1 files changed, 54 insertions, 1 deletions
diff --git a/config/c-compiler.m4 b/config/c-compiler.m4
index a7f6773ae1..7275ea69fe 100644
--- a/config/c-compiler.m4
+++ b/config/c-compiler.m4
@@ -71,8 +71,10 @@ int does_int64_work()
     return 0;
   return 1;
 }
+
+int
 main() {
-  exit(! does_int64_work());
+  return (! does_int64_work());
 }])],
 [Ac_cachevar=yes],
 [Ac_cachevar=no],
@@ -176,6 +178,33 @@ fi])# PGAC_C_STATIC_ASSERT
 
 
 
+# PGAC_C_TYPEOF
+# -------------
+# Check if the C compiler understands typeof or a variant.  Define
+# HAVE_TYPEOF if so, and define 'typeof' to the actual key word.
+#
+AC_DEFUN([PGAC_C_TYPEOF],
+[AC_CACHE_CHECK(for typeof, pgac_cv_c_typeof,
+[pgac_cv_c_typeof=no
+for pgac_kw in typeof __typeof__ decltype; do
+  AC_COMPILE_IFELSE([AC_LANG_PROGRAM([],
+[int x = 0;
+$pgac_kw(x) y;
+y = x;
+return y;])],
+[pgac_cv_c_typeof=$pgac_kw])
+  test "$pgac_cv_c_typeof" != no && break
+done])
+if test "$pgac_cv_c_typeof" != no; then
+  AC_DEFINE(HAVE_TYPEOF, 1,
+            [Define to 1 if your compiler understands `typeof' or something similar.])
+  if test "$pgac_cv_c_typeof" != typeof; then
+    AC_DEFINE_UNQUOTED(typeof, $pgac_cv_c_typeof, [Define to how the compiler spells `typeof'.])
+  fi
+fi])# PGAC_C_TYPEOF
+
+
+
 # PGAC_C_TYPES_COMPATIBLE
 # -----------------------
 # Check if the C compiler understands __builtin_types_compatible_p,
@@ -271,6 +300,30 @@ fi])# PGAC_C_BUILTIN_UNREACHABLE
 
 
 
+# PGAC_C_COMPUTED_GOTO
+# -----------------------
+# Check if the C compiler knows computed gotos (gcc extension, also
+# available in at least clang).  If so, define HAVE_COMPUTED_GOTO.
+#
+# Checking whether computed gotos are supported syntax-wise ought to
+# be enough, as the syntax is otherwise illegal.
+AC_DEFUN([PGAC_C_COMPUTED_GOTO],
+[AC_CACHE_CHECK(for computed goto support, pgac_cv_computed_goto,
+[AC_COMPILE_IFELSE([AC_LANG_PROGRAM([],
+[[void *labeladdrs[] = {&&my_label};
+  goto *labeladdrs[0];
+  my_label:
+  return 1;
+]])],
+[pgac_cv_computed_goto=yes],
+[pgac_cv_computed_goto=no])])
+if test x"$pgac_cv_computed_goto" = xyes ; then
+AC_DEFINE(HAVE_COMPUTED_GOTO, 1,
+          [Define to 1 if your compiler handles computed gotos.])
+fi])# PGAC_C_COMPUTED_GOTO
+
+
+
 # PGAC_C_VA_ARGS
 # --------------
 # Check if the C compiler understands C99-style variadic macros,