diff options
Diffstat (limited to 'doc')
| -rw-r--r-- | doc/autoconf.texi | 268 |
1 files changed, 143 insertions, 125 deletions
diff --git a/doc/autoconf.texi b/doc/autoconf.texi index eea3d452..d5ce4d1e 100644 --- a/doc/autoconf.texi +++ b/doc/autoconf.texi @@ -217,8 +217,6 @@ Existing Tests * Structures:: Structures or members that might be missing * Types:: Types that might be missing * Compilers and Preprocessors:: Checking for compiling programs -* C Compiler:: Checking its characteristics -* Fortran 77 Compiler:: Checking its characteristics * System Services:: Operating system services * UNIX Variants:: Special kludges for specific UNIX variants @@ -258,6 +256,13 @@ Types * Particular Types:: Special handling to find certain types * Generic Types:: How to find other types +Compilers and Preprocessors + +* Generic Compiler Characteristics:: Language independent tests +* C Compiler:: Checking its characteristics +* C++ Compiler:: Likewise +* Fortran 77 Compiler:: Likewise + Writing Tests * Examining Declarations:: Detecting header files and declarations @@ -1767,7 +1772,7 @@ Be sure to read the previous section, @ref{Configuration Actions}. Make @code{AC_OUTPUT} create each @file{@var{file}} by copying an input file (by default @file{@var{file}.in}), substituting the output variable values. -@c FIXME: Before we used to have this feature, which was later rejected +@c Before we used to have this feature, which was later rejected @c because it complicates the write of Makefiles: @c If the file would be unchanged, it is left untouched, to preserve @c timestamp. @@ -2734,8 +2739,6 @@ Symbols}, for how to get those symbol definitions into your program. * Structures:: Structures or members that might be missing * Types:: Types that might be missing * Compilers and Preprocessors:: Checking for compiling programs -* C Compiler:: Checking its characteristics -* Fortran 77 Compiler:: Checking its characteristics * System Services:: Operating system services * UNIX Variants:: Special kludges for specific UNIX variants @end menu @@ -4325,7 +4328,7 @@ implemented. In case of doubt, read the documentation of the former @code{AC_CHECK_TYPE}, see @ref{Obsolete Macros}. -@node Compilers and Preprocessors, C Compiler, Types, Existing Tests +@node Compilers and Preprocessors, System Services, Types, Existing Tests @section Compilers and Preprocessors @ovindex EXEEXT @@ -4344,6 +4347,41 @@ the executables can't be run, and cross-compilation is not enabled, they fail too. @xref{Manual Configuration}, for more on support for cross compiling. +@menu +* Generic Compiler Characteristics:: Language independent tests +* C Compiler:: Checking its characteristics +* C++ Compiler:: Likewise +* Fortran 77 Compiler:: Likewise +@end menu + +@node Generic Compiler Characteristics, C Compiler, Compilers and Preprocessors, Compilers and Preprocessors +@subsection Generic Compiler Characteristics + +@defmac AC_CHECK_SIZEOF (@var{type}, @ovar{unused}, @ovar{includes}) +@maindex CHECK_SIZEOF +Define @code{SIZEOF_@var{type}} (@pxref{Standard Symbols}) to be the +size in bytes of @var{type}. If @samp{type} is unknown, it gets a size +of 0. If no @var{includes} are specified, the default includes are used +(@pxref{Default Includes}). If you provide @var{include}, make sure to +include @file{stdio.h} which is required for this macro to run. + +This macro now works even when cross-compiling. The @var{unused} +argument was used when cross-compiling. + +For example, the call + +@example +AC_CHECK_SIZEOF(int *) +@end example + +@noindent +defines @code{SIZEOF_INT_P} to be 8 on DEC Alpha AXP systems. +@end defmac + + +@node C Compiler, C++ Compiler, Generic Compiler Characteristics, Compilers and Preprocessors +@subsection C Compiler Characteristics + @defmac AC_PROG_CC (@ovar{compiler-search-list}) @maindex PROG_CC @ovindex CC @@ -4417,107 +4455,6 @@ other macros to check the standard error from the preprocessor and consider the test failed if any warnings have been reported. @end defmac -@defmac AC_PROG_CXX (@ovar{compiler-search-list}) -@maindex PROG_CXX -@ovindex CXX -@ovindex CXXFLAGS -Determine a C++ compiler to use. Check if the environment variable -@code{CXX} or @code{CCC} (in that order) is set; if so, then set output -variable @code{CXX} to its value. - -Otherwise, if the macro is invoked without an argument, then search for -a C++ compiler under the likely names (first @code{g++} and @code{c++} -then other names). If none of those checks succeed, then as a last -resort set @code{CXX} to @code{gcc}. - -This macro may, however, be invoked with an optional first argument -which, if specified, must be a space separated list of C++ compilers to -search for. This just gives the user an opportunity to specify an -alternative search list for the C++ compiler. For example, if you -didn't like the default order, then you could invoke @code{AC_PROG_CXX} -like this: - -@example -AC_PROG_CXX(cl KCC CC cxx cc++ xlC aCC c++ g++ egcs gcc) -@end example - -If using the @sc{gnu} C++ compiler, set shell variable @code{GXX} to -@samp{yes}. If output variable @code{CXXFLAGS} was not already set, set -it to @option{-g -O2} for the @sc{gnu} C++ compiler (@option{-O2} on -systems where G++ does not accept @option{-g}), or @option{-g} for other -compilers. -@end defmac - -@defmac AC_PROG_CXXCPP -@maindex PROG_CXXCPP -@ovindex CXXCPP -Set output variable @code{CXXCPP} to a command that runs the C++ -preprocessor. If @samp{$CXX -E} doesn't work, @file{/lib/cpp} is used. -It is only portable to run @code{CXXCPP} on files with a @file{.c}, -@file{.C}, or @file{.cc} extension. - -If the current language is C++ (@pxref{Language Choice}), many of the -specific test macros use the value of @code{CXXCPP} indirectly by -calling @code{AC_TRY_CPP}, @code{AC_CHECK_HEADER}, -@code{AC_EGREP_HEADER}, or @code{AC_EGREP_CPP}. - -Some preprocessors don't indicate missing include files by the error -status. For such preprocessors an internal variable is set that causes -other macros to check the standard error from the preprocessor and -consider the test failed if any warnings have been reported. However, -it is not known whether such broken preprocessors exist for C++. -@end defmac - -@defmac AC_PROG_F77 (@ovar{compiler-search-list}) -@maindex PROG_FORTRAN -@ovindex F77 -@ovindex FFLAGS -Determine a Fortran 77 compiler to use. If @code{F77} is not already -set in the environment, then check for @code{g77} and @code{f77}, and -then some other names. Set the output variable @code{F77} to the name -of the compiler found. - -This macro may, however, be invoked with an optional first argument -which, if specified, must be a space separated list of Fortran 77 -compilers to search for. This just gives the user an opportunity to -specify an alternative search list for the Fortran 77 compiler. For -example, if you didn't like the default order, then you could invoke -@code{AC_PROG_F77} like this: - -@example -AC_PROG_F77(fl32 f77 fort77 xlf cf77 g77 f90 xlf90) -@end example - -If using @code{g77} (the @sc{gnu} Fortran 77 compiler), then -@code{AC_PROG_F77} will set the shell variable @code{G77} to @samp{yes}. -If the output variable @code{FFLAGS} was not already set in the -environment, then set it to @option{-g -02} for @code{g77} (or @option{-O2} -where @code{g77} does not accept @option{-g}). Otherwise, set -@code{FFLAGS} to @option{-g} for all other Fortran 77 compilers. -@end defmac - -@defmac AC_PROG_F77_C_O -@maindex PROG_F77_C_O -@cvindex F77_NO_MINUS_C_MINUS_O -Test if the Fortran 77 compiler accepts the options @option{-c} and -@option{-o} simultaneously, and define @code{F77_NO_MINUS_C_MINUS_O} if it -does not. -@end defmac - -@defmac AC_PROG_GCC_TRADITIONAL -@maindex PROG_GCC_TRADITIONAL -@ovindex CC -Add @option{-traditional} to output variable @code{CC} if using the -@sc{gnu} C compiler and @code{ioctl} does not work properly without -@option{-traditional}. That usually happens when the fixed header files -have not been installed on an old system. Since recent versions of the -@sc{gnu} C compiler fix the header files automatically when installed, -this is becoming a less prevalent problem. -@end defmac - - -@node C Compiler, Fortran 77 Compiler, Compilers and Preprocessors, Existing Tests -@section C Compiler Characteristics The following macros check for C compiler or machine architecture features. To check for characteristics not listed here, use @@ -4648,33 +4585,114 @@ size_t my_strlen PARAMS ((const char *)); @end example @end defmac -@c FIXME: What the heck is this macro doing here? Move it out of -@c the way, in its proper section!!! -@defmac AC_CHECK_SIZEOF (@var{type}, @ovar{unused}, @ovar{includes}) -@maindex CHECK_SIZEOF -Define @code{SIZEOF_@var{type}} (@pxref{Standard Symbols}) to be the -size in bytes of @var{type}. If @samp{type} is unknown, it gets a size -of 0. If no @var{includes} are specified, the default includes are used -(@pxref{Default Includes}). If you provide @var{include}, make sure to -include @file{stdio.h} which is required for this macro to run. +@defmac AC_PROG_GCC_TRADITIONAL +@maindex PROG_GCC_TRADITIONAL +@ovindex CC +Add @option{-traditional} to output variable @code{CC} if using the +@sc{gnu} C compiler and @code{ioctl} does not work properly without +@option{-traditional}. That usually happens when the fixed header files +have not been installed on an old system. Since recent versions of the +@sc{gnu} C compiler fix the header files automatically when installed, +this is becoming a less prevalent problem. +@end defmac -This macro now works even when cross-compiling. The @var{unused} -argument was used when cross-compiling. -For example, the call +@node C++ Compiler, Fortran 77 Compiler, C Compiler, Compilers and Preprocessors +@subsection C++ Compiler Characteristics + + +@defmac AC_PROG_CXX (@ovar{compiler-search-list}) +@maindex PROG_CXX +@ovindex CXX +@ovindex CXXFLAGS +Determine a C++ compiler to use. Check if the environment variable +@code{CXX} or @code{CCC} (in that order) is set; if so, then set output +variable @code{CXX} to its value. + +Otherwise, if the macro is invoked without an argument, then search for +a C++ compiler under the likely names (first @code{g++} and @code{c++} +then other names). If none of those checks succeed, then as a last +resort set @code{CXX} to @code{gcc}. + +This macro may, however, be invoked with an optional first argument +which, if specified, must be a space separated list of C++ compilers to +search for. This just gives the user an opportunity to specify an +alternative search list for the C++ compiler. For example, if you +didn't like the default order, then you could invoke @code{AC_PROG_CXX} +like this: @example -AC_CHECK_SIZEOF(int *) +AC_PROG_CXX(cl KCC CC cxx cc++ xlC aCC c++ g++ egcs gcc) @end example -@noindent -defines @code{SIZEOF_INT_P} to be 8 on DEC Alpha AXP systems. +If using the @sc{gnu} C++ compiler, set shell variable @code{GXX} to +@samp{yes}. If output variable @code{CXXFLAGS} was not already set, set +it to @option{-g -O2} for the @sc{gnu} C++ compiler (@option{-O2} on +systems where G++ does not accept @option{-g}), or @option{-g} for other +compilers. +@end defmac + +@defmac AC_PROG_CXXCPP +@maindex PROG_CXXCPP +@ovindex CXXCPP +Set output variable @code{CXXCPP} to a command that runs the C++ +preprocessor. If @samp{$CXX -E} doesn't work, @file{/lib/cpp} is used. +It is only portable to run @code{CXXCPP} on files with a @file{.c}, +@file{.C}, or @file{.cc} extension. + +If the current language is C++ (@pxref{Language Choice}), many of the +specific test macros use the value of @code{CXXCPP} indirectly by +calling @code{AC_TRY_CPP}, @code{AC_CHECK_HEADER}, +@code{AC_EGREP_HEADER}, or @code{AC_EGREP_CPP}. + +Some preprocessors don't indicate missing include files by the error +status. For such preprocessors an internal variable is set that causes +other macros to check the standard error from the preprocessor and +consider the test failed if any warnings have been reported. However, +it is not known whether such broken preprocessors exist for C++. @end defmac -@node Fortran 77 Compiler, System Services, C Compiler, Existing Tests -@section Fortran 77 Compiler Characteristics +@node Fortran 77 Compiler, , C++ Compiler, Compilers and Preprocessors +@subsection Fortran 77 Compiler Characteristics + +@defmac AC_PROG_F77 (@ovar{compiler-search-list}) +@maindex PROG_FORTRAN +@ovindex F77 +@ovindex FFLAGS +Determine a Fortran 77 compiler to use. If @code{F77} is not already +set in the environment, then check for @code{g77} and @code{f77}, and +then some other names. Set the output variable @code{F77} to the name +of the compiler found. + +This macro may, however, be invoked with an optional first argument +which, if specified, must be a space separated list of Fortran 77 +compilers to search for. This just gives the user an opportunity to +specify an alternative search list for the Fortran 77 compiler. For +example, if you didn't like the default order, then you could invoke +@code{AC_PROG_F77} like this: + +@example +AC_PROG_F77(fl32 f77 fort77 xlf cf77 g77 f90 xlf90) +@end example + +If using @code{g77} (the @sc{gnu} Fortran 77 compiler), then +@code{AC_PROG_F77} will set the shell variable @code{G77} to @samp{yes}. +If the output variable @code{FFLAGS} was not already set in the +environment, then set it to @option{-g -02} for @code{g77} (or @option{-O2} +where @code{g77} does not accept @option{-g}). Otherwise, set +@code{FFLAGS} to @option{-g} for all other Fortran 77 compilers. +@end defmac + +@defmac AC_PROG_F77_C_O +@maindex PROG_F77_C_O +@cvindex F77_NO_MINUS_C_MINUS_O +Test if the Fortran 77 compiler accepts the options @option{-c} and +@option{-o} simultaneously, and define @code{F77_NO_MINUS_C_MINUS_O} if it +does not. +@end defmac + The following macros check for Fortran 77 compiler characteristics. To check for characteristics not listed here, use @code{AC_TRY_COMPILE} @@ -4848,7 +4866,7 @@ preprocessor as above; for example, to call Fortran routines from some language other than C/C++. @end defmac -@node System Services, UNIX Variants, Fortran 77 Compiler, Existing Tests +@node System Services, UNIX Variants, Compilers and Preprocessors, Existing Tests @section System Services The following macros check for operating system services or capabilities. |