Add a script to reduce source files to required set
Running build/strip_cmakelists.sh will attempt to build the CMake
project files with each line that contains a
comment iteratively removed. This allows to minimize the number of
required source files. In particular LLVM is considerably larger than
necessary and will be minimized in the following change.
Bug: b/129772660
Change-Id: I5c062a2643b79ba444b82737f23bc0c104044f07
Reviewed-on: https://swiftshader-review.googlesource.com/c/SwiftShader/+/28254
Tested-by: Nicolas Capens <nicolascapens@google.com>
Kokoro-Presubmit: kokoro <noreply+kokoro@google.com>
Reviewed-by: Ben Clayton <bclayton@google.com>
diff --git a/build/strip_cmakelists.sh b/build/strip_cmakelists.sh
new file mode 100755
index 0000000..161fd3d
--- /dev/null
+++ b/build/strip_cmakelists.sh
@@ -0,0 +1,2 @@
+cd $(dirname $0)
+go run strip_unneeded.go --file=../CMakeLists.txt --test="cmake -DREACTOR_BACKEND=LLVM -DREACTOR_EMIT_DEBUG_INFO=1 .. && cmake --build ."
\ No newline at end of file
diff --git a/build/strip_unneeded.go b/build/strip_unneeded.go
new file mode 100644
index 0000000..a4a1bf5
--- /dev/null
+++ b/build/strip_unneeded.go
@@ -0,0 +1,123 @@
+// Copyright 2019 The SwiftShader Authors. All Rights Reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// strip_unneeded is a tool that attempts to remove unnecessary lines from a
+// file by running a test script after each marked line is removed.
+//
+// strip_unneeded will scan the file specified by the --file argument for lines
+// that contain the substring specified by the --marker argument. One-by-one
+// those marked lines will be removed from the file, after which the test script
+// specified by --test will be run. If the test passes (the process completes
+// with a 0 return code), then the line will remain removed, otherwise it is
+// restored. This will repeat for every line in the file containing the marker,
+// until all lines are tested.
+package main
+
+import (
+ "flag"
+ "fmt"
+ "io/ioutil"
+ "os"
+ "os/exec"
+ "strings"
+)
+
+var (
+ file = flag.String("file", "", "file to modify")
+ marker = flag.String("marker", "CHECK_NEEDED", "line token")
+ test = flag.String("test", "", "test script to run with each change")
+)
+
+func main() {
+ if err := run(); err != nil {
+ fmt.Println(err.Error())
+ os.Exit(1)
+ }
+}
+
+func run() error {
+ flag.Parse()
+ if *file == "" {
+ return fmt.Errorf("Missing --file argument")
+ }
+ if *marker == "" {
+ return fmt.Errorf("Missing --marker argument")
+ }
+ if *test == "" {
+ return fmt.Errorf("Missing --test argument")
+ }
+
+ // make sure the test passes with no modifications
+ if err := runTest(); err != nil {
+ return fmt.Errorf("Test fails with no modifications.\n%v", err)
+ }
+
+ // load the test file
+ body, err := ioutil.ReadFile(*file)
+ if err != nil {
+ return fmt.Errorf("Couldn't load file '%v'", *file)
+ }
+
+ // gather all the lines
+ allLines := strings.Split(string(body), "\n")
+
+ // find all the lines with the marker
+ markerLines := make([]int, 0, len(allLines))
+ for i, l := range allLines {
+ if strings.Contains(l, *marker) {
+ markerLines = append(markerLines, i)
+ }
+ }
+
+ omit := map[int]bool{}
+
+ save := func() error {
+ f, err := os.Create(*file)
+ if err != nil {
+ return err
+ }
+ defer f.Close()
+ for i, l := range allLines {
+ if !omit[i] {
+ f.WriteString(l)
+ f.WriteString("\n")
+ }
+ }
+ return nil
+ }
+
+ for i, l := range markerLines {
+ omit[l] = true
+ if err := save(); err != nil {
+ return err
+ }
+ if err := runTest(); err != nil {
+ omit[l] = false
+ fmt.Printf("%d/%d: Test fails when removing line %v: %v\n", i, len(markerLines), l, allLines[l])
+ } else {
+ fmt.Printf("%d/%d: Test passes when removing line %v: %v\n", i, len(markerLines), l, allLines[l])
+ }
+ }
+
+ return save()
+}
+
+func runTest() error {
+ cmd := exec.Command("sh", "-c", *test)
+ out, err := cmd.CombinedOutput()
+ if err != nil {
+ return fmt.Errorf("Test failed with error: %v\n%v", err, string(out))
+ }
+ return nil
+}
