Add support for __declspec(guard(nocf))
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
diff --git a/clang/lib/Sema/SemaDeclAttr.cpp b/clang/lib/Sema/SemaDeclAttr.cpp
index 7f1da40..142c6f1 100644
--- a/clang/lib/Sema/SemaDeclAttr.cpp
+++ b/clang/lib/Sema/SemaDeclAttr.cpp
@@ -6626,6 +6626,25 @@
D->addAttr(Attr::Create(S.Context, Argument, AL));
}
+static void handleCFGuardAttr(Sema &S, Decl *D, const ParsedAttr &AL) {
+ // The guard attribute takes a single identifier argument.
+
+ if (!AL.isArgIdent(0)) {
+ S.Diag(AL.getLoc(), diag::err_attribute_argument_type)
+ << AL << AANT_ArgumentIdentifier;
+ return;
+ }
+
+ CFGuardAttr::GuardArg Arg;
+ IdentifierInfo *II = AL.getArgAsIdent(0)->Ident;
+ if (!CFGuardAttr::ConvertStrToGuardArg(II->getName(), Arg)) {
+ S.Diag(AL.getLoc(), diag::warn_attribute_type_not_supported) << AL << II;
+ return;
+ }
+
+ D->addAttr(::new (S.Context) CFGuardAttr(S.Context, AL, Arg));
+}
+
//===----------------------------------------------------------------------===//
// Top Level Sema Entry Points
//===----------------------------------------------------------------------===//
@@ -7254,6 +7273,9 @@
case ParsedAttr::AT_AbiTag:
handleAbiTagAttr(S, D, AL);
break;
+ case ParsedAttr::AT_CFGuard:
+ handleCFGuardAttr(S, D, AL);
+ break;
// Thread safety attributes:
case ParsedAttr::AT_AssertExclusiveLock: