Add internal nogo analysis & checkescape tool.

See tools/nogo/README.md.

The checkescape tool is able to perform recursive escape analysis, using the
actual generated binary to confirm the results produced by the compiler itself.

As an initial use case, this replaces the manual escape analysis tests used for
go_marshal, and validates that the CopyIn and CopyOut paths will not require
any allocation or stack splits.

Updates #2243

PiperOrigin-RevId: 307532986

1 files changed, 64 insertions, 0 deletions

diff --git a/tools/nogo/register.go b/tools/nogo/register.go
new file mode 100644
index 000000000..62b499661
--- /dev/null
+++ b/tools/nogo/register.go
@@ -0,0 +1,64 @@
+// 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/gob"
+	"log"
+
+	"golang.org/x/tools/go/analysis"
+)
+
+// analyzers returns all configured analyzers.
+func analyzers() (all []*analysis.Analyzer) {
+	for a, _ := range analyzerConfig {
+		all = append(all, a)
+	}
+	return all
+}
+
+func init() {
+	// Validate basic configuration.
+	if err := analysis.Validate(analyzers()); err != nil {
+		log.Fatalf("unable to validate analyzer: %v", err)
+	}
+
+	// Register all fact types.
+	//
+	// N.B. This needs to be done recursively, because there may be
+	// analyzers in the Requires list that do not appear explicitly above.
+	registered := make(map[*analysis.Analyzer]struct{})
+	var register func(*analysis.Analyzer)
+	register = func(a *analysis.Analyzer) {
+		if _, ok := registered[a]; ok {
+			return
+		}
+
+		// Regsiter dependencies.
+		for _, da := range a.Requires {
+			register(da)
+		}
+
+		// Register local facts.
+		for _, f := range a.FactTypes {
+			gob.Register(f)
+		}
+
+		registered[a] = struct{}{} // Done.
+	}
+	for _, a := range analyzers() {
+		register(a)
+	}
+}