libtool: Autoconf macros
1
1 5.1 Autoconf macros exported by libtool
1 =======================================
1
1 Libtool uses a number of macros to interrogate the host system when it
1 is being built, and you can use some of them yourself too. Although
1 there are a great many other macros in the libtool installed m4 files,
1 these do not form part of the published interface, and are subject to
1 change between releases.
1
1 Macros in the 'LT_CMD_' namespace check for various shell commands:
1
1 -- Macro: LT_CMD_MAX_LEN
1 Finds the longest command line that can be safely passed to
1 '$SHELL' without being truncated, and store in the shell variable
1 '$max_cmd_len'. It is only an approximate value, but command lines
1 of this length or shorter are guaranteed not to be truncated.
1
1 Macros in the 'LT_FUNC_' namespace check characteristics of library
1 functions:
1
1 -- Macro: LT_FUNC_DLSYM_USCORE
1 'AC_DEFINE' the preprocessor symbol 'DLSYM_USCORE' if we have to
1 add an underscore to symbol-names passed in to 'dlsym'.
1
1 Macros in the 'LT_LIB_' namespace check characteristics of system
1 libraries:
1
1 -- Macro: LT_LIB_M
1 Set 'LIBM' to the math library or libraries required on this
1 machine, if any.
1
1 -- Macro: LT_LIB_DLLOAD
1 This is the macro used by 'libltdl' to determine what dlloaders to
1 use on this machine, if any. Several shell variables are set (and
1 'AC_SUBST'ed) depending on the dlload interfaces are available on
1 this machine. 'LT_DLLOADERS' contains a list of libtool libraries
1 that can be used, and if necessary also sets 'LIBADD_DLOPEN' if
1 additional system libraries are required by the 'dlopen' loader,
1 and 'LIBADD_SHL_LOAD' if additional system libraries are required
1 by the 'shl_load' loader, respectively. Finally some symbols are
1 set in 'config.h' depending on the loaders that are found to work:
1 'HAVE_LIBDL', 'HAVE_SHL_LOAD', 'HAVE_DYLD', 'HAVE_DLD'.
1
1 Macros in the 'LT_PATH_' namespace search the system for the full path
1 to particular system commands:
1
1 -- Macro: LT_PATH_LD
1 Add a '--with-gnu-ld' option to 'configure'. Try to find the path
1 to the linker used by '$CC', and whether it is the GNU linker. The
1 result is stored in the shell variable '$LD', which is
1 'AC_SUBST'ed.
1
1 -- Macro: LT_PATH_NM
1 Try to find a BSD-compatible 'nm' or a MS-compatible 'dumpbin'
1 command on this machine. The result is stored in the shell
1 variable '$NM', which is 'AC_SUBST'ed.
1
1 Macros in the 'LT_SYS_' namespace probe for system characteristics:
1
1 -- Macro: LT_SYS_DLOPEN_SELF
1 Tests whether a program can dlopen itself, and then also whether
1 the same program can still dlopen itself when statically linked.
1 Results are stored in the shell variables '$enable_dlopen_self' and
1 'enable_dlopen_self_static' respectively.
1
1 -- Macro: LT_SYS_DLOPEN_DEPLIBS
1 Define the preprocessor symbol 'LTDL_DLOPEN_DEPLIBS' if the OS
1 needs help to load dependent libraries for 'dlopen' (or
1 equivalent).
1
1 -- Macro: LT_SYS_DLSEARCH_PATH
1 Define the preprocessor symbol 'LT_DLSEARCH_PATH' to the system
1 default library search path.
1
1 -- Macro: LT_SYS_MODULE_EXT
1 Define the preprocessor symbol 'LT_MODULE_EXT' to the extension
1 used for runtime loadable modules. If you use libltdl to open
1 modules, then you can simply use the libtool library extension,
1 '.la'.
1
1 -- Macro: LT_SYS_MODULE_PATH
1 Define the preprocessor symbol 'LT_MODULE_PATH_VAR' to the name of
1 the shell environment variable that determines the run-time module
1 search path.
1
1 -- Macro: LT_SYS_SYMBOL_USCORE
1 Set the shell variable 'sys_symbol_underscore' to 'no' unless the
1 compiler prefixes global symbols with an underscore.
1