1 What has changed in GDB?
2 (Organized release by release)
4 *** Changes since GDB 5.1:
6 * New native configurations
8 x86 OpenBSD i[3456]86-*-openbsd*
10 *** Changes in GDB 5.1:
12 * New native configurations
14 Alpha FreeBSD alpha*-*-freebsd*
15 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
16 MIPS Linux mips*-*-linux*
17 MIPS SGI Irix 6.x mips*-sgi-irix6*
19 s390 and s390x Linux {s390,s390x}-*-linux*
23 Motorola 68HC11 and 68HC12 m68hc11-elf
25 UltraSparc running Linux sparc64-*-linux*
27 * OBSOLETE configurations and files
29 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
30 Harris/CXUX m88k m88*-harris-cxux*
31 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
32 ns32k-utek-sysv* ns32k-utek-*
33 TI TMS320C80 tic80-*-*
35 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
36 PowerPC Solaris powerpcle-*-solaris*
37 PowerPC Windows NT powerpcle-*-cygwin32
38 PowerPC Netware powerpc-*-netware*
39 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
40 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
41 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
42 Apple Macintosh (MPW) host N/A
44 stuff.c (Program to stuff files into a specially prepared space in kdb)
45 kdb-start.c (Main loop for the standalone kernel debugger)
47 Configurations that have been declared obsolete in this release have
48 been commented out. Unless there is activity to revive these
49 configurations, the next release of GDB will have their sources
52 * REMOVED configurations and files
54 Altos 3068 m68*-altos-*
57 ARM RISCix arm-*-* (as host)
61 * GDB has been converted to ISO C.
63 GDB's source code has been converted to ISO C. In particular, the
64 sources are fully protoized, and rely on standard headers being
69 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
71 * The MI enabled by default.
73 The new machine oriented interface (MI) introduced in GDB 5.0 has been
74 revised and enabled by default. Packages which use GDB as a debugging
75 engine behind a UI or another front end are encouraged to switch to
76 using the GDB/MI interface, instead of the old annotations interface
77 which is now deprecated.
79 * Support for debugging Pascal programs.
81 GDB now includes support for debugging Pascal programs. The following
82 main features are supported:
84 - Pascal-specific data types such as sets;
86 - automatic recognition of Pascal sources based on file-name
89 - Pascal-style display of data types, variables, and functions;
91 - a Pascal expression parser.
93 However, some important features are not yet supported.
95 - Pascal string operations are not supported at all;
97 - there are some problems with boolean types;
99 - Pascal type hexadecimal constants are not supported
100 because they conflict with the internal variables format;
102 - support for Pascal objects and classes is not full yet;
104 - unlike Pascal, GDB is case-sensitive for symbol names.
106 * Changes in completion.
108 Commands such as `shell', `run' and `set args', which pass arguments
109 to inferior programs, now complete on file names, similar to what
110 users expect at the shell prompt.
112 Commands which accept locations, such as `disassemble', `print',
113 `breakpoint', `until', etc. now complete on filenames as well as
114 program symbols. Thus, if you type "break foob TAB", and the source
115 files linked into the programs include `foobar.c', that file name will
116 be one of the candidates for completion. However, file names are not
117 considered for completion after you typed a colon that delimits a file
118 name from a name of a function in that file, as in "break foo.c:bar".
120 `set demangle-style' completes on available demangling styles.
122 * New platform-independent commands:
124 It is now possible to define a post-hook for a command as well as a
125 hook that runs before the command. For more details, see the
126 documentation of `hookpost' in the GDB manual.
128 * Changes in GNU/Linux native debugging.
130 Support for debugging multi-threaded programs has been completely
131 revised for all platforms except m68k and sparc. You can now debug as
132 many threads as your system allows you to have.
134 Attach/detach is supported for multi-threaded programs.
136 Support for SSE registers was added for x86. This doesn't work for
137 multi-threaded programs though.
139 * Changes in MIPS configurations.
141 Multi-arch support is enabled for all MIPS configurations.
143 GDB can now be built as native debugger on SGI Irix 6.x systems for
144 debugging n32 executables. (Debugging 64-bit executables is not yet
147 * Unified support for hardware watchpoints in all x86 configurations.
149 Most (if not all) native x86 configurations support hardware-assisted
150 breakpoints and watchpoints in a unified manner. This support
151 implements debug register sharing between watchpoints, which allows to
152 put a virtually infinite number of watchpoints on the same address,
153 and also supports watching regions up to 16 bytes with several debug
156 The new maintenance command `maintenance show-debug-regs' toggles
157 debugging print-outs in functions that insert, remove, and test
158 watchpoints and hardware breakpoints.
160 * Changes in the DJGPP native configuration.
162 New command ``info dos sysinfo'' displays assorted information about
163 the CPU, OS, memory, and DPMI server.
165 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
166 display information about segment descriptors stored in GDT, LDT, and
169 New commands ``info dos pde'' and ``info dos pte'' display entries
170 from Page Directory and Page Tables (for now works with CWSDPMI only).
171 New command ``info dos address-pte'' displays the Page Table entry for
172 a given linear address.
174 GDB can now pass command lines longer than 126 characters to the
175 program being debugged (requires an update to the libdbg.a library
176 which is part of the DJGPP development kit).
178 DWARF2 debug info is now supported.
180 It is now possible to `step' and `next' through calls to `longjmp'.
182 * Changes in documentation.
184 All GDB documentation was converted to GFDL, the GNU Free
185 Documentation License.
187 Tracepoints-related commands are now fully documented in the GDB
190 TUI, the Text-mode User Interface, is now documented in the manual.
192 Tracepoints-related commands are now fully documented in the GDB
195 The "GDB Internals" manual now has an index. It also includes
196 documentation of `ui_out' functions, GDB coding standards, x86
197 hardware watchpoints, and memory region attributes.
199 * GDB's version number moved to ``version.in''
201 The Makefile variable VERSION has been replaced by the file
202 ``version.in''. People creating GDB distributions should update the
203 contents of this file.
207 GUD support is now a standard part of the EMACS distribution.
209 *** Changes in GDB 5.0:
211 * Improved support for debugging FP programs on x86 targets
213 Unified and much-improved support for debugging floating-point
214 programs on all x86 targets. In particular, ``info float'' now
215 displays the FP registers in the same format on all x86 targets, with
216 greater level of detail.
218 * Improvements and bugfixes in hardware-assisted watchpoints
220 It is now possible to watch array elements, struct members, and
221 bitfields with hardware-assisted watchpoints. Data-read watchpoints
222 on x86 targets no longer erroneously trigger when the address is
225 * Improvements in the native DJGPP version of GDB
227 The distribution now includes all the scripts and auxiliary files
228 necessary to build the native DJGPP version on MS-DOS/MS-Windows
229 machines ``out of the box''.
231 The DJGPP version can now debug programs that use signals. It is
232 possible to catch signals that happened in the debuggee, deliver
233 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
234 would kill the program being debugged.) Programs that hook hardware
235 interrupts (keyboard, timer, etc.) can also be debugged.
237 It is now possible to debug DJGPP programs that redirect their
238 standard handles or switch them to raw (as opposed to cooked) mode, or
239 even close them. The command ``run < foo > bar'' works as expected,
240 and ``info terminal'' reports useful information about the debuggee's
241 terminal, including raw/cooked mode, redirection, etc.
243 The DJGPP version now uses termios functions for console I/O, which
244 enables debugging graphics programs. Interrupting GDB with Ctrl-C
247 DOS-style file names with drive letters are now fully supported by
250 It is now possible to debug DJGPP programs that switch their working
251 directory. It is also possible to rerun the debuggee any number of
252 times without restarting GDB; thus, you can use the same setup,
253 breakpoints, etc. for many debugging sessions.
255 * New native configurations
257 ARM GNU/Linux arm*-*-linux*
258 PowerPC GNU/Linux powerpc-*-linux*
262 Motorola MCore mcore-*-*
263 x86 VxWorks i[3456]86-*-vxworks*
264 PowerPC VxWorks powerpc-*-vxworks*
265 TI TMS320C80 tic80-*-*
267 * OBSOLETE configurations
269 Altos 3068 m68*-altos-*
270 Convex c1-*-*, c2-*-*
272 ARM RISCix arm-*-* (as host)
275 Configurations that have been declared obsolete will be commented out,
276 but the code will be left in place. If there is no activity to revive
277 these configurations before the next release of GDB, the sources will
278 be permanently REMOVED.
280 * Gould support removed
282 Support for the Gould PowerNode and NP1 has been removed.
284 * New features for SVR4
286 On SVR4 native platforms (such as Solaris), if you attach to a process
287 without first loading a symbol file, GDB will now attempt to locate and
288 load symbols from the running process's executable file.
290 * Many C++ enhancements
292 C++ support has been greatly improved. Overload resolution now works properly
293 in almost all cases. RTTI support is on the way.
295 * Remote targets can connect to a sub-program
297 A popen(3) style serial-device has been added. This device starts a
298 sub-process (such as a stand-alone simulator) and then communicates
299 with that. The sub-program to run is specified using the syntax
300 ``|<program> <args>'' vis:
302 (gdb) set remotedebug 1
303 (gdb) target extended-remote |mn10300-elf-sim program-args
305 * MIPS 64 remote protocol
307 A long standing bug in the mips64 remote protocol where by GDB
308 expected certain 32 bit registers (ex SR) to be transfered as 32
309 instead of 64 bits has been fixed.
311 The command ``set remote-mips64-transfers-32bit-regs on'' has been
312 added to provide backward compatibility with older versions of GDB.
314 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
316 The command ``set remotebinarydownload'' command has been replaced by
317 ``set remote X-packet''. Other commands in ``set remote'' family
318 include ``set remote P-packet''.
320 * Breakpoint commands accept ranges.
322 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
323 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
324 ``tracepoint passcount'' also accepts a range of tracepoints.
326 * ``apropos'' command added.
328 The ``apropos'' command searches through command names and
329 documentation strings, printing out matches, making it much easier to
330 try to find a command that does what you are looking for.
334 A new machine oriented interface (MI) has been added to GDB. This
335 interface is designed for debug environments running GDB as a separate
336 process. This is part of the long term libGDB project. See the
337 "GDB/MI" chapter of the GDB manual for further information. It can be
338 enabled by configuring with:
340 .../configure --enable-gdbmi
342 *** Changes in GDB-4.18:
344 * New native configurations
346 HP-UX 10.20 hppa*-*-hpux10.20
347 HP-UX 11.x hppa*-*-hpux11.0*
348 M68K Linux m68*-*-linux*
352 Fujitsu FR30 fr30-*-elf*
353 Intel StrongARM strongarm-*-*
354 Mitsubishi D30V d30v-*-*
356 * OBSOLETE configurations
358 Gould PowerNode, NP1 np1-*-*, pn-*-*
360 Configurations that have been declared obsolete will be commented out,
361 but the code will be left in place. If there is no activity to revive
362 these configurations before the next release of GDB, the sources will
363 be permanently REMOVED.
367 As a compatibility experiment, GDB's source files buildsym.h and
368 buildsym.c have been converted to pure standard C, no longer
369 containing any K&R compatibility code. We believe that all systems in
370 use today either come with a standard C compiler, or have a GCC port
371 available. If this is not true, please report the affected
372 configuration to bug-gdb@gnu.org immediately. See the README file for
373 information about getting a standard C compiler if you don't have one
378 GDB now uses readline 2.2.
380 * set extension-language
382 You can now control the mapping between filename extensions and source
383 languages by using the `set extension-language' command. For instance,
384 you can ask GDB to treat .c files as C++ by saying
385 set extension-language .c c++
386 The command `info extensions' lists all of the recognized extensions
387 and their associated languages.
389 * Setting processor type for PowerPC and RS/6000
391 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
392 you can use the `set processor' command to specify what variant of the
393 PowerPC family you are debugging. The command
397 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
398 following PowerPC and RS6000 variants:
400 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
401 rs6000 IBM RS6000 ("POWER") architecture, user-level view
403 403GC IBM PowerPC 403GC
404 505 Motorola PowerPC 505
405 860 Motorola PowerPC 860 or 850
406 601 Motorola PowerPC 601
407 602 Motorola PowerPC 602
408 603 Motorola/IBM PowerPC 603 or 603e
409 604 Motorola PowerPC 604 or 604e
410 750 Motorola/IBM PowerPC 750 or 750
412 At the moment, this command just tells GDB what to name the
413 special-purpose processor registers. Since almost all the affected
414 registers are inaccessible to user-level programs, this command is
415 only useful for remote debugging in its present form.
419 Thanks to a major code donation from Hewlett-Packard, GDB now has much
420 more extensive support for HP-UX. Added features include shared
421 library support, kernel threads and hardware watchpoints for 11.00,
422 support for HP's ANSI C and C++ compilers, and a compatibility mode
423 for xdb and dbx commands.
427 HP's donation includes the new concept of catchpoints, which is a
428 generalization of the old catch command. On HP-UX, it is now possible
429 to catch exec, fork, and vfork, as well as library loading.
431 This means that the existing catch command has changed; its first
432 argument now specifies the type of catch to be set up. See the
433 output of "help catch" for a list of catchpoint types.
435 * Debugging across forks
437 On HP-UX, you can choose which process to debug when a fork() happens
442 HP has donated a curses-based terminal user interface (TUI). To get
443 it, build with --enable-tui. Although this can be enabled for any
444 configuration, at present it only works for native HP debugging.
446 * GDB remote protocol additions
448 A new protocol packet 'X' that writes binary data is now available.
449 Default behavior is to try 'X', then drop back to 'M' if the stub
450 fails to respond. The settable variable `remotebinarydownload'
451 allows explicit control over the use of 'X'.
453 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
454 full 64-bit address. The command
456 set remoteaddresssize 32
458 can be used to revert to the old behaviour. For existing remote stubs
459 the change should not be noticed, as the additional address information
462 In order to assist in debugging stubs, you may use the maintenance
463 command `packet' to send any text string to the stub. For instance,
465 maint packet heythere
467 sends the packet "$heythere#<checksum>". Note that it is very easy to
468 disrupt a debugging session by sending the wrong packet at the wrong
471 The compare-sections command allows you to compare section data on the
472 target to what is in the executable file without uploading or
473 downloading, by comparing CRC checksums.
475 * Tracing can collect general expressions
477 You may now collect general expressions at tracepoints. This requires
478 further additions to the target-side stub; see tracepoint.c and
479 doc/agentexpr.texi for further details.
481 * mask-address variable for Mips
483 For Mips targets, you may control the zeroing of the upper 32 bits of
484 a 64-bit address by entering `set mask-address on'. This is mainly
485 of interest to users of embedded R4xxx and R5xxx processors.
487 * Higher serial baud rates
489 GDB's serial code now allows you to specify baud rates 57600, 115200,
490 230400, and 460800 baud. (Note that your host system may not be able
491 to achieve all of these rates.)
495 The i960 configuration now includes an initial implementation of a
496 builtin simulator, contributed by Jim Wilson.
499 *** Changes in GDB-4.17:
501 * New native configurations
503 Alpha GNU/Linux alpha*-*-linux*
504 Unixware 2.x i[3456]86-unixware2*
505 Irix 6.x mips*-sgi-irix6*
506 PowerPC GNU/Linux powerpc-*-linux*
507 PowerPC Solaris powerpcle-*-solaris*
508 Sparc GNU/Linux sparc-*-linux*
509 Motorola sysV68 R3V7.1 m68k-motorola-sysv
513 Argonaut Risc Chip (ARC) arc-*-*
514 Hitachi H8/300S h8300*-*-*
515 Matsushita MN10200 w/simulator mn10200-*-*
516 Matsushita MN10300 w/simulator mn10300-*-*
517 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
518 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
519 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
520 Mitsubishi D10V w/simulator d10v-*-*
521 Mitsubishi M32R/D w/simulator m32r-*-elf*
522 Tsqware Sparclet sparclet-*-*
523 NEC V850 w/simulator v850-*-*
525 * New debugging protocols
527 ARM with RDI protocol arm*-*-*
528 M68K with dBUG monitor m68*-*-{aout,coff,elf}
529 DDB and LSI variants of PMON protocol mips*-*-*
530 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
531 PowerPC with SDS protocol powerpc{,le}-*-eabi
532 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
536 All configurations can now understand and use the DWARF 2 debugging
537 format. The choice is automatic, if the symbol file contains DWARF 2
542 GDB now includes basic Java language support. This support is
543 only useful with Java compilers that produce native machine code.
545 * solib-absolute-prefix and solib-search-path
547 For SunOS and SVR4 shared libraries, you may now set the prefix for
548 loading absolute shared library symbol files, and the search path for
549 locating non-absolute shared library symbol files.
551 * Live range splitting
553 GDB can now effectively debug code for which GCC has performed live
554 range splitting as part of its optimization. See gdb/doc/LRS for
555 more details on the expected format of the stabs information.
559 GDB's support for the GNU Hurd, including thread debugging, has been
560 updated to work with current versions of the Hurd.
564 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
565 instruction set. ARM GDB automatically detects when Thumb
566 instructions are in use, and adjusts disassembly and backtracing
571 GDB's MIPS target configurations now handle the MIP16 16-bit
576 GDB now includes support for overlays; if an executable has been
577 linked such that multiple sections are based at the same address, GDB
578 will decide which section to use for symbolic info. You can choose to
579 control the decision manually, using overlay commands, or implement
580 additional target-side support and use "overlay load-target" to bring
581 in the overlay mapping. Do "help overlay" for more detail.
585 The command "info symbol <address>" displays information about
586 the symbol at the specified address.
590 The standard remote protocol now includes an extension that allows
591 asynchronous collection and display of trace data. This requires
592 extensive support in the target-side debugging stub. Tracing mode
593 includes a new interaction mode in GDB and new commands: see the
594 file tracepoint.c for more details.
598 Configurations for embedded MIPS now include a simulator contributed
599 by Cygnus Solutions. The simulator supports the instruction sets
600 of most MIPS variants.
604 Sparc configurations may now include the ERC32 simulator contributed
605 by the European Space Agency. The simulator is not built into
606 Sparc targets by default; configure with --enable-sim to include it.
610 For target configurations that may include multiple variants of a
611 basic architecture (such as MIPS and SH), you may now set the
612 architecture explicitly. "set arch" sets, "info arch" lists
613 the possible architectures.
615 *** Changes in GDB-4.16:
617 * New native configurations
619 Windows 95, x86 Windows NT i[345]86-*-cygwin32
620 M68K NetBSD m68k-*-netbsd*
621 PowerPC AIX 4.x powerpc-*-aix*
622 PowerPC MacOS powerpc-*-macos*
623 PowerPC Windows NT powerpcle-*-cygwin32
624 RS/6000 AIX 4.x rs6000-*-aix4*
628 ARM with RDP protocol arm-*-*
629 I960 with MON960 i960-*-coff
630 MIPS VxWorks mips*-*-vxworks*
631 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
632 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
634 Matra Sparclet sparclet-*-*
638 The powerpc-eabi configuration now includes the PSIM simulator,
639 contributed by Andrew Cagney, with assistance from Mike Meissner.
640 PSIM is a very elaborate model of the PowerPC, including not only
641 basic instruction set execution, but also details of execution unit
642 performance and I/O hardware. See sim/ppc/README for more details.
646 GDB now works with Solaris 2.5.
648 * Windows 95/NT native
650 GDB will now work as a native debugger on Windows 95 and Windows NT.
651 To build it from source, you must use the "gnu-win32" environment,
652 which uses a DLL to emulate enough of Unix to run the GNU tools.
653 Further information, binaries, and sources are available at
654 ftp.cygnus.com, under pub/gnu-win32.
656 * dont-repeat command
658 If a user-defined command includes the command `dont-repeat', then the
659 command will not be repeated if the user just types return. This is
660 useful if the command is time-consuming to run, so that accidental
661 extra keystrokes don't run the same command many times.
663 * Send break instead of ^C
665 The standard remote protocol now includes an option to send a break
666 rather than a ^C to the target in order to interrupt it. By default,
667 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
669 * Remote protocol timeout
671 The standard remote protocol includes a new variable `remotetimeout'
672 that allows you to set the number of seconds before GDB gives up trying
673 to read from the target. The default value is 2.
675 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
677 By default GDB will automatically keep track of objects as they are
678 loaded and unloaded by the dynamic linker. By using the command `set
679 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
680 when shared library events occur, thus allowing you to set breakpoints
681 in shared libraries which are explicitly loaded by the inferior.
683 Note this feature does not work on hpux8. On hpux9 you must link
684 /usr/lib/end.o into your program. This feature should work
685 automatically on hpux10.
687 * Irix 5.x hardware watchpoint support
689 Irix 5 configurations now support the use of hardware watchpoints.
691 * Mips protocol "SYN garbage limit"
693 When debugging a Mips target using the `target mips' protocol, you
694 may set the number of characters that GDB will ignore by setting
695 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
696 every character. The default value is 1050.
698 * Recording and replaying remote debug sessions
700 If you set `remotelogfile' to the name of a file, gdb will write to it
701 a recording of a remote debug session. This recording may then be
702 replayed back to gdb using "gdbreplay". See gdbserver/README for
703 details. This is useful when you have a problem with GDB while doing
704 remote debugging; you can make a recording of the session and send it
705 to someone else, who can then recreate the problem.
707 * Speedups for remote debugging
709 GDB includes speedups for downloading and stepping MIPS systems using
710 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
711 and more efficient S-record downloading.
713 * Memory use reductions and statistics collection
715 GDB now uses less memory and reports statistics about memory usage.
716 Try the `maint print statistics' command, for example.
718 *** Changes in GDB-4.15:
722 The symbol reader for AIX GDB now uses partial symbol tables. This
723 can greatly improve startup time, especially for large executables.
725 * Remote targets use caching
727 Remote targets now use a data cache to speed up communication with the
728 remote side. The data cache could lead to incorrect results because
729 it doesn't know about volatile variables, thus making it impossible to
730 debug targets which use memory mapped I/O devices. `set remotecache
731 off' turns the the data cache off.
733 * Remote targets may have threads
735 The standard remote protocol now includes support for multiple threads
736 in the target system, using new protocol commands 'H' and 'T'. See
737 gdb/remote.c for details.
741 If GDB is configured with `--enable-netrom', then it will include
742 support for the NetROM ROM emulator from XLNT Designs. The NetROM
743 acts as though it is a bank of ROM on the target board, but you can
744 write into it over the network. GDB's support consists only of
745 support for fast loading into the emulated ROM; to debug, you must use
746 another protocol, such as standard remote protocol. The usual
747 sequence is something like
749 target nrom <netrom-hostname>
751 target remote <netrom-hostname>:1235
755 GDB now includes support for the Apple Macintosh, as a host only. It
756 may be run as either an MPW tool or as a standalone application, and
757 it can debug through the serial port. All the usual GDB commands are
758 available, but to the target command, you must supply "serial" as the
759 device type instead of "/dev/ttyXX". See mpw-README in the main
760 directory for more information on how to build. The MPW configuration
761 scripts */mpw-config.in support only a few targets, and only the
762 mips-idt-ecoff target has been tested.
766 GDB configuration now uses autoconf. This is not user-visible,
767 but does simplify configuration and building.
771 GDB now supports hpux10.
773 *** Changes in GDB-4.14:
775 * New native configurations
777 x86 FreeBSD i[345]86-*-freebsd
778 x86 NetBSD i[345]86-*-netbsd
779 NS32k NetBSD ns32k-*-netbsd
780 Sparc NetBSD sparc-*-netbsd
784 A29K VxWorks a29k-*-vxworks
785 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
786 CPU32 EST-300 emulator m68*-*-est*
787 PowerPC ELF powerpc-*-elf
790 * Alpha OSF/1 support for procfs
792 GDB now supports procfs under OSF/1-2.x and higher, which makes it
793 possible to attach to running processes. As the mounting of the /proc
794 filesystem is optional on the Alpha, GDB automatically determines
795 the availability of /proc during startup. This can lead to problems
796 if /proc is unmounted after GDB has been started.
798 * Arguments to user-defined commands
800 User commands may accept up to 10 arguments separated by whitespace.
801 Arguments are accessed within the user command via $arg0..$arg9. A
804 print $arg0 + $arg1 + $arg2
806 To execute the command use:
809 Defines the command "adder" which prints the sum of its three arguments.
810 Note the arguments are text substitutions, so they may reference variables,
811 use complex expressions, or even perform inferior function calls.
813 * New `if' and `while' commands
815 This makes it possible to write more sophisticated user-defined
816 commands. Both commands take a single argument, which is the
817 expression to evaluate, and must be followed by the commands to
818 execute, one per line, if the expression is nonzero, the list being
819 terminated by the word `end'. The `if' command list may include an
820 `else' word, which causes the following commands to be executed only
821 if the expression is zero.
823 * Fortran source language mode
825 GDB now includes partial support for Fortran 77. It will recognize
826 Fortran programs and can evaluate a subset of Fortran expressions, but
827 variables and functions may not be handled correctly. GDB will work
828 with G77, but does not yet know much about symbols emitted by other
831 * Better HPUX support
833 Most debugging facilities now work on dynamic executables for HPPAs
834 running hpux9 or later. You can attach to running dynamically linked
835 processes, but by default the dynamic libraries will be read-only, so
836 for instance you won't be able to put breakpoints in them. To change
837 that behavior do the following before running the program:
843 This will cause the libraries to be mapped private and read-write.
844 To revert to the normal behavior, do this:
850 You cannot set breakpoints or examine data in the library until after
851 the library is loaded if the function/data symbols do not have
854 GDB can now also read debug symbols produced by the HP C compiler on
855 HPPAs (sorry, no C++, Fortran or 68k support).
857 * Target byte order now dynamically selectable
859 You can choose which byte order to use with a target system, via the
860 commands "set endian big" and "set endian little", and you can see the
861 current setting by using "show endian". You can also give the command
862 "set endian auto", in which case GDB will use the byte order
863 associated with the executable. Currently, only embedded MIPS
864 configurations support dynamic selection of target byte order.
866 * New DOS host serial code
868 This version uses DPMI interrupts to handle buffered I/O, so you
869 no longer need to run asynctsr when debugging boards connected to
872 *** Changes in GDB-4.13:
874 * New "complete" command
876 This lists all the possible completions for the rest of the line, if it
877 were to be given as a command itself. This is intended for use by emacs.
879 * Trailing space optional in prompt
881 "set prompt" no longer adds a space for you after the prompt you set. This
882 allows you to set a prompt which ends in a space or one that does not.
884 * Breakpoint hit counts
886 "info break" now displays a count of the number of times the breakpoint
887 has been hit. This is especially useful in conjunction with "ignore"; you
888 can ignore a large number of breakpoint hits, look at the breakpoint info
889 to see how many times the breakpoint was hit, then run again, ignoring one
890 less than that number, and this will get you quickly to the last hit of
893 * Ability to stop printing at NULL character
895 "set print null-stop" will cause GDB to stop printing the characters of
896 an array when the first NULL is encountered. This is useful when large
897 arrays actually contain only short strings.
899 * Shared library breakpoints
901 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
902 breakpoints in shared libraries before the executable is run.
904 * Hardware watchpoints
906 There is a new hardware breakpoint for the watch command for sparclite
907 targets. See gdb/sparclite/hw_breakpoint.note.
909 Hardware watchpoints are also now supported under Linux.
913 Annotations have been added. These are for use with graphical interfaces,
914 and are still experimental. Currently only gdba.el uses these.
916 * Improved Irix 5 support
918 GDB now works properly with Irix 5.2.
920 * Improved HPPA support
922 GDB now works properly with the latest GCC and GAS.
924 * New native configurations
926 Sequent PTX4 i[34]86-sequent-ptx4
927 HPPA running OSF/1 hppa*-*-osf*
928 Atari TT running SVR4 m68*-*-sysv4*
929 RS/6000 LynxOS rs6000-*-lynxos*
933 OS/9000 i[34]86-*-os9k
934 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
937 * Hitachi SH7000 and E7000-PC ICE support
939 There is now support for communicating with the Hitachi E7000-PC ICE.
940 This is available automatically when GDB is configured for the SH.
944 As usual, a variety of small fixes and improvements, both generic
945 and configuration-specific. See the ChangeLog for more detail.
947 *** Changes in GDB-4.12:
949 * Irix 5 is now supported
953 GDB-4.12 on the HPPA has a number of changes which make it unable
954 to debug the output from the currently released versions of GCC and
955 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
956 of GCC and GAS, versions of these tools designed to work with GDB-4.12
957 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
960 *** Changes in GDB-4.11:
962 * User visible changes:
966 The "set remotedebug" option is now consistent between the mips remote
967 target, remote targets using the gdb-specific protocol, UDI (AMD's
968 debug protocol for the 29k) and the 88k bug monitor. It is now an
969 integer specifying a debug level (normally 0 or 1, but 2 means more
970 debugging info for the mips target).
972 * DEC Alpha native support
974 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
975 debug info, but GDB works fairly well with the DEC compiler and should
976 work with a future GCC release. See the README file for a few
977 Alpha-specific notes.
979 * Preliminary thread implementation
981 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
983 * LynxOS native and target support for 386
985 This release has been hosted on LynxOS 2.2, and also can be configured
986 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
989 * Improvements in C++ mangling/demangling.
991 This release has much better g++ debugging, specifically in name
992 mangling/demangling, virtual function calls, print virtual table,
993 call methods, ...etc.
995 *** Changes in GDB-4.10:
997 * User visible changes:
999 Remote debugging using the GDB-specific (`target remote') protocol now
1000 supports the `load' command. This is only useful if you have some
1001 other way of getting the stub to the target system, and you can put it
1002 somewhere in memory where it won't get clobbered by the download.
1004 Filename completion now works.
1006 When run under emacs mode, the "info line" command now causes the
1007 arrow to point to the line specified. Also, "info line" prints
1008 addresses in symbolic form (as well as hex).
1010 All vxworks based targets now support a user settable option, called
1011 vxworks-timeout. This option represents the number of seconds gdb
1012 should wait for responses to rpc's. You might want to use this if
1013 your vxworks target is, perhaps, a slow software simulator or happens
1014 to be on the far side of a thin network line.
1018 This release contains support for using a DEC alpha as a GDB host for
1019 cross debugging. Native alpha debugging is not supported yet.
1022 *** Changes in GDB-4.9:
1026 This is the first GDB release which is accompanied by a matching testsuite.
1027 The testsuite requires installation of dejagnu, which should be available
1028 via ftp from most sites that carry GNU software.
1032 'Cfront' style demangling has had its name changed to 'ARM' style, to
1033 emphasize that it was written from the specifications in the C++ Annotated
1034 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
1035 disclaimers, it still generated too much confusion with users attempting to
1036 use gdb with AT&T cfront.
1040 GDB now uses a standard remote interface to a simulator library.
1041 So far, the library contains simulators for the Zilog Z8001/2, the
1042 Hitachi H8/300, H8/500 and Super-H.
1044 * New targets supported
1046 H8/300 simulator h8300-hitachi-hms or h8300hms
1047 H8/500 simulator h8500-hitachi-hms or h8500hms
1048 SH simulator sh-hitachi-hms or sh
1049 Z8000 simulator z8k-zilog-none or z8ksim
1050 IDT MIPS board over serial line mips-idt-ecoff
1052 Cross-debugging to GO32 targets is supported. It requires a custom
1053 version of the i386-stub.c module which is integrated with the
1054 GO32 memory extender.
1056 * New remote protocols
1058 MIPS remote debugging protocol.
1060 * New source languages supported
1062 This version includes preliminary support for Chill, a Pascal like language
1063 used by telecommunications companies. Chill support is also being integrated
1064 into the GNU compiler, but we don't know when it will be publically available.
1067 *** Changes in GDB-4.8:
1069 * HP Precision Architecture supported
1071 GDB now supports HP PA-RISC machines running HPUX. A preliminary
1072 version of this support was available as a set of patches from the
1073 University of Utah. GDB does not support debugging of programs
1074 compiled with the HP compiler, because HP will not document their file
1075 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
1076 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
1078 Many problems in the preliminary version have been fixed.
1080 * Faster and better demangling
1082 We have improved template demangling and fixed numerous bugs in the GNU style
1083 demangler. It can now handle type modifiers such as `static' or `const'. Wide
1084 character types (wchar_t) are now supported. Demangling of each symbol is now
1085 only done once, and is cached when the symbol table for a file is read in.
1086 This results in a small increase in memory usage for C programs, a moderate
1087 increase in memory usage for C++ programs, and a fantastic speedup in
1090 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
1091 from the specifications in the Annotated Reference Manual, which AT&T's
1092 compiler does not actually implement.
1094 * G++ multiple inheritance compiler problem
1096 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
1097 inheritance lattices was reworked to properly discover ambiguities. We
1098 recently found an example which causes this new algorithm to fail in a
1099 very subtle way, producing bad debug information for those classes.
1100 The file 'gcc.patch' (in this directory) can be applied to gcc to
1101 circumvent the problem. A future GCC release will contain a complete
1104 The previous G++ debug info problem (mentioned below for the gdb-4.7
1105 release) is fixed in gcc version 2.3.2.
1107 * Improved configure script
1109 The `configure' script will now attempt to guess your system type if
1110 you don't supply a host system type. The old scheme of supplying a
1111 host system triplet is preferable over using this. All the magic is
1112 done in the new `config.guess' script. Examine it for details.
1114 We have also brought our configure script much more in line with the FSF's
1115 version. It now supports the --with-xxx options. In particular,
1116 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
1117 The resulting GDB will not be able to read arbitrary object file formats --
1118 only the format ``expected'' to be used on the configured target system.
1119 We hope to make this the default in a future release.
1121 * Documentation improvements
1123 There's new internal documentation on how to modify GDB, and how to
1124 produce clean changes to the code. We implore people to read it
1125 before submitting changes.
1127 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
1128 M4 macros. The new texinfo.tex is provided in this release. Pre-built
1129 `info' files are also provided. To build `info' files from scratch,
1130 you will need the latest `makeinfo' release, which will be available in
1131 a future texinfo-X.Y release.
1133 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
1134 We're not sure exactly which versions have this problem, but it has
1135 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
1136 or better. If that isn't possible, there is a patch in
1137 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
1138 around this problem.
1142 GDB now supports array constants that can be used in expressions typed in by
1143 the user. The syntax is `{element, element, ...}'. Ie: you can now type
1144 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
1147 The new directory `gdb/sparclite' contains a program that demonstrates
1148 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
1150 * New native hosts supported
1152 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
1153 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
1155 * New targets supported
1157 AMD 29k family via UDI a29k-amd-udi or udi29k
1159 * New file formats supported
1161 BFD now supports reading HP/PA-RISC executables (SOM file format?),
1162 HPUX core files, and SCO 3.2v2 core files.
1166 Attaching to processes now works again; thanks for the many bug reports.
1168 We have also stomped on a bunch of core dumps caused by
1169 printf_filtered("%s") problems.
1171 We eliminated a copyright problem on the rpc and ptrace header files
1172 for VxWorks, which was discovered at the last minute during the 4.7
1173 release. You should now be able to build a VxWorks GDB.
1175 You can now interrupt gdb while an attached process is running. This
1176 will cause the attached process to stop, and give control back to GDB.
1178 We fixed problems caused by using too many file descriptors
1179 for reading symbols from object files and libraries. This was
1180 especially a problem for programs that used many (~100) shared
1183 The `step' command now only enters a subroutine if there is line number
1184 information for the subroutine. Otherwise it acts like the `next'
1185 command. Previously, `step' would enter subroutines if there was
1186 any debugging information about the routine. This avoids problems
1187 when using `cc -g1' on MIPS machines.
1189 * Internal improvements
1191 GDB's internal interfaces have been improved to make it easier to support
1192 debugging of multiple languages in the future.
1194 GDB now uses a common structure for symbol information internally.
1195 Minimal symbols (derived from linkage symbols in object files), partial
1196 symbols (from a quick scan of debug information), and full symbols
1197 contain a common subset of information, making it easier to write
1198 shared code that handles any of them.
1200 * New command line options
1202 We now accept --silent as an alias for --quiet.
1206 The memory-mapped-malloc library is now licensed under the GNU Library
1207 General Public License.
1209 *** Changes in GDB-4.7:
1211 * Host/native/target split
1213 GDB has had some major internal surgery to untangle the support for
1214 hosts and remote targets. Now, when you configure GDB for a remote
1215 target, it will no longer load in all of the support for debugging
1216 local programs on the host. When fully completed and tested, this will
1217 ensure that arbitrary host/target combinations are possible.
1219 The primary conceptual shift is to separate the non-portable code in
1220 GDB into three categories. Host specific code is required any time GDB
1221 is compiled on that host, regardless of the target. Target specific
1222 code relates to the peculiarities of the target, but can be compiled on
1223 any host. Native specific code is everything else: it can only be
1224 built when the host and target are the same system. Child process
1225 handling and core file support are two common `native' examples.
1227 GDB's use of /proc for controlling Unix child processes is now cleaner.
1228 It has been split out into a single module under the `target_ops' vector,
1229 plus two native-dependent functions for each system that uses /proc.
1231 * New hosts supported
1233 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
1234 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
1235 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
1237 * New targets supported
1239 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
1240 68030 and CPU32 m68030-*-*, m68332-*-*
1242 * New native hosts supported
1244 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
1245 (386bsd is not well tested yet)
1246 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
1248 * New file formats supported
1250 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
1251 supports reading of `a.out.adobe' object files, which are an a.out
1252 format extended with minimal information about multiple sections.
1256 `show copying' is the same as the old `info copying'.
1257 `show warranty' is the same as `info warrantee'.
1258 These were renamed for consistency. The old commands continue to work.
1260 `info handle' is a new alias for `info signals'.
1262 You can now define pre-command hooks, which attach arbitrary command
1263 scripts to any command. The commands in the hook will be executed
1264 prior to the user's command. You can also create a hook which will be
1265 executed whenever the program stops. See gdb.texinfo.
1269 We now deal with Cfront style name mangling, and can even extract type
1270 info from mangled symbols. GDB can automatically figure out which
1271 symbol mangling style your C++ compiler uses.
1273 Calling of methods and virtual functions has been improved as well.
1277 The crash that occured when debugging Sun Ansi-C compiled binaries is
1278 fixed. This was due to mishandling of the extra N_SO stabs output
1281 We also finally got Ultrix 4.2 running in house, and fixed core file
1282 support, with help from a dozen people on the net.
1284 John M. Farrell discovered that the reason that single-stepping was so
1285 slow on all of the Mips based platforms (primarily SGI and DEC) was
1286 that we were trying to demangle and lookup a symbol used for internal
1287 purposes on every instruction that was being stepped through. Changing
1288 the name of that symbol so that it couldn't be mistaken for a C++
1289 mangled symbol sped things up a great deal.
1291 Rich Pixley sped up symbol lookups in general by getting much smarter
1292 about when C++ symbol mangling is necessary. This should make symbol
1293 completion (TAB on the command line) much faster. It's not as fast as
1294 we'd like, but it's significantly faster than gdb-4.6.
1298 A new user controllable variable 'call_scratch_address' can
1299 specify the location of a scratch area to be used when GDB
1300 calls a function in the target. This is necessary because the
1301 usual method of putting the scratch area on the stack does not work
1302 in systems that have separate instruction and data spaces.
1304 We integrated changes to support the 29k UDI (Universal Debugger
1305 Interface), but discovered at the last minute that we didn't have all
1306 of the appropriate copyright paperwork. We are working with AMD to
1307 resolve this, and hope to have it available soon.
1311 We have sped up the remote serial line protocol, especially for targets
1312 with lots of registers. It now supports a new `expedited status' ('T')
1313 message which can be used in place of the existing 'S' status message.
1314 This allows the remote stub to send only the registers that GDB
1315 needs to make a quick decision about single-stepping or conditional
1316 breakpoints, eliminating the need to fetch the entire register set for
1317 each instruction being stepped through.
1319 The GDB remote serial protocol now implements a write-through cache for
1320 registers, only re-reading the registers if the target has run.
1322 There is also a new remote serial stub for SPARC processors. You can
1323 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
1324 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
1325 processor with a serial port.
1329 Configure.in files have become much easier to read and modify. A new
1330 `table driven' format makes it more obvious what configurations are
1331 supported, and what files each one uses.
1335 There is a new opcodes library which will eventually contain all of the
1336 disassembly routines and opcode tables. At present, it only contains
1337 Sparc and Z8000 routines. This will allow the assembler, debugger, and
1338 disassembler (binutils/objdump) to share these routines.
1340 The libiberty library is now copylefted under the GNU Library General
1341 Public License. This allows more liberal use, and was done so libg++
1342 can use it. This makes no difference to GDB, since the Library License
1343 grants all the rights from the General Public License.
1347 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
1348 reference to the stabs symbol info used by the debugger. It is (as far
1349 as we know) the only published document on this fascinating topic. We
1350 encourage you to read it, compare it to the stabs information on your
1351 system, and send improvements on the document in general (to
1352 bug-gdb@prep.ai.mit.edu).
1354 And, of course, many bugs have been fixed.
1357 *** Changes in GDB-4.6:
1359 * Better support for C++ function names
1361 GDB now accepts as input the "demangled form" of C++ overloaded function
1362 names and member function names, and can do command completion on such names
1363 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
1364 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
1365 Make use of command completion, it is your friend.
1367 GDB also now accepts a variety of C++ mangled symbol formats. They are
1368 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
1369 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
1370 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
1371 for the list of formats.
1373 * G++ symbol mangling problem
1375 Recent versions of gcc have a bug in how they emit debugging information for
1376 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
1377 directory) can be applied to gcc to fix the problem. Alternatively, if you
1378 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
1379 usual symptom is difficulty with setting breakpoints on methods. GDB complains
1380 about the method being non-existent. (We believe that version 2.2.2 of GCC has
1383 * New 'maintenance' command
1385 All of the commands related to hacking GDB internals have been moved out of
1386 the main command set, and now live behind the 'maintenance' command. This
1387 can also be abbreviated as 'mt'. The following changes were made:
1389 dump-me -> maintenance dump-me
1390 info all-breakpoints -> maintenance info breakpoints
1391 printmsyms -> maintenance print msyms
1392 printobjfiles -> maintenance print objfiles
1393 printpsyms -> maintenance print psymbols
1394 printsyms -> maintenance print symbols
1396 The following commands are new:
1398 maintenance demangle Call internal GDB demangler routine to
1399 demangle a C++ link name and prints the result.
1400 maintenance print type Print a type chain for a given symbol
1402 * Change to .gdbinit file processing
1404 We now read the $HOME/.gdbinit file before processing the argv arguments
1405 (e.g. reading symbol files or core files). This allows global parameters to
1406 be set, which will apply during the symbol reading. The ./.gdbinit is still
1407 read after argv processing.
1409 * New hosts supported
1411 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
1413 Linux support i386-unknown-linux or linux
1415 We are also including code to support the HP/PA running BSD and HPUX. This
1416 is almost guaranteed not to work, as we didn't have time to test or build it
1417 for this release. We are including it so that the more adventurous (or
1418 masochistic) of you can play with it. We also had major problems with the
1419 fact that the compiler that we got from HP doesn't support the -g option.
1422 * New targets supported
1424 Hitachi H8/300 h8300-hitachi-hms or h8300hms
1426 * More smarts about finding #include files
1428 GDB now remembers the compilation directory for all include files, and for
1429 all files from which C is generated (like yacc and lex sources). This
1430 greatly improves GDB's ability to find yacc/lex sources, and include files,
1431 especially if you are debugging your program from a directory different from
1432 the one that contains your sources.
1434 We also fixed a bug which caused difficulty with listing and setting
1435 breakpoints in include files which contain C code. (In the past, you had to
1436 try twice in order to list an include file that you hadn't looked at before.)
1438 * Interesting infernals change
1440 GDB now deals with arbitrary numbers of sections, where the symbols for each
1441 section must be relocated relative to that section's landing place in the
1442 target's address space. This work was needed to support ELF with embedded
1443 stabs used by Solaris-2.0.
1445 * Bug fixes (of course!)
1447 There have been loads of fixes for the following things:
1448 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
1449 i960, stabs, DOS(GO32), procfs, etc...
1451 See the ChangeLog for details.
1453 *** Changes in GDB-4.5:
1455 * New machines supported (host and target)
1457 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
1459 SGI Irix-4.x mips-sgi-irix4 or iris4
1461 * New malloc package
1463 GDB now uses a new memory manager called mmalloc, based on gmalloc.
1464 Mmalloc is capable of handling mutiple heaps of memory. It is also
1465 capable of saving a heap to a file, and then mapping it back in later.
1466 This can be used to greatly speedup the startup of GDB by using a
1467 pre-parsed symbol table which lives in a mmalloc managed heap. For
1468 more details, please read mmalloc/mmalloc.texi.
1472 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
1473 'help info proc' for details.
1475 * MIPS ecoff symbol table format
1477 The code that reads MIPS symbol table format is now supported on all hosts.
1478 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
1481 * File name changes for MS-DOS
1483 Many files in the config directories have been renamed to make it easier to
1484 support GDB on MS-DOSe systems (which have very restrictive file name
1485 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
1486 environment) is close to working but has some remaining problems. Note
1487 that debugging of DOS programs is not supported, due to limitations
1488 in the ``operating system'', but it can be used to host cross-debugging.
1490 * Cross byte order fixes
1492 Many fixes have been made to support cross debugging of Sparc and MIPS
1493 targets from hosts whose byte order differs.
1495 * New -mapped and -readnow options
1497 If memory-mapped files are available on your system through the 'mmap'
1498 system call, you can use the -mapped option on the `file' or
1499 `symbol-file' commands to cause GDB to write the symbols from your
1500 program into a reusable file. If the program you are debugging is
1501 called `/path/fred', the mapped symbol file will be `./fred.syms'.
1502 Future GDB debugging sessions will notice the presence of this file,
1503 and will quickly map in symbol information from it, rather than reading
1504 the symbol table from the executable program. Using the '-mapped'
1505 option in a GDB `file' or `symbol-file' command has the same effect as
1506 starting GDB with the '-mapped' command-line option.
1508 You can cause GDB to read the entire symbol table immediately by using
1509 the '-readnow' option with any of the commands that load symbol table
1510 information (or on the GDB command line). This makes the command
1511 slower, but makes future operations faster.
1513 The -mapped and -readnow options are typically combined in order to
1514 build a `fred.syms' file that contains complete symbol information.
1515 A simple GDB invocation to do nothing but build a `.syms' file for future
1518 gdb -batch -nx -mapped -readnow programname
1520 The `.syms' file is specific to the host machine on which GDB is run.
1521 It holds an exact image of GDB's internal symbol table. It cannot be
1522 shared across multiple host platforms.
1524 * longjmp() handling
1526 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
1527 siglongjmp() without losing control. This feature has not yet been ported to
1528 all systems. It currently works on many 386 platforms, all MIPS-based
1529 platforms (SGI, DECstation, etc), and Sun3/4.
1533 Preliminary work has been put in to support the new Solaris OS from Sun. At
1534 this time, it can control and debug processes, but it is not capable of
1539 As always, many many bug fixes. The major areas were with g++, and mipsread.
1540 People using the MIPS-based platforms should experience fewer mysterious
1541 crashes and trashed symbol tables.
1543 *** Changes in GDB-4.4:
1545 * New machines supported (host and target)
1547 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
1549 BSD Reno on Vax vax-dec-bsd
1550 Ultrix on Vax vax-dec-ultrix
1552 * New machines supported (target)
1554 AMD 29000 embedded, using EBMON a29k-none-none
1558 GDB continues to improve its handling of C++. `References' work better.
1559 The demangler has also been improved, and now deals with symbols mangled as
1560 per the Annotated C++ Reference Guide.
1562 GDB also now handles `stabs' symbol information embedded in MIPS
1563 `ecoff' symbol tables. Since the ecoff format was not easily
1564 extensible to handle new languages such as C++, this appeared to be a
1565 good way to put C++ debugging info into MIPS binaries. This option
1566 will be supported in the GNU C compiler, version 2, when it is
1569 * New features for SVR4
1571 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
1572 shared libraries. Debugging dynamically linked programs should present
1573 only minor differences from debugging statically linked programs.
1575 The `info proc' command will print out information about any process
1576 on an SVR4 system (including the one you are debugging). At the moment,
1577 it prints the address mappings of the process.
1579 If you bring up GDB on another SVR4 system, please send mail to
1580 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
1582 * Better dynamic linking support in SunOS
1584 Reading symbols from shared libraries which contain debugging symbols
1585 now works properly. However, there remain issues such as automatic
1586 skipping of `transfer vector' code during function calls, which
1587 make it harder to debug code in a shared library, than to debug the
1588 same code linked statically.
1592 GDB is now using the latest `getopt' routines from the FSF. This
1593 version accepts the -- prefix for options with long names. GDB will
1594 continue to accept the old forms (-option and +option) as well.
1595 Various single letter abbreviations for options have been explicity
1596 added to the option table so that they won't get overshadowed in the
1597 future by other options that begin with the same letter.
1601 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
1602 Many assorted bugs have been handled. Many more remain to be handled.
1603 See the various ChangeLog files (primarily in gdb and bfd) for details.
1606 *** Changes in GDB-4.3:
1608 * New machines supported (host and target)
1610 Amiga 3000 running Amix m68k-cbm-svr4 or amix
1611 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
1612 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
1614 * Almost SCO Unix support
1616 We had hoped to support:
1617 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
1618 (except for core file support), but we discovered very late in the release
1619 that it has problems with process groups that render gdb unusable. Sorry
1620 about that. I encourage people to fix it and post the fixes.
1622 * Preliminary ELF and DWARF support
1624 GDB can read ELF object files on System V Release 4, and can handle
1625 debugging records for C, in DWARF format, in ELF files. This support
1626 is preliminary. If you bring up GDB on another SVR4 system, please
1627 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
1632 GDB now uses the latest `readline' library. One user-visible change
1633 is that two tabs will list possible command completions, which previously
1634 required typing M-? (meta-question mark, or ESC ?).
1638 The `stepi' bug that many of you noticed has been squashed.
1639 Many bugs in C++ have been handled. Many more remain to be handled.
1640 See the various ChangeLog files (primarily in gdb and bfd) for details.
1642 * State of the MIPS world (in case you wondered):
1644 GDB can understand the symbol tables emitted by the compilers
1645 supplied by most vendors of MIPS-based machines, including DEC. These
1646 symbol tables are in a format that essentially nobody else uses.
1648 Some versions of gcc come with an assembler post-processor called
1649 mips-tfile. This program is required if you want to do source-level
1650 debugging of gcc-compiled programs. I believe FSF does not ship
1651 mips-tfile with gcc version 1, but it will eventually come with gcc
1654 Debugging of g++ output remains a problem. g++ version 1.xx does not
1655 really support it at all. (If you're lucky, you should be able to get
1656 line numbers and stack traces to work, but no parameters or local
1657 variables.) With some work it should be possible to improve the
1660 When gcc version 2 is released, you will have somewhat better luck.
1661 However, even then you will get confusing results for inheritance and
1664 We will eventually provide full debugging of g++ output on
1665 DECstations. This will probably involve some kind of stabs-in-ecoff
1666 encapulation, but the details have not been worked out yet.
1669 *** Changes in GDB-4.2:
1671 * Improved configuration
1673 Only one copy of `configure' exists now, and it is not self-modifying.
1674 Porting BFD is simpler.
1678 The `step' and `next' commands now only stop at the first instruction
1679 of a source line. This prevents the multiple stops that used to occur
1680 in switch statements, for-loops, etc. `Step' continues to stop if a
1681 function that has debugging information is called within the line.
1685 Lots of small bugs fixed. More remain.
1687 * New host supported (not target)
1689 Intel 386 PC clone running Mach i386-none-mach
1692 *** Changes in GDB-4.1:
1694 * Multiple source language support
1696 GDB now has internal scaffolding to handle several source languages.
1697 It determines the type of each source file from its filename extension,
1698 and will switch expression parsing and number formatting to match the
1699 language of the function in the currently selected stack frame.
1700 You can also specifically set the language to be used, with
1701 `set language c' or `set language modula-2'.
1705 GDB now has preliminary support for the GNU Modula-2 compiler,
1706 currently under development at the State University of New York at
1707 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
1708 continue through the fall of 1991 and into 1992.
1710 Other Modula-2 compilers are currently not supported, and attempting to
1711 debug programs compiled with them will likely result in an error as the
1712 symbol table is read. Feel free to work on it, though!
1714 There are hooks in GDB for strict type checking and range checking,
1715 in the `Modula-2 philosophy', but they do not currently work.
1719 GDB can now write to executable and core files (e.g. patch
1720 a variable's value). You must turn this switch on, specify
1721 the file ("exec foo" or "core foo"), *then* modify it, e.g.
1722 by assigning a new value to a variable. Modifications take
1725 * Automatic SunOS shared library reading
1727 When you run your program, GDB automatically determines where its
1728 shared libraries (if any) have been loaded, and reads their symbols.
1729 The `share' command is no longer needed. This also works when
1730 examining core files.
1734 You can specify the number of lines that the `list' command shows.
1737 * New machines supported (host and target)
1739 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
1740 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
1741 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
1743 * New hosts supported (not targets)
1745 IBM RT/PC: romp-ibm-aix or rtpc
1747 * New targets supported (not hosts)
1749 AMD 29000 embedded with COFF a29k-none-coff
1750 AMD 29000 embedded with a.out a29k-none-aout
1751 Ultracomputer remote kernel debug a29k-nyu-kern
1753 * New remote interfaces
1759 *** Changes in GDB-4.0:
1763 Wide output is wrapped at good places to make the output more readable.
1765 Gdb now supports cross-debugging from a host machine of one type to a
1766 target machine of another type. Communication with the target system
1767 is over serial lines. The ``target'' command handles connecting to the
1768 remote system; the ``load'' command will download a program into the
1769 remote system. Serial stubs for the m68k and i386 are provided. Gdb
1770 also supports debugging of realtime processes running under VxWorks,
1771 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
1772 stub on the target system.
1774 New CPUs supported include the AMD 29000 and Intel 960.
1776 GDB now reads object files and symbol tables via a ``binary file''
1777 library, which allows a single copy of GDB to debug programs of multiple
1778 object file types such as a.out and coff.
1780 There is now a GDB reference card in "doc/refcard.tex". (Make targets
1781 refcard.dvi and refcard.ps are available to format it).
1784 * Control-Variable user interface simplified
1786 All variables that control the operation of the debugger can be set
1787 by the ``set'' command, and displayed by the ``show'' command.
1789 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
1790 ``Show prompt'' produces the response:
1791 Gdb's prompt is new-gdb=>.
1793 What follows are the NEW set commands. The command ``help set'' will
1794 print a complete list of old and new set commands. ``help set FOO''
1795 will give a longer description of the variable FOO. ``show'' will show
1796 all of the variable descriptions and their current settings.
1798 confirm on/off: Enables warning questions for operations that are
1799 hard to recover from, e.g. rerunning the program while
1800 it is already running. Default is ON.
1802 editing on/off: Enables EMACS style command line editing
1803 of input. Previous lines can be recalled with
1804 control-P, the current line can be edited with control-B,
1805 you can search for commands with control-R, etc.
1808 history filename NAME: NAME is where the gdb command history
1809 will be stored. The default is .gdb_history,
1810 or the value of the environment variable
1813 history size N: The size, in commands, of the command history. The
1814 default is 256, or the value of the environment variable
1817 history save on/off: If this value is set to ON, the history file will
1818 be saved after exiting gdb. If set to OFF, the
1819 file will not be saved. The default is OFF.
1821 history expansion on/off: If this value is set to ON, then csh-like
1822 history expansion will be performed on
1823 command line input. The default is OFF.
1825 radix N: Sets the default radix for input and output. It can be set
1826 to 8, 10, or 16. Note that the argument to "radix" is interpreted
1827 in the current radix, so "set radix 10" is always a no-op.
1829 height N: This integer value is the number of lines on a page. Default
1830 is 24, the current `stty rows'' setting, or the ``li#''
1831 setting from the termcap entry matching the environment
1834 width N: This integer value is the number of characters on a line.
1835 Default is 80, the current `stty cols'' setting, or the ``co#''
1836 setting from the termcap entry matching the environment
1839 Note: ``set screensize'' is obsolete. Use ``set height'' and
1840 ``set width'' instead.
1842 print address on/off: Print memory addresses in various command displays,
1843 such as stack traces and structure values. Gdb looks
1844 more ``symbolic'' if you turn this off; it looks more
1845 ``machine level'' with it on. Default is ON.
1847 print array on/off: Prettyprint arrays. New convenient format! Default
1850 print demangle on/off: Print C++ symbols in "source" form if on,
1853 print asm-demangle on/off: Same, for assembler level printouts
1856 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
1859 * Support for Epoch Environment.
1861 The epoch environment is a version of Emacs v18 with windowing. One
1862 new command, ``inspect'', is identical to ``print'', except that if you
1863 are running in the epoch environment, the value is printed in its own
1867 * Support for Shared Libraries
1869 GDB can now debug programs and core files that use SunOS shared libraries.
1870 Symbols from a shared library cannot be referenced
1871 before the shared library has been linked with the program (this
1872 happens after you type ``run'' and before the function main() is entered).
1873 At any time after this linking (including when examining core files
1874 from dynamically linked programs), gdb reads the symbols from each
1875 shared library when you type the ``sharedlibrary'' command.
1876 It can be abbreviated ``share''.
1878 sharedlibrary REGEXP: Load shared object library symbols for files
1879 matching a unix regular expression. No argument
1880 indicates to load symbols for all shared libraries.
1882 info sharedlibrary: Status of loaded shared libraries.
1887 A watchpoint stops execution of a program whenever the value of an
1888 expression changes. Checking for this slows down execution
1889 tremendously whenever you are in the scope of the expression, but is
1890 quite useful for catching tough ``bit-spreader'' or pointer misuse
1891 problems. Some machines such as the 386 have hardware for doing this
1892 more quickly, and future versions of gdb will use this hardware.
1894 watch EXP: Set a watchpoint (breakpoint) for an expression.
1896 info watchpoints: Information about your watchpoints.
1898 delete N: Deletes watchpoint number N (same as breakpoints).
1899 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
1900 enable N: Re-enables watchpoint number N (same as breakpoints).
1903 * C++ multiple inheritance
1905 When used with a GCC version 2 compiler, GDB supports multiple inheritance
1908 * C++ exception handling
1910 Gdb now supports limited C++ exception handling. Besides the existing
1911 ability to breakpoint on an exception handler, gdb can breakpoint on
1912 the raising of an exception (before the stack is peeled back to the
1915 catch FOO: If there is a FOO exception handler in the dynamic scope,
1916 set a breakpoint to catch exceptions which may be raised there.
1917 Multiple exceptions (``catch foo bar baz'') may be caught.
1919 info catch: Lists all exceptions which may be caught in the
1920 current stack frame.
1923 * Minor command changes
1925 The command ``call func (arg, arg, ...)'' now acts like the print
1926 command, except it does not print or save a value if the function's result
1927 is void. This is similar to dbx usage.
1929 The ``up'' and ``down'' commands now always print the frame they end up
1930 at; ``up-silently'' and `down-silently'' can be used in scripts to change
1931 frames without printing.
1933 * New directory command
1935 'dir' now adds directories to the FRONT of the source search path.
1936 The path starts off empty. Source files that contain debug information
1937 about the directory in which they were compiled can be found even
1938 with an empty path; Sun CC and GCC include this information. If GDB can't
1939 find your source file in the current directory, type "dir .".
1941 * Configuring GDB for compilation
1943 For normal use, type ``./configure host''. See README or gdb.texinfo
1946 GDB now handles cross debugging. If you are remotely debugging between
1947 two different machines, type ``./configure host -target=targ''.
1948 Host is the machine where GDB will run; targ is the machine
1949 where the program that you are debugging will run.