Document av_lfg_get().

[ffmpeg] / libavutil / mem.h

diff --git a/libavutil/mem.h b/libavutil/mem.h
index 04f25720011762befc6aa24532cfc93a03e83a13..84d647d8ead861962c1b9751f75b188f85fc5350 100644 (file)
--- a/libavutil/mem.h
+++ b/libavutil/mem.h
@@ -26,34 +26,78 @@
 #ifndef FFMPEG_MEM_H
 #define FFMPEG_MEM_H
 
-#ifdef __GNUC__
-  #define DECLARE_ALIGNED(n,t,v)       t v __attribute__ ((aligned (n)))
+#ifdef __ICC
+    #define DECLARE_ALIGNED(n,t,v)      t v __attribute__ ((aligned (n)))
+    #define DECLARE_ASM_CONST(n,t,v)    const t __attribute__ ((aligned (n))) v
+#elif defined(__GNUC__)
+    #define DECLARE_ALIGNED(n,t,v)      t v __attribute__ ((aligned (n)))
+    #define DECLARE_ASM_CONST(n,t,v)    static const t v attribute_used __attribute__ ((aligned (n)))
+#elif defined(_MSC_VER)
+    #define DECLARE_ALIGNED(n,t,v)      __declspec(align(n)) t v
+    #define DECLARE_ASM_CONST(n,t,v)    __declspec(align(n)) static const t v
+#elif defined(HAVE_INLINE_ASM)
+    #error The asm code needs alignment, but we do not know how to do it for this compiler.
 #else
-  #define DECLARE_ALIGNED(n,t,v)      __declspec(align(n)) t v
+    #define DECLARE_ALIGNED(n,t,v)      t v
+    #define DECLARE_ASM_CONST(n,t,v)    static const t v
+#endif
+
+#if defined(__GNUC__) && (__GNUC__ > 3 || __GNUC__ == 3 && __GNUC_MINOR__ > 0)
+    #define av_malloc_attrib __attribute__((__malloc__))
+#else
+    #define av_malloc_attrib
+#endif
+
+#if defined(__GNUC__) && (__GNUC__ > 4 || __GNUC__ == 4 && __GNUC_MINOR__ > 2)
+    #define av_alloc_size(n) __attribute__((alloc_size(n)))
+#else
+    #define av_alloc_size(n)
 #endif
 
 /**
- * Memory allocation of size bytes with alignment suitable for all
- * memory accesses (including vectors if available on the
- * CPU). av_malloc(0) must return a non-NULL pointer.
+ * Allocate a block of \p size bytes with alignment suitable for all
+ * memory accesses (including vectors if available on the CPU).
+ * @param size Size in bytes for the memory block to be allocated.
+ * @return Pointer to the allocated block, NULL if it cannot allocate
+ * it.
+ * @see av_mallocz()
  */
-void *av_malloc(unsigned int size);
+void *av_malloc(unsigned int size) av_malloc_attrib av_alloc_size(1);
 
 /**
- * av_realloc semantics (same as glibc): If ptr is NULL and size > 0,
- * identical to malloc(size). If size is zero, it is identical to
- * free(ptr) and NULL is returned.
+ * Allocate or reallocate a block of memory.
+ * If \p ptr is NULL and \p size > 0, allocate a new block. If \p
+ * size is zero, free the memory block pointed by \p ptr.
+ * @param size Size in bytes for the memory block to be allocated or
+ * reallocated.
+ * @param ptr Pointer to a memory block already allocated with
+ * av_malloc(z)() or av_realloc() or NULL.
+ * @return Pointer to a newly reallocated block or NULL if it cannot
+ * reallocate or the function is used to free the memory block.
+ * @see av_fast_realloc()
  */
-void *av_realloc(void *ptr, unsigned int size);
+void *av_realloc(void *ptr, unsigned int size) av_alloc_size(2);
 
 /**
- * Free memory which has been allocated with av_malloc(z)() or av_realloc().
+ * Free a memory block which has been allocated with av_malloc(z)() or
+ * av_realloc().
+ * @param ptr Pointer to the memory block which should be freed.
  * @note ptr = NULL is explicitly allowed.
  * @note It is recommended that you use av_freep() instead.
+ * @see av_freep()
  */
 void av_free(void *ptr);
 
-void *av_mallocz(unsigned int size);
+/**
+ * Allocate a block of \p size bytes with alignment suitable for all
+ * memory accesses (including vectors if available on the CPU) and
+ * set to zeroes all the bytes of the block.
+ * @param size Size in bytes for the memory block to be allocated.
+ * @return Pointer to the allocated block, NULL if it cannot allocate
+ * it.
+ * @see av_malloc()
+ */
+void *av_mallocz(unsigned int size) av_malloc_attrib av_alloc_size(1);
 
 /**
  * Duplicate the string \p s.
@@ -61,11 +105,14 @@ void *av_mallocz(unsigned int size);
  * @return Pointer to a newly allocated string containing a
  * copy of \p s or NULL if it cannot be allocated.
  */
-char *av_strdup(const char *s);
+char *av_strdup(const char *s) av_malloc_attrib;
 
 /**
- * Free memory and set the pointer to NULL.
- * @param ptr Pointer to the pointer which should be freed.
+ * Free a memory block which has been allocated with av_malloc(z)() or
+ * av_realloc() and set to NULL the pointer to it.
+ * @param ptr Pointer to the pointer to the memory block which should
+ * be freed.
+ * @see av_free()
  */
 void av_freep(void *ptr);