Initial prebuilt support

Support prebuilt shared libraries as an initial proof-of-concept of
prebuilts.  Future changes will support binaries and static libraries,
and the ability to select which to use based on something besides
blueprint properties.

Test: TestPrebuilts run during m -j
Change-Id: I6e84da667e9005ae11844bad01d25cbe4ced1ce3

android/prebuilt_test.go

@@ -0,0 +1,206 @@
+// Copyright 2016 Google Inc. All rights reserved.
+//
+// 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 android
+
+import (
+	"testing"
+
+	"github.com/google/blueprint"
+)
+
+var prebuiltsTests = []struct {
+	name     string
+	modules  string
+	prebuilt bool
+}{
+	{
+		name: "no prebuilt",
+		modules: `
+			source {
+				name: "bar",
+			}`,
+		prebuilt: false,
+	},
+	{
+		name: "no source prebuilt not preferred",
+		modules: `
+			prebuilt {
+				name: "bar",
+				prefer: false,
+				srcs: ["prebuilt"],
+			}`,
+		prebuilt: true,
+	},
+	{
+		name: "no source prebuilt preferred",
+		modules: `
+			prebuilt {
+				name: "bar",
+				prefer: true,
+				srcs: ["prebuilt"],
+			}`,
+		prebuilt: true,
+	},
+	{
+		name: "prebuilt not preferred",
+		modules: `
+			source {
+				name: "bar",
+			}
+			
+			prebuilt {
+				name: "bar",
+				prefer: false,
+				srcs: ["prebuilt"],
+			}`,
+		prebuilt: false,
+	},
+	{
+		name: "prebuilt preferred",
+		modules: `
+			source {
+				name: "bar",
+			}
+			
+			prebuilt {
+				name: "bar",
+				prefer: true,
+				srcs: ["prebuilt"],
+			}`,
+		prebuilt: true,
+	},
+}
+
+func TestPrebuilts(t *testing.T) {
+	for _, test := range prebuiltsTests {
+		t.Run(test.name, func(t *testing.T) {
+			ctx := NewContext()
+			ctx.RegisterModuleType("prebuilt", newPrebuiltModule)
+			ctx.RegisterModuleType("source", newSourceModule)
+			ctx.MockFileSystem(map[string][]byte{
+				"Blueprints": []byte(`
+					source {
+						name: "foo",
+						deps: ["bar"],
+					}
+					` + test.modules),
+			})
+
+			config := TestConfig()
+
+			_, errs := ctx.ParseBlueprintsFiles("Blueprints")
+			fail(t, errs)
+			_, errs = ctx.PrepareBuildActions(config)
+			fail(t, errs)
+
+			foo := findModule(ctx, "foo")
+			if foo == nil {
+				t.Fatalf("failed to find module foo")
+			}
+
+			if test.prebuilt {
+				if !foo.(*sourceModule).dependsOnPrebuiltModule {
+					t.Errorf("doesn't depend on prebuilt module")
+				}
+
+				if foo.(*sourceModule).dependsOnSourceModule {
+					t.Errorf("depends on source module")
+				}
+			} else {
+				if foo.(*sourceModule).dependsOnPrebuiltModule {
+					t.Errorf("depends on prebuilt module")
+				}
+
+				if !foo.(*sourceModule).dependsOnSourceModule {
+					t.Errorf("doens't depend on source module")
+				}
+			}
+		})
+	}
+
+}
+
+type prebuiltModule struct {
+	ModuleBase
+	prebuilt Prebuilt
+}
+
+func newPrebuiltModule() (blueprint.Module, []interface{}) {
+	m := &prebuiltModule{}
+	return InitAndroidModule(m, &m.prebuilt.Properties)
+}
+
+func (p *prebuiltModule) Name() string {
+	return p.prebuilt.Name(p.ModuleBase.Name())
+}
+
+func (p *prebuiltModule) DepsMutator(ctx BottomUpMutatorContext) {
+}
+
+func (p *prebuiltModule) GenerateAndroidBuildActions(ModuleContext) {
+}
+
+func (p *prebuiltModule) Prebuilt() *Prebuilt {
+	return &p.prebuilt
+}
+
+type sourceModule struct {
+	ModuleBase
+	properties struct {
+		Deps []string
+	}
+	dependsOnSourceModule, dependsOnPrebuiltModule bool
+}
+
+func newSourceModule() (blueprint.Module, []interface{}) {
+	m := &sourceModule{}
+	return InitAndroidModule(m, &m.properties)
+}
+
+func (s *sourceModule) DepsMutator(ctx BottomUpMutatorContext) {
+	for _, d := range s.properties.Deps {
+		ctx.AddDependency(ctx.Module(), nil, d)
+	}
+}
+
+func (s *sourceModule) GenerateAndroidBuildActions(ctx ModuleContext) {
+	ctx.VisitDirectDeps(func(m blueprint.Module) {
+		if _, ok := m.(*sourceModule); ok {
+			s.dependsOnSourceModule = true
+		}
+		if _, ok := m.(*prebuiltModule); ok {
+			s.dependsOnPrebuiltModule = true
+		}
+	})
+}
+
+func findModule(ctx *blueprint.Context, name string) blueprint.Module {
+	var ret blueprint.Module
+	ctx.VisitAllModules(func(m blueprint.Module) {
+		if ctx.ModuleName(m) == name {
+			ret = m
+		}
+	})
+	return ret
+}
+
+func fail(t *testing.T, errs []error) {
+	if len(errs) > 0 {
+		for _, err := range errs {
+			t.Error(err)
+		}
+		t.FailNow()
+	}
+}