1 What has changed since GDB-3.5?
2 (Organized release by release)
4 *** Changes in GDB-4.4:
6 * New machines supported (host and target)
8 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
10 BSD Reno on Vax vax-dec-bsd
11 Ultrix on Vax vax-dec-ultrix
13 * New machines supported (target)
15 AMD 29000 embedded, using EBMON a29k-none-none
19 GDB continues to improve its handling of C++. `References' work better.
20 The demangler has also been improved, and now deals with symbols mangled as
21 per the Annotated C++ Reference Guide.
23 GDB also now handles `stabs' symbol information embedded in MIPS
24 `ecoff' symbol tables. Since the ecoff format was not easily
25 extensible to handle new languages such as C++, this appeared to be a
26 good way to put C++ debugging info into MIPS binaries. This option
27 will be supported in the GNU C compiler, version 2, when it is
30 * New features for SVR4
32 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
33 shared libraries. Debugging dynamically linked programs should present
34 only minor differences from debugging statically linked programs.
36 The `info proc' command will print out information about any process
37 on an SVR4 system (including the one you are debugging). At the moment,
38 it prints the address mappings of the process.
40 If you bring up GDB on another SVR4 system, please send mail to
41 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
43 * Better dynamic linking support in SunOS
45 Reading symbols from shared libraries which contain debugging symbols
46 now works properly. However, there remain issues such as automatic
47 skipping of `transfer vector' code during function calls, which
48 make it harder to debug code in a shared library, than to debug the
49 same code linked statically.
53 GDB is now using the latest `getopt' routines from the FSF. This
54 version accepts the -- prefix for options with long names. GDB will
55 continue to accept the old forms (-option and +option) as well.
56 Various single letter abbreviations for options have been explicity
57 added to the option table so that they won't get overshadowed in the
58 future by other options that begin with the same letter.
62 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
63 Many assorted bugs have been handled. Many more remain to be handled.
64 See the various ChangeLog files (primarily in gdb and bfd) for details.
67 *** Changes in GDB-4.3:
69 * New machines supported (host and target)
71 Amiga 3000 running Amix m68k-cbm-svr4 or amix
72 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
73 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
75 * Almost SCO Unix support
77 We had hoped to support:
78 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
79 (except for core file support), but we discovered very late in the release
80 that it has problems with process groups that render gdb unusable. Sorry
81 about that. I encourage people to fix it and post the fixes.
83 * Preliminary ELF and DWARF support
85 GDB can read ELF object files on System V Release 4, and can handle
86 debugging records for C, in DWARF format, in ELF files. This support
87 is preliminary. If you bring up GDB on another SVR4 system, please
88 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
93 GDB now uses the latest `readline' library. One user-visible change
94 is that two tabs will list possible command completions, which previously
95 required typing M-? (meta-question mark, or ESC ?).
99 The `stepi' bug that many of you noticed has been squashed.
100 Many bugs in C++ have been handled. Many more remain to be handled.
101 See the various ChangeLog files (primarily in gdb and bfd) for details.
103 * State of the MIPS world (in case you wondered):
105 GDB can understand the symbol tables emitted by the compilers
106 supplied by most vendors of MIPS-based machines, including DEC. These
107 symbol tables are in a format that essentially nobody else uses.
109 Some versions of gcc come with an assembler post-processor called
110 mips-tfile. This program is required if you want to do source-level
111 debugging of gcc-compiled programs. I believe FSF does not ship
112 mips-tfile with gcc version 1, but it will eventually come with gcc
115 Debugging of g++ output remains a problem. g++ version 1.xx does not
116 really support it at all. (If you're lucky, you should be able to get
117 line numbers and stack traces to work, but no parameters or local
118 variables.) With some work it should be possible to improve the
121 When gcc version 2 is released, you will have somewhat better luck.
122 However, even then you will get confusing results for inheritance and
125 We will eventually provide full debugging of g++ output on
126 DECstations. This will probably involve some kind of stabs-in-ecoff
127 encapulation, but the details have not been worked out yet.
130 *** Changes in GDB-4.2:
132 * Improved configuration
134 Only one copy of `configure' exists now, and it is not self-modifying.
135 Porting BFD is simpler.
139 The `step' and `next' commands now only stop at the first instruction
140 of a source line. This prevents the multiple stops that used to occur
141 in switch statements, for-loops, etc. `Step' continues to stop if a
142 function that has debugging information is called within the line.
146 Lots of small bugs fixed. More remain.
148 * New host supported (not target)
150 Intel 386 PC clone running Mach i386-none-mach
153 *** Changes in GDB-4.1:
155 * Multiple source language support
157 GDB now has internal scaffolding to handle several source languages.
158 It determines the type of each source file from its filename extension,
159 and will switch expression parsing and number formatting to match the
160 language of the function in the currently selected stack frame.
161 You can also specifically set the language to be used, with
162 `set language c' or `set language modula-2'.
166 GDB now has preliminary support for the GNU Modula-2 compiler,
167 currently under development at the State University of New York at
168 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
169 continue through the fall of 1991 and into 1992.
171 Other Modula-2 compilers are currently not supported, and attempting to
172 debug programs compiled with them will likely result in an error as the
173 symbol table is read. Feel free to work on it, though!
175 There are hooks in GDB for strict type checking and range checking,
176 in the `Modula-2 philosophy', but they do not currently work.
180 GDB can now write to executable and core files (e.g. patch
181 a variable's value). You must turn this switch on, specify
182 the file ("exec foo" or "core foo"), *then* modify it, e.g.
183 by assigning a new value to a variable. Modifications take
186 * Automatic SunOS shared library reading
188 When you run your program, GDB automatically determines where its
189 shared libraries (if any) have been loaded, and reads their symbols.
190 The `share' command is no longer needed. This also works when
191 examining core files.
195 You can specify the number of lines that the `list' command shows.
198 * New machines supported (host and target)
200 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
201 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
202 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
204 * New hosts supported (not targets)
206 IBM RT/PC: romp-ibm-aix or rtpc
208 * New targets supported (not hosts)
210 AMD 29000 embedded with COFF a29k-none-coff
211 AMD 29000 embedded with a.out a29k-none-aout
212 Ultracomputer remote kernel debug a29k-nyu-kern
214 * New remote interfaces
220 *** Changes in GDB-4.0:
224 Wide output is wrapped at good places to make the output more readable.
226 Gdb now supports cross-debugging from a host machine of one type to a
227 target machine of another type. Communication with the target system
228 is over serial lines. The ``target'' command handles connecting to the
229 remote system; the ``load'' command will download a program into the
230 remote system. Serial stubs for the m68k and i386 are provided. Gdb
231 also supports debugging of realtime processes running under VxWorks,
232 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
233 stub on the target system.
235 New CPUs supported include the AMD 29000 and Intel 960.
237 GDB now reads object files and symbol tables via a ``binary file''
238 library, which allows a single copy of GDB to debug programs of multiple
239 object file types such as a.out and coff.
241 There is now a GDB reference card in "doc/refcard.tex". (Make targets
242 refcard.dvi and refcard.ps are available to format it).
245 * Control-Variable user interface simplified
247 All variables that control the operation of the debugger can be set
248 by the ``set'' command, and displayed by the ``show'' command.
250 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
251 ``Show prompt'' produces the response:
252 Gdb's prompt is new-gdb=>.
254 What follows are the NEW set commands. The command ``help set'' will
255 print a complete list of old and new set commands. ``help set FOO''
256 will give a longer description of the variable FOO. ``show'' will show
257 all of the variable descriptions and their current settings.
259 confirm on/off: Enables warning questions for operations that are
260 hard to recover from, e.g. rerunning the program while
261 it is already running. Default is ON.
263 editing on/off: Enables EMACS style command line editing
264 of input. Previous lines can be recalled with
265 control-P, the current line can be edited with control-B,
266 you can search for commands with control-R, etc.
269 history filename NAME: NAME is where the gdb command history
270 will be stored. The default is .gdb_history,
271 or the value of the environment variable
274 history size N: The size, in commands, of the command history. The
275 default is 256, or the value of the environment variable
278 history save on/off: If this value is set to ON, the history file will
279 be saved after exiting gdb. If set to OFF, the
280 file will not be saved. The default is OFF.
282 history expansion on/off: If this value is set to ON, then csh-like
283 history expansion will be performed on
284 command line input. The default is OFF.
286 radix N: Sets the default radix for input and output. It can be set
287 to 8, 10, or 16. Note that the argument to "radix" is interpreted
288 in the current radix, so "set radix 10" is always a no-op.
290 height N: This integer value is the number of lines on a page. Default
291 is 24, the current `stty rows'' setting, or the ``li#''
292 setting from the termcap entry matching the environment
295 width N: This integer value is the number of characters on a line.
296 Default is 80, the current `stty cols'' setting, or the ``co#''
297 setting from the termcap entry matching the environment
300 Note: ``set screensize'' is obsolete. Use ``set height'' and
301 ``set width'' instead.
303 print address on/off: Print memory addresses in various command displays,
304 such as stack traces and structure values. Gdb looks
305 more ``symbolic'' if you turn this off; it looks more
306 ``machine level'' with it on. Default is ON.
308 print array on/off: Prettyprint arrays. New convenient format! Default
311 print demangle on/off: Print C++ symbols in "source" form if on,
314 print asm-demangle on/off: Same, for assembler level printouts
317 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
320 * Support for Epoch Environment.
322 The epoch environment is a version of Emacs v18 with windowing. One
323 new command, ``inspect'', is identical to ``print'', except that if you
324 are running in the epoch environment, the value is printed in its own
328 * Support for Shared Libraries
330 GDB can now debug programs and core files that use SunOS shared libraries.
331 Symbols from a shared library cannot be referenced
332 before the shared library has been linked with the program (this
333 happens after you type ``run'' and before the function main() is entered).
334 At any time after this linking (including when examining core files
335 from dynamically linked programs), gdb reads the symbols from each
336 shared library when you type the ``sharedlibrary'' command.
337 It can be abbreviated ``share''.
339 sharedlibrary REGEXP: Load shared object library symbols for files
340 matching a unix regular expression. No argument
341 indicates to load symbols for all shared libraries.
343 info sharedlibrary: Status of loaded shared libraries.
348 A watchpoint stops execution of a program whenever the value of an
349 expression changes. Checking for this slows down execution
350 tremendously whenever you are in the scope of the expression, but is
351 quite useful for catching tough ``bit-spreader'' or pointer misuse
352 problems. Some machines such as the 386 have hardware for doing this
353 more quickly, and future versions of gdb will use this hardware.
355 watch EXP: Set a watchpoint (breakpoint) for an expression.
357 info watchpoints: Information about your watchpoints.
359 delete N: Deletes watchpoint number N (same as breakpoints).
360 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
361 enable N: Re-enables watchpoint number N (same as breakpoints).
364 * C++ multiple inheritance
366 When used with a GCC version 2 compiler, GDB supports multiple inheritance
369 * C++ exception handling
371 Gdb now supports limited C++ exception handling. Besides the existing
372 ability to breakpoint on an exception handler, gdb can breakpoint on
373 the raising of an exception (before the stack is peeled back to the
376 catch FOO: If there is a FOO exception handler in the dynamic scope,
377 set a breakpoint to catch exceptions which may be raised there.
378 Multiple exceptions (``catch foo bar baz'') may be caught.
380 info catch: Lists all exceptions which may be caught in the
384 * Minor command changes
386 The command ``call func (arg, arg, ...)'' now acts like the print
387 command, except it does not print or save a value if the function's result
388 is void. This is similar to dbx usage.
390 The ``up'' and ``down'' commands now always print the frame they end up
391 at; ``up-silently'' and `down-silently'' can be used in scripts to change
392 frames without printing.
394 * New directory command
396 'dir' now adds directories to the FRONT of the source search path.
397 The path starts off empty. Source files that contain debug information
398 about the directory in which they were compiled can be found even
399 with an empty path; Sun CC and GCC include this information. If GDB can't
400 find your source file in the current directory, type "dir .".
402 * Configuring GDB for compilation
404 For normal use, type ``./configure host''. See README or gdb.texinfo
407 GDB now handles cross debugging. If you are remotely debugging between
408 two different machines, type ``./configure host -target=targ''.
409 Host is the machine where GDB will run; targ is the machine
410 where the program that you are debugging will run.