diff options
| -rw-r--r-- | src/wasm/wasm-validator.cpp | 57 |
1 files changed, 57 insertions, 0 deletions
diff --git a/src/wasm/wasm-validator.cpp b/src/wasm/wasm-validator.cpp index e837c2dd6..f78a2301d 100644 --- a/src/wasm/wasm-validator.cpp +++ b/src/wasm/wasm-validator.cpp @@ -327,6 +327,63 @@ public: self->pushTask(visitPoppyExpression, currp); } } + + // Also verify that only allowed expressions end up in the situation where + // the expression has type unreachable but there is no unreachable child. + // For example a Call with no unreachable child cannot be unreachable, but a + // Break can be. + if (curr->type == Type::unreachable) { + switch (curr->_id) { + case Expression::BreakId: { + // If there is a condition, that is already validated fully in + // visitBreak(). If there isn't a condition, then this is allowed to + // be unreachable even without an unreachable child. Either way, we + // can leave. + return; + } + case Expression::SwitchId: + case Expression::ReturnId: + case Expression::UnreachableId: + case Expression::ThrowId: + case Expression::RethrowId: { + // These can all be unreachable without an unreachable child. + return; + } + case Expression::CallId: { + if (curr->cast<Call>()->isReturn) { + return; + } + break; + } + case Expression::CallIndirectId: { + if (curr->cast<CallIndirect>()->isReturn) { + return; + } + break; + } + case Expression::CallRefId: { + if (curr->cast<CallRef>()->isReturn) { + return; + } + break; + } + default: { + break; + } + } + + // If we reach here, then we must have an unreachable child. + bool hasUnreachableChild = false; + for (auto* child : ChildIterator(curr)) { + if (child->type == Type::unreachable) { + hasUnreachableChild = true; + break; + } + } + self->shouldBeTrue(hasUnreachableChild, + curr, + "unreachable instruction must have unreachable child"); + } } void noteBreak(Name name, Expression* value, Expression* curr); |