X-Git-Url: https://git.ozlabs.org/?p=ccan;a=blobdiff_plain;f=ccan%2Ftal%2Ftal.h;h=42245f68660277c990561502f50b00f94297bcb5;hp=28726c324cedd9ec4c150bcd02f369c6e6180905;hb=d873aaec1339baf45c37db7cbaa2d687656343ba;hpb=7ca46909f86e8bbad4e4bb19cac1a75d4ebf3df6

diff --git a/ccan/tal/tal.h b/ccan/tal/tal.h
index 28726c32..42245f68 100644
--- a/ccan/tal/tal.h
+++ b/ccan/tal/tal.h
@@ -18,18 +18,6 @@
  */
 typedef void tal_t;
 
-/**
- * TAL_TAKE - fake tal_t to indicate function will own arguments.
- *
- * Various functions take a context on which to allocate: if you use
- * TAL_TAKE there instead, it means that the argument(s) are actually
- * tal objects.  The returned value will share the same parent; it may
- * even be the same pointer as the arguments.  The arguments themselves
- * will be reused, freed, or made a child of the return value: they are
- * no longer valid for external use.
- */
-#define TAL_TAKE ((tal_t *)-2L)
-
 /**
  * tal - basic allocator function
  * @ctx: NULL, or tal allocated object to be parent.
@@ -65,14 +53,15 @@ typedef void tal_t;
  * @p: NULL, or tal allocated object to free.
  *
  * This calls the destructors for p (if any), then does the same for all its
- * children (recursively) before finally freeing the memory.
+ * children (recursively) before finally freeing the memory.  It returns
+ * NULL, for convenience.
  *
  * Note: errno is preserved by this call.
  *
  * Example:
- *	tal_free(p);
+ *	p = tal_free(p);
  */
-void tal_free(const tal_t *p);
+void *tal_free(const tal_t *p);
 
 /**
  * tal_arr - allocate an array of objects.
@@ -123,10 +112,9 @@ void tal_free(const tal_t *p);
  *
  * This may need to perform an allocation, in which case it may fail; thus
  * it can return NULL, otherwise returns @ptr.
- *
- * Note: weird macro avoids gcc's 'warning: value computed is not used'.
  */
 #if HAVE_STATEMENT_EXPR
+/* Weird macro avoids gcc's 'warning: value computed is not used'. */
 #define tal_steal(ctx, ptr) \
 	({ (tal_typeof(ptr) tal_steal_((ctx),(ptr))); })
 #else
@@ -188,25 +176,30 @@ tal_t *tal_next(const tal_t *root, const tal_t *prev);
 tal_t *tal_parent(const tal_t *ctx);
 
 /**
- * tal_memdup - duplicate memory.
- * @ctx: NULL, or tal allocated object to be parent (or TAL_TAKE).
- * @p: the memory to copy
- * @n: the number of bytes.
- *
+ * tal_dup - duplicate an 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 array to copy (or resized & reparented if take())
+ * @n: the number of sizeof(type) entries to copy.
+ * @extra: the number of extra sizeof(type) entries to allocate.
  */
-void *tal_memdup(const tal_t *ctx, const void *p, size_t n);
+#define tal_dup(ctx, type, p, n, extra)				\
+	((type *)tal_dup_((ctx), tal_typechk_(p, type *),	\
+			  tal_sizeof_(sizeof(type), (n)),	\
+			  tal_sizeof_(sizeof(type), (extra)),	\
+			  TAL_LABEL(type, "[]")))
 
 /**
  * tal_strdup - duplicate a string
- * @ctx: NULL, or tal allocated object to be parent (or TAL_TAKE).
- * @p: the string to copy
+ * @ctx: NULL, or tal allocated object to be parent.
+ * @p: the string to copy (can be take()).
  */
 char *tal_strdup(const tal_t *ctx, const char *p);
 
 /**
  * tal_strndup - duplicate a limited amount of a string.
- * @ctx: NULL, or tal allocated object to be parent (or TAL_TAKE).
- * @p: the string to copy
+ * @ctx: NULL, or tal allocated object to be parent.
+ * @p: the string to copy (can be take()).
  * @n: the maximum length to copy.
  *
  * Always gives a nul-terminated string, with strlen() <= @n.
@@ -215,22 +208,16 @@ char *tal_strndup(const tal_t *ctx, const char *p, size_t n);
 
 /**
  * tal_asprintf - allocate a formatted string
- * @ctx: NULL, or tal allocated object to be parent (or TAL_TAKE).
- * @fmt: the printf-style format.
- *
- * If @ctx is TAL_TAKE, @fmt is freed and its parent will be the parent
- * of the return value.
+ * @ctx: NULL, or tal allocated object to be parent.
+ * @fmt: the printf-style format (can be take()).
  */
 char *tal_asprintf(const tal_t *ctx, const char *fmt, ...) PRINTF_FMT(2,3);
 
 /**
  * tal_vasprintf - allocate a formatted string (va_list version)
- * @ctx: NULL, or tal allocated object to be parent (or TAL_TAKE).
- * @fmt: the printf-style format.
+ * @ctx: NULL, or tal allocated object to be parent.
+ * @fmt: the printf-style format (can be take()).
  * @va: the va_list containing the format args.
- *
- * If @ctx is TAL_TAKE, @fmt is freed and its parent will be the parent
- * of the return value.
  */
 char *tal_vasprintf(const tal_t *ctx, const char *fmt, va_list ap)
 	PRINTF_FMT(2,0);
@@ -315,12 +302,23 @@ static inline size_t tal_sizeof_(size_t size, size_t count)
 
 #if HAVE_TYPEOF
 #define tal_typeof(ptr) (__typeof__(ptr))
+#if HAVE_STATEMENT_EXPR
+/* Careful: ptr can be const foo *, ptype is foo *.  Also, ptr could
+ * be an array, eg "hello". */
+#define tal_typechk_(ptr, ptype) ({ __typeof__((ptr)+0) _p = (ptype)(ptr); _p; })
 #else
+#define tal_typechk_(ptr, ptype) (ptr)
+#endif
+#else /* !HAVE_TYPEOF */
 #define tal_typeof(ptr)
+#define tal_typechk_(ptr, ptype) (ptr)
 #endif
 
 void *tal_alloc_(const tal_t *ctx, size_t bytes, bool clear, const char *label);
 
+void *tal_dup_(const tal_t *ctx, const void *p, size_t n, size_t extra,
+	       const char *label);
+
 tal_t *tal_steal_(const tal_t *new_parent, const tal_t *t);
 
 bool tal_resize_(tal_t **ctxp, size_t size);