Add `ReadOnly` and `InaccessibleMemOnly` attributes to the following
functions:
- `revng_stack_frame`
- `revng_call_stack_arguments`
- `ModelGEP`
- `AddressOf`
This prevents `CSE` from grouping together any of these calls, while
still enabling `DCE` to remove calls that are not used.
Before this commit, SegregateStackAccessesPass always expected to find
calls stack_size_at_call_site markers injected by
InjectStackSizeProbesAtCallSitesPass.
This is not always true, because aggressive LLVM optimizations can
remove dead code.
As an example, if the user or some analysis earlier in the pipeline
wrongly marks registers as non-arguments, the optimization pipeline will
throw away and eliminate everything that descends from the initial
values of those registers.
This commit enables SegregateStackAccessesPass to cope with calls to
stack_size_at_call_site that were eliminated, and keep going just
considering the calls that are still there.
Change company name to "rev.ng Labs Srl" in all license headers
to reflect changed company name and legal status
Add missing license headers to files that didn't have one
Before this commit, SegregateStackAccessPass did not update properly the
metadata. Missing metadata did not allow the rest of the pipeline to
detect the special call.
This commit properly copies the metadata and updates the rest of the
pipeline to take care of the special call.
* Adjust stack pointer upon returning from call.
In architecture where the return address is pushed on the stack, on
the caller side, we see the the push but not the pop. This means that,
once the stack pointer is no longer global, we need to take this into
account.
This commit fixes this increase the stack pointer of
`FinalStackOffset` right after a function call.
* Drop the size argument from the `revng_init_local_sp` function. We
will have a `revng_stack_frame` function to represent the actual stack
frame pointing to its beginning.
The PromoteStackPointerPass now trivially handles running on modules
where the global variable for the stack pointer is missing.
When the global is not found, the pass just does nothing and returns
false.
This is necessary to handle very small functions, typically from tests.
Ivan Krysak