Merge pull request #41 from aalexand/aalexand/unsource-url-mappings

Reset mapping file to empty string if it was patched to be the source URL

internal/driver/fetch.go

@@ -72,6 +72,7 @@ func fetchProfiles(s *source, o *plugin.Options) (*profile.Profile, error) {
 		return nil, err
 	}
 	p.RemoveUninteresting()
+	unsourceMappings(p)
 
 	// Save a copy of the merged profile if there is at least one remote source.
 	if save {
@@ -283,6 +284,8 @@ func collectMappingSources(p *profile.Profile, source string) plugin.MappingSour
 			// If there is no build id or source file, use the source as the
 			// mapping file. This will enable remote symbolization for this
 			// mapping, in particular for Go profiles on the legacy format.
+			// The source is reset back to empty string by unsourceMapping
+			// which is called after symbolization is finished.
 			m.File = source
 			key = source
 		}
@@ -291,6 +294,18 @@ func collectMappingSources(p *profile.Profile, source string) plugin.MappingSour
 	return ms
 }
 
+// unsourceMappings iterates over the mappings in a profile and replaces file
+// set to the remote source URL by collectMappingSources back to empty string.
+func unsourceMappings(p *profile.Profile) {
+	for _, m := range p.Mapping {
+		if m.BuildID == "" {
+			if u, err := url.Parse(m.File); err == nil && u.IsAbs() {
+				m.File = ""
+			}
+		}
+	}
+}
+
 // locateBinaries searches for binary files listed in the profile and, if found,
 // updates the profile accordingly.
 func locateBinaries(p *profile.Profile, s *source, obj plugin.ObjTool, ui plugin.UI) {

internal/driver/fetch_test.go

@@ -21,6 +21,7 @@ import (
 	"net/url"
 	"os"
 	"path/filepath"
+	"reflect"
 	"regexp"
 	"testing"
 	"time"
@@ -76,6 +77,55 @@ func TestSymbolizationPath(t *testing.T) {
 	os.Setenv("PPROF_BINARY_PATH", savePath)
 }
 
+func TestCollectMappingSources(t *testing.T) {
+	const startAddress uint64 = 0x40000
+	const url = "http://example.com"
+	for _, tc := range []struct {
+		file, buildID string
+		want          plugin.MappingSources
+	}{
+		{"/usr/bin/binary", "buildId", mappingSources("buildId", url, startAddress)},
+		{"/usr/bin/binary", "", mappingSources("/usr/bin/binary", url, startAddress)},
+		{"", "", mappingSources(url, url, startAddress)},
+	} {
+		p := &profile.Profile{
+			Mapping: []*profile.Mapping{
+				{
+					File:    tc.file,
+					BuildID: tc.buildID,
+					Start:   startAddress,
+				},
+			},
+		}
+		got := collectMappingSources(p, url)
+		if !reflect.DeepEqual(got, tc.want) {
+			t.Errorf("%s:%s, want %s, got %s", tc.file, tc.buildID, tc.want, got)
+		}
+	}
+}
+
+func TestUnsourceMappings(t *testing.T) {
+	for _, tc := range []struct {
+		file, buildID, want string
+	}{
+		{"/usr/bin/binary", "buildId", "/usr/bin/binary"},
+		{"http://example.com", "", ""},
+	} {
+		p := &profile.Profile{
+			Mapping: []*profile.Mapping{
+				{
+					File:    tc.file,
+					BuildID: tc.buildID,
+				},
+			},
+		}
+		unsourceMappings(p)
+		if got := p.Mapping[0].File; got != tc.want {
+			t.Errorf("%s:%s, want %s, got %s", tc.file, tc.buildID, tc.want, got)
+		}
+	}
+}
+
 type testObj struct {
 	home string
 }
@@ -125,6 +175,18 @@ func TestFetch(t *testing.T) {
 	}
 }
 
+// mappingSources creates MappingSources map with a single item.
+func mappingSources(key, source string, start uint64) plugin.MappingSources {
+	return plugin.MappingSources{
+		key: []struct {
+			Source string
+			Start  uint64
+		}{
+			{Source: source, Start: start},
+		},
+	}
+}
+
 // stubHTTPGet intercepts a call to http.Get and rewrites it to use
 // "file://" to get the profile directly from a file.
 func stubHTTPGet(source string, _ time.Duration) (*http.Response, error) {

internal/symbolizer/symbolizer.go

@@ -21,6 +21,7 @@ import (
 	"fmt"
 	"io/ioutil"
 	"net/http"
+	"net/url"
 	"path/filepath"
 	"strings"
 
@@ -299,6 +300,13 @@ func newMapping(prof *profile.Profile, obj plugin.ObjTool, ui plugin.UI, force b
 			continue
 		}
 
+		// Skip mappings pointing to a source URL
+		if m.BuildID == "" {
+			if u, err := url.Parse(m.File); err == nil && u.IsAbs() {
+				continue
+			}
+		}
+
 		f, err := obj.Open(m.File, m.Start, m.Limit, m.Offset)
 		if err != nil {
 			ui.PrintErr("Local symbolization failed for ", name, ": ", err)