www.digitalmars.com         C & C++   DMDScript  

digitalmars.D.learn - BetterC stack traces?

reply IchorDev <zxinsworld gmail.com> writes:
I'm trying to implement a custom exception system in BetterC. 
Does anyone know how I'd go about getting a stack trace so that I 
can print it to stdout? :)
I was thinking of utilising UDAs & `__LINE__` but it turns out 
that UDAs don't let you inject code, which is a shame!
Sep 04 2022
parent reply Paul Backus <snarwin gmail.com> writes:
On Sunday, 4 September 2022 at 17:43:01 UTC, IchorDev wrote:

 I'm trying to implement a custom exception system in BetterC. 
 Does anyone know how I'd go about getting a stack trace so that 
 I can print it to stdout? :)
 I was thinking of utilising UDAs & `__LINE__` but it turns out 
 that UDAs don't let you inject code, which is a shame!


You can use `libunwind` for this:

https://www.nongnu.org/libunwind/

It's a C library, but it should work for D too.
Sep 04 2022
parent reply IchorDev <zxinsworld gmail.com> writes:
On Sunday, 4 September 2022 at 18:49:37 UTC, Paul Backus wrote:

 You can use `libunwind` for this:

 https://www.nongnu.org/libunwind/

 It's a C library, but it should work for D too.


Ah, I'm actually trying to create my own implementation of this, 
so the goal would be to not rely on a dependency.
I can't exactly make head nor tail of the library's source other 
than that it seems to have a unique implementation on each 
processor/OS type.

I'm sure there must be something hidden in `core.internal.` for 
this. I'll look at the implementation of `rt.trace` and see if I 
can find anything.
Sep 05 2022
parent reply Paul Backus <snarwin gmail.com> writes:
On Monday, 5 September 2022 at 10:47:38 UTC, IchorDev wrote:

 Ah, I'm actually trying to create my own implementation of 
 this, so the goal would be to not rely on a dependency.
 I can't exactly make head nor tail of the library's source 
 other than that it seems to have a unique implementation on 
 each processor/OS type.

 I'm sure there must be something hidden in `core.internal.` for 
 this. I'll look at the implementation of `rt.trace` and see if 
 I can find anything.


I think this is what you are looking for:

https://github.com/dlang/dmd/blob/master/druntime/src/rt/deh.d
Sep 05 2022
parent reply Paul Backus <snarwin gmail.com> writes:
On Monday, 5 September 2022 at 12:07:35 UTC, Paul Backus wrote:

 On Monday, 5 September 2022 at 10:47:38 UTC, IchorDev wrote:

 Ah, I'm actually trying to create my own implementation of 
 this, so the goal would be to not rely on a dependency.
 I can't exactly make head nor tail of the library's source 
 other than that it seems to have a unique implementation on 
 each processor/OS type.

 I'm sure there must be something hidden in `core.internal.` 
 for this. I'll look at the implementation of `rt.trace` and 
 see if I can find anything.


 I think this is what you are looking for:

 https://github.com/dlang/dmd/blob/master/druntime/src/rt/deh.d


Digging in a little deeper, it looks like the druntime 
implementation ultimately depends on the [C++ exception handling 
ABI][1], via its platform-independent library interface. Bindings 
are defined in [`core.internal.backtrace.unwind`][2].

There is also what looks like a from-scratch implementation of 
table-based exception handling in [`rt.deh_win64_posix`][3], but 
according to a comment it is no longer used. Might be educational 
to read, though.

[1]: https://itanium-cxx-abi.github.io/cxx-abi/abi-eh.html
[2]: 
https://github.com/dlang/dmd/blob/master/druntime/src/core/internal/backtrace/unwind.d
[3]: 
https://github.com/dlang/dmd/blob/master/druntime/src/rt/deh_win64_posix.d
Sep 05 2022
parent IchorDev <zxinsworld gmail.com> writes:
On Monday, 5 September 2022 at 12:35:10 UTC, Paul Backus wrote:

 Digging in a little deeper, it looks like the druntime 
 implementation ultimately depends on the C++ exception handling 
 ABI, via its platform-independent library interface. Bindings 
 are defined in `core.internal.backtrace.unwind`
 ...


It even uses libunwind, it seems! 
[https://github.com/dlang/dmd/blob/master/druntime/src/core/internal/backtrace/handler.d](https://github.com/dlang/dmd/blob/master/druntime/src/core/internal/backtrace/handler.d)
Thanks for the pointers, too. :)
Sep 06 2022