Reland 192220 "Abstract out parts of thunk emission code, add support for simple thunks when using -cxx-abi microsoft" with relaxed assertions
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@192285 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/CGCXXABI.h b/lib/CodeGen/CGCXXABI.h
index 3a1c8d1..eaeb971 100644
--- a/lib/CodeGen/CGCXXABI.h
+++ b/lib/CodeGen/CGCXXABI.h
@@ -339,11 +339,17 @@
SourceLocation CallLoc,
llvm::Value *This) = 0;
+ virtual void adjustCallArgsForDestructorThunk(CodeGenFunction &CGF,
+ GlobalDecl GD,
+ CallArgList &CallArgs) {}
+
/// Emit any tables needed to implement virtual inheritance. For Itanium,
/// this emits virtual table tables. For the MSVC++ ABI, this emits virtual
/// base tables.
virtual void emitVirtualInheritanceTables(const CXXRecordDecl *RD) = 0;
+ virtual void setThunkLinkage(llvm::Function *Thunk, bool ForVTable) = 0;
+
virtual void EmitReturnFromThunk(CodeGenFunction &CGF,
RValue RV, QualType ResultType);
diff --git a/lib/CodeGen/CGVTables.cpp b/lib/CodeGen/CGVTables.cpp
index b987eb4..5ede565 100644
--- a/lib/CodeGen/CGVTables.cpp
+++ b/lib/CodeGen/CGVTables.cpp
@@ -333,6 +333,9 @@
// Add our adjusted 'this' pointer.
CallArgs.add(RValue::get(AdjustedThisPtr), ThisType);
+ if (isa<CXXDestructorDecl>(MD))
+ CGM.getCXXABI().adjustCallArgsForDestructorThunk(*this, GD, CallArgs);
+
// Add the rest of the parameters.
for (FunctionDecl::param_const_iterator I = MD->param_begin(),
E = MD->param_end(); I != E; ++I) {
@@ -390,14 +393,8 @@
setThunkVisibility(CGM, MD, Thunk, Fn);
}
-void CodeGenVTables::EmitThunk(GlobalDecl GD, const ThunkInfo &Thunk,
- bool UseAvailableExternallyLinkage)
-{
- if (CGM.getTarget().getCXXABI().isMicrosoft()) {
- // Emission of thunks is not supported yet in Microsoft ABI.
- return;
- }
-
+void CodeGenVTables::emitThunk(GlobalDecl GD, const ThunkInfo &Thunk,
+ bool ForVTable) {
const CGFunctionInfo &FnInfo = CGM.getTypes().arrangeGlobalDeclaration(GD);
// FIXME: re-use FnInfo in this computation.
@@ -435,9 +432,11 @@
}
llvm::Function *ThunkFn = cast<llvm::Function>(Entry);
+ bool ABIHasKeyFunctions = CGM.getTarget().getCXXABI().hasKeyFunctions();
+ bool UseAvailableExternallyLinkage = ForVTable && ABIHasKeyFunctions;
if (!ThunkFn->isDeclaration()) {
- if (UseAvailableExternallyLinkage) {
+ if (!ABIHasKeyFunctions || UseAvailableExternallyLinkage) {
// There is already a thunk emitted for this function, do nothing.
return;
}
@@ -466,14 +465,17 @@
CodeGenFunction(CGM).GenerateThunk(ThunkFn, FnInfo, GD, Thunk);
}
- if (UseAvailableExternallyLinkage)
- ThunkFn->setLinkage(llvm::GlobalValue::AvailableExternallyLinkage);
+ CGM.getCXXABI().setThunkLinkage(ThunkFn, ForVTable);
}
-void CodeGenVTables::MaybeEmitThunkAvailableExternally(GlobalDecl GD,
- const ThunkInfo &Thunk) {
- // We only want to do this when building with optimizations.
- if (!CGM.getCodeGenOpts().OptimizationLevel)
+void CodeGenVTables::maybeEmitThunkForVTable(GlobalDecl GD,
+ const ThunkInfo &Thunk) {
+ // If the ABI has key functions, only the TU with the key function should emit
+ // the thunk. However, we can allow inlining of thunks if we emit them with
+ // available_externally linkage together with vtables when optimizations are
+ // enabled.
+ if (CGM.getTarget().getCXXABI().hasKeyFunctions() &&
+ !CGM.getCodeGenOpts().OptimizationLevel)
return;
// We can't emit thunks for member functions with incomplete types.
@@ -482,7 +484,7 @@
cast<FunctionType>(MD->getType().getTypePtr())))
return;
- EmitThunk(GD, Thunk, /*UseAvailableExternallyLinkage=*/true);
+ emitThunk(GD, Thunk, /*ForVTable=*/true);
}
void CodeGenVTables::EmitThunks(GlobalDecl GD)
@@ -494,21 +496,18 @@
if (isa<CXXDestructorDecl>(MD) && GD.getDtorType() == Dtor_Base)
return;
+ const VTableContext::ThunkInfoVectorTy *ThunkInfoVector;
if (VFTContext.isValid()) {
- // FIXME: This is a temporary solution to force generation of vftables in
- // Microsoft ABI. Remove when we thread VFTableContext through CodeGen.
- VFTContext->getVFPtrOffsets(MD->getParent());
- return;
+ ThunkInfoVector = VFTContext->getThunkInfo(GD);
+ } else {
+ ThunkInfoVector = VTContext.getThunkInfo(GD);
}
- const VTableContext::ThunkInfoVectorTy *ThunkInfoVector =
- VTContext.getThunkInfo(MD);
if (!ThunkInfoVector)
return;
for (unsigned I = 0, E = ThunkInfoVector->size(); I != E; ++I)
- EmitThunk(GD, (*ThunkInfoVector)[I],
- /*UseAvailableExternallyLinkage=*/false);
+ emitThunk(GD, (*ThunkInfoVector)[I], /*ForVTable=*/false);
}
llvm::Constant *
@@ -603,7 +602,7 @@
VTableThunks[NextVTableThunkIndex].first == I) {
const ThunkInfo &Thunk = VTableThunks[NextVTableThunkIndex].second;
- MaybeEmitThunkAvailableExternally(GD, Thunk);
+ maybeEmitThunkForVTable(GD, Thunk);
Init = CGM.GetAddrOfThunk(GD, Thunk);
NextVTableThunkIndex++;
diff --git a/lib/CodeGen/CGVTables.h b/lib/CodeGen/CGVTables.h
index 9b95952..e17ad89 100644
--- a/lib/CodeGen/CGVTables.h
+++ b/lib/CodeGen/CGVTables.h
@@ -52,15 +52,12 @@
/// indices.
SecondaryVirtualPointerIndicesMapTy SecondaryVirtualPointerIndices;
- /// EmitThunk - Emit a single thunk.
- void EmitThunk(GlobalDecl GD, const ThunkInfo &Thunk,
- bool UseAvailableExternallyLinkage);
+ /// emitThunk - Emit a single thunk.
+ void emitThunk(GlobalDecl GD, const ThunkInfo &Thunk, bool ForVTable);
- /// MaybeEmitThunkAvailableExternally - Try to emit the given thunk with
- /// available_externally linkage to allow for inlining of thunks.
- /// This will be done iff optimizations are enabled and the member function
- /// doesn't contain any incomplete types.
- void MaybeEmitThunkAvailableExternally(GlobalDecl GD, const ThunkInfo &Thunk);
+ /// maybeEmitThunkForVTable - Emit the given thunk for the vtable if needed by
+ /// the ABI.
+ void maybeEmitThunkForVTable(GlobalDecl GD, const ThunkInfo &Thunk);
public:
/// CreateVTableInitializer - Create a vtable initializer for the given record
diff --git a/lib/CodeGen/ItaniumCXXABI.cpp b/lib/CodeGen/ItaniumCXXABI.cpp
index ecf5d57..1e34a16 100644
--- a/lib/CodeGen/ItaniumCXXABI.cpp
+++ b/lib/CodeGen/ItaniumCXXABI.cpp
@@ -173,6 +173,13 @@
void emitVirtualInheritanceTables(const CXXRecordDecl *RD);
+ void setThunkLinkage(llvm::Function *Thunk, bool ForVTable) {
+ // Allow inlining of thunks by emitting them with available_externally
+ // linkage together with vtables when needed.
+ if (ForVTable)
+ Thunk->setLinkage(llvm::GlobalValue::AvailableExternallyLinkage);
+ }
+
StringRef GetPureVirtualCallName() { return "__cxa_pure_virtual"; }
StringRef GetDeletedVirtualCallName() { return "__cxa_deleted_virtual"; }
diff --git a/lib/CodeGen/MicrosoftCXXABI.cpp b/lib/CodeGen/MicrosoftCXXABI.cpp
index 1d73b21..7452c86 100644
--- a/lib/CodeGen/MicrosoftCXXABI.cpp
+++ b/lib/CodeGen/MicrosoftCXXABI.cpp
@@ -173,8 +173,20 @@
CXXDtorType DtorType, SourceLocation CallLoc,
llvm::Value *This);
+ void adjustCallArgsForDestructorThunk(CodeGenFunction &CGF, GlobalDecl GD,
+ CallArgList &CallArgs) {
+ assert(GD.getDtorType() == Dtor_Deleting &&
+ "Only deleting destructor thunks are available in this ABI");
+ CallArgs.add(RValue::get(getStructorImplicitParamValue(CGF)),
+ CGM.getContext().IntTy);
+ }
+
void emitVirtualInheritanceTables(const CXXRecordDecl *RD);
+ void setThunkLinkage(llvm::Function *Thunk, bool ForVTable) {
+ Thunk->setLinkage(llvm::GlobalValue::WeakAnyLinkage);
+ }
+
void EmitGuardedInit(CodeGenFunction &CGF, const VarDecl &D,
llvm::GlobalVariable *DeclPtr,
bool PerformInit);