X-Git-Url: http://drtracing.org/?a=blobdiff_plain;f=gdb%2FREADME;h=0ec1605ce5a79ebbd4ad08d78ce8c30bc36c9483;hb=cbd7581f343d85b4216db2eefdf601f6d988062d;hp=999db4a12f71487b3a98515994dc944379bf0484;hpb=bd5635a1e2b38ee8432fcdaa6456079191375277;p=deliverable%2Fbinutils-gdb.git diff --git a/gdb/README b/gdb/README index 999db4a12f..0ec1605ce5 100644 --- a/gdb/README +++ b/gdb/README @@ -1,257 +1,731 @@ -This is GDB, the GNU source-level debugger, presently running under -un*x. This is a pre-alpha version of GDB version 4, and has NOT been -extensively tested. It surely has some bugs, both bugs that were -present in version 3 and new bugs. I have filed all the bug reports -and fixes mailed to bug-gdb, and the fixes in particular will move -into these sources as I find the time. - - => THIS VERSION IS PARTICULARLY FRAGILE! <= - - It depends on a preliminary version of a new "binary file - descriptor" library and a new global "include" directory, which - are packaged separately from GDB. You must obtain, configure - and build this library manually, then configure and build gdb. - When building gdb's for multiple platforms, you must manually - rebuild the bfd library separately for each platform. Yes, of - course, we are working on this! FIXME! - - Configure bfd for your host system by: - - cd ../bfd - edit Makefile - make - - Then you can cd ../gdb-whatever, and config and build gdb. - -This release moves the generic GNU include files, the BFD library, -and the getopt routines into the parent directory of gdb. The idea -is that a variety of GNU tools can share a common copy of these things. - -A summary of features new since gdb-3.5 is in the file `WHATS.NEW'. - -The best way to build GDB, in my opinion, is in a subdirectory. I use -a naming convention "=XXX" where XXX is the machine type I'm building -for. Nothing depends on this, it's just how I remember which -subdirectories are what. So, once you have the BFD library built for -that machine, you can do: - - cd gdb-x.yy (the directory where this README is) - mkdir =XXX (e.g. mkdir =vax) - cd =XXX - ../config.gdb machine - make - -Machine is like "vax" or "sun4". For more information type `../config.gdb'. - -Once you have done that, just `make' will do everything, producing an -executable `gdb' in this directory. - -You can also build gdb binaries in a completely different directory from its -sources, by specifying "srcdir=YYY" to config.gdb, giving it an absolute -or relative path to the source directory. - -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. You -configure it this way by specifying `config.gdb host target' where host -is where GDB runs, and target is where your program runs. - -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. -For details see the texinfo manual (distributed with emacs and as a -printed manual). - -About languages other than C... - -C++ support has been integrated into gdb. GDB should work with FORTRAN -programs (if you have problem, please send a bug report; note that you -may have to refer to some FORTRAN variables with a trailing -underscore), 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. - -About kernel debugging... - -I have't done this myself so I can't really offer any advice. -Remote debugging over serial lines is more like to be in a currently -functioning state than the standalone gdb (kdb). FIXME. - -About remote debugging... - -[This section seems to be out of date, I have never seen the "rapp" -program, though I would like to. FIXME.] -`rapp' runs under unix and acts as a remote stub (like remote-multi.shar -distributed with GDB version 3). Currently it just works over UDP -(network), not over a serial line. To get it running -* Compile GDB on the host machine as usual -* Compile rapp on the target machine, giving for both host and target - the type of the target machine -* Install "gdb" in /etc/services on both machines. - -This will get reworked before the initial release of 4.x. FIXME. - -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. - -The files remote-eb.c and remote-nindy.c are two examples of remote -interfaces for talking to existing ROM monitors (for the AMD 29000 and the -Intel 960 repsectively). There is also a remote interface for the -VxWorks realtime kernel, which communicates over TCP/IP, in remote-vx.c -and the vx-share subdirectory. - -About reporting bugs... - -The correct address for reporting bugs found with gdb is -"bug-gdb@prep.ai.mit.edu". Please email all bugs to that address. - -About xgdb... - -Hopefully a new xgdb will be in 4.x. - -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. See -XGDB-README for one person's opinion about what is wrong with the -current xgdb. 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. - -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. - -About the machine-dependent files... - -tconfig/ -This contains Makefile stuff for when the target system is . -It also specifies the name of the tm-XXX.h file for this machine. - -xconfig/ -This contains Makefile stuff for when the host system is . -It also specifies the name of the xm-XXX.h file for this machine. - -tm-XXX.h (tm.h is a link to this file, created by config.gdb). -This file contains macro definitions that express information -about the target machine's registers, stack frame format and instructions. - -xm-XXX.h (xm.h is a link to this file, created by config.gdb). -This contains macro definitions describing the host system environment, -such as byte order, host C compiler and library, ptrace support, -and core file structure. - --opcode.h --pinsn.c -These files contain the information necessary to print instructions -for your cpu type. -opcode.h includes some large initialized -data structures, which is strange for a ".h" file, but it's OK since -it is only included in one place. -opcode.h is shared -between the debugger and the assembler (if the GNU assembler has been -ported to that machine), whereas -pinsn.c is specific to GDB. - --tdep.c -This file contains any miscellaneous code required for this machine -as a target. On some machines it doesn't exist at all. Its existence -is specified in the tconfig/XXX file. - --xdep.c -This file contains any miscellaneous code required for this machine -as a host. On some machines it doesn't exist at all. Its existence -is specified in the xconfig/XXX file. - -infptrace.c -This is the low level interface to inferior processes for systems -using the Unix ptrace call in a vanilla way. Some systems have their -own routines in -xdep.c. Whether or not it is used -is specified in the xconfig/XXX file. - -coredep.c -Machine and system-dependent aspects of reading core files. Some -machines use coredep.c; some have the routines in -xdep.c. -Whether or not it is used is specified in the xconfig/XXX file. -Now that BFD is used to read core files, virtually all machines should -use coredep.c and should just provide fetch_core_registers in --xdep.c. - -exec.c -Machine and system-dependent aspects of reading executable files. -Some machines use exec.c; some have the routines in -tdep.c -Since BFD, virtually all machines should use exec.c. - -About 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. - -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. - -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 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! - -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. - -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. Thus 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. - -About debugging gdb with itself... - -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. - -When you run gdb in this 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. + README for GDB release + +This is GDB, the GNU source-level debugger. + +A summary of new features is in the file `gdb/NEWS'. + +Check the GDB home page at http://www.gnu.org/software/gdb/ for up to +date release information, mailing list links and archives, etc. + +GDB's bug tracking data base can be found at +http://www.gnu.org/software/gdb/bugs/ + +Unpacking and Installation -- quick overview +========================== + + The release is provided as a gzipped tar file called +'gdb-VERSION.tar.gz', where VERSION is the version of GDB. + + 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-VERSION 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 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-VERSION.tar.gz file, it will create a +source directory called `gdb-VERSION'. + +You can build GDB right in the source directory: + + cd gdb-VERSION + ./configure --prefix=/usr/local (or wherever you want) + make all install + +However, we recommend that an empty directory be used instead. +This way you do not clutter your source tree with binary files +and will be able to create different builds with different +configuration options. + +You can build GDB in any empty build directory: + + mkdir build + cd build + /gdb-VERSION/configure [etc...] + make all install + +(Building GDB with DJGPP tools for MS-DOS/MS-Windows is slightly +different; see the file gdb-VERSION/gdb/config/djgpp/README for details.) + + 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., `./configure sun4' or `./configure decstation'. + + Make sure that your 'configure' line ends in 'gdb-VERSION/configure': + + /berman/migchain/source/gdb-VERSION/configure # RIGHT + /berman/migchain/source/gdb-VERSION/gdb/configure # WRONG + + The GDB package contains several subdirectories, such as 'gdb', +'bfd', and 'readline'. If your 'configure' line ends in +'gdb-VERSION/gdb/configure', then you are configuring only the gdb +subdirectory, not the whole GDB package. This leads to build errors +such as: + + make: *** No rule to make target `../bfd/bfd.h', needed by `gdb.o'. Stop. + + If you get other compiler errors during this stage, see the `Reporting +Bugs' section below; there are a few known problems. + + GDB's `configure' script has many options to enable or disable +different features or dependencies. These options are not generally +known to the top-level `configure', so if you want to see a complete +list of options, invoke the subdirectory `configure', like: + + /berman/migchain/source/gdb-VERSION/gdb/configure --help + + (Take note of how this differs from the invocation used to actually +configure the build tree.) + + GDB requires a C++11 compiler. If you do not have a +C++11 compiler for your system, you may be able to download and install +the GNU CC compiler. It is available via anonymous FTP from the +directory `ftp://ftp.gnu.org/pub/gnu/gcc'. GDB also requires an ISO +C standard library. The GDB remote server, GDBserver, builds with some +non-ISO standard libraries - e.g. for Windows CE. + + GDB can optionally be built against various external libraries. +These dependencies are described below in the "`configure options" +section of this README. + + 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. + + +More Documentation +****************** + + All the documentation for GDB comes as part of the machine-readable +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/doc' subdirectory. The main Info file is +`gdb-VERSION/gdb/doc/gdb.info', and it refers to subordinate files +matching `gdb.info*' in the same directory. If necessary, you can +print out these files, or read them with any editor; but they are +easier to read using the `info' subsystem in GNU Emacs or the +standalone `info' program, available as part of the GNU Texinfo +distribution. + + 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-VERSION'), you can make the Info file by +typing: + + cd gdb/doc + make info + + 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. This file is included in the GDB +distribution, in the directory `gdb-VERSION/texinfo'. + + 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 (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 +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/texinfo' directory. + + If you have TeX and a DVI printer program installed, you can typeset +and print this manual. First switch to the `gdb' subdirectory of +the main source directory (for example, to `gdb-VERSION/gdb') and then type: + + make doc/gdb.dvi + + If you prefer to have the manual in PDF format, type this from the +`gdb/doc' subdirectory of the main source directory: + + make gdb.pdf + +For this to work, you will need the PDFTeX package to be installed. + + +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. That directory contains: + +`gdb-VERSION/{COPYING,COPYING.LIB}' + Standard GNU license files. Please read them. + +`gdb-VERSION/bfd' + source for the Binary File Descriptor library + +`gdb-VERSION/config*' + script for configuring GDB, along with other support files + +`gdb-VERSION/gdb' + the source specific to GDB itself + +`gdb-VERSION/include' + GNU include files + +`gdb-VERSION/libiberty' + source for the `-liberty' free software library + +`gdb-VERSION/opcodes' + source for the library of opcode tables and disassemblers + +`gdb-VERSION/readline' + source for the GNU command-line interface + NOTE: The readline library is compiled for use by GDB, but will + not be installed on your system when "make install" is issued. + +`gdb-VERSION/sim' + source for some simulators (ARM, D10V, SPARC, M32R, MIPS, PPC, V850, etc) + +`gdb-VERSION/texinfo' + The `texinfo.tex' file, which you need in order to make a printed + manual using TeX. + +`gdb-VERSION/etc' + Coding standards, useful files for editing GDB, and other + miscellanea. + + Note: the following instructions are for building GDB on Unix or +Unix-like systems. Instructions for building with DJGPP for +MS-DOS/MS-Windows are in the file gdb/config/djgpp/README. + + The simplest way to configure and build GDB is to run `configure' +from the `gdb-VERSION' directory. + + First switch to the `gdb-VERSION' source directory if you are +not already in it; then run `configure'. + + For example: + + cd gdb-VERSION + ./configure + make + + Running `configure' followed by `make' builds the `bfd', +`readline', `mmalloc', and `libiberty' libraries, 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 + + If you run `configure' from a directory that contains source +directories for multiple libraries or programs, `configure' creates +configuration files for every directory level underneath (unless +you tell it not to, with the `--norecursion' option). + + 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 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 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 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, you can build GDB in a separate +directory for a Sun 4 like this: + + cd gdb-VERSION + mkdir ../gdb-sun4 + cd ../gdb-sun4 + ../gdb-VERSION/configure + 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 reason to build 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' that `configure' generates in each source directory +also runs recursively. If you type `make' in a source directory such +as `gdb-VERSION' (or in a separate configured directory configured with +`--srcdir=PATH/gdb-VERSION'), 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 +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: + + ARCHITECTURE-VENDOR-OS + + For example, you can use the alias `sun4' as a HOST argument or in a +`--target=TARGET' option. The equivalent full name is +`sparc-sun-sunos4'. + + 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-sunos4.1.1 + % sh config.sub sun3 + m68k-sun-sunos4.1.1 + % sh config.sub decstation + mips-dec-ultrix4.2 + % sh config.sub hp300bsd + m68k-hp-bsd + % sh config.sub i386v + i386-pc-sysv + % sh config.sub i786v + Invalid configuration `i786v': machine `i786v' not recognized + +`config.sub' is also distributed in the GDB source directory. + + +`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 +options not listed here. There are many options to gdb's `configure' +script, some of which are only useful in special situation. +*note : (autoconf.info)Running configure scripts, for a full +explanation of `configure'. + + configure [--help] + [--prefix=DIR] + [--srcdir=PATH] + [--target=TARGET] + [--host=HOST] + [HOST] + +You may introduce options with a single `-' rather than `--' if you +prefer; but you may abbreviate option names if you use `--'. Some +more obscure GDB `configure' options are not listed here. + +`--help' + Display a quick summary of how to invoke `configure'. + +`-prefix=DIR' + Configure the source to install programs and files under directory + `DIR'. + +`--srcdir=PATH' + *Warning: using this option requires GNU `make', or another `make' + 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, + 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. + +`--host=HOST' + Configure GDB to run on the specified HOST. + + There is no convenient way to generate a list of all available + hosts. + +`HOST ...' + Same as `--host=HOST'. If you omit this, GDB will guess; it's + quite accurate. + +`--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. + +`--enable-targets=TARGET,TARGET,...' +`--enable-targets=all` + Configure GDB for cross-debugging programs running on the + specified list of targets. The special value `all' configures + GDB for debugging programs running on any target it supports. + +`--with-gdb-datadir=PATH' + Set the GDB-specific data directory. GDB will look here for + certain supporting files or scripts. This defaults to the `gdb' + subdirectory of `datadir' (which can be set using `--datadir'). + +`--with-relocated-sources=DIR' + Sets up the default source path substitution rule so that + directory names recorded in debug information will be + automatically adjusted for any directory under DIR. DIR should + be a subdirectory of GDB's configured prefix, the one mentioned + in the `--prefix' or `--exec-prefix' options to configure. This + option is useful if GDB is supposed to be moved to a different + place after it is built. + +`--enable-64-bit-bfd' + Enable 64-bit support in BFD on 32-bit hosts. + +`--disable-gdbmi' + Build GDB without the GDB/MI machine interface. + +`--enable-tui' + Build GDB with the text-mode full-screen user interface (TUI). + Requires a curses library (ncurses and cursesX are also + supported). + +`--with-curses' + Use the curses library instead of the termcap library, for + text-mode terminal operations. + +`--with-debuginfod' + Build GDB with libdebuginfod, the debuginfod client library. Used + to automatically fetch source files and separate debug files from + debuginfod servers using the associated executable's build ID. + Enabled by default if libdebuginfod is installed and found at + configure time. debuginfod is packaged with elfutils, starting + with version 0.178. You can get the latest version from + 'https://sourceware.org/elfutils/'. + +`--with-libunwind-ia64' + Use the libunwind library for unwinding function call stack on ia64 + target platforms. + See http://www.nongnu.org/libunwind/index.html for details. + +`--with-system-readline' + Use the readline library installed on the host, rather than the + library supplied as part of GDB. Readline 7 or newer is required; + this is enforced by the build system. + +`--with-system-zlib + Use the zlib library installed on the host, rather than the + library supplied as part of GDB. + +`--with-expat' + Build GDB with Expat, a library for XML parsing. (Done by + default if libexpat is installed and found at configure time.) + This library is used to read XML files supplied with GDB. If it + is unavailable, some features, such as remote protocol memory + maps, target descriptions, and shared library lists, that are + based on XML files, will not be available in GDB. If your host + does not have libexpat installed, you can get the latest version + from `http://expat.sourceforge.net'. + +`--with-libiconv-prefix[=DIR]' + Build GDB with GNU libiconv, a character set encoding conversion + library. This is not done by default, as on GNU systems the + `iconv' that is built in to the C library is sufficient. If your + host does not have a working `iconv', you can get the latest + version of GNU iconv from `https://www.gnu.org/software/libiconv/'. + + GDB's build system also supports building GNU libiconv as part of + the overall build. See the GDB manual instructions on how to do + this. + +`--with-lzma' + Build GDB with LZMA, a compression library. (Done by default if + liblzma is installed and found at configure time.) LZMA is used + by GDB's "mini debuginfo" feature, which is only useful on + platforms using the ELF object file format. If your host does + not have liblzma installed, you can get the latest version from + `https://tukaani.org/xz/'. + +`--with-mpfr' + Build GDB with GNU MPFR, a library for multiple-precision + floating-point computation with correct rounding. (Done by + default if GNU MPFR is installed and found at configure time.) + This library is used to emulate target floating-point arithmetic + during expression evaluation when the target uses different + floating-point formats than the host. If GNU MPFR is not + available, GDB will fall back to using host floating-point + arithmetic. If your host does not have GNU MPFR installed, you + can get the latest version from `http://www.mpfr.org'. + +`--with-python[=PYTHON]' + Build GDB with Python scripting support. (Done by default if + libpython is present and found at configure time.) Python makes + GDB scripting much more powerful than the restricted CLI + scripting language. If your host does not have Python installed, + you can find it on `http://www.python.org/download/'. The oldest + version of Python supported by GDB is 2.6. The optional argument + PYTHON is used to find the Python headers and libraries. It can + be either the name of a Python executable, or the name of the + directory in which Python is installed. + +`--with-guile[=GUILE]' + Build GDB with GNU Guile scripting support. (Done by default if + libguile is present and found at configure time.) If your host + does not have Guile installed, you can find it at + `https://www.gnu.org/software/guile/'. The optional argument + GUILE can be a version number, which will cause `configure' to + try to use that version of Guile; or the file name of a + `pkg-config' executable, which will be queried to find the + information needed to compile and link against Guile. + +`--enable-source-highlight' + When printing source code, use source highlighting. This requires + libsource-highlight to be installed and is enabled by default + if the library is found. + +`--with-xxhash' + Use libxxhash for hashing. This has no user-visible effect but + speeds up various GDB operations such as symbol loading. Enabled + by default if libxxhash is found. + +`--without-included-regex' + Don't use the regex library included with GDB (as part of the + libiberty library). This is the default on hosts with version 2 + of the GNU C library. + +`--with-sysroot=DIR' + Use DIR as the default system root directory for libraries whose + file names begin with `/lib' or `/usr/lib'. (The value of DIR + can be modified at run time by using the "set sysroot" command.) + If DIR is under the GDB configured prefix (set with `--prefix' or + `--exec-prefix' options), the default system root will be + automatically adjusted if and when GDB is moved to a different + location. + +`--with-system-gdbinit=FILE' + Configure GDB to automatically load a system-wide init file. + FILE should be an absolute file name. If FILE is in a directory + under the configured prefix, and GDB is moved to another location + after being built, the location of the system-wide init file will + be adjusted accordingly. + +`--with-system-gdbinit-dir=DIR' + Configure GDB to automatically load system-wide init files from + a directory. Files with extensions `.gdb', `.py' (if Python + support is enabled) and `.scm' (if Guile support is enabled) are + supported. DIR should be an absolute directory name. If DIR is + in a directory under the configured prefix, and GDB is moved to + another location after being built, the location of the system- + wide init directory will be adjusted accordingly. + +`--enable-build-warnings' + When building the GDB sources, ask the compiler to warn about any + code which looks even vaguely suspicious. It passes many + different warning flags, depending on the exact version of the + compiler you are using. + +`--enable-werror' + Treat compiler warnings as werrors. It adds the -Werror flag to + the compiler, which will fail the compilation if the compiler + outputs any warning messages. + +`--enable-ubsan' + Enable the GCC undefined behavior sanitizer. By default this is + disabled in GDB releases, but enabled when building from git. + The undefined behavior sanitizer checks for C++ undefined + behavior. It has a performance cost, so if you are looking at + GDB's performance, you should disable it. + +`--enable-unit-tests[=yes|no]' + Enable (i.e., include) support for unit tests when compiling GDB + and GDBServer. Note that if this option is not passed, GDB will + have selftests if it is a development build, and will *not* have + selftests if it is a non-development build. + +`configure' accepts other options, for compatibility with configuring +other GNU tools recursively. + + +Remote 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 an m68k, i386, or SPARC cpu and communicate properly +with the remote.c stub over a serial line. + + The directory gdbserver/ contains `gdbserver', a program that +allows remote debugging for Unix applications. GDBserver is only +supported for some native configurations. + + The file gdbserver/README includes further notes on GDBserver; in +particular, it explains how to build GDBserver for cross-debugging +(where GDBserver runs on the target machine, which is of a different +architecture than the host machine running GDB). + + +Reporting Bugs in GDB +===================== + + There are several ways of reporting bugs in GDB. The prefered +method is to use the World Wide Web: + + http://www.gnu.org/software/gdb/bugs/ + +As an alternative, the bug report can be submitted, via e-mail, to the +address "bug-gdb@gnu.org". + + When submitting a bug, please include the GDB version number, and +how you configured it (e.g., "sun4" or "mach386 host, +i586-intel-synopsys target"). Since GDB supports so many +different configurations, it is important that you be precise about +this. The simplest way to do this is to include the output from these +commands: + + % gdb --version + % gdb --config + + For more information on how/whether to report bugs, see the +Reporting Bugs chapter of the GDB manual (gdb/doc/gdb.texinfo). + + +Graphical interface to GDB -- X Windows, MS Windows +========================== + + Several graphical interfaces to GDB are available. You should +check: + + https://sourceware.org/gdb/wiki/GDB%20Front%20Ends + +for an up-to-date list. + + Emacs users will very likely enjoy the Grand Unified Debugger mode; +try typing `M-x gdb RET'. + + +Writing Code for GDB +===================== + + There is information about writing code for GDB in the file +`CONTRIBUTE' and at the website: + + http://www.gnu.org/software/gdb/ + +in particular in the wiki. + + If you are pondering writing anything but a short patch, especially +take note of the information about copyrights and copyright assignment. +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 +============= + + Included with the GDB distribution is a DejaGNU based testsuite +that can either be used to test your newly built GDB, or for +regression testing a GDB with local modifications. + + Running the testsuite requires the prior installation of DejaGNU, +which is generally available via ftp. The directory +ftp://sources.redhat.com/pub/dejagnu/ will contain a recent snapshot. +Once DejaGNU is installed, you can run the tests in one of the +following ways: + + (1) cd gdb-VERSION + make check-gdb + +or + + (2) cd gdb-VERSION/gdb + make check + +or + + (3) cd gdb-VERSION/gdb/testsuite + make site.exp (builds the site specific file) + runtest -tool gdb GDB=../gdb (or GDB= as appropriate) + +When using a `make'-based method, you can use the Makefile variable +`RUNTESTFLAGS' to pass flags to `runtest', e.g.: + + make RUNTESTFLAGS=--directory=gdb.cp check + +If you use GNU make, you can use its `-j' option to run the testsuite +in parallel. This can greatly reduce the amount of time it takes for +the testsuite to run. In this case, if you set `RUNTESTFLAGS' then, +by default, the tests will be run serially even under `-j'. You can +override this and force a parallel run by setting the `make' variable +`FORCE_PARALLEL' to any non-empty value. Note that the parallel `make +check' assumes that you want to run the entire testsuite, so it is not +compatible with some dejagnu options, like `--directory'. + +The last method gives you slightly more control in case of problems +with building one or more test executables or if you are using the +testsuite `standalone', without it being part of the GDB source tree. + +See the DejaGNU documentation for further details. + + +Copyright and License Notices +============================= + +Most files maintained by the GDB Project contain a copyright notice +as well as a license notice, usually at the start of the file. + +To reduce the length of copyright notices, consecutive years in the +copyright notice can be combined into a single range. For instance, +the following list of copyright years... + + 1986, 1988, 1989, 1991-1993, 1999, 2000, 2007, 2008, 2009, 2010, 2011 + +... is abbreviated into: + + 1986, 1988-1989, 1991-1993, 1999-2000, 2007-2011 + +Every year of each range, inclusive, is a copyrightable year that +could be listed individually. + (this is for editing this file with GNU emacs) Local Variables: