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..ba2ac070f0fc2d4b4fb76885a95faeca1f6e3e9b
--- /dev/null
+++ b/experimental/fiddle/fiddler.go
@@ -0,0 +1,156 @@
+/*
+ * 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"
+	"io"
+	"io/ioutil"
+	"os"
+	"os/exec"
+	"path"
+	"path/filepath"
+	"strings"
+	"syscall"
+
+	"github.com/skia-dev/glog"
+)
+
+func setResourceLimits() {
+	const maximumTimeInSeconds = 5
+	limit := syscall.Rlimit{maximumTimeInSeconds, maximumTimeInSeconds}
+	if err := syscall.Setrlimit(syscall.RLIMIT_CPU, &limit); err != nil {
+		glog.Fatalf("syscall.Setrlimit(RLIMIT_CPU) error: %v", err)

[jcgregorio, 2015/12/02 15:54:34]

glog.Fatal should really be restricted to being called in main(). So have
setResourceLimits() return an error, let the caller decide if this is a fatal
problem.

Same comment applies to all glog.Fatal calls below.

[hal.canary, 2015/12/02 22:34:39]

done

+	}
+	const maximumMemoryInBytes = 1 << 28
+	limit = syscall.Rlimit{maximumMemoryInBytes, maximumMemoryInBytes}
+	if err := syscall.Setrlimit(syscall.RLIMIT_AS, &limit); err != nil {
+		glog.Fatalf("syscall.Setrlimit(RLIMIT_AS) error: %v", err)
+	}
+}
+
+func trimmedBasePath(fpath string) string {
+	basename := path.Base(fpath)
+	return strings.TrimSuffix(basename, path.Ext(basename))
+}
+
+func absPath(path string) string {
+	abspath, err := filepath.Abs(path)
+	if err != nil {
+		glog.Fatalf("filepath.Abs(%s) failed: %v", path, err)
+	}
+	return abspath
+}
+
+func closeme(closer io.Closer) {
+	err := closer.Close()
+	if err != nil {
+		glog.Fatalf("Close() failed: %v", err)
+	}
+}
+
+// runs command and logs a fatal error if it fails.  If there is no
+// error, all output is discarded.
+func execCommand(input io.Reader, dir string, name string, arg ...string) {
+	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 {
+		glog.Fatalf("command failed:\n%v\n%s\n[%v]", cmd.Args, buffer.String(), err)
+	}
+}
+
+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")
+}
+
+// Compile the input

[jcgregorio, 2015/12/02 15:54:34]

Comments begin with the name of the thing being commented on:

// fiddler compiles the input.

[hal.canary, 2015/12/02 22:34:40]

done

+// @param skiaSrc: the base directory of the Skia repository.
+func fiddler(skiaSrc string, inputReader io.Reader, output io.Writer) {
+	tempDir, err := ioutil.TempDir("", "fiddle_")
+	if err != nil {
+		glog.Fatalf("ioutil.TempDir() failed: %v", err)
+	}
+	defer func() {
+		err = os.RemoveAll(tempDir)
+		if err != nil {
+			glog.Fatalf("os.RemoveAll(tempDir) failed: %v", err)
+		}
+	}()
+	binarypath := path.Join(tempDir, "fiddle")
+	fiddle_dir := path.Join(skiaSrc, "experimental", "fiddle")
+	execCommand(inputReader, fiddle_dir,
+		"c++",
+		compileArgs(skiaSrc),
+		"-I", fiddle_dir,
+		"-o", binarypath,
+		"-x", "c++", "-", "-x", "none",
+		"fiddle_main.o",
+		"-lOSMesa",
+		linkArgs(skiaSrc))
+	var buffer bytes.Buffer
+	runCmd := exec.Cmd{Path: binarypath, Stdout: output, Stderr: &buffer}
+	if err := runCmd.Run(); err != nil {
+		glog.Fatalf("execution failed:\n\n%s\n[%v]", buffer.String(), err)
+	}
+}
+
+// Compile Skia library and fiddle_main.cpp
+// @param skiaSrc: the base directory of the Skia repository.
+func fiddlerPrerequisites(skiaSrc string) {
+	cmakeDir := path.Join(skiaSrc, "cmake")
+	execCommand(nil, cmakeDir, "cmake", "-G", "Ninja", ".")
+	execCommand(nil, cmakeDir, "ninja", "skia")
+	fiddle_dir := path.Join(skiaSrc, "experimental", "fiddle")
+	execCommand(nil, fiddle_dir, "c++", compileArgs(skiaSrc), "fiddle_main.h")
+	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")
+		fiddlerPrerequisites(skiaSrc)
+	} else {
+		setResourceLimits()
+		if os.Args[2] == "-" {
+			fiddler(skiaSrc, os.Stdin, os.Stdout)
+		} else {
+			inputFile, err := os.Open(os.Args[2])
+			if err != nil {
+				glog.Fatalf("unable to open \"%s\": %v", os.Args[2], err)
+			}
+			defer closeme(inputFile)
+			fiddler(skiaSrc, inputFile, os.Stdout)
+		}
+	}
+}