From: Nick Desaulniers > Sent: 12 March 2021 17:55 > > On Thu, Mar 11, 2021 at 5:09 PM Nick Desaulniers > <ndesaulniers@xxxxxxxxxx> wrote: > > > > -Wframe-larger-than= requires stack frame information, which the > > frontend cannot provide. This diagnostic is emitted late during > > compilation once stack frame size is available. > > > > When building with LTO, the frontend simply lowers C to LLVM IR and does > > not have stack frame information, so it cannot emit this diagnostic. > > When the linker drives LTO, it restarts optimizations and lowers LLVM IR > > to object code. At that point, it has stack frame information but > > doesn't know to check for a specific max stack frame size. With LTO the linker ought to be able to do a stack frame check across multiples functions in the call stack. Clearly recursive calls cause issues. Indirect ones as well - but does CFI include enough info about what can be called from where to help? David - Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1 1PT, UK Registration No: 1397386 (Wales)
