https://gcc.gnu.org/bugzilla/show_bug.cgi?id=114759
Bug ID: 114759
Summary: Power: multiple issues with -mrop-protect
Product: gcc
Version: 14.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: target
Assignee: unassigned at gcc dot gnu.org
Reporter: bergner at gcc dot gnu.org
Target Milestone: ---
There are multiple issues with the -mrop-protect option which are all
inter-related.
1. We always define the __ROP_PROTECT__ predefined macro when using
-mrop-protect, even when we've silently disabled ROP protection because of a
too old -mcpu=CPU value. We should only emit __ROP_PROTECT__ when it's legal
to emit the ROP insns.
2. We always disable shrink-wrapping when -mrop-protect is used, even when
we've silently disabled ROP protection because of a too old -mcpu=CPU value.
We should not disable shrink-wrapping if we've disabled ROP protection.
3. We silently disable ROP protection for everything other than -mcpu=power10.
The binutils assembler accepts the ROP insns back to Power8, so we should emit
them for Power8 and later.
4. We give an error when -mrop-protect is used with any -mabi=ABI value not
equal to ELFv2, whereas a too old -mcpu=CPU value only causes us to silently
disable ROP protection. I think both scenarios should behave similarly, so
either we silently disable ROP protection for both or we give an error for
both.
This is not a regression. I consider 1. to be a correctness/wrong code bug.
