5 files changed, 128 insertions, 2 deletions
diff --git a/tools/checklocks/test/BUILD b/tools/checklocks/test/BUILD
index 4b90731f5..21a68fbdf 100644
--- a/tools/checklocks/test/BUILD
+++ b/tools/checklocks/test/BUILD
@@ -13,7 +13,9 @@ go_library(
         "branches.go",
         "closures.go",
         "defer.go",
+        "globals.go",
         "incompat.go",
+        "inferred.go",
         "locker.go",
         "methods.go",
         "parameters.go",
@@ -21,4 +23,8 @@ go_library(
         "rwmutex.go",
         "test.go",
     ],
+    # This ensures that there are no dependencies, since we want to explicitly
+    # control expected failures for analysis.
+    marshal = False,
+    stateify = False,
 )
diff --git a/tools/checklocks/test/globals.go b/tools/checklocks/test/globals.go
new file mode 100644
index 000000000..656b0c9a3
--- /dev/null
+++ b/tools/checklocks/test/globals.go
@@ -0,0 +1,85 @@
+// Copyright 2020 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 test
+
+import (
+	"sync"
+)
+
+var (
+	globalMu   sync.Mutex
+	globalRWMu sync.RWMutex
+)
+
+var globalStruct struct {
+	mu sync.Mutex
+	// +checklocks:mu
+	guardedField int
+}
+
+var otherStruct struct {
+	// +checklocks:globalMu
+	guardedField1 int
+	// +checklocks:globalRWMu
+	guardedField2 int
+	// +checklocks:globalStruct.mu
+	guardedField3 int
+}
+
+func testGlobalValid() {
+	globalMu.Lock()
+	otherStruct.guardedField1 = 1
+	globalMu.Unlock()
+
+	globalRWMu.Lock()
+	otherStruct.guardedField2 = 1
+	globalRWMu.Unlock()
+
+	globalRWMu.RLock()
+	_ = otherStruct.guardedField2
+	globalRWMu.RUnlock()
+
+	globalStruct.mu.Lock()
+	globalStruct.guardedField = 1
+	otherStruct.guardedField3 = 1
+	globalStruct.mu.Unlock()
+}
+
+// +checklocks:globalStruct.mu
+func testGlobalValidPreconditions0() {
+	globalStruct.guardedField = 1
+}
+
+// +checklocks:globalMu
+func testGlobalValidPreconditions1() {
+	otherStruct.guardedField1 = 1
+}
+
+// +checklocks:globalRWMu
+func testGlobalValidPreconditions2() {
+	otherStruct.guardedField2 = 1
+}
+
+// +checklocks:globalStruct.mu
+func testGlobalValidPreconditions3() {
+	otherStruct.guardedField3 = 1
+}
+
+func testGlobalInvalid() {
+	globalStruct.guardedField = 1 // +checklocksfail
+	otherStruct.guardedField1 = 1 // +checklocksfail
+	otherStruct.guardedField2 = 1 // +checklocksfail
+	otherStruct.guardedField3 = 1 // +checklocksfail
+}
diff --git a/tools/checklocks/test/inferred.go b/tools/checklocks/test/inferred.go
new file mode 100644
index 000000000..5495bdb2a
--- /dev/null
+++ b/tools/checklocks/test/inferred.go
@@ -0,0 +1,35 @@
+// Copyright 2020 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 test
+
+import (
+	"sync"
+)
+
+type inferredStruct struct {
+	mu             sync.Mutex
+	guardedField   int // +checklocksfail
+	unguardedField int
+}
+
+func testInferredPositive(tc *inferredStruct) {
+	tc.mu.Lock()
+	tc.guardedField = 1
+	tc.mu.Unlock()
+}
+
+func testInferredNegative(tc *inferredStruct) {
+	tc.unguardedField = 1
+}
diff --git a/tools/checklocks/test/methods.go b/tools/checklocks/test/methods.go
index 72e26fca6..b67657b61 100644
--- a/tools/checklocks/test/methods.go
+++ b/tools/checklocks/test/methods.go
@@ -103,7 +103,7 @@ type testMethodsWithEmbedded struct {
 
 	// +checklocks:mu
 	guardedField int
-	p            *testMethodsWithParameters
+	p            *testMethodsWithParameters // +checklocksignore: Inferred as protected by mu.
 }
 
 // +checklocks:t.mu
diff --git a/tools/checklocks/test/test.go b/tools/checklocks/test/test.go
index cbf6b1635..d1a9992fb 100644
--- a/tools/checklocks/test/test.go
+++ b/tools/checklocks/test/test.go
@@ -51,7 +51,7 @@ type twoLocksStruct struct {
 // twoLocksDoubleGuardStruct has two locks and a single field with two guards.
 type twoLocksDoubleGuardStruct struct {
 	mu       sync.Mutex
-	secondMu sync.Mutex
+	secondMu sync.Mutex // +checklocksignore: mu is inferred as requisite.
 	// +checklocks:mu
 	// +checklocks:secondMu
 	doubleGuardedField int