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//===--- SanitizerMetadata.cpp - Blacklist for sanitizers -----------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// Class which emits metadata consumed by sanitizer instrumentation passes.
//
//===----------------------------------------------------------------------===//
#include "SanitizerMetadata.h"
#include "CodeGenModule.h"
#include "llvm/ADT/StringRef.h"
#include "llvm/IR/Constants.h"
using namespace clang;
using namespace CodeGen;
SanitizerMetadata::SanitizerMetadata(CodeGenModule &CGM) : CGM(CGM) {}
void SanitizerMetadata::reportGlobalToASan(llvm::GlobalVariable *GV,
SourceLocation Loc, StringRef Name,
bool IsDynInit, bool IsBlacklisted) {
if (!CGM.getLangOpts().Sanitize.Address)
return;
IsDynInit &= !CGM.getSanitizerBlacklist().isIn(*GV, "init");
IsBlacklisted |= CGM.getSanitizerBlacklist().isIn(*GV);
llvm::Value *LocDescr = nullptr;
llvm::Value *GlobalName = nullptr;
llvm::LLVMContext &VMContext = CGM.getLLVMContext();
if (!IsBlacklisted) {
// Don't generate source location and global name if it is blacklisted -
// it won't be instrumented anyway.
LocDescr = getLocationMetadata(Loc);
if (!Name.empty())
GlobalName = llvm::MDString::get(VMContext, Name);
}
llvm::Value *GlobalMetadata[] = {
GV, LocDescr, GlobalName,
llvm::ConstantInt::get(llvm::Type::getInt1Ty(VMContext), IsDynInit),
llvm::ConstantInt::get(llvm::Type::getInt1Ty(VMContext), IsBlacklisted)};
llvm::MDNode *ThisGlobal = llvm::MDNode::get(VMContext, GlobalMetadata);
llvm::NamedMDNode *AsanGlobals =
CGM.getModule().getOrInsertNamedMetadata("llvm.asan.globals");
AsanGlobals->addOperand(ThisGlobal);
}
void SanitizerMetadata::reportGlobalToASan(llvm::GlobalVariable *GV,
const VarDecl &D, bool IsDynInit) {
if (!CGM.getLangOpts().Sanitize.Address)
return;
std::string QualName;
llvm::raw_string_ostream OS(QualName);
D.printQualifiedName(OS);
reportGlobalToASan(GV, D.getLocation(), OS.str(), IsDynInit);
}
void SanitizerMetadata::disableSanitizerForGlobal(llvm::GlobalVariable *GV) {
// For now, just make sure the global is not modified by the ASan
// instrumentation.
if (CGM.getLangOpts().Sanitize.Address)
reportGlobalToASan(GV, SourceLocation(), "", false, true);
}
void SanitizerMetadata::disableSanitizerForInstruction(llvm::Instruction *I) {
I->setMetadata(
CGM.getModule().getMDKindID("nosanitize"),
llvm::MDNode::get(CGM.getLLVMContext(), ArrayRef<llvm::Value *>()));
}
llvm::MDNode *SanitizerMetadata::getLocationMetadata(SourceLocation Loc) {
PresumedLoc PLoc = CGM.getContext().getSourceManager().getPresumedLoc(Loc);
if (!PLoc.isValid())
return nullptr;
llvm::LLVMContext &VMContext = CGM.getLLVMContext();
llvm::Value *LocMetadata[] = {
llvm::MDString::get(VMContext, PLoc.getFilename()),
llvm::ConstantInt::get(llvm::Type::getInt32Ty(VMContext), PLoc.getLine()),
llvm::ConstantInt::get(llvm::Type::getInt32Ty(VMContext),
PLoc.getColumn()),
};
return llvm::MDNode::get(VMContext, LocMetadata);
}
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