[wasm] Binary 11: Bump module version to 0xB.

[wasm] Binary 11: Swap the order of section name / section length.
[wasm] Binary 11: Shorter section names.
[wasm] Binary 11: Add a prefix for function type declarations.
[wasm] Binary 11: Function types encoded as pcount, p*, rcount, r*
[wasm] Fix numeric names for functions.

R=rossberg@chromium.org,jfb@chromium.org,ahaas@chromium.org
BUG=chromium:575167
LOG=Y

Review-Url: https://codereview.chromium.org/1896863003
Cr-Commit-Position: refs/heads/master@{#35897}

src/wasm/encoder.cc

@@ -80,11 +80,6 @@ void FixupSection(byte* start, byte* end) {
 
 // Returns the start of the section, where the section VarInt size is.
 byte* EmitSection(WasmSection::Code code, byte** b) {
-  // Emit a placeholder for the length.
-  byte* start = *b;
-  for (size_t padding = 0; padding != kPaddedVarintSize; ++padding) {
-    EmitUint8(b, 0xff);  // Will get fixed up later.
-  }
   // Emit the section name.
   const char* name = WasmSection::getName(code);
   TRACE("emit section: %s\n", name);
@@ -92,6 +87,12 @@ byte* EmitSection(WasmSection::Code code, byte** b) {
   EmitVarInt(b, length);  // Section name string size.
   for (size_t i = 0; i != length; ++i) EmitUint8(b, name[i]);
 
+  // Emit a placeholder for the length.
+  byte* start = *b;
+  for (size_t padding = 0; padding != kPaddedVarintSize; ++padding) {
+    EmitUint8(b, 0xff);  // Will get fixed up later.
+  }
+
   return start;
 }
 }  // namespace
@@ -586,7 +587,9 @@ WasmModuleIndex* WasmModuleWriter::WriteTo(Zone* zone) const {
     sizes.AddSection(WasmSection::Code::Signatures, signatures_.size());
     for (auto sig : signatures_) {
       sizes.Add(1 + LEBHelper::sizeof_u32v(sig->parameter_count()) +
-                    sig->parameter_count(),
+                    sig->parameter_count() +
+                    LEBHelper::sizeof_u32v(sig->return_count()) +
+                    sig->return_count(),
                 0);
     }
     TRACE("Size after signatures: %u, %u\n", (unsigned)sizes.header_size,
@@ -594,7 +597,7 @@ WasmModuleIndex* WasmModuleWriter::WriteTo(Zone* zone) const {
   }
 
   if (functions_.size() > 0) {
-    sizes.AddSection(WasmSection::Code::Functions, functions_.size());
+    sizes.AddSection(WasmSection::Code::OldFunctions, functions_.size());
     for (auto function : functions_) {
       sizes.Add(function->HeaderSize() + function->BodySize(),
                 function->NameSize());
@@ -669,22 +672,22 @@ WasmModuleIndex* WasmModuleWriter::WriteTo(Zone* zone) const {
     EmitVarInt(&header, signatures_.size());
 
     for (FunctionSig* sig : signatures_) {
+      EmitUint8(&header, kWasmFunctionTypeForm);
       EmitVarInt(&header, sig->parameter_count());
-      if (sig->return_count() > 0) {
-        EmitUint8(&header, WasmOpcodes::LocalTypeCodeFor(sig->GetReturn()));
-      } else {
-        EmitUint8(&header, kLocalVoid);
-      }
       for (size_t j = 0; j < sig->parameter_count(); j++) {
         EmitUint8(&header, WasmOpcodes::LocalTypeCodeFor(sig->GetParam(j)));
       }
+      EmitVarInt(&header, sig->return_count());
+      for (size_t j = 0; j < sig->return_count(); j++) {
+        EmitUint8(&header, WasmOpcodes::LocalTypeCodeFor(sig->GetReturn(j)));
+      }
     }
     FixupSection(section, header);
   }
 
   // -- emit functions ---------------------------------------------------------
   if (functions_.size() > 0) {
-    byte* section = EmitSection(WasmSection::Code::Functions, &header);
+    byte* section = EmitSection(WasmSection::Code::OldFunctions, &header);
     EmitVarInt(&header, functions_.size());
 
     for (auto func : functions_) {

src/wasm/module-decoder.cc

@@ -107,17 +107,6 @@ class ModuleDecoder : public Decoder {
       TRACE("DecodeSection\n");
       pos = pc_;
 
-      // Read and check the section size.
-      int section_leb_length = 0;
-      uint32_t section_length =
-          consume_u32v(&section_leb_length, "section length");
-      if (!checkAvailable(section_length)) {
-        // The section would extend beyond the end of the module.
-        break;
-      }
-      const byte* section_start = pc_;
-      const byte* expected_section_end = pc_ + section_length;
-
       // Read the section name.
       int string_leb_length = 0;
       uint32_t string_length =
@@ -128,15 +117,21 @@ class ModuleDecoder : public Decoder {
         TRACE("Section name of length %u couldn't be read\n", string_length);
         break;
       }
-      if (pc_ > expected_section_end) {
-        error(section_name_start, pc_,
-              "section name string %u longer than total section bytes %u",
-              string_length, section_length);
-      }
 
       WasmSection::Code section =
           WasmSection::lookup(section_name_start, string_length);
 
+      // Read and check the section size.
+      int section_leb_length = 0;
+      uint32_t section_length =
+          consume_u32v(&section_leb_length, "section length");
+      if (!checkAvailable(section_length)) {
+        // The section would extend beyond the end of the module.
+        break;
+      }
+      const byte* section_start = pc_;
+      const byte* expected_section_end = pc_ + section_length;
+
       current_order = CheckSectionOrder(current_order, section);
 
       switch (section) {
@@ -144,12 +139,13 @@ class ModuleDecoder : public Decoder {
           // Terminate section decoding.
           limit_ = pc_;
           break;
-        case WasmSection::Code::Memory:
+        case WasmSection::Code::Memory: {
           int length;
           module->min_mem_pages = consume_u32v(&length, "min memory");
           module->max_mem_pages = consume_u32v(&length, "max memory");
           module->mem_export = consume_u8("export memory") != 0;
           break;
+        }
         case WasmSection::Code::Signatures: {
           int length;
           uint32_t signatures_count = consume_u32v(&length, "signatures count");
@@ -159,7 +155,7 @@ class ModuleDecoder : public Decoder {
             if (failed()) break;
             TRACE("DecodeSignature[%d] module+%d\n", i,
                   static_cast<int>(pc_ - start_));
-            FunctionSig* s = consume_sig();  // read function sig.
+            FunctionSig* s = consume_sig();
             module->signatures.push_back(s);
           }
           break;
@@ -202,7 +198,7 @@ class ModuleDecoder : public Decoder {
           }
           break;
         }
-        case WasmSection::Code::Functions: {
+        case WasmSection::Code::OldFunctions: {
           int length;
           uint32_t functions_count = consume_u32v(&length, "functions count");
           module->functions.reserve(SafeReserve(functions_count));
@@ -385,7 +381,7 @@ class ModuleDecoder : public Decoder {
             TRACE("%c", *(section_name_start + i));
           }
           TRACE("'\n");
-          consume_bytes(section_length - string_length - string_leb_length);
+          consume_bytes(section_length);
           break;
       }
 
@@ -700,20 +696,48 @@ class ModuleDecoder : public Decoder {
     }
   }
 
-  // Parses an inline function signature.
+  // Parses a type entry, which is currently limited to functions only.
   FunctionSig* consume_sig() {
+    const byte* pos = pc_;
+    byte form = consume_u8("type form");
+    if (form != kWasmFunctionTypeForm) {
+      error(pos, pos, "expected function type form (0x%02x), got: 0x%02x",
+            kWasmFunctionTypeForm, form);
+      return nullptr;
+    }
     int length;
-    byte count = consume_u32v(&length, "param count");
-    LocalType ret = consume_local_type();
-    FunctionSig::Builder builder(module_zone, ret == kAstStmt ? 0 : 1, count);
-    if (ret != kAstStmt) builder.AddReturn(ret);
-
-    for (int i = 0; i < count; i++) {
+    // parse parameter types
+    uint32_t param_count = consume_u32v(&length, "param count");
+    std::vector<LocalType> params;
+    for (uint32_t i = 0; i < param_count; i++) {
       LocalType param = consume_local_type();
       if (param == kAstStmt) error(pc_ - 1, "invalid void parameter type");
-      builder.AddParam(param);
+      params.push_back(param);
+    }
+
+    // parse return types
+    const byte* pt = pc_;
+    uint32_t return_count = consume_u32v(&length, "return count");
+    if (return_count > kMaxReturnCount) {
+      error(pt, pt, "return count of %u exceeds maximum of %u", return_count,
+            kMaxReturnCount);
+      return nullptr;
+    }
+    std::vector<LocalType> returns;
+    for (uint32_t i = 0; i < return_count; i++) {
+      LocalType ret = consume_local_type();
+      if (ret == kAstStmt) error(pc_ - 1, "invalid void return type");
+      returns.push_back(ret);
     }
-    return builder.Build();
+
+    // FunctionSig stores the return types first.
+    LocalType* buffer =
+        module_zone->NewArray<LocalType>(param_count + return_count);
+    uint32_t b = 0;
+    for (uint32_t i = 0; i < return_count; i++) buffer[b++] = returns[i];
+    for (uint32_t i = 0; i < param_count; i++) buffer[b++] = params[i];
+
+    return new (module_zone) FunctionSig(return_count, param_count, buffer);
   }
 };
 

src/wasm/wasm-macro-gen.h

@@ -564,4 +564,23 @@ class LocalDeclEncoder {
 #define WASM_I32_REINTERPRET_F32(x) x, kExprI32ReinterpretF32
 #define WASM_I64_REINTERPRET_F64(x) x, kExprI64ReinterpretF64
 
+#define SIG_ENTRY_v_v kWasmFunctionTypeForm, 0, 0
+#define SIZEOF_SIG_ENTRY_v_v 3
+
+#define SIG_ENTRY_v_x(a) kWasmFunctionTypeForm, 1, a, 0
+#define SIG_ENTRY_v_xx(a, b) kWasmFunctionTypeForm, 2, a, b, 0
+#define SIG_ENTRY_v_xxx(a, b, c) kWasmFunctionTypeForm, 3, a, b, c, 0
+#define SIZEOF_SIG_ENTRY_v_x 4
+#define SIZEOF_SIG_ENTRY_v_xx 5
+#define SIZEOF_SIG_ENTRY_v_xxx 6
+
+#define SIG_ENTRY_x(r) kWasmFunctionTypeForm, 0, 1, r
+#define SIG_ENTRY_x_x(r, a) kWasmFunctionTypeForm, 1, a, 1, r
+#define SIG_ENTRY_x_xx(r, a, b) kWasmFunctionTypeForm, 2, a, b, 1, r
+#define SIG_ENTRY_x_xxx(r, a, b, c) kWasmFunctionTypeForm, 3, a, b, c, 1, r
+#define SIZEOF_SIG_ENTRY_x 4
+#define SIZEOF_SIG_ENTRY_x_x 5
+#define SIZEOF_SIG_ENTRY_x_xx 6
+#define SIZEOF_SIG_ENTRY_x_xxx 7
+
 #endif  // V8_WASM_MACRO_GEN_H_

src/wasm/wasm-module.cc

@@ -4,6 +4,7 @@
 
 #include "src/macro-assembler.h"
 #include "src/objects.h"
+#include "src/property-descriptor.h"
 #include "src/v8.h"
 
 #include "src/simulator.h"
@@ -409,6 +410,9 @@ MaybeHandle<JSObject> WasmModule::Instantiate(Isolate* isolate,
   ErrorThrower thrower(isolate, "WasmModule::Instantiate()");
   Factory* factory = isolate->factory();
 
+  PropertyDescriptor desc;
+  desc.set_writable(false);
+
   //-------------------------------------------------------------------------
   // Allocate the instance and its JS counterpart.
   //-------------------------------------------------------------------------
@@ -562,7 +566,11 @@ MaybeHandle<JSObject> WasmModule::Instantiate(Isolate* isolate,
       if (func.exported) {
         // Exported functions are installed as read-only properties on the
         // module.
-        JSObject::AddProperty(instance.js_object, name, function, READ_ONLY);
+        desc.set_value(function);
+        Maybe<bool> status = JSReceiver::DefineOwnProperty(
+            isolate, instance.js_object, name, &desc, Object::THROW_ON_ERROR);
+        if (!status.IsJust())
+          thrower.Error("export of %.*s failed.", str.length(), str.start());
       }
     }
 
@@ -593,7 +601,11 @@ MaybeHandle<JSObject> WasmModule::Instantiate(Isolate* isolate,
         Handle<JSFunction> function = compiler::CompileJSToWasmWrapper(
             isolate, &module_env, name, code, instance.js_object,
             exp.func_index);
-        JSObject::AddProperty(exports_object, name, function, READ_ONLY);
+        desc.set_value(function);
+        Maybe<bool> status = JSReceiver::DefineOwnProperty(
+            isolate, exports_object, name, &desc, Object::THROW_ON_ERROR);
+        if (!status.IsJust())
+          thrower.Error("export of %.*s failed.", str.length(), str.start());
       }
 
       if (mem_export) {

src/wasm/wasm-module.h

@@ -24,65 +24,59 @@ const size_t kMaxModuleSize = 1024 * 1024 * 1024;
 const size_t kMaxFunctionSize = 128 * 1024;
 const size_t kMaxStringSize = 256;
 const uint32_t kWasmMagic = 0x6d736100;
-const uint32_t kWasmVersion = 0x0a;
+const uint32_t kWasmVersion = 0x0b;
+const uint8_t kWasmFunctionTypeForm = 0x40;
 
 // WebAssembly sections are named as strings in the binary format, but
 // internally V8 uses an enum to handle them.
 //
-// Entries have the form F(enumerator, order, string).
-#define FOR_EACH_WASM_SECTION_TYPE(F)             \
-  F(Signatures, 1, "signatures")                  \
-  F(ImportTable, 2, "import_table")               \
-  F(FunctionSignatures, 3, "function_signatures") \
-  F(FunctionTable, 4, "function_table")           \
-  F(Memory, 5, "memory")                          \
-  F(ExportTable, 6, "export_table")               \
-  F(StartFunction, 7, "start_function")           \
-  F(FunctionBodies, 8, "function_bodies")         \
-  F(DataSegments, 9, "data_segments")             \
-  F(Names, 10, "names")                           \
-  F(Globals, 0, "globals")                        \
-  F(Functions, 0, "functions")                    \
+// Entries have the form F(enumerator, string).
+#define FOR_EACH_WASM_SECTION_TYPE(F)  \
+  F(Signatures, 1, "type")             \
+  F(ImportTable, 2, "import")          \
+  F(FunctionSignatures, 3, "function") \
+  F(FunctionTable, 4, "table")         \
+  F(Memory, 5, "memory")               \
+  F(ExportTable, 6, "export")          \
+  F(StartFunction, 7, "start")         \
+  F(FunctionBodies, 8, "code")         \
+  F(DataSegments, 9, "data")           \
+  F(Names, 10, "name")                 \
+  F(OldFunctions, 0, "old_function")   \
+  F(Globals, 0, "global")              \
   F(End, 0, "end")
 
 // Contants for the above section types: {LEB128 length, characters...}.
 #define WASM_SECTION_MEMORY 6, 'm', 'e', 'm', 'o', 'r', 'y'
-#define WASM_SECTION_SIGNATURES \
-  10, 's', 'i', 'g', 'n', 'a', 't', 'u', 'r', 'e', 's'
-#define WASM_SECTION_FUNCTIONS 9, 'f', 'u', 'n', 'c', 't', 'i', 'o', 'n', 's'
-#define WASM_SECTION_GLOBALS 7, 'g', 'l', 'o', 'b', 'a', 'l', 's'
-#define WASM_SECTION_DATA_SEGMENTS \
-  13, 'd', 'a', 't', 'a', '_', 's', 'e', 'g', 'm', 'e', 'n', 't', 's'
-#define WASM_SECTION_FUNCTION_TABLE \
-  14, 'f', 'u', 'n', 'c', 't', 'i', 'o', 'n', '_', 't', 'a', 'b', 'l', 'e'
+#define WASM_SECTION_SIGNATURES 4, 't', 'y', 'p', 'e'
+#define WASM_SECTION_OLD_FUNCTIONS \
+  12, 'o', 'l', 'd', '_', 'f', 'u', 'n', 'c', 't', 'i', 'o', 'n'
+#define WASM_SECTION_GLOBALS 6, 'g', 'l', 'o', 'b', 'a', 'l'
+#define WASM_SECTION_DATA_SEGMENTS 4, 'd', 'a', 't', 'a'
+#define WASM_SECTION_FUNCTION_TABLE 5, 't', 'a', 'b', 'l', 'e'
 #define WASM_SECTION_END 3, 'e', 'n', 'd'
-#define WASM_SECTION_START_FUNCTION \
-  14, 's', 't', 'a', 'r', 't', '_', 'f', 'u', 'n', 'c', 't', 'i', 'o', 'n'
-#define WASM_SECTION_IMPORT_TABLE \
-  12, 'i', 'm', 'p', 'o', 'r', 't', '_', 't', 'a', 'b', 'l', 'e'
-#define WASM_SECTION_EXPORT_TABLE \
-  12, 'e', 'x', 'p', 'o', 'r', 't', '_', 't', 'a', 'b', 'l', 'e'
-#define WASM_SECTION_FUNCTION_SIGNATURES                                    \
-  19, 'f', 'u', 'n', 'c', 't', 'i', 'o', 'n', '_', 's', 'i', 'g', 'n', 'a', \
-      't', 'u', 'r', 'e', 's'
-#define WASM_SECTION_FUNCTION_BODIES \
-  15, 'f', 'u', 'n', 'c', 't', 'i', 'o', 'n', '_', 'b', 'o', 'd', 'i', 'e', 's'
-#define WASM_SECTION_NAMES 5, 'n', 'a', 'm', 'e', 's'
+#define WASM_SECTION_START_FUNCTION 5, 's', 't', 'a', 'r', 't'
+#define WASM_SECTION_IMPORT_TABLE 6, 'i', 'm', 'p', 'o', 'r', 't'
+#define WASM_SECTION_EXPORT_TABLE 6, 'e', 'x', 'p', 'o', 'r', 't'
+#define WASM_SECTION_FUNCTION_SIGNATURES \
+  8, 'f', 'u', 'n', 'c', 't', 'i', 'o', 'n'
+#define WASM_SECTION_FUNCTION_BODIES 4, 'c', 'o', 'd', 'e'
+#define WASM_SECTION_NAMES 4, 'n', 'a', 'm', 'e'
 
 // Constants for the above section headers' size (LEB128 + characters).
 #define WASM_SECTION_MEMORY_SIZE ((size_t)7)
-#define WASM_SECTION_SIGNATURES_SIZE ((size_t)11)
-#define WASM_SECTION_FUNCTIONS_SIZE ((size_t)10)
-#define WASM_SECTION_GLOBALS_SIZE ((size_t)8)
-#define WASM_SECTION_DATA_SEGMENTS_SIZE ((size_t)14)
-#define WASM_SECTION_FUNCTION_TABLE_SIZE ((size_t)15)
+#define WASM_SECTION_SIGNATURES_SIZE ((size_t)5)
+#define WASM_SECTION_OLD_FUNCTIONS_SIZE ((size_t)13)
+#define WASM_SECTION_GLOBALS_SIZE ((size_t)7)
+#define WASM_SECTION_DATA_SEGMENTS_SIZE ((size_t)5)
+#define WASM_SECTION_FUNCTION_TABLE_SIZE ((size_t)6)
 #define WASM_SECTION_END_SIZE ((size_t)4)
-#define WASM_SECTION_START_FUNCTION_SIZE ((size_t)15)
-#define WASM_SECTION_IMPORT_TABLE_SIZE ((size_t)13)
-#define WASM_SECTION_EXPORT_TABLE_SIZE ((size_t)13)
-#define WASM_SECTION_FUNCTION_SIGNATURES_SIZE ((size_t)20)
-#define WASM_SECTION_FUNCTION_BODIES_SIZE ((size_t)16)
-#define WASM_SECTION_NAMES_SIZE ((size_t)6)
+#define WASM_SECTION_START_FUNCTION_SIZE ((size_t)6)
+#define WASM_SECTION_IMPORT_TABLE_SIZE ((size_t)7)
+#define WASM_SECTION_EXPORT_TABLE_SIZE ((size_t)7)
+#define WASM_SECTION_FUNCTION_SIGNATURES_SIZE ((size_t)9)
+#define WASM_SECTION_FUNCTION_BODIES_SIZE ((size_t)5)
+#define WASM_SECTION_NAMES_SIZE ((size_t)5)
 
 struct WasmSection {
   enum class Code : uint32_t {
@@ -111,6 +105,8 @@ enum WasmFunctionDeclBit {
 static const size_t kDeclMemorySize = 3;
 static const size_t kDeclDataSegmentSize = 13;
 
+static const uint32_t kMaxReturnCount = 1;
+
 // Static representation of a WASM function.
 struct WasmFunction {
   FunctionSig* sig;      // signature of the function.

test/cctest/wasm/test-run-wasm-module.cc

@@ -18,8 +18,6 @@ using namespace v8::internal;
 using namespace v8::internal::compiler;
 using namespace v8::internal::wasm;
 
-
-// TODO(titzer): fix arm64 frame alignment.
 namespace {
 void TestModule(WasmModuleIndex* module, int32_t expected_result) {
   Isolate* isolate = CcTest::InitIsolateOnce();
@@ -31,43 +29,6 @@ void TestModule(WasmModuleIndex* module, int32_t expected_result) {
 }
 }  // namespace
 
-
-// A raw test that skips the WasmModuleBuilder.
-TEST(Run_WasmModule_CallAdd_rev) {
-  static const byte data[] = {
-      WASM_MODULE_HEADER,
-      // sig#0 ------------------------------------------
-      WASM_SECTION_SIGNATURES_SIZE + 7,    // Section size.
-      WASM_SECTION_SIGNATURES, 2,          // --
-      0, kLocalI32,                        // void -> int
-      2, kLocalI32, kLocalI32, kLocalI32,  // int,int -> int
-      // func#0 (main) ----------------------------------
-      WASM_SECTION_FUNCTIONS_SIZE + 25, WASM_SECTION_FUNCTIONS, 2,
-      kDeclFunctionExport, 0, 0,  // sig index
-      8, 0,                       // body size
-      0,                          // locals
-      kExprI8Const, 77,           // --
-      kExprI8Const, 22,           // --
-      kExprCallFunction, 2, 1,    // --
-      // func#1 -----------------------------------------
-      0,                 // no name, not exported
-      1, 0,              // sig index
-      6, 0,              // body size
-      0,                 // locals
-      kExprGetLocal, 0,  // --
-      kExprGetLocal, 1,  // --
-      kExprI32Add,       // --
-  };
-
-  Isolate* isolate = CcTest::InitIsolateOnce();
-  HandleScope scope(isolate);
-  WasmJs::InstallWasmFunctionMap(isolate, isolate->native_context());
-  int32_t result =
-      CompileAndRunWasmModule(isolate, data, data + arraysize(data));
-  CHECK_EQ(99, result);
-}
-
-
 TEST(Run_WasmModule_Return114) {
   static const int32_t kReturnValue = 114;
   v8::base::AccountingAllocator allocator;

test/mjsunit/wasm/adapter-frame.js

@@ -27,8 +27,10 @@ function makeSelect(type, args, which) {
 
   var builder = new WasmModuleBuilder();
   var sig = new Array();
-  sig.push(type);
+  sig.push(args);
   for (var i = 0; i < args; i++) sig.push(type);
+  sig.push(1);
+  sig.push(type);
   builder.addFunction("select", sig)
     .addBody([kExprGetLocal, which])
     .exportFunc();

test/mjsunit/wasm/calls.js

@@ -45,7 +45,7 @@ function assertFunction(module, func) {
   var builder = new WasmModuleBuilder();
 
   builder.addMemory(1, 1, true);
-  builder.addFunction("sub", [kAstI64, kAstI64, kAstI64])
+  builder.addFunction("sub", kSig_l_ll)
     .addBody([           // --
       kExprGetLocal, 0,  // --
       kExprGetLocal, 1,  // --
@@ -67,7 +67,7 @@ function assertFunction(module, func) {
   var builder = new WasmModuleBuilder();
 
   builder.addMemory(1, 1, true);
-  builder.addFunction("sub", [kAstI32, kAstI32, kAstI32])
+  builder.addFunction("sub", kSig_i_ii)
     .addBody([
       kExprGetLocal, 0,             // --
       kExprGetLocal, 1,             // --
@@ -92,7 +92,7 @@ function assertFunction(module, func) {
 
   var kPages = 2;
   builder.addMemory(kPages, kPages, true);
-  builder.addFunction("nop", [kAstStmt])
+  builder.addFunction("nop", kSig_v_v)
     .addBody([kExprNop])
     .exportFunc();
 
@@ -109,7 +109,7 @@ function assertFunction(module, func) {
 
   var kPages = 3;
   builder.addMemory(kPages, kPages, true);
-  builder.addFunction("flt", [kAstI32, kAstF64, kAstF64])
+  builder.addFunction("flt", kSig_i_dd)
     .addBody([
       kExprGetLocal, 0,     // --
       kExprGetLocal, 1,     // --

test/mjsunit/wasm/divrem-trap.js

@@ -33,7 +33,7 @@ function assertTraps(code, msg) {
 function makeBinop(opcode) {
   var builder = new WasmModuleBuilder();
 
-  builder.addFunction("main", [kAstI32, kAstI32, kAstI32])
+  builder.addFunction("main", kSig_i_ii)
     .addBody([
       kExprGetLocal, 0,           // --
       kExprGetLocal, 1,           // --

test/mjsunit/wasm/export-table.js

@@ -11,7 +11,7 @@ load("test/mjsunit/wasm/wasm-module-builder.js");
   var kReturnValue = 88;
   var builder = new WasmModuleBuilder();
 
-  builder.addFunction("main", [kAstI32])
+  builder.addFunction("main", kSig_i)
     .addBody([
       kExprI8Const,
       kReturnValue,
@@ -32,7 +32,7 @@ load("test/mjsunit/wasm/wasm-module-builder.js");
 
   var builder = new WasmModuleBuilder();
 
-  builder.addFunction("main", [kAstI32])
+  builder.addFunction("main", kSig_i)
     .addBody([
       kExprI8Const,
       kReturnValue,
@@ -50,3 +50,25 @@ load("test/mjsunit/wasm/wasm-module-builder.js");
   assertEquals(kReturnValue, module.exports.foo());
   assertEquals(kReturnValue, module.exports.blah());
 })();
+
+
+(function testNumericName() {
+  var kReturnValue = 93;
+
+  var builder = new WasmModuleBuilder();
+
+  builder.addFunction("main", kSig_i)
+    .addBody([
+      kExprI8Const,
+      kReturnValue,
+      kExprReturn, kArity1
+    ])
+    .exportAs("0");
+
+  var module = builder.instantiate();
+
+  assertEquals("object", typeof module.exports);
+  assertEquals("function", typeof module.exports["0"]);
+
+  assertEquals(kReturnValue, module.exports["0"]());
+})();

test/mjsunit/wasm/ffi-error.js

@@ -10,7 +10,7 @@ load("test/mjsunit/wasm/wasm-module-builder.js");
 function testCallFFI(ffi) {
   var builder = new WasmModuleBuilder();
 
-  var sig_index = [kAstI32, kAstF64, kAstF64];
+  var sig_index = kSig_i_dd;
   builder.addImport("fun", sig_index);
   builder.addFunction("main", sig_index)
     .addBody([

test/mjsunit/wasm/ffi.js

@@ -10,7 +10,7 @@ load("test/mjsunit/wasm/wasm-module-builder.js");
 function testCallFFI(func, check) {
   var builder = new WasmModuleBuilder();
 
-  var sig_index = builder.addSignature([kAstI32, kAstF64, kAstF64]);
+  var sig_index = builder.addSignature(kSig_i_dd);
   builder.addImport("func", sig_index);
   builder.addFunction("main", sig_index)
     .addBody([
@@ -185,8 +185,8 @@ function testCallBinopVoid(type, func, check) {
 
   var builder = new WasmModuleBuilder();
 
-  builder.addImport("func", [kAstStmt, type, type]);
-  builder.addFunction("main", [kAstI32, type, type])
+  builder.addImport("func", makeSig_v_xx(type));
+  builder.addFunction("main", makeSig_r_xx(kAstI32, type))
     .addBody([
       kExprGetLocal, 0,            // --
       kExprGetLocal, 1,            // --
@@ -241,9 +241,9 @@ testCallBinopVoid(kAstF64);
 function testCallPrint() {
   var builder = new WasmModuleBuilder();
 
-  builder.addImport("print", [kAstStmt, kAstI32]);
-  builder.addImport("print", [kAstStmt, kAstF64]);
-  builder.addFunction("main", [kAstStmt, kAstF64])
+  builder.addImport("print", makeSig_v_x(kAstI32));
+  builder.addImport("print", makeSig_v_x(kAstF64));
+  builder.addFunction("main", makeSig_v_x(kAstF64))
     .addBody([
       kExprI8Const, 97,             // --
       kExprCallImport, kArity1, 0,  // --

test/mjsunit/wasm/function-prototype.js

@@ -10,7 +10,7 @@ load("test/mjsunit/wasm/wasm-module-builder.js");
 (function TestFunctionPrototype() {
   var builder = new WasmModuleBuilder();
 
-  builder.addFunction("nine", [kAstI32])
+  builder.addFunction("nine", kSig_i)
     .addBody([kExprI8Const, 9])
     .exportFunc();
 

test/mjsunit/wasm/gc-frame.js

@@ -10,7 +10,7 @@ load("test/mjsunit/wasm/wasm-module-builder.js");
 function makeFFI(func, t) {
   var builder = new WasmModuleBuilder();
 
-  var sig_index = builder.addSignature([t,t,t,t,t,t,t,t,t,t,t]);
+  var sig_index = builder.addSignature([10,t,t,t,t,t,t,t,t,t,t,1,t]);
   builder.addImport("func", sig_index);
   // Try to create a frame with lots of spilled values and parameters
   // on the stack to try to catch GC bugs in the reference maps for

test/mjsunit/wasm/import-table.js

@@ -10,7 +10,7 @@ load("test/mjsunit/wasm/wasm-module-builder.js");
 function testCallImport(func, check) {
   var builder = new WasmModuleBuilder();
 
-  var sig_index = builder.addSignature([kAstI32, kAstF64, kAstF64]);
+  var sig_index = builder.addSignature(kSig_i_dd);
   builder.addImport("func", sig_index);
   builder.addFunction("main", sig_index)
     .addBody([
@@ -186,8 +186,8 @@ function testCallBinopVoid(type, func, check) {
 
   var builder = new WasmModuleBuilder();
 
-  builder.addImport("func", [kAstStmt, type, type]);
-  builder.addFunction("main", [kAstI32, type, type])
+  builder.addImport("func", makeSig_v_xx(type));
+  builder.addFunction("main", makeSig_r_xx(kAstI32, type))
     .addBody([
       kExprGetLocal, 0,           // --
       kExprGetLocal, 1,           // --
@@ -241,9 +241,9 @@ testCallBinopVoid(kAstF64);
 
 function testCallPrint() {
   var builder = new WasmModuleBuilder();
-  builder.addImport("print", [kAstStmt, kAstI32]);
-  builder.addImport("print", [kAstStmt, kAstF64]);
-  builder.addFunction("main", [kAstStmt, kAstF64])
+  builder.addImport("print", makeSig_v_x(kAstI32));
+  builder.addImport("print", makeSig_r_x(kAstF64, kAstF64));
+  builder.addFunction("main", makeSig_r_x(kAstF64, kAstF64))
     .addBody([
       kExprI8Const, 97,             // --
       kExprCallImport, kArity1, 0,  // --
@@ -266,9 +266,9 @@ testCallPrint();
 function testCallImport2(foo, bar, expected) {
   var builder = new WasmModuleBuilder();
 
-  builder.addImport("foo", [kAstI32]);
-  builder.addImport("bar", [kAstI32]);
-  builder.addFunction("main", [kAstI32])
+  builder.addImport("foo", kSig_i);
+  builder.addImport("bar", kSig_i);
+  builder.addFunction("main", kSig_i)
     .addBody([
       kExprCallImport, kArity0, 0, // --
       kExprCallImport, kArity0, 1, // --

test/mjsunit/wasm/indirect-calls.js

@@ -10,7 +10,7 @@ load("test/mjsunit/wasm/wasm-module-builder.js");
 var module = (function () {
   var builder = new WasmModuleBuilder();
 
-  var sig_index = builder.addSignature([kAstI32, kAstI32, kAstI32]);
+  var sig_index = builder.addSignature(kSig_i_ii);
   builder.addImport("add", sig_index);
   builder.addFunction("add", sig_index)
     .addBody([
@@ -22,7 +22,7 @@ var module = (function () {
       kExprGetLocal, 1,             // --
       kExprI32Sub,                  // --
     ]);
-  builder.addFunction("main", [kAstI32, kAstI32, kAstI32, kAstI32])
+  builder.addFunction("main", kSig_i_iii)
     .addBody([
       kExprGetLocal, 0,
       kExprGetLocal, 1,

test/mjsunit/wasm/instantiate-module-basic.js

@@ -13,7 +13,7 @@ var module = (function Build() {
   var builder = new WasmModuleBuilder();
 
   builder.addMemory(1, 1, true);
-  builder.addFunction("main", [kAstI32])
+  builder.addFunction("main", kSig_i)
     .addBody([kExprI8Const, kReturnValue])
     .exportFunc();
 

test/mjsunit/wasm/instantiate-run-basic.js

@@ -11,7 +11,7 @@ load("test/mjsunit/wasm/wasm-module-builder.js");
   var kReturnValue = 107;
   var builder = new WasmModuleBuilder();
 
-  builder.addFunction("main", [kAstI32])
+  builder.addFunction("main", kSig_i_i)
     .addBody([kExprI8Const, kReturnValue])
     .exportFunc();
 

test/mjsunit/wasm/module-memory.js

@@ -13,7 +13,7 @@ function genModule(memory) {
   var builder = new WasmModuleBuilder();
 
   builder.addMemory(1, 1, true);
-  builder.addFunction("main", [kAstI32, kAstI32])
+  builder.addFunction("main", kSig_i_i)
     .addBody([
     // main body: while(i) { if(mem[i]) return -1; i -= 4; } return 0;
       kExprLoop,
@@ -128,7 +128,7 @@ function testOOBThrows() {
   var builder = new WasmModuleBuilder();
 
   builder.addMemory(1, 1, true);
-  builder.addFunction("geti", [kAstI32, kAstI32, kAstI32])
+  builder.addFunction("geti", kSig_i_ii)
     .addBody([
       kExprGetLocal, 0,
       kExprGetLocal, 1,

test/mjsunit/wasm/params.js

@@ -17,7 +17,7 @@ function testSelect2(type) {
 
     var builder = new WasmModuleBuilder();
 
-    builder.addFunction("select", [type, type, type])
+    builder.addFunction("select", makeSig_r_xx(type, type))
       .addBody([kExprGetLocal, which])
       .exportFunc()
 
@@ -79,7 +79,7 @@ function testSelect10(t) {
     print("type = " + t + ", which = " + which);
 
     var builder = new WasmModuleBuilder();
-    builder.addFunction("select", [t,t,t,t,t,t,t,t,t,t,t])
+    builder.addFunction("select", [10,t,t,t,t,t,t,t,t,t,t,1,t])
       .addBody([kExprGetLocal, which])
       .exportFunc();
 

test/mjsunit/wasm/stack.js

@@ -36,24 +36,24 @@ function STACK() {
 
 var builder = new WasmModuleBuilder();
 
-builder.addImport("func", [kAstStmt]);
+builder.addImport("func", kSig_v_v);
 
-builder.addFunction("main", [kAstStmt])
+builder.addFunction("main", kSig_v_v)
   .addBody([kExprCallImport, kArity0, 0])
   .exportAs("main");
 
-builder.addFunction("exec_unreachable", [kAstStmt])
+builder.addFunction("exec_unreachable", kSig_v_v)
   .addBody([kExprUnreachable])
   .exportAs("exec_unreachable");
 
 // make this function unnamed, just to test also this case
-var mem_oob_func = builder.addFunction(undefined, [kAstStmt])
+var mem_oob_func = builder.addFunction(undefined, kSig_v_v)
   // access the memory at offset -1
   .addBody([kExprI32Const, 0x7f, kExprI32LoadMem8S, 0, 0])
   .exportAs("mem_out_of_bounds");
 
 // call the mem_out_of_bounds function, in order to have two WASM stack frames
-builder.addFunction("call_mem_out_of_bounds", [kAstStmt])
+builder.addFunction("call_mem_out_of_bounds", kSig_v_v)
   .addBody([kExprCallFunction, kArity0, mem_oob_func.index])
   .exportAs("call_mem_out_of_bounds");
 

test/mjsunit/wasm/stackwalk.js

@@ -10,7 +10,7 @@ load("test/mjsunit/wasm/wasm-module-builder.js");
 function makeFFI(func) {
   var builder = new WasmModuleBuilder();
 
-  var sig_index = builder.addSignature([kAstI32, kAstF64, kAstF64]);
+  var sig_index = builder.addSignature(kSig_i_dd);
   builder.addImport("func", sig_index);
   builder.addFunction("main", sig_index)
     .addBody([

test/mjsunit/wasm/start-function.js

@@ -37,19 +37,19 @@ function assertVerifies(sig, body) {
   return module;
 }
 
-assertVerifies([kAstStmt], [kExprNop]);
-assertVerifies([kAstI32], [kExprI8Const, 0]);
+assertVerifies(kSig_v_v, [kExprNop]);
+assertVerifies(kSig_i, [kExprI8Const, 0]);
 
 // Arguments aren't allow to start functions.
-assertFails([kAstI32, kAstI32], [kExprGetLocal, 0]);
-assertFails([kAstI32, kAstI32, kAstF32], [kExprGetLocal, 0]);
-assertFails([kAstI32, kAstI32, kAstF32, kAstF64], [kExprGetLocal, 0]);
+assertFails(kSig_i_i, [kExprGetLocal, 0]);
+assertFails(kSig_i_ii, [kExprGetLocal, 0]);
+assertFails(kSig_i_dd, [kExprGetLocal, 0]);
 
 (function testInvalidIndex() {
   print("testInvalidIndex");
   var builder = new WasmModuleBuilder();
 
-  var func = builder.addFunction("", [kAstStmt])
+  var func = builder.addFunction("", kSig_v_v)
     .addBody([kExprNop]);
 
   builder.addStart(func.index + 1);
@@ -62,7 +62,7 @@ assertFails([kAstI32, kAstI32, kAstF32, kAstF64], [kExprGetLocal, 0]);
   print("testTwoStartFuncs");
   var builder = new WasmModuleBuilder();
 
-  var func = builder.addFunction("", [kAstStmt])
+  var func = builder.addFunction("", kSig_v_v)
     .addBody([kExprNop]);
 
   builder.addExplicitSection([kDeclStartFunction, 0]);
@@ -78,7 +78,7 @@ assertFails([kAstI32, kAstI32, kAstF32, kAstF64], [kExprGetLocal, 0]);
 
   builder.addMemory(12, 12, true);
 
-  var func = builder.addFunction("", [kAstStmt])
+  var func = builder.addFunction("", kSig_v_v)
     .addBody([kExprI8Const, 0, kExprI8Const, 77, kExprI32StoreMem, 0, 0]);
 
   builder.addStart(func.index);
@@ -98,7 +98,7 @@ assertFails([kAstI32, kAstI32, kAstF32, kAstF64], [kExprGetLocal, 0]);
   }};
 
   var builder = new WasmModuleBuilder();
-  var sig_index = builder.addSignature([kAstStmt]);
+  var sig_index = builder.addSignature(kSig_v_v);
 
   builder.addImport("foo", sig_index);
   var func = builder.addFunction("", sig_index)

test/mjsunit/wasm/test-wasm-module-builder.js

@@ -12,7 +12,7 @@ var debug = false;
 (function BasicTest() {
     var module = new WasmModuleBuilder();
     module.addMemory(1, 2, false);
-    module.addFunction("foo", [kAstI32])
+    module.addFunction("foo", kSig_i)
         .addBody([kExprI8Const, 11])
         .exportAs("blarg");
 
@@ -23,8 +23,8 @@ var debug = false;
 
 (function ImportTest() {
     var module = new WasmModuleBuilder();
-    var index = module.addImport("print", [kAstStmt, kAstI32]);
-    module.addFunction("foo", [kAstStmt])
+    var index = module.addImport("print", makeSig_v_x(kAstI32));
+    module.addFunction("foo", kSig_v_v)
         .addBody([kExprI8Const, 13, kExprCallImport, kArity1, index])
         .exportAs("main");
 
@@ -36,7 +36,7 @@ var debug = false;
 
 (function LocalsTest() {
     var module = new WasmModuleBuilder();
-    module.addFunction(undefined, [kAstI32, kAstI32])
+    module.addFunction(undefined, kSig_i_i)
         .addLocals({i32_count: 1})
         .addBody([kExprGetLocal, 0, kExprSetLocal, 1])
         .exportAs("main");
@@ -58,7 +58,7 @@ var debug = false;
 
     for (p of types) {
       var module = new WasmModuleBuilder();
-      module.addFunction(undefined, [p.type, p.type])
+      module.addFunction(undefined, makeSig_r_x(p.type, p.type))
         .addLocals(p.locals)
         .addBody([kExprGetLocal, 0, kExprSetLocal, 1])
         .exportAs("main");
@@ -72,9 +72,9 @@ var debug = false;
 
 (function CallTest() {
     var module = new WasmModuleBuilder();
-    module.addFunction("add", [kAstI32, kAstI32, kAstI32])
+    module.addFunction("add", kSig_i_ii)
         .addBody([kExprGetLocal, 0, kExprGetLocal, 1, kExprI32Add]);
-    module.addFunction("main", [kAstI32, kAstI32, kAstI32])
+    module.addFunction("main", kSig_i_ii)
         .addBody([kExprGetLocal, 0, kExprGetLocal, 1, kExprCallFunction, kArity2, 0])
         .exportAs("main");
 
@@ -85,9 +85,9 @@ var debug = false;
 
 (function IndirectCallTest() {
     var module = new WasmModuleBuilder();
-    module.addFunction("add", [kAstI32, kAstI32, kAstI32])
+    module.addFunction("add", kSig_i_ii)
         .addBody([kExprGetLocal, 0, kExprGetLocal, 1, kExprI32Add]);
-    module.addFunction("main", [kAstI32, kAstI32, kAstI32, kAstI32])
+    module.addFunction("main", kSig_i_iii)
         .addBody([kExprGetLocal,
                   0, kExprGetLocal, 1, kExprGetLocal, 2, kExprCallIndirect, kArity2, 0])
         .exportAs("main");
@@ -102,7 +102,7 @@ var debug = false;
 (function DataSegmentTest() {
     var module = new WasmModuleBuilder();
     module.addMemory(1, 1, false);
-    module.addFunction("load", [kAstI32, kAstI32])
+    module.addFunction("load", kSig_i_i)
         .addBody([kExprGetLocal, 0, kExprI32LoadMem, 0, 0])
         .exportAs("load");
     module.addDataSegment(0, [9, 9, 9, 9], true);
@@ -116,7 +116,7 @@ var debug = false;
 (function BasicTestWithUint8Array() {
     var module = new WasmModuleBuilder();
     module.addMemory(1, 2, false);
-    module.addFunction("foo", [kAstI32])
+    module.addFunction("foo", kSig_i)
         .addBody([kExprI8Const, 17])
         .exportAs("blarg");
 
@@ -141,8 +141,8 @@ var debug = false;
 
 (function ImportTestTwoLevel() {
     var module = new WasmModuleBuilder();
-    var index = module.addImportWithModule("mod", "print", [kAstStmt, kAstI32]);
-    module.addFunction("foo", [kAstStmt])
+    var index = module.addImportWithModule("mod", "print", makeSig_v_x(kAstI32));
+    module.addFunction("foo", kSig_v_v)
         .addBody([kExprI8Const, 19, kExprCallImport, kArity1, index])
         .exportAs("main");
 

test/mjsunit/wasm/unreachable.js

@@ -9,7 +9,7 @@ load("test/mjsunit/wasm/wasm-module-builder.js");
 
 var main = (function () {
   var builder = new WasmModuleBuilder();
-  builder.addFunction("main", [kAstStmt])
+  builder.addFunction("main", kSig_v_v)
     .addBody([kExprUnreachable])
     .exportAs("main");
 

test/mjsunit/wasm/verify-function-simple.js

@@ -8,9 +8,9 @@ load("test/mjsunit/wasm/wasm-constants.js");
 
 try {
   var data = bytes(
-      0,       kAstStmt,  // signature
-      kDeclNoLocals,      // --
-      kExprNop            // body
+      kWasmFunctionTypeForm, 0, kAstStmt,  // signature
+      kDeclNoLocals,                       // --
+      kExprNop                             // body
   );
 
   Wasm.verifyFunction(data);
@@ -23,8 +23,8 @@ try {
 var threw = false;
 try {
   var data = bytes(
-      0,       kAstI32,   // signature
-      kDeclNoLocals,      // --
+      kWasmFunctionTypeForm, 0, 1, kAstI32,     // signature
+      kDeclNoLocals,                            // --
       kExprBlock, kExprNop, kExprNop, kExprEnd  // body
   );
 

test/mjsunit/wasm/wasm-constants.js

@@ -21,7 +21,7 @@ var kWasmH1 = 0x61;
 var kWasmH2 = 0x73;
 var kWasmH3 = 0x6d;
 
-var kWasmV0 = 10;
+var kWasmV0 = 11;
 var kWasmV1 = 0;
 var kWasmV2 = 0;
 var kWasmV3 = 0;
@@ -69,11 +69,12 @@ var kArity0 = 0;
 var kArity1 = 1;
 var kArity2 = 2;
 var kArity3 = 3;
+var kWasmFunctionTypeForm = 0x40;
 
 var section_names = [
-  "memory", "signatures", "functions", "globals", "data_segments",
-  "function_table", "end", "start_function", "import_table", "export_table",
-  "function_signatures", "function_bodies", "names"];
+  "memory", "type", "old_function", "global", "data",
+  "table", "end", "start", "import", "export",
+  "function", "code", "name"];
 
 // Function declaration flags
 var kDeclFunctionName   = 0x01;
@@ -88,6 +89,33 @@ var kAstI64 = 2;
 var kAstF32 = 3;
 var kAstF64 = 4;
 
+// Useful signatures
+var kSig_i = [0, 1, kAstI32];
+var kSig_d = [0, 1, kAstF64];
+var kSig_i_i = [1, kAstI32, 1, kAstI32];
+var kSig_i_ii = [2, kAstI32, kAstI32, 1, kAstI32];
+var kSig_i_iii = [3, kAstI32, kAstI32, kAstI32, 1, kAstI32];
+var kSig_d_dd = [2, kAstF64, kAstF64, 1, kAstF64];
+var kSig_l_ll = [2, kAstI64, kAstI64, 1, kAstI64];
+var kSig_i_dd = [2, kAstF64, kAstF64, 1, kAstI32];
+var kSig_v_v = [0, 0];
+
+function makeSig_v_xx(x) {
+  return [2, x, x, 0];
+}
+
+function makeSig_v_x(x) {
+  return [1, x, 0];
+}
+
+function makeSig_r_xx(r, x) {
+  return [2, x, x, 1, r];
+}
+
+function makeSig_r_x(r, x) {
+  return [1, x, 1, r];
+}
+
 // Opcodes
 var kExprNop = 0x00;
 var kExprBlock = 0x01;

test/mjsunit/wasm/wasm-module-builder.js

@@ -53,7 +53,7 @@ WasmModuleBuilder.prototype.addExplicitSection = function(bytes) {
   return this;
 }
 
-// Add a signature; format is [rettype, param0, param1, ...]
+// Add a signature; format is [param_count, param0, param1, ..., retcount, ret0]
 WasmModuleBuilder.prototype.addSignature = function(sig) {
     // TODO: canonicalize signatures?
     this.signatures.push(sig);
@@ -132,12 +132,14 @@ function emit_bytes(bytes, data) {
 }
 
 function emit_section(bytes, section_code, content_generator) {
-    // Start the section in a temporary buffer: its full length isn't know yet.
+    // Emit section name.
+    emit_string(bytes, section_names[section_code]);
+    // Emit the section to a temporary buffer: its full length isn't know yet.
     var tmp_bytes = [];
-    emit_string(tmp_bytes, section_names[section_code]);
     content_generator(tmp_bytes);
-    // Now that we know the section length, emit it and copy the section.
+    // Emit section length.
     emit_varint(bytes, tmp_bytes.length);
+    // Copy the temporary buffer.
     Array.prototype.push.apply(bytes, tmp_bytes);
 }
 
@@ -155,8 +157,7 @@ WasmModuleBuilder.prototype.toArray = function(debug) {
         emit_section(bytes, kDeclSignatures, function(bytes) {
             emit_varint(bytes, wasm.signatures.length);
             for (sig of wasm.signatures) {
-                var params = sig.length - 1;
-                emit_varint(bytes, params);
+                emit_u8(bytes, kWasmFunctionTypeForm);
                 for (var j = 0; j < sig.length; j++) {
                     emit_u8(bytes, sig[j]);
                 }