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#ifndef ART_COMPILER_COMPILED_METHOD_H_
18#define ART_COMPILER_COMPILED_METHOD_H_
19
20#include <memory>
21#include <iosfwd>
22#include <string>
23#include <vector>
24
25#include "arch/instruction_set.h"
26#include "base/bit_utils.h"
27#include "base/length_prefixed_array.h"
28#include "method_reference.h"
29#include "utils/array_ref.h"
30
31namespace art {
32
33class CompilerDriver;
34class CompiledMethodStorage;
35
36class CompiledCode {
37 public:
38  // For Quick to supply an code blob
39  CompiledCode(CompilerDriver* compiler_driver, InstructionSet instruction_set,
40               const ArrayRef<const uint8_t>& quick_code);
41
42  virtual ~CompiledCode();
43
44  InstructionSet GetInstructionSet() const {
45    return instruction_set_;
46  }
47
48  ArrayRef<const uint8_t> GetQuickCode() const {
49    return GetArray(quick_code_);
50  }
51
52  bool operator==(const CompiledCode& rhs) const;
53
54  // To align an offset from a page-aligned value to make it suitable
55  // for code storage. For example on ARM, to ensure that PC relative
56  // valu computations work out as expected.
57  size_t AlignCode(size_t offset) const;
58  static size_t AlignCode(size_t offset, InstructionSet instruction_set);
59
60  // returns the difference between the code address and a usable PC.
61  // mainly to cope with kThumb2 where the lower bit must be set.
62  size_t CodeDelta() const;
63  static size_t CodeDelta(InstructionSet instruction_set);
64
65  // Returns a pointer suitable for invoking the code at the argument
66  // code_pointer address.  Mainly to cope with kThumb2 where the
67  // lower bit must be set to indicate Thumb mode.
68  static const void* CodePointer(const void* code_pointer,
69                                 InstructionSet instruction_set);
70
71 protected:
72  template <typename T>
73  static ArrayRef<const T> GetArray(const LengthPrefixedArray<T>* array) {
74    if (array == nullptr) {
75      return ArrayRef<const T>();
76    }
77    DCHECK_NE(array->size(), 0u);
78    return ArrayRef<const T>(&array->At(0), array->size());
79  }
80
81  CompilerDriver* GetCompilerDriver() {
82    return compiler_driver_;
83  }
84
85 private:
86  CompilerDriver* const compiler_driver_;
87
88  const InstructionSet instruction_set_;
89
90  // Used to store the PIC code for Quick.
91  const LengthPrefixedArray<uint8_t>* const quick_code_;
92};
93
94class SrcMapElem {
95 public:
96  uint32_t from_;
97  int32_t to_;
98};
99
100inline bool operator<(const SrcMapElem& lhs, const SrcMapElem& rhs) {
101  if (lhs.from_ != rhs.from_) {
102    return lhs.from_ < rhs.from_;
103  }
104  return lhs.to_ < rhs.to_;
105}
106
107inline bool operator==(const SrcMapElem& lhs, const SrcMapElem& rhs) {
108  return lhs.from_ == rhs.from_ && lhs.to_ == rhs.to_;
109}
110
111template <class Allocator>
112class SrcMap FINAL : public std::vector<SrcMapElem, Allocator> {
113 public:
114  using std::vector<SrcMapElem, Allocator>::begin;
115  using typename std::vector<SrcMapElem, Allocator>::const_iterator;
116  using std::vector<SrcMapElem, Allocator>::empty;
117  using std::vector<SrcMapElem, Allocator>::end;
118  using std::vector<SrcMapElem, Allocator>::resize;
119  using std::vector<SrcMapElem, Allocator>::shrink_to_fit;
120  using std::vector<SrcMapElem, Allocator>::size;
121
122  explicit SrcMap() {}
123  explicit SrcMap(const Allocator& alloc) : std::vector<SrcMapElem, Allocator>(alloc) {}
124
125  template <class InputIt>
126  SrcMap(InputIt first, InputIt last, const Allocator& alloc)
127      : std::vector<SrcMapElem, Allocator>(first, last, alloc) {}
128
129  void push_back(const SrcMapElem& elem) {
130    if (!empty()) {
131      // Check that the addresses are inserted in sorted order.
132      DCHECK_GE(elem.from_, this->back().from_);
133      // If two consequitive entries map to the same value, ignore the later.
134      // E.g. for map {{0, 1}, {4, 1}, {8, 2}}, all values in [0,8) map to 1.
135      if (elem.to_ == this->back().to_) {
136        return;
137      }
138    }
139    std::vector<SrcMapElem, Allocator>::push_back(elem);
140  }
141
142  // Returns true and the corresponding "to" value if the mapping is found.
143  // Oterwise returns false and 0.
144  std::pair<bool, int32_t> Find(uint32_t from) const {
145    // Finds first mapping such that lb.from_ >= from.
146    auto lb = std::lower_bound(begin(), end(), SrcMapElem {from, INT32_MIN});
147    if (lb != end() && lb->from_ == from) {
148      // Found exact match.
149      return std::make_pair(true, lb->to_);
150    } else if (lb != begin()) {
151      // The previous mapping is still in effect.
152      return std::make_pair(true, (--lb)->to_);
153    } else {
154      // Not found because 'from' is smaller than first entry in the map.
155      return std::make_pair(false, 0);
156    }
157  }
158};
159
160using DefaultSrcMap = SrcMap<std::allocator<SrcMapElem>>;
161
162class LinkerPatch {
163 public:
164  // Note: We explicitly specify the underlying type of the enum because GCC
165  // would otherwise select a bigger underlying type and then complain that
166  //     'art::LinkerPatch::patch_type_' is too small to hold all
167  //     values of 'enum class art::LinkerPatch::Type'
168  // which is ridiculous given we have only a handful of values here. If we
169  // choose to squeeze the Type into fewer than 8 bits, we'll have to declare
170  // patch_type_ as an uintN_t and do explicit static_cast<>s.
171  enum class Type : uint8_t {
172    kRecordPosition,   // Just record patch position for patchoat.
173    kMethod,
174    kCall,
175    kCallRelative,     // NOTE: Actual patching is instruction_set-dependent.
176    kType,
177    kString,
178    kStringRelative,   // NOTE: Actual patching is instruction_set-dependent.
179    kDexCacheArray,    // NOTE: Actual patching is instruction_set-dependent.
180  };
181
182  static LinkerPatch RecordPosition(size_t literal_offset) {
183    return LinkerPatch(literal_offset, Type::kRecordPosition, /* target_dex_file */ nullptr);
184  }
185
186  static LinkerPatch MethodPatch(size_t literal_offset,
187                                 const DexFile* target_dex_file,
188                                 uint32_t target_method_idx) {
189    LinkerPatch patch(literal_offset, Type::kMethod, target_dex_file);
190    patch.method_idx_ = target_method_idx;
191    return patch;
192  }
193
194  static LinkerPatch CodePatch(size_t literal_offset,
195                               const DexFile* target_dex_file,
196                               uint32_t target_method_idx) {
197    LinkerPatch patch(literal_offset, Type::kCall, target_dex_file);
198    patch.method_idx_ = target_method_idx;
199    return patch;
200  }
201
202  static LinkerPatch RelativeCodePatch(size_t literal_offset,
203                                       const DexFile* target_dex_file,
204                                       uint32_t target_method_idx) {
205    LinkerPatch patch(literal_offset, Type::kCallRelative, target_dex_file);
206    patch.method_idx_ = target_method_idx;
207    return patch;
208  }
209
210  static LinkerPatch TypePatch(size_t literal_offset,
211                               const DexFile* target_dex_file,
212                               uint32_t target_type_idx) {
213    LinkerPatch patch(literal_offset, Type::kType, target_dex_file);
214    patch.type_idx_ = target_type_idx;
215    return patch;
216  }
217
218  static LinkerPatch StringPatch(size_t literal_offset,
219                                 const DexFile* target_dex_file,
220                                 uint32_t target_string_idx) {
221    LinkerPatch patch(literal_offset, Type::kString, target_dex_file);
222    patch.string_idx_ = target_string_idx;
223    return patch;
224  }
225
226  static LinkerPatch RelativeStringPatch(size_t literal_offset,
227                                         const DexFile* target_dex_file,
228                                         uint32_t pc_insn_offset,
229                                         uint32_t target_string_idx) {
230    LinkerPatch patch(literal_offset, Type::kStringRelative, target_dex_file);
231    patch.string_idx_ = target_string_idx;
232    patch.pc_insn_offset_ = pc_insn_offset;
233    return patch;
234  }
235
236  static LinkerPatch DexCacheArrayPatch(size_t literal_offset,
237                                        const DexFile* target_dex_file,
238                                        uint32_t pc_insn_offset,
239                                        size_t element_offset) {
240    DCHECK(IsUint<32>(element_offset));
241    LinkerPatch patch(literal_offset, Type::kDexCacheArray, target_dex_file);
242    patch.pc_insn_offset_ = pc_insn_offset;
243    patch.element_offset_ = element_offset;
244    return patch;
245  }
246
247  LinkerPatch(const LinkerPatch& other) = default;
248  LinkerPatch& operator=(const LinkerPatch& other) = default;
249
250  size_t LiteralOffset() const {
251    return literal_offset_;
252  }
253
254  Type GetType() const {
255    return patch_type_;
256  }
257
258  bool IsPcRelative() const {
259    switch (GetType()) {
260      case Type::kCallRelative:
261      case Type::kStringRelative:
262      case Type::kDexCacheArray:
263        return true;
264      default:
265        return false;
266    }
267  }
268
269  MethodReference TargetMethod() const {
270    DCHECK(patch_type_ == Type::kMethod ||
271           patch_type_ == Type::kCall ||
272           patch_type_ == Type::kCallRelative);
273    return MethodReference(target_dex_file_, method_idx_);
274  }
275
276  const DexFile* TargetTypeDexFile() const {
277    DCHECK(patch_type_ == Type::kType);
278    return target_dex_file_;
279  }
280
281  uint32_t TargetTypeIndex() const {
282    DCHECK(patch_type_ == Type::kType);
283    return type_idx_;
284  }
285
286  const DexFile* TargetStringDexFile() const {
287    DCHECK(patch_type_ == Type::kString || patch_type_ == Type::kStringRelative);
288    return target_dex_file_;
289  }
290
291  uint32_t TargetStringIndex() const {
292    DCHECK(patch_type_ == Type::kString || patch_type_ == Type::kStringRelative);
293    return string_idx_;
294  }
295
296  const DexFile* TargetDexCacheDexFile() const {
297    DCHECK(patch_type_ == Type::kDexCacheArray);
298    return target_dex_file_;
299  }
300
301  size_t TargetDexCacheElementOffset() const {
302    DCHECK(patch_type_ == Type::kDexCacheArray);
303    return element_offset_;
304  }
305
306  uint32_t PcInsnOffset() const {
307    DCHECK(patch_type_ == Type::kStringRelative || patch_type_ == Type::kDexCacheArray);
308    return pc_insn_offset_;
309  }
310
311 private:
312  LinkerPatch(size_t literal_offset, Type patch_type, const DexFile* target_dex_file)
313      : target_dex_file_(target_dex_file),
314        literal_offset_(literal_offset),
315        patch_type_(patch_type) {
316    cmp1_ = 0u;
317    cmp2_ = 0u;
318    // The compiler rejects methods that are too big, so the compiled code
319    // of a single method really shouln't be anywhere close to 16MiB.
320    DCHECK(IsUint<24>(literal_offset));
321  }
322
323  const DexFile* target_dex_file_;
324  uint32_t literal_offset_ : 24;  // Method code size up to 16MiB.
325  Type patch_type_ : 8;
326  union {
327    uint32_t cmp1_;             // Used for relational operators.
328    uint32_t method_idx_;       // Method index for Call/Method patches.
329    uint32_t type_idx_;         // Type index for Type patches.
330    uint32_t string_idx_;       // String index for String patches.
331    uint32_t element_offset_;   // Element offset in the dex cache arrays.
332    static_assert(sizeof(method_idx_) == sizeof(cmp1_), "needed by relational operators");
333    static_assert(sizeof(type_idx_) == sizeof(cmp1_), "needed by relational operators");
334    static_assert(sizeof(string_idx_) == sizeof(cmp1_), "needed by relational operators");
335    static_assert(sizeof(element_offset_) == sizeof(cmp1_), "needed by relational operators");
336  };
337  union {
338    // Note: To avoid uninitialized padding on 64-bit systems, we use `size_t` for `cmp2_`.
339    // This allows a hashing function to treat an array of linker patches as raw memory.
340    size_t cmp2_;             // Used for relational operators.
341    // Literal offset of the insn loading PC (same as literal_offset if it's the same insn,
342    // may be different if the PC-relative addressing needs multiple insns).
343    uint32_t pc_insn_offset_;
344    static_assert(sizeof(pc_insn_offset_) <= sizeof(cmp2_), "needed by relational operators");
345  };
346
347  friend bool operator==(const LinkerPatch& lhs, const LinkerPatch& rhs);
348  friend bool operator<(const LinkerPatch& lhs, const LinkerPatch& rhs);
349};
350std::ostream& operator<<(std::ostream& os, const LinkerPatch::Type& type);
351
352inline bool operator==(const LinkerPatch& lhs, const LinkerPatch& rhs) {
353  return lhs.literal_offset_ == rhs.literal_offset_ &&
354      lhs.patch_type_ == rhs.patch_type_ &&
355      lhs.target_dex_file_ == rhs.target_dex_file_ &&
356      lhs.cmp1_ == rhs.cmp1_ &&
357      lhs.cmp2_ == rhs.cmp2_;
358}
359
360inline bool operator<(const LinkerPatch& lhs, const LinkerPatch& rhs) {
361  return (lhs.literal_offset_ != rhs.literal_offset_) ? lhs.literal_offset_ < rhs.literal_offset_
362      : (lhs.patch_type_ != rhs.patch_type_) ? lhs.patch_type_ < rhs.patch_type_
363      : (lhs.target_dex_file_ != rhs.target_dex_file_) ? lhs.target_dex_file_ < rhs.target_dex_file_
364      : (lhs.cmp1_ != rhs.cmp1_) ? lhs.cmp1_ < rhs.cmp1_
365      : lhs.cmp2_ < rhs.cmp2_;
366}
367
368class CompiledMethod FINAL : public CompiledCode {
369 public:
370  // Constructs a CompiledMethod.
371  // Note: Consider using the static allocation methods below that will allocate the CompiledMethod
372  //       in the swap space.
373  CompiledMethod(CompilerDriver* driver,
374                 InstructionSet instruction_set,
375                 const ArrayRef<const uint8_t>& quick_code,
376                 const size_t frame_size_in_bytes,
377                 const uint32_t core_spill_mask,
378                 const uint32_t fp_spill_mask,
379                 const ArrayRef<const SrcMapElem>& src_mapping_table,
380                 const ArrayRef<const uint8_t>& vmap_table,
381                 const ArrayRef<const uint8_t>& cfi_info,
382                 const ArrayRef<const LinkerPatch>& patches);
383
384  virtual ~CompiledMethod();
385
386  static CompiledMethod* SwapAllocCompiledMethod(
387      CompilerDriver* driver,
388      InstructionSet instruction_set,
389      const ArrayRef<const uint8_t>& quick_code,
390      const size_t frame_size_in_bytes,
391      const uint32_t core_spill_mask,
392      const uint32_t fp_spill_mask,
393      const ArrayRef<const SrcMapElem>& src_mapping_table,
394      const ArrayRef<const uint8_t>& vmap_table,
395      const ArrayRef<const uint8_t>& cfi_info,
396      const ArrayRef<const LinkerPatch>& patches);
397
398  static void ReleaseSwapAllocatedCompiledMethod(CompilerDriver* driver, CompiledMethod* m);
399
400  size_t GetFrameSizeInBytes() const {
401    return frame_size_in_bytes_;
402  }
403
404  uint32_t GetCoreSpillMask() const {
405    return core_spill_mask_;
406  }
407
408  uint32_t GetFpSpillMask() const {
409    return fp_spill_mask_;
410  }
411
412  ArrayRef<const SrcMapElem> GetSrcMappingTable() const {
413    return GetArray(src_mapping_table_);
414  }
415
416  ArrayRef<const uint8_t> GetVmapTable() const {
417    return GetArray(vmap_table_);
418  }
419
420  ArrayRef<const uint8_t> GetCFIInfo() const {
421    return GetArray(cfi_info_);
422  }
423
424  ArrayRef<const LinkerPatch> GetPatches() const {
425    return GetArray(patches_);
426  }
427
428 private:
429  // For quick code, the size of the activation used by the code.
430  const size_t frame_size_in_bytes_;
431  // For quick code, a bit mask describing spilled GPR callee-save registers.
432  const uint32_t core_spill_mask_;
433  // For quick code, a bit mask describing spilled FPR callee-save registers.
434  const uint32_t fp_spill_mask_;
435  // For quick code, a set of pairs (PC, DEX) mapping from native PC offset to DEX offset.
436  const LengthPrefixedArray<SrcMapElem>* const src_mapping_table_;
437  // For quick code, a uleb128 encoded map from GPR/FPR register to dex register. Size prefixed.
438  const LengthPrefixedArray<uint8_t>* const vmap_table_;
439  // For quick code, a FDE entry for the debug_frame section.
440  const LengthPrefixedArray<uint8_t>* const cfi_info_;
441  // For quick code, linker patches needed by the method.
442  const LengthPrefixedArray<LinkerPatch>* const patches_;
443};
444
445}  // namespace art
446
447#endif  // ART_COMPILER_COMPILED_METHOD_H_
448