X-Git-Url: https://git.ozlabs.org/?a=blobdiff_plain;f=ccan%2Ftal%2Ftal.h;h=c486f9e8e194a99b51ffdb8117788bbae86a89ed;hb=b15b3673bf0fbbff48b87bddcf402b8bcdf41c59;hp=54318e1fa116864ae5d00268b9d6c3144ba86eb3;hpb=1651e25ee7cf7a24692e7ffa0c6fc9a47218eb6d;p=ccan

diff --git a/ccan/tal/tal.h b/ccan/tal/tal.h
index 54318e1f..c486f9e8 100644
--- a/ccan/tal/tal.h
+++ b/ccan/tal/tal.h
@@ -106,6 +106,9 @@ void *tal_free(const tal_t *p);
  * This returns true on success (and may move *@p), or false on failure.
  * On success, tal_count() of *@p will be @count.
  *
+ * Note: if *p is take(), it will still be take() upon return, even if it
+ * has been moved.
+ *
  * Example:
  *	tal_resize(&p, 100);
  */
@@ -128,10 +131,11 @@ void *tal_free(const tal_t *p);
 /**
  * tal_steal - change the parent of a tal-allocated pointer.
  * @ctx: The new parent.
- * @ptr: The tal allocated object to move.
+ * @ptr: The tal allocated object to move, or NULL.
  *
  * This may need to perform an allocation, in which case it may fail; thus
- * it can return NULL, otherwise returns @ptr.
+ * it can return NULL, otherwise returns @ptr.  If @ptr is NULL, this function does
+ * nothing.
  */
 #if HAVE_STATEMENT_EXPR
 /* Weird macro avoids gcc's 'warning: value computed is not used'. */
@@ -161,7 +165,8 @@ void *tal_free(const tal_t *p);
  * @function: the function to call before it's freed.
  *
  * If @function has not been successfully added as a destructor, this returns
- * false.
+ * false.  Note that if we're inside the destructor call itself, this will
+ * return false.
  */
 #define tal_del_destructor(ptr, function)				      \
 	tal_del_destructor_((ptr), typesafe_cb(void, void *, (function), (ptr)))
@@ -192,7 +197,8 @@ void *tal_free(const tal_t *p);
  * @function: the function to call before it's freed.
  *
  * If @function has not been successfully added as a destructor, this returns
- * false.
+ * false.  Note that if we're inside the destructor call itself, this will
+ * return false.
  */
 #define tal_del_destructor(ptr, function)				      \
 	tal_del_destructor_((ptr), typesafe_cb(void, void *, (function), (ptr)))
@@ -227,7 +233,7 @@ enum tal_notify_type {
 
 /**
  * tal_add_notifier - add a callback function when this context changes.
- * @ptr: The tal allocated object.
+ * @ptr: The tal allocated object, or NULL.
  * @types: Bitwise OR of the types the callback is interested in.
  * @callback: the function to call.
  *
@@ -346,10 +352,21 @@ tal_t *tal_parent(const tal_t *ctx);
  * tal_dup - duplicate an object.
  * @ctx: The tal allocated object to be parent of the result (may be NULL).
  * @type: the type (should match type of @p!)
- * @p: the object to copy (or reparented if take())
+ * @p: the object to copy (or reparented if take()).  Must not be NULL.
  */
 #define tal_dup(ctx, type, p)					\
-	tal_dup_label(ctx, type, p, TAL_LABEL(type, ""))
+	tal_dup_label(ctx, type, p, TAL_LABEL(type, ""), false)
+
+/**
+ * tal_dup_or_null - duplicate an object, or just pass NULL.
+ * @ctx: The tal allocated object to be parent of the result (may be NULL).
+ * @type: the type (should match type of @p!)
+ * @p: the object to copy (or reparented if take())
+ *
+ * if @p is NULL, just return NULL, otherwise to tal_dup().
+ */
+#define tal_dup_or_null(ctx, type, p)					\
+	tal_dup_label(ctx, type, p, TAL_LABEL(type, ""), true)
 
 /**
  * tal_dup_arr - duplicate an array.
@@ -363,7 +380,17 @@ tal_t *tal_parent(const tal_t *ctx);
 	tal_dup_arr_label(ctx, type, p, n, extra, TAL_LABEL(type, "[]"))
 
 
-
+/**
+ * tal_dup_arr - duplicate a tal array.
+ * @ctx: The tal allocated object to be parent of the result (may be NULL).
+ * @type: the type (should match type of @p!)
+ * @p: the tal array to copy (or resized & reparented if take())
+ *
+ * The comon case of duplicating an entire tal array.
+ */
+#define tal_dup_talarr(ctx, type, p)					\
+	((type *)tal_dup_talarr_((ctx), tal_typechk_(p, type *),	\
+				 TAL_LABEL(type, "[]")))
 /* Lower-level interfaces, where you want to supply your own label string. */
 #define tal_label(ctx, type, label)						\
 	((type *)tal_alloc_((ctx), sizeof(type), false, label))
@@ -373,13 +400,13 @@ tal_t *tal_parent(const tal_t *ctx);
 	((type *)tal_alloc_arr_((ctx), sizeof(type), (count), false, label))
 #define tal_arrz_label(ctx, type, count, label)					\
 	((type *)tal_alloc_arr_((ctx), sizeof(type), (count), true, label))
-#define tal_dup_label(ctx, type, p, label)			\
+#define tal_dup_label(ctx, type, p, label, nullok)			\
 	((type *)tal_dup_((ctx), tal_typechk_(p, type *),	\
-			  sizeof(type), 1, 0,			\
+			  sizeof(type), 1, 0, nullok,		\
 			  label))
 #define tal_dup_arr_label(ctx, type, p, n, extra, label)	\
 	((type *)tal_dup_((ctx), tal_typechk_(p, type *),	\
-			  sizeof(type), (n), (extra),		\
+			  sizeof(type), (n), (extra), false,	\
 			  label))
 
 /**
@@ -450,7 +477,7 @@ bool tal_check(const tal_t *ctx, const char *errorstr);
 
 #ifdef CCAN_TAL_DEBUG
 /**
- * tal_dump - dump entire tal tree.
+ * tal_dump - dump entire tal tree to stderr.
  *
  * This is a helper for debugging tal itself, which dumps all the tal internal
  * state.
@@ -499,7 +526,9 @@ void *tal_alloc_arr_(const tal_t *ctx, size_t bytes, size_t count, bool clear,
 		     const char *label);
 
 void *tal_dup_(const tal_t *ctx, const void *p TAKES, size_t size,
-	       size_t n, size_t extra, const char *label);
+	       size_t n, size_t extra, bool nullok, const char *label);
+void *tal_dup_talarr_(const tal_t *ctx, const tal_t *src TAKES,
+		      const char *label);
 
 tal_t *tal_steal_(const tal_t *new_parent, const tal_t *t);