cmd/compile: extend dump-to-file to handle "genssa" (asm) case.
Extend the existing dump-to-file to also do assembly output
to make it easier to write debug-information tests that check
for line-numbering in particular orders.
Includes POC test (which is silent w/o -v):
go test -v -run TestDebugLines cmd/compile/internal/ssa
=== RUN TestDebugLines
Preserving temporary directory /var/folders/v6/xyzzy/T/debug_lines_test321
About to run (cd /var/folders/v6/xyzzy/T/debug_lines_test321; \
GOSSADIR=/var/folders/v6/xyzzy/T/debug_lines_test321 \
/Users/drchase/work/go/bin/go build -o foo.o \
'-gcflags=-N -l -d=ssa/genssa/dump=sayhi' \
/Users/drchase/work/go/src/cmd/compile/internal/ssa/testdata/sayhi.go )
Saw stmt# 8 for submatch '8' on dump line #7 = ' v107 00005 (+8) MOVQ AX, "".n(SP)'
Saw stmt# 9 for submatch '9' on dump line #9 = ' v87 00007 (+9) MOVUPS X15, ""..autotmp_2-32(SP)'
Saw stmt# 10 for submatch '10' on dump line #46 = ' v65 00044 (+10) MOVUPS X15, ""..autotmp_2-32(SP)'
Saw stmt# 11 for submatch '11' on dump line #83 = ' v131 00081 (+11) MOVQ "".wg+8(SP), AX'
--- PASS: TestDebugLines (4.95s)
PASS
ok cmd/compile/internal/ssa 5.685s
Includes a test to ensure that inlining information is printed correctly.
Updates #47880.
Change-Id: I83b596476a88687d71d5b65dbb94641a576d747e
Reviewed-on: https://go-review.googlesource.com/c/go/+/348970
Trust: David Chase <drchase@google.com>
Run-TryBot: David Chase <drchase@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
diff --git a/src/cmd/compile/internal/ssa/compile.go b/src/cmd/compile/internal/ssa/compile.go
index cd8eba4..f87ea5b 100644
--- a/src/cmd/compile/internal/ssa/compile.go
+++ b/src/cmd/compile/internal/ssa/compile.go
@@ -10,9 +10,11 @@
"fmt"
"hash/crc32"
"internal/buildcfg"
+ "io"
"log"
"math/rand"
"os"
+ "path/filepath"
"regexp"
"runtime"
"sort"
@@ -59,7 +61,7 @@
printFunc(f)
}
f.HTMLWriter.WritePhase("start", "start")
- if BuildDump != "" && BuildDump == f.Name {
+ if BuildDump[f.Name] {
f.dumpFile("build")
}
if checkEnabled {
@@ -163,25 +165,37 @@
phaseName = ""
}
-// dumpFile creates a file from the phase name and function name
-// Dumping is done to files to avoid buffering huge strings before
-// output.
-func (f *Func) dumpFile(phaseName string) {
+// DumpFileForPhase creates a file from the function name and phase name,
+// warning and returning nil if this is not possible.
+func (f *Func) DumpFileForPhase(phaseName string) io.WriteCloser {
f.dumpFileSeq++
fname := fmt.Sprintf("%s_%02d__%s.dump", f.Name, int(f.dumpFileSeq), phaseName)
fname = strings.Replace(fname, " ", "_", -1)
fname = strings.Replace(fname, "/", "_", -1)
fname = strings.Replace(fname, ":", "_", -1)
+ if ssaDir := os.Getenv("GOSSADIR"); ssaDir != "" {
+ fname = filepath.Join(ssaDir, fname)
+ }
+
fi, err := os.Create(fname)
if err != nil {
f.Warnl(src.NoXPos, "Unable to create after-phase dump file %s", fname)
- return
+ return nil
}
+ return fi
+}
- p := stringFuncPrinter{w: fi}
- fprintFunc(p, f)
- fi.Close()
+// dumpFile creates a file from the phase name and function name
+// Dumping is done to files to avoid buffering huge strings before
+// output.
+func (f *Func) dumpFile(phaseName string) {
+ fi := f.DumpFileForPhase(phaseName)
+ if fi != nil {
+ p := stringFuncPrinter{w: fi}
+ fprintFunc(p, f)
+ fi.Close()
+ }
}
type pass struct {
@@ -224,7 +238,9 @@
var BuildDebug int
var BuildTest int
var BuildStats int
-var BuildDump string // name of function to dump after initial build of ssa
+var BuildDump map[string]bool = make(map[string]bool) // names of functions to dump after initial build of ssa
+
+var GenssaDump map[string]bool = make(map[string]bool) // names of functions to dump after ssa has been converted to asm
// PhaseOption sets the specified flag in the specified ssa phase,
// returning empty string if this was successful or a string explaining
@@ -248,7 +264,7 @@
switch phase {
case "", "help":
lastcr := 0
- phasenames := " check, all, build, intrinsics"
+ phasenames := " check, all, build, intrinsics, genssa"
for _, p := range passes {
pn := strings.Replace(p.name, " ", "_", -1)
if len(pn)+len(phasenames)-lastcr > 70 {
@@ -278,6 +294,7 @@
Phase "all" supports flags "time", "mem", and "dump".
Phase "intrinsics" supports flags "on", "off", and "debug".
+Phase "genssa" (assembly generation) supports the flag "dump".
If the "dump" flag is specified, the output is written on a file named
<phase>__<function_name>_<seq>.dump; otherwise it is directed to stdout.
@@ -339,10 +356,11 @@
case "dump":
alldump = val != 0
if alldump {
- BuildDump = valString
+ BuildDump[valString] = true
+ GenssaDump[valString] = true
}
default:
- return fmt.Sprintf("Did not find a flag matching %s in -d=ssa/%s debug option", flag, phase)
+ return fmt.Sprintf("Did not find a flag matching %s in -d=ssa/%s debug option (expected ssa/all/{time,mem,dump=function_name})", flag, phase)
}
}
@@ -355,7 +373,7 @@
case "debug":
IntrinsicsDebug = val
default:
- return fmt.Sprintf("Did not find a flag matching %s in -d=ssa/%s debug option", flag, phase)
+ return fmt.Sprintf("Did not find a flag matching %s in -d=ssa/%s debug option (expected ssa/intrinsics/{on,off,debug})", flag, phase)
}
return ""
}
@@ -368,9 +386,18 @@
case "stats":
BuildStats = val
case "dump":
- BuildDump = valString
+ BuildDump[valString] = true
default:
- return fmt.Sprintf("Did not find a flag matching %s in -d=ssa/%s debug option", flag, phase)
+ return fmt.Sprintf("Did not find a flag matching %s in -d=ssa/%s debug option (expected ssa/build/{debug,test,stats,dump=function_name})", flag, phase)
+ }
+ return ""
+ }
+ if phase == "genssa" {
+ switch flag {
+ case "dump":
+ GenssaDump[valString] = true
+ default:
+ return fmt.Sprintf("Did not find a flag matching %s in -d=ssa/%s debug option (expected ssa/genssa/dump=function_name)", flag, phase)
}
return ""
}
diff --git a/src/cmd/compile/internal/ssa/debug_lines_test.go b/src/cmd/compile/internal/ssa/debug_lines_test.go
new file mode 100644
index 0000000..c5a0fe4
--- /dev/null
+++ b/src/cmd/compile/internal/ssa/debug_lines_test.go
@@ -0,0 +1,213 @@
+// Copyright 2021 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 ssa_test
+
+import (
+ "bufio"
+ "bytes"
+ "flag"
+ "runtime"
+ "sort"
+
+ // "flag"
+ "fmt"
+ "internal/testenv"
+ "io/ioutil"
+ "os"
+ "os/exec"
+ "path/filepath"
+ "reflect"
+ "regexp"
+ "strconv"
+ "testing"
+)
+
+// Matches lines in genssa output that are marked "isstmt", and the parenthesized plus-prefixed line number is a submatch
+var asmLine *regexp.Regexp = regexp.MustCompile(`^\s[vb][0-9]+\s+[0-9]+\s\(\+([0-9]+)\)`)
+
+// this matches e.g. ` v123456789 000007 (+9876654310) MOVUPS X15, ""..autotmp_2-32(SP)`
+
+// Matches lines in genssa output that describe an inlined file (on a Unix filesystem). Note it expects an unadventurous choice of basename.
+var inlineLine *regexp.Regexp = regexp.MustCompile(`^#\s/.*/[-a-zA-Z0-9_]+\.go:([0-9]+)`)
+
+// this matches e.g. # /pa/inline-dumpxxxx.go:6
+
+var testGoArchFlag = flag.String("arch", "", "run test for specified architecture")
+
+func testGoArch() string {
+ if *testGoArchFlag == "" {
+ return runtime.GOARCH
+ }
+ return *testGoArchFlag
+}
+
+func TestDebugLines(t *testing.T) {
+ if runtime.GOOS == "windows" {
+ t.Skip("Windows lacks $HOME which complicates workaround for 'missing $GOPATH'") // $HOME needed to work around #43938
+ }
+ // This test is potentially fragile, the goal is that debugging should step properly through "sayhi"
+ // If the blocks are reordered in a way that changes the statement order but execution flows correctly,
+ // then rearrange the expected numbers. Register abi and not-register-abi also have different sequences,
+ // at least for now.
+
+ switch testGoArch() {
+ case "arm64", "amd64": // register ABI
+ testDebugLines(t, "sayhi.go", "sayhi", []int{8, 9, 10, 11})
+
+ case "arm", "386": // probably not register ABI for a while
+ testDebugLines(t, "sayhi.go", "sayhi", []int{9, 10, 11})
+
+ default: // expect ppc64le and riscv will pick up register ABI soonish, not sure about others
+ t.Skip("skipped for many architectures, also changes w/ register ABI")
+ }
+}
+
+func TestInlineLines(t *testing.T) {
+ if runtime.GOOS == "windows" {
+ t.Skip("Windows lacks $HOME which complicates workaround for 'missing $GOPATH'") // $HOME needed to work around #43938
+ }
+ if runtime.GOARCH != "amd64" && *testGoArchFlag == "" {
+ // As of september 2021, works for everything except mips64, but still potentially fragile
+ t.Skip("only runs for amd64 unless -arch explicitly supplied")
+ }
+
+ want := [][]int{{3}, {4, 10}, {4, 10, 16}, {4, 10}, {4, 11, 16}, {4, 11}, {4}, {5, 10}, {5, 10, 16}, {5, 10}, {5, 11, 16}, {5, 11}, {5}}
+ testInlineStack(t, "inline-dump.go", "f", want)
+}
+
+func compileAndDump(t *testing.T, file, function, moreGCFlags string) []byte {
+ testenv.MustHaveGoBuild(t)
+
+ tmpdir, err := ioutil.TempDir("", "debug_lines_test")
+ if err != nil {
+ panic(fmt.Sprintf("Problem creating TempDir, error %v", err))
+ }
+ if testing.Verbose() {
+ fmt.Printf("Preserving temporary directory %s\n", tmpdir)
+ } else {
+ defer os.RemoveAll(tmpdir)
+ }
+
+ source, err := filepath.Abs(filepath.Join("testdata", file))
+ if err != nil {
+ panic(fmt.Sprintf("Could not get abspath of testdata directory and file, %v", err))
+ }
+
+ cmd := exec.Command(testenv.GoToolPath(t), "build", "-o", "foo.o", "-gcflags=-d=ssa/genssa/dump="+function+" "+moreGCFlags, source)
+ cmd.Dir = tmpdir
+ cmd.Env = replaceEnv(cmd.Env, "GOSSADIR", tmpdir)
+ cmd.Env = replaceEnv(cmd.Env, "HOME", os.Getenv("HOME")) // workaround for #43938
+ testGoos := "linux" // default to linux
+ if testGoArch() == "wasm" {
+ testGoos = "js"
+ }
+ cmd.Env = replaceEnv(cmd.Env, "GOOS", testGoos)
+ cmd.Env = replaceEnv(cmd.Env, "GOARCH", testGoArch())
+
+ if testing.Verbose() {
+ fmt.Printf("About to run %s\n", asCommandLine("", cmd))
+ }
+
+ var stdout, stderr bytes.Buffer
+ cmd.Stdout = &stdout
+ cmd.Stderr = &stderr
+
+ if err := cmd.Run(); err != nil {
+ t.Fatalf("error running cmd %s: %v\nstdout:\n%sstderr:\n%s\n", asCommandLine("", cmd), err, stdout.String(), stderr.String())
+ }
+
+ if s := stderr.String(); s != "" {
+ t.Fatalf("Wanted empty stderr, instead got:\n%s\n", s)
+ }
+
+ dumpFile := filepath.Join(tmpdir, function+"_01__genssa.dump")
+ dumpBytes, err := os.ReadFile(dumpFile)
+ if err != nil {
+ t.Fatalf("Could not read dump file %s, err=%v", dumpFile, err)
+ }
+ return dumpBytes
+}
+
+func sortInlineStacks(x [][]int) {
+ sort.Slice(x, func(i, j int) bool {
+ if len(x[i]) != len(x[j]) {
+ return len(x[i]) < len(x[j])
+ }
+ for k := range x[i] {
+ if x[i][k] != x[j][k] {
+ return x[i][k] < x[j][k]
+ }
+ }
+ return false
+ })
+}
+
+// testInlineStack ensures that inlining is described properly in the comments in the dump file
+func testInlineStack(t *testing.T, file, function string, wantStacks [][]int) {
+ // this is an inlining reporting test, not an optimization test. -N makes it less fragile
+ dumpBytes := compileAndDump(t, file, function, "-N")
+ dump := bufio.NewScanner(bytes.NewReader(dumpBytes))
+ dumpLineNum := 0
+ var gotStmts []int
+ var gotStacks [][]int
+ for dump.Scan() {
+ line := dump.Text()
+ dumpLineNum++
+ matches := inlineLine.FindStringSubmatch(line)
+ if len(matches) == 2 {
+ stmt, err := strconv.ParseInt(matches[1], 10, 32)
+ if err != nil {
+ t.Fatalf("Expected to parse a line number but saw %s instead on dump line #%d, error %v", matches[1], dumpLineNum, err)
+ }
+ if testing.Verbose() {
+ fmt.Printf("Saw stmt# %d for submatch '%s' on dump line #%d = '%s'\n", stmt, matches[1], dumpLineNum, line)
+ }
+ gotStmts = append(gotStmts, int(stmt))
+ } else if len(gotStmts) > 0 {
+ gotStacks = append(gotStacks, gotStmts)
+ gotStmts = nil
+ }
+ }
+ if len(gotStmts) > 0 {
+ gotStacks = append(gotStacks, gotStmts)
+ gotStmts = nil
+ }
+ sortInlineStacks(gotStacks)
+ sortInlineStacks(wantStacks)
+ if !reflect.DeepEqual(wantStacks, gotStacks) {
+ t.Errorf("wanted inlines %+v but got %+v", wantStacks, gotStacks)
+ }
+
+}
+
+// testDebugLines compiles testdata/<file> with flags -N -l and -d=ssa/genssa/dump=<function>
+// then verifies that the statement-marked lines in that file are the same as those in wantStmts
+// These files must all be short because this is super-fragile.
+// "go build" is run in a temporary directory that is normally deleted, unless -test.v
+func testDebugLines(t *testing.T, file, function string, wantStmts []int) {
+ dumpBytes := compileAndDump(t, file, function, "-N -l")
+ dump := bufio.NewScanner(bytes.NewReader(dumpBytes))
+ var gotStmts []int
+ dumpLineNum := 0
+ for dump.Scan() {
+ line := dump.Text()
+ dumpLineNum++
+ matches := asmLine.FindStringSubmatch(line)
+ if len(matches) == 2 {
+ stmt, err := strconv.ParseInt(matches[1], 10, 32)
+ if err != nil {
+ t.Fatalf("Expected to parse a line number but saw %s instead on dump line #%d, error %v", matches[1], dumpLineNum, err)
+ }
+ if testing.Verbose() {
+ fmt.Printf("Saw stmt# %d for submatch '%s' on dump line #%d = '%s'\n", stmt, matches[1], dumpLineNum, line)
+ }
+ gotStmts = append(gotStmts, int(stmt))
+ }
+ }
+ if !reflect.DeepEqual(wantStmts, gotStmts) {
+ t.Errorf("wanted stmts %v but got %v", wantStmts, gotStmts)
+ }
+
+}
diff --git a/src/cmd/compile/internal/ssa/func.go b/src/cmd/compile/internal/ssa/func.go
index fac876c..7728a39 100644
--- a/src/cmd/compile/internal/ssa/func.go
+++ b/src/cmd/compile/internal/ssa/func.go
@@ -43,7 +43,7 @@
logfiles map[string]writeSyncer
HTMLWriter *HTMLWriter // html writer, for debugging
DebugTest bool // default true unless $GOSSAHASH != ""; as a debugging aid, make new code conditional on this and use GOSSAHASH to binary search for failing cases
- PrintOrHtmlSSA bool // true if GOSSAFUNC matches, true even if fe.Log() (spew phase results to stdout) is false.
+ PrintOrHtmlSSA bool // true if GOSSAFUNC matches, true even if fe.Log() (spew phase results to stdout) is false. There's an odd dependence on this in debug.go for method logf.
ruleMatches map[string]int // number of times countRule was called during compilation for any given string
ABI0 *abi.ABIConfig // A copy, for no-sync access
ABI1 *abi.ABIConfig // A copy, for no-sync access
diff --git a/src/cmd/compile/internal/ssa/print.go b/src/cmd/compile/internal/ssa/print.go
index 81c64a7..96cd2c7 100644
--- a/src/cmd/compile/internal/ssa/print.go
+++ b/src/cmd/compile/internal/ssa/print.go
@@ -6,6 +6,7 @@
import (
"bytes"
+ "cmd/internal/src"
"crypto/sha256"
"fmt"
"io"
@@ -83,13 +84,26 @@
fmt.Fprintln(p.w, " "+b.LongString())
}
+func StmtString(p src.XPos) string {
+ linenumber := "(?) "
+ if p.IsKnown() {
+ pfx := ""
+ if p.IsStmt() == src.PosIsStmt {
+ pfx = "+"
+ }
+ if p.IsStmt() == src.PosNotStmt {
+ pfx = "-"
+ }
+ linenumber = fmt.Sprintf("(%s%d) ", pfx, p.Line())
+ }
+ return linenumber
+}
+
func (p stringFuncPrinter) value(v *Value, live bool) {
if !p.printDead && !live {
return
}
- fmt.Fprint(p.w, " ")
- //fmt.Fprint(p.w, v.Block.Func.fe.Pos(v.Pos))
- //fmt.Fprint(p.w, ": ")
+ fmt.Fprintf(p.w, " %s", StmtString(v.Pos))
fmt.Fprint(p.w, v.LongString())
if !live {
fmt.Fprint(p.w, " DEAD")
diff --git a/src/cmd/compile/internal/ssa/testdata/inline-dump.go b/src/cmd/compile/internal/ssa/testdata/inline-dump.go
new file mode 100644
index 0000000..97893b6
--- /dev/null
+++ b/src/cmd/compile/internal/ssa/testdata/inline-dump.go
@@ -0,0 +1,17 @@
+package foo
+
+func f(m, n int) int {
+ a := g(n)
+ b := g(m)
+ return a + b
+}
+
+func g(x int) int {
+ y := h(x + 1)
+ z := h(x - 1)
+ return y + z
+}
+
+func h(x int) int {
+ return x * x
+}
diff --git a/src/cmd/compile/internal/ssa/testdata/sayhi.go b/src/cmd/compile/internal/ssa/testdata/sayhi.go
new file mode 100644
index 0000000..680e1eb
--- /dev/null
+++ b/src/cmd/compile/internal/ssa/testdata/sayhi.go
@@ -0,0 +1,12 @@
+package foo
+
+import (
+ "fmt"
+ "sync"
+)
+
+func sayhi(n int, wg *sync.WaitGroup) {
+ fmt.Println("hi", n)
+ fmt.Println("hi", n)
+ wg.Done()
+}
diff --git a/src/cmd/compile/internal/ssagen/ssa.go b/src/cmd/compile/internal/ssagen/ssa.go
index 08f36ce..82d232f 100644
--- a/src/cmd/compile/internal/ssagen/ssa.go
+++ b/src/cmd/compile/internal/ssagen/ssa.go
@@ -6703,7 +6703,8 @@
var progToValue map[*obj.Prog]*ssa.Value
var progToBlock map[*obj.Prog]*ssa.Block
var valueToProgAfter []*obj.Prog // The first Prog following computation of a value v; v is visible at this point.
- if f.PrintOrHtmlSSA {
+ gatherPrintInfo := f.PrintOrHtmlSSA || ssa.GenssaDump[f.Name]
+ if gatherPrintInfo {
progToValue = make(map[*obj.Prog]*ssa.Value, f.NumValues())
progToBlock = make(map[*obj.Prog]*ssa.Block, f.NumBlocks())
f.Logf("genssa %s\n", f.Name)
@@ -6814,7 +6815,7 @@
valueToProgAfter[v.ID] = s.pp.Next
}
- if f.PrintOrHtmlSSA {
+ if gatherPrintInfo {
for ; x != s.pp.Next; x = x.Link {
progToValue[x] = v
}
@@ -6844,7 +6845,7 @@
x := s.pp.Next
s.SetPos(b.Pos)
Arch.SSAGenBlock(&s, b, next)
- if f.PrintOrHtmlSSA {
+ if gatherPrintInfo {
for ; x != s.pp.Next; x = x.Link {
progToBlock[x] = b
}
@@ -7023,6 +7024,54 @@
buf.WriteString("</code>")
f.HTMLWriter.WriteColumn("genssa", "genssa", "ssa-prog", buf.String())
}
+ if ssa.GenssaDump[f.Name] {
+ fi := f.DumpFileForPhase("genssa")
+ if fi != nil {
+
+ // inliningDiffers if any filename changes or if any line number except the innermost (index 0) changes.
+ inliningDiffers := func(a, b []src.Pos) bool {
+ if len(a) != len(b) {
+ return true
+ }
+ for i := range a {
+ if a[i].Filename() != b[i].Filename() {
+ return true
+ }
+ if i > 0 && a[i].Line() != b[i].Line() {
+ return true
+ }
+ }
+ return false
+ }
+
+ var allPosOld []src.Pos
+ var allPos []src.Pos
+
+ for p := pp.Text; p != nil; p = p.Link {
+ if p.Pos.IsKnown() {
+ allPos = p.AllPos(allPos)
+ if inliningDiffers(allPos, allPosOld) {
+ for i := len(allPos) - 1; i >= 0; i-- {
+ pos := allPos[i]
+ fmt.Fprintf(fi, "# %s:%d\n", pos.Filename(), pos.Line())
+ }
+ allPos, allPosOld = allPosOld, allPos // swap, not copy, so that they do not share slice storage.
+ }
+ }
+
+ var s string
+ if v, ok := progToValue[p]; ok {
+ s = v.String()
+ } else if b, ok := progToBlock[p]; ok {
+ s = b.String()
+ } else {
+ s = " " // most value and branch strings are 2-3 characters long
+ }
+ fmt.Fprintf(fi, " %-6s\t%.5d %s\t%s\n", s, p.Pc, ssa.StmtString(p.Pos), p.InstructionString())
+ }
+ fi.Close()
+ }
+ }
defframe(&s, e, f)
diff --git a/src/cmd/internal/obj/util.go b/src/cmd/internal/obj/util.go
index e8441a6..0c9dde7 100644
--- a/src/cmd/internal/obj/util.go
+++ b/src/cmd/internal/obj/util.go
@@ -7,6 +7,7 @@
import (
"bytes"
"cmd/internal/objabi"
+ "cmd/internal/src"
"fmt"
"internal/buildcfg"
"io"
@@ -47,6 +48,10 @@
return pos.Filename()
}
+func (p *Prog) AllPos(result []src.Pos) []src.Pos {
+ return p.Ctxt.AllPos(p.Pos, result)
+}
+
var armCondCode = []string{
".EQ",
".NE",
