This change came in a few hours ago and introduced a warning. The fix
is trivial, so I'm providing it. The original change was reviewed here:
https://reviews.llvm.org/D132331
For mingw target, if a symbol is not marked DSO local, a `.refptr` is
generated for it. This makes CFG check calls use an extra pointer
dereference, which adds extra overhead compared to the MSVC version,
so mark the CFG guard check funciton pointer DSO local to stop it.
This should have no effect on MSVC target.
Also adapt the existing cfguard tests to run for mingw targets, so that
this change is checked.
Reviewed By: rnk
Differential Revision: https://reviews.llvm.org/D132331
When Control Flow Guard Check is inserted, funclet bundle was not checked. Therefore, it didn't generate code correctly when a target function has "funclet" bundle.
Reviewed By: rnk
Differential Revision: https://reviews.llvm.org/D114914
Summary:
It is reasonably common to want to clone some call with different bundles.
Let's actually provide an interface to do that.
Reviewers: chandlerc, jdoerfert, dblaikie, nickdesaulniers
Reviewed By: nickdesaulniers
Subscribers: llvm-commits, hiraditya
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D83248
Summary:
Avoid using the `nocf_check` attribute with Control Flow Guard. Instead, use a
new `"guard_nocf"` function attribute to indicate that checks should not be
added on indirect calls within that function. Add support for
`__declspec(guard(nocf))` following the same syntax as MSVC.
Reviewers: rnk, dmajor, pcc, hans, aaron.ballman
Reviewed By: aaron.ballman
Subscribers: aaron.ballman, tomrittervg, hiraditya, cfe-commits, llvm-commits
Tags: #clang, #llvm
Differential Revision: https://reviews.llvm.org/D72167
Summary:
A new function pass (Transforms/CFGuard/CFGuard.cpp) inserts CFGuard checks on
indirect function calls, using either the check mechanism (X86, ARM, AArch64) or
or the dispatch mechanism (X86-64). The check mechanism requires a new calling
convention for the supported targets. The dispatch mechanism adds the target as
an operand bundle, which is processed by SelectionDAG. Another pass
(CodeGen/CFGuardLongjmp.cpp) identifies and emits valid longjmp targets, as
required by /guard:cf. This feature is enabled using the `cfguard` CC1 option.
Reviewers: thakis, rnk, theraven, pcc
Subscribers: ychen, hans, metalcanine, dmajor, tomrittervg, alex, mehdi_amini, mgorny, javed.absar, kristof.beyls, hiraditya, steven_wu, dexonsmith, cfe-commits, llvm-commits
Tags: #clang, #llvm
Differential Revision: https://reviews.llvm.org/D65761
