Description:
The current instrumentation logic for insertAfter inserts a call right before every ret or resume. This is unsafe when the return is immediately preceded by a musttail call.
LLVM requires that a musttail call be followed immediately by the return, with no intervening instructions. Inserting instrumentation there violates the verifier rules and produces invalid IR.
Steps to Reproduce:
Write a function with [[clang::musttail]] in C++ (or use another frontend that emits musttail).
Run the pass.
The verifier would potentiall fail because the injected call appears between the musttail and the ret.
Impact:
Rare in plain C++, but possible in code that explicitly uses [[clang::musttail]] or when working with frontends that emit musttail.
This is probable a very minor nitpick that will most likely never present itself, but i thought i might mention it just in case.
Description:
The current instrumentation logic for
insertAfterinserts a call right before everyretorresume.This is unsafe when the return is immediately preceded by a musttail call.LLVM requires that a musttail call be followed immediately by the return, with no intervening instructions. Inserting instrumentation there violates the verifier rules and produces invalid IR.
Steps to Reproduce:
Write a function with [[clang::musttail]] in C++ (or use another frontend that emits musttail).
Run the pass.
The verifier would potentiall fail because the injected call appears between the
musttailand theret.Impact:
Rare in plain C++, but possible in code that explicitly uses [[clang::musttail]] or when working with frontends that emit musttail.
This is probable a very minor nitpick that will most likely never present itself, but i thought i might mention it just in case.