Re: vsprintf

On Thu, 12 Apr 2007, Nicholas Clark wrote:

> So we have this to determine the return value of vsprintf:

[omitted]

> And I get:
> 
> vprintf() found.
> Your vsprintf() returns (char*).
> 
> Which is poppycock, because if I try to compile that program, I get:
> 
> $ gcc -o try try.c 
> In file included from try.c:1:
> /usr/include/varargs.h:34:2: #error "<varargs.h> is obsolete with this version of GCC."
> /usr/include/varargs.h:35:2: #error "Change your code to use <stdarg.h> instead."
> try.c:10: error: syntax error before "va_dcl"
> try.c:11: error: syntax error before '{' token
> try.c:12: warning: data definition has no type or storage class
> try.c:15: warning: parameter names (without types) in function declaration
> try.c:15: warning: data definition has no type or storage class
> try.c:16: error: syntax error before '(' token

This patch fixes that problem.  There are still some murky corners dealing 
with what happens if the test program won't compile, but at least the 
resulting default guess is likely to be right.

I didn't look at how this is used in util.c yet.  One thing at a time.

diff -r -u metaconfig-20070423/U/compline/d_vprintf.U metaconfig-andy/U/compline/d_vprintf.U
--- metaconfig-20070423/U/compline/d_vprintf.U	2007-04-23 12:22:34.000000000 -0400
+++ metaconfig-andy/U/compline/d_vprintf.U	2007-06-13 14:05:21.000000000 -0400
@@ -12,7 +12,8 @@
 ?RCS: Revision 3.0  1993/08/18  12:07:59  ram
 ?RCS: Baseline for dist 3.0 netwide release.
 ?RCS:
-?MAKE:d_vprintf d_charvspr: Compile Guess cat Csym Setvar run rm_try i_stdlib
+?MAKE:d_vprintf d_charvspr: Compile Guess cat Csym Setvar run rm_try \
+	i_stdlib i_unistd i_stdarg i_varargs
 ?MAKE:	-pick add $@ %<
 ?S:d_vprintf:
 ?S:	This variable conditionally defines the HAS_VPRINTF symbol, which
@@ -46,36 +47,73 @@
 	echo 'vprintf() found.' >&4
 	val="$define"
 	$cat >try.c <<EOF
-#include <varargs.h>
+#$i_stdarg I_STDARG  /* Only one of these can be defined by i_varhrd */
+#$i_varargs I_VARARGS
+
 #$i_stdlib I_STDLIB
+#$i_unistd I_UNISTD
+
+#ifdef I_STDARG
+#  include <stdarg.h>
+#else /* I_VARARGS */
+#  include <varargs.h>
+#endif
+
+#ifdef I_UNISTD
+#  include <unistd.h>
+#endif
+
 #ifdef I_STDLIB
-#include <stdlib.h>
+#  include <stdlib.h>
 #endif
 
-int main() { xxx("foo"); }
+#include <stdio.h> /* vsprintf prototype */
+
+#ifdef I_STDARG
+void xxx(int n, ...)
+{
+    va_list args;
+    char buf[10];
+    va_start(args, n);
+    exit((unsigned long)vsprintf(buf,"%s",args) > 10L);
+}
+int main() { xxx(1, "foo"); }
+
+#else /* I_VARARGS */
 
 xxx(va_alist)
 va_dcl
 {
-	va_list args;
-	char buf[10];
-
-	va_start(args);
-	exit((unsigned long)vsprintf(buf,"%s",args) > 10L);
+    va_list args;
+    char buf[10];
+    va_start(args);
+    exit((unsigned long)vsprintf(buf,"%s",args) > 10L);
 }
+int main() { xxx("foo"); }
+
+#endif
+
 EOF
 	set try
-	if eval $compile && $run ./try; then
-		echo "Your vsprintf() returns (int)." >&4
-		val2="$undef"
+	if eval $compile_ok; then
+		if $run ./try; then
+			echo "Your vsprintf() returns (int)." >&4
+			val2="$undef"
+		else
+			echo "Your vsprintf() returns (char*)." >&4
+			val2="$define"
+		fi
 	else
-		echo "Your vsprintf() returns (char*)." >&4
-		val2="$define"
+		echo 'I am unable to compile the vsprintf() test program.' >&4
+		# We shouldn't get here.  If we do, assume the standard signature,
+		# not the old BSD one.
+		echo 'Guessing that vsprintf() returns (int).' >&4
+		val2="$undef"
 	fi
 else
 	echo 'vprintf() NOT found.' >&4
-		val="$undef"
-		val2="$undef"
+	val="$undef"
+	val2="$undef"
 fi
 $rm_try
 set d_vprintf


-- 
    Andy Dougherty		doughera@lafayette.edu

• vsprintf by Nicholas Clark
• Re: vsprintf by Andy Dougherty
• [PATCH] Re: vsprintf by Andy Dougherty
• Re: [PATCH] Re: vsprintf by Rafael Garcia-Suarez
• Re: vsprintf by H.Merijn Brand