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List:       autoconf
Subject:    Re: AC_TYPE_UINT8_T and co
From:       Paul Eggert <eggert () CS ! UCLA ! EDU>
Date:       2007-05-31 19:37:18
Message-ID: 87r6owlr81.fsf () penguin ! cs ! ucla ! edu
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Paul Eggert <eggert@CS.UCLA.EDU> writes:

> you can approximate it this way:

... which should be documented, so I installed this:

2007-05-31  Paul Eggert  <eggert@cs.ucla.edu>

	* doc/autoconf.texi (Particular Types): Give example of use for
	AC_TYPE_INT8_T etc.

--- doc/autoconf.texi	29 May 2007 05:36:29 -0000	1.1158
+++ doc/autoconf.texi	31 May 2007 19:35:41 -0000
@@ -5911,6 +5911,19 @@ If @file{stdint.h} or @file{inttypes.h} 
 @code{int8_t}, define @code{int8_t} to a signed
 integer type that is exactly 8 bits wide and that uses two's complement
 representation, if such a type exists.
+If you are worried about porting to hosts that lack such a type, you can
+use the results of this macro in C89-or-later code as follows:
+
+@example
+#if HAVE_STDINT_H
+# include <stdint.h>
+#endif
+#if defined INT8_MAX || defined int8_t
+ @emph{code using int8_t}
+#else
+ @emph{complicated alternative using >8-bit 'signed char'}
+#endif
+@end example
 @end defmac

 @defmac AC_TYPE_INT16_T
@@ -6060,27 +6073,28 @@ If @file{stdint.h} or @file{inttypes.h} 
 @code{uint8_t}, define @code{uint8_t} to an
 unsigned integer type that is exactly 8 bits wide, if such a type
 exists.
+This is like @code{AC_TYPE_INT8_T}, except for unsigned integers.
 @end defmac

 @defmac AC_TYPE_UINT16_T
 @acindex{TYPE_UINT16_T}
 @cvindex HAVE_UINT16_T
 @cvindex uint16_t
-This is like @code{AC_TYPE_UINT8_T}, except for 16-bit unsigned integers.
+This is like @code{AC_TYPE_UINT8_T}, except for 16-bit integers.
 @end defmac

 @defmac AC_TYPE_UINT32_T
 @acindex{TYPE_UINT32_T}
 @cvindex HAVE_UINT32_T
 @cvindex uint32_t
-This is like @code{AC_TYPE_UINT8_T}, except for 32-bit unsigned integers.
+This is like @code{AC_TYPE_UINT8_T}, except for 32-bit integers.
 @end defmac

 @defmac AC_TYPE_UINT64_T
 @acindex{TYPE_UINT64_T}
 @cvindex HAVE_UINT64_T
 @cvindex uint64_t
-This is like @code{AC_TYPE_UINT8_T}, except for 64-bit unsigned integers.
+This is like @code{AC_TYPE_UINT8_T}, except for 64-bit integers.
 @end defmac

 @defmac AC_TYPE_UINTMAX_T



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