[wasm] Consider only function names from the name section.

As per WebAssembly Web API[1], the engine should only consider names
from the name section to synthesize function names in the context of
call stacks. We previously also added support to harvest the exports
table here in an attempt to improve the DevTools debugging experience,
but that needs a separate fix specifically for the inspector (which
should also take into account the imports to harvest names).

[1]: https://webassembly.github.io/spec/web-api/index.html#conventions

Fixed: chromium:1164305
Change-Id: I4bde5c8398a5164f1d8ac9060ad3743ed494c41e
Bug: chromium:1159307, chromium:1164241, chromium:1071432
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2874464
Commit-Queue: Benedikt Meurer <bmeurer@chromium.org>
Commit-Queue: Clemens Backes <clemensb@chromium.org>
Auto-Submit: Benedikt Meurer <bmeurer@chromium.org>
Reviewed-by: Clemens Backes <clemensb@chromium.org>
Cr-Commit-Position: refs/heads/master@{#74382}

src/runtime/runtime-test-wasm.cc

@@ -158,8 +158,7 @@ RUNTIME_FUNCTION(Runtime_WasmTraceEnter) {
   wasm::ModuleWireBytes wire_bytes =
       wasm::ModuleWireBytes(frame->native_module()->wire_bytes());
   wasm::WireBytesRef name_ref =
-      module->lazily_generated_names.LookupFunctionName(
-          wire_bytes, func_index, VectorOf(module->export_table));
+      module->lazily_generated_names.LookupFunctionName(wire_bytes, func_index);
   wasm::WasmName name = wire_bytes.GetNameOrNull(name_ref);
 
   wasm::WasmCode* code = frame->wasm_code();

src/wasm/module-decoder.cc

@@ -2388,8 +2388,7 @@ bool FindNameSection(Decoder* decoder) {
 }  // namespace
 
 void DecodeFunctionNames(const byte* module_start, const byte* module_end,
-                         std::unordered_map<uint32_t, WireBytesRef>* names,
-                         const Vector<const WasmExport> export_table) {
+                         std::unordered_map<uint32_t, WireBytesRef>* names) {
   DCHECK_NOT_NULL(names);
   DCHECK(names->empty());
 
@@ -2421,13 +2420,6 @@ void DecodeFunctionNames(const byte* module_start, const byte* module_end,
       }
     }
   }
-
-  // Extract from export table.
-  for (const WasmExport& exp : export_table) {
-    if (exp.kind == kExternalFunction && names->count(exp.index) == 0) {
-      names->insert(std::make_pair(exp.index, exp.name));
-    }
-  }
 }
 
 NameMap DecodeNameMap(Vector<const uint8_t> module_bytes,

src/wasm/module-decoder.h

@@ -187,13 +187,11 @@ V8_EXPORT_PRIVATE std::vector<CustomSectionOffset> DecodeCustomSections(
 // function.
 AsmJsOffsetsResult DecodeAsmJsOffsets(Vector<const uint8_t> encoded_offsets);
 
-// Decode the function names from the name section and also look at export
-// table. Returns the result as an unordered map. Only names with valid utf8
-// encoding are stored and conflicts are resolved by choosing the last name
-// read.
+// Decode the function names from the name section. Returns the result as an
+// unordered map. Only names with valid utf8 encoding are stored and conflicts
+// are resolved by choosing the last name read.
 void DecodeFunctionNames(const byte* module_start, const byte* module_end,
-                         std::unordered_map<uint32_t, WireBytesRef>* names,
-                         const Vector<const WasmExport> export_table);
+                         std::unordered_map<uint32_t, WireBytesRef>* names);
 
 // Decode the requested subsection of the name section.
 // The result will be empty if no name section is present. On encountering an

src/wasm/wasm-code-manager.cc

@@ -225,8 +225,8 @@ void WasmCode::LogCode(Isolate* isolate, const char* source_url,
 
   ModuleWireBytes wire_bytes(native_module_->wire_bytes());
   const WasmModule* module = native_module_->module();
-  WireBytesRef name_ref = module->lazily_generated_names.LookupFunctionName(
-      wire_bytes, index(), VectorOf(module->export_table));
+  WireBytesRef name_ref =
+      module->lazily_generated_names.LookupFunctionName(wire_bytes, index());
   WasmName name = wire_bytes.GetNameOrNull(name_ref);
 
   const WasmDebugSymbols& debug_symbols = module->debug_symbols;

src/wasm/wasm-module.cc

@@ -32,13 +32,12 @@ namespace internal {
 namespace wasm {
 
 WireBytesRef LazilyGeneratedNames::LookupFunctionName(
-    const ModuleWireBytes& wire_bytes, uint32_t function_index,
-    Vector<const WasmExport> export_table) const {
+    const ModuleWireBytes& wire_bytes, uint32_t function_index) const {
   base::MutexGuard lock(&mutex_);
   if (!function_names_) {
     function_names_.reset(new std::unordered_map<uint32_t, WireBytesRef>());
     DecodeFunctionNames(wire_bytes.start(), wire_bytes.end(),
-                        function_names_.get(), export_table);
+                        function_names_.get());
   }
   auto it = function_names_->find(function_index);
   if (it == function_names_->end()) return WireBytesRef();
@@ -179,7 +178,7 @@ WasmName ModuleWireBytes::GetNameOrNull(WireBytesRef ref) const {
 WasmName ModuleWireBytes::GetNameOrNull(const WasmFunction* function,
                                         const WasmModule* module) const {
   return GetNameOrNull(module->lazily_generated_names.LookupFunctionName(
-      *this, function->func_index, VectorOf(module->export_table)));
+      *this, function->func_index));
 }
 
 std::ostream& operator<<(std::ostream& os, const WasmFunctionName& name) {

src/wasm/wasm-module.h

@@ -192,8 +192,7 @@ struct ModuleWireBytes;
 class V8_EXPORT_PRIVATE LazilyGeneratedNames {
  public:
   WireBytesRef LookupFunctionName(const ModuleWireBytes& wire_bytes,
-                                  uint32_t function_index,
-                                  Vector<const WasmExport> export_table) const;
+                                  uint32_t function_index) const;
 
   void AddForTesting(int function_index, WireBytesRef name);
 

src/wasm/wasm-objects.cc

@@ -226,7 +226,7 @@ MaybeHandle<String> WasmModuleObject::GetFunctionNameOrNull(
   wasm::WireBytesRef name =
       module_object->module()->lazily_generated_names.LookupFunctionName(
           wasm::ModuleWireBytes(module_object->native_module()->wire_bytes()),
-          func_index, VectorOf(module_object->module()->export_table));
+          func_index);
   if (!name.is_set()) return {};
   return ExtractUtf8StringFromModuleBytes(isolate, module_object, name,
                                           kNoInternalize);
@@ -253,8 +253,8 @@ Vector<const uint8_t> WasmModuleObject::GetRawFunctionName(int func_index) {
   DCHECK_GT(module()->functions.size(), func_index);
   wasm::ModuleWireBytes wire_bytes(native_module()->wire_bytes());
   wasm::WireBytesRef name_ref =
-      module()->lazily_generated_names.LookupFunctionName(
-          wire_bytes, func_index, VectorOf(module()->export_table));
+      module()->lazily_generated_names.LookupFunctionName(wire_bytes,
+                                                          func_index);
   wasm::WasmName name = wire_bytes.GetNameOrNull(name_ref);
   return Vector<const uint8_t>::cast(name);
 }

test/inspector/debugger/wasm-gc-breakpoints-expected.txt

@@ -8,7 +8,7 @@ Calling main()
 Paused:
 Script wasm://wasm/22e4830a byte offset 107: Wasm opcode 0x21 (kExprLocalSet)
 Scope:
-at main (0:107):
+at func0 (0:107):
  - scope (wasm-expression-stack):
    0: Array ((ref $ArrC))
      object details:

test/inspector/debugger/wasm-unnamed-function-names-expected.txt

@@ -6,6 +6,6 @@ Paused on 'debugger;'
 Number of frames: 5
   - [0] call_debugger
   - [1] func1
-  - [2] main
+  - [2] func2
   - [3] testFunction
   - [4] 

test/message/fail/wasm-module-name.js

@@ -8,7 +8,7 @@ load("test/mjsunit/wasm/wasm-module-builder.js");
 
 var builder = new WasmModuleBuilder();
 builder.setName('test-module');
-builder.addFunction(undefined, kSig_i_v)
+builder.addFunction('main', kSig_i_v)
     .addBody([kExprUnreachable])
     .exportAs('main');
 builder.instantiate().exports.main();

test/message/fail/wasm-no-name.out

 wasm-function[0]:0x22: RuntimeError: unreachable
 RuntimeError: unreachable
-    at main (<anonymous>:wasm-function[0]:0x22)
+    at <anonymous>:wasm-function[0]:0x22
     at *%(basename)s:{NUMBER}:31

test/message/wasm-module-name-async.js

@@ -9,7 +9,7 @@ load('test/mjsunit/wasm/wasm-module-builder.js');
 
 var builder = new WasmModuleBuilder();
 builder.setName('test-module');
-builder.addFunction(undefined, kSig_i_v)
+builder.addFunction('main', kSig_i_v)
     .addBody([kExprUnreachable])
     .exportAs('main');
 let buffer = builder.toBuffer();

test/message/wasm-no-name-async.out

 RuntimeError: unreachable
-    at main (<anonymous>:wasm-function[0]:0x22)
+    at <anonymous>:wasm-function[0]:0x22
     at *%(basename)s:{NUMBER}:27
     at test/mjsunit/mjsunit.js:*

test/message/wasm-no-name-streaming.out

 RuntimeError: unreachable
-    at main (<anonymous>:wasm-function[0]:0x22)
+    at <anonymous>:wasm-function[0]:0x22
     at test/message/wasm-no-name-async.js:{NUMBER}:27
     at test/mjsunit/mjsunit.js:*

test/mjsunit/regress/wasm/regress-1046472.js

@@ -11,7 +11,7 @@ load('test/mjsunit/wasm/wasm-module-builder.js');
   builder.addMemory(16, 32, false);
   builder.addType(makeSig([kWasmI32, kWasmI32, kWasmI32], [kWasmI32]));
   // Generate function 1 (out of 1).
-  builder.addFunction(undefined, 0 /* sig */)
+  builder.addFunction('main', 0 /* sig */)
     .addBodyWithEnd([
 // signature: i_iii
 // body:

test/mjsunit/wasm/stack.js

@@ -56,8 +56,7 @@ builder.addFunction("exec_unreachable", kSig_v_v)
 // Make this function unnamed, just to test also this case.
 var mem_oob_func = builder.addFunction(undefined, kSig_i_v)
   // Access the memory at offset -1, to provoke a trap.
-  .addBody([kExprI32Const, 0x7f, kExprI32LoadMem8S, 0, 0])
-  .exportAs("mem_out_of_bounds");
+  .addBody([kExprI32Const, 0x7f, kExprI32LoadMem8S, 0, 0]);
 
 // Call the mem_out_of_bounds function, in order to have two wasm stack frames.
 builder.addFunction("call_mem_out_of_bounds", kSig_i_v)
@@ -70,9 +69,9 @@ var module = builder.instantiate({mod: {func: STACK}});
   var expected_string = 'Error\n' +
       // The line numbers below will change as this test gains / loses lines..
       '    at STACK (stack.js:38:11)\n' +                   // --
-      '    at main (<anonymous>:wasm-function[1]:0x86)\n' + // --
-      '    at testSimpleStack (stack.js:77:18)\n' +         // --
-      '    at stack.js:79:3';                               // --
+      '    at main (<anonymous>:wasm-function[1]:0x72)\n' + // --
+      '    at testSimpleStack (stack.js:76:18)\n' +         // --
+      '    at stack.js:78:3';                               // --
 
   module.exports.main();
   assertEquals(expected_string, stripPath(stack));
@@ -90,9 +89,9 @@ Error.prepareStackTrace = function(error, frames) {
   verifyStack(stack, [
       // isWasm           function   line   pos                    file  offset funcIndex
       [   false,           "STACK",    38,    0,             "stack.js"],
-      [    true,            "main",     1, 0x86, "wasm://wasm/7168ab72", '0x86',        1],
-      [   false, "testStackFrames",    88,    0,             "stack.js"],
-      [   false,              null,    97,    0,             "stack.js"]
+      [    true,            "main",     1, 0x72, "wasm://wasm/862e1cf6", '0x72',        1],
+      [   false, "testStackFrames",    87,    0,             "stack.js"],
+      [   false,              null,    96,    0,             "stack.js"]
   ]);
 })();
 
@@ -104,9 +103,9 @@ Error.prepareStackTrace = function(error, frames) {
     assertContains("unreachable", e.message);
     verifyStack(e.stack, [
         // isWasm               function   line  pos                    file  offset funcIndex
-        [    true,    "exec_unreachable",    1, 0x8b, "wasm://wasm/7168ab72", '0x8b',        2],
-        [   false, "testWasmUnreachable",  101,    0,             "stack.js"],
-        [   false,                  null,  112,    0,             "stack.js"]
+        [    true,    "exec_unreachable",    1, 0x77, "wasm://wasm/862e1cf6", '0x77',        2],
+        [   false, "testWasmUnreachable",  100,    0,             "stack.js"],
+        [   false,                  null,  111,    0,             "stack.js"]
     ]);
   }
 })();
@@ -119,10 +118,10 @@ Error.prepareStackTrace = function(error, frames) {
     assertContains("out of bounds", e.message);
     verifyStack(e.stack, [
         // isWasm                  function   line   pos                    file  offset funcIndex
-        [    true,      "mem_out_of_bounds",     1, 0x91, "wasm://wasm/7168ab72", '0x91',        3],
-        [    true, "call_mem_out_of_bounds",     1, 0x97, "wasm://wasm/7168ab72", '0x97',        4],
-        [   false, "testWasmMemOutOfBounds",   116,    0,             "stack.js"],
-        [   false,                     null,   128,    0,             "stack.js"]
+        [    true,                     null,     1, 0x7d, "wasm://wasm/862e1cf6", '0x7d',        3],
+        [    true, "call_mem_out_of_bounds",     1, 0x83, "wasm://wasm/862e1cf6", '0x83',        4],
+        [   false, "testWasmMemOutOfBounds",   115,    0,             "stack.js"],
+        [   false,                     null,   127,    0,             "stack.js"]
     ]);
   }
 })();
@@ -177,8 +176,8 @@ Error.prepareStackTrace = function(error, frames) {
     verifyStack(e.stack, [
       // isWasm         function line                     pos                    file     offset funcIndex
       [    true,          'main',   1, unreachable_pos + 0x25, 'wasm://wasm/000600e6', hexOffset,        0],
-      [   false, 'testBigOffset', 172,                      0,             'stack.js'],
-      [   false,            null, 184,                      0,             'stack.js']
+      [   false, 'testBigOffset', 171,                      0,             'stack.js'],
+      [   false,            null, 183,                      0,             'stack.js']
     ]);
   }
 })();