sql: work around lack of runtime/trace in gccgo

Moves runtime/trace support behind a "gc" build tag to allow sql_test
to build under gccgo, which does not support runtime/trace.

See golang/go#15544.

sql/logic_gc_test.go

@@ -0,0 +1,46 @@
+// Copyright 2016 The Cockroach Authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
+// implied. See the License for the specific language governing
+// permissions and limitations under the License.
+//
+// Author: Tamir Duberstein ([email protected])
+
+// +build gc
+
+package sql_test
+
+import (
+	"os"
+	"runtime/trace"
+)
+
+func (t *logicTest) traceStart(filename string) {
+	if t.traceFile != nil {
+		t.Fatalf("tracing already active")
+	}
+	var err error
+	t.traceFile, err = os.Create(filename)
+	if err != nil {
+		t.Fatalf("unable to open trace output file: %s", err)
+	}
+	if err := trace.Start(t.traceFile); err != nil {
+		t.Fatalf("unable to start tracing: %s", err)
+	}
+}
+
+func (t *logicTest) traceStop() {
+	if t.traceFile != nil {
+		trace.Stop()
+		t.traceFile.Close()
+		t.traceFile = nil
+	}
+}

sql/logic_not_gc_test.go

@@ -0,0 +1,23 @@
+// Copyright 2016 The Cockroach Authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
+// implied. See the License for the specific language governing
+// permissions and limitations under the License.
+//
+// Author: Tamir Duberstein ([email protected])
+
+// +build !gc
+
+package sql_test
+
+func (*logicTest) traceStart(_ string) {}
+
+func (*logicTest) traceStop() {}

sql/logic_test.go

@@ -29,7 +29,6 @@ import (
 	"path/filepath"
 	"reflect"
 	"regexp"
-	"runtime/trace"
 	"sort"
 	"strconv"
 	"strings"
@@ -1020,28 +1019,6 @@ func (t *logicTest) success(file string) {
 	}
 }
 
-func (t *logicTest) traceStart(filename string) {
-	if t.traceFile != nil {
-		t.Fatalf("tracing already active")
-	}
-	var err error
-	t.traceFile, err = os.Create(filename)
-	if err != nil {
-		t.Fatalf("unable to open trace output file: %s", err)
-	}
-	if err := trace.Start(t.traceFile); err != nil {
-		t.Fatalf("unable to start tracing: %s", err)
-	}
-}
-
-func (t *logicTest) traceStop() {
-	if t.traceFile != nil {
-		trace.Stop()
-		t.traceFile.Close()
-		t.traceFile = nil
-	}
-}
-
 func TestLogic(t *testing.T) {
 	defer leaktest.AfterTest(t)()