1 What has changed in GDB?
2 (Organized release by release)
4 *** Changes since GDB 5.0:
6 * New native configurations
8 Alpha FreeBSD alpha*-*-freebsd*
9 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
11 FreeBSD versions before 2.2 are no longer supported.
13 *** Changes in GDB 5.0:
15 * Improved support for debugging FP programs on x86 targets
17 Unified and much-improved support for debugging floating-point
18 programs on all x86 targets. In particular, ``info float'' now
19 displays the FP registers in the same format on all x86 targets, with
20 greater level of detail.
22 * Improvements and bugfixes in hardware-assisted watchpoints
24 It is now possible to watch array elements, struct members, and
25 bitfields with hardware-assisted watchpoints. Data-read watchpoints
26 on x86 targets no longer erroneously trigger when the address is
29 * Improvements in the native DJGPP version of GDB
31 The distribution now includes all the scripts and auxiliary files
32 necessary to build the native DJGPP version on MS-DOS/MS-Windows
33 machines ``out of the box''.
35 The DJGPP version can now debug programs that use signals. It is
36 possible to catch signals that happened in the debuggee, deliver
37 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
38 would kill the program being debugged.) Programs that hook hardware
39 interrupts (keyboard, timer, etc.) can also be debugged.
41 It is now possible to debug DJGPP programs that redirect their
42 standard handles or switch them to raw (as opposed to cooked) mode, or
43 even close them. The command ``run < foo > bar'' works as expected,
44 and ``info terminal'' reports useful information about the debuggee's
45 terminal, including raw/cooked mode, redirection, etc.
47 The DJGPP version now uses termios functions for console I/O, which
48 enables debugging graphics programs. Interrupting GDB with Ctrl-C
51 DOS-style file names with drive letters are now fully supported by
54 It is now possible to debug DJGPP programs that switch their working
55 directory. It is also possible to rerun the debuggee any number of
56 times without restarting GDB; thus, you can use the same setup,
57 breakpoints, etc. for many debugging sessions.
59 * New native configurations
61 ARM GNU/Linux arm*-*-linux*
62 PowerPC GNU/Linux powerpc-*-linux*
66 Motorola MCore mcore-*-*
67 x86 VxWorks i[3456]86-*-vxworks*
68 PowerPC VxWorks powerpc-*-vxworks*
69 TI TMS320C80 tic80-*-*
71 * OBSOLETE configurations
73 Altos 3068 m68*-altos-*
76 ARM RISCix arm-*-* (as host)
79 Configurations that have been declared obsolete will be commented out,
80 but the code will be left in place. If there is no activity to revive
81 these configurations before the next release of GDB, the sources will
82 be permanently REMOVED.
84 * Gould support removed
86 Support for the Gould PowerNode and NP1 has been removed.
88 * New features for SVR4
90 On SVR4 native platforms (such as Solaris), if you attach to a process
91 without first loading a symbol file, GDB will now attempt to locate and
92 load symbols from the running process's executable file.
94 * Many C++ enhancements
96 C++ support has been greatly improved. Overload resolution now works properly
97 in almost all cases. RTTI support is on the way.
99 * Remote targets can connect to a sub-program
101 A popen(3) style serial-device has been added. This device starts a
102 sub-process (such as a stand-alone simulator) and then communicates
103 with that. The sub-program to run is specified using the syntax
104 ``|<program> <args>'' vis:
106 (gdb) set remotedebug 1
107 (gdb) target extended-remote |mn10300-elf-sim program-args
109 * MIPS 64 remote protocol
111 A long standing bug in the mips64 remote protocol where by GDB
112 expected certain 32 bit registers (ex SR) to be transfered as 32
113 instead of 64 bits has been fixed.
115 The command ``set remote-mips64-transfers-32bit-regs on'' has been
116 added to provide backward compatibility with older versions of GDB.
118 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
120 The command ``set remotebinarydownload'' command has been replaced by
121 ``set remote X-packet''. Other commands in ``set remote'' family
122 include ``set remote P-packet''.
124 * Breakpoint commands accept ranges.
126 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
127 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
128 ``tracepoint passcount'' also accepts a range of tracepoints.
130 * ``apropos'' command added.
132 The ``apropos'' command searches through command names and
133 documentation strings, printing out matches, making it much easier to
134 try to find a command that does what you are looking for.
138 A new machine oriented interface (MI) has been added to GDB. This
139 interface is designed for debug environments running GDB as a separate
140 process. This is part of the long term libGDB project. See the
141 "GDB/MI" chapter of the GDB manual for further information. It can be
142 enabled by configuring with:
144 .../configure --enable-gdbmi
146 *** Changes in GDB-4.18:
148 * New native configurations
150 HP-UX 10.20 hppa*-*-hpux10.20
151 HP-UX 11.x hppa*-*-hpux11.0*
152 M68K Linux m68*-*-linux*
156 Fujitsu FR30 fr30-*-elf*
157 Intel StrongARM strongarm-*-*
158 Mitsubishi D30V d30v-*-*
160 * OBSOLETE configurations
162 Gould PowerNode, NP1 np1-*-*, pn-*-*
164 Configurations that have been declared obsolete will be commented out,
165 but the code will be left in place. If there is no activity to revive
166 these configurations before the next release of GDB, the sources will
167 be permanently REMOVED.
171 As a compatibility experiment, GDB's source files buildsym.h and
172 buildsym.c have been converted to pure standard C, no longer
173 containing any K&R compatibility code. We believe that all systems in
174 use today either come with a standard C compiler, or have a GCC port
175 available. If this is not true, please report the affected
176 configuration to bug-gdb@gnu.org immediately. See the README file for
177 information about getting a standard C compiler if you don't have one
182 GDB now uses readline 2.2.
184 * set extension-language
186 You can now control the mapping between filename extensions and source
187 languages by using the `set extension-language' command. For instance,
188 you can ask GDB to treat .c files as C++ by saying
189 set extension-language .c c++
190 The command `info extensions' lists all of the recognized extensions
191 and their associated languages.
193 * Setting processor type for PowerPC and RS/6000
195 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
196 you can use the `set processor' command to specify what variant of the
197 PowerPC family you are debugging. The command
201 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
202 following PowerPC and RS6000 variants:
204 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
205 rs6000 IBM RS6000 ("POWER") architecture, user-level view
207 403GC IBM PowerPC 403GC
208 505 Motorola PowerPC 505
209 860 Motorola PowerPC 860 or 850
210 601 Motorola PowerPC 601
211 602 Motorola PowerPC 602
212 603 Motorola/IBM PowerPC 603 or 603e
213 604 Motorola PowerPC 604 or 604e
214 750 Motorola/IBM PowerPC 750 or 750
216 At the moment, this command just tells GDB what to name the
217 special-purpose processor registers. Since almost all the affected
218 registers are inaccessible to user-level programs, this command is
219 only useful for remote debugging in its present form.
223 Thanks to a major code donation from Hewlett-Packard, GDB now has much
224 more extensive support for HP-UX. Added features include shared
225 library support, kernel threads and hardware watchpoints for 11.00,
226 support for HP's ANSI C and C++ compilers, and a compatibility mode
227 for xdb and dbx commands.
231 HP's donation includes the new concept of catchpoints, which is a
232 generalization of the old catch command. On HP-UX, it is now possible
233 to catch exec, fork, and vfork, as well as library loading.
235 This means that the existing catch command has changed; its first
236 argument now specifies the type of catch to be set up. See the
237 output of "help catch" for a list of catchpoint types.
239 * Debugging across forks
241 On HP-UX, you can choose which process to debug when a fork() happens
246 HP has donated a curses-based terminal user interface (TUI). To get
247 it, build with --enable-tui. Although this can be enabled for any
248 configuration, at present it only works for native HP debugging.
250 * GDB remote protocol additions
252 A new protocol packet 'X' that writes binary data is now available.
253 Default behavior is to try 'X', then drop back to 'M' if the stub
254 fails to respond. The settable variable `remotebinarydownload'
255 allows explicit control over the use of 'X'.
257 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
258 full 64-bit address. The command
260 set remoteaddresssize 32
262 can be used to revert to the old behaviour. For existing remote stubs
263 the change should not be noticed, as the additional address information
266 In order to assist in debugging stubs, you may use the maintenance
267 command `packet' to send any text string to the stub. For instance,
269 maint packet heythere
271 sends the packet "$heythere#<checksum>". Note that it is very easy to
272 disrupt a debugging session by sending the wrong packet at the wrong
275 The compare-sections command allows you to compare section data on the
276 target to what is in the executable file without uploading or
277 downloading, by comparing CRC checksums.
279 * Tracing can collect general expressions
281 You may now collect general expressions at tracepoints. This requires
282 further additions to the target-side stub; see tracepoint.c and
283 doc/agentexpr.texi for further details.
285 * mask-address variable for Mips
287 For Mips targets, you may control the zeroing of the upper 32 bits of
288 a 64-bit address by entering `set mask-address on'. This is mainly
289 of interest to users of embedded R4xxx and R5xxx processors.
291 * Higher serial baud rates
293 GDB's serial code now allows you to specify baud rates 57600, 115200,
294 230400, and 460800 baud. (Note that your host system may not be able
295 to achieve all of these rates.)
299 The i960 configuration now includes an initial implementation of a
300 builtin simulator, contributed by Jim Wilson.
303 *** Changes in GDB-4.17:
305 * New native configurations
307 Alpha GNU/Linux alpha*-*-linux*
308 Unixware 2.x i[3456]86-unixware2*
309 Irix 6.x mips*-sgi-irix6*
310 PowerPC GNU/Linux powerpc-*-linux*
311 PowerPC Solaris powerpcle-*-solaris*
312 Sparc GNU/Linux sparc-*-linux*
313 Motorola sysV68 R3V7.1 m68k-motorola-sysv
317 Argonaut Risc Chip (ARC) arc-*-*
318 Hitachi H8/300S h8300*-*-*
319 Matsushita MN10200 w/simulator mn10200-*-*
320 Matsushita MN10300 w/simulator mn10300-*-*
321 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
322 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
323 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
324 Mitsubishi D10V w/simulator d10v-*-*
325 Mitsubishi M32R/D w/simulator m32r-*-elf*
326 Tsqware Sparclet sparclet-*-*
327 NEC V850 w/simulator v850-*-*
329 * New debugging protocols
331 ARM with RDI protocol arm*-*-*
332 M68K with dBUG monitor m68*-*-{aout,coff,elf}
333 DDB and LSI variants of PMON protocol mips*-*-*
334 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
335 PowerPC with SDS protocol powerpc{,le}-*-eabi
336 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
340 All configurations can now understand and use the DWARF 2 debugging
341 format. The choice is automatic, if the symbol file contains DWARF 2
346 GDB now includes basic Java language support. This support is
347 only useful with Java compilers that produce native machine code.
349 * solib-absolute-prefix and solib-search-path
351 For SunOS and SVR4 shared libraries, you may now set the prefix for
352 loading absolute shared library symbol files, and the search path for
353 locating non-absolute shared library symbol files.
355 * Live range splitting
357 GDB can now effectively debug code for which GCC has performed live
358 range splitting as part of its optimization. See gdb/doc/LRS for
359 more details on the expected format of the stabs information.
363 GDB's support for the GNU Hurd, including thread debugging, has been
364 updated to work with current versions of the Hurd.
368 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
369 instruction set. ARM GDB automatically detects when Thumb
370 instructions are in use, and adjusts disassembly and backtracing
375 GDB's MIPS target configurations now handle the MIP16 16-bit
380 GDB now includes support for overlays; if an executable has been
381 linked such that multiple sections are based at the same address, GDB
382 will decide which section to use for symbolic info. You can choose to
383 control the decision manually, using overlay commands, or implement
384 additional target-side support and use "overlay load-target" to bring
385 in the overlay mapping. Do "help overlay" for more detail.
389 The command "info symbol <address>" displays information about
390 the symbol at the specified address.
394 The standard remote protocol now includes an extension that allows
395 asynchronous collection and display of trace data. This requires
396 extensive support in the target-side debugging stub. Tracing mode
397 includes a new interaction mode in GDB and new commands: see the
398 file tracepoint.c for more details.
402 Configurations for embedded MIPS now include a simulator contributed
403 by Cygnus Solutions. The simulator supports the instruction sets
404 of most MIPS variants.
408 Sparc configurations may now include the ERC32 simulator contributed
409 by the European Space Agency. The simulator is not built into
410 Sparc targets by default; configure with --enable-sim to include it.
414 For target configurations that may include multiple variants of a
415 basic architecture (such as MIPS and SH), you may now set the
416 architecture explicitly. "set arch" sets, "info arch" lists
417 the possible architectures.
419 *** Changes in GDB-4.16:
421 * New native configurations
423 Windows 95, x86 Windows NT i[345]86-*-cygwin32
424 M68K NetBSD m68k-*-netbsd*
425 PowerPC AIX 4.x powerpc-*-aix*
426 PowerPC MacOS powerpc-*-macos*
427 PowerPC Windows NT powerpcle-*-cygwin32
428 RS/6000 AIX 4.x rs6000-*-aix4*
432 ARM with RDP protocol arm-*-*
433 I960 with MON960 i960-*-coff
434 MIPS VxWorks mips*-*-vxworks*
435 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
436 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
438 Matra Sparclet sparclet-*-*
442 The powerpc-eabi configuration now includes the PSIM simulator,
443 contributed by Andrew Cagney, with assistance from Mike Meissner.
444 PSIM is a very elaborate model of the PowerPC, including not only
445 basic instruction set execution, but also details of execution unit
446 performance and I/O hardware. See sim/ppc/README for more details.
450 GDB now works with Solaris 2.5.
452 * Windows 95/NT native
454 GDB will now work as a native debugger on Windows 95 and Windows NT.
455 To build it from source, you must use the "gnu-win32" environment,
456 which uses a DLL to emulate enough of Unix to run the GNU tools.
457 Further information, binaries, and sources are available at
458 ftp.cygnus.com, under pub/gnu-win32.
460 * dont-repeat command
462 If a user-defined command includes the command `dont-repeat', then the
463 command will not be repeated if the user just types return. This is
464 useful if the command is time-consuming to run, so that accidental
465 extra keystrokes don't run the same command many times.
467 * Send break instead of ^C
469 The standard remote protocol now includes an option to send a break
470 rather than a ^C to the target in order to interrupt it. By default,
471 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
473 * Remote protocol timeout
475 The standard remote protocol includes a new variable `remotetimeout'
476 that allows you to set the number of seconds before GDB gives up trying
477 to read from the target. The default value is 2.
479 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
481 By default GDB will automatically keep track of objects as they are
482 loaded and unloaded by the dynamic linker. By using the command `set
483 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
484 when shared library events occur, thus allowing you to set breakpoints
485 in shared libraries which are explicitly loaded by the inferior.
487 Note this feature does not work on hpux8. On hpux9 you must link
488 /usr/lib/end.o into your program. This feature should work
489 automatically on hpux10.
491 * Irix 5.x hardware watchpoint support
493 Irix 5 configurations now support the use of hardware watchpoints.
495 * Mips protocol "SYN garbage limit"
497 When debugging a Mips target using the `target mips' protocol, you
498 may set the number of characters that GDB will ignore by setting
499 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
500 every character. The default value is 1050.
502 * Recording and replaying remote debug sessions
504 If you set `remotelogfile' to the name of a file, gdb will write to it
505 a recording of a remote debug session. This recording may then be
506 replayed back to gdb using "gdbreplay". See gdbserver/README for
507 details. This is useful when you have a problem with GDB while doing
508 remote debugging; you can make a recording of the session and send it
509 to someone else, who can then recreate the problem.
511 * Speedups for remote debugging
513 GDB includes speedups for downloading and stepping MIPS systems using
514 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
515 and more efficient S-record downloading.
517 * Memory use reductions and statistics collection
519 GDB now uses less memory and reports statistics about memory usage.
520 Try the `maint print statistics' command, for example.
522 *** Changes in GDB-4.15:
526 The symbol reader for AIX GDB now uses partial symbol tables. This
527 can greatly improve startup time, especially for large executables.
529 * Remote targets use caching
531 Remote targets now use a data cache to speed up communication with the
532 remote side. The data cache could lead to incorrect results because
533 it doesn't know about volatile variables, thus making it impossible to
534 debug targets which use memory mapped I/O devices. `set remotecache
535 off' turns the the data cache off.
537 * Remote targets may have threads
539 The standard remote protocol now includes support for multiple threads
540 in the target system, using new protocol commands 'H' and 'T'. See
541 gdb/remote.c for details.
545 If GDB is configured with `--enable-netrom', then it will include
546 support for the NetROM ROM emulator from XLNT Designs. The NetROM
547 acts as though it is a bank of ROM on the target board, but you can
548 write into it over the network. GDB's support consists only of
549 support for fast loading into the emulated ROM; to debug, you must use
550 another protocol, such as standard remote protocol. The usual
551 sequence is something like
553 target nrom <netrom-hostname>
555 target remote <netrom-hostname>:1235
559 GDB now includes support for the Apple Macintosh, as a host only. It
560 may be run as either an MPW tool or as a standalone application, and
561 it can debug through the serial port. All the usual GDB commands are
562 available, but to the target command, you must supply "serial" as the
563 device type instead of "/dev/ttyXX". See mpw-README in the main
564 directory for more information on how to build. The MPW configuration
565 scripts */mpw-config.in support only a few targets, and only the
566 mips-idt-ecoff target has been tested.
570 GDB configuration now uses autoconf. This is not user-visible,
571 but does simplify configuration and building.
575 GDB now supports hpux10.
577 *** Changes in GDB-4.14:
579 * New native configurations
581 x86 FreeBSD i[345]86-*-freebsd
582 x86 NetBSD i[345]86-*-netbsd
583 NS32k NetBSD ns32k-*-netbsd
584 Sparc NetBSD sparc-*-netbsd
588 A29K VxWorks a29k-*-vxworks
589 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
590 CPU32 EST-300 emulator m68*-*-est*
591 PowerPC ELF powerpc-*-elf
594 * Alpha OSF/1 support for procfs
596 GDB now supports procfs under OSF/1-2.x and higher, which makes it
597 possible to attach to running processes. As the mounting of the /proc
598 filesystem is optional on the Alpha, GDB automatically determines
599 the availability of /proc during startup. This can lead to problems
600 if /proc is unmounted after GDB has been started.
602 * Arguments to user-defined commands
604 User commands may accept up to 10 arguments separated by whitespace.
605 Arguments are accessed within the user command via $arg0..$arg9. A
608 print $arg0 + $arg1 + $arg2
610 To execute the command use:
613 Defines the command "adder" which prints the sum of its three arguments.
614 Note the arguments are text substitutions, so they may reference variables,
615 use complex expressions, or even perform inferior function calls.
617 * New `if' and `while' commands
619 This makes it possible to write more sophisticated user-defined
620 commands. Both commands take a single argument, which is the
621 expression to evaluate, and must be followed by the commands to
622 execute, one per line, if the expression is nonzero, the list being
623 terminated by the word `end'. The `if' command list may include an
624 `else' word, which causes the following commands to be executed only
625 if the expression is zero.
627 * Fortran source language mode
629 GDB now includes partial support for Fortran 77. It will recognize
630 Fortran programs and can evaluate a subset of Fortran expressions, but
631 variables and functions may not be handled correctly. GDB will work
632 with G77, but does not yet know much about symbols emitted by other
635 * Better HPUX support
637 Most debugging facilities now work on dynamic executables for HPPAs
638 running hpux9 or later. You can attach to running dynamically linked
639 processes, but by default the dynamic libraries will be read-only, so
640 for instance you won't be able to put breakpoints in them. To change
641 that behavior do the following before running the program:
647 This will cause the libraries to be mapped private and read-write.
648 To revert to the normal behavior, do this:
654 You cannot set breakpoints or examine data in the library until after
655 the library is loaded if the function/data symbols do not have
658 GDB can now also read debug symbols produced by the HP C compiler on
659 HPPAs (sorry, no C++, Fortran or 68k support).
661 * Target byte order now dynamically selectable
663 You can choose which byte order to use with a target system, via the
664 commands "set endian big" and "set endian little", and you can see the
665 current setting by using "show endian". You can also give the command
666 "set endian auto", in which case GDB will use the byte order
667 associated with the executable. Currently, only embedded MIPS
668 configurations support dynamic selection of target byte order.
670 * New DOS host serial code
672 This version uses DPMI interrupts to handle buffered I/O, so you
673 no longer need to run asynctsr when debugging boards connected to
676 *** Changes in GDB-4.13:
678 * New "complete" command
680 This lists all the possible completions for the rest of the line, if it
681 were to be given as a command itself. This is intended for use by emacs.
683 * Trailing space optional in prompt
685 "set prompt" no longer adds a space for you after the prompt you set. This
686 allows you to set a prompt which ends in a space or one that does not.
688 * Breakpoint hit counts
690 "info break" now displays a count of the number of times the breakpoint
691 has been hit. This is especially useful in conjunction with "ignore"; you
692 can ignore a large number of breakpoint hits, look at the breakpoint info
693 to see how many times the breakpoint was hit, then run again, ignoring one
694 less than that number, and this will get you quickly to the last hit of
697 * Ability to stop printing at NULL character
699 "set print null-stop" will cause GDB to stop printing the characters of
700 an array when the first NULL is encountered. This is useful when large
701 arrays actually contain only short strings.
703 * Shared library breakpoints
705 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
706 breakpoints in shared libraries before the executable is run.
708 * Hardware watchpoints
710 There is a new hardware breakpoint for the watch command for sparclite
711 targets. See gdb/sparclite/hw_breakpoint.note.
713 Hardware watchpoints are also now supported under Linux.
717 Annotations have been added. These are for use with graphical interfaces,
718 and are still experimental. Currently only gdba.el uses these.
720 * Improved Irix 5 support
722 GDB now works properly with Irix 5.2.
724 * Improved HPPA support
726 GDB now works properly with the latest GCC and GAS.
728 * New native configurations
730 Sequent PTX4 i[34]86-sequent-ptx4
731 HPPA running OSF/1 hppa*-*-osf*
732 Atari TT running SVR4 m68*-*-sysv4*
733 RS/6000 LynxOS rs6000-*-lynxos*
737 OS/9000 i[34]86-*-os9k
738 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
741 * Hitachi SH7000 and E7000-PC ICE support
743 There is now support for communicating with the Hitachi E7000-PC ICE.
744 This is available automatically when GDB is configured for the SH.
748 As usual, a variety of small fixes and improvements, both generic
749 and configuration-specific. See the ChangeLog for more detail.
751 *** Changes in GDB-4.12:
753 * Irix 5 is now supported
757 GDB-4.12 on the HPPA has a number of changes which make it unable
758 to debug the output from the currently released versions of GCC and
759 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
760 of GCC and GAS, versions of these tools designed to work with GDB-4.12
761 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
764 *** Changes in GDB-4.11:
766 * User visible changes:
770 The "set remotedebug" option is now consistent between the mips remote
771 target, remote targets using the gdb-specific protocol, UDI (AMD's
772 debug protocol for the 29k) and the 88k bug monitor. It is now an
773 integer specifying a debug level (normally 0 or 1, but 2 means more
774 debugging info for the mips target).
776 * DEC Alpha native support
778 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
779 debug info, but GDB works fairly well with the DEC compiler and should
780 work with a future GCC release. See the README file for a few
781 Alpha-specific notes.
783 * Preliminary thread implementation
785 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
787 * LynxOS native and target support for 386
789 This release has been hosted on LynxOS 2.2, and also can be configured
790 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
793 * Improvements in C++ mangling/demangling.
795 This release has much better g++ debugging, specifically in name
796 mangling/demangling, virtual function calls, print virtual table,
797 call methods, ...etc.
799 *** Changes in GDB-4.10:
801 * User visible changes:
803 Remote debugging using the GDB-specific (`target remote') protocol now
804 supports the `load' command. This is only useful if you have some
805 other way of getting the stub to the target system, and you can put it
806 somewhere in memory where it won't get clobbered by the download.
808 Filename completion now works.
810 When run under emacs mode, the "info line" command now causes the
811 arrow to point to the line specified. Also, "info line" prints
812 addresses in symbolic form (as well as hex).
814 All vxworks based targets now support a user settable option, called
815 vxworks-timeout. This option represents the number of seconds gdb
816 should wait for responses to rpc's. You might want to use this if
817 your vxworks target is, perhaps, a slow software simulator or happens
818 to be on the far side of a thin network line.
822 This release contains support for using a DEC alpha as a GDB host for
823 cross debugging. Native alpha debugging is not supported yet.
826 *** Changes in GDB-4.9:
830 This is the first GDB release which is accompanied by a matching testsuite.
831 The testsuite requires installation of dejagnu, which should be available
832 via ftp from most sites that carry GNU software.
836 'Cfront' style demangling has had its name changed to 'ARM' style, to
837 emphasize that it was written from the specifications in the C++ Annotated
838 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
839 disclaimers, it still generated too much confusion with users attempting to
840 use gdb with AT&T cfront.
844 GDB now uses a standard remote interface to a simulator library.
845 So far, the library contains simulators for the Zilog Z8001/2, the
846 Hitachi H8/300, H8/500 and Super-H.
848 * New targets supported
850 H8/300 simulator h8300-hitachi-hms or h8300hms
851 H8/500 simulator h8500-hitachi-hms or h8500hms
852 SH simulator sh-hitachi-hms or sh
853 Z8000 simulator z8k-zilog-none or z8ksim
854 IDT MIPS board over serial line mips-idt-ecoff
856 Cross-debugging to GO32 targets is supported. It requires a custom
857 version of the i386-stub.c module which is integrated with the
858 GO32 memory extender.
860 * New remote protocols
862 MIPS remote debugging protocol.
864 * New source languages supported
866 This version includes preliminary support for Chill, a Pascal like language
867 used by telecommunications companies. Chill support is also being integrated
868 into the GNU compiler, but we don't know when it will be publically available.
871 *** Changes in GDB-4.8:
873 * HP Precision Architecture supported
875 GDB now supports HP PA-RISC machines running HPUX. A preliminary
876 version of this support was available as a set of patches from the
877 University of Utah. GDB does not support debugging of programs
878 compiled with the HP compiler, because HP will not document their file
879 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
880 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
882 Many problems in the preliminary version have been fixed.
884 * Faster and better demangling
886 We have improved template demangling and fixed numerous bugs in the GNU style
887 demangler. It can now handle type modifiers such as `static' or `const'. Wide
888 character types (wchar_t) are now supported. Demangling of each symbol is now
889 only done once, and is cached when the symbol table for a file is read in.
890 This results in a small increase in memory usage for C programs, a moderate
891 increase in memory usage for C++ programs, and a fantastic speedup in
894 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
895 from the specifications in the Annotated Reference Manual, which AT&T's
896 compiler does not actually implement.
898 * G++ multiple inheritance compiler problem
900 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
901 inheritance lattices was reworked to properly discover ambiguities. We
902 recently found an example which causes this new algorithm to fail in a
903 very subtle way, producing bad debug information for those classes.
904 The file 'gcc.patch' (in this directory) can be applied to gcc to
905 circumvent the problem. A future GCC release will contain a complete
908 The previous G++ debug info problem (mentioned below for the gdb-4.7
909 release) is fixed in gcc version 2.3.2.
911 * Improved configure script
913 The `configure' script will now attempt to guess your system type if
914 you don't supply a host system type. The old scheme of supplying a
915 host system triplet is preferable over using this. All the magic is
916 done in the new `config.guess' script. Examine it for details.
918 We have also brought our configure script much more in line with the FSF's
919 version. It now supports the --with-xxx options. In particular,
920 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
921 The resulting GDB will not be able to read arbitrary object file formats --
922 only the format ``expected'' to be used on the configured target system.
923 We hope to make this the default in a future release.
925 * Documentation improvements
927 There's new internal documentation on how to modify GDB, and how to
928 produce clean changes to the code. We implore people to read it
929 before submitting changes.
931 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
932 M4 macros. The new texinfo.tex is provided in this release. Pre-built
933 `info' files are also provided. To build `info' files from scratch,
934 you will need the latest `makeinfo' release, which will be available in
935 a future texinfo-X.Y release.
937 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
938 We're not sure exactly which versions have this problem, but it has
939 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
940 or better. If that isn't possible, there is a patch in
941 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
946 GDB now supports array constants that can be used in expressions typed in by
947 the user. The syntax is `{element, element, ...}'. Ie: you can now type
948 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
951 The new directory `gdb/sparclite' contains a program that demonstrates
952 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
954 * New native hosts supported
956 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
957 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
959 * New targets supported
961 AMD 29k family via UDI a29k-amd-udi or udi29k
963 * New file formats supported
965 BFD now supports reading HP/PA-RISC executables (SOM file format?),
966 HPUX core files, and SCO 3.2v2 core files.
970 Attaching to processes now works again; thanks for the many bug reports.
972 We have also stomped on a bunch of core dumps caused by
973 printf_filtered("%s") problems.
975 We eliminated a copyright problem on the rpc and ptrace header files
976 for VxWorks, which was discovered at the last minute during the 4.7
977 release. You should now be able to build a VxWorks GDB.
979 You can now interrupt gdb while an attached process is running. This
980 will cause the attached process to stop, and give control back to GDB.
982 We fixed problems caused by using too many file descriptors
983 for reading symbols from object files and libraries. This was
984 especially a problem for programs that used many (~100) shared
987 The `step' command now only enters a subroutine if there is line number
988 information for the subroutine. Otherwise it acts like the `next'
989 command. Previously, `step' would enter subroutines if there was
990 any debugging information about the routine. This avoids problems
991 when using `cc -g1' on MIPS machines.
993 * Internal improvements
995 GDB's internal interfaces have been improved to make it easier to support
996 debugging of multiple languages in the future.
998 GDB now uses a common structure for symbol information internally.
999 Minimal symbols (derived from linkage symbols in object files), partial
1000 symbols (from a quick scan of debug information), and full symbols
1001 contain a common subset of information, making it easier to write
1002 shared code that handles any of them.
1004 * New command line options
1006 We now accept --silent as an alias for --quiet.
1010 The memory-mapped-malloc library is now licensed under the GNU Library
1011 General Public License.
1013 *** Changes in GDB-4.7:
1015 * Host/native/target split
1017 GDB has had some major internal surgery to untangle the support for
1018 hosts and remote targets. Now, when you configure GDB for a remote
1019 target, it will no longer load in all of the support for debugging
1020 local programs on the host. When fully completed and tested, this will
1021 ensure that arbitrary host/target combinations are possible.
1023 The primary conceptual shift is to separate the non-portable code in
1024 GDB into three categories. Host specific code is required any time GDB
1025 is compiled on that host, regardless of the target. Target specific
1026 code relates to the peculiarities of the target, but can be compiled on
1027 any host. Native specific code is everything else: it can only be
1028 built when the host and target are the same system. Child process
1029 handling and core file support are two common `native' examples.
1031 GDB's use of /proc for controlling Unix child processes is now cleaner.
1032 It has been split out into a single module under the `target_ops' vector,
1033 plus two native-dependent functions for each system that uses /proc.
1035 * New hosts supported
1037 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
1038 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
1039 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
1041 * New targets supported
1043 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
1044 68030 and CPU32 m68030-*-*, m68332-*-*
1046 * New native hosts supported
1048 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
1049 (386bsd is not well tested yet)
1050 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
1052 * New file formats supported
1054 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
1055 supports reading of `a.out.adobe' object files, which are an a.out
1056 format extended with minimal information about multiple sections.
1060 `show copying' is the same as the old `info copying'.
1061 `show warranty' is the same as `info warrantee'.
1062 These were renamed for consistency. The old commands continue to work.
1064 `info handle' is a new alias for `info signals'.
1066 You can now define pre-command hooks, which attach arbitrary command
1067 scripts to any command. The commands in the hook will be executed
1068 prior to the user's command. You can also create a hook which will be
1069 executed whenever the program stops. See gdb.texinfo.
1073 We now deal with Cfront style name mangling, and can even extract type
1074 info from mangled symbols. GDB can automatically figure out which
1075 symbol mangling style your C++ compiler uses.
1077 Calling of methods and virtual functions has been improved as well.
1081 The crash that occured when debugging Sun Ansi-C compiled binaries is
1082 fixed. This was due to mishandling of the extra N_SO stabs output
1085 We also finally got Ultrix 4.2 running in house, and fixed core file
1086 support, with help from a dozen people on the net.
1088 John M. Farrell discovered that the reason that single-stepping was so
1089 slow on all of the Mips based platforms (primarily SGI and DEC) was
1090 that we were trying to demangle and lookup a symbol used for internal
1091 purposes on every instruction that was being stepped through. Changing
1092 the name of that symbol so that it couldn't be mistaken for a C++
1093 mangled symbol sped things up a great deal.
1095 Rich Pixley sped up symbol lookups in general by getting much smarter
1096 about when C++ symbol mangling is necessary. This should make symbol
1097 completion (TAB on the command line) much faster. It's not as fast as
1098 we'd like, but it's significantly faster than gdb-4.6.
1102 A new user controllable variable 'call_scratch_address' can
1103 specify the location of a scratch area to be used when GDB
1104 calls a function in the target. This is necessary because the
1105 usual method of putting the scratch area on the stack does not work
1106 in systems that have separate instruction and data spaces.
1108 We integrated changes to support the 29k UDI (Universal Debugger
1109 Interface), but discovered at the last minute that we didn't have all
1110 of the appropriate copyright paperwork. We are working with AMD to
1111 resolve this, and hope to have it available soon.
1115 We have sped up the remote serial line protocol, especially for targets
1116 with lots of registers. It now supports a new `expedited status' ('T')
1117 message which can be used in place of the existing 'S' status message.
1118 This allows the remote stub to send only the registers that GDB
1119 needs to make a quick decision about single-stepping or conditional
1120 breakpoints, eliminating the need to fetch the entire register set for
1121 each instruction being stepped through.
1123 The GDB remote serial protocol now implements a write-through cache for
1124 registers, only re-reading the registers if the target has run.
1126 There is also a new remote serial stub for SPARC processors. You can
1127 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
1128 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
1129 processor with a serial port.
1133 Configure.in files have become much easier to read and modify. A new
1134 `table driven' format makes it more obvious what configurations are
1135 supported, and what files each one uses.
1139 There is a new opcodes library which will eventually contain all of the
1140 disassembly routines and opcode tables. At present, it only contains
1141 Sparc and Z8000 routines. This will allow the assembler, debugger, and
1142 disassembler (binutils/objdump) to share these routines.
1144 The libiberty library is now copylefted under the GNU Library General
1145 Public License. This allows more liberal use, and was done so libg++
1146 can use it. This makes no difference to GDB, since the Library License
1147 grants all the rights from the General Public License.
1151 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
1152 reference to the stabs symbol info used by the debugger. It is (as far
1153 as we know) the only published document on this fascinating topic. We
1154 encourage you to read it, compare it to the stabs information on your
1155 system, and send improvements on the document in general (to
1156 bug-gdb@prep.ai.mit.edu).
1158 And, of course, many bugs have been fixed.
1161 *** Changes in GDB-4.6:
1163 * Better support for C++ function names
1165 GDB now accepts as input the "demangled form" of C++ overloaded function
1166 names and member function names, and can do command completion on such names
1167 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
1168 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
1169 Make use of command completion, it is your friend.
1171 GDB also now accepts a variety of C++ mangled symbol formats. They are
1172 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
1173 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
1174 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
1175 for the list of formats.
1177 * G++ symbol mangling problem
1179 Recent versions of gcc have a bug in how they emit debugging information for
1180 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
1181 directory) can be applied to gcc to fix the problem. Alternatively, if you
1182 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
1183 usual symptom is difficulty with setting breakpoints on methods. GDB complains
1184 about the method being non-existent. (We believe that version 2.2.2 of GCC has
1187 * New 'maintenance' command
1189 All of the commands related to hacking GDB internals have been moved out of
1190 the main command set, and now live behind the 'maintenance' command. This
1191 can also be abbreviated as 'mt'. The following changes were made:
1193 dump-me -> maintenance dump-me
1194 info all-breakpoints -> maintenance info breakpoints
1195 printmsyms -> maintenance print msyms
1196 printobjfiles -> maintenance print objfiles
1197 printpsyms -> maintenance print psymbols
1198 printsyms -> maintenance print symbols
1200 The following commands are new:
1202 maintenance demangle Call internal GDB demangler routine to
1203 demangle a C++ link name and prints the result.
1204 maintenance print type Print a type chain for a given symbol
1206 * Change to .gdbinit file processing
1208 We now read the $HOME/.gdbinit file before processing the argv arguments
1209 (e.g. reading symbol files or core files). This allows global parameters to
1210 be set, which will apply during the symbol reading. The ./.gdbinit is still
1211 read after argv processing.
1213 * New hosts supported
1215 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
1217 Linux support i386-unknown-linux or linux
1219 We are also including code to support the HP/PA running BSD and HPUX. This
1220 is almost guaranteed not to work, as we didn't have time to test or build it
1221 for this release. We are including it so that the more adventurous (or
1222 masochistic) of you can play with it. We also had major problems with the
1223 fact that the compiler that we got from HP doesn't support the -g option.
1226 * New targets supported
1228 Hitachi H8/300 h8300-hitachi-hms or h8300hms
1230 * More smarts about finding #include files
1232 GDB now remembers the compilation directory for all include files, and for
1233 all files from which C is generated (like yacc and lex sources). This
1234 greatly improves GDB's ability to find yacc/lex sources, and include files,
1235 especially if you are debugging your program from a directory different from
1236 the one that contains your sources.
1238 We also fixed a bug which caused difficulty with listing and setting
1239 breakpoints in include files which contain C code. (In the past, you had to
1240 try twice in order to list an include file that you hadn't looked at before.)
1242 * Interesting infernals change
1244 GDB now deals with arbitrary numbers of sections, where the symbols for each
1245 section must be relocated relative to that section's landing place in the
1246 target's address space. This work was needed to support ELF with embedded
1247 stabs used by Solaris-2.0.
1249 * Bug fixes (of course!)
1251 There have been loads of fixes for the following things:
1252 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
1253 i960, stabs, DOS(GO32), procfs, etc...
1255 See the ChangeLog for details.
1257 *** Changes in GDB-4.5:
1259 * New machines supported (host and target)
1261 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
1263 SGI Irix-4.x mips-sgi-irix4 or iris4
1265 * New malloc package
1267 GDB now uses a new memory manager called mmalloc, based on gmalloc.
1268 Mmalloc is capable of handling mutiple heaps of memory. It is also
1269 capable of saving a heap to a file, and then mapping it back in later.
1270 This can be used to greatly speedup the startup of GDB by using a
1271 pre-parsed symbol table which lives in a mmalloc managed heap. For
1272 more details, please read mmalloc/mmalloc.texi.
1276 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
1277 'help info proc' for details.
1279 * MIPS ecoff symbol table format
1281 The code that reads MIPS symbol table format is now supported on all hosts.
1282 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
1285 * File name changes for MS-DOS
1287 Many files in the config directories have been renamed to make it easier to
1288 support GDB on MS-DOSe systems (which have very restrictive file name
1289 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
1290 environment) is close to working but has some remaining problems. Note
1291 that debugging of DOS programs is not supported, due to limitations
1292 in the ``operating system'', but it can be used to host cross-debugging.
1294 * Cross byte order fixes
1296 Many fixes have been made to support cross debugging of Sparc and MIPS
1297 targets from hosts whose byte order differs.
1299 * New -mapped and -readnow options
1301 If memory-mapped files are available on your system through the 'mmap'
1302 system call, you can use the -mapped option on the `file' or
1303 `symbol-file' commands to cause GDB to write the symbols from your
1304 program into a reusable file. If the program you are debugging is
1305 called `/path/fred', the mapped symbol file will be `./fred.syms'.
1306 Future GDB debugging sessions will notice the presence of this file,
1307 and will quickly map in symbol information from it, rather than reading
1308 the symbol table from the executable program. Using the '-mapped'
1309 option in a GDB `file' or `symbol-file' command has the same effect as
1310 starting GDB with the '-mapped' command-line option.
1312 You can cause GDB to read the entire symbol table immediately by using
1313 the '-readnow' option with any of the commands that load symbol table
1314 information (or on the GDB command line). This makes the command
1315 slower, but makes future operations faster.
1317 The -mapped and -readnow options are typically combined in order to
1318 build a `fred.syms' file that contains complete symbol information.
1319 A simple GDB invocation to do nothing but build a `.syms' file for future
1322 gdb -batch -nx -mapped -readnow programname
1324 The `.syms' file is specific to the host machine on which GDB is run.
1325 It holds an exact image of GDB's internal symbol table. It cannot be
1326 shared across multiple host platforms.
1328 * longjmp() handling
1330 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
1331 siglongjmp() without losing control. This feature has not yet been ported to
1332 all systems. It currently works on many 386 platforms, all MIPS-based
1333 platforms (SGI, DECstation, etc), and Sun3/4.
1337 Preliminary work has been put in to support the new Solaris OS from Sun. At
1338 this time, it can control and debug processes, but it is not capable of
1343 As always, many many bug fixes. The major areas were with g++, and mipsread.
1344 People using the MIPS-based platforms should experience fewer mysterious
1345 crashes and trashed symbol tables.
1347 *** Changes in GDB-4.4:
1349 * New machines supported (host and target)
1351 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
1353 BSD Reno on Vax vax-dec-bsd
1354 Ultrix on Vax vax-dec-ultrix
1356 * New machines supported (target)
1358 AMD 29000 embedded, using EBMON a29k-none-none
1362 GDB continues to improve its handling of C++. `References' work better.
1363 The demangler has also been improved, and now deals with symbols mangled as
1364 per the Annotated C++ Reference Guide.
1366 GDB also now handles `stabs' symbol information embedded in MIPS
1367 `ecoff' symbol tables. Since the ecoff format was not easily
1368 extensible to handle new languages such as C++, this appeared to be a
1369 good way to put C++ debugging info into MIPS binaries. This option
1370 will be supported in the GNU C compiler, version 2, when it is
1373 * New features for SVR4
1375 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
1376 shared libraries. Debugging dynamically linked programs should present
1377 only minor differences from debugging statically linked programs.
1379 The `info proc' command will print out information about any process
1380 on an SVR4 system (including the one you are debugging). At the moment,
1381 it prints the address mappings of the process.
1383 If you bring up GDB on another SVR4 system, please send mail to
1384 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
1386 * Better dynamic linking support in SunOS
1388 Reading symbols from shared libraries which contain debugging symbols
1389 now works properly. However, there remain issues such as automatic
1390 skipping of `transfer vector' code during function calls, which
1391 make it harder to debug code in a shared library, than to debug the
1392 same code linked statically.
1396 GDB is now using the latest `getopt' routines from the FSF. This
1397 version accepts the -- prefix for options with long names. GDB will
1398 continue to accept the old forms (-option and +option) as well.
1399 Various single letter abbreviations for options have been explicity
1400 added to the option table so that they won't get overshadowed in the
1401 future by other options that begin with the same letter.
1405 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
1406 Many assorted bugs have been handled. Many more remain to be handled.
1407 See the various ChangeLog files (primarily in gdb and bfd) for details.
1410 *** Changes in GDB-4.3:
1412 * New machines supported (host and target)
1414 Amiga 3000 running Amix m68k-cbm-svr4 or amix
1415 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
1416 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
1418 * Almost SCO Unix support
1420 We had hoped to support:
1421 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
1422 (except for core file support), but we discovered very late in the release
1423 that it has problems with process groups that render gdb unusable. Sorry
1424 about that. I encourage people to fix it and post the fixes.
1426 * Preliminary ELF and DWARF support
1428 GDB can read ELF object files on System V Release 4, and can handle
1429 debugging records for C, in DWARF format, in ELF files. This support
1430 is preliminary. If you bring up GDB on another SVR4 system, please
1431 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
1436 GDB now uses the latest `readline' library. One user-visible change
1437 is that two tabs will list possible command completions, which previously
1438 required typing M-? (meta-question mark, or ESC ?).
1442 The `stepi' bug that many of you noticed has been squashed.
1443 Many bugs in C++ have been handled. Many more remain to be handled.
1444 See the various ChangeLog files (primarily in gdb and bfd) for details.
1446 * State of the MIPS world (in case you wondered):
1448 GDB can understand the symbol tables emitted by the compilers
1449 supplied by most vendors of MIPS-based machines, including DEC. These
1450 symbol tables are in a format that essentially nobody else uses.
1452 Some versions of gcc come with an assembler post-processor called
1453 mips-tfile. This program is required if you want to do source-level
1454 debugging of gcc-compiled programs. I believe FSF does not ship
1455 mips-tfile with gcc version 1, but it will eventually come with gcc
1458 Debugging of g++ output remains a problem. g++ version 1.xx does not
1459 really support it at all. (If you're lucky, you should be able to get
1460 line numbers and stack traces to work, but no parameters or local
1461 variables.) With some work it should be possible to improve the
1464 When gcc version 2 is released, you will have somewhat better luck.
1465 However, even then you will get confusing results for inheritance and
1468 We will eventually provide full debugging of g++ output on
1469 DECstations. This will probably involve some kind of stabs-in-ecoff
1470 encapulation, but the details have not been worked out yet.
1473 *** Changes in GDB-4.2:
1475 * Improved configuration
1477 Only one copy of `configure' exists now, and it is not self-modifying.
1478 Porting BFD is simpler.
1482 The `step' and `next' commands now only stop at the first instruction
1483 of a source line. This prevents the multiple stops that used to occur
1484 in switch statements, for-loops, etc. `Step' continues to stop if a
1485 function that has debugging information is called within the line.
1489 Lots of small bugs fixed. More remain.
1491 * New host supported (not target)
1493 Intel 386 PC clone running Mach i386-none-mach
1496 *** Changes in GDB-4.1:
1498 * Multiple source language support
1500 GDB now has internal scaffolding to handle several source languages.
1501 It determines the type of each source file from its filename extension,
1502 and will switch expression parsing and number formatting to match the
1503 language of the function in the currently selected stack frame.
1504 You can also specifically set the language to be used, with
1505 `set language c' or `set language modula-2'.
1509 GDB now has preliminary support for the GNU Modula-2 compiler,
1510 currently under development at the State University of New York at
1511 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
1512 continue through the fall of 1991 and into 1992.
1514 Other Modula-2 compilers are currently not supported, and attempting to
1515 debug programs compiled with them will likely result in an error as the
1516 symbol table is read. Feel free to work on it, though!
1518 There are hooks in GDB for strict type checking and range checking,
1519 in the `Modula-2 philosophy', but they do not currently work.
1523 GDB can now write to executable and core files (e.g. patch
1524 a variable's value). You must turn this switch on, specify
1525 the file ("exec foo" or "core foo"), *then* modify it, e.g.
1526 by assigning a new value to a variable. Modifications take
1529 * Automatic SunOS shared library reading
1531 When you run your program, GDB automatically determines where its
1532 shared libraries (if any) have been loaded, and reads their symbols.
1533 The `share' command is no longer needed. This also works when
1534 examining core files.
1538 You can specify the number of lines that the `list' command shows.
1541 * New machines supported (host and target)
1543 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
1544 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
1545 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
1547 * New hosts supported (not targets)
1549 IBM RT/PC: romp-ibm-aix or rtpc
1551 * New targets supported (not hosts)
1553 AMD 29000 embedded with COFF a29k-none-coff
1554 AMD 29000 embedded with a.out a29k-none-aout
1555 Ultracomputer remote kernel debug a29k-nyu-kern
1557 * New remote interfaces
1563 *** Changes in GDB-4.0:
1567 Wide output is wrapped at good places to make the output more readable.
1569 Gdb now supports cross-debugging from a host machine of one type to a
1570 target machine of another type. Communication with the target system
1571 is over serial lines. The ``target'' command handles connecting to the
1572 remote system; the ``load'' command will download a program into the
1573 remote system. Serial stubs for the m68k and i386 are provided. Gdb
1574 also supports debugging of realtime processes running under VxWorks,
1575 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
1576 stub on the target system.
1578 New CPUs supported include the AMD 29000 and Intel 960.
1580 GDB now reads object files and symbol tables via a ``binary file''
1581 library, which allows a single copy of GDB to debug programs of multiple
1582 object file types such as a.out and coff.
1584 There is now a GDB reference card in "doc/refcard.tex". (Make targets
1585 refcard.dvi and refcard.ps are available to format it).
1588 * Control-Variable user interface simplified
1590 All variables that control the operation of the debugger can be set
1591 by the ``set'' command, and displayed by the ``show'' command.
1593 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
1594 ``Show prompt'' produces the response:
1595 Gdb's prompt is new-gdb=>.
1597 What follows are the NEW set commands. The command ``help set'' will
1598 print a complete list of old and new set commands. ``help set FOO''
1599 will give a longer description of the variable FOO. ``show'' will show
1600 all of the variable descriptions and their current settings.
1602 confirm on/off: Enables warning questions for operations that are
1603 hard to recover from, e.g. rerunning the program while
1604 it is already running. Default is ON.
1606 editing on/off: Enables EMACS style command line editing
1607 of input. Previous lines can be recalled with
1608 control-P, the current line can be edited with control-B,
1609 you can search for commands with control-R, etc.
1612 history filename NAME: NAME is where the gdb command history
1613 will be stored. The default is .gdb_history,
1614 or the value of the environment variable
1617 history size N: The size, in commands, of the command history. The
1618 default is 256, or the value of the environment variable
1621 history save on/off: If this value is set to ON, the history file will
1622 be saved after exiting gdb. If set to OFF, the
1623 file will not be saved. The default is OFF.
1625 history expansion on/off: If this value is set to ON, then csh-like
1626 history expansion will be performed on
1627 command line input. The default is OFF.
1629 radix N: Sets the default radix for input and output. It can be set
1630 to 8, 10, or 16. Note that the argument to "radix" is interpreted
1631 in the current radix, so "set radix 10" is always a no-op.
1633 height N: This integer value is the number of lines on a page. Default
1634 is 24, the current `stty rows'' setting, or the ``li#''
1635 setting from the termcap entry matching the environment
1638 width N: This integer value is the number of characters on a line.
1639 Default is 80, the current `stty cols'' setting, or the ``co#''
1640 setting from the termcap entry matching the environment
1643 Note: ``set screensize'' is obsolete. Use ``set height'' and
1644 ``set width'' instead.
1646 print address on/off: Print memory addresses in various command displays,
1647 such as stack traces and structure values. Gdb looks
1648 more ``symbolic'' if you turn this off; it looks more
1649 ``machine level'' with it on. Default is ON.
1651 print array on/off: Prettyprint arrays. New convenient format! Default
1654 print demangle on/off: Print C++ symbols in "source" form if on,
1657 print asm-demangle on/off: Same, for assembler level printouts
1660 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
1663 * Support for Epoch Environment.
1665 The epoch environment is a version of Emacs v18 with windowing. One
1666 new command, ``inspect'', is identical to ``print'', except that if you
1667 are running in the epoch environment, the value is printed in its own
1671 * Support for Shared Libraries
1673 GDB can now debug programs and core files that use SunOS shared libraries.
1674 Symbols from a shared library cannot be referenced
1675 before the shared library has been linked with the program (this
1676 happens after you type ``run'' and before the function main() is entered).
1677 At any time after this linking (including when examining core files
1678 from dynamically linked programs), gdb reads the symbols from each
1679 shared library when you type the ``sharedlibrary'' command.
1680 It can be abbreviated ``share''.
1682 sharedlibrary REGEXP: Load shared object library symbols for files
1683 matching a unix regular expression. No argument
1684 indicates to load symbols for all shared libraries.
1686 info sharedlibrary: Status of loaded shared libraries.
1691 A watchpoint stops execution of a program whenever the value of an
1692 expression changes. Checking for this slows down execution
1693 tremendously whenever you are in the scope of the expression, but is
1694 quite useful for catching tough ``bit-spreader'' or pointer misuse
1695 problems. Some machines such as the 386 have hardware for doing this
1696 more quickly, and future versions of gdb will use this hardware.
1698 watch EXP: Set a watchpoint (breakpoint) for an expression.
1700 info watchpoints: Information about your watchpoints.
1702 delete N: Deletes watchpoint number N (same as breakpoints).
1703 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
1704 enable N: Re-enables watchpoint number N (same as breakpoints).
1707 * C++ multiple inheritance
1709 When used with a GCC version 2 compiler, GDB supports multiple inheritance
1712 * C++ exception handling
1714 Gdb now supports limited C++ exception handling. Besides the existing
1715 ability to breakpoint on an exception handler, gdb can breakpoint on
1716 the raising of an exception (before the stack is peeled back to the
1719 catch FOO: If there is a FOO exception handler in the dynamic scope,
1720 set a breakpoint to catch exceptions which may be raised there.
1721 Multiple exceptions (``catch foo bar baz'') may be caught.
1723 info catch: Lists all exceptions which may be caught in the
1724 current stack frame.
1727 * Minor command changes
1729 The command ``call func (arg, arg, ...)'' now acts like the print
1730 command, except it does not print or save a value if the function's result
1731 is void. This is similar to dbx usage.
1733 The ``up'' and ``down'' commands now always print the frame they end up
1734 at; ``up-silently'' and `down-silently'' can be used in scripts to change
1735 frames without printing.
1737 * New directory command
1739 'dir' now adds directories to the FRONT of the source search path.
1740 The path starts off empty. Source files that contain debug information
1741 about the directory in which they were compiled can be found even
1742 with an empty path; Sun CC and GCC include this information. If GDB can't
1743 find your source file in the current directory, type "dir .".
1745 * Configuring GDB for compilation
1747 For normal use, type ``./configure host''. See README or gdb.texinfo
1750 GDB now handles cross debugging. If you are remotely debugging between
1751 two different machines, type ``./configure host -target=targ''.
1752 Host is the machine where GDB will run; targ is the machine
1753 where the program that you are debugging will run.