Direct call to eval passes strict mode through.

src/compiler.cc

 // Copyright 2010 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 530 matching lines @@
     }
   }
 
   if (result.is_null()) Top::ReportPendingMessages();
   return result;
 }
 
 
 Handle<SharedFunctionInfo> Compiler::CompileEval(Handle<String> source,
                                                  Handle<Context> context,
-                                                 bool is_global) {
+                                                 bool is_global,
+                                                 StrictModeFlag strict_mode) {
   int source_length = source->length();
   Counters::total_eval_size.Increment(source_length);
   Counters::total_compile_size.Increment(source_length);
 
   // The VM is in the COMPILER state until exiting this function.
   VMState state(COMPILER);
 
   // Do a lookup in the compilation cache; if the entry is not there, invoke
   // the compiler and add the result to the cache.
   Handle<SharedFunctionInfo> result;
-  result = CompilationCache::LookupEval(source, context, is_global);
+  result = CompilationCache::LookupEval(source,
+                                        context,
+                                        is_global,
+                                        strict_mode);
 
   if (result.is_null()) {
     // Create a script object describing the script to be compiled.
     Handle<Script> script = Factory::NewScript(source);
     CompilationInfo info(script);
     info.MarkAsEval();
     if (is_global) info.MarkAsGlobal();
+    if (strict_mode == kStrictMode) info.MarkAsStrict();
     info.SetCallingContext(context);
     result = MakeFunctionInfo(&info);
     if (!result.is_null()) {
+      // If caller is strict mode, the result must be strict as well,
+      // but not the other way around. Consider:
+      // eval("'use strict'; ...");
+      ASSERT(strict_mode == kNonStrictMode || result->strict_mode());
       CompilationCache::PutEval(source, context, is_global, result);
     }
   }
 
   return result;
 }
 
 
 bool Compiler::CompileLazy(CompilationInfo* info) {
   CompilationZoneScope zone_scope(DELETE_ON_EXIT);
@@ skipping 172 matching lines @@
   function_info->set_start_position(lit->start_position());
   function_info->set_end_position(lit->end_position());
   function_info->set_is_expression(lit->is_expression());
   function_info->set_is_toplevel(is_toplevel);
   function_info->set_inferred_name(*lit->inferred_name());
   function_info->SetThisPropertyAssignmentsInfo(
       lit->has_only_simple_this_property_assignments(),
       *lit->this_property_assignments());
   function_info->set_try_full_codegen(lit->try_full_codegen());
   function_info->set_allows_lazy_compilation(lit->AllowsLazyCompilation());
+  function_info->set_strict_mode(lit->strict_mode());
 }
 
 
 void Compiler::RecordFunctionCompilation(Logger::LogEventsAndTags tag,
                                          Handle<String> name,
                                          int start_position,
                                          CompilationInfo* info) {
   // Log the code generation. If source information is available include
   // script name and line number. Check explicitly whether logging is
   // enabled as finding the line number is not free.
@@ skipping 24 matching lines @@
                                       code->instruction_size()));
     }
   }
 
   GDBJIT(AddCode(name,
                  Handle<Script>(info->script()),
                  Handle<Code>(info->code())));
 }
 
 } }  // namespace v8::internal