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29 * no longer valid for external use.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.
42 #define tal(ctx, type) \
43 ((type *)tal_alloc_((ctx), sizeof(type), false, TAL_LABEL(type, "")))
46 * talz - zeroing allocator function
47 * @ctx: NULL, or tal allocated object to be parent.
48 * @type: the type to allocate.
50 * Equivalent to tal() followed by memset() to zero.
52 #define talz(ctx, type) \
53 ((type *)tal_alloc_((ctx), sizeof(type), true, TAL_LABEL(type, "")))
56 * tal_free - free a tal-allocated pointer.
57 * @p: NULL, or tal allocated object to free.
59 * This calls the destructors for p (if any), then does the same for all its
60 * children (recursively) before finally freeing the memory.
62 * Note: errno is preserved by this call.
64 void tal_free(const tal_t *p);
67 * tal_arr - allocate an array of objects.
68 * @ctx: NULL, or tal allocated object to be parent.
69 * @type: the type to allocate.
70 * @count: the number to allocate.
72 #define tal_arr(ctx, type, count) \
73 ((type *)tal_alloc_((ctx), tal_sizeof_(sizeof(type), (count)), false, \
74 TAL_LABEL(type, "[]")))
77 * tal_arrz - allocate an array of zeroed objects.
78 * @ctx: NULL, or tal allocated object to be parent.
79 * @type: the type to allocate.
80 * @count: the number to allocate.
82 #define tal_arrz(ctx, type, count) \
83 ((type *)tal_alloc_((ctx), tal_sizeof_(sizeof(type), (count)), true, \
84 TAL_LABEL(type, "[]")))
87 * tal_resize - enlarge or reduce a tal_arr(z).
88 * @p: The tal allocated array to resize.
89 * @count: the number to allocate.
91 * This returns the new pointer, or NULL (and destroys the old one)
94 #define tal_resize(p, count) \
95 ((tal_typeof(p) tal_realloc_((p), tal_sizeof_(sizeof(*p), (count)))))
98 * tal_steal - change the parent of a tal-allocated pointer.
99 * @ctx: The new parent.
100 * @ptr: The tal allocated object to move.
102 * This may need to perform an allocation, in which case it may fail; thus
103 * it can return NULL, otherwise returns @ptr.
105 * Weird macro avoids gcc's 'warning: value computed is not used'.
107 #if HAVE_STATEMENT_EXPR
108 #define tal_steal(ctx, ptr) \
109 ({ (tal_typeof(ptr) tal_steal_((ctx),(ptr))); })
111 #define tal_steal(ctx, ptr) \
112 (tal_typeof(ptr) tal_steal_((ctx),(ptr)))
116 * tal_add_destructor - add a callback function when this context is destroyed.
117 * @ptr: The tal allocated object.
118 * @function: the function to call before it's freed.
120 #define tal_add_destructor(ptr, function) \
121 tal_add_destructor_((ptr), typesafe_cb(void, void *, (function), (ptr)))
124 * tal_set_name - attach a name to a tal pointer.
125 * @ptr: The tal allocated object.
126 * @name: The name to use.
128 * The name is copied, unless we're certain it's a string literal.
130 #define tal_set_name(ptr, name) \
131 tal_set_name_((ptr), (name), TAL_IS_LITERAL(name))
134 * tal_name - get the name for a tal pointer.
135 * @ptr: The tal allocated object.
137 * Returns NULL if no name has been set.
139 const char *tal_name(const tal_t *ptr);
142 * tal_first - get the first tal object child.
143 * @root: The tal allocated object to start with, or NULL.
145 * Returns NULL if there are no children.
147 tal_t *tal_first(const tal_t *root);
150 * tal_next - get the next tal object child.
151 * @root: The tal allocated object to start with, or NULL.
152 * @prev: The return value from tal_first or tal_next.
154 * Returns NULL if there are no more children. This should be safe to
155 * call on an altering tree unless @prev is no longer a descendent of
158 tal_t *tal_next(const tal_t *root, const tal_t *prev);
161 * tal_parent - get the parent of a tal object.
162 * @ctx: The tal allocated object.
164 * Returns the parent, which may be NULL. Returns NULL if @ctx is NULL.
166 tal_t *tal_parent(const tal_t *ctx);
169 * tal_memdup - duplicate memory.
170 * @ctx: NULL, or tal allocated object to be parent (or TAL_TAKE).
171 * @p: the memory to copy
172 * @n: the number of bytes.
175 void *tal_memdup(const tal_t *ctx, const void *p, size_t n);
178 * tal_strdup - duplicate a string
179 * @ctx: NULL, or tal allocated object to be parent (or TAL_TAKE).
180 * @p: the string to copy
182 char *tal_strdup(const tal_t *ctx, const char *p);
185 * tal_strndup - duplicate a limited amount of a string.
186 * @ctx: NULL, or tal allocated object to be parent (or TAL_TAKE).
187 * @p: the string to copy
188 * @n: the maximum length to copy.
190 * Always gives a nul-terminated string, with strlen() <= @n.
192 char *tal_strndup(const tal_t *ctx, const char *p, size_t n);
195 * tal_asprintf - allocate a formatted string
196 * @ctx: NULL, or tal allocated object to be parent (or TAL_TAKE).
197 * @fmt: the printf-style format.
199 * If @ctx is TAL_TAKE, @fmt is freed and its parent will be the parent
200 * of the return value.
202 char *tal_asprintf(const tal_t *ctx, const char *fmt, ...) PRINTF_FMT(2,3);
205 * tal_vasprintf - allocate a formatted string (va_list version)
206 * @ctx: NULL, or tal allocated object to be parent (or TAL_TAKE).
207 * @fmt: the printf-style format.
208 * @va: the va_list containing the format args.
210 * If @ctx is TAL_TAKE, @fmt is freed and its parent will be the parent
211 * of the return value.
213 char *tal_vasprintf(const tal_t *ctx, const char *fmt, va_list ap)
218 * tal_set_backend - set the allocation or error functions to use
219 * @alloc_fn: allocator or NULL (default is malloc)
220 * @resize_fn: re-allocator or NULL (default is realloc)
221 * @free_fn: free function or NULL (default is free)
222 * @error_fn: called on errors or NULL (default is abort)
224 * The defaults are set up so tal functions never return NULL, but you
225 * can override erorr_fn to change that. error_fn can return, and is
226 * called if alloc_fn or resize_fn fail.
228 * If any parameter is NULL, that function is unchanged.
230 void tal_set_backend(void *(*alloc_fn)(size_t size),
231 void *(*resize_fn)(void *, size_t size),
232 void (*free_fn)(void *),
233 void (*error_fn)(const char *msg));
237 * tal_check - set the allocation or error functions to use
238 * @ctx: a tal context, or NULL.
239 * @errorstr: a string to prepend calls to error_fn, or NULL.
241 * This sanity-checks a tal tree (unless NDEBUG is defined, in which case
242 * it simply returns true). If errorstr is not null, error_fn is called
243 * when a problem is found, otherwise it is not.
245 bool tal_check(const tal_t *ctx, const char *errorstr);
247 #ifdef CCAN_TAL_DEBUG
249 * tal_dump - dump entire tal tree.
251 * This is a helper for debugging tal itself, which dumps all the tal internal
257 /* Internal support functions */
259 #ifdef CCAN_TAL_NO_LABELS
260 #define TAL_LABEL(type, arr) NULL
262 #ifdef CCAN_TAL_DEBUG
263 #define TAL_LABEL(type, arr) \
264 __FILE__ ":" stringify(__LINE__) ":" stringify(type) arr
266 #define TAL_LABEL(type, arr) stringify(type) arr
267 #endif /* CCAN_TAL_DEBUG */
271 #if HAVE_BUILTIN_CONSTANT_P
272 #define TAL_IS_LITERAL(str) __builtin_constant_p(str)
274 #define TAL_IS_LITERAL(str) (sizeof(&*(str)) != sizeof(char *))
277 bool tal_set_name_(tal_t *ctx, const char *name, bool literal);
279 static inline size_t tal_sizeof_(size_t size, size_t count)
281 /* Multiplication wrap */
282 if (count && unlikely(size * count / size != count))
283 return (size_t)-1024;
287 /* Make sure we don't wrap adding header. */
288 if (size > (size_t)-1024)
289 return (size_t)-1024;
295 #define tal_typeof(ptr) (__typeof__(ptr))
297 #define tal_typeof(ptr)
300 void *tal_alloc_(const tal_t *ctx, size_t bytes, bool clear, const char *label);
302 tal_t *tal_steal_(const tal_t *new_parent, const tal_t *t);
304 void *tal_realloc_(tal_t *ctx, size_t size);
306 bool tal_add_destructor_(tal_t *ctx, void (*destroy)(void *me));
308 #endif /* CCAN_TAL_H */