*/
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+ * no longer valid for external use.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.
/**
* tal_memdup - duplicate memory.
- * @ctx: NULL, or tal allocated object to be parent.
+ * @ctx: NULL, or tal allocated object to be parent (or TAL_TAKE).
* @p: the memory to copy
* @n: the number of bytes.
+ *
*/
void *tal_memdup(const tal_t *ctx, const void *p, size_t n);
/**
- * tal_strdup - duplicate a string.
- * @ctx: NULL, or tal allocated object to be parent.
+ * tal_strdup - duplicate a string
+ * @ctx: NULL, or tal allocated object to be parent (or TAL_TAKE).
* @p: the string to copy
*/
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.
+ * @ctx: NULL, or tal allocated object to be parent (or TAL_TAKE).
* @p: the string to copy
* @n: the maximum length to copy.
*
/**
* tal_asprintf - allocate a formatted string
- * @ctx: NULL, or tal allocated object to be parent.
+ * @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.
*/
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.
+ * @ctx: NULL, or tal allocated object to be parent (or TAL_TAKE).
* @fmt: the printf-style format.
* @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);