Added Control Flow Protection Flag
Cf-protection is a target independent flag that instructs the back-end to instrument control flow mechanisms like: Branch, Return, etc.
For example in X86 this flag will be used to instrument Indirect Branch Tracking instructions.
Differential Revision: https://reviews.llvm.org/D40478
Change-Id: I5126e766c0e6b84118cae0ee8a20fe78cc373dea
llvm-svn: 322063
diff --git a/clang/lib/CodeGen/CodeGenFunction.cpp b/clang/lib/CodeGen/CodeGenFunction.cpp
index 0cbe071..4a45b5a 100644
--- a/clang/lib/CodeGen/CodeGenFunction.cpp
+++ b/clang/lib/CodeGen/CodeGenFunction.cpp
@@ -887,7 +887,8 @@
}
// Apply xray attributes to the function (as a string, for now)
- if (D && ShouldXRayInstrumentFunction()) {
+ bool InstrumentXray = ShouldXRayInstrumentFunction();
+ if (D && InstrumentXray) {
if (const auto *XRayAttr = D->getAttr<XRayInstrumentAttr>()) {
if (XRayAttr->alwaysXRayInstrument())
Fn->addFnAttr("function-instrument", "xray-always");
diff --git a/clang/lib/CodeGen/CodeGenModule.cpp b/clang/lib/CodeGen/CodeGenModule.cpp
index 32c9b28..b08ead8 100644
--- a/clang/lib/CodeGen/CodeGenModule.cpp
+++ b/clang/lib/CodeGen/CodeGenModule.cpp
@@ -502,6 +502,20 @@
getModule().addModuleFlag(llvm::Module::Override, "Cross-DSO CFI", 1);
}
+ if (CodeGenOpts.CFProtectionReturn &&
+ Target.checkCFProtectionReturnSupported(getDiags())) {
+ // Indicate that we want to instrument return control flow protection.
+ getModule().addModuleFlag(llvm::Module::Override, "cf-protection-return",
+ 1);
+ }
+
+ if (CodeGenOpts.CFProtectionBranch &&
+ Target.checkCFProtectionBranchSupported(getDiags())) {
+ // Indicate that we want to instrument branch control flow protection.
+ getModule().addModuleFlag(llvm::Module::Override, "cf-protection-branch",
+ 1);
+ }
+
if (LangOpts.CUDAIsDevice && getTriple().isNVPTX()) {
// Indicate whether __nvvm_reflect should be configured to flush denormal
// floating point values to 0. (This corresponds to its "__CUDA_FTZ"