1/*
2 * Copyright (c) 1999, 2017, Oracle and/or its affiliates. All rights reserved.
3 * Copyright 2009, 2010 Red Hat, Inc.
4 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
5 *
6 * This code is free software; you can redistribute it and/or modify it
7 * under the terms of the GNU General Public License version 2 only, as
8 * published by the Free Software Foundation.
9 *
10 * This code is distributed in the hope that it will be useful, but WITHOUT
11 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
12 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
13 * version 2 for more details (a copy is included in the LICENSE file that
14 * accompanied this code).
15 *
16 * You should have received a copy of the GNU General Public License version
17 * 2 along with this work; if not, write to the Free Software Foundation,
18 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
19 *
20 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
21 * or visit www.oracle.com if you need additional information or have any
22 * questions.
23 *
24 */
25
26#include "precompiled.hpp"
27#include "shark/llvmHeaders.hpp"
28#include "shark/sharkNativeWrapper.hpp"
29#include "shark/sharkType.hpp"
30
31using namespace llvm;
32
33void SharkNativeWrapper::initialize(const char *name) {
34  // Create the function
35  _function = Function::Create(
36    SharkType::entry_point_type(),
37    GlobalVariable::InternalLinkage,
38    name);
39
40  // Get our arguments
41  Function::arg_iterator ai = function()->arg_begin();
42  Argument *method = ai++;
43  method->setName("method");
44  Argument *base_pc = ai++;
45  base_pc->setName("base_pc");
46  code_buffer()->set_base_pc(base_pc);
47  Argument *thread = ai++;
48  thread->setName("thread");
49  set_thread(thread);
50
51  // Create and push our stack frame
52  builder()->SetInsertPoint(CreateBlock());
53  _stack = SharkStack::CreateBuildAndPushFrame(this, method);
54  NOT_PRODUCT(method = NULL);
55
56  // Create the oopmap.  We use the one oopmap for every call site in
57  // the wrapper, which results in the odd mild inefficiency but is a
58  // damn sight easier to code.
59  OopMap *oopmap = new OopMap(
60    SharkStack::oopmap_slot_munge(stack()->oopmap_frame_size()),
61    SharkStack::oopmap_slot_munge(arg_size()));
62
63  // Set up the oop_tmp slot if required:
64  //  - For static methods we use it to handlize the class argument
65  //    for the call, and to protect the same during slow path locks
66  //    (if synchronized).
67  //  - For methods returning oops, we use it to protect the return
68  //    value across safepoints or slow path unlocking.
69  if (is_static() || is_returning_oop()) {
70    _oop_tmp_slot = stack()->slot_addr(
71      stack()->oop_tmp_slot_offset(),
72      SharkType::oop_type(),
73      "oop_tmp_slot");
74
75    oopmap->set_oop(SharkStack::slot2reg(stack()->oop_tmp_slot_offset()));
76  }
77
78  // Set up the monitor slot, for synchronized methods
79  if (is_synchronized()) {
80    Unimplemented();
81    _lock_slot_offset = 23;
82  }
83
84  // Start building the argument list
85  std::vector<Type*> param_types;
86  std::vector<Value*> param_values;
87  PointerType *box_type = PointerType::getUnqual(SharkType::oop_type());
88
89  // First argument is the JNIEnv
90  param_types.push_back(SharkType::jniEnv_type());
91  param_values.push_back(
92    builder()->CreateAddressOfStructEntry(
93      thread,
94      JavaThread::jni_environment_offset(),
95      SharkType::jniEnv_type(),
96      "jni_environment"));
97
98  // For static methods, the second argument is the class
99  if (is_static()) {
100    builder()->CreateStore(
101      builder()->CreateInlineOop(
102        JNIHandles::make_local(
103          target()->method_holder()->java_mirror())),
104      oop_tmp_slot());
105
106    param_types.push_back(box_type);
107    param_values.push_back(oop_tmp_slot());
108
109    _receiver_slot_offset = stack()->oop_tmp_slot_offset();
110  }
111  else if (is_returning_oop()) {
112    // The oop_tmp slot is registered in the oopmap,
113    // so we need to clear it.  This is one of the
114    // mild inefficiencies I mentioned earlier.
115    builder()->CreateStore(LLVMValue::null(), oop_tmp_slot());
116  }
117
118  // Parse the arguments
119  for (int i = 0; i < arg_size(); i++) {
120    int slot_offset = stack()->locals_slots_offset() + arg_size() - 1 - i;
121    int adjusted_offset = slot_offset;
122    BasicBlock *null, *not_null, *merge;
123    Value *box;
124    PHINode *phi;
125
126    switch (arg_type(i)) {
127    case T_VOID:
128      break;
129
130    case T_OBJECT:
131    case T_ARRAY:
132      null     = CreateBlock("null");
133      not_null = CreateBlock("not_null");
134      merge    = CreateBlock("merge");
135
136      box = stack()->slot_addr(slot_offset, SharkType::oop_type());
137      builder()->CreateCondBr(
138        builder()->CreateICmp(
139          ICmpInst::ICMP_EQ,
140          builder()->CreateLoad(box),
141          LLVMValue::null()),
142        null, not_null);
143
144      builder()->SetInsertPoint(null);
145      builder()->CreateBr(merge);
146
147      builder()->SetInsertPoint(not_null);
148      builder()->CreateBr(merge);
149
150      builder()->SetInsertPoint(merge);
151      phi = builder()->CreatePHI(box_type, 0, "boxed_object");
152      phi->addIncoming(ConstantPointerNull::get(box_type), null);
153      phi->addIncoming(box, not_null);
154      box = phi;
155
156      param_types.push_back(box_type);
157      param_values.push_back(box);
158
159      oopmap->set_oop(SharkStack::slot2reg(slot_offset));
160
161      if (i == 0 && !is_static())
162        _receiver_slot_offset = slot_offset;
163
164      break;
165
166    case T_LONG:
167    case T_DOUBLE:
168      adjusted_offset--;
169      // fall through
170
171    default:
172      Type *param_type = SharkType::to_stackType(arg_type(i));
173
174      param_types.push_back(param_type);
175      param_values.push_back(
176        builder()->CreateLoad(stack()->slot_addr(adjusted_offset, param_type)));
177    }
178  }
179
180  // The oopmap is now complete, and everything is written
181  // into the frame except the PC.
182  int pc_offset = code_buffer()->create_unique_offset();
183
184  _oop_maps = new OopMapSet();
185  oop_maps()->add_gc_map(pc_offset, oopmap);
186
187  builder()->CreateStore(
188    builder()->code_buffer_address(pc_offset),
189    stack()->slot_addr(stack()->pc_slot_offset()));
190
191  // Set up the Java frame anchor
192  stack()->CreateSetLastJavaFrame();
193
194  // Lock if necessary
195  if (is_synchronized())
196    Unimplemented();
197
198  // Change the thread state to _thread_in_native
199  CreateSetThreadState(_thread_in_native);
200
201  // Make the call
202  BasicType result_type = target()->result_type();
203  Type* return_type;
204  if (result_type == T_VOID)
205    return_type = SharkType::void_type();
206  else if (is_returning_oop())
207    return_type = box_type;
208  else
209    return_type = SharkType::to_arrayType(result_type);
210  Value* native_function = builder()->CreateIntToPtr(
211     LLVMValue::intptr_constant((intptr_t) target()->native_function()),
212     PointerType::getUnqual(
213       FunctionType::get(return_type, param_types, false)));
214  Value *result = builder()->CreateCall(
215    native_function, llvm::makeArrayRef(param_values));
216
217  // Start the transition back to _thread_in_Java
218  CreateSetThreadState(_thread_in_native_trans);
219
220  // Make sure new state is visible in the GC thread
221  if (os::is_MP()) {
222    if (UseMembar)
223      builder()->CreateFence(llvm::SequentiallyConsistent, llvm::CrossThread);
224    else
225      CreateWriteMemorySerializePage();
226  }
227
228  // Handle safepoint operations, pending suspend requests,
229  // and pending asynchronous exceptions.
230  BasicBlock *check_thread = CreateBlock("check_thread");
231  BasicBlock *do_safepoint = CreateBlock("do_safepoint");
232  BasicBlock *safepointed  = CreateBlock("safepointed");
233
234  Value *global_state = builder()->CreateLoad(
235    builder()->CreateIntToPtr(
236      LLVMValue::intptr_constant(
237        (intptr_t) SafepointSynchronize::address_of_state()),
238      PointerType::getUnqual(SharkType::jint_type())),
239    "global_state");
240
241  builder()->CreateCondBr(
242    builder()->CreateICmpNE(
243      global_state,
244      LLVMValue::jint_constant(SafepointSynchronize::_not_synchronized)),
245    do_safepoint, check_thread);
246
247  builder()->SetInsertPoint(check_thread);
248  Value *thread_state = builder()->CreateValueOfStructEntry(
249    thread,
250    JavaThread::suspend_flags_offset(),
251    SharkType::jint_type(),
252    "thread_state");
253
254  builder()->CreateCondBr(
255    builder()->CreateICmpNE(
256      thread_state,
257      LLVMValue::jint_constant(0)),
258    do_safepoint, safepointed);
259
260  builder()->SetInsertPoint(do_safepoint);
261  builder()->CreateCall(
262    builder()->check_special_condition_for_native_trans(), thread);
263  builder()->CreateBr(safepointed);
264
265  // Finally we can change the thread state to _thread_in_Java
266  builder()->SetInsertPoint(safepointed);
267  CreateSetThreadState(_thread_in_Java);
268
269  // Clear the frame anchor
270  stack()->CreateResetLastJavaFrame();
271
272  // If there is a pending exception then we can just unwind and
273  // return.  It seems totally wrong that unlocking is skipped here
274  // but apparently the template interpreter does this so we do too.
275  BasicBlock *exception    = CreateBlock("exception");
276  BasicBlock *no_exception = CreateBlock("no_exception");
277
278  builder()->CreateCondBr(
279    builder()->CreateICmpEQ(
280      CreateLoadPendingException(),
281      LLVMValue::null()),
282    no_exception, exception);
283
284  builder()->SetInsertPoint(exception);
285  CreateResetHandleBlock();
286  stack()->CreatePopFrame(0);
287  builder()->CreateRet(LLVMValue::jint_constant(0));
288
289  builder()->SetInsertPoint(no_exception);
290
291  // If the result was an oop then unbox it before
292  // releasing the handle it might be protected by
293  if (is_returning_oop()) {
294    BasicBlock *null     = builder()->GetInsertBlock();
295    BasicBlock *not_null = CreateBlock("not_null");
296    BasicBlock *merge    = CreateBlock("merge");
297
298    builder()->CreateCondBr(
299      builder()->CreateICmpNE(result, ConstantPointerNull::get(box_type)),
300      not_null, merge);
301
302    builder()->SetInsertPoint(not_null);
303#error Needs to be updated for tagged jweak; see JNIHandles.
304    Value *unboxed_result = builder()->CreateLoad(result);
305    builder()->CreateBr(merge);
306
307    builder()->SetInsertPoint(merge);
308    PHINode *phi = builder()->CreatePHI(SharkType::oop_type(), 0, "result");
309    phi->addIncoming(LLVMValue::null(), null);
310    phi->addIncoming(unboxed_result, not_null);
311    result = phi;
312  }
313
314  // Reset handle block
315  CreateResetHandleBlock();
316
317  // Unlock if necessary.
318  if (is_synchronized())
319    Unimplemented();
320
321  // Unwind and return
322  Value *result_addr = stack()->CreatePopFrame(type2size[result_type]);
323  if (result_type != T_VOID) {
324    bool needs_cast = false;
325    bool is_signed = false;
326    switch (result_type) {
327    case T_BOOLEAN:
328      result = builder()->CreateICmpNE(result, LLVMValue::jbyte_constant(0));
329      needs_cast = true;
330      break;
331
332    case T_CHAR:
333      needs_cast = true;
334      break;
335
336    case T_BYTE:
337    case T_SHORT:
338      needs_cast = true;
339      is_signed = true;
340      break;
341    }
342    if (needs_cast) {
343      result = builder()->CreateIntCast(
344        result, SharkType::to_stackType(result_type), is_signed);
345    }
346
347    builder()->CreateStore(
348      result,
349      builder()->CreateIntToPtr(
350        result_addr,
351        PointerType::getUnqual(SharkType::to_stackType(result_type))));
352  }
353  builder()->CreateRet(LLVMValue::jint_constant(0));
354}
355