blob: f5974e12ba5d600836d37acc6cccc2259fa80501 [file] [log] [blame]
// Copyright 2015 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 main
import (
"bufio"
"bytes"
"fmt"
"io"
"log"
"os"
"regexp"
"strconv"
"strings"
)
var (
hexDumpRE = regexp.MustCompile(`^\t(0x[0-9a-f]{4,})(( ([0-9a-f]{2}| )){16}) [ -\x7F]{1,16}\n`)
listingRE = regexp.MustCompile(`^\t(0x[0-9a-f]{4,}) ([0-9]{4,}) \(.*:[0-9]+\)\t`)
)
// okdiffs lists regular expressions for lines to consider minor mismatches.
// If one of these regexps matches both of a pair of unequal lines, the mismatch
// is reported but not treated as the one worth looking for.
// For example, differences in the TEXT line are typically frame size
// changes due to optimization decisions made in the body of the function.
// Better to keep looking for the actual difference.
// Similarly, forward jumps might have different offsets due to a
// change in instruction encoding later on.
// Better to find that change.
var okdiffs = []*regexp.Regexp{
regexp.MustCompile(`\) TEXT[ ].*,\$`),
regexp.MustCompile(`\) WORD[ ].*,\$`),
regexp.MustCompile(`\) (B|BR|JMP) `),
regexp.MustCompile(`\) FUNCDATA `),
regexp.MustCompile(`\\(z|x00)`),
regexp.MustCompile(`\$\([0-9]\.[0-9]+e[+\-][0-9]+\)`),
regexp.MustCompile(`size=.*value=.*args=.*locals=`),
}
func compareLogs(outfile string) string {
f1, err := os.Open(outfile + ".log")
if err != nil {
log.Fatal(err)
}
defer f1.Close()
f2, err := os.Open(outfile + ".stash.log")
if err != nil {
log.Fatal(err)
}
defer f2.Close()
b1 := bufio.NewReader(f1)
b2 := bufio.NewReader(f2)
offset := int64(0)
textOffset := offset
textLineno := 0
lineno := 0
var line1, line2 string
var prefix bytes.Buffer
Reading:
for {
var err1, err2 error
line1, err1 = b1.ReadString('\n')
line2, err2 = b2.ReadString('\n')
if strings.Contains(line1, ")\tTEXT\t") {
textOffset = offset
textLineno = lineno
}
offset += int64(len(line1))
lineno++
if err1 == io.EOF && err2 == io.EOF {
return "no differences in debugging output"
}
if lineno == 1 || line1 == line2 && err1 == nil && err2 == nil {
continue
}
// Lines are inconsistent. Worth stopping?
for _, re := range okdiffs {
if re.MatchString(line1) && re.MatchString(line2) {
fmt.Fprintf(&prefix, "inconsistent log line:\n%s:%d:\n\t%s\n%s:%d:\n\t%s\n\n",
f1.Name(), lineno, strings.TrimSuffix(line1, "\n"),
f2.Name(), lineno, strings.TrimSuffix(line2, "\n"))
continue Reading
}
}
if err1 != nil {
line1 = err1.Error()
}
if err2 != nil {
line2 = err2.Error()
}
break
}
msg := fmt.Sprintf("inconsistent log line:\n%s:%d:\n\t%s\n%s:%d:\n\t%s",
f1.Name(), lineno, strings.TrimSuffix(line1, "\n"),
f2.Name(), lineno, strings.TrimSuffix(line2, "\n"))
if m := hexDumpRE.FindStringSubmatch(line1); m != nil {
target, err := strconv.ParseUint(m[1], 0, 64)
if err != nil {
goto Skip
}
m2 := hexDumpRE.FindStringSubmatch(line2)
if m2 == nil {
goto Skip
}
fields1 := strings.Fields(m[2])
fields2 := strings.Fields(m2[2])
i := 0
for i < len(fields1) && i < len(fields2) && fields1[i] == fields2[i] {
i++
}
target += uint64(i)
f1.Seek(textOffset, 0)
b1 = bufio.NewReader(f1)
last := ""
lineno := textLineno
limitAddr := uint64(0)
lastAddr := uint64(0)
for {
line1, err1 := b1.ReadString('\n')
if err1 != nil {
break
}
lineno++
if m := listingRE.FindStringSubmatch(line1); m != nil {
addr, _ := strconv.ParseUint(m[1], 0, 64)
if addr > target {
limitAddr = addr
break
}
last = line1
lastAddr = addr
} else if hexDumpRE.FindStringSubmatch(line1) != nil {
break
}
}
if last != "" {
msg = fmt.Sprintf("assembly instruction at %#04x-%#04x:\n%s:%d\n\t%s\n\n%s",
lastAddr, limitAddr, f1.Name(), lineno-1, strings.TrimSuffix(last, "\n"), msg)
}
}
Skip:
return prefix.String() + msg
}