[WebAssembly] Make rethrow take an except_ref type argument
Summary:
In the new wasm EH proposal, `rethrow` takes an `except_ref` argument.
This change was missing in r352598.
This patch adds `llvm.wasm.rethrow.in.catch` intrinsic. This is an
intrinsic that's gonna eventually be lowered to wasm `rethrow`
instruction, but this intrinsic can appear only within a catchpad or a
cleanuppad scope. Also this intrinsic needs to be invokable - otherwise
EH pad successor for it will not be correctly generated in clang.
This also adds lowering logic for this intrinsic in
`SelectionDAGBuilder::visitInvoke`. This routine is basically a
specialized and simplified version of
`SelectionDAGBuilder::visitTargetIntrinsic`, but we can't use it
because if is only for `CallInst`s.
This deletes the previous `llvm.wasm.rethrow` intrinsic and related
tests, which was meant to be used within a `__cxa_rethrow` library
function. Turned out this needs some more logic, so the intrinsic for
this purpose will be added later.
LateEHPrepare takes a result value of `catch` and inserts it into
matching `rethrow` as an argument.
`RETHROW_IN_CATCH` is a pseudo instruction that serves as a link between
`llvm.wasm.rethrow.in.catch` and the real wasm `rethrow` instruction. To
generate a `rethrow` instruction, we need an `except_ref` argument,
which is generated from `catch` instruction. But `catch` instrutions are
added in LateEHPrepare pass, so we use `RETHROW_IN_CATCH`, which takes
no argument, until we are able to correctly lower it to `rethrow` in
LateEHPrepare.
Reviewers: dschuff
Subscribers: sbc100, jgravelle-google, sunfish, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D59352
llvm-svn: 356316
diff --git a/llvm/lib/CodeGen/WasmEHPrepare.cpp b/llvm/lib/CodeGen/WasmEHPrepare.cpp
index a58da13..865a1cf 100644
--- a/llvm/lib/CodeGen/WasmEHPrepare.cpp
+++ b/llvm/lib/CodeGen/WasmEHPrepare.cpp
@@ -104,15 +104,14 @@
Value *LSDAField = nullptr; // lsda field
Value *SelectorField = nullptr; // selector
- Function *ThrowF = nullptr; // wasm.throw() intrinsic
- Function *RethrowF = nullptr; // wasm.rethrow() intrinsic
- Function *LPadIndexF = nullptr; // wasm.landingpad.index() intrinsic
- Function *LSDAF = nullptr; // wasm.lsda() intrinsic
- Function *GetExnF = nullptr; // wasm.get.exception() intrinsic
- Function *ExtractExnF = nullptr; // wasm.extract.exception() intrinsic
- Function *GetSelectorF = nullptr; // wasm.get.ehselector() intrinsic
+ Function *ThrowF = nullptr; // wasm.throw() intrinsic
+ Function *LPadIndexF = nullptr; // wasm.landingpad.index() intrinsic
+ Function *LSDAF = nullptr; // wasm.lsda() intrinsic
+ Function *GetExnF = nullptr; // wasm.get.exception() intrinsic
+ Function *ExtractExnF = nullptr; // wasm.extract.exception() intrinsic
+ Function *GetSelectorF = nullptr; // wasm.get.ehselector() intrinsic
FunctionCallee CallPersonalityF =
- nullptr; // _Unwind_CallPersonality() wrapper
+ nullptr; // _Unwind_CallPersonality() wrapper
bool prepareEHPads(Function &F);
bool prepareThrows(Function &F);
@@ -177,29 +176,23 @@
// wasm.throw() intinsic, which will be lowered to wasm 'throw' instruction.
ThrowF = Intrinsic::getDeclaration(&M, Intrinsic::wasm_throw);
- // wasm.rethrow() intinsic, which will be lowered to wasm 'rethrow'
- // instruction.
- RethrowF = Intrinsic::getDeclaration(&M, Intrinsic::wasm_rethrow);
-
- // Insert an unreachable instruction after a call to @llvm.wasm.throw /
- // @llvm.wasm.rethrow and delete all following instructions within the BB, and
- // delete all the dead children of the BB as well.
- for (auto L : {ThrowF->users(), RethrowF->users()}) {
- for (User *U : L) {
- // A call to @llvm.wasm.throw() is only generated from __cxa_throw()
- // builtin call within libcxxabi, and cannot be an InvokeInst.
- auto *ThrowI = cast<CallInst>(U);
- if (ThrowI->getFunction() != &F)
- continue;
- Changed = true;
- auto *BB = ThrowI->getParent();
- SmallVector<BasicBlock *, 4> Succs(succ_begin(BB), succ_end(BB));
- auto &InstList = BB->getInstList();
- InstList.erase(std::next(BasicBlock::iterator(ThrowI)), InstList.end());
- IRB.SetInsertPoint(BB);
- IRB.CreateUnreachable();
- eraseDeadBBsAndChildren(Succs);
- }
+ // Insert an unreachable instruction after a call to @llvm.wasm.throw and
+ // delete all following instructions within the BB, and delete all the dead
+ // children of the BB as well.
+ for (User *U : ThrowF->users()) {
+ // A call to @llvm.wasm.throw() is only generated from __cxa_throw()
+ // builtin call within libcxxabi, and cannot be an InvokeInst.
+ auto *ThrowI = cast<CallInst>(U);
+ if (ThrowI->getFunction() != &F)
+ continue;
+ Changed = true;
+ auto *BB = ThrowI->getParent();
+ SmallVector<BasicBlock *, 4> Succs(succ_begin(BB), succ_end(BB));
+ auto &InstList = BB->getInstList();
+ InstList.erase(std::next(BasicBlock::iterator(ThrowI)), InstList.end());
+ IRB.SetInsertPoint(BB);
+ IRB.CreateUnreachable();
+ eraseDeadBBsAndChildren(Succs);
}
return Changed;