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Merged
merged 5 commits into from
Oct 7, 2024
Merged

[WebAssembly] Support type checker for new EH #111069

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98122cd
[WebAssembly] Support type checker for new EH
aheejin Oct 2, 2024
6068e77
throw_ref
aheejin Oct 3, 2024
b1c3940
Tweak error message
aheejin Oct 3, 2024
84fbd17
Merge branch 'main' into eh_typecheck
aheejin Oct 4, 2024
1f538b7
Add missing tagtype after #111079
aheejin Oct 5, 2024
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91 changes: 82 additions & 9 deletions llvm/lib/Target/WebAssembly/AsmParser/WebAssemblyAsmTypeCheck.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -59,7 +59,7 @@ void WebAssemblyAsmTypeCheck::localDecl(
}

void WebAssemblyAsmTypeCheck::dumpTypeStack(Twine Msg) {
LLVM_DEBUG({ dbgs() << Msg << getTypesString(Stack, 0) << "\n"; });
LLVM_DEBUG({ dbgs() << Msg << getTypesString(Stack) << "\n"; });
}

bool WebAssemblyAsmTypeCheck::typeError(SMLoc ErrorLoc, const Twine &Msg) {
Expand Down Expand Up @@ -116,8 +116,15 @@ std::string WebAssemblyAsmTypeCheck::getTypesString(ArrayRef<StackType> Types,
return SS.str();
}

std::string
WebAssemblyAsmTypeCheck::getTypesString(ArrayRef<wasm::ValType> Types,
size_t StartPos) {
return getTypesString(valTypesToStackTypes(Types), StartPos);
}

SmallVector<WebAssemblyAsmTypeCheck::StackType, 4>
WebAssemblyAsmTypeCheck::valTypeToStackType(ArrayRef<wasm::ValType> ValTypes) {
WebAssemblyAsmTypeCheck::valTypesToStackTypes(
ArrayRef<wasm::ValType> ValTypes) {
SmallVector<StackType, 4> Types(ValTypes.size());
std::transform(ValTypes.begin(), ValTypes.end(), Types.begin(),
[](wasm::ValType Val) -> StackType { return Val; });
Expand All @@ -127,7 +134,7 @@ WebAssemblyAsmTypeCheck::valTypeToStackType(ArrayRef<wasm::ValType> ValTypes) {
bool WebAssemblyAsmTypeCheck::checkTypes(SMLoc ErrorLoc,
ArrayRef<wasm::ValType> ValTypes,
bool ExactMatch) {
return checkTypes(ErrorLoc, valTypeToStackType(ValTypes), ExactMatch);
return checkTypes(ErrorLoc, valTypesToStackTypes(ValTypes), ExactMatch);
}

bool WebAssemblyAsmTypeCheck::checkTypes(SMLoc ErrorLoc,
Expand Down Expand Up @@ -178,14 +185,14 @@ bool WebAssemblyAsmTypeCheck::checkTypes(SMLoc ErrorLoc,
: std::max((int)BlockStackStartPos,
(int)Stack.size() - (int)Types.size());
return typeError(ErrorLoc, "type mismatch, expected " +
getTypesString(Types, 0) + " but got " +
getTypesString(Types) + " but got " +
getTypesString(Stack, StackStartPos));
}

bool WebAssemblyAsmTypeCheck::popTypes(SMLoc ErrorLoc,
ArrayRef<wasm::ValType> ValTypes,
bool ExactMatch) {
return popTypes(ErrorLoc, valTypeToStackType(ValTypes), ExactMatch);
return popTypes(ErrorLoc, valTypesToStackTypes(ValTypes), ExactMatch);
}

bool WebAssemblyAsmTypeCheck::popTypes(SMLoc ErrorLoc,
Expand Down Expand Up @@ -215,7 +222,7 @@ bool WebAssemblyAsmTypeCheck::popAnyType(SMLoc ErrorLoc) {
}

void WebAssemblyAsmTypeCheck::pushTypes(ArrayRef<wasm::ValType> ValTypes) {
Stack.append(valTypeToStackType(ValTypes));
Stack.append(valTypesToStackTypes(ValTypes));
}

bool WebAssemblyAsmTypeCheck::getLocal(SMLoc ErrorLoc, const MCOperand &LocalOp,
Expand Down Expand Up @@ -322,6 +329,63 @@ bool WebAssemblyAsmTypeCheck::endOfFunction(SMLoc ErrorLoc, bool ExactMatch) {
return checkTypes(ErrorLoc, FuncInfo.Sig.Returns, ExactMatch);
}

// Unlike checkTypes() family, this just compare the equivalence of the two
// ValType vectors
static bool compareTypes(ArrayRef<wasm::ValType> TypesA,
ArrayRef<wasm::ValType> TypesB) {
if (TypesA.size() != TypesB.size())
return true;
for (size_t I = 0, E = TypesA.size(); I < E; I++)
if (TypesA[I] != TypesB[I])
return true;
return false;
}

bool WebAssemblyAsmTypeCheck::checkTryTable(SMLoc ErrorLoc,
const MCInst &Inst) {
bool Error = false;
unsigned OpIdx = 1; // OpIdx 0 is the block type
int64_t NumCatches = Inst.getOperand(OpIdx++).getImm();
for (int64_t I = 0; I < NumCatches; I++) {
int64_t Opcode = Inst.getOperand(OpIdx++).getImm();
std::string ErrorMsgBase =
"try_table: catch index " + std::to_string(I) + ": ";

const wasm::WasmSignature *Sig = nullptr;
SmallVector<wasm::ValType> SentTypes;
if (Opcode == wasm::WASM_OPCODE_CATCH ||
Opcode == wasm::WASM_OPCODE_CATCH_REF) {
if (!getSignature(ErrorLoc, Inst.getOperand(OpIdx++),
wasm::WASM_SYMBOL_TYPE_TAG, Sig))
SentTypes.insert(SentTypes.end(), Sig->Params.begin(),
Sig->Params.end());
else
Error = true;
}
if (Opcode == wasm::WASM_OPCODE_CATCH_REF ||
Opcode == wasm::WASM_OPCODE_CATCH_ALL_REF) {
SentTypes.push_back(wasm::ValType::EXNREF);
}

unsigned Level = Inst.getOperand(OpIdx++).getImm();
if (Level < BlockInfoStack.size()) {
const auto &DestBlockInfo =
BlockInfoStack[BlockInfoStack.size() - Level - 1];
if (compareTypes(SentTypes, DestBlockInfo.Sig.Returns)) {
std::string ErrorMsg =
ErrorMsgBase + "type mismatch, catch tag type is " +
getTypesString(SentTypes) + ", but destination's type is " +
getTypesString(DestBlockInfo.Sig.Returns);
Error |= typeError(ErrorLoc, ErrorMsg);
}
} else {
Error = typeError(ErrorLoc, ErrorMsgBase + "invalid depth " +
std::to_string(Level));
}
}
return Error;
}

bool WebAssemblyAsmTypeCheck::typeCheck(SMLoc ErrorLoc, const MCInst &Inst,
OperandVector &Operands) {
auto Opc = Inst.getOpcode();
Expand Down Expand Up @@ -460,10 +524,13 @@ bool WebAssemblyAsmTypeCheck::typeCheck(SMLoc ErrorLoc, const MCInst &Inst,
return popType(ErrorLoc, Any{});
}

if (Name == "block" || Name == "loop" || Name == "if" || Name == "try") {
if (Name == "block" || Name == "loop" || Name == "if" || Name == "try" ||
Name == "try_table") {
bool Error = Name == "if" && popType(ErrorLoc, wasm::ValType::I32);
// Pop block input parameters and check their types are correct
Error |= popTypes(ErrorLoc, LastSig.Params);
if (Name == "try_table")
Error |= checkTryTable(ErrorLoc, Inst);
// Push a new block info
BlockInfoStack.push_back({LastSig, Stack.size(), Name == "loop"});
// Push back block input parameters
Expand All @@ -472,8 +539,8 @@ bool WebAssemblyAsmTypeCheck::typeCheck(SMLoc ErrorLoc, const MCInst &Inst,
}

if (Name == "end_block" || Name == "end_loop" || Name == "end_if" ||
Name == "end_try" || Name == "delegate" || Name == "else" ||
Name == "catch" || Name == "catch_all") {
Name == "end_try" || Name == "delegate" || Name == "end_try_table" ||
Name == "else" || Name == "catch" || Name == "catch_all") {
assert(!BlockInfoStack.empty());
// Check if the types on the stack match with the block return type
const auto &LastBlockInfo = BlockInfoStack.back();
Expand Down Expand Up @@ -586,6 +653,12 @@ bool WebAssemblyAsmTypeCheck::typeCheck(SMLoc ErrorLoc, const MCInst &Inst,
return Error;
}

if (Name == "throw_ref") {
bool Error = popType(ErrorLoc, wasm::ValType::EXNREF);
pushType(Polymorphic{});
return Error;
}

// The current instruction is a stack instruction which doesn't have
// explicit operands that indicate push/pop types, so we get those from
// the register version of the same instruction.
Expand Down
7 changes: 5 additions & 2 deletions llvm/lib/Target/WebAssembly/AsmParser/WebAssemblyAsmTypeCheck.h
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Original file line number Diff line number Diff line change
Expand Up @@ -65,9 +65,11 @@ class WebAssemblyAsmTypeCheck final {
void pushTypes(ArrayRef<wasm::ValType> Types);
void pushType(StackType Type) { Stack.push_back(Type); }
bool match(StackType TypeA, StackType TypeB);
std::string getTypesString(ArrayRef<StackType> Types, size_t StartPos);
std::string getTypesString(ArrayRef<wasm::ValType> Types,
size_t StartPos = 0);
std::string getTypesString(ArrayRef<StackType> Types, size_t StartPos = 0);
SmallVector<StackType, 4>
valTypeToStackType(ArrayRef<wasm::ValType> ValTypes);
valTypesToStackTypes(ArrayRef<wasm::ValType> ValTypes);

void dumpTypeStack(Twine Msg);
bool typeError(SMLoc ErrorLoc, const Twine &Msg);
Expand All @@ -80,6 +82,7 @@ class WebAssemblyAsmTypeCheck final {
bool getTable(SMLoc ErrorLoc, const MCOperand &TableOp, wasm::ValType &Type);
bool getSignature(SMLoc ErrorLoc, const MCOperand &SigOp,
wasm::WasmSymbolType Type, const wasm::WasmSignature *&Sig);
bool checkTryTable(SMLoc ErrorLoc, const MCInst &Inst);

public:
WebAssemblyAsmTypeCheck(MCAsmParser &Parser, const MCInstrInfo &MII,
Expand Down
1 change: 1 addition & 0 deletions llvm/test/MC/WebAssembly/annotations.s
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Original file line number Diff line number Diff line change
Expand Up @@ -9,6 +9,7 @@
test_annotation:
.functype test_annotation () -> ()
.tagtype __cpp_exception i32
.tagtype __c_longjmp i32
try
br 0
catch __cpp_exception
Expand Down
6 changes: 2 additions & 4 deletions llvm/test/MC/WebAssembly/eh-assembly.s
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Original file line number Diff line number Diff line change
@@ -1,6 +1,6 @@
# RUN: llvm-mc -triple=wasm32-unknown-unknown -mattr=+exception-handling --no-type-check < %s | FileCheck %s
# RUN: llvm-mc -triple=wasm32-unknown-unknown -mattr=+exception-handling < %s | FileCheck %s
# Check that it converts to .o without errors, but don't check any output:
# RUN: llvm-mc -triple=wasm32-unknown-unknown -filetype=obj -mattr=+exception-handling --no-type-check -o %t.o < %s
# RUN: llvm-mc -triple=wasm32-unknown-unknown -filetype=obj -mattr=+exception-handling -o %t.o < %s

.tagtype __cpp_exception i32
.tagtype __c_longjmp i32
Expand All @@ -24,7 +24,6 @@ eh_test:
return
end_block
throw_ref
drop
end_block
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After throw_ref, the stack is polymorphic, so you don't need to drop the i32

return
end_block
Expand Down Expand Up @@ -101,7 +100,6 @@ eh_test:
# CHECK-NEXT: return
# CHECK-NEXT: end_block
# CHECK-NEXT: throw_ref
# CHECK-NEXT: drop
# CHECK-NEXT: end_block
# CHECK-NEXT: return
# CHECK-NEXT: end_block
Expand Down
23 changes: 23 additions & 0 deletions llvm/test/MC/WebAssembly/type-checker-errors.s
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Original file line number Diff line number Diff line change
Expand Up @@ -944,3 +944,26 @@ block_param_and_return:

# CHECK: :[[@LINE+1]]:3: error: type mismatch, expected [] but got [f32]
end_function

.tagtype __cpp_exception i32

eh_test:
.functype eh_test () -> ()
block i32
block i32
block i32
block
# CHECK: :[[@LINE+4]]:11: error: try_table: catch index 0: type mismatch, catch tag type is [i32], but destination's type is []
# CHECK: :[[@LINE+3]]:11: error: try_table: catch index 1: type mismatch, catch tag type is [i32, exnref], but destination's type is [i32]
# CHECK: :[[@LINE+2]]:11: error: try_table: catch index 2: type mismatch, catch tag type is [], but destination's type is [i32]
# CHECK: :[[@LINE+1]]:11: error: try_table: catch index 3: type mismatch, catch tag type is [exnref], but destination's type is [i32]
try_table i32 (catch __cpp_exception 0) (catch_ref __cpp_exception 1) (catch_all 2) (catch_all_ref 3)
# CHECK: :[[@LINE+1]]:11: error: type mismatch, expected [i32] but got []
end_try_table
drop
end_block
end_block
end_block
end_block
drop
end_function
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