mesa: Replace a priori knowledge of gcc attributes with configure tests.

Note that I had to add support for testing the packed attribute to
m4/ax_gcc_func_attribute.m4.

Reviewed-by: Jason Ekstrand <jason.ekstrand@intel.com> [C bits]
Reviewed-by: Ian Romanick <ian.d.romanick@intel.com>

5 files changed, 240 insertions, 10 deletions

diff --git a/configure.ac b/configure.ac
index db134a2f35..13b339eaaf 100644
--- a/configure.ac
+++ b/configure.ac
@@ -140,6 +140,10 @@ AX_GCC_BUILTIN([__builtin_popcount])
 AX_GCC_BUILTIN([__builtin_popcountll])
 AX_GCC_BUILTIN([__builtin_unreachable])
 
+AX_GCC_FUNC_ATTRIBUTE([flatten])
+AX_GCC_FUNC_ATTRIBUTE([format])
+AX_GCC_FUNC_ATTRIBUTE([packed])
+
 AM_CONDITIONAL([GEN_ASM_OFFSETS], test "x$GEN_ASM_OFFSETS" = xyes)
 
 dnl Make sure the pkg-config macros are defined
diff --git a/m4/ax_gcc_func_attribute.m4 b/m4/ax_gcc_func_attribute.m4
new file mode 100644
index 0000000000..4e0ecbb56c
--- /dev/null
+++ b/m4/ax_gcc_func_attribute.m4
@@ -0,0 +1,223 @@
+# ===========================================================================
+#   http://www.gnu.org/software/autoconf-archive/ax_gcc_func_attribute.html
+# ===========================================================================
+#
+# SYNOPSIS
+#
+#   AX_GCC_FUNC_ATTRIBUTE(ATTRIBUTE)
+#
+# DESCRIPTION
+#
+#   This macro checks if the compiler supports one of GCC's function
+#   attributes; many other compilers also provide function attributes with
+#   the same syntax. Compiler warnings are used to detect supported
+#   attributes as unsupported ones are ignored by default so quieting
+#   warnings when using this macro will yield false positives.
+#
+#   The ATTRIBUTE parameter holds the name of the attribute to be checked.
+#
+#   If ATTRIBUTE is supported define HAVE_FUNC_ATTRIBUTE_<ATTRIBUTE>.
+#
+#   The macro caches its result in the ax_cv_have_func_attribute_<attribute>
+#   variable.
+#
+#   The macro currently supports the following function attributes:
+#
+#    alias
+#    aligned
+#    alloc_size
+#    always_inline
+#    artificial
+#    cold
+#    const
+#    constructor
+#    deprecated
+#    destructor
+#    dllexport
+#    dllimport
+#    error
+#    externally_visible
+#    flatten
+#    format
+#    format_arg
+#    gnu_inline
+#    hot
+#    ifunc
+#    leaf
+#    malloc
+#    noclone
+#    noinline
+#    nonnull
+#    noreturn
+#    nothrow
+#    optimize
+#    packed
+#    pure
+#    unused
+#    used
+#    visibility
+#    warning
+#    warn_unused_result
+#    weak
+#    weakref
+#
+#   Unsuppored function attributes will be tested with a prototype returning
+#   an int and not accepting any arguments and the result of the check might
+#   be wrong or meaningless so use with care.
+#
+# LICENSE
+#
+#   Copyright (c) 2013 Gabriele Svelto <gabriele.svelto@gmail.com>
+#
+#   Copying and distribution of this file, with or without modification, are
+#   permitted in any medium without royalty provided the copyright notice
+#   and this notice are preserved.  This file is offered as-is, without any
+#   warranty.
+
+#serial 2
+
+AC_DEFUN([AX_GCC_FUNC_ATTRIBUTE], [
+    AS_VAR_PUSHDEF([ac_var], [ax_cv_have_func_attribute_$1])
+
+    AC_CACHE_CHECK([for __attribute__(($1))], [ac_var], [
+        AC_LINK_IFELSE([AC_LANG_PROGRAM([
+            m4_case([$1],
+                [alias], [
+                    int foo( void ) { return 0; }
+                    int bar( void ) __attribute__(($1("foo")));
+                ],
+                [aligned], [
+                    int foo( void ) __attribute__(($1(32)));
+                ],
+                [alloc_size], [
+                    void *foo(int a) __attribute__(($1(1)));
+                ],
+                [always_inline], [
+                    inline __attribute__(($1)) int foo( void ) { return 0; }
+                ],
+                [artificial], [
+                    inline __attribute__(($1)) int foo( void ) { return 0; }
+                ],
+                [cold], [
+                    int foo( void ) __attribute__(($1));
+                ],
+                [const], [
+                    int foo( void ) __attribute__(($1));
+                ],
+                [constructor], [
+                    int foo( void ) __attribute__(($1));
+                ],
+                [deprecated], [
+                    int foo( void ) __attribute__(($1("")));
+                ],
+                [destructor], [
+                    int foo( void ) __attribute__(($1));
+                ],
+                [dllexport], [
+                    __attribute__(($1)) int foo( void ) { return 0; }
+                ],
+                [dllimport], [
+                    int foo( void ) __attribute__(($1));
+                ],
+                [error], [
+                    int foo( void ) __attribute__(($1("")));
+                ],
+                [externally_visible], [
+                    int foo( void ) __attribute__(($1));
+                ],
+                [flatten], [
+                    int foo( void ) __attribute__(($1));
+                ],
+                [format], [
+                    int foo(const char *p, ...) __attribute__(($1(printf, 1, 2)));
+                ],
+                [format_arg], [
+                    char *foo(const char *p) __attribute__(($1(1)));
+                ],
+                [gnu_inline], [
+                    inline __attribute__(($1)) int foo( void ) { return 0; }
+                ],
+                [hot], [
+                    int foo( void ) __attribute__(($1));
+                ],
+                [ifunc], [
+                    int my_foo( void ) { return 0; }
+                    static int (*resolve_foo(void))(void) { return my_foo; }
+                    int foo( void ) __attribute__(($1("resolve_foo")));
+                ],
+                [leaf], [
+                    __attribute__(($1)) int foo( void ) { return 0; }
+                ],
+                [malloc], [
+                    void *foo( void ) __attribute__(($1));
+                ],
+                [noclone], [
+                    int foo( void ) __attribute__(($1));
+                ],
+                [noinline], [
+                    __attribute__(($1)) int foo( void ) { return 0; }
+                ],
+                [nonnull], [
+                    int foo(char *p) __attribute__(($1(1)));
+                ],
+                [noreturn], [
+                    void foo( void ) __attribute__(($1));
+                ],
+                [nothrow], [
+                    int foo( void ) __attribute__(($1));
+                ],
+                [optimize], [
+                    __attribute__(($1(3))) int foo( void ) { return 0; }
+                ],
+                [packed], [
+                    struct __attribute__(($1)) foo { int bar; };
+                ],
+                [pure], [
+                    int foo( void ) __attribute__(($1));
+                ],
+                [unused], [
+                    int foo( void ) __attribute__(($1));
+                ],
+                [used], [
+                    int foo( void ) __attribute__(($1));
+                ],
+                [visibility], [
+                    int foo_def( void ) __attribute__(($1("default")));
+                    int foo_hid( void ) __attribute__(($1("hidden")));
+                    int foo_int( void ) __attribute__(($1("internal")));
+                    int foo_pro( void ) __attribute__(($1("protected")));
+                ],
+                [warning], [
+                    int foo( void ) __attribute__(($1("")));
+                ],
+                [warn_unused_result], [
+                    int foo( void ) __attribute__(($1));
+                ],
+                [weak], [
+                    int foo( void ) __attribute__(($1));
+                ],
+                [weakref], [
+                    static int foo( void ) { return 0; }
+                    static int bar( void ) __attribute__(($1("foo")));
+                ],
+                [
+                 m4_warn([syntax], [Unsupported attribute $1, the test may fail])
+                 int foo( void ) __attribute__(($1));
+                ]
+            )], [])
+            ],
+            dnl GCC doesn't exit with an error if an unknown attribute is
+            dnl provided but only outputs a warning, so accept the attribute
+            dnl only if no warning were issued.
+            [AS_IF([test -s conftest.err],
+                [AS_VAR_SET([ac_var], [no])],
+                [AS_VAR_SET([ac_var], [yes])])],
+            [AS_VAR_SET([ac_var], [no])])
+    ])
+
+    AS_IF([test yes = AS_VAR_GET([ac_var])],
+        [AC_DEFINE_UNQUOTED(AS_TR_CPP(HAVE_FUNC_ATTRIBUTE_$1), 1,
+            [Define to 1 if the system has the `$1' function attribute])], [])
+
+    AS_VAR_POPDEF([ac_var])
+])
diff --git a/scons/gallium.py b/scons/gallium.py
index ef6df1ae1a..dd5ca56a2d 100755
--- a/scons/gallium.py
+++ b/scons/gallium.py
@@ -589,7 +589,13 @@ def generate(env):
             'HAVE___BUILTIN_EXPECT',
             'HAVE___BUILTIN_FFS',
             'HAVE___BUILTIN_FFSLL',
+            'HAVE_FUNC_ATTRIBUTE_FLATTEN',
         ]
+        if distutils.version.LooseVersion(ccversion) >= distutils.version.LooseVersion('3'):
+            cppdefines += [
+                'HAVE_FUNC_ATTRIBUTE_FORMAT',
+                'HAVE_FUNC_ATTRIBUTE_PACKED',
+            ]
         if distutils.version.LooseVersion(ccversion) >= distutils.version.LooseVersion('3.4'):
             cppdefines += [
                 'HAVE___BUILTIN_CTZ',
diff --git a/src/mesa/drivers/dri/i965/intel_tex_subimage.c b/src/mesa/drivers/dri/i965/intel_tex_subimage.c
index a121816dce..cb5738a938 100644
--- a/src/mesa/drivers/dri/i965/intel_tex_subimage.c
+++ b/src/mesa/drivers/dri/i965/intel_tex_subimage.c
@@ -334,12 +334,6 @@ ytile_copy(
    }
 }
 
-#ifdef __GNUC__
-#define FLATTEN __attribute__((flatten))
-#else
-#define FLATTEN
-#endif
-
 /**
  * Copy texture data from linear to X tile layout, faster.
  *
diff --git a/src/util/macros.h b/src/util/macros.h
index 2e2f90f587..a9867b4135 100644
--- a/src/util/macros.h
+++ b/src/util/macros.h
@@ -75,24 +75,27 @@ do {                        \
 #define unreachable(str)
 #endif
 
+#ifdef HAVE_FUNC_ATTRIBUTE_FLATTEN
+#define FLATTEN __attribute__((__flatten__))
+#else
+#define FLATTEN
+#endif
 
-#if (__GNUC__ >= 3)
+#ifdef HAVE_FUNC_ATTRIBUTE_FORMAT
 #define PRINTFLIKE(f, a) __attribute__ ((format(__printf__, f, a)))
 #else
 #define PRINTFLIKE(f, a)
 #endif
 
-
 /* Used to optionally mark structures with misaligned elements or size as
  * packed, to trade off performance for space.
  */
-#if (__GNUC__ >= 3)
+#ifdef HAVE_FUNC_ATTRIBUTE_PACKED
 #define PACKED __attribute__((__packed__))
 #else
 #define PACKED
 #endif
 
-
 #ifdef __cplusplus
 /**
  * Macro function that evaluates to true if T is a trivially