1 files changed, 58 insertions, 0 deletions
diff --git a/go/tools/coverdata/coverdata.go b/go/tools/coverdata/coverdata.go
new file mode 100644
index 00000000..1a80b014
--- /dev/null
+++ b/go/tools/coverdata/coverdata.go
@@ -0,0 +1,58 @@
+/* Copyright 2018 The Bazel Authors. All rights reserved.
+
+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.
+*/
+
+// Package coverdata provides a registration function for files with
+// coverage instrumentation.
+//
+// This package is part of the Bazel Go rules, and its interface
+// should not be considered public. It may change without notice.
+package coverdata
+
+import (
+	"fmt"
+	"testing"
+)
+
+// Contains all coverage data for the program.
+var (
+	Counters = make(map[string][]uint32)
+	Blocks = make(map[string][]testing.CoverBlock)
+)
+
+// RegisterFile causes the coverage data recorded for a file to be included
+// in program-wide coverage reports. This should be called from init functions
+// in packages with coverage instrumentation.
+func RegisterFile(fileName string, counter []uint32, pos []uint32, numStmts []uint16) {
+	if 3*len(counter) != len(pos) || len(counter) != len(numStmts) {
+		panic("coverage: mismatched sizes")
+	}
+	if Counters[fileName] != nil {
+		// Already registered.
+		fmt.Printf("Already covered %s\n", fileName)
+		return
+	}
+	Counters[fileName] = counter
+	block := make([]testing.CoverBlock, len(counter))
+	for i := range counter {
+		block[i] = testing.CoverBlock{
+			Line0: pos[3*i+0],
+			Col0:  uint16(pos[3*i+2]),
+			Line1: pos[3*i+1],
+			Col1:  uint16(pos[3*i+2] >> 16),
+			Stmts: numStmts[i],
+		}
+	}
+	Blocks[fileName] = block
+}