##### http://autoconf-archive.cryp.to/ac_prototype.html # # SYNOPSIS # # AC_PROTOTYPE(function, includes, code, TAG1, values1 [, TAG2, values2 [...]]) # # DESCRIPTION # # Try all the combinations of , ... to successfully # compile . , , ... are substituted in and # with values found in , , ... # respectively. , , ... contain a list of possible # values for each corresponding tag and all combinations are tested. # When AC_TRY_COMPILE(include, code) is successfull for a given # substitution, the macro stops and defines the following macros: # FUNCTION_TAG1, FUNCTION_TAG2, ... using AC_DEFINE() with values set # to the current values of , , ... If no combination is # successfull the configure script is aborted with a message. # # Intended purpose is to find which combination of argument types is # acceptable for a given function . It is recommended to # list the most specific types first. For instance ARG1, [size_t, # int] instead of ARG1, [int, size_t]. # # Generic usage pattern: # # 1) add a call in configure.in # # AC_PROTOTYPE(...) # # 2) call autoheader to see which symbols are not covered # # 3) add the lines in acconfig.h # # /* Type of Nth argument of function */ # #undef FUNCTION_ARGN # # 4) Within the code use FUNCTION_ARGN instead of an hardwired type # # Complete example: # # 1) configure.in # # AC_PROTOTYPE(getpeername, # [ # #include # #include # ], # [ # int a = 0; # ARG2 * b = 0; # ARG3 * c = 0; # getpeername(a, b, c); # ], # ARG2, [struct sockaddr, void], # ARG3, [socklen_t, size_t, int, unsigned int, long unsigned int]) # # 2) call autoheader # # autoheader: Symbol `GETPEERNAME_ARG2' is not covered by ./acconfig.h # autoheader: Symbol `GETPEERNAME_ARG3' is not covered by ./acconfig.h # # 3) acconfig.h # # /* Type of second argument of getpeername */ # #undef GETPEERNAME_ARG2 # # /* Type of third argument of getpeername */ # #undef GETPEERNAME_ARG3 # # 4) in the code # # ... # GETPEERNAME_ARG2 name; # GETPEERNAME_ARG3 namelen; # ... # ret = getpeername(socket, &name, &namelen); # ... # # Implementation notes: generating all possible permutations of the # arguments is not easily done with the usual mixture of shell and # m4, that is why this macro is almost 100% m4 code. It generates # long but simple to read code. # # LAST MODIFICATION # # 2000-08-11 # # COPYLEFT # # Copyright (c) 2000 Loic Dachary # # This program is free software; you can redistribute it and/or # modify it under the terms of the GNU General Public License as # published by the Free Software Foundation; either version 2 of the # License, or (at your option) any later version. # # This program is distributed in the hope that it will be useful, but # WITHOUT ANY WARRANTY; without even the implied warranty of # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU # General Public License for more details. # # You should have received a copy of the GNU General Public License # along with this program; if not, write to the Free Software # Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA # 02111-1307, USA. # # As a special exception, the respective Autoconf Macro's copyright # owner gives unlimited permission to copy, distribute and modify the # configure scripts that are the output of Autoconf when processing # the Macro. You need not follow the terms of the GNU General Public # License when using or distributing such scripts, even though # portions of the text of the Macro appear in them. The GNU General # Public License (GPL) does govern all other use of the material that # constitutes the Autoconf Macro. # # This special exception to the GPL applies to versions of the # Autoconf Macro released by the Autoconf Macro Archive. When you # make and distribute a modified version of the Autoconf Macro, you # may extend this special exception to the GPL to apply to your # modified version as well. AC_DEFUN([AC_PROTOTYPE],[ dnl dnl Upper case function name dnl pushdef([function],translit([$1], [a-z], [A-Z])) dnl dnl Collect tags that will be substituted dnl pushdef([tags],[AC_PROTOTYPE_TAGS(builtin([shift],builtin([shift],builtin([shift],$@))))]) dnl dnl Wrap in a 1 time loop, when a combination is found break to stop the combinatory exploration dnl for i in 1 do AC_PROTOTYPE_LOOP(AC_PROTOTYPE_REVERSE($1, AC_PROTOTYPE_SUBST($2,tags),AC_PROTOTYPE_SUBST($3,tags),builtin([shift],builtin([shift],builtin([shift],$@))))) AC_MSG_ERROR($1 unable to find a working combination) done popdef([tags]) popdef([function]) ]) dnl dnl AC_PROTOTYPE_REVERSE(list) dnl dnl Reverse the order of the dnl AC_DEFUN([AC_PROTOTYPE_REVERSE],[ifelse($#,0,,$#,1,[[$1]],[AC_PROTOTYPE_REVERSE(builtin([shift],$@)),[$1]])]) dnl dnl AC_PROTOTYPE_SUBST(string, tag) dnl dnl Substitute all occurence of in with _VAL. dnl Assumes that tag_VAL is a macro containing the value associated to tag. dnl AC_DEFUN([AC_PROTOTYPE_SUBST],[ifelse($2,,[$1],[AC_PROTOTYPE_SUBST(patsubst([$1],[$2],[$2[]_VAL]),builtin([shift],builtin([shift],$@)))])]) dnl dnl AC_PROTOTYPE_TAGS([tag, values, [tag, values ...]]) dnl dnl Generate a list of by skipping . dnl AC_DEFUN([AC_PROTOTYPE_TAGS],[ifelse($1,,[],[$1, AC_PROTOTYPE_TAGS(builtin([shift],builtin([shift],$@)))])]) dnl dnl AC_PROTOTYPE_DEFINES(tags) dnl dnl Generate a AC_DEFINE(function_tag, tag_VAL) for each tag in list dnl Assumes that function is a macro containing the name of the function in upper case dnl and that tag_VAL is a macro containing the value associated to tag. dnl AC_DEFUN([AC_PROTOTYPE_DEFINES],[ifelse($1,,[],[AC_DEFINE(function[]_$1, $1_VAL) AC_PROTOTYPE_DEFINES(builtin([shift],$@))])]) dnl dnl AC_PROTOTYPE_STATUS(tags) dnl dnl Generates a message suitable for argument to AC_MSG_* macros. For each tag dnl in the list the message tag => tag_VAL is generated. dnl Assumes that tag_VAL is a macro containing the value associated to tag. dnl AC_DEFUN([AC_PROTOTYPE_STATUS],[ifelse($1,,[],[$1 => $1_VAL AC_PROTOTYPE_STATUS(builtin([shift],$@))])]) dnl dnl AC_PROTOTYPE_EACH(tag, values) dnl dnl Call AC_PROTOTYPE_LOOP for each values and define the macro tag_VAL to dnl the current value. dnl AC_DEFUN([AC_PROTOTYPE_EACH],[ ifelse($2,, [ ], [ pushdef([$1_VAL], $2) AC_PROTOTYPE_LOOP(rest) popdef([$1_VAL]) AC_PROTOTYPE_EACH($1, builtin([shift], builtin([shift], $@))) ]) ]) dnl dnl AC_PROTOTYPE_LOOP([tag, values, [tag, values ...]], code, include, function) dnl dnl If there is a tag/values pair, call AC_PROTOTYPE_EACH with it. dnl If there is no tag/values pair left, tries to compile the code and include dnl using AC_TRY_COMPILE. If it compiles, AC_DEFINE all the tags to their dnl current value and exit with success. dnl AC_DEFUN([AC_PROTOTYPE_LOOP],[ ifelse(builtin([eval], $# > 3), 1, [ pushdef([rest],[builtin([shift],builtin([shift],$@))]) AC_PROTOTYPE_EACH($2,$1) popdef([rest]) ], [ AC_MSG_CHECKING($3 AC_PROTOTYPE_STATUS(tags)) dnl dnl Activate fatal warnings if possible, gives better guess dnl ac_save_CPPFLAGS="$CPPFLAGS" ifelse(AC_LANG,CPLUSPLUS,if test "$GXX" = "yes" ; then CPPFLAGS="$CPPFLAGS -Werror" ; fi) ifelse(AC_LANG,C,if test "$GCC" = "yes" ; then CPPFLAGS="$CPPFLAGS -Werror" ; fi) AC_TRY_COMPILE($2, $1, [ CPPFLAGS="$ac_save_CPPFLAGS" AC_MSG_RESULT(ok) AC_PROTOTYPE_DEFINES(tags) break; ], [ CPPFLAGS="$ac_save_CPPFLAGS" AC_MSG_RESULT(not ok) ]) ] ) ])