diff options
Diffstat (limited to 'src/wasm')
| -rw-r--r-- | src/wasm/wasm-validator.cpp | 20 | ||||
| -rw-r--r-- | src/wasm/wasm.cpp | 51 |
2 files changed, 45 insertions, 26 deletions
diff --git a/src/wasm/wasm-validator.cpp b/src/wasm/wasm-validator.cpp index e30661e8f..877232521 100644 --- a/src/wasm/wasm-validator.cpp +++ b/src/wasm/wasm-validator.cpp @@ -70,9 +70,7 @@ void WasmValidator::visitBlock(Block *curr) { if (curr->list.size() > 0) { auto backType = curr->list.back()->type; if (!isConcreteWasmType(curr->type)) { - if (isConcreteWasmType(backType)) { - shouldBeTrue(curr->type == unreachable, curr, "block with no value and a last element with a value must be unreachable"); - } + shouldBeFalse(isConcreteWasmType(backType), curr, "if block is not returning a value, final element should not flow out a value"); } else { if (isConcreteWasmType(backType)) { shouldBeEqual(curr->type, backType, curr, "block with value and last element with value must match types"); @@ -118,15 +116,19 @@ void WasmValidator::visitIf(If *curr) { shouldBeEqual(curr->ifFalse->type, unreachable, curr, "unreachable if-else must have unreachable false"); } } + if (isConcreteWasmType(curr->ifTrue->type)) { + shouldBeEqual(curr->type, curr->ifTrue->type, curr, "if type must match concrete ifTrue"); + shouldBeEqualOrFirstIsUnreachable(curr->ifFalse->type, curr->ifTrue->type, curr, "other arm must match concrete ifTrue"); + } + if (isConcreteWasmType(curr->ifFalse->type)) { + shouldBeEqual(curr->type, curr->ifFalse->type, curr, "if type must match concrete ifFalse"); + shouldBeEqualOrFirstIsUnreachable(curr->ifTrue->type, curr->ifFalse->type, curr, "other arm must match concrete ifFalse"); + } } } void WasmValidator::noteBreak(Name name, Expression* value, Expression* curr) { - if (!BranchUtils::isBranchTaken(curr)) { - // if not actually taken, just note the name - namedBreakTargets.insert(name); - return; - } + namedBreakTargets.insert(name); WasmType valueType = none; Index arity = 0; if (value) { @@ -548,7 +550,7 @@ void WasmValidator::visitFunction(Function *curr) { if (returnType != unreachable) { shouldBeEqual(curr->result, returnType, curr->body, "function result must match, if function has returns"); } - if (!shouldBeTrue(namedBreakTargets.empty(), curr->body, "all named break targets must exist (even if not taken)") && !quiet) { + if (!shouldBeTrue(namedBreakTargets.empty(), curr->body, "all named break targets must exist") && !quiet) { std::cerr << "(on label " << *namedBreakTargets.begin() << ")\n"; } returnType = unreachable; diff --git a/src/wasm/wasm.cpp b/src/wasm/wasm.cpp index 4594eddd1..a781e0fa3 100644 --- a/src/wasm/wasm.cpp +++ b/src/wasm/wasm.cpp @@ -116,13 +116,12 @@ struct TypeSeeker : public PostWalker<TypeSeeker> { } void visitBreak(Break* curr) { - if (curr->name == targetName && BranchUtils::isBranchTaken(curr)) { + if (curr->name == targetName) { types.push_back(curr->value ? curr->value->type : none); } } void visitSwitch(Switch* curr) { - if (!BranchUtils::isBranchTaken(curr)) return; for (auto name : curr->targets) { if (name == targetName) types.push_back(curr->value ? curr->value->type : none); } @@ -174,16 +173,17 @@ static WasmType mergeTypes(std::vector<WasmType>& types) { // and there are no branches to it static void handleUnreachable(Block* block) { if (block->type == unreachable) return; // nothing to do + if (block->list.size() == 0) return; // nothing to do + // if we are concrete, stop - even an unreachable child + // won't change that (since we have a break with a value, + // or the final child flows out a value) + if (isConcreteWasmType(block->type)) return; + // look for an unreachable child for (auto* child : block->list) { if (child->type == unreachable) { // there is an unreachable child, so we are unreachable, unless we have a break - BranchUtils::BranchSeeker seeker(block->name); - Expression* expr = block; - seeker.walk(expr); - if (!seeker.found) { + if (!BranchUtils::BranchSeeker::hasNamed(block, block->name)) { block->type = unreachable; - } else { - block->type = seeker.valueType; } return; } @@ -199,19 +199,27 @@ void Block::finalize(WasmType type_) { void Block::finalize() { if (!name.is()) { - // nothing branches here, so this is easy if (list.size() > 0) { - // if we have an unreachable child, we are unreachable - // (we don't need to recurse into children, they can't - // break to us) + // nothing branches here, so this is easy + // normally the type is the type of the final child + type = list.back()->type; + // and even if we have an unreachable child somewhere, + // we still mark ourselves as having that type, + // (block (result i32) + // (return) + // (i32.const 10) + // ) + if (isConcreteWasmType(type)) return; + // if we are unreachable, we are done + if (type == unreachable) return; + // we may still be unreachable if we have an unreachable + // child for (auto* child : list) { if (child->type == unreachable) { type = unreachable; return; } } - // children are reachable, so last element determines type - type = list.back()->type; } else { type = none; } @@ -231,9 +239,7 @@ void If::finalize(WasmType type_) { } void If::finalize() { - if (condition->type == unreachable) { - type = unreachable; - } else if (ifFalse) { + if (ifFalse) { if (ifTrue->type == ifFalse->type) { type = ifTrue->type; } else if (isConcreteWasmType(ifTrue->type) && ifFalse->type == unreachable) { @@ -246,6 +252,17 @@ void If::finalize() { } else { type = none; // if without else } + // if the arms return a value, leave it even if the condition + // is unreachable, we still mark ourselves as having that type, e.g. + // (if (result i32) + // (unreachable) + // (i32.const 10) + // (i32.const 20 + // ) + // otherwise, if the condition is unreachable, so is the if + if (type == none && condition->type == unreachable) { + type = unreachable; + } } void Loop::finalize(WasmType type_) { |