#include "v8.h"
#include "unicode.h"
#include "log.h"
#include "ast.h"
#include "regexp-stack.h"
#include "macro-assembler.h"
#include "regexp-macro-assembler.h"
#include "ia32/macro-assembler-ia32.h"
#include "ia32/regexp-macro-assembler-ia32.h"
namespace v8 {
namespace internal {
#ifdef V8_NATIVE_REGEXP
/*
* This assembler uses the following register assignment convention
* - edx : current character. Must be loaded using LoadCurrentCharacter
* before using any of the dispatch methods.
* - edi : current position in input, as negative offset from end of string.
* Please notice that this is the byte offset, not the character offset!
* - esi : end of input (points to byte after last character in input).
* - ebp : frame pointer. Used to access arguments, local variables and
* RegExp registers.
* - esp : points to tip of C stack.
* - ecx : points to tip of backtrack stack
*
* The registers eax, ebx and ecx are free to use for computations.
*
* Each call to a public method should retain this convention.
* The stack will have the following structure:
* - direct_call (if 1, direct call from JavaScript code, if 0
* call through the runtime system)
* - stack_area_base (High end of the memory area to use as
* backtracking stack)
* - int* capture_array (int[num_saved_registers_], for output).
* - end of input (Address of end of string)
* - start of input (Address of first character in string)
* - start index (character index of start)
* - String* input_string (location of a handle containing the string)
* --- frame alignment (if applicable) ---
* - return address
* ebp-> - old ebp
* - backup of caller esi
* - backup of caller edi
* - backup of caller ebx
* - Offset of location before start of input (effectively character
* position -1). Used to initialize capture registers to a non-position.
* - Boolean at start (if 1, we are starting at the start of the string,
* otherwise 0)
* - register 0 ebp[-4] (Only positions must be stored in the first
* - register 1 ebp[-8] num_saved_registers_ registers)
* - ...
*
* The first num_saved_registers_ registers are initialized to point to
* "character -1" in the string (i.e., char_size() bytes before the first
* character of the string). The remaining registers starts out as garbage.
*
* The data up to the return address must be placed there by the calling
* code, by calling the code entry as cast to a function with the signature:
* int (*match)(String* input_string,
* int start_index,
* Address start,
* Address end,
* int* capture_output_array,
* bool at_start,
* byte* stack_area_base,
* bool direct_call)
*/
#define __ ACCESS_MASM(masm_)
RegExpMacroAssemblerIA32::RegExpMacroAssemblerIA32(
Mode mode,
int registers_to_save)
: masm_(new MacroAssembler(NULL, kRegExpCodeSize)),
mode_(mode),
num_registers_(registers_to_save),
num_saved_registers_(registers_to_save),
entry_label_(),
start_label_(),
success_label_(),
backtrack_label_(),
exit_label_() {
ASSERT_EQ(0, registers_to_save % 2);
__ jmp(&entry_label_); // We'll write the entry code later.
__ bind(&start_label_); // And then continue from here.
}
RegExpMacroAssemblerIA32::~RegExpMacroAssemblerIA32() {
delete masm_;
// Unuse labels in case we throw away the assembler without calling GetCode.
entry_label_.Unuse();
start_label_.Unuse();
success_label_.Unuse();
backtrack_label_.Unuse();
exit_label_.Unuse();
check_preempt_label_.Unuse();
stack_overflow_label_.Unuse();
}
int RegExpMacroAssemblerIA32::stack_limit_slack() {
return RegExpStack::kStackLimitSlack;
}
void RegExpMacroAssemblerIA32::AdvanceCurrentPosition(int by) {
if (by != 0) {
Label inside_string;
__ add(Operand(edi), Immediate(by * char_size()));
}
}
void RegExpMacroAssemblerIA32::AdvanceRegister(int reg, int by) {
ASSERT(reg >= 0);
ASSERT(reg < num_registers_);
if (by != 0) {
__ add(register_location(reg), Immediate(by));
}
}
void RegExpMacroAssemblerIA32::Backtrack() {
CheckPreemption();
// Pop Code* offset from backtrack stack, add Code* and jump to location.
Pop(ebx);
__ add(Operand(ebx), Immediate(masm_->CodeObject()));
__ jmp(Operand(ebx));
}
void RegExpMacroAssemblerIA32::Bind(Label* label) {
__ bind(label);
}
void RegExpMacroAssemblerIA32::CheckCharacter(uint32_t c, Label* on_equal) {
__ cmp(current_character(), c);
BranchOrBacktrack(equal, on_equal);
}
void RegExpMacroAssemblerIA32::CheckCharacterGT(uc16 limit, Label* on_greater) {
__ cmp(current_character(), limit);
BranchOrBacktrack(greater, on_greater);
}
void RegExpMacroAssemblerIA32::CheckAtStart(Label* on_at_start) {
Label not_at_start;
// Did we start the match at the start of the string at all?
__ cmp(Operand(ebp, kAtStart), Immediate(0));
BranchOrBacktrack(equal, ¬_at_start);
// If we did, are we still at the start of the input?
__ lea(eax, Operand(esi, edi, times_1, 0));
__ cmp(eax, Operand(ebp, kInputStart));
BranchOrBacktrack(equal, on_at_start);
__ bind(¬_at_start);
}
void RegExpMacroAssemblerIA32::CheckNotAtStart(Label* on_not_at_start) {
// Did we start the match at the start of the string at all?
__ cmp(Operand(ebp, kAtStart), Immediate(0));
BranchOrBacktrack(equal, on_not_at_start);
// If we did, are we still at the start of the input?
__ lea(eax, Operand(esi, edi, times_1, 0));
__ cmp(eax, Operand(ebp, kInputStart));
BranchOrBacktrack(not_equal, on_not_at_start);
}
void RegExpMacroAssemblerIA32::CheckCharacterLT(uc16 limit, Label* on_less) {
__ cmp(current_character(), limit);
BranchOrBacktrack(less, on_less);
}
void RegExpMacroAssemblerIA32::CheckCharacters(Vector<const uc16> str,
int cp_offset,
Label* on_failure,
bool check_end_of_string) {
int byte_length = str.length() * char_size();
int byte_offset = cp_offset * char_size();
if (check_end_of_string) {
// Check that there are at least str.length() characters left in the input.
__ cmp(Operand(edi), Immediate(-(byte_offset + byte_length)));
BranchOrBacktrack(greater, on_failure);
}
if (on_failure == NULL) {
// Instead of inlining a backtrack, (re)use the global backtrack target.
on_failure = &backtrack_label_;
}
for (int i = 0; i < str.length(); i++) {
if (mode_ == ASCII) {
__ cmpb(Operand(esi, edi, times_1, byte_offset + i),
static_cast<int8_t>(str[i]));
} else {
ASSERT(mode_ == UC16);
__ cmpw(Operand(esi, edi, times_1, byte_offset + i * sizeof(uc16)),
Immediate(str[i]));
}
BranchOrBacktrack(not_equal, on_failure);
}
}
void RegExpMacroAssemblerIA32::CheckGreedyLoop(Label* on_equal) {
Label fallthrough;
__ cmp(edi, Operand(backtrack_stackpointer(), 0));
__ j(not_equal, &fallthrough);
__ add(Operand(backtrack_stackpointer()), Immediate(kPointerSize)); // Pop.
BranchOrBacktrack(no_condition, on_equal);
__ bind(&fallthrough);
}
void RegExpMacroAssemblerIA32::CheckNotBackReferenceIgnoreCase(
int start_reg,
Label* on_no_match) {
Label fallthrough;
__ mov(edx, register_location(start_reg)); // Index of start of capture
__ mov(ebx, register_location(start_reg + 1)); // Index of end of capture
__ sub(ebx, Operand(edx)); // Length of capture.
// The length of a capture should not be negative. This can only happen
// if the end of the capture is unrecorded, or at a point earlier than
// the start of the capture.
BranchOrBacktrack(
