#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:
- * void COLD_ATTRIBUTE moan(const char *reason)
- * {
- * fprintf(stderr, "Error: %s (%s)\n", reason, strerror(errno));
- * }
+ * 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
- * nfmt: the 1-based number of the function's format argument.
- * narg: the 1-based number of the function's first variable argument.
+ * 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(char *prefix, char *format, ...);
+ * 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 IDEMPOTENT_ATTRIBUTE
+#define CONST_FUNCTION
+#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 config options, this is unnecessary.
- * static UNNEEDED_ATTRIBUTE int counter;
- * ...
- * #ifdef DEBUG
- * counter++;
- * #endif
- * ...
- * // With some config options, this is unnecessary.
- * static UNNEEDED_ATTRIBUTE int add_to_counter(int add)
- * {
- * counter += add;
- * }
+ * // With some preprocessor options, this is unnecessary.
+ * static UNNEEDED int counter;
+ *
+ * // With some preprocessor options, this is unnecessary.
+ * 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 _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.
+ *
+ * Used to mark a function where it is extremely unlikely that the caller
+ * can ignore the result, eg realloc().
+ *
+ * Example:
+ * // buf param may be freed by this; need return value!
+ * static char *WARN_UNUSED_RESULT enlarge(char *buf, unsigned *size)
+ * {
+ * return realloc(buf, (*size) *= 2);
+ * }
+ */
+#define WARN_UNUSED_RESULT __attribute__((warn_unused_result))
+#else
+#define WARN_UNUSED_RESULT
+#endif
+#endif
#endif /* CCAN_COMPILER_H */
projects / ccan / blobdiff