Add Windows support for the GNUstep Objective-C ABI V2.
Summary:
Introduces funclet-based unwinding for Objective-C and fixes an issue
where global blocks can't have their isa pointers initialised on
Windows.
After discussion with Dustin, this changes the name mangling of
Objective-C types to prevent a C++ catch statement of type struct X*
from catching an Objective-C object of type X*.
Reviewers: rjmccall, DHowett-MSFT
Reviewed By: rjmccall, DHowett-MSFT
Subscribers: mgrang, mstorsjo, smeenai, cfe-commits
Differential Revision: https://reviews.llvm.org/D50144
llvm-svn: 339428
diff --git a/clang/lib/CodeGen/CGObjCRuntime.cpp b/clang/lib/CodeGen/CGObjCRuntime.cpp
index a43885c..64a9df2 100644
--- a/clang/lib/CodeGen/CGObjCRuntime.cpp
+++ b/clang/lib/CodeGen/CGObjCRuntime.cpp
@@ -15,6 +15,7 @@
#include "CGObjCRuntime.h"
#include "CGCleanup.h"
+#include "CGCXXABI.h"
#include "CGRecordLayout.h"
#include "CodeGenFunction.h"
#include "CodeGenModule.h"
@@ -22,6 +23,7 @@
#include "clang/AST/StmtObjC.h"
#include "clang/CodeGen/CGFunctionInfo.h"
#include "llvm/IR/CallSite.h"
+#include "llvm/Support/SaveAndRestore.h"
using namespace clang;
using namespace CodeGen;
@@ -120,6 +122,8 @@
const Stmt *Body;
llvm::BasicBlock *Block;
llvm::Constant *TypeInfo;
+ /// Flags used to differentiate cleanups and catchalls in Windows SEH
+ unsigned Flags;
};
struct CallObjCEndCatch final : EHScopeStack::Cleanup {
@@ -148,13 +152,17 @@
if (S.getNumCatchStmts())
Cont = CGF.getJumpDestInCurrentScope("eh.cont");
+ bool useFunclets = EHPersonality::get(CGF).usesFuncletPads();
+
CodeGenFunction::FinallyInfo FinallyInfo;
- if (const ObjCAtFinallyStmt *Finally = S.getFinallyStmt())
- FinallyInfo.enter(CGF, Finally->getFinallyBody(),
- beginCatchFn, endCatchFn, exceptionRethrowFn);
+ if (!useFunclets)
+ if (const ObjCAtFinallyStmt *Finally = S.getFinallyStmt())
+ FinallyInfo.enter(CGF, Finally->getFinallyBody(),
+ beginCatchFn, endCatchFn, exceptionRethrowFn);
SmallVector<CatchHandler, 8> Handlers;
+
// Enter the catch, if there is one.
if (S.getNumCatchStmts()) {
for (unsigned I = 0, N = S.getNumCatchStmts(); I != N; ++I) {
@@ -166,10 +174,13 @@
Handler.Variable = CatchDecl;
Handler.Body = CatchStmt->getCatchBody();
Handler.Block = CGF.createBasicBlock("catch");
+ Handler.Flags = 0;
// @catch(...) always matches.
if (!CatchDecl) {
- Handler.TypeInfo = nullptr; // catch-all
+ auto catchAll = getCatchAllTypeInfo();
+ Handler.TypeInfo = catchAll.RTTI;
+ Handler.Flags = catchAll.Flags;
// Don't consider any other catches.
break;
}
@@ -179,9 +190,31 @@
EHCatchScope *Catch = CGF.EHStack.pushCatch(Handlers.size());
for (unsigned I = 0, E = Handlers.size(); I != E; ++I)
- Catch->setHandler(I, Handlers[I].TypeInfo, Handlers[I].Block);
+ Catch->setHandler(I, { Handlers[I].TypeInfo, Handlers[I].Flags }, Handlers[I].Block);
}
+ if (useFunclets)
+ if (const ObjCAtFinallyStmt *Finally = S.getFinallyStmt()) {
+ CodeGenFunction HelperCGF(CGM, /*suppressNewContext=*/true);
+ if (!CGF.CurSEHParent)
+ CGF.CurSEHParent = cast<NamedDecl>(CGF.CurFuncDecl);
+ // Outline the finally block.
+ const Stmt *FinallyBlock = Finally->getFinallyBody();
+ HelperCGF.startOutlinedSEHHelper(CGF, /*isFilter*/false, FinallyBlock);
+
+ // Emit the original filter expression, convert to i32, and return.
+ HelperCGF.EmitStmt(FinallyBlock);
+
+ HelperCGF.FinishFunction(FinallyBlock->getLocEnd());
+
+ llvm::Function *FinallyFunc = HelperCGF.CurFn;
+
+
+ // Push a cleanup for __finally blocks.
+ CGF.pushSEHCleanup(NormalAndEHCleanup, FinallyFunc);
+ }
+
+
// Emit the try body.
CGF.EmitStmt(S.getTryBody());
@@ -197,6 +230,13 @@
CatchHandler &Handler = Handlers[I];
CGF.EmitBlock(Handler.Block);
+ llvm::CatchPadInst *CPI = nullptr;
+ SaveAndRestore<llvm::Instruction *> RestoreCurrentFuncletPad(CGF.CurrentFuncletPad);
+ if (useFunclets)
+ if ((CPI = dyn_cast_or_null<llvm::CatchPadInst>(Handler.Block->getFirstNonPHI()))) {
+ CGF.CurrentFuncletPad = CPI;
+ CPI->setOperand(2, CGF.getExceptionSlot().getPointer());
+ }
llvm::Value *RawExn = CGF.getExceptionFromSlot();
// Enter the catch.
@@ -223,6 +263,8 @@
CGF.EmitAutoVarDecl(*CatchParam);
EmitInitOfCatchParam(CGF, CastExn, CatchParam);
}
+ if (CPI)
+ CGF.EHStack.pushCleanup<CatchRetScope>(NormalCleanup, CPI);
CGF.ObjCEHValueStack.push_back(Exn);
CGF.EmitStmt(Handler.Body);
@@ -232,13 +274,13 @@
cleanups.ForceCleanup();
CGF.EmitBranchThroughCleanup(Cont);
- }
+ }
// Go back to the try-statement fallthrough.
CGF.Builder.restoreIP(SavedIP);
// Pop out of the finally.
- if (S.getFinallyStmt())
+ if (!useFunclets && S.getFinallyStmt())
FinallyInfo.exit(CGF);
if (Cont.isValid())
@@ -277,7 +319,7 @@
: SyncExitFn(SyncExitFn), SyncArg(SyncArg) {}
void Emit(CodeGenFunction &CGF, Flags flags) override {
- CGF.Builder.CreateCall(SyncExitFn, SyncArg)->setDoesNotThrow();
+ CGF.EmitNounwindRuntimeCall(SyncExitFn, SyncArg);
}
};
}