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extend.texi: Document C++ restricted pointers and references.

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* extend.texi: Document C++ restricted pointers and references.

	* cp-tree.h (grok_method_quals): Return this pointer qualifiers.
	* decl.c (grokdeclarator): Adjust calls to grok_method_quals.
	* decl2.c (grok_method_quals): Accept `restrict' as applying to
	the object pointer. Return such qualifiers.
	(grokclassfn): Apply this pointer qualifiers. Cleanup unused
	variables.

From-SVN: r30587
This commit is contained in:
Nathan Sidwell 1999-11-19 13:03:00 +00:00
parent 73d65336b7
commit 535233a89f
6 changed files with 87 additions and 24 deletions
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11
gcc/ChangeLog
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@ -1,12 +1,17 @@
Fri Nov 19 10:41:15 GMT 1999 Nathan Sidwell <nathan@acm.org>
* extend.texi: Document C++ restricted pointers and references.
1999-11-19 Bernd Schmidt <bernds@cygnus.co.uk>
* cse.c (addr_affects_sp): No longer conditional on AUTO_INC_DEC.
(invalidate_skipped_set): Call it unconditionally.
(cse_set_around_loop): Likewise.
Fri Nov 18 13:39:22 CET 1999 Jam Hubicka <hubicka@freesoft.cz>
* i386.h (struct_processor_costs): New fileds int_load, int_store, fp_move,
fp_load and fp_store
Fri Nov 18 13:39:22 CET 1999 Jan Hubicka <hubicka@freesoft.cz>
* i386.h (struct_processor_costs): New fileds int_load, int_store,
fp_move, fp_load and fp_store
(REGISTER_MOVE_COST): Fix comment, calculate exactly the cost of
fp->int moves
(MEMORY_MOVE_COST): New macro.

9
gcc/cp/ChangeLog
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@ -1,3 +1,12 @@
1999-11-19 Nathan Sidwell <nathan@acm.org>
* cp-tree.h (grok_method_quals): Return this pointer qualifiers.
* decl.c (grokdeclarator): Adjust calls to grok_method_quals.
* decl2.c (grok_method_quals): Accept `restrict' as applying to
the object pointer. Return such qualifiers.
(grokclassfn): Apply this pointer qualifiers. Cleanup unused
variables.
1999-11-18 Mark Mitchell <mark@codesourcery.com>
* except.c (expand_end_catch_block): Fix typo.

2
gcc/cp/cp-tree.h
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@ -3529,7 +3529,7 @@ extern void make_rtl_for_local_static PROTO((tree));
extern void init_decl2 PROTO((void));
extern int check_java_method PROTO((tree));
extern int lang_decode_option PROTO((int, char **));
extern tree grok_method_quals PROTO((tree, tree, tree));
extern int grok_method_quals PROTO((tree, tree, tree));
extern void warn_if_unknown_interface PROTO((tree));
extern void grok_x_components PROTO((tree));
extern void maybe_retrofit_in_chrg PROTO((tree));

6
gcc/cp/decl.c
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@ -8919,7 +8919,8 @@ create_array_type_for_decl (name, type, size)
is erroneous, NULL_TREE is returned.
QUALS is used only for FUNCDEF and MEMFUNCDEF cases. For a member
function, these are the qualifiers to give to the `this' pointer.
function, these are the qualifiers to give to the `this' pointer. We
apply TYPE_QUAL_RESTRICT to the this ptr, not the object.
May return void_type_node if the declarator turned out to be a friend.
See grokfield for details. */
@ -9836,8 +9837,9 @@ grokdeclarator (declarator, declspecs, decl_context, initialized, attrlist)
if (ctype != NULL_TREE)
{
tree dummy = build_decl (TYPE_DECL, NULL_TREE, type);
ctype = grok_method_quals (ctype, dummy, quals);
grok_method_quals (ctype, dummy, quals);
type = TREE_TYPE (dummy);
ctype = TREE_TYPE (TREE_VALUE (TYPE_ARG_TYPES (type)));
quals = NULL_TREE;
}
}

31
gcc/cp/decl2.c
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@ -780,9 +780,11 @@ lang_decode_option (argc, argv)
/* Incorporate `const' and `volatile' qualifiers for member functions.
FUNCTION is a TYPE_DECL or a FUNCTION_DECL.
QUALS is a list of qualifiers. */
QUALS is a list of qualifiers. Returns any explicit
top-level qualifiers of the method's this pointer, anything other than
TYPE_UNQUALIFIED will be an extension. */
tree
int
grok_method_quals (ctype, function, quals)
tree ctype, function, quals;
{
@ -790,13 +792,16 @@ grok_method_quals (ctype, function, quals)
tree raises = TYPE_RAISES_EXCEPTIONS (fntype);
int type_quals = TYPE_UNQUALIFIED;
int dup_quals = TYPE_UNQUALIFIED;
int this_quals = TYPE_UNQUALIFIED;
do
{
int tq = cp_type_qual_from_rid (TREE_VALUE (quals));
if (type_quals & tq)
if ((type_quals | this_quals) & tq)
dup_quals |= tq;
else if (tq & TYPE_QUAL_RESTRICT)
this_quals |= tq;
else
type_quals |= tq;
quals = TREE_CHAIN (quals);
@ -817,7 +822,7 @@ grok_method_quals (ctype, function, quals)
fntype = build_exception_variant (fntype, raises);
TREE_TYPE (function) = fntype;
return ctype;
return this_quals;
}
/* Warn when -fexternal-templates is used and #pragma
@ -961,9 +966,7 @@ grokclassfn (ctype, function, flags, quals)
tree quals;
{
tree fn_name = DECL_NAME (function);
tree arg_types;
tree parm;
tree qualtype;
int this_quals = TYPE_UNQUALIFIED;
if (fn_name == NULL_TREE)
{
@ -973,26 +976,23 @@ grokclassfn (ctype, function, flags, quals)
}
if (quals)
qualtype = grok_method_quals (ctype, function, quals);
else
qualtype = ctype;
this_quals = grok_method_quals (ctype, function, quals);
arg_types = TYPE_ARG_TYPES (TREE_TYPE (function));
if (TREE_CODE (TREE_TYPE (function)) == METHOD_TYPE)
{
/* Must add the class instance variable up front. */
/* Right now we just make this a pointer. But later
we may wish to make it special. */
tree type = TREE_VALUE (arg_types);
tree type = TREE_VALUE (TYPE_ARG_TYPES (TREE_TYPE (function)));
parm = build_decl (PARM_DECL, this_identifier, type);
tree parm = build_decl (PARM_DECL, this_identifier,
cp_build_qualified_type (type, this_quals | TYPE_QUAL_CONST));
/* Mark the artificial `this' parameter as "artificial". */
SET_DECL_ARTIFICIAL (parm);
DECL_ARG_TYPE (parm) = type;
/* We can make this a register, so long as we don't
accidentally complain if someone tries to take its address. */
DECL_REGISTER (parm) = 1;
TREE_READONLY (parm) = 1;
TREE_CHAIN (parm) = last_function_parms;
last_function_parms = parm;
}
@ -1003,10 +1003,7 @@ grokclassfn (ctype, function, flags, quals)
DECL_CLASS_CONTEXT (function) = ctype;
if (flags == DTOR_FLAG || DECL_CONSTRUCTOR_P (function))
{
maybe_retrofit_in_chrg (function);
arg_types = TYPE_ARG_TYPES (TREE_TYPE (function));
}
if (flags == DTOR_FLAG)
{

50
gcc/extend.texi
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@ -3219,6 +3219,7 @@ Predefined Macros,cpp.info,The C Preprocessor}).
* Naming Results:: Giving a name to C++ function return values.
* Min and Max:: C++ Minimum and maximum operators.
* Volatiles:: What constitutes an access to a volatile object.
* Restricted Pointers:: C9X restricted pointers and references.
* C++ Interface:: You can use a single C++ header file for both
declarations and definitions.
* Template Instantiation:: Methods for ensuring that exactly one copy of
@ -3466,6 +3467,55 @@ possible to ignore the return value from functions returning volatile
references. Again, if you wish to force a read, cast the reference to
an rvalue.
@node Restricted Pointers
@section Restricting Pointer Aliasing
@cindex restricted pointers
@cindex restricted references
@cindex restricted this pointer
As with gcc, g++ understands the C9X proposal of restricted pointers,
specified with the @code{__restrict__}, or @code{__restrict} type
qualifier. Because you cannot compile C++ by specifying the -flang-isoc9x
language flag, @code{restrict} is not a keyword in C++.
In addition to allowing restricted pointers, you can specify restricted
references, which indicate that the reference is not aliased in the local
context.
@example
void fn (int *__restrict__ rptr, int &__restrict__ rref)
@{
@dots{}
@}
@end example
@noindent
In the body of @code{fn}, @var{rptr} points to an unaliased integer and
@var{rref} refers to a (different) unaliased integer.
You may also specify whether a member function's @var{this} pointer is
unaliased by using @code{__restrict__} as a member function qualifier.
@example
void T::fn () __restrict__
@{
@dots{}
@}
@end example
@noindent
Within the body of @code{T::fn}, @var{this} will have the effective
definition @code{T *__restrict__ const this}. Notice that the
interpretation of a @code{__restrict__} member function qualifier is
different to that of @code{const} or @code{volatile} qualifier, in that it
is applied to the pointer rather than the object. This is consistent with
other compilers which implement restricted pointers.
As with all outermost parameter qualifiers, @code{__restrict__} is
ignored in function definition matching. This means you only need to
specify @code{__restrict__} in a function definition, rather than
in a function prototype as well.
@node C++ Interface
@section Declarations and Definitions in One Header