+/* CC0 (Public domain) - see LICENSE file for details */
#ifndef CCAN_COMPILER_H
#define CCAN_COMPILER_H
#include "config.h"
+#ifndef COLD
#if HAVE_ATTRIBUTE_COLD
/**
- * COLD_ATTRIBUTE - a function is unlikely to be called.
+ * COLD - a function is unlikely to be called.
*
* Used to mark an unlikely code path and optimize appropriately.
* It is usually used on logging or error routines.
*
* Example:
- * static void COLD_ATTRIBUTE moan(const char *reason)
+ * static void COLD moan(const char *reason)
* {
* fprintf(stderr, "Error: %s (%s)\n", reason, strerror(errno));
* }
*/
-#define COLD_ATTRIBUTE __attribute__((cold))
+#define COLD __attribute__((__cold__))
#else
-#define COLD_ATTRIBUTE
+#define COLD
+#endif
+#endif
+
+#ifndef NORETURN
+#if HAVE_ATTRIBUTE_NORETURN
+/**
+ * NORETURN - a function does not return
+ *
+ * Used to mark a function which exits; useful for suppressing warnings.
+ *
+ * Example:
+ * static void NORETURN fail(const char *reason)
+ * {
+ * fprintf(stderr, "Error: %s (%s)\n", reason, strerror(errno));
+ * exit(1);
+ * }
+ */
+#define NORETURN __attribute__((__noreturn__))
+#else
+#define NORETURN
+#endif
#endif
+#ifndef PRINTF_FMT
#if HAVE_ATTRIBUTE_PRINTF
/**
- * PRINTF_ATTRIBUTE - a function takes printf-style arguments
+ * PRINTF_FMT - a function takes printf-style arguments
* @nfmt: the 1-based number of the function's format argument.
* @narg: the 1-based number of the function's first variable argument.
*
* This allows the compiler to check your parameters as it does for printf().
*
* Example:
- * void PRINTF_ATTRIBUTE(2,3) my_printf(const char *prefix,
- * const char *fmt, ...);
+ * void PRINTF_FMT(2,3) my_printf(const char *prefix, const char *fmt, ...);
*/
-#define PRINTF_ATTRIBUTE(nfmt, narg) \
+#define PRINTF_FMT(nfmt, narg) \
__attribute__((format(__printf__, nfmt, narg)))
#else
-#define PRINTF_ATTRIBUTE(nfmt, narg)
+#define PRINTF_FMT(nfmt, narg)
+#endif
#endif
+#ifndef CONST_FUNCTION
#if HAVE_ATTRIBUTE_CONST
/**
- * IDEMPOTENT_ATTRIBUTE - a function's return depends only on its argument
+ * CONST_FUNCTION - a function's return depends only on its argument
*
* This allows the compiler to assume that the function will return the exact
* same value for the exact same arguments. This implies that the function
* must not use global variables, or dereference pointer arguments.
*/
-#define IDEMPOTENT_ATTRIBUTE __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 IDEMPOTENT_ATTRIBUTE
+#define PURE_FUNCTION
+#endif
+#endif
#endif
#if HAVE_ATTRIBUTE_UNUSED
+#ifndef UNNEEDED
/**
- * UNNEEDED_ATTRIBUTE - a parameter/variable/function may not be needed
+ * UNNEEDED - a variable/function may not be needed
*
- * This suppresses warnings about unused variables or parameters, but tells
+ * This suppresses warnings about unused variables or functions, but tells
* the compiler that if it is unused it need not emit it into the source code.
*
* Example:
* // With some preprocessor options, this is unnecessary.
- * static UNNEEDED_ATTRIBUTE int counter;
+ * static UNNEEDED int counter;
*
* // With some preprocessor options, this is unnecessary.
- * static UNNEEDED_ATTRIBUTE void add_to_counter(int add)
+ * static UNNEEDED void add_to_counter(int add)
* {
* counter += add;
* }
*/
-#define UNNEEDED_ATTRIBUTE __attribute__((unused))
+#define UNNEEDED __attribute__((__unused__))
+#endif
+#ifndef NEEDED
#if HAVE_ATTRIBUTE_USED
/**
- * NEEDED_ATTRIBUTE - a parameter/variable/function is needed
+ * NEEDED - a variable/function is needed
*
- * This suppresses warnings about unused variables or parameters, but tells
+ * This suppresses warnings about unused variables or functions, but tells
* the compiler that it must exist even if it (seems) unused.
*
* Example:
* // Even if this is unused, these are vital for debugging.
- * static UNNEEDED_ATTRIBUTE int counter;
- * static UNNEEDED_ATTRIBUTE void dump_counter(void)
+ * static NEEDED int counter;
+ * static NEEDED void dump_counter(void)
* {
* printf("Counter is %i\n", counter);
* }
*/
-#define NEEDED_ATTRIBUTE __attribute__((used))
+#define NEEDED __attribute__((__used__))
#else
/* Before used, unused functions and vars were always emitted. */
-#define NEEDED_ATTRIBUTE __attribute__((unused))
+#define NEEDED __attribute__((__unused__))
+#endif
+#endif
+
+#ifndef UNUSED
+/**
+ * UNUSED - a parameter is unused
+ *
+ * Some compilers (eg. gcc with -W or -Wunused) warn about unused
+ * function parameters. This suppresses such warnings and indicates
+ * to the reader that it's deliberate.
+ *
+ * Example:
+ * // This is used as a callback, so needs to have this prototype.
+ * static int some_callback(void *unused UNUSED)
+ * {
+ * return 0;
+ * }
+ */
+#define UNUSED __attribute__((__unused__))
#endif
#else
-#define UNNEEDED_ATTRIBUTE
-#define NEEDED_ATTRIBUTE
+#ifndef UNNEEDED
+#define UNNEEDED
+#endif
+#ifndef NEEDED
+#define NEEDED
+#endif
+#ifndef UNUSED
+#define UNUSED
+#endif
#endif
+#ifndef IS_COMPILE_CONSTANT
#if HAVE_BUILTIN_CONSTANT_P
/**
* IS_COMPILE_CONSTANT - does the compiler know the value of this expression?
* const char *greek_name(enum greek greek);
*
* // Inline version.
- * static inline char *_greek_name(enum greek greek)
+ * static inline const char *_greek_name(enum greek greek)
* {
* switch (greek) {
* case ALPHA: return "alpha";
/* If we don't know, assume it's not. */
#define IS_COMPILE_CONSTANT(expr) 0
#endif
+#endif
+#ifndef WARN_UNUSED_RESULT
#if HAVE_WARN_UNUSED_RESULT
/**
* WARN_UNUSED_RESULT - warn if a function return value is unused.
* 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 */
projects / ccan / blobdiff