1 What has changed in GDB?
2 (Organized release by release)
4 *** Changes since GDB 5.2:
6 * GDB now supports C/C++ preprocessor macros.
8 GDB now expands preprocessor macro invocations in C/C++ expressions,
9 and provides various commands for showing macro definitions and how
12 Most compilers don't include information about macros in the debugging
13 information by default. In GCC 3.1, for example, you need to compile
14 your program with the options `-gdwarf-2 -g3'. If the macro
15 information is present in the executable, GDB will read it.
17 Here are the new commands for working with macros:
19 ** macro expand EXPRESSION
21 Expand any macro invocations in expression, and show the result.
23 ** show macro MACRO-NAME
25 Show the definition of the macro named MACRO-NAME, and where it was
28 * Multi-arched targets.
30 DEC Alpha (partial) alpha*-*-*
31 DEC VAX (partial) vax-*-*
33 National Semiconductor NS32000 (partial) ns32k-*-*
39 * New native configurations
41 Alpha NetBSD alpha*-*-netbsd*
42 SH NetBSD sh*-*-netbsdelf*
43 MIPS NetBSD mips*-*-netbsd*
44 UltraSPARC NetBSD sparc64-*-netbsd*
46 * OBSOLETE configurations and files
48 Configurations that have been declared obsolete in this release have
49 been commented out. Unless there is activity to revive these
50 configurations, the next release of GDB will have their sources
53 * REMOVED configurations and files
55 AMD 29k family via UDI a29k-amd-udi, udi29k
56 A29K VxWorks a29k-*-vxworks
57 AMD 29000 embedded, using EBMON a29k-none-none
58 AMD 29000 embedded with COFF a29k-none-coff
59 AMD 29000 embedded with a.out a29k-none-aout
61 testsuite/gdb.hp/gdb.threads-hp/ directory
63 * New command "set max-user-call-depth <nnn>"
65 This command allows the user to limit the call depth of user-defined
66 commands. The default is 1024.
68 * Changes in FreeBSD/i386 native debugging.
70 Support for the "generate-core-file" has been added.
72 * New commands "dump", "append", and "restore".
74 These commands allow data to be copied from target memory
75 to a bfd-format or binary file (dump and append), and back
76 from a file into memory (restore).
78 *** Changes in GDB 5.2:
80 * New command "set trust-readonly-sections on[off]".
82 This command is a hint that tells gdb that read-only sections
83 really are read-only (ie. that their contents will not change).
84 In this mode, gdb will go to the object file rather than the
85 target to read memory from read-only sections (such as ".text").
86 This can be a significant performance improvement on some
87 (notably embedded) targets.
89 * New command "generate-core-file" (or "gcore").
91 This new gdb command allows the user to drop a core file of the child
92 process state at any time. So far it's been implemented only for
93 GNU/Linux and Solaris, but should be relatively easily ported to other
94 hosts. Argument is core file name (defaults to core.<pid>).
96 * New command line option
98 GDB now accepts --pid or -p followed by a process id.
100 * Change in command line behavior -- corefiles vs. process ids.
102 There is a subtle behavior in the way in which GDB handles
103 command line arguments. The first non-flag argument is always
104 a program to debug, but the second non-flag argument may either
105 be a corefile or a process id. Previously, GDB would attempt to
106 open the second argument as a corefile, and if that failed, would
107 issue a superfluous error message and then attempt to attach it as
108 a process. Now, if the second argument begins with a non-digit,
109 it will be treated as a corefile. If it begins with a digit,
110 GDB will attempt to attach it as a process, and if no such process
111 is found, will then attempt to open it as a corefile.
113 * Changes in ARM configurations.
115 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
116 configuration is fully multi-arch.
118 * New native configurations
120 ARM NetBSD arm*-*-netbsd*
121 x86 OpenBSD i[3456]86-*-openbsd*
122 AMD x86-64 running GNU/Linux x86_64-*-linux-*
123 Sparc64 running FreeBSD sparc64-*-freebsd*
127 Sanyo XStormy16 xstormy16-elf
129 * OBSOLETE configurations and files
131 Configurations that have been declared obsolete in this release have
132 been commented out. Unless there is activity to revive these
133 configurations, the next release of GDB will have their sources
136 AMD 29k family via UDI a29k-amd-udi, udi29k
137 A29K VxWorks a29k-*-vxworks
138 AMD 29000 embedded, using EBMON a29k-none-none
139 AMD 29000 embedded with COFF a29k-none-coff
140 AMD 29000 embedded with a.out a29k-none-aout
142 testsuite/gdb.hp/gdb.threads-hp/ directory
144 * REMOVED configurations and files
146 TI TMS320C80 tic80-*-*
148 PowerPC Solaris powerpcle-*-solaris*
149 PowerPC Windows NT powerpcle-*-cygwin32
150 PowerPC Netware powerpc-*-netware*
151 Harris/CXUX m88k m88*-harris-cxux*
152 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
153 ns32k-utek-sysv* ns32k-utek-*
154 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
155 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
156 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
157 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
158 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
160 * Changes to command line processing
162 The new `--args' feature can be used to specify command-line arguments
163 for the inferior from gdb's command line.
165 * Changes to key bindings
167 There is a new `operate-and-get-next' function bound to `C-o'.
169 *** Changes in GDB 5.1.1
171 Fix compile problem on DJGPP.
173 Fix a problem with floating-point registers on the i386 being
176 Fix to stop GDB crashing on .debug_str debug info.
178 Numerous documentation fixes.
180 Numerous testsuite fixes.
182 *** Changes in GDB 5.1:
184 * New native configurations
186 Alpha FreeBSD alpha*-*-freebsd*
187 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
188 MIPS GNU/Linux mips*-*-linux*
189 MIPS SGI Irix 6.x mips*-sgi-irix6*
191 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
195 Motorola 68HC11 and 68HC12 m68hc11-elf
197 UltraSparc running GNU/Linux sparc64-*-linux*
199 * OBSOLETE configurations and files
201 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
202 Harris/CXUX m88k m88*-harris-cxux*
203 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
204 ns32k-utek-sysv* ns32k-utek-*
205 TI TMS320C80 tic80-*-*
207 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
208 PowerPC Solaris powerpcle-*-solaris*
209 PowerPC Windows NT powerpcle-*-cygwin32
210 PowerPC Netware powerpc-*-netware*
211 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
212 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
213 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
214 Apple Macintosh (MPW) host N/A
216 stuff.c (Program to stuff files into a specially prepared space in kdb)
217 kdb-start.c (Main loop for the standalone kernel debugger)
219 Configurations that have been declared obsolete in this release have
220 been commented out. Unless there is activity to revive these
221 configurations, the next release of GDB will have their sources
224 * REMOVED configurations and files
226 Altos 3068 m68*-altos-*
227 Convex c1-*-*, c2-*-*
229 ARM RISCix arm-*-* (as host)
233 * GDB has been converted to ISO C.
235 GDB's source code has been converted to ISO C. In particular, the
236 sources are fully protoized, and rely on standard headers being
241 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
243 * The MI enabled by default.
245 The new machine oriented interface (MI) introduced in GDB 5.0 has been
246 revised and enabled by default. Packages which use GDB as a debugging
247 engine behind a UI or another front end are encouraged to switch to
248 using the GDB/MI interface, instead of the old annotations interface
249 which is now deprecated.
251 * Support for debugging Pascal programs.
253 GDB now includes support for debugging Pascal programs. The following
254 main features are supported:
256 - Pascal-specific data types such as sets;
258 - automatic recognition of Pascal sources based on file-name
261 - Pascal-style display of data types, variables, and functions;
263 - a Pascal expression parser.
265 However, some important features are not yet supported.
267 - Pascal string operations are not supported at all;
269 - there are some problems with boolean types;
271 - Pascal type hexadecimal constants are not supported
272 because they conflict with the internal variables format;
274 - support for Pascal objects and classes is not full yet;
276 - unlike Pascal, GDB is case-sensitive for symbol names.
278 * Changes in completion.
280 Commands such as `shell', `run' and `set args', which pass arguments
281 to inferior programs, now complete on file names, similar to what
282 users expect at the shell prompt.
284 Commands which accept locations, such as `disassemble', `print',
285 `breakpoint', `until', etc. now complete on filenames as well as
286 program symbols. Thus, if you type "break foob TAB", and the source
287 files linked into the programs include `foobar.c', that file name will
288 be one of the candidates for completion. However, file names are not
289 considered for completion after you typed a colon that delimits a file
290 name from a name of a function in that file, as in "break foo.c:bar".
292 `set demangle-style' completes on available demangling styles.
294 * New platform-independent commands:
296 It is now possible to define a post-hook for a command as well as a
297 hook that runs before the command. For more details, see the
298 documentation of `hookpost' in the GDB manual.
300 * Changes in GNU/Linux native debugging.
302 Support for debugging multi-threaded programs has been completely
303 revised for all platforms except m68k and sparc. You can now debug as
304 many threads as your system allows you to have.
306 Attach/detach is supported for multi-threaded programs.
308 Support for SSE registers was added for x86. This doesn't work for
309 multi-threaded programs though.
311 * Changes in MIPS configurations.
313 Multi-arch support is enabled for all MIPS configurations.
315 GDB can now be built as native debugger on SGI Irix 6.x systems for
316 debugging n32 executables. (Debugging 64-bit executables is not yet
319 * Unified support for hardware watchpoints in all x86 configurations.
321 Most (if not all) native x86 configurations support hardware-assisted
322 breakpoints and watchpoints in a unified manner. This support
323 implements debug register sharing between watchpoints, which allows to
324 put a virtually infinite number of watchpoints on the same address,
325 and also supports watching regions up to 16 bytes with several debug
328 The new maintenance command `maintenance show-debug-regs' toggles
329 debugging print-outs in functions that insert, remove, and test
330 watchpoints and hardware breakpoints.
332 * Changes in the DJGPP native configuration.
334 New command ``info dos sysinfo'' displays assorted information about
335 the CPU, OS, memory, and DPMI server.
337 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
338 display information about segment descriptors stored in GDT, LDT, and
341 New commands ``info dos pde'' and ``info dos pte'' display entries
342 from Page Directory and Page Tables (for now works with CWSDPMI only).
343 New command ``info dos address-pte'' displays the Page Table entry for
344 a given linear address.
346 GDB can now pass command lines longer than 126 characters to the
347 program being debugged (requires an update to the libdbg.a library
348 which is part of the DJGPP development kit).
350 DWARF2 debug info is now supported.
352 It is now possible to `step' and `next' through calls to `longjmp'.
354 * Changes in documentation.
356 All GDB documentation was converted to GFDL, the GNU Free
357 Documentation License.
359 Tracepoints-related commands are now fully documented in the GDB
362 TUI, the Text-mode User Interface, is now documented in the manual.
364 Tracepoints-related commands are now fully documented in the GDB
367 The "GDB Internals" manual now has an index. It also includes
368 documentation of `ui_out' functions, GDB coding standards, x86
369 hardware watchpoints, and memory region attributes.
371 * GDB's version number moved to ``version.in''
373 The Makefile variable VERSION has been replaced by the file
374 ``version.in''. People creating GDB distributions should update the
375 contents of this file.
379 GUD support is now a standard part of the EMACS distribution.
381 *** Changes in GDB 5.0:
383 * Improved support for debugging FP programs on x86 targets
385 Unified and much-improved support for debugging floating-point
386 programs on all x86 targets. In particular, ``info float'' now
387 displays the FP registers in the same format on all x86 targets, with
388 greater level of detail.
390 * Improvements and bugfixes in hardware-assisted watchpoints
392 It is now possible to watch array elements, struct members, and
393 bitfields with hardware-assisted watchpoints. Data-read watchpoints
394 on x86 targets no longer erroneously trigger when the address is
397 * Improvements in the native DJGPP version of GDB
399 The distribution now includes all the scripts and auxiliary files
400 necessary to build the native DJGPP version on MS-DOS/MS-Windows
401 machines ``out of the box''.
403 The DJGPP version can now debug programs that use signals. It is
404 possible to catch signals that happened in the debuggee, deliver
405 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
406 would kill the program being debugged.) Programs that hook hardware
407 interrupts (keyboard, timer, etc.) can also be debugged.
409 It is now possible to debug DJGPP programs that redirect their
410 standard handles or switch them to raw (as opposed to cooked) mode, or
411 even close them. The command ``run < foo > bar'' works as expected,
412 and ``info terminal'' reports useful information about the debuggee's
413 terminal, including raw/cooked mode, redirection, etc.
415 The DJGPP version now uses termios functions for console I/O, which
416 enables debugging graphics programs. Interrupting GDB with Ctrl-C
419 DOS-style file names with drive letters are now fully supported by
422 It is now possible to debug DJGPP programs that switch their working
423 directory. It is also possible to rerun the debuggee any number of
424 times without restarting GDB; thus, you can use the same setup,
425 breakpoints, etc. for many debugging sessions.
427 * New native configurations
429 ARM GNU/Linux arm*-*-linux*
430 PowerPC GNU/Linux powerpc-*-linux*
434 Motorola MCore mcore-*-*
435 x86 VxWorks i[3456]86-*-vxworks*
436 PowerPC VxWorks powerpc-*-vxworks*
437 TI TMS320C80 tic80-*-*
439 * OBSOLETE configurations
441 Altos 3068 m68*-altos-*
442 Convex c1-*-*, c2-*-*
444 ARM RISCix arm-*-* (as host)
447 Configurations that have been declared obsolete will be commented out,
448 but the code will be left in place. If there is no activity to revive
449 these configurations before the next release of GDB, the sources will
450 be permanently REMOVED.
452 * Gould support removed
454 Support for the Gould PowerNode and NP1 has been removed.
456 * New features for SVR4
458 On SVR4 native platforms (such as Solaris), if you attach to a process
459 without first loading a symbol file, GDB will now attempt to locate and
460 load symbols from the running process's executable file.
462 * Many C++ enhancements
464 C++ support has been greatly improved. Overload resolution now works properly
465 in almost all cases. RTTI support is on the way.
467 * Remote targets can connect to a sub-program
469 A popen(3) style serial-device has been added. This device starts a
470 sub-process (such as a stand-alone simulator) and then communicates
471 with that. The sub-program to run is specified using the syntax
472 ``|<program> <args>'' vis:
474 (gdb) set remotedebug 1
475 (gdb) target extended-remote |mn10300-elf-sim program-args
477 * MIPS 64 remote protocol
479 A long standing bug in the mips64 remote protocol where by GDB
480 expected certain 32 bit registers (ex SR) to be transfered as 32
481 instead of 64 bits has been fixed.
483 The command ``set remote-mips64-transfers-32bit-regs on'' has been
484 added to provide backward compatibility with older versions of GDB.
486 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
488 The command ``set remotebinarydownload'' command has been replaced by
489 ``set remote X-packet''. Other commands in ``set remote'' family
490 include ``set remote P-packet''.
492 * Breakpoint commands accept ranges.
494 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
495 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
496 ``tracepoint passcount'' also accepts a range of tracepoints.
498 * ``apropos'' command added.
500 The ``apropos'' command searches through command names and
501 documentation strings, printing out matches, making it much easier to
502 try to find a command that does what you are looking for.
506 A new machine oriented interface (MI) has been added to GDB. This
507 interface is designed for debug environments running GDB as a separate
508 process. This is part of the long term libGDB project. See the
509 "GDB/MI" chapter of the GDB manual for further information. It can be
510 enabled by configuring with:
512 .../configure --enable-gdbmi
514 *** Changes in GDB-4.18:
516 * New native configurations
518 HP-UX 10.20 hppa*-*-hpux10.20
519 HP-UX 11.x hppa*-*-hpux11.0*
520 M68K GNU/Linux m68*-*-linux*
524 Fujitsu FR30 fr30-*-elf*
525 Intel StrongARM strongarm-*-*
526 Mitsubishi D30V d30v-*-*
528 * OBSOLETE configurations
530 Gould PowerNode, NP1 np1-*-*, pn-*-*
532 Configurations that have been declared obsolete will be commented out,
533 but the code will be left in place. If there is no activity to revive
534 these configurations before the next release of GDB, the sources will
535 be permanently REMOVED.
539 As a compatibility experiment, GDB's source files buildsym.h and
540 buildsym.c have been converted to pure standard C, no longer
541 containing any K&R compatibility code. We believe that all systems in
542 use today either come with a standard C compiler, or have a GCC port
543 available. If this is not true, please report the affected
544 configuration to bug-gdb@gnu.org immediately. See the README file for
545 information about getting a standard C compiler if you don't have one
550 GDB now uses readline 2.2.
552 * set extension-language
554 You can now control the mapping between filename extensions and source
555 languages by using the `set extension-language' command. For instance,
556 you can ask GDB to treat .c files as C++ by saying
557 set extension-language .c c++
558 The command `info extensions' lists all of the recognized extensions
559 and their associated languages.
561 * Setting processor type for PowerPC and RS/6000
563 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
564 you can use the `set processor' command to specify what variant of the
565 PowerPC family you are debugging. The command
569 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
570 following PowerPC and RS6000 variants:
572 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
573 rs6000 IBM RS6000 ("POWER") architecture, user-level view
575 403GC IBM PowerPC 403GC
576 505 Motorola PowerPC 505
577 860 Motorola PowerPC 860 or 850
578 601 Motorola PowerPC 601
579 602 Motorola PowerPC 602
580 603 Motorola/IBM PowerPC 603 or 603e
581 604 Motorola PowerPC 604 or 604e
582 750 Motorola/IBM PowerPC 750 or 750
584 At the moment, this command just tells GDB what to name the
585 special-purpose processor registers. Since almost all the affected
586 registers are inaccessible to user-level programs, this command is
587 only useful for remote debugging in its present form.
591 Thanks to a major code donation from Hewlett-Packard, GDB now has much
592 more extensive support for HP-UX. Added features include shared
593 library support, kernel threads and hardware watchpoints for 11.00,
594 support for HP's ANSI C and C++ compilers, and a compatibility mode
595 for xdb and dbx commands.
599 HP's donation includes the new concept of catchpoints, which is a
600 generalization of the old catch command. On HP-UX, it is now possible
601 to catch exec, fork, and vfork, as well as library loading.
603 This means that the existing catch command has changed; its first
604 argument now specifies the type of catch to be set up. See the
605 output of "help catch" for a list of catchpoint types.
607 * Debugging across forks
609 On HP-UX, you can choose which process to debug when a fork() happens
614 HP has donated a curses-based terminal user interface (TUI). To get
615 it, build with --enable-tui. Although this can be enabled for any
616 configuration, at present it only works for native HP debugging.
618 * GDB remote protocol additions
620 A new protocol packet 'X' that writes binary data is now available.
621 Default behavior is to try 'X', then drop back to 'M' if the stub
622 fails to respond. The settable variable `remotebinarydownload'
623 allows explicit control over the use of 'X'.
625 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
626 full 64-bit address. The command
628 set remoteaddresssize 32
630 can be used to revert to the old behaviour. For existing remote stubs
631 the change should not be noticed, as the additional address information
634 In order to assist in debugging stubs, you may use the maintenance
635 command `packet' to send any text string to the stub. For instance,
637 maint packet heythere
639 sends the packet "$heythere#<checksum>". Note that it is very easy to
640 disrupt a debugging session by sending the wrong packet at the wrong
643 The compare-sections command allows you to compare section data on the
644 target to what is in the executable file without uploading or
645 downloading, by comparing CRC checksums.
647 * Tracing can collect general expressions
649 You may now collect general expressions at tracepoints. This requires
650 further additions to the target-side stub; see tracepoint.c and
651 doc/agentexpr.texi for further details.
653 * mask-address variable for Mips
655 For Mips targets, you may control the zeroing of the upper 32 bits of
656 a 64-bit address by entering `set mask-address on'. This is mainly
657 of interest to users of embedded R4xxx and R5xxx processors.
659 * Higher serial baud rates
661 GDB's serial code now allows you to specify baud rates 57600, 115200,
662 230400, and 460800 baud. (Note that your host system may not be able
663 to achieve all of these rates.)
667 The i960 configuration now includes an initial implementation of a
668 builtin simulator, contributed by Jim Wilson.
671 *** Changes in GDB-4.17:
673 * New native configurations
675 Alpha GNU/Linux alpha*-*-linux*
676 Unixware 2.x i[3456]86-unixware2*
677 Irix 6.x mips*-sgi-irix6*
678 PowerPC GNU/Linux powerpc-*-linux*
679 PowerPC Solaris powerpcle-*-solaris*
680 Sparc GNU/Linux sparc-*-linux*
681 Motorola sysV68 R3V7.1 m68k-motorola-sysv
685 Argonaut Risc Chip (ARC) arc-*-*
686 Hitachi H8/300S h8300*-*-*
687 Matsushita MN10200 w/simulator mn10200-*-*
688 Matsushita MN10300 w/simulator mn10300-*-*
689 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
690 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
691 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
692 Mitsubishi D10V w/simulator d10v-*-*
693 Mitsubishi M32R/D w/simulator m32r-*-elf*
694 Tsqware Sparclet sparclet-*-*
695 NEC V850 w/simulator v850-*-*
697 * New debugging protocols
699 ARM with RDI protocol arm*-*-*
700 M68K with dBUG monitor m68*-*-{aout,coff,elf}
701 DDB and LSI variants of PMON protocol mips*-*-*
702 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
703 PowerPC with SDS protocol powerpc{,le}-*-eabi
704 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
708 All configurations can now understand and use the DWARF 2 debugging
709 format. The choice is automatic, if the symbol file contains DWARF 2
714 GDB now includes basic Java language support. This support is
715 only useful with Java compilers that produce native machine code.
717 * solib-absolute-prefix and solib-search-path
719 For SunOS and SVR4 shared libraries, you may now set the prefix for
720 loading absolute shared library symbol files, and the search path for
721 locating non-absolute shared library symbol files.
723 * Live range splitting
725 GDB can now effectively debug code for which GCC has performed live
726 range splitting as part of its optimization. See gdb/doc/LRS for
727 more details on the expected format of the stabs information.
731 GDB's support for the GNU Hurd, including thread debugging, has been
732 updated to work with current versions of the Hurd.
736 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
737 instruction set. ARM GDB automatically detects when Thumb
738 instructions are in use, and adjusts disassembly and backtracing
743 GDB's MIPS target configurations now handle the MIP16 16-bit
748 GDB now includes support for overlays; if an executable has been
749 linked such that multiple sections are based at the same address, GDB
750 will decide which section to use for symbolic info. You can choose to
751 control the decision manually, using overlay commands, or implement
752 additional target-side support and use "overlay load-target" to bring
753 in the overlay mapping. Do "help overlay" for more detail.
757 The command "info symbol <address>" displays information about
758 the symbol at the specified address.
762 The standard remote protocol now includes an extension that allows
763 asynchronous collection and display of trace data. This requires
764 extensive support in the target-side debugging stub. Tracing mode
765 includes a new interaction mode in GDB and new commands: see the
766 file tracepoint.c for more details.
770 Configurations for embedded MIPS now include a simulator contributed
771 by Cygnus Solutions. The simulator supports the instruction sets
772 of most MIPS variants.
776 Sparc configurations may now include the ERC32 simulator contributed
777 by the European Space Agency. The simulator is not built into
778 Sparc targets by default; configure with --enable-sim to include it.
782 For target configurations that may include multiple variants of a
783 basic architecture (such as MIPS and SH), you may now set the
784 architecture explicitly. "set arch" sets, "info arch" lists
785 the possible architectures.
787 *** Changes in GDB-4.16:
789 * New native configurations
791 Windows 95, x86 Windows NT i[345]86-*-cygwin32
792 M68K NetBSD m68k-*-netbsd*
793 PowerPC AIX 4.x powerpc-*-aix*
794 PowerPC MacOS powerpc-*-macos*
795 PowerPC Windows NT powerpcle-*-cygwin32
796 RS/6000 AIX 4.x rs6000-*-aix4*
800 ARM with RDP protocol arm-*-*
801 I960 with MON960 i960-*-coff
802 MIPS VxWorks mips*-*-vxworks*
803 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
804 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
806 Matra Sparclet sparclet-*-*
810 The powerpc-eabi configuration now includes the PSIM simulator,
811 contributed by Andrew Cagney, with assistance from Mike Meissner.
812 PSIM is a very elaborate model of the PowerPC, including not only
813 basic instruction set execution, but also details of execution unit
814 performance and I/O hardware. See sim/ppc/README for more details.
818 GDB now works with Solaris 2.5.
820 * Windows 95/NT native
822 GDB will now work as a native debugger on Windows 95 and Windows NT.
823 To build it from source, you must use the "gnu-win32" environment,
824 which uses a DLL to emulate enough of Unix to run the GNU tools.
825 Further information, binaries, and sources are available at
826 ftp.cygnus.com, under pub/gnu-win32.
828 * dont-repeat command
830 If a user-defined command includes the command `dont-repeat', then the
831 command will not be repeated if the user just types return. This is
832 useful if the command is time-consuming to run, so that accidental
833 extra keystrokes don't run the same command many times.
835 * Send break instead of ^C
837 The standard remote protocol now includes an option to send a break
838 rather than a ^C to the target in order to interrupt it. By default,
839 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
841 * Remote protocol timeout
843 The standard remote protocol includes a new variable `remotetimeout'
844 that allows you to set the number of seconds before GDB gives up trying
845 to read from the target. The default value is 2.
847 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
849 By default GDB will automatically keep track of objects as they are
850 loaded and unloaded by the dynamic linker. By using the command `set
851 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
852 when shared library events occur, thus allowing you to set breakpoints
853 in shared libraries which are explicitly loaded by the inferior.
855 Note this feature does not work on hpux8. On hpux9 you must link
856 /usr/lib/end.o into your program. This feature should work
857 automatically on hpux10.
859 * Irix 5.x hardware watchpoint support
861 Irix 5 configurations now support the use of hardware watchpoints.
863 * Mips protocol "SYN garbage limit"
865 When debugging a Mips target using the `target mips' protocol, you
866 may set the number of characters that GDB will ignore by setting
867 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
868 every character. The default value is 1050.
870 * Recording and replaying remote debug sessions
872 If you set `remotelogfile' to the name of a file, gdb will write to it
873 a recording of a remote debug session. This recording may then be
874 replayed back to gdb using "gdbreplay". See gdbserver/README for
875 details. This is useful when you have a problem with GDB while doing
876 remote debugging; you can make a recording of the session and send it
877 to someone else, who can then recreate the problem.
879 * Speedups for remote debugging
881 GDB includes speedups for downloading and stepping MIPS systems using
882 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
883 and more efficient S-record downloading.
885 * Memory use reductions and statistics collection
887 GDB now uses less memory and reports statistics about memory usage.
888 Try the `maint print statistics' command, for example.
890 *** Changes in GDB-4.15:
894 The symbol reader for AIX GDB now uses partial symbol tables. This
895 can greatly improve startup time, especially for large executables.
897 * Remote targets use caching
899 Remote targets now use a data cache to speed up communication with the
900 remote side. The data cache could lead to incorrect results because
901 it doesn't know about volatile variables, thus making it impossible to
902 debug targets which use memory mapped I/O devices. `set remotecache
903 off' turns the the data cache off.
905 * Remote targets may have threads
907 The standard remote protocol now includes support for multiple threads
908 in the target system, using new protocol commands 'H' and 'T'. See
909 gdb/remote.c for details.
913 If GDB is configured with `--enable-netrom', then it will include
914 support for the NetROM ROM emulator from XLNT Designs. The NetROM
915 acts as though it is a bank of ROM on the target board, but you can
916 write into it over the network. GDB's support consists only of
917 support for fast loading into the emulated ROM; to debug, you must use
918 another protocol, such as standard remote protocol. The usual
919 sequence is something like
921 target nrom <netrom-hostname>
923 target remote <netrom-hostname>:1235
927 GDB now includes support for the Apple Macintosh, as a host only. It
928 may be run as either an MPW tool or as a standalone application, and
929 it can debug through the serial port. All the usual GDB commands are
930 available, but to the target command, you must supply "serial" as the
931 device type instead of "/dev/ttyXX". See mpw-README in the main
932 directory for more information on how to build. The MPW configuration
933 scripts */mpw-config.in support only a few targets, and only the
934 mips-idt-ecoff target has been tested.
938 GDB configuration now uses autoconf. This is not user-visible,
939 but does simplify configuration and building.
943 GDB now supports hpux10.
945 *** Changes in GDB-4.14:
947 * New native configurations
949 x86 FreeBSD i[345]86-*-freebsd
950 x86 NetBSD i[345]86-*-netbsd
951 NS32k NetBSD ns32k-*-netbsd
952 Sparc NetBSD sparc-*-netbsd
956 A29K VxWorks a29k-*-vxworks
957 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
958 CPU32 EST-300 emulator m68*-*-est*
959 PowerPC ELF powerpc-*-elf
962 * Alpha OSF/1 support for procfs
964 GDB now supports procfs under OSF/1-2.x and higher, which makes it
965 possible to attach to running processes. As the mounting of the /proc
966 filesystem is optional on the Alpha, GDB automatically determines
967 the availability of /proc during startup. This can lead to problems
968 if /proc is unmounted after GDB has been started.
970 * Arguments to user-defined commands
972 User commands may accept up to 10 arguments separated by whitespace.
973 Arguments are accessed within the user command via $arg0..$arg9. A
976 print $arg0 + $arg1 + $arg2
978 To execute the command use:
981 Defines the command "adder" which prints the sum of its three arguments.
982 Note the arguments are text substitutions, so they may reference variables,
983 use complex expressions, or even perform inferior function calls.
985 * New `if' and `while' commands
987 This makes it possible to write more sophisticated user-defined
988 commands. Both commands take a single argument, which is the
989 expression to evaluate, and must be followed by the commands to
990 execute, one per line, if the expression is nonzero, the list being
991 terminated by the word `end'. The `if' command list may include an
992 `else' word, which causes the following commands to be executed only
993 if the expression is zero.
995 * Fortran source language mode
997 GDB now includes partial support for Fortran 77. It will recognize
998 Fortran programs and can evaluate a subset of Fortran expressions, but
999 variables and functions may not be handled correctly. GDB will work
1000 with G77, but does not yet know much about symbols emitted by other
1003 * Better HPUX support
1005 Most debugging facilities now work on dynamic executables for HPPAs
1006 running hpux9 or later. You can attach to running dynamically linked
1007 processes, but by default the dynamic libraries will be read-only, so
1008 for instance you won't be able to put breakpoints in them. To change
1009 that behavior do the following before running the program:
1015 This will cause the libraries to be mapped private and read-write.
1016 To revert to the normal behavior, do this:
1022 You cannot set breakpoints or examine data in the library until after
1023 the library is loaded if the function/data symbols do not have
1026 GDB can now also read debug symbols produced by the HP C compiler on
1027 HPPAs (sorry, no C++, Fortran or 68k support).
1029 * Target byte order now dynamically selectable
1031 You can choose which byte order to use with a target system, via the
1032 commands "set endian big" and "set endian little", and you can see the
1033 current setting by using "show endian". You can also give the command
1034 "set endian auto", in which case GDB will use the byte order
1035 associated with the executable. Currently, only embedded MIPS
1036 configurations support dynamic selection of target byte order.
1038 * New DOS host serial code
1040 This version uses DPMI interrupts to handle buffered I/O, so you
1041 no longer need to run asynctsr when debugging boards connected to
1044 *** Changes in GDB-4.13:
1046 * New "complete" command
1048 This lists all the possible completions for the rest of the line, if it
1049 were to be given as a command itself. This is intended for use by emacs.
1051 * Trailing space optional in prompt
1053 "set prompt" no longer adds a space for you after the prompt you set. This
1054 allows you to set a prompt which ends in a space or one that does not.
1056 * Breakpoint hit counts
1058 "info break" now displays a count of the number of times the breakpoint
1059 has been hit. This is especially useful in conjunction with "ignore"; you
1060 can ignore a large number of breakpoint hits, look at the breakpoint info
1061 to see how many times the breakpoint was hit, then run again, ignoring one
1062 less than that number, and this will get you quickly to the last hit of
1065 * Ability to stop printing at NULL character
1067 "set print null-stop" will cause GDB to stop printing the characters of
1068 an array when the first NULL is encountered. This is useful when large
1069 arrays actually contain only short strings.
1071 * Shared library breakpoints
1073 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
1074 breakpoints in shared libraries before the executable is run.
1076 * Hardware watchpoints
1078 There is a new hardware breakpoint for the watch command for sparclite
1079 targets. See gdb/sparclite/hw_breakpoint.note.
1081 Hardware watchpoints are also now supported under GNU/Linux.
1085 Annotations have been added. These are for use with graphical interfaces,
1086 and are still experimental. Currently only gdba.el uses these.
1088 * Improved Irix 5 support
1090 GDB now works properly with Irix 5.2.
1092 * Improved HPPA support
1094 GDB now works properly with the latest GCC and GAS.
1096 * New native configurations
1098 Sequent PTX4 i[34]86-sequent-ptx4
1099 HPPA running OSF/1 hppa*-*-osf*
1100 Atari TT running SVR4 m68*-*-sysv4*
1101 RS/6000 LynxOS rs6000-*-lynxos*
1105 OS/9000 i[34]86-*-os9k
1106 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
1109 * Hitachi SH7000 and E7000-PC ICE support
1111 There is now support for communicating with the Hitachi E7000-PC ICE.
1112 This is available automatically when GDB is configured for the SH.
1116 As usual, a variety of small fixes and improvements, both generic
1117 and configuration-specific. See the ChangeLog for more detail.
1119 *** Changes in GDB-4.12:
1121 * Irix 5 is now supported
1125 GDB-4.12 on the HPPA has a number of changes which make it unable
1126 to debug the output from the currently released versions of GCC and
1127 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
1128 of GCC and GAS, versions of these tools designed to work with GDB-4.12
1129 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
1132 *** Changes in GDB-4.11:
1134 * User visible changes:
1138 The "set remotedebug" option is now consistent between the mips remote
1139 target, remote targets using the gdb-specific protocol, UDI (AMD's
1140 debug protocol for the 29k) and the 88k bug monitor. It is now an
1141 integer specifying a debug level (normally 0 or 1, but 2 means more
1142 debugging info for the mips target).
1144 * DEC Alpha native support
1146 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
1147 debug info, but GDB works fairly well with the DEC compiler and should
1148 work with a future GCC release. See the README file for a few
1149 Alpha-specific notes.
1151 * Preliminary thread implementation
1153 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
1155 * LynxOS native and target support for 386
1157 This release has been hosted on LynxOS 2.2, and also can be configured
1158 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
1161 * Improvements in C++ mangling/demangling.
1163 This release has much better g++ debugging, specifically in name
1164 mangling/demangling, virtual function calls, print virtual table,
1165 call methods, ...etc.
1167 *** Changes in GDB-4.10:
1169 * User visible changes:
1171 Remote debugging using the GDB-specific (`target remote') protocol now
1172 supports the `load' command. This is only useful if you have some
1173 other way of getting the stub to the target system, and you can put it
1174 somewhere in memory where it won't get clobbered by the download.
1176 Filename completion now works.
1178 When run under emacs mode, the "info line" command now causes the
1179 arrow to point to the line specified. Also, "info line" prints
1180 addresses in symbolic form (as well as hex).
1182 All vxworks based targets now support a user settable option, called
1183 vxworks-timeout. This option represents the number of seconds gdb
1184 should wait for responses to rpc's. You might want to use this if
1185 your vxworks target is, perhaps, a slow software simulator or happens
1186 to be on the far side of a thin network line.
1190 This release contains support for using a DEC alpha as a GDB host for
1191 cross debugging. Native alpha debugging is not supported yet.
1194 *** Changes in GDB-4.9:
1198 This is the first GDB release which is accompanied by a matching testsuite.
1199 The testsuite requires installation of dejagnu, which should be available
1200 via ftp from most sites that carry GNU software.
1204 'Cfront' style demangling has had its name changed to 'ARM' style, to
1205 emphasize that it was written from the specifications in the C++ Annotated
1206 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
1207 disclaimers, it still generated too much confusion with users attempting to
1208 use gdb with AT&T cfront.
1212 GDB now uses a standard remote interface to a simulator library.
1213 So far, the library contains simulators for the Zilog Z8001/2, the
1214 Hitachi H8/300, H8/500 and Super-H.
1216 * New targets supported
1218 H8/300 simulator h8300-hitachi-hms or h8300hms
1219 H8/500 simulator h8500-hitachi-hms or h8500hms
1220 SH simulator sh-hitachi-hms or sh
1221 Z8000 simulator z8k-zilog-none or z8ksim
1222 IDT MIPS board over serial line mips-idt-ecoff
1224 Cross-debugging to GO32 targets is supported. It requires a custom
1225 version of the i386-stub.c module which is integrated with the
1226 GO32 memory extender.
1228 * New remote protocols
1230 MIPS remote debugging protocol.
1232 * New source languages supported
1234 This version includes preliminary support for Chill, a Pascal like language
1235 used by telecommunications companies. Chill support is also being integrated
1236 into the GNU compiler, but we don't know when it will be publically available.
1239 *** Changes in GDB-4.8:
1241 * HP Precision Architecture supported
1243 GDB now supports HP PA-RISC machines running HPUX. A preliminary
1244 version of this support was available as a set of patches from the
1245 University of Utah. GDB does not support debugging of programs
1246 compiled with the HP compiler, because HP will not document their file
1247 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
1248 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
1250 Many problems in the preliminary version have been fixed.
1252 * Faster and better demangling
1254 We have improved template demangling and fixed numerous bugs in the GNU style
1255 demangler. It can now handle type modifiers such as `static' or `const'. Wide
1256 character types (wchar_t) are now supported. Demangling of each symbol is now
1257 only done once, and is cached when the symbol table for a file is read in.
1258 This results in a small increase in memory usage for C programs, a moderate
1259 increase in memory usage for C++ programs, and a fantastic speedup in
1262 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
1263 from the specifications in the Annotated Reference Manual, which AT&T's
1264 compiler does not actually implement.
1266 * G++ multiple inheritance compiler problem
1268 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
1269 inheritance lattices was reworked to properly discover ambiguities. We
1270 recently found an example which causes this new algorithm to fail in a
1271 very subtle way, producing bad debug information for those classes.
1272 The file 'gcc.patch' (in this directory) can be applied to gcc to
1273 circumvent the problem. A future GCC release will contain a complete
1276 The previous G++ debug info problem (mentioned below for the gdb-4.7
1277 release) is fixed in gcc version 2.3.2.
1279 * Improved configure script
1281 The `configure' script will now attempt to guess your system type if
1282 you don't supply a host system type. The old scheme of supplying a
1283 host system triplet is preferable over using this. All the magic is
1284 done in the new `config.guess' script. Examine it for details.
1286 We have also brought our configure script much more in line with the FSF's
1287 version. It now supports the --with-xxx options. In particular,
1288 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
1289 The resulting GDB will not be able to read arbitrary object file formats --
1290 only the format ``expected'' to be used on the configured target system.
1291 We hope to make this the default in a future release.
1293 * Documentation improvements
1295 There's new internal documentation on how to modify GDB, and how to
1296 produce clean changes to the code. We implore people to read it
1297 before submitting changes.
1299 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
1300 M4 macros. The new texinfo.tex is provided in this release. Pre-built
1301 `info' files are also provided. To build `info' files from scratch,
1302 you will need the latest `makeinfo' release, which will be available in
1303 a future texinfo-X.Y release.
1305 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
1306 We're not sure exactly which versions have this problem, but it has
1307 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
1308 or better. If that isn't possible, there is a patch in
1309 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
1310 around this problem.
1314 GDB now supports array constants that can be used in expressions typed in by
1315 the user. The syntax is `{element, element, ...}'. Ie: you can now type
1316 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
1319 The new directory `gdb/sparclite' contains a program that demonstrates
1320 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
1322 * New native hosts supported
1324 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
1325 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
1327 * New targets supported
1329 AMD 29k family via UDI a29k-amd-udi or udi29k
1331 * New file formats supported
1333 BFD now supports reading HP/PA-RISC executables (SOM file format?),
1334 HPUX core files, and SCO 3.2v2 core files.
1338 Attaching to processes now works again; thanks for the many bug reports.
1340 We have also stomped on a bunch of core dumps caused by
1341 printf_filtered("%s") problems.
1343 We eliminated a copyright problem on the rpc and ptrace header files
1344 for VxWorks, which was discovered at the last minute during the 4.7
1345 release. You should now be able to build a VxWorks GDB.
1347 You can now interrupt gdb while an attached process is running. This
1348 will cause the attached process to stop, and give control back to GDB.
1350 We fixed problems caused by using too many file descriptors
1351 for reading symbols from object files and libraries. This was
1352 especially a problem for programs that used many (~100) shared
1355 The `step' command now only enters a subroutine if there is line number
1356 information for the subroutine. Otherwise it acts like the `next'
1357 command. Previously, `step' would enter subroutines if there was
1358 any debugging information about the routine. This avoids problems
1359 when using `cc -g1' on MIPS machines.
1361 * Internal improvements
1363 GDB's internal interfaces have been improved to make it easier to support
1364 debugging of multiple languages in the future.
1366 GDB now uses a common structure for symbol information internally.
1367 Minimal symbols (derived from linkage symbols in object files), partial
1368 symbols (from a quick scan of debug information), and full symbols
1369 contain a common subset of information, making it easier to write
1370 shared code that handles any of them.
1372 * New command line options
1374 We now accept --silent as an alias for --quiet.
1378 The memory-mapped-malloc library is now licensed under the GNU Library
1379 General Public License.
1381 *** Changes in GDB-4.7:
1383 * Host/native/target split
1385 GDB has had some major internal surgery to untangle the support for
1386 hosts and remote targets. Now, when you configure GDB for a remote
1387 target, it will no longer load in all of the support for debugging
1388 local programs on the host. When fully completed and tested, this will
1389 ensure that arbitrary host/target combinations are possible.
1391 The primary conceptual shift is to separate the non-portable code in
1392 GDB into three categories. Host specific code is required any time GDB
1393 is compiled on that host, regardless of the target. Target specific
1394 code relates to the peculiarities of the target, but can be compiled on
1395 any host. Native specific code is everything else: it can only be
1396 built when the host and target are the same system. Child process
1397 handling and core file support are two common `native' examples.
1399 GDB's use of /proc for controlling Unix child processes is now cleaner.
1400 It has been split out into a single module under the `target_ops' vector,
1401 plus two native-dependent functions for each system that uses /proc.
1403 * New hosts supported
1405 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
1406 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
1407 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
1409 * New targets supported
1411 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
1412 68030 and CPU32 m68030-*-*, m68332-*-*
1414 * New native hosts supported
1416 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
1417 (386bsd is not well tested yet)
1418 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
1420 * New file formats supported
1422 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
1423 supports reading of `a.out.adobe' object files, which are an a.out
1424 format extended with minimal information about multiple sections.
1428 `show copying' is the same as the old `info copying'.
1429 `show warranty' is the same as `info warrantee'.
1430 These were renamed for consistency. The old commands continue to work.
1432 `info handle' is a new alias for `info signals'.
1434 You can now define pre-command hooks, which attach arbitrary command
1435 scripts to any command. The commands in the hook will be executed
1436 prior to the user's command. You can also create a hook which will be
1437 executed whenever the program stops. See gdb.texinfo.
1441 We now deal with Cfront style name mangling, and can even extract type
1442 info from mangled symbols. GDB can automatically figure out which
1443 symbol mangling style your C++ compiler uses.
1445 Calling of methods and virtual functions has been improved as well.
1449 The crash that occured when debugging Sun Ansi-C compiled binaries is
1450 fixed. This was due to mishandling of the extra N_SO stabs output
1453 We also finally got Ultrix 4.2 running in house, and fixed core file
1454 support, with help from a dozen people on the net.
1456 John M. Farrell discovered that the reason that single-stepping was so
1457 slow on all of the Mips based platforms (primarily SGI and DEC) was
1458 that we were trying to demangle and lookup a symbol used for internal
1459 purposes on every instruction that was being stepped through. Changing
1460 the name of that symbol so that it couldn't be mistaken for a C++
1461 mangled symbol sped things up a great deal.
1463 Rich Pixley sped up symbol lookups in general by getting much smarter
1464 about when C++ symbol mangling is necessary. This should make symbol
1465 completion (TAB on the command line) much faster. It's not as fast as
1466 we'd like, but it's significantly faster than gdb-4.6.
1470 A new user controllable variable 'call_scratch_address' can
1471 specify the location of a scratch area to be used when GDB
1472 calls a function in the target. This is necessary because the
1473 usual method of putting the scratch area on the stack does not work
1474 in systems that have separate instruction and data spaces.
1476 We integrated changes to support the 29k UDI (Universal Debugger
1477 Interface), but discovered at the last minute that we didn't have all
1478 of the appropriate copyright paperwork. We are working with AMD to
1479 resolve this, and hope to have it available soon.
1483 We have sped up the remote serial line protocol, especially for targets
1484 with lots of registers. It now supports a new `expedited status' ('T')
1485 message which can be used in place of the existing 'S' status message.
1486 This allows the remote stub to send only the registers that GDB
1487 needs to make a quick decision about single-stepping or conditional
1488 breakpoints, eliminating the need to fetch the entire register set for
1489 each instruction being stepped through.
1491 The GDB remote serial protocol now implements a write-through cache for
1492 registers, only re-reading the registers if the target has run.
1494 There is also a new remote serial stub for SPARC processors. You can
1495 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
1496 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
1497 processor with a serial port.
1501 Configure.in files have become much easier to read and modify. A new
1502 `table driven' format makes it more obvious what configurations are
1503 supported, and what files each one uses.
1507 There is a new opcodes library which will eventually contain all of the
1508 disassembly routines and opcode tables. At present, it only contains
1509 Sparc and Z8000 routines. This will allow the assembler, debugger, and
1510 disassembler (binutils/objdump) to share these routines.
1512 The libiberty library is now copylefted under the GNU Library General
1513 Public License. This allows more liberal use, and was done so libg++
1514 can use it. This makes no difference to GDB, since the Library License
1515 grants all the rights from the General Public License.
1519 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
1520 reference to the stabs symbol info used by the debugger. It is (as far
1521 as we know) the only published document on this fascinating topic. We
1522 encourage you to read it, compare it to the stabs information on your
1523 system, and send improvements on the document in general (to
1524 bug-gdb@prep.ai.mit.edu).
1526 And, of course, many bugs have been fixed.
1529 *** Changes in GDB-4.6:
1531 * Better support for C++ function names
1533 GDB now accepts as input the "demangled form" of C++ overloaded function
1534 names and member function names, and can do command completion on such names
1535 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
1536 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
1537 Make use of command completion, it is your friend.
1539 GDB also now accepts a variety of C++ mangled symbol formats. They are
1540 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
1541 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
1542 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
1543 for the list of formats.
1545 * G++ symbol mangling problem
1547 Recent versions of gcc have a bug in how they emit debugging information for
1548 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
1549 directory) can be applied to gcc to fix the problem. Alternatively, if you
1550 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
1551 usual symptom is difficulty with setting breakpoints on methods. GDB complains
1552 about the method being non-existent. (We believe that version 2.2.2 of GCC has
1555 * New 'maintenance' command
1557 All of the commands related to hacking GDB internals have been moved out of
1558 the main command set, and now live behind the 'maintenance' command. This
1559 can also be abbreviated as 'mt'. The following changes were made:
1561 dump-me -> maintenance dump-me
1562 info all-breakpoints -> maintenance info breakpoints
1563 printmsyms -> maintenance print msyms
1564 printobjfiles -> maintenance print objfiles
1565 printpsyms -> maintenance print psymbols
1566 printsyms -> maintenance print symbols
1568 The following commands are new:
1570 maintenance demangle Call internal GDB demangler routine to
1571 demangle a C++ link name and prints the result.
1572 maintenance print type Print a type chain for a given symbol
1574 * Change to .gdbinit file processing
1576 We now read the $HOME/.gdbinit file before processing the argv arguments
1577 (e.g. reading symbol files or core files). This allows global parameters to
1578 be set, which will apply during the symbol reading. The ./.gdbinit is still
1579 read after argv processing.
1581 * New hosts supported
1583 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
1585 GNU/Linux support i386-unknown-linux or linux
1587 We are also including code to support the HP/PA running BSD and HPUX. This
1588 is almost guaranteed not to work, as we didn't have time to test or build it
1589 for this release. We are including it so that the more adventurous (or
1590 masochistic) of you can play with it. We also had major problems with the
1591 fact that the compiler that we got from HP doesn't support the -g option.
1594 * New targets supported
1596 Hitachi H8/300 h8300-hitachi-hms or h8300hms
1598 * More smarts about finding #include files
1600 GDB now remembers the compilation directory for all include files, and for
1601 all files from which C is generated (like yacc and lex sources). This
1602 greatly improves GDB's ability to find yacc/lex sources, and include files,
1603 especially if you are debugging your program from a directory different from
1604 the one that contains your sources.
1606 We also fixed a bug which caused difficulty with listing and setting
1607 breakpoints in include files which contain C code. (In the past, you had to
1608 try twice in order to list an include file that you hadn't looked at before.)
1610 * Interesting infernals change
1612 GDB now deals with arbitrary numbers of sections, where the symbols for each
1613 section must be relocated relative to that section's landing place in the
1614 target's address space. This work was needed to support ELF with embedded
1615 stabs used by Solaris-2.0.
1617 * Bug fixes (of course!)
1619 There have been loads of fixes for the following things:
1620 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
1621 i960, stabs, DOS(GO32), procfs, etc...
1623 See the ChangeLog for details.
1625 *** Changes in GDB-4.5:
1627 * New machines supported (host and target)
1629 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
1631 SGI Irix-4.x mips-sgi-irix4 or iris4
1633 * New malloc package
1635 GDB now uses a new memory manager called mmalloc, based on gmalloc.
1636 Mmalloc is capable of handling mutiple heaps of memory. It is also
1637 capable of saving a heap to a file, and then mapping it back in later.
1638 This can be used to greatly speedup the startup of GDB by using a
1639 pre-parsed symbol table which lives in a mmalloc managed heap. For
1640 more details, please read mmalloc/mmalloc.texi.
1644 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
1645 'help info proc' for details.
1647 * MIPS ecoff symbol table format
1649 The code that reads MIPS symbol table format is now supported on all hosts.
1650 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
1653 * File name changes for MS-DOS
1655 Many files in the config directories have been renamed to make it easier to
1656 support GDB on MS-DOSe systems (which have very restrictive file name
1657 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
1658 environment) is close to working but has some remaining problems. Note
1659 that debugging of DOS programs is not supported, due to limitations
1660 in the ``operating system'', but it can be used to host cross-debugging.
1662 * Cross byte order fixes
1664 Many fixes have been made to support cross debugging of Sparc and MIPS
1665 targets from hosts whose byte order differs.
1667 * New -mapped and -readnow options
1669 If memory-mapped files are available on your system through the 'mmap'
1670 system call, you can use the -mapped option on the `file' or
1671 `symbol-file' commands to cause GDB to write the symbols from your
1672 program into a reusable file. If the program you are debugging is
1673 called `/path/fred', the mapped symbol file will be `./fred.syms'.
1674 Future GDB debugging sessions will notice the presence of this file,
1675 and will quickly map in symbol information from it, rather than reading
1676 the symbol table from the executable program. Using the '-mapped'
1677 option in a GDB `file' or `symbol-file' command has the same effect as
1678 starting GDB with the '-mapped' command-line option.
1680 You can cause GDB to read the entire symbol table immediately by using
1681 the '-readnow' option with any of the commands that load symbol table
1682 information (or on the GDB command line). This makes the command
1683 slower, but makes future operations faster.
1685 The -mapped and -readnow options are typically combined in order to
1686 build a `fred.syms' file that contains complete symbol information.
1687 A simple GDB invocation to do nothing but build a `.syms' file for future
1690 gdb -batch -nx -mapped -readnow programname
1692 The `.syms' file is specific to the host machine on which GDB is run.
1693 It holds an exact image of GDB's internal symbol table. It cannot be
1694 shared across multiple host platforms.
1696 * longjmp() handling
1698 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
1699 siglongjmp() without losing control. This feature has not yet been ported to
1700 all systems. It currently works on many 386 platforms, all MIPS-based
1701 platforms (SGI, DECstation, etc), and Sun3/4.
1705 Preliminary work has been put in to support the new Solaris OS from Sun. At
1706 this time, it can control and debug processes, but it is not capable of
1711 As always, many many bug fixes. The major areas were with g++, and mipsread.
1712 People using the MIPS-based platforms should experience fewer mysterious
1713 crashes and trashed symbol tables.
1715 *** Changes in GDB-4.4:
1717 * New machines supported (host and target)
1719 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
1721 BSD Reno on Vax vax-dec-bsd
1722 Ultrix on Vax vax-dec-ultrix
1724 * New machines supported (target)
1726 AMD 29000 embedded, using EBMON a29k-none-none
1730 GDB continues to improve its handling of C++. `References' work better.
1731 The demangler has also been improved, and now deals with symbols mangled as
1732 per the Annotated C++ Reference Guide.
1734 GDB also now handles `stabs' symbol information embedded in MIPS
1735 `ecoff' symbol tables. Since the ecoff format was not easily
1736 extensible to handle new languages such as C++, this appeared to be a
1737 good way to put C++ debugging info into MIPS binaries. This option
1738 will be supported in the GNU C compiler, version 2, when it is
1741 * New features for SVR4
1743 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
1744 shared libraries. Debugging dynamically linked programs should present
1745 only minor differences from debugging statically linked programs.
1747 The `info proc' command will print out information about any process
1748 on an SVR4 system (including the one you are debugging). At the moment,
1749 it prints the address mappings of the process.
1751 If you bring up GDB on another SVR4 system, please send mail to
1752 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
1754 * Better dynamic linking support in SunOS
1756 Reading symbols from shared libraries which contain debugging symbols
1757 now works properly. However, there remain issues such as automatic
1758 skipping of `transfer vector' code during function calls, which
1759 make it harder to debug code in a shared library, than to debug the
1760 same code linked statically.
1764 GDB is now using the latest `getopt' routines from the FSF. This
1765 version accepts the -- prefix for options with long names. GDB will
1766 continue to accept the old forms (-option and +option) as well.
1767 Various single letter abbreviations for options have been explicity
1768 added to the option table so that they won't get overshadowed in the
1769 future by other options that begin with the same letter.
1773 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
1774 Many assorted bugs have been handled. Many more remain to be handled.
1775 See the various ChangeLog files (primarily in gdb and bfd) for details.
1778 *** Changes in GDB-4.3:
1780 * New machines supported (host and target)
1782 Amiga 3000 running Amix m68k-cbm-svr4 or amix
1783 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
1784 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
1786 * Almost SCO Unix support
1788 We had hoped to support:
1789 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
1790 (except for core file support), but we discovered very late in the release
1791 that it has problems with process groups that render gdb unusable. Sorry
1792 about that. I encourage people to fix it and post the fixes.
1794 * Preliminary ELF and DWARF support
1796 GDB can read ELF object files on System V Release 4, and can handle
1797 debugging records for C, in DWARF format, in ELF files. This support
1798 is preliminary. If you bring up GDB on another SVR4 system, please
1799 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
1804 GDB now uses the latest `readline' library. One user-visible change
1805 is that two tabs will list possible command completions, which previously
1806 required typing M-? (meta-question mark, or ESC ?).
1810 The `stepi' bug that many of you noticed has been squashed.
1811 Many bugs in C++ have been handled. Many more remain to be handled.
1812 See the various ChangeLog files (primarily in gdb and bfd) for details.
1814 * State of the MIPS world (in case you wondered):
1816 GDB can understand the symbol tables emitted by the compilers
1817 supplied by most vendors of MIPS-based machines, including DEC. These
1818 symbol tables are in a format that essentially nobody else uses.
1820 Some versions of gcc come with an assembler post-processor called
1821 mips-tfile. This program is required if you want to do source-level
1822 debugging of gcc-compiled programs. I believe FSF does not ship
1823 mips-tfile with gcc version 1, but it will eventually come with gcc
1826 Debugging of g++ output remains a problem. g++ version 1.xx does not
1827 really support it at all. (If you're lucky, you should be able to get
1828 line numbers and stack traces to work, but no parameters or local
1829 variables.) With some work it should be possible to improve the
1832 When gcc version 2 is released, you will have somewhat better luck.
1833 However, even then you will get confusing results for inheritance and
1836 We will eventually provide full debugging of g++ output on
1837 DECstations. This will probably involve some kind of stabs-in-ecoff
1838 encapulation, but the details have not been worked out yet.
1841 *** Changes in GDB-4.2:
1843 * Improved configuration
1845 Only one copy of `configure' exists now, and it is not self-modifying.
1846 Porting BFD is simpler.
1850 The `step' and `next' commands now only stop at the first instruction
1851 of a source line. This prevents the multiple stops that used to occur
1852 in switch statements, for-loops, etc. `Step' continues to stop if a
1853 function that has debugging information is called within the line.
1857 Lots of small bugs fixed. More remain.
1859 * New host supported (not target)
1861 Intel 386 PC clone running Mach i386-none-mach
1864 *** Changes in GDB-4.1:
1866 * Multiple source language support
1868 GDB now has internal scaffolding to handle several source languages.
1869 It determines the type of each source file from its filename extension,
1870 and will switch expression parsing and number formatting to match the
1871 language of the function in the currently selected stack frame.
1872 You can also specifically set the language to be used, with
1873 `set language c' or `set language modula-2'.
1877 GDB now has preliminary support for the GNU Modula-2 compiler,
1878 currently under development at the State University of New York at
1879 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
1880 continue through the fall of 1991 and into 1992.
1882 Other Modula-2 compilers are currently not supported, and attempting to
1883 debug programs compiled with them will likely result in an error as the
1884 symbol table is read. Feel free to work on it, though!
1886 There are hooks in GDB for strict type checking and range checking,
1887 in the `Modula-2 philosophy', but they do not currently work.
1891 GDB can now write to executable and core files (e.g. patch
1892 a variable's value). You must turn this switch on, specify
1893 the file ("exec foo" or "core foo"), *then* modify it, e.g.
1894 by assigning a new value to a variable. Modifications take
1897 * Automatic SunOS shared library reading
1899 When you run your program, GDB automatically determines where its
1900 shared libraries (if any) have been loaded, and reads their symbols.
1901 The `share' command is no longer needed. This also works when
1902 examining core files.
1906 You can specify the number of lines that the `list' command shows.
1909 * New machines supported (host and target)
1911 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
1912 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
1913 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
1915 * New hosts supported (not targets)
1917 IBM RT/PC: romp-ibm-aix or rtpc
1919 * New targets supported (not hosts)
1921 AMD 29000 embedded with COFF a29k-none-coff
1922 AMD 29000 embedded with a.out a29k-none-aout
1923 Ultracomputer remote kernel debug a29k-nyu-kern
1925 * New remote interfaces
1931 *** Changes in GDB-4.0:
1935 Wide output is wrapped at good places to make the output more readable.
1937 Gdb now supports cross-debugging from a host machine of one type to a
1938 target machine of another type. Communication with the target system
1939 is over serial lines. The ``target'' command handles connecting to the
1940 remote system; the ``load'' command will download a program into the
1941 remote system. Serial stubs for the m68k and i386 are provided. Gdb
1942 also supports debugging of realtime processes running under VxWorks,
1943 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
1944 stub on the target system.
1946 New CPUs supported include the AMD 29000 and Intel 960.
1948 GDB now reads object files and symbol tables via a ``binary file''
1949 library, which allows a single copy of GDB to debug programs of multiple
1950 object file types such as a.out and coff.
1952 There is now a GDB reference card in "doc/refcard.tex". (Make targets
1953 refcard.dvi and refcard.ps are available to format it).
1956 * Control-Variable user interface simplified
1958 All variables that control the operation of the debugger can be set
1959 by the ``set'' command, and displayed by the ``show'' command.
1961 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
1962 ``Show prompt'' produces the response:
1963 Gdb's prompt is new-gdb=>.
1965 What follows are the NEW set commands. The command ``help set'' will
1966 print a complete list of old and new set commands. ``help set FOO''
1967 will give a longer description of the variable FOO. ``show'' will show
1968 all of the variable descriptions and their current settings.
1970 confirm on/off: Enables warning questions for operations that are
1971 hard to recover from, e.g. rerunning the program while
1972 it is already running. Default is ON.
1974 editing on/off: Enables EMACS style command line editing
1975 of input. Previous lines can be recalled with
1976 control-P, the current line can be edited with control-B,
1977 you can search for commands with control-R, etc.
1980 history filename NAME: NAME is where the gdb command history
1981 will be stored. The default is .gdb_history,
1982 or the value of the environment variable
1985 history size N: The size, in commands, of the command history. The
1986 default is 256, or the value of the environment variable
1989 history save on/off: If this value is set to ON, the history file will
1990 be saved after exiting gdb. If set to OFF, the
1991 file will not be saved. The default is OFF.
1993 history expansion on/off: If this value is set to ON, then csh-like
1994 history expansion will be performed on
1995 command line input. The default is OFF.
1997 radix N: Sets the default radix for input and output. It can be set
1998 to 8, 10, or 16. Note that the argument to "radix" is interpreted
1999 in the current radix, so "set radix 10" is always a no-op.
2001 height N: This integer value is the number of lines on a page. Default
2002 is 24, the current `stty rows'' setting, or the ``li#''
2003 setting from the termcap entry matching the environment
2006 width N: This integer value is the number of characters on a line.
2007 Default is 80, the current `stty cols'' setting, or the ``co#''
2008 setting from the termcap entry matching the environment
2011 Note: ``set screensize'' is obsolete. Use ``set height'' and
2012 ``set width'' instead.
2014 print address on/off: Print memory addresses in various command displays,
2015 such as stack traces and structure values. Gdb looks
2016 more ``symbolic'' if you turn this off; it looks more
2017 ``machine level'' with it on. Default is ON.
2019 print array on/off: Prettyprint arrays. New convenient format! Default
2022 print demangle on/off: Print C++ symbols in "source" form if on,
2025 print asm-demangle on/off: Same, for assembler level printouts
2028 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
2031 * Support for Epoch Environment.
2033 The epoch environment is a version of Emacs v18 with windowing. One
2034 new command, ``inspect'', is identical to ``print'', except that if you
2035 are running in the epoch environment, the value is printed in its own
2039 * Support for Shared Libraries
2041 GDB can now debug programs and core files that use SunOS shared libraries.
2042 Symbols from a shared library cannot be referenced
2043 before the shared library has been linked with the program (this
2044 happens after you type ``run'' and before the function main() is entered).
2045 At any time after this linking (including when examining core files
2046 from dynamically linked programs), gdb reads the symbols from each
2047 shared library when you type the ``sharedlibrary'' command.
2048 It can be abbreviated ``share''.
2050 sharedlibrary REGEXP: Load shared object library symbols for files
2051 matching a unix regular expression. No argument
2052 indicates to load symbols for all shared libraries.
2054 info sharedlibrary: Status of loaded shared libraries.
2059 A watchpoint stops execution of a program whenever the value of an
2060 expression changes. Checking for this slows down execution
2061 tremendously whenever you are in the scope of the expression, but is
2062 quite useful for catching tough ``bit-spreader'' or pointer misuse
2063 problems. Some machines such as the 386 have hardware for doing this
2064 more quickly, and future versions of gdb will use this hardware.
2066 watch EXP: Set a watchpoint (breakpoint) for an expression.
2068 info watchpoints: Information about your watchpoints.
2070 delete N: Deletes watchpoint number N (same as breakpoints).
2071 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
2072 enable N: Re-enables watchpoint number N (same as breakpoints).
2075 * C++ multiple inheritance
2077 When used with a GCC version 2 compiler, GDB supports multiple inheritance
2080 * C++ exception handling
2082 Gdb now supports limited C++ exception handling. Besides the existing
2083 ability to breakpoint on an exception handler, gdb can breakpoint on
2084 the raising of an exception (before the stack is peeled back to the
2087 catch FOO: If there is a FOO exception handler in the dynamic scope,
2088 set a breakpoint to catch exceptions which may be raised there.
2089 Multiple exceptions (``catch foo bar baz'') may be caught.
2091 info catch: Lists all exceptions which may be caught in the
2092 current stack frame.
2095 * Minor command changes
2097 The command ``call func (arg, arg, ...)'' now acts like the print
2098 command, except it does not print or save a value if the function's result
2099 is void. This is similar to dbx usage.
2101 The ``up'' and ``down'' commands now always print the frame they end up
2102 at; ``up-silently'' and `down-silently'' can be used in scripts to change
2103 frames without printing.
2105 * New directory command
2107 'dir' now adds directories to the FRONT of the source search path.
2108 The path starts off empty. Source files that contain debug information
2109 about the directory in which they were compiled can be found even
2110 with an empty path; Sun CC and GCC include this information. If GDB can't
2111 find your source file in the current directory, type "dir .".
2113 * Configuring GDB for compilation
2115 For normal use, type ``./configure host''. See README or gdb.texinfo
2118 GDB now handles cross debugging. If you are remotely debugging between
2119 two different machines, type ``./configure host -target=targ''.
2120 Host is the machine where GDB will run; targ is the machine
2121 where the program that you are debugging will run.