* Don't use __attribute__ if not using GNU C.

git-svn-id: svn://svn.zoy.org/elk/trunk@99 55e467fa-43c5-0310-a8a2-de718669efc6

configure.ac

@@ -353,10 +353,22 @@ AC_CHECK_LIB(gdbm, gdbm_open, ac_cv_have_gdbm=yes)
 AM_CONDITIONAL(HAVE_GDBM, test "${ac_cv_have_gdbm}" = "yes")
 
 dnl
-dnl  Check for available warning flags
+dnl  Check for available compiler features
 dnl
 CFLAGS_save="${CFLAGS}"
 
+AC_CACHE_CHECK([__attribute__ ((noreturn)) support with function pointers],
+  [ac_cv_c_attribute_noreturn],
+  [ac_cv_c_attribute_noreturn=no
+    CFLAGS="${CFLAGS_save} -Werror"
+    AC_TRY_COMPILE([],
+    [extern void foobar() __attribute__ ((noreturn));],
+    [ac_cv_c_attribute_noreturn=yes])
+    CFLAGS="${CFLAGS_save}"])
+if test "${ac_cv_c_attribute_noreturn}" != "no"; then
+  AC_DEFINE(HAVE_ATTRIBUTE_NORETURN, 1, Support for __attribute__((noreturn)))
+fi
+
 AC_CACHE_CHECK([if \$CC accepts -Wall],
   [ac_cv_c_Wall],
   [CFLAGS="-Wall ${CFLAGS_save}"

include/extern.h

@@ -109,8 +109,13 @@ extern Object The_Environment, Global_Environment;
 
 /* Error handling
  */
+#ifdef HAVE_ATTRIBUTE_NORETURN
 extern void Primitive_Error P_((const char*, ...)) __attribute__ ((__noreturn__));
 extern void Fatal_Error P_((const char*, ...)) __attribute__ ((__noreturn__));
+#else
+extern void Primitive_Error P_((const char*, ...));
+extern void Fatal_Error P_((const char*, ...));
+#endif
 extern void Range_Error P_((Object));
 extern void Panic P_((const char*));
 extern Object P_Error P_((int, Object*));
@@ -468,9 +473,14 @@ extern void Terminate_Type P_((int));
  */
 extern TYPEDESCR *Types;
 extern Object P_Type P_((Object));
+#ifdef HAVE_ATTRIBUTE_NORETURN
 extern void Wrong_Type P_((Object, int)) __attribute__ ((__noreturn__));
 extern void Wrong_Type_Combination P_((Object, const char*))
     __attribute__ ((__noreturn__));
+#else
+extern void Wrong_Type P_((Object, int));
+extern void Wrong_Type_Combination P_((Object, const char*));
+#endif
 extern int Define_Type P_((int, const char*, int (*)(Object), int,
     int (*)(Object, Object), int (*)(Object, Object),
     int (*)(Object, Object, int, int, int),

src/error.c

@@ -34,8 +34,13 @@
 
 #include "kernel.h"
 
+#ifdef HAVE_ATTRIBUTE_NORETURN
 void Reset () __attribute__ ((__noreturn__));
 void Err_Handler () __attribute__ ((__noreturn__));
+#else
+void Reset ();
+void Err_Handler ();
+#endif
 
 Object Arg_True;
 

src/exception.c

@@ -32,7 +32,11 @@
 
 #include <stdlib.h>
 
+#ifdef HAVE_ATTRIBUTE_NORETURN
 extern void Reset () __attribute__ ((__noreturn__));
+#else
+extern void Reset ();
+#endif
 
 int Intr_Was_Ignored;
 unsigned long int Intr_Level;

src/libelk.c

@@ -120,7 +120,11 @@ void Exit_Handler () {
 #ifndef HAVE_ATEXIT
 /* Hack: __GNUC_MINOR__ was introduced together with __attribute__ */
 #ifdef __GNUC_MINOR__
+#ifdef HAVE_ATTRIBUTE_NORETURN
 extern void _exit() __attribute__ ((noreturn));
+#else
+extern void _exit();
+#endif
 #endif
 #ifndef PROFILING
 void exit (n) {

src/proc.c

@@ -55,8 +55,12 @@
 extern void Switch_Environment (Object);
 extern unsigned int Stack_Size ();
 extern void Uncatchable_Error (char *);
+#ifdef HAVE_ATTRIBUTE_NORETURN
 extern void Funcall_Control_Point (Object, Object, int)
         __attribute__ ((__noreturn__));
+#else
+extern void Funcall_Control_Point (Object, Object, int);
+#endif
 extern void Pop_Frame ();
 extern void Push_Frame (Object);
 

src/read.c

@@ -52,7 +52,11 @@ extern char *index();
 extern double atof();
 
 int Skip_Comment (Object);
+#ifdef HAVE_ATTRIBUTE_NORETURN
 void Reader_Error (Object, char *) __attribute__ ((__noreturn__));
+#else
+void Reader_Error (Object, char *);
+#endif
 
 Object Sym_Quote,
        Sym_Quasiquote,