X-Git-Url: https://ruderich.org/simon/gitweb/?a=blobdiff_plain;f=configure.ac;h=3b007c5d29b51404c86d151d222ea5136acf31c5;hb=0a2617527c9b46a587a8f34571a54347cd5c4b5a;hp=a5279d06ef0dd6d1648bdd71c0beab43b7308b56;hpb=b22a078b8de5bfb84866d4f1e165b604279fe9f9;p=coloredstderr%2Fcoloredstderr.git

diff --git a/configure.ac b/configure.ac
index a5279d0..3b007c5 100644
--- a/configure.ac
+++ b/configure.ac
@@ -32,17 +32,30 @@ dnl Used by test suite.
 AC_PROG_SED
 AC_PROG_EGREP
 
-AC_CHECK_HEADERS([fcntl.h])
+if test "x$GCC" = xyes; then
+    CFLAGS="-Wall -Wextra -Wconversion $CFLAGS"
+fi
+
+AC_CHECK_HEADERS([fcntl.h error.h])
 
 AC_TYPE_PID_T
 AC_TYPE_SIZE_T
 AC_TYPE_SSIZE_T
 
 AC_C_INLINE
+AX_C___ATTRIBUTE__
 
 AC_FUNC_FORK
 AC_CHECK_FUNCS([dup2 memmove setenv strdup])
 
+dnl Thanks to gperftools' configure.ac (https://code.google.com/p/gperftools).
+AC_MSG_CHECKING([for __builtin_expect])
+AC_LINK_IFELSE([AC_LANG_PROGRAM([],[return __builtin_expect(main != 0, 1)])],
+               [AC_DEFINE([HAVE___BUILTIN_EXPECT], 1,
+                          [Define to 1 if the compiler supports __builtin_expect().])
+                AC_MSG_RESULT([yes])],
+               [AC_MSG_RESULT([no])])
+
 AC_SEARCH_LIBS([dlsym], [dl], [], [AC_MSG_ERROR([dlsym() is required])])
 
 AC_ARG_ENABLE([debug],
@@ -51,5 +64,8 @@ AC_ARG_ENABLE([debug],
                    AC_DEFINE([DEBUG], 1, [Define to enable debug output.])
                fi])
 
+dnl Used in tests/Makefile.am to build the test only if error() is available.
+AM_CONDITIONAL([HAVE_ERROR_H],[test "x$ac_cv_header_error_h" = xyes])
+
 AC_CONFIG_FILES([Makefile src/Makefile tests/Makefile])
 AC_OUTPUT