www.digitalmars.com         C & C++   DMDScript  

digitalmars.D - LWDR SAOC Milestone 1, Weekly Report for 22nd SEP to 29th SEP

reply Dylan Graham <dylan.graham2000 gmail.com> writes:
[Source Code](https://github.com/hmmdyl/LWDR)
[Plan](https://github.com/hmmdyl/SAoC2021/blob/main/plan.md)
[Proposal](https://github.com/hmmdyl/SAoC2021/blob/main/proposal.md)
[SAOC 
Projects](https://dlang.org/blog/2021/08/30/saoc-2021-projects/)

[Report for week 1 of milestone 
1](https://forum.dlang.org/thread/vodbtqqwvdmapnjzlzaq forum.dlang.org)

Light Weight D Runtime.
30th September, 2021
Symmetry Autumn of Code, Week 2 of Milestone 1.

Hi all,
My apologies for posting this update late. Over the past week, I 
completed testing for task 3 - manual deallocation of delegates. 
I'm pleased to say that from my internal tests it appears to be 
working well. Tests have been completed on an STM32F407. Progress 
has been made on task 1 - support for `ModuleInfo` and 
static/module constructors and destructors.

I've had to slightly deviate from the plan due to how [LDC 
handles](https://github.com/ldc-developers/druntime/blob/ldc/sr
/rt/sections_ldc.d) module information. The original plan was based off DMD's
implementation, but those hooks are unavailable on LDC (obviously, in
retrospect -_- ). Instead, LDC relies on a linked list, and the initial pointer
is available as `_Dmodule_ref`. The linked list contains pointers to
`ModuleInfo`, which LWDR can then iterate over.

There hasn't been much formal code written, instead I've been 
doing tests and ensuring that it behaves as expected. There was a 
bug where a `shared static this() {...}` constructor was unable 
to see TLS variables, despite them being allocated. It was due to 
an alignment issue during allocation. This still needs to be 
corrected - it is a very quick fix, fortunately.

To reduce program size, I have been applying 
[`LDC_no_moduleinfo`](https://wiki.dlang.org/LDC-specific_language_change
#LDC_no_moduleinfo) and
[`LDC_no_typeinfo`](https://wiki.dlang.org/LDC-specific_language_chan
es#LDC_no_typeinfo) pragmas to LWDR's internal modules and types, respectively.
Public facing modules and types do not have these pragmas. In debug mode, which
the `-O0` and `-gc` flags, this saved ~1KB of program memory.

To cut down on the size of `ModuleInfo`, I have made it so the 
[`unitTest` 
function](https://github.com/hmmdyl/LWDR/blob/master/source/object.d#L748) is
only compiled in when unit tests are active. This is in accordance with my
previous work to reduce the size of vtables for `TypeInfo`. It may interfere
with custom unit testing libraries.

Going forward next week, I will need to fix the alignment issue, 
and work on the `minfo` module, which will handle ctor sorting 
and dispatches calls to module constructors and destructors.

All the best,
Dylan Graham
Sep 29 2021
next sibling parent reply kinke <noone nowhere.com> writes:
On Thursday, 30 September 2021 at 06:53:41 UTC, Dylan Graham 
wrote:

 I've had to slightly deviate from the plan due to how [LDC 
 handles](https://github.com/ldc-developers/druntime/blob/ldc/sr
/rt/sections_ldc.d) module information. The original plan was based off DMD's
implementation, but those hooks are unavailable on LDC (obviously, in
retrospect -_- ). Instead, LDC relies on a linked list, and the initial pointer
is available as `_Dmodule_ref`. The linked list contains pointers to
`ModuleInfo`, which LWDR can then iterate over.


That's just the fallback for unknown/exotic OS like Solaris. 
Changing the compiler to emit the ModuleInfo pointers into the 
`__minfo` section would be a simple change in 
https://github.com/ldc-developers/ldc/blob/f9ba17248eb53021c91130b0cb7c6c00a3f8074c/gen/mo
ules.cpp#L107-L126, e.g., generally for ELF targets with unknown OS.
Sep 30 2021
parent Dylan Graham <dylan.graham2000 gmail.com> writes:
On Thursday, 30 September 2021 at 08:10:40 UTC, kinke wrote:

 On Thursday, 30 September 2021 at 06:53:41 UTC, Dylan Graham 
 wrote:

 I've had to slightly deviate from the plan due to how [LDC 
 handles](https://github.com/ldc-developers/druntime/blob/ldc/sr
/rt/sections_ldc.d) module information. The original plan was based off DMD's
implementation, but those hooks are unavailable on LDC (obviously, in
retrospect -_- ). Instead, LDC relies on a linked list, and the initial pointer
is available as `_Dmodule_ref`. The linked list contains pointers to
`ModuleInfo`, which LWDR can then iterate over.


 That's just the fallback for unknown/exotic OS like Solaris. 
 Changing the compiler to emit the ModuleInfo pointers into the 
 `__minfo` section would be a simple change in 
 https://github.com/ldc-developers/ldc/blob/f9ba17248eb53021c91130b0cb7c6c00a3f8074c/gen/mo
ules.cpp#L107-L126, e.g., generally for ELF targets with unknown OS.


Thanks for the information, but I'd prefer not to modify the 
compiler just to make LWDR work (mtriple is `arm-none-eabi`). 
It's not an issue at all - the LDC version is running perfectly. 
I simply should have looked a bit harder.
Sep 30 2021
prev sibling parent reply Imperatorn <johan_forsberg_86 hotmail.com> writes:
On Thursday, 30 September 2021 at 06:53:41 UTC, Dylan Graham 
wrote:

 [Source Code](https://github.com/hmmdyl/LWDR)
 [Plan](https://github.com/hmmdyl/SAoC2021/blob/main/plan.md)
 [Proposal](https://github.com/hmmdyl/SAoC2021/blob/main/proposal.md)
 [SAOC 
 Projects](https://dlang.org/blog/2021/08/30/saoc-2021-projects/)

 [...]


Well done. Keep it up!
Sep 30 2021
parent reply Dylan Graham <dylan.graham2000 gmail.com> writes:
On Thursday, 30 September 2021 at 23:01:40 UTC, Imperatorn wrote:

 On Thursday, 30 September 2021 at 06:53:41 UTC, Dylan Graham 
 wrote:

 [Source Code](https://github.com/hmmdyl/LWDR)
 [Plan](https://github.com/hmmdyl/SAoC2021/blob/main/plan.md)
 [Proposal](https://github.com/hmmdyl/SAoC2021/blob/main/proposal.md)
 [SAOC 
 Projects](https://dlang.org/blog/2021/08/30/saoc-2021-projects/)

 [...]


 Well done. Keep it up!


Thank you :)
Oct 01 2021
parent reply Imperatorn <johan_forsberg_86 hotmail.com> writes:
On Friday, 1 October 2021 at 22:44:08 UTC, Dylan Graham wrote:

 On Thursday, 30 September 2021 at 23:01:40 UTC, Imperatorn 
 wrote:

 On Thursday, 30 September 2021 at 06:53:41 UTC, Dylan Graham 
 wrote:

 [Source Code](https://github.com/hmmdyl/LWDR)
 [Plan](https://github.com/hmmdyl/SAoC2021/blob/main/plan.md)
 [Proposal](https://github.com/hmmdyl/SAoC2021/blob/main/proposal.md)
 [SAOC 
 Projects](https://dlang.org/blog/2021/08/30/saoc-2021-projects/)

 [...]


 Well done. Keep it up!


 Thank you :)


No, thank *you* 😁

This is actually important for me/us that are in the embedded 
space.

Will experiment with this in about a month or two ☀️
Oct 02 2021
parent Dylan Graham <dylan.graham2000 gmail.com> writes:
On Saturday, 2 October 2021 at 07:15:19 UTC, Imperatorn wrote:

 On Friday, 1 October 2021 at 22:44:08 UTC, Dylan Graham wrote:

 On Thursday, 30 September 2021 at 23:01:40 UTC, Imperatorn 
 wrote:

 On Thursday, 30 September 2021 at 06:53:41 UTC, Dylan Graham 
 wrote:

 [Source Code](https://github.com/hmmdyl/LWDR)
 [Plan](https://github.com/hmmdyl/SAoC2021/blob/main/plan.md)
 [Proposal](https://github.com/hmmdyl/SAoC2021/blob/main/proposal.md)
 [SAOC 
 Projects](https://dlang.org/blog/2021/08/30/saoc-2021-projects/)

 [...]


 Well done. Keep it up!


 Thank you :)


 No, thank *you* 😁

 This is actually important for me/us that are in the embedded 
 space.

 Will experiment with this in about a month or two ☀️


That is exciting! Let me know if you run into any problems and 
I'll try to fix them ASAP.
Oct 05 2021