- README for gdb-4.7 release
- Stu Grossman & John Gilmore 23 October 1992
+ README for gdb-4.9 release
+ Updated 10-May-93 by Fred Fish
This is GDB, the GNU source-level debugger, presently running under un*x.
A summary of new features is in the file `NEWS'.
==========================
In this release, the GDB debugger sources, the generic GNU include
-files, the BFD ("binary file description") library, the readline library,
-and other libraries all have directories of their own underneath
-the gdb-4.7 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.
-
-When you unpack the gdb-4.7.tar.Z file, you'll get a directory called
-`gdb-4.7', which contains:
-
- COPYING.LIB config/ configure.texi mmalloc/
- Makefile.in config.sub* gdb/ move-if-change*
- README configure* glob/ opcodes/
- bfd/ configure.in include/ readline/
- cfg-paper.texi configure.man libiberty/ texinfo/
+files, the BFD ("binary file description") library, the readline
+library, and other libraries all have directories of their own
+underneath the gdb-4.9 directory. The idea is that a variety of GNU
+tools can share a common copy of these things. Be aware of variation
+over time--for example don't try to build gdb with a copy of bfd from
+a release other than the gdb release (such as a binutils or gas
+release), especially if the releases are more than a few weeks apart.
+Configuration scripts and makefiles exist to cruise up and down this
+directory tree and automatically build all the pieces in the right
+order.
+
+When you unpack the gdb-4.9.tar.z or gdb-4.9.tar.Z file, you'll find
+a directory called `gdb-4.9', which contains:
+
+ Makefile.in config.sub* glob/ opcodes/
+ README configure* include/ readline/
+ bfd/ configure.in libiberty/ texinfo/
+ config/ etc/ mmalloc/
+ config.guess* gdb/ move-if-change*
To build GDB, you can just do:
- cd gdb-4.7
- ./configure HOSTTYPE (e.g. sun4, decstation)
+ cd gdb-4.9
+ ./configure
make
cp gdb/gdb /usr/local/bin/gdb (or wherever you want)
This will configure and build all the libraries as well as GDB.
+If `configure' can't determine your system type, specify one as its
+argument, e.g. sun4 or decstation.
+
If you get compiler warnings during this stage, see the `Reporting Bugs'
section below; there are a few known problems.
More Documentation
******************
- The GDB 4 release includes an already-formatted reference card, ready
-for printing with PostScript or GhostScript, in the `gdb' subdirectory
-of the main source directory--in `gdb-4.7/gdb/refcard.ps' of the
-version 4.7 release. If you can use PostScript or GhostScript with your
-printer, you can print the reference card immediately with `refcard.ps'.
+ The GDB 4 release includes an already-formatted reference card,
+ready for printing with PostScript or GhostScript, in the `gdb'
+subdirectory of the main source directory. (In `gdb-4.9/gdb/refcard.ps'.)
+If you can use PostScript or GhostScript with your printer, you can
+print the reference card immediately with `refcard.ps'.
The release also includes the source for the reference card. You
can format it, using TeX, by typing:
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-4.7', in the case of version 4.7), you can make
+source directory (`gdb-4.9', in the case of version 4.9), 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
+ If you want to typeset and print copies of this manual, you need TeX,
+a program to print its DVI output files, and `texinfo.tex', the Texinfo
definitions file.
- TeX is typesetting program; it does not print files directly, but
+ TeX is a 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.
+use depends on your system; `lpr -d' is common; another (for PostScript
+devices) 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
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-4.7/gdb') and then type:
+the main source directory (for example, to `gdb-4.9/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
-program.
+`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 4.7 distribution is in the `gdb-4.7'
+ For example, the GDB version 4.9 distribution is in the `gdb-4.9'
directory. That directory contains:
-`gdb-4.7/configure (and supporting files)'
+`gdb-4.9/configure (and supporting files)'
script for configuring GDB and all its supporting libraries.
-`gdb-4.7/gdb'
+`gdb-4.9/gdb'
the source specific to GDB itself
-`gdb-4.7/bfd'
+`gdb-4.9/bfd'
source for the Binary File Descriptor library
-`gdb-4.7/include'
+`gdb-4.9/include'
GNU include files
-`gdb-4.7/libiberty'
+`gdb-4.9/libiberty'
source for the `-liberty' free software library
-`gdb-4.7/opcodes'
+`gdb-4.9/opcodes'
source for the library of opcode tables and disassemblers
-`gdb-4.7/readline'
+`gdb-4.9/readline'
source for the GNU command-line interface
-`gdb-4.7/glob'
+`gdb-4.9/glob'
source for the GNU filename pattern-matching subroutine
-`gdb-4.7/mmalloc'
+`gdb-4.9/mmalloc'
source for the GNU memory-mapped malloc package
+'gdb-4.9/sim'
+ source for some simulators (z8000, H8/300, H8/500, etc)
+
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-4.7' directory.
+is the `gdb-4.9' 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
For example:
- cd gdb-4.7
+ cd gdb-4.9
./configure HOST
make
sh configure HOST
If you run `configure' from a directory that contains source
-directories for multiple libraries or programs, such as the `gdb-4.7'
-source directory for version 4.7, `configure' creates configuration
+directories for multiple libraries or programs, such as the `gdb-4.9'
+source directory for version 4.9, `configure' creates configuration
files for every directory level underneath (unless you tell it not to,
with the `--norecursion' option).
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 4.7, type the following to configure only
+ For example, with version 4.9, type the following to configure only
the `bfd' subdirectory:
- cd gdb-4.7/bfd
+ cd gdb-4.9/bfd
../configure HOST
You can install `gdb' anywhere; it has no hardwired paths. However,
processes whose programs are not readable.
-Compiling GDB in Another Directory
-===================================
+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
+you 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.
+feature correctly (GNU `make' and SunOS 'make' are two that should),
+running `make' in each of these directories 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. (You'll also
-need to specify a path to find `configure' itself from your working
+`--srcdir' option to specify where to find the source. (You also need
+to specify a path to find `configure' itself from your working
directory. If the path to `configure' would be the same as the
argument to `--srcdir', you can leave out the `--srcdir' option; it
will be assumed.)
- For example, with version 4.7, you can build GDB in a separate
+ For example, with version 4.9, you can build GDB in a separate
directory for a Sun 4 like this:
- cd gdb-4.7
+ cd gdb-4.9
mkdir ../gdb-sun4
cd ../gdb-sun4
- ../gdb-4.7/configure sun4
+ ../gdb-4.9/configure sun4
make
When `configure' builds a configuration using a remote source
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
+ The `Makefile' that `configure' generates in each source directory
also runs recursively. If you type `make' in a source directory such
-as `gdb-4.7' (or in a separate configured directory configured with
-`--srcdir=PATH/gdb-4.7'), you will build all the required libraries,
-then build GDB.
+as `gdb-4.9' (or in a separate configured directory configured with
+`--srcdir=PATH/gdb-4.9'), you will build all the required libraries,
+and 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
with each other.
-Specifying Names for Hosts and Targets
-=======================================
+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
ARCHITECTURE-VENDOR-OS
For example, you can use the alias `sun4' as a HOST argument or in a
-`--target=TARGET' option, but the equivalent full name is
+`--target=TARGET' option. The equivalent full name is
`sparc-sun-sunos4'.
The `configure' script accompanying GDB does not provide any query
Invalid configuration `i786v': machine `i786v' not recognized
`config.sub' is also distributed in the GDB source directory
-(`gdb-4.7', for version 4.7).
+(`gdb-4.9', for version 4.9).
-`configure' Options
-====================
+`configure' options
+===================
Here is a summary of the `configure' options and arguments that are
most often useful for building GDB. `configure' also has several other
`--srcdir=PATH'
*Warning: using this option requires GNU `make', or another `make'
- that implements the `VPATH' feature.*
+ that compatibly implements the `VPATH' feature.*
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,
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.
+GDB provides some support for debugging C++ programs, however that support
+only works well with GNU C++, and even then only on systems that use stabs
+debugging format. In particular, cfront based compilers such as Sun's C++
+are not fully supported.
+
+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.
+
+Pascal programs which use sets, subranges, file variables, or nested functions
+will not currently work.
+
+Partial Modula-2 and Chill support is now in GDB.
Kernel debugging
The files m68k-stub.c, i386-stub.c, and sparc-stub.c are examples of
remote stubs to be used with remote.c. They are designed to run
-standalone on a 68k, 386, or SPARC cpu and communicate properly with
+standalone on an m68k, i386, or SPARC 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
Some working remote interfaces for talking to existing ROM monitors
are:
+ remote-adapt.c AMD 29000 "Adapt"
remote-eb.c AMD 29000 "EBMON"
+ remote-es1800.c Ericsson 1800 monitor
remote-hms.c Hitachi Micro Systems H8/300 monitor
- remote-nindy.c Intel 960 "Nindy"
- remote-adapt.c AMD 29000 "Adapt"
+ remote-mips.c MIPS remote debugging protocol
remote-mm.c AMD 29000 "minimon"
+ remote-nindy.c Intel 960 "Nindy"
+ remote-sim.c Generalized simulator protocol
+ remote-st2000.c Tandem ST-2000 monitor
+ remote-udi.c AMD 29000 using the AMD "Universal Debug Interface"
+ remote-vx.c VxWorks realtime kernel
+ remote-z8k.c Zilog Z8000 simulator
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.
+Remote-udi.c and the 29k-share subdirectory contain a remote interface
+for AMD 29000 programs, which uses the AMD "Universal Debug Interface".
+This allows GDB to talk to software simulators, emulators, and/or bare
+hardware boards, via network or serial interfaces. Note that GDB only
+provides an interface that speaks UDI, not a complete solution. You
+will need something on the other end that also speaks UDI.
+
Reporting Bugs
===============
The correct address for reporting bugs found in gdb is
-"bug-gdb@prep.ai.mit.edu". Please email all bugs to that address.
-Please include the GDB version number (e.g. gdb-4.7), 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.
+"bug-gdb@prep.ai.mit.edu". Please email all bugs, and all requests for
+help with GDB, to that address. Please include the GDB version number
+(e.g. gdb-4.9), and how you configured it (e.g. "sun4" or "mach386
+host, i586-intel-synopsys target"). If you include the banner that GDB
+prints when it starts up, that will give us enough information.
+
+For more information on how/whether to report bugs, see the GDB Bugs
+section of the GDB manual (gdb/doc/gdb.texinfo).
+
+Known bugs:
+
+ * Under Ultrix 4.2 (DECstation-3100) or Alphas under OSF/1, we have
+ seen problems with backtraces after interrupting the inferior out
+ of a read(). The problem is caused by ptrace() returning an
+ incorrect value for the frame pointer register (register 15 or
+ 30). As far as we can tell, this is a kernel problem. Any help
+ with this would be greatly appreciated.
+
+ * On the SPARC GDB reports incorrect values of struct arguments to
+ functions, for the seventh and subsequent arguments. We have been looking
+ at this but no fix is available yet.
+
+ * On DECstations there are warnings about shift counts out of range in
+ various BFD modules. None of them is a cause for alarm, they are actually
+ a result of bugs in the DECstation compiler.
+
+ * On Solaris (2.1, at least) using the "run" command when the program
+ is already running restarts the program, but may leave a core dump
+ from the previous execution in the current directory. Other SVR4
+ based systems don't seem to have this problem, using the same gdb
+ source code.
+
+ * Notes for the DEC Alpha using OSF/1:
+ The debugging output of native cc has two known problems; we view these
+ as compiler bugs.
+ The linker miscompacts symbol tables, which causes gdb to confuse the
+ type of variables or results in `struct <illegal>' type outputs.
+ dbx has the same problems with those executables. A workaround is to
+ specify -Wl,-b when linking, but that will increase the executable size
+ considerably.
+ If a structure has incomplete type in one file (e.g. "struct foo *"
+ without a definition for "struct foo"), gdb will be unable to find the
+ structure definition from another file.
+ It has been reported that the Ultrix 4.3A compiler on decstations has the
+ same problems.
+
+ If you intend to compile gdb with gcc-2.4.5, be warned that the file
+ bfd/libbfd.c will be miscompiled due to a bug in gcc, you have
+ to compile this file with native cc. You will get many warnings from
+ gcc while compiling gdb, but these can be ignored for now. Again, these
+ problems are Alpha-specific.
GDB can produce warnings about symbols that it does not understand. By
default, these warnings are disabled. You can enable them by executing
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
-bug-gdb@prep.ai.mit.edu. There's lots of information about doing your
-own port in the file gdb-4.7/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
-assignment from gnu@prep.ai.mit.edu, as described in the section
-`Writing Code for GDB' below.
-
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.
+There is an "xxgdb", which seems to work for simple operations,
+which was posted to comp.sources.x.
-For those intersted in auto display of source and the availability of
+For those interested 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
=====================
-Documentation about GDB's internals is in the subdirectory doc, as
-`gdbint.texinfo'. In particular, there is a `cookbook' there on how
-to port GDB to a new machine. You can read it by hand, print it
-by using TeX and texinfo, or process it into an `info' file for use
-with Emacs' info mode or the standalone `info' program.
-
-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.
-
-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
-assignment to gnu@prep.ai.mit.edu. Do this early, like before the
-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
-a copy, you can request one by sending mail to gnu@prep.ai.mit.edu.
-
-Please try to avoid making machine-specific changes to
-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
-conditionalized on a specific feature of an operating system (set in
-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!
-
-There is a list of all known `feature-test macros' in gdbint.texinfo.
-Each such macro should be defined (or left undefined) in a host-dependent,
-target-dependent, or native-dependent include file. Not all of the
-macros are cleanly separated this way, yet. As you make changes, move
-the code toward cleanliness.
-
-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
-to be helpful for any purpose other than your changes. For example,
-if you want to modify dbxread.c to deal with DBX debugging symbols
-which are in COFF files rather than BSD a.out files, do something
-along the lines of a macro GET_NEXT_SYMBOL, which could have
-different definitions for COFF and a.out, rather than trying to put
-the necessary changes throughout all the code in dbxread.c that
-currently assumes BSD format.
-
-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.
-
-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.
-
-
-Debugging gdb with itself
-==========================
+There is a lot of information about writing code for GDB in the
+internals manual, distributed with GDB in gdb/doc/gdbint.texinfo. You
+can read it by hand, print it by using TeX and texinfo, or process it
+into an `info' file for use with Emacs' info mode or the standalone
+`info' program. In particular, see the nodes Getting Started,
+Debugging GDB, New Architectures, Coding Style, Clean Design, and
+Submitting Patches.
+
+If you are pondering writing anything but a short patch, especially
+take note of the information about copyrights in the node Submitting
+Patches. It can take quite a while to get all the paperwork done, so
+we encourage you to start that process as soon as you decide you are
+planning to work on something, or at least well ahead of when you
+think you will be ready to submit the patches.
+
+
+GDB Testsuite
+=============
+
+There is a dejagnu based testsuite available for testing your newly
+built gdb, or for regression testing gdb's with local modifications.
+The testsuite is distributed separately from the base gdb distribution
+for the convenience of people that wish to get either gdb or the testsuite
+separately.
+
+The name of the testsuite is gdb-4.9-testsuite.tar.z. You unpack it in the
+same directory in which you unpacked the base gdb distribution, and it
+will create and populate the directory gdb-4.9/gdb/testsuite.
+
+Running the testsuite requires the prior installation of dejagnu, which
+should be available via ftp. Once dejagnu is installed, you can run
+the tests in one of two ways:
+
+ (1) cd gdb-4.9/gdb (assuming you also unpacked gdb)
+ make check
-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".
+or
-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 details.
+ (2) cd gdb-4.9/gdb/testsuite
+ make (builds the test executables)
+ make site.exp (builds the site specific file)
+ runtest -tool gdb GDB=../gdb (or GDB=<somepath> as appropriate)
-I strongly recommend printing out the reference card and using it.
-Send reference-card suggestions to bug-gdb@prep.ai.mit.edu, just like bugs.
+The second method gives you slightly more control in case of problems with
+building one or more test executables, in case you wish to remove some
+test executables before running the tests, or if you are using the testsuite
+'standalone', without it being part of the gdb source tree.
-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.
+See the dejagnu documentation for further details.
-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)
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