1 What has changed in GDB?
2 (Organized release by release)
4 *** Changes in GDB-4.15:
6 * Remote targets use caching
8 Remote targets now use a data cache to speed up communication with the
10 The data cache could lead to incorrect results because it doesn't know
11 about volatile variables, thus making it impossible to debug targets
12 which use memory mapped I/O devices. `set remotecache off' turns the
15 * New native configurations
17 Microsoft NT and Microsoft Windows95 i[345]86-*-win32
21 ARM via RDP protocol arm-*-*
23 *** Changes in GDB-4.14:
25 * New native configurations
27 x86 FreeBSD i[345]86-*-freebsd
28 x86 NetBSD i[345]86-*-netbsd
29 NS32k NetBSD ns32k-*-netbsd
30 Sparc NetBSD sparc-*-netbsd
34 A29K VxWorks a29k-*-vxworks
35 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
36 CPU32 EST-300 emulator m68*-*-est*
37 PowerPC ELF powerpc-*-elf
40 * Alpha OSF/1 support for procfs
42 GDB now supports procfs under OSF/1-2.x and higher, which makes it
43 possible to attach to running processes. As the mounting of the /proc
44 filesystem is optional on the Alpha, GDB automatically determines
45 the availability of /proc during startup. This can lead to problems
46 if /proc is unmounted after GDB has been started.
48 * Arguments to user-defined commands
50 User commands may accept up to 10 arguments separated by whitespace.
51 Arguments are accessed within the user command via $arg0..$arg9. A
54 print $arg0 + $arg1 + $arg2
56 To execute the command use:
59 Defines the command "adder" which prints the sum of its three arguments.
60 Note the arguments are text substitutions, so they may reference variables,
61 use complex expressions, or even perform inferior function calls.
63 * New `if' and `while' commands
65 This makes it possible to write more sophisticated user-defined
66 commands. Both commands take a single argument, which is the
67 expression to evaluate, and must be followed by the commands to
68 execute, one per line, if the expression is nonzero, the list being
69 terminated by the word `end'. The `if' command list may include an
70 `else' word, which causes the following commands to be executed only
71 if the expression is zero.
73 * Fortran source language mode
75 GDB now includes partial support for Fortran 77. It will recognize
76 Fortran programs and can evaluate a subset of Fortran expressions, but
77 variables and functions may not be handled correctly. GDB will work
78 with G77, but does not yet know much about symbols emitted by other
83 Most debugging facilities now work on dynamic executables for HPPAs
84 running hpux9 or later. You can attach to running dynamically linked
85 processes, but by default the dynamic libraries will be read-only, so
86 for instance you won't be able to put breakpoints in them. To change
87 that behavior do the following before running the program:
93 This will cause the libraries to be mapped private and read-write.
94 To revert to the normal behavior, do this:
100 You cannot set breakpoints or examine data in the library until after
101 the library is loaded if the function/data symbols do not have
104 GDB can now also read debug symbols produced by the HP C compiler on
105 HPPAs (sorry, no C++, Fortran or 68k support).
107 * Target byte order now dynamically selectable
109 You can choose which byte order to use with a target system, via the
110 commands "set endian big" and "set endian little", and you can see the
111 current setting by using "show endian". You can also give the command
112 "set endian auto", in which case GDB will use the byte order
113 associated with the executable. Currently, only embedded MIPS
114 configurations support dynamic selection of target byte order.
116 * New DOS host serial code
118 This version uses DPMI interrupts to handle buffered I/O, so you
119 no longer need to run asynctsr when debugging boards connected to
122 *** Changes in GDB-4.13:
124 * New "complete" command
126 This lists all the possible completions for the rest of the line, if it
127 were to be given as a command itself. This is intended for use by emacs.
129 * Trailing space optional in prompt
131 "set prompt" no longer adds a space for you after the prompt you set. This
132 allows you to set a prompt which ends in a space or one that does not.
134 * Breakpoint hit counts
136 "info break" now displays a count of the number of times the breakpoint
137 has been hit. This is especially useful in conjunction with "ignore"; you
138 can ignore a large number of breakpoint hits, look at the breakpoint info
139 to see how many times the breakpoint was hit, then run again, ignoring one
140 less than that number, and this will get you quickly to the last hit of
143 * Ability to stop printing at NULL character
145 "set print null-stop" will cause GDB to stop printing the characters of
146 an array when the first NULL is encountered. This is useful when large
147 arrays actually contain only short strings.
149 * Shared library breakpoints
151 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
152 breakpoints in shared libraries before the executable is run.
154 * Hardware watchpoints
156 There is a new hardware breakpoint for the watch command for sparclite
157 targets. See gdb/sparclite/hw_breakpoint.note.
159 Hardware watchpoints are also now supported under Linux.
163 Annotations have been added. These are for use with graphical interfaces,
164 and are still experimental. Currently only gdba.el uses these.
166 * Improved Irix 5 support
168 GDB now works properly with Irix 5.2.
170 * Improved HPPA support
172 GDB now works properly with the latest GCC and GAS.
174 * New native configurations
176 Sequent PTX4 i[34]86-sequent-ptx4
177 HPPA running OSF/1 hppa*-*-osf*
178 Atari TT running SVR4 m68*-*-sysv4*
179 RS/6000 LynxOS rs6000-*-lynxos*
183 OS/9000 i[34]86-*-os9k
184 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
187 * Hitachi SH7000 and E7000-PC ICE support
189 There is now support for communicating with the Hitachi E7000-PC ICE.
190 This is available automatically when GDB is configured for the SH.
194 As usual, a variety of small fixes and improvements, both generic
195 and configuration-specific. See the ChangeLog for more detail.
197 *** Changes in GDB-4.12:
199 * Irix 5 is now supported
203 GDB-4.12 on the HPPA has a number of changes which make it unable
204 to debug the output from the currently released versions of GCC and
205 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
206 of GCC and GAS, versions of these tools designed to work with GDB-4.12
207 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
210 *** Changes in GDB-4.11:
212 * User visible changes:
216 The "set remotedebug" option is now consistent between the mips remote
217 target, remote targets using the gdb-specific protocol, UDI (AMD's
218 debug protocol for the 29k) and the 88k bug monitor. It is now an
219 integer specifying a debug level (normally 0 or 1, but 2 means more
220 debugging info for the mips target).
222 * DEC Alpha native support
224 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
225 debug info, but GDB works fairly well with the DEC compiler and should
226 work with a future GCC release. See the README file for a few
227 Alpha-specific notes.
229 * Preliminary thread implementation
231 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
233 * LynxOS native and target support for 386
235 This release has been hosted on LynxOS 2.2, and also can be configured
236 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
239 * Improvements in C++ mangling/demangling.
241 This release has much better g++ debugging, specifically in name
242 mangling/demangling, virtual function calls, print virtual table,
243 call methods, ...etc.
245 *** Changes in GDB-4.10:
247 * User visible changes:
249 Remote debugging using the GDB-specific (`target remote') protocol now
250 supports the `load' command. This is only useful if you have some
251 other way of getting the stub to the target system, and you can put it
252 somewhere in memory where it won't get clobbered by the download.
254 Filename completion now works.
256 When run under emacs mode, the "info line" command now causes the
257 arrow to point to the line specified. Also, "info line" prints
258 addresses in symbolic form (as well as hex).
260 All vxworks based targets now support a user settable option, called
261 vxworks-timeout. This option represents the number of seconds gdb
262 should wait for responses to rpc's. You might want to use this if
263 your vxworks target is, perhaps, a slow software simulator or happens
264 to be on the far side of a thin network line.
268 This release contains support for using a DEC alpha as a GDB host for
269 cross debugging. Native alpha debugging is not supported yet.
272 *** Changes in GDB-4.9:
276 This is the first GDB release which is accompanied by a matching testsuite.
277 The testsuite requires installation of dejagnu, which should be available
278 via ftp from most sites that carry GNU software.
282 'Cfront' style demangling has had its name changed to 'ARM' style, to
283 emphasize that it was written from the specifications in the C++ Annotated
284 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
285 disclaimers, it still generated too much confusion with users attempting to
286 use gdb with AT&T cfront.
290 GDB now uses a standard remote interface to a simulator library.
291 So far, the library contains simulators for the Zilog Z8001/2, the
292 Hitachi H8/300, H8/500 and Super-H.
294 * New targets supported
296 H8/300 simulator h8300-hitachi-hms or h8300hms
297 H8/500 simulator h8500-hitachi-hms or h8500hms
298 SH simulator sh-hitachi-hms or sh
299 Z8000 simulator z8k-zilog-none or z8ksim
300 IDT MIPS board over serial line mips-idt-ecoff
302 Cross-debugging to GO32 targets is supported. It requires a custom
303 version of the i386-stub.c module which is integrated with the
304 GO32 memory extender.
306 * New remote protocols
308 MIPS remote debugging protocol.
310 * New source languages supported
312 This version includes preliminary support for Chill, a Pascal like language
313 used by telecommunications companies. Chill support is also being integrated
314 into the GNU compiler, but we don't know when it will be publically available.
317 *** Changes in GDB-4.8:
319 * HP Precision Architecture supported
321 GDB now supports HP PA-RISC machines running HPUX. A preliminary
322 version of this support was available as a set of patches from the
323 University of Utah. GDB does not support debugging of programs
324 compiled with the HP compiler, because HP will not document their file
325 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
326 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
328 Many problems in the preliminary version have been fixed.
330 * Faster and better demangling
332 We have improved template demangling and fixed numerous bugs in the GNU style
333 demangler. It can now handle type modifiers such as `static' or `const'. Wide
334 character types (wchar_t) are now supported. Demangling of each symbol is now
335 only done once, and is cached when the symbol table for a file is read in.
336 This results in a small increase in memory usage for C programs, a moderate
337 increase in memory usage for C++ programs, and a fantastic speedup in
340 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
341 from the specifications in the Annotated Reference Manual, which AT&T's
342 compiler does not actually implement.
344 * G++ multiple inheritance compiler problem
346 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
347 inheritance lattices was reworked to properly discover ambiguities. We
348 recently found an example which causes this new algorithm to fail in a
349 very subtle way, producing bad debug information for those classes.
350 The file 'gcc.patch' (in this directory) can be applied to gcc to
351 circumvent the problem. A future GCC release will contain a complete
354 The previous G++ debug info problem (mentioned below for the gdb-4.7
355 release) is fixed in gcc version 2.3.2.
357 * Improved configure script
359 The `configure' script will now attempt to guess your system type if
360 you don't supply a host system type. The old scheme of supplying a
361 host system triplet is preferable over using this. All the magic is
362 done in the new `config.guess' script. Examine it for details.
364 We have also brought our configure script much more in line with the FSF's
365 version. It now supports the --with-xxx options. In particular,
366 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
367 The resulting GDB will not be able to read arbitrary object file formats --
368 only the format ``expected'' to be used on the configured target system.
369 We hope to make this the default in a future release.
371 * Documentation improvements
373 There's new internal documentation on how to modify GDB, and how to
374 produce clean changes to the code. We implore people to read it
375 before submitting changes.
377 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
378 M4 macros. The new texinfo.tex is provided in this release. Pre-built
379 `info' files are also provided. To build `info' files from scratch,
380 you will need the latest `makeinfo' release, which will be available in
381 a future texinfo-X.Y release.
383 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
384 We're not sure exactly which versions have this problem, but it has
385 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
386 or better. If that isn't possible, there is a patch in
387 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
392 GDB now supports array constants that can be used in expressions typed in by
393 the user. The syntax is `{element, element, ...}'. Ie: you can now type
394 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
397 The new directory `gdb/sparclite' contains a program that demonstrates
398 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
400 * New native hosts supported
402 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
403 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
405 * New targets supported
407 AMD 29k family via UDI a29k-amd-udi or udi29k
409 * New file formats supported
411 BFD now supports reading HP/PA-RISC executables (SOM file format?),
412 HPUX core files, and SCO 3.2v2 core files.
416 Attaching to processes now works again; thanks for the many bug reports.
418 We have also stomped on a bunch of core dumps caused by
419 printf_filtered("%s") problems.
421 We eliminated a copyright problem on the rpc and ptrace header files
422 for VxWorks, which was discovered at the last minute during the 4.7
423 release. You should now be able to build a VxWorks GDB.
425 You can now interrupt gdb while an attached process is running. This
426 will cause the attached process to stop, and give control back to GDB.
428 We fixed problems caused by using too many file descriptors
429 for reading symbols from object files and libraries. This was
430 especially a problem for programs that used many (~100) shared
433 The `step' command now only enters a subroutine if there is line number
434 information for the subroutine. Otherwise it acts like the `next'
435 command. Previously, `step' would enter subroutines if there was
436 any debugging information about the routine. This avoids problems
437 when using `cc -g1' on MIPS machines.
439 * Internal improvements
441 GDB's internal interfaces have been improved to make it easier to support
442 debugging of multiple languages in the future.
444 GDB now uses a common structure for symbol information internally.
445 Minimal symbols (derived from linkage symbols in object files), partial
446 symbols (from a quick scan of debug information), and full symbols
447 contain a common subset of information, making it easier to write
448 shared code that handles any of them.
450 * New command line options
452 We now accept --silent as an alias for --quiet.
456 The memory-mapped-malloc library is now licensed under the GNU Library
457 General Public License.
459 *** Changes in GDB-4.7:
461 * Host/native/target split
463 GDB has had some major internal surgery to untangle the support for
464 hosts and remote targets. Now, when you configure GDB for a remote
465 target, it will no longer load in all of the support for debugging
466 local programs on the host. When fully completed and tested, this will
467 ensure that arbitrary host/target combinations are possible.
469 The primary conceptual shift is to separate the non-portable code in
470 GDB into three categories. Host specific code is required any time GDB
471 is compiled on that host, regardless of the target. Target specific
472 code relates to the peculiarities of the target, but can be compiled on
473 any host. Native specific code is everything else: it can only be
474 built when the host and target are the same system. Child process
475 handling and core file support are two common `native' examples.
477 GDB's use of /proc for controlling Unix child processes is now cleaner.
478 It has been split out into a single module under the `target_ops' vector,
479 plus two native-dependent functions for each system that uses /proc.
481 * New hosts supported
483 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
484 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
485 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
487 * New targets supported
489 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
490 68030 and CPU32 m68030-*-*, m68332-*-*
492 * New native hosts supported
494 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
495 (386bsd is not well tested yet)
496 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
498 * New file formats supported
500 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
501 supports reading of `a.out.adobe' object files, which are an a.out
502 format extended with minimal information about multiple sections.
506 `show copying' is the same as the old `info copying'.
507 `show warranty' is the same as `info warrantee'.
508 These were renamed for consistency. The old commands continue to work.
510 `info handle' is a new alias for `info signals'.
512 You can now define pre-command hooks, which attach arbitrary command
513 scripts to any command. The commands in the hook will be executed
514 prior to the user's command. You can also create a hook which will be
515 executed whenever the program stops. See gdb.texinfo.
519 We now deal with Cfront style name mangling, and can even extract type
520 info from mangled symbols. GDB can automatically figure out which
521 symbol mangling style your C++ compiler uses.
523 Calling of methods and virtual functions has been improved as well.
527 The crash that occured when debugging Sun Ansi-C compiled binaries is
528 fixed. This was due to mishandling of the extra N_SO stabs output
531 We also finally got Ultrix 4.2 running in house, and fixed core file
532 support, with help from a dozen people on the net.
534 John M. Farrell discovered that the reason that single-stepping was so
535 slow on all of the Mips based platforms (primarily SGI and DEC) was
536 that we were trying to demangle and lookup a symbol used for internal
537 purposes on every instruction that was being stepped through. Changing
538 the name of that symbol so that it couldn't be mistaken for a C++
539 mangled symbol sped things up a great deal.
541 Rich Pixley sped up symbol lookups in general by getting much smarter
542 about when C++ symbol mangling is necessary. This should make symbol
543 completion (TAB on the command line) much faster. It's not as fast as
544 we'd like, but it's significantly faster than gdb-4.6.
548 A new user controllable variable 'call_scratch_address' can
549 specify the location of a scratch area to be used when GDB
550 calls a function in the target. This is necessary because the
551 usual method of putting the scratch area on the stack does not work
552 in systems that have separate instruction and data spaces.
554 We integrated changes to support the 29k UDI (Universal Debugger
555 Interface), but discovered at the last minute that we didn't have all
556 of the appropriate copyright paperwork. We are working with AMD to
557 resolve this, and hope to have it available soon.
561 We have sped up the remote serial line protocol, especially for targets
562 with lots of registers. It now supports a new `expedited status' ('T')
563 message which can be used in place of the existing 'S' status message.
564 This allows the remote stub to send only the registers that GDB
565 needs to make a quick decision about single-stepping or conditional
566 breakpoints, eliminating the need to fetch the entire register set for
567 each instruction being stepped through.
569 The GDB remote serial protocol now implements a write-through cache for
570 registers, only re-reading the registers if the target has run.
572 There is also a new remote serial stub for SPARC processors. You can
573 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
574 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
575 processor with a serial port.
579 Configure.in files have become much easier to read and modify. A new
580 `table driven' format makes it more obvious what configurations are
581 supported, and what files each one uses.
585 There is a new opcodes library which will eventually contain all of the
586 disassembly routines and opcode tables. At present, it only contains
587 Sparc and Z8000 routines. This will allow the assembler, debugger, and
588 disassembler (binutils/objdump) to share these routines.
590 The libiberty library is now copylefted under the GNU Library General
591 Public License. This allows more liberal use, and was done so libg++
592 can use it. This makes no difference to GDB, since the Library License
593 grants all the rights from the General Public License.
597 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
598 reference to the stabs symbol info used by the debugger. It is (as far
599 as we know) the only published document on this fascinating topic. We
600 encourage you to read it, compare it to the stabs information on your
601 system, and send improvements on the document in general (to
602 bug-gdb@prep.ai.mit.edu).
604 And, of course, many bugs have been fixed.
607 *** Changes in GDB-4.6:
609 * Better support for C++ function names
611 GDB now accepts as input the "demangled form" of C++ overloaded function
612 names and member function names, and can do command completion on such names
613 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
614 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
615 Make use of command completion, it is your friend.
617 GDB also now accepts a variety of C++ mangled symbol formats. They are
618 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
619 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
620 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
621 for the list of formats.
623 * G++ symbol mangling problem
625 Recent versions of gcc have a bug in how they emit debugging information for
626 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
627 directory) can be applied to gcc to fix the problem. Alternatively, if you
628 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
629 usual symptom is difficulty with setting breakpoints on methods. GDB complains
630 about the method being non-existent. (We believe that version 2.2.2 of GCC has
633 * New 'maintenance' command
635 All of the commands related to hacking GDB internals have been moved out of
636 the main command set, and now live behind the 'maintenance' command. This
637 can also be abbreviated as 'mt'. The following changes were made:
639 dump-me -> maintenance dump-me
640 info all-breakpoints -> maintenance info breakpoints
641 printmsyms -> maintenance print msyms
642 printobjfiles -> maintenance print objfiles
643 printpsyms -> maintenance print psymbols
644 printsyms -> maintenance print symbols
646 The following commands are new:
648 maintenance demangle Call internal GDB demangler routine to
649 demangle a C++ link name and prints the result.
650 maintenance print type Print a type chain for a given symbol
652 * Change to .gdbinit file processing
654 We now read the $HOME/.gdbinit file before processing the argv arguments
655 (e.g. reading symbol files or core files). This allows global parameters to
656 be set, which will apply during the symbol reading. The ./.gdbinit is still
657 read after argv processing.
659 * New hosts supported
661 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
663 Linux support i386-unknown-linux or linux
665 We are also including code to support the HP/PA running BSD and HPUX. This
666 is almost guaranteed not to work, as we didn't have time to test or build it
667 for this release. We are including it so that the more adventurous (or
668 masochistic) of you can play with it. We also had major problems with the
669 fact that the compiler that we got from HP doesn't support the -g option.
672 * New targets supported
674 Hitachi H8/300 h8300-hitachi-hms or h8300hms
676 * More smarts about finding #include files
678 GDB now remembers the compilation directory for all include files, and for
679 all files from which C is generated (like yacc and lex sources). This
680 greatly improves GDB's ability to find yacc/lex sources, and include files,
681 especially if you are debugging your program from a directory different from
682 the one that contains your sources.
684 We also fixed a bug which caused difficulty with listing and setting
685 breakpoints in include files which contain C code. (In the past, you had to
686 try twice in order to list an include file that you hadn't looked at before.)
688 * Interesting infernals change
690 GDB now deals with arbitrary numbers of sections, where the symbols for each
691 section must be relocated relative to that section's landing place in the
692 target's address space. This work was needed to support ELF with embedded
693 stabs used by Solaris-2.0.
695 * Bug fixes (of course!)
697 There have been loads of fixes for the following things:
698 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
699 i960, stabs, DOS(GO32), procfs, etc...
701 See the ChangeLog for details.
703 *** Changes in GDB-4.5:
705 * New machines supported (host and target)
707 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
709 SGI Irix-4.x mips-sgi-irix4 or iris4
713 GDB now uses a new memory manager called mmalloc, based on gmalloc.
714 Mmalloc is capable of handling mutiple heaps of memory. It is also
715 capable of saving a heap to a file, and then mapping it back in later.
716 This can be used to greatly speedup the startup of GDB by using a
717 pre-parsed symbol table which lives in a mmalloc managed heap. For
718 more details, please read mmalloc/mmalloc.texi.
722 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
723 'help info proc' for details.
725 * MIPS ecoff symbol table format
727 The code that reads MIPS symbol table format is now supported on all hosts.
728 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
731 * File name changes for MS-DOS
733 Many files in the config directories have been renamed to make it easier to
734 support GDB on MS-DOSe systems (which have very restrictive file name
735 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
736 environment) is close to working but has some remaining problems. Note
737 that debugging of DOS programs is not supported, due to limitations
738 in the ``operating system'', but it can be used to host cross-debugging.
740 * Cross byte order fixes
742 Many fixes have been made to support cross debugging of Sparc and MIPS
743 targets from hosts whose byte order differs.
745 * New -mapped and -readnow options
747 If memory-mapped files are available on your system through the 'mmap'
748 system call, you can use the -mapped option on the `file' or
749 `symbol-file' commands to cause GDB to write the symbols from your
750 program into a reusable file. If the program you are debugging is
751 called `/path/fred', the mapped symbol file will be `./fred.syms'.
752 Future GDB debugging sessions will notice the presence of this file,
753 and will quickly map in symbol information from it, rather than reading
754 the symbol table from the executable program. Using the '-mapped'
755 option in a GDB `file' or `symbol-file' command has the same effect as
756 starting GDB with the '-mapped' command-line option.
758 You can cause GDB to read the entire symbol table immediately by using
759 the '-readnow' option with any of the commands that load symbol table
760 information (or on the GDB command line). This makes the command
761 slower, but makes future operations faster.
763 The -mapped and -readnow options are typically combined in order to
764 build a `fred.syms' file that contains complete symbol information.
765 A simple GDB invocation to do nothing but build a `.syms' file for future
768 gdb -batch -nx -mapped -readnow programname
770 The `.syms' file is specific to the host machine on which GDB is run.
771 It holds an exact image of GDB's internal symbol table. It cannot be
772 shared across multiple host platforms.
776 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
777 siglongjmp() without losing control. This feature has not yet been ported to
778 all systems. It currently works on many 386 platforms, all MIPS-based
779 platforms (SGI, DECstation, etc), and Sun3/4.
783 Preliminary work has been put in to support the new Solaris OS from Sun. At
784 this time, it can control and debug processes, but it is not capable of
789 As always, many many bug fixes. The major areas were with g++, and mipsread.
790 People using the MIPS-based platforms should experience fewer mysterious
791 crashes and trashed symbol tables.
793 *** Changes in GDB-4.4:
795 * New machines supported (host and target)
797 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
799 BSD Reno on Vax vax-dec-bsd
800 Ultrix on Vax vax-dec-ultrix
802 * New machines supported (target)
804 AMD 29000 embedded, using EBMON a29k-none-none
808 GDB continues to improve its handling of C++. `References' work better.
809 The demangler has also been improved, and now deals with symbols mangled as
810 per the Annotated C++ Reference Guide.
812 GDB also now handles `stabs' symbol information embedded in MIPS
813 `ecoff' symbol tables. Since the ecoff format was not easily
814 extensible to handle new languages such as C++, this appeared to be a
815 good way to put C++ debugging info into MIPS binaries. This option
816 will be supported in the GNU C compiler, version 2, when it is
819 * New features for SVR4
821 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
822 shared libraries. Debugging dynamically linked programs should present
823 only minor differences from debugging statically linked programs.
825 The `info proc' command will print out information about any process
826 on an SVR4 system (including the one you are debugging). At the moment,
827 it prints the address mappings of the process.
829 If you bring up GDB on another SVR4 system, please send mail to
830 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
832 * Better dynamic linking support in SunOS
834 Reading symbols from shared libraries which contain debugging symbols
835 now works properly. However, there remain issues such as automatic
836 skipping of `transfer vector' code during function calls, which
837 make it harder to debug code in a shared library, than to debug the
838 same code linked statically.
842 GDB is now using the latest `getopt' routines from the FSF. This
843 version accepts the -- prefix for options with long names. GDB will
844 continue to accept the old forms (-option and +option) as well.
845 Various single letter abbreviations for options have been explicity
846 added to the option table so that they won't get overshadowed in the
847 future by other options that begin with the same letter.
851 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
852 Many assorted bugs have been handled. Many more remain to be handled.
853 See the various ChangeLog files (primarily in gdb and bfd) for details.
856 *** Changes in GDB-4.3:
858 * New machines supported (host and target)
860 Amiga 3000 running Amix m68k-cbm-svr4 or amix
861 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
862 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
864 * Almost SCO Unix support
866 We had hoped to support:
867 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
868 (except for core file support), but we discovered very late in the release
869 that it has problems with process groups that render gdb unusable. Sorry
870 about that. I encourage people to fix it and post the fixes.
872 * Preliminary ELF and DWARF support
874 GDB can read ELF object files on System V Release 4, and can handle
875 debugging records for C, in DWARF format, in ELF files. This support
876 is preliminary. If you bring up GDB on another SVR4 system, please
877 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
882 GDB now uses the latest `readline' library. One user-visible change
883 is that two tabs will list possible command completions, which previously
884 required typing M-? (meta-question mark, or ESC ?).
888 The `stepi' bug that many of you noticed has been squashed.
889 Many bugs in C++ have been handled. Many more remain to be handled.
890 See the various ChangeLog files (primarily in gdb and bfd) for details.
892 * State of the MIPS world (in case you wondered):
894 GDB can understand the symbol tables emitted by the compilers
895 supplied by most vendors of MIPS-based machines, including DEC. These
896 symbol tables are in a format that essentially nobody else uses.
898 Some versions of gcc come with an assembler post-processor called
899 mips-tfile. This program is required if you want to do source-level
900 debugging of gcc-compiled programs. I believe FSF does not ship
901 mips-tfile with gcc version 1, but it will eventually come with gcc
904 Debugging of g++ output remains a problem. g++ version 1.xx does not
905 really support it at all. (If you're lucky, you should be able to get
906 line numbers and stack traces to work, but no parameters or local
907 variables.) With some work it should be possible to improve the
910 When gcc version 2 is released, you will have somewhat better luck.
911 However, even then you will get confusing results for inheritance and
914 We will eventually provide full debugging of g++ output on
915 DECstations. This will probably involve some kind of stabs-in-ecoff
916 encapulation, but the details have not been worked out yet.
919 *** Changes in GDB-4.2:
921 * Improved configuration
923 Only one copy of `configure' exists now, and it is not self-modifying.
924 Porting BFD is simpler.
928 The `step' and `next' commands now only stop at the first instruction
929 of a source line. This prevents the multiple stops that used to occur
930 in switch statements, for-loops, etc. `Step' continues to stop if a
931 function that has debugging information is called within the line.
935 Lots of small bugs fixed. More remain.
937 * New host supported (not target)
939 Intel 386 PC clone running Mach i386-none-mach
942 *** Changes in GDB-4.1:
944 * Multiple source language support
946 GDB now has internal scaffolding to handle several source languages.
947 It determines the type of each source file from its filename extension,
948 and will switch expression parsing and number formatting to match the
949 language of the function in the currently selected stack frame.
950 You can also specifically set the language to be used, with
951 `set language c' or `set language modula-2'.
955 GDB now has preliminary support for the GNU Modula-2 compiler,
956 currently under development at the State University of New York at
957 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
958 continue through the fall of 1991 and into 1992.
960 Other Modula-2 compilers are currently not supported, and attempting to
961 debug programs compiled with them will likely result in an error as the
962 symbol table is read. Feel free to work on it, though!
964 There are hooks in GDB for strict type checking and range checking,
965 in the `Modula-2 philosophy', but they do not currently work.
969 GDB can now write to executable and core files (e.g. patch
970 a variable's value). You must turn this switch on, specify
971 the file ("exec foo" or "core foo"), *then* modify it, e.g.
972 by assigning a new value to a variable. Modifications take
975 * Automatic SunOS shared library reading
977 When you run your program, GDB automatically determines where its
978 shared libraries (if any) have been loaded, and reads their symbols.
979 The `share' command is no longer needed. This also works when
980 examining core files.
984 You can specify the number of lines that the `list' command shows.
987 * New machines supported (host and target)
989 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
990 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
991 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
993 * New hosts supported (not targets)
995 IBM RT/PC: romp-ibm-aix or rtpc
997 * New targets supported (not hosts)
999 AMD 29000 embedded with COFF a29k-none-coff
1000 AMD 29000 embedded with a.out a29k-none-aout
1001 Ultracomputer remote kernel debug a29k-nyu-kern
1003 * New remote interfaces
1009 *** Changes in GDB-4.0:
1013 Wide output is wrapped at good places to make the output more readable.
1015 Gdb now supports cross-debugging from a host machine of one type to a
1016 target machine of another type. Communication with the target system
1017 is over serial lines. The ``target'' command handles connecting to the
1018 remote system; the ``load'' command will download a program into the
1019 remote system. Serial stubs for the m68k and i386 are provided. Gdb
1020 also supports debugging of realtime processes running under VxWorks,
1021 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
1022 stub on the target system.
1024 New CPUs supported include the AMD 29000 and Intel 960.
1026 GDB now reads object files and symbol tables via a ``binary file''
1027 library, which allows a single copy of GDB to debug programs of multiple
1028 object file types such as a.out and coff.
1030 There is now a GDB reference card in "doc/refcard.tex". (Make targets
1031 refcard.dvi and refcard.ps are available to format it).
1034 * Control-Variable user interface simplified
1036 All variables that control the operation of the debugger can be set
1037 by the ``set'' command, and displayed by the ``show'' command.
1039 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
1040 ``Show prompt'' produces the response:
1041 Gdb's prompt is new-gdb=>.
1043 What follows are the NEW set commands. The command ``help set'' will
1044 print a complete list of old and new set commands. ``help set FOO''
1045 will give a longer description of the variable FOO. ``show'' will show
1046 all of the variable descriptions and their current settings.
1048 confirm on/off: Enables warning questions for operations that are
1049 hard to recover from, e.g. rerunning the program while
1050 it is already running. Default is ON.
1052 editing on/off: Enables EMACS style command line editing
1053 of input. Previous lines can be recalled with
1054 control-P, the current line can be edited with control-B,
1055 you can search for commands with control-R, etc.
1058 history filename NAME: NAME is where the gdb command history
1059 will be stored. The default is .gdb_history,
1060 or the value of the environment variable
1063 history size N: The size, in commands, of the command history. The
1064 default is 256, or the value of the environment variable
1067 history save on/off: If this value is set to ON, the history file will
1068 be saved after exiting gdb. If set to OFF, the
1069 file will not be saved. The default is OFF.
1071 history expansion on/off: If this value is set to ON, then csh-like
1072 history expansion will be performed on
1073 command line input. The default is OFF.
1075 radix N: Sets the default radix for input and output. It can be set
1076 to 8, 10, or 16. Note that the argument to "radix" is interpreted
1077 in the current radix, so "set radix 10" is always a no-op.
1079 height N: This integer value is the number of lines on a page. Default
1080 is 24, the current `stty rows'' setting, or the ``li#''
1081 setting from the termcap entry matching the environment
1084 width N: This integer value is the number of characters on a line.
1085 Default is 80, the current `stty cols'' setting, or the ``co#''
1086 setting from the termcap entry matching the environment
1089 Note: ``set screensize'' is obsolete. Use ``set height'' and
1090 ``set width'' instead.
1092 print address on/off: Print memory addresses in various command displays,
1093 such as stack traces and structure values. Gdb looks
1094 more ``symbolic'' if you turn this off; it looks more
1095 ``machine level'' with it on. Default is ON.
1097 print array on/off: Prettyprint arrays. New convenient format! Default
1100 print demangle on/off: Print C++ symbols in "source" form if on,
1103 print asm-demangle on/off: Same, for assembler level printouts
1106 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
1109 * Support for Epoch Environment.
1111 The epoch environment is a version of Emacs v18 with windowing. One
1112 new command, ``inspect'', is identical to ``print'', except that if you
1113 are running in the epoch environment, the value is printed in its own
1117 * Support for Shared Libraries
1119 GDB can now debug programs and core files that use SunOS shared libraries.
1120 Symbols from a shared library cannot be referenced
1121 before the shared library has been linked with the program (this
1122 happens after you type ``run'' and before the function main() is entered).
1123 At any time after this linking (including when examining core files
1124 from dynamically linked programs), gdb reads the symbols from each
1125 shared library when you type the ``sharedlibrary'' command.
1126 It can be abbreviated ``share''.
1128 sharedlibrary REGEXP: Load shared object library symbols for files
1129 matching a unix regular expression. No argument
1130 indicates to load symbols for all shared libraries.
1132 info sharedlibrary: Status of loaded shared libraries.
1137 A watchpoint stops execution of a program whenever the value of an
1138 expression changes. Checking for this slows down execution
1139 tremendously whenever you are in the scope of the expression, but is
1140 quite useful for catching tough ``bit-spreader'' or pointer misuse
1141 problems. Some machines such as the 386 have hardware for doing this
1142 more quickly, and future versions of gdb will use this hardware.
1144 watch EXP: Set a watchpoint (breakpoint) for an expression.
1146 info watchpoints: Information about your watchpoints.
1148 delete N: Deletes watchpoint number N (same as breakpoints).
1149 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
1150 enable N: Re-enables watchpoint number N (same as breakpoints).
1153 * C++ multiple inheritance
1155 When used with a GCC version 2 compiler, GDB supports multiple inheritance
1158 * C++ exception handling
1160 Gdb now supports limited C++ exception handling. Besides the existing
1161 ability to breakpoint on an exception handler, gdb can breakpoint on
1162 the raising of an exception (before the stack is peeled back to the
1165 catch FOO: If there is a FOO exception handler in the dynamic scope,
1166 set a breakpoint to catch exceptions which may be raised there.
1167 Multiple exceptions (``catch foo bar baz'') may be caught.
1169 info catch: Lists all exceptions which may be caught in the
1170 current stack frame.
1173 * Minor command changes
1175 The command ``call func (arg, arg, ...)'' now acts like the print
1176 command, except it does not print or save a value if the function's result
1177 is void. This is similar to dbx usage.
1179 The ``up'' and ``down'' commands now always print the frame they end up
1180 at; ``up-silently'' and `down-silently'' can be used in scripts to change
1181 frames without printing.
1183 * New directory command
1185 'dir' now adds directories to the FRONT of the source search path.
1186 The path starts off empty. Source files that contain debug information
1187 about the directory in which they were compiled can be found even
1188 with an empty path; Sun CC and GCC include this information. If GDB can't
1189 find your source file in the current directory, type "dir .".
1191 * Configuring GDB for compilation
1193 For normal use, type ``./configure host''. See README or gdb.texinfo
1196 GDB now handles cross debugging. If you are remotely debugging between
1197 two different machines, type ``./configure host -target=targ''.
1198 Host is the machine where GDB will run; targ is the machine
1199 where the program that you are debugging will run.
projects / binutils-gdb.git / blob