Including the following changes:
* The definition of the new internal function .ACCESS_WITH_SIZE
in internal-fn.def.
* C FE converts every reference to a FAM with a "counted_by" attribute
to a call to the internal function .ACCESS_WITH_SIZE.
(build_component_ref in c_typeck.cc)
This includes the case when the object is statically allocated and
initialized.
In order to make this working, the routines initializer_constant_valid_p_1
and output_constant in varasm.cc are updated to handle calls to
.ACCESS_WITH_SIZE.
(initializer_constant_valid_p_1 and output_constant in varasm.c)
However, for the reference inside "offsetof", the "counted_by" attribute is
ignored since it's not useful at all.
(c_parser_postfix_expression in c/c-parser.cc)
In addtion to "offsetof", for the reference inside operator "typeof" and
"alignof", we ignore counted_by attribute too.
When building ADDR_EXPR for the .ACCESS_WITH_SIZE in C FE,
replace the call with its first argument.
* Convert every call to .ACCESS_WITH_SIZE to its first argument.
(expand_ACCESS_WITH_SIZE in internal-fn.cc)
* Adjust alias analysis to exclude the new internal from clobbering anything.
(ref_maybe_used_by_call_p_1 and call_may_clobber_ref_p_1 in tree-ssa-alias.cc)
* Adjust dead code elimination to eliminate the call to .ACCESS_WITH_SIZE when
it's LHS is eliminated as dead code.
(eliminate_unnecessary_stmts in tree-ssa-dce.cc)
* Provide the utility routines to check the call is .ACCESS_WITH_SIZE and
get the reference from the call to .ACCESS_WITH_SIZE.
(is_access_with_size_p and get_ref_from_access_with_size in tree.cc)
gcc/c/ChangeLog:
* c-parser.cc (c_parser_postfix_expression): Ignore the counted-by
attribute when build_component_ref inside offsetof operator.
* c-tree.h (build_component_ref): Add one more parameter.
* c-typeck.cc (build_counted_by_ref): New function.
(build_access_with_size_for_counted_by): New function.
(build_component_ref): Check the counted-by attribute and build
call to .ACCESS_WITH_SIZE.
(build_unary_op): When building ADDR_EXPR for
.ACCESS_WITH_SIZE, use its first argument.
(lvalue_p): Accept call to .ACCESS_WITH_SIZE.
gcc/ChangeLog:
* internal-fn.cc (expand_ACCESS_WITH_SIZE): New function.
* internal-fn.def (ACCESS_WITH_SIZE): New internal function.
* tree-ssa-alias.cc (ref_maybe_used_by_call_p_1): Special case
IFN_ACCESS_WITH_SIZE.
(call_may_clobber_ref_p_1): Special case IFN_ACCESS_WITH_SIZE.
* tree-ssa-dce.cc (eliminate_unnecessary_stmts): Eliminate the call
to .ACCESS_WITH_SIZE when its LHS is dead.
* tree.cc (process_call_operands): Adjust side effect for function
.ACCESS_WITH_SIZE.
(is_access_with_size_p): New function.
(get_ref_from_access_with_size): New function.
* tree.h (is_access_with_size_p): New prototype.
(get_ref_from_access_with_size): New prototype.
* varasm.cc (initializer_constant_valid_p_1): Handle call to
.ACCESS_WITH_SIZE.
(output_constant): Handle call to .ACCESS_WITH_SIZE.
gcc/testsuite/ChangeLog:
* gcc.dg/flex-array-counted-by-2.c: New test.
---
gcc/c/c-parser.cc | 10 +-
gcc/c/c-tree.h| 2 +-
gcc/c/c-typeck.cc | 128 +-
gcc/internal-fn.cc| 35 +
gcc/internal-fn.def | 4 +
.../gcc.dg/flex-array-counted-by-2.c | 112 +++
gcc/tree-ssa-alias.cc | 2 +
gcc/tree-ssa-dce.cc | 5 +-
gcc/tree.cc | 25 +++-
gcc/tree.h| 8 ++
gcc/varasm.cc | 10 ++
11 files changed, 331 insertions(+), 10 deletions(-)
create mode 100644 gcc/testsuite/gcc.dg/flex-array-counted-by-2.c
diff --git a/gcc/c/c-parser.cc b/gcc/c/c-parser.cc
index c31349dae2ff..a6ed5ac43bb1 100644
--- a/gcc/c/c-parser.cc
+++ b/gcc/c/c-parser.cc
@@ -10850,9 +10850,12 @@ c_parser_postfix_expression (c_parser *parser)
if (c_parser_next_token_is (parser, CPP_NAME))
{
c_token *comp_tok = c_parser_peek_token (parser);
+ /* Ignore the counted_by attribute for reference inside
+ offsetof since the information is not useful at all. */
offsetof_ref
= build_component_ref (loc, offsetof_ref, comp_tok->value,
-comp_tok->location, UNKNOWN_LOCATION);
+comp_tok->location, UNKNOWN_LOCATION,
+false);
c_parser_consume_token (parser);
while (c_parser_next_token_is (parser, CPP_DOT)
||
