internal/trace: clean up parser.go

parser.go is an old file that contains trace v1 definitions and a second
equivalent definition for stack frames. These are redundant and useless.
Delete these definitions and rename the file to fakep.go, which
describes the only thing left in this file, a bunch of fake P IDs used
by the trace viewer.

We should consider moving the fake P definitions elsewhere, too.

Change-Id: Ifd0768bd73c39009069445afe0155f1e352f00c3
Reviewed-on: https://go-review.googlesource.com/c/go/+/644875
Reviewed-by: Michael Pratt <mpratt@google.com>
Auto-Submit: Michael Knyszek <mknyszek@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>

6 files changed, 30 insertions, 105 deletions

diff --git a/src/cmd/trace/pprof.go b/src/cmd/trace/pprof.go
index d27dfa7aa3..a66419aedf 100644
--- a/src/cmd/trace/pprof.go
+++ b/src/cmd/trace/pprof.go
@@ -306,18 +306,15 @@ func (m *stackMap) profile() []traceviewer.ProfileRecord {
 	prof := make([]traceviewer.ProfileRecord, 0, len(m.stacks))
 	for stack, record := range m.stacks {
 		rec := *record
-		for i, frame := range slices.Collect(stack.Frames()) {
-			rec.Stack = append(rec.Stack, &trace.Frame{
-				PC:   frame.PC,
-				Fn:   frame.Func,
-				File: frame.File,
-				Line: int(frame.Line),
-			})
+		var i int
+		for frame := range stack.Frames() {
+			rec.Stack = append(rec.Stack, frame)
 			// Cut this off at pprofMaxStack because that's as far
 			// as our deduplication goes.
 			if i >= pprofMaxStack {
 				break
 			}
+			i++
 		}
 		prof = append(prof, rec)
 	}
diff --git a/src/cmd/trace/viewer.go b/src/cmd/trace/viewer.go
index 6ce74b75b8..da83e81ab9 100644
--- a/src/cmd/trace/viewer.go
+++ b/src/cmd/trace/viewer.go
@@ -8,22 +8,14 @@ import (
 	"fmt"
 	"internal/trace"
 	"internal/trace/traceviewer"
+	"slices"
 	"time"
 )
 
 // viewerFrames returns the frames of the stack of ev. The given frame slice is
 // used to store the frames to reduce allocations.
-func viewerFrames(stk trace.Stack) []*trace.Frame {
-	var frames []*trace.Frame
-	for f := range stk.Frames() {
-		frames = append(frames, &trace.Frame{
-			PC:   f.PC,
-			Fn:   f.Func,
-			File: f.File,
-			Line: int(f.Line),
-		})
-	}
-	return frames
+func viewerFrames(stk trace.Stack) []trace.StackFrame {
+	return slices.Collect(stk.Frames())
 }
 
 func viewerGState(state trace.GoState, inMarkAssist bool) traceviewer.GState {
diff --git a/src/internal/trace/fakep.go b/src/internal/trace/fakep.go
new file mode 100644
index 0000000000..8d580c3a3a
--- /dev/null
+++ b/src/internal/trace/fakep.go
@@ -0,0 +1,15 @@
+// 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 trace
+
+const (
+	// Special P identifiers:
+	FakeP    = 1000000 + iota
+	TimerP   // depicts timer unblocks
+	NetpollP // depicts network unblocks
+	SyscallP // depicts returns from syscalls
+	GCP      // depicts GC state
+	ProfileP // depicts recording of CPU profile samples
+)
diff --git a/src/internal/trace/parser.go b/src/internal/trace/parser.go
deleted file mode 100644
index d6fff84d55..0000000000
--- a/src/internal/trace/parser.go
+++ /dev/null
@@ -1,79 +0,0 @@
-// 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 trace
-
-// Frame is a frame in stack traces.
-type Frame struct {
-	PC   uint64
-	Fn   string
-	File string
-	Line int
-}
-
-const (
-	// Special P identifiers:
-	FakeP    = 1000000 + iota
-	TimerP   // depicts timer unblocks
-	NetpollP // depicts network unblocks
-	SyscallP // depicts returns from syscalls
-	GCP      // depicts GC state
-	ProfileP // depicts recording of CPU profile samples
-)
-
-// Event types in the trace.
-// Verbatim copy from src/runtime/trace.go with the "trace" prefix removed.
-const (
-	EvNone              = 0  // unused
-	EvBatch             = 1  // start of per-P batch of events [pid, timestamp]
-	EvFrequency         = 2  // contains tracer timer frequency [frequency (ticks per second)]
-	EvStack             = 3  // stack [stack id, number of PCs, array of {PC, func string ID, file string ID, line}]
-	EvGomaxprocs        = 4  // current value of GOMAXPROCS [timestamp, GOMAXPROCS, stack id]
-	EvProcStart         = 5  // start of P [timestamp, thread id]
-	EvProcStop          = 6  // stop of P [timestamp]
-	EvGCStart           = 7  // GC start [timestamp, seq, stack id]
-	EvGCDone            = 8  // GC done [timestamp]
-	EvSTWStart          = 9  // GC mark termination start [timestamp, kind]
-	EvSTWDone           = 10 // GC mark termination done [timestamp]
-	EvGCSweepStart      = 11 // GC sweep start [timestamp, stack id]
-	EvGCSweepDone       = 12 // GC sweep done [timestamp, swept, reclaimed]
-	EvGoCreate          = 13 // goroutine creation [timestamp, new goroutine id, new stack id, stack id]
-	EvGoStart           = 14 // goroutine starts running [timestamp, goroutine id, seq]
-	EvGoEnd             = 15 // goroutine ends [timestamp]
-	EvGoStop            = 16 // goroutine stops (like in select{}) [timestamp, stack]
-	EvGoSched           = 17 // goroutine calls Gosched [timestamp, stack]
-	EvGoPreempt         = 18 // goroutine is preempted [timestamp, stack]
-	EvGoSleep           = 19 // goroutine calls Sleep [timestamp, stack]
-	EvGoBlock           = 20 // goroutine blocks [timestamp, stack]
-	EvGoUnblock         = 21 // goroutine is unblocked [timestamp, goroutine id, seq, stack]
-	EvGoBlockSend       = 22 // goroutine blocks on chan send [timestamp, stack]
-	EvGoBlockRecv       = 23 // goroutine blocks on chan recv [timestamp, stack]
-	EvGoBlockSelect     = 24 // goroutine blocks on select [timestamp, stack]
-	EvGoBlockSync       = 25 // goroutine blocks on Mutex/RWMutex [timestamp, stack]
-	EvGoBlockCond       = 26 // goroutine blocks on Cond [timestamp, stack]
-	EvGoBlockNet        = 27 // goroutine blocks on network [timestamp, stack]
-	EvGoSysCall         = 28 // syscall enter [timestamp, stack]
-	EvGoSysExit         = 29 // syscall exit [timestamp, goroutine id, seq, real timestamp]
-	EvGoSysBlock        = 30 // syscall blocks [timestamp]
-	EvGoWaiting         = 31 // denotes that goroutine is blocked when tracing starts [timestamp, goroutine id]
-	EvGoInSyscall       = 32 // denotes that goroutine is in syscall when tracing starts [timestamp, goroutine id]
-	EvHeapAlloc         = 33 // gcController.heapLive change [timestamp, heap live bytes]
-	EvHeapGoal          = 34 // gcController.heapGoal change [timestamp, heap goal bytes]
-	EvTimerGoroutine    = 35 // denotes timer goroutine [timer goroutine id]
-	EvFutileWakeup      = 36 // denotes that the previous wakeup of this goroutine was futile [timestamp]
-	EvString            = 37 // string dictionary entry [ID, length, string]
-	EvGoStartLocal      = 38 // goroutine starts running on the same P as the last event [timestamp, goroutine id]
-	EvGoUnblockLocal    = 39 // goroutine is unblocked on the same P as the last event [timestamp, goroutine id, stack]
-	EvGoSysExitLocal    = 40 // syscall exit on the same P as the last event [timestamp, goroutine id, real timestamp]
-	EvGoStartLabel      = 41 // goroutine starts running with label [timestamp, goroutine id, seq, label string id]
-	EvGoBlockGC         = 42 // goroutine blocks on GC assist [timestamp, stack]
-	EvGCMarkAssistStart = 43 // GC mark assist start [timestamp, stack]
-	EvGCMarkAssistDone  = 44 // GC mark assist done [timestamp]
-	EvUserTaskCreate    = 45 // trace.NewTask [timestamp, internal task id, internal parent id, name string, stack]
-	EvUserTaskEnd       = 46 // end of task [timestamp, internal task id, stack]
-	EvUserRegion        = 47 // trace.WithRegion [timestamp, internal task id, mode(0:start, 1:end), name string, stack]
-	EvUserLog           = 48 // trace.Log [timestamp, internal id, key string id, stack, value string]
-	EvCPUSample         = 49 // CPU profiling sample [timestamp, real timestamp, real P id (-1 when absent), goroutine id, stack]
-	EvCount             = 50
-)
diff --git a/src/internal/trace/traceviewer/emitter.go b/src/internal/trace/traceviewer/emitter.go
index c74f1c2ecf..d2227d681e 100644
--- a/src/internal/trace/traceviewer/emitter.go
+++ b/src/internal/trace/traceviewer/emitter.go
@@ -683,12 +683,12 @@ func (e *Emitter) processMeta(sectionID uint64, name string, priority int) {
 
 // Stack emits the given frames and returns a unique id for the stack. No
 // pointers to the given data are being retained beyond the call to Stack.
-func (e *Emitter) Stack(stk []*trace.Frame) int {
+func (e *Emitter) Stack(stk []trace.StackFrame) int {
 	return e.buildBranch(e.frameTree, stk)
 }
 
 // buildBranch builds one branch in the prefix tree rooted at ctx.frameTree.
-func (e *Emitter) buildBranch(parent frameNode, stk []*trace.Frame) int {
+func (e *Emitter) buildBranch(parent frameNode, stk []trace.StackFrame) int {
 	if len(stk) == 0 {
 		return parent.id
 	}
@@ -702,7 +702,7 @@ func (e *Emitter) buildBranch(parent frameNode, stk []*trace.Frame) int {
 		node.id = e.frameSeq
 		node.children = make(map[uint64]frameNode)
 		parent.children[frame.PC] = node
-		e.c.ConsumeViewerFrame(strconv.Itoa(node.id), format.Frame{Name: fmt.Sprintf("%v:%v", frame.Fn, frame.Line), Parent: parent.id})
+		e.c.ConsumeViewerFrame(strconv.Itoa(node.id), format.Frame{Name: fmt.Sprintf("%v:%v", frame.Func, frame.Line), Parent: parent.id})
 	}
 	return e.buildBranch(node, stk)
 }
diff --git a/src/internal/trace/traceviewer/pprof.go b/src/internal/trace/traceviewer/pprof.go
index 1377b3c614..141b2687b7 100644
--- a/src/internal/trace/traceviewer/pprof.go
+++ b/src/internal/trace/traceviewer/pprof.go
@@ -82,7 +82,7 @@ func SVGProfileHandlerFunc(f ProfileFunc) http.HandlerFunc {
 }
 
 type ProfileRecord struct {
-	Stack []*trace.Frame
+	Stack []trace.StackFrame
 	Count uint64
 	Time  time.Duration
 }
@@ -103,16 +103,16 @@ func BuildProfile(prof []ProfileRecord) *profile.Profile {
 		for _, frame := range rec.Stack {
 			loc := locs[frame.PC]
 			if loc == nil {
-				fn := funcs[frame.File+frame.Fn]
+				fn := funcs[frame.File+frame.Func]
 				if fn == nil {
 					fn = &profile.Function{
 						ID:         uint64(len(p.Function) + 1),
-						Name:       frame.Fn,
-						SystemName: frame.Fn,
+						Name:       frame.Func,
+						SystemName: frame.Func,
 						Filename:   frame.File,
 					}
 					p.Function = append(p.Function, fn)
-					funcs[frame.File+frame.Fn] = fn
+					funcs[frame.File+frame.Func] = fn
 				}
 				loc = &profile.Location{
 					ID:      uint64(len(p.Location) + 1),