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diff --git a/util/autoconf/autoconf.info-2 b/util/autoconf/autoconf.info-2 deleted file mode 100644 index ae8fc7b..0000000 --- a/util/autoconf/autoconf.info-2 +++ /dev/null @@ -1,1214 +0,0 @@ -This is Info file autoconf.info, produced by Makeinfo-1.55 from the -input file ./autoconf.texi. - -START-INFO-DIR-ENTRY -* Autoconf: (autoconf). Create source code configuration scripts. -END-INFO-DIR-ENTRY - - This file documents the GNU Autoconf package for creating scripts to -configure source code packages using templates and an `m4' macro -package. - - Copyright (C) 1992, 1993, 1994 Free Software Foundation, Inc. - - Permission is granted to make and distribute verbatim copies of this -manual provided the copyright notice and this permission notice are -preserved on all copies. - - Permission is granted to copy and distribute modified versions of -this manual under the conditions for verbatim copying, provided that -the entire resulting derived work is distributed under the terms of a -permission notice identical to this one. - - Permission is granted to copy and distribute translations of this -manual into another language, under the above conditions for modified -versions, except that this permission notice may be stated in a -translation approved by the Foundation. - - -File: autoconf.info, Node: Versions, Prev: Default Prefix, Up: Setup - -Version Numbers in `configure' -============================== - - The following macros manage version numbers for `configure' scripts. -Using them is optional. - - - Macro: AC_PREREQ (VERSION) - Ensure that a recent enough version of Autoconf is being used. If - the version of Autoconf being used to create `configure' is earlier - than VERSION, print an error message on the standard error output - and do not create `configure'. For example: - - AC_PREREQ(1.8) - - This macro is useful if your `configure.in' relies on non-obvious - behavior that changed between Autoconf releases. If it merely - needs recently added macros, then `AC_PREREQ' is less useful, - because the `autoconf' program already tells the user which macros - are not found. The same thing happens if `configure.in' is - processed by a version of Autoconf older than when `AC_PREREQ' was - added. - - - Macro: AC_REVISION (REVISION-INFO) - Copy revision stamp REVISION-INFO into the `configure' script, - with any dollar signs or double-quotes removed. This macro lets - you put a revision stamp from `configure.in' into `configure' - without RCS or CVS changing it when you check in `configure'. That - way, you can determine easily which revision of `configure.in' a - particular `configure' corresponds to. - - It is a good idea to call this macro before `AC_INIT' so that the - revision number is near the top of both `configure.in' and - `configure'. To support doing that, the `AC_REVISION' output - begins with `#!/bin/sh', like the normal start of a `configure' - script does. - - For example, this line in `configure.in': - - AC_REVISION($Revision$)dnl - - produces this in `configure': - - #!/bin/sh - # From configure.in Revision: 1.30 - - -File: autoconf.info, Node: Existing Tests, Next: Writing Tests, Prev: Setup, Up: Top - -Existing Tests -************** - - These macros test for particular system features that packages might -need or want to use. If you need to test for a kind of feature that -none of these macros check for, you can probably do it by calling -primitive test macros with appropriate arguments (*note Writing -Tests::.). - - These tests print messages telling the user which feature they're -checking for, and what they find. They cache their results for future -`configure' runs (*note Caching Results::.). - - Some of these macros set output variables. *Note Makefile -Substitutions::, for how to get their values. The phrase "define NAME" -is used below as a shorthand to mean "define C preprocessor symbol NAME -to the value 1". *Note Defining Symbols::, for how to get those symbol -definitions into your program. - -* Menu: - -* Alternative Programs:: Selecting between alternative programs. -* Libraries:: Library archives that might be missing. -* Library Functions:: C library functions that might be missing. -* Header Files:: Header files that might be missing. -* Structures:: Structures or members that might be missing. -* Typedefs:: `typedef's that might be missing. -* Compiler Characteristics:: C compiler or machine architecture features. -* System Services:: Operating system services. -* UNIX Variants:: Special kludges for specific UNIX variants. - - -File: autoconf.info, Node: Alternative Programs, Next: Libraries, Up: Existing Tests - -Alternative Programs -==================== - - These macros check for the presence or behavior of particular -programs. They are used to choose between several alternative programs -and to decide what to do once one has been chosen. If there is no -macro specifically defined to check for a program you need, and you -don't need to check for any special properties of it, then you can use -one of the general program check macros. - -* Menu: - -* Particular Programs:: Special handling to find certain programs. -* Generic Programs:: How to find other programs. - - -File: autoconf.info, Node: Particular Programs, Next: Generic Programs, Up: Alternative Programs - -Particular Program Checks -------------------------- - - These macros check for particular programs--whether they exist, and -in some cases whether they support certain features. - - - Macro: AC_DECL_YYTEXT - Define `YYTEXT_POINTER' if `yytext' is a `char *' instead of a - `char []'. Also set output variable `LEX_OUTPUT_ROOT' to the base - of the file name that the lexer generates; usually `lex.yy', but - sometimes something else. These results vary according to whether - `lex' or `flex' is being used. - - - Macro: AC_PROG_AWK - Check for `mawk', `gawk', `nawk', and `awk', in that order, and - set output variable `AWK' to the first one that it finds. It - tries `mawk' first because that is reported to be the fastest - implementation. - - - Macro: AC_PROG_CC - Determine a C compiler to use. If `CC' is not already set in the - environment, check for `gcc', and use `cc' if it's not found. Set - output variable `CC' to the name of the compiler found. - - If using the GNU C compiler, set shell variable `GCC' to `yes', - empty otherwise. If output variable `CFLAGS' was not already set, - set it to `-g -O' for the GNU C compiler (`-O' on systems where - GCC does not accept `-g'), or `-g' for other compilers. - - - Macro: AC_PROG_CC_C_O - If the C compiler does not accept the `-c' and `-o' options - simultaneously, define `NO_MINUS_C_MINUS_O'. - - - Macro: AC_PROG_CPP - Set output variable `CPP' to a command that runs the C - preprocessor. If `$CC -E' doesn't work, it uses `/lib/cpp'. It - is only portable to run `CPP' on files with a `.c' extension. - - If the current language is C (*note Language Choice::.), many of - the specific test macros use the value of `CPP' indirectly by - calling `AC_TRY_CPP', `AC_CHECK_HEADER', `AC_EGREP_HEADER', or - `AC_EGREP_CPP'. - - - Macro: AC_PROG_CXX - Determine a C++ compiler to use. Check if the environment variable - `CXX' or `CCC' (in that order) is set; if so, set output variable - `CXX' to its value. Otherwise search for a C++ compiler under - likely names (`c++', `g++', `gcc', `CC', and `cxx'). If none of - those checks succeed, as a last resort set `CXX' to `gcc'. - - If using the GNU C++ compiler, set shell variable `GXX' to `yes', - empty otherwise. If output variable `CXXFLAGS' was not already - set, set it to `-g -O' for the GNU C++ compiler (`-O' on systems - where G++ does not accept `-g'), or `-g' for other compilers. - - - Macro: AC_PROG_CXXCPP - Set output variable `CXXCPP' to a command that runs the C++ - preprocessor. If `$CXX -E' doesn't work, it uses `/lib/cpp'. It - is only portable to run `CXXCPP' on files with a `.c', `.C', or - `.cc' extension. - - If the current language is C++ (*note Language Choice::.), many of - the specific test macros use the value of `CXXCPP' indirectly by - calling `AC_TRY_CPP', `AC_CHECK_HEADER', `AC_EGREP_HEADER', or - `AC_EGREP_CPP'. - - - Macro: AC_PROG_GCC_TRADITIONAL - Add `-traditional' to output variable `CC' if using the GNU C - compiler and `ioctl' does not work properly without - `-traditional'. That usually happens when the fixed header files - have not been installed on an old system. Since recent versions - of the GNU C compiler fix the header files automatically when - installed, this is becoming a less prevalent problem. - - - Macro: AC_PROG_INSTALL - Set output variable `INSTALL' to the path of a BSD compatible - `install' program, if one is found in the current `PATH'. - Otherwise, set `INSTALL' to `DIR/install-sh -c', checking the - directories specified to `AC_CONFIG_AUX_DIR' (or its default - directories) to determine DIR (*note Output::.). Also set the - variable `INSTALL_PROGRAM' to `${INSTALL}' and `INSTALL_DATA' to - `${INSTALL} -m 644'. - - This macro screens out various instances of `install' known to not - work. It prefers to find a C program rather than a shell script, - for speed. Instead of `install-sh', it can also use `install.sh', - but that name is obsolete because some `make' programs have a rule - that creates `install' from it if there is no `Makefile'. - - A copy of `install-sh' which you may use comes with Autoconf. If - you use `AC_PROG_INSTALL', you must include either `install-sh' or - `install.sh' in your distribution, or `configure' will produce an - error message saying it can't find them--even if the system you're - on has a good `install' program. This check is a safety measure - to prevent you from accidentally leaving that file out, which - would prevent your package from installing on systems that don't - have a BSD-compatible `install' program. - - If you need to use your own installation program because it has - features not found in standard `install' programs, there is no - reason to use `AC_PROG_INSTALL'; just put the pathname of your - program into your `Makefile.in' files. - - - Macro: AC_PROG_LEX - If `flex' is found, set output variable `LEX' to `flex' and - `LEXLIB' to `-lfl', if that library is in a standard place. - Otherwise set `LEX' to `lex' and `LEXLIB' to `-ll'. - - - Macro: AC_PROG_LN_S - If `ln -s' works on the current filesystem (the operating system - and filesystem support symbolic links), set output variable `LN_S' - to `ln -s', otherwise set it to `ln'. - - - Macro: AC_PROG_RANLIB - Set output variable `RANLIB' to `ranlib' if `ranlib' is found, - otherwise to `:' (do nothing). - - - Macro: AC_PROG_YACC - If `bison' is found, set output variable `YACC' to `bison -y'. - Otherwise, if `byacc' is found, set `YACC' to `byacc'. Otherwise - set `YACC' to `yacc'. - - -File: autoconf.info, Node: Generic Programs, Prev: Particular Programs, Up: Alternative Programs - -Generic Program Checks ----------------------- - - These macros are used to find programs not covered by the particular -test macros. If you need to check the behavior of a program as well as -find out whether it is present, you have to write your own test for it -(*note Writing Tests::.). - - - Macro: AC_CHECK_PROG (VARIABLE, PROG-TO-CHECK-FOR, VALUE-IF-FOUND [, - VALUE-IF-NOT-FOUND]) - Check whether program PROG-TO-CHECK-FOR exists in `PATH'. If it - is found, set VARIABLE to VALUE-IF-FOUND, otherwise to - VALUE-IF-NOT-FOUND, if given. If VARIABLE was already set, do - nothing. Calls `AC_SUBST' for VARIABLE. - - - Macro: AC_CHECK_PROGS (VARIABLE, PROGS-TO-CHECK-FOR [, - VALUE-IF-NOT-FOUND]) - Check for each program in the whitespace-separated list - PROGS-TO-CHECK-FOR exists in `PATH'. If it is found, set VARIABLE - to the name of that program. Otherwise, continue checking the - next program in the list. If none of the programs in the list are - found, set VARIABLE to VALUE-IF-NOT-FOUND; if VALUE-IF-NOT-FOUND - is not specified, the value of VARIABLE is not changed. Calls - `AC_SUBST' for VARIABLE. - - - Macro: AC_PATH_PROG (VARIABLE, PROG-TO-CHECK-FOR [, - VALUE-IF-NOT-FOUND]) - Like `AC_CHECK_PROG', but set VARIABLE to the entire path of - PROG-TO-CHECK-FOR if found. - - - Macro: AC_PATH_PROGS (VARIABLE, PROGS-TO-CHECK-FOR [, - VALUE-IF-NOT-FOUND]) - Like `AC_CHECK_PROGS', but if any of PROGS-TO-CHECK-FOR are found, - set VARIABLE to the entire path of the program found. - - -File: autoconf.info, Node: Libraries, Next: Library Functions, Prev: Alternative Programs, Up: Existing Tests - -Library Files -============= - - The following macros check for the presence of certain C library -archive files. - - - Macro: AC_CHECK_LIB (LIBRARY, FUNCTION [, ACTION-IF-FOUND [, - ACTION-IF-NOT-FOUND [, OTHER-LIBRARIES]]]) - Try to ensure that C function FUNCTION is available by checking - whether a test C program can be linked with the library LIBRARY to - get the function. LIBRARY is the base name of the library; e.g., - to check for `-lmp', use `mp' as the LIBRARY argument. - - ACTION-IF-FOUND is a list of shell commands to run if the link - with the library succeeds; ACTION-IF-NOT-FOUND is a list of shell - commands to run if the link fails. If ACTION-IF-FOUND and - ACTION-IF-NOT-FOUND are not specified, the default action is to - add `-lLIBRARY' to `LIBS' and define `HAVE_LIBLIBRARY' (in all - capitals). - - If linking with LIBRARY results in unresolved symbols, which would - be resolved by linking with additional libraries, give those - libraries as the OTHER-LIBRARIES argument, separated by spaces: - `-lX11 -lXt'. Otherwise this macro will fail to detect that - LIBRARY is present, because linking the test program will always - fail with unresolved symbols. - - - Macro: AC_HAVE_LIBRARY (LIBRARY, [, ACTION-IF-FOUND [, - ACTION-IF-NOT-FOUND [, OTHER-LIBRARIES]]]) - This macro is equivalent to calling `AC_CHECK_LIB' with a FUNCTION - argument of `main'. In addition, LIBRARY can be written as any of - `foo', `-lfoo', or `libfoo.a'. In all of those cases, the - compiler is passed `-lfoo'. However, LIBRARY can not be a shell - variable; it must be a literal name. This macro is considered - obsolete. - - -File: autoconf.info, Node: Library Functions, Next: Header Files, Prev: Libraries, Up: Existing Tests - -Library Functions -================= - - The following macros check for particular C library functions. If -there is no macro specifically defined to check for a function you need, -and you don't need to check for any special properties of it, then you -can use one of the general function check macros. - -* Menu: - -* Particular Functions:: Special handling to find certain functions. -* Generic Functions:: How to find other functions. - - -File: autoconf.info, Node: Particular Functions, Next: Generic Functions, Up: Library Functions - -Particular Function Checks --------------------------- - - These macros check for particular C functions--whether they exist, -and in some cases how they respond when given certain arguments. - - - Macro: AC_FUNC_ALLOCA - Check how to get `alloca'. Tries to get a builtin version by - checking for `alloca.h' or the predefined C preprocessor macros - `__GNUC__' and `_AIX'. If this macro finds `alloca.h', it defines - `HAVE_ALLOCA_H'. - - If those attempts fail, it looks for the function in the standard C - library. If any of those methods succeed, it defines - `HAVE_ALLOCA'. Otherwise, it sets the output variable `ALLOCA' to - `alloca.o' and defines `C_ALLOCA' (so programs can periodically - call `alloca(0)' to garbage collect). This variable is separate - from `LIBOBJS' so multiple programs can share the value of - `ALLOCA' without needing to create an actual library, in case only - some of them use the code in `LIBOBJS'. - - This macro does not try to get `alloca' from the System V R3 - `libPW' or the System V R4 `libucb' because those libraries - contain some incompatible functions that cause trouble. Some - versions do not even contain `alloca' or contain a buggy version. - If you still want to use their `alloca', use `ar' to extract - `alloca.o' from them instead of compiling `alloca.c'. - - Source files that use `alloca' should start with a piece of code - like the following, to declare it properly. In some versions of - AIX, the declaration of `alloca' must precede everything else - except for comments and preprocessor directives. The `#pragma' - directive is indented so that pre-ANSI C compilers will ignore it, - rather than choke on it. - - /* AIX requires this to be the first thing in the file. */ - #ifdef __GNUC__ - # define alloca __builtin_alloca - #else - # if HAVE_ALLOCA_H - # include <alloca.h> - # else - # ifdef _AIX - #pragma alloca - # else - # ifndef alloca /* predefined by HP cc +Olibcalls */ - char *alloca (); - # endif - # endif - # endif - #endif - - - Macro: AC_FUNC_CLOSEDIR_VOID - If the `closedir' function does not return a meaningful value, - define `CLOSEDIR_VOID'. Otherwise, callers ought to check its - return value for an error indicator. - - - Macro: AC_FUNC_GETLOADAVG - Check how to get the system load averages. If the system has the - `getloadavg' function, this macro defines `HAVE_GETLOADAVG', and - adds to `LIBS' any libraries needed to get that function. - - Otherwise, it adds `getloadavg.o' to the output variable - `LIBOBJS', and possibly defines several other C preprocessor - macros and output variables: - - 1. It defines `SVR4', `DGUX', `UMAX', or `UMAX4_3' if on those - systems. - - 2. If it finds `nlist.h', it defines `NLIST_STRUCT'. - - 3. If `struct nlist' has an `n_un' member, it defines - `NLIST_NAME_UNION'. - - 4. If compiling `getloadavg.c' defines `LDAV_PRIVILEGED', - programs need to be installed specially on this system for - `getloadavg' to work, and this macro defines - `GETLOADAVG_PRIVILEGED'. - - 5. This macro sets the output variable `NEED_SETGID'. The value - is `true' if special installation is required, `false' if not. - If `NEED_SETGID' is `true', this macro sets `KMEM_GROUP' to - the name of the group that should own the installed program. - - - Macro: AC_FUNC_GETMNTENT - Check for the `getmntent' in the `sun' and `seq' libraries, for - Irix 4 and PTX, respectively. Then, if `getmntent' is available, - define `HAVE_GETMNTENT'. - - - Macro: AC_FUNC_MEMCMP - If the `memcmp' function is not available, or does not work on - 8-bit data (like the one on SunOS 4.1.3), add `memcmp.o' to output - variable `LIBOBJS'. - - - Macro: AC_FUNC_MMAP - If the `mmap' function exists and works correctly on memory mapped - files, define `HAVE_MMAP'. - - - Macro: AC_FUNC_SETVBUF_REVERSED - If `setvbuf' takes the buffering type as its second argument and - the buffer pointer as the third, instead of the other way around, - define `SETVBUF_REVERSED'. This is the case on System V before - release 3. - - - Macro: AC_FUNC_STRCOLL - If the `strcoll' function exists and works correctly, define - `HAVE_STRCOLL'. This does a bit more than - `AC_CHECK_FUNCS(strcoll)', because some systems have incorrect - definitions of `strcoll', which should not be used. - - - Macro: AC_FUNC_STRFTIME - Check for `strftime' in the `intl' library, for SCO UNIX. Then, - if `strftime' is available, define `HAVE_STRFTIME'. - - - Macro: AC_FUNC_UTIME_NULL - If `utime(FILE, NULL)' sets FILE's timestamp to the present, - define `HAVE_UTIME_NULL'. - - - Macro: AC_FUNC_VFORK - If `vfork.h' is found, define `HAVE_VFORK_H'. If a working - `vfork' is not found, define `vfork' to be `fork'. This macro - checks for several known errors in implementations of `vfork' and - considers the system to not have a working `vfork' if it detects - any of them. - - - Macro: AC_FUNC_VPRINTF - If `vprintf' is found, define `HAVE_VPRINTF'. Otherwise, if - `_doprnt' is found, define `HAVE_DOPRNT'. (If `vprintf' is - available, you may assume that `vfprintf' and `vsprintf' are also - available.) - - - Macro: AC_FUNC_WAIT3 - If `wait3' is found and fills in the contents of its third argument - (a `struct rusage *'), which HP-UX does not do, define - `HAVE_WAIT3'. - - -File: autoconf.info, Node: Generic Functions, Prev: Particular Functions, Up: Library Functions - -Generic Function Checks ------------------------ - - These macros are used to find functions not covered by the particular -test macros. If the functions might be in libraries other than the -default C library, first call `AC_CHECK_LIB' for those libraries. If -you need to check the behavior of a function as well as find out -whether it is present, you have to write your own test for it (*note -Writing Tests::.). - - - Macro: AC_CHECK_FUNC (FUNCTION, ACTION-IF-FOUND [, - ACTION-IF-NOT-FOUND]) - If C function FUNCTION is available, run shell commands - ACTION-IF-FOUND, otherwise ACTION-IF-NOT-FOUND. If you just want - to define a symbol if the function is available, consider using - `AC_CHECK_FUNCS' instead. This macro checks for functions with C - linkage even when `AC_LANG_CPLUSPLUS' has been called, since C++ is - more standardized than C is. (*note Language Choice::., for more - information about selecting the language for checks.) - - - Macro: AC_CHECK_FUNCS (FUNCTION... [, ACTION-IF-FOUND [, - ACTION-IF-NOT-FOUND]]) - For each given FUNCTION in the whitespace-separated argument list - that is available, define `HAVE_FUNCTION' (in all capitals). If - ACTION-IF-FOUND is given, it is additional shell code to execute - when one of the functions is found. You can give it a value of - `break' to break out of the loop on the first match. If - ACTION-IF-NOT-FOUND is given, it is executed when one of the - functions is not found. - - - Macro: AC_REPLACE_FUNCS (FUNCTION-NAME...) - For each given FUNCTION-NAME in the whitespace-separated argument - list that is not in the C library, add `FUNCTION-NAME.o' to the - value of the output variable `LIBOBJS'. - - -File: autoconf.info, Node: Header Files, Next: Structures, Prev: Library Functions, Up: Existing Tests - -Header Files -============ - - The following macros check for the presence of certain C header -files. If there is no macro specifically defined to check for a header -file you need, and you don't need to check for any special properties of -it, then you can use one of the general header file check macros. - -* Menu: - -* Particular Headers:: Special handling to find certain headers. -* Generic Headers:: How to find other headers. - - -File: autoconf.info, Node: Particular Headers, Next: Generic Headers, Up: Header Files - -Particular Header Checks ------------------------- - - These macros check for particular system header files--whether they -exist, and in some cases whether they declare certain symbols. - - - Macro: AC_DECL_SYS_SIGLIST - Define `SYS_SIGLIST_DECLARED' if the variable `sys_siglist' is - declared in a system header file, either `signal.h' or `unistd.h'. - - - Macro: AC_DIR_HEADER - Like calling `AC_HEADER_DIRENT' and `AC_FUNC_CLOSEDIR_VOID', but - defines a different set of C preprocessor macros to indicate which - header file is found. This macro and the names it defines are - considered obsolete. The names it defines are: - - `dirent.h' - `DIRENT' - - `sys/ndir.h' - `SYSNDIR' - - `sys/dir.h' - `SYSDIR' - - `ndir.h' - `NDIR' - - In addition, if the `closedir' function does not return a - meaningful value, define `VOID_CLOSEDIR'. - - - Macro: AC_HEADER_DIRENT - Check for the following header files, and for the first one that is - found and defines `DIR', define the listed C preprocessor macro: - - `dirent.h' - `HAVE_DIRENT_H' - - `sys/ndir.h' - `HAVE_SYS_NDIR_H' - - `sys/dir.h' - `HAVE_SYS_DIR_H' - - `ndir.h' - `HAVE_NDIR_H' - - The directory library declarations in the source code should look - something like the following: - - #if HAVE_DIRENT_H - # include <dirent.h> - # define NAMLEN(dirent) strlen((dirent)->d_name) - #else - # define dirent direct - # define NAMLEN(dirent) (dirent)->d_namlen - # if HAVE_SYS_NDIR_H - # include <sys/ndir.h> - # endif - # if HAVE_SYS_DIR_H - # include <sys/dir.h> - # endif - # if HAVE_NDIR_H - # include <ndir.h> - # endif - #endif - - Using the above declarations, the program would declare variables - to be type `struct dirent', not `struct direct', and would access - the length of a directory entry name by passing a pointer to a - `struct dirent' to the `NAMLEN' macro. - - This macro also checks for the SCO Xenix `dir' and `x' libraries. - - - Macro: AC_HEADER_MAJOR - If `sys/types.h' does not define `major', `minor', and `makedev', - but `sys/mkdev.h' does, define `MAJOR_IN_MKDEV'; otherwise, if - `sys/sysmacros.h' does, define `MAJOR_IN_SYSMACROS'. - - - Macro: AC_HEADER_STDC - Define `STDC_HEADERS' if the system has ANSI C header files. - Specifically, this macro checks for `stdlib.h', `stdarg.h', - `string.h', and `float.h'; if the system has those, it probably - has the rest of the ANSI C header files. This macro also checks - whether `string.h' declares `memchr' (and thus presumably the - other `mem' functions), whether `stdlib.h' declare `free' (and - thus presumably `malloc' and other related functions), and whether - the `ctype.h' macros work on characters with the high bit set, as - ANSI C requires. - - Use `STDC_HEADERS' instead of `__STDC__' to determine whether the - system has ANSI-compliant header files (and probably C library - functions) because many systems that have GCC do not have ANSI C - header files. - - On systems without ANSI C headers, there is so much variation that - it is probably easier to declare the functions you use than to - figure out exactly what the system header files declare. Some - systems contain a mix of functions ANSI and BSD; some are mostly - ANSI but lack `memmove'; some define the BSD functions as macros in - `string.h' or `strings.h'; some have only the BSD functions but - `string.h'; some declare the memory functions in `memory.h', some - in `string.h'; etc. It is probably sufficient to check for one - string function and one memory function; if the library has the - ANSI versions of those then it probably has most of the others. - If you put the following in `configure.in': - - AC_HEADER_STDC - AC_CHECK_FUNCS(strchr memcpy) - - then, in your code, you can put declarations like this: - - #if STDC_HEADERS - # include <string.h> - #else - # ifndef HAVE_STRCHR - # define strchr index - # define strrchr rindex - # endif - char *strchr (), *strrchr (); - # ifndef HAVE_MEMCPY - # define memcpy(d, s, n) bcopy ((s), (d), (n)) - # define memmove(d, s, n) bcopy ((s), (d), (n)) - # endif - #endif - - If you use a function like `memchr', `memset', `strtok', or - `strspn', which have no BSD equivalent, then macros won't suffice; - you must provide an implementation of each function. An easy way - to incorporate your implementations only when needed (since the - ones in system C libraries may be hand optimized) is to, taking - `memchr' for example, put it in `memchr.c' and use - `AC_REPLACE_FUNCS(memchr)'. - - - Macro: AC_HEADER_SYS_WAIT - If `sys/wait.h' exists and is compatible with POSIX.1, define - `HAVE_SYS_WAIT_H'. Incompatibility can occur if `sys/wait.h' does - not exist, or if it uses the old BSD `union wait' instead of `int' - to store a status value. If `sys/wait.h' is not POSIX.1 - compatible, then instead of including it, define the POSIX.1 - macros with their usual interpretations. Here is an example: - - #include <sys/types.h> - #if HAVE_SYS_WAIT_H - # include <sys/wait.h> - #endif - #ifndef WEXITSTATUS - # define WEXITSTATUS(stat_val) ((unsigned)(stat_val) >> 8) - #endif - #ifndef WIFEXITED - # define WIFEXITED(stat_val) (((stat_val) & 255) == 0) - #endif - - - Macro: AC_MEMORY_H - Define `NEED_MEMORY_H' if `memcpy', `memcmp', etc. are not - declared in `string.h' and `memory.h' exists. This macro is - obsolete; instead, use `AC_CHECK_HEADERS(memory.h)'. See the - example for `AC_HEADER_STDC'. - - - Macro: AC_UNISTD_H - Define `HAVE_UNISTD_H' if the system has `unistd.h'. This macro - is obsolete; instead, use `AC_CHECK_HEADERS(unistd.h)'. - - The way to check if the system supports POSIX.1 is: - - #if HAVE_UNISTD_H - # include <sys/types.h> - # include <unistd.h> - #endif - - #ifdef _POSIX_VERSION - /* Code for POSIX.1 systems. */ - #endif - - `_POSIX_VERSION' is defined when `unistd.h' is included on POSIX.1 - systems. If there is no `unistd.h', it is definitely not a - POSIX.1 system. However, some non-POSIX.1 systems do have - `unistd.h'. - - - Macro: AC_USG - Define `USG' if the system does not have `strings.h', `rindex', - `bzero', etc. This implies that it has `string.h', `strrchr', - `memset', etc. - - The symbol `USG' is obsolete. Instead of this macro, see the - example for `AC_HEADER_STDC'. - - -File: autoconf.info, Node: Generic Headers, Prev: Particular Headers, Up: Header Files - -Generic Header Checks ---------------------- - - These macros are used to find system header files not covered by the -particular test macros. If you need to check the contents of a header -as well as find out whether it is present, you have to write your own -test for it (*note Writing Tests::.). - - - Macro: AC_CHECK_HEADER (HEADER-FILE, ACTION-IF-FOUND [, - ACTION-IF-NOT-FOUND]) - If the system header file HEADER-FILE exists, execute shell - commands ACTION-IF-FOUND, otherwise execute ACTION-IF-NOT-FOUND. - If you just want to define a symbol if the header file is - available, consider using `AC_CHECK_HEADERS' instead. - - - Macro: AC_CHECK_HEADERS (HEADER-FILE... [, ACTION-IF-FOUND [, - ACTION-IF-NOT-FOUND]]) - For each given system header file HEADER-FILE in the - whitespace-separated argument list that exists, define - `HAVE_HEADER-FILE' (in all capitals). If ACTION-IF-FOUND is - given, it is additional shell code to execute when one of the - header files is found. You can give it a value of `break' to - break out of the loop on the first match. If ACTION-IF-NOT-FOUND - is given, it is executed when one of the header files is not found. - - -File: autoconf.info, Node: Structures, Next: Typedefs, Prev: Header Files, Up: Existing Tests - -Structures -========== - - The following macros check for certain structures or structure -members. To check structures not listed here, use `AC_EGREP_CPP' -(*note Examining Declarations::.) or `AC_TRY_COMPILE' (*note Examining -Syntax::.). - - - Macro: AC_HEADER_STAT - If the macros `S_ISDIR', `S_ISREG' et al. defined in `sys/stat.h' - do not work properly (returning false positives), define - `STAT_MACROS_BROKEN'. This is the case on Tektronix UTekV, Amdahl - UTS and Motorola System V/88. - - - Macro: AC_HEADER_TIME - If a program may include both `time.h' and `sys/time.h', define - `TIME_WITH_SYS_TIME'. On some older systems, `sys/time.h' - includes `time.h', but `time.h' is not protected against multiple - inclusion, so programs should not explicitly include both files. - This macro is useful in programs that use, for example, `struct - timeval' or `struct timezone' as well as `struct tm'. It is best - used in conjunction with `HAVE_SYS_TIME_H', which can be checked - for using `AC_CHECK_HEADERS(sys/time.h)'. - - #if TIME_WITH_SYS_TIME - # include <sys/time.h> - # include <time.h> - #else - # if HAVE_SYS_TIME_H - # include <sys/time.h> - # else - # include <time.h> - # endif - #endif - - - Macro: AC_STRUCT_ST_BLKSIZE - If `struct stat' contains an `st_blksize' member, define - `HAVE_ST_BLKSIZE'. - - - Macro: AC_STRUCT_ST_BLOCKS - If `struct stat' contains an `st_blocks' member, define - `HAVE_ST_BLOCKS'. Otherwise, add `fileblocks.o' to the output - variable `LIBOBJS'. - - - Macro: AC_STRUCT_ST_RDEV - If `struct stat' contains an `st_rdev' member, define - `HAVE_ST_RDEV'. - - - Macro: AC_STRUCT_TM - If `time.h' does not define `struct tm', define `TM_IN_SYS_TIME', - which means that including `sys/time.h' had better define `struct - tm'. - - - Macro: AC_STRUCT_TIMEZONE - Figure out how to get the current timezone. If `struct tm' has a - `tm_zone' member, define `HAVE_TM_ZONE'. Otherwise, if the - external array `tzname' is found, define `HAVE_TZNAME'. - - -File: autoconf.info, Node: Typedefs, Next: Compiler Characteristics, Prev: Structures, Up: Existing Tests - -Typedefs -======== - - The following macros check for C typedefs. If there is no macro -specifically defined to check for a typedef you need, and you don't need -to check for any special properties of it, then you can use a general -typedef check macro. - -* Menu: - -* Particular Typedefs:: Special handling to find certain types. -* Generic Typedefs:: How to find other types. - - -File: autoconf.info, Node: Particular Typedefs, Next: Generic Typedefs, Up: Typedefs - -Particular Typedef Checks -------------------------- - - These macros check for particular C typedefs in `sys/types.h' and -`stdlib.h' (if it exists). - - - Macro: AC_TYPE_GETGROUPS - Define `GETGROUPS_T' to be whichever of `gid_t' or `int' is the - base type of the array argument to `getgroups'. - - - Macro: AC_TYPE_MODE_T - If `mode_t' is not defined, define `mode_t' to be `int'. - - - Macro: AC_TYPE_OFF_T - If `off_t' is not defined, define `off_t' to be `long'. - - - Macro: AC_TYPE_PID_T - If `pid_t' is not defined, define `pid_t' to be `int'. - - - Macro: AC_TYPE_SIGNAL - If `signal.h' declares `signal' as returning a pointer to a - function returning `void', define `RETSIGTYPE' to be `void'; - otherwise, define it to be `int'. - - Define signal handlers as returning type `RETSIGTYPE': - - RETSIGTYPE - hup_handler () - { - ... - } - - - Macro: AC_TYPE_SIZE_T - If `size_t' is not defined, define `size_t' to be `unsigned'. - - - Macro: AC_TYPE_UID_T - If `uid_t' is not defined, define `uid_t' to be `int' and `gid_t' - to be `int'. - - -File: autoconf.info, Node: Generic Typedefs, Prev: Particular Typedefs, Up: Typedefs - -Generic Typedef Checks ----------------------- - - This macro is used to check for typedefs not covered by the -particular test macros. - - - Macro: AC_CHECK_TYPE (TYPE, DEFAULT) - If the type TYPE is not defined in `sys/types.h' or `stdlib.h' (if - it exists), define it to be the C (or C++) builtin type DEFAULT; - e.g., `short' or `unsigned'. - - -File: autoconf.info, Node: Compiler Characteristics, Next: System Services, Prev: Typedefs, Up: Existing Tests - -Compiler Characteristics -======================== - - The following macros check for C compiler or machine architecture -features. To check for characteristics not listed here, use -`AC_TRY_COMPILE' (*note Examining Syntax::.) or `AC_TRY_RUN' (*note Run -Time::.) - - - Macro: AC_C_BIGENDIAN - If words are stored with the most significant byte first (like - Motorola and SPARC, but not Intel and VAX, CPUs), define - `WORDS_BIGENDIAN'. - - - Macro: AC_C_CONST - If the C compiler does not fully support the keyword `const', - define `const' to be empty. Some C compilers that do not define - `__STDC__' do support `const'; some compilers that define - `__STDC__' do not completely support `const'. Programs can simply - use `const' as if every C compiler supported it; for those that - don't, the `Makefile' or configuration header file will define it - as empty. - - - Macro: AC_C_INLINE - If the C compiler is a version of GCC that supports the keyword - `__inline' but not `inline' (such as some NeXT versions), define - `inline' to be `__inline'. - - - Macro: AC_C_CHAR_UNSIGNED - If the C type `char' is unsigned, define `__CHAR_UNSIGNED__', - unless the C compiler predefines it. - - - Macro: AC_C_LONG_DOUBLE - If the C compiler supports the `long double' type, define - `HAVE_LONG_DOUBLE'. Some C compilers that do not define - `__STDC__' do support the `long double' type; some compilers that - define `__STDC__' do not support `long double'. - - - Macro: AC_CHECK_SIZEOF (TYPE) - Define `SIZEOF_UCTYPE' to be the size in bytes of the C (or C++) - builtin type TYPE, e.g. `int' or `char *'. If `type' is unknown - to the compiler, it gets a size of 0. UCTYPE is TYPE, with - lowercase converted to uppercase, spaces changed to underscores, - and asterisks changed to `P'. For example, the call - AC_CHECK_SIZEOF(int *) - - defines `SIZEOF_INT_P' to be 8 on DEC Alpha AXP systems. - - - Macro: AC_INT_16_BITS - If the C type `int' is 16 bits wide, define `INT_16_BITS'. This - macro is obsolete; it is more general to use - `AC_CHECK_SIZEOF(int)' instead. - - - Macro: AC_LONG_64_BITS - If the C type `long int' is 64 bits wide, define `LONG_64_BITS'. - This macro is obsolete; it is more general to use - `AC_CHECK_SIZEOF(long)' instead. - - -File: autoconf.info, Node: System Services, Next: UNIX Variants, Prev: Compiler Characteristics, Up: Existing Tests - -System Services -=============== - - The following macros check for operating system services or -capabilities. - - - Macro: AC_SYS_INTERPRETER - Check whether the system supports starting scripts with a line of - the form `#!/bin/csh' to select the interpreter to use for the - script. After running this macro, shell code in `configure.in' - can check the variable `ac_cv_sys_interpreter'; it will be set to - `yes' if the system supports `#!', `no' if not. - - - Macro: AC_PATH_X - Try to locate the X Window System include files and libraries. If - the user gave the command line options `--x-includes=DIR' and - `--x-libraries=DIR', use those directories. If either or both - were not given, get the missing values by running `xmkmf' on a - trivial `Imakefile' and examining the `Makefile' that it produces. - If that fails (such as if `xmkmf' is not present), look for them - in several directories where they often reside. If either method - is successful, set the shell variables `x_includes' and - `x_libraries' to their locations, unless they are in directories - the compiler searches by default. - - If both methods fail, or the user gave the command line option - `--without-x', set the shell variable `no_x' to `yes'; otherwise - set it to the empty string. - - - Macro: AC_PATH_XTRA - An enhanced version of `AC_PATH_X'. Add the C compiler flags that - X needs to output variable `X_CFLAGS', and the X linker flags to - `X_LIBS'. If X is not available, add `-DX_DISPLAY_MISSING' to - `X_CFLAGS'. - - Also check for special libraries that some systems need in order to - compile X programs. Add any that the system needs to output - variable `X_EXTRA_LIBS'. And check for special X11R6 libraries - that need to be linked with before `-lX11', and add any found to - the output variable `X_PRE_LIBS'. - - - Macro: AC_SYS_LONG_FILE_NAMES - If the system supports file names longer than 14 characters, define - `HAVE_LONG_FILE_NAMES'. - - - Macro: AC_SYS_RESTARTABLE_SYSCALLS - If the system automatically restarts a system call that is - interrupted by a signal, define `HAVE_RESTARTABLE_SYSCALLS'. - - -File: autoconf.info, Node: UNIX Variants, Prev: System Services, Up: Existing Tests - -UNIX Variants -============= - - The following macros check for certain operating systems that need -special treatment for some programs, due to exceptional oddities in -their header files or libraries. These macros are warts; they will be -replaced by a more systematic approach, based on the functions they make -available or the environments they provide. - - - Macro: AC_AIX - If on AIX, define `_ALL_SOURCE'. Allows the use of some BSD - functions. Should be called before any macros that run the C - compiler. - - - Macro: AC_DYNIX_SEQ - If on Dynix/PTX (Sequent UNIX), add `-lseq' to output variable - `LIBS'. This macro is obsolete; instead, use `AC_FUNC_GETMNTENT'. - - - Macro: AC_IRIX_SUN - If on IRIX (Silicon Graphics UNIX), add `-lsun' to output variable - `LIBS'. This macro is obsolete. If you were using it to get - `getmntent', use `AC_FUNC_GETMNTENT' instead. If you used it for - the NIS versions of the password and group functions, use - `AC_CHECK_LIB(sun, getpwnam)'. - - - Macro: AC_ISC_POSIX - If on a POSIXized ISC UNIX, define `_POSIX_SOURCE' and add - `-posix' (for the GNU C compiler) or `-Xp' (for other C compilers) - to output variable `CC'. This allows the use of POSIX facilities. - Must be called after `AC_PROG_CC' and before any other macros - that run the C compiler. - - - Macro: AC_MINIX - If on Minix, define `_MINIX' and `_POSIX_SOURCE' and define - `_POSIX_1_SOURCE' to be 2. This allows the use of POSIX - facilities. Should be called before any macros that run the C - compiler. - - - Macro: AC_SCO_INTL - If on SCO UNIX, add `-lintl' to output variable `LIBS'. This - macro is obsolete; instead, use `AC_FUNC_STRFTIME'. - - - Macro: AC_XENIX_DIR - If on Xenix, add `-lx' to output variable `LIBS'. Also, if - `dirent.h' is being used, add `-ldir' to `LIBS'. This macro is - obsolete; use `AC_HEADER_DIRENT' instead. - - -File: autoconf.info, Node: Writing Tests, Next: Results, Prev: Existing Tests, Up: Top - -Writing Tests -************* - - If the existing feature tests don't do something you need, you have -to write new ones. These macros are the building blocks. They provide -ways for other macros to check whether various kinds of features are -available and report the results. - - This chapter contains some suggestions and some of the reasons why -the existing tests are written the way they are. You can also learn a -lot about how to write Autoconf tests by looking at the existing ones. -If something goes wrong in one or more of the Autoconf tests, this -information can help you understand the assumptions behind them, which -might help you figure out how to best solve the problem. - - These macros check the output of the C compiler system. They do not -cache the results of their tests for future use (*note Caching -Results::.), because they don't know enough about the information they -are checking for to generate a cache variable name. They also do not -print any messages, for the same reason. The checks for particular -kinds of C features call these macros and do cache their results and -print messages about what they're checking for. - -* Menu: - -* Examining Declarations:: Detecting header files and declarations. -* Examining Syntax:: Detecting language syntax features. -* Examining Libraries:: Detecting functions and global variables. -* Run Time:: Testing for run-time features. -* Portable Shell:: Shell script portability pitfalls. -* Testing Values and Files:: Checking strings and files. -* Multiple Cases:: Tests for several possible values. -* Language Choice:: Selecting which language to use for testing. - - -File: autoconf.info, Node: Examining Declarations, Next: Examining Syntax, Up: Writing Tests - -Examining Declarations -====================== - - The macro `AC_TRY_CPP' is used to check whether particular header -files exist. You can check for one at a time, or more than one if you -need several header files to all exist for some purpose. - - - Macro: AC_TRY_CPP (INCLUDES, ACTION-IF-TRUE [, ACTION-IF-FALSE]) - INCLUDES is C or C++ `#include' statements and declarations, on - which shell variable, backquote, and backslash substitutions are - performed. (Actually, it can be any C program, but other - statements are probably not useful.) If the preprocessor produces - no error messages while processing it, run shell commands - ACTION-IF-TRUE. Otherwise run shell commands ACTION-IF-FALSE. - - This macro uses `CPPFLAGS', but not `CFLAGS', because `-g', `-O', - etc. are not valid options to many C preprocessors. - - Here is now to find out whether a header file contains a particular -declaration, such as a typedef, a structure, a structure member, or a -function. Use `AC_EGREP_HEADER' instead of running `grep' directly on -the header file; on some systems the symbol might be defined in another -header file that the file you are checking `#include's. - - - Macro: AC_EGREP_HEADER (PATTERN, HEADER-FILE, ACTION-IF-FOUND [, - ACTION-IF-NOT-FOUND]) - If the output of running the preprocessor on the system header file - HEADER-FILE matches the `egrep' regular expression PATTERN, - execute shell commands ACTION-IF-FOUND, otherwise execute - ACTION-IF-NOT-FOUND. - - To check for C preprocessor symbols, either defined by header files -or predefined by the C preprocessor, use `AC_EGREP_CPP'. Here is an -example of the latter: - - AC_EGREP_CPP(yes, - [#ifdef _AIX - yes - #endif - ], is_aix=yes, is_aix=no) - - - Macro: AC_EGREP_CPP (PATTERN, PROGRAM, ACTION-IF-FOUND [, - ACTION-IF-NOT-FOUND]) - PROGRAM is the text of a C or C++ program, on which shell - variable, backquote, and backslash substitutions are performed. - If the output of running the preprocessor on PROGRAM matches the - `egrep' regular expression PATTERN, execute shell commands - ACTION-IF-FOUND, otherwise execute ACTION-IF-NOT-FOUND. - - This macro calls `AC_PROG_CPP' or `AC_PROG_CXXCPP' (depending on - which language is current, *note Language Choice::.), if it hasn't - been called already. - - -File: autoconf.info, Node: Examining Syntax, Next: Examining Libraries, Prev: Examining Declarations, Up: Writing Tests - -Examining Syntax -================ - - To check for a syntax feature of the C or C++ compiler, such as -whether it recognizes a certain keyword, use `AC_TRY_COMPILE' to try to -compile a small program that uses that feature. You can also use it to -check for structures and structure members that are not present on all -systems. - - - Macro: AC_TRY_COMPILE (INCLUDES, FUNCTION-BODY, ACTION-IF-FOUND [, - ACTION-IF-NOT-FOUND]) - Create a test C program to see whether a function whose body - consists of FUNCTION-BODY can be compiled; INCLUDES is any - `#include' statements needed by the code in FUNCTION-BODY. If the - file compiles successfully, run shell commands ACTION-IF-FOUND, - otherwise run ACTION-IF-NOT-FOUND. This macro uses `CFLAGS' or - `CXXFLAGS', and `CPPFLAGS', when compiling. It does not try to - link; use `AC_TRY_LINK' if you need to do that (*note Examining - Libraries::.). - - -File: autoconf.info, Node: Examining Libraries, Next: Run Time, Prev: Examining Syntax, Up: Writing Tests - -Examining Libraries -=================== - - To check for a library, a function, or a global variable, Autoconf -`configure' scripts try to compile and link a small program that uses -it. This is unlike Metaconfig, which by default uses `nm' or `ar' on -the C library to try to figure out which functions are available. -Trying to link with the function is usually a more reliable approach -because it avoids dealing with the variations in the options and output -formats of `nm' and `ar' and in the location of the standard libraries. -It also allows configuring for cross-compilation or checking a -function's runtime behavior if needed. On the other hand, it can be -slower than scanning the libraries once. - - A few systems have linkers that do not return a failure exit status -when there are unresolved functions in the link. This bug makes the -configuration scripts produced by Autoconf unusable on those systems. -However, some of them can be given options that make the exit status -correct. This is a problem that Autoconf does not currently handle -automatically. - - `AC_TRY_LINK' is used to compile test programs to test for functions -and global variables. It is also used (by `AC_CHECK_LIB') to check for -libraries, by adding the library being checked for to `LIBS' -temporarily and trying to link a small program. - - - Macro: AC_TRY_LINK (INCLUDES, FUNCTION-BODY, ACTION-IF-FOUND [, - ACTION-IF-NOT-FOUND]) - Create a test C program to see whether a function whose body - consists of FUNCTION-BODY can be compiled and linked; INCLUDES is - any `#include' statements needed by the code in FUNCTION-BODY. If - the file compiles and links successfully, run shell commands - ACTION-IF-FOUND, otherwise run ACTION-IF-NOT-FOUND. This macro - uses `CFLAGS' or `CXXFLAGS', `CPPFLAGS', `LDFLAGS', and `LIBS' - when compiling. - - - Macro: AC_COMPILE_CHECK (ECHO-TEXT, INCLUDES, FUNCTION-BODY, - ACTION-IF-FOUND [, ACTION-IF-NOT-FOUND]) - This is an obsolete version of `AC_TRY_LINK', with the addition - that it prints `checking for ECHO-TEXT' to the standard output - first, if ECHO-TEXT is non-empty. Use `AC_MSG_CHECKING' and - `AC_MSG_RESULT' instead to print messages (*note Printing - Messages::.). - |