[Dwarf-discuss] Proposal to encode Changed Function Signatures in dwarf

[Y Song]

On Sun, Jan 4, 2026 at 9:49 AM David Blaikie <dblaikie@gmail.com> wrote:
>
> Coming back to the fundamental problem you're trying to solve - am I understanding correctly it is this:
>
> Compiler optimizes a function and doesn't preserve it's ABI.
> You want to allow your users of BPF to write a call to, or reimplementation of (which is it? is it some third thing?) this function that matches the lowered/non-ABI matching signature.

Yes. There is no reimplementation here. Users should just use the
*real* signatures.

> So you'd like DWARF (well, BPF, which is built from DWARF? encoded in DWARF?) to encode a source signature that is equivalent to the optimized/new calling convention of the function?

There is no BPF involved here. The signature changed should be encoded in dwarf.

>
> But folks here are pushing back by suggesting that that optimized calling convention may not be representable in the source language? which I think is accurate/fair...

Could you clarify here? In the compiler, we can capture the changed
signature. BTW, currently we only target the C language as it is our
use case.