Declare fast forward from 3.1-2

[kerberos/krb5-strength.git] / portable / macros.h

diff --git a/portable/macros.h b/portable/macros.h
index 8d5adbdf9c2227e5c6a76bbe94e3b74393d7cfb2..5d77fb75af7bd8465308dc4cac47d4f53a9ab08f 100644 (file)
--- a/portable/macros.h
+++ b/portable/macros.h
@@ -1,8 +1,20 @@
 /*
  * Portability macros used in include files.
  *
- * Written by Russ Allbery <rra@stanford.edu>
- * This work is hereby placed in the public domain by its author.
+ * The canonical version of this file is maintained in the rra-c-util package,
+ * which can be found at <https://www.eyrie.org/~eagle/software/rra-c-util/>.
+ *
+ * Written by Russ Allbery <eagle@eyrie.org>
+ * Copyright 2015 Russ Allbery <eagle@eyrie.org>
+ * Copyright 2008, 2011-2012
+ *     The Board of Trustees of the Leland Stanford Junior University
+ *
+ * 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.
+ *
+ * SPDX-License-Identifier: FSFAP
  */
 
 #ifndef PORTABLE_MACROS_H
@@ -14,9 +26,33 @@
  * (to avoid confusion with other macros).
  */
 #ifndef __attribute__
-# if __GNUC__ < 2 || (__GNUC__ == 2 && __GNUC_MINOR__ < 7)
-#  define __attribute__(spec)   /* empty */
-# endif
+#    if __GNUC__ < 2 || (__GNUC__ == 2 && __GNUC_MINOR__ < 7)
+#        define __attribute__(spec) /* empty */
+#    endif
+#endif
+
+/*
+ * We use __alloc_size__, but it was only available in fairly recent versions
+ * of GCC.  Suppress warnings about the unknown attribute if GCC is too old.
+ * We know that we're GCC at this point, so we can use the GCC variadic macro
+ * extension, which will still work with versions of GCC too old to have C99
+ * variadic macro support.
+ */
+#if !defined(__attribute__) && !defined(__alloc_size__)
+#    if (__GNUC__ < 4 || (__GNUC__ == 4 && __GNUC_MINOR__ < 3)) \
+        && !defined(__clang__)
+#        define __alloc_size__(spec, args...) /* empty */
+#    endif
+#endif
+
+/*
+ * LLVM and Clang pretend to be GCC but don't support all of the __attribute__
+ * settings that GCC does.  For them, suppress warnings about unknown
+ * attributes on declarations.  This unfortunately will affect the entire
+ * compilation context, but there's no push and pop available.
+ */
+#if !defined(__attribute__) && (defined(__llvm__) || defined(__clang__))
+#    pragma GCC diagnostic ignored "-Wattributes"
 #endif
 
 /*
@@ -26,11 +62,11 @@
 #undef BEGIN_DECLS
 #undef END_DECLS
 #ifdef __cplusplus
-# define BEGIN_DECLS    extern "C" {
-# define END_DECLS      }
+#    define BEGIN_DECLS extern "C" {
+#    define END_DECLS   }
 #else
-# define BEGIN_DECLS    /* empty */
-# define END_DECLS      /* empty */
+#    define BEGIN_DECLS /* empty */
+#    define END_DECLS   /* empty */
 #endif
 
 #endif /* !PORTABLE_MACROS_H */