Merge "Suppress false positive memory leak warnings."

am: cfd44ee74f

* commit 'cfd44ee74f2318565d188ee0b2dd08911519d55e':
  Suppress false positive memory leak warnings.

1 files changed, 20 insertions, 0 deletions

diff --git a/libcutils/str_parms.c b/libcutils/str_parms.c
index 4f23d09c5..8dafdedac 100644
--- a/libcutils/str_parms.c
+++ b/libcutils/str_parms.c
@@ -31,6 +31,20 @@
 
 #define UNUSED __attribute__((unused))
 
+/* When an object is allocated but not freed in a function,
+ * because its ownership is released to other object like a hashmap,
+ * call RELEASE_OWNERSHIP to tell the clang analyzer and avoid
+ * false warnings about potential memory leak.
+ * For now, a "temporary" assignment to global variables
+ * is enough to confuse the clang static analyzer.
+ */
+#ifdef __clang_analyzer__
+static void *released_pointer;
+#define RELEASE_OWNERSHIP(x) { released_pointer = x; released_pointer = 0; }
+#else
+#define RELEASE_OWNERSHIP(x)
+#endif
+
 struct str_parms {
     Hashmap *map;
 };
@@ -170,9 +184,12 @@ struct str_parms *str_parms_create_str(const char *_string)
 
         /* if we replaced a value, free it */
         old_val = hashmapPut(str_parms->map, key, value);
+        RELEASE_OWNERSHIP(value);
         if (old_val) {
             free(old_val);
             free(key);
+        } else {
+            RELEASE_OWNERSHIP(key);
         }
 
         items++;
@@ -222,10 +239,13 @@ int str_parms_add_str(struct str_parms *str_parms, const char *key,
             goto clean_up;
         }
         // For new keys, hashmap takes ownership of tmp_key and tmp_val.
+        RELEASE_OWNERSHIP(tmp_key);
+        RELEASE_OWNERSHIP(tmp_val);
         tmp_key = tmp_val = NULL;
     } else {
         // For existing keys, hashmap takes ownership of tmp_val.
         // (It also gives up ownership of old_val.)
+        RELEASE_OWNERSHIP(tmp_val);
         tmp_val = NULL;
     }