1 // Copyright 2008 the V8 project authors. All rights reserved.
2 // Redistribution and use in source and binary forms, with or without
3 // modification, are permitted provided that the following conditions are
4 // met:
5 //
6 // * Redistributions of source code must retain the above copyright
7 // notice, this list of conditions and the following disclaimer.
8 // * Redistributions in binary form must reproduce the above
9 // copyright notice, this list of conditions and the following
10 // disclaimer in the documentation and/or other materials provided
11 // with the distribution.
12 // * Neither the name of Google Inc. nor the names of its
13 // contributors may be used to endorse or promote products derived
14 // from this software without specific prior written permission.
15 //
16 // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
17 // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
18 // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
19 // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
20 // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
21 // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
22 // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23 // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24 // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
26 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27
28 #include "v8.h"
29 #include "ast.h"
30 #include "assembler.h"
31 #include "regexp-stack.h"
32 #include "regexp-macro-assembler.h"
33 #if V8_TARGET_ARCH_ARM
34 #include "arm/simulator-arm.h"
35 #elif V8_TARGET_ARCH_IA32
36 #include "ia32/simulator-ia32.h"
37 #elif V8_TARGET_ARCH_X64
38 #include "x64/simulator-x64.h"
39 #endif
40
41 namespace v8 {
42 namespace internal {
43
RegExpMacroAssembler()44 RegExpMacroAssembler::RegExpMacroAssembler() {
45 }
46
47
~RegExpMacroAssembler()48 RegExpMacroAssembler::~RegExpMacroAssembler() {
49 }
50
51
CanReadUnaligned()52 bool RegExpMacroAssembler::CanReadUnaligned() {
53 #ifdef V8_HOST_CAN_READ_UNALIGNED
54 return true;
55 #else
56 return false;
57 #endif
58 }
59
60
61 #ifdef V8_NATIVE_REGEXP // Avoid unused code, e.g., on ARM.
62
NativeRegExpMacroAssembler()63 NativeRegExpMacroAssembler::NativeRegExpMacroAssembler() {
64 }
65
66
~NativeRegExpMacroAssembler()67 NativeRegExpMacroAssembler::~NativeRegExpMacroAssembler() {
68 }
69
70
CanReadUnaligned()71 bool NativeRegExpMacroAssembler::CanReadUnaligned() {
72 #ifdef V8_TARGET_CAN_READ_UNALIGNED
73 return true;
74 #else
75 return false;
76 #endif
77 }
78
StringCharacterPosition(String * subject,int start_index)79 const byte* NativeRegExpMacroAssembler::StringCharacterPosition(
80 String* subject,
81 int start_index) {
82 // Not just flat, but ultra flat.
83 ASSERT(subject->IsExternalString() || subject->IsSeqString());
84 ASSERT(start_index >= 0);
85 ASSERT(start_index <= subject->length());
86 if (subject->IsAsciiRepresentation()) {
87 const byte* address;
88 if (StringShape(subject).IsExternal()) {
89 const char* data = ExternalAsciiString::cast(subject)->resource()->data();
90 address = reinterpret_cast<const byte*>(data);
91 } else {
92 ASSERT(subject->IsSeqAsciiString());
93 char* data = SeqAsciiString::cast(subject)->GetChars();
94 address = reinterpret_cast<const byte*>(data);
95 }
96 return address + start_index;
97 }
98 const uc16* data;
99 if (StringShape(subject).IsExternal()) {
100 data = ExternalTwoByteString::cast(subject)->resource()->data();
101 } else {
102 ASSERT(subject->IsSeqTwoByteString());
103 data = SeqTwoByteString::cast(subject)->GetChars();
104 }
105 return reinterpret_cast<const byte*>(data + start_index);
106 }
107
108
Match(Handle<Code> regexp_code,Handle<String> subject,int * offsets_vector,int offsets_vector_length,int previous_index)109 NativeRegExpMacroAssembler::Result NativeRegExpMacroAssembler::Match(
110 Handle<Code> regexp_code,
111 Handle<String> subject,
112 int* offsets_vector,
113 int offsets_vector_length,
114 int previous_index) {
115
116 ASSERT(subject->IsFlat());
117 ASSERT(previous_index >= 0);
118 ASSERT(previous_index <= subject->length());
119
120 // No allocations before calling the regexp, but we can't use
121 // AssertNoAllocation, since regexps might be preempted, and another thread
122 // might do allocation anyway.
123
124 String* subject_ptr = *subject;
125 // Character offsets into string.
126 int start_offset = previous_index;
127 int end_offset = subject_ptr->length();
128
129 bool is_ascii = subject->IsAsciiRepresentation();
130
131 if (StringShape(subject_ptr).IsCons()) {
132 subject_ptr = ConsString::cast(subject_ptr)->first();
133 } else if (StringShape(subject_ptr).IsSliced()) {
134 SlicedString* slice = SlicedString::cast(subject_ptr);
135 start_offset += slice->start();
136 end_offset += slice->start();
137 subject_ptr = slice->buffer();
138 }
139 // Ensure that an underlying string has the same ascii-ness.
140 ASSERT(subject_ptr->IsAsciiRepresentation() == is_ascii);
141 ASSERT(subject_ptr->IsExternalString() || subject_ptr->IsSeqString());
142 // String is now either Sequential or External
143 int char_size_shift = is_ascii ? 0 : 1;
144 int char_length = end_offset - start_offset;
145
146 const byte* input_start =
147 StringCharacterPosition(subject_ptr, start_offset);
148 int byte_length = char_length << char_size_shift;
149 const byte* input_end = input_start + byte_length;
150 Result res = Execute(*regexp_code,
151 subject_ptr,
152 start_offset,
153 input_start,
154 input_end,
155 offsets_vector,
156 previous_index == 0);
157
158 if (res == SUCCESS) {
159 // Capture values are relative to start_offset only.
160 // Convert them to be relative to start of string.
161 for (int i = 0; i < offsets_vector_length; i++) {
162 if (offsets_vector[i] >= 0) {
163 offsets_vector[i] += previous_index;
164 }
165 }
166 }
167
168 return res;
169 }
170
171
Execute(Code * code,String * input,int start_offset,const byte * input_start,const byte * input_end,int * output,bool at_start)172 NativeRegExpMacroAssembler::Result NativeRegExpMacroAssembler::Execute(
173 Code* code,
174 String* input,
175 int start_offset,
176 const byte* input_start,
177 const byte* input_end,
178 int* output,
179 bool at_start) {
180 typedef int (*matcher)(String*, int, const byte*,
181 const byte*, int*, int, Address);
182 matcher matcher_func = FUNCTION_CAST<matcher>(code->entry());
183
184 int at_start_val = at_start ? 1 : 0;
185
186 // Ensure that the minimum stack has been allocated.
187 RegExpStack stack;
188 Address stack_base = RegExpStack::stack_base();
189
190 int result = CALL_GENERATED_REGEXP_CODE(matcher_func,
191 input,
192 start_offset,
193 input_start,
194 input_end,
195 output,
196 at_start_val,
197 stack_base);
198 ASSERT(result <= SUCCESS);
199 ASSERT(result >= RETRY);
200
201 if (result == EXCEPTION && !Top::has_pending_exception()) {
202 // We detected a stack overflow (on the backtrack stack) in RegExp code,
203 // but haven't created the exception yet.
204 Top::StackOverflow();
205 }
206 return static_cast<Result>(result);
207 }
208
209
210 static unibrow::Mapping<unibrow::Ecma262Canonicalize> canonicalize;
211
CaseInsensitiveCompareUC16(Address byte_offset1,Address byte_offset2,size_t byte_length)212 int NativeRegExpMacroAssembler::CaseInsensitiveCompareUC16(
213 Address byte_offset1,
214 Address byte_offset2,
215 size_t byte_length) {
216 // This function is not allowed to cause a garbage collection.
217 // A GC might move the calling generated code and invalidate the
218 // return address on the stack.
219 ASSERT(byte_length % 2 == 0);
220 uc16* substring1 = reinterpret_cast<uc16*>(byte_offset1);
221 uc16* substring2 = reinterpret_cast<uc16*>(byte_offset2);
222 size_t length = byte_length >> 1;
223
224 for (size_t i = 0; i < length; i++) {
225 unibrow::uchar c1 = substring1[i];
226 unibrow::uchar c2 = substring2[i];
227 if (c1 != c2) {
228 unibrow::uchar s1[1] = { c1 };
229 canonicalize.get(c1, '\0', s1);
230 if (s1[0] != c2) {
231 unibrow::uchar s2[1] = { c2 };
232 canonicalize.get(c2, '\0', s2);
233 if (s1[0] != s2[0]) {
234 return 0;
235 }
236 }
237 }
238 }
239 return 1;
240 }
241
242
GrowStack(Address stack_pointer,Address * stack_base)243 Address NativeRegExpMacroAssembler::GrowStack(Address stack_pointer,
244 Address* stack_base) {
245 size_t size = RegExpStack::stack_capacity();
246 Address old_stack_base = RegExpStack::stack_base();
247 ASSERT(old_stack_base == *stack_base);
248 ASSERT(stack_pointer <= old_stack_base);
249 ASSERT(static_cast<size_t>(old_stack_base - stack_pointer) <= size);
250 Address new_stack_base = RegExpStack::EnsureCapacity(size * 2);
251 if (new_stack_base == NULL) {
252 return NULL;
253 }
254 *stack_base = new_stack_base;
255 intptr_t stack_content_size = old_stack_base - stack_pointer;
256 return new_stack_base - stack_content_size;
257 }
258
259 #endif // V8_NATIVE_REGEXP
260 } } // namespace v8::internal
261