code review 7746045: runtime: fix gdb printing of maps

runtime: fix gdb printing of maps
Fixes issue 5098

[khr, 2013-03-22 16:11:50]

Hello minux.ma@gmail.com (cc: golang-dev@googlegroups.com),

I'd like you to review this change to
https://code.google.com/p/go/

[bradfitz, 2013-03-22 16:14:08]

Is the hashmap.c change unrelated?

On Fri, Mar 22, 2013 at 9:11 AM, <khr@golang.org> wrote:

> Reviewers: minux,
>
> Message:
> Hello minux.ma@gmail.com (cc: golang-dev@googlegroups.com),
>
> I'd like you to review this change to
> https://code.google.com/p/go/
>
>
> Description:
> runtime: fix gdb printing of maps
> Fixes issue 5098
>
> Please review this at
https://codereview.appspot.**com/7746045/<https://codereview.appspot.com/7746...
>
> Affected files:
>   M src/cmd/ld/dwarf.c
>   M src/pkg/runtime/hashmap.c
>   M src/pkg/runtime/runtime-gdb.py
>
>
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>
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>

[khr1, 2013-03-22 16:16:32]

It's not unrelated...  It's kind of a bug but had no practical impact
before this change.  But it must be in sync with the new code, so it had to
be fixed.


On Fri, Mar 22, 2013 at 9:14 AM, Brad Fitzpatrick <bradfitz@golang.org>wrote:

> Is the hashmap.c change unrelated?
>
> On Fri, Mar 22, 2013 at 9:11 AM, <khr@golang.org> wrote:
>
>> Reviewers: minux,
>>
>> Message:
>> Hello minux.ma@gmail.com (cc: golang-dev@googlegroups.com),
>>
>> I'd like you to review this change to
>> https://code.google.com/p/go/
>>
>>
>> Description:
>> runtime: fix gdb printing of maps
>> Fixes issue 5098
>>
>> Please review this at
https://codereview.appspot.**com/7746045/<https://codereview.appspot.com/7746...
>>
>> Affected files:
>>   M src/cmd/ld/dwarf.c
>>   M src/pkg/runtime/hashmap.c
>>   M src/pkg/runtime/runtime-gdb.py
>>
>>
>>
>> --
>>
>> ---You received this message because you are subscribed to the Google
>> Groups "golang-dev" group.
>> To unsubscribe from this group and stop receiving emails from it, send an
>> email to
golang-dev+unsubscribe@**googlegroups.com<golang-dev%2Bunsubscribe@googlegrou...
>> .
>> For more options, visit
https://groups.google.com/**groups/opt_out<https://groups.google.com/groups/o...
>> .
>>
>>
>>
>

[rsc, 2013-03-22 16:54:38]

LGTM

Thanks.

[minux1, 2013-03-22 19:16:02]

I got this when i tried out this CL with gdb 7.3 on Darwin/amd64:

(gdb) b 'main.main'
Breakpoint 1 at 0x2000: file /Users/minux/go/go2.hg/src/map.go, line 7.
(gdb) source pkg/runtime/runtime-gdb.py
Loading Go Runtime support.
(gdb) r
Starting program: /Users/minux/go/go2.hg/src/map
[New Thread 0x1903 of process 87477]

Breakpoint 1, main.main () at /Users/minux/go/go2.hg/src/map.go:7
7	func main() {
(gdb) p 'main.M'
$1 = (map[string]int) 0x0
(gdb) n
8		M = make(map[string]int)
(gdb) p 'main.M'
$2 = (map[string]int) 0x0
(gdb) p *'main.M'
$3 = struct hash<string,int><error reading variable: Cannot access
memory at address 0x2000155bd>
(gdb) n
9		M["a"] = 1
(gdb) p *'main.M'
$4 = struct hash<string,int><error reading variable: Cannot access
memory at address 0xa>
(gdb) n
10		fmt.Println(M)
(gdb) p *'main.M'
$5 = struct hash<string,int><error reading variable: Cannot access
memory at address 0x3937393336333108>
(gdb) n
map[a:1]
11	}

[khr1, 2013-03-22 20:24:48]

Sorry, looks like I cleaned up one too many lines of testing code.  Try now.


On Fri, Mar 22, 2013 at 12:15 PM, minux <minux.ma@gmail.com> wrote:

> I got this when i tried out this CL with gdb 7.3 on Darwin/amd64:
>
> (gdb) b 'main.main'
> Breakpoint 1 at 0x2000: file /Users/minux/go/go2.hg/src/map.go, line 7.
> (gdb) source pkg/runtime/runtime-gdb.py
> Loading Go Runtime support.
> (gdb) r
> Starting program: /Users/minux/go/go2.hg/src/map
> [New Thread 0x1903 of process 87477]
>
> Breakpoint 1, main.main () at /Users/minux/go/go2.hg/src/map.go:7
> 7       func main() {
> (gdb) p 'main.M'
> $1 = (map[string]int) 0x0
> (gdb) n
> 8               M = make(map[string]int)
> (gdb) p 'main.M'
> $2 = (map[string]int) 0x0
> (gdb) p *'main.M'
> $3 = struct hash<string,int><error reading variable: Cannot access
> memory at address 0x2000155bd>
> (gdb) n
> 9               M["a"] = 1
> (gdb) p *'main.M'
> $4 = struct hash<string,int><error reading variable: Cannot access
> memory at address 0xa>
> (gdb) n
> 10              fmt.Println(M)
> (gdb) p *'main.M'
> $5 = struct hash<string,int><error reading variable: Cannot access
> memory at address 0x3937393336333108>
> (gdb) n
> map[a:1]
> 11      }
>

[khr1, 2013-03-26 23:35:01]

minux, have you had a chance to look at this yet?


On Fri, Mar 22, 2013 at 1:24 PM, Keith Randall <khr@google.com> wrote:

> Sorry, looks like I cleaned up one too many lines of testing code.  Try
> now.
>
>
> On Fri, Mar 22, 2013 at 12:15 PM, minux <minux.ma@gmail.com> wrote:
>
>> I got this when i tried out this CL with gdb 7.3 on Darwin/amd64:
>>
>> (gdb) b 'main.main'
>> Breakpoint 1 at 0x2000: file /Users/minux/go/go2.hg/src/map.go, line 7.
>> (gdb) source pkg/runtime/runtime-gdb.py
>> Loading Go Runtime support.
>> (gdb) r
>> Starting program: /Users/minux/go/go2.hg/src/map
>> [New Thread 0x1903 of process 87477]
>>
>> Breakpoint 1, main.main () at /Users/minux/go/go2.hg/src/map.go:7
>> 7       func main() {
>> (gdb) p 'main.M'
>> $1 = (map[string]int) 0x0
>> (gdb) n
>> 8               M = make(map[string]int)
>> (gdb) p 'main.M'
>> $2 = (map[string]int) 0x0
>> (gdb) p *'main.M'
>> $3 = struct hash<string,int><error reading variable: Cannot access
>> memory at address 0x2000155bd>
>> (gdb) n
>> 9               M["a"] = 1
>> (gdb) p *'main.M'
>> $4 = struct hash<string,int><error reading variable: Cannot access
>> memory at address 0xa>
>> (gdb) n
>> 10              fmt.Println(M)
>> (gdb) p *'main.M'
>> $5 = struct hash<string,int><error reading variable: Cannot access
>> memory at address 0x3937393336333108>
>> (gdb) n
>> map[a:1]
>> 11      }
>>
>
>

[khr, 2013-03-29 18:04:10]

*** Submitted as https://code.google.com/p/go/source/detail?r=e5ff184d8a45 ***

runtime: fix gdb printing of maps
Fixes issue 5098

R=minux.ma, bradfitz, khr, rsc
CC=golang-dev
https://codereview.appspot.com/7746045

[minux1, 2013-03-30 10:35:09]

LGTM. Thank you!