1// Copyright 2015 Google Inc. All rights reserved. 2// 3// Licensed under the Apache License, Version 2.0 (the "License"); 4// you may not use this file except in compliance with the License. 5// You may obtain a copy of the License at 6// 7// http://www.apache.org/licenses/LICENSE-2.0 8// 9// Unless required by applicable law or agreed to in writing, software 10// distributed under the License is distributed on an "AS IS" BASIS, 11// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 12// See the License for the specific language governing permissions and 13// limitations under the License. 14 15package common 16 17import ( 18 "fmt" 19 "path/filepath" 20 21 "github.com/google/blueprint" 22 23 "android/soong/glob" 24) 25 26// This file supports globbing source files in Blueprints files. 27// 28// The build.ninja file needs to be regenerated any time a file matching the glob is added 29// or removed. The naive solution is to have the build.ninja file depend on all the 30// traversed directories, but this will cause the regeneration step to run every time a 31// non-matching file is added to a traversed directory, including backup files created by 32// editors. 33// 34// The solution implemented here optimizes out regenerations when the directory modifications 35// don't match the glob by having the build.ninja file depend on an intermedate file that 36// is only updated when a file matching the glob is added or removed. The intermediate file 37// depends on the traversed directories via a depfile. The depfile is used to avoid build 38// errors if a directory is deleted - a direct dependency on the deleted directory would result 39// in a build failure with a "missing and no known rule to make it" error. 40 41var ( 42 globCmd = filepath.Join("${bootstrap.BinDir}", "soong_glob") 43 44 // globRule rule traverses directories to produce a list of files that match $glob 45 // and writes it to $out if it has changed, and writes the directories to $out.d 46 globRule = pctx.StaticRule("globRule", 47 blueprint.RuleParams{ 48 Command: fmt.Sprintf(`%s -o $out $excludes "$glob"`, globCmd), 49 CommandDeps: []string{globCmd}, 50 Description: "glob $glob", 51 52 Restat: true, 53 Deps: blueprint.DepsGCC, 54 Depfile: "$out.d", 55 }, 56 "glob", "excludes") 57) 58 59func hasGlob(in []string) bool { 60 for _, s := range in { 61 if glob.IsGlob(s) { 62 return true 63 } 64 } 65 66 return false 67} 68 69// The subset of ModuleContext and SingletonContext needed by Glob 70type globContext interface { 71 Build(pctx blueprint.PackageContext, params blueprint.BuildParams) 72 AddNinjaFileDeps(deps ...string) 73} 74 75func Glob(ctx globContext, outDir string, globPattern string, excludes []string) ([]string, error) { 76 fileListFile := filepath.Join(outDir, "glob", globToString(globPattern)) 77 depFile := fileListFile + ".d" 78 79 // Get a globbed file list, and write out fileListFile and depFile 80 files, err := glob.GlobWithDepFile(globPattern, fileListFile, depFile, excludes) 81 if err != nil { 82 return nil, err 83 } 84 85 GlobRule(ctx, globPattern, excludes, fileListFile, depFile) 86 87 // Make build.ninja depend on the fileListFile 88 ctx.AddNinjaFileDeps(fileListFile) 89 90 return files, nil 91} 92 93func GlobRule(ctx globContext, globPattern string, excludes []string, 94 fileListFile, depFile string) { 95 96 // Create a rule to rebuild fileListFile if a directory in depFile changes. fileListFile 97 // will only be rewritten if it has changed, preventing unnecesary build.ninja regenerations. 98 ctx.Build(pctx, blueprint.BuildParams{ 99 Rule: globRule, 100 Outputs: []string{fileListFile}, 101 Args: map[string]string{ 102 "glob": globPattern, 103 "excludes": JoinWithPrefixAndQuote(excludes, "-e "), 104 }, 105 }) 106} 107 108func globToString(glob string) string { 109 ret := "" 110 for _, c := range glob { 111 if c >= 'a' && c <= 'z' || 112 c >= 'A' && c <= 'Z' || 113 c >= '0' && c <= '9' || 114 c == '_' || c == '-' || c == '/' { 115 ret += string(c) 116 } 117 } 118 119 return ret 120} 121