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1 // Copyright 2017 the V8 project authors. All rights reserved.
2 // Use of this source code is governed by a BSD-style license that can be
3 // found in the LICENSE file.
4 
5 #ifndef V8_BUILTINS_BUILTINS_REGEXP_GEN_H_
6 #define V8_BUILTINS_BUILTINS_REGEXP_GEN_H_
7 
8 #include "src/base/optional.h"
9 #include "src/codegen/code-stub-assembler.h"
10 #include "src/common/message-template.h"
11 
12 namespace v8 {
13 namespace internal {
14 
15 class RegExpBuiltinsAssembler : public CodeStubAssembler {
16  public:
RegExpBuiltinsAssembler(compiler::CodeAssemblerState * state)17   explicit RegExpBuiltinsAssembler(compiler::CodeAssemblerState* state)
18       : CodeStubAssembler(state) {}
19 
20   TNode<Smi> SmiZero();
21   TNode<IntPtrT> IntPtrZero();
22 
23   TNode<RawPtrT> LoadCodeObjectEntry(TNode<Code> code);
24 
25   // Allocate a RegExpResult with the given length (the number of captures,
26   // including the match itself), index (the index where the match starts),
27   // and input string.
28   TNode<JSRegExpResult> AllocateRegExpResult(
29       TNode<Context> context, TNode<Smi> length, TNode<Smi> index,
30       TNode<String> input, TNode<JSRegExp> regexp, TNode<Number> last_index,
31       TNode<FixedArray>* elements_out = nullptr);
32 
33   TNode<Object> FastLoadLastIndexBeforeSmiCheck(TNode<JSRegExp> regexp);
FastLoadLastIndex(TNode<JSRegExp> regexp)34   TNode<Smi> FastLoadLastIndex(TNode<JSRegExp> regexp) {
35     return CAST(FastLoadLastIndexBeforeSmiCheck(regexp));
36   }
37   TNode<Object> SlowLoadLastIndex(TNode<Context> context, TNode<Object> regexp);
38 
39   void FastStoreLastIndex(TNode<JSRegExp> regexp, TNode<Smi> value);
40   void SlowStoreLastIndex(TNode<Context> context, TNode<Object> regexp,
41                           TNode<Object> value);
42 
43   // Loads {var_string_start} and {var_string_end} with the corresponding
44   // offsets into the given {string_data}.
45   void GetStringPointers(TNode<RawPtrT> string_data, TNode<IntPtrT> offset,
46                          TNode<IntPtrT> last_index,
47                          TNode<IntPtrT> string_length,
48                          String::Encoding encoding,
49                          TVariable<RawPtrT>* var_string_start,
50                          TVariable<RawPtrT>* var_string_end);
51 
52   // Low level logic around the actual call into pattern matching code.
53   TNode<HeapObject> RegExpExecInternal(TNode<Context> context,
54                                        TNode<JSRegExp> regexp,
55                                        TNode<String> string,
56                                        TNode<Number> last_index,
57                                        TNode<RegExpMatchInfo> match_info);
58 
59   TNode<JSRegExpResult> ConstructNewResultFromMatchInfo(
60       TNode<Context> context, TNode<JSRegExp> regexp,
61       TNode<RegExpMatchInfo> match_info, TNode<String> string,
62       TNode<Number> last_index);
63 
64   // Fast path check logic.
65   //
66   // Are you afraid? If not, you should be.
67   //
68   // It's complicated. Fast path checks protect certain assumptions, e.g. that
69   // relevant properties on the regexp prototype (such as exec, @@split, global)
70   // are unmodified.
71   //
72   // These assumptions differ by callsite. For example, RegExpPrototypeExec
73   // cares whether the exec property has been modified; but it's totally fine
74   // to modify other prototype properties. On the other hand,
75   // StringPrototypeSplit does care very much whether @@split has been changed.
76   //
77   // We want to keep regexp execution on the fast path as much as possible.
78   // Ideally, we could simply check if the regexp prototype has been modified;
79   // yet common web frameworks routinely mutate it for various reasons. But most
80   // of these mutations should happen in a way that still allows us to remain
81   // on the fast path. To support this, the fast path check logic necessarily
82   // becomes more involved.
83   //
84   // There are multiple knobs to twiddle for regexp fast path checks. We support
85   // checks that completely ignore the prototype, checks that verify specific
86   // properties on the prototype (the caller must ensure it passes in the right
87   // ones), and strict checks that additionally ensure the prototype is
88   // unchanged (we use these when we'd have to check multiple properties we
89   // don't care too much about, e.g. all individual flag getters).
90 
91   using DescriptorIndexNameValue =
92       PrototypeCheckAssembler::DescriptorIndexNameValue;
93 
94   void BranchIfFastRegExp(
95       TNode<Context> context, TNode<HeapObject> object, TNode<Map> map,
96       PrototypeCheckAssembler::Flags prototype_check_flags,
97       base::Optional<DescriptorIndexNameValue> additional_property_to_check,
98       Label* if_isunmodified, Label* if_ismodified);
99 
100   // Strict: Does not tolerate any changes to the prototype map.
101   // Permissive: Allows changes to the prototype map except for the exec
102   //             property.
103   void BranchIfFastRegExp_Strict(TNode<Context> context,
104                                  TNode<HeapObject> object,
105                                  Label* if_isunmodified, Label* if_ismodified);
106   void BranchIfFastRegExp_Permissive(TNode<Context> context,
107                                      TNode<HeapObject> object,
108                                      Label* if_isunmodified,
109                                      Label* if_ismodified);
110 
111   // Performs fast path checks on the given object itself, but omits prototype
112   // checks.
113   TNode<BoolT> IsFastRegExpNoPrototype(TNode<Context> context,
114                                        TNode<Object> object);
115   TNode<BoolT> IsFastRegExpNoPrototype(TNode<Context> context,
116                                        TNode<Object> object, TNode<Map> map);
117 
118   void BranchIfRegExpResult(const TNode<Context> context,
119                             const TNode<Object> object, Label* if_isunmodified,
120                             Label* if_ismodified);
121 
122   TNode<String> FlagsGetter(TNode<Context> context, TNode<Object> regexp,
123                             const bool is_fastpath);
124 
125   TNode<BoolT> FastFlagGetter(TNode<JSRegExp> regexp, JSRegExp::Flag flag);
FastFlagGetterGlobal(TNode<JSRegExp> regexp)126   TNode<BoolT> FastFlagGetterGlobal(TNode<JSRegExp> regexp) {
127     return FastFlagGetter(regexp, JSRegExp::kGlobal);
128   }
FastFlagGetterUnicode(TNode<JSRegExp> regexp)129   TNode<BoolT> FastFlagGetterUnicode(TNode<JSRegExp> regexp) {
130     return FastFlagGetter(regexp, JSRegExp::kUnicode);
131   }
132   TNode<BoolT> SlowFlagGetter(TNode<Context> context, TNode<Object> regexp,
133                               JSRegExp::Flag flag);
134   TNode<BoolT> FlagGetter(TNode<Context> context, TNode<Object> regexp,
135                           JSRegExp::Flag flag, bool is_fastpath);
136 
137   TNode<Object> RegExpInitialize(const TNode<Context> context,
138                                  const TNode<JSRegExp> regexp,
139                                  const TNode<Object> maybe_pattern,
140                                  const TNode<Object> maybe_flags);
141 
142   TNode<Number> AdvanceStringIndex(TNode<String> string, TNode<Number> index,
143                                    TNode<BoolT> is_unicode, bool is_fastpath);
144 
AdvanceStringIndexFast(TNode<String> string,TNode<Smi> index,TNode<BoolT> is_unicode)145   TNode<Smi> AdvanceStringIndexFast(TNode<String> string, TNode<Smi> index,
146                                     TNode<BoolT> is_unicode) {
147     return CAST(AdvanceStringIndex(string, index, is_unicode, true));
148   }
149 
AdvanceStringIndexSlow(TNode<String> string,TNode<Number> index,TNode<BoolT> is_unicode)150   TNode<Smi> AdvanceStringIndexSlow(TNode<String> string, TNode<Number> index,
151                                     TNode<BoolT> is_unicode) {
152     return CAST(AdvanceStringIndex(string, index, is_unicode, false));
153   }
154 
155   TNode<JSArray> RegExpPrototypeSplitBody(TNode<Context> context,
156                                           TNode<JSRegExp> regexp,
157                                           const TNode<String> string,
158                                           const TNode<Smi> limit);
159 };
160 
161 class RegExpMatchAllAssembler : public RegExpBuiltinsAssembler {
162  public:
RegExpMatchAllAssembler(compiler::CodeAssemblerState * state)163   explicit RegExpMatchAllAssembler(compiler::CodeAssemblerState* state)
164       : RegExpBuiltinsAssembler(state) {}
165 
166   TNode<Object> CreateRegExpStringIterator(TNode<NativeContext> native_context,
167                                            TNode<Object> regexp,
168                                            TNode<String> string,
169                                            TNode<BoolT> global,
170                                            TNode<BoolT> full_unicode);
171 };
172 
173 }  // namespace internal
174 }  // namespace v8
175 
176 #endif  // V8_BUILTINS_BUILTINS_REGEXP_GEN_H_
177