1 #!/usr/bin/env bash 2 3 # Copyright 2016 The Go Authors. All rights reserved. 4 # Use of this source code is governed by a BSD-style 5 # license that can be found in the LICENSE file. 6 7 # A simple script to compare differences between 8 # assembly listings for packages built with different 9 # compiler flags. It is useful to inspect the impact 10 # of a compiler change across all std lib packages. 11 # 12 # The script builds the std library (make.bash) once 13 # with FLAGS1 and once with FLAGS2 and compares the 14 # "go build <pkg>" assembly output for each package 15 # and lists the packages with differences. 16 # 17 # It leaves and old.txt and new.txt file in the package 18 # directories for the packages with differences. 19 20 FLAGS1="-newexport=0" 21 FLAGS2="-newexport=1" 22 23 echo 24 echo 25 echo "1a) clean build using $FLAGS1" 26 (export GO_GCFLAGS="$FLAGS1"; sh make.bash) 27 28 echo 29 echo 30 echo "1b) save go build output for all packages" 31 for pkg in `go list std`; do 32 echo $pkg 33 DIR=$GOROOT/src/$pkg 34 go build -gcflags "$FLAGS1 -S" -o /dev/null $pkg &> $DIR/old.txt 35 done 36 37 echo 38 echo 39 echo "2a) clean build using $FLAGS2" 40 (export GO_GCFLAGS="$FLAGS2"; sh make.bash) 41 42 echo 43 echo 44 echo "2b) save go build output for all packages" 45 for pkg in `go list std`; do 46 echo $pkg 47 DIR=$GOROOT/src/$pkg 48 go build -gcflags "$FLAGS2 -S" -o /dev/null $pkg &> $DIR/new.txt 49 done 50 51 echo 52 echo 53 echo "3) compare assembly files" 54 for pkg in `go list std`; do 55 DIR=$GOROOT/src/$pkg 56 57 if cmp $DIR/old.txt $DIR/new.txt &> /dev/null 58 then rm $DIR/old.txt $DIR/new.txt 59 else echo "==> $DIR" 60 fi 61 done 62
