Improved function entry hook coverage

src/x64/code-stubs-x64.cc

 // Copyright 2012 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 4111 matching lines @@
   // rbx: pointer to C function  (C callee-saved)
   // rbp: frame pointer of calling JS frame (restored after C call)
   // rsp: stack pointer  (restored after C call)
   // rsi: current context (restored)
 
   // NOTE: Invocations of builtins may return failure objects
   // instead of a proper result. The builtin entry handles
   // this by performing a garbage collection and retrying the
   // builtin once.
 
+  ProfileEntryHookStub::MaybeCallEntryHook(masm);
+
   // Enter the exit frame that transitions from JavaScript to C++.
 #ifdef _WIN64
   int arg_stack_space = (result_size_ < 2 ? 2 : 4);
 #else
   int arg_stack_space = 0;
 #endif
   __ EnterExitFrame(arg_stack_space, save_doubles_);
 
   // rax: Holds the context at this point, but should not be used.
   //      On entry to code generated by GenerateCore, it must hold
@@ skipping 60 matching lines @@
 
   __ bind(&throw_normal_exception);
   __ Throw(rax);
 }
 
 
 void JSEntryStub::GenerateBody(MacroAssembler* masm, bool is_construct) {
   Label invoke, handler_entry, exit;
   Label not_outermost_js, not_outermost_js_2;
 
+  ProfileEntryHookStub::MaybeCallEntryHook(masm);
+
   {  // NOLINT. Scope block confuses linter.
     MacroAssembler::NoRootArrayScope uninitialized_root_register(masm);
     // Set up frame.
     __ push(rbp);
     __ movq(rbp, rsp);
 
     // Push the stack frame type marker twice.
     int marker = is_construct ? StackFrame::ENTRY_CONSTRUCT : StackFrame::ENTRY;
     // Scratch register is neither callee-save, nor an argument register on any
     // platform. It's free to use at this point.
@@ skipping 2434 matching lines @@
   __ pop(rcx);
   int additional_offset = function_mode_ == JS_FUNCTION_STUB_MODE
       ? kPointerSize
       : 0;
   __ lea(rsp, MemOperand(rsp, rbx, times_pointer_size, additional_offset));
   __ jmp(rcx);  // Return to IC Miss stub, continuation still on stack.
 }
 
 
 void ProfileEntryHookStub::MaybeCallEntryHook(MacroAssembler* masm) {
-  if (entry_hook_ != NULL) {
+  if (masm->isolate()->function_entry_hook() != NULL) {
+    // It's always safe to call the entry hook stub, as the hook itself
+    // is not allowed to call back to V8.
+    AllowStubCallsScope allow_stub_calls(masm, true);
+
     ProfileEntryHookStub stub;
     masm->CallStub(&stub);
   }
 }
 
 
 void ProfileEntryHookStub::Generate(MacroAssembler* masm) {
-  // Save volatile registers.
-  // Live registers at this point are the same as at the start of any
-  // JS function:
-  //   o rdi: the JS function object being called (i.e. ourselves)
-  //   o rsi: our context
-  //   o rbp: our caller's frame pointer
-  //   o rsp: stack pointer (pointing to return address)
-  //   o rcx: rcx is zero for method calls and non-zero for function calls.
-#ifdef _WIN64
-  const int kNumSavedRegisters = 1;
-
-  __ push(rcx);
-#else
-  const int kNumSavedRegisters = 3;
-
-  __ push(rcx);
-  __ push(rdi);
-  __ push(rsi);
-#endif
+  // This stub can be called from essentially anywhere, so it needs to save
+  // all volatile and callee-save registers.
+  const size_t kNumSavedRegisters = 2;
+  __ push(arg_reg_1);
+  __ push(arg_reg_2);
 
   // Calculate the original stack pointer and store it in the second arg.
-#ifdef _WIN64
-  __ lea(rdx, Operand(rsp, (kNumSavedRegisters + 1) * kPointerSize));
-#else
-  __ lea(rsi, Operand(rsp, (kNumSavedRegisters + 1) * kPointerSize));
-#endif
+  __ lea(arg_reg_2, Operand(rsp, (kNumSavedRegisters + 1) * kPointerSize));
 
   // Calculate the function address to the first arg.
-#ifdef _WIN64
-  __ movq(rcx, Operand(rsp, kNumSavedRegisters * kPointerSize));
-  __ subq(rcx, Immediate(Assembler::kShortCallInstructionLength));
-#else
-  __ movq(rdi, Operand(rsp, kNumSavedRegisters * kPointerSize));
-  __ subq(rdi, Immediate(Assembler::kShortCallInstructionLength));
-#endif
+  __ movq(arg_reg_1, Operand(rsp, kNumSavedRegisters * kPointerSize));
+  __ subq(arg_reg_1, Immediate(Assembler::kShortCallInstructionLength));
+
+  // Save the remainder of the volatile registers.
+  masm->PushCallerSaved(kSaveFPRegs, arg_reg_1, arg_reg_2);
 
   // Call the entry hook function.
-  __ movq(rax, &entry_hook_, RelocInfo::NONE64);
-  __ movq(rax, Operand(rax, 0));
+  __ movq(rax, FUNCTION_ADDR(masm->isolate()->function_entry_hook()),
+          RelocInfo::NONE64);
 
   AllowExternalCallThatCantCauseGC scope(masm);
 
   const int kArgumentCount = 2;
   __ PrepareCallCFunction(kArgumentCount);
   __ CallCFunction(rax, kArgumentCount);
 
   // Restore volatile regs.
-#ifdef _WIN64
-  __ pop(rcx);
-#else
-  __ pop(rsi);
-  __ pop(rdi);
-  __ pop(rcx);
-#endif
+  masm->PopCallerSaved(kSaveFPRegs, arg_reg_1, arg_reg_2);
+  __ pop(arg_reg_2);
+  __ pop(arg_reg_1);
 
   __ Ret();
 }
 
 
 template<class T>
 static void CreateArrayDispatch(MacroAssembler* masm) {
   int last_index = GetSequenceIndexFromFastElementsKind(
       TERMINAL_FAST_ELEMENTS_KIND);
   for (int i = 0; i <= last_index; ++i) {
@@ skipping 268 matching lines @@
   __ bind(&fast_elements_case);
   GenerateCase(masm, FAST_ELEMENTS);
 }
 
 
 #undef __
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_X64