1 // Copyright 2018 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 15 // This tool reads "make"-like dependency files, and outputs a canonical version 16 // that can be used by ninja. Ninja doesn't support multiple output files (even 17 // though it doesn't care what the output file is, or whether it matches what is 18 // expected). 19 package main 20 21 import ( 22 "bytes" 23 "flag" 24 "fmt" 25 "io/ioutil" 26 "log" 27 "os" 28 ) 29 30 func main() { 31 flag.Usage = func() { 32 fmt.Fprintf(os.Stderr, "Usage: %s [-o <output>] <depfile.d> [<depfile.d>...]", os.Args[0]) 33 flag.PrintDefaults() 34 } 35 output := flag.String("o", "", "Optional output file (defaults to rewriting source if necessary)") 36 flag.Parse() 37 38 if flag.NArg() < 1 { 39 log.Fatal("Expected at least one input file as an argument") 40 } 41 42 var mergedDeps *Deps 43 var firstInput []byte 44 45 for i, arg := range flag.Args() { 46 input, err := ioutil.ReadFile(arg) 47 if err != nil { 48 log.Fatalf("Error opening %q: %v", arg, err) 49 } 50 51 deps, err := Parse(arg, bytes.NewBuffer(append([]byte(nil), input...))) 52 if err != nil { 53 log.Fatalf("Failed to parse: %v", err) 54 } 55 56 if i == 0 { 57 mergedDeps = deps 58 firstInput = input 59 } else { 60 mergedDeps.Inputs = append(mergedDeps.Inputs, deps.Inputs...) 61 } 62 } 63 64 new := mergedDeps.Print() 65 66 if *output == "" || *output == flag.Arg(0) { 67 if !bytes.Equal(firstInput, new) { 68 err := ioutil.WriteFile(flag.Arg(0), new, 0666) 69 if err != nil { 70 log.Fatalf("Failed to write: %v", err) 71 } 72 } 73 } else { 74 err := ioutil.WriteFile(*output, new, 0666) 75 if err != nil { 76 log.Fatalf("Failed to write to %q: %v", *output, err) 77 } 78 } 79 } 80
