1 What has changed in GDB?
2 (Organized release by release)
4 *** Changes since GDB 5.2:
7 *** Changes in GDB 5.2:
9 * New command "set trust-readonly-sections on[off]".
11 This command is a hint that tells gdb that read-only sections
12 really are read-only (ie. that their contents will not change).
13 In this mode, gdb will go to the object file rather than the
14 target to read memory from read-only sections (such as ".text").
15 This can be a significant performance improvement on some
16 (notably embedded) targets.
18 * New command "generate-core-file" (or "gcore").
20 This new gdb command allows the user to drop a core file of the child
21 process state at any time. So far it's been implemented only for
22 GNU/Linux and Solaris, but should be relatively easily ported to other
23 hosts. Argument is core file name (defaults to core.<pid>).
25 * New command line option
27 GDB now accepts --pid or -p followed by a process id.
29 * Change in command line behavior -- corefiles vs. process ids.
31 There is a subtle behavior in the way in which GDB handles
32 command line arguments. The first non-flag argument is always
33 a program to debug, but the second non-flag argument may either
34 be a corefile or a process id. Previously, GDB would attempt to
35 open the second argument as a corefile, and if that failed, would
36 issue a superfluous error message and then attempt to attach it as
37 a process. Now, if the second argument begins with a non-digit,
38 it will be treated as a corefile. If it begins with a digit,
39 GDB will attempt to attach it as a process, and if no such process
40 is found, will then attempt to open it as a corefile.
42 * Changes in ARM configurations.
44 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
45 configuration is fully multi-arch.
47 * New native configurations
49 ARM NetBSD arm*-*-netbsd*
50 x86 OpenBSD i[3456]86-*-openbsd*
51 AMD x86-64 running GNU/Linux x86_64-*-linux-*
52 Sparc64 running FreeBSD sparc64-*-freebsd*
56 Sanyo XStormy16 xstormy16-elf
58 * OBSOLETE configurations and files
60 Configurations that have been declared obsolete in this release have
61 been commented out. Unless there is activity to revive these
62 configurations, the next release of GDB will have their sources
65 AMD 29k family via UDI a29k-amd-udi, udi29k
66 A29K VxWorks a29k-*-vxworks
67 AMD 29000 embedded, using EBMON a29k-none-none
68 AMD 29000 embedded with COFF a29k-none-coff
69 AMD 29000 embedded with a.out a29k-none-aout
71 testsuite/gdb.hp/gdb.threads-hp/ directory
73 * REMOVED configurations and files
75 TI TMS320C80 tic80-*-*
77 PowerPC Solaris powerpcle-*-solaris*
78 PowerPC Windows NT powerpcle-*-cygwin32
79 PowerPC Netware powerpc-*-netware*
80 Harris/CXUX m88k m88*-harris-cxux*
81 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
82 ns32k-utek-sysv* ns32k-utek-*
83 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
84 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
85 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
86 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
87 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
89 * Changes to command line processing
91 The new `--args' feature can be used to specify command-line arguments
92 for the inferior from gdb's command line.
94 * Changes to key bindings
96 There is a new `operate-and-get-next' function bound to `C-o'.
98 *** Changes in GDB 5.1.1
100 Fix compile problem on DJGPP.
102 Fix a problem with floating-point registers on the i386 being
105 Fix to stop GDB crashing on .debug_str debug info.
107 Numerous documentation fixes.
109 Numerous testsuite fixes.
111 *** Changes in GDB 5.1:
113 * New native configurations
115 Alpha FreeBSD alpha*-*-freebsd*
116 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
117 MIPS GNU/Linux mips*-*-linux*
118 MIPS SGI Irix 6.x mips*-sgi-irix6*
120 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
124 Motorola 68HC11 and 68HC12 m68hc11-elf
126 UltraSparc running GNU/Linux sparc64-*-linux*
128 * OBSOLETE configurations and files
130 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
131 Harris/CXUX m88k m88*-harris-cxux*
132 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
133 ns32k-utek-sysv* ns32k-utek-*
134 TI TMS320C80 tic80-*-*
136 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
137 PowerPC Solaris powerpcle-*-solaris*
138 PowerPC Windows NT powerpcle-*-cygwin32
139 PowerPC Netware powerpc-*-netware*
140 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
141 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
142 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
143 Apple Macintosh (MPW) host N/A
145 stuff.c (Program to stuff files into a specially prepared space in kdb)
146 kdb-start.c (Main loop for the standalone kernel debugger)
148 Configurations that have been declared obsolete in this release have
149 been commented out. Unless there is activity to revive these
150 configurations, the next release of GDB will have their sources
153 * REMOVED configurations and files
155 Altos 3068 m68*-altos-*
156 Convex c1-*-*, c2-*-*
158 ARM RISCix arm-*-* (as host)
162 * GDB has been converted to ISO C.
164 GDB's source code has been converted to ISO C. In particular, the
165 sources are fully protoized, and rely on standard headers being
170 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
172 * The MI enabled by default.
174 The new machine oriented interface (MI) introduced in GDB 5.0 has been
175 revised and enabled by default. Packages which use GDB as a debugging
176 engine behind a UI or another front end are encouraged to switch to
177 using the GDB/MI interface, instead of the old annotations interface
178 which is now deprecated.
180 * Support for debugging Pascal programs.
182 GDB now includes support for debugging Pascal programs. The following
183 main features are supported:
185 - Pascal-specific data types such as sets;
187 - automatic recognition of Pascal sources based on file-name
190 - Pascal-style display of data types, variables, and functions;
192 - a Pascal expression parser.
194 However, some important features are not yet supported.
196 - Pascal string operations are not supported at all;
198 - there are some problems with boolean types;
200 - Pascal type hexadecimal constants are not supported
201 because they conflict with the internal variables format;
203 - support for Pascal objects and classes is not full yet;
205 - unlike Pascal, GDB is case-sensitive for symbol names.
207 * Changes in completion.
209 Commands such as `shell', `run' and `set args', which pass arguments
210 to inferior programs, now complete on file names, similar to what
211 users expect at the shell prompt.
213 Commands which accept locations, such as `disassemble', `print',
214 `breakpoint', `until', etc. now complete on filenames as well as
215 program symbols. Thus, if you type "break foob TAB", and the source
216 files linked into the programs include `foobar.c', that file name will
217 be one of the candidates for completion. However, file names are not
218 considered for completion after you typed a colon that delimits a file
219 name from a name of a function in that file, as in "break foo.c:bar".
221 `set demangle-style' completes on available demangling styles.
223 * New platform-independent commands:
225 It is now possible to define a post-hook for a command as well as a
226 hook that runs before the command. For more details, see the
227 documentation of `hookpost' in the GDB manual.
229 * Changes in GNU/Linux native debugging.
231 Support for debugging multi-threaded programs has been completely
232 revised for all platforms except m68k and sparc. You can now debug as
233 many threads as your system allows you to have.
235 Attach/detach is supported for multi-threaded programs.
237 Support for SSE registers was added for x86. This doesn't work for
238 multi-threaded programs though.
240 * Changes in MIPS configurations.
242 Multi-arch support is enabled for all MIPS configurations.
244 GDB can now be built as native debugger on SGI Irix 6.x systems for
245 debugging n32 executables. (Debugging 64-bit executables is not yet
248 * Unified support for hardware watchpoints in all x86 configurations.
250 Most (if not all) native x86 configurations support hardware-assisted
251 breakpoints and watchpoints in a unified manner. This support
252 implements debug register sharing between watchpoints, which allows to
253 put a virtually infinite number of watchpoints on the same address,
254 and also supports watching regions up to 16 bytes with several debug
257 The new maintenance command `maintenance show-debug-regs' toggles
258 debugging print-outs in functions that insert, remove, and test
259 watchpoints and hardware breakpoints.
261 * Changes in the DJGPP native configuration.
263 New command ``info dos sysinfo'' displays assorted information about
264 the CPU, OS, memory, and DPMI server.
266 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
267 display information about segment descriptors stored in GDT, LDT, and
270 New commands ``info dos pde'' and ``info dos pte'' display entries
271 from Page Directory and Page Tables (for now works with CWSDPMI only).
272 New command ``info dos address-pte'' displays the Page Table entry for
273 a given linear address.
275 GDB can now pass command lines longer than 126 characters to the
276 program being debugged (requires an update to the libdbg.a library
277 which is part of the DJGPP development kit).
279 DWARF2 debug info is now supported.
281 It is now possible to `step' and `next' through calls to `longjmp'.
283 * Changes in documentation.
285 All GDB documentation was converted to GFDL, the GNU Free
286 Documentation License.
288 Tracepoints-related commands are now fully documented in the GDB
291 TUI, the Text-mode User Interface, is now documented in the manual.
293 Tracepoints-related commands are now fully documented in the GDB
296 The "GDB Internals" manual now has an index. It also includes
297 documentation of `ui_out' functions, GDB coding standards, x86
298 hardware watchpoints, and memory region attributes.
300 * GDB's version number moved to ``version.in''
302 The Makefile variable VERSION has been replaced by the file
303 ``version.in''. People creating GDB distributions should update the
304 contents of this file.
308 GUD support is now a standard part of the EMACS distribution.
310 *** Changes in GDB 5.0:
312 * Improved support for debugging FP programs on x86 targets
314 Unified and much-improved support for debugging floating-point
315 programs on all x86 targets. In particular, ``info float'' now
316 displays the FP registers in the same format on all x86 targets, with
317 greater level of detail.
319 * Improvements and bugfixes in hardware-assisted watchpoints
321 It is now possible to watch array elements, struct members, and
322 bitfields with hardware-assisted watchpoints. Data-read watchpoints
323 on x86 targets no longer erroneously trigger when the address is
326 * Improvements in the native DJGPP version of GDB
328 The distribution now includes all the scripts and auxiliary files
329 necessary to build the native DJGPP version on MS-DOS/MS-Windows
330 machines ``out of the box''.
332 The DJGPP version can now debug programs that use signals. It is
333 possible to catch signals that happened in the debuggee, deliver
334 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
335 would kill the program being debugged.) Programs that hook hardware
336 interrupts (keyboard, timer, etc.) can also be debugged.
338 It is now possible to debug DJGPP programs that redirect their
339 standard handles or switch them to raw (as opposed to cooked) mode, or
340 even close them. The command ``run < foo > bar'' works as expected,
341 and ``info terminal'' reports useful information about the debuggee's
342 terminal, including raw/cooked mode, redirection, etc.
344 The DJGPP version now uses termios functions for console I/O, which
345 enables debugging graphics programs. Interrupting GDB with Ctrl-C
348 DOS-style file names with drive letters are now fully supported by
351 It is now possible to debug DJGPP programs that switch their working
352 directory. It is also possible to rerun the debuggee any number of
353 times without restarting GDB; thus, you can use the same setup,
354 breakpoints, etc. for many debugging sessions.
356 * New native configurations
358 ARM GNU/Linux arm*-*-linux*
359 PowerPC GNU/Linux powerpc-*-linux*
363 Motorola MCore mcore-*-*
364 x86 VxWorks i[3456]86-*-vxworks*
365 PowerPC VxWorks powerpc-*-vxworks*
366 TI TMS320C80 tic80-*-*
368 * OBSOLETE configurations
370 Altos 3068 m68*-altos-*
371 Convex c1-*-*, c2-*-*
373 ARM RISCix arm-*-* (as host)
376 Configurations that have been declared obsolete will be commented out,
377 but the code will be left in place. If there is no activity to revive
378 these configurations before the next release of GDB, the sources will
379 be permanently REMOVED.
381 * Gould support removed
383 Support for the Gould PowerNode and NP1 has been removed.
385 * New features for SVR4
387 On SVR4 native platforms (such as Solaris), if you attach to a process
388 without first loading a symbol file, GDB will now attempt to locate and
389 load symbols from the running process's executable file.
391 * Many C++ enhancements
393 C++ support has been greatly improved. Overload resolution now works properly
394 in almost all cases. RTTI support is on the way.
396 * Remote targets can connect to a sub-program
398 A popen(3) style serial-device has been added. This device starts a
399 sub-process (such as a stand-alone simulator) and then communicates
400 with that. The sub-program to run is specified using the syntax
401 ``|<program> <args>'' vis:
403 (gdb) set remotedebug 1
404 (gdb) target extended-remote |mn10300-elf-sim program-args
406 * MIPS 64 remote protocol
408 A long standing bug in the mips64 remote protocol where by GDB
409 expected certain 32 bit registers (ex SR) to be transfered as 32
410 instead of 64 bits has been fixed.
412 The command ``set remote-mips64-transfers-32bit-regs on'' has been
413 added to provide backward compatibility with older versions of GDB.
415 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
417 The command ``set remotebinarydownload'' command has been replaced by
418 ``set remote X-packet''. Other commands in ``set remote'' family
419 include ``set remote P-packet''.
421 * Breakpoint commands accept ranges.
423 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
424 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
425 ``tracepoint passcount'' also accepts a range of tracepoints.
427 * ``apropos'' command added.
429 The ``apropos'' command searches through command names and
430 documentation strings, printing out matches, making it much easier to
431 try to find a command that does what you are looking for.
435 A new machine oriented interface (MI) has been added to GDB. This
436 interface is designed for debug environments running GDB as a separate
437 process. This is part of the long term libGDB project. See the
438 "GDB/MI" chapter of the GDB manual for further information. It can be
439 enabled by configuring with:
441 .../configure --enable-gdbmi
443 *** Changes in GDB-4.18:
445 * New native configurations
447 HP-UX 10.20 hppa*-*-hpux10.20
448 HP-UX 11.x hppa*-*-hpux11.0*
449 M68K GNU/Linux m68*-*-linux*
453 Fujitsu FR30 fr30-*-elf*
454 Intel StrongARM strongarm-*-*
455 Mitsubishi D30V d30v-*-*
457 * OBSOLETE configurations
459 Gould PowerNode, NP1 np1-*-*, pn-*-*
461 Configurations that have been declared obsolete will be commented out,
462 but the code will be left in place. If there is no activity to revive
463 these configurations before the next release of GDB, the sources will
464 be permanently REMOVED.
468 As a compatibility experiment, GDB's source files buildsym.h and
469 buildsym.c have been converted to pure standard C, no longer
470 containing any K&R compatibility code. We believe that all systems in
471 use today either come with a standard C compiler, or have a GCC port
472 available. If this is not true, please report the affected
473 configuration to bug-gdb@gnu.org immediately. See the README file for
474 information about getting a standard C compiler if you don't have one
479 GDB now uses readline 2.2.
481 * set extension-language
483 You can now control the mapping between filename extensions and source
484 languages by using the `set extension-language' command. For instance,
485 you can ask GDB to treat .c files as C++ by saying
486 set extension-language .c c++
487 The command `info extensions' lists all of the recognized extensions
488 and their associated languages.
490 * Setting processor type for PowerPC and RS/6000
492 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
493 you can use the `set processor' command to specify what variant of the
494 PowerPC family you are debugging. The command
498 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
499 following PowerPC and RS6000 variants:
501 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
502 rs6000 IBM RS6000 ("POWER") architecture, user-level view
504 403GC IBM PowerPC 403GC
505 505 Motorola PowerPC 505
506 860 Motorola PowerPC 860 or 850
507 601 Motorola PowerPC 601
508 602 Motorola PowerPC 602
509 603 Motorola/IBM PowerPC 603 or 603e
510 604 Motorola PowerPC 604 or 604e
511 750 Motorola/IBM PowerPC 750 or 750
513 At the moment, this command just tells GDB what to name the
514 special-purpose processor registers. Since almost all the affected
515 registers are inaccessible to user-level programs, this command is
516 only useful for remote debugging in its present form.
520 Thanks to a major code donation from Hewlett-Packard, GDB now has much
521 more extensive support for HP-UX. Added features include shared
522 library support, kernel threads and hardware watchpoints for 11.00,
523 support for HP's ANSI C and C++ compilers, and a compatibility mode
524 for xdb and dbx commands.
528 HP's donation includes the new concept of catchpoints, which is a
529 generalization of the old catch command. On HP-UX, it is now possible
530 to catch exec, fork, and vfork, as well as library loading.
532 This means that the existing catch command has changed; its first
533 argument now specifies the type of catch to be set up. See the
534 output of "help catch" for a list of catchpoint types.
536 * Debugging across forks
538 On HP-UX, you can choose which process to debug when a fork() happens
543 HP has donated a curses-based terminal user interface (TUI). To get
544 it, build with --enable-tui. Although this can be enabled for any
545 configuration, at present it only works for native HP debugging.
547 * GDB remote protocol additions
549 A new protocol packet 'X' that writes binary data is now available.
550 Default behavior is to try 'X', then drop back to 'M' if the stub
551 fails to respond. The settable variable `remotebinarydownload'
552 allows explicit control over the use of 'X'.
554 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
555 full 64-bit address. The command
557 set remoteaddresssize 32
559 can be used to revert to the old behaviour. For existing remote stubs
560 the change should not be noticed, as the additional address information
563 In order to assist in debugging stubs, you may use the maintenance
564 command `packet' to send any text string to the stub. For instance,
566 maint packet heythere
568 sends the packet "$heythere#<checksum>". Note that it is very easy to
569 disrupt a debugging session by sending the wrong packet at the wrong
572 The compare-sections command allows you to compare section data on the
573 target to what is in the executable file without uploading or
574 downloading, by comparing CRC checksums.
576 * Tracing can collect general expressions
578 You may now collect general expressions at tracepoints. This requires
579 further additions to the target-side stub; see tracepoint.c and
580 doc/agentexpr.texi for further details.
582 * mask-address variable for Mips
584 For Mips targets, you may control the zeroing of the upper 32 bits of
585 a 64-bit address by entering `set mask-address on'. This is mainly
586 of interest to users of embedded R4xxx and R5xxx processors.
588 * Higher serial baud rates
590 GDB's serial code now allows you to specify baud rates 57600, 115200,
591 230400, and 460800 baud. (Note that your host system may not be able
592 to achieve all of these rates.)
596 The i960 configuration now includes an initial implementation of a
597 builtin simulator, contributed by Jim Wilson.
600 *** Changes in GDB-4.17:
602 * New native configurations
604 Alpha GNU/Linux alpha*-*-linux*
605 Unixware 2.x i[3456]86-unixware2*
606 Irix 6.x mips*-sgi-irix6*
607 PowerPC GNU/Linux powerpc-*-linux*
608 PowerPC Solaris powerpcle-*-solaris*
609 Sparc GNU/Linux sparc-*-linux*
610 Motorola sysV68 R3V7.1 m68k-motorola-sysv
614 Argonaut Risc Chip (ARC) arc-*-*
615 Hitachi H8/300S h8300*-*-*
616 Matsushita MN10200 w/simulator mn10200-*-*
617 Matsushita MN10300 w/simulator mn10300-*-*
618 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
619 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
620 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
621 Mitsubishi D10V w/simulator d10v-*-*
622 Mitsubishi M32R/D w/simulator m32r-*-elf*
623 Tsqware Sparclet sparclet-*-*
624 NEC V850 w/simulator v850-*-*
626 * New debugging protocols
628 ARM with RDI protocol arm*-*-*
629 M68K with dBUG monitor m68*-*-{aout,coff,elf}
630 DDB and LSI variants of PMON protocol mips*-*-*
631 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
632 PowerPC with SDS protocol powerpc{,le}-*-eabi
633 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
637 All configurations can now understand and use the DWARF 2 debugging
638 format. The choice is automatic, if the symbol file contains DWARF 2
643 GDB now includes basic Java language support. This support is
644 only useful with Java compilers that produce native machine code.
646 * solib-absolute-prefix and solib-search-path
648 For SunOS and SVR4 shared libraries, you may now set the prefix for
649 loading absolute shared library symbol files, and the search path for
650 locating non-absolute shared library symbol files.
652 * Live range splitting
654 GDB can now effectively debug code for which GCC has performed live
655 range splitting as part of its optimization. See gdb/doc/LRS for
656 more details on the expected format of the stabs information.
660 GDB's support for the GNU Hurd, including thread debugging, has been
661 updated to work with current versions of the Hurd.
665 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
666 instruction set. ARM GDB automatically detects when Thumb
667 instructions are in use, and adjusts disassembly and backtracing
672 GDB's MIPS target configurations now handle the MIP16 16-bit
677 GDB now includes support for overlays; if an executable has been
678 linked such that multiple sections are based at the same address, GDB
679 will decide which section to use for symbolic info. You can choose to
680 control the decision manually, using overlay commands, or implement
681 additional target-side support and use "overlay load-target" to bring
682 in the overlay mapping. Do "help overlay" for more detail.
686 The command "info symbol <address>" displays information about
687 the symbol at the specified address.
691 The standard remote protocol now includes an extension that allows
692 asynchronous collection and display of trace data. This requires
693 extensive support in the target-side debugging stub. Tracing mode
694 includes a new interaction mode in GDB and new commands: see the
695 file tracepoint.c for more details.
699 Configurations for embedded MIPS now include a simulator contributed
700 by Cygnus Solutions. The simulator supports the instruction sets
701 of most MIPS variants.
705 Sparc configurations may now include the ERC32 simulator contributed
706 by the European Space Agency. The simulator is not built into
707 Sparc targets by default; configure with --enable-sim to include it.
711 For target configurations that may include multiple variants of a
712 basic architecture (such as MIPS and SH), you may now set the
713 architecture explicitly. "set arch" sets, "info arch" lists
714 the possible architectures.
716 *** Changes in GDB-4.16:
718 * New native configurations
720 Windows 95, x86 Windows NT i[345]86-*-cygwin32
721 M68K NetBSD m68k-*-netbsd*
722 PowerPC AIX 4.x powerpc-*-aix*
723 PowerPC MacOS powerpc-*-macos*
724 PowerPC Windows NT powerpcle-*-cygwin32
725 RS/6000 AIX 4.x rs6000-*-aix4*
729 ARM with RDP protocol arm-*-*
730 I960 with MON960 i960-*-coff
731 MIPS VxWorks mips*-*-vxworks*
732 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
733 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
735 Matra Sparclet sparclet-*-*
739 The powerpc-eabi configuration now includes the PSIM simulator,
740 contributed by Andrew Cagney, with assistance from Mike Meissner.
741 PSIM is a very elaborate model of the PowerPC, including not only
742 basic instruction set execution, but also details of execution unit
743 performance and I/O hardware. See sim/ppc/README for more details.
747 GDB now works with Solaris 2.5.
749 * Windows 95/NT native
751 GDB will now work as a native debugger on Windows 95 and Windows NT.
752 To build it from source, you must use the "gnu-win32" environment,
753 which uses a DLL to emulate enough of Unix to run the GNU tools.
754 Further information, binaries, and sources are available at
755 ftp.cygnus.com, under pub/gnu-win32.
757 * dont-repeat command
759 If a user-defined command includes the command `dont-repeat', then the
760 command will not be repeated if the user just types return. This is
761 useful if the command is time-consuming to run, so that accidental
762 extra keystrokes don't run the same command many times.
764 * Send break instead of ^C
766 The standard remote protocol now includes an option to send a break
767 rather than a ^C to the target in order to interrupt it. By default,
768 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
770 * Remote protocol timeout
772 The standard remote protocol includes a new variable `remotetimeout'
773 that allows you to set the number of seconds before GDB gives up trying
774 to read from the target. The default value is 2.
776 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
778 By default GDB will automatically keep track of objects as they are
779 loaded and unloaded by the dynamic linker. By using the command `set
780 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
781 when shared library events occur, thus allowing you to set breakpoints
782 in shared libraries which are explicitly loaded by the inferior.
784 Note this feature does not work on hpux8. On hpux9 you must link
785 /usr/lib/end.o into your program. This feature should work
786 automatically on hpux10.
788 * Irix 5.x hardware watchpoint support
790 Irix 5 configurations now support the use of hardware watchpoints.
792 * Mips protocol "SYN garbage limit"
794 When debugging a Mips target using the `target mips' protocol, you
795 may set the number of characters that GDB will ignore by setting
796 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
797 every character. The default value is 1050.
799 * Recording and replaying remote debug sessions
801 If you set `remotelogfile' to the name of a file, gdb will write to it
802 a recording of a remote debug session. This recording may then be
803 replayed back to gdb using "gdbreplay". See gdbserver/README for
804 details. This is useful when you have a problem with GDB while doing
805 remote debugging; you can make a recording of the session and send it
806 to someone else, who can then recreate the problem.
808 * Speedups for remote debugging
810 GDB includes speedups for downloading and stepping MIPS systems using
811 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
812 and more efficient S-record downloading.
814 * Memory use reductions and statistics collection
816 GDB now uses less memory and reports statistics about memory usage.
817 Try the `maint print statistics' command, for example.
819 *** Changes in GDB-4.15:
823 The symbol reader for AIX GDB now uses partial symbol tables. This
824 can greatly improve startup time, especially for large executables.
826 * Remote targets use caching
828 Remote targets now use a data cache to speed up communication with the
829 remote side. The data cache could lead to incorrect results because
830 it doesn't know about volatile variables, thus making it impossible to
831 debug targets which use memory mapped I/O devices. `set remotecache
832 off' turns the the data cache off.
834 * Remote targets may have threads
836 The standard remote protocol now includes support for multiple threads
837 in the target system, using new protocol commands 'H' and 'T'. See
838 gdb/remote.c for details.
842 If GDB is configured with `--enable-netrom', then it will include
843 support for the NetROM ROM emulator from XLNT Designs. The NetROM
844 acts as though it is a bank of ROM on the target board, but you can
845 write into it over the network. GDB's support consists only of
846 support for fast loading into the emulated ROM; to debug, you must use
847 another protocol, such as standard remote protocol. The usual
848 sequence is something like
850 target nrom <netrom-hostname>
852 target remote <netrom-hostname>:1235
856 GDB now includes support for the Apple Macintosh, as a host only. It
857 may be run as either an MPW tool or as a standalone application, and
858 it can debug through the serial port. All the usual GDB commands are
859 available, but to the target command, you must supply "serial" as the
860 device type instead of "/dev/ttyXX". See mpw-README in the main
861 directory for more information on how to build. The MPW configuration
862 scripts */mpw-config.in support only a few targets, and only the
863 mips-idt-ecoff target has been tested.
867 GDB configuration now uses autoconf. This is not user-visible,
868 but does simplify configuration and building.
872 GDB now supports hpux10.
874 *** Changes in GDB-4.14:
876 * New native configurations
878 x86 FreeBSD i[345]86-*-freebsd
879 x86 NetBSD i[345]86-*-netbsd
880 NS32k NetBSD ns32k-*-netbsd
881 Sparc NetBSD sparc-*-netbsd
885 A29K VxWorks a29k-*-vxworks
886 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
887 CPU32 EST-300 emulator m68*-*-est*
888 PowerPC ELF powerpc-*-elf
891 * Alpha OSF/1 support for procfs
893 GDB now supports procfs under OSF/1-2.x and higher, which makes it
894 possible to attach to running processes. As the mounting of the /proc
895 filesystem is optional on the Alpha, GDB automatically determines
896 the availability of /proc during startup. This can lead to problems
897 if /proc is unmounted after GDB has been started.
899 * Arguments to user-defined commands
901 User commands may accept up to 10 arguments separated by whitespace.
902 Arguments are accessed within the user command via $arg0..$arg9. A
905 print $arg0 + $arg1 + $arg2
907 To execute the command use:
910 Defines the command "adder" which prints the sum of its three arguments.
911 Note the arguments are text substitutions, so they may reference variables,
912 use complex expressions, or even perform inferior function calls.
914 * New `if' and `while' commands
916 This makes it possible to write more sophisticated user-defined
917 commands. Both commands take a single argument, which is the
918 expression to evaluate, and must be followed by the commands to
919 execute, one per line, if the expression is nonzero, the list being
920 terminated by the word `end'. The `if' command list may include an
921 `else' word, which causes the following commands to be executed only
922 if the expression is zero.
924 * Fortran source language mode
926 GDB now includes partial support for Fortran 77. It will recognize
927 Fortran programs and can evaluate a subset of Fortran expressions, but
928 variables and functions may not be handled correctly. GDB will work
929 with G77, but does not yet know much about symbols emitted by other
932 * Better HPUX support
934 Most debugging facilities now work on dynamic executables for HPPAs
935 running hpux9 or later. You can attach to running dynamically linked
936 processes, but by default the dynamic libraries will be read-only, so
937 for instance you won't be able to put breakpoints in them. To change
938 that behavior do the following before running the program:
944 This will cause the libraries to be mapped private and read-write.
945 To revert to the normal behavior, do this:
951 You cannot set breakpoints or examine data in the library until after
952 the library is loaded if the function/data symbols do not have
955 GDB can now also read debug symbols produced by the HP C compiler on
956 HPPAs (sorry, no C++, Fortran or 68k support).
958 * Target byte order now dynamically selectable
960 You can choose which byte order to use with a target system, via the
961 commands "set endian big" and "set endian little", and you can see the
962 current setting by using "show endian". You can also give the command
963 "set endian auto", in which case GDB will use the byte order
964 associated with the executable. Currently, only embedded MIPS
965 configurations support dynamic selection of target byte order.
967 * New DOS host serial code
969 This version uses DPMI interrupts to handle buffered I/O, so you
970 no longer need to run asynctsr when debugging boards connected to
973 *** Changes in GDB-4.13:
975 * New "complete" command
977 This lists all the possible completions for the rest of the line, if it
978 were to be given as a command itself. This is intended for use by emacs.
980 * Trailing space optional in prompt
982 "set prompt" no longer adds a space for you after the prompt you set. This
983 allows you to set a prompt which ends in a space or one that does not.
985 * Breakpoint hit counts
987 "info break" now displays a count of the number of times the breakpoint
988 has been hit. This is especially useful in conjunction with "ignore"; you
989 can ignore a large number of breakpoint hits, look at the breakpoint info
990 to see how many times the breakpoint was hit, then run again, ignoring one
991 less than that number, and this will get you quickly to the last hit of
994 * Ability to stop printing at NULL character
996 "set print null-stop" will cause GDB to stop printing the characters of
997 an array when the first NULL is encountered. This is useful when large
998 arrays actually contain only short strings.
1000 * Shared library breakpoints
1002 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
1003 breakpoints in shared libraries before the executable is run.
1005 * Hardware watchpoints
1007 There is a new hardware breakpoint for the watch command for sparclite
1008 targets. See gdb/sparclite/hw_breakpoint.note.
1010 Hardware watchpoints are also now supported under GNU/Linux.
1014 Annotations have been added. These are for use with graphical interfaces,
1015 and are still experimental. Currently only gdba.el uses these.
1017 * Improved Irix 5 support
1019 GDB now works properly with Irix 5.2.
1021 * Improved HPPA support
1023 GDB now works properly with the latest GCC and GAS.
1025 * New native configurations
1027 Sequent PTX4 i[34]86-sequent-ptx4
1028 HPPA running OSF/1 hppa*-*-osf*
1029 Atari TT running SVR4 m68*-*-sysv4*
1030 RS/6000 LynxOS rs6000-*-lynxos*
1034 OS/9000 i[34]86-*-os9k
1035 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
1038 * Hitachi SH7000 and E7000-PC ICE support
1040 There is now support for communicating with the Hitachi E7000-PC ICE.
1041 This is available automatically when GDB is configured for the SH.
1045 As usual, a variety of small fixes and improvements, both generic
1046 and configuration-specific. See the ChangeLog for more detail.
1048 *** Changes in GDB-4.12:
1050 * Irix 5 is now supported
1054 GDB-4.12 on the HPPA has a number of changes which make it unable
1055 to debug the output from the currently released versions of GCC and
1056 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
1057 of GCC and GAS, versions of these tools designed to work with GDB-4.12
1058 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
1061 *** Changes in GDB-4.11:
1063 * User visible changes:
1067 The "set remotedebug" option is now consistent between the mips remote
1068 target, remote targets using the gdb-specific protocol, UDI (AMD's
1069 debug protocol for the 29k) and the 88k bug monitor. It is now an
1070 integer specifying a debug level (normally 0 or 1, but 2 means more
1071 debugging info for the mips target).
1073 * DEC Alpha native support
1075 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
1076 debug info, but GDB works fairly well with the DEC compiler and should
1077 work with a future GCC release. See the README file for a few
1078 Alpha-specific notes.
1080 * Preliminary thread implementation
1082 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
1084 * LynxOS native and target support for 386
1086 This release has been hosted on LynxOS 2.2, and also can be configured
1087 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
1090 * Improvements in C++ mangling/demangling.
1092 This release has much better g++ debugging, specifically in name
1093 mangling/demangling, virtual function calls, print virtual table,
1094 call methods, ...etc.
1096 *** Changes in GDB-4.10:
1098 * User visible changes:
1100 Remote debugging using the GDB-specific (`target remote') protocol now
1101 supports the `load' command. This is only useful if you have some
1102 other way of getting the stub to the target system, and you can put it
1103 somewhere in memory where it won't get clobbered by the download.
1105 Filename completion now works.
1107 When run under emacs mode, the "info line" command now causes the
1108 arrow to point to the line specified. Also, "info line" prints
1109 addresses in symbolic form (as well as hex).
1111 All vxworks based targets now support a user settable option, called
1112 vxworks-timeout. This option represents the number of seconds gdb
1113 should wait for responses to rpc's. You might want to use this if
1114 your vxworks target is, perhaps, a slow software simulator or happens
1115 to be on the far side of a thin network line.
1119 This release contains support for using a DEC alpha as a GDB host for
1120 cross debugging. Native alpha debugging is not supported yet.
1123 *** Changes in GDB-4.9:
1127 This is the first GDB release which is accompanied by a matching testsuite.
1128 The testsuite requires installation of dejagnu, which should be available
1129 via ftp from most sites that carry GNU software.
1133 'Cfront' style demangling has had its name changed to 'ARM' style, to
1134 emphasize that it was written from the specifications in the C++ Annotated
1135 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
1136 disclaimers, it still generated too much confusion with users attempting to
1137 use gdb with AT&T cfront.
1141 GDB now uses a standard remote interface to a simulator library.
1142 So far, the library contains simulators for the Zilog Z8001/2, the
1143 Hitachi H8/300, H8/500 and Super-H.
1145 * New targets supported
1147 H8/300 simulator h8300-hitachi-hms or h8300hms
1148 H8/500 simulator h8500-hitachi-hms or h8500hms
1149 SH simulator sh-hitachi-hms or sh
1150 Z8000 simulator z8k-zilog-none or z8ksim
1151 IDT MIPS board over serial line mips-idt-ecoff
1153 Cross-debugging to GO32 targets is supported. It requires a custom
1154 version of the i386-stub.c module which is integrated with the
1155 GO32 memory extender.
1157 * New remote protocols
1159 MIPS remote debugging protocol.
1161 * New source languages supported
1163 This version includes preliminary support for Chill, a Pascal like language
1164 used by telecommunications companies. Chill support is also being integrated
1165 into the GNU compiler, but we don't know when it will be publically available.
1168 *** Changes in GDB-4.8:
1170 * HP Precision Architecture supported
1172 GDB now supports HP PA-RISC machines running HPUX. A preliminary
1173 version of this support was available as a set of patches from the
1174 University of Utah. GDB does not support debugging of programs
1175 compiled with the HP compiler, because HP will not document their file
1176 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
1177 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
1179 Many problems in the preliminary version have been fixed.
1181 * Faster and better demangling
1183 We have improved template demangling and fixed numerous bugs in the GNU style
1184 demangler. It can now handle type modifiers such as `static' or `const'. Wide
1185 character types (wchar_t) are now supported. Demangling of each symbol is now
1186 only done once, and is cached when the symbol table for a file is read in.
1187 This results in a small increase in memory usage for C programs, a moderate
1188 increase in memory usage for C++ programs, and a fantastic speedup in
1191 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
1192 from the specifications in the Annotated Reference Manual, which AT&T's
1193 compiler does not actually implement.
1195 * G++ multiple inheritance compiler problem
1197 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
1198 inheritance lattices was reworked to properly discover ambiguities. We
1199 recently found an example which causes this new algorithm to fail in a
1200 very subtle way, producing bad debug information for those classes.
1201 The file 'gcc.patch' (in this directory) can be applied to gcc to
1202 circumvent the problem. A future GCC release will contain a complete
1205 The previous G++ debug info problem (mentioned below for the gdb-4.7
1206 release) is fixed in gcc version 2.3.2.
1208 * Improved configure script
1210 The `configure' script will now attempt to guess your system type if
1211 you don't supply a host system type. The old scheme of supplying a
1212 host system triplet is preferable over using this. All the magic is
1213 done in the new `config.guess' script. Examine it for details.
1215 We have also brought our configure script much more in line with the FSF's
1216 version. It now supports the --with-xxx options. In particular,
1217 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
1218 The resulting GDB will not be able to read arbitrary object file formats --
1219 only the format ``expected'' to be used on the configured target system.
1220 We hope to make this the default in a future release.
1222 * Documentation improvements
1224 There's new internal documentation on how to modify GDB, and how to
1225 produce clean changes to the code. We implore people to read it
1226 before submitting changes.
1228 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
1229 M4 macros. The new texinfo.tex is provided in this release. Pre-built
1230 `info' files are also provided. To build `info' files from scratch,
1231 you will need the latest `makeinfo' release, which will be available in
1232 a future texinfo-X.Y release.
1234 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
1235 We're not sure exactly which versions have this problem, but it has
1236 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
1237 or better. If that isn't possible, there is a patch in
1238 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
1239 around this problem.
1243 GDB now supports array constants that can be used in expressions typed in by
1244 the user. The syntax is `{element, element, ...}'. Ie: you can now type
1245 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
1248 The new directory `gdb/sparclite' contains a program that demonstrates
1249 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
1251 * New native hosts supported
1253 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
1254 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
1256 * New targets supported
1258 AMD 29k family via UDI a29k-amd-udi or udi29k
1260 * New file formats supported
1262 BFD now supports reading HP/PA-RISC executables (SOM file format?),
1263 HPUX core files, and SCO 3.2v2 core files.
1267 Attaching to processes now works again; thanks for the many bug reports.
1269 We have also stomped on a bunch of core dumps caused by
1270 printf_filtered("%s") problems.
1272 We eliminated a copyright problem on the rpc and ptrace header files
1273 for VxWorks, which was discovered at the last minute during the 4.7
1274 release. You should now be able to build a VxWorks GDB.
1276 You can now interrupt gdb while an attached process is running. This
1277 will cause the attached process to stop, and give control back to GDB.
1279 We fixed problems caused by using too many file descriptors
1280 for reading symbols from object files and libraries. This was
1281 especially a problem for programs that used many (~100) shared
1284 The `step' command now only enters a subroutine if there is line number
1285 information for the subroutine. Otherwise it acts like the `next'
1286 command. Previously, `step' would enter subroutines if there was
1287 any debugging information about the routine. This avoids problems
1288 when using `cc -g1' on MIPS machines.
1290 * Internal improvements
1292 GDB's internal interfaces have been improved to make it easier to support
1293 debugging of multiple languages in the future.
1295 GDB now uses a common structure for symbol information internally.
1296 Minimal symbols (derived from linkage symbols in object files), partial
1297 symbols (from a quick scan of debug information), and full symbols
1298 contain a common subset of information, making it easier to write
1299 shared code that handles any of them.
1301 * New command line options
1303 We now accept --silent as an alias for --quiet.
1307 The memory-mapped-malloc library is now licensed under the GNU Library
1308 General Public License.
1310 *** Changes in GDB-4.7:
1312 * Host/native/target split
1314 GDB has had some major internal surgery to untangle the support for
1315 hosts and remote targets. Now, when you configure GDB for a remote
1316 target, it will no longer load in all of the support for debugging
1317 local programs on the host. When fully completed and tested, this will
1318 ensure that arbitrary host/target combinations are possible.
1320 The primary conceptual shift is to separate the non-portable code in
1321 GDB into three categories. Host specific code is required any time GDB
1322 is compiled on that host, regardless of the target. Target specific
1323 code relates to the peculiarities of the target, but can be compiled on
1324 any host. Native specific code is everything else: it can only be
1325 built when the host and target are the same system. Child process
1326 handling and core file support are two common `native' examples.
1328 GDB's use of /proc for controlling Unix child processes is now cleaner.
1329 It has been split out into a single module under the `target_ops' vector,
1330 plus two native-dependent functions for each system that uses /proc.
1332 * New hosts supported
1334 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
1335 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
1336 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
1338 * New targets supported
1340 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
1341 68030 and CPU32 m68030-*-*, m68332-*-*
1343 * New native hosts supported
1345 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
1346 (386bsd is not well tested yet)
1347 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
1349 * New file formats supported
1351 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
1352 supports reading of `a.out.adobe' object files, which are an a.out
1353 format extended with minimal information about multiple sections.
1357 `show copying' is the same as the old `info copying'.
1358 `show warranty' is the same as `info warrantee'.
1359 These were renamed for consistency. The old commands continue to work.
1361 `info handle' is a new alias for `info signals'.
1363 You can now define pre-command hooks, which attach arbitrary command
1364 scripts to any command. The commands in the hook will be executed
1365 prior to the user's command. You can also create a hook which will be
1366 executed whenever the program stops. See gdb.texinfo.
1370 We now deal with Cfront style name mangling, and can even extract type
1371 info from mangled symbols. GDB can automatically figure out which
1372 symbol mangling style your C++ compiler uses.
1374 Calling of methods and virtual functions has been improved as well.
1378 The crash that occured when debugging Sun Ansi-C compiled binaries is
1379 fixed. This was due to mishandling of the extra N_SO stabs output
1382 We also finally got Ultrix 4.2 running in house, and fixed core file
1383 support, with help from a dozen people on the net.
1385 John M. Farrell discovered that the reason that single-stepping was so
1386 slow on all of the Mips based platforms (primarily SGI and DEC) was
1387 that we were trying to demangle and lookup a symbol used for internal
1388 purposes on every instruction that was being stepped through. Changing
1389 the name of that symbol so that it couldn't be mistaken for a C++
1390 mangled symbol sped things up a great deal.
1392 Rich Pixley sped up symbol lookups in general by getting much smarter
1393 about when C++ symbol mangling is necessary. This should make symbol
1394 completion (TAB on the command line) much faster. It's not as fast as
1395 we'd like, but it's significantly faster than gdb-4.6.
1399 A new user controllable variable 'call_scratch_address' can
1400 specify the location of a scratch area to be used when GDB
1401 calls a function in the target. This is necessary because the
1402 usual method of putting the scratch area on the stack does not work
1403 in systems that have separate instruction and data spaces.
1405 We integrated changes to support the 29k UDI (Universal Debugger
1406 Interface), but discovered at the last minute that we didn't have all
1407 of the appropriate copyright paperwork. We are working with AMD to
1408 resolve this, and hope to have it available soon.
1412 We have sped up the remote serial line protocol, especially for targets
1413 with lots of registers. It now supports a new `expedited status' ('T')
1414 message which can be used in place of the existing 'S' status message.
1415 This allows the remote stub to send only the registers that GDB
1416 needs to make a quick decision about single-stepping or conditional
1417 breakpoints, eliminating the need to fetch the entire register set for
1418 each instruction being stepped through.
1420 The GDB remote serial protocol now implements a write-through cache for
1421 registers, only re-reading the registers if the target has run.
1423 There is also a new remote serial stub for SPARC processors. You can
1424 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
1425 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
1426 processor with a serial port.
1430 Configure.in files have become much easier to read and modify. A new
1431 `table driven' format makes it more obvious what configurations are
1432 supported, and what files each one uses.
1436 There is a new opcodes library which will eventually contain all of the
1437 disassembly routines and opcode tables. At present, it only contains
1438 Sparc and Z8000 routines. This will allow the assembler, debugger, and
1439 disassembler (binutils/objdump) to share these routines.
1441 The libiberty library is now copylefted under the GNU Library General
1442 Public License. This allows more liberal use, and was done so libg++
1443 can use it. This makes no difference to GDB, since the Library License
1444 grants all the rights from the General Public License.
1448 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
1449 reference to the stabs symbol info used by the debugger. It is (as far
1450 as we know) the only published document on this fascinating topic. We
1451 encourage you to read it, compare it to the stabs information on your
1452 system, and send improvements on the document in general (to
1453 bug-gdb@prep.ai.mit.edu).
1455 And, of course, many bugs have been fixed.
1458 *** Changes in GDB-4.6:
1460 * Better support for C++ function names
1462 GDB now accepts as input the "demangled form" of C++ overloaded function
1463 names and member function names, and can do command completion on such names
1464 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
1465 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
1466 Make use of command completion, it is your friend.
1468 GDB also now accepts a variety of C++ mangled symbol formats. They are
1469 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
1470 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
1471 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
1472 for the list of formats.
1474 * G++ symbol mangling problem
1476 Recent versions of gcc have a bug in how they emit debugging information for
1477 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
1478 directory) can be applied to gcc to fix the problem. Alternatively, if you
1479 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
1480 usual symptom is difficulty with setting breakpoints on methods. GDB complains
1481 about the method being non-existent. (We believe that version 2.2.2 of GCC has
1484 * New 'maintenance' command
1486 All of the commands related to hacking GDB internals have been moved out of
1487 the main command set, and now live behind the 'maintenance' command. This
1488 can also be abbreviated as 'mt'. The following changes were made:
1490 dump-me -> maintenance dump-me
1491 info all-breakpoints -> maintenance info breakpoints
1492 printmsyms -> maintenance print msyms
1493 printobjfiles -> maintenance print objfiles
1494 printpsyms -> maintenance print psymbols
1495 printsyms -> maintenance print symbols
1497 The following commands are new:
1499 maintenance demangle Call internal GDB demangler routine to
1500 demangle a C++ link name and prints the result.
1501 maintenance print type Print a type chain for a given symbol
1503 * Change to .gdbinit file processing
1505 We now read the $HOME/.gdbinit file before processing the argv arguments
1506 (e.g. reading symbol files or core files). This allows global parameters to
1507 be set, which will apply during the symbol reading. The ./.gdbinit is still
1508 read after argv processing.
1510 * New hosts supported
1512 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
1514 GNU/Linux support i386-unknown-linux or linux
1516 We are also including code to support the HP/PA running BSD and HPUX. This
1517 is almost guaranteed not to work, as we didn't have time to test or build it
1518 for this release. We are including it so that the more adventurous (or
1519 masochistic) of you can play with it. We also had major problems with the
1520 fact that the compiler that we got from HP doesn't support the -g option.
1523 * New targets supported
1525 Hitachi H8/300 h8300-hitachi-hms or h8300hms
1527 * More smarts about finding #include files
1529 GDB now remembers the compilation directory for all include files, and for
1530 all files from which C is generated (like yacc and lex sources). This
1531 greatly improves GDB's ability to find yacc/lex sources, and include files,
1532 especially if you are debugging your program from a directory different from
1533 the one that contains your sources.
1535 We also fixed a bug which caused difficulty with listing and setting
1536 breakpoints in include files which contain C code. (In the past, you had to
1537 try twice in order to list an include file that you hadn't looked at before.)
1539 * Interesting infernals change
1541 GDB now deals with arbitrary numbers of sections, where the symbols for each
1542 section must be relocated relative to that section's landing place in the
1543 target's address space. This work was needed to support ELF with embedded
1544 stabs used by Solaris-2.0.
1546 * Bug fixes (of course!)
1548 There have been loads of fixes for the following things:
1549 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
1550 i960, stabs, DOS(GO32), procfs, etc...
1552 See the ChangeLog for details.
1554 *** Changes in GDB-4.5:
1556 * New machines supported (host and target)
1558 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
1560 SGI Irix-4.x mips-sgi-irix4 or iris4
1562 * New malloc package
1564 GDB now uses a new memory manager called mmalloc, based on gmalloc.
1565 Mmalloc is capable of handling mutiple heaps of memory. It is also
1566 capable of saving a heap to a file, and then mapping it back in later.
1567 This can be used to greatly speedup the startup of GDB by using a
1568 pre-parsed symbol table which lives in a mmalloc managed heap. For
1569 more details, please read mmalloc/mmalloc.texi.
1573 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
1574 'help info proc' for details.
1576 * MIPS ecoff symbol table format
1578 The code that reads MIPS symbol table format is now supported on all hosts.
1579 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
1582 * File name changes for MS-DOS
1584 Many files in the config directories have been renamed to make it easier to
1585 support GDB on MS-DOSe systems (which have very restrictive file name
1586 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
1587 environment) is close to working but has some remaining problems. Note
1588 that debugging of DOS programs is not supported, due to limitations
1589 in the ``operating system'', but it can be used to host cross-debugging.
1591 * Cross byte order fixes
1593 Many fixes have been made to support cross debugging of Sparc and MIPS
1594 targets from hosts whose byte order differs.
1596 * New -mapped and -readnow options
1598 If memory-mapped files are available on your system through the 'mmap'
1599 system call, you can use the -mapped option on the `file' or
1600 `symbol-file' commands to cause GDB to write the symbols from your
1601 program into a reusable file. If the program you are debugging is
1602 called `/path/fred', the mapped symbol file will be `./fred.syms'.
1603 Future GDB debugging sessions will notice the presence of this file,
1604 and will quickly map in symbol information from it, rather than reading
1605 the symbol table from the executable program. Using the '-mapped'
1606 option in a GDB `file' or `symbol-file' command has the same effect as
1607 starting GDB with the '-mapped' command-line option.
1609 You can cause GDB to read the entire symbol table immediately by using
1610 the '-readnow' option with any of the commands that load symbol table
1611 information (or on the GDB command line). This makes the command
1612 slower, but makes future operations faster.
1614 The -mapped and -readnow options are typically combined in order to
1615 build a `fred.syms' file that contains complete symbol information.
1616 A simple GDB invocation to do nothing but build a `.syms' file for future
1619 gdb -batch -nx -mapped -readnow programname
1621 The `.syms' file is specific to the host machine on which GDB is run.
1622 It holds an exact image of GDB's internal symbol table. It cannot be
1623 shared across multiple host platforms.
1625 * longjmp() handling
1627 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
1628 siglongjmp() without losing control. This feature has not yet been ported to
1629 all systems. It currently works on many 386 platforms, all MIPS-based
1630 platforms (SGI, DECstation, etc), and Sun3/4.
1634 Preliminary work has been put in to support the new Solaris OS from Sun. At
1635 this time, it can control and debug processes, but it is not capable of
1640 As always, many many bug fixes. The major areas were with g++, and mipsread.
1641 People using the MIPS-based platforms should experience fewer mysterious
1642 crashes and trashed symbol tables.
1644 *** Changes in GDB-4.4:
1646 * New machines supported (host and target)
1648 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
1650 BSD Reno on Vax vax-dec-bsd
1651 Ultrix on Vax vax-dec-ultrix
1653 * New machines supported (target)
1655 AMD 29000 embedded, using EBMON a29k-none-none
1659 GDB continues to improve its handling of C++. `References' work better.
1660 The demangler has also been improved, and now deals with symbols mangled as
1661 per the Annotated C++ Reference Guide.
1663 GDB also now handles `stabs' symbol information embedded in MIPS
1664 `ecoff' symbol tables. Since the ecoff format was not easily
1665 extensible to handle new languages such as C++, this appeared to be a
1666 good way to put C++ debugging info into MIPS binaries. This option
1667 will be supported in the GNU C compiler, version 2, when it is
1670 * New features for SVR4
1672 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
1673 shared libraries. Debugging dynamically linked programs should present
1674 only minor differences from debugging statically linked programs.
1676 The `info proc' command will print out information about any process
1677 on an SVR4 system (including the one you are debugging). At the moment,
1678 it prints the address mappings of the process.
1680 If you bring up GDB on another SVR4 system, please send mail to
1681 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
1683 * Better dynamic linking support in SunOS
1685 Reading symbols from shared libraries which contain debugging symbols
1686 now works properly. However, there remain issues such as automatic
1687 skipping of `transfer vector' code during function calls, which
1688 make it harder to debug code in a shared library, than to debug the
1689 same code linked statically.
1693 GDB is now using the latest `getopt' routines from the FSF. This
1694 version accepts the -- prefix for options with long names. GDB will
1695 continue to accept the old forms (-option and +option) as well.
1696 Various single letter abbreviations for options have been explicity
1697 added to the option table so that they won't get overshadowed in the
1698 future by other options that begin with the same letter.
1702 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
1703 Many assorted bugs have been handled. Many more remain to be handled.
1704 See the various ChangeLog files (primarily in gdb and bfd) for details.
1707 *** Changes in GDB-4.3:
1709 * New machines supported (host and target)
1711 Amiga 3000 running Amix m68k-cbm-svr4 or amix
1712 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
1713 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
1715 * Almost SCO Unix support
1717 We had hoped to support:
1718 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
1719 (except for core file support), but we discovered very late in the release
1720 that it has problems with process groups that render gdb unusable. Sorry
1721 about that. I encourage people to fix it and post the fixes.
1723 * Preliminary ELF and DWARF support
1725 GDB can read ELF object files on System V Release 4, and can handle
1726 debugging records for C, in DWARF format, in ELF files. This support
1727 is preliminary. If you bring up GDB on another SVR4 system, please
1728 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
1733 GDB now uses the latest `readline' library. One user-visible change
1734 is that two tabs will list possible command completions, which previously
1735 required typing M-? (meta-question mark, or ESC ?).
1739 The `stepi' bug that many of you noticed has been squashed.
1740 Many bugs in C++ have been handled. Many more remain to be handled.
1741 See the various ChangeLog files (primarily in gdb and bfd) for details.
1743 * State of the MIPS world (in case you wondered):
1745 GDB can understand the symbol tables emitted by the compilers
1746 supplied by most vendors of MIPS-based machines, including DEC. These
1747 symbol tables are in a format that essentially nobody else uses.
1749 Some versions of gcc come with an assembler post-processor called
1750 mips-tfile. This program is required if you want to do source-level
1751 debugging of gcc-compiled programs. I believe FSF does not ship
1752 mips-tfile with gcc version 1, but it will eventually come with gcc
1755 Debugging of g++ output remains a problem. g++ version 1.xx does not
1756 really support it at all. (If you're lucky, you should be able to get
1757 line numbers and stack traces to work, but no parameters or local
1758 variables.) With some work it should be possible to improve the
1761 When gcc version 2 is released, you will have somewhat better luck.
1762 However, even then you will get confusing results for inheritance and
1765 We will eventually provide full debugging of g++ output on
1766 DECstations. This will probably involve some kind of stabs-in-ecoff
1767 encapulation, but the details have not been worked out yet.
1770 *** Changes in GDB-4.2:
1772 * Improved configuration
1774 Only one copy of `configure' exists now, and it is not self-modifying.
1775 Porting BFD is simpler.
1779 The `step' and `next' commands now only stop at the first instruction
1780 of a source line. This prevents the multiple stops that used to occur
1781 in switch statements, for-loops, etc. `Step' continues to stop if a
1782 function that has debugging information is called within the line.
1786 Lots of small bugs fixed. More remain.
1788 * New host supported (not target)
1790 Intel 386 PC clone running Mach i386-none-mach
1793 *** Changes in GDB-4.1:
1795 * Multiple source language support
1797 GDB now has internal scaffolding to handle several source languages.
1798 It determines the type of each source file from its filename extension,
1799 and will switch expression parsing and number formatting to match the
1800 language of the function in the currently selected stack frame.
1801 You can also specifically set the language to be used, with
1802 `set language c' or `set language modula-2'.
1806 GDB now has preliminary support for the GNU Modula-2 compiler,
1807 currently under development at the State University of New York at
1808 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
1809 continue through the fall of 1991 and into 1992.
1811 Other Modula-2 compilers are currently not supported, and attempting to
1812 debug programs compiled with them will likely result in an error as the
1813 symbol table is read. Feel free to work on it, though!
1815 There are hooks in GDB for strict type checking and range checking,
1816 in the `Modula-2 philosophy', but they do not currently work.
1820 GDB can now write to executable and core files (e.g. patch
1821 a variable's value). You must turn this switch on, specify
1822 the file ("exec foo" or "core foo"), *then* modify it, e.g.
1823 by assigning a new value to a variable. Modifications take
1826 * Automatic SunOS shared library reading
1828 When you run your program, GDB automatically determines where its
1829 shared libraries (if any) have been loaded, and reads their symbols.
1830 The `share' command is no longer needed. This also works when
1831 examining core files.
1835 You can specify the number of lines that the `list' command shows.
1838 * New machines supported (host and target)
1840 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
1841 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
1842 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
1844 * New hosts supported (not targets)
1846 IBM RT/PC: romp-ibm-aix or rtpc
1848 * New targets supported (not hosts)
1850 AMD 29000 embedded with COFF a29k-none-coff
1851 AMD 29000 embedded with a.out a29k-none-aout
1852 Ultracomputer remote kernel debug a29k-nyu-kern
1854 * New remote interfaces
1860 *** Changes in GDB-4.0:
1864 Wide output is wrapped at good places to make the output more readable.
1866 Gdb now supports cross-debugging from a host machine of one type to a
1867 target machine of another type. Communication with the target system
1868 is over serial lines. The ``target'' command handles connecting to the
1869 remote system; the ``load'' command will download a program into the
1870 remote system. Serial stubs for the m68k and i386 are provided. Gdb
1871 also supports debugging of realtime processes running under VxWorks,
1872 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
1873 stub on the target system.
1875 New CPUs supported include the AMD 29000 and Intel 960.
1877 GDB now reads object files and symbol tables via a ``binary file''
1878 library, which allows a single copy of GDB to debug programs of multiple
1879 object file types such as a.out and coff.
1881 There is now a GDB reference card in "doc/refcard.tex". (Make targets
1882 refcard.dvi and refcard.ps are available to format it).
1885 * Control-Variable user interface simplified
1887 All variables that control the operation of the debugger can be set
1888 by the ``set'' command, and displayed by the ``show'' command.
1890 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
1891 ``Show prompt'' produces the response:
1892 Gdb's prompt is new-gdb=>.
1894 What follows are the NEW set commands. The command ``help set'' will
1895 print a complete list of old and new set commands. ``help set FOO''
1896 will give a longer description of the variable FOO. ``show'' will show
1897 all of the variable descriptions and their current settings.
1899 confirm on/off: Enables warning questions for operations that are
1900 hard to recover from, e.g. rerunning the program while
1901 it is already running. Default is ON.
1903 editing on/off: Enables EMACS style command line editing
1904 of input. Previous lines can be recalled with
1905 control-P, the current line can be edited with control-B,
1906 you can search for commands with control-R, etc.
1909 history filename NAME: NAME is where the gdb command history
1910 will be stored. The default is .gdb_history,
1911 or the value of the environment variable
1914 history size N: The size, in commands, of the command history. The
1915 default is 256, or the value of the environment variable
1918 history save on/off: If this value is set to ON, the history file will
1919 be saved after exiting gdb. If set to OFF, the
1920 file will not be saved. The default is OFF.
1922 history expansion on/off: If this value is set to ON, then csh-like
1923 history expansion will be performed on
1924 command line input. The default is OFF.
1926 radix N: Sets the default radix for input and output. It can be set
1927 to 8, 10, or 16. Note that the argument to "radix" is interpreted
1928 in the current radix, so "set radix 10" is always a no-op.
1930 height N: This integer value is the number of lines on a page. Default
1931 is 24, the current `stty rows'' setting, or the ``li#''
1932 setting from the termcap entry matching the environment
1935 width N: This integer value is the number of characters on a line.
1936 Default is 80, the current `stty cols'' setting, or the ``co#''
1937 setting from the termcap entry matching the environment
1940 Note: ``set screensize'' is obsolete. Use ``set height'' and
1941 ``set width'' instead.
1943 print address on/off: Print memory addresses in various command displays,
1944 such as stack traces and structure values. Gdb looks
1945 more ``symbolic'' if you turn this off; it looks more
1946 ``machine level'' with it on. Default is ON.
1948 print array on/off: Prettyprint arrays. New convenient format! Default
1951 print demangle on/off: Print C++ symbols in "source" form if on,
1954 print asm-demangle on/off: Same, for assembler level printouts
1957 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
1960 * Support for Epoch Environment.
1962 The epoch environment is a version of Emacs v18 with windowing. One
1963 new command, ``inspect'', is identical to ``print'', except that if you
1964 are running in the epoch environment, the value is printed in its own
1968 * Support for Shared Libraries
1970 GDB can now debug programs and core files that use SunOS shared libraries.
1971 Symbols from a shared library cannot be referenced
1972 before the shared library has been linked with the program (this
1973 happens after you type ``run'' and before the function main() is entered).
1974 At any time after this linking (including when examining core files
1975 from dynamically linked programs), gdb reads the symbols from each
1976 shared library when you type the ``sharedlibrary'' command.
1977 It can be abbreviated ``share''.
1979 sharedlibrary REGEXP: Load shared object library symbols for files
1980 matching a unix regular expression. No argument
1981 indicates to load symbols for all shared libraries.
1983 info sharedlibrary: Status of loaded shared libraries.
1988 A watchpoint stops execution of a program whenever the value of an
1989 expression changes. Checking for this slows down execution
1990 tremendously whenever you are in the scope of the expression, but is
1991 quite useful for catching tough ``bit-spreader'' or pointer misuse
1992 problems. Some machines such as the 386 have hardware for doing this
1993 more quickly, and future versions of gdb will use this hardware.
1995 watch EXP: Set a watchpoint (breakpoint) for an expression.
1997 info watchpoints: Information about your watchpoints.
1999 delete N: Deletes watchpoint number N (same as breakpoints).
2000 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
2001 enable N: Re-enables watchpoint number N (same as breakpoints).
2004 * C++ multiple inheritance
2006 When used with a GCC version 2 compiler, GDB supports multiple inheritance
2009 * C++ exception handling
2011 Gdb now supports limited C++ exception handling. Besides the existing
2012 ability to breakpoint on an exception handler, gdb can breakpoint on
2013 the raising of an exception (before the stack is peeled back to the
2016 catch FOO: If there is a FOO exception handler in the dynamic scope,
2017 set a breakpoint to catch exceptions which may be raised there.
2018 Multiple exceptions (``catch foo bar baz'') may be caught.
2020 info catch: Lists all exceptions which may be caught in the
2021 current stack frame.
2024 * Minor command changes
2026 The command ``call func (arg, arg, ...)'' now acts like the print
2027 command, except it does not print or save a value if the function's result
2028 is void. This is similar to dbx usage.
2030 The ``up'' and ``down'' commands now always print the frame they end up
2031 at; ``up-silently'' and `down-silently'' can be used in scripts to change
2032 frames without printing.
2034 * New directory command
2036 'dir' now adds directories to the FRONT of the source search path.
2037 The path starts off empty. Source files that contain debug information
2038 about the directory in which they were compiled can be found even
2039 with an empty path; Sun CC and GCC include this information. If GDB can't
2040 find your source file in the current directory, type "dir .".
2042 * Configuring GDB for compilation
2044 For normal use, type ``./configure host''. See README or gdb.texinfo
2047 GDB now handles cross debugging. If you are remotely debugging between
2048 two different machines, type ``./configure host -target=targ''.
2049 Host is the machine where GDB will run; targ is the machine
2050 where the program that you are debugging will run.