[PATCH] Warn about unclosed pragma omp declare target.

[Ilya Tocar <tocarip.intel@gmail.com>]

Hi,

As discussed here in https://gcc.gnu.org/ml/gcc/2014-01/msg00189.html
Gcc should complain about pragma omp declare target without
corresponding pragma omp end declare target. This patch adds a warning
for those cases.
Bootstraps/passes make-check.
Ok for trunk?

ChangeLog:

2014-07-29  Ilya Tocar  <ilya.tocar@intel.com>

	* c-decl.c (omp_declare_target_location_stack): New.
	* c-lang.h (omp_declare_target_location_stack): Declare.
	* c-parser.c (warn_unclosed_pragma_omp_target): New.
	(c_parser_translation_unit): Call it.
	(c_parser_omp_declare_target): Remeber location.
	(c_parser_omp_end_declare_target): Forget location.

And ChangeLog for testsuite:

2014-07-29  Ilya Tocar  <ilya.tocar@intel.com>

	* gcc.dg/gomp//target-3.c: New testcase.

---
 gcc/c/c-decl.c                       |  3 +++
 gcc/c/c-lang.h                       |  3 +++
 gcc/c/c-parser.c                     | 22 +++++++++++++++++++++-
 gcc/testsuite/gcc.dg/gomp/target-3.c | 33 +++++++++++++++++++++++++++++++++
 4 files changed, 60 insertions(+), 1 deletion(-)
 create mode 100644 gcc/testsuite/gcc.dg/gomp/target-3.c

diff --git a/gcc/c/c-decl.c b/gcc/c/c-decl.c
index 2a4b439..2dd5b2c 100644
--- a/gcc/c/c-decl.c
+++ b/gcc/c/c-decl.c
@@ -158,6 +158,9 @@ enum machine_mode c_default_pointer_mode = VOIDmode;
 /* If non-zero, implicit "omp declare target" attribute is added into the
    attribute lists.  */
 int current_omp_declare_target_attribute;
+
+/* Holds locations of currently open "omp declare target" pragmas.  */
+vec<location_t> omp_declare_target_location_stack;
 \f
 /* Each c_binding structure describes one binding of an identifier to
    a decl.  All the decls in a scope - irrespective of namespace - are
diff --git a/gcc/c/c-lang.h b/gcc/c/c-lang.h
index e974906..cef995c 100644
--- a/gcc/c/c-lang.h
+++ b/gcc/c/c-lang.h
@@ -59,4 +59,7 @@ struct GTY(()) language_function {
    attribute lists.  */
 extern GTY(()) int current_omp_declare_target_attribute;
 
+/* Holds locations of currently open "omp declare target" pragmas.  */
+extern vec<location_t> omp_declare_target_location_stack;
+
 #endif /* ! GCC_C_LANG_H */
diff --git a/gcc/c/c-parser.c b/gcc/c/c-parser.c
index e32bf04..0b96fe9 100644
--- a/gcc/c/c-parser.c
+++ b/gcc/c/c-parser.c
@@ -1255,6 +1255,8 @@ static bool c_parser_cilk_verify_simd (c_parser *, enum pragma_context);
 static tree c_parser_array_notation (location_t, c_parser *, tree, tree);
 static tree c_parser_cilk_clause_vectorlength (c_parser *, tree, bool);
 
+static void warn_unclosed_pragma_omp_target ();
+
 /* Parse a translation unit (C90 6.7, C99 6.9).
 
    translation-unit:
@@ -1290,6 +1292,8 @@ c_parser_translation_unit (c_parser *parser)
 	}
       while (c_parser_next_token_is_not (parser, CPP_EOF));
     }
+
+  warn_unclosed_pragma_omp_target ();
 }
 
 /* Parse an external declaration (C90 6.7, C99 6.9).
@@ -13068,8 +13072,10 @@ c_finish_omp_declare_simd (c_parser *parser, tree fndecl, tree parms,
 static void
 c_parser_omp_declare_target (c_parser *parser)
 {
+  location_t loc = c_parser_peek_token (parser)->location;
   c_parser_skip_to_pragma_eol (parser);
   current_omp_declare_target_attribute++;
+  omp_declare_target_location_stack.safe_push (loc);
 }
 
 static void
@@ -13104,7 +13110,10 @@ c_parser_omp_end_declare_target (c_parser *parser)
     error_at (loc, "%<#pragma omp end declare target%> without corresponding "
 		   "%<#pragma omp declare target%>");
   else
-    current_omp_declare_target_attribute--;
+    {
+      current_omp_declare_target_attribute--;
+      omp_declare_target_location_stack.pop ();
+    }
 }
 
 
@@ -14267,4 +14276,15 @@ c_parser_array_notation (location_t loc, c_parser *parser, tree initial_index,
   return value_tree;
 }
 
+static void
+warn_unclosed_pragma_omp_target ()
+{
+  int i;
+  for (i = 0; i < current_omp_declare_target_attribute; i++)
+    warning_at (omp_declare_target_location_stack[i], 0,
+		"%<#pragma omp declare target%> without corresponding "
+		"%<#pragma omp end declare target%>");
+  omp_declare_target_location_stack.release ();
+}
+
 #include "gt-c-c-parser.h"
diff --git a/gcc/testsuite/gcc.dg/gomp/target-3.c b/gcc/testsuite/gcc.dg/gomp/target-3.c
new file mode 100644
index 0000000..d50604f
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/gomp/target-3.c
@@ -0,0 +1,33 @@
+/* { dg-do compile } */
+/* { dg-options "-fopenmp" } */
+
+#pragma omp declare target
+int tgtv = 6;
+
+int
+tgt (void)
+{
+  tgtv++;
+  return 0;
+}
+#pragma omp end declare target
+
+#pragma omp declare target        /* { dg-warning "'#pragma omp declare target' without corresponding '#pragma omp end declare target'" } */
+int tgtv1 = 6;
+#pragma omp declare target	  /* { dg-warning "'#pragma omp declare target' without corresponding '#pragma omp end declare target'" } */
+
+int
+tgt2 (void)
+{
+  tgtv1++;
+  return 0;
+}
+
+#pragma omp declare target
+int
+tgt3 (void)
+{
+  tgtv1++;
+  return 0;
+}
+#pragma omp end declare target
-- 
1.8.3.1