2010-09-27 Basile Starynkevitch <basile@starynkevitch.net>

	MELT branch merged with trunk rev 164647



git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/branches/melt-branch@164648 138bc75d-0d04-0410-961f-82ee72b054a4

1 files changed, 40 insertions, 15 deletions

diff --git a/gcc/doc/extend.texi b/gcc/doc/extend.texi
index 4f2cc077101..7073c902abd 100644
--- a/gcc/doc/extend.texi
+++ b/gcc/doc/extend.texi
@@ -568,7 +568,7 @@ the containing function.  You should specify, for @var{result}, a value
 returned by @code{__builtin_apply}.
 @end deftypefn
 
-@deftypefn {Built-in Function} __builtin_va_arg_pack ()
+@deftypefn {Built-in Function} {} __builtin_va_arg_pack ()
 This built-in function represents all anonymous arguments of an inline
 function.  It can be used only in inline functions which will be always
 inlined, never compiled as a separate function, such as those using
@@ -594,7 +594,7 @@ myprintf (FILE *f, const char *format, ...)
 @end smallexample
 @end deftypefn
 
-@deftypefn {Built-in Function} __builtin_va_arg_pack_len ()
+@deftypefn {Built-in Function} {size_t} __builtin_va_arg_pack_len ()
 This built-in function returns the number of anonymous arguments of
 an inline function.  It can be used only in inline functions which
 will be always inlined, never compiled as a separate function, such
@@ -796,8 +796,8 @@ This example is perfectly equivalent to
 x ? x : y
 @end smallexample
 
-@cindex side effect in ?:
-@cindex ?: side effect
+@cindex side effect in @code{?:}
+@cindex @code{?:} side effect
 @noindent
 In this simple case, the ability to omit the middle operand is not
 especially useful.  When it becomes useful is when the first operand does,
@@ -2671,6 +2671,31 @@ SRAM. The function will be put into a specific section named
 @code{.l1.text}. With @option{-mfdpic}, callers of such functions will use
 an inlined PLT.
 
+@item leaf
+@cindex @code{leaf} function attribute
+Calls to external functions with this attribute must return to the current
+compilation unit only by return or by exception handling. In particular, leaf
+functions are not allowed to call callback function passed to it from current
+compilation unit or directly call functions exported by the unit or longjmp
+into the unit.  Still leaf function might call functions from other complation
+units and thus they are not neccesarily leaf in the sense that they contains no
+function calls at all.
+
+The attribute is intended for library functions to improve dataflow analysis.
+Compiler takes the hint that any data not escaping current compilation unit can
+not be used or modified by the leaf function.  For example, function @code{sin}
+is leaf, function @code{qsort} is not.
+
+Note that the leaf functions might invoke signals and signal handlers might be
+defined in the current compilation unit and use static variables. Only
+compliant way to write such a signal handler is to declare such variables
+@code{volatile}.
+
+The attribute has no effect on functions defined within current compilation
+unit.  This is to allow easy merging of multiple compilation units into one,
+for example, by using the link time optimization.  For this reason the
+attribute is not allowed on types to annotate indirect calls.
+
 @item long_call/short_call
 @cindex indirect calls on ARM
 This attribute specifies how a particular function is called on
@@ -3900,7 +3925,7 @@ extension is irrelevant.
 
 @node C++ Comments
 @section C++ Style Comments
-@cindex //
+@cindex @code{//}
 @cindex C++ comments
 @cindex comments, C++ style
 
@@ -12370,7 +12395,7 @@ bit-fields.  See the Solaris man page for @code{cmn_err} for more information.
 @node Pragmas
 @section Pragmas Accepted by GCC
 @cindex pragmas
-@cindex #pragma
+@cindex @code{#pragma}
 
 GCC supports several types of pragmas, primarily in order to compile
 code originally written for other compilers.  Note that in general
@@ -12936,8 +12961,8 @@ versions earlier than 4.4.
 
 @node Unnamed Fields
 @section Unnamed struct/union fields within structs/unions
-@cindex struct
-@cindex union
+@cindex @code{struct}
+@cindex @code{union}
 
 As permitted by ISO C1X and for compatibility with other compilers,
 GCC allows you to define
@@ -12989,7 +13014,7 @@ previously defined structure or union type with a tag.
 @section Thread-Local Storage
 @cindex Thread-Local Storage
 @cindex @acronym{TLS}
-@cindex __thread
+@cindex @code{__thread}
 
 Thread-local storage (@acronym{TLS}) is a mechanism by which variables
 are allocated such that there is one instance of the variable per extant
@@ -13442,15 +13467,15 @@ vtable will still be emitted in every translation unit which defines it.
 Make sure that any inline virtuals are declared inline in the class
 body, even if they are not defined there.
 
-@item type_info objects
-@cindex type_info
+@item @code{type_info} objects
+@cindex @code{type_info}
 @cindex RTTI
 C++ requires information about types to be written out in order to
 implement @samp{dynamic_cast}, @samp{typeid} and exception handling.
-For polymorphic classes (classes with virtual functions), the type_info
+For polymorphic classes (classes with virtual functions), the @samp{type_info}
 object is written out along with the vtable so that @samp{dynamic_cast}
 can determine the dynamic type of a class object at runtime.  For all
-other types, we write out the type_info object when it is used: when
+other types, we write out the @samp{type_info} object when it is used: when
 applying @samp{typeid} to an expression, throwing an object, or
 referring to a type in a catch clause or exception specification.
 
@@ -13770,7 +13795,7 @@ Some attributes only make sense for C++ programs.
 
 @table @code
 @item init_priority (@var{priority})
-@cindex init_priority attribute
+@cindex @code{init_priority} attribute
 
 
 In Standard C++, objects defined at namespace scope are guaranteed to be
@@ -13795,7 +13820,7 @@ Note that the particular values of @var{priority} do not matter; only their
 relative ordering.
 
 @item java_interface
-@cindex java_interface attribute
+@cindex @code{java_interface} attribute
 
 This type attribute informs C++ that the class is a Java interface.  It may
 only be applied to classes declared within an @code{extern "Java"} block.