1 /* Licensed under BSD-MIT - see LICENSE file for details */
5 #include <ccan/compiler/compiler.h>
6 #include <ccan/likely/likely.h>
7 #include <ccan/typesafe_cb/typesafe_cb.h>
8 #include <ccan/str/str.h>
14 * tal_t - convenient alias for void to mark tal pointers.
16 * Since any pointer can be a tal-allocated pointer, it's often
17 * useful to use this typedef to mark them explicitly.
22 * TAL_TAKE - fake tal_t to indicate function will own arguments.
24 * Various functions take a context on which to allocate: if you use
25 * TAL_TAKE there instead, it means that the argument(s) are actually
26 * tal objects. The returned value will share the same parent; it may
27 * even be the same pointer as the arguments. The arguments themselves
28 * will be reused, freed, or made a child of the return value: they are
29 * no longer valid for external use.
31 #define TAL_TAKE ((tal_t *)-2L)
34 * tal - basic allocator function
35 * @ctx: NULL, or tal allocated object to be parent.
36 * @type: the type to allocate.
38 * Allocates a specific type, with a given parent context. The name
39 * of the object is a string of the type, but if CCAN_TAL_DEBUG is
40 * defined it also contains the file and line which allocated it.
43 * int *p = tal(NULL, int);
46 #define tal(ctx, type) \
47 ((type *)tal_alloc_((ctx), sizeof(type), false, TAL_LABEL(type, "")))
50 * talz - zeroing allocator function
51 * @ctx: NULL, or tal allocated object to be parent.
52 * @type: the type to allocate.
54 * Equivalent to tal() followed by memset() to zero.
57 * p = talz(NULL, int);
60 #define talz(ctx, type) \
61 ((type *)tal_alloc_((ctx), sizeof(type), true, TAL_LABEL(type, "")))
64 * tal_free - free a tal-allocated pointer.
65 * @p: NULL, or tal allocated object to free.
67 * This calls the destructors for p (if any), then does the same for all its
68 * children (recursively) before finally freeing the memory.
70 * Note: errno is preserved by this call.
75 void tal_free(const tal_t *p);
78 * tal_arr - allocate an array of objects.
79 * @ctx: NULL, or tal allocated object to be parent.
80 * @type: the type to allocate.
81 * @count: the number to allocate.
84 * p = tal_arr(NULL, int, 2);
88 #define tal_arr(ctx, type, count) \
89 ((type *)tal_alloc_((ctx), tal_sizeof_(sizeof(type), (count)), false, \
90 TAL_LABEL(type, "[]")))
93 * tal_arrz - allocate an array of zeroed objects.
94 * @ctx: NULL, or tal allocated object to be parent.
95 * @type: the type to allocate.
96 * @count: the number to allocate.
99 * p = tal_arrz(NULL, int, 2);
100 * assert(p[0] == 0 && p[1] == 0);
102 #define tal_arrz(ctx, type, count) \
103 ((type *)tal_alloc_((ctx), tal_sizeof_(sizeof(type), (count)), true, \
104 TAL_LABEL(type, "[]")))
107 * tal_resize - enlarge or reduce a tal_arr[z].
108 * @p: A pointer to the tal allocated array to resize.
109 * @count: the number to allocate.
111 * This returns true on success (and may move *@p), or false on failure.
114 * tal_resize(&p, 100);
116 #define tal_resize(p, count) \
117 tal_resize_((void **)(p), tal_sizeof_(sizeof**(p), (count)))
120 * tal_steal - change the parent of a tal-allocated pointer.
121 * @ctx: The new parent.
122 * @ptr: The tal allocated object to move.
124 * This may need to perform an allocation, in which case it may fail; thus
125 * it can return NULL, otherwise returns @ptr.
127 * Note: weird macro avoids gcc's 'warning: value computed is not used'.
129 #if HAVE_STATEMENT_EXPR
130 #define tal_steal(ctx, ptr) \
131 ({ (tal_typeof(ptr) tal_steal_((ctx),(ptr))); })
133 #define tal_steal(ctx, ptr) \
134 (tal_typeof(ptr) tal_steal_((ctx),(ptr)))
138 * tal_add_destructor - add a callback function when this context is destroyed.
139 * @ptr: The tal allocated object.
140 * @function: the function to call before it's freed.
142 #define tal_add_destructor(ptr, function) \
143 tal_add_destructor_((ptr), typesafe_cb(void, void *, (function), (ptr)))
146 * tal_set_name - attach a name to a tal pointer.
147 * @ptr: The tal allocated object.
148 * @name: The name to use.
150 * The name is copied, unless we're certain it's a string literal.
152 #define tal_set_name(ptr, name) \
153 tal_set_name_((ptr), (name), TAL_IS_LITERAL(name))
156 * tal_name - get the name for a tal pointer.
157 * @ptr: The tal allocated object.
159 * Returns NULL if no name has been set.
161 const char *tal_name(const tal_t *ptr);
164 * tal_first - get the first tal object child.
165 * @root: The tal allocated object to start with, or NULL.
167 * Returns NULL if there are no children.
169 tal_t *tal_first(const tal_t *root);
172 * tal_next - get the next tal object child.
173 * @root: The tal allocated object to start with, or NULL.
174 * @prev: The return value from tal_first or tal_next.
176 * Returns NULL if there are no more children. This should be safe to
177 * call on an altering tree unless @prev is no longer a descendent of
180 tal_t *tal_next(const tal_t *root, const tal_t *prev);
183 * tal_parent - get the parent of a tal object.
184 * @ctx: The tal allocated object.
186 * Returns the parent, which may be NULL. Returns NULL if @ctx is NULL.
188 tal_t *tal_parent(const tal_t *ctx);
191 * tal_memdup - duplicate memory.
192 * @ctx: NULL, or tal allocated object to be parent (or TAL_TAKE).
193 * @p: the memory to copy
194 * @n: the number of bytes.
197 void *tal_memdup(const tal_t *ctx, const void *p, size_t n);
200 * tal_strdup - duplicate a string
201 * @ctx: NULL, or tal allocated object to be parent (or TAL_TAKE).
202 * @p: the string to copy
204 char *tal_strdup(const tal_t *ctx, const char *p);
207 * tal_strndup - duplicate a limited amount of a string.
208 * @ctx: NULL, or tal allocated object to be parent (or TAL_TAKE).
209 * @p: the string to copy
210 * @n: the maximum length to copy.
212 * Always gives a nul-terminated string, with strlen() <= @n.
214 char *tal_strndup(const tal_t *ctx, const char *p, size_t n);
217 * tal_asprintf - allocate a formatted string
218 * @ctx: NULL, or tal allocated object to be parent (or TAL_TAKE).
219 * @fmt: the printf-style format.
221 * If @ctx is TAL_TAKE, @fmt is freed and its parent will be the parent
222 * of the return value.
224 char *tal_asprintf(const tal_t *ctx, const char *fmt, ...) PRINTF_FMT(2,3);
227 * tal_vasprintf - allocate a formatted string (va_list version)
228 * @ctx: NULL, or tal allocated object to be parent (or TAL_TAKE).
229 * @fmt: the printf-style format.
230 * @va: the va_list containing the format args.
232 * If @ctx is TAL_TAKE, @fmt is freed and its parent will be the parent
233 * of the return value.
235 char *tal_vasprintf(const tal_t *ctx, const char *fmt, va_list ap)
240 * tal_set_backend - set the allocation or error functions to use
241 * @alloc_fn: allocator or NULL (default is malloc)
242 * @resize_fn: re-allocator or NULL (default is realloc)
243 * @free_fn: free function or NULL (default is free)
244 * @error_fn: called on errors or NULL (default is abort)
246 * The defaults are set up so tal functions never return NULL, but you
247 * can override erorr_fn to change that. error_fn can return, and is
248 * called if alloc_fn or resize_fn fail.
250 * If any parameter is NULL, that function is unchanged.
252 void tal_set_backend(void *(*alloc_fn)(size_t size),
253 void *(*resize_fn)(void *, size_t size),
254 void (*free_fn)(void *),
255 void (*error_fn)(const char *msg));
259 * tal_check - set the allocation or error functions to use
260 * @ctx: a tal context, or NULL.
261 * @errorstr: a string to prepend calls to error_fn, or NULL.
263 * This sanity-checks a tal tree (unless NDEBUG is defined, in which case
264 * it simply returns true). If errorstr is not null, error_fn is called
265 * when a problem is found, otherwise it is not.
267 bool tal_check(const tal_t *ctx, const char *errorstr);
269 #ifdef CCAN_TAL_DEBUG
271 * tal_dump - dump entire tal tree.
273 * This is a helper for debugging tal itself, which dumps all the tal internal
279 /* Internal support functions */
281 #ifdef CCAN_TAL_NO_LABELS
282 #define TAL_LABEL(type, arr) NULL
284 #ifdef CCAN_TAL_DEBUG
285 #define TAL_LABEL(type, arr) \
286 __FILE__ ":" stringify(__LINE__) ":" stringify(type) arr
288 #define TAL_LABEL(type, arr) stringify(type) arr
289 #endif /* CCAN_TAL_DEBUG */
293 #if HAVE_BUILTIN_CONSTANT_P
294 #define TAL_IS_LITERAL(str) __builtin_constant_p(str)
296 #define TAL_IS_LITERAL(str) (sizeof(&*(str)) != sizeof(char *))
299 bool tal_set_name_(tal_t *ctx, const char *name, bool literal);
301 static inline size_t tal_sizeof_(size_t size, size_t count)
303 /* Multiplication wrap */
304 if (count && unlikely(size * count / size != count))
305 return (size_t)-1024;
309 /* Make sure we don't wrap adding header. */
310 if (size > (size_t)-1024)
311 return (size_t)-1024;
317 #define tal_typeof(ptr) (__typeof__(ptr))
319 #define tal_typeof(ptr)
322 void *tal_alloc_(const tal_t *ctx, size_t bytes, bool clear, const char *label);
324 tal_t *tal_steal_(const tal_t *new_parent, const tal_t *t);
326 bool tal_resize_(tal_t **ctxp, size_t size);
328 bool tal_add_destructor_(tal_t *ctx, void (*destroy)(void *me));
330 #endif /* CCAN_TAL_H */