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	calls with new or now-built-in versions. Make sure that all calls to AC_DEFINE have a third argument, for possible use of autoheader in the future.
		
			
				
	
	
		
			95 lines
		
	
	
		
			2.9 KiB
		
	
	
	
		
			Plaintext
		
	
	
	
	
	
			
		
		
	
	
			95 lines
		
	
	
		
			2.9 KiB
		
	
	
	
		
			Plaintext
		
	
	
	
	
	
| # Macros to detect C compiler features
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| # $Header: /cvsroot/pgsql/config/c-compiler.m4,v 1.5 2002/03/29 17:32:53 petere Exp $
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| 
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| 
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| # PGAC_C_SIGNED
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| # -------------
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| # Check if the C compiler understands signed types.
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| AC_DEFUN([PGAC_C_SIGNED],
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| [AC_CACHE_CHECK(for signed types, pgac_cv_c_signed,
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| [AC_TRY_COMPILE([],
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| [signed char c; signed short s; signed int i;],
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| [pgac_cv_c_signed=yes],
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| [pgac_cv_c_signed=no])])
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| if test x"$pgac_cv_c_signed" = xno ; then
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|   AC_DEFINE(signed,, [Define empty if the C compiler does not understand signed types])
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| fi])# PGAC_C_SIGNED
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| 
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| 
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| 
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| # PGAC_TYPE_64BIT_INT(TYPE)
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| # -------------------------
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| # Check if TYPE is a working 64 bit integer type. Set HAVE_TYPE_64 to
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| # yes or no respectively, and define HAVE_TYPE_64 if yes.
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| AC_DEFUN([PGAC_TYPE_64BIT_INT],
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| [define([Ac_define], [translit([have_$1_64], [a-z *], [A-Z_P])])dnl
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| define([Ac_cachevar], [translit([pgac_cv_type_$1_64], [ *], [_p])])dnl
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| AC_CACHE_CHECK([whether $1 is 64 bits], [Ac_cachevar],
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| [AC_TRY_RUN(
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| [typedef $1 int64;
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| 
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| /*
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|  * These are globals to discourage the compiler from folding all the
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|  * arithmetic tests down to compile-time constants.
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|  */
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| int64 a = 20000001;
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| int64 b = 40000005;
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| 
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| int does_int64_work()
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| {
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|   int64 c,d;
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| 
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|   if (sizeof(int64) != 8)
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|     return 0;			/* definitely not the right size */
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| 
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|   /* Do perfunctory checks to see if 64-bit arithmetic seems to work */
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|   c = a * b;
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|   d = (c + b) / b;
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|   if (d != a+1)
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|     return 0;
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|   return 1;
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| }
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| main() {
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|   exit(! does_int64_work());
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| }],
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| [Ac_cachevar=yes],
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| [Ac_cachevar=no],
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| [Ac_cachevar=no
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| dnl We will do better here with Autoconf 2.50
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| AC_MSG_WARN([64 bit arithmetic disabled when cross-compiling])])])
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| 
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| Ac_define=$Ac_cachevar
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| if test x"$Ac_cachevar" = xyes ; then
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|   AC_DEFINE(Ac_define,, [Set to 1 if `]$1[' is 64 bits])
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| fi
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| undefine([Ac_define])dnl
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| undefine([Ac_cachevar])dnl
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| ])# PGAC_TYPE_64BIT_INT
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| 
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| 
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| 
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| # PGAC_CHECK_ALIGNOF(TYPE, [INCLUDES = DEFAULT-INCLUDES])
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| # -----------------------------------------------------
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| # Find the alignment requirement of the given type. Define the result
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| # as ALIGNOF_TYPE.  This macro works even when cross compiling.
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| # (Modelled after AC_CHECK_SIZEOF.)
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| 
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| AC_DEFUN([PGAC_CHECK_ALIGNOF],
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| [AS_LITERAL_IF([$1], [],
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|                [AC_FATAL([$0: requires literal arguments])])dnl
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| AC_CHECK_TYPE([$1], [], [], [$2])
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| AC_CACHE_CHECK([alignment of $1], [AS_TR_SH([pgac_cv_alignof_$1])],
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| [if test "$AS_TR_SH([ac_cv_type_$1])" = yes; then
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|   _AC_COMPUTE_INT([((char*) & pgac_struct.field) - ((char*) & pgac_struct)],
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|                   [AS_TR_SH([pgac_cv_alignof_$1])],
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|                   [AC_INCLUDES_DEFAULT([$2])
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| struct { char filler; $1 field; } pgac_struct;],
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|                   [AC_MSG_ERROR([cannot compute alignment of $1, 77])])
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| else
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|   AS_TR_SH([pgac_cv_alignof_$1])=0
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| fi])dnl
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| AC_DEFINE_UNQUOTED(AS_TR_CPP(alignof_$1),
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|                    [$AS_TR_SH([pgac_cv_alignof_$1])],
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|                    [The alignment requirement of a `$1'])
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| ])# PGAC_CHECK_ALIGNOF
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