github.com/westcoastroms/westcoastroms-build@v0.0.0-20190928114312-2350e5a73030/build/kati/make-c/main.go (about)

     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  
    15  // make-c is simple program to measure time to parse Makefiles in android.
    16  package main
    17  
    18  import (
    19  	"bufio"
    20  	"bytes"
    21  	"fmt"
    22  	"os/exec"
    23  	"time"
    24  )
    25  
    26  func main() {
    27  	parseDone := make(chan bool)
    28  	cmd := exec.Command("make", "-n")
    29  	r, err := cmd.StdoutPipe()
    30  	if err != nil {
    31  		panic(err)
    32  	}
    33  	t := time.Now()
    34  	go func() {
    35  		s := bufio.NewScanner(r)
    36  		for s.Scan() {
    37  			if bytes.HasPrefix(s.Bytes(), []byte("echo ")) {
    38  				parseDone <- true
    39  				return
    40  			}
    41  			fmt.Println(s.Text())
    42  		}
    43  		if err := s.Err(); err != nil {
    44  			panic(err)
    45  		}
    46  		panic("unexpected end of make?")
    47  	}()
    48  	err = cmd.Start()
    49  	if err != nil {
    50  		panic(err)
    51  	}
    52  	select {
    53  	case <-parseDone:
    54  		fmt.Printf("make -c: %v\n", time.Since(t))
    55  	}
    56  	cmd.Process.Kill()
    57  	cmd.Wait()
    58  }