[wasm-c-api] Add test for Table operations

Change-Id: Id1c46ca22002c358155823e3caae18f0ed9c47f5
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1691033
Commit-Queue: Jakob Kummerow <jkummerow@chromium.org>
Reviewed-by: Andreas Haas <ahaas@chromium.org>
Cr-Commit-Position: refs/heads/master@{#62651}

src/wasm/wasm-module-builder.cc

@@ -277,7 +277,10 @@ uint32_t WasmModuleBuilder::AllocateIndirectFunctions(uint32_t count) {
   if (count > FLAG_wasm_max_table_size - index) {
     return std::numeric_limits<uint32_t>::max();
   }
-  indirect_functions_.resize(indirect_functions_.size() + count);
+  DCHECK(max_table_size_ == 0 ||
+         indirect_functions_.size() + count <= max_table_size_);
+  indirect_functions_.resize(indirect_functions_.size() + count,
+                             WasmElemSegment::kNullIndex);
   return index;
 }
 
@@ -286,6 +289,12 @@ void WasmModuleBuilder::SetIndirectFunction(uint32_t indirect,
   indirect_functions_[indirect] = direct;
 }
 
+void WasmModuleBuilder::SetMaxTableSize(uint32_t max) {
+  DCHECK_GE(FLAG_wasm_max_table_size, max);
+  DCHECK_GE(max, indirect_functions_.size());
+  max_table_size_ = max;
+}
+
 uint32_t WasmModuleBuilder::AddImport(Vector<const char> name,
                                       FunctionSig* sig) {
   DCHECK(adding_imports_allowed_);
@@ -419,7 +428,10 @@ void WasmModuleBuilder::WriteTo(ZoneBuffer* buffer) const {
     buffer->write_u8(kLocalFuncRef);
     buffer->write_u8(kHasMaximumFlag);
     buffer->write_size(indirect_functions_.size());
-    buffer->write_size(indirect_functions_.size());
+    size_t max =
+        max_table_size_ > 0 ? max_table_size_ : indirect_functions_.size();
+    DCHECK_GE(max, indirect_functions_.size());
+    buffer->write_size(max);
     FixupSection(buffer, start);
   }
 
@@ -547,13 +559,24 @@ void WasmModuleBuilder::WriteTo(ZoneBuffer* buffer) const {
     size_t start = EmitSection(kElementSectionCode, buffer);
     buffer->write_u8(1);              // count of entries
     buffer->write_u8(0);              // table index
+    uint32_t first_element = 0;
+    while (first_element < indirect_functions_.size() &&
+           indirect_functions_[first_element] == WasmElemSegment::kNullIndex) {
+      first_element++;
+    }
+    uint32_t last_element =
+        static_cast<uint32_t>(indirect_functions_.size() - 1);
+    while (last_element >= first_element &&
+           indirect_functions_[last_element] == WasmElemSegment::kNullIndex) {
+      last_element--;
+    }
     buffer->write_u8(kExprI32Const);  // offset
-    buffer->write_u32v(0);
+    buffer->write_u32v(first_element);
     buffer->write_u8(kExprEnd);
-    buffer->write_size(indirect_functions_.size());  // element count
-
-    for (auto index : indirect_functions_) {
-      buffer->write_size(index + function_imports_.size());
+    uint32_t element_count = last_element - first_element + 1;
+    buffer->write_size(element_count);
+    for (uint32_t i = first_element; i <= last_element; i++) {
+      buffer->write_size(indirect_functions_[i] + function_imports_.size());
     }
 
     FixupSection(buffer, start);

src/wasm/wasm-module-builder.h

@@ -237,8 +237,12 @@ class V8_EXPORT_PRIVATE WasmModuleBuilder : public ZoneObject {
                            bool mutability);
   void AddDataSegment(const byte* data, uint32_t size, uint32_t dest);
   uint32_t AddSignature(FunctionSig* sig);
+  // In the current implementation, it's supported to have uninitialized slots
+  // at the beginning and/or end of the indirect function table, as long as
+  // the filled slots form a contiguous block in the middle.
   uint32_t AllocateIndirectFunctions(uint32_t count);
   void SetIndirectFunction(uint32_t indirect, uint32_t direct);
+  void SetMaxTableSize(uint32_t max);
   void MarkStartFunction(WasmFunctionBuilder* builder);
   void AddExport(Vector<const char> name, WasmFunctionBuilder* builder);
   uint32_t AddExportedGlobal(ValueType type, bool mutability,
@@ -318,6 +322,7 @@ class V8_EXPORT_PRIVATE WasmModuleBuilder : public ZoneObject {
   ZoneVector<WasmGlobal> globals_;
   ZoneUnorderedMap<FunctionSig, uint32_t> signature_map_;
   int start_function_index_;
+  uint32_t max_table_size_ = 0;
   uint32_t min_memory_size_;
   uint32_t max_memory_size_;
   bool has_max_memory_size_;

test/wasm-api-tests/BUILD.gn

@@ -36,6 +36,7 @@ v8_executable("wasm_api_tests") {
     "reflect.cc",
     "run-all-wasm-api-tests.cc",
     "serialize.cc",
+    "table.cc",
     "wasm-api-test.h",
   ]
 }

test/wasm-api-tests/table.cc

+// Copyright 2019 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "test/wasm-api-tests/wasm-api-test.h"
+
+namespace v8 {
+namespace internal {
+namespace wasm {
+
+using ::wasm::FUNCREF;
+using ::wasm::Limits;
+using ::wasm::TableType;
+
+namespace {
+
+own<Trap*> Negate(const Val args[], Val results[]) {
+  results[0] = Val(-args[0].i32());
+  return nullptr;
+}
+
+void ExpectTrap(const Func* func, int arg1, int arg2) {
+  Val args[2] = {Val::i32(arg1), Val::i32(arg2)};
+  Val results[1];
+  own<Trap*> trap = func->call(args, results);
+  EXPECT_NE(nullptr, trap);
+}
+
+void ExpectResult(int expected, const Func* func, int arg1, int arg2) {
+  Val args[2] = {Val::i32(arg1), Val::i32(arg2)};
+  Val results[1];
+  own<Trap*> trap = func->call(args, results);
+  EXPECT_EQ(nullptr, trap);
+  EXPECT_EQ(expected, results[0].i32());
+}
+
+}  // namespace
+
+TEST_F(WasmCapiTest, Table) {
+  builder()->AllocateIndirectFunctions(2);
+  builder()->SetMaxTableSize(10);
+  builder()->AddExportedTable(CStrVector("table"), 0);
+  const uint32_t sig_i_i_index = builder()->AddSignature(wasm_i_i_sig());
+  ValueType reps[] = {kWasmI32, kWasmI32, kWasmI32};
+  FunctionSig call_sig(1, 2, reps);
+  byte call_code[] = {
+      WASM_CALL_INDIRECT1(sig_i_i_index, WASM_GET_LOCAL(1), WASM_GET_LOCAL(0))};
+  AddExportedFunction(CStrVector("call_indirect"), call_code, sizeof(call_code),
+                      &call_sig);
+  byte f_code[] = {WASM_GET_LOCAL(0)};
+  AddExportedFunction(CStrVector("f"), f_code, sizeof(f_code), wasm_i_i_sig());
+  byte g_code[] = {WASM_I32V_1(42)};
+  AddExportedFunction(CStrVector("g"), g_code, sizeof(g_code), wasm_i_i_sig());
+  // Set table[1] to {f}, which has function index 1.
+  builder()->SetIndirectFunction(1, 1);
+
+  Instantiate(nullptr);
+
+  Func* call_indirect = GetExportedFunction(0);
+  Func* f = GetExportedFunction(1);
+  Func* g = GetExportedFunction(2);
+  Table* table = GetExportedTable(3);
+  own<Func*> h = Func::make(store(), cpp_i_i_sig(), Negate);
+
+  // Check initial table state.
+  EXPECT_EQ(2u, table->size());
+  EXPECT_EQ(nullptr, table->get(0));
+  EXPECT_NE(nullptr, table->get(1));
+  ExpectTrap(call_indirect, 0, 0);
+  ExpectResult(7, call_indirect, 7, 1);
+  ExpectTrap(call_indirect, 0, 2);
+
+  // Mutate table.
+  EXPECT_TRUE(table->set(0, g));
+  EXPECT_TRUE(table->set(1, nullptr));
+  EXPECT_FALSE(table->set(2, f));
+  EXPECT_NE(nullptr, table->get(0));
+  EXPECT_EQ(nullptr, table->get(1));
+  ExpectResult(42, call_indirect, 7, 0);
+  ExpectTrap(call_indirect, 0, 1);
+  ExpectTrap(call_indirect, 0, 2);
+
+  // Grow table.
+  EXPECT_TRUE(table->grow(3));
+  EXPECT_EQ(5u, table->size());
+  EXPECT_TRUE(table->set(2, f));
+  EXPECT_TRUE(table->set(3, h.get()));
+  EXPECT_FALSE(table->set(5, nullptr));
+  EXPECT_NE(nullptr, table->get(2));
+  EXPECT_NE(nullptr, table->get(3));
+  EXPECT_EQ(nullptr, table->get(4));
+  ExpectResult(5, call_indirect, 5, 2);
+  ExpectResult(-6, call_indirect, 6, 3);
+  ExpectTrap(call_indirect, 0, 4);
+  ExpectTrap(call_indirect, 0, 5);
+  EXPECT_TRUE(table->grow(2, f));
+  EXPECT_EQ(7u, table->size());
+  EXPECT_NE(nullptr, table->get(5));
+  EXPECT_NE(nullptr, table->get(6));
+  EXPECT_FALSE(table->grow(5));
+  EXPECT_TRUE(table->grow(3));
+  EXPECT_TRUE(table->grow(0));
+
+  // Create standalone table.
+  // TODO(wasm+): Once Wasm allows multiple tables, turn this into import.
+  own<TableType*> tabletype =
+      TableType::make(ValType::make(FUNCREF), Limits(5, 5));
+  own<Table*> table2 = Table::make(store(), tabletype.get());
+  EXPECT_EQ(5u, table2->size());
+  EXPECT_FALSE(table2->grow(1));
+  EXPECT_TRUE(table2->grow(0));
+}
+
+}  // namespace wasm
+}  // namespace internal
+}  // namespace v8

test/wasm-api-tests/wasm-api-test.h

@@ -42,6 +42,7 @@ using ::wasm::Module;
 using ::wasm::own;
 using ::wasm::Ref;
 using ::wasm::Store;
+using ::wasm::Table;
 using ::wasm::Trap;
 using ::wasm::Val;
 using ::wasm::ValType;
@@ -115,6 +116,15 @@ class WasmCapiTest : public ::testing::Test {
     return memory;
   }
 
+  Table* GetExportedTable(size_t index) {
+    DCHECK_GT(exports_.size(), index);
+    Extern* exported = exports_[index];
+    DCHECK_EQ(exported->kind(), ::wasm::EXTERN_TABLE);
+    Table* table = exported->table();
+    DCHECK_NE(table, nullptr);
+    return table;
+  }
+
   void Shutdown() {
     instance_.reset();
     module_.reset();