecommunications companies. Chill support is also being integrated
368 into the GNU compiler, but we don't know when it will be publically available.
371 *** Changes in GDB-4.8:
373 * HP Precision Architecture supported
375 GDB now supports HP PA-RISC machines running HPUX. A preliminary
376 version of this support was available as a set of patches from the
377 University of Utah. GDB does not support debugging of programs
378 compiled with the HP compiler, because HP will not document their file
379 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
380 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
382 Many problems in the preliminary version have been fixed.
384 * Faster and better demangling
386 We have improved template demangling and fixed numerous bugs in the GNU style
387 demangler. It can now handle type modifiers such as `static' or `const'. Wide
388 character types (wchar_t) are now supported. Demangling of each symbol is now
389 only done once, and is cached when the symbol table for a file is read in.
390 This results in a small increase in memory usage for C programs, a moderate
391 increase in memory usage for C++ programs, and a fantastic speedup in
394 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
395 from the specifications in the Annotated Reference Manual, which AT&T's
396 compiler does not actually implement.
398 * G++ multiple inheritance compiler problem
400 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
401 inheritance lattices was reworked to properly discover ambiguities. We
402 recently found an example which causes this new algorithm to fail in a
403 very subtle way, producing bad debug information for those classes.
404 The file 'gcc.patch' (in this directory) can be applied to gcc to
405 circumvent the problem. A future GCC release will contain a complete
408 The previous G++ debug info problem (mentioned below for the gdb-4.7
409 release) is fixed in gcc version 2.3.2.
411 * Improved configure script
413 The `configure' script will now attempt to guess your system type if
414 you don't supply a host system type. The old scheme of supplying a
415 host system triplet is preferable over using this. All the magic is
416 done in the new `config.guess' script. Examine it for details.
418 We have also brought our configure script much more in line with the FSF's
419 version. It now supports the --with-xxx options. In particular,
420 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
421 The resulting GDB will not be able to read arbitrary object file formats --
422 only the format ``expected'' to be used on the configured target system.
423 We hope to make this the default in a future release.
425 * Documentation improvements
427 There's new internal documentation on how to modify GDB, and how to
428 produce clean changes to the code. We implore people to read it
429 before submitting changes.
431 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
432 M4 macros. The new texinfo.tex is provided in this release. Pre-built
433 `info' files are also provided. To build `info' files from scratch,
434 you will need the latest `makeinfo' release, which will be available in
435 a future texinfo-X.Y release.
437 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
438 We're not sure exactly which versions have this problem, but it has
439 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
440 or better. If that isn't possible, there is a patch in
441 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
446 GDB now supports array constants that can be used in expressions typed in by
447 the user. The syntax is `{element, element, ...}'. Ie: you can now type
448 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
451 The new directory `gdb/sparclite' contains a program that demonstrates
452 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
454 * New native hosts supported
456 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
457 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
459 * New targets supported
461 AMD 29k family via UDI a29k-amd-udi or udi29k
463 * New file formats supported
465 BFD now supports reading HP/PA-RISC executables (SOM file format?),
466 HPUX core files, and SCO 3.2v2 core files.
470 Attaching to processes now works again; thanks for the many bug reports.
472 We have also stomped on a bunch of core dumps caused by
473 printf_filtered("%s") problems.
475 We eliminated a copyright problem on the rpc and ptrace header files
476 for VxWorks, which was discovered at the last minute during the 4.7
477 release. You should now be able to build a VxWorks GDB.
479 You can now interrupt gdb while an attached process is running. This
480 will cause the attached process to stop, and give control back to GDB.
482 We fixed problems caused by using too many file descriptors
483 for reading symbols from object files and libraries. This was
484 especially a problem for programs that used many (~100) shared
487 The `step' command now only enters a subroutine if there is line number
488 information for the subroutine. Otherwise it acts like the `next'
489 command. Previously, `step' would enter subroutines if there was
490 any debugging information about the routine. This avoids problems
491 when using `cc -g1' on MIPS machines.
493 * Internal improvements
495 GDB's internal interfaces have been improved to make it easier to support
496 debugging of multiple languages in the future.
498 GDB now uses a common structure for symbol information internally.
499 Minimal symbols (derived from linkage symbols in object files), partial
500 symbols (from a quick scan of debug information), and full symbols
501 contain a common subset of information, making it easier to write
502 shared code that handles any of them.
504 * New command line options
506 We now accept --silent as an alias for --quiet.
510 The memory-mapped-malloc library is now licensed under the GNU Library
511 General Public License.
513 *** Changes in GDB-4.7:
515 * Host/native/target split
517 GDB has had some major internal surgery to untangle the support for
518 hosts and remote targets. Now, when you configure GDB for a remote
519 target, it will no longer load in all of the support for debugging
520 local programs on the host. When fully completed and tested, this will
521 ensure that arbitrary host/target combinations are possible.
523 The primary conceptual shift is to separate the non-portable code in
524 GDB into three categories. Host specific code is required any time GDB
525 is compiled on that host, regardless of the target. Target specific
526 code relates to the peculiarities of the target, but can be compiled on
527 any host. Native specific code is everything else: it can only be
528 built when the host and target are the same system. Child process
529 handling and core file support are two common `native' examples.
531 GDB's use of /proc for controlling Unix child processes is now cleaner.
532 It has been split out into a single module under the `target_ops' vector,
533 plus two native-dependent functions for each system that uses /proc.
535 * New hosts supported
537 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
538 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
539 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
541 * New targets supported
543 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
544 68030 and CPU32 m68030-*-*, m68332-*-*
546 * New native hosts supported
548 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
549 (386bsd is not well tested yet)
550 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
552 * New file formats supported
554 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
555 supports reading of `a.out.adobe' object files, which are an a.out
556 format extended with minimal information about multiple sections.
560 `show copying' is the same as the old `info copying'.
561 `show warranty' is the same as `info warrantee'.
562 These were renamed for consistency. The old commands continue to work.
564 `info handle' is a new alias for `info signals'.
566 You can now define pre-command hooks, which attach arbitrary command
567 scripts to any command. The commands in the hook will be executed
568 prior to the user's command. You can also create a hook which will be
569 executed whenever the program stops. See gdb.texinfo.
573 We now deal with Cfront style name mangling, and can even extract type
574 info from mangled symbols. GDB can automatically figure out which
575 symbol mangling style your C++ compiler uses.
577 Calling of methods and virtual functions has been improved as well.
581 The crash that occured when debugging Sun Ansi-C compiled binaries is
582 fixed. This was due to mishandling of the extra N_SO stabs output
585 We also finally got Ultrix 4.2 running in house, and fixed core file
586 support, with help from a dozen people on the net.
588 John M. Farrell discovered that the reason that single-stepping was so
589 slow on all of the Mips based platforms (primarily SGI and DEC) was
590 that we were trying to demangle and lookup a symbol used for internal
591 purposes on every instruction that was being stepped through. Changing
592 the name of that symbol so that it couldn't be mistaken for a C++
593 mangled symbol sped things up a great deal.
595 Rich Pixley sped up symbol lookups in general by getting much smarter
596 about when C++ symbol mangling is necessary. This should make symbol
597 completion (TAB on the command line) much faster. It's not as fast as
598 we'd like, but it's significantly faster than gdb-4.6.
602 A new user controllable variable 'call_scratch_address' can
603 specify the location of a scratch area to be used when GDB
604 calls a function in the target. This is necessary because the
605 usual method of putting the scratch area on the stack does not work
606 in systems that have separate instruction and data spaces.
608 We integrated changes to support the 29k UDI (Universal Debugger
609 Interface), but discovered at the last minute that we didn't have all
610 of the appropriate copyright paperwork. We are working with AMD to
611 resolve this, and hope to have it available soon.
615 We have sped up the remote serial line protocol, especially for targets
616 with lots of registers. It now supports a new `expedited status' ('T')
617 message which can be used in place of the existing 'S' status message.
618 This allows the remote stub to send only the registers that GDB
619 needs to make a quick decision about single-stepping or conditional
620 breakpoints, eliminating the need to fetch the entire register set for
621 each instruction being stepped through.
623 The GDB remote serial protocol now implements a write-through cache for
624 registers, only re-reading the registers if the target has run.
626 There is also a new remote serial stub for SPARC processors. You can
627 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
628 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
629 processor with a serial port.
633 Configure.in files have become much easier to read and modify. A new
634 `table driven' format makes it more obvious what configurations are
635 supported, and what files each one uses.
639 There is a new opcodes library which will eventually contain all of the
640 disassembly routines and opcode tables. At present, it only contains
641 Sparc and Z8000 routines. This will allow the assembler, debugger, and
642 disassembler (binutils/objdump) to share these routines.
644 The libiberty library is now copylefted under the GNU Library General
645 Public License. This allows more liberal use, and was done so libg++
646 can use it. This makes no difference to GDB, since the Library License
647 grants all the rights from the General Public License.
651 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
652 reference to the stabs symbol info used by the debugger. It is (as far
653 as we know) the only published document on this fascinating topic. We
654 encourage you to read it, compare it to the stabs information on your
655 system, and send improvements on the document in general (to
656 bug-gdb@prep.ai.mit.edu).
658 And, of course, many bugs have been fixed.
661 *** Changes in GDB-4.6:
663 * Better support for C++ function names
665 GDB now accepts as input the "demangled form" of C++ overloaded function
666 names and member function names, and can do command completion on such names
667 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
668 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
669 Make use of command completion, it is your friend.
671 GDB also now accepts a variety of C++ mangled symbol formats. They are
672 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
673 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
674 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
675 for the list of formats.
677 * G++ symbol mangling problem
679 Recent versions of gcc have a bug in how they emit debugging information for
680 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
681 directory) can be applied to gcc to fix the problem. Alternatively, if you
682 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
683 usual symptom is difficulty with setting breakpoints on methods. GDB complains
684 about the method being non-existent. (We believe that version 2.2.2 of GCC has
687 * New 'maintenance' command
689 All of the commands related to hacking GDB internals have been moved out of
690 the main command set, and now live behind the 'maintenance' command. This
691 can also be abbreviated as 'mt'. The following changes were made:
693 dump-me -> maintenance dump-me
694 info all-breakpoints -> maintenance info breakpoints
695 printmsyms -> maintenance print msyms
696 printobjfiles -> maintenance print objfiles
697 printpsyms -> maintenance print psymbols
698 printsyms -> maintenance print symbols
700 The following commands are new:
702 maintenance demangle Call internal GDB demangler routine to
703 demangle a C++ link name and prints the result.
704 maintenance print type Print a type chain for a given symbol
706 * Change to .gdbinit file processing
708 We now read the $HOME/.gdbinit file before processing the argv arguments
709 (e.g. reading symbol files or core files). This allows global parameters to
710 be set, which will apply during the symbol reading. The ./.gdbinit is still
711 read after argv processing.
713 * New hosts supported
715 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
717 Linux support i386-unknown-linux or linux
719 We are also including code to support the HP/PA running BSD and HPUX. This
720 is almost guaranteed not to work, as we didn't have time to test or build it
721 for this release. We are including it so that the more adventurous (or
722 masochistic) of you can play with it. We also had major problems with the
723 fact that the compiler that we got from HP doesn't support the -g option.
726 * New targets supported
728 Hitachi H8/300 h8300-hitachi-hms or h8300hms
730 * More smarts about finding #include files
732 GDB now remembers the compilation directory for all include files, and for
733 all files from which C is generated (like yacc and lex sources). This
734 greatly improves GDB's ability to find yacc/lex sources, and include files,
735 especially if you are debugging your program from a directory different from
736 the one that contains your sources.
738 We also fixed a bug which caused difficulty with listing and setting
739 breakpoints in include files which contain C code. (In the past, you had to
740 try twice in order to list an include file that you hadn't looked at before.)
742 * Interesting infernals change
744 GDB now deals with arbitrary numbers of sections, where the symbols for each
745 section must be relocated relative to that section's landing place in the
746 target's address space. This work was needed to support ELF with embedded
747 stabs used by Solaris-2.0.
749 * Bug fixes (of course!)
751 There have been loads of fixes for the following things:
752 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
753 i960, stabs, DOS(GO32), procfs, etc...
755 See the ChangeLog for details.
757 *** Changes in GDB-4.5:
759 * New machines supported (host and target)
761 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
763 SGI Irix-4.x mips-sgi-irix4 or iris4
767 GDB now uses a new memory manager called mmalloc, based on gmalloc.
768 Mmalloc is capable of handling mutiple heaps of memory. It is also
769 capable of saving a heap to a file, and then mapping it back in later.
770 This can be used to greatly speedup the startup of GDB by using a
771 pre-parsed symbol table which lives in a mmalloc managed heap. For
772 more details, please read mmalloc/mmalloc.texi.
776 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
777 'help info proc' for details.
779 * MIPS ecoff symbol table format
781 The code that reads MIPS symbol table format is now supported on all hosts.
782 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
785 * File name changes for MS-DOS
787 Many files in the config directories have been renamed to make it easier to
788 support GDB on MS-DOSe systems (which have very restrictive file name
789 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
790 environment) is close to working but has some remaining problems. Note
791 that debugging of DOS programs is not supported, due to limitations
792 in the ``operating system'', but it can be used to host cross-debugging.
794 * Cross byte order fixes
796 Many fixes have been made to support cross debugging of Sparc and MIPS
797 targets from hosts whose byte order differs.
799 * New -mapped and -readnow options
801 If memory-mapped files are available on your system through the 'mmap'
802 system call, you can use the -mapped option on the `file' or
803 `symbol-file' commands to cause GDB to write the symbols from your
804 program into a reusable file. If the program you are debugging is
805 called `/path/fred', the mapped symbol file will be `./fred.syms'.
806 Future GDB debugging sessions will notice the presence of this file,
807 and will quickly map in symbol information from it, rather than reading
808 the symbol table from the executable program. Using the '-mapped'
809 option in a GDB `file' or `symbol-file' command has the same effect as
810 starting GDB with the '-mapped' command-line option.
812 You can cause GDB to read the entire symbol table immediately by using
813 the '-readnow' option with any of the commands that load symbol table
814 information (or on the GDB command line). This makes the command
815 slower, but makes future operations faster.
817 The -mapped and -readnow options are typically combined in order to
818 build a `fred.syms' file that contains complete symbol information.
819 A simple GDB invocation to do nothing but build a `.syms' file for future
822 gdb -batch -nx -mapped -readnow programname
824 The `.syms' file is specific to the host machine on which GDB is run.
825 It holds an exact image of GDB's internal symbol table. It cannot be
826 shared across multiple host platforms.
830 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
831 siglongjmp() without losing control. This feature has not yet been ported to
832 all systems. It currently works on many 386 platforms, all MIPS-based
833 platforms (SGI, DECstation, etc), and Sun3/4.
837 Preliminary work has been put in to support the new Solaris OS from Sun. At
838 this time, it can control and debug processes, but it is not capable of
843 As always, many many bug fixes. The major areas were with g++, and mipsread.
844 People using the MIPS-based platforms should experience fewer mysterious
845 crashes and trashed symbol tables.
847 *** Changes in GDB-4.4:
849 * New machines supported (host and target)
851 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
853 BSD Reno on Vax vax-dec-bsd
854 Ultrix on Vax vax-dec-ultrix
856 * New machines supported (target)
858 AMD 29000 embedded, using EBMON a29k-none-none
862 GDB continues to improve its handling of C++. `References' work better.
863 The demangler has also been improved, and now deals with symbols mangled as
864 per the Annotated C++ Reference Guide.
866 GDB also now handles `stabs' symbol information embedded in MIPS
867 `ecoff' symbol tables. Since the ecoff format was not easily
868 extensible to handle new languages such as C++, this appeared to be a
869 good way to put C++ debugging info into MIPS binaries. This option
870 will be supported in the GNU C compiler, version 2, when it is
873 * New features for SVR4
875 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
876 shared libraries. Debugging dynamically linked programs should present
877 only minor differences from debugging statically linked programs.
879 The `info proc' command will print out information about any process
880 on an SVR4 system (including the one you are debugging). At the moment,
881 it prints the address mappings of the process.
883 If you bring up GDB on another SVR4 system, please send mail to
884 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
886 * Better dynamic linking support in SunOS
888 Reading symbols from shared libraries which contain debugging symbols
889 now works properly. However, there remain issues such as automatic
890 skipping of `transfer vector' code during function calls, which
891 make it harder to debug code in a shared library, than to debug the
892 same code linked statically.
896 GDB is now using the latest `getopt' routines from the FSF. This
897 version accepts the -- prefix for options with long names. GDB will
898 continue to accept the old forms (-option and +option) as well.
899 Various single letter abbreviations for options have been explicity
900 added to the option table so that they won't get overshadowed in the
901 future by other options that begin with the same letter.
905 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
906 Many assorted bugs have been handled. Many more remain to be handled.
907 See the various ChangeLog files (primarily in gdb and bfd) for details.
910 *** Changes in GDB-4.3:
912 * New machines supported (host and target)
914 Amiga 3000 running Amix m68k-cbm-svr4 or amix
915 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
916 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
918 * Almost SCO Unix support
920 We had hoped to support:
921 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
922 (except for core file support), but we discovered very late in the release
923 that it has problems with process groups that render gdb unusable. Sorry
924 about that. I encourage people to fix it and post the fixes.
926 * Preliminary ELF and DWARF support
928 GDB can read ELF object files on System V Release 4, and can handle
929 debugging records for C, in DWARF format, in ELF files. This support
930 is preliminary. If you bring up GDB on another SVR4 system, please
931 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
936 GDB now uses the latest `readline' library. One user-visible change
937 is that two tabs will list possible command completions, which previously
938 required typing M-? (meta-question mark, or ESC ?).
942 The `stepi' bug that many of you noticed has been squashed.
943 Many bugs in C++ have been handled. Many more remain to be handled.
944 See the various ChangeLog files (primarily in gdb and bfd) for details.
946 * State of the MIPS world (in case you wondered):
948 GDB can understand the symbol tables emitted by the compilers
949 supplied by most vendors of MIPS-based machines, including DEC. These
950 symbol tables are in a format that essentially nobody else uses.
952 Some versions of gcc come with an assembler post-processor called
953 mips-tfile. This program is required if you want to do source-level
954 debugging of gcc-compiled programs. I believe FSF does not ship
955 mips-tfile with gcc version 1, but it will eventually come with gcc
958 Debugging of g++ output remains a problem. g++ version 1.xx does not
959 really support it at all. (If you're lucky, you should be able to get
960 line numbers and stack traces to work, but no parameters or local
961 variables.) With some work it should be possible to improve the
964 When gcc version 2 is released, you will have somewhat better luck.
965 However, even then you will get confusing results for inheritance and
968 We will eventually provide full debugging of g++ output on
969 DECstations. This will probably involve some kind of stabs-in-ecoff
970 encapulation, but the details have not been worked out yet.
973 *** Changes in GDB-4.2:
975 * Improved configuration
977 Only one copy of `configure' exists now, and it is not self-modifying.
978 Porting BFD is simpler.
982 The `step' and `next' commands now only stop at the first instruction
983 of a source line. This prevents the multiple stops that used to occur
984 in switch statements, for-loops, etc. `Step' continues to stop if a
985 function that has debugging information is called within the line.
989 Lots of small bugs fixed. More remain.
991 * New host supported (not target)
993 Intel 386 PC clone running Mach i386-none-mach
996 *** Changes in GDB-4.1:
998 * Multiple source language support
1000 GDB now has internal scaffolding to handle several source languages.
1001 It determines the type of each source file from its filename extension,
1002 and will switch expression parsing and number formatting to match the
1003 language of the function in the currently selected stack frame.
1004 You can also specifically set the language to be used, with
1005 `set language c' or `set language modula-2'.
1009 GDB now has preliminary support for the GNU Modula-2 compiler,
1010 currently under development at the State University of New York at
1011 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
1012 continue through the fall of 1991 and into 1992.
1014 Other Modula-2 compilers are currently not supported, and attempting to
1015 debug programs compiled with them will likely result in an error as the
1016 symbol table is read. Feel free to work on it, though!
1018 There are hooks in GDB for strict type checking and range checking,
1019 in the `Modula-2 philosophy', but they do not currently work.
1023 GDB can now write to executable and core files (e.g. patch
1024 a variable's value). You must turn this switch on, specify
1025 the file ("exec foo" or "core foo"), *then* modify it, e.g.
1026 by assigning a new value to a variable. Modifications take
1029 * Automatic SunOS shared library reading
1031 When you run your program, GDB automatically determines where its
1032 shared libraries (if any) have been loaded, and reads their symbols.
1033 The `share' command is no longer needed. This also works when
1034 examining core files.
1038 You can specify the number of lines that the `list' command shows.
1041 * New machines supported (host and target)
1043 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
1044 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
1045 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
1047 * New hosts supported (not targets)
1049 IBM RT/PC: romp-ibm-aix or rtpc
1051 * New targets supported (not hosts)
1053 AMD 29000 embedded with COFF a29k-none-coff
1054 AMD 29000 embedded with a.out a29k-none-aout
1055 Ultracomputer remote kernel debug a29k-nyu-kern
1057 * New remote interfaces
1063 *** Changes in GDB-4.0:
1067 Wide output is wrapped at good places to make the output more readable.
1069 Gdb now supports cross-debugging from a host machine of one type to a
1070 target machine of another type. Communication with the target system
1071 is over serial lines. The ``target'' command handles connecting to the
1072 remote system; the ``load'' command will download a program into the
1073 remote system. Serial stubs for the m68k and i386 are provided. Gdb
1074 also supports debugging of realtime processes running under VxWorks,
1075 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
1076 stub on the target system.
1078 New CPUs supported include the AMD 29000 and Intel 960.
1080 GDB now reads object files and symbol tables via a ``binary file''
1081 library, which allows a single copy of GDB to debug programs of multiple
1082 object file types such as a.out and coff.
1084 There is now a GDB reference card in "doc/refcard.tex". (Make targets
1085 refcard.dvi and refcard.ps are available to format it).
1088 * Control-Variable user interface simplified
1090 All variables that control the operation of the debugger can be set
1091 by the ``set'' command, and displayed by the ``show'' command.
1093 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
1094 ``Show prompt'' produces the response:
1095 Gdb's prompt is new-gdb=>.
1097 What follows are the NEW set commands. The command ``help set'' will
1098 print a complete list of old and new set commands. ``help set FOO''
1099 will give a longer description of the variable FOO. ``show'' will show
1100 all of the variable descriptions and their current settings.
1102 confirm on/off: Enables warning questions for operations that are
1103 hard to recover from, e.g. rerunning the program while
1104 it is already running. Default is ON.
1106 editing on/off: Enables EMACS style command line editing
1107 of input. Previous lines can be recalled with
1108 control-P, the current line can be edited with control-B,
1109 you can search for commands with control-R, etc.
1112 history filename NAME: NAME is where the gdb command history
1113 will be stored. The default is .gdb_history,
1114 or the value of the environment variable
1117 history size N: The size, in commands, of the command history. The
1118 default is 256, or the value of the environment variable
1121 history save on/off: If this value is set to ON, the history file will
1122 be saved after exiting gdb. If set to OFF, the
1123 file will not be saved. The default is OFF.
1125 history expansion on/off: If this value is set to ON, then csh-like
1126 history expansion will be performed on
1127 command line input. The default is OFF.
1129 radix N: Sets the default radix for input and output. It can be set
1130 to 8, 10, or 16. Note that the argument to "radix" is interpreted
1131 in the current radix, so "set radix 10" is always a no-op.
1133 height N: This integer value is the number of lines on a page. Default
1134 is 24, the current `stty rows'' setting, or the ``li#''
1135 setting from the termcap entry matching the environment
1138 width N: This integer value is the number of characters on a line.
1139 Default is 80, the current `stty cols'' setting, or the ``co#''
1140 setting from the termcap entry matching the environment
1143 Note: ``set screensize'' is obsolete. Use ``set height'' and
1144 ``set width'' instead.
1146 print address on/off: Print memory addresses in various command displays,
1147 such as stack traces and structure values. Gdb looks
1148 more ``symbolic'' if you turn this off; it looks more
1149 ``machine level'' with it on. Default is ON.
1151 print array on/off: Prettyprint arrays. New convenient format! Default
1154 print demangle on/off: Print C++ symbols in "source" form if on,
1157 print asm-demangle on/off: Same, for assembler level printouts
1160 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
1163 * Support for Epoch Environment.
1165 The epoch environment is a version of Emacs v18 with windowing. One
1166 new command, ``inspect'', is identical to ``print'', except that if you
1167 are running in the epoch environment, the value is printed in its own
1171 * Support for Shared Libraries
1173 GDB can now debug programs and core files that use SunOS shared libraries.
1174 Symbols from a shared library cannot be referenced
1175 before the shared library has been linked with the program (this
1176 happens after you type ``run'' and before the function main() is entered).
1177 At any time after this linking (including when examining core files
1178 from dynamically linked programs), gdb reads the symbols from each
1179 shared library when you type the ``sharedlibrary'' command.
1180 It can be abbreviated ``share''.
1182 sharedlibrary REGEXP: Load shared object library symbols for files
1183 matching a unix regular expression. No argument
1184 indicates to load symbols for all shared libraries.
1186 info sharedlibrary: Status of loaded shared libraries.
1191 A watchpoint stops execution of a program whenever the value of an
1192 expression changes. Checking for this slows down execution
1193 tremendously whenever you are in the scope of the expression, but is
1194 quite useful for catching tough ``bit-spreader'' or pointer misuse
1195 problems. Some machines such as the 386 have hardware for doing this
1196 more quickly, and future versions of gdb will use this hardware.
1198 watch EXP: Set a watchpoint (breakpoint) for an expression.
1200 info watchpoints: Information about your watchpoints.
1202 delete N: Deletes watchpoint number N (same as breakpoints).
1203 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
1204 enable N: Re-enables watchpoint number N (same as breakpoints).
1207 * C++ multiple inheritance
1209 When used with a GCC version 2 compiler, GDB supports multiple inheritance
1212 * C++ exception handling
1214 Gdb now supports limited C++ exception handling. Besides the existing
1215 ability to breakpoint on an exception handler, gdb can breakpoint on
1216 the raising of an exception (before the stack is peeled back to the
1219 catch FOO: If there is a FOO exception handler in the dynamic scope,
1220 set a breakpoint to catch exceptions which may be raised there.
1221 Multiple exceptions (``catch foo bar baz'') may be caught.
1223 info catch: Lists all exceptions which may be caught in the
1224 current stack frame.
1227 * Minor command changes
1229 The command ``call func (arg, arg, ...)'' now acts like the print
1230 command, except it does not print or save a value if the function's result
1231 is void. This is similar to dbx usage.
1233 The ``up'' and ``down'' commands now always print the frame they end up
1234 at; ``up-silently'' and `down-silently'' can be used in scripts to change
1235 frames without printing.
1237 * New directory command
1239 'dir' now adds directories to the FRONT of the source search path.
1240 The path starts off empty. Source files that contain debug information
1241 about the directory in which they were compiled can be found even
1242 with an empty path; Sun CC and GCC include this information. If GDB can't
1243 find your source file in the current directory, type "dir .".
1245 * Configuring GDB for compilation
1247 For normal use, type ``./configure host''. See README or gdb.texinfo
1250 GDB now handles cross debugging. If you are remotely debugging between
1251 two different machines, type ``./configure host -target=targ''.
1252 Host is the machine where GDB will run; targ is the machine
1253 where the program that you are debugging will run.
projects / deliverable / binutils-gdb.git / blob