Remove use of obsolescent Autoconf macros

Remove the use of the following macros, which are obsolescent according
to the Autoconf documentation:

- AC_C_CONST
- AC_C_STRINGIZE
- AC_C_VOLATILE
- AC_FUNC_MEMCMP

4 files changed, 3 insertions, 109 deletions

diff --git a/src/include/c.h b/src/include/c.h
index 6e19c6df878..beb20b0e6cb 100644
--- a/src/include/c.h
+++ b/src/include/c.h
@@ -130,28 +130,12 @@
  * CppConcat
  *		Concatenate two arguments together, using the C preprocessor.
  *
- * Note: the standard Autoconf macro AC_C_STRINGIZE actually only checks
- * whether #identifier works, but if we have that we likely have ## too.
+ * Note: There used to be support here for pre-ANSI C compilers that didn't
+ * support # and ##.  Nowadays, these macros are just for clarity and/or
+ * backward compatibility with existing PostgreSQL code.
  */
-#if defined(HAVE_STRINGIZE)
-
 #define CppAsString(identifier) #identifier
 #define CppConcat(x, y)			x##y
-#else							/* !HAVE_STRINGIZE */
-
-#define CppAsString(identifier) "identifier"
-
-/*
- * CppIdentity -- On Reiser based cpp's this is used to concatenate
- *		two tokens.  That is
- *				CppIdentity(A)B ==> AB
- *		We renamed it to _private_CppIdentity because it should not
- *		be referenced outside this file.  On other cpp's it
- *		produces  A  B.
- */
-#define _priv_CppIdentity(x)x
-#define CppConcat(x, y)			_priv_CppIdentity(x)y
-#endif   /* !HAVE_STRINGIZE */
 
 /*
  * dummyret is used to set return values in macros that use ?: to make
diff --git a/src/include/pg_config.h.in b/src/include/pg_config.h.in
index 5eac52d93a9..d482e58fe50 100644
--- a/src/include/pg_config.h.in
+++ b/src/include/pg_config.h.in
@@ -457,9 +457,6 @@
 /* Define to 1 if you have the `strerror_r' function. */
 #undef HAVE_STRERROR_R
 
-/* Define to 1 if cpp supports the ANSI # stringizing operator. */
-#undef HAVE_STRINGIZE
-
 /* Define to 1 if you have the <strings.h> header file. */
 #undef HAVE_STRINGS_H
 
@@ -839,9 +836,6 @@
 /* Define for large files, on AIX-style hosts. */
 #undef _LARGE_FILES
 
-/* Define to empty if `const' does not conform to ANSI C. */
-#undef const
-
 /* Define to `__inline__' or `__inline' if that's what the C compiler
    calls it, or to nothing if 'inline' is not supported under any name.  */
 #ifndef __cplusplus
@@ -858,7 +852,3 @@
 /* Define to the type of an unsigned integer type wide enough to hold a
    pointer, if such a type exists, and if the system does not define it. */
 #undef uintptr_t
-
-/* Define to empty if the keyword `volatile' does not work. Warning: valid
-   code using `volatile' can become incorrect without. Disable with care. */
-#undef volatile
diff --git a/src/include/pg_config.h.win32 b/src/include/pg_config.h.win32
index 54db287aff6..b69414fd484 100644
--- a/src/include/pg_config.h.win32
+++ b/src/include/pg_config.h.win32
@@ -360,9 +360,6 @@
 /* Define to 1 if you have the `strerror_r' function. */
 /* #undef HAVE_STRERROR_R */
 
-/* Define to 1 if cpp supports the ANSI # stringizing operator. */
-#define HAVE_STRINGIZE 1
-
 /* Define to 1 if you have the <strings.h> header file. */
 /*#define HAVE_STRINGS_H 1 */
 
@@ -674,9 +671,6 @@
 /* Define for large files, on AIX-style hosts. */
 /* #undef _LARGE_FILES */
 
-/* Define to empty if `const' does not conform to ANSI C. */
-/* #undef const */
-
 /* Define to `__inline__' or `__inline' if that's what the C compiler
    calls it, or to nothing if 'inline' is not supported under any name.  */
 #ifndef __cplusplus
@@ -685,7 +679,3 @@
 
 /* Define to empty if the C compiler does not understand signed types. */
 /* #undef signed */
-
-/* Define to empty if the keyword `volatile' does not work. Warning: valid
-   code using `volatile' can become incorrect without. Disable with care. */
-/* #undef volatile */
diff --git a/src/port/memcmp.c b/src/port/memcmp.c
deleted file mode 100644
index dc8fa4a7975..00000000000
--- a/src/port/memcmp.c
+++ /dev/null
@@ -1,70 +0,0 @@
-/*-------------------------------------------------------------------------
- *
- * memcmp.c
- *	  compares memory bytes
- *
- * Portions Copyright (c) 1996-2013, PostgreSQL Global Development Group
- *
- *
- * IDENTIFICATION
- *	  src/port/memcmp.c
- *
- * This file was taken from NetBSD and is used by SunOS because memcmp
- * on that platform does not properly compare negative bytes. The
- * NetBSD copyright terms follow.
- */
-
-/*-
- * Copyright (c) 1990, 1993
- *	The Regents of the University of California.  All rights reserved.
- *
- * This code is derived from software contributed to Berkeley by
- * Chris Torek.
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions
- * are met:
- * 1. Redistributions of source code must retain the above copyright
- *	  notice, this list of conditions and the following disclaimer.
- * 2. Redistributions in binary form must reproduce the above copyright
- *	  notice, this list of conditions and the following disclaimer in the
- *	  documentation and/or other materials provided with the distribution.
- * 3. Neither the name of the University nor the names of its contributors
- *	  may be used to endorse or promote products derived from this software
- *	  without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
- * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
- * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
- * ARE DISCLAIMED.	IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
- * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
- * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
- * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
- * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
- * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
- * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
- * SUCH DAMAGE.
- */
-
-#include "c.h"
-
-
-/*
- * Compare memory regions.
- */
-int
-memcmp(const void *s1, const void *s2, size_t n)
-{
-	if (n != 0)
-	{
-		const unsigned char *p1 = s1,
-				   *p2 = s2;
-
-		do
-		{
-			if (*p1++ != *p2++)
-				return (*--p1 - *--p2);
-		} while (--n != 0);
-	}
-	return 0;
-}