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

2 files changed, 103 insertions, 0 deletions

diff --git a/tools/checkescape/test2/BUILD b/tools/checkescape/test2/BUILD
new file mode 100644
index 000000000..5a11e4b43
--- /dev/null
+++ b/tools/checkescape/test2/BUILD
@@ -0,0 +1,9 @@
+load("//tools:defs.bzl", "go_library")
+
+package(licenses = ["notice"])
+
+go_library(
+    name = "test2",
+    srcs = ["test2.go"],
+    deps = ["//tools/checkescape/test1"],
+)
diff --git a/tools/checkescape/test2/test2.go b/tools/checkescape/test2/test2.go
new file mode 100644
index 000000000..7fce3e3be
--- /dev/null
+++ b/tools/checkescape/test2/test2.go
@@ -0,0 +1,94 @@
+// 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 test2 is a test package that imports test1.
+package test2
+
+import (
+	"gvisor.dev/gvisor/tools/checkescape/test1"
+)
+
+// +checkescape:all
+//go:nosplit
+func interfaceFunctionCrossPkg() {
+	var i test1.Interface
+	test1.InterfaceFunction(i)
+}
+
+// +checkesacape:all
+//go:nosplit
+func typeFunctionCrossPkg() {
+	var t test1.Type
+	test1.TypeFunction(&t)
+}
+
+// +mustescape:builtin
+//go:noinline
+func builtinMapCrossPkg(x int) map[string]bool {
+	return test1.BuiltinMap(x)
+}
+
+// +mustescape:builtin
+//go:noinline
+func builtinClosureCrossPkg(x int) func() {
+	return test1.BuiltinClosure(x)
+}
+
+// +mustescape:builtin
+//go:noinline
+func builtinMakeSliceCrossPkg(x int) []byte {
+	return test1.BuiltinMakeSlice(x)
+}
+
+// +mustescape:builtin
+//go:noinline
+func builtinAppendCrossPkg() []byte {
+	return test1.BuiltinAppend(nil)
+}
+
+// +mustescape:builtin
+//go:noinline
+func builtinChanCrossPkg() chan int {
+	return test1.BuiltinChan()
+}
+
+// +mustescape:heap
+//go:noinline
+func heapCrossPkg() *test1.Type {
+	return test1.Heap()
+}
+
+// +mustescape:interface
+//go:noinline
+func dispatchCrossPkg(i test1.Interface) {
+	test1.Dispatch(i)
+}
+
+// +mustescape:dynamic
+//go:noinline
+func dynamicCrossPkg(f func()) {
+	test1.Dynamic(f)
+}
+
+// +mustescape:unknown
+//go:noinline
+func unknownCrossPkg() {
+	test1.Unknown()
+}
+
+// +mustescape:stack
+//go:noinline
+func splitCrosssPkt() {
+	test1.Split()
+}