Drop parameter names from ScopeInfo

Change-Id: I5fd42cd70aaba15cfef32eea54232f8292aaa874
Reviewed-on: https://chromium-review.googlesource.com/1105775Reviewed-by: Jakob Gruber <jgruber@chromium.org>
Commit-Queue: Toon Verwaest <verwaest@chromium.org>
Cr-Commit-Position: refs/heads/master@{#53841}

src/frames.cc

@@ -2004,13 +2004,6 @@ void JavaScriptFrame::Print(StringStream* accumulator,
   int parameters_count = ComputeParametersCount();
   for (int i = 0; i < parameters_count; i++) {
     accumulator->Add(",");
-    // If we have a name for the parameter we print it. Nameless
-    // parameters are either because we have more actual parameters
-    // than formal parameters or because we have no scope information.
-    if (i < scope_info->ParameterCount()) {
-      accumulator->PrintName(scope_info->ParameterName(i));
-      accumulator->Add("=");
-    }
     accumulator->Add("%o", GetParameter(i));
   }
 

src/gdb-jit.cc

@@ -1176,10 +1176,14 @@ class DebugInfoSection : public DebugSection {
       int internal_slots = Context::MIN_CONTEXT_SLOTS;
       int current_abbreviation = 4;
 
+      EmbeddedVector<char, 256> buffer;
+      StringBuilder builder(buffer.start(), buffer.length());
+
       for (int param = 0; param < params; ++param) {
         w->WriteULEB128(current_abbreviation++);
-        w->WriteString(
-            scope->ParameterName(param)->ToCString(DISALLOW_NULLS).get());
+        builder.Reset();
+        builder.AddFormatted("param%d", param);
+        w->WriteString(builder.Finalize());
         w->Write<uint32_t>(ty_offset);
         Writer::Slot<uint32_t> block_size = w->CreateSlotHere<uint32_t>();
         uintptr_t block_start = w->position();
@@ -1190,9 +1194,6 @@ class DebugInfoSection : public DebugSection {
         block_size.set(static_cast<uint32_t>(w->position() - block_start));
       }
 
-      EmbeddedVector<char, 256> buffer;
-      StringBuilder builder(buffer.start(), buffer.length());
-
       // See contexts.h for more information.
       DCHECK_EQ(Context::MIN_CONTEXT_SLOTS, 4);
       DCHECK_EQ(Context::SCOPE_INFO_INDEX, 0);

src/objects-printer.cc

@@ -2023,8 +2023,6 @@ void ScopeInfo::ScopeInfoPrint(std::ostream& os) {  // NOLINT
   }
   os << "\n - length: " << length();
   if (length() > 0) {
-    PrintScopeInfoList(this, os, "parameters", 0, ParameterNamesIndex(),
-                       ParameterCount());
     PrintScopeInfoList(this, os, "context slots", Context::MIN_CONTEXT_SLOTS,
                        ContextLocalNamesIndex(), ContextLocalCount());
     // TODO(neis): Print module stuff if present.

src/objects/scope-info.cc

@@ -139,8 +139,8 @@ Handle<ScopeInfo> ScopeInfo::Create(Isolate* isolate, Zone* zone, Scope* scope,
   const bool has_receiver = receiver_info == STACK || receiver_info == CONTEXT;
   const int parameter_count = scope->num_parameters();
   const bool has_outer_scope_info = !outer_scope.is_null();
-  const int length = kVariablePartIndex + parameter_count +
-                     2 * context_local_count + (has_receiver ? 1 : 0) +
+  const int length = kVariablePartIndex + 2 * context_local_count +
+                     (has_receiver ? 1 : 0) +
                      (has_function_name ? kFunctionNameEntries : 0) +
                      (has_inferred_function_name ? 1 : 0) +
                      (has_position_info ? kPositionInfoEntries : 0) +
@@ -187,14 +187,6 @@ Handle<ScopeInfo> ScopeInfo::Create(Isolate* isolate, Zone* zone, Scope* scope,
   scope_info->SetContextLocalCount(context_local_count);
 
   int index = kVariablePartIndex;
-  // Add parameters.
-  DCHECK_EQ(index, scope_info->ParameterNamesIndex());
-  if (scope->is_declaration_scope()) {
-    for (int i = 0; i < parameter_count; ++i) {
-      scope_info->set(index++,
-                      *scope->AsDeclarationScope()->parameter(i)->name());
-    }
-  }
 
   // Add context locals' names and info, module variables' names and info.
   // Context locals are added using their index.
@@ -350,7 +342,6 @@ Handle<ScopeInfo> ScopeInfo::CreateForWithScope(
   scope_info->SetContextLocalCount(0);
 
   int index = kVariablePartIndex;
-  DCHECK_EQ(index, scope_info->ParameterNamesIndex());
   DCHECK_EQ(index, scope_info->ReceiverInfoIndex());
   DCHECK_EQ(index, scope_info->FunctionNameInfoIndex());
   DCHECK_EQ(index, scope_info->InferredFunctionNameIndex());
@@ -387,8 +378,8 @@ Handle<ScopeInfo> ScopeInfo::CreateForBootstrapping(Isolate* isolate,
   const bool has_receiver = !is_empty_function;
   const bool has_inferred_function_name = is_empty_function;
   const bool has_position_info = true;
-  const int length = kVariablePartIndex + parameter_count +
-                     2 * context_local_count + (has_receiver ? 1 : 0) +
+  const int length = kVariablePartIndex + 2 * context_local_count +
+                     (has_receiver ? 1 : 0) +
                      (is_empty_function ? kFunctionNameEntries : 0) +
                      (has_inferred_function_name ? 1 : 0) +
                      (has_position_info ? kPositionInfoEntries : 0);
@@ -630,13 +621,6 @@ ModuleInfo* ScopeInfo::ModuleDescriptorInfo() const {
   return ModuleInfo::cast(get(ModuleInfoIndex()));
 }
 
-String* ScopeInfo::ParameterName(int var) const {
-  DCHECK_LE(0, var);
-  DCHECK_LT(var, ParameterCount());
-  int info_index = ParameterNamesIndex() + var;
-  return String::cast(get(info_index));
-}
-
 String* ScopeInfo::ContextLocalName(int var) const {
   DCHECK_LE(0, var);
   DCHECK_LT(var, ContextLocalCount());
@@ -775,24 +759,6 @@ int ScopeInfo::ContextSlotIndex(Handle<ScopeInfo> scope_info,
   return -1;
 }
 
-int ScopeInfo::ParameterIndex(String* name) const {
-  DCHECK(name->IsInternalizedString());
-  if (length() == 0) return -1;
-  // We must read parameters from the end since for
-  // multiply declared parameters the value of the
-  // last declaration of that parameter is used
-  // inside a function (and thus we need to look
-  // at the last index). Was bug# 1110337.
-  int start = ParameterNamesIndex();
-  int end = start + ParameterCount();
-  for (int i = end - 1; i >= start; --i) {
-    if (name == get(i)) {
-      return i - start;
-    }
-  }
-  return -1;
-}
-
 int ScopeInfo::ReceiverContextSlotIndex() const {
   if (length() > 0 && ReceiverVariableField::decode(Flags()) == CONTEXT) {
     return Smi::ToInt(get(ReceiverInfoIndex()));
@@ -815,15 +781,11 @@ FunctionKind ScopeInfo::function_kind() const {
   return FunctionKindField::decode(Flags());
 }
 
-int ScopeInfo::ParameterNamesIndex() const {
+int ScopeInfo::ContextLocalNamesIndex() const {
   DCHECK_LT(0, length());
   return kVariablePartIndex;
 }
 
-int ScopeInfo::ContextLocalNamesIndex() const {
-  return ParameterNamesIndex() + ParameterCount();
-}
-
 int ScopeInfo::ContextLocalInfosIndex() const {
   return ContextLocalNamesIndex() + ContextLocalCount();
 }

src/objects/scope-info.h

@@ -108,9 +108,6 @@ class ScopeInfo : public FixedArray {
 
   ModuleInfo* ModuleDescriptorInfo() const;
 
-  // Return the name of the given parameter.
-  String* ParameterName(int var) const;
-
   // Return the name of the given context local.
   String* ContextLocalName(int var) const;
 
@@ -146,11 +143,6 @@ class ScopeInfo : public FixedArray {
                   InitializationFlag* init_flag,
                   MaybeAssignedFlag* maybe_assigned_flag);
 
-  // Lookup support for serialized scope info. Returns the
-  // parameter index for a given parameter name if the parameter is present;
-  // otherwise returns a value < 0. The name must be an internalized string.
-  int ParameterIndex(String* name) const;
-
   // Lookup support for serialized scope info. Returns the function context
   // slot index if the function name is present and context-allocated (named
   // function expressions, only), otherwise returns a value < 0. The name
@@ -217,42 +209,36 @@ class ScopeInfo : public FixedArray {
 
  private:
   // The layout of the variable part of a ScopeInfo is as follows:
-  // 1. ParameterNames:
-  //    This part stores the names of the parameters for function scopes. One
-  //    slot is used per parameter, so in total this part occupies
-  //    ParameterCount() slots in the array. For other scopes than function
-  //    scopes ParameterCount() is 0.
-  // 2. ContextLocalNames:
+  // 1. ContextLocalNames:
   //    Contains the names of local variables and parameters that are allocated
   //    in the context. They are stored in increasing order of the context slot
   //    index starting with Context::MIN_CONTEXT_SLOTS. One slot is used per
   //    context local, so in total this part occupies ContextLocalCount() slots
   //    in the array.
-  // 3. ContextLocalInfos:
+  // 2. ContextLocalInfos:
   //    Contains the variable modes and initialization flags corresponding to
   //    the context locals in ContextLocalNames. One slot is used per
   //    context local, so in total this part occupies ContextLocalCount()
   //    slots in the array.
-  // 4. ReceiverInfo:
+  // 3. ReceiverInfo:
   //    If the scope binds a "this" value, one slot is reserved to hold the
   //    context or stack slot index for the variable.
-  // 5. FunctionNameInfo:
+  // 4. FunctionNameInfo:
   //    If the scope belongs to a named function expression this part contains
   //    information about the function variable. It always occupies two array
   //    slots:  a. The name of the function variable.
   //            b. The context or stack slot index for the variable.
-  // 6. InferredFunctionName:
+  // 5. InferredFunctionName:
   //    Contains the function's inferred name.
-  // 7. SourcePosition:
+  // 6. SourcePosition:
   //    Contains two slots with a) the startPosition and b) the endPosition if
   //    the scope belongs to a function or script.
-  // 8. OuterScopeInfoIndex:
+  // 7. OuterScopeInfoIndex:
   //    The outer scope's ScopeInfo or the hole if there's none.
-  // 9. ModuleInfo, ModuleVariableCount, and ModuleVariables:
+  // 8. ModuleInfo, ModuleVariableCount, and ModuleVariables:
   //    For a module scope, this part contains the ModuleInfo, the number of
   //    MODULE-allocated variables, and the metadata of those variables.  For
   //    non-module scopes it is empty.
-  int ParameterNamesIndex() const;
   int ContextLocalNamesIndex() const;
   int ContextLocalInfosIndex() const;
   int ReceiverInfoIndex() const;

test/cctest/test-heap-profiler.cc

@@ -343,7 +343,7 @@ TEST(HeapSnapshotCodeObjects) {
 
   CompileRun(
       "function lazy(x) { return x - 1; }\n"
-      "function compiled(x) { return x + 1; }\n"
+      "function compiled(x) { ()=>x; return x + 1; }\n"
       "var anonymous = (function() { return function() { return 0; } })();\n"
       "compiled(1)");
   const v8::HeapSnapshot* snapshot = heap_profiler->TakeHeapSnapshot();