Line data    Source code

       1             : // Copyright 2016 the V8 project authors. All rights reserved.
       2             : // Use of this source code is governed by a BSD-style license that can be
       3             : // found in the LICENSE file.
       4             : 
       5             : #ifndef V8_WASM_WASM_LIMITS_H_
       6             : #define V8_WASM_WASM_LIMITS_H_
       7             : 
       8             : #include <cstddef>
       9             : #include <cstdint>
      10             : #include <limits>
      11             : 
      12             : #include "src/wasm/wasm-constants.h"
      13             : 
      14             : namespace v8 {
      15             : namespace internal {
      16             : namespace wasm {
      17             : 
      18             : constexpr size_t kSpecMaxWasmMemoryPages = 65536;
      19             : 
      20             : // The following limits are imposed by V8 on WebAssembly modules.
      21             : // The limits are agreed upon with other engines for consistency.
      22             : constexpr size_t kV8MaxWasmTypes = 1000000;
      23             : constexpr size_t kV8MaxWasmFunctions = 1000000;
      24             : constexpr size_t kV8MaxWasmImports = 100000;
      25             : constexpr size_t kV8MaxWasmExports = 100000;
      26             : constexpr size_t kV8MaxWasmGlobals = 1000000;
      27             : constexpr size_t kV8MaxWasmExceptions = 1000000;
      28             : constexpr size_t kV8MaxWasmExceptionTypes = 1000000;
      29             : constexpr size_t kV8MaxWasmDataSegments = 100000;
      30             : // Don't use this limit directly, but use the value of {max_mem_pages()}.
      31             : constexpr size_t kV8MaxWasmMemoryPages = 32767;  // = ~ 2 GiB
      32             : constexpr size_t kV8MaxWasmStringSize = 100000;
      33             : constexpr size_t kV8MaxWasmModuleSize = 1024 * 1024 * 1024;  // = 1 GiB
      34             : constexpr size_t kV8MaxWasmFunctionSize = 7654321;
      35             : constexpr size_t kV8MaxWasmFunctionLocals = 50000;
      36             : constexpr size_t kV8MaxWasmFunctionParams = 1000;
      37             : constexpr size_t kV8MaxWasmFunctionMultiReturns = 1000;
      38             : constexpr size_t kV8MaxWasmFunctionReturns = 1;
      39             : // Don't use this limit directly, but use the value of FLAG_wasm_max_table_size.
      40             : constexpr size_t kV8MaxWasmTableSize = 10000000;
      41             : constexpr size_t kV8MaxWasmTableInitEntries = 10000000;
      42             : constexpr size_t kV8MaxWasmTables = 1;
      43             : constexpr size_t kV8MaxWasmMemories = 1;
      44             : 
      45             : static_assert(kV8MaxWasmMemoryPages <= kSpecMaxWasmMemoryPages,
      46             :               "v8 should not be more permissive than the spec");
      47             : static_assert(kV8MaxWasmTableSize <= 4294967295,  // 2^32 - 1
      48             :               "v8 should not exceed WebAssembly's non-web embedding limits");
      49             : static_assert(kV8MaxWasmTableInitEntries <= kV8MaxWasmTableSize,
      50             :               "JS-API should not exceed v8's limit");
      51             : 
      52             : constexpr uint64_t kWasmMaxHeapOffset =
      53             :     static_cast<uint64_t>(
      54             :         std::numeric_limits<uint32_t>::max())  // maximum base value
      55             :     + std::numeric_limits<uint32_t>::max();    // maximum index value
      56             : 
      57             : // Defined in wasm-engine.cc.
      58             : // TODO(wasm): Make this size_t for wasm64. Currently the --wasm-max-mem-pages
      59             : // flag is only uint32_t.
      60             : uint32_t max_mem_pages();
      61             : uint32_t max_table_init_entries();
      62             : 
      63             : inline uint64_t max_mem_bytes() {
      64     1509727 :   return uint64_t{max_mem_pages()} * kWasmPageSize;
      65             : }
      66             : 
      67             : }  // namespace wasm
      68             : }  // namespace internal
      69             : }  // namespace v8
      70             : 
      71             : #endif  // V8_WASM_WASM_LIMITS_H_