564 lines
22 KiB
Plaintext
564 lines
22 KiB
Plaintext
README for gdb-4.9 release
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Updated 10-May-93 by Fred Fish
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This is GDB, the GNU source-level debugger, presently running under un*x.
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A summary of new features is in the file `NEWS'.
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Unpacking and Installation -- quick overview
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==========================
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In this release, the GDB debugger sources, the generic GNU include
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files, the BFD ("binary file description") library, the readline
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library, and other libraries all have directories of their own
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underneath the gdb-4.9 directory. The idea is that a variety of GNU
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tools can share a common copy of these things. Be aware of variation
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over time--for example don't try to build gdb with a copy of bfd from
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a release other than the gdb release (such as a binutils or gas
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release), especially if the releases are more than a few weeks apart.
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Configuration scripts and makefiles exist to cruise up and down this
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directory tree and automatically build all the pieces in the right
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order.
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When you unpack the gdb-4.9.tar.z or gdb-4.9.tar.Z file, you'll find
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a directory called `gdb-4.9', which contains:
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Makefile.in config.sub* glob/ opcodes/
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README configure* include/ readline/
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bfd/ configure.in libiberty/ texinfo/
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config/ etc/ mmalloc/
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config.guess* gdb/ move-if-change*
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To build GDB, you can just do:
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cd gdb-4.9
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./configure
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make
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cp gdb/gdb /usr/local/bin/gdb (or wherever you want)
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This will configure and build all the libraries as well as GDB.
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If `configure' can't determine your system type, specify one as its
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argument, e.g. sun4 or decstation.
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If you get compiler warnings during this stage, see the `Reporting Bugs'
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section below; there are a few known problems.
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GDB can be used as a cross-debugger, running on a machine of one type
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while debugging a program running on a machine of another type. See below.
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More Documentation
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******************
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The GDB 4 release includes an already-formatted reference card,
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ready for printing with PostScript or GhostScript, in the `gdb'
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subdirectory of the main source directory. (In `gdb-4.9/gdb/refcard.ps'.)
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If you can use PostScript or GhostScript with your printer, you can
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print the reference card immediately with `refcard.ps'.
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The release also includes the source for the reference card. You
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can format it, using TeX, by typing:
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make refcard.dvi
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The GDB reference card is designed to print in landscape mode on US
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"letter" size paper; that is, on a sheet 11 inches wide by 8.5 inches
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high. You will need to specify this form of printing as an option to
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your DVI output program.
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All the documentation for GDB comes as part of the machine-readable
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distribution. The documentation is written in Texinfo format, which is
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a documentation system that uses a single source file to produce both
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on-line information and a printed manual. You can use one of the Info
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formatting commands to create the on-line version of the documentation
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and TeX (or `texi2roff') to typeset the printed version.
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GDB includes an already formatted copy of the on-line Info version of
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this manual in the `gdb' subdirectory. The main Info file is
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`gdb-VERSION-NUMBER/gdb/gdb.info', and it refers to subordinate files
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matching `gdb.info*' in the same directory. If necessary, you can
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print out these files, or read them with any editor; but they are
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easier to read using the `info' subsystem in GNU Emacs or the
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standalone `info' program, available as part of the GNU Texinfo
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distribution.
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If you want to format these Info files yourself, you need one of the
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Info formatting programs, such as `texinfo-format-buffer' or `makeinfo'.
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If you have `makeinfo' installed, and are in the top level GDB
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source directory (`gdb-4.9', in the case of version 4.9), you can make
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the Info file by typing:
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cd gdb
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make gdb.info
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If you want to typeset and print copies of this manual, you need TeX,
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a program to print its DVI output files, and `texinfo.tex', the Texinfo
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definitions file.
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TeX is a typesetting program; it does not print files directly, but
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produces output files called DVI files. To print a typeset document,
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you need a program to print DVI files. If your system has TeX
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installed, chances are it has such a program. The precise command to
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use depends on your system; `lpr -d' is common; another (for PostScript
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devices) is `dvips'. The DVI print command may require a file name
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without any extension or a `.dvi' extension.
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TeX also requires a macro definitions file called `texinfo.tex'.
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This file tells TeX how to typeset a document written in Texinfo
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format. On its own, TeX cannot read, much less typeset a Texinfo file.
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`texinfo.tex' is distributed with GDB and is located in the
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`gdb-VERSION-NUMBER/texinfo' directory.
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If you have TeX and a DVI printer program installed, you can typeset
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and print this manual. First switch to the the `gdb' subdirectory of
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the main source directory (for example, to `gdb-4.9/gdb') and then type:
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make gdb.dvi
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Installing GDB
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**************
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GDB comes with a `configure' script that automates the process of
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preparing GDB for installation; you can then use `make' to build the
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`gdb' program.
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The GDB distribution includes all the source code you need for GDB in
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a single directory, whose name is usually composed by appending the
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version number to `gdb'.
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For example, the GDB version 4.9 distribution is in the `gdb-4.9'
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directory. That directory contains:
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`gdb-4.9/configure (and supporting files)'
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script for configuring GDB and all its supporting libraries.
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`gdb-4.9/gdb'
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the source specific to GDB itself
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`gdb-4.9/bfd'
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source for the Binary File Descriptor library
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`gdb-4.9/include'
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GNU include files
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`gdb-4.9/libiberty'
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source for the `-liberty' free software library
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`gdb-4.9/opcodes'
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source for the library of opcode tables and disassemblers
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`gdb-4.9/readline'
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source for the GNU command-line interface
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`gdb-4.9/glob'
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source for the GNU filename pattern-matching subroutine
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`gdb-4.9/mmalloc'
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source for the GNU memory-mapped malloc package
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'gdb-4.9/sim'
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source for some simulators (z8000, H8/300, H8/500, etc)
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The simplest way to configure and build GDB is to run `configure'
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from the `gdb-VERSION-NUMBER' source directory, which in this example
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is the `gdb-4.9' directory.
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First switch to the `gdb-VERSION-NUMBER' source directory if you are
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not already in it; then run `configure'. Pass the identifier for the
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platform on which GDB will run as an argument.
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For example:
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cd gdb-4.9
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./configure HOST
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make
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where HOST is an identifier such as `sun4' or `decstation', that
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identifies the platform where GDB will run.
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Running `configure HOST' followed by `make' builds the `bfd',
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`readline', `mmalloc', and `libiberty' libraries, then `gdb' itself.
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The configured source files, and the binaries, are left in the
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corresponding source directories.
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`configure' is a Bourne-shell (`/bin/sh') script; if your system
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does not recognize this automatically when you run a different shell,
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you may need to run `sh' on it explicitly:
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sh configure HOST
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If you run `configure' from a directory that contains source
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directories for multiple libraries or programs, such as the `gdb-4.9'
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source directory for version 4.9, `configure' creates configuration
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files for every directory level underneath (unless you tell it not to,
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with the `--norecursion' option).
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You can run the `configure' script from any of the subordinate
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directories in the GDB distribution, if you only want to configure that
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subdirectory; but be sure to specify a path to it.
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For example, with version 4.9, type the following to configure only
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the `bfd' subdirectory:
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cd gdb-4.9/bfd
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../configure HOST
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You can install `gdb' anywhere; it has no hardwired paths. However,
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you should make sure that the shell on your path (named by the `SHELL'
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environment variable) is publicly readable. Remember that GDB uses the
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shell to start your program--some systems refuse to let GDB debug child
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processes whose programs are not readable.
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Compiling GDB in another directory
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==================================
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If you want to run GDB versions for several host or target machines,
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you need a different `gdb' compiled for each combination of host and
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target. `configure' is designed to make this easy by allowing you to
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generate each configuration in a separate subdirectory, rather than in
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the source directory. If your `make' program handles the `VPATH'
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feature correctly (GNU `make' and SunOS 'make' are two that should),
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running `make' in each of these directories builds the `gdb' program
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specified there.
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To build `gdb' in a separate directory, run `configure' with the
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`--srcdir' option to specify where to find the source. (You also need
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to specify a path to find `configure' itself from your working
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directory. If the path to `configure' would be the same as the
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argument to `--srcdir', you can leave out the `--srcdir' option; it
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will be assumed.)
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For example, with version 4.9, you can build GDB in a separate
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directory for a Sun 4 like this:
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cd gdb-4.9
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mkdir ../gdb-sun4
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cd ../gdb-sun4
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../gdb-4.9/configure sun4
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make
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When `configure' builds a configuration using a remote source
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directory, it creates a tree for the binaries with the same structure
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(and using the same names) as the tree under the source directory. In
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the example, you'd find the Sun 4 library `libiberty.a' in the
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directory `gdb-sun4/libiberty', and GDB itself in `gdb-sun4/gdb'.
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One popular reason to build several GDB configurations in separate
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directories is to configure GDB for cross-compiling (where GDB runs on
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one machine--the host--while debugging programs that run on another
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machine--the target). You specify a cross-debugging target by giving
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the `--target=TARGET' option to `configure'.
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When you run `make' to build a program or library, you must run it
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in a configured directory--whatever directory you were in when you
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called `configure' (or one of its subdirectories).
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The `Makefile' that `configure' generates in each source directory
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also runs recursively. If you type `make' in a source directory such
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as `gdb-4.9' (or in a separate configured directory configured with
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`--srcdir=PATH/gdb-4.9'), you will build all the required libraries,
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and then build GDB.
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When you have multiple hosts or targets configured in separate
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directories, you can run `make' on them in parallel (for example, if
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they are NFS-mounted on each of the hosts); they will not interfere
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with each other.
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Specifying names for hosts and targets
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======================================
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The specifications used for hosts and targets in the `configure'
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script are based on a three-part naming scheme, but some short
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predefined aliases are also supported. The full naming scheme encodes
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three pieces of information in the following pattern:
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ARCHITECTURE-VENDOR-OS
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For example, you can use the alias `sun4' as a HOST argument or in a
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`--target=TARGET' option. The equivalent full name is
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`sparc-sun-sunos4'.
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The `configure' script accompanying GDB does not provide any query
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facility to list all supported host and target names or aliases.
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`configure' calls the Bourne shell script `config.sub' to map
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abbreviations to full names; you can read the script, if you wish, or
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you can use it to test your guesses on abbreviations--for example:
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% sh config.sub sun4
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sparc-sun-sunos411
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% sh config.sub sun3
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m68k-sun-sunos411
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% sh config.sub decstation
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mips-dec-ultrix42
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% sh config.sub hp300bsd
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m68k-hp-bsd
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% sh config.sub i386v
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i386-unknown-sysv
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% sh config.sub i786v
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Invalid configuration `i786v': machine `i786v' not recognized
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`config.sub' is also distributed in the GDB source directory
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(`gdb-4.9', for version 4.9).
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`configure' options
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===================
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Here is a summary of the `configure' options and arguments that are
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most often useful for building GDB. `configure' also has several other
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options not listed here. *note : (configure.info)What Configure Does,
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for a full explanation of `configure'.
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configure [--help]
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[--prefix=DIR]
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[--srcdir=PATH]
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[--norecursion] [--rm]
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[--target=TARGET] HOST
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You may introduce options with a single `-' rather than `--' if you
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prefer; but you may abbreviate option names if you use `--'.
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`--help'
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Display a quick summary of how to invoke `configure'.
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`-prefix=DIR'
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Configure the source to install programs and files under directory
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`DIR'.
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`--srcdir=PATH'
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*Warning: using this option requires GNU `make', or another `make'
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that compatibly implements the `VPATH' feature.*
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Use this option to make configurations in directories separate
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from the GDB source directories. Among other things, you can use
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this to build (or maintain) several configurations simultaneously,
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in separate directories. `configure' writes configuration
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specific files in the current directory, but arranges for them to
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use the source in the directory PATH. `configure' will create
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directories under the working directory in parallel to the source
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directories below PATH.
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`--norecursion'
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Configure only the directory level where `configure' is executed;
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do not propagate configuration to subdirectories.
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`--rm'
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Remove the configuration that the other arguments specify.
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`--target=TARGET'
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Configure GDB for cross-debugging programs running on the specified
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TARGET. Without this option, GDB is configured to debug programs
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that run on the same machine (HOST) as GDB itself.
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There is no convenient way to generate a list of all available
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targets.
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`HOST ...'
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Configure GDB to run on the specified HOST.
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There is no convenient way to generate a list of all available
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hosts.
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`configure' accepts other options, for compatibility with configuring
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other GNU tools recursively; but these are the only options that affect
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GDB or its supporting libraries.
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Languages other than C
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=======================
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GDB provides some support for debugging C++ programs, however that support
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only works well with GNU C++, and even then only on systems that use stabs
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debugging format. In particular, cfront based compilers such as Sun's C++
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are not fully supported.
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GDB should work with FORTRAN programs. If you have problems, please send a
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bug report; you may have to refer to some FORTRAN variables with a trailing
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underscore.
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Pascal programs which use sets, subranges, file variables, or nested functions
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will not currently work.
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Partial Modula-2 and Chill support is now in GDB.
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Kernel debugging
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=================
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I have't done this myself so I can't really offer any advice.
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Remote debugging over serial lines works fine, but the kernel debugging
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code in here has not been tested in years. Van Jacobson has
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better kernel debugging, but the UC lawyers won't let FSF have it.
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Remote debugging
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=================
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The files m68k-stub.c, i386-stub.c, and sparc-stub.c are examples of
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remote stubs to be used with remote.c. They are designed to run
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standalone on an m68k, i386, or SPARC cpu and communicate properly with
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the remote.c stub over a serial line.
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The file rem-multi.shar contains a general stub that can probably
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run on various different flavors of unix to allow debugging over a
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serial line from one machine to another.
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Some working remote interfaces for talking to existing ROM monitors
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are:
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remote-adapt.c AMD 29000 "Adapt"
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remote-eb.c AMD 29000 "EBMON"
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remote-es1800.c Ericsson 1800 monitor
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remote-hms.c Hitachi Micro Systems H8/300 monitor
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remote-mips.c MIPS remote debugging protocol
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remote-mm.c AMD 29000 "minimon"
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remote-nindy.c Intel 960 "Nindy"
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remote-sim.c Generalized simulator protocol
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remote-st2000.c Tandem ST-2000 monitor
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remote-udi.c AMD 29000 using the AMD "Universal Debug Interface"
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remote-vx.c VxWorks realtime kernel
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remote-z8k.c Zilog Z8000 simulator
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Remote-vx.c and the vx-share subdirectory contain a remote interface for the
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VxWorks realtime kernel, which communicates over TCP using the Sun
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RPC library. This would be a useful starting point for other remote-
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via-ethernet back ends.
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Remote-udi.c and the 29k-share subdirectory contain a remote interface
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for AMD 29000 programs, which uses the AMD "Universal Debug Interface".
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This allows GDB to talk to software simulators, emulators, and/or bare
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hardware boards, via network or serial interfaces. Note that GDB only
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provides an interface that speaks UDI, not a complete solution. You
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will need something on the other end that also speaks UDI.
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Reporting Bugs
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===============
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The correct address for reporting bugs found in gdb is
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"bug-gdb@prep.ai.mit.edu". Please email all bugs, and all requests for
|
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help with GDB, to that address. Please include the GDB version number
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(e.g. gdb-4.9), and how you configured it (e.g. "sun4" or "mach386
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host, i586-intel-synopsys target"). If you include the banner that GDB
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prints when it starts up, that will give us enough information.
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For more information on how/whether to report bugs, see the GDB Bugs
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section of the GDB manual (gdb/doc/gdb.texinfo).
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Known bugs:
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* Under Ultrix 4.2 (DECstation-3100) or Alphas under OSF/1, we have
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seen problems with backtraces after interrupting the inferior out
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of a read(). The problem is caused by ptrace() returning an
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incorrect value for the frame pointer register (register 15 or
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30). As far as we can tell, this is a kernel problem. Any help
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with this would be greatly appreciated.
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* On the SPARC GDB reports incorrect values of struct arguments to
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functions, for the seventh and subsequent arguments. We have been looking
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at this but no fix is available yet.
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* On DECstations there are warnings about shift counts out of range in
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various BFD modules. None of them is a cause for alarm, they are actually
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a result of bugs in the DECstation compiler.
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* Notes for the DEC Alpha using OSF/1:
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The debugging output of native cc has two known problems; we view these
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as compiler bugs.
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The linker miscompacts symbol tables, which causes gdb to confuse the
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type of variables or results in `struct <illegal>' type outputs.
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dbx has the same problems with those executables. A workaround is to
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specify -Wl,-b when linking, but that will increase the executable size
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considerably.
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If a structure has incomplete type in one file (e.g. "struct foo *"
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without a definition for "struct foo"), gdb will be unable to find the
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structure definition from another file.
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It has been reported that the Ultrix 4.3A compiler on decstations has the
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same problems.
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If you compile gdb with gcc-2.4.5, you will get many warnings,
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but these can be ignored for now. Again, this problem is Alpha-specific.
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GDB can produce warnings about symbols that it does not understand. By
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default, these warnings are disabled. You can enable them by executing
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`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.
|
||
|
||
|
||
X Windows versus GDB
|
||
=====================
|
||
|
||
There is an "xxgdb", which seems to work for simple operations,
|
||
which was posted to comp.sources.x.
|
||
|
||
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
|
||
=====================
|
||
|
||
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
|
||
|
||
or
|
||
|
||
(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)
|
||
|
||
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.
|
||
|
||
See the dejagnu documentation for further details.
|
||
|
||
|
||
(this is for editing this file with GNU emacs)
|
||
Local Variables:
|
||
mode: text
|
||
End:
|