[wasm] Indirect calls without function table cause validation errors.

src/wasm/ast-decoder.cc

Index: src/wasm/ast-decoder.cc
diff --git a/src/wasm/ast-decoder.cc b/src/wasm/ast-decoder.cc
index ea7ddcf52813b5f2b6dcdfd0c2a56403b3ab7c13..9075acf7d9c654d64c64d9421aa8a97646c54a83 100644
--- a/src/wasm/ast-decoder.cc
+++ b/src/wasm/ast-decoder.cc
@@ -1136,14 +1136,17 @@ class WasmFullDecoder : public WasmDecoder {
             break;
           }
           case kExprCallIndirect: {
+            uint32_t table_index = 0;
             CallIndirectOperand operand(this, pc_);
-            if (Validate(pc_, operand)) {
+            if (Validate(pc_, operand) && module_->IsValidTable(table_index)) {

[titzer, 2016/11/07 09:24:11]

Why not just move this logic into the Validate method?

[ahaas, 2016/11/07 09:35:56]

Done. I misunderstood the Validate method.

               Value index = Pop(0, kAstI32);
               TFNode** buffer = PopArgs(operand.sig);
               if (buffer) buffer[0] = index.node;
               TFNode** rets = nullptr;
               BUILD(CallIndirect, operand.index, buffer, &rets, position());
               PushReturns(operand.sig, rets);
+            } else {
+              error("function table has to exist to execute call_indirect");
             }
             len = 1 + operand.length;
             break;