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C PATCH to fix a crash on invalid (PR c/81289)

Message ID 20170802100252.GU3397@redhat.com
State New
Headers show

Commit Message

Marek Polacek Aug. 2, 2017, 10:02 a.m. UTC 
The compiler could crash in c_parser_unary_expression in case CPP_MULT:
 7050         exp_loc = c_parser_peek_token (parser)->location;
 7051         op = c_parser_cast_expression (parser, NULL);
 7052         finish = op.get_finish ();
 ...
 7054         location_t combined_loc = make_location (op_loc, op_loc, finish);
 7055         ret.value = build_indirect_ref (combined_loc, op.value, RO_UNARY_STAR);
because there was a parse error and op.get_finish () points to garbage.  The
fix is to use set_error which properly resets src_range in c_expr.

Bootstrapped/regtested on x86_64-linux and ppc64le-linux, ok for trunk?

2017-08-02  Marek Polacek  <polacek@redhat.com>

	PR c/81289
	* c-parser.c (c_parser_unary_expression): Use set_error.

	* gcc.dg/noncompile/pr81289.c: New test.


	Marek

Comments

Joseph Myers Aug. 2, 2017, 11:42 a.m. UTC | #1 
On Wed, 2 Aug 2017, Marek Polacek wrote:

> 2017-08-02  Marek Polacek  <polacek@redhat.com>
> 
> 	PR c/81289
> 	* c-parser.c (c_parser_unary_expression): Use set_error.
> 
> 	* gcc.dg/noncompile/pr81289.c: New test.

OK.
diff mbox

Patch

diff --git gcc/c/c-parser.c gcc/c/c-parser.c
index 16cd3579972..d018fbc5961 100644
--- gcc/c/c-parser.c
+++ gcc/c/c-parser.c
@@ -7099,9 +7099,9 @@  c_parser_unary_expression (c_parser *parser)
       else
 	{
 	  c_parser_error (parser, "expected identifier");
-	  ret.value = error_mark_node;
+	  ret.set_error ();
 	}
-	return ret;
+      return ret;
     case CPP_KEYWORD:
       switch (c_parser_peek_token (parser)->keyword)
 	{
diff --git gcc/testsuite/gcc.dg/noncompile/pr81289.c gcc/testsuite/gcc.dg/noncompile/pr81289.c
index e69de29bb2d..dd211466718 100644
--- gcc/testsuite/gcc.dg/noncompile/pr81289.c
+++ gcc/testsuite/gcc.dg/noncompile/pr81289.c
@@ -0,0 +1,8 @@ 
+/* PR c/81289 */
+/* { dg-do compile } */
+
+int
+fn (int mm)
+{
+  mm == *&&
+} /* { dg-error "expected identifier" } */