Convert the contents of talloc_guide.txt to doxygen-style talloc.h comments

talloc_guide.txt was partly outdated, and as going through talloc.h now shows
it was incomplete.

1 files changed, 1023 insertions, 1 deletions

diff --git a/lib/talloc/talloc.h b/lib/talloc/talloc.h
index 5c8d5c5fe2..4b50ba99c2 100644
--- a/lib/talloc/talloc.h
+++ b/lib/talloc/talloc.h
@@ -29,7 +29,119 @@
 #include <stdio.h>
 #include <stdarg.h>
 
-/* this is only needed for compatibility with the old talloc */
+/** \mainpage
+ *
+ * \section intro_sec Introduction
+ *
+ * Talloc is a hierarchical, reference counted memory pool system with
+ * destructors. Quite a mouthful really, but not too bad once you get used to
+ * it.
+ *
+ * Perhaps the biggest difference from other memory pool systems is that there
+ * is no distinction between a "talloc context" and a "talloc pointer". Any
+ * pointer returned from talloc() is itself a valid talloc context. This means
+ * you can do this:
+ *
+ * \code
+ * struct foo *X = talloc(mem_ctx, struct foo);
+ * X->name = talloc_strdup(X, "foo");
+ * \endcode
+ *
+ * and the pointer X->name would be a "child" of the talloc context "X" which
+ * is itself a child of mem_ctx. So if you do talloc_free(mem_ctx) then it is
+ * all destroyed, whereas if you do talloc_free(X) then just X and X->name are
+ * destroyed, and if you do talloc_free(X->name) then just the name element of
+ * X is destroyed.
+ *
+ * If you think about this, then what this effectively gives you is an n-ary
+ * tree, where you can free any part of the tree with talloc_free().
+ *
+ * \section named_blocks Named blocks
+ *
+ * Every talloc chunk has a name that can be used as a dynamic type-checking
+ * system. If for some reason like a callback function you had to cast a
+ * "struct foo *" to a "void *" variable, later you can safely reassign the
+ * "void *" pointer to a "struct foo *" by using the talloc_get_type() or
+ * talloc_get_type_abort() macros.
+ *
+ * \code
+ * struct foo *X = talloc_get_type_abort(ptr, struct foo);
+ * \endcode
+ *
+ * This will abort if "ptr" does not contain a pointer that has been created
+ * with talloc(mem_ctx, struct foo).
+ *
+ * \section multi_threading Multi-Threading
+ *
+ * talloc itself does not deal with threads. It is thread-safe (assuming the
+ * underlying "malloc" is), as long as each thread uses different memory
+ * contexts.
+ *
+ * If two threads uses the same context then they need to synchronize in order
+ * to be safe. In particular:
+ *
+ *
+ * - when using talloc_enable_leak_report(), giving directly NULL as a
+ *   parent context implicitly refers to a hidden "null context" global
+ *   variable, so this should not be used in a multi-threaded environment
+ *   without proper synchronization
+ * - the context returned by talloc_autofree_context() is also global so
+ *   shouldn't be used by several threads simultaneously without
+ *   synchronization.
+ */
+
+/** \defgroup talloc_basic Basic Talloc Routines
+ *
+ * This module contains the basic talloc routines that are used in everyday
+ * programming.
+ */
+
+/** \defgroup talloc_ref Talloc References
+ *
+ * This module contains the definitions around talloc references
+ */
+
+/** \defgroup talloc_array Array routines
+ *
+ * Talloc contains some handy helpers for handling Arrays conveniently
+ */
+
+/** \defgroup talloc_string String handling routines
+ *
+ * Talloc contains some handy string handling functions
+ */
+
+/** \defgroup talloc_debug Debugging support routines
+ *
+ * To aid memory debugging, talloc contains routines to inspect the currently
+ * allocated memory hierarchy.
+ */
+
+/**
+ * \typedef TALLOC_CTX
+ * \brief Define a talloc parent type
+ * \ingroup talloc_basic
+ *
+ * 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. You will frequently
+ * write code like
+ *
+ * \code
+ * struct foo *foo_create(TALLOC_CTX *mem_ctx)
+ * {
+ *	struct foo *result;
+ *	result = talloc(mem_ctx, struct foo);
+ *	if (result == NULL) return NULL;
+ *	... initialize foo ...
+ *	return result;
+ * }
+ * \endcode
+ *
+ * In this type of allocating functions it is handy to have a general
+ * TALLOC_CTX type to indicate which parent to put allocated structures on.
+ */
 typedef void TALLOC_CTX;
 
 /*
@@ -58,6 +170,62 @@ typedef void TALLOC_CTX;
 #endif
 #endif
 
+/**
+ * \def talloc_set_destructor
+ * \brief Assign a function to be called when a chunk is freed
+ * \param ptr The talloc chunk to add a destructor to
+ * \param function The destructor function to be called
+ * \ingroup talloc_basic
+ *
+ * The function talloc_set_destructor() sets the "destructor" for the pointer
+ * "ptr". A destructor is a function that is called when the memory used by a
+ * pointer is about to be released. The destructor receives the pointer as an
+ * argument, and should return 0 for success and -1 for failure.
+ *
+ * The destructor can do anything it wants to, including freeing other pieces
+ * of memory. A common use for destructors is to clean up operating system
+ * resources (such as open file descriptors) contained in the structure the
+ * destructor is placed on.
+ *
+ * You can only place one destructor on a pointer. If you need more than one
+ * destructor then you can create a zero-length child of the pointer and place
+ * an additional destructor on that.
+ *
+ * To remove a destructor call talloc_set_destructor() with NULL for the
+ * destructor.
+ *
+ * If your destructor attempts to talloc_free() the pointer that it is the
+ * destructor for then talloc_free() will return -1 and the free will be
+ * ignored. This would be a pointless operation anyway, as the destructor is
+ * only called when the memory is just about to go away.
+ */
+
+/**
+ * \def talloc_steal(ctx, ptr)
+ * \brief Change a talloc chunk's parent
+ * \param ctx The new parent context
+ * \param ptr The talloc chunk to move
+ * \return ptr
+ * \ingroup talloc_basic
+ *
+ * The talloc_steal() function changes the parent context of a talloc
+ * pointer. It is typically used when the context that the pointer is
+ * currently a child of is going to be freed and you wish to keep the
+ * memory for a longer time.
+ *
+ * The talloc_steal() function returns the pointer that you pass it. It
+ * does not have any failure modes.
+ *
+ * NOTE: It is possible to produce loops in the parent/child relationship
+ * if you are not careful with talloc_steal(). No guarantees are provided
+ * as to your sanity or the safety of your data if you do this.
+ *
+ * To make the changed hierarchy less error-prone, you might consider to use
+ * talloc_move().
+ *
+ * talloc_steal (ctx, NULL) will return NULL with no sideeffects.
+ */
+
 /* try to make talloc_set_destructor() and talloc_steal() type safe,
    if we have a recent gcc */
 #if (__GNUC__ >= 3)
@@ -77,34 +245,359 @@ typedef void TALLOC_CTX;
 #define talloc_steal(ctx, ptr) (_TALLOC_TYPEOF(ptr))_talloc_steal((ctx),(ptr))
 #endif
 
+/**
+ * \def talloc_reference(ctx, ptr)
+ * \brief Create an additional talloc parent to a pointer
+ * \param ctx The additional parent
+ * \param ptr The pointer you want to create an additional parent for
+ * \return ptr
+ * \ingroup talloc_ref
+ *
+ * The talloc_reference() function makes "context" an additional parent of
+ * "ptr".
+ *
+ * The return value of talloc_reference() is always the original pointer
+ * "ptr", unless talloc ran out of memory in creating the reference in which
+ * case it will return NULL (each additional reference consumes around 48
+ * bytes of memory on intel x86 platforms).
+ *
+ * If "ptr" is NULL, then the function is a no-op, and simply returns NULL.
+ *
+ * After creating a reference you can free it in one of the following ways:
+ *
+ * - you can talloc_free() any parent of the original pointer. That
+ *   will reduce the number of parents of this pointer by 1, and will
+ *   cause this pointer to be freed if it runs out of parents.
+ *
+ * - you can talloc_free() the pointer itself. That will destroy the
+ *   most recently established parent to the pointer and leave the
+ *   pointer as a child of its current parent.
+ *
+ * For more control on which parent to remove, see talloc_unlink()
+ */
 #define talloc_reference(ctx, ptr) (_TALLOC_TYPEOF(ptr))_talloc_reference((ctx),(ptr))
+
+
+/**
+ * \def talloc_move(ctx, ptr)
+ * \brief Change a talloc chunk's parent
+ * \param ctx The new parent context
+ * \param ptr Pointer to the talloc chunk to move
+ * \return ptr
+ * \ingroup talloc_basic
+ *
+ * talloc_move() has the same effect as talloc_steal(), and additionally sets
+ * the source pointer to NULL. You would use it like this:
+ *
+ * \code
+ * struct foo *X = talloc(tmp_ctx, struct foo);
+ * struct foo *Y;
+ * Y = talloc_move(new_ctx, &X);
+ * \endcode
+ */
 #define talloc_move(ctx, ptr) (_TALLOC_TYPEOF(*(ptr)))_talloc_move((ctx),(void *)(ptr))
 
 /* useful macros for creating type checked pointers */
+
+/**
+ * \def talloc(ctx, type)
+ * \brief Main entry point to allocate structures
+ * \param ctx The talloc context to hang the result off
+ * \param type The type that we want to allocate
+ * \return Pointer to a piece of memory, properly cast to "type *"
+ * \ingroup talloc_basic
+ *
+ * The talloc() macro is the core of the talloc library. It takes a memory
+ * context and a type, and returns a pointer to a new area of memory of the
+ * given type.
+ *
+ * The returned pointer is itself a talloc context, so you can use it as the
+ * context argument to more calls to talloc if you wish.
+ *
+ * The returned pointer is a "child" of the supplied context. This means that
+ * if you talloc_free() the context then the new child disappears as
+ * well. Alternatively you can free just the child.
+ *
+ * The context argument to talloc() can be NULL, in which case a new top
+ * level context is created.
+ */
 #define talloc(ctx, type) (type *)talloc_named_const(ctx, sizeof(type), #type)
+
+/**
+ * \def talloc_size(ctx, size)
+ * \brief Untyped allocation
+ * \param ctx The talloc context to hang the result off
+ * \param size Number of char's that you want to allocate
+ * \return The allocated memory chunk
+ * \ingroup talloc_basic
+ *
+ * The function talloc_size() should be used when you don't have a convenient
+ * type to pass to talloc(). Unlike talloc(), it is not type safe (as it
+ * returns a void *), so you are on your own for type checking.
+ */
 #define talloc_size(ctx, size) talloc_named_const(ctx, size, __location__)
+
+/**
+ * \def talloc_ptrtype(ctx, ptr)
+ * \brief Allocate into a typed pointer
+ * \param ctx The talloc context to hang the result off
+ * \param ptr The pointer you want to assign the result to
+ * \result The allocated memory chunk, properly cast
+ * \ingroup talloc_basic
+ *
+ * The talloc_ptrtype() macro should be used when you have a pointer and
+ * want to allocate memory to point at with this pointer. When compiling
+ * with gcc >= 3 it is typesafe. Note this is a wrapper of talloc_size()
+ * and talloc_get_name() will return the current location in the source file.
+ * and not the type.
+ */
 #define talloc_ptrtype(ctx, ptr) (_TALLOC_TYPEOF(ptr))talloc_size(ctx, sizeof(*(ptr)))
 
+/**
+ * \def talloc_new(ctx)
+ * \brief Allocate a new 0-sized talloc chunk
+ * \param ctx The talloc parent context
+ * \return A new talloc chunk
+ * \ingroup talloc_basic
+ *
+ * This is a utility macro that creates a new memory context hanging off an
+ * exiting context, automatically naming it "talloc_new: __location__" where
+ * __location__ is the source line it is called from. It is particularly
+ * useful for creating a new temporary working context.
+ */
 #define talloc_new(ctx) talloc_named_const(ctx, 0, "talloc_new: " __location__)
 
+/**
+ * \def talloc_zero(ctx, type)
+ * \brief Allocate a 0-initizialized structure
+ * \param ctx The talloc context to hang the result off
+ * \param type The type that we want to allocate
+ * \return Pointer to a piece of memory, properly cast to "type *"
+ * \ingroup talloc_basic
+ *
+ * The talloc_zero() macro is equivalent to:
+ *
+ * \code
+ * ptr = talloc(ctx, type);
+ * if (ptr) memset(ptr, 0, sizeof(type));
+ * \endcode
+ */
 #define talloc_zero(ctx, type) (type *)_talloc_zero(ctx, sizeof(type), #type)
+
+/**
+ * \def talloc_zero_size(ctx, size)
+ * \brief Untyped, 0-initialized allocation
+ * \param ctx The talloc context to hang the result off
+ * \param size Number of char's that you want to allocate
+ * \return The allocated memory chunk
+ * \ingroup talloc_basic
+ *
+ * The talloc_zero_size() macro is equivalent to:
+ *
+ * \code
+ * ptr = talloc_size(ctx, size);
+ * if (ptr) memset(ptr, 0, size);
+ * \endcode
+ */
+
 #define talloc_zero_size(ctx, size) _talloc_zero(ctx, size, __location__)
 
 #define talloc_zero_array(ctx, type, count) (type *)_talloc_zero_array(ctx, sizeof(type), count, #type)
+
+/**
+ * \def talloc_array(ctx, type, count)
+ * \brief Allocate an array
+ * \param ctx The talloc context to hang the result off
+ * \param type The type that we want to allocate
+ * \param count The number of "type" elements you want to allocate
+ * \return The allocated result, properly cast to "type *"
+ * \ingroup talloc_array
+ *
+ * The talloc_array() macro is equivalent to::
+ *
+ * \code
+ * (type *)talloc_size(ctx, sizeof(type) * count);
+ * \endcode
+ *
+ * except that it provides integer overflow protection for the multiply,
+ * returning NULL if the multiply overflows.
+ */
 #define talloc_array(ctx, type, count) (type *)_talloc_array(ctx, sizeof(type), count, #type)
+
+/**
+ * \def talloc_array_size(ctx, size, count)
+ * \brief Allocate an array
+ * \param ctx The talloc context to hang the result off
+ * \param size The size of an array element
+ * \param count The number of "type" elements you want to allocate
+ * \return The allocated result, properly cast to "type *"
+ * \ingroup talloc_array
+ *
+ * The talloc_array_size() function is useful when the type is not
+ * known. It operates in the same way as talloc_array(), but takes a size
+ * instead of a type.
+ */
 #define talloc_array_size(ctx, size, count) _talloc_array(ctx, size, count, __location__)
+
+/**
+ * \def talloc_array_ptrtype(ctx, ptr, count)
+ * \brief Allocate an array into a typed pointer
+ * \param ctx The talloc context to hang the result off
+ * \param ptr The pointer you want to assign the result to
+ * \param count The number of elements you want to allocate
+ * \result The allocated memory chunk, properly cast
+ * \ingroup talloc_array
+ *
+ * The talloc_array_ptrtype() macro should be used when you have a pointer to
+ * an array and want to allocate memory of an array to point at with this
+ * pointer. When compiling with gcc >= 3 it is typesafe. Note this is a
+ * wrapper of talloc_array_size() and talloc_get_name() will return the
+ * current location in the source file.  and not the type.
+ */
 #define talloc_array_ptrtype(ctx, ptr, count) (_TALLOC_TYPEOF(ptr))talloc_array_size(ctx, sizeof(*(ptr)), count)
+
+/**
+ * \def talloc_array_length(ctx)
+ * \brief Return the number of elements in a talloc'ed array
+ * \param ctx The talloc'ed array
+ * \return The number of elements in ctx
+ * \ingroup talloc_array
+ *
+ * A talloc chunk carries its own size, so for talloc'ed arrays it is not
+ * necessary to store the number of elements explicitly.
+ */
 #define talloc_array_length(ctx) ((ctx) ? talloc_get_size(ctx)/sizeof(*ctx) : 0)
 
+/**
+ * \def talloc_realloc(ctx, p, type, count)
+ * \brief Change the size of a talloc array
+ * \param ctx The parent context used if "p" is NULL
+ * \param p The chunk to be resized
+ * \param type The type of the array element inside p
+ * \param count The intended number of array elements
+ * \return The new array
+ * \ingroup talloc_array
+ *
+ * The talloc_realloc() macro changes the size of a talloc
+ * pointer. The "count" argument is the number of elements of type "type"
+ * that you want the resulting pointer to hold.
+ *
+ * talloc_realloc() has the following equivalences::
+ *
+ * \code
+ * talloc_realloc(context, NULL, type, 1) ==> talloc(context, type);
+ * talloc_realloc(context, NULL, type, N) ==> talloc_array(context, type, N);
+ * talloc_realloc(context, ptr, type, 0)  ==> talloc_free(ptr);
+ * \endcode
+ *
+ * The "context" argument is only used if "ptr" is NULL, otherwise it is
+ * ignored.
+ *
+ * talloc_realloc() returns the new pointer, or NULL on failure. The call
+ * will fail either due to a lack of memory, or because the pointer has
+ * more than one parent (see talloc_reference()).
+ */
 #define talloc_realloc(ctx, p, type, count) (type *)_talloc_realloc_array(ctx, p, sizeof(type), count, #type)
+
+/**
+ * \def talloc_realloc_size(ctx, ptr, size)
+ * \brief Untyped realloc
+ * \param ctx The parent context used if "ptr" is NULL
+ * \param ptr The chunk to be resized
+ * \param size The new chunk size
+ * \return The new chunk
+ * \ingroup talloc_array
+ *
+ * The talloc_realloc_size() function is useful when the type is not known so
+ * the typesafe talloc_realloc() cannot be used.
+ */
 #define talloc_realloc_size(ctx, ptr, size) _talloc_realloc(ctx, ptr, size, __location__)
 
+/**
+ * \def talloc_memdup(t, p, size)
+ * \brief Duplicate a memory area into a talloc chunk
+ * \param t The talloc context to hang the result off
+ * \param p The memory chunk you want to duplicate
+ * \param size Number of char's that you want copy
+ * \return The allocated memory chunk
+ * \ingroup talloc_basic
+ *
+ * The talloc_memdup() function is equivalent to::
+ *
+ * \code
+ * ptr = talloc_size(ctx, size);
+ * if (ptr) memcpy(ptr, p, size);
+ * \endcode
+ */
 #define talloc_memdup(t, p, size) _talloc_memdup(t, p, size, __location__)
 
+/**
+ * \def talloc_set_type(ptr, type)
+ * \brief Assign a type to a talloc chunk
+ * \param ptr The talloc chunk to assign the type to
+ * \param type The type to assign
+ * \ingroup talloc_basic
+ *
+ * This macro allows you to force the name of a pointer to be a
+ * particular type. This can be used in conjunction with
+ * talloc_get_type() to do type checking on void* pointers.
+ *
+ * It is equivalent to this::
+ *
+ * \code
+ * talloc_set_name_const(ptr, #type)
+ * \endcode
+ */
 #define talloc_set_type(ptr, type) talloc_set_name_const(ptr, #type)
+
+/**
+ * \def talloc_get_type(ptr, type)
+ * \brief Get a typed pointer out of a talloc pointer
+ * \param ptr The talloc pointer to check
+ * \param type The type to check against
+ * \return ptr, properly cast, or NULL
+ * \ingroup talloc_basic
+ *
+ * This macro allows you to do type checking on talloc pointers. It is
+ * particularly useful for void* private pointers. It is equivalent to
+ * this:
+ *
+ * \code
+ * (type *)talloc_check_name(ptr, #type)
+ * \endcode
+ */
+
 #define talloc_get_type(ptr, type) (type *)talloc_check_name(ptr, #type)
+
+/**
+ * \def talloc_get_type_abort(ptr, type)
+ * \brief Helper macro to safely turn a void * into a typed pointer
+ * \param ptr The void * to convert
+ * \param type The type that this chunk contains
+ * \return Same value as ptr, type-checked and properly cast
+ * \ingroup talloc_basic
+ *
+ * This macro is used together with talloc(mem_ctx, struct foo). If you had to
+ * assing the talloc chunk pointer to some void * variable,
+ * talloc_get_type_abort() is the recommended way to get the convert the void
+ * pointer back to a typed pointer.
+ */
 #define talloc_get_type_abort(ptr, type) (type *)_talloc_get_type_abort(ptr, #type, __location__)
 
+/**
+ * \def talloc_find_parent_bytype(ptr, type)
+ * \brief Find a parent context by type
+ * \param ptr The talloc chunk to start from
+ * \param type The type of the parent to look for
+ * \ingroup talloc_basic
+ *
+ * Find a parent memory context of the current context that has the given
+ * name. This can be very useful in complex programs where it may be
+ * difficult to pass all information down to the level you need, but you
+ * know the structure you want is a parent of another context.
+ *
+ * Like talloc_find_parent_byname() but takes a type, making it typesafe.
+ */
 #define talloc_find_parent_bytype(ptr, type) (type *)talloc_find_parent_byname(ptr, #type)
 
 #if TALLOC_DEPRECATED
@@ -122,67 +615,596 @@ typedef void TALLOC_CTX;
 void *_talloc(const void *context, size_t size);
 void *talloc_pool(const void *context, size_t size);
 void _talloc_set_destructor(const void *ptr, int (*destructor)(void *));
+
+/**
+ * \brief Increase the reference count of a talloc chunk
+ * \param ptr
+ * \return success?
+ * \ingroup talloc_ref
+ *
+ * The talloc_increase_ref_count(ptr) function is exactly equivalent to:
+ *
+ * \code
+ * talloc_reference(NULL, ptr);
+ * \endcode
+ *
+ * You can use either syntax, depending on which you think is clearer in
+ * your code.
+ *
+ * It returns 0 on success and -1 on failure.
+ */
 int talloc_increase_ref_count(const void *ptr);
+
+/**
+ * \brief Return the number of references to a talloc chunk
+ * \param ptr The chunk you are interested in
+ * \return Number of refs
+ * \ingroup talloc_ref
+ */
 size_t talloc_reference_count(const void *ptr);
 void *_talloc_reference(const void *context, const void *ptr);
+
+/**
+ * \brief Remove a specific parent from a talloc chunk
+ * \param context The talloc parent to remove
+ * \param ptr The talloc ptr you want to remove the parent from
+ * \ingroup talloc_ref
+ *
+ * The talloc_unlink() function removes a specific parent from ptr. The
+ * context passed must either be a context used in talloc_reference() with
+ * this pointer, or must be a direct parent of ptr.
+ *
+ * Note that if the parent has already been removed using talloc_free() then
+ * this function will fail and will return -1.  Likewise, if "ptr" is NULL,
+ * then the function will make no modifications and return -1.
+ *
+ * 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.
+ */
 int talloc_unlink(const void *context, void *ptr);
+
+/**
+ * \brief Assign a name to a talloc chunk
+ * \param ptr The talloc chunk to assign a name to
+ * \param fmt Format string for the name
+ * \param ... printf-style additional arguments
+ * \return The assigned name
+ * \ingroup talloc_basic
+ *
+ * Each talloc pointer has a "name". The name is used principally for
+ * debugging purposes, although it is also possible to set and get the name on
+ * a pointer in as a way of "marking" pointers in your code.
+ *
+ * The main use for names on pointer is for "talloc reports". See
+ * talloc_report() and talloc_report_full() for details. Also see
+ * talloc_enable_leak_report() and talloc_enable_leak_report_full().
+ *
+ * The talloc_set_name() function allocates memory as a child of the
+ * pointer. It is logically equivalent to:
+ *
+ * \code
+ * talloc_set_name_const(ptr, talloc_asprintf(ptr, fmt, ...));
+ * \endcode
+ *
+ * Note that multiple calls to talloc_set_name() will allocate more memory
+ * without releasing the name. All of the memory is released when the ptr is
+ * freed using talloc_free().
+ */
 const char *talloc_set_name(const void *ptr, const char *fmt, ...) PRINTF_ATTRIBUTE(2,3);
+
+/**
+ * \brief Assign a name to a talloc chunk
+ * \param ptr The talloc chunk to assign a name to
+ * \param name Format string for the name
+ * \ingroup talloc_basic
+ *
+ * The function talloc_set_name_const() is just like talloc_set_name(), but it
+ * takes a string constant, and is much faster. It is extensively used by the
+ * "auto naming" macros, such as talloc_p().
+ *
+ * This function does not allocate any memory. It just copies the supplied
+ * pointer into the internal representation of the talloc ptr. This means you
+ * must not pass a name pointer to memory that will disappear before the ptr
+ * is freed with talloc_free().
+ */
 void talloc_set_name_const(const void *ptr, const char *name);
+
+/**
+ * \brief Create a named talloc chunk
+ * \param context The talloc context to hang the result off
+ * \param size Number of char's that you want to allocate
+ * \param fmt Format string for the name
+ * \param ... printf-style additional arguments
+ * \return The allocated memory chunk
+ * \ingroup talloc_basic
+ *
+ * The talloc_named() function creates a named talloc pointer. It is
+ * equivalent to:
+ *
+ * \code
+ * ptr = talloc_size(context, size);
+ * talloc_set_name(ptr, fmt, ....);
+ * \endcode
+ *
+ */
 void *talloc_named(const void *context, size_t size, 
 		   const char *fmt, ...) PRINTF_ATTRIBUTE(3,4);
+
+/**
+ * \brief Basic routine to allocate a chunk of memory
+ * \param context The parent context
+ * \param size The number of char's that we want to allocate
+ * \param name The name the talloc block has
+ * \return The allocated chunk
+ * \ingroup talloc_basic
+ *
+ * This is equivalent to:
+ *
+ * \code
+ * ptr = talloc_size(context, size);
+ * talloc_set_name_const(ptr, name);
+ * \endcode
+ */
 void *talloc_named_const(const void *context, size_t size, const char *name);
+
+/**
+ * \brief Return the name of a talloc chunk
+ * \param ptr The talloc chunk
+ * \return The name
+ * \ingroup talloc_basic
+ *
+ * This returns the current name for the given talloc pointer. See
+ * talloc_set_name() for details.
+ */
 const char *talloc_get_name(const void *ptr);
+
+/**
+ * \brief Verify that a talloc chunk carries a specified name
+ * \param ptr The talloc chunk to check
+ * \param name The name to check agains
+ * \ingroup talloc_basic
+ *
+ * This function checks if a pointer has the specified name. If it does
+ * then the pointer is returned. It it doesn't then NULL is returned.
+ */
 void *talloc_check_name(const void *ptr, const char *name);
+
 void *_talloc_get_type_abort(const void *ptr, const char *name, const char *location);
 void *talloc_parent(const void *ptr);
 const char *talloc_parent_name(const void *ptr);
+
+/**
+ * \brief Create a new top level talloc context
+ * \param fmt Format string for the name
+ * \param ... printf-style additional arguments
+ * \return The allocated memory chunk
+ * \ingroup talloc_basic
+ *
+ * This function creates a zero length named talloc context as a top level
+ * context. It is equivalent to:
+ *
+ * \code
+ *   talloc_named(NULL, 0, fmt, ...);
+ * \endcode
+ */
 void *talloc_init(const char *fmt, ...) PRINTF_ATTRIBUTE(1,2);
+
+/**
+ * \brief Free a chunk of talloc memory
+ * \param ptr The chunk to be freed
+ * \return success?
+ * \ingroup talloc_basic
+ *
+ * The talloc_free() function frees a piece of talloc memory, and all its
+ * children. You can call talloc_free() on any pointer returned by talloc().
+ *
+ * The return value of talloc_free() indicates success or failure, with 0
+ * returned for success and -1 for failure. The only possible failure
+ * condition is if the pointer had a destructor attached to it and the
+ * destructor returned -1. See talloc_set_destructor() for details on
+ * destructors.
+ *
+ * If this pointer has an additional parent when talloc_free() is called
+ * then the memory is not actually released, but instead the most
+ * recently established parent is destroyed. See talloc_reference() for
+ * details on establishing additional parents.
+ *
+ * For more control on which parent is removed, see talloc_unlink()
+ *
+ * talloc_free() operates recursively on its children.
+ */
 int talloc_free(void *ptr);
+
+/**
+ * \brief Free a talloc chunk's children
+ * \param ptr The chunk that you want to free the children of
+ * \return success?
+ * \ingroup talloc_basic
+ *
+ * The talloc_free_children() walks along the list of all children of a talloc
+ * context and talloc_free()s only the children, not the context itself.
+ */
 void talloc_free_children(void *ptr);
 void *_talloc_realloc(const void *context, void *ptr, size_t size, const char *name);
 void *_talloc_steal(const void *new_ctx, const void *ptr);
 void *_talloc_move(const void *new_ctx, const void *pptr);
+
+/**
+ * \brief Return the total size of a talloc chunk including its children
+ * \param ptr The talloc chunk
+ * \return The total size
+ * \ingroup talloc_basic
+ *
+ * The talloc_total_size() function returns the total size in bytes used
+ * by this pointer and all child pointers. Mostly useful for debugging.
+ *
+ * Passing NULL is allowed, but it will only give a meaningful result if
+ * talloc_enable_leak_report() or talloc_enable_leak_report_full() has
+ * been called.
+ */
 size_t talloc_total_size(const void *ptr);
+
+/**
+ * \brief Return the number of talloc chunks hanging off a chunk
+ * \param ptr The talloc chunk
+ * \return The total size
+ * \ingroup talloc_basic
+ *
+ * The talloc_total_blocks() function returns the total memory block
+ * count used by this pointer and all child pointers. Mostly useful for
+ * debugging.
+ *
+ * Passing NULL is allowed, but it will only give a meaningful result if
+ * talloc_enable_leak_report() or talloc_enable_leak_report_full() has
+ * been called.
+ */
 size_t talloc_total_blocks(const void *ptr);
+
+/**
+ * \brief Walk a complete talloc hierarchy
+ * \param ptr The talloc chunk
+ * \param depth Internal parameter to control recursion. Call with 0.
+ * \param max_depth Maximum recursion level.
+ * \param callback Function to be called on every chunk
+ * \param private_data Private pointer passed to callback
+ * \ingroup talloc_debug
+ *
+ * This provides a more flexible reports than talloc_report(). It
+ * will recursively call the callback for the entire tree of memory
+ * referenced by the pointer. References in the tree are passed with
+ * is_ref = 1 and the pointer that is referenced.
+ *
+ * You can pass NULL for the pointer, in which case a report is
+ * printed for the top level memory context, but only if
+ * talloc_enable_leak_report() or talloc_enable_leak_report_full()
+ * has been called.
+ *
+ * The recursion is stopped when depth >= max_depth.
+ * max_depth = -1 means only stop at leaf nodes.
+ */
 void talloc_report_depth_cb(const void *ptr, int depth, int max_depth,
 			    void (*callback)(const void *ptr,
 			  		     int depth, int max_depth,
 					     int is_ref,
 					     void *private_data),
 			    void *private_data);
+
+/**
+ * \brief Print a talloc hierarchy
+ * \param ptr The talloc chunk
+ * \param depth Internal parameter to control recursion. Call with 0.
+ * \param max_depth Maximum recursion level.
+ * \param f The file handle to print to
+ * \ingroup talloc_debug
+ *
+ * This provides a more flexible reports than talloc_report(). It
+ * will let you specify the depth and max_depth.
+ */
 void talloc_report_depth_file(const void *ptr, int depth, int max_depth, FILE *f);
+
+/**
+ * \brief Print a summary report of all memory used by ptr
+ * \param ptr The talloc chunk
+ * \param f The file handle to print to
+ * \ingroup talloc_debug
+ *
+ * This provides a more detailed report than talloc_report(). It will
+ * recursively print the ensire tree of memory referenced by the
+ * pointer. References in the tree are shown by giving the name of the
+ * pointer that is referenced.
+ *
+ * You can pass NULL for the pointer, in which case a report is printed
+ * for the top level memory context, but only if
+ * talloc_enable_leak_report() or talloc_enable_leak_report_full() has
+ * been called.
+ */
 void talloc_report_full(const void *ptr, FILE *f);
+
+/**
+ * \brief Print a summary report of all memory used by ptr
+ * \param ptr The talloc chunk
+ * \param f The file handle to print to
+ * \ingroup talloc_debug
+ *
+ * The talloc_report() function prints a summary report of all memory
+ * used by ptr. One line of report is printed for each immediate child of
+ * ptr, showing the total memory and number of blocks used by that child.
+ *
+ * You can pass NULL for the pointer, in which case a report is printed
+ * for the top level memory context, but only if
+ * talloc_enable_leak_report() or talloc_enable_leak_report_full() has
+ * been called.
+ */
 void talloc_report(const void *ptr, FILE *f);
+
+/**
+ * \brief Enable tracking the use of NULL memory contexts
+ * \ingroup talloc_debug
+ *
+ * This enables tracking of the NULL memory context without enabling leak
+ * reporting on exit. Useful for when you want to do your own leak
+ * reporting call via talloc_report_null_full();
+ */
 void talloc_enable_null_tracking(void);
+
+/**
+ * \brief Disable tracking of the NULL memory context
+ * \ingroup talloc_debug
+ *
+ * This disables tracking of the NULL memory context.
+ */
+
 void talloc_disable_null_tracking(void);
+
+/**
+ * \brief Enable calling of talloc_report(NULL, stderr) when a program exits
+ * \ingroup talloc_debug
+ *
+ * This enables calling of talloc_report(NULL, stderr) when the program
+ * exits. In Samba4 this is enabled by using the --leak-report command
+ * line option.
+ *
+ * For it to be useful, this function must be called before any other
+ * talloc function as it establishes a "null context" that acts as the
+ * top of the tree. If you don't call this function first then passing
+ * NULL to talloc_report() or talloc_report_full() won't give you the
+ * full tree printout.
+ *
+ * Here is a typical talloc report:
+ *
+\verbatim
+talloc report on 'null_context' (total 267 bytes in 15 blocks)
+         libcli/auth/spnego_parse.c:55  contains     31 bytes in   2 blocks
+         libcli/auth/spnego_parse.c:55  contains     31 bytes in   2 blocks
+         iconv(UTF8,CP850)              contains     42 bytes in   2 blocks
+         libcli/auth/spnego_parse.c:55  contains     31 bytes in   2 blocks
+         iconv(CP850,UTF8)              contains     42 bytes in   2 blocks
+         iconv(UTF8,UTF-16LE)           contains     45 bytes in   2 blocks
+         iconv(UTF-16LE,UTF8)           contains     45 bytes in   2 blocks
+\endverbatim
+ */
 void talloc_enable_leak_report(void);
+
+/**
+ * \brief Enable calling of talloc_report(NULL, stderr) when a program exits
+ * \ingroup talloc_debug
+ *
+ * This enables calling of talloc_report_full(NULL, stderr) when the
+ * program exits. In Samba4 this is enabled by using the
+ * --leak-report-full command line option.
+ *
+ * For it to be useful, this function must be called before any other
+ * talloc function as it establishes a "null context" that acts as the
+ * top of the tree. If you don't call this function first then passing
+ * NULL to talloc_report() or talloc_report_full() won't give you the
+ * full tree printout.
+ *
+ * Here is a typical full report:
+\verbatim
+full talloc report on 'root' (total 18 bytes in 8 blocks)
+    p1                             contains     18 bytes in   7 blocks (ref 0)
+        r1                             contains     13 bytes in   2 blocks (ref 0)
+            reference to: p2
+        p2                             contains      1 bytes in   1 blocks (ref 1)
+        x3                             contains      1 bytes in   1 blocks (ref 0)
+        x2                             contains      1 bytes in   1 blocks (ref 0)
+        x1                             contains      1 bytes in   1 blocks (ref 0)
+\endverbatim
+*/
 void talloc_enable_leak_report_full(void);
 void *_talloc_zero(const void *ctx, size_t size, const char *name);
 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);
+
+/**
+ * \brief Provide a function version of talloc_realloc_size
+ * \param context The parent context used if "ptr" is NULL
+ * \param ptr The chunk to be resized
+ * \param size The new chunk size
+ * \return The new chunk
+ * \ingroup talloc_array
+ *
+ * This is a non-macro version of talloc_realloc(), which is useful as
+ * libraries sometimes want a ralloc function pointer. A realloc()
+ * implementation encapsulates the functionality of malloc(), free() and
+ * realloc() in one call, which is why it is useful to be able to pass around
+ * a single function pointer.
+*/
 void *talloc_realloc_fn(const void *context, void *ptr, size_t size);
+
+/**
+ * \brief Provide a talloc context that is freed at program exit
+ * \return A talloc context
+ * \ingroup talloc_basic
+ *
+ * This is a handy utility function that returns a talloc context
+ * which will be automatically freed on program exit. This can be used
+ * to reduce the noise in memory leak reports.
+ */
 void *talloc_autofree_context(void);
+
+/**
+ * \brief Get the size of a talloc chunk
+ * \param ctx The talloc chunk
+ * \return The size
+ * \ingroup talloc_basic
+ *
+ * This function lets you know the amount of memory alloced so far by
+ * this context. It does NOT account for subcontext memory.
+ * This can be used to calculate the size of an array.
+ */
 size_t talloc_get_size(const void *ctx);
+
+/**
+ * \brief Find a parent context by name
+ * \param ctx The talloc chunk to start from
+ * \param name The name of the parent we look for
+ * \ingroup talloc_basic
+ *
+ * Find a parent memory context of the current context that has the given
+ * name. This can be very useful in complex programs where it may be
+ * difficult to pass all information down to the level you need, but you
+ * know the structure you want is a parent of another context.
+ */
 void *talloc_find_parent_byname(const void *ctx, const char *name);
 void talloc_show_parents(const void *context, FILE *file);
 int talloc_is_parent(const void *context, const void *ptr);
 
+/**
+ * \brief Duplicate a string into a talloc chunk
+ * \param t The talloc context to hang the result off
+ * \param p The string you want to duplicate
+ * \return The duplicated string
+ * \ingroup talloc_string
+ *
+ * The talloc_strdup() function is equivalent to:
+ *
+ * \code
+ * ptr = talloc_size(ctx, strlen(p)+1);
+ * if (ptr) memcpy(ptr, p, strlen(p)+1);
+ * \endcode
+ *
+ * This functions sets the name of the new pointer to the passed
+ * string. This is equivalent to:
+ *
+ * \code
+ * talloc_set_name_const(ptr, ptr)
+ * \endcode
+ */
 char *talloc_strdup(const void *t, const char *p);
 char *talloc_strdup_append(char *s, const char *a);
 char *talloc_strdup_append_buffer(char *s, const char *a);
 
+/**
+ * \brief Duplicate a length-limited string into a talloc chunk
+ * \param t The talloc context to hang the result off
+ * \param p The string you want to duplicate
+ * \param n The maximum string length to duplicate
+ * \return The duplicated string
+ * \ingroup talloc_string
+ *
+ * The talloc_strndup() function is the talloc equivalent of the C
+ * library function strndup()
+ *
+ * This functions sets the name of the new pointer to the passed
+ * string. This is equivalent to:
+ *
+ * \code
+ * talloc_set_name_const(ptr, ptr)
+ * \endcode
+ */
 char *talloc_strndup(const void *t, const char *p, size_t n);
 char *talloc_strndup_append(char *s, const char *a, size_t n);
 char *talloc_strndup_append_buffer(char *s, const char *a, size_t n);
 
+/**
+ * \brief Format a string given a va_list
+ * \param t The talloc context to hang the result off
+ * \param fmt The format string
+ * \param ap The parameters used to fill fmt
+ * \return The formatted string
+ * \ingroup talloc_string
+ *
+ * The talloc_vasprintf() function is the talloc equivalent of the C
+ * library function vasprintf()
+ *
+ * This functions sets the name of the new pointer to the new
+ * string. This is equivalent to:
+ *
+ * \code
+ * talloc_set_name_const(ptr, ptr)
+ * \endcode
+ */
 char *talloc_vasprintf(const void *t, const char *fmt, va_list ap) PRINTF_ATTRIBUTE(2,0);
 char *talloc_vasprintf_append(char *s, const char *fmt, va_list ap) PRINTF_ATTRIBUTE(2,0);
 char *talloc_vasprintf_append_buffer(char *s, const char *fmt, va_list ap) PRINTF_ATTRIBUTE(2,0);
 
+/**
+ * \brief Format a string
+ * \param t The talloc context to hang the result off
+ * \param fmt The format string
+ * \param ... The parameters used to fill fmt
+ * \return The formatted string
+ * \ingroup talloc_string
+ *
+ * The talloc_asprintf() function is the talloc equivalent of the C
+ * library function asprintf()
+ *
+ * This functions sets the name of the new pointer to the new
+ * string. This is equivalent to:
+ *
+ * \code
+ * talloc_set_name_const(ptr, ptr)
+ * \endcode
+ */
 char *talloc_asprintf(const void *t, const char *fmt, ...) PRINTF_ATTRIBUTE(2,3);
+
+/**
+ * \brief Append a formatted string to another string
+ * \param s The string to append to
+ * \param fmt The format string
+ * \param ... The parameters used to fill fmt
+ * \return The formatted string
+ * \ingroup talloc_string
+ *
+ * The talloc_asprintf_append() function appends the given formatted string to
+ * the given string. Use this varient when the string in the current talloc
+ * buffer may have been truncated in length.
+ *
+ * This functions sets the name of the new pointer to the new
+ * string. This is equivalent to:
+ *
+ * \code
+ * talloc_set_name_const(ptr, ptr)
+ * \endcode
+ */
 char *talloc_asprintf_append(char *s, const char *fmt, ...) PRINTF_ATTRIBUTE(2,3);
+
+/**
+ * \brief Append a formatted string to another string
+ * \param s The string to append to
+ * \param fmt The format string
+ * \param ... The parameters used to fill fmt
+ * \return The formatted string
+ * \ingroup talloc_string
+ *
+ * The talloc_asprintf_append() function appends the given formatted string to
+ * the end of the currently allocated talloc buffer. This routine should be
+ * used if you create a large string step by step. talloc_asprintf() or
+ * talloc_asprintf_append() call strlen() at every
+ * step. talloc_asprintf_append_buffer() uses the existing buffer size of the
+ * talloc chunk to calculate where to append the string.
+ *
+ * This functions sets the name of the new pointer to the new
+ * string. This is equivalent to:
+ *
+ * \code
+ * talloc_set_name_const(ptr, ptr)
+ * \endcode
+ */
 char *talloc_asprintf_append_buffer(char *s, const char *fmt, ...) PRINTF_ATTRIBUTE(2,3);
 
 void talloc_set_abort_fn(void (*abort_fn)(const char *reason));