1 files changed, 117 insertions, 0 deletions
diff --git a/src/cmd/compile/internal/gc/util.go b/src/cmd/compile/internal/gc/util.go
new file mode 100644
index 0000000..b82a983
--- /dev/null
+++ b/src/cmd/compile/internal/gc/util.go
@@ -0,0 +1,117 @@
+// Copyright 2015 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package gc
+
+import (
+	"net/url"
+	"os"
+	"path/filepath"
+	"runtime"
+	"runtime/pprof"
+	tracepkg "runtime/trace"
+	"strings"
+
+	"cmd/compile/internal/base"
+)
+
+func profileName(fn, suffix string) string {
+	if strings.HasSuffix(fn, string(os.PathSeparator)) {
+		err := os.MkdirAll(fn, 0755)
+		if err != nil {
+			base.Fatalf("%v", err)
+		}
+	}
+	if fi, statErr := os.Stat(fn); statErr == nil && fi.IsDir() {
+		fn = filepath.Join(fn, url.PathEscape(base.Ctxt.Pkgpath)+suffix)
+	}
+	return fn
+}
+
+func startProfile() {
+	if base.Flag.CPUProfile != "" {
+		fn := profileName(base.Flag.CPUProfile, ".cpuprof")
+		f, err := os.Create(fn)
+		if err != nil {
+			base.Fatalf("%v", err)
+		}
+		if err := pprof.StartCPUProfile(f); err != nil {
+			base.Fatalf("%v", err)
+		}
+		base.AtExit(pprof.StopCPUProfile)
+	}
+	if base.Flag.MemProfile != "" {
+		if base.Flag.MemProfileRate != 0 {
+			runtime.MemProfileRate = base.Flag.MemProfileRate
+		}
+		const (
+			gzipFormat = 0
+			textFormat = 1
+		)
+		// compilebench parses the memory profile to extract memstats,
+		// which are only written in the legacy (text) pprof format.
+		// See golang.org/issue/18641 and runtime/pprof/pprof.go:writeHeap.
+		// gzipFormat is what most people want, otherwise
+		var format = textFormat
+		fn := base.Flag.MemProfile
+		if strings.HasSuffix(fn, string(os.PathSeparator)) {
+			err := os.MkdirAll(fn, 0755)
+			if err != nil {
+				base.Fatalf("%v", err)
+			}
+		}
+		if fi, statErr := os.Stat(fn); statErr == nil && fi.IsDir() {
+			fn = filepath.Join(fn, url.PathEscape(base.Ctxt.Pkgpath)+".memprof")
+			format = gzipFormat
+		}
+
+		f, err := os.Create(fn)
+
+		if err != nil {
+			base.Fatalf("%v", err)
+		}
+		base.AtExit(func() {
+			// Profile all outstanding allocations.
+			runtime.GC()
+			if err := pprof.Lookup("heap").WriteTo(f, format); err != nil {
+				base.Fatalf("%v", err)
+			}
+		})
+	} else {
+		// Not doing memory profiling; disable it entirely.
+		runtime.MemProfileRate = 0
+	}
+	if base.Flag.BlockProfile != "" {
+		f, err := os.Create(profileName(base.Flag.BlockProfile, ".blockprof"))
+		if err != nil {
+			base.Fatalf("%v", err)
+		}
+		runtime.SetBlockProfileRate(1)
+		base.AtExit(func() {
+			pprof.Lookup("block").WriteTo(f, 0)
+			f.Close()
+		})
+	}
+	if base.Flag.MutexProfile != "" {
+		f, err := os.Create(profileName(base.Flag.MutexProfile, ".mutexprof"))
+		if err != nil {
+			base.Fatalf("%v", err)
+		}
+		runtime.SetMutexProfileFraction(1)
+		base.AtExit(func() {
+			pprof.Lookup("mutex").WriteTo(f, 0)
+			f.Close()
+		})
+	}
+	if base.Flag.TraceProfile != "" {
+		f, err := os.Create(profileName(base.Flag.TraceProfile, ".trace"))
+		if err != nil {
+			base.Fatalf("%v", err)
+		}
+		if err := tracepkg.Start(f); err != nil {
+			base.Fatalf("%v", err)
+		}
+		base.AtExit(tracepkg.Stop)
+	}
+}