/*

 * Copyright (c) 2003, 2017, Oracle and/or its affiliates. All rights reserved.

 * Copyright 2007, 2008, 2010, 2015 Red Hat, Inc.

 * 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 "precompiled.hpp"

#include "asm/assembler.hpp"

#include "assembler_zero.inline.hpp"

#include "interpreter/interpreter.hpp"

#include "nativeInst_zero.hpp"

#include "oops/instanceOop.hpp"

#include "oops/method.hpp"

#include "oops/objArrayKlass.hpp"

#include "oops/oop.inline.hpp"

#include "prims/methodHandles.hpp"

#include "runtime/frame.inline.hpp"

#include "runtime/handles.inline.hpp"

#include "runtime/sharedRuntime.hpp"

#include "runtime/stubCodeGenerator.hpp"

#include "runtime/stubRoutines.hpp"

#include "runtime/thread.inline.hpp"

#include "stack_zero.inline.hpp"

#ifdef COMPILER2

#include "opto/runtime.hpp"

#endif

// For SafeFetch we need POSIX tls and setjmp

#include <setjmp.h>

#include <pthread.h>

static pthread_key_t g_jmpbuf_key;

// return the currently active jump buffer for this thread

//  - if there is any, NULL otherwise. Called from

//    zero signal handlers.

extern sigjmp_buf* get_jmp_buf_for_continuation() {

  return (sigjmp_buf*) pthread_getspecific(g_jmpbuf_key);

}

// Declaration and definition of StubGenerator (no .hpp file).

// For a more detailed description of the stub routine structure

// see the comment in stubRoutines.hpp

class StubGenerator: public StubCodeGenerator {

 private:

  // The call stub is used to call Java from C

  static void call_stub(

    JavaCallWrapper *call_wrapper,

    intptr_t*        result,

    BasicType        result_type,

    Method*          method,

    address          entry_point,

    intptr_t*        parameters,

    int              parameter_words,

    TRAPS) {

    JavaThread *thread = (JavaThread *) THREAD;

    ZeroStack *stack = thread->zero_stack();

    // Make sure we have no pending exceptions

    assert(!HAS_PENDING_EXCEPTION, "call_stub called with pending exception");

    // Set up the stack if necessary

    bool stack_needs_teardown = false;

    if (stack->needs_setup()) {

      size_t zero_stack_size = stack->suggest_size(thread);

      stack->setup(alloca(zero_stack_size), zero_stack_size);

      stack_needs_teardown = true;

    }

    // Allocate and initialize our frame

    EntryFrame *frame =

      EntryFrame::build(parameters, parameter_words, call_wrapper, THREAD);

    if (!HAS_PENDING_EXCEPTION) {

      // Push the frame

      thread->push_zero_frame(frame);

      // Make the call

      Interpreter::invoke_method(method, entry_point, THREAD);

      // Store the result

      if (!HAS_PENDING_EXCEPTION) {

        switch (result_type) {

        case T_INT:

          *(jint *) result = *(jint *) stack->sp();

          break;

        case T_LONG:

          *(jlong *) result = *(jlong *) stack->sp();

          break;

        case T_FLOAT:

          *(jfloat *) result = *(jfloat *) stack->sp();

          break;

        case T_DOUBLE:

          *(jdouble *) result = *(jdouble *) stack->sp();

          break;

        case T_OBJECT:

          *(oop *) result = *(oop *) stack->sp();

          break;

        default:

          ShouldNotReachHere();

        }

      }

      // Unwind the frame

      thread->pop_zero_frame();

    }

    // Tear down the stack if necessary

    if (stack_needs_teardown)

      stack->teardown();

  }

  // These stubs get called from some dumb test routine.

  // I'll write them properly when they're called from

  // something that's actually doing something.

  static void fake_arraycopy_stub(address src, address dst, int count) {

    assert(count == 0, "huh?");

  }

  void generate_arraycopy_stubs() {

    // Call the conjoint generation methods immediately after

    // the disjoint ones so that short branches from the former

    // to the latter can be generated.

    StubRoutines::_jbyte_disjoint_arraycopy  = (address) fake_arraycopy_stub;

    StubRoutines::_jbyte_arraycopy           = (address) fake_arraycopy_stub;

    StubRoutines::_jshort_disjoint_arraycopy = (address) fake_arraycopy_stub;

    StubRoutines::_jshort_arraycopy          = (address) fake_arraycopy_stub;

    StubRoutines::_jint_disjoint_arraycopy   = (address) fake_arraycopy_stub;

    StubRoutines::_jint_arraycopy            = (address) fake_arraycopy_stub;

    StubRoutines::_jlong_disjoint_arraycopy  = (address) fake_arraycopy_stub;

    StubRoutines::_jlong_arraycopy           = (address) fake_arraycopy_stub;

    StubRoutines::_oop_disjoint_arraycopy    = ShouldNotCallThisStub();

    StubRoutines::_oop_arraycopy             = ShouldNotCallThisStub();

    StubRoutines::_checkcast_arraycopy       = ShouldNotCallThisStub();

    StubRoutines::_unsafe_arraycopy          = ShouldNotCallThisStub();

    StubRoutines::_generic_arraycopy         = ShouldNotCallThisStub();

    // We don't generate specialized code for HeapWord-aligned source

    // arrays, so just use the code we've already generated

    StubRoutines::_arrayof_jbyte_disjoint_arraycopy =

      StubRoutines::_jbyte_disjoint_arraycopy;

    StubRoutines::_arrayof_jbyte_arraycopy =

      StubRoutines::_jbyte_arraycopy;

    StubRoutines::_arrayof_jshort_disjoint_arraycopy =

      StubRoutines::_jshort_disjoint_arraycopy;

    StubRoutines::_arrayof_jshort_arraycopy =

      StubRoutines::_jshort_arraycopy;

    StubRoutines::_arrayof_jint_disjoint_arraycopy =

      StubRoutines::_jint_disjoint_arraycopy;

    StubRoutines::_arrayof_jint_arraycopy =

      StubRoutines::_jint_arraycopy;

    StubRoutines::_arrayof_jlong_disjoint_arraycopy =

      StubRoutines::_jlong_disjoint_arraycopy;

    StubRoutines::_arrayof_jlong_arraycopy =

      StubRoutines::_jlong_arraycopy;

    StubRoutines::_arrayof_oop_disjoint_arraycopy =

      StubRoutines::_oop_disjoint_arraycopy;

    StubRoutines::_arrayof_oop_arraycopy =

      StubRoutines::_oop_arraycopy;

  }

  static int SafeFetch32(int *adr, int errValue) {

    // set up a jump buffer; anchor the pointer to the jump buffer in tls; then

    // do the pointer access. If pointer is invalid, we crash; in signal

    // handler, we retrieve pointer to jmp buffer from tls, and jump back.

    //

    // Note: the jump buffer itself - which can get pretty large depending on

    // the architecture - lives on the stack and that is fine, because we will

    // not rewind the stack: either we crash, in which case signal handler

    // frame is below us, or we don't crash, in which case it does not matter.

    sigjmp_buf jb;

    if (sigsetjmp(jb, 1)) {

      // we crashed. clean up tls and return default value.

      pthread_setspecific(g_jmpbuf_key, NULL);

      return errValue;

    } else {

      // preparation phase

      pthread_setspecific(g_jmpbuf_key, &jb);

    }

    int value = errValue;

    value = *adr;

    // all went well. clean tls.

    pthread_setspecific(g_jmpbuf_key, NULL);

    return value;

  }

  static intptr_t SafeFetchN(intptr_t *adr, intptr_t errValue) {

    sigjmp_buf jb;

    if (sigsetjmp(jb, 1)) {

      // we crashed. clean up tls and return default value.

      pthread_setspecific(g_jmpbuf_key, NULL);

      return errValue;

    } else {

      // preparation phase

      pthread_setspecific(g_jmpbuf_key, &jb);

    }

    intptr_t value = errValue;

    value = *adr;

    // all went well. clean tls.

    pthread_setspecific(g_jmpbuf_key, NULL);

    return value;

  }

  void generate_initial() {

    // Generates all stubs and initializes the entry points

    // entry points that exist in all platforms Note: This is code

    // that could be shared among different platforms - however the

    // benefit seems to be smaller than the disadvantage of having a

    // much more complicated generator structure. See also comment in

    // stubRoutines.hpp.

    StubRoutines::_forward_exception_entry   = ShouldNotCallThisStub();

    StubRoutines::_call_stub_entry           = (address) call_stub;

    StubRoutines::_catch_exception_entry     = ShouldNotCallThisStub();

    // atomic calls

    StubRoutines::_atomic_xchg_entry         = ShouldNotCallThisStub();

    StubRoutines::_atomic_xchg_long_entry    = ShouldNotCallThisStub();

    StubRoutines::_atomic_cmpxchg_entry      = ShouldNotCallThisStub();

    StubRoutines::_atomic_cmpxchg_byte_entry = ShouldNotCallThisStub();

    StubRoutines::_atomic_cmpxchg_long_entry = ShouldNotCallThisStub();

    StubRoutines::_atomic_add_entry          = ShouldNotCallThisStub();

    StubRoutines::_atomic_add_long_entry     = ShouldNotCallThisStub();

    StubRoutines::_fence_entry               = ShouldNotCallThisStub();

  }

  void generate_all() {

    // Generates all stubs and initializes the entry points

    // These entry points require SharedInfo::stack0 to be set up in

    // non-core builds and need to be relocatable, so they each

    // fabricate a RuntimeStub internally.

    StubRoutines::_throw_AbstractMethodError_entry =

      ShouldNotCallThisStub();

    StubRoutines::_throw_NullPointerException_at_call_entry =

      ShouldNotCallThisStub();

    StubRoutines::_throw_StackOverflowError_entry =

      ShouldNotCallThisStub();

    // support for verify_oop (must happen after universe_init)

    StubRoutines::_verify_oop_subroutine_entry =

      ShouldNotCallThisStub();

    // arraycopy stubs used by compilers

    generate_arraycopy_stubs();

    // Safefetch stubs.

    pthread_key_create(&g_jmpbuf_key, NULL);

    StubRoutines::_safefetch32_entry = CAST_FROM_FN_PTR(address, StubGenerator::SafeFetch32);

    StubRoutines::_safefetch32_fault_pc = NULL;

    StubRoutines::_safefetch32_continuation_pc = NULL;

    StubRoutines::_safefetchN_entry = CAST_FROM_FN_PTR(address, StubGenerator::SafeFetchN);

    StubRoutines::_safefetchN_fault_pc = NULL;

    StubRoutines::_safefetchN_continuation_pc = NULL;

  }

 public:

  StubGenerator(CodeBuffer* code, bool all) : StubCodeGenerator(code) {

    if (all) {

      generate_all();

    } else {

      generate_initial();

    }

  }

};

void StubGenerator_generate(CodeBuffer* code, bool all) {

  StubGenerator g(code, all);

}

EntryFrame *EntryFrame::build(const intptr_t*  parameters,

                              int              parameter_words,

                              JavaCallWrapper* call_wrapper,

                              TRAPS) {

  ZeroStack *stack = ((JavaThread *) THREAD)->zero_stack();

  stack->overflow_check(header_words + parameter_words, CHECK_NULL);

  stack->push(0); // next_frame, filled in later

  intptr_t *fp = stack->sp();

  assert(fp - stack->sp() == next_frame_off, "should be");

  stack->push(ENTRY_FRAME);

  assert(fp - stack->sp() == frame_type_off, "should be");

  stack->push((intptr_t) call_wrapper);

  assert(fp - stack->sp() == call_wrapper_off, "should be");

  for (int i = 0; i < parameter_words; i++)

    stack->push(parameters[i]);

  return (EntryFrame *) fp;

}