[debugger] break at each initialization in a multiple var declaration.

src/parsing/pattern-rewriter.cc

 // Copyright 2015 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 "src/ast/ast.h"
 #include "src/messages.h"
 #include "src/parsing/parameter-initializer-rewriter.h"
 #include "src/parsing/parser.h"
 
 namespace v8 {
@@ skipping 212 matching lines @@
     ZoneList<Expression*>* arguments =
         new (zone()) ZoneList<Expression*>(3, zone());
     // We have at least 1 parameter.
     arguments->Add(
         factory()->NewStringLiteral(name, descriptor_->declaration_pos),
         zone());
     CallRuntime* initialize;
 
     if (IsImmutableVariableMode(descriptor_->mode)) {
       arguments->Add(value, zone());
-      value = NULL;  // zap the value to avoid the unnecessary assignment
-
       // Construct the call to Runtime_InitializeConstGlobal
       // and add it to the initialization statement block.
       // Note that the function does different things depending on
       // the number of arguments (1 or 2).
-      initialize =
-          factory()->NewCallRuntime(Runtime::kInitializeConstGlobal, arguments,
-                                    descriptor_->initialization_pos);
+      initialize = factory()->NewCallRuntime(Runtime::kInitializeConstGlobal,
+                                             arguments, value->position());
+      value = NULL;  // zap the value to avoid the unnecessary assignment
     } else {
       // Add language mode.
       // We may want to pass singleton to avoid Literal allocations.
       LanguageMode language_mode = initialization_scope->language_mode();
-      arguments->Add(factory()->NewNumberLiteral(language_mode,
-                                                 descriptor_->declaration_pos),
-                     zone());
+      arguments->Add(
+          factory()->NewNumberLiteral(language_mode, RelocInfo::kNoPosition),
+          zone());
 
       // Be careful not to assign a value to the global variable if
       // we're in a with. The initialization value should not
       // necessarily be stored in the global object in that case,
       // which is why we need to generate a separate assignment node.
       if (value != NULL && !descriptor_->scope->inside_with()) {
         arguments->Add(value, zone());
-        value = NULL;  // zap the value to avoid the unnecessary assignment
         // Construct the call to Runtime_InitializeVarGlobal
         // and add it to the initialization statement block.
-        initialize =
-            factory()->NewCallRuntime(Runtime::kInitializeVarGlobal, arguments,
-                                      descriptor_->declaration_pos);
+        initialize = factory()->NewCallRuntime(Runtime::kInitializeVarGlobal,
+                                               arguments, value->position());
+        value = NULL;  // zap the value to avoid the unnecessary assignment
       } else {
         initialize = NULL;
       }
     }
 
     if (initialize != NULL) {
       block_->statements()->Add(
           factory()->NewExpressionStatement(initialize, initialize->position()),
           zone());
     }
   } else if (value != nullptr && (descriptor_->mode == CONST_LEGACY ||
                                   IsLexicalVariableMode(descriptor_->mode))) {
     // Constant initializations always assign to the declared constant which
     // is always at the function scope level. This is only relevant for
     // dynamically looked-up variables and constants (the
     // start context for constant lookups is always the function context,
     // while it is the top context for var declared variables). Sigh...
     // For 'let' and 'const' declared variables in harmony mode the
     // initialization also always assigns to the declared variable.
     DCHECK_NOT_NULL(proxy);
     DCHECK_NOT_NULL(proxy->var());
     DCHECK_NOT_NULL(value);
     // Add break location for destructured sub-pattern.
-    int pos =
-        IsSubPattern() ? pattern->position() : descriptor_->initialization_pos;
+    int pos = IsSubPattern() ? pattern->position() : value->position();
     Assignment* assignment =
         factory()->NewAssignment(Token::INIT, proxy, value, pos);
     block_->statements()->Add(
         factory()->NewExpressionStatement(assignment, pos), zone());
     value = NULL;
   }
 
   // Add an assignment node to the initialization statement block if we still
   // have a pending initialization value.
   if (value != NULL) {
     DCHECK(descriptor_->mode == VAR);
     // 'var' initializations are simply assignments (with all the consequences
     // if they are inside a 'with' statement - they may change a 'with' object
     // property).
     VariableProxy* proxy = initialization_scope->NewUnresolved(factory(), name);
     // Add break location for destructured sub-pattern.
-    int pos =
-        IsSubPattern() ? pattern->position() : descriptor_->initialization_pos;
+    int pos = IsSubPattern() ? pattern->position() : value->position();
     Assignment* assignment =
         factory()->NewAssignment(Token::INIT, proxy, value, pos);
     block_->statements()->Add(
         factory()->NewExpressionStatement(assignment, pos), zone());
   }
 }
 
 
 Variable* Parser::PatternRewriter::CreateTempVar(Expression* value) {
   auto temp = scope()->NewTemporary(ast_value_factory()->empty_string());
@@ skipping 305 matching lines @@
 NOT_A_PATTERN(TryFinallyStatement)
 NOT_A_PATTERN(UnaryOperation)
 NOT_A_PATTERN(VariableDeclaration)
 NOT_A_PATTERN(WhileStatement)
 NOT_A_PATTERN(WithStatement)
 NOT_A_PATTERN(Yield)
 
 #undef NOT_A_PATTERN
 }  // namespace internal
 }  // namespace v8