[PATCH] PR c/70281: C FE: fix uninitialized range for __builtin_types_compatible_p

[PATCH] PR c/70281: C FE: fix uninitialized range for __builtin_types_compatible_p

[David Malcolm]

PR c/70281 reports another case where Valgrind identified an uninitialized
src_range in a c_expr in the C frontend, this time in
the parsing of __builtin_types_compatible_p.

For gcc 7 I hope to fix this more robustly (via poisoning the values in
a c_expr ctor), but for now, this patch fixes the specific issue found.

Successfully bootstrapped on x86_64-pc-linux-gnu; adds 7 PASS results
to gcc.sum.

OK for trunk?

gcc/c/ChangeLog:
	PR c/70281
	* c-parser.c (c_parser_postfix_expression): Set the source range
	for uses of "__builtin_types_compatible_p".

gcc/testsuite/ChangeLog:
	PR c/70281
	* gcc.dg/plugin/diagnostic-test-expressions-1.c
	(test_builtin_types_compatible_p): New test function.
	* gcc.dg/pr70281.c: New test case.
---
 gcc/c/c-parser.c                                       |  6 ++++--
 .../gcc.dg/plugin/diagnostic-test-expressions-1.c      | 18 ++++++++++++++++++
 gcc/testsuite/gcc.dg/pr70281.c                         |  9 +++++++++
 3 files changed, 31 insertions(+), 2 deletions(-)
 create mode 100644 gcc/testsuite/gcc.dg/pr70281.c

diff --git a/gcc/c/c-parser.c b/gcc/c/c-parser.c
index 60ec996..b80b279 100644
--- a/gcc/c/c-parser.c
+++ b/gcc/c/c-parser.c
@@ -7782,9 +7782,10 @@ c_parser_postfix_expression (c_parser *parser)
 	      expr.value = error_mark_node;
 	      break;
 	    }
-	  c_parser_skip_until_found (parser, CPP_CLOSE_PAREN,
-				     "expected %<)%>");
 	  {
+	    location_t close_paren_loc = c_parser_peek_token (parser)->location;
+	    c_parser_skip_until_found (parser, CPP_CLOSE_PAREN,
+				       "expected %<)%>");
 	    tree e1, e2;
 	    e1 = groktypename (t1, NULL, NULL);
 	    e2 = groktypename (t2, NULL, NULL);
@@ -7799,6 +7800,7 @@ c_parser_postfix_expression (c_parser *parser)
 
 	    expr.value
 	      = comptypes (e1, e2) ? integer_one_node : integer_zero_node;
+	    set_c_expr_source_range (&expr, loc, close_paren_loc);
 	  }
 	  break;
 	case RID_BUILTIN_CALL_WITH_STATIC_CHAIN:
diff --git a/gcc/testsuite/gcc.dg/plugin/diagnostic-test-expressions-1.c b/gcc/testsuite/gcc.dg/plugin/diagnostic-test-expressions-1.c
index 49ad670..c2d27d7 100644
--- a/gcc/testsuite/gcc.dg/plugin/diagnostic-test-expressions-1.c
+++ b/gcc/testsuite/gcc.dg/plugin/diagnostic-test-expressions-1.c
@@ -534,6 +534,24 @@ void test_builtin_choose_expr (int i)
 }
 
 extern int f (int);
+
+void test_builtin_types_compatible_p (unsigned long i)
+{
+  __emit_expression_range (0,
+			   f (i) + __builtin_types_compatible_p (long, int)); /* { dg-warning "range" } */
+/* { dg-begin-multiline-output "" }
+       f (i) + __builtin_types_compatible_p (long, int));
+       ~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+   { dg-end-multiline-output "" } */
+
+  __emit_expression_range (0,
+			   __builtin_types_compatible_p (long, int) + f (i)); /* { dg-warning "range" } */
+/* { dg-begin-multiline-output "" }
+       __builtin_types_compatible_p (long, int) + f (i));
+       ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~
+   { dg-end-multiline-output "" } */
+}
+
 void test_builtin_call_with_static_chain (int i, void *ptr)
 {
   __emit_expression_range (0, __builtin_call_with_static_chain (f (i), ptr));  /* { dg-warning "range" } */
diff --git a/gcc/testsuite/gcc.dg/pr70281.c b/gcc/testsuite/gcc.dg/pr70281.c
new file mode 100644
index 0000000..9447fb1
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/pr70281.c
@@ -0,0 +1,9 @@
+/* { dg-options "-Wall -fdiagnostics-show-caret" } */
+int bch_stats_show ()
+{
+  return __builtin_types_compatible_p (unsigned, int) ? "" : "";  /* { dg-warning "cast" } */
+/* { dg-begin-multiline-output "" }
+   return __builtin_types_compatible_p (unsigned, int) ? "" : "";
+          ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~
+   { dg-end-multiline-output "" } */
+}
-- 
1.8.5.3

Re: [PATCH] PR c/70281: C FE: fix uninitialized range for __builtin_types_compatible_p

[Jeff Law]

On 03/18/2016 10:25 AM, David Malcolm wrote:
> PR c/70281 reports another case where Valgrind identified an uninitialized
> src_range in a c_expr in the C frontend, this time in
> the parsing of __builtin_types_compatible_p.
>
> For gcc 7 I hope to fix this more robustly (via poisoning the values in
> a c_expr ctor), but for now, this patch fixes the specific issue found.
>
> Successfully bootstrapped on x86_64-pc-linux-gnu; adds 7 PASS results
> to gcc.sum.
>
> OK for trunk?
>
> gcc/c/ChangeLog:
> 	PR c/70281
> 	* c-parser.c (c_parser_postfix_expression): Set the source range
> 	for uses of "__builtin_types_compatible_p".
>
> gcc/testsuite/ChangeLog:
> 	PR c/70281
> 	* gcc.dg/plugin/diagnostic-test-expressions-1.c
> 	(test_builtin_types_compatible_p): New test function.
> 	* gcc.dg/pr70281.c: New test case.
OK
jeff