Problems and workarounds for debugging C3 on Windows

[heavymetalmixer]

After watching the same pattern as with Zig (ziglang/zig#22039) I thought it could be an issue from LLVM, but with C3 there are other small issues added on top of it:

1. LLDB starts debugging the line AFTER the breakpoint. Now, this doesn't mean "line number" but code line, so the if developer wrote down the next code line 4 lines below, LLDB will jump 4 lines down.

2. Both LLDB and MSVC Debugger ignore module declarations (the thing at the top of the file) and imports. MSVC debugger jumps to the main function if there's a breakpoint on an import or module, LLDB looks for the next breakpoint and ends the debugging session if there's none.

[lerno]

What happens with the MSVC debugger in the first case.

[heavymetalmixer]

What happens with the MSVC debugger in the first case.

The MSVC debugger starts at the breakpoint unlike LLDB.

[lerno]

Does compiling C with Clang give the right output then?

[heavymetalmixer]

Does compiling C with Clang give the right output then?

Yeah, as it should on both C and C++.

[lerno]

Could you perhaps create a small sample and dump the LLVM here for C and the corresponding C3 program? Maybe paste in a gist if it's too big.

[heavymetalmixer]

Could you perhaps create a small sample and dump the LLVM here for C and the corresponding C3 program? Maybe paste in a gist if it's too big.

I'm sorry if this si frustrating to you. I'm a novice and I don't know how to make an LLVM dump, so i used llvm-pdbutil dump to get info about the PDB file and I got the following:

llvm-pdbutil dump -summary main.pdb

                          Summary
============================================================
  Block Size: 4096
  Number of blocks: 1398
  Number of streams: 240
  Signature: 849705519
  Age: 1
  GUID: {32A57A2F-08C4-FC45-4C4C-44205044422E}
  Features: 0x1
  Has Debug Info: true
  Has Types: true
  Has IDs: true
  Has Globals: true
  Has Publics: true
  Is incrementally linked: false
  Has conflicting types: false
  Is stripped: false

The code is a simple Hello World:

#include <stdio.h>

int main(void) {
    printf("Hello world!\n");
    return 0;
}

If this isn't what you're looking for, let mw know what I should do.