[infra] Add code coverage report generation for Go projects (#3142)

* Golang coverage report

* Enables golang coverage report for gonids and go-dns

* Generates summary for golang coverage reports

* Performance profile for golang projects

3 files changed, 71 insertions, 1 deletions

diff --git a/infra/base-images/base-builder/Dockerfile b/infra/base-images/base-builder/Dockerfile
index 6b6299e28..70599f379 100644
--- a/infra/base-images/base-builder/Dockerfile
+++ b/infra/base-images/base-builder/Dockerfile
@@ -152,6 +152,7 @@ COPY compile compile_afl compile_dataflow compile_libfuzzer compile_honggfuzz \
     precompile_honggfuzz srcmap write_labels.py /usr/local/bin/
 
 COPY detect_repo.py /opt/cifuzz/
+COPY ossfuzz_coverage_runner.go $GOPATH
 
 RUN precompile_honggfuzz
 
diff --git a/infra/base-images/base-builder/compile b/infra/base-images/base-builder/compile
index 2a9876af2..cdbbfe0a9 100755
--- a/infra/base-images/base-builder/compile
+++ b/infra/base-images/base-builder/compile
@@ -92,7 +92,7 @@ BUILD_CMD="bash -eux $SRC/build.sh"
 
 # We need to preserve source code files for generating a code coverage report.
 # We need exact files that were compiled, so copy both $SRC and $WORK dirs.
-COPY_SOURCES_CMD="cp -rL --parents $SRC $WORK /usr/include /usr/local/include $OUT"
+COPY_SOURCES_CMD="cp -rL --parents $SRC $WORK /usr/include /usr/local/include $GOPATH $OUT"
 
 if [ "${BUILD_UID-0}" -ne "0" ]; then
   adduser -u $BUILD_UID --disabled-password --gecos '' builder
diff --git a/infra/base-images/base-builder/ossfuzz_coverage_runner.go b/infra/base-images/base-builder/ossfuzz_coverage_runner.go
new file mode 100644
index 000000000..d433da246
--- /dev/null
+++ b/infra/base-images/base-builder/ossfuzz_coverage_runner.go
@@ -0,0 +1,69 @@
+// Copyright 2020 Google LLC
+//
+// 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 mypackagebeingfuzzed
+
+import (
+	"io/ioutil"
+	"os"
+	"runtime/pprof"
+	"testing"
+)
+
+func TestFuzzCorpus(t *testing.T) {
+	dir := os.Getenv("FUZZ_CORPUS_DIR")
+	if dir == "" {
+		t.Logf("No fuzzing corpus directory set")
+		return
+	}
+	infos, err := ioutil.ReadDir(dir)
+	if err != nil {
+		t.Logf("Not fuzzing corpus directory %s", err)
+		return
+	}
+	filename := ""
+	defer func() {
+		if r := recover(); r != nil {
+			t.Error("Fuzz panicked in "+filename, r)
+		}
+	}()
+	profname := os.Getenv("FUZZ_PROFILE_NAME")
+	if profname != "" {
+		f, err := os.Create(profname + ".cpu.prof")
+		if err != nil {
+			t.Logf("error creating profile file %s\n", err)
+		} else {
+			_ = pprof.StartCPUProfile(f)
+		}
+	}
+	for i := range infos {
+		filename = dir + infos[i].Name()
+		data, err := ioutil.ReadFile(filename)
+		if err != nil {
+			t.Error("Failed to read corpus file", err)
+		}
+		FuzzFunction(data)
+	}
+	if profname != "" {
+		pprof.StopCPUProfile()
+		f, err := os.Create(profname + ".heap.prof")
+		if err != nil {
+			t.Logf("error creating heap profile file %s\n", err)
+		}
+		if err = pprof.WriteHeapProfile(f); err != nil {
+			t.Logf("error writing heap profile file %s\n", err)
+		}
+		f.Close()
+	}
+}