Add nogo configuration.

This splits the nogo rules into a separate configuration yaml file, and
allows for multiple files to be provided.

Because attrs cannot be passed down to aspects, this required that all
findings are propagated up the aspect Provider. This doesn't mean that
any extra work must be done, just that this information must be carried
through the graph, and some additional starlark complexity is required.

PiperOrigin-RevId: 339076357

1 files changed, 63 insertions, 0 deletions

diff --git a/tools/nogo/findings.go b/tools/nogo/findings.go
new file mode 100644
index 000000000..5bd850269
--- /dev/null
+++ b/tools/nogo/findings.go
@@ -0,0 +1,63 @@
+// Copyright 2019 The gVisor 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.
+
+package nogo
+
+import (
+	"encoding/json"
+	"fmt"
+	"go/token"
+	"io/ioutil"
+)
+
+// Finding is a single finding.
+type Finding struct {
+	Category AnalyzerName
+	Position token.Position
+	Message  string
+}
+
+// String implements fmt.Stringer.String.
+func (f *Finding) String() string {
+	return fmt.Sprintf("%s: %s: %s", f.Category, f.Position.String(), f.Message)
+}
+
+// WriteFindingsToFile writes findings to a file.
+func WriteFindingsToFile(findings []Finding, filename string) error {
+	content, err := WriteFindingsToBytes(findings)
+	if err != nil {
+		return err
+	}
+	return ioutil.WriteFile(filename, content, 0644)
+}
+
+// WriteFindingsToBytes serializes findings as bytes.
+func WriteFindingsToBytes(findings []Finding) ([]byte, error) {
+	return json.Marshal(findings)
+}
+
+// ExtractFindingsFromFile loads findings from a file.
+func ExtractFindingsFromFile(filename string) ([]Finding, error) {
+	content, err := ioutil.ReadFile(filename)
+	if err != nil {
+		return nil, err
+	}
+	return ExtractFindingsFromBytes(content)
+}
+
+// ExtractFindingsFromBytes loads findings from bytes.
+func ExtractFindingsFromBytes(content []byte) (findings []Finding, err error) {
+	err = json.Unmarshal(content, &findings)
+	return findings, err
+}