From patchwork Mon Jun 21 14:53:03 2010
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Subject: [trans-mem] add support for C++ transaction expressions
Date: Mon, 21 Jun 2010 04:53:03 -0000
From: Aldy Hernandez <aldyh@redhat.com>
X-Patchwork-Id: 56323
Message-Id: <20100621145301.GA10641@redhat.com>
To: rth@redhat.com, gcc-patches@gcc.gnu.org

Hi.

This patch adds transaction expression support for C++.

No test, because there's already a common one here:

	testsuite/c-c++-common/tm/trxn-expr.c

OK for branch?

	* cp/parser.c (cp_parser_unary_expression): Handle
	RID_TRANSACTION.
	(cp_parser_transaction_expression): New.


Index: cp/parser.c
===================================================================
--- cp/parser.c	(revision 160538)
+++ cp/parser.c	(working copy)
@@ -1893,6 +1893,8 @@ static void cp_parser_label_declaration
 
 static tree cp_parser_transaction
   (cp_parser *);
+static tree cp_parser_transaction_expression
+  (cp_parser *);
 static bool cp_parser_function_transaction
   (cp_parser *);
 static tree cp_parser_transaction_cancel
@@ -5582,6 +5584,9 @@ cp_parser_unary_expression (cp_parser *p
 	  }
 	  break;
 
+	case RID_TRANSACTION:
+	  return cp_parser_transaction_expression (parser);
+
 	default:
 	  break;
 	}
@@ -23058,6 +23063,55 @@ cp_parser_transaction (cp_parser *parser
   return stmt;
 }
 
+/* Parse a __transaction expression.
+
+   transaction-expression:
+     __transaction txn-attribute[opt] txn-exception-spec[opt]
+	compound-statement
+
+   ??? The exception specification is not yet implemented.
+*/
+
+static tree
+cp_parser_transaction_expression (cp_parser *parser)
+{
+  unsigned char old_in = parser->in_transaction;
+  unsigned char this_in = 1;
+  cp_token *token;
+  tree ret, attrs;
+
+  token = cp_parser_require_keyword (parser, RID_TRANSACTION,
+				     "%<__transaction%>");
+  gcc_assert (token != NULL);
+
+  attrs = cp_parser_txn_attribute_opt (parser);
+  if (attrs)
+    {
+      this_in |= parse_tm_stmt_attr (attrs, (TM_STMT_ATTR_ATOMIC
+					     | TM_STMT_ATTR_RELAXED));
+      /* The [[ atomic ]] attribute is the same as no attribute.  */
+      this_in &= ~TM_STMT_ATTR_ATOMIC;
+    }
+
+  parser->in_transaction = this_in;
+  if (cp_lexer_next_token_is (parser->lexer, CPP_OPEN_PAREN))
+    {
+      tree expr = cp_parser_expression (parser, /*cast_p=*/false, NULL);
+      ret = build1 (TRANSACTION_EXPR, TREE_TYPE (expr), expr);
+      if (this_in & TM_STMT_ATTR_RELAXED)
+	TRANSACTION_EXPR_RELAXED (ret) = 1;
+      SET_EXPR_LOCATION (ret, token->location);
+    }
+  else
+    {
+      cp_parser_error (parser, "expected %<(%>");
+      ret = error_mark_node;
+    }
+  parser->in_transaction = old_in;
+
+  return ret;
+}
+
 /* Parse a function-transaction-block.
 
    function-transaction-block: