1 What has changed in GDB?
2 (Organized release by release)
4 *** Changes since GDB 5.1:
6 * New command "set trust-readonly-sections on[off]".
8 This command is a hint that tells gdb that read-only sections
9 really are read-only (ie. that their contents will not change).
10 In this mode, gdb will go to the object file rather than the
11 target to read memory from read-only sections (such as ".text").
12 This can be a significant performance improvement on some
13 (notably embedded) targets.
15 * New command "generate-core-file" (or "gcore").
17 This new gdb command allows the user to drop a core file of the child
18 process state at any time. So far it's been implemented only for
19 GNU/Linux and Solaris, but should be relatively easily ported to other
20 hosts. Argument is core file name (defaults to core.<pid>).
22 * New command line option
24 GDB now accepts --pid or -p followed by a process id.
26 * Change in command line behavior -- corefiles vs. process ids.
28 There is a subtle behavior in the way in which GDB handles
29 command line arguments. The first non-flag argument is always
30 a program to debug, but the second non-flag argument may either
31 be a corefile or a process id. Previously, GDB would attempt to
32 open the second argument as a corefile, and if that failed, would
33 issue a superfluous error message and then attempt to attach it as
34 a process. Now, if the second argument begins with a non-digit,
35 it will be treated as a corefile. If it begins with a digit,
36 GDB will attempt to attach it as a process, and if no such process
37 is found, will then attempt to open it as a corefile.
39 * Changes in ARM configurations.
41 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
42 configuration is fully multi-arch.
44 * New native configurations
46 ARM NetBSD arm*-*-netbsd*
47 x86 OpenBSD i[3456]86-*-openbsd*
48 AMD x86-64 running GNU/Linux x86_64-*-linux-*
52 Sanyo XStormy16 xstormy16-elf
54 * OBSOLETE configurations and files
56 Configurations that have been declared obsolete in this release have
57 been commented out. Unless there is activity to revive these
58 configurations, the next release of GDB will have their sources
61 AMD 29k family via UDI a29k-amd-udi, udi29k
62 A29K VxWorks a29k-*-vxworks
63 AMD 29000 embedded, using EBMON a29k-none-none
64 AMD 29000 embedded with COFF a29k-none-coff
65 AMD 29000 embedded with a.out a29k-none-aout
67 testsuite/gdb.hp/gdb.threads-hp/ directory
69 * REMOVED configurations and files
71 TI TMS320C80 tic80-*-*
73 PowerPC Solaris powerpcle-*-solaris*
74 PowerPC Windows NT powerpcle-*-cygwin32
75 PowerPC Netware powerpc-*-netware*
76 Harris/CXUX m88k m88*-harris-cxux*
77 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
78 ns32k-utek-sysv* ns32k-utek-*
79 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
80 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
81 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
82 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
83 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
85 * Changes to command line processing
87 The new `--args' feature can be used to specify command-line arguments
88 for the inferior from gdb's command line.
90 * Changes to key bindings
92 There is a new `operate-and-get-next' function bound to `C-o'.
94 *** Changes in GDB 5.1.1
96 Fix compile problem on DJGPP.
98 Fix a problem with floating-point registers on the i386 being
101 Fix to stop GDB crashing on .debug_str debug info.
103 Numerous documentation fixes.
105 Numerous testsuite fixes.
107 *** Changes in GDB 5.1:
109 * New native configurations
111 Alpha FreeBSD alpha*-*-freebsd*
112 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
113 MIPS GNU/Linux mips*-*-linux*
114 MIPS SGI Irix 6.x mips*-sgi-irix6*
116 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
120 Motorola 68HC11 and 68HC12 m68hc11-elf
122 UltraSparc running GNU/Linux sparc64-*-linux*
124 * OBSOLETE configurations and files
126 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
127 Harris/CXUX m88k m88*-harris-cxux*
128 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
129 ns32k-utek-sysv* ns32k-utek-*
130 TI TMS320C80 tic80-*-*
132 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
133 PowerPC Solaris powerpcle-*-solaris*
134 PowerPC Windows NT powerpcle-*-cygwin32
135 PowerPC Netware powerpc-*-netware*
136 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
137 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
138 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
139 Apple Macintosh (MPW) host N/A
141 stuff.c (Program to stuff files into a specially prepared space in kdb)
142 kdb-start.c (Main loop for the standalone kernel debugger)
144 Configurations that have been declared obsolete in this release have
145 been commented out. Unless there is activity to revive these
146 configurations, the next release of GDB will have their sources
149 * REMOVED configurations and files
151 Altos 3068 m68*-altos-*
152 Convex c1-*-*, c2-*-*
154 ARM RISCix arm-*-* (as host)
158 * GDB has been converted to ISO C.
160 GDB's source code has been converted to ISO C. In particular, the
161 sources are fully protoized, and rely on standard headers being
166 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
168 * The MI enabled by default.
170 The new machine oriented interface (MI) introduced in GDB 5.0 has been
171 revised and enabled by default. Packages which use GDB as a debugging
172 engine behind a UI or another front end are encouraged to switch to
173 using the GDB/MI interface, instead of the old annotations interface
174 which is now deprecated.
176 * Support for debugging Pascal programs.
178 GDB now includes support for debugging Pascal programs. The following
179 main features are supported:
181 - Pascal-specific data types such as sets;
183 - automatic recognition of Pascal sources based on file-name
186 - Pascal-style display of data types, variables, and functions;
188 - a Pascal expression parser.
190 However, some important features are not yet supported.
192 - Pascal string operations are not supported at all;
194 - there are some problems with boolean types;
196 - Pascal type hexadecimal constants are not supported
197 because they conflict with the internal variables format;
199 - support for Pascal objects and classes is not full yet;
201 - unlike Pascal, GDB is case-sensitive for symbol names.
203 * Changes in completion.
205 Commands such as `shell', `run' and `set args', which pass arguments
206 to inferior programs, now complete on file names, similar to what
207 users expect at the shell prompt.
209 Commands which accept locations, such as `disassemble', `print',
210 `breakpoint', `until', etc. now complete on filenames as well as
211 program symbols. Thus, if you type "break foob TAB", and the source
212 files linked into the programs include `foobar.c', that file name will
213 be one of the candidates for completion. However, file names are not
214 considered for completion after you typed a colon that delimits a file
215 name from a name of a function in that file, as in "break foo.c:bar".
217 `set demangle-style' completes on available demangling styles.
219 * New platform-independent commands:
221 It is now possible to define a post-hook for a command as well as a
222 hook that runs before the command. For more details, see the
223 documentation of `hookpost' in the GDB manual.
225 * Changes in GNU/Linux native debugging.
227 Support for debugging multi-threaded programs has been completely
228 revised for all platforms except m68k and sparc. You can now debug as
229 many threads as your system allows you to have.
231 Attach/detach is supported for multi-threaded programs.
233 Support for SSE registers was added for x86. This doesn't work for
234 multi-threaded programs though.
236 * Changes in MIPS configurations.
238 Multi-arch support is enabled for all MIPS configurations.
240 GDB can now be built as native debugger on SGI Irix 6.x systems for
241 debugging n32 executables. (Debugging 64-bit executables is not yet
244 * Unified support for hardware watchpoints in all x86 configurations.
246 Most (if not all) native x86 configurations support hardware-assisted
247 breakpoints and watchpoints in a unified manner. This support
248 implements debug register sharing between watchpoints, which allows to
249 put a virtually infinite number of watchpoints on the same address,
250 and also supports watching regions up to 16 bytes with several debug
253 The new maintenance command `maintenance show-debug-regs' toggles
254 debugging print-outs in functions that insert, remove, and test
255 watchpoints and hardware breakpoints.
257 * Changes in the DJGPP native configuration.
259 New command ``info dos sysinfo'' displays assorted information about
260 the CPU, OS, memory, and DPMI server.
262 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
263 display information about segment descriptors stored in GDT, LDT, and
266 New commands ``info dos pde'' and ``info dos pte'' display entries
267 from Page Directory and Page Tables (for now works with CWSDPMI only).
268 New command ``info dos address-pte'' displays the Page Table entry for
269 a given linear address.
271 GDB can now pass command lines longer than 126 characters to the
272 program being debugged (requires an update to the libdbg.a library
273 which is part of the DJGPP development kit).
275 DWARF2 debug info is now supported.
277 It is now possible to `step' and `next' through calls to `longjmp'.
279 * Changes in documentation.
281 All GDB documentation was converted to GFDL, the GNU Free
282 Documentation License.
284 Tracepoints-related commands are now fully documented in the GDB
287 TUI, the Text-mode User Interface, is now documented in the manual.
289 Tracepoints-related commands are now fully documented in the GDB
292 The "GDB Internals" manual now has an index. It also includes
293 documentation of `ui_out' functions, GDB coding standards, x86
294 hardware watchpoints, and memory region attributes.
296 * GDB's version number moved to ``version.in''
298 The Makefile variable VERSION has been replaced by the file
299 ``version.in''. People creating GDB distributions should update the
300 contents of this file.
304 GUD support is now a standard part of the EMACS distribution.
306 *** Changes in GDB 5.0:
308 * Improved support for debugging FP programs on x86 targets
310 Unified and much-improved support for debugging floating-point
311 programs on all x86 targets. In particular, ``info float'' now
312 displays the FP registers in the same format on all x86 targets, with
313 greater level of detail.
315 * Improvements and bugfixes in hardware-assisted watchpoints
317 It is now possible to watch array elements, struct members, and
318 bitfields with hardware-assisted watchpoints. Data-read watchpoints
319 on x86 targets no longer erroneously trigger when the address is
322 * Improvements in the native DJGPP version of GDB
324 The distribution now includes all the scripts and auxiliary files
325 necessary to build the native DJGPP version on MS-DOS/MS-Windows
326 machines ``out of the box''.
328 The DJGPP version can now debug programs that use signals. It is
329 possible to catch signals that happened in the debuggee, deliver
330 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
331 would kill the program being debugged.) Programs that hook hardware
332 interrupts (keyboard, timer, etc.) can also be debugged.
334 It is now possible to debug DJGPP programs that redirect their
335 standard handles or switch them to raw (as opposed to cooked) mode, or
336 even close them. The command ``run < foo > bar'' works as expected,
337 and ``info terminal'' reports useful information about the debuggee's
338 terminal, including raw/cooked mode, redirection, etc.
340 The DJGPP version now uses termios functions for console I/O, which
341 enables debugging graphics programs. Interrupting GDB with Ctrl-C
344 DOS-style file names with drive letters are now fully supported by
347 It is now possible to debug DJGPP programs that switch their working
348 directory. It is also possible to rerun the debuggee any number of
349 times without restarting GDB; thus, you can use the same setup,
350 breakpoints, etc. for many debugging sessions.
352 * New native configurations
354 ARM GNU/Linux arm*-*-linux*
355 PowerPC GNU/Linux powerpc-*-linux*
359 Motorola MCore mcore-*-*
360 x86 VxWorks i[3456]86-*-vxworks*
361 PowerPC VxWorks powerpc-*-vxworks*
362 TI TMS320C80 tic80-*-*
364 * OBSOLETE configurations
366 Altos 3068 m68*-altos-*
367 Convex c1-*-*, c2-*-*
369 ARM RISCix arm-*-* (as host)
372 Configurations that have been declared obsolete will be commented out,
373 but the code will be left in place. If there is no activity to revive
374 these configurations before the next release of GDB, the sources will
375 be permanently REMOVED.
377 * Gould support removed
379 Support for the Gould PowerNode and NP1 has been removed.
381 * New features for SVR4
383 On SVR4 native platforms (such as Solaris), if you attach to a process
384 without first loading a symbol file, GDB will now attempt to locate and
385 load symbols from the running process's executable file.
387 * Many C++ enhancements
389 C++ support has been greatly improved. Overload resolution now works properly
390 in almost all cases. RTTI support is on the way.
392 * Remote targets can connect to a sub-program
394 A popen(3) style serial-device has been added. This device starts a
395 sub-process (such as a stand-alone simulator) and then communicates
396 with that. The sub-program to run is specified using the syntax
397 ``|<program> <args>'' vis:
399 (gdb) set remotedebug 1
400 (gdb) target extended-remote |mn10300-elf-sim program-args
402 * MIPS 64 remote protocol
404 A long standing bug in the mips64 remote protocol where by GDB
405 expected certain 32 bit registers (ex SR) to be transfered as 32
406 instead of 64 bits has been fixed.
408 The command ``set remote-mips64-transfers-32bit-regs on'' has been
409 added to provide backward compatibility with older versions of GDB.
411 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
413 The command ``set remotebinarydownload'' command has been replaced by
414 ``set remote X-packet''. Other commands in ``set remote'' family
415 include ``set remote P-packet''.
417 * Breakpoint commands accept ranges.
419 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
420 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
421 ``tracepoint passcount'' also accepts a range of tracepoints.
423 * ``apropos'' command added.
425 The ``apropos'' command searches through command names and
426 documentation strings, printing out matches, making it much easier to
427 try to find a command that does what you are looking for.
431 A new machine oriented interface (MI) has been added to GDB. This
432 interface is designed for debug environments running GDB as a separate
433 process. This is part of the long term libGDB project. See the
434 "GDB/MI" chapter of the GDB manual for further information. It can be
435 enabled by configuring with:
437 .../configure --enable-gdbmi
439 *** Changes in GDB-4.18:
441 * New native configurations
443 HP-UX 10.20 hppa*-*-hpux10.20
444 HP-UX 11.x hppa*-*-hpux11.0*
445 M68K GNU/Linux m68*-*-linux*
449 Fujitsu FR30 fr30-*-elf*
450 Intel StrongARM strongarm-*-*
451 Mitsubishi D30V d30v-*-*
453 * OBSOLETE configurations
455 Gould PowerNode, NP1 np1-*-*, pn-*-*
457 Configurations that have been declared obsolete will be commented out,
458 but the code will be left in place. If there is no activity to revive
459 these configurations before the next release of GDB, the sources will
460 be permanently REMOVED.
464 As a compatibility experiment, GDB's source files buildsym.h and
465 buildsym.c have been converted to pure standard C, no longer
466 containing any K&R compatibility code. We believe that all systems in
467 use today either come with a standard C compiler, or have a GCC port
468 available. If this is not true, please report the affected
469 configuration to bug-gdb@gnu.org immediately. See the README file for
470 information about getting a standard C compiler if you don't have one
475 GDB now uses readline 2.2.
477 * set extension-language
479 You can now control the mapping between filename extensions and source
480 languages by using the `set extension-language' command. For instance,
481 you can ask GDB to treat .c files as C++ by saying
482 set extension-language .c c++
483 The command `info extensions' lists all of the recognized extensions
484 and their associated languages.
486 * Setting processor type for PowerPC and RS/6000
488 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
489 you can use the `set processor' command to specify what variant of the
490 PowerPC family you are debugging. The command
494 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
495 following PowerPC and RS6000 variants:
497 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
498 rs6000 IBM RS6000 ("POWER") architecture, user-level view
500 403GC IBM PowerPC 403GC
501 505 Motorola PowerPC 505
502 860 Motorola PowerPC 860 or 850
503 601 Motorola PowerPC 601
504 602 Motorola PowerPC 602
505 603 Motorola/IBM PowerPC 603 or 603e
506 604 Motorola PowerPC 604 or 604e
507 750 Motorola/IBM PowerPC 750 or 750
509 At the moment, this command just tells GDB what to name the
510 special-purpose processor registers. Since almost all the affected
511 registers are inaccessible to user-level programs, this command is
512 only useful for remote debugging in its present form.
516 Thanks to a major code donation from Hewlett-Packard, GDB now has much
517 more extensive support for HP-UX. Added features include shared
518 library support, kernel threads and hardware watchpoints for 11.00,
519 support for HP's ANSI C and C++ compilers, and a compatibility mode
520 for xdb and dbx commands.
524 HP's donation includes the new concept of catchpoints, which is a
525 generalization of the old catch command. On HP-UX, it is now possible
526 to catch exec, fork, and vfork, as well as library loading.
528 This means that the existing catch command has changed; its first
529 argument now specifies the type of catch to be set up. See the
530 output of "help catch" for a list of catchpoint types.
532 * Debugging across forks
534 On HP-UX, you can choose which process to debug when a fork() happens
539 HP has donated a curses-based terminal user interface (TUI). To get
540 it, build with --enable-tui. Although this can be enabled for any
541 configuration, at present it only works for native HP debugging.
543 * GDB remote protocol additions
545 A new protocol packet 'X' that writes binary data is now available.
546 Default behavior is to try 'X', then drop back to 'M' if the stub
547 fails to respond. The settable variable `remotebinarydownload'
548 allows explicit control over the use of 'X'.
550 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
551 full 64-bit address. The command
553 set remoteaddresssize 32
555 can be used to revert to the old behaviour. For existing remote stubs
556 the change should not be noticed, as the additional address information
559 In order to assist in debugging stubs, you may use the maintenance
560 command `packet' to send any text string to the stub. For instance,
562 maint packet heythere
564 sends the packet "$heythere#<checksum>". Note that it is very easy to
565 disrupt a debugging session by sending the wrong packet at the wrong
568 The compare-sections command allows you to compare section data on the
569 target to what is in the executable file without uploading or
570 downloading, by comparing CRC checksums.
572 * Tracing can collect general expressions
574 You may now collect general expressions at tracepoints. This requires
575 further additions to the target-side stub; see tracepoint.c and
576 doc/agentexpr.texi for further details.
578 * mask-address variable for Mips
580 For Mips targets, you may control the zeroing of the upper 32 bits of
581 a 64-bit address by entering `set mask-address on'. This is mainly
582 of interest to users of embedded R4xxx and R5xxx processors.
584 * Higher serial baud rates
586 GDB's serial code now allows you to specify baud rates 57600, 115200,
587 230400, and 460800 baud. (Note that your host system may not be able
588 to achieve all of these rates.)
592 The i960 configuration now includes an initial implementation of a
593 builtin simulator, contributed by Jim Wilson.
596 *** Changes in GDB-4.17:
598 * New native configurations
600 Alpha GNU/Linux alpha*-*-linux*
601 Unixware 2.x i[3456]86-unixware2*
602 Irix 6.x mips*-sgi-irix6*
603 PowerPC GNU/Linux powerpc-*-linux*
604 PowerPC Solaris powerpcle-*-solaris*
605 Sparc GNU/Linux sparc-*-linux*
606 Motorola sysV68 R3V7.1 m68k-motorola-sysv
610 Argonaut Risc Chip (ARC) arc-*-*
611 Hitachi H8/300S h8300*-*-*
612 Matsushita MN10200 w/simulator mn10200-*-*
613 Matsushita MN10300 w/simulator mn10300-*-*
614 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
615 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
616 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
617 Mitsubishi D10V w/simulator d10v-*-*
618 Mitsubishi M32R/D w/simulator m32r-*-elf*
619 Tsqware Sparclet sparclet-*-*
620 NEC V850 w/simulator v850-*-*
622 * New debugging protocols
624 ARM with RDI protocol arm*-*-*
625 M68K with dBUG monitor m68*-*-{aout,coff,elf}
626 DDB and LSI variants of PMON protocol mips*-*-*
627 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
628 PowerPC with SDS protocol powerpc{,le}-*-eabi
629 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
633 All configurations can now understand and use the DWARF 2 debugging
634 format. The choice is automatic, if the symbol file contains DWARF 2
639 GDB now includes basic Java language support. This support is
640 only useful with Java compilers that produce native machine code.
642 * solib-absolute-prefix and solib-search-path
644 For SunOS and SVR4 shared libraries, you may now set the prefix for
645 loading absolute shared library symbol files, and the search path for
646 locating non-absolute shared library symbol files.
648 * Live range splitting
650 GDB can now effectively debug code for which GCC has performed live
651 range splitting as part of its optimization. See gdb/doc/LRS for
652 more details on the expected format of the stabs information.
656 GDB's support for the GNU Hurd, including thread debugging, has been
657 updated to work with current versions of the Hurd.
661 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
662 instruction set. ARM GDB automatically detects when Thumb
663 instructions are in use, and adjusts disassembly and backtracing
668 GDB's MIPS target configurations now handle the MIP16 16-bit
673 GDB now includes support for overlays; if an executable has been
674 linked such that multiple sections are based at the same address, GDB
675 will decide which section to use for symbolic info. You can choose to
676 control the decision manually, using overlay commands, or implement
677 additional target-side support and use "overlay load-target" to bring
678 in the overlay mapping. Do "help overlay" for more detail.
682 The command "info symbol <address>" displays information about
683 the symbol at the specified address.
687 The standard remote protocol now includes an extension that allows
688 asynchronous collection and display of trace data. This requires
689 extensive support in the target-side debugging stub. Tracing mode
690 includes a new interaction mode in GDB and new commands: see the
691 file tracepoint.c for more details.
695 Configurations for embedded MIPS now include a simulator contributed
696 by Cygnus Solutions. The simulator supports the instruction sets
697 of most MIPS variants.
701 Sparc configurations may now include the ERC32 simulator contributed
702 by the European Space Agency. The simulator is not built into
703 Sparc targets by default; configure with --enable-sim to include it.
707 For target configurations that may include multiple variants of a
708 basic architecture (such as MIPS and SH), you may now set the
709 architecture explicitly. "set arch" sets, "info arch" lists
710 the possible architectures.
712 *** Changes in GDB-4.16:
714 * New native configurations
716 Windows 95, x86 Windows NT i[345]86-*-cygwin32
717 M68K NetBSD m68k-*-netbsd*
718 PowerPC AIX 4.x powerpc-*-aix*
719 PowerPC MacOS powerpc-*-macos*
720 PowerPC Windows NT powerpcle-*-cygwin32
721 RS/6000 AIX 4.x rs6000-*-aix4*
725 ARM with RDP protocol arm-*-*
726 I960 with MON960 i960-*-coff
727 MIPS VxWorks mips*-*-vxworks*
728 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
729 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
731 Matra Sparclet sparclet-*-*
735 The powerpc-eabi configuration now includes the PSIM simulator,
736 contributed by Andrew Cagney, with assistance from Mike Meissner.
737 PSIM is a very elaborate model of the PowerPC, including not only
738 basic instruction set execution, but also details of execution unit
739 performance and I/O hardware. See sim/ppc/README for more details.
743 GDB now works with Solaris 2.5.
745 * Windows 95/NT native
747 GDB will now work as a native debugger on Windows 95 and Windows NT.
748 To build it from source, you must use the "gnu-win32" environment,
749 which uses a DLL to emulate enough of Unix to run the GNU tools.
750 Further information, binaries, and sources are available at
751 ftp.cygnus.com, under pub/gnu-win32.
753 * dont-repeat command
755 If a user-defined command includes the command `dont-repeat', then the
756 command will not be repeated if the user just types return. This is
757 useful if the command is time-consuming to run, so that accidental
758 extra keystrokes don't run the same command many times.
760 * Send break instead of ^C
762 The standard remote protocol now includes an option to send a break
763 rather than a ^C to the target in order to interrupt it. By default,
764 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
766 * Remote protocol timeout
768 The standard remote protocol includes a new variable `remotetimeout'
769 that allows you to set the number of seconds before GDB gives up trying
770 to read from the target. The default value is 2.
772 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
774 By default GDB will automatically keep track of objects as they are
775 loaded and unloaded by the dynamic linker. By using the command `set
776 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
777 when shared library events occur, thus allowing you to set breakpoints
778 in shared libraries which are explicitly loaded by the inferior.
780 Note this feature does not work on hpux8. On hpux9 you must link
781 /usr/lib/end.o into your program. This feature should work
782 automatically on hpux10.
784 * Irix 5.x hardware watchpoint support
786 Irix 5 configurations now support the use of hardware watchpoints.
788 * Mips protocol "SYN garbage limit"
790 When debugging a Mips target using the `target mips' protocol, you
791 may set the number of characters that GDB will ignore by setting
792 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
793 every character. The default value is 1050.
795 * Recording and replaying remote debug sessions
797 If you set `remotelogfile' to the name of a file, gdb will write to it
798 a recording of a remote debug session. This recording may then be
799 replayed back to gdb using "gdbreplay". See gdbserver/README for
800 details. This is useful when you have a problem with GDB while doing
801 remote debugging; you can make a recording of the session and send it
802 to someone else, who can then recreate the problem.
804 * Speedups for remote debugging
806 GDB includes speedups for downloading and stepping MIPS systems using
807 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
808 and more efficient S-record downloading.
810 * Memory use reductions and statistics collection
812 GDB now uses less memory and reports statistics about memory usage.
813 Try the `maint print statistics' command, for example.
815 *** Changes in GDB-4.15:
819 The symbol reader for AIX GDB now uses partial symbol tables. This
820 can greatly improve startup time, especially for large executables.
822 * Remote targets use caching
824 Remote targets now use a data cache to speed up communication with the
825 remote side. The data cache could lead to incorrect results because
826 it doesn't know about volatile variables, thus making it impossible to
827 debug targets which use memory mapped I/O devices. `set remotecache
828 off' turns the the data cache off.
830 * Remote targets may have threads
832 The standard remote protocol now includes support for multiple threads
833 in the target system, using new protocol commands 'H' and 'T'. See
834 gdb/remote.c for details.
838 If GDB is configured with `--enable-netrom', then it will include
839 support for the NetROM ROM emulator from XLNT Designs. The NetROM
840 acts as though it is a bank of ROM on the target board, but you can
841 write into it over the network. GDB's support consists only of
842 support for fast loading into the emulated ROM; to debug, you must use
843 another protocol, such as standard remote protocol. The usual
844 sequence is something like
846 target nrom <netrom-hostname>
848 target remote <netrom-hostname>:1235
852 GDB now includes support for the Apple Macintosh, as a host only. It
853 may be run as either an MPW tool or as a standalone application, and
854 it can debug through the serial port. All the usual GDB commands are
855 available, but to the target command, you must supply "serial" as the
856 device type instead of "/dev/ttyXX". See mpw-README in the main
857 directory for more information on how to build. The MPW configuration
858 scripts */mpw-config.in support only a few targets, and only the
859 mips-idt-ecoff target has been tested.
863 GDB configuration now uses autoconf. This is not user-visible,
864 but does simplify configuration and building.
868 GDB now supports hpux10.
870 *** Changes in GDB-4.14:
872 * New native configurations
874 x86 FreeBSD i[345]86-*-freebsd
875 x86 NetBSD i[345]86-*-netbsd
876 NS32k NetBSD ns32k-*-netbsd
877 Sparc NetBSD sparc-*-netbsd
881 A29K VxWorks a29k-*-vxworks
882 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
883 CPU32 EST-300 emulator m68*-*-est*
884 PowerPC ELF powerpc-*-elf
887 * Alpha OSF/1 support for procfs
889 GDB now supports procfs under OSF/1-2.x and higher, which makes it
890 possible to attach to running processes. As the mounting of the /proc
891 filesystem is optional on the Alpha, GDB automatically determines
892 the availability of /proc during startup. This can lead to problems
893 if /proc is unmounted after GDB has been started.
895 * Arguments to user-defined commands
897 User commands may accept up to 10 arguments separated by whitespace.
898 Arguments are accessed within the user command via $arg0..$arg9. A
901 print $arg0 + $arg1 + $arg2
903 To execute the command use:
906 Defines the command "adder" which prints the sum of its three arguments.
907 Note the arguments are text substitutions, so they may reference variables,
908 use complex expressions, or even perform inferior function calls.
910 * New `if' and `while' commands
912 This makes it possible to write more sophisticated user-defined
913 commands. Both commands take a single argument, which is the
914 expression to evaluate, and must be followed by the commands to
915 execute, one per line, if the expression is nonzero, the list being
916 terminated by the word `end'. The `if' command list may include an
917 `else' word, which causes the following commands to be executed only
918 if the expression is zero.
920 * Fortran source language mode
922 GDB now includes partial support for Fortran 77. It will recognize
923 Fortran programs and can evaluate a subset of Fortran expressions, but
924 variables and functions may not be handled correctly. GDB will work
925 with G77, but does not yet know much about symbols emitted by other
928 * Better HPUX support
930 Most debugging facilities now work on dynamic executables for HPPAs
931 running hpux9 or later. You can attach to running dynamically linked
932 processes, but by default the dynamic libraries will be read-only, so
933 for instance you won't be able to put breakpoints in them. To change
934 that behavior do the following before running the program:
940 This will cause the libraries to be mapped private and read-write.
941 To revert to the normal behavior, do this:
947 You cannot set breakpoints or examine data in the library until after
948 the library is loaded if the function/data symbols do not have
951 GDB can now also read debug symbols produced by the HP C compiler on
952 HPPAs (sorry, no C++, Fortran or 68k support).
954 * Target byte order now dynamically selectable
956 You can choose which byte order to use with a target system, via the
957 commands "set endian big" and "set endian little", and you can see the
958 current setting by using "show endian". You can also give the command
959 "set endian auto", in which case GDB will use the byte order
960 associated with the executable. Currently, only embedded MIPS
961 configurations support dynamic selection of target byte order.
963 * New DOS host serial code
965 This version uses DPMI interrupts to handle buffered I/O, so you
966 no longer need to run asynctsr when debugging boards connected to
969 *** Changes in GDB-4.13:
971 * New "complete" command
973 This lists all the possible completions for the rest of the line, if it
974 were to be given as a command itself. This is intended for use by emacs.
976 * Trailing space optional in prompt
978 "set prompt" no longer adds a space for you after the prompt you set. This
979 allows you to set a prompt which ends in a space or one that does not.
981 * Breakpoint hit counts
983 "info break" now displays a count of the number of times the breakpoint
984 has been hit. This is especially useful in conjunction with "ignore"; you
985 can ignore a large number of breakpoint hits, look at the breakpoint info
986 to see how many times the breakpoint was hit, then run again, ignoring one
987 less than that number, and this will get you quickly to the last hit of
990 * Ability to stop printing at NULL character
992 "set print null-stop" will cause GDB to stop printing the characters of
993 an array when the first NULL is encountered. This is useful when large
994 arrays actually contain only short strings.
996 * Shared library breakpoints
998 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
999 breakpoints in shared libraries before the executable is run.
1001 * Hardware watchpoints
1003 There is a new hardware breakpoint for the watch command for sparclite
1004 targets. See gdb/sparclite/hw_breakpoint.note.
1006 Hardware watchpoints are also now supported under GNU/Linux.
1010 Annotations have been added. These are for use with graphical interfaces,
1011 and are still experimental. Currently only gdba.el uses these.
1013 * Improved Irix 5 support
1015 GDB now works properly with Irix 5.2.
1017 * Improved HPPA support
1019 GDB now works properly with the latest GCC and GAS.
1021 * New native configurations
1023 Sequent PTX4 i[34]86-sequent-ptx4
1024 HPPA running OSF/1 hppa*-*-osf*
1025 Atari TT running SVR4 m68*-*-sysv4*
1026 RS/6000 LynxOS rs6000-*-lynxos*
1030 OS/9000 i[34]86-*-os9k
1031 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
1034 * Hitachi SH7000 and E7000-PC ICE support
1036 There is now support for communicating with the Hitachi E7000-PC ICE.
1037 This is available automatically when GDB is configured for the SH.
1041 As usual, a variety of small fixes and improvements, both generic
1042 and configuration-specific. See the ChangeLog for more detail.
1044 *** Changes in GDB-4.12:
1046 * Irix 5 is now supported
1050 GDB-4.12 on the HPPA has a number of changes which make it unable
1051 to debug the output from the currently released versions of GCC and
1052 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
1053 of GCC and GAS, versions of these tools designed to work with GDB-4.12
1054 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
1057 *** Changes in GDB-4.11:
1059 * User visible changes:
1063 The "set remotedebug" option is now consistent between the mips remote
1064 target, remote targets using the gdb-specific protocol, UDI (AMD's
1065 debug protocol for the 29k) and the 88k bug monitor. It is now an
1066 integer specifying a debug level (normally 0 or 1, but 2 means more
1067 debugging info for the mips target).
1069 * DEC Alpha native support
1071 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
1072 debug info, but GDB works fairly well with the DEC compiler and should
1073 work with a future GCC release. See the README file for a few
1074 Alpha-specific notes.
1076 * Preliminary thread implementation
1078 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
1080 * LynxOS native and target support for 386
1082 This release has been hosted on LynxOS 2.2, and also can be configured
1083 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
1086 * Improvements in C++ mangling/demangling.
1088 This release has much better g++ debugging, specifically in name
1089 mangling/demangling, virtual function calls, print virtual table,
1090 call methods, ...etc.
1092 *** Changes in GDB-4.10:
1094 * User visible changes:
1096 Remote debugging using the GDB-specific (`target remote') protocol now
1097 supports the `load' command. This is only useful if you have some
1098 other way of getting the stub to the target system, and you can put it
1099 somewhere in memory where it won't get clobbered by the download.
1101 Filename completion now works.
1103 When run under emacs mode, the "info line" command now causes the
1104 arrow to point to the line specified. Also, "info line" prints
1105 addresses in symbolic form (as well as hex).
1107 All vxworks based targets now support a user settable option, called
1108 vxworks-timeout. This option represents the number of seconds gdb
1109 should wait for responses to rpc's. You might want to use this if
1110 your vxworks target is, perhaps, a slow software simulator or happens
1111 to be on the far side of a thin network line.
1115 This release contains support for using a DEC alpha as a GDB host for
1116 cross debugging. Native alpha debugging is not supported yet.
1119 *** Changes in GDB-4.9:
1123 This is the first GDB release which is accompanied by a matching testsuite.
1124 The testsuite requires installation of dejagnu, which should be available
1125 via ftp from most sites that carry GNU software.
1129 'Cfront' style demangling has had its name changed to 'ARM' style, to
1130 emphasize that it was written from the specifications in the C++ Annotated
1131 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
1132 disclaimers, it still generated too much confusion with users attempting to
1133 use gdb with AT&T cfront.
1137 GDB now uses a standard remote interface to a simulator library.
1138 So far, the library contains simulators for the Zilog Z8001/2, the
1139 Hitachi H8/300, H8/500 and Super-H.
1141 * New targets supported
1143 H8/300 simulator h8300-hitachi-hms or h8300hms
1144 H8/500 simulator h8500-hitachi-hms or h8500hms
1145 SH simulator sh-hitachi-hms or sh
1146 Z8000 simulator z8k-zilog-none or z8ksim
1147 IDT MIPS board over serial line mips-idt-ecoff
1149 Cross-debugging to GO32 targets is supported. It requires a custom
1150 version of the i386-stub.c module which is integrated with the
1151 GO32 memory extender.
1153 * New remote protocols
1155 MIPS remote debugging protocol.
1157 * New source languages supported
1159 This version includes preliminary support for Chill, a Pascal like language
1160 used by telecommunications companies. Chill support is also being integrated
1161 into the GNU compiler, but we don't know when it will be publically available.
1164 *** Changes in GDB-4.8:
1166 * HP Precision Architecture supported
1168 GDB now supports HP PA-RISC machines running HPUX. A preliminary
1169 version of this support was available as a set of patches from the
1170 University of Utah. GDB does not support debugging of programs
1171 compiled with the HP compiler, because HP will not document their file
1172 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
1173 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
1175 Many problems in the preliminary version have been fixed.
1177 * Faster and better demangling
1179 We have improved template demangling and fixed numerous bugs in the GNU style
1180 demangler. It can now handle type modifiers such as `static' or `const'. Wide
1181 character types (wchar_t) are now supported. Demangling of each symbol is now
1182 only done once, and is cached when the symbol table for a file is read in.
1183 This results in a small increase in memory usage for C programs, a moderate
1184 increase in memory usage for C++ programs, and a fantastic speedup in
1187 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
1188 from the specifications in the Annotated Reference Manual, which AT&T's
1189 compiler does not actually implement.
1191 * G++ multiple inheritance compiler problem
1193 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
1194 inheritance lattices was reworked to properly discover ambiguities. We
1195 recently found an example which causes this new algorithm to fail in a
1196 very subtle way, producing bad debug information for those classes.
1197 The file 'gcc.patch' (in this directory) can be applied to gcc to
1198 circumvent the problem. A future GCC release will contain a complete
1201 The previous G++ debug info problem (mentioned below for the gdb-4.7
1202 release) is fixed in gcc version 2.3.2.
1204 * Improved configure script
1206 The `configure' script will now attempt to guess your system type if
1207 you don't supply a host system type. The old scheme of supplying a
1208 host system triplet is preferable over using this. All the magic is
1209 done in the new `config.guess' script. Examine it for details.
1211 We have also brought our configure script much more in line with the FSF's
1212 version. It now supports the --with-xxx options. In particular,
1213 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
1214 The resulting GDB will not be able to read arbitrary object file formats --
1215 only the format ``expected'' to be used on the configured target system.
1216 We hope to make this the default in a future release.
1218 * Documentation improvements
1220 There's new internal documentation on how to modify GDB, and how to
1221 produce clean changes to the code. We implore people to read it
1222 before submitting changes.
1224 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
1225 M4 macros. The new texinfo.tex is provided in this release. Pre-built
1226 `info' files are also provided. To build `info' files from scratch,
1227 you will need the latest `makeinfo' release, which will be available in
1228 a future texinfo-X.Y release.
1230 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
1231 We're not sure exactly which versions have this problem, but it has
1232 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
1233 or better. If that isn't possible, there is a patch in
1234 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
1235 around this problem.
1239 GDB now supports array constants that can be used in expressions typed in by
1240 the user. The syntax is `{element, element, ...}'. Ie: you can now type
1241 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
1244 The new directory `gdb/sparclite' contains a program that demonstrates
1245 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
1247 * New native hosts supported
1249 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
1250 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
1252 * New targets supported
1254 AMD 29k family via UDI a29k-amd-udi or udi29k
1256 * New file formats supported
1258 BFD now supports reading HP/PA-RISC executables (SOM file format?),
1259 HPUX core files, and SCO 3.2v2 core files.
1263 Attaching to processes now works again; thanks for the many bug reports.
1265 We have also stomped on a bunch of core dumps caused by
1266 printf_filtered("%s") problems.
1268 We eliminated a copyright problem on the rpc and ptrace header files
1269 for VxWorks, which was discovered at the last minute during the 4.7
1270 release. You should now be able to build a VxWorks GDB.
1272 You can now interrupt gdb while an attached process is running. This
1273 will cause the attached process to stop, and give control back to GDB.
1275 We fixed problems caused by using too many file descriptors
1276 for reading symbols from object files and libraries. This was
1277 especially a problem for programs that used many (~100) shared
1280 The `step' command now only enters a subroutine if there is line number
1281 information for the subroutine. Otherwise it acts like the `next'
1282 command. Previously, `step' would enter subroutines if there was
1283 any debugging information about the routine. This avoids problems
1284 when using `cc -g1' on MIPS machines.
1286 * Internal improvements
1288 GDB's internal interfaces have been improved to make it easier to support
1289 debugging of multiple languages in the future.
1291 GDB now uses a common structure for symbol information internally.
1292 Minimal symbols (derived from linkage symbols in object files), partial
1293 symbols (from a quick scan of debug information), and full symbols
1294 contain a common subset of information, making it easier to write
1295 shared code that handles any of them.
1297 * New command line options
1299 We now accept --silent as an alias for --quiet.
1303 The memory-mapped-malloc library is now licensed under the GNU Library
1304 General Public License.
1306 *** Changes in GDB-4.7:
1308 * Host/native/target split
1310 GDB has had some major internal surgery to untangle the support for
1311 hosts and remote targets. Now, when you configure GDB for a remote
1312 target, it will no longer load in all of the support for debugging
1313 local programs on the host. When fully completed and tested, this will
1314 ensure that arbitrary host/target combinations are possible.
1316 The primary conceptual shift is to separate the non-portable code in
1317 GDB into three categories. Host specific code is required any time GDB
1318 is compiled on that host, regardless of the target. Target specific
1319 code relates to the peculiarities of the target, but can be compiled on
1320 any host. Native specific code is everything else: it can only be
1321 built when the host and target are the same system. Child process
1322 handling and core file support are two common `native' examples.
1324 GDB's use of /proc for controlling Unix child processes is now cleaner.
1325 It has been split out into a single module under the `target_ops' vector,
1326 plus two native-dependent functions for each system that uses /proc.
1328 * New hosts supported
1330 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
1331 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
1332 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
1334 * New targets supported
1336 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
1337 68030 and CPU32 m68030-*-*, m68332-*-*
1339 * New native hosts supported
1341 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
1342 (386bsd is not well tested yet)
1343 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
1345 * New file formats supported
1347 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
1348 supports reading of `a.out.adobe' object files, which are an a.out
1349 format extended with minimal information about multiple sections.
1353 `show copying' is the same as the old `info copying'.
1354 `show warranty' is the same as `info warrantee'.
1355 These were renamed for consistency. The old commands continue to work.
1357 `info handle' is a new alias for `info signals'.
1359 You can now define pre-command hooks, which attach arbitrary command
1360 scripts to any command. The commands in the hook will be executed
1361 prior to the user's command. You can also create a hook which will be
1362 executed whenever the program stops. See gdb.texinfo.
1366 We now deal with Cfront style name mangling, and can even extract type
1367 info from mangled symbols. GDB can automatically figure out which
1368 symbol mangling style your C++ compiler uses.
1370 Calling of methods and virtual functions has been improved as well.
1374 The crash that occured when debugging Sun Ansi-C compiled binaries is
1375 fixed. This was due to mishandling of the extra N_SO stabs output
1378 We also finally got Ultrix 4.2 running in house, and fixed core file
1379 support, with help from a dozen people on the net.
1381 John M. Farrell discovered that the reason that single-stepping was so
1382 slow on all of the Mips based platforms (primarily SGI and DEC) was
1383 that we were trying to demangle and lookup a symbol used for internal
1384 purposes on every instruction that was being stepped through. Changing
1385 the name of that symbol so that it couldn't be mistaken for a C++
1386 mangled symbol sped things up a great deal.
1388 Rich Pixley sped up symbol lookups in general by getting much smarter
1389 about when C++ symbol mangling is necessary. This should make symbol
1390 completion (TAB on the command line) much faster. It's not as fast as
1391 we'd like, but it's significantly faster than gdb-4.6.
1395 A new user controllable variable 'call_scratch_address' can
1396 specify the location of a scratch area to be used when GDB
1397 calls a function in the target. This is necessary because the
1398 usual method of putting the scratch area on the stack does not work
1399 in systems that have separate instruction and data spaces.
1401 We integrated changes to support the 29k UDI (Universal Debugger
1402 Interface), but discovered at the last minute that we didn't have all
1403 of the appropriate copyright paperwork. We are working with AMD to
1404 resolve this, and hope to have it available soon.
1408 We have sped up the remote serial line protocol, especially for targets
1409 with lots of registers. It now supports a new `expedited status' ('T')
1410 message which can be used in place of the existing 'S' status message.
1411 This allows the remote stub to send only the registers that GDB
1412 needs to make a quick decision about single-stepping or conditional
1413 breakpoints, eliminating the need to fetch the entire register set for
1414 each instruction being stepped through.
1416 The GDB remote serial protocol now implements a write-through cache for
1417 registers, only re-reading the registers if the target has run.
1419 There is also a new remote serial stub for SPARC processors. You can
1420 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
1421 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
1422 processor with a serial port.
1426 Configure.in files have become much easier to read and modify. A new
1427 `table driven' format makes it more obvious what configurations are
1428 supported, and what files each one uses.
1432 There is a new opcodes library which will eventually contain all of the
1433 disassembly routines and opcode tables. At present, it only contains
1434 Sparc and Z8000 routines. This will allow the assembler, debugger, and
1435 disassembler (binutils/objdump) to share these routines.
1437 The libiberty library is now copylefted under the GNU Library General
1438 Public License. This allows more liberal use, and was done so libg++
1439 can use it. This makes no difference to GDB, since the Library License
1440 grants all the rights from the General Public License.
1444 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
1445 reference to the stabs symbol info used by the debugger. It is (as far
1446 as we know) the only published document on this fascinating topic. We
1447 encourage you to read it, compare it to the stabs information on your
1448 system, and send improvements on the document in general (to
1449 bug-gdb@prep.ai.mit.edu).
1451 And, of course, many bugs have been fixed.
1454 *** Changes in GDB-4.6:
1456 * Better support for C++ function names
1458 GDB now accepts as input the "demangled form" of C++ overloaded function
1459 names and member function names, and can do command completion on such names
1460 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
1461 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
1462 Make use of command completion, it is your friend.
1464 GDB also now accepts a variety of C++ mangled symbol formats. They are
1465 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
1466 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
1467 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
1468 for the list of formats.
1470 * G++ symbol mangling problem
1472 Recent versions of gcc have a bug in how they emit debugging information for
1473 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
1474 directory) can be applied to gcc to fix the problem. Alternatively, if you
1475 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
1476 usual symptom is difficulty with setting breakpoints on methods. GDB complains
1477 about the method being non-existent. (We believe that version 2.2.2 of GCC has
1480 * New 'maintenance' command
1482 All of the commands related to hacking GDB internals have been moved out of
1483 the main command set, and now live behind the 'maintenance' command. This
1484 can also be abbreviated as 'mt'. The following changes were made:
1486 dump-me -> maintenance dump-me
1487 info all-breakpoints -> maintenance info breakpoints
1488 printmsyms -> maintenance print msyms
1489 printobjfiles -> maintenance print objfiles
1490 printpsyms -> maintenance print psymbols
1491 printsyms -> maintenance print symbols
1493 The following commands are new:
1495 maintenance demangle Call internal GDB demangler routine to
1496 demangle a C++ link name and prints the result.
1497 maintenance print type Print a type chain for a given symbol
1499 * Change to .gdbinit file processing
1501 We now read the $HOME/.gdbinit file before processing the argv arguments
1502 (e.g. reading symbol files or core files). This allows global parameters to
1503 be set, which will apply during the symbol reading. The ./.gdbinit is still
1504 read after argv processing.
1506 * New hosts supported
1508 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
1510 GNU/Linux support i386-unknown-linux or linux
1512 We are also including code to support the HP/PA running BSD and HPUX. This
1513 is almost guaranteed not to work, as we didn't have time to test or build it
1514 for this release. We are including it so that the more adventurous (or
1515 masochistic) of you can play with it. We also had major problems with the
1516 fact that the compiler that we got from HP doesn't support the -g option.
1519 * New targets supported
1521 Hitachi H8/300 h8300-hitachi-hms or h8300hms
1523 * More smarts about finding #include files
1525 GDB now remembers the compilation directory for all include files, and for
1526 all files from which C is generated (like yacc and lex sources). This
1527 greatly improves GDB's ability to find yacc/lex sources, and include files,
1528 especially if you are debugging your program from a directory different from
1529 the one that contains your sources.
1531 We also fixed a bug which caused difficulty with listing and setting
1532 breakpoints in include files which contain C code. (In the past, you had to
1533 try twice in order to list an include file that you hadn't looked at before.)
1535 * Interesting infernals change
1537 GDB now deals with arbitrary numbers of sections, where the symbols for each
1538 section must be relocated relative to that section's landing place in the
1539 target's address space. This work was needed to support ELF with embedded
1540 stabs used by Solaris-2.0.
1542 * Bug fixes (of course!)
1544 There have been loads of fixes for the following things:
1545 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
1546 i960, stabs, DOS(GO32), procfs, etc...
1548 See the ChangeLog for details.
1550 *** Changes in GDB-4.5:
1552 * New machines supported (host and target)
1554 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
1556 SGI Irix-4.x mips-sgi-irix4 or iris4
1558 * New malloc package
1560 GDB now uses a new memory manager called mmalloc, based on gmalloc.
1561 Mmalloc is capable of handling mutiple heaps of memory. It is also
1562 capable of saving a heap to a file, and then mapping it back in later.
1563 This can be used to greatly speedup the startup of GDB by using a
1564 pre-parsed symbol table which lives in a mmalloc managed heap. For
1565 more details, please read mmalloc/mmalloc.texi.
1569 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
1570 'help info proc' for details.
1572 * MIPS ecoff symbol table format
1574 The code that reads MIPS symbol table format is now supported on all hosts.
1575 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
1578 * File name changes for MS-DOS
1580 Many files in the config directories have been renamed to make it easier to
1581 support GDB on MS-DOSe systems (which have very restrictive file name
1582 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
1583 environment) is close to working but has some remaining problems. Note
1584 that debugging of DOS programs is not supported, due to limitations
1585 in the ``operating system'', but it can be used to host cross-debugging.
1587 * Cross byte order fixes
1589 Many fixes have been made to support cross debugging of Sparc and MIPS
1590 targets from hosts whose byte order differs.
1592 * New -mapped and -readnow options
1594 If memory-mapped files are available on your system through the 'mmap'
1595 system call, you can use the -mapped option on the `file' or
1596 `symbol-file' commands to cause GDB to write the symbols from your
1597 program into a reusable file. If the program you are debugging is
1598 called `/path/fred', the mapped symbol file will be `./fred.syms'.
1599 Future GDB debugging sessions will notice the presence of this file,
1600 and will quickly map in symbol information from it, rather than reading
1601 the symbol table from the executable program. Using the '-mapped'
1602 option in a GDB `file' or `symbol-file' command has the same effect as
1603 starting GDB with the '-mapped' command-line option.
1605 You can cause GDB to read the entire symbol table immediately by using
1606 the '-readnow' option with any of the commands that load symbol table
1607 information (or on the GDB command line). This makes the command
1608 slower, but makes future operations faster.
1610 The -mapped and -readnow options are typically combined in order to
1611 build a `fred.syms' file that contains complete symbol information.
1612 A simple GDB invocation to do nothing but build a `.syms' file for future
1615 gdb -batch -nx -mapped -readnow programname
1617 The `.syms' file is specific to the host machine on which GDB is run.
1618 It holds an exact image of GDB's internal symbol table. It cannot be
1619 shared across multiple host platforms.
1621 * longjmp() handling
1623 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
1624 siglongjmp() without losing control. This feature has not yet been ported to
1625 all systems. It currently works on many 386 platforms, all MIPS-based
1626 platforms (SGI, DECstation, etc), and Sun3/4.
1630 Preliminary work has been put in to support the new Solaris OS from Sun. At
1631 this time, it can control and debug processes, but it is not capable of
1636 As always, many many bug fixes. The major areas were with g++, and mipsread.
1637 People using the MIPS-based platforms should experience fewer mysterious
1638 crashes and trashed symbol tables.
1640 *** Changes in GDB-4.4:
1642 * New machines supported (host and target)
1644 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
1646 BSD Reno on Vax vax-dec-bsd
1647 Ultrix on Vax vax-dec-ultrix
1649 * New machines supported (target)
1651 AMD 29000 embedded, using EBMON a29k-none-none
1655 GDB continues to improve its handling of C++. `References' work better.
1656 The demangler has also been improved, and now deals with symbols mangled as
1657 per the Annotated C++ Reference Guide.
1659 GDB also now handles `stabs' symbol information embedded in MIPS
1660 `ecoff' symbol tables. Since the ecoff format was not easily
1661 extensible to handle new languages such as C++, this appeared to be a
1662 good way to put C++ debugging info into MIPS binaries. This option
1663 will be supported in the GNU C compiler, version 2, when it is
1666 * New features for SVR4
1668 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
1669 shared libraries. Debugging dynamically linked programs should present
1670 only minor differences from debugging statically linked programs.
1672 The `info proc' command will print out information about any process
1673 on an SVR4 system (including the one you are debugging). At the moment,
1674 it prints the address mappings of the process.
1676 If you bring up GDB on another SVR4 system, please send mail to
1677 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
1679 * Better dynamic linking support in SunOS
1681 Reading symbols from shared libraries which contain debugging symbols
1682 now works properly. However, there remain issues such as automatic
1683 skipping of `transfer vector' code during function calls, which
1684 make it harder to debug code in a shared library, than to debug the
1685 same code linked statically.
1689 GDB is now using the latest `getopt' routines from the FSF. This
1690 version accepts the -- prefix for options with long names. GDB will
1691 continue to accept the old forms (-option and +option) as well.
1692 Various single letter abbreviations for options have been explicity
1693 added to the option table so that they won't get overshadowed in the
1694 future by other options that begin with the same letter.
1698 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
1699 Many assorted bugs have been handled. Many more remain to be handled.
1700 See the various ChangeLog files (primarily in gdb and bfd) for details.
1703 *** Changes in GDB-4.3:
1705 * New machines supported (host and target)
1707 Amiga 3000 running Amix m68k-cbm-svr4 or amix
1708 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
1709 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
1711 * Almost SCO Unix support
1713 We had hoped to support:
1714 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
1715 (except for core file support), but we discovered very late in the release
1716 that it has problems with process groups that render gdb unusable. Sorry
1717 about that. I encourage people to fix it and post the fixes.
1719 * Preliminary ELF and DWARF support
1721 GDB can read ELF object files on System V Release 4, and can handle
1722 debugging records for C, in DWARF format, in ELF files. This support
1723 is preliminary. If you bring up GDB on another SVR4 system, please
1724 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
1729 GDB now uses the latest `readline' library. One user-visible change
1730 is that two tabs will list possible command completions, which previously
1731 required typing M-? (meta-question mark, or ESC ?).
1735 The `stepi' bug that many of you noticed has been squashed.
1736 Many bugs in C++ have been handled. Many more remain to be handled.
1737 See the various ChangeLog files (primarily in gdb and bfd) for details.
1739 * State of the MIPS world (in case you wondered):
1741 GDB can understand the symbol tables emitted by the compilers
1742 supplied by most vendors of MIPS-based machines, including DEC. These
1743 symbol tables are in a format that essentially nobody else uses.
1745 Some versions of gcc come with an assembler post-processor called
1746 mips-tfile. This program is required if you want to do source-level
1747 debugging of gcc-compiled programs. I believe FSF does not ship
1748 mips-tfile with gcc version 1, but it will eventually come with gcc
1751 Debugging of g++ output remains a problem. g++ version 1.xx does not
1752 really support it at all. (If you're lucky, you should be able to get
1753 line numbers and stack traces to work, but no parameters or local
1754 variables.) With some work it should be possible to improve the
1757 When gcc version 2 is released, you will have somewhat better luck.
1758 However, even then you will get confusing results for inheritance and
1761 We will eventually provide full debugging of g++ output on
1762 DECstations. This will probably involve some kind of stabs-in-ecoff
1763 encapulation, but the details have not been worked out yet.
1766 *** Changes in GDB-4.2:
1768 * Improved configuration
1770 Only one copy of `configure' exists now, and it is not self-modifying.
1771 Porting BFD is simpler.
1775 The `step' and `next' commands now only stop at the first instruction
1776 of a source line. This prevents the multiple stops that used to occur
1777 in switch statements, for-loops, etc. `Step' continues to stop if a
1778 function that has debugging information is called within the line.
1782 Lots of small bugs fixed. More remain.
1784 * New host supported (not target)
1786 Intel 386 PC clone running Mach i386-none-mach
1789 *** Changes in GDB-4.1:
1791 * Multiple source language support
1793 GDB now has internal scaffolding to handle several source languages.
1794 It determines the type of each source file from its filename extension,
1795 and will switch expression parsing and number formatting to match the
1796 language of the function in the currently selected stack frame.
1797 You can also specifically set the language to be used, with
1798 `set language c' or `set language modula-2'.
1802 GDB now has preliminary support for the GNU Modula-2 compiler,
1803 currently under development at the State University of New York at
1804 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
1805 continue through the fall of 1991 and into 1992.
1807 Other Modula-2 compilers are currently not supported, and attempting to
1808 debug programs compiled with them will likely result in an error as the
1809 symbol table is read. Feel free to work on it, though!
1811 There are hooks in GDB for strict type checking and range checking,
1812 in the `Modula-2 philosophy', but they do not currently work.
1816 GDB can now write to executable and core files (e.g. patch
1817 a variable's value). You must turn this switch on, specify
1818 the file ("exec foo" or "core foo"), *then* modify it, e.g.
1819 by assigning a new value to a variable. Modifications take
1822 * Automatic SunOS shared library reading
1824 When you run your program, GDB automatically determines where its
1825 shared libraries (if any) have been loaded, and reads their symbols.
1826 The `share' command is no longer needed. This also works when
1827 examining core files.
1831 You can specify the number of lines that the `list' command shows.
1834 * New machines supported (host and target)
1836 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
1837 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
1838 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
1840 * New hosts supported (not targets)
1842 IBM RT/PC: romp-ibm-aix or rtpc
1844 * New targets supported (not hosts)
1846 AMD 29000 embedded with COFF a29k-none-coff
1847 AMD 29000 embedded with a.out a29k-none-aout
1848 Ultracomputer remote kernel debug a29k-nyu-kern
1850 * New remote interfaces
1856 *** Changes in GDB-4.0:
1860 Wide output is wrapped at good places to make the output more readable.
1862 Gdb now supports cross-debugging from a host machine of one type to a
1863 target machine of another type. Communication with the target system
1864 is over serial lines. The ``target'' command handles connecting to the
1865 remote system; the ``load'' command will download a program into the
1866 remote system. Serial stubs for the m68k and i386 are provided. Gdb
1867 also supports debugging of realtime processes running under VxWorks,
1868 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
1869 stub on the target system.
1871 New CPUs supported include the AMD 29000 and Intel 960.
1873 GDB now reads object files and symbol tables via a ``binary file''
1874 library, which allows a single copy of GDB to debug programs of multiple
1875 object file types such as a.out and coff.
1877 There is now a GDB reference card in "doc/refcard.tex". (Make targets
1878 refcard.dvi and refcard.ps are available to format it).
1881 * Control-Variable user interface simplified
1883 All variables that control the operation of the debugger can be set
1884 by the ``set'' command, and displayed by the ``show'' command.
1886 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
1887 ``Show prompt'' produces the response:
1888 Gdb's prompt is new-gdb=>.
1890 What follows are the NEW set commands. The command ``help set'' will
1891 print a complete list of old and new set commands. ``help set FOO''
1892 will give a longer description of the variable FOO. ``show'' will show
1893 all of the variable descriptions and their current settings.
1895 confirm on/off: Enables warning questions for operations that are
1896 hard to recover from, e.g. rerunning the program while
1897 it is already running. Default is ON.
1899 editing on/off: Enables EMACS style command line editing
1900 of input. Previous lines can be recalled with
1901 control-P, the current line can be edited with control-B,
1902 you can search for commands with control-R, etc.
1905 history filename NAME: NAME is where the gdb command history
1906 will be stored. The default is .gdb_history,
1907 or the value of the environment variable
1910 history size N: The size, in commands, of the command history. The
1911 default is 256, or the value of the environment variable
1914 history save on/off: If this value is set to ON, the history file will
1915 be saved after exiting gdb. If set to OFF, the
1916 file will not be saved. The default is OFF.
1918 history expansion on/off: If this value is set to ON, then csh-like
1919 history expansion will be performed on
1920 command line input. The default is OFF.
1922 radix N: Sets the default radix for input and output. It can be set
1923 to 8, 10, or 16. Note that the argument to "radix" is interpreted
1924 in the current radix, so "set radix 10" is always a no-op.
1926 height N: This integer value is the number of lines on a page. Default
1927 is 24, the current `stty rows'' setting, or the ``li#''
1928 setting from the termcap entry matching the environment
1931 width N: This integer value is the number of characters on a line.
1932 Default is 80, the current `stty cols'' setting, or the ``co#''
1933 setting from the termcap entry matching the environment
1936 Note: ``set screensize'' is obsolete. Use ``set height'' and
1937 ``set width'' instead.
1939 print address on/off: Print memory addresses in various command displays,
1940 such as stack traces and structure values. Gdb looks
1941 more ``symbolic'' if you turn this off; it looks more
1942 ``machine level'' with it on. Default is ON.
1944 print array on/off: Prettyprint arrays. New convenient format! Default
1947 print demangle on/off: Print C++ symbols in "source" form if on,
1950 print asm-demangle on/off: Same, for assembler level printouts
1953 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
1956 * Support for Epoch Environment.
1958 The epoch environment is a version of Emacs v18 with windowing. One
1959 new command, ``inspect'', is identical to ``print'', except that if you
1960 are running in the epoch environment, the value is printed in its own
1964 * Support for Shared Libraries
1966 GDB can now debug programs and core files that use SunOS shared libraries.
1967 Symbols from a shared library cannot be referenced
1968 before the shared library has been linked with the program (this
1969 happens after you type ``run'' and before the function main() is entered).
1970 At any time after this linking (including when examining core files
1971 from dynamically linked programs), gdb reads the symbols from each
1972 shared library when you type the ``sharedlibrary'' command.
1973 It can be abbreviated ``share''.
1975 sharedlibrary REGEXP: Load shared object library symbols for files
1976 matching a unix regular expression. No argument
1977 indicates to load symbols for all shared libraries.
1979 info sharedlibrary: Status of loaded shared libraries.
1984 A watchpoint stops execution of a program whenever the value of an
1985 expression changes. Checking for this slows down execution
1986 tremendously whenever you are in the scope of the expression, but is
1987 quite useful for catching tough ``bit-spreader'' or pointer misuse
1988 problems. Some machines such as the 386 have hardware for doing this
1989 more quickly, and future versions of gdb will use this hardware.
1991 watch EXP: Set a watchpoint (breakpoint) for an expression.
1993 info watchpoints: Information about your watchpoints.
1995 delete N: Deletes watchpoint number N (same as breakpoints).
1996 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
1997 enable N: Re-enables watchpoint number N (same as breakpoints).
2000 * C++ multiple inheritance
2002 When used with a GCC version 2 compiler, GDB supports multiple inheritance
2005 * C++ exception handling
2007 Gdb now supports limited C++ exception handling. Besides the existing
2008 ability to breakpoint on an exception handler, gdb can breakpoint on
2009 the raising of an exception (before the stack is peeled back to the
2012 catch FOO: If there is a FOO exception handler in the dynamic scope,
2013 set a breakpoint to catch exceptions which may be raised there.
2014 Multiple exceptions (``catch foo bar baz'') may be caught.
2016 info catch: Lists all exceptions which may be caught in the
2017 current stack frame.
2020 * Minor command changes
2022 The command ``call func (arg, arg, ...)'' now acts like the print
2023 command, except it does not print or save a value if the function's result
2024 is void. This is similar to dbx usage.
2026 The ``up'' and ``down'' commands now always print the frame they end up
2027 at; ``up-silently'' and `down-silently'' can be used in scripts to change
2028 frames without printing.
2030 * New directory command
2032 'dir' now adds directories to the FRONT of the source search path.
2033 The path starts off empty. Source files that contain debug information
2034 about the directory in which they were compiled can be found even
2035 with an empty path; Sun CC and GCC include this information. If GDB can't
2036 find your source file in the current directory, type "dir .".
2038 * Configuring GDB for compilation
2040 For normal use, type ``./configure host''. See README or gdb.texinfo
2043 GDB now handles cross debugging. If you are remotely debugging between
2044 two different machines, type ``./configure host -target=targ''.
2045 Host is the machine where GDB will run; targ is the machine
2046 where the program that you are debugging will run.