Re: [C PATCH] Fix statement frontiers handling in the C FE (PR c/84721)

Re: [C PATCH] Fix statement frontiers handling in the C FE (PR c/84721)

[Marek Polacek]

On Tue, Mar 06, 2018 at 09:51:57PM +0100, Jakub Jelinek wrote:
> Hi!
> 
> The C FE in multiple spots checks building_stmt_list_p () to decide if
> we are inside of parsing of functions or outside of that.
> 
> Unfortunately, that breaks with add_debug_begin_stmt which pushes
> DEBUG_BEGIN_STMTs regardless of the scope it appears in; e.g. on the
> testcase below it pushes DEBUG_BEGIN_STMT already for the int a
> declaration in column 1 on line 5, and so with -g building_stmt_list_p ()
> is pretty much always true.
> 
> Fixed by only pushing DEBUG_BEGIN_STMTs when the building_stmt_list_p ()
> predicate is true, they aren't really useful outside of functions anyway.
> 
> Bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk?

Ok.

	Marek

[C PATCH] Fix statement frontiers handling in the C FE (PR c/84721)

[Jakub Jelinek]

Hi!

The C FE in multiple spots checks building_stmt_list_p () to decide if
we are inside of parsing of functions or outside of that.

Unfortunately, that breaks with add_debug_begin_stmt which pushes
DEBUG_BEGIN_STMTs regardless of the scope it appears in; e.g. on the
testcase below it pushes DEBUG_BEGIN_STMT already for the int a
declaration in column 1 on line 5, and so with -g building_stmt_list_p ()
is pretty much always true.

Fixed by only pushing DEBUG_BEGIN_STMTs when the building_stmt_list_p ()
predicate is true, they aren't really useful outside of functions anyway.

Bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk?

2018-03-06  Jakub Jelinek  <jakub@redhat.com>

	PR c/84721
	* c-parser.c (add_debug_begin_stmt): Don't add DEBUG_BEGIN_STMT if
	!building_stmt_list_p ().

	* gcc.dg/pr84721.c: New test.

--- gcc/c/c-parser.c.jj	2018-02-06 13:12:49.320804579 +0100
+++ gcc/c/c-parser.c	2018-03-06 10:56:54.207194189 +0100
@@ -1654,7 +1654,8 @@ static void c_finish_oacc_routine (struc
 static void
 add_debug_begin_stmt (location_t loc)
 {
-  if (!MAY_HAVE_DEBUG_MARKER_STMTS)
+  /* Don't add DEBUG_BEGIN_STMTs outside of functions, see PR84721.  */
+  if (!MAY_HAVE_DEBUG_MARKER_STMTS || !building_stmt_list_p ())
     return;
 
   tree stmt = build0 (DEBUG_BEGIN_STMT, void_type_node);
--- gcc/testsuite/gcc.dg/pr84721.c.jj	2018-03-06 11:03:23.798005268 +0100
+++ gcc/testsuite/gcc.dg/pr84721.c	2018-03-06 11:02:59.741016937 +0100
@@ -0,0 +1,6 @@
+/* PR c/84721 */
+/* { dg-do compile } */
+/* { dg-options "-g -O2" } */
+
+int a[({ int b })];		/* { dg-error "braced-group within expression allowed only inside a function" } */
+int c[({ int d () {}; })];	/* { dg-error "braced-group within expression allowed only inside a function" } */

	Jakub