damus

tal.h (18447B)

---

 /* Licensed under BSD-MIT - see LICENSE file for details */
 #ifndef CCAN_TAL_H
 #define CCAN_TAL_H
 #include "config.h"
 #include <ccan/compiler/compiler.h>
 #include <ccan/likely/likely.h>
 #include <ccan/typesafe_cb/typesafe_cb.h>
 #include <ccan/str/str.h>
 #include <ccan/take/take.h>
 #include <stdlib.h>
 #include <stdbool.h>
 #include <stdarg.h>
 
 /* Define this for better optimization if you never override errfn
  * to something tat returns */
 #ifdef CCAN_TAL_NEVER_RETURN_NULL
 #define TAL_RETURN_PTR RETURNS_NONNULL
 #else
 #define TAL_RETURN_PTR
 #endif /* CCAN_TAL_NEVER_RETURN_NULL */
 
 /**
  * tal_t - convenient alias for void to mark tal pointers.
  *
  * Since any pointer can be a tal-allocated pointer, it's often
  * useful to use this typedef to mark them explicitly.
  */
 typedef void tal_t;
 
 /**
  * tal - basic allocator function
  * @ctx: NULL, or tal allocated object to be parent.
  * @type: the type to allocate.
  *
  * Allocates a specific type, with a given parent context.  The name
  * of the object is a string of the type, but if CCAN_TAL_DEBUG is
  * defined it also contains the file and line which allocated it.
  *
  * tal_count() of the return will be 1.
  *
  * Example:
  *	int *p = tal(NULL, int);
  *	*p = 1;
  */
 #define tal(ctx, type)							\
 	tal_label(ctx, type, TAL_LABEL(type, ""))
 
 /**
  * talz - zeroing allocator function
  * @ctx: NULL, or tal allocated object to be parent.
  * @type: the type to allocate.
  *
  * Equivalent to tal() followed by memset() to zero.
  *
  * Example:
  *	p = talz(NULL, int);
  *	assert(*p == 0);
  */
 #define talz(ctx, type)							\
 	talz_label(ctx, type, TAL_LABEL(type, ""))
 
 /**
  * tal_free - free a tal-allocated pointer.
  * @p: NULL, or tal allocated object to free.
  *
  * This calls the destructors for p (if any), then does the same for all its
  * children (recursively) before finally freeing the memory.  It returns
  * NULL, for convenience.
  *
  * Note: errno is preserved by this call, and also saved and restored
  * for any destructors or notifiers.
  *
  * Example:
  *	p = tal_free(p);
  */
 void *tal_free(const tal_t *p);
 
 /**
  * tal_arr - allocate an array of objects.
  * @ctx: NULL, or tal allocated object to be parent.
  * @type: the type to allocate.
  * @count: the number to allocate.
  *
  * tal_count() of the returned pointer will be @count.
  *
  * Example:
  *	p = tal_arr(NULL, int, 2);
  *	p[0] = 0;
  *	p[1] = 1;
  */
 #define tal_arr(ctx, type, count)					\
 	tal_arr_label(ctx, type, count, TAL_LABEL(type, "[]"))
 
 /**
  * tal_arrz - allocate an array of zeroed objects.
  * @ctx: NULL, or tal allocated object to be parent.
  * @type: the type to allocate.
  * @count: the number to allocate.
  *
  * Equivalent to tal_arr() followed by memset() to zero.
  *
  * Example:
  *	p = tal_arrz(NULL, int, 2);
  *	assert(p[0] == 0 && p[1] == 0);
  */
 #define tal_arrz(ctx, type, count) \
 	tal_arrz_label(ctx, type, count, TAL_LABEL(type, "[]"))
 
 /**
  * tal_resize - enlarge or reduce a tal object.
  * @p: A pointer to the tal allocated array to resize.
  * @count: the number to allocate.
  *
  * This returns true on success (and may move *@p), or false on failure.
  * On success, tal_count() of *@p will be @count.
  *
  * Note: if *p is take(), it will still be take() upon return, even if it
  * has been moved.
  *
  * Example:
  *	tal_resize(&p, 100);
  */
 #define tal_resize(p, count) \
 	tal_resize_((void **)(p), sizeof**(p), (count), false)
 
 /**
  * tal_resizez - enlarge or reduce a tal object; zero out extra.
  * @p: A pointer to the tal allocated array to resize.
  * @count: the number to allocate.
  *
  * This returns true on success (and may move *@p), or false on failure.
  *
  * Example:
  *	tal_resizez(&p, 200);
  */
 #define tal_resizez(p, count) \
 	tal_resize_((void **)(p), sizeof**(p), (count), true)
 
 /**
  * tal_steal - change the parent of a tal-allocated pointer.
  * @ctx: The new parent.
  * @ptr: The tal allocated object to move, or NULL.
  *
  * This may need to perform an allocation, in which case it may fail; thus
  * it can return NULL, otherwise returns @ptr.  If @ptr is NULL, this function does
  * nothing.
  */
 #if HAVE_STATEMENT_EXPR
 /* Weird macro avoids gcc's 'warning: value computed is not used'. */
 #define tal_steal(ctx, ptr) \
 	({ (tal_typeof(ptr) tal_steal_((ctx),(ptr))); })
 #else
 #define tal_steal(ctx, ptr) \
 	(tal_typeof(ptr) tal_steal_((ctx),(ptr)))
 #endif
 
 /**
  * tal_add_destructor - add a callback function when this context is destroyed.
  * @ptr: The tal allocated object.
  * @function: the function to call before it's freed.
  *
  * This is a more convenient form of tal_add_notifier(@ptr,
  * TAL_NOTIFY_FREE, ...), in that the function prototype takes only @ptr.
  *
  * Note that this can only fail if your allocfn fails and your errorfn returns.
  */
 #define tal_add_destructor(ptr, function)				      \
 	tal_add_destructor_((ptr), typesafe_cb(void, void *, (function), (ptr)))
 
 /**
  * tal_del_destructor - remove a destructor callback function.
  * @ptr: The tal allocated object.
  * @function: the function to call before it's freed.
  *
  * If @function has not been successfully added as a destructor, this returns
  * false.  Note that if we're inside the destructor call itself, this will
  * return false.
  */
 #define tal_del_destructor(ptr, function)				      \
 	tal_del_destructor_((ptr), typesafe_cb(void, void *, (function), (ptr)))
 
 /**
  * tal_add_destructor2 - add a 2-arg callback function when context is destroyed.
  * @ptr: The tal allocated object.
  * @function: the function to call before it's freed.
  * @arg: the extra argument to the function.
  *
  * Sometimes an extra argument is required for a destructor; this
  * saves the extra argument internally to avoid the caller having to
  * do an extra allocation.
  *
  * Note that this can only fail if your allocfn fails and your errorfn returns.
  */
 #define tal_add_destructor2(ptr, function, arg)				\
 	tal_add_destructor2_((ptr),					\
 			     typesafe_cb_cast(void (*)(tal_t *, void *), \
 					      void (*)(__typeof__(ptr), \
 						       __typeof__(arg)), \
 					      (function)),		\
 			     (arg))
 
 /**
  * tal_del_destructor - remove a destructor callback function.
  * @ptr: The tal allocated object.
  * @function: the function to call before it's freed.
  *
  * If @function has not been successfully added as a destructor, this returns
  * false.  Note that if we're inside the destructor call itself, this will
  * return false.
  */
 #define tal_del_destructor(ptr, function)				      \
 	tal_del_destructor_((ptr), typesafe_cb(void, void *, (function), (ptr)))
 
 /**
  * tal_del_destructor2 - remove 2-arg callback function.
  * @ptr: The tal allocated object.
  * @function: the function to call before it's freed.
  * @arg: the extra argument to the function.
  *
  * If @function has not been successfully added as a destructor with
  * @arg, this returns false.
  */
 #define tal_del_destructor2(ptr, function, arg)				\
 	tal_del_destructor2_((ptr),					\
 			     typesafe_cb_cast(void (*)(tal_t *, void *), \
 					      void (*)(__typeof__(ptr), \
 						       __typeof__(arg)), \
 					      (function)),		\
 			     (arg))
 enum tal_notify_type {
 	TAL_NOTIFY_FREE = 1,
 	TAL_NOTIFY_STEAL = 2,
 	TAL_NOTIFY_MOVE = 4,
 	TAL_NOTIFY_RESIZE = 8,
 	TAL_NOTIFY_RENAME = 16,
 	TAL_NOTIFY_ADD_CHILD = 32,
 	TAL_NOTIFY_DEL_CHILD = 64,
 	TAL_NOTIFY_ADD_NOTIFIER = 128,
 	TAL_NOTIFY_DEL_NOTIFIER = 256
 };
 
 /**
  * tal_add_notifier - add a callback function when this context changes.
  * @ptr: The tal allocated object, or NULL.
  * @types: Bitwise OR of the types the callback is interested in.
  * @callback: the function to call.
  *
  * Note that this can only fail if your allocfn fails and your errorfn
  * returns.  Also note that notifiers are not reliable in the case
  * where an allocation fails, as they may be called before any
  * allocation is actually done.
  *
  * TAL_NOTIFY_FREE is called when @ptr is freed, either directly or
  * because an ancestor is freed: @info is the argument to tal_free().
  * It is exactly equivalent to a destructor, with more information.
  * errno is set to the value it was at the call of tal_free().
  *
  * TAL_NOTIFY_STEAL is called when @ptr's parent changes: @info is the
  * new parent.
  *
  * TAL_NOTIFY_MOVE is called when @ptr is realloced (via tal_resize)
  * and moved.  In this case, @ptr arg here is the new memory, and
  * @info is the old pointer.
  *
  * TAL_NOTIFY_RESIZE is called when @ptr is realloced via tal_resize:
  * @info is the new size, in bytes.  If the pointer has moved,
  * TAL_NOTIFY_MOVE callbacks are called first.
  *
  * TAL_NOTIFY_ADD_CHILD/TAL_NOTIFY_DEL_CHILD are called when @ptr is
  * the context for a tal() allocating call, or a direct child is
  * tal_free()d: @info is the child.  Note that TAL_NOTIFY_DEL_CHILD is
  * not called when this context is tal_free()d: TAL_NOTIFY_FREE is
  * considered sufficient for that case.
  *
  * TAL_NOTIFY_ADD_NOTIFIER/TAL_NOTIFIER_DEL_NOTIFIER are called when a
  * notifier is added or removed (not for this notifier): @info is the
  * callback.  This is also called for tal_add_destructor and
  * tal_del_destructor.
  */
 #define tal_add_notifier(ptr, types, callback)				\
 	tal_add_notifier_((ptr), (types),				\
 			  typesafe_cb_postargs(void, tal_t *, (callback), \
 					       (ptr),			\
 					       enum tal_notify_type, void *))
 
 /**
  * tal_del_notifier - remove a notifier callback function.
  * @ptr: The tal allocated object.
  * @callback: the function to call.
  */
 #define tal_del_notifier(ptr, callback)					\
 	tal_del_notifier_((ptr),					\
 			  typesafe_cb_postargs(void, void *, (callback), \
 					       (ptr),			\
 					       enum tal_notify_type, void *), \
 			  false, NULL)
 
 /**
  * tal_set_name - attach a name to a tal pointer.
  * @ptr: The tal allocated object.
  * @name: The name to use.
  *
  * The name is copied, unless we're certain it's a string literal.
  */
 #define tal_set_name(ptr, name)				      \
     tal_set_name_((ptr), (name), TAL_IS_LITERAL(name))
 
 /**
  * tal_name - get the name for a tal pointer.
  * @ptr: The tal allocated object.
  *
  * Returns NULL if no name has been set.
  */
 const char *tal_name(const tal_t *ptr);
 
 /**
  * tal_count - get the count of objects in a tal object.
  * @ptr: The tal allocated object (or NULL)
  *
  * Returns 0 if @ptr is NULL.  Note that if the allocation was done as a
  * different type to @ptr, the result may not match the @count argument
  * (or implied 1) of that allocation!
  */
 #define tal_count(p) (tal_bytelen(p) / sizeof(*p))
 
 /**
  * tal_bytelen - get the count of bytes in a tal object.
  * @ptr: The tal allocated object (or NULL)
  *
  * Returns 0 if @ptr is NULL.
  */
 size_t tal_bytelen(const tal_t *ptr);
 
 /**
  * tal_first - get the first immediate tal object child.
  * @root: The tal allocated object to start with, or NULL.
  *
  * Returns NULL if there are no children.
  */
 tal_t *tal_first(const tal_t *root);
 
 /**
  * tal_next - get the next immediate tal object child.
  * @prev: The return value from tal_first or tal_next.
  *
  * Returns NULL if there are no more immediate children.  This should be safe to
  * call on an altering tree unless @prev is no longer valid.
  */
 tal_t *tal_next(const tal_t *prev);
 
 /**
  * tal_parent - get the parent of a tal object.
  * @ctx: The tal allocated object.
  *
  * Returns the parent, which may be NULL.  Returns NULL if @ctx is NULL.
  */
 tal_t *tal_parent(const tal_t *ctx);
 
 /**
  * tal_dup - duplicate an object.
  * @ctx: The tal allocated object to be parent of the result (may be NULL).
  * @type: the type (should match type of @p!)
  * @p: the object to copy (or reparented if take()).  Must not be NULL.
  */
 #define tal_dup(ctx, type, p)					\
 	tal_dup_label(ctx, type, p, TAL_LABEL(type, ""), false)
 
 /**
  * tal_dup_or_null - duplicate an object, or just pass NULL.
  * @ctx: The tal allocated object to be parent of the result (may be NULL).
  * @type: the type (should match type of @p!)
  * @p: the object to copy (or reparented if take())
  *
  * if @p is NULL, just return NULL, otherwise to tal_dup().
  */
 #define tal_dup_or_null(ctx, type, p)					\
 	tal_dup_label(ctx, type, p, TAL_LABEL(type, ""), true)
 
 /**
  * tal_dup_arr - duplicate an array.
  * @ctx: The tal allocated object to be parent of the result (may be NULL).
  * @type: the type (should match type of @p!)
  * @p: the array to copy (or resized & reparented if take())
  * @n: the number of sizeof(type) entries to copy.
  * @extra: the number of extra sizeof(type) entries to allocate.
  */
 #define tal_dup_arr(ctx, type, p, n, extra)			\
 	tal_dup_arr_label(ctx, type, p, n, extra, TAL_LABEL(type, "[]"))
 
 
 /**
  * tal_dup_arr - duplicate a tal array.
  * @ctx: The tal allocated object to be parent of the result (may be NULL).
  * @type: the type (should match type of @p!)
  * @p: the tal array to copy (or resized & reparented if take())
  *
  * The comon case of duplicating an entire tal array.
  */
 #define tal_dup_talarr(ctx, type, p)					\
 	((type *)tal_dup_talarr_((ctx), tal_typechk_(p, type *),	\
 				 TAL_LABEL(type, "[]")))
 /* Lower-level interfaces, where you want to supply your own label string. */
 #define tal_label(ctx, type, label)						\
 	((type *)tal_alloc_((ctx), sizeof(type), false, label))
 #define talz_label(ctx, type, label)						\
 	((type *)tal_alloc_((ctx), sizeof(type), true, label))
 #define tal_arr_label(ctx, type, count, label)					\
 	((type *)tal_alloc_arr_((ctx), sizeof(type), (count), false, label))
 #define tal_arrz_label(ctx, type, count, label)					\
 	((type *)tal_alloc_arr_((ctx), sizeof(type), (count), true, label))
 #define tal_dup_label(ctx, type, p, label, nullok)			\
 	((type *)tal_dup_((ctx), tal_typechk_(p, type *),	\
 			  sizeof(type), 1, 0, nullok,		\
 			  label))
 #define tal_dup_arr_label(ctx, type, p, n, extra, label)	\
 	((type *)tal_dup_((ctx), tal_typechk_(p, type *),	\
 			  sizeof(type), (n), (extra), false,	\
 			  label))
 
 /**
  * tal_set_backend - set the allocation or error functions to use
  * @alloc_fn: allocator or NULL (default is malloc)
  * @resize_fn: re-allocator or NULL (default is realloc)
  * @free_fn: free function or NULL (default is free)
  * @error_fn: called on errors or NULL (default is abort)
  *
  * The defaults are set up so tal functions never return NULL, but you
  * can override error_fn to change that.  error_fn can return (only if
  * you haven't defined CCAN_TAL_NEVER_RETURN_NULL!), and is
  * called if alloc_fn or resize_fn fail.
  *
  * If any parameter is NULL, that function is unchanged.
  */
 void tal_set_backend(void *(*alloc_fn)(size_t size),
 		     void *(*resize_fn)(void *, size_t size),
 		     void (*free_fn)(void *),
 		     void (*error_fn)(const char *msg));
 
 /**
  * tal_expand - expand a tal array with contents.
  * @a1p: a pointer to the tal array to expand.
  * @a2: the second array (can be take()).
  * @num2: the number of elements in the second array.
  *
  * Note that *@a1 and @a2 should be the same type.  tal_count(@a1) will
  * be increased by @num2.
  *
  * Example:
  *	int *arr1 = tal_arrz(NULL, int, 2);
  *	int arr2[2] = { 1, 3 };
  *
  *	tal_expand(&arr1, arr2, 2);
  *	assert(tal_count(arr1) == 4);
  *	assert(arr1[2] == 1);
  *	assert(arr1[3] == 3);
  */
 #define tal_expand(a1p, a2, num2)				\
 	tal_expand_((void **)(a1p), (a2), sizeof**(a1p),	\
 		    (num2) + 0*sizeof(*(a1p) == (a2)))
 
 /**
  * tal_cleanup - remove pointers from NULL node
  *
  * Internally, tal keeps a list of nodes allocated from @ctx NULL; this
  * prevents valgrind from noticing memory leaks.  This re-initializes
  * that list to empty.
  *
  * It also calls take_cleanup() for you.
  */
 void tal_cleanup(void);
 
 
 /**
  * tal_check - sanity check a tal context and its children.
  * @ctx: a tal context, or NULL.
  * @errorstr: a string to prepend calls to error_fn, or NULL.
  *
  * This sanity-checks a tal tree (unless NDEBUG is defined, in which case
  * it simply returns true).  If errorstr is not null, error_fn is called
  * when a problem is found, otherwise it is not.
  *
  * See also:
  *	tal_set_backend()
  */
 bool tal_check(const tal_t *ctx, const char *errorstr);
 
 #ifdef CCAN_TAL_DEBUG
 /**
  * tal_dump - dump entire tal tree to stderr.
  *
  * This is a helper for debugging tal itself, which dumps all the tal internal
  * state.
  */
 void tal_dump(void);
 #endif
 
 /* Internal support functions */
 #ifndef TAL_LABEL
 #ifdef CCAN_TAL_NO_LABELS
 #define TAL_LABEL(type, arr) NULL
 #else
 #ifdef CCAN_TAL_DEBUG
 #define TAL_LABEL(type, arr) \
 	__FILE__ ":" stringify(__LINE__) ":" stringify(type) arr
 #else
 #define TAL_LABEL(type, arr) stringify(type) arr
 #endif /* CCAN_TAL_DEBUG */
 #endif
 #endif
 
 #if HAVE_BUILTIN_CONSTANT_P
 #define TAL_IS_LITERAL(str) __builtin_constant_p(str)
 #else
 #define TAL_IS_LITERAL(str) (sizeof(&*(str)) != sizeof(char *))
 #endif
 
 bool tal_set_name_(tal_t *ctx, const char *name, bool literal);
 
 #if HAVE_TYPEOF
 #define tal_typeof(ptr) (__typeof__(ptr))
 #if HAVE_STATEMENT_EXPR
 /* Careful: ptr can be const foo *, ptype is foo *.  Also, ptr could
  * be an array, eg "hello". */
 #define tal_typechk_(ptr, ptype) ({ __typeof__((ptr)+0) _p = (ptype)(ptr); _p; })
 #else
 #define tal_typechk_(ptr, ptype) (ptr)
 #endif
 #else /* !HAVE_TYPEOF */
 #define tal_typeof(ptr)
 #define tal_typechk_(ptr, ptype) (ptr)
 #endif
 
 void *tal_alloc_(const tal_t *ctx, size_t bytes, bool clear, const char *label)
 	TAL_RETURN_PTR;
 void *tal_alloc_arr_(const tal_t *ctx, size_t bytes, size_t count, bool clear,
 		     const char *label)
 	TAL_RETURN_PTR;
 
 void *tal_dup_(const tal_t *ctx, const void *p TAKES, size_t size,
 	       size_t n, size_t extra, bool nullok, const char *label);
 void *tal_dup_talarr_(const tal_t *ctx, const tal_t *src TAKES,
 		      const char *label);
 
 tal_t *tal_steal_(const tal_t *new_parent, const tal_t *t);
 
 bool tal_resize_(tal_t **ctxp, size_t size, size_t count, bool clear);
 bool tal_expand_(tal_t **ctxp, const void *src TAKES, size_t size, size_t count);
 
 bool tal_add_destructor_(const tal_t *ctx, void (*destroy)(void *me));
 bool tal_add_destructor2_(const tal_t *ctx, void (*destroy)(void *me, void *arg),
 			  void *arg);
 bool tal_del_destructor_(const tal_t *ctx, void (*destroy)(void *me));
 bool tal_del_destructor2_(const tal_t *ctx, void (*destroy)(void *me, void *arg),
 			  void *arg);
 
 bool tal_add_notifier_(const tal_t *ctx, enum tal_notify_type types,
 		       void (*notify)(tal_t *ctx, enum tal_notify_type,
 				      void *info));
 bool tal_del_notifier_(const tal_t *ctx,
 		       void (*notify)(tal_t *ctx, enum tal_notify_type,
 				      void *info),
 		       bool match_extra_arg, void *arg);
 #endif /* CCAN_TAL_H */