llvm-project/llvm/lib/IR/LLVMContext.cpp
Ahmed Bougacha c703f852c9 [IR] Define "ptrauth" operand bundle.
This introduces a new "ptrauth" operand bundle to be used in
call/invoke. At the IR level, it's semantically equivalent to an
@llvm.ptrauth.auth followed by an indirect call, but it additionally
provides additional hardening, by preventing the intermediate raw
pointer from being exposed.

This mostly adds the IR definition, verifier checks, and support in
a couple of general helper functions. Clang IRGen and backend support
will come separately.

Note that we'll eventually want to support this bundle in indirectbr as
well, for similar reasons.  indirectbr currently doesn't support bundles
at all, and the IR data structures need to be updated to allow that.

Differential Revision: https://reviews.llvm.org/D113685
2022-02-14 11:27:35 -08:00

363 lines
12 KiB
C++

//===-- LLVMContext.cpp - Implement LLVMContext ---------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
//
// This file implements LLVMContext, as a wrapper around the opaque
// class LLVMContextImpl.
//
//===----------------------------------------------------------------------===//
#include "llvm/IR/LLVMContext.h"
#include "LLVMContextImpl.h"
#include "llvm/ADT/SmallVector.h"
#include "llvm/ADT/StringMap.h"
#include "llvm/ADT/StringRef.h"
#include "llvm/ADT/Twine.h"
#include "llvm/IR/DiagnosticInfo.h"
#include "llvm/IR/DiagnosticPrinter.h"
#include "llvm/IR/LLVMRemarkStreamer.h"
#include "llvm/Remarks/RemarkStreamer.h"
#include "llvm/Support/Casting.h"
#include "llvm/Support/ErrorHandling.h"
#include "llvm/Support/raw_ostream.h"
#include <cassert>
#include <cstdlib>
#include <string>
#include <utility>
using namespace llvm;
LLVMContext::LLVMContext() : pImpl(new LLVMContextImpl(*this)) {
// Create the fixed metadata kinds. This is done in the same order as the
// MD_* enum values so that they correspond.
std::pair<unsigned, StringRef> MDKinds[] = {
#define LLVM_FIXED_MD_KIND(EnumID, Name, Value) {EnumID, Name},
#include "llvm/IR/FixedMetadataKinds.def"
#undef LLVM_FIXED_MD_KIND
};
for (auto &MDKind : MDKinds) {
unsigned ID = getMDKindID(MDKind.second);
assert(ID == MDKind.first && "metadata kind id drifted");
(void)ID;
}
auto *DeoptEntry = pImpl->getOrInsertBundleTag("deopt");
assert(DeoptEntry->second == LLVMContext::OB_deopt &&
"deopt operand bundle id drifted!");
(void)DeoptEntry;
auto *FuncletEntry = pImpl->getOrInsertBundleTag("funclet");
assert(FuncletEntry->second == LLVMContext::OB_funclet &&
"funclet operand bundle id drifted!");
(void)FuncletEntry;
auto *GCTransitionEntry = pImpl->getOrInsertBundleTag("gc-transition");
assert(GCTransitionEntry->second == LLVMContext::OB_gc_transition &&
"gc-transition operand bundle id drifted!");
(void)GCTransitionEntry;
auto *CFGuardTargetEntry = pImpl->getOrInsertBundleTag("cfguardtarget");
assert(CFGuardTargetEntry->second == LLVMContext::OB_cfguardtarget &&
"cfguardtarget operand bundle id drifted!");
(void)CFGuardTargetEntry;
auto *PreallocatedEntry = pImpl->getOrInsertBundleTag("preallocated");
assert(PreallocatedEntry->second == LLVMContext::OB_preallocated &&
"preallocated operand bundle id drifted!");
(void)PreallocatedEntry;
auto *GCLiveEntry = pImpl->getOrInsertBundleTag("gc-live");
assert(GCLiveEntry->second == LLVMContext::OB_gc_live &&
"gc-transition operand bundle id drifted!");
(void)GCLiveEntry;
auto *ClangAttachedCall =
pImpl->getOrInsertBundleTag("clang.arc.attachedcall");
assert(ClangAttachedCall->second == LLVMContext::OB_clang_arc_attachedcall &&
"clang.arc.attachedcall operand bundle id drifted!");
(void)ClangAttachedCall;
auto *PtrauthEntry = pImpl->getOrInsertBundleTag("ptrauth");
assert(PtrauthEntry->second == LLVMContext::OB_ptrauth &&
"ptrauth operand bundle id drifted!");
(void)PtrauthEntry;
SyncScope::ID SingleThreadSSID =
pImpl->getOrInsertSyncScopeID("singlethread");
assert(SingleThreadSSID == SyncScope::SingleThread &&
"singlethread synchronization scope ID drifted!");
(void)SingleThreadSSID;
SyncScope::ID SystemSSID =
pImpl->getOrInsertSyncScopeID("");
assert(SystemSSID == SyncScope::System &&
"system synchronization scope ID drifted!");
(void)SystemSSID;
}
LLVMContext::~LLVMContext() { delete pImpl; }
void LLVMContext::addModule(Module *M) {
pImpl->OwnedModules.insert(M);
}
void LLVMContext::removeModule(Module *M) {
pImpl->OwnedModules.erase(M);
}
//===----------------------------------------------------------------------===//
// Recoverable Backend Errors
//===----------------------------------------------------------------------===//
void LLVMContext::setDiagnosticHandlerCallBack(
DiagnosticHandler::DiagnosticHandlerTy DiagnosticHandler,
void *DiagnosticContext, bool RespectFilters) {
pImpl->DiagHandler->DiagHandlerCallback = DiagnosticHandler;
pImpl->DiagHandler->DiagnosticContext = DiagnosticContext;
pImpl->RespectDiagnosticFilters = RespectFilters;
}
void LLVMContext::setDiagnosticHandler(std::unique_ptr<DiagnosticHandler> &&DH,
bool RespectFilters) {
pImpl->DiagHandler = std::move(DH);
pImpl->RespectDiagnosticFilters = RespectFilters;
}
void LLVMContext::setDiagnosticsHotnessRequested(bool Requested) {
pImpl->DiagnosticsHotnessRequested = Requested;
}
bool LLVMContext::getDiagnosticsHotnessRequested() const {
return pImpl->DiagnosticsHotnessRequested;
}
void LLVMContext::setDiagnosticsHotnessThreshold(Optional<uint64_t> Threshold) {
pImpl->DiagnosticsHotnessThreshold = Threshold;
}
uint64_t LLVMContext::getDiagnosticsHotnessThreshold() const {
return pImpl->DiagnosticsHotnessThreshold.getValueOr(UINT64_MAX);
}
bool LLVMContext::isDiagnosticsHotnessThresholdSetFromPSI() const {
return !pImpl->DiagnosticsHotnessThreshold.hasValue();
}
remarks::RemarkStreamer *LLVMContext::getMainRemarkStreamer() {
return pImpl->MainRemarkStreamer.get();
}
const remarks::RemarkStreamer *LLVMContext::getMainRemarkStreamer() const {
return const_cast<LLVMContext *>(this)->getMainRemarkStreamer();
}
void LLVMContext::setMainRemarkStreamer(
std::unique_ptr<remarks::RemarkStreamer> RemarkStreamer) {
pImpl->MainRemarkStreamer = std::move(RemarkStreamer);
}
LLVMRemarkStreamer *LLVMContext::getLLVMRemarkStreamer() {
return pImpl->LLVMRS.get();
}
const LLVMRemarkStreamer *LLVMContext::getLLVMRemarkStreamer() const {
return const_cast<LLVMContext *>(this)->getLLVMRemarkStreamer();
}
void LLVMContext::setLLVMRemarkStreamer(
std::unique_ptr<LLVMRemarkStreamer> RemarkStreamer) {
pImpl->LLVMRS = std::move(RemarkStreamer);
}
DiagnosticHandler::DiagnosticHandlerTy
LLVMContext::getDiagnosticHandlerCallBack() const {
return pImpl->DiagHandler->DiagHandlerCallback;
}
void *LLVMContext::getDiagnosticContext() const {
return pImpl->DiagHandler->DiagnosticContext;
}
void LLVMContext::setYieldCallback(YieldCallbackTy Callback, void *OpaqueHandle)
{
pImpl->YieldCallback = Callback;
pImpl->YieldOpaqueHandle = OpaqueHandle;
}
void LLVMContext::yield() {
if (pImpl->YieldCallback)
pImpl->YieldCallback(this, pImpl->YieldOpaqueHandle);
}
void LLVMContext::emitError(const Twine &ErrorStr) {
diagnose(DiagnosticInfoInlineAsm(ErrorStr));
}
void LLVMContext::emitError(const Instruction *I, const Twine &ErrorStr) {
assert (I && "Invalid instruction");
diagnose(DiagnosticInfoInlineAsm(*I, ErrorStr));
}
static bool isDiagnosticEnabled(const DiagnosticInfo &DI) {
// Optimization remarks are selective. They need to check whether the regexp
// pattern, passed via one of the -pass-remarks* flags, matches the name of
// the pass that is emitting the diagnostic. If there is no match, ignore the
// diagnostic and return.
//
// Also noisy remarks are only enabled if we have hotness information to sort
// them.
if (auto *Remark = dyn_cast<DiagnosticInfoOptimizationBase>(&DI))
return Remark->isEnabled() &&
(!Remark->isVerbose() || Remark->getHotness());
return true;
}
const char *
LLVMContext::getDiagnosticMessagePrefix(DiagnosticSeverity Severity) {
switch (Severity) {
case DS_Error:
return "error";
case DS_Warning:
return "warning";
case DS_Remark:
return "remark";
case DS_Note:
return "note";
}
llvm_unreachable("Unknown DiagnosticSeverity");
}
void LLVMContext::diagnose(const DiagnosticInfo &DI) {
if (auto *OptDiagBase = dyn_cast<DiagnosticInfoOptimizationBase>(&DI))
if (LLVMRemarkStreamer *RS = getLLVMRemarkStreamer())
RS->emit(*OptDiagBase);
// If there is a report handler, use it.
if (pImpl->DiagHandler &&
(!pImpl->RespectDiagnosticFilters || isDiagnosticEnabled(DI)) &&
pImpl->DiagHandler->handleDiagnostics(DI))
return;
if (!isDiagnosticEnabled(DI))
return;
// Otherwise, print the message with a prefix based on the severity.
DiagnosticPrinterRawOStream DP(errs());
errs() << getDiagnosticMessagePrefix(DI.getSeverity()) << ": ";
DI.print(DP);
errs() << "\n";
if (DI.getSeverity() == DS_Error)
exit(1);
}
void LLVMContext::emitError(uint64_t LocCookie, const Twine &ErrorStr) {
diagnose(DiagnosticInfoInlineAsm(LocCookie, ErrorStr));
}
//===----------------------------------------------------------------------===//
// Metadata Kind Uniquing
//===----------------------------------------------------------------------===//
/// Return a unique non-zero ID for the specified metadata kind.
unsigned LLVMContext::getMDKindID(StringRef Name) const {
// If this is new, assign it its ID.
return pImpl->CustomMDKindNames.insert(
std::make_pair(
Name, pImpl->CustomMDKindNames.size()))
.first->second;
}
/// getHandlerNames - Populate client-supplied smallvector using custom
/// metadata name and ID.
void LLVMContext::getMDKindNames(SmallVectorImpl<StringRef> &Names) const {
Names.resize(pImpl->CustomMDKindNames.size());
for (StringMap<unsigned>::const_iterator I = pImpl->CustomMDKindNames.begin(),
E = pImpl->CustomMDKindNames.end(); I != E; ++I)
Names[I->second] = I->first();
}
void LLVMContext::getOperandBundleTags(SmallVectorImpl<StringRef> &Tags) const {
pImpl->getOperandBundleTags(Tags);
}
StringMapEntry<uint32_t> *
LLVMContext::getOrInsertBundleTag(StringRef TagName) const {
return pImpl->getOrInsertBundleTag(TagName);
}
uint32_t LLVMContext::getOperandBundleTagID(StringRef Tag) const {
return pImpl->getOperandBundleTagID(Tag);
}
SyncScope::ID LLVMContext::getOrInsertSyncScopeID(StringRef SSN) {
return pImpl->getOrInsertSyncScopeID(SSN);
}
void LLVMContext::getSyncScopeNames(SmallVectorImpl<StringRef> &SSNs) const {
pImpl->getSyncScopeNames(SSNs);
}
void LLVMContext::setGC(const Function &Fn, std::string GCName) {
auto It = pImpl->GCNames.find(&Fn);
if (It == pImpl->GCNames.end()) {
pImpl->GCNames.insert(std::make_pair(&Fn, std::move(GCName)));
return;
}
It->second = std::move(GCName);
}
const std::string &LLVMContext::getGC(const Function &Fn) {
return pImpl->GCNames[&Fn];
}
void LLVMContext::deleteGC(const Function &Fn) {
pImpl->GCNames.erase(&Fn);
}
bool LLVMContext::shouldDiscardValueNames() const {
return pImpl->DiscardValueNames;
}
bool LLVMContext::isODRUniquingDebugTypes() const { return !!pImpl->DITypeMap; }
void LLVMContext::enableDebugTypeODRUniquing() {
if (pImpl->DITypeMap)
return;
pImpl->DITypeMap.emplace();
}
void LLVMContext::disableDebugTypeODRUniquing() { pImpl->DITypeMap.reset(); }
void LLVMContext::setDiscardValueNames(bool Discard) {
pImpl->DiscardValueNames = Discard;
}
OptPassGate &LLVMContext::getOptPassGate() const {
return pImpl->getOptPassGate();
}
void LLVMContext::setOptPassGate(OptPassGate& OPG) {
pImpl->setOptPassGate(OPG);
}
const DiagnosticHandler *LLVMContext::getDiagHandlerPtr() const {
return pImpl->DiagHandler.get();
}
std::unique_ptr<DiagnosticHandler> LLVMContext::getDiagnosticHandler() {
return std::move(pImpl->DiagHandler);
}
void LLVMContext::enableOpaquePointers() const {
assert(pImpl->PointerTypes.empty() && pImpl->ASPointerTypes.empty() &&
"Must be called before creating any pointer types");
pImpl->setOpaquePointers(true);
}
bool LLVMContext::supportsTypedPointers() const {
return !pImpl->getOpaquePointers();
}