r17895: - talloc_increase_ref_count() can fail

- make talloc_reference() typesafe when gcc >= 3 is used

metze
(This used to be commit 933d1b47ad614d02cc02b602e704948b342febdb)

4 files changed, 16 insertions, 7 deletions

diff --git a/source4/lib/talloc/talloc.3.xml b/source4/lib/talloc/talloc.3.xml
index 952083a805..247bb28ed9 100644
--- a/source4/lib/talloc/talloc.3.xml
+++ b/source4/lib/talloc/talloc.3.xml
@@ -235,7 +235,7 @@
 	  about to go away.
         </para>
     </refsect2>
-    <refsect2><title>void talloc_increase_ref_count(const void *<emphasis role="italic">ptr</emphasis>);</title>
+    <refsect2><title>int talloc_increase_ref_count(const void *<emphasis role="italic">ptr</emphasis>);</title>
         <para>
 	  The talloc_increase_ref_count(<emphasis
 	  role="italic">ptr</emphasis>) function is exactly equivalent to:
@@ -245,6 +245,9 @@
 	  You can use either syntax, depending on which you think is
 	  clearer in your code.
         </para>
+        <para>
+	  It returns 0 on success and -1 on failure.
+        </para>
     </refsect2>
     <refsect2 id="talloc_set_name"><title>void talloc_set_name(const void *ptr, const char *fmt, ...);</title>
         <para>
diff --git a/source4/lib/talloc/talloc.c b/source4/lib/talloc/talloc.c
index cc04a2425a..ba457afd6b 100644
--- a/source4/lib/talloc/talloc.c
+++ b/source4/lib/talloc/talloc.c
@@ -219,9 +219,12 @@ void _talloc_set_destructor(const void *ptr, int (*destructor)(void *))
 /*
   increase the reference count on a piece of memory. 
 */
-void talloc_increase_ref_count(const void *ptr)
+int talloc_increase_ref_count(const void *ptr)
 {
-	talloc_reference(null_context, ptr);
+	if (!talloc_reference(null_context, ptr)) {
+		return -1;
+	}
+	return 0;
 }
 
 /*
@@ -243,7 +246,7 @@ static int talloc_reference_destructor(struct talloc_reference_handle *handle)
   same underlying data, and you want to be able to free the two instances separately,
   and in either order
 */
-void *talloc_reference(const void *context, const void *ptr)
+void *_talloc_reference(const void *context, const void *ptr)
 {
 	struct talloc_chunk *tc;
 	struct talloc_reference_handle *handle;
diff --git a/source4/lib/talloc/talloc.h b/source4/lib/talloc/talloc.h
index f080f0498d..9d6edd88ba 100644
--- a/source4/lib/talloc/talloc.h
+++ b/source4/lib/talloc/talloc.h
@@ -64,11 +64,13 @@ typedef void TALLOC_CTX;
 /* this extremely strange macro is to avoid some braindamaged warning
    stupidity in gcc 4.1.x */
 #define talloc_steal(ctx, ptr) ({ _TALLOC_TYPEOF(ptr) __talloc_steal_ret = (_TALLOC_TYPEOF(ptr))_talloc_steal((ctx),(ptr)); __talloc_steal_ret; })
+#define talloc_reference(ctx, ptr) (_TALLOC_TYPEOF(ptr))_talloc_reference((ctx),(ptr))
 #else
 #define talloc_set_destructor(ptr, function) \
 	_talloc_set_destructor((ptr), (int (*)(void *))(function))
 #define _TALLOC_TYPEOF(ptr) void *
 #define talloc_steal(ctx, ptr) (_TALLOC_TYPEOF(ptr))_talloc_steal((ctx),(ptr))
+#define talloc_reference(ctx, ptr) (_TALLOC_TYPEOF(ptr))_talloc_reference((ctx),(ptr))
 #endif
 
 /* useful macros for creating type checked pointers */
@@ -107,8 +109,8 @@ typedef void TALLOC_CTX;
 /* The following definitions come from talloc.c  */
 void *_talloc(const void *context, size_t size);
 void _talloc_set_destructor(const void *ptr, int (*destructor)(void *));
-void talloc_increase_ref_count(const void *ptr);
-void *talloc_reference(const void *context, const void *ptr);
+int talloc_increase_ref_count(const void *ptr);
+void *_talloc_reference(const void *context, const void *ptr);
 int talloc_unlink(const void *context, void *ptr);
 const char *talloc_set_name(const void *ptr, const char *fmt, ...) PRINTF_ATTRIBUTE(2,3);
 void talloc_set_name_const(const void *ptr, const char *name);
diff --git a/source4/lib/talloc/talloc_guide.txt b/source4/lib/talloc/talloc_guide.txt
index 7f1a3ea6cd..2c32fb1a87 100644
--- a/source4/lib/talloc/talloc_guide.txt
+++ b/source4/lib/talloc/talloc_guide.txt
@@ -193,7 +193,7 @@ destructor is only called when the memory is just about to go away.
 
 
 =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-
-void talloc_increase_ref_count(const void *ptr);
+int talloc_increase_ref_count(const void *ptr);
 
 The talloc_increase_ref_count(ptr) function is exactly equivalent to:
 
@@ -202,6 +202,7 @@ The talloc_increase_ref_count(ptr) function is exactly equivalent to:
 You can use either syntax, depending on which you think is clearer in
 your code.
 
+It returns 0 on success and -1 on failure.
 
 =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-
 void talloc_set_name(const void *ptr, const char *fmt, ...);