llvm-project

d8fa68f9 - [CIR] Fix bugs with array new in a ternary expression (#198869)

[CIR] Fix bugs with array new in a ternary expression (#198869) While attempting to compile Clang with CIR enabled, we ran into a problem with the cleanup handling for array new inside of a ternary operation. The reduced test case ended up showing different failure modes with and without exceptions enabled, but it failed in both cases. With exceptions enabled, we were failing to spill the value to be returned and reload it outside of the cleanup scope. With exceptions disabled, we were pushing an effectively empty entry on the EH stack and later asserting when trying to pop it. This change fixes the spill and reload problem by inserting a RunCleanupsScope RAII object around the ternary branch generation code with a call to forceCleanups to generate the spill and reload. The assertion failure is fixed by replacing the assert call with code to safely handle the condition of having an empty cleanup on the EH stack. We should probably modify the code that pushes EH-only cleanups to avoid doing so when exceptions are disabled, but that's a more extensive change and having the new handler as a safe backstop seems like a good idea. Manual inspection revealed a second location where we're generating a cir.ternary operation that had the same spill and reload problem described above, so that is fixed here too. Assisted-by: Cursor / claude-opus-4.7-thinking-xhigh