[strong] Function arity check should be based on required parameters

src/arm/builtins-arm.cc

 // Copyright 2012 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/v8.h"
 
 #if V8_TARGET_ARCH_ARM
 
 #include "src/codegen.h"
 #include "src/debug.h"
@@ skipping 1706 matching lines @@
     __ sub(r0, r0, Operand(kPointerSize));
     __ b(ne, &copy);
 
     __ b(&invoke);
   }
 
   {  // Too few parameters: Actual < expected
     __ bind(&too_few);
 
     // If the function is strong we need to throw an error.
-    Label weak_function;
+    Label no_strong_error;
     __ ldr(r4, FieldMemOperand(r1, JSFunction::kSharedFunctionInfoOffset));
-    __ ldr(r4, FieldMemOperand(r4, SharedFunctionInfo::kCompilerHintsOffset));
-    __ tst(r4, Operand(1 << (SharedFunctionInfo::kStrongModeFunction +
+    __ ldr(r5, FieldMemOperand(r4, SharedFunctionInfo::kCompilerHintsOffset));
+    __ tst(r5, Operand(1 << (SharedFunctionInfo::kStrongModeFunction +
                              kSmiTagSize)));
-    __ b(eq, &weak_function);
+    __ b(eq, &no_strong_error);
+
+    // What we really care about is the required number of arguments.
+    __ ldr(r4, FieldMemOperand(r4, SharedFunctionInfo::kLengthOffset));
+    __ cmp(r0, Operand::SmiUntag(r4));
+    __ b(ge, &no_strong_error);
 
     {
       FrameScope frame(masm, StackFrame::MANUAL);
       EnterArgumentsAdaptorFrame(masm);
       __ CallRuntime(Runtime::kThrowStrongModeTooFewArguments, 0);
     }
 
-    __ bind(&weak_function);
+    __ bind(&no_strong_error);
     EnterArgumentsAdaptorFrame(masm);
 
     // Calculate copy start address into r0 and copy end address is fp.
     // r0: actual number of arguments as a smi
     // r1: function
     // r2: expected number of arguments
     // r3: code entry to call
     __ add(r0, fp, Operand::PointerOffsetFromSmiKey(r0));
 
     // Copy the arguments (including the receiver) to the new stack frame.
@@ skipping 53 matching lines @@
     __ bkpt(0);
   }
 }
 
 
 #undef __
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_ARM