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      1 /*
      2  * Copyright (C) 2011 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 "art_method-inl.h"
     18 #include "check_reference_map_visitor.h"
     19 #include "jni.h"
     20 
     21 namespace art {
     22 
     23 #define CHECK_REGS_CONTAIN_REFS(dex_pc, abort_if_not_found, ...) do {                 \
     24   int t[] = {__VA_ARGS__};                                                            \
     25   int t_size = sizeof(t) / sizeof(*t);                                                \
     26   const OatQuickMethodHeader* method_header = GetCurrentOatQuickMethodHeader();       \
     27   uintptr_t native_quick_pc = method_header->ToNativeQuickPc(GetMethod(),             \
     28                                                  dex_pc,                              \
     29                                                  /* is_catch_handler */ false,        \
     30                                                  abort_if_not_found);                 \
     31   if (native_quick_pc != UINTPTR_MAX) {                                               \
     32     CheckReferences(t, t_size, method_header->NativeQuickPcOffset(native_quick_pc));  \
     33   }                                                                                   \
     34 } while (false);
     35 
     36 struct ReferenceMap2Visitor : public CheckReferenceMapVisitor {
     37   explicit ReferenceMap2Visitor(Thread* thread) REQUIRES_SHARED(Locks::mutator_lock_)
     38       : CheckReferenceMapVisitor(thread) {}
     39 
     40   bool VisitFrame() REQUIRES_SHARED(Locks::mutator_lock_) {
     41     if (CheckReferenceMapVisitor::VisitFrame()) {
     42       return true;
     43     }
     44     ArtMethod* m = GetMethod();
     45     std::string m_name(m->GetName());
     46 
     47     // Given the method name and the number of times the method has been called,
     48     // we know the Dex registers with live reference values. Assert that what we
     49     // find is what is expected.
     50     if (m_name.compare("f") == 0) {
     51       CHECK_REGS_CONTAIN_REFS(0x03U, true, 8);  // v8: this
     52       CHECK_REGS_CONTAIN_REFS(0x06U, true, 8, 1);  // v8: this, v1: x
     53       CHECK_REGS_CONTAIN_REFS(0x0cU, true, 8, 3, 1);  // v8: this, v3: y, v1: x
     54       CHECK_REGS_CONTAIN_REFS(0x10U, true, 8, 3, 1);  // v8: this, v3: y, v1: x
     55       // v2 is added because of the instruction at DexPC 0024. Object merges with 0 is Object. See:
     56       //   0024: move-object v3, v2
     57       //   0025: goto 0013
     58       // Detailed dex instructions for ReferenceMap.java are at the end of this function.
     59       // CHECK_REGS_CONTAIN_REFS(8, 3, 2, 1);  // v8: this, v3: y, v2: y, v1: x
     60       // We eliminate the non-live registers at a return, so only v3 is live.
     61       // Note that it is OK for a compiler to not have a dex map at this dex PC because
     62       // a return is not necessarily a safepoint.
     63       CHECK_REGS_CONTAIN_REFS(0x14U, false, 2);  // v2: y
     64       // Note that v0: ex can be eliminated because it's a dead merge of two different exceptions.
     65       CHECK_REGS_CONTAIN_REFS(0x18U, true, 8, 2, 1);  // v8: this, v2: y, v1: x (dead v0: ex)
     66       CHECK_REGS_CONTAIN_REFS(0x22U, true, 8, 2, 1);  // v8: this, v2: y, v1: x (dead v0: ex)
     67 
     68       if (!GetCurrentOatQuickMethodHeader()->IsOptimized()) {
     69         CHECK_REGS_CONTAIN_REFS(0x27U, true, 8, 4, 2, 1);  // v8: this, v4: ex, v2: y, v1: x
     70       }
     71       CHECK_REGS_CONTAIN_REFS(0x29U, true, 8, 4, 2, 1);  // v8: this, v4: ex, v2: y, v1: x
     72       CHECK_REGS_CONTAIN_REFS(0x2cU, true, 8, 4, 2, 1);  // v8: this, v4: ex, v2: y, v1: x
     73       // Note that it is OK for a compiler to not have a dex map at these two dex PCs because
     74       // a goto is not necessarily a safepoint.
     75       CHECK_REGS_CONTAIN_REFS(0x2fU, false, 8, 4, 3, 2, 1);  // v8: this, v4: ex, v3: y, v2: y, v1: x
     76       CHECK_REGS_CONTAIN_REFS(0x32U, false, 8, 3, 2, 1, 0);  // v8: this, v3: y, v2: y, v1: x, v0: ex
     77     }
     78 
     79     return true;
     80   }
     81 };
     82 
     83 // DEX code
     84 //
     85 // 0000: const/4 v4, #int 2 // #2
     86 // 0001: const/4 v7, #int 0 // #0
     87 // 0002: const/4 v6, #int 1 // #1
     88 // 0003: new-array v1, v4, [Ljava/lang/Object; // type@0007
     89 // 0005: const/4 v2, #int 0 // #0
     90 // 0006: new-instance v3, Ljava/lang/Object; // type@0003
     91 // 0008: invoke-direct {v3}, Ljava/lang/Object;.<init>:()V // method@0004
     92 // 000b: const/4 v4, #int 2 // #2
     93 // 000c: aput-object v3, v1, v4
     94 // 000e: aput-object v3, v1, v6
     95 // 0010: invoke-virtual {v8, v7}, LMain;.refmap:(I)I // method@0003
     96 // 0013: move-object v2, v3
     97 // 0014: return-object v2
     98 // 0015: move-exception v0
     99 // 0016: if-nez v2, 0020 // +000a
    100 // 0018: new-instance v4, Ljava/lang/Object; // type@0003
    101 // 001a: invoke-direct {v4}, Ljava/lang/Object;.<init>:()V // method@0004
    102 // 001d: const/4 v5, #int 1 // #1
    103 // 001e: aput-object v4, v1, v5
    104 // 0020: aput-object v2, v1, v6
    105 // 0022: invoke-virtual {v8, v7}, LMain;.refmap:(I)I // method@0003
    106 // 0025: goto 0014 // -0011
    107 // 0026: move-exception v4
    108 // 0027: aput-object v2, v1, v6
    109 // 0029: invoke-virtual {v8, v7}, LMain;.refmap:(I)I // method@0003
    110 // 002c: throw v4
    111 // 002d: move-exception v4
    112 // 002e: move-object v2, v3
    113 // 002f: goto 0027 // -0008
    114 // 0030: move-exception v0
    115 // 0031: move-object v2, v3
    116 // 0032: goto 0016 // -001c
    117 //    catches       : 3
    118 //      0x0006 - 0x000b
    119 //        Ljava/lang/Exception; -> 0x0015
    120 //        <any> -> 0x0026
    121 //      0x000c - 0x000e
    122 //        Ljava/lang/Exception; -> 0x0030
    123 //        <any> -> 0x002d
    124 //      0x0018 - 0x0020
    125 //        <any> -> 0x0026
    126 //    positions     :
    127 //      0x0003 line=22
    128 //      0x0005 line=23
    129 //      0x0006 line=25
    130 //      0x000b line=26
    131 //      0x000e line=32
    132 //      0x0010 line=33
    133 //      0x0014 line=35
    134 //      0x0015 line=27
    135 //      0x0016 line=28
    136 //      0x0018 line=29
    137 //      0x0020 line=32
    138 //      0x0022 line=33
    139 //      0x0026 line=31
    140 //      0x0027 line=32
    141 //      0x0029 line=33
    142 //      0x002c line=31
    143 //      0x0030 line=27
    144 //    locals        :
    145 //      0x0006 - 0x000b reg=2 y Ljava/lang/Object;
    146 //      0x000b - 0x0014 reg=3 y Ljava/lang/Object;
    147 //      0x0015 - 0x0016 reg=2 y Ljava/lang/Object;
    148 //      0x0016 - 0x0026 reg=0 ex Ljava/lang/Exception;
    149 //      0x002d - 0x002f reg=3 y Ljava/lang/Object;
    150 //      0x002f - 0x0030 reg=2 y Ljava/lang/Object;
    151 //      0x0030 - 0x0032 reg=3 y Ljava/lang/Object;
    152 //      0x0031 - 0x0033 reg=0 ex Ljava/lang/Exception;
    153 //      0x0005 - 0x0033 reg=1 x [Ljava/lang/Object;
    154 //      0x0032 - 0x0033 reg=2 y Ljava/lang/Object;
    155 //      0x0000 - 0x0033 reg=8 this LMain;
    156 
    157 extern "C" JNIEXPORT jint JNICALL Java_Main_refmap(JNIEnv*, jobject, jint count) {
    158   // Visitor
    159   ScopedObjectAccess soa(Thread::Current());
    160   ReferenceMap2Visitor mapper(soa.Self());
    161   mapper.WalkStack();
    162 
    163   return count + 1;
    164 }
    165 
    166 }  // namespace art
    167