Variables are not showing properly. Specifically the trouble I'm having is with this pointers.

I have a simple struct and toString and this shows in the watches/locals but it expands to not found:

-		this	0x0000028d3a7d12c8 {0x000000005da0e220}
-			0x000000005da0e220	
		x	D0001: Error: Expression couldn't be evaluated	

simply doing auto This = this;

This works.

I've noticed other weird issues in the watches and locals not showing variables.

On 01/10/2019 06:05, Brett wrote:
> Variables are not showing properly. Specifically the trouble I'm having is with this pointers.
> 
> I have a simple struct and toString and this shows in the watches/locals but it expands to not found:
> 
> -        this    0x0000028d3a7d12c8 {0x000000005da0e220}
> -            0x000000005da0e220
>         x    D0001: Error: Expression couldn't be evaluated
> 
> simply doing auto This = this;
> 
> This works.
> 
> I've noticed other weird issues in the watches and locals not showing variables.
> 

A test case would be helpful...

I can only suspect that 'this' is stored in some register, but that it is not reflected in the debug information. It looks like your struct contains a pointer, maybe the value shown doesn't point to existing memory? Does `This` show the same pointer values, but proper fields?

On Tuesday, 1 October 2019 at 06:12:42 UTC, Rainer Schuetze wrote:
>
>
> On 01/10/2019 06:05, Brett wrote:
>> Variables are not showing properly. Specifically the trouble I'm having is with this pointers.
>> 
>> I have a simple struct and toString and this shows in the watches/locals but it expands to not found:
>> 
>> -        this    0x0000028d3a7d12c8 {0x000000005da0e220}
>> -            0x000000005da0e220
>>         x    D0001: Error: Expression couldn't be evaluated
>> 
>> simply doing auto This = this;
>> 
>> This works.
>> 
>> I've noticed other weird issues in the watches and locals not showing variables.
>> 
>
> A test case would be helpful...
>
> I can only suspect that 'this' is stored in some register, but that it is not reflected in the debug information. It looks like your struct contains a pointer, maybe the value shown doesn't point to existing memory? Does `This` show the same pointer values, but proper fields?

-		this	0x0000016ff0f6b588 {0x000000000001ffff}	P**
+			0x000000000001ffff	P*
-		This	{x=131071}	P

auto This = this;

This is not showing as a pointer, this is a double pointer and seems to be referring to the first value.

Not sure if the address is right, probably is, seems the problem is that this is being treating as a **.

I don't have any reduced test case now but it should be simple to do or find the bug I imagine.

It literally is just

struct P { long x; auto foo() { auto This = this; } }

type of thing with a bunch of other stuff that is irrelevant to the problem.

It shouldn't matter how P is being used(I am using pointers to P in arrays P*[] in some cases that may be throwing something off that is malformed already).

But clearly since `auto This = this` is correct, this is either 1. A debugging map error(when it displays this automatically it screws up and dereferences it twice) or 2. Or most likely 1.

The reason being is that the code uses this and works fine so it is no actually dereferencing junk.

Recently you modified the code to fix a pointer bug with variables in the watch(null values I believe) and so chances are that screwed up this. It used to work fine so is a relatively new thing and the bug is clearly an extra dereferencing issue and only a "visual" problem.

On 01/10/2019 17:41, Brett wrote:
> On Tuesday, 1 October 2019 at 06:12:42 UTC, Rainer Schuetze wrote:
>>
>>
>> On 01/10/2019 06:05, Brett wrote:
>>> Variables are not showing properly. Specifically the trouble I'm having is with this pointers.
>>>
>>> I have a simple struct and toString and this shows in the watches/locals but it expands to not found:
>>>
>>> -        this    0x0000028d3a7d12c8 {0x000000005da0e220}
>>> -            0x000000005da0e220
>>>         x    D0001: Error: Expression couldn't be evaluated
>>>
>>> simply doing auto This = this;
>>>
>>> This works.
>>>
>>> I've noticed other weird issues in the watches and locals not showing variables.
>>>
>>
>> A test case would be helpful...
>>
>> I can only suspect that 'this' is stored in some register, but that it is not reflected in the debug information. It looks like your struct contains a pointer, maybe the value shown doesn't point to existing memory? Does `This` show the same pointer values, but proper fields?
> 
> -        this    0x0000016ff0f6b588 {0x000000000001ffff}    P**
> +            0x000000000001ffff    P*
> -        This    {x=131071}    P
> 
> auto This = this;
> 
> This is not showing as a pointer, this is a double pointer and seems to be referring to the first value.
> 
> Not sure if the address is right, probably is, seems the problem is that this is being treating as a **.
> 
> I don't have any reduced test case now but it should be simple to do or find the bug I imagine.
> 
> It literally is just
> 
> struct P { long x; auto foo() { auto This = this; } }
> 
> type of thing with a bunch of other stuff that is irrelevant to the problem.
> 
> It shouldn't matter how P is being used(I am using pointers to P in arrays P*[] in some cases that may be throwing something off that is malformed already).
> 
> But clearly since `auto This = this` is correct, this is either 1. A debugging map error(when it displays this automatically it screws up and dereferences it twice) or 2. Or most likely 1.
> 
> The reason being is that the code uses this and works fine so it is no actually dereferencing junk.
> 
> Recently you modified the code to fix a pointer bug with variables in the watch(null values I believe) and so chances are that screwed up this. It used to work fine so is a relatively new thing and the bug is clearly an extra dereferencing issue and only a "visual" problem.
> 
>

I cannot easily reproduce the issue, but it might already be fixed by the same patch as the one avoiding crashes with pointers to empty arrays.

You can try to replace "c:\Program Files (x86)\Microsoft Visual
Studio\2019\Community\Common7\Packages\Debugger\MagoNatCC.dll" (or
similar path depending on the VS version) with the
Appveyor artifact here:
https://ci.appveyor.com/project/rainers/mago/builds/27804605/artifacts

This version also contains some of your recent suggestions.

On Tuesday, 1 October 2019 at 18:44:37 UTC, Rainer Schuetze wrote:
>
>
> On 01/10/2019 17:41, Brett wrote:
>> On Tuesday, 1 October 2019 at 06:12:42 UTC, Rainer Schuetze wrote:
>>>
>>>
>>> On 01/10/2019 06:05, Brett wrote:
>>>> Variables are not showing properly. Specifically the trouble I'm having is with this pointers.
>>>>
>>>> I have a simple struct and toString and this shows in the watches/locals but it expands to not found:
>>>>
>>>> -        this    0x0000028d3a7d12c8 {0x000000005da0e220}
>>>> -            0x000000005da0e220
>>>>         x    D0001: Error: Expression couldn't be evaluated
>>>>
>>>> simply doing auto This = this;
>>>>
>>>> This works.
>>>>
>>>> I've noticed other weird issues in the watches and locals not showing variables.
>>>>
>>>
>>> A test case would be helpful...
>>>
>>> I can only suspect that 'this' is stored in some register, but that it is not reflected in the debug information. It looks like your struct contains a pointer, maybe the value shown doesn't point to existing memory? Does `This` show the same pointer values, but proper fields?
>> 
>> -        this    0x0000016ff0f6b588 {0x000000000001ffff}    P**
>> +            0x000000000001ffff    P*
>> -        This    {x=131071}    P
>> 
>> auto This = this;
>> 
>> This is not showing as a pointer, this is a double pointer and seems to be referring to the first value.
>> 
>> Not sure if the address is right, probably is, seems the problem is that this is being treating as a **.
>> 
>> I don't have any reduced test case now but it should be simple to do or find the bug I imagine.
>> 
>> It literally is just
>> 
>> struct P { long x; auto foo() { auto This = this; } }
>> 
>> type of thing with a bunch of other stuff that is irrelevant to the problem.
>> 
>> It shouldn't matter how P is being used(I am using pointers to P in arrays P*[] in some cases that may be throwing something off that is malformed already).
>> 
>> But clearly since `auto This = this` is correct, this is either 1. A debugging map error(when it displays this automatically it screws up and dereferences it twice) or 2. Or most likely 1.
>> 
>> The reason being is that the code uses this and works fine so it is no actually dereferencing junk.
>> 
>> Recently you modified the code to fix a pointer bug with variables in the watch(null values I believe) and so chances are that screwed up this. It used to work fine so is a relatively new thing and the bug is clearly an extra dereferencing issue and only a "visual" problem.
>> 
>>
>
> I cannot easily reproduce the issue, but it might already be fixed by the same patch as the one avoiding crashes with pointers to empty arrays.
>
> You can try to replace "c:\Program Files (x86)\Microsoft Visual
> Studio\2019\Community\Common7\Packages\Debugger\MagoNatCC.dll" (or
> similar path depending on the VS version) with the
> Appveyor artifact here:
> https://ci.appveyor.com/project/rainers/mago/builds/27804605/artifacts
>
> This version also contains some of your recent suggestions.

This did not fix it ;/ I'm not 100% sure I updated correctly but it seemed correct(The browser remembered the saved dir from last time and I just used it and overwrote the dll).

Surely this should be a simple bug to find? Somewhere in the code this is automatically watched and for some reason it's type is off.

Do you know the location of that code that you could paste a reference to? I'll look at it and see if I can see anything.

I wonder if you could easily modify Visual D so that one could "break" in to it to do some debugging. It might be much easier. If, for example, I could run a piece of code that somehow triggers debugging of Visual D around the code being debugged(a BP of a BP in some sense) then it might be easier. I realize that it doesn't quite work this way but if I could just get some VisualD code to pop up in another debugger running parallel then I could debug some of these problems myself. I have had no success building visual D myself so if there was a debug build that worked I could download that and use it.

There is definitely some weird dereferencing issue in the code.  I'll eventually get around to making a test case but it won't be for a few days.

On 02/10/2019 07:46, Brett wrote:
> On Tuesday, 1 October 2019 at 18:44:37 UTC, Rainer Schuetze wrote:
>>
>>
>> On 01/10/2019 17:41, Brett wrote:
>>> On Tuesday, 1 October 2019 at 06:12:42 UTC, Rainer Schuetze wrote:
>>>>
>>>>
>>>> On 01/10/2019 06:05, Brett wrote:
>>>>> Variables are not showing properly. Specifically the trouble I'm having is with this pointers.
>>>>>
>>>>> I have a simple struct and toString and this shows in the watches/locals but it expands to not found:
>>>>>
>>>>> -        this    0x0000028d3a7d12c8 {0x000000005da0e220}
>>>>> -            0x000000005da0e220
>>>>>         x    D0001: Error: Expression couldn't be evaluated
>>>>>
>>>>> simply doing auto This = this;
>>>>>
>>>>> This works.
>>>>>
>>>>> I've noticed other weird issues in the watches and locals not showing variables.
>>>>>
>>>>
>>>> A test case would be helpful...
>>>>
>>>> I can only suspect that 'this' is stored in some register, but that it is not reflected in the debug information. It looks like your struct contains a pointer, maybe the value shown doesn't point to existing memory? Does `This` show the same pointer values, but proper fields?
>>>
>>> -        this    0x0000016ff0f6b588 {0x000000000001ffff}    P**
>>> +            0x000000000001ffff    P*
>>> -        This    {x=131071}    P
>>>
>>> auto This = this;
>>>
>>> This is not showing as a pointer, this is a double pointer and seems to be referring to the first value.
>>>
>>> Not sure if the address is right, probably is, seems the problem is that this is being treating as a **.
>>>
>>> I don't have any reduced test case now but it should be simple to do or find the bug I imagine.
>>>
>>> It literally is just
>>>
>>> struct P { long x; auto foo() { auto This = this; } }
>>>
>>> type of thing with a bunch of other stuff that is irrelevant to the problem.
>>>
>>> It shouldn't matter how P is being used(I am using pointers to P in arrays P*[] in some cases that may be throwing something off that is malformed already).
>>>
>>> But clearly since `auto This = this` is correct, this is either 1. A debugging map error(when it displays this automatically it screws up and dereferences it twice) or 2. Or most likely 1.
>>>
>>> The reason being is that the code uses this and works fine so it is no actually dereferencing junk.
>>>
>>> Recently you modified the code to fix a pointer bug with variables in the watch(null values I believe) and so chances are that screwed up this. It used to work fine so is a relatively new thing and the bug is clearly an extra dereferencing issue and only a "visual" problem.
>>>
>>>
>>
>> I cannot easily reproduce the issue, but it might already be fixed by the same patch as the one avoiding crashes with pointers to empty arrays.
>>
>> You can try to replace "c:\Program Files (x86)\Microsoft Visual
>> Studio\2019\Community\Common7\Packages\Debugger\MagoNatCC.dll" (or
>> similar path depending on the VS version) with the
>> Appveyor artifact here:
>> https://ci.appveyor.com/project/rainers/mago/builds/27804605/artifacts
>>
>> This version also contains some of your recent suggestions.
> 
> This did not fix it ;/ I'm not 100% sure I updated correctly but it seemed correct(The browser remembered the saved dir from last time and I just used it and overwrote the dll).
> 
> Surely this should be a simple bug to find? Somewhere in the code this is automatically watched and for some reason it's type is off.
> 
> Do you know the location of that code that you could paste a reference to? I'll look at it and see if I can see anything.
> 
> I wonder if you could easily modify Visual D so that one could "break" in to it to do some debugging. It might be much easier. If, for example, I could run a piece of code that somehow triggers debugging of Visual D around the code being debugged(a BP of a BP in some sense) then it might be easier. I realize that it doesn't quite work this way but if I could just get some VisualD code to pop up in another debugger running parallel then I could debug some of these problems myself. I have had no success building visual D myself so if there was a debug build that worked I could download that and use it.

You don't have to compile Visual D, but mago: https://github.com/rainers/mago

Ignore the readme, load MagoDbg_2010.sln into VS2013 or newer, and build Expression/MagoNatCC for configuration "Debug Static DE|Win32". Then replace the DLL in the VS debugger folder with bin\Win32\Debug\MagoNatCC.dll.

If you hit an issue, you can start a new instance of VS with the mago solution and attach its debugger to the other running VS (devenv.exe).

There is actually some automatic dereferencing going on (avoiding extra
nesting in watches) here

https://github.com/rainers/mago/blob/master/EED/EED/EED.cpp#L213, https://github.com/rainers/mago/blob/master/EED/EED/EED.cpp#L315 and https://github.com/rainers/mago/blob/master/EED/EED/EnumValues.cpp#L845

which might have gotten out-of-sync recently. I think I just noticed an issue and triggered a new build on Appveyor.

On Wednesday, 2 October 2019 at 06:25:15 UTC, Rainer Schuetze wrote:
>
>
> On 02/10/2019 07:46, Brett wrote:
>> On Tuesday, 1 October 2019 at 18:44:37 UTC, Rainer Schuetze wrote:
>>>
>>>
>>> On 01/10/2019 17:41, Brett wrote:
>>>> On Tuesday, 1 October 2019 at 06:12:42 UTC, Rainer Schuetze wrote:
>>>>>
>>>>>
>>>>> On 01/10/2019 06:05, Brett wrote:
>>>>>> Variables are not showing properly. Specifically the trouble I'm having is with this pointers.
>>>>>>
>>>>>> I have a simple struct and toString and this shows in the watches/locals but it expands to not found:
>>>>>>
>>>>>> -        this    0x0000028d3a7d12c8 {0x000000005da0e220}
>>>>>> -            0x000000005da0e220
>>>>>>         x    D0001: Error: Expression couldn't be evaluated
>>>>>>
>>>>>> simply doing auto This = this;
>>>>>>
>>>>>> This works.
>>>>>>
>>>>>> I've noticed other weird issues in the watches and locals not showing variables.
>>>>>>
>>>>>
>>>>> A test case would be helpful...
>>>>>
>>>>> I can only suspect that 'this' is stored in some register, but that it is not reflected in the debug information. It looks like your struct contains a pointer, maybe the value shown doesn't point to existing memory? Does `This` show the same pointer values, but proper fields?
>>>>
>>>> -        this    0x0000016ff0f6b588 {0x000000000001ffff}    P**
>>>> +            0x000000000001ffff    P*
>>>> -        This    {x=131071}    P
>>>>
>>>> auto This = this;
>>>>
>>>> This is not showing as a pointer, this is a double pointer and seems to be referring to the first value.
>>>>
>>>> Not sure if the address is right, probably is, seems the problem is that this is being treating as a **.
>>>>
>>>> I don't have any reduced test case now but it should be simple to do or find the bug I imagine.
>>>>
>>>> It literally is just
>>>>
>>>> struct P { long x; auto foo() { auto This = this; } }
>>>>
>>>> type of thing with a bunch of other stuff that is irrelevant to the problem.
>>>>
>>>> It shouldn't matter how P is being used(I am using pointers to P in arrays P*[] in some cases that may be throwing something off that is malformed already).
>>>>
>>>> But clearly since `auto This = this` is correct, this is either 1. A debugging map error(when it displays this automatically it screws up and dereferences it twice) or 2. Or most likely 1.
>>>>
>>>> The reason being is that the code uses this and works fine so it is no actually dereferencing junk.
>>>>
>>>> Recently you modified the code to fix a pointer bug with variables in the watch(null values I believe) and so chances are that screwed up this. It used to work fine so is a relatively new thing and the bug is clearly an extra dereferencing issue and only a "visual" problem.
>>>>
>>>>
>>>
>>> I cannot easily reproduce the issue, but it might already be fixed by the same patch as the one avoiding crashes with pointers to empty arrays.
>>>
>>> You can try to replace "c:\Program Files (x86)\Microsoft Visual
>>> Studio\2019\Community\Common7\Packages\Debugger\MagoNatCC.dll" (or
>>> similar path depending on the VS version) with the
>>> Appveyor artifact here:
>>> https://ci.appveyor.com/project/rainers/mago/builds/27804605/artifacts
>>>
>>> This version also contains some of your recent suggestions.
>> 
>> This did not fix it ;/ I'm not 100% sure I updated correctly but it seemed correct(The browser remembered the saved dir from last time and I just used it and overwrote the dll).
>> 
>> Surely this should be a simple bug to find? Somewhere in the code this is automatically watched and for some reason it's type is off.
>> 
>> Do you know the location of that code that you could paste a reference to? I'll look at it and see if I can see anything.
>> 
>> I wonder if you could easily modify Visual D so that one could "break" in to it to do some debugging. It might be much easier. If, for example, I could run a piece of code that somehow triggers debugging of Visual D around the code being debugged(a BP of a BP in some sense) then it might be easier. I realize that it doesn't quite work this way but if I could just get some VisualD code to pop up in another debugger running parallel then I could debug some of these problems myself. I have had no success building visual D myself so if there was a debug build that worked I could download that and use it.
>
> You don't have to compile Visual D, but mago: https://github.com/rainers/mago
>
> Ignore the readme, load MagoDbg_2010.sln into VS2013 or newer, and build Expression/MagoNatCC for configuration "Debug Static DE|Win32". Then replace the DLL in the VS debugger folder with bin\Win32\Debug\MagoNatCC.dll.

I was able to build and copy the file and all that but when I attach and add a BP on, say line 345 below the BP is missing and says symbols are not loaded. I took all the pdb's and put them in a directory and added the dir too the symbols dir in the VS options but it is still missing. Also the "modules" are not showing any symbols for mago... all visual studio stuff(mainly .net, not sure why they would be showing).

"This breakpoints will not currently be hit. Symbols not loaded"...

I use attach to process then find devenv.exe of the target D app(not the app itself but the visual studio process running it since I imagine that is the one running the mago dll).


I've copied the pdb's to the same dir as the mago dll's... Visual studio simply won't load them ;/ This is with the debug static build.

Any idea? Am I doing it wrong?

> If you hit an issue, you can start a new instance of VS with the mago solution and attach its debugger to the other running VS (devenv.exe).

yes, I can't get Bp's to work though ;/

> There is actually some automatic dereferencing going on (avoiding extra
> nesting in watches) here
>
> https://github.com/rainers/mago/blob/master/EED/EED/EED.cpp#L213, https://github.com/rainers/mago/blob/master/EED/EED/EED.cpp#L315 and https://github.com/rainers/mago/blob/master/EED/EED/EnumValues.cpp#L845
>
> which might have gotten out-of-sync recently. I think I just noticed an issue and triggered a new build on Appveyor.

I tried but it doesn't seem to be working ;/

On 02/10/2019 18:04, Brett wrote:
> I was able to build and copy the file and all that but when I attach and add a BP on, say line 345 below the BP is missing and says symbols are not loaded. I took all the pdb's and put them in a directory and added the dir too the symbols dir in the VS options but it is still missing. Also the "modules" are not showing any symbols for mago... all visual studio stuff(mainly .net, not sure why they would be showing).
> 
> "This breakpoints will not currently be hit. Symbols not loaded"...
> 
> I use attach to process then find devenv.exe of the target D app(not the app itself but the visual studio process running it since I imagine that is the one running the mago dll).
> 

Copying the pdb should not be necessary because it is referenced by the absolute path.

I suspect that you have selected "Managed code" only when attaching to the process. You have to select/add "Native code".

On Wednesday, 2 October 2019 at 20:48:42 UTC, Rainer Schuetze wrote:
>
>
> On 02/10/2019 18:04, Brett wrote:
>> I was able to build and copy the file and all that but when I attach and add a BP on, say line 345 below the BP is missing and says symbols are not loaded. I took all the pdb's and put them in a directory and added the dir too the symbols dir in the VS options but it is still missing. Also the "modules" are not showing any symbols for mago... all visual studio stuff(mainly .net, not sure why they would be showing).
>> 
>> "This breakpoints will not currently be hit. Symbols not loaded"...
>> 
>> I use attach to process then find devenv.exe of the target D app(not the app itself but the visual studio process running it since I imagine that is the one running the mago dll).
>> 
>
> Copying the pdb should not be necessary because it is referenced by the absolute path.

I copied just to be sure.(using the build environment to copy every build)

>
> I suspect that you have selected "Managed code" only when attaching to the process. You have to select/add "Native code".

No ;/ It was automatic, I then set it to native and same problem.

;/ I tried again and it worked. I made sure to set native and managed. I thought I tried that but... it's still not loading but now it does show it and the info says that the image does not match.

Not sure why but at least it seems to be working now! I had to delete everything and start over. In any case, now I can play around with it and see what I can come up with ;)

Thanks!



I thought

On 01/10/2019 17:41, Brett wrote:
>         this    0x0000016ff0f6b588 {0x000000000001ffff}    P**
> +            0x000000000001ffff    P*
> -        This    {x=131071}    P
> 
> auto This = this;
> 
> This is not showing as a pointer, this is a double pointer and seems to be referring to the first value.

The double indirection looks bad. I don't think that mago adds indirections, it only removes some to reduce clutter.

I suspect that the debug info is broken. The best tool for dumping it is https://github.com/Microsoft/microsoft-pdb/tree/master/cvdump/cvdump.exe