Delay dependency errors to ninja time for unbundled builds

Unbundled builds may use a subset of the tree, which can bring in unused
modules but not their dependencies.  Delay handling of dependency errors
for unbundled builds to ninja time, which will prevent errors if only
modules with satisified dependencies are built.

Change-Id: Ib93bae93fcfa0b55df500a30d8e35231ffb0987c

cc/cc.go

@@ -740,7 +740,7 @@ func (c *CCBase) depsToPathsFromList(ctx common.AndroidModuleContext,
 				return
 			}
 		})
-		if !found {
+		if !found && !inList(n, ctx.GetMissingDependencies()) {
 			ctx.ModuleErrorf("unsatisified dependency on %q", n)
 		}
 	}

cmd/soong_build/main.go

@@ -44,5 +44,7 @@ func main() {
 	// Temporary hack
 	//ctx.SetIgnoreUnknownModuleTypes(true)
 
+	ctx.SetAllowMissingDependencies(configuration.AllowMissingDependencies())
+
 	bootstrap.Main(ctx, configuration, configuration.ConfigFileName, configuration.ProductVariablesFileName)
 }

common/config.go

@@ -22,8 +22,12 @@ import (
 	"runtime"
 	"strings"
 	"sync"
+
+	"github.com/google/blueprint/proptools"
 )
 
+var Bool = proptools.Bool
+
 // The configuration file name
 const configFileName = "soong.config"
 const productVariablesFileName = "soong.variables"
@@ -287,3 +291,7 @@ func (c *config) DefaultAppCertificateDir(ctx PathContext) SourcePath {
 func (c *config) DefaultAppCertificate(ctx PathContext) SourcePath {
 	return c.DefaultAppCertificateDir(ctx).Join(ctx, "testkey")
 }
+
+func (c *config) AllowMissingDependencies() bool {
+	return Bool(c.ProductVariables.Unbundled_build)
+}

common/defs.go

@@ -59,6 +59,13 @@ var (
 			Description: "symlink $out",
 		},
 		"fromPath")
+
+	ErrorRule = pctx.StaticRule("Error",
+		blueprint.RuleParams{
+			Command:     `echo "$error" && false`,
+			Description: "error building $out",
+		},
+		"error")
 )
 
 func init() {

common/module.go

@@ -15,7 +15,9 @@
 package common
 
 import (
+	"fmt"
 	"path/filepath"
+	"strings"
 
 	"android/soong"
 	"android/soong/glob"
@@ -363,6 +365,7 @@ func (a *AndroidModuleBase) GenerateBuildActions(ctx blueprint.ModuleContext) {
 		androidBaseContextImpl: a.androidBaseContextFactory(ctx),
 		installDeps:            a.computeInstallDeps(ctx),
 		installFiles:           a.installFiles,
+		missingDeps:            ctx.GetMissingDependencies(),
 	}
 
 	if !a.Enabled() {
@@ -397,9 +400,28 @@ type androidModuleContext struct {
 	installDeps     Paths
 	installFiles    Paths
 	checkbuildFiles Paths
+	missingDeps     []string
+}
+
+func (a *androidModuleContext) ninjaError(outputs []string, err error) {
+	a.ModuleContext.Build(pctx, blueprint.BuildParams{
+		Rule:     ErrorRule,
+		Outputs:  outputs,
+		Optional: true,
+		Args: map[string]string{
+			"error": err.Error(),
+		},
+	})
+	return
 }
 
 func (a *androidModuleContext) Build(pctx blueprint.PackageContext, params blueprint.BuildParams) {
+	if a.missingDeps != nil {
+		a.ninjaError(params.Outputs, fmt.Errorf("module %s missing dependencies: %s\n",
+			a.ModuleName(), strings.Join(a.missingDeps, ", ")))
+		return
+	}
+
 	params.Optional = true
 	a.ModuleContext.Build(pctx, params)
 }
@@ -425,9 +447,19 @@ func (a *androidModuleContext) ModuleBuild(pctx blueprint.PackageContext, params
 		bparams.Implicits = append(bparams.Implicits, params.Implicit.String())
 	}
 
+	if a.missingDeps != nil {
+		a.ninjaError(bparams.Outputs, fmt.Errorf("module %s missing dependencies: %s\n",
+			a.ModuleName(), strings.Join(a.missingDeps, ", ")))
+		return
+	}
+
 	a.ModuleContext.Build(pctx, bparams)
 }
 
+func (a *androidModuleContext) GetMissingDependencies() []string {
+	return a.missingDeps
+}
+
 func (a *androidBaseContextImpl) Arch() Arch {
 	return a.arch
 }