From 8b97aba305f21a5040ac5df4a59f41d01815645a Mon Sep 17 00:00:00 2001
From: Derek Schuff <dschuff@chromium.org>
Date: Fri, 14 Jul 2017 18:47:10 -0700
Subject: Validation for AtomicRMW and cmpxchg (#1092)

Also fix cases where fail() had the arguments backwards. Wasn't an error because lol templates.
Also fix printModuleComponent template to SFINAE on Expression* so we properly get the specialized version.
---
 src/wasm/wasm-validator.cpp | 26 +++++++++++++++++++++++++-
 1 file changed, 25 insertions(+), 1 deletion(-)

(limited to 'src/wasm/wasm-validator.cpp')

diff --git a/src/wasm/wasm-validator.cpp b/src/wasm/wasm-validator.cpp
index c1f44a68b..1b328ec19 100644
--- a/src/wasm/wasm-validator.cpp
+++ b/src/wasm/wasm-validator.cpp
@@ -220,22 +220,46 @@ void WasmValidator::visitSetLocal(SetLocal *curr) {
   }
 }
 void WasmValidator::visitLoad(Load *curr) {
+  if (curr->isAtomic && !getModule()->memory.shared) fail("Atomic operation with non-shared memory", curr);
   validateMemBytes(curr->bytes, curr->type, curr);
   validateAlignment(curr->align, curr->type, curr->bytes, curr->isAtomic, curr);
   shouldBeEqualOrFirstIsUnreachable(curr->ptr->type, i32, curr, "load pointer type must be i32");
 }
 void WasmValidator::visitStore(Store *curr) {
+  if (curr->isAtomic && !getModule()->memory.shared) fail("Atomic operation with non-shared memory", curr);
   validateMemBytes(curr->bytes, curr->valueType, curr);
   validateAlignment(curr->align, curr->type, curr->bytes, curr->isAtomic, curr);
   shouldBeEqualOrFirstIsUnreachable(curr->ptr->type, i32, curr, "store pointer type must be i32");
   shouldBeUnequal(curr->value->type, none, curr, "store value type must not be none");
   shouldBeEqualOrFirstIsUnreachable(curr->value->type, curr->valueType, curr, "store value type must match");
 }
+void WasmValidator::shouldBeIntOrUnreachable(WasmType ty, Expression* curr, const char* text) {
+  switch (ty) {
+    case i32:
+    case i64:
+    case unreachable: {
+      break;
+    }
+    default: fail(text, curr);
+  }
+}
 void WasmValidator::visitAtomicRMW(AtomicRMW* curr) {
+  if (!getModule()->memory.shared) fail("Atomic operation with non-shared memory", curr);
   validateMemBytes(curr->bytes, curr->type, curr);
+  shouldBeEqualOrFirstIsUnreachable(curr->ptr->type, i32, curr, "AtomicRMW pointer type must be i32");
+  shouldBeEqualOrFirstIsUnreachable(curr->value->type, curr->type, curr, "AtomicRMW result type must match operand");
+  shouldBeIntOrUnreachable(curr->type, curr, "Atomic operations are only valid on int types");
 }
 void WasmValidator::visitAtomicCmpxchg(AtomicCmpxchg* curr) {
+  if (!getModule()->memory.shared) fail("Atomic operation with non-shared memory", curr);
   validateMemBytes(curr->bytes, curr->type, curr);
+  shouldBeEqualOrFirstIsUnreachable(curr->ptr->type, i32, curr, "cmpxchg pointer type must be i32");
+  if (curr->expected->type != unreachable && curr->replacement->type != unreachable) {
+    shouldBeEqual(curr->expected->type, curr->replacement->type, curr, "cmpxchg operand types must match");
+  }
+  shouldBeEqualOrFirstIsUnreachable(curr->expected->type, curr->type, curr, "Cmpxchg result type must match expected");
+  shouldBeEqualOrFirstIsUnreachable(curr->replacement->type, curr->type, curr, "Cmpxchg result type must match replacement");
+  shouldBeIntOrUnreachable(curr->expected->type, curr, "Atomic operations are only valid on int types");
 }
 void WasmValidator::validateMemBytes(uint8_t bytes, WasmType ty, Expression* curr) {
   switch (bytes) {
@@ -655,7 +679,7 @@ void WasmValidator::validateBinaryenIR(Module& wasm) {
 }
 
 template <typename T, typename S>
-std::ostream& WasmValidator::fail(T curr, S text) {
+std::ostream& WasmValidator::fail(S text, T curr) {
   valid = false;
   auto& ret = printFailureHeader() << text << ", on \n";
   return printModuleComponent(curr, ret);
-- 
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