lib/gis: improve diagnostic capabilities for compilers and/or static analyzers

include/grass/defs/gis.h

@@ -81,10 +81,47 @@ int G_adjust_window_ll(struct Cell_head *cellhd);
 #define G_incr_void_ptr(ptr, size) \
     ((void *)((const unsigned char *)(ptr) + (size)))
 
-void *G__malloc(const char *, int, size_t);
-void *G__calloc(const char *, int, size_t, size_t);
-void *G__realloc(const char *, int, void *, size_t);
-void G_free(void *);
+// Improve diagnostic capabilities for compilers and/or static analyzers
+
+#ifndef __has_attribute
+#define __has_attribute(x) 0
+#endif
+
+#if __has_attribute(malloc) && defined(__GNUC__) && (__GNUC__ >= 11)
+#define G_ATTR_MALLOC __attribute__((malloc, (malloc(G_free, 1))))
+#elif __has_attribute(malloc)
+#define G_ATTR_MALLOC __attribute__((malloc))
+#else
+#define G_ATTR_MALLOC
+#endif
+
+#if __has_attribute(alloc_size)
+#define G_ATTR_ALLOC_SIZE1(N)    __attribute__((alloc_size(N)))
+#define G_ATTR_ALLOC_SIZE2(N, M) __attribute__((alloc_size(N, M)))
+#else
+#define G_ATTR_ALLOC_SIZE1(N)
+#define G_ATTR_ALLOC_SIZE2(N, M)
+#endif
+
+// Clang Static Analyzer ownership annotations
+#if defined(__clang__) && __has_attribute(ownership_returns) && \
+    __has_attribute(ownership_takes)
+#define G_ATTR_OWNSHIP_RET  __attribute__((ownership_returns(malloc)))
+#define G_ATTR_OWNSHIP_TAKE __attribute__((ownership_takes(malloc, 1)))
+#else
+#define G_ATTR_OWNSHIP_RET
+#define G_ATTR_OWNSHIP_TAKE
+#endif
+
+#define G_MALLOC_ATTR  G_ATTR_MALLOC G_ATTR_ALLOC_SIZE1(3) G_ATTR_OWNSHIP_RET
+#define G_CALLOC_ATTR  G_ATTR_MALLOC G_ATTR_ALLOC_SIZE2(3, 4) G_ATTR_OWNSHIP_RET
+#define G_REALLOC_ATTR G_ATTR_ALLOC_SIZE1(4)
+#define G_FREE_ATTR    G_ATTR_OWNSHIP_TAKE
+
+void *G__malloc(const char *, int, size_t) G_MALLOC_ATTR;
+void *G__calloc(const char *, int, size_t, size_t) G_CALLOC_ATTR;
+void *G__realloc(const char *, int, void *, size_t) G_REALLOC_ATTR;
+void G_free(void *) G_FREE_ATTR;
 
 #ifndef G_incr_void_ptr
 void *G_incr_void_ptr(const void *, size_t);