1 What has changed in GDB?
2 (Organized release by release)
4 *** Changes since GDB 5.0:
6 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
8 * New native configurations
10 Alpha FreeBSD alpha*-*-freebsd*
11 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
15 * OBSOLETE configurations
17 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
19 Configurations that have been declared obsolete in this release have
20 been commented out. Unless there is activity to revive these
21 configurations, the next release of GDB will have their sources
24 * REMOVED configurations
26 Altos 3068 m68*-altos-*
29 ARM RISCix arm-*-* (as host)
34 * All MIPS configurations are multi-arched.
36 Multi-arch support is enabled for all MIPS configurations.
40 GUD support is now a standard part of the EMACS distribution.
42 *** Changes in GDB 5.0:
44 * Improved support for debugging FP programs on x86 targets
46 Unified and much-improved support for debugging floating-point
47 programs on all x86 targets. In particular, ``info float'' now
48 displays the FP registers in the same format on all x86 targets, with
49 greater level of detail.
51 * Improvements and bugfixes in hardware-assisted watchpoints
53 It is now possible to watch array elements, struct members, and
54 bitfields with hardware-assisted watchpoints. Data-read watchpoints
55 on x86 targets no longer erroneously trigger when the address is
58 * Improvements in the native DJGPP version of GDB
60 The distribution now includes all the scripts and auxiliary files
61 necessary to build the native DJGPP version on MS-DOS/MS-Windows
62 machines ``out of the box''.
64 The DJGPP version can now debug programs that use signals. It is
65 possible to catch signals that happened in the debuggee, deliver
66 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
67 would kill the program being debugged.) Programs that hook hardware
68 interrupts (keyboard, timer, etc.) can also be debugged.
70 It is now possible to debug DJGPP programs that redirect their
71 standard handles or switch them to raw (as opposed to cooked) mode, or
72 even close them. The command ``run < foo > bar'' works as expected,
73 and ``info terminal'' reports useful information about the debuggee's
74 terminal, including raw/cooked mode, redirection, etc.
76 The DJGPP version now uses termios functions for console I/O, which
77 enables debugging graphics programs. Interrupting GDB with Ctrl-C
80 DOS-style file names with drive letters are now fully supported by
83 It is now possible to debug DJGPP programs that switch their working
84 directory. It is also possible to rerun the debuggee any number of
85 times without restarting GDB; thus, you can use the same setup,
86 breakpoints, etc. for many debugging sessions.
88 * New native configurations
90 ARM GNU/Linux arm*-*-linux*
91 PowerPC GNU/Linux powerpc-*-linux*
95 Motorola MCore mcore-*-*
96 x86 VxWorks i[3456]86-*-vxworks*
97 PowerPC VxWorks powerpc-*-vxworks*
98 TI TMS320C80 tic80-*-*
100 * OBSOLETE configurations
102 Altos 3068 m68*-altos-*
103 Convex c1-*-*, c2-*-*
105 ARM RISCix arm-*-* (as host)
108 Configurations that have been declared obsolete will be commented out,
109 but the code will be left in place. If there is no activity to revive
110 these configurations before the next release of GDB, the sources will
111 be permanently REMOVED.
113 * Gould support removed
115 Support for the Gould PowerNode and NP1 has been removed.
117 * New features for SVR4
119 On SVR4 native platforms (such as Solaris), if you attach to a process
120 without first loading a symbol file, GDB will now attempt to locate and
121 load symbols from the running process's executable file.
123 * Many C++ enhancements
125 C++ support has been greatly improved. Overload resolution now works properly
126 in almost all cases. RTTI support is on the way.
128 * Remote targets can connect to a sub-program
130 A popen(3) style serial-device has been added. This device starts a
131 sub-process (such as a stand-alone simulator) and then communicates
132 with that. The sub-program to run is specified using the syntax
133 ``|<program> <args>'' vis:
135 (gdb) set remotedebug 1
136 (gdb) target extended-remote |mn10300-elf-sim program-args
138 * MIPS 64 remote protocol
140 A long standing bug in the mips64 remote protocol where by GDB
141 expected certain 32 bit registers (ex SR) to be transfered as 32
142 instead of 64 bits has been fixed.
144 The command ``set remote-mips64-transfers-32bit-regs on'' has been
145 added to provide backward compatibility with older versions of GDB.
147 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
149 The command ``set remotebinarydownload'' command has been replaced by
150 ``set remote X-packet''. Other commands in ``set remote'' family
151 include ``set remote P-packet''.
153 * Breakpoint commands accept ranges.
155 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
156 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
157 ``tracepoint passcount'' also accepts a range of tracepoints.
159 * ``apropos'' command added.
161 The ``apropos'' command searches through command names and
162 documentation strings, printing out matches, making it much easier to
163 try to find a command that does what you are looking for.
167 A new machine oriented interface (MI) has been added to GDB. This
168 interface is designed for debug environments running GDB as a separate
169 process. This is part of the long term libGDB project. See the
170 "GDB/MI" chapter of the GDB manual for further information. It can be
171 enabled by configuring with:
173 .../configure --enable-gdbmi
175 *** Changes in GDB-4.18:
177 * New native configurations
179 HP-UX 10.20 hppa*-*-hpux10.20
180 HP-UX 11.x hppa*-*-hpux11.0*
181 M68K Linux m68*-*-linux*
185 Fujitsu FR30 fr30-*-elf*
186 Intel StrongARM strongarm-*-*
187 Mitsubishi D30V d30v-*-*
189 * OBSOLETE configurations
191 Gould PowerNode, NP1 np1-*-*, pn-*-*
193 Configurations that have been declared obsolete will be commented out,
194 but the code will be left in place. If there is no activity to revive
195 these configurations before the next release of GDB, the sources will
196 be permanently REMOVED.
200 As a compatibility experiment, GDB's source files buildsym.h and
201 buildsym.c have been converted to pure standard C, no longer
202 containing any K&R compatibility code. We believe that all systems in
203 use today either come with a standard C compiler, or have a GCC port
204 available. If this is not true, please report the affected
205 configuration to bug-gdb@gnu.org immediately. See the README file for
206 information about getting a standard C compiler if you don't have one
211 GDB now uses readline 2.2.
213 * set extension-language
215 You can now control the mapping between filename extensions and source
216 languages by using the `set extension-language' command. For instance,
217 you can ask GDB to treat .c files as C++ by saying
218 set extension-language .c c++
219 The command `info extensions' lists all of the recognized extensions
220 and their associated languages.
222 * Setting processor type for PowerPC and RS/6000
224 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
225 you can use the `set processor' command to specify what variant of the
226 PowerPC family you are debugging. The command
230 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
231 following PowerPC and RS6000 variants:
233 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
234 rs6000 IBM RS6000 ("POWER") architecture, user-level view
236 403GC IBM PowerPC 403GC
237 505 Motorola PowerPC 505
238 860 Motorola PowerPC 860 or 850
239 601 Motorola PowerPC 601
240 602 Motorola PowerPC 602
241 603 Motorola/IBM PowerPC 603 or 603e
242 604 Motorola PowerPC 604 or 604e
243 750 Motorola/IBM PowerPC 750 or 750
245 At the moment, this command just tells GDB what to name the
246 special-purpose processor registers. Since almost all the affected
247 registers are inaccessible to user-level programs, this command is
248 only useful for remote debugging in its present form.
252 Thanks to a major code donation from Hewlett-Packard, GDB now has much
253 more extensive support for HP-UX. Added features include shared
254 library support, kernel threads and hardware watchpoints for 11.00,
255 support for HP's ANSI C and C++ compilers, and a compatibility mode
256 for xdb and dbx commands.
260 HP's donation includes the new concept of catchpoints, which is a
261 generalization of the old catch command. On HP-UX, it is now possible
262 to catch exec, fork, and vfork, as well as library loading.
264 This means that the existing catch command has changed; its first
265 argument now specifies the type of catch to be set up. See the
266 output of "help catch" for a list of catchpoint types.
268 * Debugging across forks
270 On HP-UX, you can choose which process to debug when a fork() happens
275 HP has donated a curses-based terminal user interface (TUI). To get
276 it, build with --enable-tui. Although this can be enabled for any
277 configuration, at present it only works for native HP debugging.
279 * GDB remote protocol additions
281 A new protocol packet 'X' that writes binary data is now available.
282 Default behavior is to try 'X', then drop back to 'M' if the stub
283 fails to respond. The settable variable `remotebinarydownload'
284 allows explicit control over the use of 'X'.
286 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
287 full 64-bit address. The command
289 set remoteaddresssize 32
291 can be used to revert to the old behaviour. For existing remote stubs
292 the change should not be noticed, as the additional address information
295 In order to assist in debugging stubs, you may use the maintenance
296 command `packet' to send any text string to the stub. For instance,
298 maint packet heythere
300 sends the packet "$heythere#<checksum>". Note that it is very easy to
301 disrupt a debugging session by sending the wrong packet at the wrong
304 The compare-sections command allows you to compare section data on the
305 target to what is in the executable file without uploading or
306 downloading, by comparing CRC checksums.
308 * Tracing can collect general expressions
310 You may now collect general expressions at tracepoints. This requires
311 further additions to the target-side stub; see tracepoint.c and
312 doc/agentexpr.texi for further details.
314 * mask-address variable for Mips
316 For Mips targets, you may control the zeroing of the upper 32 bits of
317 a 64-bit address by entering `set mask-address on'. This is mainly
318 of interest to users of embedded R4xxx and R5xxx processors.
320 * Higher serial baud rates
322 GDB's serial code now allows you to specify baud rates 57600, 115200,
323 230400, and 460800 baud. (Note that your host system may not be able
324 to achieve all of these rates.)
328 The i960 configuration now includes an initial implementation of a
329 builtin simulator, contributed by Jim Wilson.
332 *** Changes in GDB-4.17:
334 * New native configurations
336 Alpha GNU/Linux alpha*-*-linux*
337 Unixware 2.x i[3456]86-unixware2*
338 Irix 6.x mips*-sgi-irix6*
339 PowerPC GNU/Linux powerpc-*-linux*
340 PowerPC Solaris powerpcle-*-solaris*
341 Sparc GNU/Linux sparc-*-linux*
342 Motorola sysV68 R3V7.1 m68k-motorola-sysv
346 Argonaut Risc Chip (ARC) arc-*-*
347 Hitachi H8/300S h8300*-*-*
348 Matsushita MN10200 w/simulator mn10200-*-*
349 Matsushita MN10300 w/simulator mn10300-*-*
350 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
351 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
352 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
353 Mitsubishi D10V w/simulator d10v-*-*
354 Mitsubishi M32R/D w/simulator m32r-*-elf*
355 Tsqware Sparclet sparclet-*-*
356 NEC V850 w/simulator v850-*-*
358 * New debugging protocols
360 ARM with RDI protocol arm*-*-*
361 M68K with dBUG monitor m68*-*-{aout,coff,elf}
362 DDB and LSI variants of PMON protocol mips*-*-*
363 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
364 PowerPC with SDS protocol powerpc{,le}-*-eabi
365 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
369 All configurations can now understand and use the DWARF 2 debugging
370 format. The choice is automatic, if the symbol file contains DWARF 2
375 GDB now includes basic Java language support. This support is
376 only useful with Java compilers that produce native machine code.
378 * solib-absolute-prefix and solib-search-path
380 For SunOS and SVR4 shared libraries, you may now set the prefix for
381 loading absolute shared library symbol files, and the search path for
382 locating non-absolute shared library symbol files.
384 * Live range splitting
386 GDB can now effectively debug code for which GCC has performed live
387 range splitting as part of its optimization. See gdb/doc/LRS for
388 more details on the expected format of the stabs information.
392 GDB's support for the GNU Hurd, including thread debugging, has been
393 updated to work with current versions of the Hurd.
397 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
398 instruction set. ARM GDB automatically detects when Thumb
399 instructions are in use, and adjusts disassembly and backtracing
404 GDB's MIPS target configurations now handle the MIP16 16-bit
409 GDB now includes support for overlays; if an executable has been
410 linked such that multiple sections are based at the same address, GDB
411 will decide which section to use for symbolic info. You can choose to
412 control the decision manually, using overlay commands, or implement
413 additional target-side support and use "overlay load-target" to bring
414 in the overlay mapping. Do "help overlay" for more detail.
418 The command "info symbol <address>" displays information about
419 the symbol at the specified address.
423 The standard remote protocol now includes an extension that allows
424 asynchronous collection and display of trace data. This requires
425 extensive support in the target-side debugging stub. Tracing mode
426 includes a new interaction mode in GDB and new commands: see the
427 file tracepoint.c for more details.
431 Configurations for embedded MIPS now include a simulator contributed
432 by Cygnus Solutions. The simulator supports the instruction sets
433 of most MIPS variants.
437 Sparc configurations may now include the ERC32 simulator contributed
438 by the European Space Agency. The simulator is not built into
439 Sparc targets by default; configure with --enable-sim to include it.
443 For target configurations that may include multiple variants of a
444 basic architecture (such as MIPS and SH), you may now set the
445 architecture explicitly. "set arch" sets, "info arch" lists
446 the possible architectures.
448 *** Changes in GDB-4.16:
450 * New native configurations
452 Windows 95, x86 Windows NT i[345]86-*-cygwin32
453 M68K NetBSD m68k-*-netbsd*
454 PowerPC AIX 4.x powerpc-*-aix*
455 PowerPC MacOS powerpc-*-macos*
456 PowerPC Windows NT powerpcle-*-cygwin32
457 RS/6000 AIX 4.x rs6000-*-aix4*
461 ARM with RDP protocol arm-*-*
462 I960 with MON960 i960-*-coff
463 MIPS VxWorks mips*-*-vxworks*
464 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
465 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
467 Matra Sparclet sparclet-*-*
471 The powerpc-eabi configuration now includes the PSIM simulator,
472 contributed by Andrew Cagney, with assistance from Mike Meissner.
473 PSIM is a very elaborate model of the PowerPC, including not only
474 basic instruction set execution, but also details of execution unit
475 performance and I/O hardware. See sim/ppc/README for more details.
479 GDB now works with Solaris 2.5.
481 * Windows 95/NT native
483 GDB will now work as a native debugger on Windows 95 and Windows NT.
484 To build it from source, you must use the "gnu-win32" environment,
485 which uses a DLL to emulate enough of Unix to run the GNU tools.
486 Further information, binaries, and sources are available at
487 ftp.cygnus.com, under pub/gnu-win32.
489 * dont-repeat command
491 If a user-defined command includes the command `dont-repeat', then the
492 command will not be repeated if the user just types return. This is
493 useful if the command is time-consuming to run, so that accidental
494 extra keystrokes don't run the same command many times.
496 * Send break instead of ^C
498 The standard remote protocol now includes an option to send a break
499 rather than a ^C to the target in order to interrupt it. By default,
500 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
502 * Remote protocol timeout
504 The standard remote protocol includes a new variable `remotetimeout'
505 that allows you to set the number of seconds before GDB gives up trying
506 to read from the target. The default value is 2.
508 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
510 By default GDB will automatically keep track of objects as they are
511 loaded and unloaded by the dynamic linker. By using the command `set
512 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
513 when shared library events occur, thus allowing you to set breakpoints
514 in shared libraries which are explicitly loaded by the inferior.
516 Note this feature does not work on hpux8. On hpux9 you must link
517 /usr/lib/end.o into your program. This feature should work
518 automatically on hpux10.
520 * Irix 5.x hardware watchpoint support
522 Irix 5 configurations now support the use of hardware watchpoints.
524 * Mips protocol "SYN garbage limit"
526 When debugging a Mips target using the `target mips' protocol, you
527 may set the number of characters that GDB will ignore by setting
528 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
529 every character. The default value is 1050.
531 * Recording and replaying remote debug sessions
533 If you set `remotelogfile' to the name of a file, gdb will write to it
534 a recording of a remote debug session. This recording may then be
535 replayed back to gdb using "gdbreplay". See gdbserver/README for
536 details. This is useful when you have a problem with GDB while doing
537 remote debugging; you can make a recording of the session and send it
538 to someone else, who can then recreate the problem.
540 * Speedups for remote debugging
542 GDB includes speedups for downloading and stepping MIPS systems using
543 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
544 and more efficient S-record downloading.
546 * Memory use reductions and statistics collection
548 GDB now uses less memory and reports statistics about memory usage.
549 Try the `maint print statistics' command, for example.
551 *** Changes in GDB-4.15:
555 The symbol reader for AIX GDB now uses partial symbol tables. This
556 can greatly improve startup time, especially for large executables.
558 * Remote targets use caching
560 Remote targets now use a data cache to speed up communication with the
561 remote side. The data cache could lead to incorrect results because
562 it doesn't know about volatile variables, thus making it impossible to
563 debug targets which use memory mapped I/O devices. `set remotecache
564 off' turns the the data cache off.
566 * Remote targets may have threads
568 The standard remote protocol now includes support for multiple threads
569 in the target system, using new protocol commands 'H' and 'T'. See
570 gdb/remote.c for details.
574 If GDB is configured with `--enable-netrom', then it will include
575 support for the NetROM ROM emulator from XLNT Designs. The NetROM
576 acts as though it is a bank of ROM on the target board, but you can
577 write into it over the network. GDB's support consists only of
578 support for fast loading into the emulated ROM; to debug, you must use
579 another protocol, such as standard remote protocol. The usual
580 sequence is something like
582 target nrom <netrom-hostname>
584 target remote <netrom-hostname>:1235
588 GDB now includes support for the Apple Macintosh, as a host only. It
589 may be run as either an MPW tool or as a standalone application, and
590 it can debug through the serial port. All the usual GDB commands are
591 available, but to the target command, you must supply "serial" as the
592 device type instead of "/dev/ttyXX". See mpw-README in the main
593 directory for more information on how to build. The MPW configuration
594 scripts */mpw-config.in support only a few targets, and only the
595 mips-idt-ecoff target has been tested.
599 GDB configuration now uses autoconf. This is not user-visible,
600 but does simplify configuration and building.
604 GDB now supports hpux10.
606 *** Changes in GDB-4.14:
608 * New native configurations
610 x86 FreeBSD i[345]86-*-freebsd
611 x86 NetBSD i[345]86-*-netbsd
612 NS32k NetBSD ns32k-*-netbsd
613 Sparc NetBSD sparc-*-netbsd
617 A29K VxWorks a29k-*-vxworks
618 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
619 CPU32 EST-300 emulator m68*-*-est*
620 PowerPC ELF powerpc-*-elf
623 * Alpha OSF/1 support for procfs
625 GDB now supports procfs under OSF/1-2.x and higher, which makes it
626 possible to attach to running processes. As the mounting of the /proc
627 filesystem is optional on the Alpha, GDB automatically determines
628 the availability of /proc during startup. This can lead to problems
629 if /proc is unmounted after GDB has been started.
631 * Arguments to user-defined commands
633 User commands may accept up to 10 arguments separated by whitespace.
634 Arguments are accessed within the user command via $arg0..$arg9. A
637 print $arg0 + $arg1 + $arg2
639 To execute the command use:
642 Defines the command "adder" which prints the sum of its three arguments.
643 Note the arguments are text substitutions, so they may reference variables,
644 use complex expressions, or even perform inferior function calls.
646 * New `if' and `while' commands
648 This makes it possible to write more sophisticated user-defined
649 commands. Both commands take a single argument, which is the
650 expression to evaluate, and must be followed by the commands to
651 execute, one per line, if the expression is nonzero, the list being
652 terminated by the word `end'. The `if' command list may include an
653 `else' word, which causes the following commands to be executed only
654 if the expression is zero.
656 * Fortran source language mode
658 GDB now includes partial support for Fortran 77. It will recognize
659 Fortran programs and can evaluate a subset of Fortran expressions, but
660 variables and functions may not be handled correctly. GDB will work
661 with G77, but does not yet know much about symbols emitted by other
664 * Better HPUX support
666 Most debugging facilities now work on dynamic executables for HPPAs
667 running hpux9 or later. You can attach to running dynamically linked
668 processes, but by default the dynamic libraries will be read-only, so
669 for instance you won't be able to put breakpoints in them. To change
670 that behavior do the following before running the program:
676 This will cause the libraries to be mapped private and read-write.
677 To revert to the normal behavior, do this:
683 You cannot set breakpoints or examine data in the library until after
684 the library is loaded if the function/data symbols do not have
687 GDB can now also read debug symbols produced by the HP C compiler on
688 HPPAs (sorry, no C++, Fortran or 68k support).
690 * Target byte order now dynamically selectable
692 You can choose which byte order to use with a target system, via the
693 commands "set endian big" and "set endian little", and you can see the
694 current setting by using "show endian". You can also give the command
695 "set endian auto", in which case GDB will use the byte order
696 associated with the executable. Currently, only embedded MIPS
697 configurations support dynamic selection of target byte order.
699 * New DOS host serial code
701 This version uses DPMI interrupts to handle buffered I/O, so you
702 no longer need to run asynctsr when debugging boards connected to
705 *** Changes in GDB-4.13:
707 * New "complete" command
709 This lists all the possible completions for the rest of the line, if it
710 were to be given as a command itself. This is intended for use by emacs.
712 * Trailing space optional in prompt
714 "set prompt" no longer adds a space for you after the prompt you set. This
715 allows you to set a prompt which ends in a space or one that does not.
717 * Breakpoint hit counts
719 "info break" now displays a count of the number of times the breakpoint
720 has been hit. This is especially useful in conjunction with "ignore"; you
721 can ignore a large number of breakpoint hits, look at the breakpoint info
722 to see how many times the breakpoint was hit, then run again, ignoring one
723 less than that number, and this will get you quickly to the last hit of
726 * Ability to stop printing at NULL character
728 "set print null-stop" will cause GDB to stop printing the characters of
729 an array when the first NULL is encountered. This is useful when large
730 arrays actually contain only short strings.
732 * Shared library breakpoints
734 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
735 breakpoints in shared libraries before the executable is run.
737 * Hardware watchpoints
739 There is a new hardware breakpoint for the watch command for sparclite
740 targets. See gdb/sparclite/hw_breakpoint.note.
742 Hardware watchpoints are also now supported under Linux.
746 Annotations have been added. These are for use with graphical interfaces,
747 and are still experimental. Currently only gdba.el uses these.
749 * Improved Irix 5 support
751 GDB now works properly with Irix 5.2.
753 * Improved HPPA support
755 GDB now works properly with the latest GCC and GAS.
757 * New native configurations
759 Sequent PTX4 i[34]86-sequent-ptx4
760 HPPA running OSF/1 hppa*-*-osf*
761 Atari TT running SVR4 m68*-*-sysv4*
762 RS/6000 LynxOS rs6000-*-lynxos*
766 OS/9000 i[34]86-*-os9k
767 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
770 * Hitachi SH7000 and E7000-PC ICE support
772 There is now support for communicating with the Hitachi E7000-PC ICE.
773 This is available automatically when GDB is configured for the SH.
777 As usual, a variety of small fixes and improvements, both generic
778 and configuration-specific. See the ChangeLog for more detail.
780 *** Changes in GDB-4.12:
782 * Irix 5 is now supported
786 GDB-4.12 on the HPPA has a number of changes which make it unable
787 to debug the output from the currently released versions of GCC and
788 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
789 of GCC and GAS, versions of these tools designed to work with GDB-4.12
790 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
793 *** Changes in GDB-4.11:
795 * User visible changes:
799 The "set remotedebug" option is now consistent between the mips remote
800 target, remote targets using the gdb-specific protocol, UDI (AMD's
801 debug protocol for the 29k) and the 88k bug monitor. It is now an
802 integer specifying a debug level (normally 0 or 1, but 2 means more
803 debugging info for the mips target).
805 * DEC Alpha native support
807 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
808 debug info, but GDB works fairly well with the DEC compiler and should
809 work with a future GCC release. See the README file for a few
810 Alpha-specific notes.
812 * Preliminary thread implementation
814 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
816 * LynxOS native and target support for 386
818 This release has been hosted on LynxOS 2.2, and also can be configured
819 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
822 * Improvements in C++ mangling/demangling.
824 This release has much better g++ debugging, specifically in name
825 mangling/demangling, virtual function calls, print virtual table,
826 call methods, ...etc.
828 *** Changes in GDB-4.10:
830 * User visible changes:
832 Remote debugging using the GDB-specific (`target remote') protocol now
833 supports the `load' command. This is only useful if you have some
834 other way of getting the stub to the target system, and you can put it
835 somewhere in memory where it won't get clobbered by the download.
837 Filename completion now works.
839 When run under emacs mode, the "info line" command now causes the
840 arrow to point to the line specified. Also, "info line" prints
841 addresses in symbolic form (as well as hex).
843 All vxworks based targets now support a user settable option, called
844 vxworks-timeout. This option represents the number of seconds gdb
845 should wait for responses to rpc's. You might want to use this if
846 your vxworks target is, perhaps, a slow software simulator or happens
847 to be on the far side of a thin network line.
851 This release contains support for using a DEC alpha as a GDB host for
852 cross debugging. Native alpha debugging is not supported yet.
855 *** Changes in GDB-4.9:
859 This is the first GDB release which is accompanied by a matching testsuite.
860 The testsuite requires installation of dejagnu, which should be available
861 via ftp from most sites that carry GNU software.
865 'Cfront' style demangling has had its name changed to 'ARM' style, to
866 emphasize that it was written from the specifications in the C++ Annotated
867 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
868 disclaimers, it still generated too much confusion with users attempting to
869 use gdb with AT&T cfront.
873 GDB now uses a standard remote interface to a simulator library.
874 So far, the library contains simulators for the Zilog Z8001/2, the
875 Hitachi H8/300, H8/500 and Super-H.
877 * New targets supported
879 H8/300 simulator h8300-hitachi-hms or h8300hms
880 H8/500 simulator h8500-hitachi-hms or h8500hms
881 SH simulator sh-hitachi-hms or sh
882 Z8000 simulator z8k-zilog-none or z8ksim
883 IDT MIPS board over serial line mips-idt-ecoff
885 Cross-debugging to GO32 targets is supported. It requires a custom
886 version of the i386-stub.c module which is integrated with the
887 GO32 memory extender.
889 * New remote protocols
891 MIPS remote debugging protocol.
893 * New source languages supported
895 This version includes preliminary support for Chill, a Pascal like language
896 used by telecommunications companies. Chill support is also being integrated
897 into the GNU compiler, but we don't know when it will be publically available.
900 *** Changes in GDB-4.8:
902 * HP Precision Architecture supported
904 GDB now supports HP PA-RISC machines running HPUX. A preliminary
905 version of this support was available as a set of patches from the
906 University of Utah. GDB does not support debugging of programs
907 compiled with the HP compiler, because HP will not document their file
908 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
909 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
911 Many problems in the preliminary version have been fixed.
913 * Faster and better demangling
915 We have improved template demangling and fixed numerous bugs in the GNU style
916 demangler. It can now handle type modifiers such as `static' or `const'. Wide
917 character types (wchar_t) are now supported. Demangling of each symbol is now
918 only done once, and is cached when the symbol table for a file is read in.
919 This results in a small increase in memory usage for C programs, a moderate
920 increase in memory usage for C++ programs, and a fantastic speedup in
923 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
924 from the specifications in the Annotated Reference Manual, which AT&T's
925 compiler does not actually implement.
927 * G++ multiple inheritance compiler problem
929 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
930 inheritance lattices was reworked to properly discover ambiguities. We
931 recently found an example which causes this new algorithm to fail in a
932 very subtle way, producing bad debug information for those classes.
933 The file 'gcc.patch' (in this directory) can be applied to gcc to
934 circumvent the problem. A future GCC release will contain a complete
937 The previous G++ debug info problem (mentioned below for the gdb-4.7
938 release) is fixed in gcc version 2.3.2.
940 * Improved configure script
942 The `configure' script will now attempt to guess your system type if
943 you don't supply a host system type. The old scheme of supplying a
944 host system triplet is preferable over using this. All the magic is
945 done in the new `config.guess' script. Examine it for details.
947 We have also brought our configure script much more in line with the FSF's
948 version. It now supports the --with-xxx options. In particular,
949 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
950 The resulting GDB will not be able to read arbitrary object file formats --
951 only the format ``expected'' to be used on the configured target system.
952 We hope to make this the default in a future release.
954 * Documentation improvements
956 There's new internal documentation on how to modify GDB, and how to
957 produce clean changes to the code. We implore people to read it
958 before submitting changes.
960 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
961 M4 macros. The new texinfo.tex is provided in this release. Pre-built
962 `info' files are also provided. To build `info' files from scratch,
963 you will need the latest `makeinfo' release, which will be available in
964 a future texinfo-X.Y release.
966 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
967 We're not sure exactly which versions have this problem, but it has
968 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
969 or better. If that isn't possible, there is a patch in
970 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
975 GDB now supports array constants that can be used in expressions typed in by
976 the user. The syntax is `{element, element, ...}'. Ie: you can now type
977 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
980 The new directory `gdb/sparclite' contains a program that demonstrates
981 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
983 * New native hosts supported
985 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
986 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
988 * New targets supported
990 AMD 29k family via UDI a29k-amd-udi or udi29k
992 * New file formats supported
994 BFD now supports reading HP/PA-RISC executables (SOM file format?),
995 HPUX core files, and SCO 3.2v2 core files.
999 Attaching to processes now works again; thanks for the many bug reports.
1001 We have also stomped on a bunch of core dumps caused by
1002 printf_filtered("%s") problems.
1004 We eliminated a copyright problem on the rpc and ptrace header files
1005 for VxWorks, which was discovered at the last minute during the 4.7
1006 release. You should now be able to build a VxWorks GDB.
1008 You can now interrupt gdb while an attached process is running. This
1009 will cause the attached process to stop, and give control back to GDB.
1011 We fixed problems caused by using too many file descriptors
1012 for reading symbols from object files and libraries. This was
1013 especially a problem for programs that used many (~100) shared
1016 The `step' command now only enters a subroutine if there is line number
1017 information for the subroutine. Otherwise it acts like the `next'
1018 command. Previously, `step' would enter subroutines if there was
1019 any debugging information about the routine. This avoids problems
1020 when using `cc -g1' on MIPS machines.
1022 * Internal improvements
1024 GDB's internal interfaces have been improved to make it easier to support
1025 debugging of multiple languages in the future.
1027 GDB now uses a common structure for symbol information internally.
1028 Minimal symbols (derived from linkage symbols in object files), partial
1029 symbols (from a quick scan of debug information), and full symbols
1030 contain a common subset of information, making it easier to write
1031 shared code that handles any of them.
1033 * New command line options
1035 We now accept --silent as an alias for --quiet.
1039 The memory-mapped-malloc library is now licensed under the GNU Library
1040 General Public License.
1042 *** Changes in GDB-4.7:
1044 * Host/native/target split
1046 GDB has had some major internal surgery to untangle the support for
1047 hosts and remote targets. Now, when you configure GDB for a remote
1048 target, it will no longer load in all of the support for debugging
1049 local programs on the host. When fully completed and tested, this will
1050 ensure that arbitrary host/target combinations are possible.
1052 The primary conceptual shift is to separate the non-portable code in
1053 GDB into three categories. Host specific code is required any time GDB
1054 is compiled on that host, regardless of the target. Target specific
1055 code relates to the peculiarities of the target, but can be compiled on
1056 any host. Native specific code is everything else: it can only be
1057 built when the host and target are the same system. Child process
1058 handling and core file support are two common `native' examples.
1060 GDB's use of /proc for controlling Unix child processes is now cleaner.
1061 It has been split out into a single module under the `target_ops' vector,
1062 plus two native-dependent functions for each system that uses /proc.
1064 * New hosts supported
1066 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
1067 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
1068 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
1070 * New targets supported
1072 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
1073 68030 and CPU32 m68030-*-*, m68332-*-*
1075 * New native hosts supported
1077 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
1078 (386bsd is not well tested yet)
1079 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
1081 * New file formats supported
1083 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
1084 supports reading of `a.out.adobe' object files, which are an a.out
1085 format extended with minimal information about multiple sections.
1089 `show copying' is the same as the old `info copying'.
1090 `show warranty' is the same as `info warrantee'.
1091 These were renamed for consistency. The old commands continue to work.
1093 `info handle' is a new alias for `info signals'.
1095 You can now define pre-command hooks, which attach arbitrary command
1096 scripts to any command. The commands in the hook will be executed
1097 prior to the user's command. You can also create a hook which will be
1098 executed whenever the program stops. See gdb.texinfo.
1102 We now deal with Cfront style name mangling, and can even extract type
1103 info from mangled symbols. GDB can automatically figure out which
1104 symbol mangling style your C++ compiler uses.
1106 Calling of methods and virtual functions has been improved as well.
1110 The crash that occured when debugging Sun Ansi-C compiled binaries is
1111 fixed. This was due to mishandling of the extra N_SO stabs output
1114 We also finally got Ultrix 4.2 running in house, and fixed core file
1115 support, with help from a dozen people on the net.
1117 John M. Farrell discovered that the reason that single-stepping was so
1118 slow on all of the Mips based platforms (primarily SGI and DEC) was
1119 that we were trying to demangle and lookup a symbol used for internal
1120 purposes on every instruction that was being stepped through. Changing
1121 the name of that symbol so that it couldn't be mistaken for a C++
1122 mangled symbol sped things up a great deal.
1124 Rich Pixley sped up symbol lookups in general by getting much smarter
1125 about when C++ symbol mangling is necessary. This should make symbol
1126 completion (TAB on the command line) much faster. It's not as fast as
1127 we'd like, but it's significantly faster than gdb-4.6.
1131 A new user controllable variable 'call_scratch_address' can
1132 specify the location of a scratch area to be used when GDB
1133 calls a function in the target. This is necessary because the
1134 usual method of putting the scratch area on the stack does not work
1135 in systems that have separate instruction and data spaces.
1137 We integrated changes to support the 29k UDI (Universal Debugger
1138 Interface), but discovered at the last minute that we didn't have all
1139 of the appropriate copyright paperwork. We are working with AMD to
1140 resolve this, and hope to have it available soon.
1144 We have sped up the remote serial line protocol, especially for targets
1145 with lots of registers. It now supports a new `expedited status' ('T')
1146 message which can be used in place of the existing 'S' status message.
1147 This allows the remote stub to send only the registers that GDB
1148 needs to make a quick decision about single-stepping or conditional
1149 breakpoints, eliminating the need to fetch the entire register set for
1150 each instruction being stepped through.
1152 The GDB remote serial protocol now implements a write-through cache for
1153 registers, only re-reading the registers if the target has run.
1155 There is also a new remote serial stub for SPARC processors. You can
1156 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
1157 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
1158 processor with a serial port.
1162 Configure.in files have become much easier to read and modify. A new
1163 `table driven' format makes it more obvious what configurations are
1164 supported, and what files each one uses.
1168 There is a new opcodes library which will eventually contain all of the
1169 disassembly routines and opcode tables. At present, it only contains
1170 Sparc and Z8000 routines. This will allow the assembler, debugger, and
1171 disassembler (binutils/objdump) to share these routines.
1173 The libiberty library is now copylefted under the GNU Library General
1174 Public License. This allows more liberal use, and was done so libg++
1175 can use it. This makes no difference to GDB, since the Library License
1176 grants all the rights from the General Public License.
1180 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
1181 reference to the stabs symbol info used by the debugger. It is (as far
1182 as we know) the only published document on this fascinating topic. We
1183 encourage you to read it, compare it to the stabs information on your
1184 system, and send improvements on the document in general (to
1185 bug-gdb@prep.ai.mit.edu).
1187 And, of course, many bugs have been fixed.
1190 *** Changes in GDB-4.6:
1192 * Better support for C++ function names
1194 GDB now accepts as input the "demangled form" of C++ overloaded function
1195 names and member function names, and can do command completion on such names
1196 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
1197 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
1198 Make use of command completion, it is your friend.
1200 GDB also now accepts a variety of C++ mangled symbol formats. They are
1201 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
1202 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
1203 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
1204 for the list of formats.
1206 * G++ symbol mangling problem
1208 Recent versions of gcc have a bug in how they emit debugging information for
1209 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
1210 directory) can be applied to gcc to fix the problem. Alternatively, if you
1211 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
1212 usual symptom is difficulty with setting breakpoints on methods. GDB complains
1213 about the method being non-existent. (We believe that version 2.2.2 of GCC has
1216 * New 'maintenance' command
1218 All of the commands related to hacking GDB internals have been moved out of
1219 the main command set, and now live behind the 'maintenance' command. This
1220 can also be abbreviated as 'mt'. The following changes were made:
1222 dump-me -> maintenance dump-me
1223 info all-breakpoints -> maintenance info breakpoints
1224 printmsyms -> maintenance print msyms
1225 printobjfiles -> maintenance print objfiles
1226 printpsyms -> maintenance print psymbols
1227 printsyms -> maintenance print symbols
1229 The following commands are new:
1231 maintenance demangle Call internal GDB demangler routine to
1232 demangle a C++ link name and prints the result.
1233 maintenance print type Print a type chain for a given symbol
1235 * Change to .gdbinit file processing
1237 We now read the $HOME/.gdbinit file before processing the argv arguments
1238 (e.g. reading symbol files or core files). This allows global parameters to
1239 be set, which will apply during the symbol reading. The ./.gdbinit is still
1240 read after argv processing.
1242 * New hosts supported
1244 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
1246 Linux support i386-unknown-linux or linux
1248 We are also including code to support the HP/PA running BSD and HPUX. This
1249 is almost guaranteed not to work, as we didn't have time to test or build it
1250 for this release. We are including it so that the more adventurous (or
1251 masochistic) of you can play with it. We also had major problems with the
1252 fact that the compiler that we got from HP doesn't support the -g option.
1255 * New targets supported
1257 Hitachi H8/300 h8300-hitachi-hms or h8300hms
1259 * More smarts about finding #include files
1261 GDB now remembers the compilation directory for all include files, and for
1262 all files from which C is generated (like yacc and lex sources). This
1263 greatly improves GDB's ability to find yacc/lex sources, and include files,
1264 especially if you are debugging your program from a directory different from
1265 the one that contains your sources.
1267 We also fixed a bug which caused difficulty with listing and setting
1268 breakpoints in include files which contain C code. (In the past, you had to
1269 try twice in order to list an include file that you hadn't looked at before.)
1271 * Interesting infernals change
1273 GDB now deals with arbitrary numbers of sections, where the symbols for each
1274 section must be relocated relative to that section's landing place in the
1275 target's address space. This work was needed to support ELF with embedded
1276 stabs used by Solaris-2.0.
1278 * Bug fixes (of course!)
1280 There have been loads of fixes for the following things:
1281 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
1282 i960, stabs, DOS(GO32), procfs, etc...
1284 See the ChangeLog for details.
1286 *** Changes in GDB-4.5:
1288 * New machines supported (host and target)
1290 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
1292 SGI Irix-4.x mips-sgi-irix4 or iris4
1294 * New malloc package
1296 GDB now uses a new memory manager called mmalloc, based on gmalloc.
1297 Mmalloc is capable of handling mutiple heaps of memory. It is also
1298 capable of saving a heap to a file, and then mapping it back in later.
1299 This can be used to greatly speedup the startup of GDB by using a
1300 pre-parsed symbol table which lives in a mmalloc managed heap. For
1301 more details, please read mmalloc/mmalloc.texi.
1305 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
1306 'help info proc' for details.
1308 * MIPS ecoff symbol table format
1310 The code that reads MIPS symbol table format is now supported on all hosts.
1311 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
1314 * File name changes for MS-DOS
1316 Many files in the config directories have been renamed to make it easier to
1317 support GDB on MS-DOSe systems (which have very restrictive file name
1318 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
1319 environment) is close to working but has some remaining problems. Note
1320 that debugging of DOS programs is not supported, due to limitations
1321 in the ``operating system'', but it can be used to host cross-debugging.
1323 * Cross byte order fixes
1325 Many fixes have been made to support cross debugging of Sparc and MIPS
1326 targets from hosts whose byte order differs.
1328 * New -mapped and -readnow options
1330 If memory-mapped files are available on your system through the 'mmap'
1331 system call, you can use the -mapped option on the `file' or
1332 `symbol-file' commands to cause GDB to write the symbols from your
1333 program into a reusable file. If the program you are debugging is
1334 called `/path/fred', the mapped symbol file will be `./fred.syms'.
1335 Future GDB debugging sessions will notice the presence of this file,
1336 and will quickly map in symbol information from it, rather than reading
1337 the symbol table from the executable program. Using the '-mapped'
1338 option in a GDB `file' or `symbol-file' command has the same effect as
1339 starting GDB with the '-mapped' command-line option.
1341 You can cause GDB to read the entire symbol table immediately by using
1342 the '-readnow' option with any of the commands that load symbol table
1343 information (or on the GDB command line). This makes the command
1344 slower, but makes future operations faster.
1346 The -mapped and -readnow options are typically combined in order to
1347 build a `fred.syms' file that contains complete symbol information.
1348 A simple GDB invocation to do nothing but build a `.syms' file for future
1351 gdb -batch -nx -mapped -readnow programname
1353 The `.syms' file is specific to the host machine on which GDB is run.
1354 It holds an exact image of GDB's internal symbol table. It cannot be
1355 shared across multiple host platforms.
1357 * longjmp() handling
1359 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
1360 siglongjmp() without losing control. This feature has not yet been ported to
1361 all systems. It currently works on many 386 platforms, all MIPS-based
1362 platforms (SGI, DECstation, etc), and Sun3/4.
1366 Preliminary work has been put in to support the new Solaris OS from Sun. At
1367 this time, it can control and debug processes, but it is not capable of
1372 As always, many many bug fixes. The major areas were with g++, and mipsread.
1373 People using the MIPS-based platforms should experience fewer mysterious
1374 crashes and trashed symbol tables.
1376 *** Changes in GDB-4.4:
1378 * New machines supported (host and target)
1380 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
1382 BSD Reno on Vax vax-dec-bsd
1383 Ultrix on Vax vax-dec-ultrix
1385 * New machines supported (target)
1387 AMD 29000 embedded, using EBMON a29k-none-none
1391 GDB continues to improve its handling of C++. `References' work better.
1392 The demangler has also been improved, and now deals with symbols mangled as
1393 per the Annotated C++ Reference Guide.
1395 GDB also now handles `stabs' symbol information embedded in MIPS
1396 `ecoff' symbol tables. Since the ecoff format was not easily
1397 extensible to handle new languages such as C++, this appeared to be a
1398 good way to put C++ debugging info into MIPS binaries. This option
1399 will be supported in the GNU C compiler, version 2, when it is
1402 * New features for SVR4
1404 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
1405 shared libraries. Debugging dynamically linked programs should present
1406 only minor differences from debugging statically linked programs.
1408 The `info proc' command will print out information about any process
1409 on an SVR4 system (including the one you are debugging). At the moment,
1410 it prints the address mappings of the process.
1412 If you bring up GDB on another SVR4 system, please send mail to
1413 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
1415 * Better dynamic linking support in SunOS
1417 Reading symbols from shared libraries which contain debugging symbols
1418 now works properly. However, there remain issues such as automatic
1419 skipping of `transfer vector' code during function calls, which
1420 make it harder to debug code in a shared library, than to debug the
1421 same code linked statically.
1425 GDB is now using the latest `getopt' routines from the FSF. This
1426 version accepts the -- prefix for options with long names. GDB will
1427 continue to accept the old forms (-option and +option) as well.
1428 Various single letter abbreviations for options have been explicity
1429 added to the option table so that they won't get overshadowed in the
1430 future by other options that begin with the same letter.
1434 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
1435 Many assorted bugs have been handled. Many more remain to be handled.
1436 See the various ChangeLog files (primarily in gdb and bfd) for details.
1439 *** Changes in GDB-4.3:
1441 * New machines supported (host and target)
1443 Amiga 3000 running Amix m68k-cbm-svr4 or amix
1444 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
1445 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
1447 * Almost SCO Unix support
1449 We had hoped to support:
1450 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
1451 (except for core file support), but we discovered very late in the release
1452 that it has problems with process groups that render gdb unusable. Sorry
1453 about that. I encourage people to fix it and post the fixes.
1455 * Preliminary ELF and DWARF support
1457 GDB can read ELF object files on System V Release 4, and can handle
1458 debugging records for C, in DWARF format, in ELF files. This support
1459 is preliminary. If you bring up GDB on another SVR4 system, please
1460 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
1465 GDB now uses the latest `readline' library. One user-visible change
1466 is that two tabs will list possible command completions, which previously
1467 required typing M-? (meta-question mark, or ESC ?).
1471 The `stepi' bug that many of you noticed has been squashed.
1472 Many bugs in C++ have been handled. Many more remain to be handled.
1473 See the various ChangeLog files (primarily in gdb and bfd) for details.
1475 * State of the MIPS world (in case you wondered):
1477 GDB can understand the symbol tables emitted by the compilers
1478 supplied by most vendors of MIPS-based machines, including DEC. These
1479 symbol tables are in a format that essentially nobody else uses.
1481 Some versions of gcc come with an assembler post-processor called
1482 mips-tfile. This program is required if you want to do source-level
1483 debugging of gcc-compiled programs. I believe FSF does not ship
1484 mips-tfile with gcc version 1, but it will eventually come with gcc
1487 Debugging of g++ output remains a problem. g++ version 1.xx does not
1488 really support it at all. (If you're lucky, you should be able to get
1489 line numbers and stack traces to work, but no parameters or local
1490 variables.) With some work it should be possible to improve the
1493 When gcc version 2 is released, you will have somewhat better luck.
1494 However, even then you will get confusing results for inheritance and
1497 We will eventually provide full debugging of g++ output on
1498 DECstations. This will probably involve some kind of stabs-in-ecoff
1499 encapulation, but the details have not been worked out yet.
1502 *** Changes in GDB-4.2:
1504 * Improved configuration
1506 Only one copy of `configure' exists now, and it is not self-modifying.
1507 Porting BFD is simpler.
1511 The `step' and `next' commands now only stop at the first instruction
1512 of a source line. This prevents the multiple stops that used to occur
1513 in switch statements, for-loops, etc. `Step' continues to stop if a
1514 function that has debugging information is called within the line.
1518 Lots of small bugs fixed. More remain.
1520 * New host supported (not target)
1522 Intel 386 PC clone running Mach i386-none-mach
1525 *** Changes in GDB-4.1:
1527 * Multiple source language support
1529 GDB now has internal scaffolding to handle several source languages.
1530 It determines the type of each source file from its filename extension,
1531 and will switch expression parsing and number formatting to match the
1532 language of the function in the currently selected stack frame.
1533 You can also specifically set the language to be used, with
1534 `set language c' or `set language modula-2'.
1538 GDB now has preliminary support for the GNU Modula-2 compiler,
1539 currently under development at the State University of New York at
1540 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
1541 continue through the fall of 1991 and into 1992.
1543 Other Modula-2 compilers are currently not supported, and attempting to
1544 debug programs compiled with them will likely result in an error as the
1545 symbol table is read. Feel free to work on it, though!
1547 There are hooks in GDB for strict type checking and range checking,
1548 in the `Modula-2 philosophy', but they do not currently work.
1552 GDB can now write to executable and core files (e.g. patch
1553 a variable's value). You must turn this switch on, specify
1554 the file ("exec foo" or "core foo"), *then* modify it, e.g.
1555 by assigning a new value to a variable. Modifications take
1558 * Automatic SunOS shared library reading
1560 When you run your program, GDB automatically determines where its
1561 shared libraries (if any) have been loaded, and reads their symbols.
1562 The `share' command is no longer needed. This also works when
1563 examining core files.
1567 You can specify the number of lines that the `list' command shows.
1570 * New machines supported (host and target)
1572 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
1573 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
1574 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
1576 * New hosts supported (not targets)
1578 IBM RT/PC: romp-ibm-aix or rtpc
1580 * New targets supported (not hosts)
1582 AMD 29000 embedded with COFF a29k-none-coff
1583 AMD 29000 embedded with a.out a29k-none-aout
1584 Ultracomputer remote kernel debug a29k-nyu-kern
1586 * New remote interfaces
1592 *** Changes in GDB-4.0:
1596 Wide output is wrapped at good places to make the output more readable.
1598 Gdb now supports cross-debugging from a host machine of one type to a
1599 target machine of another type. Communication with the target system
1600 is over serial lines. The ``target'' command handles connecting to the
1601 remote system; the ``load'' command will download a program into the
1602 remote system. Serial stubs for the m68k and i386 are provided. Gdb
1603 also supports debugging of realtime processes running under VxWorks,
1604 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
1605 stub on the target system.
1607 New CPUs supported include the AMD 29000 and Intel 960.
1609 GDB now reads object files and symbol tables via a ``binary file''
1610 library, which allows a single copy of GDB to debug programs of multiple
1611 object file types such as a.out and coff.
1613 There is now a GDB reference card in "doc/refcard.tex". (Make targets
1614 refcard.dvi and refcard.ps are available to format it).
1617 * Control-Variable user interface simplified
1619 All variables that control the operation of the debugger can be set
1620 by the ``set'' command, and displayed by the ``show'' command.
1622 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
1623 ``Show prompt'' produces the response:
1624 Gdb's prompt is new-gdb=>.
1626 What follows are the NEW set commands. The command ``help set'' will
1627 print a complete list of old and new set commands. ``help set FOO''
1628 will give a longer description of the variable FOO. ``show'' will show
1629 all of the variable descriptions and their current settings.
1631 confirm on/off: Enables warning questions for operations that are
1632 hard to recover from, e.g. rerunning the program while
1633 it is already running. Default is ON.
1635 editing on/off: Enables EMACS style command line editing
1636 of input. Previous lines can be recalled with
1637 control-P, the current line can be edited with control-B,
1638 you can search for commands with control-R, etc.
1641 history filename NAME: NAME is where the gdb command history
1642 will be stored. The default is .gdb_history,
1643 or the value of the environment variable
1646 history size N: The size, in commands, of the command history. The
1647 default is 256, or the value of the environment variable
1650 history save on/off: If this value is set to ON, the history file will
1651 be saved after exiting gdb. If set to OFF, the
1652 file will not be saved. The default is OFF.
1654 history expansion on/off: If this value is set to ON, then csh-like
1655 history expansion will be performed on
1656 command line input. The default is OFF.
1658 radix N: Sets the default radix for input and output. It can be set
1659 to 8, 10, or 16. Note that the argument to "radix" is interpreted
1660 in the current radix, so "set radix 10" is always a no-op.
1662 height N: This integer value is the number of lines on a page. Default
1663 is 24, the current `stty rows'' setting, or the ``li#''
1664 setting from the termcap entry matching the environment
1667 width N: This integer value is the number of characters on a line.
1668 Default is 80, the current `stty cols'' setting, or the ``co#''
1669 setting from the termcap entry matching the environment
1672 Note: ``set screensize'' is obsolete. Use ``set height'' and
1673 ``set width'' instead.
1675 print address on/off: Print memory addresses in various command displays,
1676 such as stack traces and structure values. Gdb looks
1677 more ``symbolic'' if you turn this off; it looks more
1678 ``machine level'' with it on. Default is ON.
1680 print array on/off: Prettyprint arrays. New convenient format! Default
1683 print demangle on/off: Print C++ symbols in "source" form if on,
1686 print asm-demangle on/off: Same, for assembler level printouts
1689 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
1692 * Support for Epoch Environment.
1694 The epoch environment is a version of Emacs v18 with windowing. One
1695 new command, ``inspect'', is identical to ``print'', except that if you
1696 are running in the epoch environment, the value is printed in its own
1700 * Support for Shared Libraries
1702 GDB can now debug programs and core files that use SunOS shared libraries.
1703 Symbols from a shared library cannot be referenced
1704 before the shared library has been linked with the program (this
1705 happens after you type ``run'' and before the function main() is entered).
1706 At any time after this linking (including when examining core files
1707 from dynamically linked programs), gdb reads the symbols from each
1708 shared library when you type the ``sharedlibrary'' command.
1709 It can be abbreviated ``share''.
1711 sharedlibrary REGEXP: Load shared object library symbols for files
1712 matching a unix regular expression. No argument
1713 indicates to load symbols for all shared libraries.
1715 info sharedlibrary: Status of loaded shared libraries.
1720 A watchpoint stops execution of a program whenever the value of an
1721 expression changes. Checking for this slows down execution
1722 tremendously whenever you are in the scope of the expression, but is
1723 quite useful for catching tough ``bit-spreader'' or pointer misuse
1724 problems. Some machines such as the 386 have hardware for doing this
1725 more quickly, and future versions of gdb will use this hardware.
1727 watch EXP: Set a watchpoint (breakpoint) for an expression.
1729 info watchpoints: Information about your watchpoints.
1731 delete N: Deletes watchpoint number N (same as breakpoints).
1732 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
1733 enable N: Re-enables watchpoint number N (same as breakpoints).
1736 * C++ multiple inheritance
1738 When used with a GCC version 2 compiler, GDB supports multiple inheritance
1741 * C++ exception handling
1743 Gdb now supports limited C++ exception handling. Besides the existing
1744 ability to breakpoint on an exception handler, gdb can breakpoint on
1745 the raising of an exception (before the stack is peeled back to the
1748 catch FOO: If there is a FOO exception handler in the dynamic scope,
1749 set a breakpoint to catch exceptions which may be raised there.
1750 Multiple exceptions (``catch foo bar baz'') may be caught.
1752 info catch: Lists all exceptions which may be caught in the
1753 current stack frame.
1756 * Minor command changes
1758 The command ``call func (arg, arg, ...)'' now acts like the print
1759 command, except it does not print or save a value if the function's result
1760 is void. This is similar to dbx usage.
1762 The ``up'' and ``down'' commands now always print the frame they end up
1763 at; ``up-silently'' and `down-silently'' can be used in scripts to change
1764 frames without printing.
1766 * New directory command
1768 'dir' now adds directories to the FRONT of the source search path.
1769 The path starts off empty. Source files that contain debug information
1770 about the directory in which they were compiled can be found even
1771 with an empty path; Sun CC and GCC include this information. If GDB can't
1772 find your source file in the current directory, type "dir .".
1774 * Configuring GDB for compilation
1776 For normal use, type ``./configure host''. See README or gdb.texinfo
1779 GDB now handles cross debugging. If you are remotely debugging between
1780 two different machines, type ``./configure host -target=targ''.
1781 Host is the machine where GDB will run; targ is the machine
1782 where the program that you are debugging will run.