experiment/fiddle

experimental/fiddle/fiddler.go

+/*
+ * Copyright 2015 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+package main
+
+// Example use:
+//   git clone https://skia.googlesource.com/skia.git
+//   cd skia
+//   SKIA=$PWD
+//   cd experimental/fiddle
+//   go build fiddler.go
+//   # compile prerequisites
+//   ./fiddler "$SKIA"
+//   # compile and run a fiddle
+//   ./fiddler "$SKIA" draw.cpp | ./parse-fiddle-output
+//   # compile and run a different fiddle
+//   ./fiddler "$SKIA" ANOTHER_FIDDLE.cpp | ./parse-fiddle-output
+
+import (
+        "bytes"
+        "fmt"
+        "io"
+        "io/ioutil"
+        "os"
+        "os/exec"
+        "path"
+        "syscall"
+
+        "github.com/skia-dev/glog"
+)
+
+func setResourceLimits() error {
+        const maximumTimeInSeconds = 5
+        limit := syscall.Rlimit{maximumTimeInSeconds, maximumTimeInSeconds}
+        if err := syscall.Setrlimit(syscall.RLIMIT_CPU, &limit); err != nil {
+                return err
+        }
+        const maximumMemoryInBytes = 1 << 28
+        limit = syscall.Rlimit{maximumMemoryInBytes, maximumMemoryInBytes}
+        return syscall.Setrlimit(syscall.RLIMIT_AS, &limit)
+}
+
+// execCommand runs command and returns an error if it fails.  If there is no
+// error, all output is discarded.
+func execCommand(input io.Reader, dir string, name string, arg ...string) error {
+        var buffer bytes.Buffer
+        cmd := exec.Command(name, arg...)
+        cmd.Dir = dir
+        cmd.Stdout = &buffer
+        cmd.Stderr = &buffer
+        cmd.Stdin = input
+        if err := cmd.Run(); err != nil {
+                return fmt.Errorf("execution failed:\n\n%s\n[%v]", buffer.String(), err)
+        }
+        return nil
+}
+
+func compileArgs(skiaSrc string) string {
+        return "@" + path.Join(skiaSrc, "cmake", "skia_compile_arguments.txt")
+}
+
+func linkArgs(skiaSrc string) string {
+        return "@" + path.Join(skiaSrc, "cmake", "skia_link_arguments.txt")
+}
+
+// fiddler compiles the input, links against skia, and runs the executable.
+// @param skiaSrc: the base directory of the Skia repository
+// @param inputReader: C++ fiddle source
+// @param output: stdout of executable sent here
+// @param tempDir: where to place the compiled executable
+func fiddler(skiaSrc string, inputReader io.Reader, output io.Writer, tempDir string) error {
+        binarypath := path.Join(tempDir, "fiddle")
+        fiddle_dir := path.Join(skiaSrc, "experimental", "fiddle")
+        if err := execCommand(inputReader, fiddle_dir,
+                "c++",
+                compileArgs(skiaSrc),
+                "-I", fiddle_dir,
+                "-o", binarypath,
+                "-x", "c++", "-", "-x", "none",
+                "fiddle_main.o",
+                "-lOSMesa",
+                linkArgs(skiaSrc),
+        ); err != nil {
+                return err
+        }
+        var buffer bytes.Buffer
+        runCmd := exec.Cmd{Path: binarypath, Stdout: output, Stderr: &buffer}
+        if err := runCmd.Run(); err != nil {
+                return fmt.Errorf("execution failed:\n\n%s\n[%v]", buffer.String(), err)
+        }
+        return nil
+}
+
+// Compile Skia library and fiddle_main.cpp
+// @param skiaSrc: the base directory of the Skia repository.
+func fiddlerPrerequisites(skiaSrc string) error {
+        cmakeDir := path.Join(skiaSrc, "cmake")
+        if err := execCommand(nil, cmakeDir, "cmake", "-G", "Ninja", "."); err != nil {
+                return err
+        }
+        if err := execCommand(nil, cmakeDir, "ninja", "skia"); err != nil {
+                return err
+        }
+        fiddle_dir := path.Join(skiaSrc, "experimental", "fiddle")
+        if err := execCommand(nil, fiddle_dir, "c++", compileArgs(skiaSrc),
+                "fiddle_main.h"); err != nil {
+                return err
+        }
+        return execCommand(nil, fiddle_dir, "c++", compileArgs(skiaSrc),
+                "-c", "-o", "fiddle_main.o", "fiddle_main.cpp")
+}
+
+func main() {
+        if len(os.Args) < 2 {
+                glog.Fatalf("usage: %s SKIA_SRC_PATH [PATH_TO_DRAW.CPP]", os.Args[0])
+        }
+        skiaSrc := os.Args[1]
+        if len(os.Args) < 3 {
+                // execCommand(nil, skiaSrc, "git", "fetch")
+                // execCommand(nil, skiaSrc, "git", "checkout", "origin/master")
+                if err := fiddlerPrerequisites(skiaSrc); err != nil {
+                        glog.Fatal(err)
+                }
+        } else {
+                if err := setResourceLimits(); err != nil {
+                        glog.Fatal(err)
+                }
+                tempDir, err := ioutil.TempDir("", "fiddle_")
+                if err != nil {
+                        glog.Fatal(err)
+                }
+                defer func() {
+                        err = os.RemoveAll(tempDir)
+                        if err != nil {
+                                glog.Fatalf("os.RemoveAll(tempDir) failed: %v", err)
+                        }
+                }()
+                if os.Args[2] == "-" {
+                        if err := fiddler(skiaSrc, os.Stdin, os.Stdout, tempDir); err != nil {
+                                glog.Fatal(err)
+                        }
+                } else {
+                        inputFile, err := os.Open(os.Args[2])
+                        if err != nil {
+                                glog.Fatalf("unable to open \"%s\": %v", os.Args[2], err)
+                        }
+                        defer func(closer io.Closer) {

[jcgregorio, 2015/12/10 14:44:57]

util.Close(inputFile)

+                                err := closer.Close()
+                                if err != nil {
+                                        glog.Fatalf("Close() failed: %v", err)
+                                }
+                        }(inputFile)
+                        if err = fiddler(skiaSrc, inputFile, os.Stdout, tempDir); err != nil {
+                                glog.Fatal(err)
+                        }
+                }
+        }
+}