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29 * no longer valid for external use.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 void tal_free(const tal_t *p);
65 * tal_arr - allocate an array of objects.
66 * @ctx: NULL, or tal allocated object to be parent.
67 * @type: the type to allocate.
68 * @count: the number to allocate.
70 #define tal_arr(ctx, type, count) \
71 ((type *)tal_alloc_((ctx), tal_sizeof_(sizeof(type), (count)), false, \
72 TAL_LABEL(type, "[]")))
75 * tal_arrz - allocate an array of zeroed objects.
76 * @ctx: NULL, or tal allocated object to be parent.
77 * @type: the type to allocate.
78 * @count: the number to allocate.
80 #define tal_arrz(ctx, type, count) \
81 ((type *)tal_alloc_((ctx), tal_sizeof_(sizeof(type), (count)), true, \
82 TAL_LABEL(type, "[]")))
85 * tal_resize - enlarge or reduce a tal_arr(z).
86 * @p: The tal allocated array to resize.
87 * @count: the number to allocate.
89 * This returns the new pointer, or NULL (and destroys the old one)
92 #define tal_resize(p, count) \
93 ((tal_typeof(p) tal_realloc_((p), tal_sizeof_(sizeof(*p), (count)))))
96 * tal_steal - change the parent of a tal-allocated pointer.
97 * @ctx: The new parent.
98 * @ptr: The tal allocated object to move.
100 * This may need to perform an allocation, in which case it may fail; thus
101 * it can return NULL, otherwise returns @ptr.
103 * Weird macro avoids gcc's 'warning: value computed is not used'.
105 #if HAVE_STATEMENT_EXPR
106 #define tal_steal(ctx, ptr) \
107 ({ (tal_typeof(ptr) tal_steal_((ctx),(ptr))); })
109 #define tal_steal(ctx, ptr) \
110 (tal_typeof(ptr) tal_steal_((ctx),(ptr)))
114 * tal_add_destructor - add a callback function when this context is destroyed.
115 * @ptr: The tal allocated object.
116 * @function: the function to call before it's freed.
118 #define tal_add_destructor(ptr, function) \
119 tal_add_destructor_((ptr), typesafe_cb(void, void *, (function), (ptr)))
122 * tal_set_name - attach a name to a tal pointer.
123 * @ptr: The tal allocated object.
124 * @name: The name to use.
126 * The name is copied, unless we're certain it's a string literal.
128 #define tal_set_name(ptr, name) \
129 tal_set_name_((ptr), (name), TAL_IS_LITERAL(name))
132 * tal_name - get the name for a tal pointer.
133 * @ptr: The tal allocated object.
135 * Returns NULL if no name has been set.
137 const char *tal_name(const tal_t *ptr);
140 * tal_first - get the first tal object child.
141 * @root: The tal allocated object to start with, or NULL.
143 * Returns NULL if there are no children.
145 tal_t *tal_first(const tal_t *root);
148 * tal_next - get the next tal object child.
149 * @root: The tal allocated object to start with, or NULL.
150 * @prev: The return value from tal_first or tal_next.
152 * Returns NULL if there are no more children. This should be safe to
153 * call on an altering tree unless @prev is no longer a descendent of
156 tal_t *tal_next(const tal_t *root, const tal_t *prev);
159 * tal_parent - get the parent of a tal object.
160 * @ctx: The tal allocated object.
162 * Returns the parent, which may be NULL. Returns NULL if @ctx is NULL.
164 tal_t *tal_parent(const tal_t *ctx);
167 * tal_memdup - duplicate memory.
168 * @ctx: NULL, or tal allocated object to be parent (or TAL_TAKE).
169 * @p: the memory to copy
170 * @n: the number of bytes.
173 void *tal_memdup(const tal_t *ctx, const void *p, size_t n);
176 * tal_strdup - duplicate a string
177 * @ctx: NULL, or tal allocated object to be parent (or TAL_TAKE).
178 * @p: the string to copy
180 char *tal_strdup(const tal_t *ctx, const char *p);
183 * tal_strndup - duplicate a limited amount of a string.
184 * @ctx: NULL, or tal allocated object to be parent (or TAL_TAKE).
185 * @p: the string to copy
186 * @n: the maximum length to copy.
188 * Always gives a nul-terminated string, with strlen() <= @n.
190 char *tal_strndup(const tal_t *ctx, const char *p, size_t n);
193 * tal_asprintf - allocate a formatted string
194 * @ctx: NULL, or tal allocated object to be parent (or TAL_TAKE).
195 * @fmt: the printf-style format.
197 * If @ctx is TAL_TAKE, @fmt is freed and its parent will be the parent
198 * of the return value.
200 char *tal_asprintf(const tal_t *ctx, const char *fmt, ...) PRINTF_FMT(2,3);
203 * tal_vasprintf - allocate a formatted string (va_list version)
204 * @ctx: NULL, or tal allocated object to be parent (or TAL_TAKE).
205 * @fmt: the printf-style format.
206 * @va: the va_list containing the format args.
208 * If @ctx is TAL_TAKE, @fmt is freed and its parent will be the parent
209 * of the return value.
211 char *tal_vasprintf(const tal_t *ctx, const char *fmt, va_list ap)
216 * tal_set_backend - set the allocation or error functions to use
217 * @alloc_fn: allocator or NULL (default is malloc)
218 * @resize_fn: re-allocator or NULL (default is realloc)
219 * @free_fn: free function or NULL (default is free)
220 * @error_fn: called on errors or NULL (default is abort)
222 * The defaults are set up so tal functions never return NULL, but you
223 * can override erorr_fn to change that. error_fn can return, and is
224 * called if alloc_fn or resize_fn fail.
226 * If any parameter is NULL, that function is unchanged.
228 void tal_set_backend(void *(*alloc_fn)(size_t size),
229 void *(*resize_fn)(void *, size_t size),
230 void (*free_fn)(void *),
231 void (*error_fn)(const char *msg));
235 * tal_check - set the allocation or error functions to use
236 * @ctx: a tal context, or NULL.
237 * @errorstr: a string to prepend calls to error_fn, or NULL.
239 * This sanity-checks a tal tree (unless NDEBUG is defined, in which case
240 * it simply returns true). If errorstr is not null, error_fn is called
241 * when a problem is found, otherwise it is not.
243 bool tal_check(const tal_t *ctx, const char *errorstr);
245 #ifdef CCAN_TAL_DEBUG
247 * tal_dump - dump entire tal tree.
249 * This is a helper for debugging tal itself, which dumps all the tal internal
255 /* Internal support functions */
257 #ifdef CCAN_TAL_NO_LABELS
258 #define TAL_LABEL(type, arr) NULL
260 #ifdef CCAN_TAL_DEBUG
261 #define TAL_LABEL(type, arr) \
262 __FILE__ ":" stringify(__LINE__) ":" stringify(type) arr
264 #define TAL_LABEL(type, arr) stringify(type) arr
265 #endif /* CCAN_TAL_DEBUG */
269 #if HAVE_BUILTIN_CONSTANT_P
270 #define TAL_IS_LITERAL(str) __builtin_constant_p(str)
272 #define TAL_IS_LITERAL(str) (sizeof(&*(str)) != sizeof(char *))
275 bool tal_set_name_(tal_t *ctx, const char *name, bool literal);
277 static inline size_t tal_sizeof_(size_t size, size_t count)
279 /* Multiplication wrap */
280 if (count && unlikely(size * count / size != count))
281 return (size_t)-1024;
285 /* Make sure we don't wrap adding header. */
286 if (size > (size_t)-1024)
287 return (size_t)-1024;
293 #define tal_typeof(ptr) (__typeof__(ptr))
295 #define tal_typeof(ptr)
298 void *tal_alloc_(const tal_t *ctx, size_t bytes, bool clear, const char *label);
300 tal_t *tal_steal_(const tal_t *new_parent, const tal_t *t);
302 void *tal_realloc_(tal_t *ctx, size_t size);
304 bool tal_add_destructor_(tal_t *ctx, void (*destroy)(void *me));
306 #endif /* CCAN_TAL_H */