1 What has changed in GDB?
2 (Organized release by release)
4 *** Changes in GDB-4.17:
6 * New native configurations
8 Alpha GNU/Linux alpha*-*-linux*
9 Unixware 2.x i[3456]86-unixware2*
10 Irix 6.x mips*-sgi-irix6*
11 PowerPC GNU/Linux powerpc-*-linux*
12 PowerPC Solaris powerpcle-*-solaris*
13 Sparc GNU/Linux sparc-*-linux*
14 Motorola sysV68 R3V7.1 m68k-motorola-sysv
18 Argonaut Risc Chip (ARC) arc-*-*
19 Hitachi H8/300S h8300*-*-*
20 Matsushita MN10200 w/simulator mn10200-*-*
21 Matsushita MN10300 w/simulator mn10300-*-*
22 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
23 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
24 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
25 Mitsubishi D10V w/simulator d10v-*-*
26 Mitsubishi M32R/D w/simulator m32r-*-elf*
27 Tsqware Sparclet sparclet-*-*
28 NEC V850 w/simulator v850-*-*
30 * New debugging protocols
32 ARM with RDI protocol arm*-*-*
33 M68K with dBUG monitor m68*-*-{aout,coff,elf}
34 DDB and LSI variants of PMON protocol mips*-*-*
35 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
36 PowerPC with SDS protocol powerpc{,le}-*-eabi
37 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
41 All configurations can now understand and use the DWARF 2 debugging
42 format. The choice is automatic, if the symbol file contains DWARF 2
48 GDB now includes basic Java language support. This support is
49 only useful with Java compilers that produce native machine code.
52 * solib-absolute-prefix and solib-search-path
54 For SunOS and SVR4 shared libraries, you may now set the prefix for
55 loading absolute shared library symbol files, and the search path for
56 locating non-absolute shared library symbol files.
58 * Live range splitting
60 GDB can now effectively debug code for which GCC has performed live
61 range splitting as part of its optimization. See gdb/doc/LRS for
62 more details on the expected format of the stabs information.
66 GDB's support for the GNU Hurd, including thread debugging, has been
67 updated to work with current versions of the Hurd.
71 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
72 instruction set. ARM GDB automatically detects when Thumb
73 instructions are in use, and adjusts disassembly and backtracing
78 GDB's MIPS target configurations now handle the MIP16 16-bit
83 GDB now includes support for overlays; if an executable has been
84 linked such that multiple sections are based at the same address, GDB
85 will decide which section to use for symbolic info. You can choose to
86 control the decision manually, using overlay commands, or implement
87 additional target-side support and use "overlay load-target" to bring
88 in the overlay mapping. Do "help overlay" for more detail.
92 The command "info symbol <address>" displays information about
93 the symbol at the specified address.
97 The standard remote protocol now includes an extension that allows
98 asynchronous collection and display of trace data. This requires
99 extensive support in the target-side debugging stub. Tracing mode
100 includes a new interaction mode in GDB and new commands: see the
101 file tracepoint.c for more details.
105 Configurations for embedded MIPS now include a simulator contributed
106 by Cygnus Solutions. The simulator supports the instruction sets
107 of most MIPS variants.
111 Sparc configurations may now include the ERC32 simulator contributed
112 by the European Space Agency. The simulator is not built into
113 Sparc targets by default; configure with --enable-sim to include it.
117 For target configurations that may include multiple variants of a
118 basic architecture (such as MIPS and SH), you may now set the
119 architecture explicitly. "set arch" sets, "info arch" lists
120 the possible architectures.
122 *** Changes in GDB-4.16:
124 * New native configurations
126 Windows 95, x86 Windows NT i[345]86-*-cygwin32
127 M68K NetBSD m68k-*-netbsd*
128 PowerPC AIX 4.x powerpc-*-aix*
129 PowerPC MacOS powerpc-*-macos*
130 PowerPC Windows NT powerpcle-*-cygwin32
131 RS/6000 AIX 4.x rs6000-*-aix4*
135 ARM with RDP protocol arm-*-*
136 I960 with MON960 i960-*-coff
137 MIPS VxWorks mips*-*-vxworks*
138 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
139 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
141 Matra Sparclet sparclet-*-*
145 The powerpc-eabi configuration now includes the PSIM simulator,
146 contributed by Andrew Cagney, with assistance from Mike Meissner.
147 PSIM is a very elaborate model of the PowerPC, including not only
148 basic instruction set execution, but also details of execution unit
149 performance and I/O hardware. See sim/ppc/README for more details.
153 GDB now works with Solaris 2.5.
155 * Windows 95/NT native
157 GDB will now work as a native debugger on Windows 95 and Windows NT.
158 To build it from source, you must use the "gnu-win32" environment,
159 which uses a DLL to emulate enough of Unix to run the GNU tools.
160 Further information, binaries, and sources are available at
161 ftp.cygnus.com, under pub/gnu-win32.
163 * dont-repeat command
165 If a user-defined command includes the command `dont-repeat', then the
166 command will not be repeated if the user just types return. This is
167 useful if the command is time-consuming to run, so that accidental
168 extra keystrokes don't run the same command many times.
170 * Send break instead of ^C
172 The standard remote protocol now includes an option to send a break
173 rather than a ^C to the target in order to interrupt it. By default,
174 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
176 * Remote protocol timeout
178 The standard remote protocol includes a new variable `remotetimeout'
179 that allows you to set the number of seconds before GDB gives up trying
180 to read from the target. The default value is 2.
182 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
184 By default GDB will automatically keep track of objects as they are
185 loaded and unloaded by the dynamic linker. By using the command `set
186 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
187 when shared library events occur, thus allowing you to set breakpoints
188 in shared libraries which are explicitly loaded by the inferior.
190 Note this feature does not work on hpux8. On hpux9 you must link
191 /usr/lib/end.o into your program. This feature should work
192 automatically on hpux10.
194 * Irix 5.x hardware watchpoint support
196 Irix 5 configurations now support the use of hardware watchpoints.
198 * Mips protocol "SYN garbage limit"
200 When debugging a Mips target using the `target mips' protocol, you
201 may set the number of characters that GDB will ignore by setting
202 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
203 every character. The default value is 1050.
205 * Recording and replaying remote debug sessions
207 If you set `remotelogfile' to the name of a file, gdb will write to it
208 a recording of a remote debug session. This recording may then be
209 replayed back to gdb using "gdbreplay". See gdbserver/README for
210 details. This is useful when you have a problem with GDB while doing
211 remote debugging; you can make a recording of the session and send it
212 to someone else, who can then recreate the problem.
214 * Speedups for remote debugging
216 GDB includes speedups for downloading and stepping MIPS systems using
217 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
218 and more efficient S-record downloading.
220 * Memory use reductions and statistics collection
222 GDB now uses less memory and reports statistics about memory usage.
223 Try the `maint print statistics' command, for example.
225 *** Changes in GDB-4.15:
229 The symbol reader for AIX GDB now uses partial symbol tables. This
230 can greatly improve startup time, especially for large executables.
232 * Remote targets use caching
234 Remote targets now use a data cache to speed up communication with the
235 remote side. The data cache could lead to incorrect results because
236 it doesn't know about volatile variables, thus making it impossible to
237 debug targets which use memory mapped I/O devices. `set remotecache
238 off' turns the the data cache off.
240 * Remote targets may have threads
242 The standard remote protocol now includes support for multiple threads
243 in the target system, using new protocol commands 'H' and 'T'. See
244 gdb/remote.c for details.
248 If GDB is configured with `--enable-netrom', then it will include
249 support for the NetROM ROM emulator from XLNT Designs. The NetROM
250 acts as though it is a bank of ROM on the target board, but you can
251 write into it over the network. GDB's support consists only of
252 support for fast loading into the emulated ROM; to debug, you must use
253 another protocol, such as standard remote protocol. The usual
254 sequence is something like
256 target nrom <netrom-hostname>
258 target remote <netrom-hostname>:1235
262 GDB now includes support for the Apple Macintosh, as a host only. It
263 may be run as either an MPW tool or as a standalone application, and
264 it can debug through the serial port. All the usual GDB commands are
265 available, but to the target command, you must supply "serial" as the
266 device type instead of "/dev/ttyXX". See mpw-README in the main
267 directory for more information on how to build. The MPW configuration
268 scripts */mpw-config.in support only a few targets, and only the
269 mips-idt-ecoff target has been tested.
273 GDB configuration now uses autoconf. This is not user-visible,
274 but does simplify configuration and building.
278 GDB now supports hpux10.
280 *** Changes in GDB-4.14:
282 * New native configurations
284 x86 FreeBSD i[345]86-*-freebsd
285 x86 NetBSD i[345]86-*-netbsd
286 NS32k NetBSD ns32k-*-netbsd
287 Sparc NetBSD sparc-*-netbsd
291 A29K VxWorks a29k-*-vxworks
292 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
293 CPU32 EST-300 emulator m68*-*-est*
294 PowerPC ELF powerpc-*-elf
297 * Alpha OSF/1 support for procfs
299 GDB now supports procfs under OSF/1-2.x and higher, which makes it
300 possible to attach to running processes. As the mounting of the /proc
301 filesystem is optional on the Alpha, GDB automatically determines
302 the availability of /proc during startup. This can lead to problems
303 if /proc is unmounted after GDB has been started.
305 * Arguments to user-defined commands
307 User commands may accept up to 10 arguments separated by whitespace.
308 Arguments are accessed within the user command via $arg0..$arg9. A
311 print $arg0 + $arg1 + $arg2
313 To execute the command use:
316 Defines the command "adder" which prints the sum of its three arguments.
317 Note the arguments are text substitutions, so they may reference variables,
318 use complex expressions, or even perform inferior function calls.
320 * New `if' and `while' commands
322 This makes it possible to write more sophisticated user-defined
323 commands. Both commands take a single argument, which is the
324 expression to evaluate, and must be followed by the commands to
325 execute, one per line, if the expression is nonzero, the list being
326 terminated by the word `end'. The `if' command list may include an
327 `else' word, which causes the following commands to be executed only
328 if the expression is zero.
330 * Fortran source language mode
332 GDB now includes partial support for Fortran 77. It will recognize
333 Fortran programs and can evaluate a subset of Fortran expressions, but
334 variables and functions may not be handled correctly. GDB will work
335 with G77, but does not yet know much about symbols emitted by other
338 * Better HPUX support
340 Most debugging facilities now work on dynamic executables for HPPAs
341 running hpux9 or later. You can attach to running dynamically linked
342 processes, but by default the dynamic libraries will be read-only, so
343 for instance you won't be able to put breakpoints in them. To change
344 that behavior do the following before running the program:
350 This will cause the libraries to be mapped private and read-write.
351 To revert to the normal behavior, do this:
357 You cannot set breakpoints or examine data in the library until after
358 the library is loaded if the function/data symbols do not have
361 GDB can now also read debug symbols produced by the HP C compiler on
362 HPPAs (sorry, no C++, Fortran or 68k support).
364 * Target byte order now dynamically selectable
366 You can choose which byte order to use with a target system, via the
367 commands "set endian big" and "set endian little", and you can see the
368 current setting by using "show endian". You can also give the command
369 "set endian auto", in which case GDB will use the byte order
370 associated with the executable. Currently, only embedded MIPS
371 configurations support dynamic selection of target byte order.
373 * New DOS host serial code
375 This version uses DPMI interrupts to handle buffered I/O, so you
376 no longer need to run asynctsr when debugging boards connected to
379 *** Changes in GDB-4.13:
381 * New "complete" command
383 This lists all the possible completions for the rest of the line, if it
384 were to be given as a command itself. This is intended for use by emacs.
386 * Trailing space optional in prompt
388 "set prompt" no longer adds a space for you after the prompt you set. This
389 allows you to set a prompt which ends in a space or one that does not.
391 * Breakpoint hit counts
393 "info break" now displays a count of the number of times the breakpoint
394 has been hit. This is especially useful in conjunction with "ignore"; you
395 can ignore a large number of breakpoint hits, look at the breakpoint info
396 to see how many times the breakpoint was hit, then run again, ignoring one
397 less than that number, and this will get you quickly to the last hit of
400 * Ability to stop printing at NULL character
402 "set print null-stop" will cause GDB to stop printing the characters of
403 an array when the first NULL is encountered. This is useful when large
404 arrays actually contain only short strings.
406 * Shared library breakpoints
408 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
409 breakpoints in shared libraries before the executable is run.
411 * Hardware watchpoints
413 There is a new hardware breakpoint for the watch command for sparclite
414 targets. See gdb/sparclite/hw_breakpoint.note.
416 Hardware watchpoints are also now supported under Linux.
420 Annotations have been added. These are for use with graphical interfaces,
421 and are still experimental. Currently only gdba.el uses these.
423 * Improved Irix 5 support
425 GDB now works properly with Irix 5.2.
427 * Improved HPPA support
429 GDB now works properly with the latest GCC and GAS.
431 * New native configurations
433 Sequent PTX4 i[34]86-sequent-ptx4
434 HPPA running OSF/1 hppa*-*-osf*
435 Atari TT running SVR4 m68*-*-sysv4*
436 RS/6000 LynxOS rs6000-*-lynxos*
440 OS/9000 i[34]86-*-os9k
441 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
444 * Hitachi SH7000 and E7000-PC ICE support
446 There is now support for communicating with the Hitachi E7000-PC ICE.
447 This is available automatically when GDB is configured for the SH.
451 As usual, a variety of small fixes and improvements, both generic
452 and configuration-specific. See the ChangeLog for more detail.
454 *** Changes in GDB-4.12:
456 * Irix 5 is now supported
460 GDB-4.12 on the HPPA has a number of changes which make it unable
461 to debug the output from the currently released versions of GCC and
462 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
463 of GCC and GAS, versions of these tools designed to work with GDB-4.12
464 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
467 *** Changes in GDB-4.11:
469 * User visible changes:
473 The "set remotedebug" option is now consistent between the mips remote
474 target, remote targets using the gdb-specific protocol, UDI (AMD's
475 debug protocol for the 29k) and the 88k bug monitor. It is now an
476 integer specifying a debug level (normally 0 or 1, but 2 means more
477 debugging info for the mips target).
479 * DEC Alpha native support
481 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
482 debug info, but GDB works fairly well with the DEC compiler and should
483 work with a future GCC release. See the README file for a few
484 Alpha-specific notes.
486 * Preliminary thread implementation
488 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
490 * LynxOS native and target support for 386
492 This release has been hosted on LynxOS 2.2, and also can be configured
493 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
496 * Improvements in C++ mangling/demangling.
498 This release has much better g++ debugging, specifically in name
499 mangling/demangling, virtual function calls, print virtual table,
500 call methods, ...etc.
502 *** Changes in GDB-4.10:
504 * User visible changes:
506 Remote debugging using the GDB-specific (`target remote') protocol now
507 supports the `load' command. This is only useful if you have some
508 other way of getting the stub to the target system, and you can put it
509 somewhere in memory where it won't get clobbered by the download.
511 Filename completion now works.
513 When run under emacs mode, the "info line" command now causes the
514 arrow to point to the line specified. Also, "info line" prints
515 addresses in symbolic form (as well as hex).
517 All vxworks based targets now support a user settable option, called
518 vxworks-timeout. This option represents the number of seconds gdb
519 should wait for responses to rpc's. You might want to use this if
520 your vxworks target is, perhaps, a slow software simulator or happens
521 to be on the far side of a thin network line.
525 This release contains support for using a DEC alpha as a GDB host for
526 cross debugging. Native alpha debugging is not supported yet.
529 *** Changes in GDB-4.9:
533 This is the first GDB release which is accompanied by a matching testsuite.
534 The testsuite requires installation of dejagnu, which should be available
535 via ftp from most sites that carry GNU software.
539 'Cfront' style demangling has had its name changed to 'ARM' style, to
540 emphasize that it was written from the specifications in the C++ Annotated
541 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
542 disclaimers, it still generated too much confusion with users attempting to
543 use gdb with AT&T cfront.
547 GDB now uses a standard remote interface to a simulator library.
548 So far, the library contains simulators for the Zilog Z8001/2, the
549 Hitachi H8/300, H8/500 and Super-H.
551 * New targets supported
553 H8/300 simulator h8300-hitachi-hms or h8300hms
554 H8/500 simulator h8500-hitachi-hms or h8500hms
555 SH simulator sh-hitachi-hms or sh
556 Z8000 simulator z8k-zilog-none or z8ksim
557 IDT MIPS board over serial line mips-idt-ecoff
559 Cross-debugging to GO32 targets is supported. It requires a custom
560 version of the i386-stub.c module which is integrated with the
561 GO32 memory extender.
563 * New remote protocols
565 MIPS remote debugging protocol.
567 * New source languages supported
569 This version includes preliminary support for Chill, a Pascal like language
570 used by telecommunications companies. Chill support is also being integrated
571 into the GNU compiler, but we don't know when it will be publically available.
574 *** Changes in GDB-4.8:
576 * HP Precision Architecture supported
578 GDB now supports HP PA-RISC machines running HPUX. A preliminary
579 version of this support was available as a set of patches from the
580 University of Utah. GDB does not support debugging of programs
581 compiled with the HP compiler, because HP will not document their file
582 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
583 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
585 Many problems in the preliminary version have been fixed.
587 * Faster and better demangling
589 We have improved template demangling and fixed numerous bugs in the GNU style
590 demangler. It can now handle type modifiers such as `static' or `const'. Wide
591 character types (wchar_t) are now supported. Demangling of each symbol is now
592 only done once, and is cached when the symbol table for a file is read in.
593 This results in a small increase in memory usage for C programs, a moderate
594 increase in memory usage for C++ programs, and a fantastic speedup in
597 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
598 from the specifications in the Annotated Reference Manual, which AT&T's
599 compiler does not actually implement.
601 * G++ multiple inheritance compiler problem
603 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
604 inheritance lattices was reworked to properly discover ambiguities. We
605 recently found an example which causes this new algorithm to fail in a
606 very subtle way, producing bad debug information for those classes.
607 The file 'gcc.patch' (in this directory) can be applied to gcc to
608 circumvent the problem. A future GCC release will contain a complete
611 The previous G++ debug info problem (mentioned below for the gdb-4.7
612 release) is fixed in gcc version 2.3.2.
614 * Improved configure script
616 The `configure' script will now attempt to guess your system type if
617 you don't supply a host system type. The old scheme of supplying a
618 host system triplet is preferable over using this. All the magic is
619 done in the new `config.guess' script. Examine it for details.
621 We have also brought our configure script much more in line with the FSF's
622 version. It now supports the --with-xxx options. In particular,
623 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
624 The resulting GDB will not be able to read arbitrary object file formats --
625 only the format ``expected'' to be used on the configured target system.
626 We hope to make this the default in a future release.
628 * Documentation improvements
630 There's new internal documentation on how to modify GDB, and how to
631 produce clean changes to the code. We implore people to read it
632 before submitting changes.
634 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
635 M4 macros. The new texinfo.tex is provided in this release. Pre-built
636 `info' files are also provided. To build `info' files from scratch,
637 you will need the latest `makeinfo' release, which will be available in
638 a future texinfo-X.Y release.
640 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
641 We're not sure exactly which versions have this problem, but it has
642 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
643 or better. If that isn't possible, there is a patch in
644 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
649 GDB now supports array constants that can be used in expressions typed in by
650 the user. The syntax is `{element, element, ...}'. Ie: you can now type
651 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
654 The new directory `gdb/sparclite' contains a program that demonstrates
655 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
657 * New native hosts supported
659 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
660 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
662 * New targets supported
664 AMD 29k family via UDI a29k-amd-udi or udi29k
666 * New file formats supported
668 BFD now supports reading HP/PA-RISC executables (SOM file format?),
669 HPUX core files, and SCO 3.2v2 core files.
673 Attaching to processes now works again; thanks for the many bug reports.
675 We have also stomped on a bunch of core dumps caused by
676 printf_filtered("%s") problems.
678 We eliminated a copyright problem on the rpc and ptrace header files
679 for VxWorks, which was discovered at the last minute during the 4.7
680 release. You should now be able to build a VxWorks GDB.
682 You can now interrupt gdb while an attached process is running. This
683 will cause the attached process to stop, and give control back to GDB.
685 We fixed problems caused by using too many file descriptors
686 for reading symbols from object files and libraries. This was
687 especially a problem for programs that used many (~100) shared
690 The `step' command now only enters a subroutine if there is line number
691 information for the subroutine. Otherwise it acts like the `next'
692 command. Previously, `step' would enter subroutines if there was
693 any debugging information about the routine. This avoids problems
694 when using `cc -g1' on MIPS machines.
696 * Internal improvements
698 GDB's internal interfaces have been improved to make it easier to support
699 debugging of multiple languages in the future.
701 GDB now uses a common structure for symbol information internally.
702 Minimal symbols (derived from linkage symbols in object files), partial
703 symbols (from a quick scan of debug information), and full symbols
704 contain a common subset of information, making it easier to write
705 shared code that handles any of them.
707 * New command line options
709 We now accept --silent as an alias for --quiet.
713 The memory-mapped-malloc library is now licensed under the GNU Library
714 General Public License.
716 *** Changes in GDB-4.7:
718 * Host/native/target split
720 GDB has had some major internal surgery to untangle the support for
721 hosts and remote targets. Now, when you configure GDB for a remote
722 target, it will no longer load in all of the support for debugging
723 local programs on the host. When fully completed and tested, this will
724 ensure that arbitrary host/target combinations are possible.
726 The primary conceptual shift is to separate the non-portable code in
727 GDB into three categories. Host specific code is required any time GDB
728 is compiled on that host, regardless of the target. Target specific
729 code relates to the peculiarities of the target, but can be compiled on
730 any host. Native specific code is everything else: it can only be
731 built when the host and target are the same system. Child process
732 handling and core file support are two common `native' examples.
734 GDB's use of /proc for controlling Unix child processes is now cleaner.
735 It has been split out into a single module under the `target_ops' vector,
736 plus two native-dependent functions for each system that uses /proc.
738 * New hosts supported
740 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
741 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
742 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
744 * New targets supported
746 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
747 68030 and CPU32 m68030-*-*, m68332-*-*
749 * New native hosts supported
751 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
752 (386bsd is not well tested yet)
753 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
755 * New file formats supported
757 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
758 supports reading of `a.out.adobe' object files, which are an a.out
759 format extended with minimal information about multiple sections.
763 `show copying' is the same as the old `info copying'.
764 `show warranty' is the same as `info warrantee'.
765 These were renamed for consistency. The old commands continue to work.
767 `info handle' is a new alias for `info signals'.
769 You can now define pre-command hooks, which attach arbitrary command
770 scripts to any command. The commands in the hook will be executed
771 prior to the user's command. You can also create a hook which will be
772 executed whenever the program stops. See gdb.texinfo.
776 We now deal with Cfront style name mangling, and can even extract type
777 info from mangled symbols. GDB can automatically figure out which
778 symbol mangling style your C++ compiler uses.
780 Calling of methods and virtual functions has been improved as well.
784 The crash that occured when debugging Sun Ansi-C compiled binaries is
785 fixed. This was due to mishandling of the extra N_SO stabs output
788 We also finally got Ultrix 4.2 running in house, and fixed core file
789 support, with help from a dozen people on the net.
791 John M. Farrell discovered that the reason that single-stepping was so
792 slow on all of the Mips based platforms (primarily SGI and DEC) was
793 that we were trying to demangle and lookup a symbol used for internal
794 purposes on every instruction that was being stepped through. Changing
795 the name of that symbol so that it couldn't be mistaken for a C++
796 mangled symbol sped things up a great deal.
798 Rich Pixley sped up symbol lookups in general by getting much smarter
799 about when C++ symbol mangling is necessary. This should make symbol
800 completion (TAB on the command line) much faster. It's not as fast as
801 we'd like, but it's significantly faster than gdb-4.6.
805 A new user controllable variable 'call_scratch_address' can
806 specify the location of a scratch area to be used when GDB
807 calls a function in the target. This is necessary because the
808 usual method of putting the scratch area on the stack does not work
809 in systems that have separate instruction and data spaces.
811 We integrated changes to support the 29k UDI (Universal Debugger
812 Interface), but discovered at the last minute that we didn't have all
813 of the appropriate copyright paperwork. We are working with AMD to
814 resolve this, and hope to have it available soon.
818 We have sped up the remote serial line protocol, especially for targets
819 with lots of registers. It now supports a new `expedited status' ('T')
820 message which can be used in place of the existing 'S' status message.
821 This allows the remote stub to send only the registers that GDB
822 needs to make a quick decision about single-stepping or conditional
823 breakpoints, eliminating the need to fetch the entire register set for
824 each instruction being stepped through.
826 The GDB remote serial protocol now implements a write-through cache for
827 registers, only re-reading the registers if the target has run.
829 There is also a new remote serial stub for SPARC processors. You can
830 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
831 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
832 processor with a serial port.
836 Configure.in files have become much easier to read and modify. A new
837 `table driven' format makes it more obvious what configurations are
838 supported, and what files each one uses.
842 There is a new opcodes library which will eventually contain all of the
843 disassembly routines and opcode tables. At present, it only contains
844 Sparc and Z8000 routines. This will allow the assembler, debugger, and
845 disassembler (binutils/objdump) to share these routines.
847 The libiberty library is now copylefted under the GNU Library General
848 Public License. This allows more liberal use, and was done so libg++
849 can use it. This makes no difference to GDB, since the Library License
850 grants all the rights from the General Public License.
854 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
855 reference to the stabs symbol info used by the debugger. It is (as far
856 as we know) the only published document on this fascinating topic. We
857 encourage you to read it, compare it to the stabs information on your
858 system, and send improvements on the document in general (to
861 And, of course, many bugs have been fixed.
864 *** Changes in GDB-4.6:
866 * Better support for C++ function names
868 GDB now accepts as input the "demangled form" of C++ overloaded function
869 names and member function names, and can do command completion on such names
870 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
871 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
872 Make use of command completion, it is your friend.
874 GDB also now accepts a variety of C++ mangled symbol formats. They are
875 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
876 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
877 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
878 for the list of formats.
880 * G++ symbol mangling problem
882 Recent versions of gcc have a bug in how they emit debugging information for
883 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
884 directory) can be applied to gcc to fix the problem. Alternatively, if you
885 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
886 usual symptom is difficulty with setting breakpoints on methods. GDB complains
887 about the method being non-existent. (We believe that version 2.2.2 of GCC has
890 * New 'maintenance' command
892 All of the commands related to hacking GDB internals have been moved out of
893 the main command set, and now live behind the 'maintenance' command. This
894 can also be abbreviated as 'mt'. The following changes were made:
896 dump-me -> maintenance dump-me
897 info all-breakpoints -> maintenance info breakpoints
898 printmsyms -> maintenance print msyms
899 printobjfiles -> maintenance print objfiles
900 printpsyms -> maintenance print psymbols
901 printsyms -> maintenance print symbols
903 The following commands are new:
905 maintenance demangle Call internal GDB demangler routine to
906 demangle a C++ link name and prints the result.
907 maintenance print type Print a type chain for a given symbol
909 * Change to .gdbinit file processing
911 We now read the $HOME/.gdbinit file before processing the argv arguments
912 (e.g. reading symbol files or core files). This allows global parameters to
913 be set, which will apply during the symbol reading. The ./.gdbinit is still
914 read after argv processing.
916 * New hosts supported
918 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
920 Linux support i386-unknown-linux or linux
922 We are also including code to support the HP/PA running BSD and HPUX. This
923 is almost guaranteed not to work, as we didn't have time to test or build it
924 for this release. We are including it so that the more adventurous (or
925 masochistic) of you can play with it. We also had major problems with the
926 fact that the compiler that we got from HP doesn't support the -g option.
929 * New targets supported
931 Hitachi H8/300 h8300-hitachi-hms or h8300hms
933 * More smarts about finding #include files
935 GDB now remembers the compilation directory for all include files, and for
936 all files from which C is generated (like yacc and lex sources). This
937 greatly improves GDB's ability to find yacc/lex sources, and include files,
938 especially if you are debugging your program from a directory different from
939 the one that contains your sources.
941 We also fixed a bug which caused difficulty with listing and setting
942 breakpoints in include files which contain C code. (In the past, you had to
943 try twice in order to list an include file that you hadn't looked at before.)
945 * Interesting infernals change
947 GDB now deals with arbitrary numbers of sections, where the symbols for each
948 section must be relocated relative to that section's landing place in the
949 target's address space. This work was needed to support ELF with embedded
950 stabs used by Solaris-2.0.
952 * Bug fixes (of course!)
954 There have been loads of fixes for the following things:
955 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
956 i960, stabs, DOS(GO32), procfs, etc...
958 See the ChangeLog for details.
960 *** Changes in GDB-4.5:
962 * New machines supported (host and target)
964 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
966 SGI Irix-4.x mips-sgi-irix4 or iris4
970 GDB now uses a new memory manager called mmalloc, based on gmalloc.
971 Mmalloc is capable of handling mutiple heaps of memory. It is also
972 capable of saving a heap to a file, and then mapping it back in later.
973 This can be used to greatly speedup the startup of GDB by using a
974 pre-parsed symbol table which lives in a mmalloc managed heap. For
975 more details, please read mmalloc/mmalloc.texi.
979 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
980 'help info proc' for details.
982 * MIPS ecoff symbol table format
984 The code that reads MIPS symbol table format is now supported on all hosts.
985 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
988 * File name changes for MS-DOS
990 Many files in the config directories have been renamed to make it easier to
991 support GDB on MS-DOSe systems (which have very restrictive file name
992 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
993 environment) is close to working but has some remaining problems. Note
994 that debugging of DOS programs is not supported, due to limitations
995 in the ``operating system'', but it can be used to host cross-debugging.
997 * Cross byte order fixes
999 Many fixes have been made to support cross debugging of Sparc and MIPS
1000 targets from hosts whose byte order differs.
1002 * New -mapped and -readnow options
1004 If memory-mapped files are available on your system through the 'mmap'
1005 system call, you can use the -mapped option on the `file' or
1006 `symbol-file' commands to cause GDB to write the symbols from your
1007 program into a reusable file. If the program you are debugging is
1008 called `/path/fred', the mapped symbol file will be `./fred.syms'.
1009 Future GDB debugging sessions will notice the presence of this file,
1010 and will quickly map in symbol information from it, rather than reading
1011 the symbol table from the executable program. Using the '-mapped'
1012 option in a GDB `file' or `symbol-file' command has the same effect as
1013 starting GDB with the '-mapped' command-line option.
1015 You can cause GDB to read the entire symbol table immediately by using
1016 the '-readnow' option with any of the commands that load symbol table
1017 information (or on the GDB command line). This makes the command
1018 slower, but makes future operations faster.
1020 The -mapped and -readnow options are typically combined in order to
1021 build a `fred.syms' file that contains complete symbol information.
1022 A simple GDB invocation to do nothing but build a `.syms' file for future
1025 gdb -batch -nx -mapped -readnow programname
1027 The `.syms' file is specific to the host machine on which GDB is run.
1028 It holds an exact image of GDB's internal symbol table. It cannot be
1029 shared across multiple host platforms.
1031 * longjmp() handling
1033 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
1034 siglongjmp() without losing control. This feature has not yet been ported to
1035 all systems. It currently works on many 386 platforms, all MIPS-based
1036 platforms (SGI, DECstation, etc), and Sun3/4.
1040 Preliminary work has been put in to support the new Solaris OS from Sun. At
1041 this time, it can control and debug processes, but it is not capable of
1046 As always, many many bug fixes. The major areas were with g++, and mipsread.
1047 People using the MIPS-based platforms should experience fewer mysterious
1048 crashes and trashed symbol tables.
1050 *** Changes in GDB-4.4:
1052 * New machines supported (host and target)
1054 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
1056 BSD Reno on Vax vax-dec-bsd
1057 Ultrix on Vax vax-dec-ultrix
1059 * New machines supported (target)
1061 AMD 29000 embedded, using EBMON a29k-none-none
1065 GDB continues to improve its handling of C++. `References' work better.
1066 The demangler has also been improved, and now deals with symbols mangled as
1067 per the Annotated C++ Reference Guide.
1069 GDB also now handles `stabs' symbol information embedded in MIPS
1070 `ecoff' symbol tables. Since the ecoff format was not easily
1071 extensible to handle new languages such as C++, this appeared to be a
1072 good way to put C++ debugging info into MIPS binaries. This option
1073 will be supported in the GNU C compiler, version 2, when it is
1076 * New features for SVR4
1078 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
1079 shared libraries. Debugging dynamically linked programs should present
1080 only minor differences from debugging statically linked programs.
1082 The `info proc' command will print out information about any process
1083 on an SVR4 system (including the one you are debugging). At the moment,
1084 it prints the address mappings of the process.
1086 If you bring up GDB on another SVR4 system, please send mail to
1089 * Better dynamic linking support in SunOS
1091 Reading symbols from shared libraries which contain debugging symbols
1092 now works properly. However, there remain issues such as automatic
1093 skipping of `transfer vector' code during function calls, which
1094 make it harder to debug code in a shared library, than to debug the
1095 same code linked statically.
1099 GDB is now using the latest `getopt' routines from the FSF. This
1100 version accepts the -- prefix for options with long names. GDB will
1101 continue to accept the old forms (-option and +option) as well.
1102 Various single letter abbreviations for options have been explicity
1103 added to the option table so that they won't get overshadowed in the
1104 future by other options that begin with the same letter.
1108 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
1109 Many assorted bugs have been handled. Many more remain to be handled.
1110 See the various ChangeLog files (primarily in gdb and bfd) for details.
1113 *** Changes in GDB-4.3:
1115 * New machines supported (host and target)
1117 Amiga 3000 running Amix m68k-cbm-svr4 or amix
1118 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
1119 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
1121 * Almost SCO Unix support
1123 We had hoped to support:
1124 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
1125 (except for core file support), but we discovered very late in the release
1126 that it has problems with process groups that render gdb unusable. Sorry
1127 about that. I encourage people to fix it and post the fixes.
1129 * Preliminary ELF and DWARF support
1131 GDB can read ELF object files on System V Release 4, and can handle
1132 debugging records for C, in DWARF format, in ELF files. This support
1133 is preliminary. If you bring up GDB on another SVR4 system, please
1139 GDB now uses the latest `readline' library. One user-visible change
1140 is that two tabs will list possible command completions, which previously
1141 required typing M-? (meta-question mark, or ESC ?).
1145 The `stepi' bug that many of you noticed has been squashed.
1146 Many bugs in C++ have been handled. Many more remain to be handled.
1147 See the various ChangeLog files (primarily in gdb and bfd) for details.
1149 * State of the MIPS world (in case you wondered):
1151 GDB can understand the symbol tables emitted by the compilers
1152 supplied by most vendors of MIPS-based machines, including DEC. These
1153 symbol tables are in a format that essentially nobody else uses.
1155 Some versions of gcc come with an assembler post-processor called
1156 mips-tfile. This program is required if you want to do source-level
1157 debugging of gcc-compiled programs. I believe FSF does not ship
1158 mips-tfile with gcc version 1, but it will eventually come with gcc
1161 Debugging of g++ output remains a problem. g++ version 1.xx does not
1162 really support it at all. (If you're lucky, you should be able to get
1163 line numbers and stack traces to work, but no parameters or local
1164 variables.) With some work it should be possible to improve the
1167 When gcc version 2 is released, you will have somewhat better luck.
1168 However, even then you will get confusing results for inheritance and
1171 We will eventually provide full debugging of g++ output on
1172 DECstations. This will probably involve some kind of stabs-in-ecoff
1173 encapulation, but the details have not been worked out yet.
1176 *** Changes in GDB-4.2:
1178 * Improved configuration
1180 Only one copy of `configure' exists now, and it is not self-modifying.
1181 Porting BFD is simpler.
1185 The `step' and `next' commands now only stop at the first instruction
1186 of a source line. This prevents the multiple stops that used to occur
1187 in switch statements, for-loops, etc. `Step' continues to stop if a
1188 function that has debugging information is called within the line.
1192 Lots of small bugs fixed. More remain.
1194 * New host supported (not target)
1196 Intel 386 PC clone running Mach i386-none-mach
1199 *** Changes in GDB-4.1:
1201 * Multiple source language support
1203 GDB now has internal scaffolding to handle several source languages.
1204 It determines the type of each source file from its filename extension,
1205 and will switch expression parsing and number formatting to match the
1206 language of the function in the currently selected stack frame.
1207 You can also specifically set the language to be used, with
1208 `set language c' or `set language modula-2'.
1212 GDB now has preliminary support for the GNU Modula-2 compiler,
1213 currently under development at the State University of New York at
1214 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
1215 continue through the fall of 1991 and into 1992.
1217 Other Modula-2 compilers are currently not supported, and attempting to
1218 debug programs compiled with them will likely result in an error as the
1219 symbol table is read. Feel free to work on it, though!
1221 There are hooks in GDB for strict type checking and range checking,
1222 in the `Modula-2 philosophy', but they do not currently work.
1226 GDB can now write to executable and core files (e.g. patch
1227 a variable's value). You must turn this switch on, specify
1228 the file ("exec foo" or "core foo"), *then* modify it, e.g.
1229 by assigning a new value to a variable. Modifications take
1232 * Automatic SunOS shared library reading
1234 When you run your program, GDB automatically determines where its
1235 shared libraries (if any) have been loaded, and reads their symbols.
1236 The `share' command is no longer needed. This also works when
1237 examining core files.
1241 You can specify the number of lines that the `list' command shows.
1244 * New machines supported (host and target)
1246 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
1247 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
1248 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
1250 * New hosts supported (not targets)
1252 IBM RT/PC: romp-ibm-aix or rtpc
1254 * New targets supported (not hosts)
1256 AMD 29000 embedded with COFF a29k-none-coff
1257 AMD 29000 embedded with a.out a29k-none-aout
1258 Ultracomputer remote kernel debug a29k-nyu-kern
1260 * New remote interfaces
1266 *** Changes in GDB-4.0:
1270 Wide output is wrapped at good places to make the output more readable.
1272 Gdb now supports cross-debugging from a host machine of one type to a
1273 target machine of another type. Communication with the target system
1274 is over serial lines. The ``target'' command handles connecting to the
1275 remote system; the ``load'' command will download a program into the
1276 remote system. Serial stubs for the m68k and i386 are provided. Gdb
1277 also supports debugging of realtime processes running under VxWorks,
1278 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
1279 stub on the target system.
1281 New CPUs supported include the AMD 29000 and Intel 960.
1283 GDB now reads object files and symbol tables via a ``binary file''
1284 library, which allows a single copy of GDB to debug programs of multiple
1285 object file types such as a.out and coff.
1287 There is now a GDB reference card in "doc/refcard.tex". (Make targets
1288 refcard.dvi and refcard.ps are available to format it).
1291 * Control-Variable user interface simplified
1293 All variables that control the operation of the debugger can be set
1294 by the ``set'' command, and displayed by the ``show'' command.
1296 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
1297 ``Show prompt'' produces the response:
1298 Gdb's prompt is new-gdb=>.
1300 What follows are the NEW set commands. The command ``help set'' will
1301 print a complete list of old and new set commands. ``help set FOO''
1302 will give a longer description of the variable FOO. ``show'' will show
1303 all of the variable descriptions and their current settings.
1305 confirm on/off: Enables warning questions for operations that are
1306 hard to recover from, e.g. rerunning the program while
1307 it is already running. Default is ON.
1309 editing on/off: Enables EMACS style command line editing
1310 of input. Previous lines can be recalled with
1311 control-P, the current line can be edited with control-B,
1312 you can search for commands with control-R, etc.
1315 history filename NAME: NAME is where the gdb command history
1316 will be stored. The default is .gdb_history,
1317 or the value of the environment variable
1320 history size N: The size, in commands, of the command history. The
1321 default is 256, or the value of the environment variable
1324 history save on/off: If this value is set to ON, the history file will
1325 be saved after exiting gdb. If set to OFF, the
1326 file will not be saved. The default is OFF.
1328 history expansion on/off: If this value is set to ON, then csh-like
1329 history expansion will be performed on
1330 command line input. The default is OFF.
1332 radix N: Sets the default radix for input and output. It can be set
1333 to 8, 10, or 16. Note that the argument to "radix" is interpreted
1334 in the current radix, so "set radix 10" is always a no-op.
1336 height N: This integer value is the number of lines on a page. Default
1337 is 24, the current `stty rows'' setting, or the ``li#''
1338 setting from the termcap entry matching the environment
1341 width N: This integer value is the number of characters on a line.
1342 Default is 80, the current `stty cols'' setting, or the ``co#''
1343 setting from the termcap entry matching the environment
1346 Note: ``set screensize'' is obsolete. Use ``set height'' and
1347 ``set width'' instead.
1349 print address on/off: Print memory addresses in various command displays,
1350 such as stack traces and structure values. Gdb looks
1351 more ``symbolic'' if you turn this off; it looks more
1352 ``machine level'' with it on. Default is ON.
1354 print array on/off: Prettyprint arrays. New convenient format! Default
1357 print demangle on/off: Print C++ symbols in "source" form if on,
1360 print asm-demangle on/off: Same, for assembler level printouts
1363 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
1366 * Support for Epoch Environment.
1368 The epoch environment is a version of Emacs v18 with windowing. One
1369 new command, ``inspect'', is identical to ``print'', except that if you
1370 are running in the epoch environment, the value is printed in its own
1374 * Support for Shared Libraries
1376 GDB can now debug programs and core files that use SunOS shared libraries.
1377 Symbols from a shared library cannot be referenced
1378 before the shared library has been linked with the program (this
1379 happens after you type ``run'' and before the function main() is entered).
1380 At any time after this linking (including when examining core files
1381 from dynamically linked programs), gdb reads the symbols from each
1382 shared library when you type the ``sharedlibrary'' command.
1383 It can be abbreviated ``share''.
1385 sharedlibrary REGEXP: Load shared object library symbols for files
1386 matching a unix regular expression. No argument
1387 indicates to load symbols for all shared libraries.
1389 info sharedlibrary: Status of loaded shared libraries.
1394 A watchpoint stops execution of a program whenever the value of an
1395 expression changes. Checking for this slows down execution
1396 tremendously whenever you are in the scope of the expression, but is
1397 quite useful for catching tough ``bit-spreader'' or pointer misuse
1398 problems. Some machines such as the 386 have hardware for doing this
1399 more quickly, and future versions of gdb will use this hardware.
1401 watch EXP: Set a watchpoint (breakpoint) for an expression.
1403 info watchpoints: Information about your watchpoints.
1405 delete N: Deletes watchpoint number N (same as breakpoints).
1406 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
1407 enable N: Re-enables watchpoint number N (same as breakpoints).
1410 * C++ multiple inheritance
1412 When used with a GCC version 2 compiler, GDB supports multiple inheritance
1415 * C++ exception handling
1417 Gdb now supports limited C++ exception handling. Besides the existing
1418 ability to breakpoint on an exception handler, gdb can breakpoint on
1419 the raising of an exception (before the stack is peeled back to the
1422 catch FOO: If there is a FOO exception handler in the dynamic scope,
1423 set a breakpoint to catch exceptions which may be raised there.
1424 Multiple exceptions (``catch foo bar baz'') may be caught.
1426 info catch: Lists all exceptions which may be caught in the
1427 current stack frame.
1430 * Minor command changes
1432 The command ``call func (arg, arg, ...)'' now acts like the print
1433 command, except it does not print or save a value if the function's result
1434 is void. This is similar to dbx usage.
1436 The ``up'' and ``down'' commands now always print the frame they end up
1437 at; ``up-silently'' and `down-silently'' can be used in scripts to change
1438 frames without printing.
1440 * New directory command
1442 'dir' now adds directories to the FRONT of the source search path.
1443 The path starts off empty. Source files that contain debug information
1444 about the directory in which they were compiled can be found even
1445 with an empty path; Sun CC and GCC include this information. If GDB can't
1446 find your source file in the current directory, type "dir .".
1448 * Configuring GDB for compilation
1450 For normal use, type ``./configure host''. See README or gdb.texinfo
1453 GDB now handles cross debugging. If you are remotely debugging between
1454 two different machines, type ``./configure host -target=targ''.
1455 Host is the machine where GDB will run; targ is the machine
1456 where the program that you are debugging will run.