1 files changed, 195 insertions, 0 deletions
diff --git a/src/cmd/pprof/internal/symbolizer/symbolizer.go b/src/cmd/pprof/internal/symbolizer/symbolizer.go
new file mode 100644
index 000000000..86de5640d
--- /dev/null
+++ b/src/cmd/pprof/internal/symbolizer/symbolizer.go
@@ -0,0 +1,195 @@
+// Copyright 2014 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 symbolizer provides a routine to populate a profile with
+// symbol, file and line number information. It relies on the
+// addr2liner and demangler packages to do the actual work.
+package symbolizer
+
+import (
+	"fmt"
+	"os"
+	"path/filepath"
+	"strings"
+
+	"cmd/pprof/internal/plugin"
+	"cmd/pprof/internal/profile"
+)
+
+// Symbolize adds symbol and line number information to all locations
+// in a profile. mode enables some options to control
+// symbolization. Currently only recognizes "force", which causes it
+// to overwrite any existing data.
+func Symbolize(mode string, prof *profile.Profile, obj plugin.ObjTool, ui plugin.UI) error {
+	force := false
+	// Disable some mechanisms based on mode string.
+	for _, o := range strings.Split(strings.ToLower(mode), ":") {
+		switch o {
+		case "force":
+			force = true
+		default:
+		}
+	}
+
+	if len(prof.Mapping) == 0 {
+		return fmt.Errorf("no known mappings")
+	}
+
+	mt, err := newMapping(prof, obj, ui, force)
+	if err != nil {
+		return err
+	}
+	defer mt.close()
+
+	functions := make(map[profile.Function]*profile.Function)
+	for _, l := range mt.prof.Location {
+		m := l.Mapping
+		segment := mt.segments[m]
+		if segment == nil {
+			// Nothing to do
+			continue
+		}
+
+		stack, err := segment.SourceLine(l.Address)
+		if err != nil || len(stack) == 0 {
+			// No answers from addr2line
+			continue
+		}
+
+		l.Line = make([]profile.Line, len(stack))
+		for i, frame := range stack {
+			if frame.Func != "" {
+				m.HasFunctions = true
+			}
+			if frame.File != "" {
+				m.HasFilenames = true
+			}
+			if frame.Line != 0 {
+				m.HasLineNumbers = true
+			}
+			f := &profile.Function{
+				Name:       frame.Func,
+				SystemName: frame.Func,
+				Filename:   frame.File,
+			}
+			if fp := functions[*f]; fp != nil {
+				f = fp
+			} else {
+				functions[*f] = f
+				f.ID = uint64(len(mt.prof.Function)) + 1
+				mt.prof.Function = append(mt.prof.Function, f)
+			}
+			l.Line[i] = profile.Line{
+				Function: f,
+				Line:     int64(frame.Line),
+			}
+		}
+
+		if len(stack) > 0 {
+			m.HasInlineFrames = true
+		}
+	}
+	return nil
+}
+
+// newMapping creates a mappingTable for a profile.
+func newMapping(prof *profile.Profile, obj plugin.ObjTool, ui plugin.UI, force bool) (*mappingTable, error) {
+	mt := &mappingTable{
+		prof:     prof,
+		segments: make(map[*profile.Mapping]plugin.ObjFile),
+	}
+
+	// Identify used mappings
+	mappings := make(map[*profile.Mapping]bool)
+	for _, l := range prof.Location {
+		mappings[l.Mapping] = true
+	}
+
+	for _, m := range prof.Mapping {
+		if !mappings[m] {
+			continue
+		}
+		// Do not attempt to re-symbolize a mapping that has already been symbolized.
+		if !force && (m.HasFunctions || m.HasFilenames || m.HasLineNumbers) {
+			continue
+		}
+
+		f, err := locateFile(obj, m.File, m.BuildID, m.Start)
+		if err != nil {
+			ui.PrintErr("Local symbolization failed for ", filepath.Base(m.File), ": ", err)
+			// Move on to other mappings
+			continue
+		}
+
+		if fid := f.BuildID(); m.BuildID != "" && fid != "" && fid != m.BuildID {
+			// Build ID mismatch - ignore.
+			f.Close()
+			continue
+		}
+
+		mt.segments[m] = f
+	}
+
+	return mt, nil
+}
+
+// locateFile opens a local file for symbolization on the search path
+// at $PPROF_BINARY_PATH. Looks inside these directories for files
+// named $BUILDID/$BASENAME and $BASENAME (if build id is available).
+func locateFile(obj plugin.ObjTool, file, buildID string, start uint64) (plugin.ObjFile, error) {
+	// Construct search path to examine
+	searchPath := os.Getenv("PPROF_BINARY_PATH")
+	if searchPath == "" {
+		// Use $HOME/pprof/binaries as default directory for local symbolization binaries
+		searchPath = filepath.Join(os.Getenv("HOME"), "pprof", "binaries")
+	}
+
+	// Collect names to search: {buildid/basename, basename}
+	var fileNames []string
+	if baseName := filepath.Base(file); buildID != "" {
+		fileNames = []string{filepath.Join(buildID, baseName), baseName}
+	} else {
+		fileNames = []string{baseName}
+	}
+	for _, path := range filepath.SplitList(searchPath) {
+		for nameIndex, name := range fileNames {
+			file := filepath.Join(path, name)
+			if f, err := obj.Open(file, start); err == nil {
+				fileBuildID := f.BuildID()
+				if buildID == "" || buildID == fileBuildID {
+					return f, nil
+				}
+				f.Close()
+				if nameIndex == 0 {
+					// If this is the first name, the path includes the build id. Report inconsistency.
+					return nil, fmt.Errorf("found file %s with inconsistent build id %s", file, fileBuildID)
+				}
+			}
+		}
+	}
+	// Try original file name
+	f, err := obj.Open(file, start)
+	if err == nil && buildID != "" {
+		if fileBuildID := f.BuildID(); fileBuildID != "" && fileBuildID != buildID {
+			// Mismatched build IDs, ignore
+			f.Close()
+			return nil, fmt.Errorf("mismatched build ids %s != %s", fileBuildID, buildID)
+		}
+	}
+	return f, err
+}
+
+// mappingTable contains the mechanisms for symbolization of a
+// profile.
+type mappingTable struct {
+	prof     *profile.Profile
+	segments map[*profile.Mapping]plugin.ObjFile
+}
+
+// Close releases any external processes being used for the mapping.
+func (mt *mappingTable) close() {
+	for _, segment := range mt.segments {
+		segment.Close()
+	}
+}