re PR c/59218 (atomic transactions: accesses to volatiles not disallowed in transaction_safe code)

	PR c/59218

	* trans-mem.c (volatile_lvalue_p): Rename from volatile_var_p.
	(diagnose_tm_1_op): Also diagnose volatile accesses in
	transaction_safe function.

From-SVN: r228392

gcc/ChangeLog

+2015-10-02  Jason Merrill  <jason@redhat.com>
+
+	PR c/59218
+	* trans-mem.c (volatile_lvalue_p): Rename from volatile_var_p.
+	(diagnose_tm_1_op): Also diagnose volatile accesses in
+	transaction_safe function.
+
 2015-10-02  Jonathan Wakely  <jwakely@redhat.com>
 
 	* system.h (malloc.h): Don't include obsolete header.

gcc/testsuite/c-c++-common/tm/volatile-1.c

+// Transaction-unsafe testcase from TM TS.
+// { dg-options -fgnu-tm }
+
+volatile int * p = 0;
+__attribute ((transaction_safe))
+int f() {
+  int x = 0;	     // ok: not volatile
+  p = &x;	     // ok: the pointer is not volatile
+  int i = *p;	     // { dg-error "volatile" "read through volatile glvalue" }
+}

gcc/testsuite/gcc.dg/tm/pr46654.c

@@ -7,7 +7,7 @@ int y;
 void foo(volatile int x)
 {
   __transaction_atomic {
-    x = 5; /* { dg-error "invalid volatile use of 'x' inside transaction" } */
+    x = 5; /* { dg-error "invalid use of volatile lvalue inside transaction" } */
     x += y;
     y++;
   }
@@ -20,7 +20,7 @@ volatile int i = 0;
 void george()
 {
   __transaction_atomic {
-   if (i == 2) /* { dg-error "invalid volatile use of 'i' inside transaction" } */
+   if (i == 2) /* { dg-error "invalid use of volatile lvalue inside transaction" } */
      i = 1;
   }
 }

gcc/trans-mem.c

@@ -594,32 +594,36 @@ struct diagnose_tm
   gimple *stmt;
 };
 
-/* Return true if T is a volatile variable of some kind.  */
+/* Return true if T is a volatile lvalue of some kind.  */
 
 static bool
-volatile_var_p (tree t)
+volatile_lvalue_p (tree t)
 {
-  return (SSA_VAR_P (t)
+  return ((SSA_VAR_P (t) || REFERENCE_CLASS_P (t))
 	  && TREE_THIS_VOLATILE (TREE_TYPE (t)));
 }
 
 /* Tree callback function for diagnose_tm pass.  */
 
 static tree
-diagnose_tm_1_op (tree *tp, int *walk_subtrees ATTRIBUTE_UNUSED,
-		  void *data)
+diagnose_tm_1_op (tree *tp, int *walk_subtrees, void *data)
 {
   struct walk_stmt_info *wi = (struct walk_stmt_info *) data;
   struct diagnose_tm *d = (struct diagnose_tm *) wi->info;
 
-  if (volatile_var_p (*tp)
-      && d->block_flags & DIAG_TM_SAFE
-      && !d->saw_volatile)
+  if (TYPE_P (*tp))
+    *walk_subtrees = false;
+  else if (volatile_lvalue_p (*tp)
+	   && !d->saw_volatile)
     {
       d->saw_volatile = 1;
-      error_at (gimple_location (d->stmt),
-		"invalid volatile use of %qD inside transaction",
-		*tp);
+      if (d->block_flags & DIAG_TM_SAFE)
+	error_at (gimple_location (d->stmt),
+		  "invalid use of volatile lvalue inside transaction");
+      else if (d->func_flags & DIAG_TM_SAFE)
+	error_at (gimple_location (d->stmt),
+		  "invalid use of volatile lvalue inside %<transaction_safe%>"
+		  "function");
     }
 
   return NULL_TREE;
@@ -4298,7 +4302,7 @@ ipa_tm_scan_irr_block (basic_block bb)
 	    {
 	      tree lhs = gimple_assign_lhs (stmt);
 	      tree rhs = gimple_assign_rhs1 (stmt);
-	      if (volatile_var_p (lhs) || volatile_var_p (rhs))
+	      if (volatile_lvalue_p (lhs) || volatile_lvalue_p (rhs))
 		return true;
 	    }
 	  break;
@@ -4306,7 +4310,7 @@ ipa_tm_scan_irr_block (basic_block bb)
 	case GIMPLE_CALL:
 	  {
 	    tree lhs = gimple_call_lhs (stmt);
-	    if (lhs && volatile_var_p (lhs))
+	    if (lhs && volatile_lvalue_p (lhs))
 	      return true;
 
 	    if (is_tm_pure_call (stmt))