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>
13 * tal_t - convenient alias for void to mark tal pointers.
15 * Since any pointer can be a tal-allocated pointer, it's often
16 * useful to use this typedef to mark them explicitly.
21 * TAL_TAKE - fake tal_t to indicate function will own arguments.
23 * Various functions take a context on which to allocate: if you use
24 * TAL_TAKE there instead, it means that the argument(s) are actually
25 * tal objects. The returned value will share the same parent; it may
26 * even be the same pointer as the arguments. The arguments themselves
27 * will be reused, freed, or made a child of the return value: they are
28 * no longer valid for external use.
30 #define TAL_TAKE ((tal_t *)-2L)
33 * tal - basic allocator function
34 * @ctx: NULL, or tal allocated object to be parent.
35 * @type: the type to allocate.
37 * Allocates a specific type, with a given parent context.
39 #define tal(ctx, type) tal_arr((ctx), type, 1)
42 * talz - zeroing allocator function
43 * @ctx: NULL, or tal allocated object to be parent.
44 * @type: the type to allocate.
46 * Equivalent to tal() followed by memset() to zero.
48 #define talz(ctx, type) tal_arrz((ctx), type, 1)
51 * tal_free - free a tal-allocated pointer.
52 * @p: NULL, or tal allocated object to free.
54 * This calls the destructors for p (if any), then does the same for all its
55 * children (recursively) before finally freeing the memory.
57 void tal_free(const tal_t *p);
60 * tal_arr - allocate an array of objects.
61 * @ctx: NULL, or tal allocated object to be parent.
62 * @type: the type to allocate.
63 * @count: the number to allocate.
65 #define tal_arr(ctx, type, count) \
66 ((type *)tal_alloc_((ctx), tal_sizeof_(sizeof(type), (count)), false))
69 * tal_arrz - allocate an array of zeroed objects.
70 * @ctx: NULL, or tal allocated object to be parent.
71 * @type: the type to allocate.
72 * @count: the number to allocate.
74 #define tal_arrz(ctx, type, count) \
75 ((type *)tal_alloc_((ctx), tal_sizeof_(sizeof(type), (count)), true))
78 * tal_resize - enlarge or reduce a tal_arr(z).
79 * @p: The tal allocated array to resize.
80 * @count: the number to allocate.
82 * This returns the new pointer, or NULL (and destroys the old one)
85 #define tal_resize(p, count) \
86 ((tal_typeof(p) tal_realloc_((p), tal_sizeof_(sizeof(*p), (count)))))
89 * tal_steal - change the parent of a tal-allocated pointer.
90 * @ctx: The new parent.
91 * @ptr: The tal allocated object to move.
93 * This may need to perform an allocation, in which case it may fail; thus
94 * it can return NULL, otherwise returns @ptr.
96 * Weird macro avoids gcc's 'warning: value computed is not used'.
98 #if HAVE_STATEMENT_EXPR
99 #define tal_steal(ctx, ptr) \
100 ({ (tal_typeof(ptr) tal_steal_((ctx),(ptr))); })
102 #define tal_steal(ctx, ptr) \
103 (tal_typeof(ptr) tal_steal_((ctx),(ptr)))
107 * tal_add_destructor - add a callback function when this context is destroyed.
108 * @ptr: The tal allocated object.
109 * @function: the function to call before it's freed.
111 #define tal_add_destructor(ptr, function) \
112 tal_add_destructor_((ptr), typesafe_cb(void, void *, (function), (ptr)))
115 * tal_set_name - attach a name to a tal pointer.
116 * @ptr: The tal allocated object.
117 * @name: The name to use.
119 * The name is copied, unless we're certain it's a string literal.
121 #define tal_set_name(ptr, name) \
122 tal_set_name_((ptr), (name), TAL_IS_LITERAL(name))
125 * tal_name - get the name for a tal pointer.
126 * @ptr: The tal allocated object.
128 * Returns NULL if no name has been set.
130 const char *tal_name(const tal_t *ptr);
133 * tal_first - get the first tal object child.
134 * @root: The tal allocated object to start with, or NULL.
136 * Returns NULL if there are no children.
138 tal_t *tal_first(const tal_t *root);
141 * tal_next - get the next tal object child.
142 * @root: The tal allocated object to start with, or NULL.
143 * @prev: The return value from tal_first or tal_next.
145 * Returns NULL if there are no more children. This should be safe to
146 * call on an altering tree unless @prev is no longer a descendent of
149 tal_t *tal_next(const tal_t *root, const tal_t *prev);
152 * tal_parent - get the parent of a tal object.
153 * @ctx: The tal allocated object.
155 * Returns the parent, which may be NULL.
157 tal_t *tal_parent(const tal_t *ctx);
160 * tal_memdup - duplicate memory.
161 * @ctx: NULL, or tal allocated object to be parent (or TAL_TAKE).
162 * @p: the memory to copy
163 * @n: the number of bytes.
166 void *tal_memdup(const tal_t *ctx, const void *p, size_t n);
169 * tal_strdup - duplicate a string
170 * @ctx: NULL, or tal allocated object to be parent (or TAL_TAKE).
171 * @p: the string to copy
173 char *tal_strdup(const tal_t *ctx, const char *p);
176 * tal_strndup - duplicate a limited amount of a string.
177 * @ctx: NULL, or tal allocated object to be parent (or TAL_TAKE).
178 * @p: the string to copy
179 * @n: the maximum length to copy.
181 * Always gives a nul-terminated string, with strlen() <= @n.
183 char *tal_strndup(const tal_t *ctx, const char *p, size_t n);
186 * tal_asprintf - allocate a formatted string
187 * @ctx: NULL, or tal allocated object to be parent (or TAL_TAKE).
188 * @fmt: the printf-style format.
190 * If @ctx is TAL_TAKE, @fmt is freed and its parent will be the parent
191 * of the return value.
193 char *tal_asprintf(const tal_t *ctx, const char *fmt, ...) PRINTF_FMT(2,3);
196 * tal_vasprintf - allocate a formatted string (va_list version)
197 * @ctx: NULL, or tal allocated object to be parent (or TAL_TAKE).
198 * @fmt: the printf-style format.
199 * @va: the va_list containing the format args.
201 * If @ctx is TAL_TAKE, @fmt is freed and its parent will be the parent
202 * of the return value.
204 char *tal_vasprintf(const tal_t *ctx, const char *fmt, va_list ap)
209 * tal_set_backend - set the allocation or error functions to use
210 * @alloc_fn: allocator or NULL (default is malloc)
211 * @resize_fn: re-allocator or NULL (default is realloc)
212 * @free_fn: free function or NULL (default is free)
213 * @error_fn: called on errors or NULL (default is abort)
215 * The defaults are set up so tal functions never return NULL, but you
216 * can override erorr_fn to change that. error_fn can return, and is
217 * called if alloc_fn or resize_fn fail.
219 * If any parameter is NULL, that function is unchanged.
221 void tal_set_backend(void *(*alloc_fn)(size_t size),
222 void *(*resize_fn)(void *, size_t size),
223 void (*free_fn)(void *),
224 void (*error_fn)(const char *msg));
228 * tal_check - set the allocation or error functions to use
229 * @ctx: a tal context, or NULL.
230 * @errorstr: a string to prepend calls to error_fn, or NULL.
232 * This sanity-checks a tal tree (unless NDEBUG is defined, in which case
233 * it simply returns true). If errorstr is not null, error_fn is called
234 * when a problem is found, otherwise it is not.
236 bool tal_check(const tal_t *ctx, const char *errorstr);
238 #ifdef CCAN_TAL_DEBUG
240 * tal_dump - dump entire tal tree.
242 * This is a helper for debugging tal itself, which dumps all the tal internal
248 /* Internal support functions */
249 #if HAVE_BUILTIN_CONSTANT_P
250 #define TAL_IS_LITERAL(str) __builtin_constant_p(str)
252 #define TAL_IS_LITERAL(str) (sizeof(&*(str)) != sizeof(char *))
255 bool tal_set_name_(tal_t *ctx, const char *name, bool literal);
257 static inline size_t tal_sizeof_(size_t size, size_t count)
259 /* Multiplication wrap */
260 if (count && unlikely(size * count / size != count))
261 return (size_t)-1024;
265 /* Make sure we don't wrap adding header. */
266 if (size > (size_t)-1024)
267 return (size_t)-1024;
273 #define tal_typeof(ptr) (__typeof__(ptr))
275 #define tal_typeof(ptr)
278 void *tal_alloc_(const tal_t *ctx, size_t bytes, bool clear);
280 tal_t *tal_steal_(const tal_t *new_parent, const tal_t *t);
282 void *tal_realloc_(tal_t *ctx, size_t size);
284 bool tal_add_destructor_(tal_t *ctx, void (*destroy)(void *me));
286 #endif /* CCAN_TAL_H */