Re-land r236052, "[SEH] Add 32-bit lowering code for __try"
This reverts r236167.
LLVM should be ready for this now.
llvm-svn: 239415
diff --git a/clang/lib/CodeGen/CGException.cpp b/clang/lib/CodeGen/CGException.cpp
index d9a3f0b..71c548d 100644
--- a/clang/lib/CodeGen/CGException.cpp
+++ b/clang/lib/CodeGen/CGException.cpp
@@ -20,6 +20,7 @@
#include "clang/AST/StmtCXX.h"
#include "clang/AST/StmtObjC.h"
#include "clang/AST/StmtVisitor.h"
+#include "clang/Basic/TargetBuiltins.h"
#include "llvm/IR/CallSite.h"
#include "llvm/IR/Intrinsics.h"
#include "llvm/IR/IntrinsicInst.h"
@@ -1274,14 +1275,6 @@
}
void CodeGenFunction::EmitSEHTryStmt(const SEHTryStmt &S) {
- // FIXME: Implement SEH on other architectures.
- const llvm::Triple &T = CGM.getTarget().getTriple();
- if (T.getArch() != llvm::Triple::x86_64 ||
- !T.isKnownWindowsMSVCEnvironment()) {
- ErrorUnsupported(&S, "__try statement");
- return;
- }
-
EnterSEHTryStmt(S);
{
JumpDest TryExit = getJumpDestInCurrentScope("__try.__leave");
@@ -1306,25 +1299,39 @@
void Emit(CodeGenFunction &CGF, Flags F) override {
ASTContext &Context = CGF.getContext();
- QualType ArgTys[2] = {Context.UnsignedCharTy, Context.VoidPtrTy};
- FunctionProtoType::ExtProtoInfo EPI;
- const auto *FTP = cast<FunctionType>(
- Context.getFunctionType(Context.VoidTy, ArgTys, EPI));
-
- CallArgList Args;
- llvm::Value *IsForEH =
- llvm::ConstantInt::get(CGF.ConvertType(ArgTys[0]), F.isForEHCleanup());
- Args.add(RValue::get(IsForEH), ArgTys[0]);
-
CodeGenModule &CGM = CGF.CGM;
- llvm::Value *Zero = llvm::ConstantInt::get(CGM.Int32Ty, 0);
- llvm::Value *FrameAddr = CGM.getIntrinsic(llvm::Intrinsic::frameaddress);
- llvm::Value *FP = CGF.Builder.CreateCall(FrameAddr, Zero);
- Args.add(RValue::get(FP), ArgTys[1]);
- const CGFunctionInfo &FnInfo =
- CGM.getTypes().arrangeFreeFunctionCall(Args, FTP, /*chainCall=*/false);
- CGF.EmitCall(FnInfo, OutlinedFinally, ReturnValueSlot(), Args);
+ // In 64-bit, we call the child function with arguments. In 32-bit, we store
+ // zero in the parent frame and use framerecover to check the value.
+ const CGFunctionInfo *FnInfo;
+ CallArgList Args;
+ if (CGF.getTarget().getTriple().getArch() == llvm::Triple::x86_64) {
+ // Compute the two argument values.
+ QualType ArgTys[2] = {Context.UnsignedCharTy, Context.VoidPtrTy};
+ llvm::Value *FrameAddr = CGM.getIntrinsic(llvm::Intrinsic::frameaddress);
+ llvm::Value *FP =
+ CGF.Builder.CreateCall(FrameAddr, {CGF.Builder.getInt32(0)});
+ llvm::Value *IsForEH =
+ llvm::ConstantInt::get(CGF.ConvertType(ArgTys[0]), F.isForEHCleanup());
+ Args.add(RValue::get(IsForEH), ArgTys[0]);
+ Args.add(RValue::get(FP), ArgTys[1]);
+
+ // Arrange a two-arg function info and type.
+ FunctionProtoType::ExtProtoInfo EPI;
+ const auto *FPT = cast<FunctionProtoType>(
+ Context.getFunctionType(Context.VoidTy, ArgTys, EPI));
+ FnInfo = &CGM.getTypes().arrangeFreeFunctionCall(Args, FPT,
+ /*chainCall=*/false);
+ } else {
+ // Emit the zero store if this is normal control flow. There are no
+ // explicit arguments.
+ if (F.isForNormalCleanup() && CGF.ChildAbnormalTerminationSlot)
+ CGF.Builder.CreateStore(CGF.Builder.getInt32(0),
+ CGF.ChildAbnormalTerminationSlot);
+ FnInfo = &CGM.getTypes().arrangeNullaryFunction();
+ }
+
+ CGF.EmitCall(*FnInfo, OutlinedFinally, ReturnValueSlot(), Args);
}
};
}
@@ -1335,6 +1342,7 @@
CodeGenFunction &ParentCGF;
const VarDecl *ParentThis;
SmallVector<const VarDecl *, 4> Captures;
+ llvm::Value *AbnormalTermination = nullptr;
CaptureFinder(CodeGenFunction &ParentCGF, const VarDecl *ParentThis)
: ParentCGF(ParentCGF), ParentThis(ParentThis) {}
@@ -1361,25 +1369,93 @@
void VisitCXXThisExpr(const CXXThisExpr *E) {
Captures.push_back(ParentThis);
}
+
+ void VisitCallExpr(const CallExpr *E) {
+ // We only need to add parent frame allocations for these builtins in x86.
+ if (ParentCGF.getTarget().getTriple().getArch() != llvm::Triple::x86)
+ return;
+
+ unsigned ID = E->getBuiltinCallee();
+ switch (ID) {
+ case Builtin::BI__abnormal_termination:
+ case Builtin::BI_abnormal_termination:
+ // This is the simple case where we are the outermost finally. All we
+ // have to do here is make sure we escape this and recover it in the
+ // outlined handler.
+ if (!AbnormalTermination)
+ AbnormalTermination = ParentCGF.CreateMemTemp(
+ ParentCGF.getContext().IntTy, "abnormal_termination");
+ break;
+ }
+ }
};
}
+llvm::Value *CodeGenFunction::recoverAddrOfEscapedLocal(
+ CodeGenFunction &ParentCGF, llvm::Value *ParentVar, llvm::Value *ParentFP) {
+ llvm::CallInst *RecoverCall = nullptr;
+ CGBuilderTy Builder(AllocaInsertPt);
+ if (auto *ParentAlloca = dyn_cast<llvm::AllocaInst>(ParentVar)) {
+ // Mark the variable escaped if nobody else referenced it and compute the
+ // frameescape index.
+ auto InsertPair = ParentCGF.EscapedLocals.insert(
+ std::make_pair(ParentAlloca, ParentCGF.EscapedLocals.size()));
+ int FrameEscapeIdx = InsertPair.first->second;
+ // call i8* @llvm.framerecover(i8* bitcast(@parentFn), i8* %fp, i32 N)
+ llvm::Function *FrameRecoverFn = llvm::Intrinsic::getDeclaration(
+ &CGM.getModule(), llvm::Intrinsic::framerecover);
+ llvm::Constant *ParentI8Fn =
+ llvm::ConstantExpr::getBitCast(ParentCGF.CurFn, Int8PtrTy);
+ RecoverCall = Builder.CreateCall(
+ FrameRecoverFn, {ParentI8Fn, ParentFP,
+ llvm::ConstantInt::get(Int32Ty, FrameEscapeIdx)});
+
+ } else {
+ // If the parent didn't have an alloca, we're doing some nested outlining.
+ // Just clone the existing framerecover call, but tweak the FP argument to
+ // use our FP value. All other arguments are constants.
+ auto *ParentRecover =
+ cast<llvm::IntrinsicInst>(ParentVar->stripPointerCasts());
+ assert(ParentRecover->getIntrinsicID() == llvm::Intrinsic::framerecover &&
+ "expected alloca or framerecover in parent LocalDeclMap");
+ RecoverCall = cast<llvm::CallInst>(ParentRecover->clone());
+ RecoverCall->setArgOperand(1, ParentFP);
+ RecoverCall->insertBefore(AllocaInsertPt);
+ }
+
+ // Bitcast the variable, rename it, and insert it in the local decl map.
+ llvm::Value *ChildVar =
+ Builder.CreateBitCast(RecoverCall, ParentVar->getType());
+ ChildVar->setName(ParentVar->getName());
+ return ChildVar;
+}
+
void CodeGenFunction::EmitCapturedLocals(CodeGenFunction &ParentCGF,
- const Stmt *OutlinedStmt,
- llvm::Value *ParentFP) {
+ const Stmt *OutlinedStmt) {
// Find all captures in the Stmt.
CaptureFinder Finder(ParentCGF, ParentCGF.CXXABIThisDecl);
Finder.Visit(OutlinedStmt);
// Typically there are no captures and we can exit early.
- if (Finder.Captures.empty())
+ if (Finder.Captures.empty() && !Finder.AbnormalTermination)
return;
- // Prepare the first two arguments to llvm.framerecover.
- llvm::Function *FrameRecoverFn = llvm::Intrinsic::getDeclaration(
- &CGM.getModule(), llvm::Intrinsic::framerecover);
- llvm::Constant *ParentI8Fn =
- llvm::ConstantExpr::getBitCast(ParentCGF.CurFn, Int8PtrTy);
+ // The parent FP is passed in as EBP on x86 and the second argument on x64.
+ llvm::Value *ParentFP;
+ if (CGM.getTarget().getTriple().getArch() == llvm::Triple::x86_64) {
+ auto AI = CurFn->arg_begin();
+ ++AI;
+ ParentFP = AI;
+ } else {
+ CGBuilderTy Builder(AllocaInsertPt);
+ ParentFP = Builder.CreateCall(
+ CGM.getIntrinsic(llvm::Intrinsic::frameaddress), {Builder.getInt32(1)});
+
+ // Inlining will break llvm.frameaddress(1), so disable it.
+ // FIXME: We could teach the inliner about the special meaning of
+ // frameaddress, framerecover, and frameescape to remove this limitation.
+ CurFn->addFnAttr(llvm::Attribute::NoInline);
+ }
// Create llvm.framerecover calls for all captures.
for (const VarDecl *VD : Finder.Captures) {
@@ -1402,39 +1478,16 @@
continue;
llvm::Value *ParentVar = I->second;
- llvm::CallInst *RecoverCall = nullptr;
- CGBuilderTy Builder(AllocaInsertPt);
- if (auto *ParentAlloca = dyn_cast<llvm::AllocaInst>(ParentVar)) {
- // Mark the variable escaped if nobody else referenced it and compute the
- // frameescape index.
- auto InsertPair =
- ParentCGF.EscapedLocals.insert(std::make_pair(ParentAlloca, -1));
- if (InsertPair.second)
- InsertPair.first->second = ParentCGF.EscapedLocals.size() - 1;
- int FrameEscapeIdx = InsertPair.first->second;
- // call i8* @llvm.framerecover(i8* bitcast(@parentFn), i8* %fp, i32 N)
- RecoverCall = Builder.CreateCall(
- FrameRecoverFn, {ParentI8Fn, ParentFP,
- llvm::ConstantInt::get(Int32Ty, FrameEscapeIdx)});
+ LocalDeclMap[VD] =
+ recoverAddrOfEscapedLocal(ParentCGF, ParentVar, ParentFP);
+ }
- } else {
- // If the parent didn't have an alloca, we're doing some nested outlining.
- // Just clone the existing framerecover call, but tweak the FP argument to
- // use our FP value. All other arguments are constants.
- auto *ParentRecover =
- cast<llvm::IntrinsicInst>(ParentVar->stripPointerCasts());
- assert(ParentRecover->getIntrinsicID() == llvm::Intrinsic::framerecover &&
- "expected alloca or framerecover in parent LocalDeclMap");
- RecoverCall = cast<llvm::CallInst>(ParentRecover->clone());
- RecoverCall->setArgOperand(1, ParentFP);
- RecoverCall->insertBefore(AllocaInsertPt);
- }
-
- // Bitcast the variable, rename it, and insert it in the local decl map.
- llvm::Value *ChildVar =
- Builder.CreateBitCast(RecoverCall, ParentVar->getType());
- ChildVar->setName(ParentVar->getName());
- LocalDeclMap[VD] = ChildVar;
+ // AbnormalTermination is just another capture, but it has no Decl.
+ if (Finder.AbnormalTermination) {
+ AbnormalTerminationSlot = recoverAddrOfEscapedLocal(
+ ParentCGF, Finder.AbnormalTermination, ParentFP);
+ // Save the slot on the parent so it can store 1 and 0 to it.
+ ParentCGF.ChildAbnormalTerminationSlot = Finder.AbnormalTermination;
}
}
@@ -1469,10 +1522,7 @@
OutlinedStmt->getLocStart(), OutlinedStmt->getLocStart());
CGM.SetLLVMFunctionAttributes(nullptr, FnInfo, CurFn);
-
- auto AI = Fn->arg_begin();
- ++AI;
- EmitCapturedLocals(ParentCGF, OutlinedStmt, &*AI);
+ EmitCapturedLocals(ParentCGF, OutlinedStmt);
}
/// Create a stub filter function that will ultimately hold the code of the
@@ -1484,14 +1534,16 @@
const Expr *FilterExpr = Except.getFilterExpr();
SourceLocation StartLoc = FilterExpr->getLocStart();
- SEHPointersDecl = ImplicitParamDecl::Create(
- getContext(), nullptr, StartLoc,
- &getContext().Idents.get("exception_pointers"), getContext().VoidPtrTy);
FunctionArgList Args;
- Args.push_back(SEHPointersDecl);
- Args.push_back(ImplicitParamDecl::Create(
- getContext(), nullptr, StartLoc,
- &getContext().Idents.get("frame_pointer"), getContext().VoidPtrTy));
+ if (CGM.getTarget().getTriple().getArch() == llvm::Triple::x86_64) {
+ SEHPointersDecl = ImplicitParamDecl::Create(
+ getContext(), nullptr, StartLoc,
+ &getContext().Idents.get("exception_pointers"), getContext().VoidPtrTy);
+ Args.push_back(SEHPointersDecl);
+ Args.push_back(ImplicitParamDecl::Create(
+ getContext(), nullptr, StartLoc,
+ &getContext().Idents.get("frame_pointer"), getContext().VoidPtrTy));
+ }
// Get the mangled function name.
SmallString<128> Name;
@@ -1532,13 +1584,15 @@
SourceLocation StartLoc = FinallyBlock->getLocStart();
FunctionArgList Args;
- Args.push_back(ImplicitParamDecl::Create(
- getContext(), nullptr, StartLoc,
- &getContext().Idents.get("abnormal_termination"),
- getContext().UnsignedCharTy));
- Args.push_back(ImplicitParamDecl::Create(
- getContext(), nullptr, StartLoc,
- &getContext().Idents.get("frame_pointer"), getContext().VoidPtrTy));
+ if (CGM.getTarget().getTriple().getArch() == llvm::Triple::x86_64) {
+ Args.push_back(ImplicitParamDecl::Create(
+ getContext(), nullptr, StartLoc,
+ &getContext().Idents.get("abnormal_termination"),
+ getContext().UnsignedCharTy));
+ Args.push_back(ImplicitParamDecl::Create(
+ getContext(), nullptr, StartLoc,
+ &getContext().Idents.get("frame_pointer"), getContext().VoidPtrTy));
+ }
// Get the mangled function name.
SmallString<128> Name;
@@ -1570,7 +1624,7 @@
// };
// void *exn.slot =
// (void *)(uintptr_t)exception_pointers->ExceptionRecord->ExceptionCode;
- llvm::Value *Ptrs = Builder.CreateLoad(GetAddrOfLocalVar(SEHPointersDecl));
+ llvm::Value *Ptrs = EmitSEHExceptionInfo();
llvm::Type *RecordTy = CGM.Int32Ty->getPointerTo();
llvm::Type *PtrsTy = llvm::StructType::get(RecordTy, CGM.VoidPtrTy, nullptr);
Ptrs = Builder.CreateBitCast(Ptrs, PtrsTy->getPointerTo());
@@ -1585,6 +1639,9 @@
}
llvm::Value *CodeGenFunction::EmitSEHExceptionInfo() {
+ if (CGM.getTarget().getTriple().getArch() != llvm::Triple::x86_64)
+ return Builder.CreateCall(
+ CGM.getIntrinsic(llvm::Intrinsic::eh_exceptioninfo), {});
// Sema should diagnose calling this builtin outside of a filter context, but
// don't crash if we screw up.
if (!SEHPointersDecl)
@@ -1602,6 +1659,8 @@
}
llvm::Value *CodeGenFunction::EmitSEHAbnormalTermination() {
+ if (CGM.getTarget().getTriple().getArch() != llvm::Triple::x86_64)
+ return Builder.CreateLoad(AbnormalTerminationSlot);
// Abnormal termination is just the first parameter to the outlined finally
// helper.
auto AI = CurFn->arg_begin();
@@ -1611,9 +1670,15 @@
void CodeGenFunction::EnterSEHTryStmt(const SEHTryStmt &S) {
CodeGenFunction HelperCGF(CGM, /*suppressNewContext=*/true);
if (const SEHFinallyStmt *Finally = S.getFinallyHandler()) {
- // Push a cleanup for __finally blocks.
+ // Outline the finally block.
llvm::Function *FinallyFunc =
HelperCGF.GenerateSEHFinallyFunction(*this, *Finally);
+
+ // Store 1 to indicate abnormal termination if an exception is thrown.
+ if (ChildAbnormalTerminationSlot)
+ Builder.CreateStore(Builder.getInt32(1), ChildAbnormalTerminationSlot);
+
+ // Push a cleanup for __finally blocks.
EHStack.pushCleanup<PerformSEHFinally>(NormalAndEHCleanup, FinallyFunc);
return;
}
@@ -1645,6 +1710,7 @@
// Just pop the cleanup if it's a __finally block.
if (S.getFinallyHandler()) {
PopCleanupBlock();
+ ChildAbnormalTerminationSlot = nullptr;
return;
}