diff --git a/libiberty/ChangeLog b/libiberty/ChangeLog
index 679b382e051f..6217c8c888a7 100644
--- a/libiberty/ChangeLog
+++ b/libiberty/ChangeLog
@@ -1,3 +1,22 @@
+2003-04-14  Roger Sayle  <roger@eyesopen.com>
+
+	* argv.c: Use ANSI_PROTOTYPES instead of __STDC__.
+	* memchr.c: Likewise.
+	* strcasecmp.c: Likewise.
+	* strncasecmp.c: Likewise.
+	* strncmp.c: Likewise.
+	* xatexit.c: Likewise.
+	* xmalloc.c: Likewise.
+
+	* copysign.c: Use traditional function declaration instead of DEFUN.
+	* sigsetmask.c: Likewise.
+
+	* memcmp.c: Both of the above, ANSI_PROTOTYPES and DEFUN.
+	* memset.c: Likewise.
+
+	* memcpy.c: ANSI_PROTOTYPES, DEFUN and prototype bcopy.
+	* memmove.c: Likewise.
+
 2003-04-14  Roger Sayle  <roger@eyesopen.com>
 
 	* strdup.c (strdup): Tweak implementation to use memcpy.
diff --git a/libiberty/argv.c b/libiberty/argv.c
index 4205579a5765..e4a03793b65d 100644
--- a/libiberty/argv.c
+++ b/libiberty/argv.c
@@ -29,7 +29,7 @@ Boston, MA 02111-1307, USA.  */
 
 /*  Routines imported from standard C runtime libraries. */
 
-#ifdef __STDC__
+#ifdef ANSI_PROTOTYPES
 
 #include <stddef.h>
 #include <string.h>
diff --git a/libiberty/copysign.c b/libiberty/copysign.c
index 5c48a5422eba..d288be239eb4 100644
--- a/libiberty/copysign.c
+++ b/libiberty/copysign.c
@@ -131,7 +131,9 @@ typedef union
 
 #if defined(__IEEE_BIG_ENDIAN) || defined(__IEEE_LITTLE_ENDIAN)
 
-double DEFUN(copysign, (x, y), double x AND double y)
+double
+copysign (x, y)
+     double x, y;
 {
   __ieee_double_shape_type a,b;
   b.value = y;  
@@ -142,7 +144,9 @@ double DEFUN(copysign, (x, y), double x AND double y)
 
 #else
 
-double DEFUN(copysign, (x, y), double x AND double y)
+double
+copysign (x, y)
+     double x, y;
 {
   if ((x < 0 && y > 0) || (x > 0 && y < 0))
     return -x;
diff --git a/libiberty/memchr.c b/libiberty/memchr.c
index f94bea018f53..3948125963d2 100644
--- a/libiberty/memchr.c
+++ b/libiberty/memchr.c
@@ -15,7 +15,7 @@ returned.
 */
 
 #include <ansidecl.h>
-#ifdef __STDC__
+#ifdef ANSI_PROTOTYPES
 #include <stddef.h>
 #else
 #define size_t unsigned long
diff --git a/libiberty/memcmp.c b/libiberty/memcmp.c
index d8d3997d0661..92f2b6e64257 100644
--- a/libiberty/memcmp.c
+++ b/libiberty/memcmp.c
@@ -16,15 +16,17 @@ as if comparing unsigned char arrays.
 */
 
 #include <ansidecl.h>
-#ifdef __STDC__
+#ifdef ANSI_PROTOTYPES
 #include <stddef.h>
 #else
 #define size_t unsigned long
 #endif
 
 int
-DEFUN(memcmp, (str1, str2, count),
-      const PTR str1 AND const PTR str2 AND size_t count)
+memcmp (str1, str2, count)
+     const PTR str1;
+     const PTR str2;
+     size_t count;
 {
   register const unsigned char *s1 = (const unsigned char*)str1;
   register const unsigned char *s2 = (const unsigned char*)str2;
diff --git a/libiberty/memcpy.c b/libiberty/memcpy.c
index 0f2bac7ac2c8..5eece7a0a001 100644
--- a/libiberty/memcpy.c
+++ b/libiberty/memcpy.c
@@ -13,14 +13,19 @@ Copies @var{length} bytes from memory region @var{in} to region
 */
 
 #include <ansidecl.h>
-#ifdef __STDC__
+#ifdef ANSI_PROTOTYPES
 #include <stddef.h>
 #else
 #define size_t unsigned long
 #endif
 
+void bcopy PARAMS((const void*, void*, size_t));
+
 PTR
-DEFUN(memcpy, (out, in, length), PTR out AND const PTR in AND size_t length)
+memcpy (out, in, length)
+     PTR out;
+     const PTR in;
+     size_t length;
 {
     bcopy(in, out, length);
     return out;
diff --git a/libiberty/memmove.c b/libiberty/memmove.c
index 3ec73208ca73..00ac053401bf 100644
--- a/libiberty/memmove.c
+++ b/libiberty/memmove.c
@@ -13,12 +13,14 @@ Copies @var{count} bytes from memory area @var{from} to memory area
 */
 
 #include <ansidecl.h>
-#ifdef __STDC__
+#ifdef ANSI_PROTOTYPES
 #include <stddef.h>
 #else
 #define size_t unsigned long
 #endif
 
+void bcopy PARAMS ((const void*, void*, size_t));
+
 PTR
 memmove (s1, s2, n)
      PTR s1;
diff --git a/libiberty/memset.c b/libiberty/memset.c
index 489ca1748157..5119f858ad06 100644
--- a/libiberty/memset.c
+++ b/libiberty/memset.c
@@ -13,15 +13,17 @@ Sets the first @var{count} bytes of @var{s} to the constant byte
 */
 
 #include <ansidecl.h>
-#ifdef __STDC__
+#ifdef ANSI_PROTOTYPES
 #include <stddef.h>
 #else
 #define size_t unsigned long
 #endif
 
 PTR
-DEFUN(memset, (dest, val, len),
-      PTR dest AND register int val AND register size_t len)
+memset (dest, val, len)
+     PTR dest;
+     register int val;
+     register size_t len;
 {
   register unsigned char *ptr = (unsigned char*)dest;
   while (len-- > 0)
diff --git a/libiberty/sigsetmask.c b/libiberty/sigsetmask.c
index f705fbb2df2b..4de3e4b1eb82 100644
--- a/libiberty/sigsetmask.c
+++ b/libiberty/sigsetmask.c
@@ -25,8 +25,8 @@ extern void abort PARAMS ((void)) ATTRIBUTE_NORETURN;
 
 #ifdef SIG_SETMASK
 int
-DEFUN(sigsetmask,(set),
-      int set)
+sigsetmask (set)
+      int set;
 {
     sigset_t new;
     sigset_t old;
diff --git a/libiberty/strcasecmp.c b/libiberty/strcasecmp.c
index 4bfe65077121..d2608dc0b878 100644
--- a/libiberty/strcasecmp.c
+++ b/libiberty/strcasecmp.c
@@ -25,7 +25,7 @@ static char sccsid[] = "@(#)strcasecmp.c	5.5 (Berkeley) 11/24/87";
 #endif /* LIBC_SCCS and not lint */
 
 #include <ansidecl.h>
-#ifdef __STDC__
+#ifdef ANSI_PROTOTYPES
 #include <stddef.h>
 #else
 #define size_t unsigned long
diff --git a/libiberty/strncasecmp.c b/libiberty/strncasecmp.c
index 77cb42177019..10feee82198e 100644
--- a/libiberty/strncasecmp.c
+++ b/libiberty/strncasecmp.c
@@ -25,7 +25,7 @@ static char sccsid[] = "@(#)strcasecmp.c	5.5 (Berkeley) 11/24/87";
 #endif /* LIBC_SCCS and not lint */
 
 #include <ansidecl.h>
-#ifdef __STDC__
+#ifdef ANSI_PROTOTYPES
 #include <stddef.h>
 #else
 #define size_t unsigned long
diff --git a/libiberty/strncmp.c b/libiberty/strncmp.c
index 819cea6cb58b..ad87e1fde8ba 100644
--- a/libiberty/strncmp.c
+++ b/libiberty/strncmp.c
@@ -13,7 +13,7 @@ Compares the first @var{n} bytes of two strings, returning a value as
 */
 
 #include <ansidecl.h>
-#ifdef __STDC__
+#ifdef ANSI_PROTOTYPES
 #include <stddef.h>
 #else
 #define size_t unsigned long
diff --git a/libiberty/xatexit.c b/libiberty/xatexit.c
index abf340737e41..075599c61f95 100644
--- a/libiberty/xatexit.c
+++ b/libiberty/xatexit.c
@@ -27,7 +27,7 @@ failure.  If you use @code{xatexit} to register functions, you must use
 
 #include <stdio.h>
 
-#ifdef __STDC__
+#ifdef ANSI_PROTOTYPES
 #include <stddef.h>
 #else
 #define size_t unsigned long
diff --git a/libiberty/xmalloc.c b/libiberty/xmalloc.c
index 4c8249ae70bf..c3fe1a84f4d2 100644
--- a/libiberty/xmalloc.c
+++ b/libiberty/xmalloc.c
@@ -68,7 +68,7 @@ function will be called to print an error message and terminate execution.
 
 #include <stdio.h>
 
-#ifdef __STDC__
+#ifdef ANSI_PROTOTYPES
 #include <stddef.h>
 #else
 #define size_t unsigned long