1 What has changed in GDB?
2 (Organized release by release)
4 *** Changes since GDB-4.18:
6 * Improved support for debugging FP programs on x86 targets
8 Unified and much-improved support for debugging floating-point
9 programs on all x86 targets. In particular, ``info float'' now
10 displays the FP registers in the same format on all x86 targets, with
11 greater level of detail.
13 * Improvements and bugfixes in hardware-assisted watchpoints
15 It is now possible to watch array elements, struct members, and
16 bitfields with hardware-assisted watchpoints. Data-read watchpoints
17 on x86 targets no longer erroneously trigger when the address is
20 * Improvements in the native DJGPP version of GDB
22 The distribution now includes all the scripts and auxiliary files
23 necessary to build the native DJGPP version on MS-DOS/MS-Windows
24 machines ``out of the box''.
26 The DJGPP version can now debug programs that use signals. It is
27 possible to catch signals that happened in the debuggee, deliver
28 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
29 would kill the program being debugged.) Programs that hook hardware
30 interrupts (keyboard, timer, etc.) can also be debugged.
32 It is now possible to debug DJGPP programs that redirect their
33 standard handles or switch them to raw (as opposed to cooked) mode, or
34 even close them. The command ``run < foo > bar'' works as expected,
35 and ``info terminal'' reports useful information about the debuggee's
36 terminal, including raw/cooked mode, redirection, etc.
38 The DJGPP version now uses termios functions for console I/O, which
39 enables debugging graphics programs. Interrupting GDB with Ctrl-C
42 DOS-style file names with drive letters are now fully supported by
45 It is now possible to debug DJGPP programs that switch their working
46 directory. It is also possible to rerun the debuggee any number of
47 times without restarting GDB; thus, you can use the same setup,
48 breakpoints, etc. for many debugging sessions.
50 * New native configurations
52 ARM GNU/Linux arm*-*-linux*
53 PowerPC GNU/Linux powerpc-*-linux*
57 Motorola MCore mcore-*-*
58 x86 VxWorks i[3456]86-*-vxworks*
59 PowerPC VxWorks powerpc-*-vxworks*
60 TI TMS320C80 tic80-*-*
62 * OBSOLETE configurations
64 Altos 3068 m68*-altos-*
67 ARM RISCix arm-*-* (as host)
70 * New features for SVR4
72 On SVR4 native platforms (such as Solaris), if you attach to a process
73 without first loading a symbol file, GDB will now attempt to locate and
74 load symbols from the running process's executable file.
76 * Many C++ enhancements
78 C++ support has been greatly improved. Overload resolution now works properly
79 in almost all cases. RTTI support is on the way.
81 * Remote targets can connect to a sub-program
83 A popen(3) style serial-device has been added. This device starts a
84 sub-process (such as a stand-alone simulator) and then communicates
85 with that. The sub-program to run is specified using the syntax
86 ``|<program> <args>'' vis:
88 (gdb) set remotedebug 1
89 (gdb) target extended-remote |mn10300-elf-sim program-args
91 * MIPS 64 remote protocol
93 A long standing bug in the mips64 remote protocol where by GDB
94 expected certain 32 bit registers (ex SR) to be transfered as 32
95 instead of 64 bits has been fixed.
97 The command ``set remote-mips64-transfers-32bit-regs on'' has been
98 added to provide backward compatibility with older versions of GDB.
100 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
102 The command ``set remotebinarydownload'' command has been replaced by
103 ``set remote X-packet''. Other commands in ``set remote'' family
104 include ``set remote P-packet''.
106 * Breakpoint commands accept ranges.
108 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
109 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
110 ``tracepoint passcount'' also accepts a range of tracepoints.
112 * ``apropos'' command added.
114 The ``apropos'' command searches through command names and
115 documentation strings, printing out matches, making it much easier to
116 try to find a command that does what you are looking for.
120 A new machine oriented interface (MI) has been added to GDB. This
121 interface is designed for debug environments running GDB as a separate
122 process. This is part of the long term libGDB project. See
123 gdb/mi/gdbmi.texinfo for further information. It can be enabled by
126 .../configure --enable-gdbmi
128 *** Changes in GDB-4.18:
130 * New native configurations
132 HP-UX 10.20 hppa*-*-hpux10.20
133 HP-UX 11.x hppa*-*-hpux11.0*
134 M68K Linux m68*-*-linux*
138 Fujitsu FR30 fr30-*-elf*
139 Intel StrongARM strongarm-*-*
140 Mitsubishi D30V d30v-*-*
142 * OBSOLETE configurations
144 Gould PowerNode, NP1 np1-*-*, pn-*-*
146 Configurations that have been declared obsolete will be commented out,
147 but the code will be left in place. If there is no activity to revive
148 these configurations before the next release of GDB, the sources will
149 be permanently REMOVED.
153 As a compatibility experiment, GDB's source files buildsym.h and
154 buildsym.c have been converted to pure standard C, no longer
155 containing any K&R compatibility code. We believe that all systems in
156 use today either come with a standard C compiler, or have a GCC port
157 available. If this is not true, please report the affected
158 configuration to bug-gdb@gnu.org immediately. See the README file for
159 information about getting a standard C compiler if you don't have one
164 GDB now uses readline 2.2.
166 * set extension-language
168 You can now control the mapping between filename extensions and source
169 languages by using the `set extension-language' command. For instance,
170 you can ask GDB to treat .c files as C++ by saying
171 set extension-language .c c++
172 The command `info extensions' lists all of the recognized extensions
173 and their associated languages.
175 * Setting processor type for PowerPC and RS/6000
177 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
178 you can use the `set processor' command to specify what variant of the
179 PowerPC family you are debugging. The command
183 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
184 following PowerPC and RS6000 variants:
186 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
187 rs6000 IBM RS6000 ("POWER") architecture, user-level view
189 403GC IBM PowerPC 403GC
190 505 Motorola PowerPC 505
191 860 Motorola PowerPC 860 or 850
192 601 Motorola PowerPC 601
193 602 Motorola PowerPC 602
194 603 Motorola/IBM PowerPC 603 or 603e
195 604 Motorola PowerPC 604 or 604e
196 750 Motorola/IBM PowerPC 750 or 750
198 At the moment, this command just tells GDB what to name the
199 special-purpose processor registers. Since almost all the affected
200 registers are inaccessible to user-level programs, this command is
201 only useful for remote debugging in its present form.
205 Thanks to a major code donation from Hewlett-Packard, GDB now has much
206 more extensive support for HP-UX. Added features include shared
207 library support, kernel threads and hardware watchpoints for 11.00,
208 support for HP's ANSI C and C++ compilers, and a compatibility mode
209 for xdb and dbx commands.
213 HP's donation includes the new concept of catchpoints, which is a
214 generalization of the old catch command. On HP-UX, it is now possible
215 to catch exec, fork, and vfork, as well as library loading.
217 This means that the existing catch command has changed; its first
218 argument now specifies the type of catch to be set up. See the
219 output of "help catch" for a list of catchpoint types.
221 * Debugging across forks
223 On HP-UX, you can choose which process to debug when a fork() happens
228 HP has donated a curses-based terminal user interface (TUI). To get
229 it, build with --enable-tui. Although this can be enabled for any
230 configuration, at present it only works for native HP debugging.
232 * GDB remote protocol additions
234 A new protocol packet 'X' that writes binary data is now available.
235 Default behavior is to try 'X', then drop back to 'M' if the stub
236 fails to respond. The settable variable `remotebinarydownload'
237 allows explicit control over the use of 'X'.
239 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
240 full 64-bit address. The command
242 set remoteaddresssize 32
244 can be used to revert to the old behaviour. For existing remote stubs
245 the change should not be noticed, as the additional address information
248 In order to assist in debugging stubs, you may use the maintenance
249 command `packet' to send any text string to the stub. For instance,
251 maint packet heythere
253 sends the packet "$heythere#<checksum>". Note that it is very easy to
254 disrupt a debugging session by sending the wrong packet at the wrong
257 The compare-sections command allows you to compare section data on the
258 target to what is in the executable file without uploading or
259 downloading, by comparing CRC checksums.
261 * Tracing can collect general expressions
263 You may now collect general expressions at tracepoints. This requires
264 further additions to the target-side stub; see tracepoint.c and
265 doc/agentexpr.texi for further details.
267 * mask-address variable for Mips
269 For Mips targets, you may control the zeroing of the upper 32 bits of
270 a 64-bit address by entering `set mask-address on'. This is mainly
271 of interest to users of embedded R4xxx and R5xxx processors.
273 * Higher serial baud rates
275 GDB's serial code now allows you to specify baud rates 57600, 115200,
276 230400, and 460800 baud. (Note that your host system may not be able
277 to achieve all of these rates.)
281 The i960 configuration now includes an initial implementation of a
282 builtin simulator, contributed by Jim Wilson.
285 *** Changes in GDB-4.17:
287 * New native configurations
289 Alpha GNU/Linux alpha*-*-linux*
290 Unixware 2.x i[3456]86-unixware2*
291 Irix 6.x mips*-sgi-irix6*
292 PowerPC GNU/Linux powerpc-*-linux*
293 PowerPC Solaris powerpcle-*-solaris*
294 Sparc GNU/Linux sparc-*-linux*
295 Motorola sysV68 R3V7.1 m68k-motorola-sysv
299 Argonaut Risc Chip (ARC) arc-*-*
300 Hitachi H8/300S h8300*-*-*
301 Matsushita MN10200 w/simulator mn10200-*-*
302 Matsushita MN10300 w/simulator mn10300-*-*
303 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
304 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
305 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
306 Mitsubishi D10V w/simulator d10v-*-*
307 Mitsubishi M32R/D w/simulator m32r-*-elf*
308 Tsqware Sparclet sparclet-*-*
309 NEC V850 w/simulator v850-*-*
311 * New debugging protocols
313 ARM with RDI protocol arm*-*-*
314 M68K with dBUG monitor m68*-*-{aout,coff,elf}
315 DDB and LSI variants of PMON protocol mips*-*-*
316 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
317 PowerPC with SDS protocol powerpc{,le}-*-eabi
318 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
322 All configurations can now understand and use the DWARF 2 debugging
323 format. The choice is automatic, if the symbol file contains DWARF 2
328 GDB now includes basic Java language support. This support is
329 only useful with Java compilers that produce native machine code.
331 * solib-absolute-prefix and solib-search-path
333 For SunOS and SVR4 shared libraries, you may now set the prefix for
334 loading absolute shared library symbol files, and the search path for
335 locating non-absolute shared library symbol files.
337 * Live range splitting
339 GDB can now effectively debug code for which GCC has performed live
340 range splitting as part of its optimization. See gdb/doc/LRS for
341 more details on the expected format of the stabs information.
345 GDB's support for the GNU Hurd, including thread debugging, has been
346 updated to work with current versions of the Hurd.
350 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
351 instruction set. ARM GDB automatically detects when Thumb
352 instructions are in use, and adjusts disassembly and backtracing
357 GDB's MIPS target configurations now handle the MIP16 16-bit
362 GDB now includes support for overlays; if an executable has been
363 linked such that multiple sections are based at the same address, GDB
364 will decide which section to use for symbolic info. You can choose to
365 control the decision manually, using overlay commands, or implement
366 additional target-side support and use "overlay load-target" to bring
367 in the overlay mapping. Do "help overlay" for more detail.
371 The command "info symbol <address>" displays information about
372 the symbol at the specified address.
376 The standard remote protocol now includes an extension that allows
377 asynchronous collection and display of trace data. This requires
378 extensive support in the target-side debugging stub. Tracing mode
379 includes a new interaction mode in GDB and new commands: see the
380 file tracepoint.c for more details.
384 Configurations for embedded MIPS now include a simulator contributed
385 by Cygnus Solutions. The simulator supports the instruction sets
386 of most MIPS variants.
390 Sparc configurations may now include the ERC32 simulator contributed
391 by the European Space Agency. The simulator is not built into
392 Sparc targets by default; configure with --enable-sim to include it.
396 For target configurations that may include multiple variants of a
397 basic architecture (such as MIPS and SH), you may now set the
398 architecture explicitly. "set arch" sets, "info arch" lists
399 the possible architectures.
401 *** Changes in GDB-4.16:
403 * New native configurations
405 Windows 95, x86 Windows NT i[345]86-*-cygwin32
406 M68K NetBSD m68k-*-netbsd*
407 PowerPC AIX 4.x powerpc-*-aix*
408 PowerPC MacOS powerpc-*-macos*
409 PowerPC Windows NT powerpcle-*-cygwin32
410 RS/6000 AIX 4.x rs6000-*-aix4*
414 ARM with RDP protocol arm-*-*
415 I960 with MON960 i960-*-coff
416 MIPS VxWorks mips*-*-vxworks*
417 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
418 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
420 Matra Sparclet sparclet-*-*
424 The powerpc-eabi configuration now includes the PSIM simulator,
425 contributed by Andrew Cagney, with assistance from Mike Meissner.
426 PSIM is a very elaborate model of the PowerPC, including not only
427 basic instruction set execution, but also details of execution unit
428 performance and I/O hardware. See sim/ppc/README for more details.
432 GDB now works with Solaris 2.5.
434 * Windows 95/NT native
436 GDB will now work as a native debugger on Windows 95 and Windows NT.
437 To build it from source, you must use the "gnu-win32" environment,
438 which uses a DLL to emulate enough of Unix to run the GNU tools.
439 Further information, binaries, and sources are available at
440 ftp.cygnus.com, under pub/gnu-win32.
442 * dont-repeat command
444 If a user-defined command includes the command `dont-repeat', then the
445 command will not be repeated if the user just types return. This is
446 useful if the command is time-consuming to run, so that accidental
447 extra keystrokes don't run the same command many times.
449 * Send break instead of ^C
451 The standard remote protocol now includes an option to send a break
452 rather than a ^C to the target in order to interrupt it. By default,
453 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
455 * Remote protocol timeout
457 The standard remote protocol includes a new variable `remotetimeout'
458 that allows you to set the number of seconds before GDB gives up trying
459 to read from the target. The default value is 2.
461 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
463 By default GDB will automatically keep track of objects as they are
464 loaded and unloaded by the dynamic linker. By using the command `set
465 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
466 when shared library events occur, thus allowing you to set breakpoints
467 in shared libraries which are explicitly loaded by the inferior.
469 Note this feature does not work on hpux8. On hpux9 you must link
470 /usr/lib/end.o into your program. This feature should work
471 automatically on hpux10.
473 * Irix 5.x hardware watchpoint support
475 Irix 5 configurations now support the use of hardware watchpoints.
477 * Mips protocol "SYN garbage limit"
479 When debugging a Mips target using the `target mips' protocol, you
480 may set the number of characters that GDB will ignore by setting
481 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
482 every character. The default value is 1050.
484 * Recording and replaying remote debug sessions
486 If you set `remotelogfile' to the name of a file, gdb will write to it
487 a recording of a remote debug session. This recording may then be
488 replayed back to gdb using "gdbreplay". See gdbserver/README for
489 details. This is useful when you have a problem with GDB while doing
490 remote debugging; you can make a recording of the session and send it
491 to someone else, who can then recreate the problem.
493 * Speedups for remote debugging
495 GDB includes speedups for downloading and stepping MIPS systems using
496 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
497 and more efficient S-record downloading.
499 * Memory use reductions and statistics collection
501 GDB now uses less memory and reports statistics about memory usage.
502 Try the `maint print statistics' command, for example.
504 *** Changes in GDB-4.15:
508 The symbol reader for AIX GDB now uses partial symbol tables. This
509 can greatly improve startup time, especially for large executables.
511 * Remote targets use caching
513 Remote targets now use a data cache to speed up communication with the
514 remote side. The data cache could lead to incorrect results because
515 it doesn't know about volatile variables, thus making it impossible to
516 debug targets which use memory mapped I/O devices. `set remotecache
517 off' turns the the data cache off.
519 * Remote targets may have threads
521 The standard remote protocol now includes support for multiple threads
522 in the target system, using new protocol commands 'H' and 'T'. See
523 gdb/remote.c for details.
527 If GDB is configured with `--enable-netrom', then it will include
528 support for the NetROM ROM emulator from XLNT Designs. The NetROM
529 acts as though it is a bank of ROM on the target board, but you can
530 write into it over the network. GDB's support consists only of
531 support for fast loading into the emulated ROM; to debug, you must use
532 another protocol, such as standard remote protocol. The usual
533 sequence is something like
535 target nrom <netrom-hostname>
537 target remote <netrom-hostname>:1235
541 GDB now includes support for the Apple Macintosh, as a host only. It
542 may be run as either an MPW tool or as a standalone application, and
543 it can debug through the serial port. All the usual GDB commands are
544 available, but to the target command, you must supply "serial" as the
545 device type instead of "/dev/ttyXX". See mpw-README in the main
546 directory for more information on how to build. The MPW configuration
547 scripts */mpw-config.in support only a few targets, and only the
548 mips-idt-ecoff target has been tested.
552 GDB configuration now uses autoconf. This is not user-visible,
553 but does simplify configuration and building.
557 GDB now supports hpux10.
559 *** Changes in GDB-4.14:
561 * New native configurations
563 x86 FreeBSD i[345]86-*-freebsd
564 x86 NetBSD i[345]86-*-netbsd
565 NS32k NetBSD ns32k-*-netbsd
566 Sparc NetBSD sparc-*-netbsd
570 A29K VxWorks a29k-*-vxworks
571 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
572 CPU32 EST-300 emulator m68*-*-est*
573 PowerPC ELF powerpc-*-elf
576 * Alpha OSF/1 support for procfs
578 GDB now supports procfs under OSF/1-2.x and higher, which makes it
579 possible to attach to running processes. As the mounting of the /proc
580 filesystem is optional on the Alpha, GDB automatically determines
581 the availability of /proc during startup. This can lead to problems
582 if /proc is unmounted after GDB has been started.
584 * Arguments to user-defined commands
586 User commands may accept up to 10 arguments separated by whitespace.
587 Arguments are accessed within the user command via $arg0..$arg9. A
590 print $arg0 + $arg1 + $arg2
592 To execute the command use:
595 Defines the command "adder" which prints the sum of its three arguments.
596 Note the arguments are text substitutions, so they may reference variables,
597 use complex expressions, or even perform inferior function calls.
599 * New `if' and `while' commands
601 This makes it possible to write more sophisticated user-defined
602 commands. Both commands take a single argument, which is the
603 expression to evaluate, and must be followed by the commands to
604 execute, one per line, if the expression is nonzero, the list being
605 terminated by the word `end'. The `if' command list may include an
606 `else' word, which causes the following commands to be executed only
607 if the expression is zero.
609 * Fortran source language mode
611 GDB now includes partial support for Fortran 77. It will recognize
612 Fortran programs and can evaluate a subset of Fortran expressions, but
613 variables and functions may not be handled correctly. GDB will work
614 with G77, but does not yet know much about symbols emitted by other
617 * Better HPUX support
619 Most debugging facilities now work on dynamic executables for HPPAs
620 running hpux9 or later. You can attach to running dynamically linked
621 processes, but by default the dynamic libraries will be read-only, so
622 for instance you won't be able to put breakpoints in them. To change
623 that behavior do the following before running the program:
629 This will cause the libraries to be mapped private and read-write.
630 To revert to the normal behavior, do this:
636 You cannot set breakpoints or examine data in the library until after
637 the library is loaded if the function/data symbols do not have
640 GDB can now also read debug symbols produced by the HP C compiler on
641 HPPAs (sorry, no C++, Fortran or 68k support).
643 * Target byte order now dynamically selectable
645 You can choose which byte order to use with a target system, via the
646 commands "set endian big" and "set endian little", and you can see the
647 current setting by using "show endian". You can also give the command
648 "set endian auto", in which case GDB will use the byte order
649 associated with the executable. Currently, only embedded MIPS
650 configurations support dynamic selection of target byte order.
652 * New DOS host serial code
654 This version uses DPMI interrupts to handle buffered I/O, so you
655 no longer need to run asynctsr when debugging boards connected to
658 *** Changes in GDB-4.13:
660 * New "complete" command
662 This lists all the possible completions for the rest of the line, if it
663 were to be given as a command itself. This is intended for use by emacs.
665 * Trailing space optional in prompt
667 "set prompt" no longer adds a space for you after the prompt you set. This
668 allows you to set a prompt which ends in a space or one that does not.
670 * Breakpoint hit counts
672 "info break" now displays a count of the number of times the breakpoint
673 has been hit. This is especially useful in conjunction with "ignore"; you
674 can ignore a large number of breakpoint hits, look at the breakpoint info
675 to see how many times the breakpoint was hit, then run again, ignoring one
676 less than that number, and this will get you quickly to the last hit of
679 * Ability to stop printing at NULL character
681 "set print null-stop" will cause GDB to stop printing the characters of
682 an array when the first NULL is encountered. This is useful when large
683 arrays actually contain only short strings.
685 * Shared library breakpoints
687 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
688 breakpoints in shared libraries before the executable is run.
690 * Hardware watchpoints
692 There is a new hardware breakpoint for the watch command for sparclite
693 targets. See gdb/sparclite/hw_breakpoint.note.
695 Hardware watchpoints are also now supported under Linux.
699 Annotations have been added. These are for use with graphical interfaces,
700 and are still experimental. Currently only gdba.el uses these.
702 * Improved Irix 5 support
704 GDB now works properly with Irix 5.2.
706 * Improved HPPA support
708 GDB now works properly with the latest GCC and GAS.
710 * New native configurations
712 Sequent PTX4 i[34]86-sequent-ptx4
713 HPPA running OSF/1 hppa*-*-osf*
714 Atari TT running SVR4 m68*-*-sysv4*
715 RS/6000 LynxOS rs6000-*-lynxos*
719 OS/9000 i[34]86-*-os9k
720 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
723 * Hitachi SH7000 and E7000-PC ICE support
725 There is now support for communicating with the Hitachi E7000-PC ICE.
726 This is available automatically when GDB is configured for the SH.
730 As usual, a variety of small fixes and improvements, both generic
731 and configuration-specific. See the ChangeLog for more detail.
733 *** Changes in GDB-4.12:
735 * Irix 5 is now supported
739 GDB-4.12 on the HPPA has a number of changes which make it unable
740 to debug the output from the currently released versions of GCC and
741 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
742 of GCC and GAS, versions of these tools designed to work with GDB-4.12
743 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
746 *** Changes in GDB-4.11:
748 * User visible changes:
752 The "set remotedebug" option is now consistent between the mips remote
753 target, remote targets using the gdb-specific protocol, UDI (AMD's
754 debug protocol for the 29k) and the 88k bug monitor. It is now an
755 integer specifying a debug level (normally 0 or 1, but 2 means more
756 debugging info for the mips target).
758 * DEC Alpha native support
760 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
761 debug info, but GDB works fairly well with the DEC compiler and should
762 work with a future GCC release. See the README file for a few
763 Alpha-specific notes.
765 * Preliminary thread implementation
767 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
769 * LynxOS native and target support for 386
771 This release has been hosted on LynxOS 2.2, and also can be configured
772 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
775 * Improvements in C++ mangling/demangling.
777 This release has much better g++ debugging, specifically in name
778 mangling/demangling, virtual function calls, print virtual table,
779 call methods, ...etc.
781 *** Changes in GDB-4.10:
783 * User visible changes:
785 Remote debugging using the GDB-specific (`target remote') protocol now
786 supports the `load' command. This is only useful if you have some
787 other way of getting the stub to the target system, and you can put it
788 somewhere in memory where it won't get clobbered by the download.
790 Filename completion now works.
792 When run under emacs mode, the "info line" command now causes the
793 arrow to point to the line specified. Also, "info line" prints
794 addresses in symbolic form (as well as hex).
796 All vxworks based targets now support a user settable option, called
797 vxworks-timeout. This option represents the number of seconds gdb
798 should wait for responses to rpc's. You might want to use this if
799 your vxworks target is, perhaps, a slow software simulator or happens
800 to be on the far side of a thin network line.
804 This release contains support for using a DEC alpha as a GDB host for
805 cross debugging. Native alpha debugging is not supported yet.
808 *** Changes in GDB-4.9:
812 This is the first GDB release which is accompanied by a matching testsuite.
813 The testsuite requires installation of dejagnu, which should be available
814 via ftp from most sites that carry GNU software.
818 'Cfront' style demangling has had its name changed to 'ARM' style, to
819 emphasize that it was written from the specifications in the C++ Annotated
820 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
821 disclaimers, it still generated too much confusion with users attempting to
822 use gdb with AT&T cfront.
826 GDB now uses a standard remote interface to a simulator library.
827 So far, the library contains simulators for the Zilog Z8001/2, the
828 Hitachi H8/300, H8/500 and Super-H.
830 * New targets supported
832 H8/300 simulator h8300-hitachi-hms or h8300hms
833 H8/500 simulator h8500-hitachi-hms or h8500hms
834 SH simulator sh-hitachi-hms or sh
835 Z8000 simulator z8k-zilog-none or z8ksim
836 IDT MIPS board over serial line mips-idt-ecoff
838 Cross-debugging to GO32 targets is supported. It requires a custom
839 version of the i386-stub.c module which is integrated with the
840 GO32 memory extender.
842 * New remote protocols
844 MIPS remote debugging protocol.
846 * New source languages supported
848 This version includes preliminary support for Chill, a Pascal like language
849 used by telecommunications companies. Chill support is also being integrated
850 into the GNU compiler, but we don't know when it will be publically available.
853 *** Changes in GDB-4.8:
855 * HP Precision Architecture supported
857 GDB now supports HP PA-RISC machines running HPUX. A preliminary
858 version of this support was available as a set of patches from the
859 University of Utah. GDB does not support debugging of programs
860 compiled with the HP compiler, because HP will not document their file
861 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
862 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
864 Many problems in the preliminary version have been fixed.
866 * Faster and better demangling
868 We have improved template demangling and fixed numerous bugs in the GNU style
869 demangler. It can now handle type modifiers such as `static' or `const'. Wide
870 character types (wchar_t) are now supported. Demangling of each symbol is now
871 only done once, and is cached when the symbol table for a file is read in.
872 This results in a small increase in memory usage for C programs, a moderate
873 increase in memory usage for C++ programs, and a fantastic speedup in
876 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
877 from the specifications in the Annotated Reference Manual, which AT&T's
878 compiler does not actually implement.
880 * G++ multiple inheritance compiler problem
882 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
883 inheritance lattices was reworked to properly discover ambiguities. We
884 recently found an example which causes this new algorithm to fail in a
885 very subtle way, producing bad debug information for those classes.
886 The file 'gcc.patch' (in this directory) can be applied to gcc to
887 circumvent the problem. A future GCC release will contain a complete
890 The previous G++ debug info problem (mentioned below for the gdb-4.7
891 release) is fixed in gcc version 2.3.2.
893 * Improved configure script
895 The `configure' script will now attempt to guess your system type if
896 you don't supply a host system type. The old scheme of supplying a
897 host system triplet is preferable over using this. All the magic is
898 done in the new `config.guess' script. Examine it for details.
900 We have also brought our configure script much more in line with the FSF's
901 version. It now supports the --with-xxx options. In particular,
902 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
903 The resulting GDB will not be able to read arbitrary object file formats --
904 only the format ``expected'' to be used on the configured target system.
905 We hope to make this the default in a future release.
907 * Documentation improvements
909 There's new internal documentation on how to modify GDB, and how to
910 produce clean changes to the code. We implore people to read it
911 before submitting changes.
913 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
914 M4 macros. The new texinfo.tex is provided in this release. Pre-built
915 `info' files are also provided. To build `info' files from scratch,
916 you will need the latest `makeinfo' release, which will be available in
917 a future texinfo-X.Y release.
919 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
920 We're not sure exactly which versions have this problem, but it has
921 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
922 or better. If that isn't possible, there is a patch in
923 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
928 GDB now supports array constants that can be used in expressions typed in by
929 the user. The syntax is `{element, element, ...}'. Ie: you can now type
930 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
933 The new directory `gdb/sparclite' contains a program that demonstrates
934 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
936 * New native hosts supported
938 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
939 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
941 * New targets supported
943 AMD 29k family via UDI a29k-amd-udi or udi29k
945 * New file formats supported
947 BFD now supports reading HP/PA-RISC executables (SOM file format?),
948 HPUX core files, and SCO 3.2v2 core files.
952 Attaching to processes now works again; thanks for the many bug reports.
954 We have also stomped on a bunch of core dumps caused by
955 printf_filtered("%s") problems.
957 We eliminated a copyright problem on the rpc and ptrace header files
958 for VxWorks, which was discovered at the last minute during the 4.7
959 release. You should now be able to build a VxWorks GDB.
961 You can now interrupt gdb while an attached process is running. This
962 will cause the attached process to stop, and give control back to GDB.
964 We fixed problems caused by using too many file descriptors
965 for reading symbols from object files and libraries. This was
966 especially a problem for programs that used many (~100) shared
969 The `step' command now only enters a subroutine if there is line number
970 information for the subroutine. Otherwise it acts like the `next'
971 command. Previously, `step' would enter subroutines if there was
972 any debugging information about the routine. This avoids problems
973 when using `cc -g1' on MIPS machines.
975 * Internal improvements
977 GDB's internal interfaces have been improved to make it easier to support
978 debugging of multiple languages in the future.
980 GDB now uses a common structure for symbol information internally.
981 Minimal symbols (derived from linkage symbols in object files), partial
982 symbols (from a quick scan of debug information), and full symbols
983 contain a common subset of information, making it easier to write
984 shared code that handles any of them.
986 * New command line options
988 We now accept --silent as an alias for --quiet.
992 The memory-mapped-malloc library is now licensed under the GNU Library
993 General Public License.
995 *** Changes in GDB-4.7:
997 * Host/native/target split
999 GDB has had some major internal surgery to untangle the support for
1000 hosts and remote targets. Now, when you configure GDB for a remote
1001 target, it will no longer load in all of the support for debugging
1002 local programs on the host. When fully completed and tested, this will
1003 ensure that arbitrary host/target combinations are possible.
1005 The primary conceptual shift is to separate the non-portable code in
1006 GDB into three categories. Host specific code is required any time GDB
1007 is compiled on that host, regardless of the target. Target specific
1008 code relates to the peculiarities of the target, but can be compiled on
1009 any host. Native specific code is everything else: it can only be
1010 built when the host and target are the same system. Child process
1011 handling and core file support are two common `native' examples.
1013 GDB's use of /proc for controlling Unix child processes is now cleaner.
1014 It has been split out into a single module under the `target_ops' vector,
1015 plus two native-dependent functions for each system that uses /proc.
1017 * New hosts supported
1019 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
1020 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
1021 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
1023 * New targets supported
1025 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
1026 68030 and CPU32 m68030-*-*, m68332-*-*
1028 * New native hosts supported
1030 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
1031 (386bsd is not well tested yet)
1032 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
1034 * New file formats supported
1036 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
1037 supports reading of `a.out.adobe' object files, which are an a.out
1038 format extended with minimal information about multiple sections.
1042 `show copying' is the same as the old `info copying'.
1043 `show warranty' is the same as `info warrantee'.
1044 These were renamed for consistency. The old commands continue to work.
1046 `info handle' is a new alias for `info signals'.
1048 You can now define pre-command hooks, which attach arbitrary command
1049 scripts to any command. The commands in the hook will be executed
1050 prior to the user's command. You can also create a hook which will be
1051 executed whenever the program stops. See gdb.texinfo.
1055 We now deal with Cfront style name mangling, and can even extract type
1056 info from mangled symbols. GDB can automatically figure out which
1057 symbol mangling style your C++ compiler uses.
1059 Calling of methods and virtual functions has been improved as well.
1063 The crash that occured when debugging Sun Ansi-C compiled binaries is
1064 fixed. This was due to mishandling of the extra N_SO stabs output
1067 We also finally got Ultrix 4.2 running in house, and fixed core file
1068 support, with help from a dozen people on the net.
1070 John M. Farrell discovered that the reason that single-stepping was so
1071 slow on all of the Mips based platforms (primarily SGI and DEC) was
1072 that we were trying to demangle and lookup a symbol used for internal
1073 purposes on every instruction that was being stepped through. Changing
1074 the name of that symbol so that it couldn't be mistaken for a C++
1075 mangled symbol sped things up a great deal.
1077 Rich Pixley sped up symbol lookups in general by getting much smarter
1078 about when C++ symbol mangling is necessary. This should make symbol
1079 completion (TAB on the command line) much faster. It's not as fast as
1080 we'd like, but it's significantly faster than gdb-4.6.
1084 A new user controllable variable 'call_scratch_address' can
1085 specify the location of a scratch area to be used when GDB
1086 calls a function in the target. This is necessary because the
1087 usual method of putting the scratch area on the stack does not work
1088 in systems that have separate instruction and data spaces.
1090 We integrated changes to support the 29k UDI (Universal Debugger
1091 Interface), but discovered at the last minute that we didn't have all
1092 of the appropriate copyright paperwork. We are working with AMD to
1093 resolve this, and hope to have it available soon.
1097 We have sped up the remote serial line protocol, especially for targets
1098 with lots of registers. It now supports a new `expedited status' ('T')
1099 message which can be used in place of the existing 'S' status message.
1100 This allows the remote stub to send only the registers that GDB
1101 needs to make a quick decision about single-stepping or conditional
1102 breakpoints, eliminating the need to fetch the entire register set for
1103 each instruction being stepped through.
1105 The GDB remote serial protocol now implements a write-through cache for
1106 registers, only re-reading the registers if the target has run.
1108 There is also a new remote serial stub for SPARC processors. You can
1109 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
1110 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
1111 processor with a serial port.
1115 Configure.in files have become much easier to read and modify. A new
1116 `table driven' format makes it more obvious what configurations are
1117 supported, and what files each one uses.
1121 There is a new opcodes library which will eventually contain all of the
1122 disassembly routines and opcode tables. At present, it only contains
1123 Sparc and Z8000 routines. This will allow the assembler, debugger, and
1124 disassembler (binutils/objdump) to share these routines.
1126 The libiberty library is now copylefted under the GNU Library General
1127 Public License. This allows more liberal use, and was done so libg++
1128 can use it. This makes no difference to GDB, since the Library License
1129 grants all the rights from the General Public License.
1133 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
1134 reference to the stabs symbol info used by the debugger. It is (as far
1135 as we know) the only published document on this fascinating topic. We
1136 encourage you to read it, compare it to the stabs information on your
1137 system, and send improvements on the document in general (to
1138 bug-gdb@prep.ai.mit.edu).
1140 And, of course, many bugs have been fixed.
1143 *** Changes in GDB-4.6:
1145 * Better support for C++ function names
1147 GDB now accepts as input the "demangled form" of C++ overloaded function
1148 names and member function names, and can do command completion on such names
1149 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
1150 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
1151 Make use of command completion, it is your friend.
1153 GDB also now accepts a variety of C++ mangled symbol formats. They are
1154 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
1155 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
1156 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
1157 for the list of formats.
1159 * G++ symbol mangling problem
1161 Recent versions of gcc have a bug in how they emit debugging information for
1162 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
1163 directory) can be applied to gcc to fix the problem. Alternatively, if you
1164 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
1165 usual symptom is difficulty with setting breakpoints on methods. GDB complains
1166 about the method being non-existent. (We believe that version 2.2.2 of GCC has
1169 * New 'maintenance' command
1171 All of the commands related to hacking GDB internals have been moved out of
1172 the main command set, and now live behind the 'maintenance' command. This
1173 can also be abbreviated as 'mt'. The following changes were made:
1175 dump-me -> maintenance dump-me
1176 info all-breakpoints -> maintenance info breakpoints
1177 printmsyms -> maintenance print msyms
1178 printobjfiles -> maintenance print objfiles
1179 printpsyms -> maintenance print psymbols
1180 printsyms -> maintenance print symbols
1182 The following commands are new:
1184 maintenance demangle Call internal GDB demangler routine to
1185 demangle a C++ link name and prints the result.
1186 maintenance print type Print a type chain for a given symbol
1188 * Change to .gdbinit file processing
1190 We now read the $HOME/.gdbinit file before processing the argv arguments
1191 (e.g. reading symbol files or core files). This allows global parameters to
1192 be set, which will apply during the symbol reading. The ./.gdbinit is still
1193 read after argv processing.
1195 * New hosts supported
1197 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
1199 Linux support i386-unknown-linux or linux
1201 We are also including code to support the HP/PA running BSD and HPUX. This
1202 is almost guaranteed not to work, as we didn't have time to test or build it
1203 for this release. We are including it so that the more adventurous (or
1204 masochistic) of you can play with it. We also had major problems with the
1205 fact that the compiler that we got from HP doesn't support the -g option.
1208 * New targets supported
1210 Hitachi H8/300 h8300-hitachi-hms or h8300hms
1212 * More smarts about finding #include files
1214 GDB now remembers the compilation directory for all include files, and for
1215 all files from which C is generated (like yacc and lex sources). This
1216 greatly improves GDB's ability to find yacc/lex sources, and include files,
1217 especially if you are debugging your program from a directory different from
1218 the one that contains your sources.
1220 We also fixed a bug which caused difficulty with listing and setting
1221 breakpoints in include files which contain C code. (In the past, you had to
1222 try twice in order to list an include file that you hadn't looked at before.)
1224 * Interesting infernals change
1226 GDB now deals with arbitrary numbers of sections, where the symbols for each
1227 section must be relocated relative to that section's landing place in the
1228 target's address space. This work was needed to support ELF with embedded
1229 stabs used by Solaris-2.0.
1231 * Bug fixes (of course!)
1233 There have been loads of fixes for the following things:
1234 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
1235 i960, stabs, DOS(GO32), procfs, etc...
1237 See the ChangeLog for details.
1239 *** Changes in GDB-4.5:
1241 * New machines supported (host and target)
1243 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
1245 SGI Irix-4.x mips-sgi-irix4 or iris4
1247 * New malloc package
1249 GDB now uses a new memory manager called mmalloc, based on gmalloc.
1250 Mmalloc is capable of handling mutiple heaps of memory. It is also
1251 capable of saving a heap to a file, and then mapping it back in later.
1252 This can be used to greatly speedup the startup of GDB by using a
1253 pre-parsed symbol table which lives in a mmalloc managed heap. For
1254 more details, please read mmalloc/mmalloc.texi.
1258 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
1259 'help info proc' for details.
1261 * MIPS ecoff symbol table format
1263 The code that reads MIPS symbol table format is now supported on all hosts.
1264 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
1267 * File name changes for MS-DOS
1269 Many files in the config directories have been renamed to make it easier to
1270 support GDB on MS-DOSe systems (which have very restrictive file name
1271 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
1272 environment) is close to working but has some remaining problems. Note
1273 that debugging of DOS programs is not supported, due to limitations
1274 in the ``operating system'', but it can be used to host cross-debugging.
1276 * Cross byte order fixes
1278 Many fixes have been made to support cross debugging of Sparc and MIPS
1279 targets from hosts whose byte order differs.
1281 * New -mapped and -readnow options
1283 If memory-mapped files are available on your system through the 'mmap'
1284 system call, you can use the -mapped option on the `file' or
1285 `symbol-file' commands to cause GDB to write the symbols from your
1286 program into a reusable file. If the program you are debugging is
1287 called `/path/fred', the mapped symbol file will be `./fred.syms'.
1288 Future GDB debugging sessions will notice the presence of this file,
1289 and will quickly map in symbol information from it, rather than reading
1290 the symbol table from the executable program. Using the '-mapped'
1291 option in a GDB `file' or `symbol-file' command has the same effect as
1292 starting GDB with the '-mapped' command-line option.
1294 You can cause GDB to read the entire symbol table immediately by using
1295 the '-readnow' option with any of the commands that load symbol table
1296 information (or on the GDB command line). This makes the command
1297 slower, but makes future operations faster.
1299 The -mapped and -readnow options are typically combined in order to
1300 build a `fred.syms' file that contains complete symbol information.
1301 A simple GDB invocation to do nothing but build a `.syms' file for future
1304 gdb -batch -nx -mapped -readnow programname
1306 The `.syms' file is specific to the host machine on which GDB is run.
1307 It holds an exact image of GDB's internal symbol table. It cannot be
1308 shared across multiple host platforms.
1310 * longjmp() handling
1312 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
1313 siglongjmp() without losing control. This feature has not yet been ported to
1314 all systems. It currently works on many 386 platforms, all MIPS-based
1315 platforms (SGI, DECstation, etc), and Sun3/4.
1319 Preliminary work has been put in to support the new Solaris OS from Sun. At
1320 this time, it can control and debug processes, but it is not capable of
1325 As always, many many bug fixes. The major areas were with g++, and mipsread.
1326 People using the MIPS-based platforms should experience fewer mysterious
1327 crashes and trashed symbol tables.
1329 *** Changes in GDB-4.4:
1331 * New machines supported (host and target)
1333 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
1335 BSD Reno on Vax vax-dec-bsd
1336 Ultrix on Vax vax-dec-ultrix
1338 * New machines supported (target)
1340 AMD 29000 embedded, using EBMON a29k-none-none
1344 GDB continues to improve its handling of C++. `References' work better.
1345 The demangler has also been improved, and now deals with symbols mangled as
1346 per the Annotated C++ Reference Guide.
1348 GDB also now handles `stabs' symbol information embedded in MIPS
1349 `ecoff' symbol tables. Since the ecoff format was not easily
1350 extensible to handle new languages such as C++, this appeared to be a
1351 good way to put C++ debugging info into MIPS binaries. This option
1352 will be supported in the GNU C compiler, version 2, when it is
1355 * New features for SVR4
1357 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
1358 shared libraries. Debugging dynamically linked programs should present
1359 only minor differences from debugging statically linked programs.
1361 The `info proc' command will print out information about any process
1362 on an SVR4 system (including the one you are debugging). At the moment,
1363 it prints the address mappings of the process.
1365 If you bring up GDB on another SVR4 system, please send mail to
1366 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
1368 * Better dynamic linking support in SunOS
1370 Reading symbols from shared libraries which contain debugging symbols
1371 now works properly. However, there remain issues such as automatic
1372 skipping of `transfer vector' code during function calls, which
1373 make it harder to debug code in a shared library, than to debug the
1374 same code linked statically.
1378 GDB is now using the latest `getopt' routines from the FSF. This
1379 version accepts the -- prefix for options with long names. GDB will
1380 continue to accept the old forms (-option and +option) as well.
1381 Various single letter abbreviations for options have been explicity
1382 added to the option table so that they won't get overshadowed in the
1383 future by other options that begin with the same letter.
1387 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
1388 Many assorted bugs have been handled. Many more remain to be handled.
1389 See the various ChangeLog files (primarily in gdb and bfd) for details.
1392 *** Changes in GDB-4.3:
1394 * New machines supported (host and target)
1396 Amiga 3000 running Amix m68k-cbm-svr4 or amix
1397 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
1398 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
1400 * Almost SCO Unix support
1402 We had hoped to support:
1403 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
1404 (except for core file support), but we discovered very late in the release
1405 that it has problems with process groups that render gdb unusable. Sorry
1406 about that. I encourage people to fix it and post the fixes.
1408 * Preliminary ELF and DWARF support
1410 GDB can read ELF object files on System V Release 4, and can handle
1411 debugging records for C, in DWARF format, in ELF files. This support
1412 is preliminary. If you bring up GDB on another SVR4 system, please
1413 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
1418 GDB now uses the latest `readline' library. One user-visible change
1419 is that two tabs will list possible command completions, which previously
1420 required typing M-? (meta-question mark, or ESC ?).
1424 The `stepi' bug that many of you noticed has been squashed.
1425 Many bugs in C++ have been handled. Many more remain to be handled.
1426 See the various ChangeLog files (primarily in gdb and bfd) for details.
1428 * State of the MIPS world (in case you wondered):
1430 GDB can understand the symbol tables emitted by the compilers
1431 supplied by most vendors of MIPS-based machines, including DEC. These
1432 symbol tables are in a format that essentially nobody else uses.
1434 Some versions of gcc come with an assembler post-processor called
1435 mips-tfile. This program is required if you want to do source-level
1436 debugging of gcc-compiled programs. I believe FSF does not ship
1437 mips-tfile with gcc version 1, but it will eventually come with gcc
1440 Debugging of g++ output remains a problem. g++ version 1.xx does not
1441 really support it at all. (If you're lucky, you should be able to get
1442 line numbers and stack traces to work, but no parameters or local
1443 variables.) With some work it should be possible to improve the
1446 When gcc version 2 is released, you will have somewhat better luck.
1447 However, even then you will get confusing results for inheritance and
1450 We will eventually provide full debugging of g++ output on
1451 DECstations. This will probably involve some kind of stabs-in-ecoff
1452 encapulation, but the details have not been worked out yet.
1455 *** Changes in GDB-4.2:
1457 * Improved configuration
1459 Only one copy of `configure' exists now, and it is not self-modifying.
1460 Porting BFD is simpler.
1464 The `step' and `next' commands now only stop at the first instruction
1465 of a source line. This prevents the multiple stops that used to occur
1466 in switch statements, for-loops, etc. `Step' continues to stop if a
1467 function that has debugging information is called within the line.
1471 Lots of small bugs fixed. More remain.
1473 * New host supported (not target)
1475 Intel 386 PC clone running Mach i386-none-mach
1478 *** Changes in GDB-4.1:
1480 * Multiple source language support
1482 GDB now has internal scaffolding to handle several source languages.
1483 It determines the type of each source file from its filename extension,
1484 and will switch expression parsing and number formatting to match the
1485 language of the function in the currently selected stack frame.
1486 You can also specifically set the language to be used, with
1487 `set language c' or `set language modula-2'.
1491 GDB now has preliminary support for the GNU Modula-2 compiler,
1492 currently under development at the State University of New York at
1493 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
1494 continue through the fall of 1991 and into 1992.
1496 Other Modula-2 compilers are currently not supported, and attempting to
1497 debug programs compiled with them will likely result in an error as the
1498 symbol table is read. Feel free to work on it, though!
1500 There are hooks in GDB for strict type checking and range checking,
1501 in the `Modula-2 philosophy', but they do not currently work.
1505 GDB can now write to executable and core files (e.g. patch
1506 a variable's value). You must turn this switch on, specify
1507 the file ("exec foo" or "core foo"), *then* modify it, e.g.
1508 by assigning a new value to a variable. Modifications take
1511 * Automatic SunOS shared library reading
1513 When you run your program, GDB automatically determines where its
1514 shared libraries (if any) have been loaded, and reads their symbols.
1515 The `share' command is no longer needed. This also works when
1516 examining core files.
1520 You can specify the number of lines that the `list' command shows.
1523 * New machines supported (host and target)
1525 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
1526 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
1527 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
1529 * New hosts supported (not targets)
1531 IBM RT/PC: romp-ibm-aix or rtpc
1533 * New targets supported (not hosts)
1535 AMD 29000 embedded with COFF a29k-none-coff
1536 AMD 29000 embedded with a.out a29k-none-aout
1537 Ultracomputer remote kernel debug a29k-nyu-kern
1539 * New remote interfaces
1545 *** Changes in GDB-4.0:
1549 Wide output is wrapped at good places to make the output more readable.
1551 Gdb now supports cross-debugging from a host machine of one type to a
1552 target machine of another type. Communication with the target system
1553 is over serial lines. The ``target'' command handles connecting to the
1554 remote system; the ``load'' command will download a program into the
1555 remote system. Serial stubs for the m68k and i386 are provided. Gdb
1556 also supports debugging of realtime processes running under VxWorks,
1557 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
1558 stub on the target system.
1560 New CPUs supported include the AMD 29000 and Intel 960.
1562 GDB now reads object files and symbol tables via a ``binary file''
1563 library, which allows a single copy of GDB to debug programs of multiple
1564 object file types such as a.out and coff.
1566 There is now a GDB reference card in "doc/refcard.tex". (Make targets
1567 refcard.dvi and refcard.ps are available to format it).
1570 * Control-Variable user interface simplified
1572 All variables that control the operation of the debugger can be set
1573 by the ``set'' command, and displayed by the ``show'' command.
1575 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
1576 ``Show prompt'' produces the response:
1577 Gdb's prompt is new-gdb=>.
1579 What follows are the NEW set commands. The command ``help set'' will
1580 print a complete list of old and new set commands. ``help set FOO''
1581 will give a longer description of the variable FOO. ``show'' will show
1582 all of the variable descriptions and their current settings.
1584 confirm on/off: Enables warning questions for operations that are
1585 hard to recover from, e.g. rerunning the program while
1586 it is already running. Default is ON.
1588 editing on/off: Enables EMACS style command line editing
1589 of input. Previous lines can be recalled with
1590 control-P, the current line can be edited with control-B,
1591 you can search for commands with control-R, etc.
1594 history filename NAME: NAME is where the gdb command history
1595 will be stored. The default is .gdb_history,
1596 or the value of the environment variable
1599 history size N: The size, in commands, of the command history. The
1600 default is 256, or the value of the environment variable
1603 history save on/off: If this value is set to ON, the history file will
1604 be saved after exiting gdb. If set to OFF, the
1605 file will not be saved. The default is OFF.
1607 history expansion on/off: If this value is set to ON, then csh-like
1608 history expansion will be performed on
1609 command line input. The default is OFF.
1611 radix N: Sets the default radix for input and output. It can be set
1612 to 8, 10, or 16. Note that the argument to "radix" is interpreted
1613 in the current radix, so "set radix 10" is always a no-op.
1615 height N: This integer value is the number of lines on a page. Default
1616 is 24, the current `stty rows'' setting, or the ``li#''
1617 setting from the termcap entry matching the environment
1620 width N: This integer value is the number of characters on a line.
1621 Default is 80, the current `stty cols'' setting, or the ``co#''
1622 setting from the termcap entry matching the environment
1625 Note: ``set screensize'' is obsolete. Use ``set height'' and
1626 ``set width'' instead.
1628 print address on/off: Print memory addresses in various command displays,
1629 such as stack traces and structure values. Gdb looks
1630 more ``symbolic'' if you turn this off; it looks more
1631 ``machine level'' with it on. Default is ON.
1633 print array on/off: Prettyprint arrays. New convenient format! Default
1636 print demangle on/off: Print C++ symbols in "source" form if on,
1639 print asm-demangle on/off: Same, for assembler level printouts
1642 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
1645 * Support for Epoch Environment.
1647 The epoch environment is a version of Emacs v18 with windowing. One
1648 new command, ``inspect'', is identical to ``print'', except that if you
1649 are running in the epoch environment, the value is printed in its own
1653 * Support for Shared Libraries
1655 GDB can now debug programs and core files that use SunOS shared libraries.
1656 Symbols from a shared library cannot be referenced
1657 before the shared library has been linked with the program (this
1658 happens after you type ``run'' and before the function main() is entered).
1659 At any time after this linking (including when examining core files
1660 from dynamically linked programs), gdb reads the symbols from each
1661 shared library when you type the ``sharedlibrary'' command.
1662 It can be abbreviated ``share''.
1664 sharedlibrary REGEXP: Load shared object library symbols for files
1665 matching a unix regular expression. No argument
1666 indicates to load symbols for all shared libraries.
1668 info sharedlibrary: Status of loaded shared libraries.
1673 A watchpoint stops execution of a program whenever the value of an
1674 expression changes. Checking for this slows down execution
1675 tremendously whenever you are in the scope of the expression, but is
1676 quite useful for catching tough ``bit-spreader'' or pointer misuse
1677 problems. Some machines such as the 386 have hardware for doing this
1678 more quickly, and future versions of gdb will use this hardware.
1680 watch EXP: Set a watchpoint (breakpoint) for an expression.
1682 info watchpoints: Information about your watchpoints.
1684 delete N: Deletes watchpoint number N (same as breakpoints).
1685 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
1686 enable N: Re-enables watchpoint number N (same as breakpoints).
1689 * C++ multiple inheritance
1691 When used with a GCC version 2 compiler, GDB supports multiple inheritance
1694 * C++ exception handling
1696 Gdb now supports limited C++ exception handling. Besides the existing
1697 ability to breakpoint on an exception handler, gdb can breakpoint on
1698 the raising of an exception (before the stack is peeled back to the
1701 catch FOO: If there is a FOO exception handler in the dynamic scope,
1702 set a breakpoint to catch exceptions which may be raised there.
1703 Multiple exceptions (``catch foo bar baz'') may be caught.
1705 info catch: Lists all exceptions which may be caught in the
1706 current stack frame.
1709 * Minor command changes
1711 The command ``call func (arg, arg, ...)'' now acts like the print
1712 command, except it does not print or save a value if the function's result
1713 is void. This is similar to dbx usage.
1715 The ``up'' and ``down'' commands now always print the frame they end up
1716 at; ``up-silently'' and `down-silently'' can be used in scripts to change
1717 frames without printing.
1719 * New directory command
1721 'dir' now adds directories to the FRONT of the source search path.
1722 The path starts off empty. Source files that contain debug information
1723 about the directory in which they were compiled can be found even
1724 with an empty path; Sun CC and GCC include this information. If GDB can't
1725 find your source file in the current directory, type "dir .".
1727 * Configuring GDB for compilation
1729 For normal use, type ``./configure host''. See README or gdb.texinfo
1732 GDB now handles cross debugging. If you are remotely debugging between
1733 two different machines, type ``./configure host -target=targ''.
1734 Host is the machine where GDB will run; targ is the machine
1735 where the program that you are debugging will run.
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