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 - basic allocator function
22 * @ctx: NULL, or tal allocated object to be parent.
23 * @type: the type to allocate.
25 * Allocates a specific type, with a given parent context.
27 #define tal(ctx, type) tal_arr((ctx), type, 1)
30 * talz - zeroing allocator function
31 * @ctx: NULL, or tal allocated object to be parent.
32 * @type: the type to allocate.
34 * Equivalent to tal() followed by memset() to zero.
36 #define talz(ctx, type) tal_arrz((ctx), type, 1)
39 * tal_free - free a tal-allocated pointer.
40 * @p: NULL, or tal allocated object to free.
42 * This calls the destructors for p (if any), then does the same for all its
43 * children (recursively) before finally freeing the memory.
45 void tal_free(const tal_t *p);
48 * tal_arr - allocate an array of objects.
49 * @ctx: NULL, or tal allocated object to be parent.
50 * @type: the type to allocate.
51 * @count: the number to allocate.
53 #define tal_arr(ctx, type, count) \
54 ((type *)tal_alloc_((ctx), tal_sizeof_(sizeof(type), (count)), false))
57 * tal_arrz - allocate an array of zeroed objects.
58 * @ctx: NULL, or tal allocated object to be parent.
59 * @type: the type to allocate.
60 * @count: the number to allocate.
62 #define tal_arrz(ctx, type, count) \
63 ((type *)tal_alloc_((ctx), tal_sizeof_(sizeof(type), (count)), true))
66 * tal_resize - enlarge or reduce a tal_arr(z).
67 * @p: The tal allocated array to resize.
68 * @count: the number to allocate.
70 * This returns the new pointer, or NULL (and destroys the old one)
73 #define tal_resize(p, count) \
74 ((tal_typeof(p) tal_realloc_((p), tal_sizeof_(sizeof(*p), (count)))))
77 * tal_steal - change the parent of a tal-allocated pointer.
78 * @ctx: The new parent.
79 * @ptr: The tal allocated object to move.
81 * This may need to perform an allocation, in which case it may fail; thus
82 * it can return NULL, otherwise returns @ptr.
84 * Weird macro avoids gcc's 'warning: value computed is not used'.
86 #if HAVE_STATEMENT_EXPR
87 #define tal_steal(ctx, ptr) \
88 ({ (tal_typeof(ptr) tal_steal_((ctx),(ptr))); })
90 #define tal_steal(ctx, ptr) \
91 (tal_typeof(ptr) tal_steal_((ctx),(ptr)))
95 * tal_add_destructor - add a callback function when this context is destroyed.
96 * @ptr: The tal allocated object.
97 * @function: the function to call before it's freed.
99 #define tal_add_destructor(ptr, function) \
100 tal_add_destructor_((ptr), typesafe_cb(void, void *, (function), (ptr)))
103 * tal_set_name - attach a name to a tal pointer.
104 * @ptr: The tal allocated object.
105 * @name: The name to use.
107 * The name is copied, unless we're certain it's a string literal.
109 #define tal_set_name(ptr, name) \
110 tal_set_name_((ptr), (name), TAL_IS_LITERAL(name))
113 * tal_name - get the name for a tal pointer.
114 * @ptr: The tal allocated object.
116 * Returns NULL if no name has been set.
118 const char *tal_name(const tal_t *ptr);
121 * tal_first - get the first tal object child.
122 * @root: The tal allocated object to start with, or NULL.
124 * Returns NULL if there are no children.
126 tal_t *tal_first(const tal_t *root);
129 * tal_next - get the next tal object child.
130 * @root: The tal allocated object to start with, or NULL.
131 * @prev: The return value from tal_first or tal_next.
133 * Returns NULL if there are no more children. This should be safe to
134 * call on an altering tree unless @prev is no longer a descendent of
137 tal_t *tal_next(const tal_t *root, const tal_t *prev);
140 * tal_parent - get the parent of a tal object.
141 * @ctx: The tal allocated object.
143 * Returns the parent, which may be NULL.
145 tal_t *tal_parent(const tal_t *ctx);
148 * tal_memdup - duplicate memory.
149 * @ctx: NULL, or tal allocated object to be parent.
150 * @p: the memory to copy
151 * @n: the number of bytes.
153 void *tal_memdup(const tal_t *ctx, const void *p, size_t n);
156 * tal_strdup - duplicate a string.
157 * @ctx: NULL, or tal allocated object to be parent.
158 * @p: the string to copy
160 char *tal_strdup(const tal_t *ctx, const char *p);
163 * tal_strndup - duplicate a limited amount of a string.
164 * @ctx: NULL, or tal allocated object to be parent.
165 * @p: the string to copy
166 * @n: the maximum length to copy.
168 * Always gives a nul-terminated string, with strlen() <= @n.
170 char *tal_strndup(const tal_t *ctx, const char *p, size_t n);
173 * tal_asprintf - allocate a formatted string
174 * @ctx: NULL, or tal allocated object to be parent.
175 * @fmt: the printf-style format.
177 char *tal_asprintf(const tal_t *ctx, const char *fmt, ...) PRINTF_FMT(2,3);
180 * tal_vasprintf - allocate a formatted string (va_list version)
181 * @ctx: NULL, or tal allocated object to be parent.
182 * @fmt: the printf-style format.
183 * @va: the va_list containing the format args.
185 char *tal_vasprintf(const tal_t *ctx, const char *fmt, va_list ap)
190 * tal_set_backend - set the allocation or error functions to use
191 * @alloc_fn: allocator or NULL (default is malloc)
192 * @resize_fn: re-allocator or NULL (default is realloc)
193 * @free_fn: free function or NULL (default is free)
194 * @error_fn: called on errors or NULL (default is abort)
196 * The defaults are set up so tal functions never return NULL, but you
197 * can override erorr_fn to change that. error_fn can return, and is
198 * called if alloc_fn or resize_fn fail.
200 * If any parameter is NULL, that function is unchanged.
202 void tal_set_backend(void *(*alloc_fn)(size_t size),
203 void *(*resize_fn)(void *, size_t size),
204 void (*free_fn)(void *),
205 void (*error_fn)(const char *msg));
209 * tal_check - set the allocation or error functions to use
210 * @ctx: a tal context, or NULL.
211 * @errorstr: a string to prepend calls to error_fn, or NULL.
213 * This sanity-checks a tal tree (unless NDEBUG is defined, in which case
214 * it simply returns true). If errorstr is not null, error_fn is called
215 * when a problem is found, otherwise it is not.
217 bool tal_check(const tal_t *ctx, const char *errorstr);
219 #ifdef CCAN_TAL_DEBUG
221 * tal_dump - dump entire tal tree.
223 * This is a helper for debugging tal itself, which dumps all the tal internal
229 /* Internal support functions */
230 #if HAVE_BUILTIN_CONSTANT_P
231 #define TAL_IS_LITERAL(str) __builtin_constant_p(str)
233 #define TAL_IS_LITERAL(str) (sizeof(&*(str)) != sizeof(char *))
236 bool tal_set_name_(tal_t *ctx, const char *name, bool literal);
238 static inline size_t tal_sizeof_(size_t size, size_t count)
240 /* Multiplication wrap */
241 if (count && unlikely(size * count / size != count))
242 return (size_t)-1024;
246 /* Make sure we don't wrap adding header. */
247 if (size > (size_t)-1024)
248 return (size_t)-1024;
254 #define tal_typeof(ptr) (__typeof__(ptr))
256 #define tal_typeof(ptr)
259 void *tal_alloc_(const tal_t *ctx, size_t bytes, bool clear);
261 tal_t *tal_steal_(const tal_t *new_parent, const tal_t *t);
263 void *tal_realloc_(tal_t *ctx, size_t size);
265 bool tal_add_destructor_(tal_t *ctx, void (*destroy)(void *me));
267 #endif /* CCAN_TAL_H */