r2641: talloc_p() now produces a named talloc pointer, with the name

auto-derived from the type you are allocating. This is done with
basically zero overhead by relying on the stringify operator in cpp
producing string constants.

the result is that --leak-check nicely names all pointers that come
from talloc_p()
(This used to be commit bd86ebe2972af4d424df20db1e422919aa6203d0)

2 files changed, 32 insertions, 4 deletions

diff --git a/source4/include/talloc.h b/source4/include/talloc.h
index dec004b7ef..5af7fd1da0 100644
--- a/source4/include/talloc.h
+++ b/source4/include/talloc.h
@@ -25,7 +25,7 @@
 typedef void TALLOC_CTX;
 
 /* useful macros for creating type checked pointers */
-#define talloc_p(ctx, type) (type *)talloc(ctx, sizeof(type))
+#define talloc_p(ctx, type) (type *)talloc_named_const(ctx, sizeof(type), #type)
 #define talloc_array_p(ctx, type, count) (type *)talloc_array(ctx, sizeof(type), count)
 #define talloc_realloc_p(p, type, count) (type *)talloc_realloc_array(p, sizeof(type), count)
 
diff --git a/source4/lib/talloc.c b/source4/lib/talloc.c
index 114d0de43b..3e42fc68f8 100644
--- a/source4/lib/talloc.c
+++ b/source4/lib/talloc.c
@@ -39,7 +39,7 @@ struct talloc_chunk {
 	uint_t magic;
 	uint_t ref_count;
 	int (*destructor)(void *);
-	char *name;
+	const char *name;
 };
 
 /* panic if we get a bad magic value */
@@ -133,7 +133,7 @@ static void talloc_set_name_v(void *ptr, const char *fmt, va_list ap) PRINTF_ATT
 static void talloc_set_name_v(void *ptr, const char *fmt, va_list ap)
 {
 	struct talloc_chunk *tc = talloc_chunk_from_ptr(ptr);
-	vasprintf(&tc->name, fmt, ap);
+	tc->name = talloc_vasprintf(ptr, fmt, ap);
 }
 
 /*
@@ -148,6 +148,16 @@ void talloc_set_name(void *ptr, const char *fmt, ...) _PRINTF_ATTRIBUTE(2,3)
 }
 
 /*
+   more efficient way to add a name to a pointer - the name must point to a 
+   true string constant
+*/
+void talloc_set_name_const(void *ptr, const char *name)
+{
+	struct talloc_chunk *tc = talloc_chunk_from_ptr(ptr);
+	tc->name = name;
+}
+
+/*
   create a named talloc pointer. Any talloc pointer can be named, and
   talloc_named() operates just like talloc() except that it allows you
   to name the pointer.
@@ -171,6 +181,25 @@ void *talloc_named(void *context, size_t size,
 }
 
 /*
+  create a named talloc pointer. Any talloc pointer can be named, and
+  talloc_named() operates just like talloc() except that it allows you
+  to name the pointer.
+*/
+void *talloc_named_const(void *context, size_t size, const char *name)
+{
+	void *ptr;
+
+	ptr = talloc(context, size);
+	if (ptr == NULL) {
+		return NULL;
+	}
+
+	talloc_set_name_const(ptr, name);
+
+	return ptr;
+}
+
+/*
   return the name of a talloc ptr, or "UNNAMED"
 */
 const char *talloc_get_name(void *ptr)
@@ -250,7 +279,6 @@ int talloc_free(void *ptr)
 	}
 
 	tc->magic = TALLOC_MAGIC_FREE;
-	if (tc->name) free(tc->name);
 
 	free(tc);
 	return 0;