#include <stdio.h>
#include <stdarg.h>
#include <ccan/typesafe_cb/typesafe_cb.h>
+#include <ccan/compiler/compiler.h>
#include "config.h"
/*
#define __location__ __FILE__ ":" __TALLOC_STRING_LINE3__
#endif
-#if HAVE_ATTRIBUTE_PRINTF
-/** Use gcc attribute to check printf fns. a1 is the 1-based index of
- * the parameter containing the format, and a2 the index of the first
- * argument. Note that some gcc 2.x versions don't handle this
- * properly **/
-#define PRINTF_ATTRIBUTE(a1, a2) __attribute__ ((format (__printf__, a1, a2)))
-#else
-#define PRINTF_ATTRIBUTE(a1, a2)
-#endif
-
/* try to make talloc_set_destructor() and talloc_steal() type safe,
if we have a recent gcc */
#if HAVE_TYPEOF
*/
#define talloc(ctx, type) (type *)talloc_named_const(ctx, sizeof(type), #type)
+/**
+ * TALLOC_CTX - indicate that a pointer is used as a talloc parent.
+ *
+ * As talloc is a hierarchial memory allocator, every talloc chunk is a
+ * potential parent to other talloc chunks. So defining a separate type for a
+ * talloc chunk is not strictly necessary. TALLOC_CTX is defined nevertheless,
+ * as it provides an indicator for function arguments.
+ *
+ * Example:
+ * struct foo {
+ * int val;
+ * };
+ *
+ * static struct foo *foo_new(TALLOC_CTX *mem_ctx)
+ * {
+ * struct foo *foo = talloc(mem_ctx, struct foo);
+ * if (foo)
+ * foo->val = 0;
+ * return foo;
+ * }
+ */
+typedef void TALLOC_CTX;
+
+/**
+ * talloc_set - allocate dynamic memory for a type, into a pointer
+ * @ptr: pointer to the pointer to assign.
+ * @ctx: context to be parent of this allocation, or NULL.
+ *
+ * talloc_set() does a talloc, but also adds a destructor which will make the
+ * pointer invalid when it is freed. This can find many use-after-free bugs.
+ *
+ * Note that the destructor is chained off a zero-length allocation, and so
+ * is not affected by talloc_set_destructor().
+ *
+ * Example:
+ * unsigned int *b, *a;
+ * a = talloc(NULL, unsigned int);
+ * talloc_set(&b, a);
+ * talloc_free(a);
+ * *b = 1; // This will crash!
+ *
+ * See Also:
+ * talloc.
+ */
+#define talloc_set(pptr, ctx) \
+ _talloc_set((pptr), (ctx), sizeof(&**(pptr)), __location__)
+
/**
* talloc_free - free talloc'ed memory and its children
* @ptr: the talloced pointer to free
int talloc_free(const void *ptr);
/**
- * talloc_set_destructor: set a destructor for when this pointer is freed
+ * talloc_set_destructor - set a destructor for when this pointer is freed
* @ptr: the talloc pointer to set the destructor on
* @destructor: the function to be called
*
* return 0;
* }
*
- * int *open_file(const char *filename)
+ * static int *open_file(const char *filename)
* {
* int *fd = talloc(NULL, int);
* *fd = open(filename, O_RDONLY);
* talloc, talloc_free
*/
#define talloc_set_destructor(ptr, function) \
- _talloc_set_destructor((ptr), typesafe_cb(int, (function), (ptr)))
+ _talloc_set_destructor((ptr), typesafe_cb_def(int, (function), (ptr)))
/**
* talloc_zero - allocate zeroed dynamic memory for a type
*
* Example:
* void *mem = talloc_size(NULL, 100);
+ * memset(mem, 0xFF, 100);
*
* See Also:
* talloc, talloc_array, talloc_zero_size
* a = talloc(NULL, unsigned int);
* b = talloc(NULL, unsigned int);
* c = talloc(a, unsigned int);
- * // b also serves as a parent of c.
- * talloc_reference(b, c);
+ * // b also serves as a parent of c (don't care about errors)
+ * (void)talloc_reference(b, c);
*/
#define talloc_reference(ctx, ptr) (_TALLOC_TYPEOF(ptr))_talloc_reference((ctx),(ptr))
/**
- * talloc_unlink: remove a specific parent from a talloc pointer.
+ * talloc_unlink - remove a specific parent from a talloc pointer.
* @context: the parent to remove
* @ptr: the talloc pointer
*
* Usually you can just use talloc_free() instead of talloc_unlink(), but
* sometimes it is useful to have the additional control on which parent is
* removed.
+ *
* Example:
* unsigned int *a, *b, *c;
* a = talloc(NULL, unsigned int);
* b = talloc(NULL, unsigned int);
* c = talloc(a, unsigned int);
* // b also serves as a parent of c.
- * talloc_reference(b, c);
+ * (void)talloc_reference(b, c);
* talloc_unlink(b, c);
*/
int talloc_unlink(const void *context, void *ptr);
*
* talloc_set_name_const(ptr, ptr)
*/
-char *talloc_append_string(char *orig, const char *append);
+char *WARN_UNUSED_RESULT talloc_append_string(char *orig, const char *append);
/**
* talloc_asprintf_append - sprintf onto the end of a talloc buffer.
* equivalent to:
* talloc_set_name_const(ptr, ptr)
*/
-char *talloc_asprintf_append(char *s, const char *fmt, ...) PRINTF_ATTRIBUTE(2,3);
+char *WARN_UNUSED_RESULT talloc_asprintf_append(char *s, const char *fmt, ...)
+ PRINTF_ATTRIBUTE(2,3);
/**
* talloc_vasprintf - vsprintf into a talloc buffer.
* The talloc_vasprintf_append() function is equivalent to
* talloc_asprintf_append(), except it takes a va_list.
*/
-char *talloc_vasprintf_append(char *s, const char *fmt, va_list ap) PRINTF_ATTRIBUTE(2,0);
+char *WARN_UNUSED_RESULT talloc_vasprintf_append(char *s, const char *fmt, va_list ap)
+ PRINTF_ATTRIBUTE(2,0);
/**
* talloc_set_type - force the name of a pointer to a particular type
/* The following definitions come from talloc.c */
void *_talloc(const void *context, size_t size);
+void _talloc_set(void *ptr, const void *ctx, size_t size, const char *name);
void _talloc_set_destructor(const void *ptr, int (*destructor)(void *));
size_t talloc_reference_count(const void *ptr);
void *_talloc_reference(const void *context, const void *ptr);
-void *_talloc_realloc(const void *context, void *ptr, size_t size, const char *name);
+void *WARN_UNUSED_RESULT _talloc_realloc(const void *context, void *ptr, size_t size, const char *name);
void *talloc_parent(const void *ptr);
const char *talloc_parent_name(const void *ptr);
void *_talloc_steal(const void *new_ctx, const void *ptr);
void *_talloc_memdup(const void *t, const void *p, size_t size, const char *name);
void *_talloc_array(const void *ctx, size_t el_size, unsigned count, const char *name);
void *_talloc_zero_array(const void *ctx, size_t el_size, unsigned count, const char *name);
-void *_talloc_realloc_array(const void *ctx, void *ptr, size_t el_size, unsigned count, const char *name);
+void *WARN_UNUSED_RESULT _talloc_realloc_array(const void *ctx, void *ptr, size_t el_size, unsigned count, const char *name);
void *talloc_realloc_fn(const void *context, void *ptr, size_t size);
void talloc_show_parents(const void *context, FILE *file);
int talloc_is_parent(const void *context, const void *ptr);
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