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runtime: repair slice, string, and channel printing in gdb
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"Something" changed the names of types in gdb, causing the
pretty-printer matchers to fail to match.  This tracks that
change.

Updated runtime-gdb_test.go to include a slice and a channel printing test.

(The straightforward printing of a slicevar doesn't work because
of compiler DWARF problems describing the slicevar, not gdb problems).

Change-Id: I21607a955b9c894f11ecf3763aea2a6dd59a3f42
Reviewed-on: https://go-review.googlesource.com/c/go/+/235926
Run-TryBot: David Chase <[email protected]>
TryBot-Result: Gobot Gobot <[email protected]>
Reviewed-by: Than McIntosh <[email protected]>
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@dr2chase
dr2chase committed Jun 2, 2020
1 parent 1193958 commit ee776b4
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Showing 2 changed files with 60 additions and 14 deletions.
19 changes: 12 additions & 7 deletions src/runtime/runtime-gdb.py
View file
Original file line number Diff line number Diff line change
Expand Up @@ -18,6 +18,7 @@
from __future__ import print_function
import re
import sys
import gdb

print("Loading Go Runtime support.", file=sys.stderr)
#http://python3porting.com/differences.html
Expand All @@ -27,6 +28,12 @@
goobjfile = gdb.current_objfile() or gdb.objfiles()[0]
goobjfile.pretty_printers = []

# Older gdb renders some types differently.
def oldnew(old, new):
if (gdb.VERSION[0] == '7'):
return old
return new

# G state (runtime2.go)

def read_runtime_const(varname, default):
Expand Down Expand Up @@ -102,7 +109,7 @@ def __getitem__(self, i):
class StringTypePrinter:
"Pretty print Go strings."

pattern = re.compile(r'^struct string( \*)?$')
pattern = re.compile(oldnew(r'^struct string( \*)?$',r'^string$'))

def __init__(self, val):
self.val = val
Expand All @@ -118,7 +125,7 @@ def to_string(self):
class SliceTypePrinter:
"Pretty print slices."

pattern = re.compile(r'^struct \[\]')
pattern = re.compile(oldnew(r'^struct \[\]',r'^\[\]'))

def __init__(self, val):
self.val = val
Expand All @@ -127,7 +134,7 @@ def display_hint(self):
return 'array'

def to_string(self):
return str(self.val.type)[6:] # skip 'struct '
return str(self.val.type)[oldnew(6,0):] # skip 'struct ' for old gdb

def children(self):
sval = SliceValue(self.val)
Expand Down Expand Up @@ -195,7 +202,7 @@ class ChanTypePrinter:
to inspect their contents with this pretty printer.
"""

pattern = re.compile(r'^struct hchan<.*>$')
pattern = re.compile(oldnew(r'^struct hchan<.*>$',r'^chan '))

def __init__(self, val):
self.val = val
Expand All @@ -209,7 +216,7 @@ def to_string(self):
def children(self):
# see chan.c chanbuf(). et is the type stolen from hchan<T>::recvq->first->elem
et = [x.type for x in self.val['recvq']['first'].type.target().fields() if x.name == 'elem'][0]
ptr = (self.val.address + 1).cast(et.pointer())
ptr = (self.val.address["buf"]).cast(et)
for i in range(self.val["qcount"]):
j = (self.val["recvx"] + i) % self.val["dataqsiz"]
yield ('[{0}]'.format(i), (ptr + j).dereference())
Expand All @@ -229,8 +236,6 @@ def matcher(val):
return matcher

goobjfile.pretty_printers.extend([makematcher(var) for var in vars().values() if hasattr(var, 'pattern')])


#
# Utilities
#
Expand Down
55 changes: 48 additions & 7 deletions src/runtime/runtime-gdb_test.go
View file
Original file line number Diff line number Diff line change
Expand Up @@ -55,7 +55,9 @@ func checkGdbEnvironment(t *testing.T) {
}
}

func checkGdbVersion(t *testing.T) {
// checkGdbVersion ensures gdb version is supported, and returns major version
// to allow testing conditional on gdb version.
func checkGdbVersion(t *testing.T) int {
// Issue 11214 reports various failures with older versions of gdb.
out, err := exec.Command("gdb", "--version").CombinedOutput()
if err != nil {
Expand All @@ -75,6 +77,7 @@ func checkGdbVersion(t *testing.T) {
t.Skipf("skipping: gdb version %d.%d too old", major, minor)
}
t.Logf("gdb version %d.%d", major, minor)
return major
}

func checkGdbPython(t *testing.T) {
Expand Down Expand Up @@ -115,8 +118,17 @@ import "runtime"
var gslice []string
func main() {
mapvar := make(map[string]string, 13)
slicemap := make(map[string][]string,11)
chanint := make(chan int, 10)
chanstr := make(chan string, 10)
chanint <- 99
chanint <- 11
chanstr <- "spongepants"
chanstr <- "squarebob"
mapvar["abc"] = "def"
mapvar["ghi"] = "jkl"
slicemap["a"] = []string{"b","c","d"}
slicemap["e"] = []string{"f","g","h"}
strvar := "abc"
ptrvar := &strvar
slicevar := make([]string, 0, 16)
Expand All @@ -125,6 +137,7 @@ func main() {
runtime.KeepAlive(ptrvar)
_ = ptrvar // set breakpoint here
gslice = slicevar
fmt.Printf("%v, %v, %v\n", slicemap, <-chanint, <-chanstr)
runtime.KeepAlive(mapvar)
} // END_OF_PROGRAM
`
Expand Down Expand Up @@ -157,7 +170,7 @@ func testGdbPython(t *testing.T, cgo bool) {

checkGdbEnvironment(t)
t.Parallel()
checkGdbVersion(t)
gdbMajor := checkGdbVersion(t)
checkGdbPython(t)

dir, err := ioutil.TempDir("", "go-build")
Expand Down Expand Up @@ -227,9 +240,18 @@ func testGdbPython(t *testing.T, cgo bool) {
"-ex", "echo BEGIN print mapvar\n",
"-ex", "print mapvar",
"-ex", "echo END\n",
"-ex", "echo BEGIN print slicemap\n",
"-ex", "print slicemap",
"-ex", "echo END\n",
"-ex", "echo BEGIN print strvar\n",
"-ex", "print strvar",
"-ex", "echo END\n",
"-ex", "echo BEGIN print chanint\n",
"-ex", "print chanint",
"-ex", "echo END\n",
"-ex", "echo BEGIN print chanstr\n",
"-ex", "print chanstr",
"-ex", "echo END\n",
"-ex", "echo BEGIN info locals\n",
"-ex", "info locals",
"-ex", "echo END\n",
Expand Down Expand Up @@ -290,6 +312,25 @@ func testGdbPython(t *testing.T, cgo bool) {
t.Fatalf("print mapvar failed: %s", bl)
}

// 2 orders, and possible differences in spacing.
sliceMapSfx1 := `map[string][]string = {["e"] = []string = {"f", "g", "h"}, ["a"] = []string = {"b", "c", "d"}}`
sliceMapSfx2 := `map[string][]string = {["a"] = []string = {"b", "c", "d"}, ["e"] = []string = {"f", "g", "h"}}`
if bl := strings.ReplaceAll(blocks["print slicemap"], " ", " "); !strings.HasSuffix(bl, sliceMapSfx1) && !strings.HasSuffix(bl, sliceMapSfx2) {
t.Fatalf("print slicemap failed: %s", bl)
}

if gdbMajor > 7 {
chanIntSfx := `chan int = {99, 11}`
if bl := strings.ReplaceAll(blocks["print chanint"], " ", " "); !strings.HasSuffix(bl, chanIntSfx) {
t.Fatalf("print chanint failed: %s", bl)
}

chanStrSfx := `chan string = {"spongepants", "squarebob"}`
if bl := strings.ReplaceAll(blocks["print chanstr"], " ", " "); !strings.HasSuffix(bl, chanStrSfx) {
t.Fatalf("print chanstr failed: %s", bl)
}
}

strVarRe := regexp.MustCompile(`^\$[0-9]+ = (0x[0-9a-f]+\s+)?"abc"$`)
if bl := blocks["print strvar"]; !strVarRe.MatchString(bl) {
t.Fatalf("print strvar failed: %s", bl)
Expand Down Expand Up @@ -366,7 +407,7 @@ func TestGdbBacktrace(t *testing.T) {

checkGdbEnvironment(t)
t.Parallel()
checkGdbVersion(t)
_ = checkGdbVersion(t)

dir, err := ioutil.TempDir("", "go-build")
if err != nil {
Expand Down Expand Up @@ -440,7 +481,7 @@ func main() {
func TestGdbAutotmpTypes(t *testing.T) {
checkGdbEnvironment(t)
t.Parallel()
checkGdbVersion(t)
_ = checkGdbVersion(t)

if runtime.GOOS == "aix" && testing.Short() {
t.Skip("TestGdbAutotmpTypes is too slow on aix/ppc64")
Expand Down Expand Up @@ -513,7 +554,7 @@ func main() {
func TestGdbConst(t *testing.T) {
checkGdbEnvironment(t)
t.Parallel()
checkGdbVersion(t)
_ = checkGdbVersion(t)

dir, err := ioutil.TempDir("", "go-build")
if err != nil {
Expand Down Expand Up @@ -580,7 +621,7 @@ func crash() {
func TestGdbPanic(t *testing.T) {
checkGdbEnvironment(t)
t.Parallel()
checkGdbVersion(t)
_ = checkGdbVersion(t)

dir, err := ioutil.TempDir("", "go-build")
if err != nil {
Expand Down Expand Up @@ -658,7 +699,7 @@ func TestGdbInfCallstack(t *testing.T) {
}

t.Parallel()
checkGdbVersion(t)
_ = checkGdbVersion(t)

dir, err := ioutil.TempDir("", "go-build")
if err != nil {
Expand Down

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