cmd/compile: leave Pos unset for racewalk enter/exit

The locations chosen for racewalking inserted code can
be wrong and thus cause unwanted next/step behavior in
debuggers.  Forcing the positions to be unset results in
better behavior.

Test added, and test harness corrected to deal with
changes to gdb's output caused by -racewalk.

Incidental changes in Delve (not part of the usual testing,
but provided because we care about Delve) also reflected
in this CL.

Fixes #22600.

Change-Id: Idd0218afed52ab8c68efd9eabbdff3c92ea2b996
Reviewed-on: https://go-review.googlesource.com/78336
Run-TryBot: David Chase <drchase@google.com>
Reviewed-by: Alessandro Arzilli <alessandro.arzilli@gmail.com>
Reviewed-by: Keith Randall <khr@golang.org>

diff --git a/src/cmd/compile/internal/gc/racewalk.go b/src/cmd/compile/internal/gc/racewalk.go
index 90bfdbf688c7efa6843996dc29c2e6cb6a58e1de..4b92ce9e0edeed947c9bacfcc8063c9203c30245 100644 (file)
--- a/src/cmd/compile/internal/gc/racewalk.go
+++ b/src/cmd/compile/internal/gc/racewalk.go
@@ -70,11 +70,15 @@ func instrument(fn *Node) {
                nodpc := *nodfp
                nodpc.Type = types.Types[TUINTPTR]
                nodpc.Xoffset = int64(-Widthptr)
+               savedLineno := lineno
+               lineno = src.NoXPos
                nd := mkcall("racefuncenter", nil, nil, &nodpc)
+
                fn.Func.Enter.Prepend(nd)
                nd = mkcall("racefuncexit", nil, nil)
                fn.Func.Exit.Append(nd)
                fn.Func.Dcl = append(fn.Func.Dcl, &nodpc)
+               lineno = savedLineno
        }
 
        if Debug['W'] != 0 {

diff --git a/src/cmd/compile/internal/ssa/debug_test.go b/src/cmd/compile/internal/ssa/debug_test.go
index 0930c65142bd960295da2703c60e2dcf5455f070..0e349025122a94bf16fc377b6e41d409ca3861e0 100644 (file)
--- a/src/cmd/compile/internal/ssa/debug_test.go
+++ b/src/cmd/compile/internal/ssa/debug_test.go
@@ -132,6 +132,9 @@ func TestNexting(t *testing.T) {
        t.Run("dbg-"+debugger, func(t *testing.T) {
                testNexting(t, "hist", "dbg", "-N -l")
        })
+       t.Run("dbg-race-"+debugger, func(t *testing.T) {
+               testNexting(t, "i22600", "dbg-race", "-N -l", "-race")
+       })
        t.Run("opt-"+debugger, func(t *testing.T) {
                // If this is test is run with a runtime compiled with -N -l, it is very likely to fail.
                // This occurs in the noopt builders (for example).
@@ -148,7 +151,7 @@ func TestNexting(t *testing.T) {
        })
 }
 
-func testNexting(t *testing.T, base, tag, gcflags string) {
+func testNexting(t *testing.T, base, tag, gcflags string, moreArgs ...string) {
        // (1) In testdata, build sample.go into sample
        // (2) Run debugger gathering a history
        // (3) Read expected history from testdata/sample.<variant>.nexts
@@ -171,7 +174,11 @@ func testNexting(t *testing.T, base, tag, gcflags string) {
                defer os.RemoveAll(tmpdir)
        }
 
-       runGo(t, "", "build", "-o", exe, "-gcflags=all="+gcflags, filepath.Join("testdata", base+".go"))
+       runGoArgs := []string{"build", "-o", exe, "-gcflags=all=" + gcflags}
+       runGoArgs = append(runGoArgs, moreArgs...)
+       runGoArgs = append(runGoArgs, filepath.Join("testdata", base+".go"))
+
+       runGo(t, "", runGoArgs...)
 
        var h1 *nextHist
        nextlog := logbase + "-" + debugger + ".nexts"
@@ -533,7 +540,7 @@ func newGdb(tag, executable string, args ...string) dbgr {
        s := &gdbState{tag: tag, cmd: cmd, args: args}
        s.atLineRe = regexp.MustCompile("(^|\n)([0-9]+)(.*)")
        s.funcFileLinePCre = regexp.MustCompile(
-               "([^ ]+) [(][)][ \\t\\n]+at ([^:]+):([0-9]+)")
+               "([^ ]+) [(][^)]*[)][ \\t\\n]+at ([^:]+):([0-9]+)")
        // runtime.main () at /Users/drchase/GoogleDrive/work/go/src/runtime/proc.go:201
        //                                    function              file    line
        // Thread 2 hit Breakpoint 1, main.main () at /Users/drchase/GoogleDrive/work/debug/hist.go:18

diff --git a/src/cmd/compile/internal/ssa/testdata/hist.opt-dlv.nexts b/src/cmd/compile/internal/ssa/testdata/hist.opt-dlv.nexts
index 5a0a8be00d104f161b6de66ba754961e7575eacd..a6321d904beadcca801b58605668bce58624eb10 100644 (file)
--- a/src/cmd/compile/internal/ssa/testdata/hist.opt-dlv.nexts
+++ b/src/cmd/compile/internal/ssa/testdata/hist.opt-dlv.nexts
@@ -9,3 +9,98 @@
 63:            hist := make([]int, 7)                                //gdb-opt=(sink,dx/O,dy/O)
 64:            var reader io.Reader = strings.NewReader(cannedInput) //gdb-dbg=(hist/A,cannedInput/A)
 19:            "strings"
+65:            if len(os.Args) > 1 {
+14:            "bufio"
+74:            for scanner.Scan() { //gdb-opt=(scanner/A)
+76:                    i, err := strconv.ParseInt(s, 10, 64)
+77:                    if err != nil { //gdb-dbg=(i) //gdb-opt=(err,hist,i)
+81:                    hist = ensure(int(i), hist)
+82:                    hist[int(i)]++
+74:            for scanner.Scan() { //gdb-opt=(scanner/A)
+76:                    i, err := strconv.ParseInt(s, 10, 64)
+77:                    if err != nil { //gdb-dbg=(i) //gdb-opt=(err,hist,i)
+81:                    hist = ensure(int(i), hist)
+82:                    hist[int(i)]++
+74:            for scanner.Scan() { //gdb-opt=(scanner/A)
+76:                    i, err := strconv.ParseInt(s, 10, 64)
+77:                    if err != nil { //gdb-dbg=(i) //gdb-opt=(err,hist,i)
+81:                    hist = ensure(int(i), hist)
+82:                    hist[int(i)]++
+74:            for scanner.Scan() { //gdb-opt=(scanner/A)
+76:                    i, err := strconv.ParseInt(s, 10, 64)
+77:                    if err != nil { //gdb-dbg=(i) //gdb-opt=(err,hist,i)
+81:                    hist = ensure(int(i), hist)
+82:                    hist[int(i)]++
+74:            for scanner.Scan() { //gdb-opt=(scanner/A)
+76:                    i, err := strconv.ParseInt(s, 10, 64)
+77:                    if err != nil { //gdb-dbg=(i) //gdb-opt=(err,hist,i)
+81:                    hist = ensure(int(i), hist)
+82:                    hist[int(i)]++
+74:            for scanner.Scan() { //gdb-opt=(scanner/A)
+76:                    i, err := strconv.ParseInt(s, 10, 64)
+77:                    if err != nil { //gdb-dbg=(i) //gdb-opt=(err,hist,i)
+81:                    hist = ensure(int(i), hist)
+82:                    hist[int(i)]++
+74:            for scanner.Scan() { //gdb-opt=(scanner/A)
+76:                    i, err := strconv.ParseInt(s, 10, 64)
+77:                    if err != nil { //gdb-dbg=(i) //gdb-opt=(err,hist,i)
+81:                    hist = ensure(int(i), hist)
+82:                    hist[int(i)]++
+74:            for scanner.Scan() { //gdb-opt=(scanner/A)
+76:                    i, err := strconv.ParseInt(s, 10, 64)
+77:                    if err != nil { //gdb-dbg=(i) //gdb-opt=(err,hist,i)
+81:                    hist = ensure(int(i), hist)
+82:                    hist[int(i)]++
+74:            for scanner.Scan() { //gdb-opt=(scanner/A)
+76:                    i, err := strconv.ParseInt(s, 10, 64)
+77:                    if err != nil { //gdb-dbg=(i) //gdb-opt=(err,hist,i)
+81:                    hist = ensure(int(i), hist)
+82:                    hist[int(i)]++
+74:            for scanner.Scan() { //gdb-opt=(scanner/A)
+86:            for i, a := range hist {
+87:                    if a == 0 { //gdb-opt=(a,n,t)
+88:                            continue
+87:                    if a == 0 { //gdb-opt=(a,n,t)
+92:                    fmt.Fprintf(os.Stderr, "%d\t%d\t%d\t%d\t%d\n", i, a, n, i*a, t) //gdb-dbg=(n,i,t)
+91:                    n += a
+92:                    fmt.Fprintf(os.Stderr, "%d\t%d\t%d\t%d\t%d\n", i, a, n, i*a, t) //gdb-dbg=(n,i,t)
+90:                    t += i * a
+92:                    fmt.Fprintf(os.Stderr, "%d\t%d\t%d\t%d\t%d\n", i, a, n, i*a, t) //gdb-dbg=(n,i,t)
+90:                    t += i * a
+92:                    fmt.Fprintf(os.Stderr, "%d\t%d\t%d\t%d\t%d\n", i, a, n, i*a, t) //gdb-dbg=(n,i,t)
+86:            for i, a := range hist {
+92:                    fmt.Fprintf(os.Stderr, "%d\t%d\t%d\t%d\t%d\n", i, a, n, i*a, t) //gdb-dbg=(n,i,t)
+87:                    if a == 0 { //gdb-opt=(a,n,t)
+92:                    fmt.Fprintf(os.Stderr, "%d\t%d\t%d\t%d\t%d\n", i, a, n, i*a, t) //gdb-dbg=(n,i,t)
+91:                    n += a
+92:                    fmt.Fprintf(os.Stderr, "%d\t%d\t%d\t%d\t%d\n", i, a, n, i*a, t) //gdb-dbg=(n,i,t)
+90:                    t += i * a
+92:                    fmt.Fprintf(os.Stderr, "%d\t%d\t%d\t%d\t%d\n", i, a, n, i*a, t) //gdb-dbg=(n,i,t)
+90:                    t += i * a
+92:                    fmt.Fprintf(os.Stderr, "%d\t%d\t%d\t%d\t%d\n", i, a, n, i*a, t) //gdb-dbg=(n,i,t)
+86:            for i, a := range hist {
+92:                    fmt.Fprintf(os.Stderr, "%d\t%d\t%d\t%d\t%d\n", i, a, n, i*a, t) //gdb-dbg=(n,i,t)
+87:                    if a == 0 { //gdb-opt=(a,n,t)
+88:                            continue
+87:                    if a == 0 { //gdb-opt=(a,n,t)
+92:                    fmt.Fprintf(os.Stderr, "%d\t%d\t%d\t%d\t%d\n", i, a, n, i*a, t) //gdb-dbg=(n,i,t)
+91:                    n += a
+92:                    fmt.Fprintf(os.Stderr, "%d\t%d\t%d\t%d\t%d\n", i, a, n, i*a, t) //gdb-dbg=(n,i,t)
+90:                    t += i * a
+92:                    fmt.Fprintf(os.Stderr, "%d\t%d\t%d\t%d\t%d\n", i, a, n, i*a, t) //gdb-dbg=(n,i,t)
+90:                    t += i * a
+92:                    fmt.Fprintf(os.Stderr, "%d\t%d\t%d\t%d\t%d\n", i, a, n, i*a, t) //gdb-dbg=(n,i,t)
+86:            for i, a := range hist {
+92:                    fmt.Fprintf(os.Stderr, "%d\t%d\t%d\t%d\t%d\n", i, a, n, i*a, t) //gdb-dbg=(n,i,t)
+87:                    if a == 0 { //gdb-opt=(a,n,t)
+92:                    fmt.Fprintf(os.Stderr, "%d\t%d\t%d\t%d\t%d\n", i, a, n, i*a, t) //gdb-dbg=(n,i,t)
+91:                    n += a
+92:                    fmt.Fprintf(os.Stderr, "%d\t%d\t%d\t%d\t%d\n", i, a, n, i*a, t) //gdb-dbg=(n,i,t)
+90:                    t += i * a
+92:                    fmt.Fprintf(os.Stderr, "%d\t%d\t%d\t%d\t%d\n", i, a, n, i*a, t) //gdb-dbg=(n,i,t)
+90:                    t += i * a
+92:                    fmt.Fprintf(os.Stderr, "%d\t%d\t%d\t%d\t%d\n", i, a, n, i*a, t) //gdb-dbg=(n,i,t)
+86:            for i, a := range hist {
+92:                    fmt.Fprintf(os.Stderr, "%d\t%d\t%d\t%d\t%d\n", i, a, n, i*a, t) //gdb-dbg=(n,i,t)
+87:                    if a == 0 { //gdb-opt=(a,n,t)
+88:                            continue

diff --git a/src/cmd/compile/internal/ssa/testdata/i22600.dbg-race-gdb.nexts b/src/cmd/compile/internal/ssa/testdata/i22600.dbg-race-gdb.nexts
new file mode 100644 (file)
index 0000000..681167d
--- /dev/null
+++ b/src/cmd/compile/internal/ssa/testdata/i22600.dbg-race-gdb.nexts
@@ -0,0 +1,6 @@
+  src/cmd/compile/internal/ssa/testdata/i22600.go
+8:     func main() {
+9:             pwd, err := os.Getwd()
+10:            if err != nil {
+14:            fmt.Println(pwd)
+15:    }

diff --git a/src/cmd/compile/internal/ssa/testdata/i22600.go b/src/cmd/compile/internal/ssa/testdata/i22600.go
new file mode 100644 (file)
index 0000000..8cecd14
--- /dev/null
+++ b/src/cmd/compile/internal/ssa/testdata/i22600.go
@@ -0,0 +1,15 @@
+package main
+
+import (
+       "fmt"
+       "os"
+)
+
+func main() {
+       pwd, err := os.Getwd()
+       if err != nil {
+               fmt.Println(err)
+               os.Exit(1)
+       }
+       fmt.Println(pwd)
+}