Move AllowMissingDependencies check from PathsForSource to PathForSource

This reapplies Id7925999a27ea75a05e9301bbf1eb9f9a6bc4652 with
additional fixes to not use PathForSource in PathForModuleSrc.

PathsForSource was handling the AllowMissingDependencies case, but
PathForSource was not.  Refactor PathForSource and
ExistentPathForSource, and add logic to PathForSource to fall back
to behavior similar to ExistentPathForSource when
AllowMissingDependencies is set.

PathForModuleSrc uses PathForSource, which causes too many
globs (>50k).  The AllowMissingDependencies check doesn't make
much sense for PathForModuleSrc, since we already know the
project containing the definition of the module exists, we can
expect its local source files to exist.  Use pathForSource and
do an manual existence check instead.

Test: paths_test.go
Test: m ALLOW_MISSING_DEPENDENCIES=true
Change-Id: If1690a708393964d3030cb908beaf7b6897c0084

1 files changed, 75 insertions, 76 deletions

diff --git a/android/paths.go b/android/paths.go
index fa2e10e4..3b1cea67 100644
--- a/android/paths.go
+++ b/android/paths.go
@@ -195,20 +195,6 @@ type Paths []Path
 
 // PathsForSource returns Paths rooted from SrcDir
 func PathsForSource(ctx PathContext, paths []string) Paths {
-	if ctx.Config().AllowMissingDependencies() {
-		if modCtx, ok := ctx.(ModuleContext); ok {
-			ret := make(Paths, 0, len(paths))
-			for _, path := range paths {
-				p := ExistentPathForSource(ctx, path)
-				if p.Valid() {
-					ret = append(ret, p.Path())
-				} else {
-					modCtx.AddMissingDependencies([]string{path})
-				}
-			}
-			return ret
-		}
-	}
 	ret := make(Paths, len(paths))
 	for i, path := range paths {
 		ret[i] = PathForSource(ctx, path)
@@ -507,100 +493,100 @@ func safePathForSource(ctx PathContext, path string) SourcePath {
 	return ret
 }
 
-// PathForSource joins the provided path components and validates that the result
-// neither escapes the source dir nor is in the out dir.
-// On error, it will return a usable, but invalid SourcePath, and report a ModuleError.
-func PathForSource(ctx PathContext, pathComponents ...string) SourcePath {
+// pathForSource creates a SourcePath from pathComponents, but does not check that it exists.
+func pathForSource(ctx PathContext, pathComponents ...string) (SourcePath, error) {
 	p, err := validatePath(pathComponents...)
 	ret := SourcePath{basePath{p, ctx.Config(), ""}}
 	if err != nil {
-		reportPathError(ctx, err)
-		return ret
+		return ret, err
 	}
 
 	abs, err := filepath.Abs(ret.String())
 	if err != nil {
-		reportPathError(ctx, err)
-		return ret
+		return ret, err
 	}
 	buildroot, err := filepath.Abs(ctx.Config().buildDir)
 	if err != nil {
-		reportPathError(ctx, err)
-		return ret
+		return ret, err
 	}
 	if strings.HasPrefix(abs, buildroot) {
-		reportPathErrorf(ctx, "source path %s is in output", abs)
-		return ret
+		return ret, fmt.Errorf("source path %s is in output", abs)
+	}
+
+	if pathtools.IsGlob(ret.String()) {
+		return ret, fmt.Errorf("path may not contain a glob: %s", ret.String())
+	}
+
+	return ret, nil
+}
+
+// existsWithDependencies returns true if the path exists, and adds appropriate dependencies to rerun if the
+// path does not exist.
+func existsWithDependencies(ctx PathContext, path SourcePath) (exists bool, err error) {
+	var files []string
+
+	if gctx, ok := ctx.(PathGlobContext); ok {
+		// Use glob to produce proper dependencies, even though we only want
+		// a single file.
+		files, err = gctx.GlobWithDeps(path.String(), nil)
+	} else {
+		var deps []string
+		// We cannot add build statements in this context, so we fall back to
+		// AddNinjaFileDeps
+		files, deps, err = pathtools.Glob(path.String(), nil)
+		ctx.AddNinjaFileDeps(deps...)
 	}
 
-	if exists, _, err := ctx.Fs().Exists(ret.String()); err != nil {
-		reportPathErrorf(ctx, "%s: %s", ret, err.Error())
+	if err != nil {
+		return false, fmt.Errorf("glob: %s", err.Error())
+	}
+
+	return len(files) > 0, nil
+}
+
+// PathForSource joins the provided path components and validates that the result
+// neither escapes the source dir nor is in the out dir.
+// On error, it will return a usable, but invalid SourcePath, and report a ModuleError.
+func PathForSource(ctx PathContext, pathComponents ...string) SourcePath {
+	path, err := pathForSource(ctx, pathComponents...)
+	if err != nil {
+		reportPathError(ctx, err)
+	}
+
+	if modCtx, ok := ctx.(ModuleContext); ok && ctx.Config().AllowMissingDependencies() {
+		exists, err := existsWithDependencies(ctx, path)
+		if err != nil {
+			reportPathError(ctx, err)
+		}
+		if !exists {
+			modCtx.AddMissingDependencies([]string{path.String()})
+		}
+	} else if exists, _, err := ctx.Fs().Exists(path.String()); err != nil {
+		reportPathErrorf(ctx, "%s: %s", path, err.Error())
 	} else if !exists {
-		reportPathErrorf(ctx, "source path %s does not exist", ret)
+		reportPathErrorf(ctx, "source path %s does not exist", path)
 	}
-	return ret
+	return path
 }
 
 // ExistentPathForSource returns an OptionalPath with the SourcePath if the
 // path exists, or an empty OptionalPath if it doesn't exist. Dependencies are added
 // so that the ninja file will be regenerated if the state of the path changes.
 func ExistentPathForSource(ctx PathContext, pathComponents ...string) OptionalPath {
-	p, err := validatePath(pathComponents...)
+	path, err := pathForSource(ctx, pathComponents...)
 	if err != nil {
 		reportPathError(ctx, err)
 		return OptionalPath{}
 	}
-	path := SourcePath{basePath{p, ctx.Config(), ""}}
 
-	abs, err := filepath.Abs(path.String())
+	exists, err := existsWithDependencies(ctx, path)
 	if err != nil {
 		reportPathError(ctx, err)
 		return OptionalPath{}
 	}
-	buildroot, err := filepath.Abs(ctx.Config().buildDir)
-	if err != nil {
-		reportPathError(ctx, err)
+	if !exists {
 		return OptionalPath{}
 	}
-	if strings.HasPrefix(abs, buildroot) {
-		reportPathErrorf(ctx, "source path %s is in output", abs)
-		return OptionalPath{}
-	}
-
-	if pathtools.IsGlob(path.String()) {
-		reportPathErrorf(ctx, "path may not contain a glob: %s", path.String())
-		return OptionalPath{}
-	}
-
-	if gctx, ok := ctx.(PathGlobContext); ok {
-		// Use glob to produce proper dependencies, even though we only want
-		// a single file.
-		files, err := gctx.GlobWithDeps(path.String(), nil)
-		if err != nil {
-			reportPathErrorf(ctx, "glob: %s", err.Error())
-			return OptionalPath{}
-		}
-
-		if len(files) == 0 {
-			return OptionalPath{}
-		}
-	} else {
-		// We cannot add build statements in this context, so we fall back to
-		// AddNinjaFileDeps
-		files, dirs, err := pathtools.Glob(path.String(), nil)
-		if err != nil {
-			reportPathErrorf(ctx, "glob: %s", err.Error())
-			return OptionalPath{}
-		}
-
-		ctx.AddNinjaFileDeps(dirs...)
-
-		if len(files) == 0 {
-			return OptionalPath{}
-		}
-
-		ctx.AddNinjaFileDeps(path.String())
-	}
 	return OptionalPathForPath(path)
 }
 
@@ -721,8 +707,21 @@ func PathForModuleSrc(ctx ModuleContext, paths ...string) ModuleSrcPath {
 	if err != nil {
 		reportPathError(ctx, err)
 	}
-	path := ModuleSrcPath{PathForSource(ctx, ctx.ModuleDir(), p)}
+
+	srcPath, err := pathForSource(ctx, ctx.ModuleDir(), p)
+	if err != nil {
+		reportPathError(ctx, err)
+	}
+
+	path := ModuleSrcPath{srcPath}
 	path.basePath.rel = p
+
+	if exists, _, err := ctx.Fs().Exists(path.String()); err != nil {
+		reportPathErrorf(ctx, "%s: %s", path, err.Error())
+	} else if !exists {
+		reportPathErrorf(ctx, "module source path %s does not exist", path)
+	}
+
 	return path
 }