experiment/fiddle

experimental/fiddle/fiddler.go

Index: experimental/fiddle/fiddler.go
diff --git a/experimental/fiddle/fiddler.go b/experimental/fiddle/fiddler.go
new file mode 100644
index 0000000000000000000000000000000000000000..d3056c95d3f0cecbbcff9a1aa41a75972a1346be
--- /dev/null
+++ b/experimental/fiddle/fiddler.go
@@ -0,0 +1,159 @@
+/*
+ * 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=$PWD
+//   cd experimental/fiddle
+//   go get github.com/skia-dev/glog
+//   go get go.skia.org/infra/go/util
+//   go build fiddler.go
+//   # compile prerequisites
+//   ./fiddler "$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"
+	"go.skia.org/infra/go/util"
+)
+
+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)
+			}
+			util.Close(inputFile)
+			if err = fiddler(skiaSrc, inputFile, os.Stdout, tempDir); err != nil {
+				glog.Fatal(err)
+			}
+		}
+	}
+}