+ README for gdb-4.4 release
+ John Gilmore & Stu Grossman 31 Jan 1992
+
This is GDB, the GNU source-level debugger, presently running under un*x.
+A summary of new features is in the file `WHATS.NEW'.
-Before compiling GDB, you must tell GDB what kind of machine you are
-running on. To do this, type `config.gdb machine', where machine is
-something like `vax' or `sun2'. For a list of valid machine types,
-type `config.gdb'.
-Normally config.gdb edits the makefile as necessary. If you have to
-edit the makefile on a standard machine listed in config.gdb this
-should be considered a bug and reported as such.
+Unpacking and Installation -- quick overview
+==========================
-Once these files are set up, just `make' will do everything,
-producing an executable `gdb' in this directory.
+In this release, the GDB debugger sources, the generic GNU include
+files, the BFD ("binary file description") library, the readline library,
+and a miscellaneous library all have directories of their own underneath
+the gdb-4.4 directory. The idea is that a variety of GNU tools can
+share a common copy of these things. Configuration scripts and
+makefiles exist to cruise up and down this directory tree and
+automatically build all the pieces in the right order.
-If you want a new (current to this release) version of the manual, you
-will have to use the gdb.texinfo file provided with this distribution.
-The gdb.texinfo file requires the texinfo-format-buffer command from
-emacs 18.55 or later.
+When you unpack the gdb-4.4.tar.Z file, you'll get a directory called
+`gdb-4.4', which contains:
-About languages other than C...
+ DOC.configure bfd/ configure* glob/ readline/
+ Makefile.in config/ configure.in include/ texinfo/
+ README config.sub* gdb/ libiberty/
-C++ support has been integrated into gdb. GDB should work with
-FORTRAN programs (if you have problem, please send a bug report), but
-I am not aware of anyone who is working on getting it to use the
-syntax of any language other than C or C++. Pascal programs which use
-sets, subranges, file variables, or nested functions will not
-currently work.
+To build GDB, you can just do:
-About -gg format...
+ cd gdb-4.4
+ ./configure HOSTTYPE (e.g. sun4, decstation)
+ make
+ cp gdb/gdb /usr/local/bin/gdb (or wherever you want)
-Currently GDB version 3.x does *not* support GCC's -gg format. This
-is because it (in theory) has fast enough startup on dbx debugging
-format object files that -gg format is unnecessary (and hence
-undesirable, since it wastes space and processing power in gcc). I
-would like to hear people's opinions on the amount of time currently
-spent in startup; is it fast enough?
+This will configure and build all the libraries as well as GDB.
+If you get compiler warnings during this stage, see the `Reporting Bugs'
+section below; there are a few known problems.
-About remote debugging...
+GDB can be used as a cross-debugger, running on a machine of one type
+while debugging a program running on a machine of another type. See below.
-The two files remote-multi.shar and remote-sa.m68k.shar contain two
-examples of a remote stub to be used with remote.c. The the -multi
-file is a general stub that can probably be running on various
-different flavors of unix to allow debugging over a serial line from
-one machine to another. The remote-sa.m68k.shar is designed to run
-standalone on a 68k type cpu and communicate properley with the
-remote.c stub over a serial line.
-About reporting bugs...
+More Documentation
+==================
-The correct address for reporting bugs found with gdb is
+ The GDB 4 release includes an already-formatted reference card,
+ready for printing on a PostScript or GhostScript printer, in the `gdb'
+subdirectory of the main source directory--in `gdb-4.4/gdb/refcard.ps'
+of the version 4.4 release. If you have a PostScript or GhostScript
+printer, you can print the reference card by just sending `refcard.ps'
+to the printer.
-About xgdb...
+ If all you have is TeX, format the GDB reference card by typing:
-xgdb.c was provided to us by the user community; it is not an integral
-part of the gdb distribution. The problem of providing visual
-debugging support on top of gdb is peripheral to the GNU project and
-(at least right now) we can't afford to put time into it. So while we
-will be happy to incorporate user fixes to xgdb.c, we do not guarantee
-that it will work and we will not fix bugs reported in it. Someone is
-working on writing a new XGDB, so improving (e.g. by fixing it so that
-it will work, if it doesn't currently) the current one is not worth it.
+ make refcard.dvi
-For those intersted in auto display of source and the availability of
-an editor while debugging I suggest trying gdb-mode in gnu-emacs.
-Comments on this mode are welcome.
+ The GDB reference card is designed to print in landscape mode on US
+"letter" size paper; that is, on a sheet 11 inches wide by 8.5 inches
+high. You will need to specify this form of printing as an option to
+your DVI output program.
+
+ All the documentation for GDB comes as part of the online
+distribution. The documentation is written in Texinfo format,
+which is a documentation system that uses a single source file to
+produce both on-line information and a printed manual. You can use
+one of the Info formatting commands to create the on-line version of
+the documentation and TeX (or `texi2roff') to typeset the printed
+version.
+
+ GDB includes an already formatted copy of the on-line Info version
+of this manual in the `gdb' subdirectory. The main Info file is
+`gdb-VERSION-NUMBER/gdb/gdb.info', and it refers to subordinate files
+matching `gdb.info*' in the same directory.
+
+ If you want to format these Info files yourself, you need one of the
+Info formatting programs, such as `texinfo-format-buffer' or
+`makeinfo'.
+
+ If you have `makeinfo' installed, and are in the top level GDB
+source directory (`gdb-4.4', in the case of version 4.4), you can make
+the Info file by typing:
+
+ cd gdb
+ make gdb.info
+
+ If you want to typeset and print copies of this manual, you need
+TeX, a printing program such as `lpr', and `texinfo.tex', the Texinfo
+definitions file.
+
+ TeX is typesetting program; it does not print files directly, but
+produces output files called DVI files. To print a typeset document,
+you need a program to print DVI files. If your system has TeX
+installed, chances are it has such a program. The precise command to
+use depends on your system; `lpr -d' is common; another is `dvips'.
+The DVI print command may require a file name without any extension or
+a `.dvi' extension.
+
+ TeX also requires a macro definitions file called `texinfo.tex'.
+This file tells TeX how to typeset a document written in Texinfo
+format. On its own, TeX cannot read, much less typeset a Texinfo
+file. `texinfo.tex' is distributed with GDB and is located in the
+`gdb-VERSION-NUMBER/texinfo' directory.
+
+ If you have TeX and a DVI printer program installed, you can
+typeset and print this manual. First switch to the the `gdb'
+subdirectory of the main source directory (for example, to
+`gdb-4.4/gdb') and then type:
+
+ make gdb.dvi
+
+Installing GDB
+==============
+
+ GDB comes with a `configure' script that automates the process of
+preparing GDB for installation; you can then use `make' to build the
+`gdb' program.
+
+ The GDB distribution includes all the source code you need for GDB
+in a single directory, whose name is usually composed by appending the
+version number to `gdb'.
+
+ For example, the GDB version 4.4 distribution is in the `gdb-4.4'
+directory. That directory contains:
+
+`gdb-4.4/configure (and supporting files)'
+ script for configuring GDB and all its supporting libraries.
+
+`gdb-4.4/gdb'
+ the source specific to GDB itself
+
+`gdb-4.4/bfd'
+ source for the Binary File Descriptor Library
+
+`gdb-4.4/include'
+ GNU include files
+
+`gdb-4.4/libiberty'
+ source for the `-liberty' free software library
+
+`gdb-4.4/readline'
+ source for the GNU command-line interface
+
+ The simplest way to configure and build GDB is to run `configure'
+from the `gdb-VERSION-NUMBER' source directory, which in this example
+is the `gdb-4.4' directory.
+
+ First switch to the `gdb-VERSION-NUMBER' source directory if you
+are not already in it; then run `configure'. Pass the identifier for
+the platform on which GDB will run as an argument.
+
+ For example:
+
+ cd gdb-4.4
+ ./configure HOST
+ make
+
+where HOST is an identifier such as `sun4' or `decstation', that
+identifies the platform where GDB will run.
+
+ These `configure' and `make' commands build the three libraries `bfd',
+`readline', and `libiberty', then `gdb' itself. The configured source
+files, and the binaries, are left in the corresponding source
+directories.
+
+ `configure' is a Bourne-shell (`/bin/sh') script; if your system
+does not recognize this automatically when you run a different shell,
+you may need to run `sh' on it explicitly:
+
+ sh configure HOST
+
+ If you run `configure' from a directory that contains source
+directories for multiple libraries or programs, such as the `gdb-4.4'
+source directory for version 4.4, `configure' creates configuration
+files for every directory level underneath (unless you tell it not to,
+with the `--norecursion' option).
+
+ You can run the `configure' script from any of the subordinate
+directories in the GDB distribution, if you only want to configure
+that subdirectory; but be sure to specify a path to it.
+
+ For example, with version 4.4, type the following to configure only
+the `bfd' subdirectory:
+
+ cd gdb-4.4/bfd
+ ../configure HOST
+
+ You can install `gdb' anywhere; it has no hardwired paths.
+However, you should make sure that the shell on your path (named by
+the `SHELL' environment variable) is publicly readable. Remember that
+GDB uses the shell to start your program--some systems refuse to let
+GDB debug child processes whose programs are not readable.
+
+
+Compiling GDB in Another Directory
+==================================
+
+ If you want to run GDB versions for several host or target machines,
+you'll need a different `gdb' compiled for each combination of host
+and target. `configure' is designed to make this easy by allowing you
+to generate each configuration in a separate subdirectory, rather than
+in the source directory. If your `make' program handles the `VPATH'
+feature (GNU `make' does), running `make' in each of these directories
+then builds the `gdb' program specified there.
+
+ To build `gdb' in a separate directory, run `configure' with the
+`--srcdir' option to specify where to find the source. (Remember,
+you'll also need to specify a path to find `configure' itself from
+your working directory.)
+
+ For example, with version 4.4, you can build GDB in a separate
+directory for a Sun 4 like this:
+
+ cd gdb-4.4
+ mkdir ../gdb-sun4
+ cd ../gdb-sun4
+ ../gdb-4.4/configure --srcdir=../gdb-4.4 sun4
+ make
+
+ When `configure' builds a configuration using a remote source
+directory, it creates a tree for the binaries with the same structure
+(and using the same names) as the tree under the source directory. In
+the example, you'd find the Sun 4 library `libiberty.a' in the
+directory `gdb-sun4/libiberty', and GDB itself in `gdb-sun4/gdb'.
+
+ One popular use for building several GDB configurations in separate
+directories is to configure GDB for cross-compiling (where GDB runs on
+one machine--the host--while debugging programs that run on another
+machine--the target). You specify a cross-debugging target by giving
+the `--target=TARGET' option to `configure'.
+
+ When you run `make' to build a program or library, you must run it
+in a configured directory--whatever directory you were in when you
+called `configure' (or one of its subdirectories).
+
+ The `Makefile' generated by `configure' for each source directory
+also runs recursively. If you type `make' in a source directory such
+as `gdb-4.4' (or in a separate configured directory configured with
+`--srcdir=PATH/gdb-4.4'), you will build all the required libraries,
+then build GDB.
+
+ When you have multiple hosts or targets configured in separate
+directories, you can run `make' on them in parallel (for example, if
+they are NFS-mounted on each of the hosts); they will not interfere
+with each other.
+
+
+Specifying Names for Hosts and Targets
+======================================
+
+ The specifications used for hosts and targets in the `configure'
+script are based on a three-part naming scheme, but some short
+predefined aliases are also supported. The full naming scheme encodes
+three pieces of information in the following pattern:
-About the machine-dependent files...
+ ARCHITECTURE-VENDOR-OS
-m-<machine>.h (param.h is a link to this file).
-This file contains macro definitions that express information
-about the machine's registers, stack frame format and instructions.
+ For example, you can use the alias `sun4' as a HOST argument or in
+a `+target=TARGET' option, but the equivalent full name is
+`sparc-sun-sunos4'.
-<machine>-opcode.h (opcode.h is a link to this file).
-<machine>-pinsn.c (pinsn.c is a link to this file).
-These files contain the information necessary to print instructions
-for your cpu type.
+ The following table shows all the architectures, hosts, and OS
+prefixes that `configure' recognizes in GDB version 4.4. Entries in
+the "OS prefix" column ending in a `*' may be followed by a release
+number.
-<machine>-dep.c (dep.c is a link to this file).
-Those routines which provide a low level interface to ptrace and which
-tend to be machine-dependent. (The machine-independent routines are in
-`infrun.c' and `inflow.c')
-About writing code for GDB...
+ ARCHITECTURE VENDOR OS prefix
+ ------------+--------------------------+---------------------------
+ | |
+ 580 | altos hp | aix* msdos*
+ a29k | amd ibm | amigados newsos*
+ alliant | amdahl intel | aout nindy*
+ arm | aout isi | bout osf*
+ c1 | apollo little | bsd* sco*
+ c2 | att mips | coff sunos*
+ cray2 | bcs motorola | ctix* svr4
+ h8300 | bout ncr | dgux* sym*
+ i386 | bull next | dynix* sysv*
+ i860 | cbm nyu | ebmon ultrix*
+ i960 | coff sco | esix* unicos*
+ m68000 | convergent sequent | hds unos*
+ m68k | convex sgi | hpux* uts
+ m88k | cray sony | irix* v88r*
+ mips | dec sun | isc* vms*
+ ns32k | encore unicom | kern vxworks*
+ pyramid | gould utek | mach*
+ romp | hitachi wrs |
+ rs6000 | |
+ sparc | |
+ tahoe | |
+ tron | |
+ vax | |
+ xmp | |
+ ymp | |
+
+ *Warning:* `configure' can represent a very large number of
+ combinations of architecture, vendor, and OS. There is by no
+ means support available for all possible combinations!
+
+ The `configure' script accompanying GDB does not provide any query
+facility to list all supported host and target names or aliases.
+`configure' calls the Bourne shell script `config.sub' to map
+abbreviations to full names; you can read the script, if you wish, or
+you can use it to test your guesses on abbreviations--for example:
+
+ % sh config.sub sun4
+ sparc-sun-sunos4
+ % sh config.sub sun3
+ m68k-sun-sunos4
+ % sh config.sub decstation
+ mips-dec-ultrix
+ % sh config.sub hp300bsd
+ m68k-hp-bsd
+ % sh config.sub i386v
+ i386-none-sysv
+ % sh config.sub i486v
+ *** Configuration "i486v" not recognized
+
+`config.sub' is also distributed in the GDB source directory
+(`gdb-4.4', for version 4.4).
+
+
+`configure' Options
+===================
+
+ Here is a summary of all the `configure' options and arguments that
+you might use for building GDB:
+
+ configure [--destdir=DIR] [--srcdir=PATH]
+ [--norecursion] [--rm]
+ [--target=TARGET] HOST
+
+You may introduce options with a single `-' rather than `--' if you
+prefer; but you may abbreviate option names if you use `--'.
+
+`--destdir=DIR'
+ DIR is an installation directory *path prefix*. After you
+ configure with this option, `make install' will install GDB as
+ `DIR/bin/gdb', and the libraries in `DIR/lib'. If you specify
+ `--destdir=/usr/local', for example, `make install' creates
+ `/usr/local/bin/gdb'.
+
+`--srcdir=PATH'
+ Use this option to make configurations in directories separate
+ from the GDB source directories. Among other things, you can use
+ this to build (or maintain) several configurations
+ simultaneously, in separate directories. `configure' writes
+ configuration specific files in the current directory, but
+ arranges for them to use the source in the directory PATH.
+ `configure' will create directories under the working directory
+ in parallel to the source directories below PATH.
+
+`--norecursion'
+ Configure only the directory level where `configure' is executed;
+ do not propagate configuration to subdirectories.
+
+`--rm'
+ Remove the configuration that the other arguments specify.
+
+`--target=TARGET'
+ Configure GDB for cross-debugging programs running on the
+ specified TARGET. Without this option, GDB is configured to debug
+ programs that run on the same machine (HOST) as GDB itself.
+
+ There is no convenient way to generate a list of all available
+ targets.
+
+`HOST ...'
+ Configure GDB to run on the specified HOST.
+
+ There is no convenient way to generate a list of all available
+ hosts.
+
+`configure' accepts other options, for compatibility with configuring
+other GNU tools recursively; but these are the only options that
+affect GDB or its supporting libraries.
+
+
+ Languages other than C
+
+GDB provides some support for debugging C++ progams. Partial Modula-2
+support is now in GDB. GDB should work with FORTRAN programs. (If you
+have problems, please send a bug report; you may have to refer to some
+FORTRAN variables with a trailing underscore). I am not aware of
+anyone who is working on getting gdb to use the syntax of any other
+language. Pascal programs which use sets, subranges, file variables,
+or nested functions will not currently work.
+
+
+ Kernel debugging
+
+I have't done this myself so I can't really offer any advice.
+Remote debugging over serial lines works fine, but the kernel debugging
+code in here has not been tested in years. Van Jacobson claims to have
+better kernel debugging.
+
+
+ Remote debugging
+
+The files m68k-stub.c and i386-stub.c contain two examples of remote
+stubs to be used with remote.c. They are designeded to run standalone
+on a 68k or 386 cpu and communicate properly with the remote.c stub
+over a serial line.
+
+The file rem-multi.shar contains a general stub that can probably
+run on various different flavors of unix to allow debugging over a
+serial line from one machine to another.
+
+Some working remote interfaces for talking to existing ROM monitors
+are:
+ remote-eb.c AMD 29000 "EBMON"
+ remote-nindy.c Intel 960 "Nindy"
+ remote-adapt.c AMD 29000 "Adapt"
+ remote-mm.c AMD 29000 "minimon"
+
+Remote-vx.c and the vx-share subdirectory contain a remote interface for the
+VxWorks realtime kernel, which communicates over TCP using the Sun
+RPC library. This would be a useful starting point for other remote-
+via-ethernet back ends.
+
+
+ Reporting Bugs
+
+The correct address for reporting bugs found in gdb is
+Please include the GDB version number (e.g. gdb-4.4), and how
+you configured it (e.g. "sun4" or "mach386 host, i586-intel-synopsys
+target").
+
+A known bug:
+
+ * If you run with a watchpoint enabled, breakpoints will become
+ erratic and might not stop the program. Disabling or deleting the
+ watchpoint will fix the problem.
+
+GDB can produce warnings about symbols that it does not understand. By
+default, these warnings are disabled. You can enable them by executing
+`set complaint 10' (which you can put in your ~/.gdbinit if you like).
+I recommend doing this if you are working on a compiler, assembler,
+linker, or gdb, since it will point out problems that you may be able
+to fix. Warnings produced during symbol reading indicate some mismatch
+between the object file and GDB's symbol reading code. In many cases,
+it's a mismatch between the specs for the object file format, and what
+the compiler actually outputs or the debugger actually understands.
+
+If you port gdb to a new machine, please send the required changes to
+own port in the file gdb-4.4/gdb/doc/gdbint.texinfo, which you can
+print out, or read with `info' (see the Makefile.in there). If your
+changes are more than a few lines, obtain and send in a copyright
+`Writing Code for GDB'.
+
+
+ X Windows versus GDB
+
+xgdb is obsolete. We are not doing any development or support of it.
+
+There is an "xxgdb", which shows more promise, which was posted to
+comp.sources.x.
+
+For those intersted in auto display of source and the availability of
+an editor while debugging I suggest trying gdb-mode in gnu-emacs
+(Try typing M-x gdb RETURN). Comments on this mode are welcome.
+
+
+ Writing Code for GDB
We appreciate having users contribute code that is of general use, but
for it to be included in future GDB releases it must be cleanly
-written. We do not want to include changes that will needlessly make future
-maintainance difficult. It is not much harder to do things right, and
-in the long term it is worth it to the GNU project, and probably to
-you individually as well.
+written. We do not want to include changes that will needlessly make
+future maintainance difficult. It is not much harder to do things
+right, and in the long term it is worth it to the GNU project, and
+probably to you individually as well.
+
+If you make substantial changes, you'll have to file a copyright
+assignment with the Free Software Foundation before we can produce a
+release that includes your changes. Send mail requesting the copyright
+changes actually work, or even before you start them, because a manager
+or lawyer on your end will probably make this a slow process.
Please code according to the GNU coding standards. If you do not have
Please try to avoid making machine-specific changes to
-machine-independent files (i.e. all files except "param.h" and
-"dep.c". "pinsn.c" and "opcode.h" are processor-specific but not
-operating system-dependent). If this is unavoidable, put a hook in
-the machine-independent file which calls a (possibly)
-machine-dependent macro (for example, the IGNORE_SYMBOL macro can be
-used for any symbols which need to be ignored on a specific machine.
-Calling IGNORE_SYMBOL in dbxread.c is a lot cleaner than a maze of #if
+machine-independent files. If this is unavoidable, put a hook in the
+machine-independent file which calls a (possibly) machine-dependent
+macro (for example, the IGNORE_SYMBOL macro can be used for any
+symbols which need to be ignored on a specific machine. Calling
+IGNORE_SYMBOL in dbxread.c is a lot cleaner than a maze of #if
defined's). The machine-independent code should do whatever "most"
machines want if the macro is not defined in param.h. Using #if
-defined can sometimes be OK (e.g. SET_STACK_LIMIT_HUGE) but should be
+defined can sometimes be OK (e.g. SET_STACK_LIMIT_HUGE) but should be
conditionalized on a specific feature of an operating system (set in
-param.h) rather than something like #if defined(vax) or #if
-defined(SYSV).
+tm.h or xm.h) rather than something like #if defined(vax) or #if
+defined(SYSV). If you use an #ifdef on some symbol that is defined
+in a header file (e.g. #ifdef TIOCSETP), *please* make sure that you
+have #include'd the relevant header file in that module!
It is better to replace entire routines which may be system-specific,
rather than put in a whole bunch of hooks which are probably not going
the necessary changes throughout all the code in dbxread.c that
currently assumes BSD format.
-Please avoid duplicating code. For example, if something needs to be
-changed in read_inferior_memory, it is very painful because there is a
-copy in every dep.c file. The correct way to do this is to put (in
-this case) the standard ptrace interfaces in a separate file ptrace.c,
-which is used by all systems which have ptrace. ptrace.c would deal
-with variations between systems the same way any system-independent
-file would (hooks, #if defined, etc.).
+When generalizing GDB along a particular interface, please use an
+attribute-struct rather than inserting tests or switch statements
+everywhere. For example, GDB has been generalized to handle multiple
+kinds of remote interfaces -- not by #ifdef's everywhere, but by
+defining the "target_ops" structure and having a current target (as
+well as a stack of targets below it, for memory references). Whenever
+something needs to be done that depends on which remote interface we
+are using, a flag in the current target_ops structure is tested (e.g.
+`target_has_stack'), or a function is called through a pointer in the
+current target_ops structure. In this way, when a new remote interface
+is added, only one module needs to be touched -- the one that actually
+implements the new remote interface. Other examples of
+attribute-structs are BFD access to multiple kinds of object file
+formats, or GDB's access to multiple source languages.
-About debugging gdb with itself...
+Please avoid duplicating code. For example, in GDB 3.x all the stuff
+in infptrace.c was duplicated in *-dep.c, and so changing something
+was very painful. In GDB 4.x, these have all been consolidated
+into infptrace.c. infptrace.c can deal with variations between
+systems the same way any system-independent file would (hooks, #if
+defined, etc.), and machines which are radically different don't need
+to use infptrace.c at all. The same was true of core_file_command
+and exec_file_command.
-You probably want to do a "make TAGS" after you configure your
-distribution; this will put the machine dependent routines for your
-local machine where they will be accessed first by a M-period .
-Also, make sure that you've compiled gdb with your local cc or taken
-appropriate precautions regarding ansification of include files. See
-the Makefile for more information.
+ Debugging gdb with itself
-The "info" command, when executed without a subcommand in a gdb being
+If gdb is limping on your machine, this is the preferred way to get it
+fully functional. Be warned that in some ancient Unix systems, like
+Ultrix 4.0, a program can't be running in one process while it is being
+debugged in another. Rather than doing "./gdb ./gdb", which works on
+Suns and such, you can copy gdb to gdb2 and then do "./gdb ./gdb2".
+
+When you run gdb in the gdb source directory, it will read a ".gdbinit"
+file that sets up some simple things to make debugging gdb easier. The
+"info" command, when executed without a subcommand in a gdb being
debugged by gdb, will pop you back up to the top level gdb. See
-.gdbinit for more details.
+.gdbinit for details.
+
+I strongly recommend printing out the reference card and using it.
+
+If you use emacs, you will probably want to do a "make TAGS" after you
+configure your distribution; this will put the machine dependent
+routines for your local machine where they will be accessed first by a
+M-period.
+Also, make sure that you've either compiled gdb with your local cc, or
+have run `fixincludes' if you are compiling with gcc.
+\f
+(this is for editing this file with GNU emacs)
+Local Variables:
+mode: text
+End:
projects / binutils.git / blobdiff