1 What has changed in GDB?
2 (Organized release by release)
4 *** Changes since GDB-4.17:
6 * New native configurations
8 HP-UX 10.20 hppa*-*-hpux10.20
9 HP-UX 11.x hppa*-*-hpux11.0*
10 M68K Linux m68*-*-linux*
14 Fujitsu FR30 fr30-*-elf*
15 Mitsubishi D30V d30v-*-*
19 GDB now uses readline 2.2.
21 ** The PowerPC and RS6000 targets now have a `set processor' command.
23 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
24 you can use the `set processor' command to specify what variant of the
25 PowerPC family you are debugging. The command
29 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
30 following PowerPC and RS6000 variants:
32 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
33 rs6000 IBM RS6000 ("POWER") architecture, user-level view
35 403GC IBM PowerPC 403GC
36 505 Motorola PowerPC 505
37 860 Motorola PowerPC 860 or 850
38 601 Motorola PowerPC 601
39 602 Motorola PowerPC 602
40 603 Motorola/IBM PowerPC 603 or 603e
41 604 Motorola PowerPC 604 or 604e
42 750 Motorola/IBM PowerPC 750 or 750
44 At the moment, this command just tells GDB what to name the
45 special-purpose processor registers. Since almost all the affected
46 registers are inaccessible to user-level programs, this command is
47 only useful for remote debugging in its present form.
51 Thanks to a major code donation from HP, GDB now has much more
52 extensive support for HP-UX. Added features include shared library
53 support, kernel threads and hardware watchpoints for 11.00, support
54 for HP's ANSI C and C++ compilers, and compatibility mode for xdb
59 HP's donation includes the new concept of catchpoints, which is a
60 generalization of the old catch command. On HP-UX, it is now possible
61 to catch exec, fork, and vfork, as well as library loading.
63 * Debugging Across Forks
65 On HP-UX, you can choose which process to debug when a fork() happens
70 HP has donated a curses-based terminal user interface (TUI). To get
71 it, build with --enable-tui.
75 A new protocol packet 'X' that writes binary data is now available.
76 Default behavior is to try 'X', then drop back to 'M' if the stub
77 fails to respond. The settable variable `remotebinarydownload'
78 allows explicit control over the use of 'X'.
80 For 64 bit targets, the memory packets ("M" and "m") can now contain a
81 full 64 bit address. The class-obscure gdb command:
82 set targetaddresssize 32
83 can be used to revert to the old behavour. For existing remote stubs
84 the change should not be noticed as the additional address information
87 * Changes to particular targets
89 *** Changes in GDB-4.17:
91 * New native configurations
93 Alpha GNU/Linux alpha*-*-linux*
94 Unixware 2.x i[3456]86-unixware2*
95 Irix 6.x mips*-sgi-irix6*
96 PowerPC GNU/Linux powerpc-*-linux*
97 PowerPC Solaris powerpcle-*-solaris*
98 Sparc GNU/Linux sparc-*-linux*
99 Motorola sysV68 R3V7.1 m68k-motorola-sysv
103 Argonaut Risc Chip (ARC) arc-*-*
104 Hitachi H8/300S h8300*-*-*
105 Matsushita MN10200 w/simulator mn10200-*-*
106 Matsushita MN10300 w/simulator mn10300-*-*
107 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
108 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
109 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
110 Mitsubishi D10V w/simulator d10v-*-*
111 Mitsubishi M32R/D w/simulator m32r-*-elf*
112 Tsqware Sparclet sparclet-*-*
113 NEC V850 w/simulator v850-*-*
115 * New debugging protocols
117 ARM with RDI protocol arm*-*-*
118 M68K with dBUG monitor m68*-*-{aout,coff,elf}
119 DDB and LSI variants of PMON protocol mips*-*-*
120 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
121 PowerPC with SDS protocol powerpc{,le}-*-eabi
122 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
126 All configurations can now understand and use the DWARF 2 debugging
127 format. The choice is automatic, if the symbol file contains DWARF 2
133 GDB now includes basic Java language support. This support is
134 only useful with Java compilers that produce native machine code.
137 * solib-absolute-prefix and solib-search-path
139 For SunOS and SVR4 shared libraries, you may now set the prefix for
140 loading absolute shared library symbol files, and the search path for
141 locating non-absolute shared library symbol files.
143 * Live range splitting
145 GDB can now effectively debug code for which GCC has performed live
146 range splitting as part of its optimization. See gdb/doc/LRS for
147 more details on the expected format of the stabs information.
151 GDB's support for the GNU Hurd, including thread debugging, has been
152 updated to work with current versions of the Hurd.
156 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
157 instruction set. ARM GDB automatically detects when Thumb
158 instructions are in use, and adjusts disassembly and backtracing
163 GDB's MIPS target configurations now handle the MIP16 16-bit
168 GDB now includes support for overlays; if an executable has been
169 linked such that multiple sections are based at the same address, GDB
170 will decide which section to use for symbolic info. You can choose to
171 control the decision manually, using overlay commands, or implement
172 additional target-side support and use "overlay load-target" to bring
173 in the overlay mapping. Do "help overlay" for more detail.
177 The command "info symbol <address>" displays information about
178 the symbol at the specified address.
182 The standard remote protocol now includes an extension that allows
183 asynchronous collection and display of trace data. This requires
184 extensive support in the target-side debugging stub. Tracing mode
185 includes a new interaction mode in GDB and new commands: see the
186 file tracepoint.c for more details.
190 Configurations for embedded MIPS now include a simulator contributed
191 by Cygnus Solutions. The simulator supports the instruction sets
192 of most MIPS variants.
196 Sparc configurations may now include the ERC32 simulator contributed
197 by the European Space Agency. The simulator is not built into
198 Sparc targets by default; configure with --enable-sim to include it.
202 For target configurations that may include multiple variants of a
203 basic architecture (such as MIPS and SH), you may now set the
204 architecture explicitly. "set arch" sets, "info arch" lists
205 the possible architectures.
207 *** Changes in GDB-4.16:
209 * New native configurations
211 Windows 95, x86 Windows NT i[345]86-*-cygwin32
212 M68K NetBSD m68k-*-netbsd*
213 PowerPC AIX 4.x powerpc-*-aix*
214 PowerPC MacOS powerpc-*-macos*
215 PowerPC Windows NT powerpcle-*-cygwin32
216 RS/6000 AIX 4.x rs6000-*-aix4*
220 ARM with RDP protocol arm-*-*
221 I960 with MON960 i960-*-coff
222 MIPS VxWorks mips*-*-vxworks*
223 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
224 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
226 Matra Sparclet sparclet-*-*
230 The powerpc-eabi configuration now includes the PSIM simulator,
231 contributed by Andrew Cagney, with assistance from Mike Meissner.
232 PSIM is a very elaborate model of the PowerPC, including not only
233 basic instruction set execution, but also details of execution unit
234 performance and I/O hardware. See sim/ppc/README for more details.
238 GDB now works with Solaris 2.5.
240 * Windows 95/NT native
242 GDB will now work as a native debugger on Windows 95 and Windows NT.
243 To build it from source, you must use the "gnu-win32" environment,
244 which uses a DLL to emulate enough of Unix to run the GNU tools.
245 Further information, binaries, and sources are available at
246 ftp.cygnus.com, under pub/gnu-win32.
248 * dont-repeat command
250 If a user-defined command includes the command `dont-repeat', then the
251 command will not be repeated if the user just types return. This is
252 useful if the command is time-consuming to run, so that accidental
253 extra keystrokes don't run the same command many times.
255 * Send break instead of ^C
257 The standard remote protocol now includes an option to send a break
258 rather than a ^C to the target in order to interrupt it. By default,
259 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
261 * Remote protocol timeout
263 The standard remote protocol includes a new variable `remotetimeout'
264 that allows you to set the number of seconds before GDB gives up trying
265 to read from the target. The default value is 2.
267 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
269 By default GDB will automatically keep track of objects as they are
270 loaded and unloaded by the dynamic linker. By using the command `set
271 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
272 when shared library events occur, thus allowing you to set breakpoints
273 in shared libraries which are explicitly loaded by the inferior.
275 Note this feature does not work on hpux8. On hpux9 you must link
276 /usr/lib/end.o into your program. This feature should work
277 automatically on hpux10.
279 * Irix 5.x hardware watchpoint support
281 Irix 5 configurations now support the use of hardware watchpoints.
283 * Mips protocol "SYN garbage limit"
285 When debugging a Mips target using the `target mips' protocol, you
286 may set the number of characters that GDB will ignore by setting
287 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
288 every character. The default value is 1050.
290 * Recording and replaying remote debug sessions
292 If you set `remotelogfile' to the name of a file, gdb will write to it
293 a recording of a remote debug session. This recording may then be
294 replayed back to gdb using "gdbreplay". See gdbserver/README for
295 details. This is useful when you have a problem with GDB while doing
296 remote debugging; you can make a recording of the session and send it
297 to someone else, who can then recreate the problem.
299 * Speedups for remote debugging
301 GDB includes speedups for downloading and stepping MIPS systems using
302 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
303 and more efficient S-record downloading.
305 * Memory use reductions and statistics collection
307 GDB now uses less memory and reports statistics about memory usage.
308 Try the `maint print statistics' command, for example.
310 *** Changes in GDB-4.15:
314 The symbol reader for AIX GDB now uses partial symbol tables. This
315 can greatly improve startup time, especially for large executables.
317 * Remote targets use caching
319 Remote targets now use a data cache to speed up communication with the
320 remote side. The data cache could lead to incorrect results because
321 it doesn't know about volatile variables, thus making it impossible to
322 debug targets which use memory mapped I/O devices. `set remotecache
323 off' turns the the data cache off.
325 * Remote targets may have threads
327 The standard remote protocol now includes support for multiple threads
328 in the target system, using new protocol commands 'H' and 'T'. See
329 gdb/remote.c for details.
333 If GDB is configured with `--enable-netrom', then it will include
334 support for the NetROM ROM emulator from XLNT Designs. The NetROM
335 acts as though it is a bank of ROM on the target board, but you can
336 write into it over the network. GDB's support consists only of
337 support for fast loading into the emulated ROM; to debug, you must use
338 another protocol, such as standard remote protocol. The usual
339 sequence is something like
341 target nrom <netrom-hostname>
343 target remote <netrom-hostname>:1235
347 GDB now includes support for the Apple Macintosh, as a host only. It
348 may be run as either an MPW tool or as a standalone application, and
349 it can debug through the serial port. All the usual GDB commands are
350 available, but to the target command, you must supply "serial" as the
351 device type instead of "/dev/ttyXX". See mpw-README in the main
352 directory for more information on how to build. The MPW configuration
353 scripts */mpw-config.in support only a few targets, and only the
354 mips-idt-ecoff target has been tested.
358 GDB configuration now uses autoconf. This is not user-visible,
359 but does simplify configuration and building.
363 GDB now supports hpux10.
365 *** Changes in GDB-4.14:
367 * New native configurations
369 x86 FreeBSD i[345]86-*-freebsd
370 x86 NetBSD i[345]86-*-netbsd
371 NS32k NetBSD ns32k-*-netbsd
372 Sparc NetBSD sparc-*-netbsd
376 A29K VxWorks a29k-*-vxworks
377 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
378 CPU32 EST-300 emulator m68*-*-est*
379 PowerPC ELF powerpc-*-elf
382 * Alpha OSF/1 support for procfs
384 GDB now supports procfs under OSF/1-2.x and higher, which makes it
385 possible to attach to running processes. As the mounting of the /proc
386 filesystem is optional on the Alpha, GDB automatically determines
387 the availability of /proc during startup. This can lead to problems
388 if /proc is unmounted after GDB has been started.
390 * Arguments to user-defined commands
392 User commands may accept up to 10 arguments separated by whitespace.
393 Arguments are accessed within the user command via $arg0..$arg9. A
396 print $arg0 + $arg1 + $arg2
398 To execute the command use:
401 Defines the command "adder" which prints the sum of its three arguments.
402 Note the arguments are text substitutions, so they may reference variables,
403 use complex expressions, or even perform inferior function calls.
405 * New `if' and `while' commands
407 This makes it possible to write more sophisticated user-defined
408 commands. Both commands take a single argument, which is the
409 expression to evaluate, and must be followed by the commands to
410 execute, one per line, if the expression is nonzero, the list being
411 terminated by the word `end'. The `if' command list may include an
412 `else' word, which causes the following commands to be executed only
413 if the expression is zero.
415 * Fortran source language mode
417 GDB now includes partial support for Fortran 77. It will recognize
418 Fortran programs and can evaluate a subset of Fortran expressions, but
419 variables and functions may not be handled correctly. GDB will work
420 with G77, but does not yet know much about symbols emitted by other
423 * Better HPUX support
425 Most debugging facilities now work on dynamic executables for HPPAs
426 running hpux9 or later. You can attach to running dynamically linked
427 processes, but by default the dynamic libraries will be read-only, so
428 for instance you won't be able to put breakpoints in them. To change
429 that behavior do the following before running the program:
435 This will cause the libraries to be mapped private and read-write.
436 To revert to the normal behavior, do this:
442 You cannot set breakpoints or examine data in the library until after
443 the library is loaded if the function/data symbols do not have
446 GDB can now also read debug symbols produced by the HP C compiler on
447 HPPAs (sorry, no C++, Fortran or 68k support).
449 * Target byte order now dynamically selectable
451 You can choose which byte order to use with a target system, via the
452 commands "set endian big" and "set endian little", and you can see the
453 current setting by using "show endian". You can also give the command
454 "set endian auto", in which case GDB will use the byte order
455 associated with the executable. Currently, only embedded MIPS
456 configurations support dynamic selection of target byte order.
458 * New DOS host serial code
460 This version uses DPMI interrupts to handle buffered I/O, so you
461 no longer need to run asynctsr when debugging boards connected to
464 *** Changes in GDB-4.13:
466 * New "complete" command
468 This lists all the possible completions for the rest of the line, if it
469 were to be given as a command itself. This is intended for use by emacs.
471 * Trailing space optional in prompt
473 "set prompt" no longer adds a space for you after the prompt you set. This
474 allows you to set a prompt which ends in a space or one that does not.
476 * Breakpoint hit counts
478 "info break" now displays a count of the number of times the breakpoint
479 has been hit. This is especially useful in conjunction with "ignore"; you
480 can ignore a large number of breakpoint hits, look at the breakpoint info
481 to see how many times the breakpoint was hit, then run again, ignoring one
482 less than that number, and this will get you quickly to the last hit of
485 * Ability to stop printing at NULL character
487 "set print null-stop" will cause GDB to stop printing the characters of
488 an array when the first NULL is encountered. This is useful when large
489 arrays actually contain only short strings.
491 * Shared library breakpoints
493 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
494 breakpoints in shared libraries before the executable is run.
496 * Hardware watchpoints
498 There is a new hardware breakpoint for the watch command for sparclite
499 targets. See gdb/sparclite/hw_breakpoint.note.
501 Hardware watchpoints are also now supported under Linux.
505 Annotations have been added. These are for use with graphical interfaces,
506 and are still experimental. Currently only gdba.el uses these.
508 * Improved Irix 5 support
510 GDB now works properly with Irix 5.2.
512 * Improved HPPA support
514 GDB now works properly with the latest GCC and GAS.
516 * New native configurations
518 Sequent PTX4 i[34]86-sequent-ptx4
519 HPPA running OSF/1 hppa*-*-osf*
520 Atari TT running SVR4 m68*-*-sysv4*
521 RS/6000 LynxOS rs6000-*-lynxos*
525 OS/9000 i[34]86-*-os9k
526 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
529 * Hitachi SH7000 and E7000-PC ICE support
531 There is now support for communicating with the Hitachi E7000-PC ICE.
532 This is available automatically when GDB is configured for the SH.
536 As usual, a variety of small fixes and improvements, both generic
537 and configuration-specific. See the ChangeLog for more detail.
539 *** Changes in GDB-4.12:
541 * Irix 5 is now supported
545 GDB-4.12 on the HPPA has a number of changes which make it unable
546 to debug the output from the currently released versions of GCC and
547 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
548 of GCC and GAS, versions of these tools designed to work with GDB-4.12
549 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
552 *** Changes in GDB-4.11:
554 * User visible changes:
558 The "set remotedebug" option is now consistent between the mips remote
559 target, remote targets using the gdb-specific protocol, UDI (AMD's
560 debug protocol for the 29k) and the 88k bug monitor. It is now an
561 integer specifying a debug level (normally 0 or 1, but 2 means more
562 debugging info for the mips target).
564 * DEC Alpha native support
566 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
567 debug info, but GDB works fairly well with the DEC compiler and should
568 work with a future GCC release. See the README file for a few
569 Alpha-specific notes.
571 * Preliminary thread implementation
573 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
575 * LynxOS native and target support for 386
577 This release has been hosted on LynxOS 2.2, and also can be configured
578 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
581 * Improvements in C++ mangling/demangling.
583 This release has much better g++ debugging, specifically in name
584 mangling/demangling, virtual function calls, print virtual table,
585 call methods, ...etc.
587 *** Changes in GDB-4.10:
589 * User visible changes:
591 Remote debugging using the GDB-specific (`target remote') protocol now
592 supports the `load' command. This is only useful if you have some
593 other way of getting the stub to the target system, and you can put it
594 somewhere in memory where it won't get clobbered by the download.
596 Filename completion now works.
598 When run under emacs mode, the "info line" command now causes the
599 arrow to point to the line specified. Also, "info line" prints
600 addresses in symbolic form (as well as hex).
602 All vxworks based targets now support a user settable option, called
603 vxworks-timeout. This option represents the number of seconds gdb
604 should wait for responses to rpc's. You might want to use this if
605 your vxworks target is, perhaps, a slow software simulator or happens
606 to be on the far side of a thin network line.
610 This release contains support for using a DEC alpha as a GDB host for
611 cross debugging. Native alpha debugging is not supported yet.
614 *** Changes in GDB-4.9:
618 This is the first GDB release which is accompanied by a matching testsuite.
619 The testsuite requires installation of dejagnu, which should be available
620 via ftp from most sites that carry GNU software.
624 'Cfront' style demangling has had its name changed to 'ARM' style, to
625 emphasize that it was written from the specifications in the C++ Annotated
626 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
627 disclaimers, it still generated too much confusion with users attempting to
628 use gdb with AT&T cfront.
632 GDB now uses a standard remote interface to a simulator library.
633 So far, the library contains simulators for the Zilog Z8001/2, the
634 Hitachi H8/300, H8/500 and Super-H.
636 * New targets supported
638 H8/300 simulator h8300-hitachi-hms or h8300hms
639 H8/500 simulator h8500-hitachi-hms or h8500hms
640 SH simulator sh-hitachi-hms or sh
641 Z8000 simulator z8k-zilog-none or z8ksim
642 IDT MIPS board over serial line mips-idt-ecoff
644 Cross-debugging to GO32 targets is supported. It requires a custom
645 version of the i386-stub.c module which is integrated with the
646 GO32 memory extender.
648 * New remote protocols
650 MIPS remote debugging protocol.
652 * New source languages supported
654 This version includes preliminary support for Chill, a Pascal like language
655 used by telecommunications companies. Chill support is also being integrated
656 into the GNU compiler, but we don't know when it will be publically available.
659 *** Changes in GDB-4.8:
661 * HP Precision Architecture supported
663 GDB now supports HP PA-RISC machines running HPUX. A preliminary
664 version of this support was available as a set of patches from the
665 University of Utah. GDB does not support debugging of programs
666 compiled with the HP compiler, because HP will not document their file
667 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
668 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
670 Many problems in the preliminary version have been fixed.
672 * Faster and better demangling
674 We have improved template demangling and fixed numerous bugs in the GNU style
675 demangler. It can now handle type modifiers such as `static' or `const'. Wide
676 character types (wchar_t) are now supported. Demangling of each symbol is now
677 only done once, and is cached when the symbol table for a file is read in.
678 This results in a small increase in memory usage for C programs, a moderate
679 increase in memory usage for C++ programs, and a fantastic speedup in
682 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
683 from the specifications in the Annotated Reference Manual, which AT&T's
684 compiler does not actually implement.
686 * G++ multiple inheritance compiler problem
688 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
689 inheritance lattices was reworked to properly discover ambiguities. We
690 recently found an example which causes this new algorithm to fail in a
691 very subtle way, producing bad debug information for those classes.
692 The file 'gcc.patch' (in this directory) can be applied to gcc to
693 circumvent the problem. A future GCC release will contain a complete
696 The previous G++ debug info problem (mentioned below for the gdb-4.7
697 release) is fixed in gcc version 2.3.2.
699 * Improved configure script
701 The `configure' script will now attempt to guess your system type if
702 you don't supply a host system type. The old scheme of supplying a
703 host system triplet is preferable over using this. All the magic is
704 done in the new `config.guess' script. Examine it for details.
706 We have also brought our configure script much more in line with the FSF's
707 version. It now supports the --with-xxx options. In particular,
708 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
709 The resulting GDB will not be able to read arbitrary object file formats --
710 only the format ``expected'' to be used on the configured target system.
711 We hope to make this the default in a future release.
713 * Documentation improvements
715 There's new internal documentation on how to modify GDB, and how to
716 produce clean changes to the code. We implore people to read it
717 before submitting changes.
719 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
720 M4 macros. The new texinfo.tex is provided in this release. Pre-built
721 `info' files are also provided. To build `info' files from scratch,
722 you will need the latest `makeinfo' release, which will be available in
723 a future texinfo-X.Y release.
725 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
726 We're not sure exactly which versions have this problem, but it has
727 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
728 or better. If that isn't possible, there is a patch in
729 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
734 GDB now supports array constants that can be used in expressions typed in by
735 the user. The syntax is `{element, element, ...}'. Ie: you can now type
736 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
739 The new directory `gdb/sparclite' contains a program that demonstrates
740 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
742 * New native hosts supported
744 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
745 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
747 * New targets supported
749 AMD 29k family via UDI a29k-amd-udi or udi29k
751 * New file formats supported
753 BFD now supports reading HP/PA-RISC executables (SOM file format?),
754 HPUX core files, and SCO 3.2v2 core files.
758 Attaching to processes now works again; thanks for the many bug reports.
760 We have also stomped on a bunch of core dumps caused by
761 printf_filtered("%s") problems.
763 We eliminated a copyright problem on the rpc and ptrace header files
764 for VxWorks, which was discovered at the last minute during the 4.7
765 release. You should now be able to build a VxWorks GDB.
767 You can now interrupt gdb while an attached process is running. This
768 will cause the attached process to stop, and give control back to GDB.
770 We fixed problems caused by using too many file descriptors
771 for reading symbols from object files and libraries. This was
772 especially a problem for programs that used many (~100) shared
775 The `step' command now only enters a subroutine if there is line number
776 information for the subroutine. Otherwise it acts like the `next'
777 command. Previously, `step' would enter subroutines if there was
778 any debugging information about the routine. This avoids problems
779 when using `cc -g1' on MIPS machines.
781 * Internal improvements
783 GDB's internal interfaces have been improved to make it easier to support
784 debugging of multiple languages in the future.
786 GDB now uses a common structure for symbol information internally.
787 Minimal symbols (derived from linkage symbols in object files), partial
788 symbols (from a quick scan of debug information), and full symbols
789 contain a common subset of information, making it easier to write
790 shared code that handles any of them.
792 * New command line options
794 We now accept --silent as an alias for --quiet.
798 The memory-mapped-malloc library is now licensed under the GNU Library
799 General Public License.
801 *** Changes in GDB-4.7:
803 * Host/native/target split
805 GDB has had some major internal surgery to untangle the support for
806 hosts and remote targets. Now, when you configure GDB for a remote
807 target, it will no longer load in all of the support for debugging
808 local programs on the host. When fully completed and tested, this will
809 ensure that arbitrary host/target combinations are possible.
811 The primary conceptual shift is to separate the non-portable code in
812 GDB into three categories. Host specific code is required any time GDB
813 is compiled on that host, regardless of the target. Target specific
814 code relates to the peculiarities of the target, but can be compiled on
815 any host. Native specific code is everything else: it can only be
816 built when the host and target are the same system. Child process
817 handling and core file support are two common `native' examples.
819 GDB's use of /proc for controlling Unix child processes is now cleaner.
820 It has been split out into a single module under the `target_ops' vector,
821 plus two native-dependent functions for each system that uses /proc.
823 * New hosts supported
825 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
826 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
827 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
829 * New targets supported
831 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
832 68030 and CPU32 m68030-*-*, m68332-*-*
834 * New native hosts supported
836 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
837 (386bsd is not well tested yet)
838 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
840 * New file formats supported
842 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
843 supports reading of `a.out.adobe' object files, which are an a.out
844 format extended with minimal information about multiple sections.
848 `show copying' is the same as the old `info copying'.
849 `show warranty' is the same as `info warrantee'.
850 These were renamed for consistency. The old commands continue to work.
852 `info handle' is a new alias for `info signals'.
854 You can now define pre-command hooks, which attach arbitrary command
855 scripts to any command. The commands in the hook will be executed
856 prior to the user's command. You can also create a hook which will be
857 executed whenever the program stops. See gdb.texinfo.
861 We now deal with Cfront style name mangling, and can even extract type
862 info from mangled symbols. GDB can automatically figure out which
863 symbol mangling style your C++ compiler uses.
865 Calling of methods and virtual functions has been improved as well.
869 The crash that occured when debugging Sun Ansi-C compiled binaries is
870 fixed. This was due to mishandling of the extra N_SO stabs output
873 We also finally got Ultrix 4.2 running in house, and fixed core file
874 support, with help from a dozen people on the net.
876 John M. Farrell discovered that the reason that single-stepping was so
877 slow on all of the Mips based platforms (primarily SGI and DEC) was
878 that we were trying to demangle and lookup a symbol used for internal
879 purposes on every instruction that was being stepped through. Changing
880 the name of that symbol so that it couldn't be mistaken for a C++
881 mangled symbol sped things up a great deal.
883 Rich Pixley sped up symbol lookups in general by getting much smarter
884 about when C++ symbol mangling is necessary. This should make symbol
885 completion (TAB on the command line) much faster. It's not as fast as
886 we'd like, but it's significantly faster than gdb-4.6.
890 A new user controllable variable 'call_scratch_address' can
891 specify the location of a scratch area to be used when GDB
892 calls a function in the target. This is necessary because the
893 usual method of putting the scratch area on the stack does not work
894 in systems that have separate instruction and data spaces.
896 We integrated changes to support the 29k UDI (Universal Debugger
897 Interface), but discovered at the last minute that we didn't have all
898 of the appropriate copyright paperwork. We are working with AMD to
899 resolve this, and hope to have it available soon.
903 We have sped up the remote serial line protocol, especially for targets
904 with lots of registers. It now supports a new `expedited status' ('T')
905 message which can be used in place of the existing 'S' status message.
906 This allows the remote stub to send only the registers that GDB
907 needs to make a quick decision about single-stepping or conditional
908 breakpoints, eliminating the need to fetch the entire register set for
909 each instruction being stepped through.
911 The GDB remote serial protocol now implements a write-through cache for
912 registers, only re-reading the registers if the target has run.
914 There is also a new remote serial stub for SPARC processors. You can
915 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
916 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
917 processor with a serial port.
921 Configure.in files have become much easier to read and modify. A new
922 `table driven' format makes it more obvious what configurations are
923 supported, and what files each one uses.
927 There is a new opcodes library which will eventually contain all of the
928 disassembly routines and opcode tables. At present, it only contains
929 Sparc and Z8000 routines. This will allow the assembler, debugger, and
930 disassembler (binutils/objdump) to share these routines.
932 The libiberty library is now copylefted under the GNU Library General
933 Public License. This allows more liberal use, and was done so libg++
934 can use it. This makes no difference to GDB, since the Library License
935 grants all the rights from the General Public License.
939 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
940 reference to the stabs symbol info used by the debugger. It is (as far
941 as we know) the only published document on this fascinating topic. We
942 encourage you to read it, compare it to the stabs information on your
943 system, and send improvements on the document in general (to
944 bug-gdb@prep.ai.mit.edu).
946 And, of course, many bugs have been fixed.
949 *** Changes in GDB-4.6:
951 * Better support for C++ function names
953 GDB now accepts as input the "demangled form" of C++ overloaded function
954 names and member function names, and can do command completion on such names
955 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
956 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
957 Make use of command completion, it is your friend.
959 GDB also now accepts a variety of C++ mangled symbol formats. They are
960 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
961 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
962 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
963 for the list of formats.
965 * G++ symbol mangling problem
967 Recent versions of gcc have a bug in how they emit debugging information for
968 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
969 directory) can be applied to gcc to fix the problem. Alternatively, if you
970 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
971 usual symptom is difficulty with setting breakpoints on methods. GDB complains
972 about the method being non-existent. (We believe that version 2.2.2 of GCC has
975 * New 'maintenance' command
977 All of the commands related to hacking GDB internals have been moved out of
978 the main command set, and now live behind the 'maintenance' command. This
979 can also be abbreviated as 'mt'. The following changes were made:
981 dump-me -> maintenance dump-me
982 info all-breakpoints -> maintenance info breakpoints
983 printmsyms -> maintenance print msyms
984 printobjfiles -> maintenance print objfiles
985 printpsyms -> maintenance print psymbols
986 printsyms -> maintenance print symbols
988 The following commands are new:
990 maintenance demangle Call internal GDB demangler routine to
991 demangle a C++ link name and prints the result.
992 maintenance print type Print a type chain for a given symbol
994 * Change to .gdbinit file processing
996 We now read the $HOME/.gdbinit file before processing the argv arguments
997 (e.g. reading symbol files or core files). This allows global parameters to
998 be set, which will apply during the symbol reading. The ./.gdbinit is still
999 read after argv processing.
1001 * New hosts supported
1003 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
1005 Linux support i386-unknown-linux or linux
1007 We are also including code to support the HP/PA running BSD and HPUX. This
1008 is almost guaranteed not to work, as we didn't have time to test or build it
1009 for this release. We are including it so that the more adventurous (or
1010 masochistic) of you can play with it. We also had major problems with the
1011 fact that the compiler that we got from HP doesn't support the -g option.
1014 * New targets supported
1016 Hitachi H8/300 h8300-hitachi-hms or h8300hms
1018 * More smarts about finding #include files
1020 GDB now remembers the compilation directory for all include files, and for
1021 all files from which C is generated (like yacc and lex sources). This
1022 greatly improves GDB's ability to find yacc/lex sources, and include files,
1023 especially if you are debugging your program from a directory different from
1024 the one that contains your sources.
1026 We also fixed a bug which caused difficulty with listing and setting
1027 breakpoints in include files which contain C code. (In the past, you had to
1028 try twice in order to list an include file that you hadn't looked at before.)
1030 * Interesting infernals change
1032 GDB now deals with arbitrary numbers of sections, where the symbols for each
1033 section must be relocated relative to that section's landing place in the
1034 target's address space. This work was needed to support ELF with embedded
1035 stabs used by Solaris-2.0.
1037 * Bug fixes (of course!)
1039 There have been loads of fixes for the following things:
1040 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
1041 i960, stabs, DOS(GO32), procfs, etc...
1043 See the ChangeLog for details.
1045 *** Changes in GDB-4.5:
1047 * New machines supported (host and target)
1049 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
1051 SGI Irix-4.x mips-sgi-irix4 or iris4
1053 * New malloc package
1055 GDB now uses a new memory manager called mmalloc, based on gmalloc.
1056 Mmalloc is capable of handling mutiple heaps of memory. It is also
1057 capable of saving a heap to a file, and then mapping it back in later.
1058 This can be used to greatly speedup the startup of GDB by using a
1059 pre-parsed symbol table which lives in a mmalloc managed heap. For
1060 more details, please read mmalloc/mmalloc.texi.
1064 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
1065 'help info proc' for details.
1067 * MIPS ecoff symbol table format
1069 The code that reads MIPS symbol table format is now supported on all hosts.
1070 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
1073 * File name changes for MS-DOS
1075 Many files in the config directories have been renamed to make it easier to
1076 support GDB on MS-DOSe systems (which have very restrictive file name
1077 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
1078 environment) is close to working but has some remaining problems. Note
1079 that debugging of DOS programs is not supported, due to limitations
1080 in the ``operating system'', but it can be used to host cross-debugging.
1082 * Cross byte order fixes
1084 Many fixes have been made to support cross debugging of Sparc and MIPS
1085 targets from hosts whose byte order differs.
1087 * New -mapped and -readnow options
1089 If memory-mapped files are available on your system through the 'mmap'
1090 system call, you can use the -mapped option on the `file' or
1091 `symbol-file' commands to cause GDB to write the symbols from your
1092 program into a reusable file. If the program you are debugging is
1093 called `/path/fred', the mapped symbol file will be `./fred.syms'.
1094 Future GDB debugging sessions will notice the presence of this file,
1095 and will quickly map in symbol information from it, rather than reading
1096 the symbol table from the executable program. Using the '-mapped'
1097 option in a GDB `file' or `symbol-file' command has the same effect as
1098 starting GDB with the '-mapped' command-line option.
1100 You can cause GDB to read the entire symbol table immediately by using
1101 the '-readnow' option with any of the commands that load symbol table
1102 information (or on the GDB command line). This makes the command
1103 slower, but makes future operations faster.
1105 The -mapped and -readnow options are typically combined in order to
1106 build a `fred.syms' file that contains complete symbol information.
1107 A simple GDB invocation to do nothing but build a `.syms' file for future
1110 gdb -batch -nx -mapped -readnow programname
1112 The `.syms' file is specific to the host machine on which GDB is run.
1113 It holds an exact image of GDB's internal symbol table. It cannot be
1114 shared across multiple host platforms.
1116 * longjmp() handling
1118 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
1119 siglongjmp() without losing control. This feature has not yet been ported to
1120 all systems. It currently works on many 386 platforms, all MIPS-based
1121 platforms (SGI, DECstation, etc), and Sun3/4.
1125 Preliminary work has been put in to support the new Solaris OS from Sun. At
1126 this time, it can control and debug processes, but it is not capable of
1131 As always, many many bug fixes. The major areas were with g++, and mipsread.
1132 People using the MIPS-based platforms should experience fewer mysterious
1133 crashes and trashed symbol tables.
1135 *** Changes in GDB-4.4:
1137 * New machines supported (host and target)
1139 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
1141 BSD Reno on Vax vax-dec-bsd
1142 Ultrix on Vax vax-dec-ultrix
1144 * New machines supported (target)
1146 AMD 29000 embedded, using EBMON a29k-none-none
1150 GDB continues to improve its handling of C++. `References' work better.
1151 The demangler has also been improved, and now deals with symbols mangled as
1152 per the Annotated C++ Reference Guide.
1154 GDB also now handles `stabs' symbol information embedded in MIPS
1155 `ecoff' symbol tables. Since the ecoff format was not easily
1156 extensible to handle new languages such as C++, this appeared to be a
1157 good way to put C++ debugging info into MIPS binaries. This option
1158 will be supported in the GNU C compiler, version 2, when it is
1161 * New features for SVR4
1163 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
1164 shared libraries. Debugging dynamically linked programs should present
1165 only minor differences from debugging statically linked programs.
1167 The `info proc' command will print out information about any process
1168 on an SVR4 system (including the one you are debugging). At the moment,
1169 it prints the address mappings of the process.
1171 If you bring up GDB on another SVR4 system, please send mail to
1172 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
1174 * Better dynamic linking support in SunOS
1176 Reading symbols from shared libraries which contain debugging symbols
1177 now works properly. However, there remain issues such as automatic
1178 skipping of `transfer vector' code during function calls, which
1179 make it harder to debug code in a shared library, than to debug the
1180 same code linked statically.
1184 GDB is now using the latest `getopt' routines from the FSF. This
1185 version accepts the -- prefix for options with long names. GDB will
1186 continue to accept the old forms (-option and +option) as well.
1187 Various single letter abbreviations for options have been explicity
1188 added to the option table so that they won't get overshadowed in the
1189 future by other options that begin with the same letter.
1193 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
1194 Many assorted bugs have been handled. Many more remain to be handled.
1195 See the various ChangeLog files (primarily in gdb and bfd) for details.
1198 *** Changes in GDB-4.3:
1200 * New machines supported (host and target)
1202 Amiga 3000 running Amix m68k-cbm-svr4 or amix
1203 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
1204 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
1206 * Almost SCO Unix support
1208 We had hoped to support:
1209 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
1210 (except for core file support), but we discovered very late in the release
1211 that it has problems with process groups that render gdb unusable. Sorry
1212 about that. I encourage people to fix it and post the fixes.
1214 * Preliminary ELF and DWARF support
1216 GDB can read ELF object files on System V Release 4, and can handle
1217 debugging records for C, in DWARF format, in ELF files. This support
1218 is preliminary. If you bring up GDB on another SVR4 system, please
1219 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
1224 GDB now uses the latest `readline' library. One user-visible change
1225 is that two tabs will list possible command completions, which previously
1226 required typing M-? (meta-question mark, or ESC ?).
1230 The `stepi' bug that many of you noticed has been squashed.
1231 Many bugs in C++ have been handled. Many more remain to be handled.
1232 See the various ChangeLog files (primarily in gdb and bfd) for details.
1234 * State of the MIPS world (in case you wondered):
1236 GDB can understand the symbol tables emitted by the compilers
1237 supplied by most vendors of MIPS-based machines, including DEC. These
1238 symbol tables are in a format that essentially nobody else uses.
1240 Some versions of gcc come with an assembler post-processor called
1241 mips-tfile. This program is required if you want to do source-level
1242 debugging of gcc-compiled programs. I believe FSF does not ship
1243 mips-tfile with gcc version 1, but it will eventually come with gcc
1246 Debugging of g++ output remains a problem. g++ version 1.xx does not
1247 really support it at all. (If you're lucky, you should be able to get
1248 line numbers and stack traces to work, but no parameters or local
1249 variables.) With some work it should be possible to improve the
1252 When gcc version 2 is released, you will have somewhat better luck.
1253 However, even then you will get confusing results for inheritance and
1256 We will eventually provide full debugging of g++ output on
1257 DECstations. This will probably involve some kind of stabs-in-ecoff
1258 encapulation, but the details have not been worked out yet.
1261 *** Changes in GDB-4.2:
1263 * Improved configuration
1265 Only one copy of `configure' exists now, and it is not self-modifying.
1266 Porting BFD is simpler.
1270 The `step' and `next' commands now only stop at the first instruction
1271 of a source line. This prevents the multiple stops that used to occur
1272 in switch statements, for-loops, etc. `Step' continues to stop if a
1273 function that has debugging information is called within the line.
1277 Lots of small bugs fixed. More remain.
1279 * New host supported (not target)
1281 Intel 386 PC clone running Mach i386-none-mach
1284 *** Changes in GDB-4.1:
1286 * Multiple source language support
1288 GDB now has internal scaffolding to handle several source languages.
1289 It determines the type of each source file from its filename extension,
1290 and will switch expression parsing and number formatting to match the
1291 language of the function in the currently selected stack frame.
1292 You can also specifically set the language to be used, with
1293 `set language c' or `set language modula-2'.
1297 GDB now has preliminary support for the GNU Modula-2 compiler,
1298 currently under development at the State University of New York at
1299 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
1300 continue through the fall of 1991 and into 1992.
1302 Other Modula-2 compilers are currently not supported, and attempting to
1303 debug programs compiled with them will likely result in an error as the
1304 symbol table is read. Feel free to work on it, though!
1306 There are hooks in GDB for strict type checking and range checking,
1307 in the `Modula-2 philosophy', but they do not currently work.
1311 GDB can now write to executable and core files (e.g. patch
1312 a variable's value). You must turn this switch on, specify
1313 the file ("exec foo" or "core foo"), *then* modify it, e.g.
1314 by assigning a new value to a variable. Modifications take
1317 * Automatic SunOS shared library reading
1319 When you run your program, GDB automatically determines where its
1320 shared libraries (if any) have been loaded, and reads their symbols.
1321 The `share' command is no longer needed. This also works when
1322 examining core files.
1326 You can specify the number of lines that the `list' command shows.
1329 * New machines supported (host and target)
1331 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
1332 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
1333 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
1335 * New hosts supported (not targets)
1337 IBM RT/PC: romp-ibm-aix or rtpc
1339 * New targets supported (not hosts)
1341 AMD 29000 embedded with COFF a29k-none-coff
1342 AMD 29000 embedded with a.out a29k-none-aout
1343 Ultracomputer remote kernel debug a29k-nyu-kern
1345 * New remote interfaces
1351 *** Changes in GDB-4.0:
1355 Wide output is wrapped at good places to make the output more readable.
1357 Gdb now supports cross-debugging from a host machine of one type to a
1358 target machine of another type. Communication with the target system
1359 is over serial lines. The ``target'' command handles connecting to the
1360 remote system; the ``load'' command will download a program into the
1361 remote system. Serial stubs for the m68k and i386 are provided. Gdb
1362 also supports debugging of realtime processes running under VxWorks,
1363 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
1364 stub on the target system.
1366 New CPUs supported include the AMD 29000 and Intel 960.
1368 GDB now reads object files and symbol tables via a ``binary file''
1369 library, which allows a single copy of GDB to debug programs of multiple
1370 object file types such as a.out and coff.
1372 There is now a GDB reference card in "doc/refcard.tex". (Make targets
1373 refcard.dvi and refcard.ps are available to format it).
1376 * Control-Variable user interface simplified
1378 All variables that control the operation of the debugger can be set
1379 by the ``set'' command, and displayed by the ``show'' command.
1381 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
1382 ``Show prompt'' produces the response:
1383 Gdb's prompt is new-gdb=>.
1385 What follows are the NEW set commands. The command ``help set'' will
1386 print a complete list of old and new set commands. ``help set FOO''
1387 will give a longer description of the variable FOO. ``show'' will show
1388 all of the variable descriptions and their current settings.
1390 confirm on/off: Enables warning questions for operations that are
1391 hard to recover from, e.g. rerunning the program while
1392 it is already running. Default is ON.
1394 editing on/off: Enables EMACS style command line editing
1395 of input. Previous lines can be recalled with
1396 control-P, the current line can be edited with control-B,
1397 you can search for commands with control-R, etc.
1400 history filename NAME: NAME is where the gdb command history
1401 will be stored. The default is .gdb_history,
1402 or the value of the environment variable
1405 history size N: The size, in commands, of the command history. The
1406 default is 256, or the value of the environment variable
1409 history save on/off: If this value is set to ON, the history file will
1410 be saved after exiting gdb. If set to OFF, the
1411 file will not be saved. The default is OFF.
1413 history expansion on/off: If this value is set to ON, then csh-like
1414 history expansion will be performed on
1415 command line input. The default is OFF.
1417 radix N: Sets the default radix for input and output. It can be set
1418 to 8, 10, or 16. Note that the argument to "radix" is interpreted
1419 in the current radix, so "set radix 10" is always a no-op.
1421 height N: This integer value is the number of lines on a page. Default
1422 is 24, the current `stty rows'' setting, or the ``li#''
1423 setting from the termcap entry matching the environment
1426 width N: This integer value is the number of characters on a line.
1427 Default is 80, the current `stty cols'' setting, or the ``co#''
1428 setting from the termcap entry matching the environment
1431 Note: ``set screensize'' is obsolete. Use ``set height'' and
1432 ``set width'' instead.
1434 print address on/off: Print memory addresses in various command displays,
1435 such as stack traces and structure values. Gdb looks
1436 more ``symbolic'' if you turn this off; it looks more
1437 ``machine level'' with it on. Default is ON.
1439 print array on/off: Prettyprint arrays. New convenient format! Default
1442 print demangle on/off: Print C++ symbols in "source" form if on,
1445 print asm-demangle on/off: Same, for assembler level printouts
1448 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
1451 * Support for Epoch Environment.
1453 The epoch environment is a version of Emacs v18 with windowing. One
1454 new command, ``inspect'', is identical to ``print'', except that if you
1455 are running in the epoch environment, the value is printed in its own
1459 * Support for Shared Libraries
1461 GDB can now debug programs and core files that use SunOS shared libraries.
1462 Symbols from a shared library cannot be referenced
1463 before the shared library has been linked with the program (this
1464 happens after you type ``run'' and before the function main() is entered).
1465 At any time after this linking (including when examining core files
1466 from dynamically linked programs), gdb reads the symbols from each
1467 shared library when you type the ``sharedlibrary'' command.
1468 It can be abbreviated ``share''.
1470 sharedlibrary REGEXP: Load shared object library symbols for files
1471 matching a unix regular expression. No argument
1472 indicates to load symbols for all shared libraries.
1474 info sharedlibrary: Status of loaded shared libraries.
1479 A watchpoint stops execution of a program whenever the value of an
1480 expression changes. Checking for this slows down execution
1481 tremendously whenever you are in the scope of the expression, but is
1482 quite useful for catching tough ``bit-spreader'' or pointer misuse
1483 problems. Some machines such as the 386 have hardware for doing this
1484 more quickly, and future versions of gdb will use this hardware.
1486 watch EXP: Set a watchpoint (breakpoint) for an expression.
1488 info watchpoints: Information about your watchpoints.
1490 delete N: Deletes watchpoint number N (same as breakpoints).
1491 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
1492 enable N: Re-enables watchpoint number N (same as breakpoints).
1495 * C++ multiple inheritance
1497 When used with a GCC version 2 compiler, GDB supports multiple inheritance
1500 * C++ exception handling
1502 Gdb now supports limited C++ exception handling. Besides the existing
1503 ability to breakpoint on an exception handler, gdb can breakpoint on
1504 the raising of an exception (before the stack is peeled back to the
1507 catch FOO: If there is a FOO exception handler in the dynamic scope,
1508 set a breakpoint to catch exceptions which may be raised there.
1509 Multiple exceptions (``catch foo bar baz'') may be caught.
1511 info catch: Lists all exceptions which may be caught in the
1512 current stack frame.
1515 * Minor command changes
1517 The command ``call func (arg, arg, ...)'' now acts like the print
1518 command, except it does not print or save a value if the function's result
1519 is void. This is similar to dbx usage.
1521 The ``up'' and ``down'' commands now always print the frame they end up
1522 at; ``up-silently'' and `down-silently'' can be used in scripts to change
1523 frames without printing.
1525 * New directory command
1527 'dir' now adds directories to the FRONT of the source search path.
1528 The path starts off empty. Source files that contain debug information
1529 about the directory in which they were compiled can be found even
1530 with an empty path; Sun CC and GCC include this information. If GDB can't
1531 find your source file in the current directory, type "dir .".
1533 * Configuring GDB for compilation
1535 For normal use, type ``./configure host''. See README or gdb.texinfo
1538 GDB now handles cross debugging. If you are remotely debugging between
1539 two different machines, type ``./configure host -target=targ''.
1540 Host is the machine where GDB will run; targ is the machine
1541 where the program that you are debugging will run.