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 (or if the meaning is not documented here, then one of the source files where they are used is indicated) are:

GDBINIT_FILENAME

The default name of GDB's initialization file (normally `.gdbinit').

MEM_FNS_DECLARED

Your host config file defines this if it includes declarations of memcpy and memset. Define this to avoid conflicts between the native include files and the declarations in `defs.h'.

NO_SYS_FILE

Define this if your system does not have a <sys/file.h>.

SIGWINCH_HANDLER

If your host defines SIGWINCH, you can define this to be the name of a function to be called if SIGWINCH is received.

SIGWINCH_HANDLER_BODY

Define this to expand into code that will define the function named by the expansion of SIGWINCH_HANDLER.

ALIGN_STACK_ON_STARTUP

Define this if your system is of a sort that will crash in tgetent if the stack happens not to be longword-aligned when main is called. This is a rare situation, but is known to occur on several different types of systems.

CRLF_SOURCE_FILES

Define this if host files use \r\n rather than \n as a line terminator. This will cause source file listings to omit \r characters when printing. It must be possible to open files in binary mode using O_BINARY or, for fopen, "rb".

DEFAULT_PROMPT

The default value of the prompt string (normally "(gdb) ").

DEV_TTY

The name of the generic TTY device, defaults to "/dev/tty".

FCLOSE_PROVIDED

Define this if the system declares fclose in the headers included in defs.h. This isn't needed unless your compiler is unusually anal.

FOPEN_RB

Define this if binary files are opened the same way as text files.

GETENV_PROVIDED

Define this if the system declares getenv in its headers included in defs.h. This isn't needed unless your compiler is unusually anal.

HAVE_MMAP

In some cases, use the system call mmap for reading symbol tables. For some machines this allows for sharing and quick updates.

HAVE_SIGSETMASK

Define this if the host system has job control, but does not define sigsetmask(). Currently, this is only true of the RS/6000.

HAVE_TERMIO

Define this if the host system has termio.h.

HOST_BYTE_ORDER

The ordering of bytes in the host. This must be defined to be either BIG_ENDIAN or LITTLE_ENDIAN.

INT_MAX

INT_MIN

LONG_MAX

UINT_MAX

ULONG_MAX

Values for host-side constants.

ISATTY

Substitute for isatty, if not available.

KERNEL_U_ADDR

Define this to the address of the 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.

KERNEL_U_ADDR_BSD

Define this to cause GDB to determine the address of u at runtime, by using Berkeley-style nlist on the kernel's image in the root directory.

KERNEL_U_ADDR_HPUX

Define this to cause GDB to determine the address of u at runtime, by using HP-style nlist on the kernel's image in the root directory.

LONGEST

This is the longest integer type available on the host. If not defined, it will default to long long or long, depending on CC_HAS_LONG_LONG.

CC_HAS_LONG_LONG

Define this if the host C compiler supports "long long". This is set by the configure script.

PRINTF_HAS_LONG_LONG

Define this if the host can handle printing of long long integers via the printf format directive "ll". This is set by the configure script.

HAVE_LONG_DOUBLE

Define this if the host C compiler supports "long double". This is set by the configure script.

PRINTF_HAS_LONG_DOUBLE

Define this if the host can handle printing of long double float-point numbers via the printf format directive "Lg". This is set by the configure script.

SCANF_HAS_LONG_DOUBLE

Define this if the host can handle the parsing of long double float-point numbers via the scanf format directive directive "Lg". This is set by the configure script.

LSEEK_NOT_LINEAR

Define this if lseek (n) does not necessarily move to byte number n in the file. This is only used when reading source files. It is normally faster to define CRLF_SOURCE_FILES when possible.

L_SET

This macro is used as the argument to lseek (or, most commonly, bfd_seek). FIXME, should be replaced by SEEK_SET instead, which is the POSIX equivalent.

MAINTENANCE_CMDS

If the value of this is 1, then a number of optional maintenance commands are compiled in.

MALLOC_INCOMPATIBLE

Define this if the system's prototype for malloc differs from the ANSI definition.

MMAP_BASE_ADDRESS

When using HAVE_MMAP, the first mapping should go at this address.

MMAP_INCREMENT

when using HAVE_MMAP, this is the increment between mappings.

NEED_POSIX_SETPGID

Define this to use the POSIX version of setpgid to determine whether job control is available.

NORETURN

If defined, this should be one or more tokens, such as volatile, that can be used in both the declaration and definition of functions to indicate that they never return. The default is already set correctly if compiling with GCC. This will almost never need to be defined.

ATTR_NORETURN

If defined, this should be one or more tokens, such as __attribute__ ((noreturn)), that can be used in the declarations of functions to indicate that they never return. The default is already set correctly if compiling with GCC. This will almost never need to be defined.

USE_MMALLOC

GDB will use the mmalloc library for memory allocation for symbol reading if this symbol is defined. Be careful defining it since there are systems on which mmalloc does not work for some reason. One example is the DECstation, where its RPC library can't cope with our redefinition of malloc to call mmalloc. When defining USE_MMALLOC, you will also have to set MMALLOC in the Makefile, to point to the mmalloc library. This define is set when you configure with --with-mmalloc.

NO_MMCHECK

Define this if you are using mmalloc, but don't want the overhead of checking the heap with mmcheck. Note that on some systems, the C runtime makes calls to malloc prior to calling main, and if free is ever called with these pointers after calling mmcheck to enable checking, a memory corruption abort is certain to occur. These systems can still use mmalloc, but must define NO_MMCHECK.

MMCHECK_FORCE

Define this to 1 if the C runtime allocates memory prior to mmcheck being called, but that memory is never freed so we don't have to worry about it triggering a memory corruption abort. The default is 0, which means that mmcheck will only install the heap checking functions if there has not yet been any memory allocation calls, and if it fails to install the functions, gdb will issue a warning. This is currently defined if you configure using --with-mmalloc.

NO_SIGINTERRUPT

Define this to indicate that siginterrupt() is not available.

R_OK

Define if this is not in a system .h file.

SEEK_CUR

SEEK_SET

Define these to appropriate value for the system lseek(), if not already defined.

STOP_SIGNAL

This is the signal for stopping GDB. Defaults to SIGTSTP. (Only redefined for the Convex.)

USE_O_NOCTTY

???

USG

Means that System V (prior to SVR4) include files are in use. (FIXME: This symbol is abused in `infrun.c', `regex.c', `remote-nindy.c', and `utils.c' for other things, at the moment.)

lint

Define this to help lint in some stupid way.

volatile

Define this to override the defaults of __volatile__ or /**/.

Platform-specific host conditionals.

ALTOS_AS

xm-altos.h

MOTOROLA

xm-altos.h

NBPG

altos-xdep.c

DELTA88

m88k-xdep.c

DGUX

m88k-xdep.c

F_OK

xm-ultra3.h

UPAGES

altos-xdep.c

Regex conditionals.

C_ALLOCA

regex.c

NFAILURES

regex.c

RE_NREGS

regex.h

SIGN_EXTEND_CHAR

regex.c

SWITCH_ENUM_BUG

regex.c

SYNTAX_TABLE

regex.c

Sword

regex.c

sparc

regex.c

Go to the first, previous, next, last section, table of contents.