ccan/compiler: add cpu_supports() macro.

[ccan] / ccan / compiler / compiler.h

diff --git a/ccan/compiler/compiler.h b/ccan/compiler/compiler.h
index fcb89c8f2a68a9aa90f5cba4746a98910c0a551d..1bbb3b8b61c6cb4a0fd44ab39e5bf7505eaa91bd 100644 (file)
--- a/ccan/compiler/compiler.h
+++ b/ccan/compiler/compiler.h
@@ -1,3 +1,4 @@
+/* CC0 (Public domain) - see LICENSE file for details */
 #ifndef CCAN_COMPILER_H
 #define CCAN_COMPILER_H
 #include "config.h"
@@ -16,7 +17,7 @@
  *     fprintf(stderr, "Error: %s (%s)\n", reason, strerror(errno));
  * }
  */
-#define COLD __attribute__((cold))
+#define COLD __attribute__((__cold__))
 #else
 #define COLD
 #endif
@@ -36,7 +37,7 @@
  *     exit(1);
  * }
  */
-#define NORETURN __attribute__((noreturn))
+#define NORETURN __attribute__((__noreturn__))
 #else
 #define NORETURN
 #endif
@@ -70,10 +71,24 @@
  * same value for the exact same arguments.  This implies that the function
  * must not use global variables, or dereference pointer arguments.
  */
-#define CONST_FUNCTION __attribute__((const))
+#define CONST_FUNCTION __attribute__((__const__))
 #else
 #define CONST_FUNCTION
 #endif
+
+#ifndef PURE_FUNCTION
+#if HAVE_ATTRIBUTE_PURE
+/**
+ * PURE_FUNCTION - a function is pure
+ *
+ * A pure function is one that has no side effects other than it's return value
+ * and uses no inputs other than it's arguments and global variables.
+ */
+#define PURE_FUNCTION __attribute__((__pure__))
+#else
+#define PURE_FUNCTION
+#endif
+#endif
 #endif
 
 #if HAVE_ATTRIBUTE_UNUSED
@@ -94,7 +109,7 @@
  *     counter += add;
  * }
  */
-#define UNNEEDED __attribute__((unused))
+#define UNNEEDED __attribute__((__unused__))
 #endif
 
 #ifndef NEEDED
@@ -113,10 +128,10 @@
  *             printf("Counter is %i\n", counter);
  *     }
  */
-#define NEEDED __attribute__((used))
+#define NEEDED __attribute__((__used__))
 #else
 /* Before used, unused functions and vars were always emitted. */
-#define NEEDED __attribute__((unused))
+#define NEEDED __attribute__((__unused__))
 #endif
 #endif
 
@@ -135,7 +150,7 @@
  *             return 0;
  *     }
  */
-#define UNUSED __attribute__((unused))
+#define UNUSED __attribute__((__unused__))
 #endif
 #else
 #ifndef UNNEEDED
@@ -208,9 +223,82 @@
  *     return realloc(buf, (*size) *= 2);
  * }
  */
-#define WARN_UNUSED_RESULT __attribute__((warn_unused_result))
+#define WARN_UNUSED_RESULT __attribute__((__warn_unused_result__))
 #else
 #define WARN_UNUSED_RESULT
 #endif
 #endif
+
+
+#if HAVE_ATTRIBUTE_DEPRECATED
+/**
+ * WARN_DEPRECATED - warn that a function/type/variable is deprecated when used.
+ *
+ * Used to mark a function, type or variable should not be used.
+ *
+ * Example:
+ * WARN_DEPRECATED char *oldfunc(char *buf);
+ */
+#define WARN_DEPRECATED __attribute__((__deprecated__))
+#else
+#define WARN_DEPRECATED
+#endif
+
+
+#if HAVE_ATTRIBUTE_NONNULL
+/**
+ * NO_NULL_ARGS - specify that no arguments to this function can be NULL.
+ *
+ * The compiler will warn if any pointer args are NULL.
+ *
+ * Example:
+ * NO_NULL_ARGS char *my_copy(char *buf);
+ */
+#define NO_NULL_ARGS __attribute__((__nonnull__))
+
+/**
+ * NON_NULL_ARGS - specify that some arguments to this function can't be NULL.
+ * @...: 1-based argument numbers for which args can't be NULL.
+ *
+ * The compiler will warn if any of the specified pointer args are NULL.
+ *
+ * Example:
+ * char *my_copy2(char *buf, char *maybenull) NON_NULL_ARGS(1);
+ */
+#define NON_NULL_ARGS(...) __attribute__((__nonnull__(__VA_ARGS__)))
+#else
+#define NO_NULL_ARGS
+#define NON_NULL_ARGS(...)
+#endif
+
+
+#if HAVE_ATTRIBUTE_SENTINEL
+/**
+ * LAST_ARG_NULL - specify the last argument of a variadic function must be NULL.
+ *
+ * The compiler will warn if the last argument isn't NULL.
+ *
+ * Example:
+ * char *join_string(char *buf, ...) LAST_ARG_NULL;
+ */
+#define LAST_ARG_NULL __attribute__((__sentinel__))
+#else
+#define LAST_ARG_NULL
+#endif
+
+#if HAVE_BUILTIN_CPU_SUPPORTS
+/**
+ * cpu_supports - test if current CPU supports the named feature.
+ *
+ * This takes a literal string, and currently only works on glibc platforms.
+ *
+ * Example:
+ * if (cpu_supports("mmx"))
+ *     printf("MMX support engaged!\n");
+ */
+#define cpu_supports(x) __builtin_cpu_supports(x)
+#else
+#define cpu_supports(x) 0
+#endif /* HAVE_BUILTIN_CPU_SUPPORTS */
+
 #endif /* CCAN_COMPILER_H */