1 What has changed in GDB?
2 (Organized release by release)
4 *** Changes in GDB 5.0:
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 Configurations that have been declared obsolete will be commented out,
71 but the code will be left in place. If there is no activity to revive
72 these configurations before the next release of GDB, the sources will
73 be permanently REMOVED.
75 * Gould support removed
77 Support for the Gould PowerNode and NP1 has been removed.
79 * New features for SVR4
81 On SVR4 native platforms (such as Solaris), if you attach to a process
82 without first loading a symbol file, GDB will now attempt to locate and
83 load symbols from the running process's executable file.
85 * Many C++ enhancements
87 C++ support has been greatly improved. Overload resolution now works properly
88 in almost all cases. RTTI support is on the way.
90 * Remote targets can connect to a sub-program
92 A popen(3) style serial-device has been added. This device starts a
93 sub-process (such as a stand-alone simulator) and then communicates
94 with that. The sub-program to run is specified using the syntax
95 ``|<program> <args>'' vis:
97 (gdb) set remotedebug 1
98 (gdb) target extended-remote |mn10300-elf-sim program-args
100 * MIPS 64 remote protocol
102 A long standing bug in the mips64 remote protocol where by GDB
103 expected certain 32 bit registers (ex SR) to be transfered as 32
104 instead of 64 bits has been fixed.
106 The command ``set remote-mips64-transfers-32bit-regs on'' has been
107 added to provide backward compatibility with older versions of GDB.
109 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
111 The command ``set remotebinarydownload'' command has been replaced by
112 ``set remote X-packet''. Other commands in ``set remote'' family
113 include ``set remote P-packet''.
115 * Breakpoint commands accept ranges.
117 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
118 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
119 ``tracepoint passcount'' also accepts a range of tracepoints.
121 * ``apropos'' command added.
123 The ``apropos'' command searches through command names and
124 documentation strings, printing out matches, making it much easier to
125 try to find a command that does what you are looking for.
129 A new machine oriented interface (MI) has been added to GDB. This
130 interface is designed for debug environments running GDB as a separate
131 process. This is part of the long term libGDB project. See the
132 "GDB/MI" chapter of the GDB manual for further information. It can be
133 enabled by configuring with:
135 .../configure --enable-gdbmi
137 *** Changes in GDB-4.18:
139 * New native configurations
141 HP-UX 10.20 hppa*-*-hpux10.20
142 HP-UX 11.x hppa*-*-hpux11.0*
143 M68K Linux m68*-*-linux*
147 Fujitsu FR30 fr30-*-elf*
148 Intel StrongARM strongarm-*-*
149 Mitsubishi D30V d30v-*-*
151 * OBSOLETE configurations
153 Gould PowerNode, NP1 np1-*-*, pn-*-*
155 Configurations that have been declared obsolete will be commented out,
156 but the code will be left in place. If there is no activity to revive
157 these configurations before the next release of GDB, the sources will
158 be permanently REMOVED.
162 As a compatibility experiment, GDB's source files buildsym.h and
163 buildsym.c have been converted to pure standard C, no longer
164 containing any K&R compatibility code. We believe that all systems in
165 use today either come with a standard C compiler, or have a GCC port
166 available. If this is not true, please report the affected
167 configuration to bug-gdb@gnu.org immediately. See the README file for
168 information about getting a standard C compiler if you don't have one
173 GDB now uses readline 2.2.
175 * set extension-language
177 You can now control the mapping between filename extensions and source
178 languages by using the `set extension-language' command. For instance,
179 you can ask GDB to treat .c files as C++ by saying
180 set extension-language .c c++
181 The command `info extensions' lists all of the recognized extensions
182 and their associated languages.
184 * Setting processor type for PowerPC and RS/6000
186 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
187 you can use the `set processor' command to specify what variant of the
188 PowerPC family you are debugging. The command
192 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
193 following PowerPC and RS6000 variants:
195 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
196 rs6000 IBM RS6000 ("POWER") architecture, user-level view
198 403GC IBM PowerPC 403GC
199 505 Motorola PowerPC 505
200 860 Motorola PowerPC 860 or 850
201 601 Motorola PowerPC 601
202 602 Motorola PowerPC 602
203 603 Motorola/IBM PowerPC 603 or 603e
204 604 Motorola PowerPC 604 or 604e
205 750 Motorola/IBM PowerPC 750 or 750
207 At the moment, this command just tells GDB what to name the
208 special-purpose processor registers. Since almost all the affected
209 registers are inaccessible to user-level programs, this command is
210 only useful for remote debugging in its present form.
214 Thanks to a major code donation from Hewlett-Packard, GDB now has much
215 more extensive support for HP-UX. Added features include shared
216 library support, kernel threads and hardware watchpoints for 11.00,
217 support for HP's ANSI C and C++ compilers, and a compatibility mode
218 for xdb and dbx commands.
222 HP's donation includes the new concept of catchpoints, which is a
223 generalization of the old catch command. On HP-UX, it is now possible
224 to catch exec, fork, and vfork, as well as library loading.
226 This means that the existing catch command has changed; its first
227 argument now specifies the type of catch to be set up. See the
228 output of "help catch" for a list of catchpoint types.
230 * Debugging across forks
232 On HP-UX, you can choose which process to debug when a fork() happens
237 HP has donated a curses-based terminal user interface (TUI). To get
238 it, build with --enable-tui. Although this can be enabled for any
239 configuration, at present it only works for native HP debugging.
241 * GDB remote protocol additions
243 A new protocol packet 'X' that writes binary data is now available.
244 Default behavior is to try 'X', then drop back to 'M' if the stub
245 fails to respond. The settable variable `remotebinarydownload'
246 allows explicit control over the use of 'X'.
248 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
249 full 64-bit address. The command
251 set remoteaddresssize 32
253 can be used to revert to the old behaviour. For existing remote stubs
254 the change should not be noticed, as the additional address information
257 In order to assist in debugging stubs, you may use the maintenance
258 command `packet' to send any text string to the stub. For instance,
260 maint packet heythere
262 sends the packet "$heythere#<checksum>". Note that it is very easy to
263 disrupt a debugging session by sending the wrong packet at the wrong
266 The compare-sections command allows you to compare section data on the
267 target to what is in the executable file without uploading or
268 downloading, by comparing CRC checksums.
270 * Tracing can collect general expressions
272 You may now collect general expressions at tracepoints. This requires
273 further additions to the target-side stub; see tracepoint.c and
274 doc/agentexpr.texi for further details.
276 * mask-address variable for Mips
278 For Mips targets, you may control the zeroing of the upper 32 bits of
279 a 64-bit address by entering `set mask-address on'. This is mainly
280 of interest to users of embedded R4xxx and R5xxx processors.
282 * Higher serial baud rates
284 GDB's serial code now allows you to specify baud rates 57600, 115200,
285 230400, and 460800 baud. (Note that your host system may not be able
286 to achieve all of these rates.)
290 The i960 configuration now includes an initial implementation of a
291 builtin simulator, contributed by Jim Wilson.
294 *** Changes in GDB-4.17:
296 * New native configurations
298 Alpha GNU/Linux alpha*-*-linux*
299 Unixware 2.x i[3456]86-unixware2*
300 Irix 6.x mips*-sgi-irix6*
301 PowerPC GNU/Linux powerpc-*-linux*
302 PowerPC Solaris powerpcle-*-solaris*
303 Sparc GNU/Linux sparc-*-linux*
304 Motorola sysV68 R3V7.1 m68k-motorola-sysv
308 Argonaut Risc Chip (ARC) arc-*-*
309 Hitachi H8/300S h8300*-*-*
310 Matsushita MN10200 w/simulator mn10200-*-*
311 Matsushita MN10300 w/simulator mn10300-*-*
312 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
313 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
314 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
315 Mitsubishi D10V w/simulator d10v-*-*
316 Mitsubishi M32R/D w/simulator m32r-*-elf*
317 Tsqware Sparclet sparclet-*-*
318 NEC V850 w/simulator v850-*-*
320 * New debugging protocols
322 ARM with RDI protocol arm*-*-*
323 M68K with dBUG monitor m68*-*-{aout,coff,elf}
324 DDB and LSI variants of PMON protocol mips*-*-*
325 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
326 PowerPC with SDS protocol powerpc{,le}-*-eabi
327 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
331 All configurations can now understand and use the DWARF 2 debugging
332 format. The choice is automatic, if the symbol file contains DWARF 2
337 GDB now includes basic Java language support. This support is
338 only useful with Java compilers that produce native machine code.
340 * solib-absolute-prefix and solib-search-path
342 For SunOS and SVR4 shared libraries, you may now set the prefix for
343 loading absolute shared library symbol files, and the search path for
344 locating non-absolute shared library symbol files.
346 * Live range splitting
348 GDB can now effectively debug code for which GCC has performed live
349 range splitting as part of its optimization. See gdb/doc/LRS for
350 more details on the expected format of the stabs information.
354 GDB's support for the GNU Hurd, including thread debugging, has been
355 updated to work with current versions of the Hurd.
359 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
360 instruction set. ARM GDB automatically detects when Thumb
361 instructions are in use, and adjusts disassembly and backtracing
366 GDB's MIPS target configurations now handle the MIP16 16-bit
371 GDB now includes support for overlays; if an executable has been
372 linked such that multiple sections are based at the same address, GDB
373 will decide which section to use for symbolic info. You can choose to
374 control the decision manually, using overlay commands, or implement
375 additional target-side support and use "overlay load-target" to bring
376 in the overlay mapping. Do "help overlay" for more detail.
380 The command "info symbol <address>" displays information about
381 the symbol at the specified address.
385 The standard remote protocol now includes an extension that allows
386 asynchronous collection and display of trace data. This requires
387 extensive support in the target-side debugging stub. Tracing mode
388 includes a new interaction mode in GDB and new commands: see the
389 file tracepoint.c for more details.
393 Configurations for embedded MIPS now include a simulator contributed
394 by Cygnus Solutions. The simulator supports the instruction sets
395 of most MIPS variants.
399 Sparc configurations may now include the ERC32 simulator contributed
400 by the European Space Agency. The simulator is not built into
401 Sparc targets by default; configure with --enable-sim to include it.
405 For target configurations that may include multiple variants of a
406 basic architecture (such as MIPS and SH), you may now set the
407 architecture explicitly. "set arch" sets, "info arch" lists
408 the possible architectures.
410 *** Changes in GDB-4.16:
412 * New native configurations
414 Windows 95, x86 Windows NT i[345]86-*-cygwin32
415 M68K NetBSD m68k-*-netbsd*
416 PowerPC AIX 4.x powerpc-*-aix*
417 PowerPC MacOS powerpc-*-macos*
418 PowerPC Windows NT powerpcle-*-cygwin32
419 RS/6000 AIX 4.x rs6000-*-aix4*
423 ARM with RDP protocol arm-*-*
424 I960 with MON960 i960-*-coff
425 MIPS VxWorks mips*-*-vxworks*
426 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
427 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
429 Matra Sparclet sparclet-*-*
433 The powerpc-eabi configuration now includes the PSIM simulator,
434 contributed by Andrew Cagney, with assistance from Mike Meissner.
435 PSIM is a very elaborate model of the PowerPC, including not only
436 basic instruction set execution, but also details of execution unit
437 performance and I/O hardware. See sim/ppc/README for more details.
441 GDB now works with Solaris 2.5.
443 * Windows 95/NT native
445 GDB will now work as a native debugger on Windows 95 and Windows NT.
446 To build it from source, you must use the "gnu-win32" environment,
447 which uses a DLL to emulate enough of Unix to run the GNU tools.
448 Further information, binaries, and sources are available at
449 ftp.cygnus.com, under pub/gnu-win32.
451 * dont-repeat command
453 If a user-defined command includes the command `dont-repeat', then the
454 command will not be repeated if the user just types return. This is
455 useful if the command is time-consuming to run, so that accidental
456 extra keystrokes don't run the same command many times.
458 * Send break instead of ^C
460 The standard remote protocol now includes an option to send a break
461 rather than a ^C to the target in order to interrupt it. By default,
462 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
464 * Remote protocol timeout
466 The standard remote protocol includes a new variable `remotetimeout'
467 that allows you to set the number of seconds before GDB gives up trying
468 to read from the target. The default value is 2.
470 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
472 By default GDB will automatically keep track of objects as they are
473 loaded and unloaded by the dynamic linker. By using the command `set
474 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
475 when shared library events occur, thus allowing you to set breakpoints
476 in shared libraries which are explicitly loaded by the inferior.
478 Note this feature does not work on hpux8. On hpux9 you must link
479 /usr/lib/end.o into your program. This feature should work
480 automatically on hpux10.
482 * Irix 5.x hardware watchpoint support
484 Irix 5 configurations now support the use of hardware watchpoints.
486 * Mips protocol "SYN garbage limit"
488 When debugging a Mips target using the `target mips' protocol, you
489 may set the number of characters that GDB will ignore by setting
490 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
491 every character. The default value is 1050.
493 * Recording and replaying remote debug sessions
495 If you set `remotelogfile' to the name of a file, gdb will write to it
496 a recording of a remote debug session. This recording may then be
497 replayed back to gdb using "gdbreplay". See gdbserver/README for
498 details. This is useful when you have a problem with GDB while doing
499 remote debugging; you can make a recording of the session and send it
500 to someone else, who can then recreate the problem.
502 * Speedups for remote debugging
504 GDB includes speedups for downloading and stepping MIPS systems using
505 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
506 and more efficient S-record downloading.
508 * Memory use reductions and statistics collection
510 GDB now uses less memory and reports statistics about memory usage.
511 Try the `maint print statistics' command, for example.
513 *** Changes in GDB-4.15:
517 The symbol reader for AIX GDB now uses partial symbol tables. This
518 can greatly improve startup time, especially for large executables.
520 * Remote targets use caching
522 Remote targets now use a data cache to speed up communication with the
523 remote side. The data cache could lead to incorrect results because
524 it doesn't know about volatile variables, thus making it impossible to
525 debug targets which use memory mapped I/O devices. `set remotecache
526 off' turns the the data cache off.
528 * Remote targets may have threads
530 The standard remote protocol now includes support for multiple threads
531 in the target system, using new protocol commands 'H' and 'T'. See
532 gdb/remote.c for details.
536 If GDB is configured with `--enable-netrom', then it will include
537 support for the NetROM ROM emulator from XLNT Designs. The NetROM
538 acts as though it is a bank of ROM on the target board, but you can
539 write into it over the network. GDB's support consists only of
540 support for fast loading into the emulated ROM; to debug, you must use
541 another protocol, such as standard remote protocol. The usual
542 sequence is something like
544 target nrom <netrom-hostname>
546 target remote <netrom-hostname>:1235
550 GDB now includes support for the Apple Macintosh, as a host only. It
551 may be run as either an MPW tool or as a standalone application, and
552 it can debug through the serial port. All the usual GDB commands are
553 available, but to the target command, you must supply "serial" as the
554 device type instead of "/dev/ttyXX". See mpw-README in the main
555 directory for more information on how to build. The MPW configuration
556 scripts */mpw-config.in support only a few targets, and only the
557 mips-idt-ecoff target has been tested.
561 GDB configuration now uses autoconf. This is not user-visible,
562 but does simplify configuration and building.
566 GDB now supports hpux10.
568 *** Changes in GDB-4.14:
570 * New native configurations
572 x86 FreeBSD i[345]86-*-freebsd
573 x86 NetBSD i[345]86-*-netbsd
574 NS32k NetBSD ns32k-*-netbsd
575 Sparc NetBSD sparc-*-netbsd
579 A29K VxWorks a29k-*-vxworks
580 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
581 CPU32 EST-300 emulator m68*-*-est*
582 PowerPC ELF powerpc-*-elf
585 * Alpha OSF/1 support for procfs
587 GDB now supports procfs under OSF/1-2.x and higher, which makes it
588 possible to attach to running processes. As the mounting of the /proc
589 filesystem is optional on the Alpha, GDB automatically determines
590 the availability of /proc during startup. This can lead to problems
591 if /proc is unmounted after GDB has been started.
593 * Arguments to user-defined commands
595 User commands may accept up to 10 arguments separated by whitespace.
596 Arguments are accessed within the user command via $arg0..$arg9. A
599 print $arg0 + $arg1 + $arg2
601 To execute the command use:
604 Defines the command "adder" which prints the sum of its three arguments.
605 Note the arguments are text substitutions, so they may reference variables,
606 use complex expressions, or even perform inferior function calls.
608 * New `if' and `while' commands
610 This makes it possible to write more sophisticated user-defined
611 commands. Both commands take a single argument, which is the
612 expression to evaluate, and must be followed by the commands to
613 execute, one per line, if the expression is nonzero, the list being
614 terminated by the word `end'. The `if' command list may include an
615 `else' word, which causes the following commands to be executed only
616 if the expression is zero.
618 * Fortran source language mode
620 GDB now includes partial support for Fortran 77. It will recognize
621 Fortran programs and can evaluate a subset of Fortran expressions, but
622 variables and functions may not be handled correctly. GDB will work
623 with G77, but does not yet know much about symbols emitted by other
626 * Better HPUX support
628 Most debugging facilities now work on dynamic executables for HPPAs
629 running hpux9 or later. You can attach to running dynamically linked
630 processes, but by default the dynamic libraries will be read-only, so
631 for instance you won't be able to put breakpoints in them. To change
632 that behavior do the following before running the program:
638 This will cause the libraries to be mapped private and read-write.
639 To revert to the normal behavior, do this:
645 You cannot set breakpoints or examine data in the library until after
646 the library is loaded if the function/data symbols do not have
649 GDB can now also read debug symbols produced by the HP C compiler on
650 HPPAs (sorry, no C++, Fortran or 68k support).
652 * Target byte order now dynamically selectable
654 You can choose which byte order to use with a target system, via the
655 commands "set endian big" and "set endian little", and you can see the
656 current setting by using "show endian". You can also give the command
657 "set endian auto", in which case GDB will use the byte order
658 associated with the executable. Currently, only embedded MIPS
659 configurations support dynamic selection of target byte order.
661 * New DOS host serial code
663 This version uses DPMI interrupts to handle buffered I/O, so you
664 no longer need to run asynctsr when debugging boards connected to
667 *** Changes in GDB-4.13:
669 * New "complete" command
671 This lists all the possible completions for the rest of the line, if it
672 were to be given as a command itself. This is intended for use by emacs.
674 * Trailing space optional in prompt
676 "set prompt" no longer adds a space for you after the prompt you set. This
677 allows you to set a prompt which ends in a space or one that does not.
679 * Breakpoint hit counts
681 "info break" now displays a count of the number of times the breakpoint
682 has been hit. This is especially useful in conjunction with "ignore"; you
683 can ignore a large number of breakpoint hits, look at the breakpoint info
684 to see how many times the breakpoint was hit, then run again, ignoring one
685 less than that number, and this will get you quickly to the last hit of
688 * Ability to stop printing at NULL character
690 "set print null-stop" will cause GDB to stop printing the characters of
691 an array when the first NULL is encountered. This is useful when large
692 arrays actually contain only short strings.
694 * Shared library breakpoints
696 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
697 breakpoints in shared libraries before the executable is run.
699 * Hardware watchpoints
701 There is a new hardware breakpoint for the watch command for sparclite
702 targets. See gdb/sparclite/hw_breakpoint.note.
704 Hardware watchpoints are also now supported under Linux.
708 Annotations have been added. These are for use with graphical interfaces,
709 and are still experimental. Currently only gdba.el uses these.
711 * Improved Irix 5 support
713 GDB now works properly with Irix 5.2.
715 * Improved HPPA support
717 GDB now works properly with the latest GCC and GAS.
719 * New native configurations
721 Sequent PTX4 i[34]86-sequent-ptx4
722 HPPA running OSF/1 hppa*-*-osf*
723 Atari TT running SVR4 m68*-*-sysv4*
724 RS/6000 LynxOS rs6000-*-lynxos*
728 OS/9000 i[34]86-*-os9k
729 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
732 * Hitachi SH7000 and E7000-PC ICE support
734 There is now support for communicating with the Hitachi E7000-PC ICE.
735 This is available automatically when GDB is configured for the SH.
739 As usual, a variety of small fixes and improvements, both generic
740 and configuration-specific. See the ChangeLog for more detail.
742 *** Changes in GDB-4.12:
744 * Irix 5 is now supported
748 GDB-4.12 on the HPPA has a number of changes which make it unable
749 to debug the output from the currently released versions of GCC and
750 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
751 of GCC and GAS, versions of these tools designed to work with GDB-4.12
752 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
755 *** Changes in GDB-4.11:
757 * User visible changes:
761 The "set remotedebug" option is now consistent between the mips remote
762 target, remote targets using the gdb-specific protocol, UDI (AMD's
763 debug protocol for the 29k) and the 88k bug monitor. It is now an
764 integer specifying a debug level (normally 0 or 1, but 2 means more
765 debugging info for the mips target).
767 * DEC Alpha native support
769 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
770 debug info, but GDB works fairly well with the DEC compiler and should
771 work with a future GCC release. See the README file for a few
772 Alpha-specific notes.
774 * Preliminary thread implementation
776 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
778 * LynxOS native and target support for 386
780 This release has been hosted on LynxOS 2.2, and also can be configured
781 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
784 * Improvements in C++ mangling/demangling.
786 This release has much better g++ debugging, specifically in name
787 mangling/demangling, virtual function calls, print virtual table,
788 call methods, ...etc.
790 *** Changes in GDB-4.10:
792 * User visible changes:
794 Remote debugging using the GDB-specific (`target remote') protocol now
795 supports the `load' command. This is only useful if you have some
796 other way of getting the stub to the target system, and you can put it
797 somewhere in memory where it won't get clobbered by the download.
799 Filename completion now works.
801 When run under emacs mode, the "info line" command now causes the
802 arrow to point to the line specified. Also, "info line" prints
803 addresses in symbolic form (as well as hex).
805 All vxworks based targets now support a user settable option, called
806 vxworks-timeout. This option represents the number of seconds gdb
807 should wait for responses to rpc's. You might want to use this if
808 your vxworks target is, perhaps, a slow software simulator or happens
809 to be on the far side of a thin network line.
813 This release contains support for using a DEC alpha as a GDB host for
814 cross debugging. Native alpha debugging is not supported yet.
817 *** Changes in GDB-4.9:
821 This is the first GDB release which is accompanied by a matching testsuite.
822 The testsuite requires installation of dejagnu, which should be available
823 via ftp from most sites that carry GNU software.
827 'Cfront' style demangling has had its name changed to 'ARM' style, to
828 emphasize that it was written from the specifications in the C++ Annotated
829 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
830 disclaimers, it still generated too much confusion with users attempting to
831 use gdb with AT&T cfront.
835 GDB now uses a standard remote interface to a simulator library.
836 So far, the library contains simulators for the Zilog Z8001/2, the
837 Hitachi H8/300, H8/500 and Super-H.
839 * New targets supported
841 H8/300 simulator h8300-hitachi-hms or h8300hms
842 H8/500 simulator h8500-hitachi-hms or h8500hms
843 SH simulator sh-hitachi-hms or sh
844 Z8000 simulator z8k-zilog-none or z8ksim
845 IDT MIPS board over serial line mips-idt-ecoff
847 Cross-debugging to GO32 targets is supported. It requires a custom
848 version of the i386-stub.c module which is integrated with the
849 GO32 memory extender.
851 * New remote protocols
853 MIPS remote debugging protocol.
855 * New source languages supported
857 This version includes preliminary support for Chill, a Pascal like language
858 used by telecommunications companies. Chill support is also being integrated
859 into the GNU compiler, but we don't know when it will be publically available.
862 *** Changes in GDB-4.8:
864 * HP Precision Architecture supported
866 GDB now supports HP PA-RISC machines running HPUX. A preliminary
867 version of this support was available as a set of patches from the
868 University of Utah. GDB does not support debugging of programs
869 compiled with the HP compiler, because HP will not document their file
870 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
871 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
873 Many problems in the preliminary version have been fixed.
875 * Faster and better demangling
877 We have improved template demangling and fixed numerous bugs in the GNU style
878 demangler. It can now handle type modifiers such as `static' or `const'. Wide
879 character types (wchar_t) are now supported. Demangling of each symbol is now
880 only done once, and is cached when the symbol table for a file is read in.
881 This results in a small increase in memory usage for C programs, a moderate
882 increase in memory usage for C++ programs, and a fantastic speedup in
885 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
886 from the specifications in the Annotated Reference Manual, which AT&T's
887 compiler does not actually implement.
889 * G++ multiple inheritance compiler problem
891 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
892 inheritance lattices was reworked to properly discover ambiguities. We
893 recently found an example which causes this new algorithm to fail in a
894 very subtle way, producing bad debug information for those classes.
895 The file 'gcc.patch' (in this directory) can be applied to gcc to
896 circumvent the problem. A future GCC release will contain a complete
899 The previous G++ debug info problem (mentioned below for the gdb-4.7
900 release) is fixed in gcc version 2.3.2.
902 * Improved configure script
904 The `configure' script will now attempt to guess your system type if
905 you don't supply a host system type. The old scheme of supplying a
906 host system triplet is preferable over using this. All the magic is
907 done in the new `config.guess' script. Examine it for details.
909 We have also brought our configure script much more in line with the FSF's
910 version. It now supports the --with-xxx options. In particular,
911 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
912 The resulting GDB will not be able to read arbitrary object file formats --
913 only the format ``expected'' to be used on the configured target system.
914 We hope to make this the default in a future release.
916 * Documentation improvements
918 There's new internal documentation on how to modify GDB, and how to
919 produce clean changes to the code. We implore people to read it
920 before submitting changes.
922 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
923 M4 macros. The new texinfo.tex is provided in this release. Pre-built
924 `info' files are also provided. To build `info' files from scratch,
925 you will need the latest `makeinfo' release, which will be available in
926 a future texinfo-X.Y release.
928 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
929 We're not sure exactly which versions have this problem, but it has
930 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
931 or better. If that isn't possible, there is a patch in
932 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
937 GDB now supports array constants that can be used in expressions typed in by
938 the user. The syntax is `{element, element, ...}'. Ie: you can now type
939 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
942 The new directory `gdb/sparclite' contains a program that demonstrates
943 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
945 * New native hosts supported
947 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
948 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
950 * New targets supported
952 AMD 29k family via UDI a29k-amd-udi or udi29k
954 * New file formats supported
956 BFD now supports reading HP/PA-RISC executables (SOM file format?),
957 HPUX core files, and SCO 3.2v2 core files.
961 Attaching to processes now works again; thanks for the many bug reports.
963 We have also stomped on a bunch of core dumps caused by
964 printf_filtered("%s") problems.
966 We eliminated a copyright problem on the rpc and ptrace header files
967 for VxWorks, which was discovered at the last minute during the 4.7
968 release. You should now be able to build a VxWorks GDB.
970 You can now interrupt gdb while an attached process is running. This
971 will cause the attached process to stop, and give control back to GDB.
973 We fixed problems caused by using too many file descriptors
974 for reading symbols from object files and libraries. This was
975 especially a problem for programs that used many (~100) shared
978 The `step' command now only enters a subroutine if there is line number
979 information for the subroutine. Otherwise it acts like the `next'
980 command. Previously, `step' would enter subroutines if there was
981 any debugging information about the routine. This avoids problems
982 when using `cc -g1' on MIPS machines.
984 * Internal improvements
986 GDB's internal interfaces have been improved to make it easier to support
987 debugging of multiple languages in the future.
989 GDB now uses a common structure for symbol information internally.
990 Minimal symbols (derived from linkage symbols in object files), partial
991 symbols (from a quick scan of debug information), and full symbols
992 contain a common subset of information, making it easier to write
993 shared code that handles any of them.
995 * New command line options
997 We now accept --silent as an alias for --quiet.
1001 The memory-mapped-malloc library is now licensed under the GNU Library
1002 General Public License.
1004 *** Changes in GDB-4.7:
1006 * Host/native/target split
1008 GDB has had some major internal surgery to untangle the support for
1009 hosts and remote targets. Now, when you configure GDB for a remote
1010 target, it will no longer load in all of the support for debugging
1011 local programs on the host. When fully completed and tested, this will
1012 ensure that arbitrary host/target combinations are possible.
1014 The primary conceptual shift is to separate the non-portable code in
1015 GDB into three categories. Host specific code is required any time GDB
1016 is compiled on that host, regardless of the target. Target specific
1017 code relates to the peculiarities of the target, but can be compiled on
1018 any host. Native specific code is everything else: it can only be
1019 built when the host and target are the same system. Child process
1020 handling and core file support are two common `native' examples.
1022 GDB's use of /proc for controlling Unix child processes is now cleaner.
1023 It has been split out into a single module under the `target_ops' vector,
1024 plus two native-dependent functions for each system that uses /proc.
1026 * New hosts supported
1028 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
1029 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
1030 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
1032 * New targets supported
1034 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
1035 68030 and CPU32 m68030-*-*, m68332-*-*
1037 * New native hosts supported
1039 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
1040 (386bsd is not well tested yet)
1041 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
1043 * New file formats supported
1045 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
1046 supports reading of `a.out.adobe' object files, which are an a.out
1047 format extended with minimal information about multiple sections.
1051 `show copying' is the same as the old `info copying'.
1052 `show warranty' is the same as `info warrantee'.
1053 These were renamed for consistency. The old commands continue to work.
1055 `info handle' is a new alias for `info signals'.
1057 You can now define pre-command hooks, which attach arbitrary command
1058 scripts to any command. The commands in the hook will be executed
1059 prior to the user's command. You can also create a hook which will be
1060 executed whenever the program stops. See gdb.texinfo.
1064 We now deal with Cfront style name mangling, and can even extract type
1065 info from mangled symbols. GDB can automatically figure out which
1066 symbol mangling style your C++ compiler uses.
1068 Calling of methods and virtual functions has been improved as well.
1072 The crash that occured when debugging Sun Ansi-C compiled binaries is
1073 fixed. This was due to mishandling of the extra N_SO stabs output
1076 We also finally got Ultrix 4.2 running in house, and fixed core file
1077 support, with help from a dozen people on the net.
1079 John M. Farrell discovered that the reason that single-stepping was so
1080 slow on all of the Mips based platforms (primarily SGI and DEC) was
1081 that we were trying to demangle and lookup a symbol used for internal
1082 purposes on every instruction that was being stepped through. Changing
1083 the name of that symbol so that it couldn't be mistaken for a C++
1084 mangled symbol sped things up a great deal.
1086 Rich Pixley sped up symbol lookups in general by getting much smarter
1087 about when C++ symbol mangling is necessary. This should make symbol
1088 completion (TAB on the command line) much faster. It's not as fast as
1089 we'd like, but it's significantly faster than gdb-4.6.
1093 A new user controllable variable 'call_scratch_address' can
1094 specify the location of a scratch area to be used when GDB
1095 calls a function in the target. This is necessary because the
1096 usual method of putting the scratch area on the stack does not work
1097 in systems that have separate instruction and data spaces.
1099 We integrated changes to support the 29k UDI (Universal Debugger
1100 Interface), but discovered at the last minute that we didn't have all
1101 of the appropriate copyright paperwork. We are working with AMD to
1102 resolve this, and hope to have it available soon.
1106 We have sped up the remote serial line protocol, especially for targets
1107 with lots of registers. It now supports a new `expedited status' ('T')
1108 message which can be used in place of the existing 'S' status message.
1109 This allows the remote stub to send only the registers that GDB
1110 needs to make a quick decision about single-stepping or conditional
1111 breakpoints, eliminating the need to fetch the entire register set for
1112 each instruction being stepped through.
1114 The GDB remote serial protocol now implements a write-through cache for
1115 registers, only re-reading the registers if the target has run.
1117 There is also a new remote serial stub for SPARC processors. You can
1118 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
1119 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
1120 processor with a serial port.
1124 Configure.in files have become much easier to read and modify. A new
1125 `table driven' format makes it more obvious what configurations are
1126 supported, and what files each one uses.
1130 There is a new opcodes library which will eventually contain all of the
1131 disassembly routines and opcode tables. At present, it only contains
1132 Sparc and Z8000 routines. This will allow the assembler, debugger, and
1133 disassembler (binutils/objdump) to share these routines.
1135 The libiberty library is now copylefted under the GNU Library General
1136 Public License. This allows more liberal use, and was done so libg++
1137 can use it. This makes no difference to GDB, since the Library License
1138 grants all the rights from the General Public License.
1142 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
1143 reference to the stabs symbol info used by the debugger. It is (as far
1144 as we know) the only published document on this fascinating topic. We
1145 encourage you to read it, compare it to the stabs information on your
1146 system, and send improvements on the document in general (to
1147 bug-gdb@prep.ai.mit.edu).
1149 And, of course, many bugs have been fixed.
1152 *** Changes in GDB-4.6:
1154 * Better support for C++ function names
1156 GDB now accepts as input the "demangled form" of C++ overloaded function
1157 names and member function names, and can do command completion on such names
1158 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
1159 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
1160 Make use of command completion, it is your friend.
1162 GDB also now accepts a variety of C++ mangled symbol formats. They are
1163 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
1164 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
1165 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
1166 for the list of formats.
1168 * G++ symbol mangling problem
1170 Recent versions of gcc have a bug in how they emit debugging information for
1171 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
1172 directory) can be applied to gcc to fix the problem. Alternatively, if you
1173 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
1174 usual symptom is difficulty with setting breakpoints on methods. GDB complains
1175 about the method being non-existent. (We believe that version 2.2.2 of GCC has
1178 * New 'maintenance' command
1180 All of the commands related to hacking GDB internals have been moved out of
1181 the main command set, and now live behind the 'maintenance' command. This
1182 can also be abbreviated as 'mt'. The following changes were made:
1184 dump-me -> maintenance dump-me
1185 info all-breakpoints -> maintenance info breakpoints
1186 printmsyms -> maintenance print msyms
1187 printobjfiles -> maintenance print objfiles
1188 printpsyms -> maintenance print psymbols
1189 printsyms -> maintenance print symbols
1191 The following commands are new:
1193 maintenance demangle Call internal GDB demangler routine to
1194 demangle a C++ link name and prints the result.
1195 maintenance print type Print a type chain for a given symbol
1197 * Change to .gdbinit file processing
1199 We now read the $HOME/.gdbinit file before processing the argv arguments
1200 (e.g. reading symbol files or core files). This allows global parameters to
1201 be set, which will apply during the symbol reading. The ./.gdbinit is still
1202 read after argv processing.
1204 * New hosts supported
1206 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
1208 Linux support i386-unknown-linux or linux
1210 We are also including code to support the HP/PA running BSD and HPUX. This
1211 is almost guaranteed not to work, as we didn't have time to test or build it
1212 for this release. We are including it so that the more adventurous (or
1213 masochistic) of you can play with it. We also had major problems with the
1214 fact that the compiler that we got from HP doesn't support the -g option.
1217 * New targets supported
1219 Hitachi H8/300 h8300-hitachi-hms or h8300hms
1221 * More smarts about finding #include files
1223 GDB now remembers the compilation directory for all include files, and for
1224 all files from which C is generated (like yacc and lex sources). This
1225 greatly improves GDB's ability to find yacc/lex sources, and include files,
1226 especially if you are debugging your program from a directory different from
1227 the one that contains your sources.
1229 We also fixed a bug which caused difficulty with listing and setting
1230 breakpoints in include files which contain C code. (In the past, you had to
1231 try twice in order to list an include file that you hadn't looked at before.)
1233 * Interesting infernals change
1235 GDB now deals with arbitrary numbers of sections, where the symbols for each
1236 section must be relocated relative to that section's landing place in the
1237 target's address space. This work was needed to support ELF with embedded
1238 stabs used by Solaris-2.0.
1240 * Bug fixes (of course!)
1242 There have been loads of fixes for the following things:
1243 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
1244 i960, stabs, DOS(GO32), procfs, etc...
1246 See the ChangeLog for details.
1248 *** Changes in GDB-4.5:
1250 * New machines supported (host and target)
1252 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
1254 SGI Irix-4.x mips-sgi-irix4 or iris4
1256 * New malloc package
1258 GDB now uses a new memory manager called mmalloc, based on gmalloc.
1259 Mmalloc is capable of handling mutiple heaps of memory. It is also
1260 capable of saving a heap to a file, and then mapping it back in later.
1261 This can be used to greatly speedup the startup of GDB by using a
1262 pre-parsed symbol table which lives in a mmalloc managed heap. For
1263 more details, please read mmalloc/mmalloc.texi.
1267 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
1268 'help info proc' for details.
1270 * MIPS ecoff symbol table format
1272 The code that reads MIPS symbol table format is now supported on all hosts.
1273 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
1276 * File name changes for MS-DOS
1278 Many files in the config directories have been renamed to make it easier to
1279 support GDB on MS-DOSe systems (which have very restrictive file name
1280 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
1281 environment) is close to working but has some remaining problems. Note
1282 that debugging of DOS programs is not supported, due to limitations
1283 in the ``operating system'', but it can be used to host cross-debugging.
1285 * Cross byte order fixes
1287 Many fixes have been made to support cross debugging of Sparc and MIPS
1288 targets from hosts whose byte order differs.
1290 * New -mapped and -readnow options
1292 If memory-mapped files are available on your system through the 'mmap'
1293 system call, you can use the -mapped option on the `file' or
1294 `symbol-file' commands to cause GDB to write the symbols from your
1295 program into a reusable file. If the program you are debugging is
1296 called `/path/fred', the mapped symbol file will be `./fred.syms'.
1297 Future GDB debugging sessions will notice the presence of this file,
1298 and will quickly map in symbol information from it, rather than reading
1299 the symbol table from the executable program. Using the '-mapped'
1300 option in a GDB `file' or `symbol-file' command has the same effect as
1301 starting GDB with the '-mapped' command-line option.
1303 You can cause GDB to read the entire symbol table immediately by using
1304 the '-readnow' option with any of the commands that load symbol table
1305 information (or on the GDB command line). This makes the command
1306 slower, but makes future operations faster.
1308 The -mapped and -readnow options are typically combined in order to
1309 build a `fred.syms' file that contains complete symbol information.
1310 A simple GDB invocation to do nothing but build a `.syms' file for future
1313 gdb -batch -nx -mapped -readnow programname
1315 The `.syms' file is specific to the host machine on which GDB is run.
1316 It holds an exact image of GDB's internal symbol table. It cannot be
1317 shared across multiple host platforms.
1319 * longjmp() handling
1321 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
1322 siglongjmp() without losing control. This feature has not yet been ported to
1323 all systems. It currently works on many 386 platforms, all MIPS-based
1324 platforms (SGI, DECstation, etc), and Sun3/4.
1328 Preliminary work has been put in to support the new Solaris OS from Sun. At
1329 this time, it can control and debug processes, but it is not capable of
1334 As always, many many bug fixes. The major areas were with g++, and mipsread.
1335 People using the MIPS-based platforms should experience fewer mysterious
1336 crashes and trashed symbol tables.
1338 *** Changes in GDB-4.4:
1340 * New machines supported (host and target)
1342 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
1344 BSD Reno on Vax vax-dec-bsd
1345 Ultrix on Vax vax-dec-ultrix
1347 * New machines supported (target)
1349 AMD 29000 embedded, using EBMON a29k-none-none
1353 GDB continues to improve its handling of C++. `References' work better.
1354 The demangler has also been improved, and now deals with symbols mangled as
1355 per the Annotated C++ Reference Guide.
1357 GDB also now handles `stabs' symbol information embedded in MIPS
1358 `ecoff' symbol tables. Since the ecoff format was not easily
1359 extensible to handle new languages such as C++, this appeared to be a
1360 good way to put C++ debugging info into MIPS binaries. This option
1361 will be supported in the GNU C compiler, version 2, when it is
1364 * New features for SVR4
1366 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
1367 shared libraries. Debugging dynamically linked programs should present
1368 only minor differences from debugging statically linked programs.
1370 The `info proc' command will print out information about any process
1371 on an SVR4 system (including the one you are debugging). At the moment,
1372 it prints the address mappings of the process.
1374 If you bring up GDB on another SVR4 system, please send mail to
1375 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
1377 * Better dynamic linking support in SunOS
1379 Reading symbols from shared libraries which contain debugging symbols
1380 now works properly. However, there remain issues such as automatic
1381 skipping of `transfer vector' code during function calls, which
1382 make it harder to debug code in a shared library, than to debug the
1383 same code linked statically.
1387 GDB is now using the latest `getopt' routines from the FSF. This
1388 version accepts the -- prefix for options with long names. GDB will
1389 continue to accept the old forms (-option and +option) as well.
1390 Various single letter abbreviations for options have been explicity
1391 added to the option table so that they won't get overshadowed in the
1392 future by other options that begin with the same letter.
1396 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
1397 Many assorted bugs have been handled. Many more remain to be handled.
1398 See the various ChangeLog files (primarily in gdb and bfd) for details.
1401 *** Changes in GDB-4.3:
1403 * New machines supported (host and target)
1405 Amiga 3000 running Amix m68k-cbm-svr4 or amix
1406 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
1407 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
1409 * Almost SCO Unix support
1411 We had hoped to support:
1412 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
1413 (except for core file support), but we discovered very late in the release
1414 that it has problems with process groups that render gdb unusable. Sorry
1415 about that. I encourage people to fix it and post the fixes.
1417 * Preliminary ELF and DWARF support
1419 GDB can read ELF object files on System V Release 4, and can handle
1420 debugging records for C, in DWARF format, in ELF files. This support
1421 is preliminary. If you bring up GDB on another SVR4 system, please
1422 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
1427 GDB now uses the latest `readline' library. One user-visible change
1428 is that two tabs will list possible command completions, which previously
1429 required typing M-? (meta-question mark, or ESC ?).
1433 The `stepi' bug that many of you noticed has been squashed.
1434 Many bugs in C++ have been handled. Many more remain to be handled.
1435 See the various ChangeLog files (primarily in gdb and bfd) for details.
1437 * State of the MIPS world (in case you wondered):
1439 GDB can understand the symbol tables emitted by the compilers
1440 supplied by most vendors of MIPS-based machines, including DEC. These
1441 symbol tables are in a format that essentially nobody else uses.
1443 Some versions of gcc come with an assembler post-processor called
1444 mips-tfile. This program is required if you want to do source-level
1445 debugging of gcc-compiled programs. I believe FSF does not ship
1446 mips-tfile with gcc version 1, but it will eventually come with gcc
1449 Debugging of g++ output remains a problem. g++ version 1.xx does not
1450 really support it at all. (If you're lucky, you should be able to get
1451 line numbers and stack traces to work, but no parameters or local
1452 variables.) With some work it should be possible to improve the
1455 When gcc version 2 is released, you will have somewhat better luck.
1456 However, even then you will get confusing results for inheritance and
1459 We will eventually provide full debugging of g++ output on
1460 DECstations. This will probably involve some kind of stabs-in-ecoff
1461 encapulation, but the details have not been worked out yet.
1464 *** Changes in GDB-4.2:
1466 * Improved configuration
1468 Only one copy of `configure' exists now, and it is not self-modifying.
1469 Porting BFD is simpler.
1473 The `step' and `next' commands now only stop at the first instruction
1474 of a source line. This prevents the multiple stops that used to occur
1475 in switch statements, for-loops, etc. `Step' continues to stop if a
1476 function that has debugging information is called within the line.
1480 Lots of small bugs fixed. More remain.
1482 * New host supported (not target)
1484 Intel 386 PC clone running Mach i386-none-mach
1487 *** Changes in GDB-4.1:
1489 * Multiple source language support
1491 GDB now has internal scaffolding to handle several source languages.
1492 It determines the type of each source file from its filename extension,
1493 and will switch expression parsing and number formatting to match the
1494 language of the function in the currently selected stack frame.
1495 You can also specifically set the language to be used, with
1496 `set language c' or `set language modula-2'.
1500 GDB now has preliminary support for the GNU Modula-2 compiler,
1501 currently under development at the State University of New York at
1502 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
1503 continue through the fall of 1991 and into 1992.
1505 Other Modula-2 compilers are currently not supported, and attempting to
1506 debug programs compiled with them will likely result in an error as the
1507 symbol table is read. Feel free to work on it, though!
1509 There are hooks in GDB for strict type checking and range checking,
1510 in the `Modula-2 philosophy', but they do not currently work.
1514 GDB can now write to executable and core files (e.g. patch
1515 a variable's value). You must turn this switch on, specify
1516 the file ("exec foo" or "core foo"), *then* modify it, e.g.
1517 by assigning a new value to a variable. Modifications take
1520 * Automatic SunOS shared library reading
1522 When you run your program, GDB automatically determines where its
1523 shared libraries (if any) have been loaded, and reads their symbols.
1524 The `share' command is no longer needed. This also works when
1525 examining core files.
1529 You can specify the number of lines that the `list' command shows.
1532 * New machines supported (host and target)
1534 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
1535 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
1536 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
1538 * New hosts supported (not targets)
1540 IBM RT/PC: romp-ibm-aix or rtpc
1542 * New targets supported (not hosts)
1544 AMD 29000 embedded with COFF a29k-none-coff
1545 AMD 29000 embedded with a.out a29k-none-aout
1546 Ultracomputer remote kernel debug a29k-nyu-kern
1548 * New remote interfaces
1554 *** Changes in GDB-4.0:
1558 Wide output is wrapped at good places to make the output more readable.
1560 Gdb now supports cross-debugging from a host machine of one type to a
1561 target machine of another type. Communication with the target system
1562 is over serial lines. The ``target'' command handles connecting to the
1563 remote system; the ``load'' command will download a program into the
1564 remote system. Serial stubs for the m68k and i386 are provided. Gdb
1565 also supports debugging of realtime processes running under VxWorks,
1566 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
1567 stub on the target system.
1569 New CPUs supported include the AMD 29000 and Intel 960.
1571 GDB now reads object files and symbol tables via a ``binary file''
1572 library, which allows a single copy of GDB to debug programs of multiple
1573 object file types such as a.out and coff.
1575 There is now a GDB reference card in "doc/refcard.tex". (Make targets
1576 refcard.dvi and refcard.ps are available to format it).
1579 * Control-Variable user interface simplified
1581 All variables that control the operation of the debugger can be set
1582 by the ``set'' command, and displayed by the ``show'' command.
1584 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
1585 ``Show prompt'' produces the response:
1586 Gdb's prompt is new-gdb=>.
1588 What follows are the NEW set commands. The command ``help set'' will
1589 print a complete list of old and new set commands. ``help set FOO''
1590 will give a longer description of the variable FOO. ``show'' will show
1591 all of the variable descriptions and their current settings.
1593 confirm on/off: Enables warning questions for operations that are
1594 hard to recover from, e.g. rerunning the program while
1595 it is already running. Default is ON.
1597 editing on/off: Enables EMACS style command line editing
1598 of input. Previous lines can be recalled with
1599 control-P, the current line can be edited with control-B,
1600 you can search for commands with control-R, etc.
1603 history filename NAME: NAME is where the gdb command history
1604 will be stored. The default is .gdb_history,
1605 or the value of the environment variable
1608 history size N: The size, in commands, of the command history. The
1609 default is 256, or the value of the environment variable
1612 history save on/off: If this value is set to ON, the history file will
1613 be saved after exiting gdb. If set to OFF, the
1614 file will not be saved. The default is OFF.
1616 history expansion on/off: If this value is set to ON, then csh-like
1617 history expansion will be performed on
1618 command line input. The default is OFF.
1620 radix N: Sets the default radix for input and output. It can be set
1621 to 8, 10, or 16. Note that the argument to "radix" is interpreted
1622 in the current radix, so "set radix 10" is always a no-op.
1624 height N: This integer value is the number of lines on a page. Default
1625 is 24, the current `stty rows'' setting, or the ``li#''
1626 setting from the termcap entry matching the environment
1629 width N: This integer value is the number of characters on a line.
1630 Default is 80, the current `stty cols'' setting, or the ``co#''
1631 setting from the termcap entry matching the environment
1634 Note: ``set screensize'' is obsolete. Use ``set height'' and
1635 ``set width'' instead.
1637 print address on/off: Print memory addresses in various command displays,
1638 such as stack traces and structure values. Gdb looks
1639 more ``symbolic'' if you turn this off; it looks more
1640 ``machine level'' with it on. Default is ON.
1642 print array on/off: Prettyprint arrays. New convenient format! Default
1645 print demangle on/off: Print C++ symbols in "source" form if on,
1648 print asm-demangle on/off: Same, for assembler level printouts
1651 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
1654 * Support for Epoch Environment.
1656 The epoch environment is a version of Emacs v18 with windowing. One
1657 new command, ``inspect'', is identical to ``print'', except that if you
1658 are running in the epoch environment, the value is printed in its own
1662 * Support for Shared Libraries
1664 GDB can now debug programs and core files that use SunOS shared libraries.
1665 Symbols from a shared library cannot be referenced
1666 before the shared library has been linked with the program (this
1667 happens after you type ``run'' and before the function main() is entered).
1668 At any time after this linking (including when examining core files
1669 from dynamically linked programs), gdb reads the symbols from each
1670 shared library when you type the ``sharedlibrary'' command.
1671 It can be abbreviated ``share''.
1673 sharedlibrary REGEXP: Load shared object library symbols for files
1674 matching a unix regular expression. No argument
1675 indicates to load symbols for all shared libraries.
1677 info sharedlibrary: Status of loaded shared libraries.
1682 A watchpoint stops execution of a program whenever the value of an
1683 expression changes. Checking for this slows down execution
1684 tremendously whenever you are in the scope of the expression, but is
1685 quite useful for catching tough ``bit-spreader'' or pointer misuse
1686 problems. Some machines such as the 386 have hardware for doing this
1687 more quickly, and future versions of gdb will use this hardware.
1689 watch EXP: Set a watchpoint (breakpoint) for an expression.
1691 info watchpoints: Information about your watchpoints.
1693 delete N: Deletes watchpoint number N (same as breakpoints).
1694 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
1695 enable N: Re-enables watchpoint number N (same as breakpoints).
1698 * C++ multiple inheritance
1700 When used with a GCC version 2 compiler, GDB supports multiple inheritance
1703 * C++ exception handling
1705 Gdb now supports limited C++ exception handling. Besides the existing
1706 ability to breakpoint on an exception handler, gdb can breakpoint on
1707 the raising of an exception (before the stack is peeled back to the
1710 catch FOO: If there is a FOO exception handler in the dynamic scope,
1711 set a breakpoint to catch exceptions which may be raised there.
1712 Multiple exceptions (``catch foo bar baz'') may be caught.
1714 info catch: Lists all exceptions which may be caught in the
1715 current stack frame.
1718 * Minor command changes
1720 The command ``call func (arg, arg, ...)'' now acts like the print
1721 command, except it does not print or save a value if the function's result
1722 is void. This is similar to dbx usage.
1724 The ``up'' and ``down'' commands now always print the frame they end up
1725 at; ``up-silently'' and `down-silently'' can be used in scripts to change
1726 frames without printing.
1728 * New directory command
1730 'dir' now adds directories to the FRONT of the source search path.
1731 The path starts off empty. Source files that contain debug information
1732 about the directory in which they were compiled can be found even
1733 with an empty path; Sun CC and GCC include this information. If GDB can't
1734 find your source file in the current directory, type "dir .".
1736 * Configuring GDB for compilation
1738 For normal use, type ``./configure host''. See README or gdb.texinfo
1741 GDB now handles cross debugging. If you are remotely debugging between
1742 two different machines, type ``./configure host -target=targ''.
1743 Host is the machine where GDB will run; targ is the machine
1744 where the program that you are debugging will run.
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