@ifinfo
@format
START-INFO-DIR-ENTRY
-* Gdb Internals: (gdbint). The GNU debugger internals.
+* Gdb-Internals: (gdbint). The GNU debugger's internals.
END-INFO-DIR-ENTRY
@end format
@end ifinfo
@ifinfo
This file documents the internals of the GNU debugger GDB.
-Copyright (C) 1990, 1991 Free Software Foundation, Inc.
+Copyright 1990, 1991, 1992 Free Software Foundation, Inc.
Contributed by Cygnus Support. Written by John Gilmore.
Permission is granted to make and distribute verbatim copies of
@end tex
@vskip 0pt plus 1filll
-Copyright @copyright{} 1990, 1991 Free Software Foundation, Inc.
+Copyright @copyright{} 1990, 1991, 1992 Free Software Foundation, Inc.
Permission is granted to make and distribute verbatim copies of
this manual provided the copyright notice and this permission notice
@end titlepage
-@node Top, README, (dir), (dir)
+@node Top
+@top
+This documents the internals of the GNU debugger, GDB. It is a
+collection of miscellaneous information with little form at this point.
+Mostly, it is a repository into which you can put information about
+GDB as you discover it (or as you design changes to GDB).
@menu
* README:: The README File
* New Architectures:: Defining a New Host or Target Architecture
* Config:: Adding a New Configuration
* Host:: Adding a New Host
+* Native:: Adding a New Native Configuration
* Target:: Adding a New Target
* Languages:: Defining New Source Languages
* Releases:: Configuring GDB for Release
+* Partial Symbol Tables:: How GDB reads symbols quickly at startup
* BFD support for GDB:: How BFD and GDB interface
* Symbol Reading:: Defining New Symbol Readers
* Cleanups:: Cleanups
* Wrapping:: Wrapping Output Lines
+* Frames:: Keeping track of function calls
+* Remote Stubs:: Code that runs in targets and talks to GDB
+* Coding Style:: Strunk and White for GDB maintainers
+* Clean Design:: Frank Lloyd Wright for GDB maintainers
+* Submitting Patches:: How to get your changes into GDB releases
+* Host Conditionals:: What features exist in the host
+* Target Conditionals:: What features exist in the target
+* Native Conditionals:: Conditionals for when host and target are same
+* Obsolete Conditionals:: Conditionals that don't exist any more
@end menu
-@node README, New Architectures, Top, Top
+@node README
@chapter The @file{README} File
Check the @file{README} file, it often has useful information that does not
appear anywhere else in the directory.
-@node New Architectures, Config, README, Top
+@node New Architectures
@chapter Defining a New Host or Target Architecture
When building support for a new host and/or target, much of the work you
@dfn{Host} refers to attributes of the system where GDB runs.
@dfn{Target} refers to the system where the program being debugged
-executes. In most cases they are the same machine; unfortunately, that
-means you must add @emph{both} host and target support for new machines
-in this category.
-
-The @file{xconfig/*}, @file{xm-*.h} and @file{*-xdep.c} files are for
-host support. Similarly, the @file{tconfig/*}, @file{tm-*.h} and
-@file{*-tdep.c} files are for target support. The question is, what
-features or aspects of a debugging or cross-debugging environment are
-considered to be ``host'' support?
+executes. In most cases they are the same machine, in which case
+a third type of @dfn{Native} attributes come into play.
Defines and include files needed to build on the host are host support.
Examples are tty support, system defined types, host byte order, host
float format.
-Unix child process support is considered an aspect of the host. Since
-when you fork on the host you are still on the host, the various macros
-needed for finding the registers in the upage, running @code{ptrace}, and such
-are all in the host-dependent files.
+Defines and information needed to handle the target format are target
+dependent. Examples are the stack frame format, instruction set,
+breakpoint instruction, registers, and how to set up and tear down the stack
+to call a function.
+
+Information that is only needed when the host and target are the same,
+is native dependent. One example is Unix child process support; if the
+host and target are not the same, doing a fork to start the target
+process is a bad idea. The various macros needed for finding the
+registers in the @code{upage}, running @code{ptrace}, and such are all in the
+native-dependent files.
+
+Another example of native-dependent code is support for features
+that are really part of the target environment, but which require
+@code{#include} files that are only available on the host system.
+Core file handling and @code{setjmp} handling are two common cases.
+
+When you want to make GDB work ``native'' on a particular
+machine, you have to include all three kinds of information.
+
+The dependent information in GDB is organized into files by naming
+conventions.
-@c FIXME so what kinds of things are target support?
+Host-Dependent Files
+@table @file
+@item config/*.mh
+Sets Makefile parameters
+@item xm-*.h
+Global #include's and #define's and definitions
+@item *-xdep.c
+Global variables and functions
+@end table
+
+Native-Dependent Files
+@table @file
+@item config/*.mh
+Sets Makefile parameters (for @emph{both} host and native)
+@item nm-*.h
+#include's and #define's and definitions. This file
+is only included by the small number of modules that need it,
+so beware of doing feature-test #define's from its macros.
+@item *-nat.c
+global variables and functions
+@end table
-This is still somewhat of a grey area; I (John Gilmore) didn't do the
-@file{xm-*} and @file{tm-*} split for gdb (it was done by Jim Kingdon)
-so I have had to figure out the grounds on which it was split, and make
-my own choices as I evolve it. I have moved many things out of the xdep
-files actually, partly as a result of BFD and partly by removing
-duplicated code.
+Target-Dependent Files
+@table @file
+@item config/*.mt
+Sets Makefile parameters
+@item tm-*.h
+Global #include's and #define's and definitions
+@item *-tdep.c
+Global variables and functions
+@end table
+At this writing, most supported hosts have had their host and native
+dependencies sorted out properly. There are a few stragglers, which
+can be recognized by the absence of NATDEPFILES lines in their
+@file{config/*.mh}.
-@node Config, Host, New Architectures, Top
+@node Config
@chapter Adding a New Configuration
Most of the work in making GDB compile on a new machine is in specifying
create a new file @file{bfd/hosts/h-@var{xxx}.h}. Examine the
other @file{h-*.h} files as templates, and create one that brings in the
right include files for your system, and defines any host-specific
-macros needed by GDB.
+macros needed by BFD, the Binutils, GNU LD, or the Opcodes directories.
+(They all share the bfd @file{hosts} directory and the @file{configure.host}
+file.)
-Then edit @file{bfd/configure.in}. Add shell script code to recognize your
+Then edit @file{bfd/configure.host}. Add a line to recognize your
@code{@var{xarch}-@var{xvend}-@var{xos}} configuration, and set
@code{my_host} to @var{xxx} when you recognize it. This will cause your
file @file{h-@var{xxx}.h} to be linked to @file{sysdep.h} at configuration
-time.
+time. When creating the line that recognizes your configuration,
+only match the fields that you really need to match; e.g. don't match
+match the architecture or manufacturer if the OS is sufficient
+to distinguish the configuration that your @file{h-@var{xxx}.h} file supports.
+Don't match the manufacturer name unless you really need to.
+This should make future ports easier.
Also, if this host requires any changes to the Makefile, create a file
-@file{bfd/config/hm-@var{xxx}}, which includes the required lines.
+@file{bfd/config/@var{xxx}.mh}, which includes the required lines.
-(If you have the binary utilities and/or GNU ld in the same tree,
-you'll also have to edit @file{binutils/configure.in} or
-@file{ld/configure.in} to match what you've done in the @file{bfd}
-directory.)
-
-It's likely that the @file{libiberty} and @file{readline} directories
+It's possible that the @file{libiberty} and @file{readline} directories
won't need any changes for your configuration, but if they do, you can
change the @file{configure.in} file there to recognize your system and
-map to an @file{hm-@var{xxx}} file. Then add @file{hm-@var{xxx}}
+map to an @file{mh-@var{xxx}} file. Then add @file{mh-@var{xxx}}
to the @file{config/} subdirectory, to set any makefile variables you
need. The only current options in there are things like @samp{-DSYSV}.
+(This @file{mh-@var{xxx}} naming convention differs from elsewhere
+in GDB, by historical accident. It should be cleaned up so that all
+such files are called @file{@var{xxx}.mh}.)
Aha! Now to configure GDB itself! Edit
@file{gdb/configure.in} to recognize your system and set @code{gdb_host}
@c Would it be simpler to just use different per-host and per-target
@c *scripts*, and call them from {configure} ?
-Finally, you'll need to specify and define GDB's host- and
-target-dependent files used for your configuration; the next two
-chapters discuss those.
+Finally, you'll need to specify and define GDB's host-, native-, and
+target-dependent @file{.h} and @file{.c} files used for your
+configuration; the next two chapters discuss those.
-@node Host, Target, Config, Top
+@node Host
@chapter Adding a New Host
Once you have specified a new configuration for your host
-(@pxref{Config,,Adding a New Configuration}), there are two remaining
+(@pxref{Config,,Adding a New Configuration}), there are three remaining
pieces to making GDB work on a new machine. First, you have to make it
host on the new machine (compile there, handle that machine's terminals
properly, etc). If you will be cross-debugging to some other kind of
If you want to use GDB to debug programs that run on the new machine,
you have to get it to understand the machine's object files, symbol
-files, and interfaces to processes. @pxref{Target,,Adding a New Target}
+files, and interfaces to processes; @pxref{Target,,Adding a New Target}
+and @pxref{Native,,Adding a New Native Configuration}
Several files control GDB's configuration for host systems:
@table @file
-@item gdb/xconfig/@var{xxx}
-Specifies what object files are needed when hosting on machine @var{xxx},
-by defining the makefile macro @samp{XDEPFILES=@dots{}}. Also
-specifies the header file which describes @var{xxx}, by defining
+@item gdb/config/mh-@var{xxx}
+Specifies Makefile fragments needed when hosting on machine @var{xxx}.
+In particular, this lists the required machine-dependent object files,
+by defining @samp{XDEPFILES=@dots{}}. Also
+specifies the header file which describes host @var{xxx}, by defining
@samp{XM_FILE= xm-@var{xxx}.h}. You can also define @samp{CC},
@samp{REGEX} and @samp{REGEX1}, @samp{SYSV_DEFINE}, @samp{XM_CFLAGS},
@samp{XM_ADD_FILES}, @samp{XM_CLIBS}, @samp{XM_CDEPS},
@item gdb/@var{xxx}-xdep.c
Contains any miscellaneous C code required for this machine
-as a host. On some machines it doesn't exist at all.
+as a host. On many machines it doesn't exist at all. If it does
+exist, put @file{@var{xxx}-xdep.o} into the @code{XDEPFILES} line
+in @file{gdb/config/mh-@var{xxx}}.
@end table
+@subheading Generic Host Support Files
+
There are some ``generic'' versions of routines that can be used by
-various host systems. These can be customized in various ways by macros
+various systems. These can be customized in various ways by macros
defined in your @file{xm-@var{xxx}.h} file. If these routines work for
the @var{xxx} host, you can just include the generic file's name (with
@samp{.o}, not @samp{.c}) in @code{XDEPFILES}.
Otherwise, if your machine needs custom support routines, you will need
to write routines that perform the same functions as the generic file.
Put them into @code{@var{xxx}-xdep.c}, and put @code{@var{xxx}-xdep.o}
-into @code{XDEPFILES}.
-
-@subheading Generic Host Support Files
+into @code{XDEPFILES}.
@table @file
+@item ser-bsd.c
+This contains serial line support for Berkeley-derived Unix systems.
-@item infptrace.c
-This is the low level interface to inferior processes for systems
-using the Unix @code{ptrace} call in a vanilla way.
+@item ser-go32.c
+This contains serial line support for 32-bit programs running under DOS
+using the GO32 execution environment.
-@item coredep.c::fetch_core_registers()
-Support for reading registers out of a core file. This routine calls
-@code{register_addr()}, see below.
-Now that BFD is used to read core files, virtually all machines should
-use @code{coredep.c}, and should just provide @code{fetch_core_registers} in
-@code{@var{xxx}-xdep.c}.
-
-@item coredep.c::register_addr()
-If your @code{xm-@var{xxx}.h} file defines the macro
-@code{REGISTER_U_ADDR(reg)} to be the offset within the @samp{user}
-struct of a register (represented as a GDB register number),
-@file{coredep.c} will define the @code{register_addr()} function and use
-the macro in it. If you do not define @code{REGISTER_U_ADDR}, but you
-are using the standard @code{fetch_core_registers()}, you will need to
-define your own version of @code{register_addr()}, put it into your
-@code{@var{xxx}-xdep.c} file, and be sure @code{@var{xxx}-xdep.o} is in
-the @code{XDEPFILES} list. If you have your own
-@code{fetch_core_registers()}, you may not need a separate
-@code{register_addr()}. Many custom @code{fetch_core_registers()}
-implementations simply locate the registers themselves.@refill
+@item ser-termios.c
+This contains serial line support for System V-derived Unix systems.
@end table
-Object files needed when the target system is an @var{xxx} are listed
-in the file @file{tconfig/@var{xxx}}, in the makefile macro
-@samp{TDEPFILES = }@dots{}. The header file that defines the target
-system should be called @file{tm-@var{xxx}.h}, and should be specified
-as the value of @samp{TM_FILE} in @file{tconfig/@var{xxx}}. You can
-also define @samp{TM_CFLAGS}, @samp{TM_CLIBS}, and @samp{TM_CDEPS} in
-there; see @file{Makefile.in}.
-
-Now, you are now ready to try configuring GDB to compile for your system.
-From the top level (above @file{bfd}, @file{gdb}, etc), do:
+Now, you are now ready to try configuring GDB to compile using your system
+as its host. From the top level (above @file{bfd}, @file{gdb}, etc), do:
@example
./configure @var{xxx} +target=vxworks960
make
@end example
+Repeat until the program configures, compiles, links, and runs.
+When run, it won't be able to do much (unless you have a VxWorks/960
+board on your network) but you will know that the host support is
+pretty well done.
+
Good luck! Comments and suggestions about this section are particularly
welcome; send them to @samp{bug-gdb@@prep.ai.mit.edu}.
-When hosting GDB on a new operating system, to make it possible to debug
+@node Native
+@chapter Adding a New Native Configuration
+
+If you are making GDB run native on the @var{xxx} machine, you have
+plenty more work to do. Several files control GDB's configuration for
+native support:
+
+@table @file
+@item gdb/config/@var{xxx}.mh
+Specifies Makefile fragments needed when hosting @emph{or native}
+on machine @var{xxx}.
+In particular, this lists the required native-dependent object files,
+by defining @samp{NATDEPFILES=@dots{}}. Also
+specifies the header file which describes native support on @var{xxx},
+by defining @samp{NM_FILE= nm-@var{xxx}.h}.
+You can also define @samp{NAT_CFLAGS},
+@samp{NAT_ADD_FILES}, @samp{NAT_CLIBS}, @samp{NAT_CDEPS},
+etc.; see @file{Makefile.in}.
+
+@item gdb/nm-@var{xxx}.h
+(@file{nm.h} is a link to this file, created by configure).
+Contains C macro definitions describing the native system environment,
+such as child process control and core file support.
+Crib from existing @file{nm-*.h} files to create a new one.
+
+@item gdb/@var{xxx}-nat.c
+Contains any miscellaneous C code required for this native support
+of this machine. On some machines it doesn't exist at all.
+@end table
+
+@subheading Generic Native Support Files
+
+There are some ``generic'' versions of routines that can be used by
+various systems. These can be customized in various ways by macros
+defined in your @file{nm-@var{xxx}.h} file. If these routines work for
+the @var{xxx} host, you can just include the generic file's name (with
+@samp{.o}, not @samp{.c}) in @code{NATDEPFILES}.
+
+Otherwise, if your machine needs custom support routines, you will need
+to write routines that perform the same functions as the generic file.
+Put them into @code{@var{xxx}-nat.c}, and put @code{@var{xxx}-nat.o}
+into @code{NATDEPFILES}.
+
+@table @file
+
+@item inftarg.c
+This contains the @emph{target_ops vector} that supports Unix child
+processes on systems which use ptrace and wait to control the child.
+
+@item procfs.c
+This contains the @emph{target_ops vector} that supports Unix child
+processes on systems which use /proc to control the child.
+
+@item fork-child.c
+This does the low-level grunge that uses Unix system calls
+to do a "fork and exec" to start up a child process.
+
+@item infptrace.c
+This is the low level interface to inferior processes for systems
+using the Unix @code{ptrace} call in a vanilla way.
+
+@item coredep.c::fetch_core_registers()
+Support for reading registers out of a core file. This routine calls
+@code{register_addr()}, see below.
+Now that BFD is used to read core files, virtually all machines should
+use @code{coredep.c}, and should just provide @code{fetch_core_registers} in
+@code{@var{xxx}-nat.c} (or @code{REGISTER_U_ADDR} in @code{nm-@var{xxx}.h}).
+
+@item coredep.c::register_addr()
+If your @code{nm-@var{xxx}.h} file defines the macro
+@code{REGISTER_U_ADDR(addr, blockend, regno)}, it should be defined to
+set @code{addr} to the offset within the @samp{user}
+struct of GDB register number @code{regno}. @code{blockend} is the
+offset within the ``upage'' of @code{u.u_ar0}.
+If @code{REGISTER_U_ADDR} is defined,
+@file{coredep.c} will define the @code{register_addr()} function and use
+the macro in it. If you do not define @code{REGISTER_U_ADDR}, but you
+are using the standard @code{fetch_core_registers()}, you will need to
+define your own version of @code{register_addr()}, put it into your
+@code{@var{xxx}-nat.c} file, and be sure @code{@var{xxx}-nat.o} is in
+the @code{NATDEPFILES} list. If you have your own
+@code{fetch_core_registers()}, you may not need a separate
+@code{register_addr()}. Many custom @code{fetch_core_registers()}
+implementations simply locate the registers themselves.@refill
+@end table
+
+When making GDB run native on a new operating system,
+to make it possible to debug
core files, you will need to either write specific code for parsing your
OS's core files, or customize @file{bfd/trad-core.c}. First, use
whatever @code{#include} files your machine uses to define the struct of
Then back in GDB, you need a matching routine called
@code{fetch_core_registers()}. If you can use the generic one, it's in
-@file{core-dep.c}; if not, it's in your @file{@var{xxx}-xdep.c} file.
+@file{coredep.c}; if not, it's in your @file{@var{xxx}-nat.c} file.
It will be passed a char pointer to the entire ``registers'' segment,
its length, and a zero; or a char pointer to the entire ``regs2''
segment, its length, and a 2. The routine should suck out the supplied
(@xref{New Architectures,,Defining a New Host or Target Architecture},
for more info about this.)
+If your system uses @file{/proc} to control processes, and uses ELF
+format core files, then you may be able to use the same routines
+for reading the registers out of processes and out of core files.
-@node Target, Languages, Host, Top
+@node Target
@chapter Adding a New Target
For a new target called @var{ttt}, first specify the configuration as
described in @ref{Config,,Adding a New Configuration}. If your new
target is the same as your new host, you've probably already done that.
-A variety of files specify attributes of the target environment:
+A variety of files specify attributes of the GDB target environment:
@table @file
-@item gdb/tconfig/@var{ttt}
+@item gdb/config/@var{ttt}.mt
+Contains a Makefile fragment specific to this target.
Specifies what object files are needed for target @var{ttt}, by
-defining the makefile macro @samp{TDEPFILES=@dots{}}.
+defining @samp{TDEPFILES=@dots{}}.
Also specifies the header file which describes @var{ttt}, by defining
-@samp{TM_FILE= tm-@var{ttt}.h}. You can also define @samp{CC},
-@samp{REGEX} and @samp{REGEX1}, @samp{SYSV_DEFINE}, @samp{TM_CFLAGS},
+@samp{TM_FILE= tm-@var{ttt}.h}. You can also define @samp{TM_CFLAGS},
+@samp{TM_CLIBS}, @samp{TM_CDEPS},
and other Makefile variables here; see @file{Makefile.in}.
@item gdb/tm-@var{ttt}.h
configuration.)
-@node Languages, Releases, Target, Top
+@node Languages
@chapter Adding a Source Language to GDB
To add other languages to GDB's expression parser, follow the following steps:
@end table
-@node Releases, BFD support for GDB, Languages, Top
+@node Releases
@chapter Configuring GDB for Release
From the top level directory (containing @file{gdb}, @file{bfd},
@file{libiberty}, and so on):
@example
-make gdb.tar.Z
+make -f Makefile.in gdb.tar.Z
@end example
This will properly configure, clean, rebuild any files that are
distributed pre-built (e.g. @file{c-exp.tab.c} or @file{refcard.ps}),
-and will then make a tarfile.
+and will then make a tarfile. (If the top level directory has already
+beenn configured, you can just do @code{make gdb.tar.Z} instead.)
This procedure requires:
@itemize @bullet
split the document into one overall file and five or so included files.
-@node BFD support for GDB, Symbol Reading, Releases, Top
+@node Partial Symbol Tables
+@chapter Partial Symbol Tables
+
+GDB has three types of symbol tables.
+
+@itemize @bullet
+@item full symbol tables (symtabs). These contain the main
+information about symbols and addresses.
+@item partial symbol tables (psymtabs). These contain enough
+information to know when to read the corresponding
+part of the full symbol table.
+@item minimal symbol tables (msymtabs). These contain information
+gleaned from non-debugging symbols.
+@end itemize
+
+This section describes partial symbol tables.
+
+A psymtab is constructed by doing a very quick pass over an executable
+file's debugging information. Small amounts of information are
+extracted -- enough to identify which parts of the symbol table will
+need to be re-read and fully digested later, when the user needs the
+information. The speed of this pass causes GDB to start up very
+quickly. Later, as the detailed rereading occurs, it occurs in small
+pieces, at various times, and the delay therefrom is mostly invisible to
+the user. (@xref{Symbol Reading}.)
+
+The symbols that show up in a file's psymtab should be, roughly, those
+visible to the debugger's user when the program is not running code from
+that file. These include external symbols and types, static
+symbols and types, and enum values declared at file scope.
+
+The psymtab also contains the range of instruction addresses that the
+full symbol table would represent.
+
+The idea is that there are only two ways for the user (or much of
+the code in the debugger) to reference a symbol:
+
+@itemize @bullet
+
+@item by its address
+(e.g. execution stops at some address which is inside a function
+in this file). The address will be noticed to be in the
+range of this psymtab, and the full symtab will be read in.
+@code{find_pc_function}, @code{find_pc_line}, and other @code{find_pc_@dots{}}
+functions handle this.
+
+@item by its name
+(e.g. the user asks to print a variable, or set a breakpoint on a
+function). Global names and file-scope names will be found in the
+psymtab, which will cause the symtab to be pulled in. Local names will
+have to be qualified by a global name, or a file-scope name, in which
+case we will have already read in the symtab as we evaluated the
+qualifier. Or, a local symbol can be referenced when
+we are "in" a local scope, in which case the first case applies.
+@code{lookup_symbol} does most of the work here.
+
+@end itemize
+
+The only reason that psymtabs exist is to cause a symtab to be read in
+at the right moment. Any symbol that can be elided from a psymtab,
+while still causing that to happen, should not appear in it. Since
+psymtabs don't have the idea of scope, you can't put local symbols in
+them anyway. Psymtabs don't have the idea of the type of a symbol,
+either, so types need not appear, unless they will be referenced by
+name.
+
+It is a bug for GDB to behave one way when only a psymtab has been read,
+and another way if the corresponding symtab has been read in. Such
+bugs are typically caused by a psymtab that does not contain all the
+visible symbols, or which has the wrong instruction address ranges.
+
+The psymtab for a particular section of a symbol-file (objfile)
+could be thrown away after the symtab has been read in. The symtab
+should always be searched before the psymtab, so the psymtab will
+never be used (in a bug-free environment). Currently,
+psymtabs are allocated on an obstack, and all the psymbols themselves
+are allocated in a pair of large arrays on an obstack, so there is
+little to be gained by trying to free them unless you want to do a lot
+more work.
+
+@node BFD support for GDB
@chapter Binary File Descriptor Library Support for GDB
BFD provides support for GDB in several ways:
@c Reading,,Symbol Reading}.
-@node Symbol Reading, Cleanups, BFD support for GDB, Top
+@node Symbol Reading
@chapter Symbol Reading
GDB reads symbols from "symbol files". The usual symbol file is the
@end table
-@node Cleanups, Wrapping, Symbol Reading, Top
+@node Cleanups
@chapter Cleanups
Cleanups are a structured way to deal with things that need to be done
Syntax:
@table @code
+@item struct cleanup *@var{old_chain};
+Declare a variable which will hold a cleanup chain handle.
+
@item @var{old_chain} = make_cleanup (@var{function}, @var{arg});
Make a cleanup which will cause @var{function} to be called with @var{arg}
(a @code{char *}) later. The result, @var{old_chain}, is a handle that can be
since they might never return to your code (they @samp{longjmp} instead).
-@node Wrapping, , Cleanups, Top
+@node Wrapping
@chapter Wrapping Output Lines
Output that goes through @code{printf_filtered} or @code{fputs_filtered} or
warnings are a good example.
+@node Frames
+@chapter Frames
+
+A frame is a construct that GDB uses to keep track of calling and called
+functions.
+
+@table @code
+@item FRAME_FP
+in the machine description has no meaning to the machine-independent
+part of GDB, except that it is used when setting up a new frame from
+scratch, as follows:
+
+@example
+ create_new_frame (read_register (FP_REGNUM), read_pc ()));
+@end example
+
+Other than that, all the meaning imparted to @code{FP_REGNUM} is imparted by
+the machine-dependent code. So, @code{FP_REGNUM} can have any value that
+is convenient for the code that creates new frames. (@code{create_new_frame}
+calls @code{INIT_EXTRA_FRAME_INFO} if it is defined; that is where you should
+use the @code{FP_REGNUM} value, if your frames are nonstandard.)
+
+@item FRAME_CHAIN
+Given a GDB frame, determine the address of the calling function's
+frame. This will be used to create a new GDB frame struct, and then
+@code{INIT_EXTRA_FRAME_INFO} and @code{INIT_FRAME_PC} will be called for
+the new frame.
+@end table
+
+@node Remote Stubs
+@chapter Remote Stubs
+
+GDB's file @file{remote.c} talks a serial protocol to code that runs
+in the target system. GDB provides several sample ``stubs'' that can
+be integrated into target programs or operating systems for this purpose;
+they are named @file{*-stub.c}.
+
+The GDB user's manual describes how to put such a stub into your target
+code. What follows is a discussion of integrating the SPARC stub
+into a complicated operating system (rather than a simple program),
+by Stu Grossman, the author of this stub.
+
+The trap handling code in the stub assumes the following upon entry to
+trap_low:
+
+@enumerate
+@item %l1 and %l2 contain pc and npc respectively at the time of the trap
+@item traps are disabled
+@item you are in the correct trap window
+@end enumerate
+
+As long as your trap handler can guarantee those conditions, then there is no
+reason why you shouldn't be able to `share' traps with the stub. The stub has
+no requirement that it be jumped to directly from the hardware trap vector.
+That is why it calls @code{exceptionHandler()}, which is provided by the external
+environment. For instance, this could setup the hardware traps to actually
+execute code which calls the stub first, and then transfers to its own trap
+handler.
+
+For the most point, there probably won't be much of an issue with `sharing'
+traps, as the traps we use are usually not used by the kernel, and often
+indicate unrecoverable error conditions. Anyway, this is all controlled by a
+table, and is trivial to modify.
+The most important trap for us is for @code{ta 1}. Without that, we
+can't single step or do breakpoints. Everything else is unnecessary
+for the proper operation of the debugger/stub.
+
+From reading the stub, it's probably not obvious how breakpoints work. They
+are simply done by deposit/examine operations from GDB.
+
+@node Coding Style
+@chapter Coding Style
+
+GDB is generally written using the GNU coding standards, as described in
+@file{standards.texi}, which you can get from the Free Software
+Foundation. There are some additional considerations for GDB maintainers
+that reflect the unique environment and style of GDB maintenance.
+If you follow these guidelines, GDB will be more consistent and easier
+to maintain.
+
+GDB's policy on the use of prototypes is that prototypes are used
+to @emph{declare} functions but never to @emph{define} them. Simple
+macros are used in the declarations, so that a non-ANSI compiler can
+compile GDB without trouble. The simple macro calls are used like
+this:
+
+@example @code
+extern int
+memory_remove_breakpoint PARAMS ((CORE_ADDR, char *));
+@end example
+
+Note the double parentheses around the parameter types. This allows
+an arbitrary number of parameters to be described, without freaking
+out the C preprocessor. When the function has no parameters, it
+should be described like:
+
+@example @code
+void
+noprocess PARAMS ((void));
+@end example
+
+The @code{PARAMS} macro expands to its argument in ANSI C, or to a simple
+@code{()} in traditional C.
+
+All external functions should have a @code{PARAMS} declaration in a
+header file that callers include. All static functions should have such
+a declaration near the top of their source file.
+
+We don't have a gcc option that will properly check that these rules
+have been followed, but it's GDB policy, and we periodically check it
+using the tools available (plus manual labor), and clean up any remnants.
+
+@node Clean Design
+@chapter Clean Design
+
+In addition to getting the syntax right, there's the little question of
+semantics. Some things are done in certain ways in GDB because long
+experience has shown that the more obvious ways caused various kinds of
+trouble. In particular:
+
+@table @bullet
+@item
+You can't assume the byte order of anything that comes from a
+target (including @var{value}s, object files, and instructions). Such
+things must be byte-swapped using @code{SWAP_TARGET_AND_HOST} in GDB,
+or one of the swap routines defined in @file{bfd.h}, such as @code{bfd_get_32}.
+
+@item
+You can't assume that you know what interface is being used to talk to
+the target system. All references to the target must go through the
+current @code{target_ops} vector.
+
+@item
+You can't assume that the host and target machines are the same machine
+(except in the ``native'' support modules).
+In particular, you can't assume that the target machine's header files
+will be available on the host machine. Target code must bring along its
+own header files -- written from scratch or explicitly donated by their
+owner, to avoid copyright problems.
+
+@item
+Insertion of new @code{#ifdef}'s will be frowned upon. It's much better
+to write the code portably than to conditionalize it for various systems.
+
+@item
+New @code{#ifdef}'s which test for specific compilers or manufacturers
+or operating systems are unacceptable. All @code{#ifdef}'s should test
+for features. The information about which configurations contain which
+features should be segregated into the configuration files. Experience
+has proven far too often that a feature unique to one particular system
+often creeps into other systems; and that a conditional based on
+some predefined macro for your current system will become worthless
+over time, as new versions of your system come out that behave differently
+with regard to this feature.
+
+@item
+Adding code that handles specific architectures, operating systems, target
+interfaces, or hosts, is not acceptable in generic code. If a hook
+is needed at that point, invent a generic hook and define it for your
+configuration, with something like:
+
+@example
+#ifdef WRANGLE_SIGNALS
+ WRANGLE_SIGNALS (signo);
+#endif
+@end example
+
+In your host, target, or native configuration file, as appropriate,
+define @code{WRANGLE_SIGNALS} to do the machine-dependent thing. Take
+a bit of care in defining the hook, so that it can be used by other
+ports in the future, if they need a hook in the same place.
+
+@item
+@emph{Do} write code that doesn't depend on the sizes of C data types,
+the format of the host's floating point numbers, the alignment of anything,
+or the order of evaluation of expressions. In short, follow good
+programming practices for writing portable C code.
+
+@end table
+
+@node Submitting Patches
+@chapter Submitting Patches
+
+Thanks for thinking of offering your changes back to the community of
+GDB users. In general we like to get well designed enhancements.
+Thanks also for checking in advance about the best way to transfer the
+changes.
+
+The two main problems with getting your patches in are,
+
+@table @bullet
+@item
+The GDB maintainers will only install "cleanly designed" patches.
+You may not always agree on what is clean design.
+@pxref{Coding Style}, @pxref{Clean Design}.
+
+@item
+If the maintainers don't have time to put the patch in when it
+arrives, or if there is any question about a patch, it
+goes into a large queue with everyone else's patches and
+bug reports.
+@end table
+
+I don't know how to get past these problems except by continuing to try.
+
+There are two issues here -- technical and legal.
+
+The legal issue is that to incorporate substantial changes requires a
+copyright assignment from you and/or your employer, granting ownership of the changes to
+the Free Software Foundation. You can get the standard document for
+doing this by sending mail to @code{gnu@@prep.ai.mit.edu} and asking for it.
+I recommend that people write in "All programs owned by the
+Free Software Foundation" as "NAME OF PROGRAM", so that changes in
+many programs (not just GDB, but GAS, Emacs, GCC, etc) can be
+contributed with only one piece of legalese pushed through the
+bureacracy and filed with the FSF. I can't start merging changes until
+this paperwork is received by the FSF (their rules, which I follow since
+I maintain it for them).
+
+Technically, the easiest way to receive changes is to receive each
+feature as a small context diff or unidiff, suitable for "patch".
+Each message sent to me should include the changes to C code and
+header files for a single feature, plus ChangeLog entries for each
+directory where files were modified, and diffs for any changes needed
+to the manuals (gdb/doc/gdb.texi or gdb/doc/gdbint.texi). If there
+are a lot of changes for a single feature, they can be split down
+into multiple messages.
+
+In this way, if I read and like the feature, I can add it to the
+sources with a single patch command, do some testing, and check it in.
+If you leave out the ChangeLog, I have to write one. If you leave
+out the doc, I have to puzzle out what needs documenting. Etc.
+
+The reason to send each change in a separate message is that I will
+not install some of the changes. They'll be returned to you with
+questions or comments. If I'm doing my job, my message back to you
+will say what you have to fix in order to make the change acceptable.
+The reason to have separate messages for separate features is so
+that other changes (which I @emph{am} willing to accept) can be installed
+while one or more changes are being reworked. If multiple features
+are sent in a single message, I tend to not put in the effort to sort
+out the acceptable changes from the unacceptable, so none of the
+features get installed until all are acceptable.
+
+If this sounds painful or authoritarian, well, it is. But I get a lot
+of bug reports and a lot of patches, and most of them don't get
+installed because I don't have the time to finish the job that the bug
+reporter or the contributor could have done. Patches that arrive
+complete, working, and well designed, tend to get installed on the day
+they arrive. The others go into a queue and get installed if and when
+I scan back over the queue -- which can literally take months
+sometimes. It's in both our interests to make patch installation easy
+-- you get your changes installed, and I make some forward progress on
+GDB in a normal 12-hour day (instead of them having to wait until I
+have a 14-hour or 16-hour day to spend cleaning up patches before I
+can install them).
+
+@node Host Conditionals
+@chapter Host Conditionals
+
+When GDB is configured and compiled, various macros are defined or left
+undefined, to control compilation based on the attributes of the host
+system. These macros and their meanings are:
+
+@emph{NOTE: For now, both host and target conditionals are here.
+Eliminate target conditionals from this list as they are identified.}
+
+@table @code
+@item ALIGN_SIZE
+alloca.c
+@item BLOCK_ADDRESS_FUNCTION_RELATIVE
+dbxread.c
+@item GDBINIT_FILENAME
+main.c
+@item KERNELDEBUG
+tm-hppa.h
+@item MEM_FNS_DECLARED
+Your host config file defines this if it includes
+declarations of @code{memcpy} and @code{memset}. Define this
+to avoid conflicts between the native include
+files and the declarations in @file{defs.h}.
+@item NO_SYS_FILE
+dbxread.c
+@item PYRAMID_CONTROL_FRAME_DEBUGGING
+pyr-xdep.c
+@item SIGWINCH_HANDLER_BODY
+utils.c
+@item 1
+buildsym.c
+@item 1
+dbxread.c
+@item 1
+dbxread.c
+@item 1
+buildsym.c
+@item 1
+dwarfread.c
+@item 1
+valops.c
+@item 1
+valops.c
+@item 1
+pyr-xdep.c
+@item ADDITIONAL_OPTIONS
+main.c
+@item ADDITIONAL_OPTION_CASES
+main.c
+@item ADDITIONAL_OPTION_HANDLER
+main.c
+@item ADDITIONAL_OPTION_HELP
+main.c
+@item ADDR_BITS_REMOVE
+defs.h
+@item AIX_BUGGY_PTRACE_CONTINUE
+infptrace.c
+@item ALIGN_STACK_ON_STARTUP
+main.c
+@item ALTOS
+altos-xdep.c
+@item ALTOS_AS
+xm-altos.h
+@item ASCII_COFF
+remote-adapt.c
+@item BADMAG
+coffread.c
+@item BCS
+tm-delta88.h
+@item BEFORE_MAIN_LOOP_HOOK
+main.c
+@item BELIEVE_PCC_PROMOTION
+coffread.c
+@item BELIEVE_PCC_PROMOTION_TYPE
+stabsread.c
+@item BIG_ENDIAN
+defs.h
+@item BITS_BIG_ENDIAN
+defs.h
+@item BKPT_AT_MAIN
+solib.c
+@item BLOCK_ADDRESS_ABSOLUTE
+dbxread.c
+@item BPT_VECTOR
+tm-68k.h
+@item BREAKPOINT
+tm-68k.h
+@item BREAKPOINT_DEBUG
+breakpoint.c
+@item BROKEN_LARGE_ALLOCA
+Avoid large @code{alloca}'s. For example, on sun's, Large alloca's fail
+because the attempt to increase the stack limit in main() fails because
+shared libraries are allocated just below the initial stack limit. The
+SunOS kernel will not allow the stack to grow into the area occupied by
+the shared libraries.
+@item BSTRING
+regex.c
+@item CALL_DUMMY
+valops.c
+@item CALL_DUMMY_LOCATION
+inferior.h
+@item CALL_DUMMY_STACK_ADJUST
+valops.c
+@item CANNOT_FETCH_REGISTER
+hppabsd-xdep.c
+@item CANNOT_STORE_REGISTER
+findvar.c
+@item CFRONT_PRODUCER
+dwarfread.c
+@item CHILD_PREPARE_TO_STORE
+inftarg.c
+@item CLEAR_DEFERRED_STORES
+inflow.c
+@item CLEAR_SOLIB
+objfiles.c
+@item COFF_ENCAPSULATE
+hppabsd-tdep.c
+@item COFF_FORMAT
+symm-tdep.c
+@item COFF_NO_LONG_FILE_NAMES
+coffread.c
+@item CORE_NEEDS_RELOCATION
+stack.c
+@item CPLUS_MARKER
+cplus-dem.c
+@item CREATE_INFERIOR_HOOK
+infrun.c
+@item C_ALLOCA
+regex.c
+@item C_GLBLREG
+coffread.c
+@item DAMON
+xcoffexec.c
+@item DBXREAD_ONLY
+partial-stab.h
+@item DBX_PARM_SYMBOL_CLASS
+stabsread.c
+@item DEBUG
+remote-adapt.c
+@item DEBUG_INFO
+partial-stab.h
+@item DEBUG_PTRACE
+hppabsd-xdep.c
+@item DECR_PC_AFTER_BREAK
+breakpoint.c
+@item DEFAULT_PROMPT
+main.c
+@item DELTA88
+m88k-xdep.c
+@item DEV_TTY
+symmisc.c
+@item DGUX
+m88k-xdep.c
+@item DISABLE_UNSETTABLE_BREAK
+breakpoint.c
+@item DONT_USE_REMOTE
+remote.c
+@item DO_DEFERRED_STORES
+infrun.c
+@item DO_REGISTERS_INFO
+infcmd.c
+@item END_OF_TEXT_DEFAULT
+dbxread.c
+@item EXTERN
+buildsym.h
+@item EXTRACT_RETURN_VALUE
+tm-68k.h
+@item EXTRACT_STRUCT_VALUE_ADDRESS
+values.c
+@item EXTRA_FRAME_INFO
+frame.h
+@item EXTRA_SYMTAB_INFO
+symtab.h
+@item FILES_INFO_HOOK
+target.c
+@item FIXME
+coffread.c
+@item FLOAT_INFO
+infcmd.c
+@item FOPEN_RB
+defs.h
+@item FP0_REGNUM
+a68v-xdep.c
+@item FPC_REGNUM
+mach386-xdep.c
+@item FP_REGNUM
+parse.c
+@item FRAMELESS_FUNCTION_INVOCATION
+blockframe.c
+@item FRAME_ARGS_ADDRESS_CORRECT
+stack.c
+@item FRAME_CHAIN_COMBINE
+blockframe.c
+@item FRAME_CHAIN_VALID
+frame.h
+@item FRAME_CHAIN_VALID_ALTERNATE
+frame.h
+@item FRAME_FIND_SAVED_REGS
+stack.c
+@item FRAME_GET_BASEREG_VALUE
+frame.h
+@item FRAME_NUM_ARGS
+tm-68k.h
+@item FRAME_SPECIFICATION_DYADIC
+stack.c
+@item FUNCTION_EPILOGUE_SIZE
+coffread.c
+@item F_OK
+xm-ultra3.h
+@item GCC2_COMPILED_FLAG_SYMBOL
+dbxread.c
+@item GCC_COMPILED_FLAG_SYMBOL
+dbxread.c
+@item GCC_MANGLE_BUG
+symtab.c
+@item GCC_PRODUCER
+dwarfread.c
+@item GET_SAVED_REGISTER
+findvar.c
+@item GPLUS_PRODUCER
+dwarfread.c
+@item GR64_REGNUM
+remote-adapt.c
+@item GR64_REGNUM
+remote-mm.c
+@item HANDLE_RBRAC
+partial-stab.h
+@item HAVE_68881
+m68k-tdep.c
+@item HAVE_MMAP
+In some cases, use the system call @code{mmap} for reading symbol
+tables. For some machines this allows for sharing and quick updates.
+@item HAVE_REGISTER_WINDOWS
+findvar.c
+@item HAVE_SIGSETMASK
+main.c
+@item HAVE_TERMIO
+inflow.c
+@item HEADER_SEEK_FD
+arm-tdep.c
+@item HOSTING_ONLY
+xm-rtbsd.h
+@item HOST_BYTE_ORDER
+ieee-float.c
+@item HPUX_ASM
+xm-hp300hpux.h
+@item HPUX_VERSION_5
+hp300ux-xdep.c
+@item HP_OS_BUG
+infrun.c
+@item I80960
+remote-vx.c
+@item IBM6000_HOST
+breakpoint.c
+@item IBM6000_TARGET
+buildsym.c
+@item IEEE_DEBUG
+ieee-float.c
+@item IEEE_FLOAT
+valprint.c
+@item IGNORE_SYMBOL
+dbxread.c
+@item INIT_EXTRA_FRAME_INFO
+blockframe.c
+@item INIT_EXTRA_SYMTAB_INFO
+symfile.c
+@item INIT_FRAME_PC
+blockframe.c
+@item INNER_THAN
+valops.c
+@item INT_MAX
+defs.h
+@item INT_MIN
+defs.h
+@item IN_GDB
+i960-pinsn.c
+@item IN_SIGTRAMP
+infrun.c
+@item IN_SOLIB_TRAMPOLINE
+infrun.c
+@item ISATTY
+main.c
+@item IS_TRAPPED_INTERNALVAR
+values.c
+@item KERNELDEBUG
+dbxread.c
+@item KERNEL_DEBUGGING
+tm-ultra3.h
+@item KERNEL_U_ADDR
+Define this to the address of the @code{u} structure (the ``user struct'',
+also known as the ``u-page'') in kernel virtual memory. GDB needs to know
+this so that it can subtract this address from absolute addresses in
+the upage, that are obtained via ptrace or from core files. On systems
+that don't need this value, set it to zero.
+@item KERNEL_U_ADDR_BSD
+Define this to cause GDB to determine the address of @code{u} at runtime,
+by using Berkeley-style @code{nlist} on the kernel's image in the root
+directory.
+@item KERNEL_U_ADDR_HPUX
+Define this to cause GDB to determine the address of @code{u} at runtime,
+by using HP-style @code{nlist} on the kernel's image in the root
+directory.
+@item LCC_PRODUCER
+dwarfread.c
+@item LITTLE_ENDIAN
+defs.h
+@item LOG_FILE
+remote-adapt.c
+@item LONGERNAMES
+cplus-dem.c
+@item LONGEST
+defs.h
+@item LONG_LONG
+defs.h
+@item LONG_MAX
+defs.h
+@item LSEEK_NOT_LINEAR
+source.c
+@item L_LNNO32
+coffread.c
+@item L_SET
+This macro is used as the argument to lseek (or, most commonly, bfd_seek).
+FIXME, it should be replaced by SEEK_SET instead, which is the POSIX equivalent.
+@item MACHKERNELDEBUG
+hppabsd-tdep.c
+@item MAIN
+cplus-dem.c
+@item MAINTENANCE
+dwarfread.c
+@item MAINTENANCE_CMDS
+breakpoint.c
+@item MAINTENANCE_CMDS
+maint.c
+@item MALLOC_INCOMPATIBLE
+Define this if the system's prototype for @code{malloc} differs from the
+@sc{ANSI} definition.
+@item MIPSEL
+mips-tdep.c
+@item MMAP_BASE_ADDRESS
+When using HAVE_MMAP, the first mapping should go at this address.
+@item MMAP_INCREMENT
+when using HAVE_MMAP, this is the increment between mappings.
+@item MONO
+ser-go32.c
+@item MOTOROLA
+xm-altos.h
+@item NBPG
+altos-xdep.c
+@item NEED_POSIX_SETPGID
+infrun.c
+@item NEED_TEXT_START_END
+exec.c
+@item NFAILURES
+regex.c
+@item NNPC_REGNUM
+infrun.c
+@item NORETURN
+defs.h
+@item NOTDEF
+regex.c
+@item NOTDEF
+remote-adapt.c
+@item NOTDEF
+remote-mm.c
+@item NOTICE_SIGNAL_HANDLING_CHANGE
+infrun.c
+@item NO_DEFINE_SYMBOL
+xcoffread.c
+@item NO_HIF_SUPPORT
+remote-mm.c
+@item NO_JOB_CONTROL
+signals.h
+@item NO_MALLOC_CHECK
+utils.c
+@item NO_MMALLOC
+utils.c
+@item NO_MMALLOC
+objfiles.c
+@item NO_MMALLOC
+utils.c
+@item NO_SIGINTERRUPT
+remote-adapt.c
+@item NO_SINGLE_STEP
+infptrace.c
+@item NO_TYPEDEFS
+xcoffread.c
+@item NO_TYPEDEFS
+xcoffread.c
+@item NPC_REGNUM
+infcmd.c
+@item NS32K_SVC_IMMED_OPERANDS
+ns32k-opcode.h
+@item NUMERIC_REG_NAMES
+mips-tdep.c
+@item N_SETV
+dbxread.c
+@item N_SET_MAGIC
+hppabsd-tdep.c
+@item NaN
+tm-umax.h
+@item ONE_PROCESS_WRITETEXT
+breakpoint.c
+@item O_BINARY
+exec.c
+@item O_RDONLY
+xm-ultra3.h
+@item PC
+convx-opcode.h
+@item PCC_SOL_BROKEN
+dbxread.c
+@item PC_IN_CALL_DUMMY
+inferior.h
+@item PC_LOAD_SEGMENT
+stack.c
+@item PC_REGNUM
+parse.c
+@item PRINT_RANDOM_SIGNAL
+infcmd.c
+@item PRINT_REGISTER_HOOK
+infcmd.c
+@item PRINT_TYPELESS_INTEGER
+valprint.c
+@item PROCESS_LINENUMBER_HOOK
+buildsym.c
+@item PROLOGUE_FIRSTLINE_OVERLAP
+infrun.c
+@item PSIGNAL_IN_SIGNAL_H
+defs.h
+@item PS_REGNUM
+parse.c
+@item PTRACE_ARG3_TYPE
+inferior.h
+@item PTRACE_FP_BUG
+mach386-xdep.c
+@item PT_ATTACH
+hppabsd-xdep.c
+@item PT_DETACH
+hppabsd-xdep.c
+@item PT_KILL
+infptrace.c
+@item PUSH_ARGUMENTS
+valops.c
+@item PYRAMID_CONTROL_FRAME_DEBUGGING
+pyr-xdep.c
+@item PYRAMID_CORE
+pyr-xdep.c
+@item PYRAMID_PTRACE
+pyr-xdep.c
+@item REGISTER_BYTES
+remote.c
+@item REGISTER_NAMES
+tm-29k.h
+@item REG_STACK_SEGMENT
+exec.c
+@item REG_STRUCT_HAS_ADDR
+findvar.c
+@item RE_NREGS
+regex.h
+@item R_FP
+dwarfread.c
+@item R_OK
+xm-altos.h
+@item SDB_REG_TO_REGNUM
+coffread.c
+@item SEEK_END
+state.c
+@item SEEK_SET
+state.c
+@item SEM
+coffread.c
+@item SET_STACK_LIMIT_HUGE
+When defined, stack limits will be raised to their maximum. Use this
+if your host supports @code{setrlimit} and you have trouble with
+@code{stringtab} in @file{dbxread.c}.
+
+Also used in @file{fork-child.c} to return stack limits before child
+processes are forked.
+@item SHELL_COMMAND_CONCAT
+infrun.c
+@item SHELL_FILE
+infrun.c
+@item SHIFT_INST_REGS
+breakpoint.c
+@item SIGN_EXTEND_CHAR
+regex.c
+@item SIGTRAP_STOP_AFTER_LOAD
+infrun.c
+@item SKIP_PROLOGUE
+tm-68k.h
+@item SKIP_PROLOGUE_FRAMELESS_P
+blockframe.c
+@item SKIP_TRAMPOLINE_CODE
+infrun.c
+@item SOLIB_ADD
+core.c
+@item SOLIB_CREATE_INFERIOR_HOOK
+infrun.c
+@item SP_REGNUM
+parse.c
+@item STAB_REG_TO_REGNUM
+stabsread.h
+@item STACK_ALIGN
+valops.c
+@item STACK_DIRECTION
+alloca.c
+@item START_INFERIOR_TRAPS_EXPECTED
+infrun.c
+@item STOP_SIGNAL
+main.c
+@item STORE_RETURN_VALUE
+tm-68k.h
+@item SUN4_COMPILER_FEATURE
+infrun.c
+@item SUN_FIXED_LBRAC_BUG
+dbxread.c
+@item SVR4_SHARED_LIBS
+solib.c
+@item SWITCH_ENUM_BUG
+regex.c
+@item SYM1
+tm-ultra3.h
+@item SYMBOL_RELOADING_DEFAULT
+symfile.c
+@item SYNTAX_TABLE
+regex.c
+@item Sword
+regex.c
+@item TDESC
+infrun.c
+@item TIOCGETC
+inflow.c
+@item TIOCGLTC
+inflow.c
+@item TIOCGPGRP
+inflow.c
+@item TIOCLGET
+inflow.c
+@item TIOCLSET
+inflow.c
+@item TIOCNOTTY
+inflow.c
+@item TM_FILE_OVERRIDE
+defs.h
+@item T_ARG
+coffread.c
+@item T_VOID
+coffread.c
+@item UINT_MAX
+defs.h
+@item UPAGES
+altos-xdep.c
+@item USER
+m88k-tdep.c
+@item USE_GAS
+xm-news.h
+@item USE_O_NOCTTY
+inflow.c
+@item USE_STRUCT_CONVENTION
+values.c
+@item USG
+Means that System V (prior to SVR4) include files are in use.
+(FIXME: This symbol is abused in @file{infrun.c}, @file{regex.c},
+@file{remote-nindy.c}, and @file{utils.c} for other things, at the moment.)
+@item USIZE
+xm-m88k.h
+@item U_FPSTATE
+i386-xdep.c
+@item VARIABLES_INSIDE_BLOCK
+dbxread.c
+@item WRS_ORIG
+remote-vx.c
+@item _LANG_c
+language.c
+@item _LANG_m2
+language.c
+@item __GNUC__
+news-xdep.c
+@item __GO32__
+inflow.c
+@item __HAVE_68881__
+m68k-stub.c
+@item __HPUX_ASM__
+xm-hp300hpux.h
+@item __INT_VARARGS_H
+printcmd.c
+@item __not_on_pyr_yet
+pyr-xdep.c
+@item alloca
+defs.h
+@item const
+defs.h
+@item GOULD_PN
+gould-pinsn.c
+@item emacs
+alloca.c
+@item hp800
+xm-hppabsd.h
+@item hpux
+hppabsd-core.c
+@item lint
+valarith.c
+@item longest_to_int
+defs.h
+@item mc68020
+m68k-stub.c
+@item notdef
+gould-pinsn.c
+@item ns32k_opcodeT
+ns32k-opcode.h
+@item sgi
+mips-tdep.c
+@item sparc
+regex.c
+@item static
+alloca.c
+@item sun
+m68k-tdep.c
+@item sun386
+tm-sun386.h
+@item test
+regex.c
+@item ultrix
+xm-mips.h
+@item volatile
+defs.h
+@item x_name
+coffread.c
+@item x_zeroes
+coffread.c
+@end table
+
+@node Target Conditionals
+@chapter Target Conditionals
+
+When GDB is configured and compiled, various macros are defined or left
+undefined, to control compilation based on the attributes of the target
+system. These macros and their meanings are:
+
+@emph{NOTE: For now, both host and target conditionals are here.
+Eliminate host conditionals from this list as they are identified.}
+
+@table @code
+@item PUSH_DUMMY_FRAME
+Used in @samp{call_function_by_hand} to create an artificial stack frame.
+@item POP_FRAME
+Used in @samp{call_function_by_hand} to remove an artificial stack frame.
+@item ALIGN_SIZE
+alloca.c
+@item BLOCK_ADDRESS_FUNCTION_RELATIVE
+dbxread.c
+@item GDBINIT_FILENAME
+main.c
+@item KERNELDEBUG
+tm-hppa.h
+@item NO_SYS_FILE
+dbxread.c
+@item PYRAMID_CONTROL_FRAME_DEBUGGING
+pyr-xdep.c
+@item SIGWINCH_HANDLER_BODY
+utils.c
+@item ADDITIONAL_OPTIONS
+main.c
+@item ADDITIONAL_OPTION_CASES
+main.c
+@item ADDITIONAL_OPTION_HANDLER
+main.c
+@item ADDITIONAL_OPTION_HELP
+main.c
+@item ADDR_BITS_REMOVE
+defs.h
+@item ALIGN_STACK_ON_STARTUP
+main.c
+@item ALTOS
+altos-xdep.c
+@item ALTOS_AS
+xm-altos.h
+@item ASCII_COFF
+remote-adapt.c
+@item BADMAG
+coffread.c
+@item BCS
+tm-delta88.h
+@item BEFORE_MAIN_LOOP_HOOK
+main.c
+@item BELIEVE_PCC_PROMOTION
+coffread.c
+@item BELIEVE_PCC_PROMOTION_TYPE
+stabsread.c
+@item BIG_ENDIAN
+defs.h
+@item BITS_BIG_ENDIAN
+defs.h
+@item BKPT_AT_MAIN
+solib.c
+@item BLOCK_ADDRESS_ABSOLUTE
+dbxread.c
+@item BPT_VECTOR
+tm-68k.h
+@item BREAKPOINT
+tm-68k.h
+@item BREAKPOINT_DEBUG
+breakpoint.c
+@item BSTRING
+regex.c
+@item CALL_DUMMY
+valops.c
+@item CALL_DUMMY_LOCATION
+inferior.h
+@item CALL_DUMMY_STACK_ADJUST
+valops.c
+@item CANNOT_FETCH_REGISTER
+hppabsd-xdep.c
+@item CANNOT_STORE_REGISTER
+findvar.c
+@item CFRONT_PRODUCER
+dwarfread.c
+@item CHILD_PREPARE_TO_STORE
+inftarg.c
+@item CLEAR_DEFERRED_STORES
+inflow.c
+@item CLEAR_SOLIB
+objfiles.c
+@item COFF_ENCAPSULATE
+hppabsd-tdep.c
+@item COFF_FORMAT
+symm-tdep.c
+@item COFF_NO_LONG_FILE_NAMES
+coffread.c
+@item CORE_NEEDS_RELOCATION
+stack.c
+@item CPLUS_MARKER
+cplus-dem.c
+@item CREATE_INFERIOR_HOOK
+infrun.c
+@item C_ALLOCA
+regex.c
+@item C_GLBLREG
+coffread.c
+@item DAMON
+xcoffexec.c
+@item DBXREAD_ONLY
+partial-stab.h
+@item DBX_PARM_SYMBOL_CLASS
+stabsread.c
+@item DEBUG
+remote-adapt.c
+@item DEBUG_INFO
+partial-stab.h
+@item DEBUG_PTRACE
+hppabsd-xdep.c
+@item DECR_PC_AFTER_BREAK
+breakpoint.c
+@item DEFAULT_PROMPT
+main.c
+@item DELTA88
+m88k-xdep.c
+@item DEV_TTY
+symmisc.c
+@item DGUX
+m88k-xdep.c
+@item DISABLE_UNSETTABLE_BREAK
+breakpoint.c
+@item DONT_USE_REMOTE
+remote.c
+@item DO_DEFERRED_STORES
+infrun.c
+@item DO_REGISTERS_INFO
+infcmd.c
+@item END_OF_TEXT_DEFAULT
+dbxread.c
+@item EXTERN
+buildsym.h
+@item EXTRACT_RETURN_VALUE
+tm-68k.h
+@item EXTRACT_STRUCT_VALUE_ADDRESS
+values.c
+@item EXTRA_FRAME_INFO
+frame.h
+@item EXTRA_SYMTAB_INFO
+symtab.h
+@item FILES_INFO_HOOK
+target.c
+@item FIXME
+coffread.c
+@item FLOAT_INFO
+infcmd.c
+@item FOPEN_RB
+defs.h
+@item FP0_REGNUM
+a68v-xdep.c
+@item FPC_REGNUM
+mach386-xdep.c
+@item FP_REGNUM
+parse.c
+@item FPU
+Unused? 6-oct-92 rich@@cygnus.com. FIXME.
+@item FRAMELESS_FUNCTION_INVOCATION
+blockframe.c
+@item FRAME_ARGS_ADDRESS_CORRECT
+stack.c
+@item FRAME_CHAIN_COMBINE
+blockframe.c
+@item FRAME_CHAIN_VALID
+frame.h
+@item FRAME_CHAIN_VALID_ALTERNATE
+frame.h
+@item FRAME_FIND_SAVED_REGS
+stack.c
+@item FRAME_GET_BASEREG_VALUE
+frame.h
+@item FRAME_NUM_ARGS
+tm-68k.h
+@item FRAME_SPECIFICATION_DYADIC
+stack.c
+@item FUNCTION_EPILOGUE_SIZE
+coffread.c
+@item F_OK
+xm-ultra3.h
+@item GCC2_COMPILED_FLAG_SYMBOL
+dbxread.c
+@item GCC_COMPILED_FLAG_SYMBOL
+dbxread.c
+@item GCC_MANGLE_BUG
+symtab.c
+@item GCC_PRODUCER
+dwarfread.c
+@item GDB_TARGET_IS_HPPA
+This determines whether horrible kludge code in dbxread.c and partial-stab.h
+is used to mangle multiple-symbol-table files from HPPA's. This should all
+be ripped out, and a scheme like elfread.c used.
+@item GDB_TARGET_IS_MACH386
+mach386-xdep.c
+@item GDB_TARGET_IS_SUN3
+a68v-xdep.c
+@item GDB_TARGET_IS_SUN386
+sun386-xdep.c
+@item GET_LONGJMP_TARGET
+For most machines, this is a target-dependent parameter. On the DECstation
+and the Iris, this is a native-dependent parameter, since <setjmp.h> is
+needed to define it.
+
+This macro determines the target PC address that longjmp() will jump
+to, assuming that we have just stopped at a longjmp breakpoint. It
+takes a CORE_ADDR * as argument, and stores the target PC value through
+this pointer. It examines the current state of the machine as needed.
+@item GET_SAVED_REGISTER
+findvar.c
+@item GPLUS_PRODUCER
+dwarfread.c
+@item GR64_REGNUM
+remote-adapt.c
+@item GR64_REGNUM
+remote-mm.c
+@item HANDLE_RBRAC
+partial-stab.h
+@item HAVE_68881
+m68k-tdep.c
+@item HAVE_REGISTER_WINDOWS
+findvar.c
+@item HAVE_SIGSETMASK
+main.c
+@item HAVE_TERMIO
+inflow.c
+@item HEADER_SEEK_FD
+arm-tdep.c
+@item HOSTING_ONLY
+xm-rtbsd.h
+@item HOST_BYTE_ORDER
+ieee-float.c
+@item HPUX_ASM
+xm-hp300hpux.h
+@item HPUX_VERSION_5
+hp300ux-xdep.c
+@item HP_OS_BUG
+infrun.c
+@item I80960
+remote-vx.c
+@item IBM6000_HOST
+breakpoint.c
+@item IBM6000_TARGET
+buildsym.c
+@item IEEE_DEBUG
+ieee-float.c
+@item IEEE_FLOAT
+valprint.c
+@item IGNORE_SYMBOL
+dbxread.c
+@item INIT_EXTRA_FRAME_INFO
+blockframe.c
+@item INIT_EXTRA_SYMTAB_INFO
+symfile.c
+@item INIT_FRAME_PC
+blockframe.c
+@item INNER_THAN
+valops.c
+@item INT_MAX
+defs.h
+@item INT_MIN
+defs.h
+@item IN_GDB
+i960-pinsn.c
+@item IN_SIGTRAMP
+infrun.c
+@item IN_SOLIB_TRAMPOLINE
+infrun.c
+@item ISATTY
+main.c
+@item IS_TRAPPED_INTERNALVAR
+values.c
+@item KERNELDEBUG
+dbxread.c
+@item KERNEL_DEBUGGING
+tm-ultra3.h
+@item LCC_PRODUCER
+dwarfread.c
+@item LITTLE_ENDIAN
+defs.h
+@item LOG_FILE
+remote-adapt.c
+@item LONGERNAMES
+cplus-dem.c
+@item LONGEST
+defs.h
+@item LONG_LONG
+defs.h
+@item LONG_MAX
+defs.h
+@item L_LNNO32
+coffread.c
+@item MACHKERNELDEBUG
+hppabsd-tdep.c
+@item MAIN
+cplus-dem.c
+@item MAINTENANCE
+dwarfread.c
+@item MAINTENANCE_CMDS
+breakpoint.c
+@item MAINTENANCE_CMDS
+maint.c
+@item MIPSEL
+mips-tdep.c
+@item MOTOROLA
+xm-altos.h
+@item NBPG
+altos-xdep.c
+@item NEED_POSIX_SETPGID
+infrun.c
+@item NEED_TEXT_START_END
+exec.c
+@item NFAILURES
+regex.c
+@item NNPC_REGNUM
+infrun.c
+@item NORETURN
+defs.h
+@item NOTDEF
+regex.c
+@item NOTDEF
+remote-adapt.c
+@item NOTDEF
+remote-mm.c
+@item NOTICE_SIGNAL_HANDLING_CHANGE
+infrun.c
+@item NO_DEFINE_SYMBOL
+xcoffread.c
+@item NO_HIF_SUPPORT
+remote-mm.c
+@item NO_JOB_CONTROL
+signals.h
+@item NO_MALLOC_CHECK
+utils.c
+@item NO_MMALLOC
+utils.c
+@item NO_MMALLOC
+objfiles.c
+@item NO_MMALLOC
+utils.c
+@item NO_SIGINTERRUPT
+remote-adapt.c
+@item NO_SINGLE_STEP
+infptrace.c
+@item NO_TYPEDEFS
+xcoffread.c
+@item NO_TYPEDEFS
+xcoffread.c
+@item NPC_REGNUM
+infcmd.c
+@item NS32K_SVC_IMMED_OPERANDS
+ns32k-opcode.h
+@item NUMERIC_REG_NAMES
+mips-tdep.c
+@item N_SETV
+dbxread.c
+@item N_SET_MAGIC
+hppabsd-tdep.c
+@item NaN
+tm-umax.h
+@item ONE_PROCESS_WRITETEXT
+breakpoint.c
+@item PC
+convx-opcode.h
+@item PCC_SOL_BROKEN
+dbxread.c
+@item PC_IN_CALL_DUMMY
+inferior.h
+@item PC_LOAD_SEGMENT
+stack.c
+@item PC_REGNUM
+parse.c
+@item PRINT_RANDOM_SIGNAL
+infcmd.c
+@item PRINT_REGISTER_HOOK
+infcmd.c
+@item PRINT_TYPELESS_INTEGER
+valprint.c
+@item PROCESS_LINENUMBER_HOOK
+buildsym.c
+@item PROLOGUE_FIRSTLINE_OVERLAP
+infrun.c
+@item PSIGNAL_IN_SIGNAL_H
+defs.h
+@item PS_REGNUM
+parse.c
+@item PTRACE_ARG3_TYPE
+inferior.h
+@item PTRACE_FP_BUG
+mach386-xdep.c
+@item PUSH_ARGUMENTS
+valops.c
+@item REGISTER_BYTES
+remote.c
+@item REGISTER_NAMES
+tm-29k.h
+@item REG_STACK_SEGMENT
+exec.c
+@item REG_STRUCT_HAS_ADDR
+findvar.c
+@item RE_NREGS
+regex.h
+@item R_FP
+dwarfread.c
+@item R_OK
+xm-altos.h
+@item SDB_REG_TO_REGNUM
+coffread.c
+@item SEEK_END
+state.c
+@item SEEK_SET
+state.c
+@item SEM
+coffread.c
+@item SET_STACK_LIMIT_HUGE
+infrun.c
+@item SHELL_COMMAND_CONCAT
+infrun.c
+@item SHELL_FILE
+infrun.c
+@item SHIFT_INST_REGS
+breakpoint.c
+@item SIGN_EXTEND_CHAR
+regex.c
+@item SIGTRAP_STOP_AFTER_LOAD
+infrun.c
+@item SKIP_PROLOGUE
+tm-68k.h
+@item SKIP_PROLOGUE_FRAMELESS_P
+blockframe.c
+@item SKIP_TRAMPOLINE_CODE
+infrun.c
+@item SOLIB_ADD
+core.c
+@item SOLIB_CREATE_INFERIOR_HOOK
+infrun.c
+@item SP_REGNUM
+parse.c
+@item STAB_REG_TO_REGNUM
+stabsread.h
+@item STACK_ALIGN
+valops.c
+@item STACK_DIRECTION
+alloca.c
+@item START_INFERIOR_TRAPS_EXPECTED
+infrun.c
+@item STOP_SIGNAL
+main.c
+@item STORE_RETURN_VALUE
+tm-68k.h
+@item SUN4_COMPILER_FEATURE
+infrun.c
+@item SUN_FIXED_LBRAC_BUG
+dbxread.c
+@item SVR4_SHARED_LIBS
+solib.c
+@item SWITCH_ENUM_BUG
+regex.c
+@item SYM1
+tm-ultra3.h
+@item SYMBOL_RELOADING_DEFAULT
+symfile.c
+@item SYNTAX_TABLE
+regex.c
+@item Sword
+regex.c
+@item TARGET_BYTE_ORDER
+defs.h
+@item TARGET_CHAR_BIT
+defs.h
+@item TARGET_COMPLEX_BIT
+defs.h
+@item TARGET_DOUBLE_BIT
+defs.h
+@item TARGET_DOUBLE_COMPLEX_BIT
+defs.h
+@item TARGET_FLOAT_BIT
+defs.h
+@item TARGET_INT_BIT
+defs.h
+@item TARGET_LONG_BIT
+defs.h
+@item TARGET_LONG_DOUBLE_BIT
+defs.h
+@item TARGET_LONG_LONG_BIT
+defs.h
+@item TARGET_PTR_BIT
+defs.h
+@item TARGET_SHORT_BIT
+defs.h
+@item TDESC
+infrun.c
+@item TM_FILE_OVERRIDE
+defs.h
+@item T_ARG
+coffread.c
+@item T_VOID
+coffread.c
+@item UINT_MAX
+defs.h
+@item USER
+m88k-tdep.c
+@item USE_GAS
+xm-news.h
+@item USE_STRUCT_CONVENTION
+values.c
+@item USIZE
+xm-m88k.h
+@item U_FPSTATE
+i386-xdep.c
+@item VARIABLES_INSIDE_BLOCK
+dbxread.c
+@item WRS_ORIG
+remote-vx.c
+@item _LANG_c
+language.c
+@item _LANG_m2
+language.c
+@item __GO32__
+inflow.c
+@item __HAVE_68881__
+m68k-stub.c
+@item __HPUX_ASM__
+xm-hp300hpux.h
+@item __INT_VARARGS_H
+printcmd.c
+@item __not_on_pyr_yet
+pyr-xdep.c
+@item GOULD_PN
+gould-pinsn.c
+@item emacs
+alloca.c
+@item hp800
+xm-hppabsd.h
+@item hpux
+hppabsd-core.c
+@item longest_to_int
+defs.h
+@item mc68020
+m68k-stub.c
+@item ns32k_opcodeT
+ns32k-opcode.h
+@item sgi
+mips-tdep.c
+@item sparc
+regex.c
+@item static
+alloca.c
+@item sun
+m68k-tdep.c
+@item sun386
+tm-sun386.h
+@item test
+regex.c
+@item x_name
+coffread.c
+@item x_zeroes
+coffread.c
+@end table
+
+@node Native Conditionals
+@chapter Native Conditionals
+
+When GDB is configured and compiled, various macros are defined or left
+undefined, to control compilation when the host and target systems
+are the same. These macros should be defined (or left undefined)
+in @file{nm-@var{system}.h}.
+
+@table @code
+@item ATTACH_DETACH
+If defined, then gdb will include support for the @code{attach} and
+@code{detach} commands.
+@item FETCH_INFERIOR_REGISTERS
+Define this if the native-dependent code will provide its
+own routines
+@code{fetch_inferior_registers} and @code{store_inferior_registers} in
+@file{@var{HOST}-nat.c}.
+If this symbol is @emph{not} defined, and @file{infptrace.c}
+is included in this configuration, the default routines in
+@file{infptrace.c} are used for these functions.
+@item GET_LONGJMP_TARGET
+For most machines, this is a target-dependent parameter. On the DECstation
+and the Iris, this is a native-dependent parameter, since <setjmp.h> is
+needed to define it.
+
+This macro determines the target PC address that longjmp() will jump
+to, assuming that we have just stopped at a longjmp breakpoint. It
+takes a CORE_ADDR * as argument, and stores the target PC value through
+this pointer. It examines the current state of the machine as needed.
+@item PROC_NAME_FMT
+Defines the format for the name of a @file{/proc} device. Should be
+defined in @file{nm.h} @emph{only} in order to override the default
+definition in @file{procfs.c}.
+@item REGISTER_U_ADDR
+Defines the offset of the registers in the ``u area''; @pxref{Host}.
+@item USE_PROC_FS
+This determines whether small routines in @file{*-tdep.c}, which
+translate register values
+between GDB's internal representation and the /proc representation,
+are compiled.
+@item U_REGS_OFFSET
+This is the offset of the registers in the upage. It need only be
+defined if the generic ptrace register access routines in
+@file{infptrace.c} are being used (that is,
+@file{infptrace.c} is configured in, and
+@code{FETCH_INFERIOR_REGISTERS} is not defined). If the default value
+from @file{infptrace.c} is good enough, leave it undefined.
+
+The default value means that u.u_ar0 @emph{points to} the location of the
+registers. I'm guessing that @code{#define U_REGS_OFFSET 0} means that
+u.u_ar0 @emph{is} the location of the registers.
+@end table
+
+@node Obsolete Conditionals
+@chapter Obsolete Conditionals
+
+Fragments of old code in GDB sometimes reference or set the following
+configuration macros. They should not be used by new code, and
+old uses should be removed as those parts of the debugger are
+otherwise touched.
+
+@table @code
+@item STACK_END_ADDR
+This macro used to define where the end of the stack appeared, for use
+in interpreting core file formats that don't record this address in the
+core file itself. This information is now configured in BFD, and GDB
+gets the info portably from there. The values in GDB's configuration
+files should be moved into BFD configuration files (if needed there),
+and deleted from all of GDB's config files.
+
+Any @file{@var{foo}-xdep.c} file that references STACK_END_ADDR
+is so old that it has never been converted to use BFD. Now that's old!
+@end table
@contents
@bye
-
projects / deliverable / binutils-gdb.git / blobdiff