From 8ecba1ad26d4e75fc26a176f3e3eaca92c1d049b Mon Sep 17 00:00:00 2001
From: Gregory Maxwell <greg@xiph.org>
Date: Mon, 14 May 2012 01:58:05 -0400
Subject: [PATCH] Make vararray and restrict checks fail GCC 2.95.3's broken
implementation.
---
configure.ac | 45 ++++++++++++++++++++++++++++++++++++++++-----
1 file changed, 40 insertions(+), 5 deletions(-)
diff --git a/configure.ac b/configure.ac
index df65008c7..1e3068fc1 100644
--- a/configure.ac
+++ b/configure.ac
@@ -51,15 +51,50 @@ AC_PROG_CC_C99
AC_C_BIGENDIAN
AC_C_CONST
AC_C_INLINE
-AC_C_RESTRICT
+
+#Use a hacked up version of autoconf's AC_C_RESTRICT because it's not
+#strong enough a test to detect old buggy versions of GCC (e.g. 2.95.3)
+AC_CACHE_CHECK([for C/C++ restrict keyword], ac_cv_c_restrict,
+ [ac_cv_c_restrict=no
+ # The order here caters to the fact that C++ does not require restrict.
+ for ac_kw in __restrict __restrict__ _Restrict restrict; do
+ AC_COMPILE_IFELSE([AC_LANG_PROGRAM(
+ [[typedef int * int_ptr;
+ int foo (int_ptr $ac_kw ip, int * $ac_kw baz[]) {
+ return ip[0];
+ }]],
+ [[int s[1];
+ int * $ac_kw t = s;
+ t[0] = 0;
+ return foo(t, (void *)0)]])],
+ [ac_cv_c_restrict=$ac_kw])
+ test "$ac_cv_c_restrict" != no && break
+ done
+ ])
+ AH_VERBATIM([restrict],
+[/* Define to the equivalent of the C99 'restrict' keyword, or to
+ nothing if this is not supported. Do not define if restrict is
+ supported directly. */
+#undef restrict
+/* Work around a bug in Sun C++: it does not support _Restrict or
+ __restrict__, even though the corresponding Sun C compiler ends up with
+ "#define restrict _Restrict" or "#define restrict __restrict__" in the
+ previous line. Perhaps some future version of Sun C++ will work with
+ restrict; if so, hopefully it defines __RESTRICT like Sun C does. */
+#if defined __SUNPRO_CC && !defined __RESTRICT
+# define _Restrict
+# define __restrict__
+#endif])
+ case $ac_cv_c_restrict in
+ restrict) ;;
+ no) AC_DEFINE([restrict], []) ;;
+ *) AC_DEFINE_UNQUOTED([restrict], [$ac_cv_c_restrict]) ;;
+ esac
AC_DEFINE([OPUS_BUILD], [], [This is a build of OPUS])
AC_MSG_CHECKING(for C99 variable-size arrays)
-AC_TRY_COMPILE( , [
-int foo=10;
-int array[foo];
-],
+AC_TRY_COMPILE( [], [static int x; char a[++x]; a[sizeof a - 1] = 0; int N; return a[0];],
[has_var_arrays=yes;AC_DEFINE([VAR_ARRAYS], [], [Use C99 variable-size arrays])
],
has_var_arrays=no
--
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