Vendor pprof

Signed-off-by: Kemal Akkoyun <kakkoyun@gmail.com>

.github/workflows/go.yml

@@ -24,4 +24,4 @@ jobs:
         run: make build
 
       - name: Test
-        run: go test -v ./...
+        run: make go/test

Makefile

@@ -22,8 +22,12 @@ clean:
 .PHONY: build
 build: ui go/bin
 
+.PHONY: go/deps
+go/deps: internal/pprof
+	go mod tidy
+
 .PHONY: go/bin
-go/bin:
+go/bin: go/deps
 	mkdir -p ./bin
 	go build -o bin/ ./cmd/parca
 	cp parca.yaml bin/
@@ -38,6 +42,10 @@ go-fmt:
 .PHONY: check-license
 check-license:
 	./scripts/check-license.sh
+
+.PHONY: go/test
+go/test:
+	 go test -v `go list ./... | grep -v ./internal`
 
 .PHONY: ui
 ui:
@@ -89,3 +97,11 @@ dev/up: deploy/manifests
 .PHONY: dev/down
 dev/down:
 	source ./scripts/local-dev.sh && down
+
+internal/pprof:
+	rm -rf internal/pprof
+	rm -rf tmp/pprof
+	git clone https://github.com/google/pprof tmp/pprof
+	cp -r tmp/pprof/internal internal/pprof
+	find internal/pprof -type f -exec sed -i 's/github.com\/google\/pprof\/internal/github.com\/parca-dev\/parca\/internal\/pprof/g' {} +
+	rm -rf tmp/pprof

internal/pprof/binutils/addr2liner.go

@@ -0,0 +1,238 @@
+// Copyright 2014 Google Inc. All Rights Reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package binutils
+
+import (
+	"bufio"
+	"fmt"
+	"io"
+	"os/exec"
+	"strconv"
+	"strings"
+	"sync"
+
+	"github.com/parca-dev/parca/internal/pprof/plugin"
+)
+
+const (
+	defaultAddr2line = "addr2line"
+
+	// addr2line may produce multiple lines of output. We
+	// use this sentinel to identify the end of the output.
+	sentinel = ^uint64(0)
+)
+
+// addr2Liner is a connection to an addr2line command for obtaining
+// address and line number information from a binary.
+type addr2Liner struct {
+	mu   sync.Mutex
+	rw   lineReaderWriter
+	base uint64
+
+	// nm holds an addr2Liner using nm tool. Certain versions of addr2line
+	// produce incomplete names due to
+	// https://sourceware.org/bugzilla/show_bug.cgi?id=17541. As a workaround,
+	// the names from nm are used when they look more complete. See addrInfo()
+	// code below for the exact heuristic.
+	nm *addr2LinerNM
+}
+
+// lineReaderWriter is an interface to abstract the I/O to an addr2line
+// process. It writes a line of input to the job, and reads its output
+// one line at a time.
+type lineReaderWriter interface {
+	write(string) error
+	readLine() (string, error)
+	close()
+}
+
+type addr2LinerJob struct {
+	cmd *exec.Cmd
+	in  io.WriteCloser
+	out *bufio.Reader
+}
+
+func (a *addr2LinerJob) write(s string) error {
+	_, err := fmt.Fprint(a.in, s+"\n")
+	return err
+}
+
+func (a *addr2LinerJob) readLine() (string, error) {
+	s, err := a.out.ReadString('\n')
+	if err != nil {
+		return "", err
+	}
+	return strings.TrimSpace(s), nil
+}
+
+// close releases any resources used by the addr2liner object.
+func (a *addr2LinerJob) close() {
+	a.in.Close()
+	a.cmd.Wait()
+}
+
+// newAddr2liner starts the given addr2liner command reporting
+// information about the given executable file. If file is a shared
+// library, base should be the address at which it was mapped in the
+// program under consideration.
+func newAddr2Liner(cmd, file string, base uint64) (*addr2Liner, error) {
+	if cmd == "" {
+		cmd = defaultAddr2line
+	}
+
+	j := &addr2LinerJob{
+		cmd: exec.Command(cmd, "-aif", "-e", file),
+	}
+
+	var err error
+	if j.in, err = j.cmd.StdinPipe(); err != nil {
+		return nil, err
+	}
+
+	outPipe, err := j.cmd.StdoutPipe()
+	if err != nil {
+		return nil, err
+	}
+
+	j.out = bufio.NewReader(outPipe)
+	if err := j.cmd.Start(); err != nil {
+		return nil, err
+	}
+
+	a := &addr2Liner{
+		rw:   j,
+		base: base,
+	}
+
+	return a, nil
+}
+
+// readFrame parses the addr2line output for a single address. It
+// returns a populated plugin.Frame and whether it has reached the end of the
+// data.
+func (d *addr2Liner) readFrame() (plugin.Frame, bool) {
+	funcname, err := d.rw.readLine()
+	if err != nil {
+		return plugin.Frame{}, true
+	}
+	if strings.HasPrefix(funcname, "0x") {
+		// If addr2line returns a hex address we can assume it is the
+		// sentinel. Read and ignore next two lines of output from
+		// addr2line
+		d.rw.readLine()
+		d.rw.readLine()
+		return plugin.Frame{}, true
+	}
+
+	fileline, err := d.rw.readLine()
+	if err != nil {
+		return plugin.Frame{}, true
+	}
+
+	linenumber := 0
+
+	if funcname == "??" {
+		funcname = ""
+	}
+
+	if fileline == "??:0" {
+		fileline = ""
+	} else {
+		if i := strings.LastIndex(fileline, ":"); i >= 0 {
+			// Remove discriminator, if present
+			if disc := strings.Index(fileline, " (discriminator"); disc > 0 {
+				fileline = fileline[:disc]
+			}
+			// If we cannot parse a number after the last ":", keep it as
+			// part of the filename.
+			if line, err := strconv.Atoi(fileline[i+1:]); err == nil {
+				linenumber = line
+				fileline = fileline[:i]
+			}
+		}
+	}
+
+	return plugin.Frame{
+		Func: funcname,
+		File: fileline,
+		Line: linenumber}, false
+}
+
+func (d *addr2Liner) rawAddrInfo(addr uint64) ([]plugin.Frame, error) {
+	d.mu.Lock()
+	defer d.mu.Unlock()
+
+	if err := d.rw.write(fmt.Sprintf("%x", addr-d.base)); err != nil {
+		return nil, err
+	}
+
+	if err := d.rw.write(fmt.Sprintf("%x", sentinel)); err != nil {
+		return nil, err
+	}
+
+	resp, err := d.rw.readLine()
+	if err != nil {
+		return nil, err
+	}
+
+	if !strings.HasPrefix(resp, "0x") {
+		return nil, fmt.Errorf("unexpected addr2line output: %s", resp)
+	}
+
+	var stack []plugin.Frame
+	for {
+		frame, end := d.readFrame()
+		if end {
+			break
+		}
+
+		if frame != (plugin.Frame{}) {
+			stack = append(stack, frame)
+		}
+	}
+	return stack, err
+}
+
+// addrInfo returns the stack frame information for a specific program
+// address. It returns nil if the address could not be identified.
+func (d *addr2Liner) addrInfo(addr uint64) ([]plugin.Frame, error) {
+	stack, err := d.rawAddrInfo(addr)
+	if err != nil {
+		return nil, err
+	}
+
+	// Certain versions of addr2line produce incomplete names due to
+	// https://sourceware.org/bugzilla/show_bug.cgi?id=17541. Attempt to replace
+	// the name with a better one from nm.
+	if len(stack) > 0 && d.nm != nil {
+		nm, err := d.nm.addrInfo(addr)
+		if err == nil && len(nm) > 0 {
+			// Last entry in frame list should match since it is non-inlined. As a
+			// simple heuristic, we only switch to the nm-based name if it is longer
+			// by 2 or more characters. We consider nm names that are longer by 1
+			// character insignificant to avoid replacing foo with _foo on MacOS (for
+			// unknown reasons read2line produces the former and nm produces the
+			// latter on MacOS even though both tools are asked to produce mangled
+			// names).
+			nmName := nm[len(nm)-1].Func
+			a2lName := stack[len(stack)-1].Func
+			if len(nmName) > len(a2lName)+1 {
+				stack[len(stack)-1].Func = nmName
+			}
+		}
+	}
+
+	return stack, nil
+}