[llvm] r233354 - WinEH: Create a parent frame alloca for HandlerType xdata tables
Kaylor, Andrew
andrew.kaylor at intel.com
Fri Mar 27 09:52:36 PDT 2015
This doesn't look the way I would have expected it to.
Why are you creating an alloca for the parent frame pointer? I would have expected the intrinisic to return a pointer to the stack offset where the parent frame pointer needs to be stored and the catch handler to store it directly there.
-Andy
-----Original Message-----
From: llvm-commits-bounces at cs.uiuc.edu [mailto:llvm-commits-bounces at cs.uiuc.edu] On Behalf Of David Majnemer
Sent: Thursday, March 26, 2015 9:17 PM
To: llvm-commits at cs.uiuc.edu
Subject: [llvm] r233354 - WinEH: Create a parent frame alloca for HandlerType xdata tables
Author: majnemer
Date: Thu Mar 26 23:17:07 2015
New Revision: 233354
URL: http://llvm.org/viewvc/llvm-project?rev=233354&view=rev
Log:
WinEH: Create a parent frame alloca for HandlerType xdata tables
We don't have any logic to emit those tables yet, so the SDAG lowering of this intrinsic is just a stub. We can see the intrinsic in the prepared IR, though.
Modified:
llvm/trunk/docs/ExceptionHandling.rst
llvm/trunk/include/llvm/IR/Intrinsics.td
llvm/trunk/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
llvm/trunk/lib/CodeGen/WinEHPrepare.cpp
llvm/trunk/lib/IR/Verifier.cpp
llvm/trunk/test/CodeGen/WinEH/cppeh-catch-unwind.ll
Modified: llvm/trunk/docs/ExceptionHandling.rst
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/docs/ExceptionHandling.rst?rev=233354&r1=233353&r2=233354&view=diff
==============================================================================
--- llvm/trunk/docs/ExceptionHandling.rst (original)
+++ llvm/trunk/docs/ExceptionHandling.rst Thu Mar 26 23:17:07 2015
@@ -551,6 +551,17 @@ This object is used by Windows native ex where xdata unwind information is used. It is typically an 8 byte chunk of memory treated as two 32-bit integers.
+``llvm.eh.parentframe``
+----------------------
+
+.. code-block:: llvm
+
+ void @llvm.eh.parentframe(i8*)
+
+This intrinsic designates the provided static alloca as the object
+which holds the address of the parent frame.
+This object is used by Windows native exception handling on non-x86
+platforms where xdata unwind information is used.
SJLJ Intrinsics
---------------
Modified: llvm/trunk/include/llvm/IR/Intrinsics.td
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/IR/Intrinsics.td?rev=233354&r1=233353&r2=233354&view=diff
==============================================================================
--- llvm/trunk/include/llvm/IR/Intrinsics.td (original)
+++ llvm/trunk/include/llvm/IR/Intrinsics.td Thu Mar 26 23:17:07 2015
@@ -425,6 +425,10 @@ def int_eh_actions : Intrinsic<[llvm_ptr // for WinEH.
def int_eh_unwindhelp : Intrinsic<[], [llvm_ptr_ty], []>;
+// Designates the provided static alloca as the object which holds the
+address // of the parent frame. Required for WinEH.
+def int_eh_parentframe : Intrinsic<[], [llvm_ptrptr_ty], []>;
+
// __builtin_unwind_init is an undocumented GCC intrinsic that causes all // callee-saved registers to be saved and restored (regardless of whether they // are used) in the calling function. It is used by libgcc_eh.
Modified: llvm/trunk/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp?rev=233354&r1=233353&r2=233354&view=diff
==============================================================================
--- llvm/trunk/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp (original)
+++ llvm/trunk/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp Thu Mar
+++ 26 23:17:07 2015
@@ -5446,13 +5446,23 @@ SelectionDAGBuilder::visitIntrinsicCall(
case Intrinsic::eh_begincatch:
case Intrinsic::eh_endcatch:
llvm_unreachable("begin/end catch intrinsics not lowered in codegen");
+ case Intrinsic::eh_parentframe: {
+ AllocaInst *Slot =
+ cast<AllocaInst>(I.getArgOperand(0)->stripPointerCasts());
+ assert(FuncInfo.StaticAllocaMap.count(Slot) &&
+ "can only use static allocas with llvm.eh.parentframe");
+ int FI = FuncInfo.StaticAllocaMap[Slot];
+ // TODO: Save this in the not-yet-existent WinEHFuncInfo struct.
+ (void)FI;
+ return nullptr;
+ }
case Intrinsic::eh_unwindhelp: {
AllocaInst *Slot =
cast<AllocaInst>(I.getArgOperand(0)->stripPointerCasts());
assert(FuncInfo.StaticAllocaMap.count(Slot) &&
"can only use static allocas with llvm.eh.unwindhelp");
int FI = FuncInfo.StaticAllocaMap[Slot];
- // TODO: Save this in the not-yet-existant WinEHFuncInfo struct.
+ // TODO: Save this in the not-yet-existent WinEHFuncInfo struct.
(void)FI;
return nullptr;
}
Modified: llvm/trunk/lib/CodeGen/WinEHPrepare.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/WinEHPrepare.cpp?rev=233354&r1=233353&r2=233354&view=diff
==============================================================================
--- llvm/trunk/lib/CodeGen/WinEHPrepare.cpp (original)
+++ llvm/trunk/lib/CodeGen/WinEHPrepare.cpp Thu Mar 26 23:17:07 2015
@@ -695,6 +695,16 @@ bool WinEHPrepare::outlineHandler(Action
if (!LPadMap.isInitialized())
LPadMap.mapLandingPad(LPad);
if (auto *CatchAction = dyn_cast<CatchHandler>(Action)) {
+ // Insert an alloca for the object which holds the address of the parent's
+ // frame pointer. The stack offset of this object needs to be encoded in
+ // xdata.
+ AllocaInst *ParentFrame = new AllocaInst(Int8PtrType, "parentframe", Entry);
+ Builder.CreateStore(&Handler->getArgumentList().back(), ParentFrame,
+ /*isStore=*/true);
+ Function *ParentFrameFn =
+ Intrinsic::getDeclaration(M, Intrinsic::eh_parentframe);
+ Builder.CreateCall(ParentFrameFn, ParentFrame);
+
Constant *Sel = CatchAction->getSelector();
Director.reset(new WinEHCatchDirector(Handler, Sel, VarInfo, LPadMap));
LPadMap.remapSelector(VMap, ConstantInt::get(Type::getInt32Ty(Context), 1));
Modified: llvm/trunk/lib/IR/Verifier.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/IR/Verifier.cpp?rev=233354&r1=233353&r2=233354&view=diff
==============================================================================
--- llvm/trunk/lib/IR/Verifier.cpp (original)
+++ llvm/trunk/lib/IR/Verifier.cpp Thu Mar 26 23:17:07 2015
@@ -2909,6 +2909,13 @@ void Verifier::visitIntrinsicFunctionCal
break;
}
+ case Intrinsic::eh_parentframe: {
+ auto *AI = dyn_cast<AllocaInst>(CI.getArgOperand(0)->stripPointerCasts());
+ Assert(AI && AI->isStaticAlloca(),
+ "llvm.eh.parentframe requires a static alloca", &CI);
+ break;
+ }
+
case Intrinsic::eh_unwindhelp: {
auto *AI = dyn_cast<AllocaInst>(CI.getArgOperand(0)->stripPointerCasts());
Assert(AI && AI->isStaticAlloca(),
Modified: llvm/trunk/test/CodeGen/WinEH/cppeh-catch-unwind.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/WinEH/cppeh-catch-unwind.ll?rev=233354&r1=233353&r2=233354&view=diff
==============================================================================
--- llvm/trunk/test/CodeGen/WinEH/cppeh-catch-unwind.ll (original)
+++ llvm/trunk/test/CodeGen/WinEH/cppeh-catch-unwind.ll Thu Mar 26
+++ 23:17:07 2015
@@ -180,6 +180,9 @@ eh.resume:
; CHECK-LABEL: define internal i8* @"\01?test@@YAXXZ.catch"(i8*, i8*) { ; CHECK: entry:
+; CHECK: [[PARENTFRAME:\%.+]] = alloca i8*
+; CHECK: store volatile i8* %1, i8** [[PARENTFRAME]]
+; CHECK: call void @llvm.eh.parentframe(i8** [[PARENTFRAME]])
; CHECK: [[RECOVER_TMP1:\%.+]] = call i8* @llvm.framerecover(i8* bitcast (void ()* @"\01?test@@YAXXZ" to i8*), i8* %1, i32 0)
; CHECK: [[TMP1_PTR:\%.+]] = bitcast i8* [[RECOVER_TMP1]] to i32*
; CHECK: call void @"\01?handle_exception@@YAXXZ"()
@@ -196,6 +199,9 @@ eh.resume:
; CHECK-LABEL: define internal i8* @"\01?test@@YAXXZ.catch1"(i8*, i8*) { ; CHECK: entry:
+; CHECK: [[PARENTFRAME:\%.+]] = alloca i8*
+; CHECK: store volatile i8* %1, i8** [[PARENTFRAME]]
+; CHECK: call void @llvm.eh.parentframe(i8** [[PARENTFRAME]])
; CHECK: [[RECOVER_TMP0:\%.+]] = call i8* @llvm.framerecover(i8* bitcast (void ()* @"\01?test@@YAXXZ" to i8*), i8* %1, i32 2)
; CHECK: [[TMP0_PTR:\%.+]] = bitcast i8* [[RECOVER_TMP0]] to i32*
; CHECK: invoke void @"\01?handle_exception@@YAXXZ"()
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