/*

 * Copyright (c) 1997, 2019, Oracle and/or its affiliates. All rights reserved.

 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

 * This code is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 only, as

 * published by the Free Software Foundation.

 *

 * This code is distributed in the hope that it will be useful, but WITHOUT

 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

 * version 2 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

 *

 * You should have received a copy of the GNU General Public License version

 * 2 along with this work; if not, write to the Free Software Foundation,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 *

 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

 * or visit www.oracle.com if you need additional information or have any

 * questions.

 *

 */

#include "asm/assembler.hpp"

#include "runtime/icache.hpp"

#include "runtime/os.hpp"

#include "runtime/safepointMechanism.hpp"

// We have interfaces for the following instructions:

// - NativeInstruction

// - - NativeCall

// - - NativeMovConstReg

// - - NativeMovConstRegPatching

// - - NativeMovRegMem

// - - NativeMovRegMemPatching

// - - NativeJump

// - - NativeFarJump

// - - NativeIllegalOpCode

// - - NativeGeneralJump

// - - NativeReturn

// - - NativeReturnX (return with argument)

// - - NativePushConst

// - - NativeTstRegMem

// The base class for different kinds of native instruction abstractions.

// Provides the primitive operations to manipulate code relative to this.

class NativeInstruction {

  friend class Relocation;

 public:

  enum Intel_specific_constants {

    nop_instruction_code        = 0x90,

    nop_instruction_size        =    1

  };

  bool is_nop()                        { return ubyte_at(0) == nop_instruction_code; }

  inline bool is_call();

  inline bool is_call_reg();

  inline bool is_illegal();

  inline bool is_return();

  inline bool is_jump();

  inline bool is_jump_reg();

  inline bool is_far_jump();

  inline bool is_cond_jump();

  inline bool is_safepoint_poll();

  inline bool is_mov_literal64();

 protected:

  address addr_at(int offset) const    { return address(this) + offset; }

  s_char sbyte_at(int offset) const    { return *(s_char*) addr_at(offset); }

  u_char ubyte_at(int offset) const    { return *(u_char*) addr_at(offset); }

  jint int_at(int offset) const         { return *(jint*) addr_at(offset); }

  intptr_t ptr_at(int offset) const    { return *(intptr_t*) addr_at(offset); }

  oop  oop_at (int offset) const       { return *(oop*) addr_at(offset); }

  void set_char_at(int offset, char c)        { *addr_at(offset) = (u_char)c; wrote(offset); }

  void set_int_at(int offset, jint  i)        { *(jint*)addr_at(offset) = i;  wrote(offset); }

  void set_ptr_at (int offset, intptr_t  ptr) { *(intptr_t*) addr_at(offset) = ptr;  wrote(offset); }

  void set_oop_at (int offset, oop  o)        { *(oop*) addr_at(offset) = o;  wrote(offset); }

  // This doesn't really do anything on Intel, but it is the place where

  // cache invalidation belongs, generically:

  void wrote(int offset);

 public:

  // unit test stuff

  static void test() {}                 // override for testing

  inline friend NativeInstruction* nativeInstruction_at(address address);

};

inline NativeInstruction* nativeInstruction_at(address address) {

  NativeInstruction* inst = (NativeInstruction*)address;

#ifdef ASSERT

  //inst->verify();

#endif

  return inst;

}

class NativePltCall: public NativeInstruction {

public:

  enum Intel_specific_constants {

    instruction_code           = 0xE8,

    instruction_size           =    5,

    instruction_offset         =    0,

    displacement_offset        =    1,

    return_address_offset      =    5

  };

  address instruction_address() const { return addr_at(instruction_offset); }

  address next_instruction_address() const { return addr_at(return_address_offset); }

  address displacement_address() const { return addr_at(displacement_offset); }

  int displacement() const { return (jint) int_at(displacement_offset); }

  address return_address() const { return addr_at(return_address_offset); }

  address destination() const;

  address plt_entry() const;

  address plt_jump() const;

  address plt_load_got() const;

  address plt_resolve_call() const;

  address plt_c2i_stub() const;

  void set_stub_to_clean();

  void  reset_to_plt_resolve_call();

  void  set_destination_mt_safe(address dest);

  void verify() const;

};

inline NativePltCall* nativePltCall_at(address address) {

  NativePltCall* call = (NativePltCall*) address;

#ifdef ASSERT

  call->verify();

#endif

  return call;

}

inline NativePltCall* nativePltCall_before(address addr) {

  address at = addr - NativePltCall::instruction_size;

  return nativePltCall_at(at);

}

class NativeCall;

inline NativeCall* nativeCall_at(address address);

// The NativeCall is an abstraction for accessing/manipulating native call imm32/rel32off

// instructions (used to manipulate inline caches, primitive & dll calls, etc.).

class NativeCall: public NativeInstruction {

 public:

  enum Intel_specific_constants {

    instruction_code            = 0xE8,

    instruction_size            =    5,

    instruction_offset          =    0,

    displacement_offset         =    1,

    return_address_offset       =    5

  };

  enum { cache_line_size = BytesPerWord };  // conservative estimate!

  address instruction_address() const       { return addr_at(instruction_offset); }

  address next_instruction_address() const  { return addr_at(return_address_offset); }

  int   displacement() const                { return (jint) int_at(displacement_offset); }

  address displacement_address() const      { return addr_at(displacement_offset); }

  address return_address() const            { return addr_at(return_address_offset); }

  address destination() const;

  void  set_destination(address dest)       {

#ifdef AMD64

    intptr_t disp = dest - return_address();

    guarantee(disp == (intptr_t)(jint)disp, "must be 32-bit offset");

#endif // AMD64

    set_int_at(displacement_offset, dest - return_address());

  }

  void  set_destination_mt_safe(address dest);

  void  verify_alignment() { assert((intptr_t)addr_at(displacement_offset) % BytesPerInt == 0, "must be aligned"); }

  void  verify();

  void  print();

  // Creation

  inline friend NativeCall* nativeCall_at(address address);

  inline friend NativeCall* nativeCall_before(address return_address);

  static bool is_call_at(address instr) {

    return ((*instr) & 0xFF) == NativeCall::instruction_code;

  }

  static bool is_call_before(address return_address) {

    return is_call_at(return_address - NativeCall::return_address_offset);

  }

  static bool is_call_to(address instr, address target) {

    return nativeInstruction_at(instr)->is_call() &&

      nativeCall_at(instr)->destination() == target;

  }

#if INCLUDE_AOT

  static bool is_far_call(address instr, address target) {

    intptr_t disp = target - (instr + sizeof(int32_t));

    return !Assembler::is_simm32(disp);

  }

#endif

  // MT-safe patching of a call instruction.

  static void insert(address code_pos, address entry);

  static void replace_mt_safe(address instr_addr, address code_buffer);

};

inline NativeCall* nativeCall_at(address address) {

  NativeCall* call = (NativeCall*)(address - NativeCall::instruction_offset);

#ifdef ASSERT

  call->verify();

#endif

  return call;

}

inline NativeCall* nativeCall_before(address return_address) {

  NativeCall* call = (NativeCall*)(return_address - NativeCall::return_address_offset);

#ifdef ASSERT

  call->verify();

#endif

  return call;

}

class NativeCallReg: public NativeInstruction {

 public:

  enum Intel_specific_constants {

    instruction_code            = 0xFF,

    instruction_offset          =    0,

    return_address_offset_norex =    2,

    return_address_offset_rex   =    3

  };

  int next_instruction_offset() const  {

    if (ubyte_at(0) == NativeCallReg::instruction_code) {

      return return_address_offset_norex;

    } else {

      return return_address_offset_rex;

    }

  }

};

// An interface for accessing/manipulating native mov reg, imm32 instructions.

// (used to manipulate inlined 32bit data dll calls, etc.)

class NativeMovConstReg: public NativeInstruction {

#ifdef AMD64

  static const bool has_rex = true;

  static const int rex_size = 1;

#else

  static const bool has_rex = false;

  static const int rex_size = 0;

#endif // AMD64

 public:

  enum Intel_specific_constants {

    instruction_code            = 0xB8,

    instruction_size            =    1 + rex_size + wordSize,

    instruction_offset          =    0,

    data_offset                 =    1 + rex_size,

    next_instruction_offset     =    instruction_size,

    register_mask               = 0x07

  };

  address instruction_address() const       { return addr_at(instruction_offset); }

  address next_instruction_address() const  { return addr_at(next_instruction_offset); }

  intptr_t data() const                     { return ptr_at(data_offset); }

  void  set_data(intptr_t x)                { set_ptr_at(data_offset, x); }

  void  verify();

  void  print();

  // unit test stuff

  static void test() {}

  // Creation

  inline friend NativeMovConstReg* nativeMovConstReg_at(address address);

  inline friend NativeMovConstReg* nativeMovConstReg_before(address address);

};

inline NativeMovConstReg* nativeMovConstReg_at(address address) {

  NativeMovConstReg* test = (NativeMovConstReg*)(address - NativeMovConstReg::instruction_offset);

#ifdef ASSERT

  test->verify();

#endif

  return test;

}

inline NativeMovConstReg* nativeMovConstReg_before(address address) {

  NativeMovConstReg* test = (NativeMovConstReg*)(address - NativeMovConstReg::instruction_size - NativeMovConstReg::instruction_offset);

#ifdef ASSERT

  test->verify();

#endif

  return test;

}

class NativeMovConstRegPatching: public NativeMovConstReg {

 private:

    friend NativeMovConstRegPatching* nativeMovConstRegPatching_at(address address) {

    NativeMovConstRegPatching* test = (NativeMovConstRegPatching*)(address - instruction_offset);

    #ifdef ASSERT

      test->verify();

    #endif

    return test;

  }

};

// An interface for accessing/manipulating native moves of the form:

//      mov[b/w/l/q] [reg + offset], reg   (instruction_code_reg2mem)

//      mov[b/w/l/q] reg, [reg+offset]     (instruction_code_mem2reg

//      mov[s/z]x[w/b/q] [reg + offset], reg

//      fld_s  [reg+offset]

//      fld_d  [reg+offset]

//      fstp_s [reg + offset]

//      fstp_d [reg + offset]

//      mov_literal64  scratch,<pointer> ; mov[b/w/l/q] 0(scratch),reg | mov[b/w/l/q] reg,0(scratch)

//

// Warning: These routines must be able to handle any instruction sequences

// that are generated as a result of the load/store byte,word,long

// macros.  For example: The load_unsigned_byte instruction generates

// an xor reg,reg inst prior to generating the movb instruction.  This

// class must skip the xor instruction.

class NativeMovRegMem: public NativeInstruction {

 public:

  enum Intel_specific_constants {

    instruction_prefix_wide_lo          = Assembler::REX,

    instruction_prefix_wide_hi          = Assembler::REX_WRXB,

    instruction_code_xor                = 0x33,

    instruction_extended_prefix         = 0x0F,

    instruction_code_mem2reg_movslq     = 0x63,

    instruction_code_mem2reg_movzxb     = 0xB6,

    instruction_code_mem2reg_movsxb     = 0xBE,

    instruction_code_mem2reg_movzxw     = 0xB7,

    instruction_code_mem2reg_movsxw     = 0xBF,

    instruction_operandsize_prefix      = 0x66,

    instruction_code_reg2mem            = 0x89,

    instruction_code_mem2reg            = 0x8b,

    instruction_code_reg2memb           = 0x88,

    instruction_code_mem2regb           = 0x8a,

    instruction_code_float_s            = 0xd9,

    instruction_code_float_d            = 0xdd,

    instruction_code_long_volatile      = 0xdf,

    instruction_code_xmm_ss_prefix      = 0xf3,

    instruction_code_xmm_sd_prefix      = 0xf2,

    instruction_code_xmm_code           = 0x0f,

    instruction_code_xmm_load           = 0x10,

    instruction_code_xmm_store          = 0x11,

    instruction_code_xmm_lpd            = 0x12,

    instruction_code_lea                = 0x8d,

    instruction_VEX_prefix_2bytes       = Assembler::VEX_2bytes,

    instruction_VEX_prefix_3bytes       = Assembler::VEX_3bytes,

    instruction_EVEX_prefix_4bytes      = Assembler::EVEX_4bytes,

    instruction_size                    = 4,

    instruction_offset                  = 0,

    data_offset                         = 2,

    next_instruction_offset             = 4

  };

  // helper

  int instruction_start() const;

  address instruction_address() const;

  address next_instruction_address() const;

  int   offset() const;

  void  set_offset(int x);

  void  add_offset_in_bytes(int add_offset)     { set_offset ( ( offset() + add_offset ) ); }

  void verify();

  void print ();

  // unit test stuff

  static void test() {}

 private:

  inline friend NativeMovRegMem* nativeMovRegMem_at (address address);

};

inline NativeMovRegMem* nativeMovRegMem_at (address address) {

  NativeMovRegMem* test = (NativeMovRegMem*)(address - NativeMovRegMem::instruction_offset);

#ifdef ASSERT

  test->verify();

#endif

  return test;

}

// An interface for accessing/manipulating native leal instruction of form:

//        leal reg, [reg + offset]

class NativeLoadAddress: public NativeMovRegMem {

#ifdef AMD64

  static const bool has_rex = true;

  static const int rex_size = 1;

#else

  static const bool has_rex = false;

  static const int rex_size = 0;

#endif // AMD64

 public:

  enum Intel_specific_constants {

    instruction_prefix_wide             = Assembler::REX_W,

    instruction_prefix_wide_extended    = Assembler::REX_WB,

    lea_instruction_code                = 0x8D,

    mov64_instruction_code              = 0xB8

  };

  void verify();

  void print ();

  // unit test stuff

  static void test() {}

 private:

  friend NativeLoadAddress* nativeLoadAddress_at (address address) {

    NativeLoadAddress* test = (NativeLoadAddress*)(address - instruction_offset);

    #ifdef ASSERT

      test->verify();

    #endif

    return test;

  }

};

// destination is rbx or rax

// mov rbx, [rip + offset]

class NativeLoadGot: public NativeInstruction {

#ifdef AMD64

  static const bool has_rex = true;

  static const int rex_size = 1;

#else

  static const bool has_rex = false;

  static const int rex_size = 0;

#endif

public:

  enum Intel_specific_constants {

    rex_prefix = 0x48,

    instruction_code = 0x8b,

    modrm_rbx_code = 0x1d,

    modrm_rax_code = 0x05,

    instruction_length = 6 + rex_size,

    offset_offset = 2 + rex_size

  };

  address instruction_address() const { return addr_at(0); }

  address rip_offset_address() const { return addr_at(offset_offset); }

  int rip_offset() const { return int_at(offset_offset); }

  address return_address() const { return addr_at(instruction_length); }

  address got_address() const { return return_address() + rip_offset(); }

  address next_instruction_address() const { return return_address(); }

  intptr_t data() const;

  void set_data(intptr_t data) {

    intptr_t *addr = (intptr_t *) got_address();

    *addr = data;

  }

  void verify() const;

private:

  void report_and_fail() const;

};

inline NativeLoadGot* nativeLoadGot_at(address addr) {

  NativeLoadGot* load = (NativeLoadGot*) addr;

#ifdef ASSERT

  load->verify();

#endif

  return load;

}

// jump rel32off

class NativeJump: public NativeInstruction {

 public:

  enum Intel_specific_constants {

    instruction_code            = 0xe9,

    instruction_size            =    5,

    instruction_offset          =    0,

    data_offset                 =    1,

    next_instruction_offset     =    5

  };

  address instruction_address() const       { return addr_at(instruction_offset); }

  address next_instruction_address() const  { return addr_at(next_instruction_offset); }

  address jump_destination() const          {

     address dest = (int_at(data_offset)+next_instruction_address());

     // 32bit used to encode unresolved jmp as jmp -1

     // 64bit can't produce this so it used jump to self.

     // Now 32bit and 64bit use jump to self as the unresolved address

     // which the inline cache code (and relocs) know about

     // return -1 if jump to self

    dest = (dest == (address) this) ? (address) -1 : dest;

    return dest;

  }

  void  set_jump_destination(address dest)  {

    intptr_t val = dest - next_instruction_address();

    if (dest == (address) -1) {

      val = -5; // jump to self

    }

#ifdef AMD64