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[PATCH] PR c++/68795: fix uninitialized close_paren_loc in cp_parser_postfix_expression
- From: David Malcolm <dmalcolm at redhat dot com>
- To: gcc-patches at gcc dot gnu dot org
- Cc: David Malcolm <dmalcolm at redhat dot com>
- Date: Thu, 17 Dec 2015 13:32:06 -0500
- Subject: [PATCH] PR c++/68795: fix uninitialized close_paren_loc in cp_parser_postfix_expression
- Authentication-results: sourceware.org; auth=none
cp_parser_parenthesized_expression_list can leave *close_paren_loc
untouched if an error occurs; specifically when following this goto:
7402 if (expr == error_mark_node)
7403 goto skip_comma;
which can lead to cp_parser_postfix_expression attempting to
use uninitialized data for the finishing location of a
parenthesized expression.
The attached patch fixes this by having cp_parser_postfix_expression
initialize the underlying location to UNKNOWN_LOCATION, and only use
it if it's been written to.
Verified the fix manually by compiling
g++.old-deja/g++.ns/invalid1.C
before and after under valgrind.
Successfully bootstrapped®rtested on x86_64-pc-linux-gnu.
OK for trunk?
gcc/cp/ChangeLog:
* parser.c (cp_parser_postfix_expression): Initialize
close_paren_loc to UNKNOWN_LOCATION; only use it if
it has been written to by
cp_parser_parenthesized_expression_list.
(cp_parser_postfix_dot_deref_expression): Likewise.
(cp_parser_parenthesized_expression_list): Document the behavior
with respect to the CLOSE_PAREN_LOC param.
---
gcc/cp/parser.c | 18 ++++++++++++------
1 file changed, 12 insertions(+), 6 deletions(-)
diff --git a/gcc/cp/parser.c b/gcc/cp/parser.c
index a420cf1..56dfe42 100644
--- a/gcc/cp/parser.c
+++ b/gcc/cp/parser.c
@@ -6664,7 +6664,7 @@ cp_parser_postfix_expression (cp_parser *parser, bool address_p, bool cast_p,
bool saved_non_integral_constant_expression_p = false;
tsubst_flags_t complain = complain_flags (decltype_p);
vec<tree, va_gc> *args;
- location_t close_paren_loc;
+ location_t close_paren_loc = UNKNOWN_LOCATION;
is_member_access = false;
@@ -6826,10 +6826,13 @@ cp_parser_postfix_expression (cp_parser *parser, bool address_p, bool cast_p,
koenig_p,
complain);
- location_t combined_loc = make_location (token->location,
- start_loc,
- close_paren_loc);
- postfix_expression.set_location (combined_loc);
+ if (close_paren_loc)
+ {
+ location_t combined_loc = make_location (token->location,
+ start_loc,
+ close_paren_loc);
+ postfix_expression.set_location (combined_loc);
+ }
/* The POSTFIX_EXPRESSION is certainly no longer an id. */
idk = CP_ID_KIND_NONE;
@@ -7298,7 +7301,10 @@ cp_parser_postfix_dot_deref_expression (cp_parser *parser,
plain identifier argument, normal_attr for an attribute that wants
an expression, or non_attr if we aren't parsing an attribute list. If
NON_CONSTANT_P is non-NULL, *NON_CONSTANT_P indicates whether or
- not all of the expressions in the list were constant. */
+ not all of the expressions in the list were constant.
+ If CLOSE_PAREN_LOC is non-NULL, and no errors occur, then *CLOSE_PAREN_LOC
+ will be written to with the location of the closing parenthesis. If
+ an error occurs, it may or may not be written to. */
static vec<tree, va_gc> *
cp_parser_parenthesized_expression_list (cp_parser* parser,
--
1.8.5.3