From dfe473e6af0a31cad7a7b26f5dead358d9bbf536 Mon Sep 17 00:00:00 2001 From: Alon Zakai Date: Wed, 27 May 2020 13:30:12 -0700 Subject: Flat IR: local.set's value should not be a control flow (#2589) --- src/ir/flat.h | 14 ++++++++++---- 1 file changed, 10 insertions(+), 4 deletions(-) (limited to 'src/ir/flat.h') diff --git a/src/ir/flat.h b/src/ir/flat.h index d54d4771f..706ca5a86 100644 --- a/src/ir/flat.h +++ b/src/ir/flat.h @@ -45,11 +45,14 @@ // 1. Aside from a local.set, the operands of an instruction must be a // local.get, a const, or an unreachable. Anything else is written // to a local earlier. -// 2. Disallow block, loop, and if return values, and do not allow the -// function body to have a concrete type, i.e., do not use +// 2. Disallow control flow (block, loop, if, and try) return values, and do +// not allow the function body to have a concrete type, i.e., do not use // control flow to pass around values. // 3. Disallow local.tee, setting a local is always done in a local.set // on a non-nested-expression location. +// 4. local.set cannot have an operand that is control flow (control flow with +// values is prohibited already, but e.g. a block ending in unreachable, +// which can normally be nested, is also disallowed). // #ifndef wasm_ir_flat_h @@ -72,8 +75,11 @@ inline void verifyFlatness(Function* func) { if (Properties::isControlFlowStructure(curr)) { verify(!curr->type.isConcrete(), "control flow structures must not flow values"); - } else if (curr->is()) { - verify(!curr->type.isConcrete(), "tees are not allowed, only sets"); + } else if (auto* set = curr->dynCast()) { + verify(!set->isTee() || set->type == Type::unreachable, + "tees are not allowed, only sets"); + verify(!Properties::isControlFlowStructure(set->value), + "set values cannot be control flow"); } else { for (auto* child : ChildIterator(curr)) { verify(Properties::isConstantExpression(child) || -- cgit v1.2.3