1/*
2 * Copyright (C) 2014 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 *      http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17# include "mir_method_info.h"
18
19#include "dex/compiler_ir.h"
20#include "dex/quick/dex_file_method_inliner.h"
21#include "dex/quick/dex_file_to_method_inliner_map.h"
22#include "dex/verified_method.h"
23#include "driver/compiler_driver.h"
24#include "driver/dex_compilation_unit.h"
25#include "driver/compiler_driver-inl.h"
26#include "driver/compiler_options.h"
27#include "mirror/class_loader.h"  // Only to allow casts in Handle<ClassLoader>.
28#include "mirror/dex_cache.h"     // Only to allow casts in Handle<DexCache>.
29#include "scoped_thread_state_change.h"
30#include "handle_scope-inl.h"
31
32namespace art {
33
34void MirMethodLoweringInfo::Resolve(CompilerDriver* compiler_driver,
35                                    const DexCompilationUnit* mUnit,
36                                    MirMethodLoweringInfo* method_infos, size_t count) {
37  if (kIsDebugBuild) {
38    DCHECK(method_infos != nullptr);
39    DCHECK_NE(count, 0u);
40    for (auto it = method_infos, end = method_infos + count; it != end; ++it) {
41      MirMethodLoweringInfo unresolved(it->MethodIndex(), it->GetInvokeType(), it->IsQuickened());
42      unresolved.declaring_dex_file_ = it->declaring_dex_file_;
43      unresolved.vtable_idx_ = it->vtable_idx_;
44      if (it->target_dex_file_ != nullptr) {
45        unresolved.target_dex_file_ = it->target_dex_file_;
46        unresolved.target_method_idx_ = it->target_method_idx_;
47      }
48      if (kIsDebugBuild) {
49        unresolved.CheckEquals(*it);
50      }
51    }
52  }
53
54  // We're going to resolve methods and check access in a tight loop. It's better to hold
55  // the lock and needed references once than re-acquiring them again and again.
56  ScopedObjectAccess soa(Thread::Current());
57  StackHandleScope<4> hs(soa.Self());
58  Handle<mirror::DexCache> dex_cache(hs.NewHandle(compiler_driver->GetDexCache(mUnit)));
59  Handle<mirror::ClassLoader> class_loader(
60      hs.NewHandle(compiler_driver->GetClassLoader(soa, mUnit)));
61  Handle<mirror::Class> referrer_class(hs.NewHandle(
62      compiler_driver->ResolveCompilingMethodsClass(soa, dex_cache, class_loader, mUnit)));
63  auto current_dex_cache(hs.NewHandle<mirror::DexCache>(nullptr));
64  // Even if the referrer class is unresolved (i.e. we're compiling a method without class
65  // definition) we still want to resolve methods and record all available info.
66  Runtime* const runtime = Runtime::Current();
67  const DexFile* const dex_file = mUnit->GetDexFile();
68  const bool use_jit = runtime->UseJit();
69  const VerifiedMethod* const verified_method = mUnit->GetVerifiedMethod();
70  DexFileToMethodInlinerMap* inliner_map = compiler_driver->GetMethodInlinerMap();
71  DexFileMethodInliner* default_inliner =
72      (inliner_map != nullptr) ? inliner_map->GetMethodInliner(dex_file) : nullptr;
73
74  for (auto it = method_infos, end = method_infos + count; it != end; ++it) {
75    // For quickened invokes, the dex method idx is actually the mir offset.
76    if (it->IsQuickened()) {
77      const auto* dequicken_ref = verified_method->GetDequickenIndex(it->method_idx_);
78      CHECK(dequicken_ref != nullptr);
79      it->target_dex_file_ = dequicken_ref->dex_file;
80      it->target_method_idx_ = dequicken_ref->index;
81    }
82    // Remember devirtualized invoke target and set the called method to the default.
83    MethodReference devirt_ref(it->target_dex_file_, it->target_method_idx_);
84    MethodReference* devirt_target = (it->target_dex_file_ != nullptr) ? &devirt_ref : nullptr;
85    InvokeType invoke_type = it->GetInvokeType();
86    ArtMethod* resolved_method = nullptr;
87
88    bool string_init = false;
89    if (default_inliner->IsStringInitMethodIndex(it->MethodIndex())) {
90      string_init = true;
91      invoke_type = kDirect;
92    }
93
94    if (!it->IsQuickened()) {
95      it->target_dex_file_ = dex_file;
96      it->target_method_idx_ = it->MethodIndex();
97      current_dex_cache.Assign(dex_cache.Get());
98      resolved_method = compiler_driver->ResolveMethod(soa, dex_cache, class_loader, mUnit,
99                                                       it->target_method_idx_, invoke_type, true);
100    } else {
101      // The method index is actually the dex PC in this case.
102      // Calculate the proper dex file and target method idx.
103      CHECK(use_jit);
104      CHECK_EQ(invoke_type, kVirtual);
105      // Don't devirt if we are in a different dex file since we can't have direct invokes in
106      // another dex file unless we always put a direct / patch pointer.
107      devirt_target = nullptr;
108      current_dex_cache.Assign(runtime->GetClassLinker()->FindDexCache(*it->target_dex_file_));
109      CHECK(current_dex_cache.Get() != nullptr);
110      DexCompilationUnit cu(
111          mUnit->GetCompilationUnit(), mUnit->GetClassLoader(), mUnit->GetClassLinker(),
112          *it->target_dex_file_, nullptr /* code_item not used */, 0u /* class_def_idx not used */,
113          it->target_method_idx_, 0u /* access_flags not used */,
114          nullptr /* verified_method not used */);
115      resolved_method = compiler_driver->ResolveMethod(soa, current_dex_cache, class_loader, &cu,
116                                                       it->target_method_idx_, invoke_type, false);
117      if (resolved_method == nullptr) {
118        // If the method is null then it should be a miranda method, in this case try
119        // re-loading it, this time as an interface method. The actual miranda method is in the
120        // vtable, but it will resolve to an interface method.
121        resolved_method = compiler_driver->ResolveMethod(
122            soa, current_dex_cache, class_loader, &cu, it->target_method_idx_, kInterface, false);
123        CHECK(resolved_method != nullptr);
124      }
125      if (resolved_method != nullptr) {
126        // Since this was a dequickened virtual, it is guaranteed to be resolved. However, it may be
127        // resolved to an interface method. If this is the case then change the invoke type to
128        // interface with the assumption that sharp_type will be kVirtual.
129        if (resolved_method->GetInvokeType() == kInterface) {
130          it->flags_ = (it->flags_ & ~(kInvokeTypeMask << kBitInvokeTypeBegin)) |
131              (static_cast<uint16_t>(kInterface) << kBitInvokeTypeBegin);
132        }
133      }
134    }
135    if (UNLIKELY(resolved_method == nullptr)) {
136      continue;
137    }
138
139    compiler_driver->GetResolvedMethodDexFileLocation(resolved_method,
140        &it->declaring_dex_file_, &it->declaring_class_idx_, &it->declaring_method_idx_);
141    if (!it->IsQuickened()) {
142      // For quickened invoke virtuals we may have desharpened to an interface method which
143      // wont give us the right method index, in this case blindly dispatch or else we can't
144      // compile the method. Converting the invoke to interface dispatch doesn't work since we
145      // have no way to get the dex method index for quickened invoke virtuals in the interface
146      // trampolines.
147      it->vtable_idx_ =
148          compiler_driver->GetResolvedMethodVTableIndex(resolved_method, invoke_type);
149    }
150
151    MethodReference target_method(it->target_dex_file_, it->target_method_idx_);
152    int fast_path_flags = compiler_driver->IsFastInvoke(
153        soa, current_dex_cache, class_loader, mUnit, referrer_class.Get(), resolved_method,
154        &invoke_type, &target_method, devirt_target, &it->direct_code_, &it->direct_method_);
155    const bool is_referrers_class = referrer_class.Get() == resolved_method->GetDeclaringClass();
156    const bool is_class_initialized =
157        compiler_driver->IsMethodsClassInitialized(referrer_class.Get(), resolved_method);
158
159    // Check if the target method is intrinsic or special.
160    InlineMethodFlags is_intrinsic_or_special = kNoInlineMethodFlags;
161    if (inliner_map != nullptr) {
162      auto* inliner = (target_method.dex_file == dex_file)
163          ? default_inliner
164          : inliner_map->GetMethodInliner(target_method.dex_file);
165      is_intrinsic_or_special = inliner->IsIntrinsicOrSpecial(target_method.dex_method_index);
166    }
167
168    uint16_t other_flags = it->flags_ &
169        ~(kFlagFastPath | kFlagIsIntrinsic | kFlagIsSpecial | kFlagClassIsInitialized |
170            (kInvokeTypeMask << kBitSharpTypeBegin));
171    it->flags_ = other_flags |
172        // String init path is a special always-fast path.
173        (fast_path_flags != 0 || string_init ? kFlagFastPath : 0u) |
174        ((is_intrinsic_or_special & kInlineIntrinsic) != 0 ? kFlagIsIntrinsic : 0u) |
175        ((is_intrinsic_or_special & kInlineSpecial) != 0 ? kFlagIsSpecial : 0u) |
176        (static_cast<uint16_t>(invoke_type) << kBitSharpTypeBegin) |
177        (is_referrers_class ? kFlagIsReferrersClass : 0u) |
178        (is_class_initialized ? kFlagClassIsInitialized : 0u);
179    it->target_dex_file_ = target_method.dex_file;
180    it->target_method_idx_ = target_method.dex_method_index;
181    it->stats_flags_ = fast_path_flags;
182    if (string_init) {
183      it->direct_code_ = 0;
184    }
185  }
186}
187
188}  // namespace art
189