3 files changed, 36 insertions, 18 deletions

diff --git a/src/wasm-ast-checker.c b/src/wasm-ast-checker.c
index 6b659965..e6f25c9d 100644
--- a/src/wasm-ast-checker.c
+++ b/src/wasm-ast-checker.c
@@ -645,6 +645,10 @@ static void check_expr(Context* ctx, const WasmExpr* expr) {
 
     case WASM_EXPR_TYPE_CALL_INDIRECT: {
       const WasmFuncType* func_type;
+      if (!ctx->current_module->table) {
+        print_error(ctx, CHECK_STYLE_FULL, &expr->loc,
+                    "found call_indirect operator, but no table");
+      }
       if (WASM_SUCCEEDED(
               check_func_type_var(ctx, &expr->call_indirect.var, &func_type))) {
         WasmCheckType type = pop_type(ctx);
diff --git a/src/wasm-binary-reader-interpreter.c b/src/wasm-binary-reader-interpreter.c
index ad11bccb..bcc8193d 100644
--- a/src/wasm-binary-reader-interpreter.c
+++ b/src/wasm-binary-reader-interpreter.c
@@ -607,12 +607,14 @@ static void pop_typecheck_label(Context* ctx) {
 }
 
 static void push_expr(Context* ctx, WasmType type, WasmOpcode opcode) {
-  LOGF("%3" PRIzd ": push %s:%s (#%u)\n", ctx->expr_stack.size,
-       s_opcode_name[opcode], s_type_names[type], ctx->expr_count);
-  ExprNode* expr;
-  expr = wasm_append_expr_node(ctx->allocator, &ctx->expr_stack);
-  expr->index = ctx->expr_count;
-  expr->type = type;
+  if (type != WASM_TYPE_VOID) {
+    LOGF("%3" PRIzd ": push %s:%s (#%u)\n", ctx->expr_stack.size,
+         s_opcode_name[opcode], s_type_names[type], ctx->expr_count);
+    ExprNode* expr;
+    expr = wasm_append_expr_node(ctx->allocator, &ctx->expr_stack);
+    expr->index = ctx->expr_count;
+    expr->type = type;
+  }
   ctx->expr_count++;
 }
 
@@ -944,6 +946,9 @@ static WasmResult on_call_indirect_expr(uint32_t sig_index, void* user_data) {
   Context* ctx = user_data;
   WasmInterpreterFuncSignature* sig = get_signature(ctx, sig_index);
 
+  WasmType entry_index = pop_expr(ctx);
+  CHECK_RESULT(check_type(ctx, WASM_TYPE_I32, entry_index, "call_indirect"));
+
   uint32_t i;
   for (i = sig->param_types.size; i > 0; --i) {
     WasmType arg = pop_expr(ctx);
@@ -951,8 +956,6 @@ static WasmResult on_call_indirect_expr(uint32_t sig_index, void* user_data) {
         check_type(ctx, sig->param_types.data[i - 1], arg, "call_indirect"));
   }
 
-  WasmType entry_index = pop_expr(ctx);
-  CHECK_RESULT(check_type(ctx, WASM_TYPE_I32, entry_index, "call_indirect"));
   push_expr(ctx, sig->result_type, WASM_OPCODE_CALL_INDIRECT);
   return WASM_OK;
 }
@@ -1608,11 +1611,8 @@ static WasmResult on_emit_call_indirect_expr(uint32_t sig_index,
   WasmInterpreterFuncSignature* sig = get_signature(ctx, sig_index);
   CHECK_RESULT(emit_opcode(ctx, WASM_OPCODE_CALL_INDIRECT));
   CHECK_RESULT(emit_i32(ctx, sig_index));
-  uint32_t result_count = get_value_count(sig->result_type);
-  /* the callee cleans up the params for us, but we have to clean up the
-   * function table index */
-  adjust_value_stack(ctx, result_count - sig->param_types.size);
-  CHECK_RESULT(emit_discard_keep(ctx, 1, result_count));
+  adjust_value_stack(ctx,
+                     get_value_count(sig->result_type) - sig->param_types.size);
   adjust_value_stack(ctx, -1);
   CHECK_RESULT(maybe_emit_discard(ctx, ctx->expr_count));
   ctx->expr_count++;
diff --git a/src/wasm-interpreter.c b/src/wasm-interpreter.c
index 5e33aea5..4a8813f5 100644
--- a/src/wasm-interpreter.c
+++ b/src/wasm-interpreter.c
@@ -594,6 +594,22 @@ static WASM_INLINE void read_table_entry_at(const uint8_t* pc,
   *out_keep = *(pc + WASM_TABLE_ENTRY_KEEP_OFFSET);
 }
 
+static WasmBool signatures_are_equal(WasmInterpreterModule* module,
+                                     uint32_t sig_index_0,
+                                     uint32_t sig_index_1) {
+  WasmInterpreterFuncSignature* sig_0 = &module->sigs.data[sig_index_0];
+  WasmInterpreterFuncSignature* sig_1 = &module->sigs.data[sig_index_1];
+  if (sig_0->result_type != sig_1->result_type)
+    return WASM_FALSE;
+  if (sig_0->param_types.size != sig_1->param_types.size)
+    return WASM_FALSE;
+  size_t i;
+  for (i = 0; i < sig_0->param_types.size; ++i)
+    if (sig_0->param_types.data[i] != sig_1->param_types.data[i])
+      return WASM_FALSE;
+  return WASM_TRUE;
+}
+
 WasmInterpreterResult wasm_run_interpreter(WasmInterpreterModule* module,
                                            WasmInterpreterThread* thread,
                                            uint32_t num_instructions,
@@ -718,14 +734,12 @@ WasmInterpreterResult wasm_run_interpreter(WasmInterpreterModule* module,
       case WASM_OPCODE_CALL_INDIRECT: {
         uint32_t sig_index = read_u32(&pc);
         assert(sig_index < module->sigs.size);
-        WasmInterpreterFuncSignature* sig = &module->sigs.data[sig_index];
-        uint32_t num_args = sig->param_types.size;
-        VALUE_TYPE_I32 entry_index = PICK(num_args + 1).i32;
+        VALUE_TYPE_I32 entry_index = POP_I32();
         TRAP_IF(entry_index >= module->func_table.size, UNDEFINED_TABLE_INDEX);
         WasmInterpreterFuncTableEntry* entry =
             &module->func_table.data[entry_index];
-        TRAP_IF(entry->sig_index != sig_index,
-                INDIRECT_CALL_SIGNATURE_MISMATCH);
+        TRAP_UNLESS(signatures_are_equal(module, entry->sig_index, sig_index),
+                    INDIRECT_CALL_SIGNATURE_MISMATCH);
         PUSH_CALL();
         GOTO(entry->func_offset);
         break;