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SyntaxAnalysis.cpp
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989 lines (809 loc) · 25.3 KB
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#include <iostream>
#include <fstream>
#include <string>
#include <list>
#include <queue>
#include "SyntaxAnalysis.h"
#include "SemanticAnalysis.h"
using namespace std;
bool SyntaxAnalysis::isVt(string str) {
int i;
for (i = 0; i < vt_num; i++) {
if (Vt[i] == str)
return true;
}
return false;
}
set<int> SyntaxAnalysis::emptyIndex(){
int i;
set<int> tmp;
for (i = 0; i < grammar.size(); i++) {
if (grammar[i].pright == "#") {
tmp.insert(i);
}
}
return tmp;
}
//获取文法中的终结符号
string SyntaxAnalysis::getVt(string production) {
int k;
if (production.substr(0, 9) == "character") {
return "character";
}
else if (production.substr(0, 3) == "num") {
return "num";
}
else if (production.substr(0, 2) == "id") {
return "id";
}
//优先匹配双字符,防止要匹配>=时匹配到>就退出
for (k = 3; k < 27; k++)
{ //这里应该注意:使用最长匹配
if (production.substr(0, 2) == Vt[k])
return production.substr(0, 2);
}
for (k = 3; k < 27; k++)
{
if (production.substr(0, 1) == Vt[k])
return Vt[k];
}
//匹配关键字
string tmp;
for (k = 27; k < vt_num; k++)
{
tmp = production.substr(0, Vt[k].length());
if (tmp == Vt[k])
{
return tmp;
}
}
//如果运行到这里,说明这个终结符不是终结符号表里的,认为小写字母也属于终结符
/*if (production[0] >= 'a' && production[0] <= 'z')
{
return production.substr(0, 1);
}*/
}
//将一条产生式的右部划分成非终结符号和终结符号的组合
vector<string> SyntaxAnalysis::splitRight(string right) {
vector<string> v;
int j;
int length = right.length();
for (j = 0; j < length; j++)
{
//跳过空格
if (right[j] == ' ')
{
continue;
}
if (right[j] >= 'A' && right[j] <= 'Z')
{ //非终结符
string Vn="";
if ((j == length - 1) || (j + 1 < length && right[j + 1] != '\''))//处理类似于S'的非终结符号
Vn = Vn + right[j];
else
Vn = Vn + right[j] + '\'';
v.push_back(Vn);
j = j + Vn.length() - 1;
Vn.clear();
}
else
{ //终结符
string vt;
vt = getVt(right.substr(j, length - j));
v.push_back(vt);
j = j + vt.length() - 1;
vt.clear();
}
}
return v;
}
//读取文法产生式
void SyntaxAnalysis::readGrammarFile(string path) {
ifstream file;
file.open(path, ios_base::in);
if (!file.is_open()) {
cout << "无法打开文件,请重试!" << endl;
}
string str;
Production p;
vector<string> tmp;
while (getline(file, str)) {
if (str[1] == '-') {
tmp = SyntaxAnalysis::splitRight(str.substr(3, str.length() - 3));
p.pleft = str[0];
p.pright = str.substr(3, str.length() - 3);
p.right = tmp;
grammar.push_back(p);
//读文件时便可以创建非终结符号集Vn
Vn.insert(p.pleft);
}
//处理带有'的非终结符号
else {
tmp = SyntaxAnalysis::splitRight(str.substr(4, str.length() - 4));
p.pleft = str.substr(0,2);
p.pright = str.substr(4, str.length() - 4);
p.right = tmp;
grammar.push_back(p);
//读文件时便可以创建非终结符号集Vn
Vn.insert(p.pleft);
}
}
int i = 0;
for (auto it = Vn.begin(); it != Vn.end(); it++) {
myVn[i] = *it;
i++;
}
file.close();
}
//递归求单个symbol的First集
set<string> SyntaxAnalysis::getSymbolFirst(string symbol) {
set<string> tmp;
//bool emptyFlag = false;//symbol是否能推导为空
//终结符号的First集为它本身
if (isVt(symbol)) {
tmp.insert(symbol);
return tmp;
}
else {//symbol为非终结符号
int i;
//遍历产生式集合
for (i = 0; i < grammar.size(); i++) {
//左部为symbol的产生式
if (grammar[i].pleft == symbol) {
//若为左递归则跳过该产生式
if (grammar[i].pleft == grammar[i].right[0])
continue;
string fir_right = grammar[i].right[0];
//产生式右部第一个符号为终结符号
if (isVt(fir_right)) {
tmp.insert(fir_right);//加入First集中
//若symbol能推导为空
//if (emptyFlag) {
// //tmp.
//}
}
else {
//set<int> s;
set<string> next;
//s = emptyIndex();
//检验fir_right能否推导为空
//for (auto it = s.begin(); it != s.end(); it++) {
//if (grammar[*it].pleft == fir_right) {
//emptyFlag = true;
//break;
//}
//}
next = getSymbolFirst(fir_right);
tmp.insert(next.begin(), next.end());//将tmp与next合并
}
}
}
return tmp;
}
}
void SyntaxAnalysis::getFirst() {
set<string> s;
int i, j;
//先建立终结符号的First集,即为它自身
for (i = 0; i < vt_num; i++) {
s.insert(Vt[i]);
allFirst[Vt[i]].insert(s.begin(), s.end());
s.clear();
}
for (i = 0; i < grammar.size(); i++) {
for (j = 0; j < grammar[i].right.size(); j++) {
s = getSymbolFirst(grammar[i].right[j]);
//s只包含空时,求产生式右部的下一个符号的First集
if (!(s.size() == 1 && s.count("#") == 1))
break;
}
allFirst[grammar[i].pleft].insert(s.begin(), s.end());
allFirst[grammar[i].pright].insert(s.begin(), s.end());//set合并
}
}
//求非终结符号symbol的Follow集
set<string> SyntaxAnalysis::getSymbolFollow(string symbol) {
set<string> s;
int i;
//若symbol为开始符号,结束符$加入其Follow集
if (symbol == start_symbol) {
s.insert("$");
return s;
}
//遍历产生式集合
for (i = 0; i < grammar.size(); i++) {
//symbol不在第i条产生式的右部则在下一条产生式中寻找
if (grammar[i].pright.find(symbol) == grammar[i].pright.npos)
continue;
else {
int j, index, k;
string next;
for (j = 0; j < grammar[i].right.size(); j++) {
if (grammar[i].right[j] == symbol) {
index = j + 1;//下一个符号的索引
set<string> tmp;
//恰好为右部最后一个符号
if (index == grammar[i].right.size()) {
if (grammar[i].pleft == symbol)
continue;//若该条产生式左部恰好为symbol,FOLLOW(symbol)属于FOLLOW(symbol)无意义,找该条产生式右部的下一个符号
//tmp = getSymbolFollow(grammar[i].pleft);//求产生式左部的FOLLOW集(会因栈溢出而报错)
tmp = allFollow[grammar[i].pleft];//要求左部的FOLLOW集在求symbol的FOLLOW集前已经求出
s.insert(tmp.begin(), tmp.end());
}
else {
for (k = index; k < grammar[i].right.size(); k++) {
next = grammar[i].right[k];
tmp = allFirst[next];//求其First集
if (!tmp.count("#")) {
s.insert(tmp.begin(), tmp.end());
break;//不含空则可以直接跳出对后面First集的求解
}
else {
tmp.erase("#");
s.insert(tmp.begin(), tmp.end());
}
if (k == grammar[i].right.size() - 1) {//指针指向右部最后一个符号且之前仍未退出该循环体
if (grammar[i].pleft == symbol)
break;//若该条产生式左部恰好为symbol,FOLLOW(symbol)属于FOLLOW(symbol)无意义,找该条产生式右部的下一个符号
//tmp = getSymbolFollow(grammar[i].pleft);//求产生式左部的FOLLOW集(会因栈溢出而报错)
tmp = allFollow[grammar[i].pleft];//要求左部的FOLLOW集在求symbol的FOLLOW集中已经求出
s.insert(tmp.begin(), tmp.end());
}
}
}
}
}
}
}
return s;
}
void SyntaxAnalysis::getFollow() {
set<string> s;
int i;
//计算所有产生式左部的Follow集,因为非终结符号一定在左部
for (i = 0; i < grammar.size(); i++) {
s = getSymbolFollow(grammar[i].pleft);
allFollow[grammar[i].pleft].insert(s.begin(), s.end());
}
//特殊处理存在的环路
allFollow["G"].insert(allFollow["J"].begin(), allFollow["J"].end());
allFollow["G"].insert(allFollow["K"].begin(), allFollow["K"].end());
}
void SyntaxAnalysis::writeFirstFile(string path) {
ofstream file;
file.open(path, ios::out);
for (auto i = allFirst.begin(); i != allFirst.end(); i++) {
file << "First(" << i->first << ") = { ";
for (auto j = i->second.begin(); j != i->second.end(); j++) {
file << *j << " ";
}
file << "}" << endl;
}
file.close();
}
void SyntaxAnalysis::writeFollowFile(string path) {
ofstream file;
file.open(path, ios::out);
for (auto i = allFollow.begin(); i != allFollow.end(); i++) {
file << "Follow(" << i->first << ") = { ";
for (auto j = i->second.begin(); j != i->second.end(); j++) {
file << *j << " ";
}
file << "}" << endl;
}
file.close();
}
int SyntaxAnalysis::setTermType(Term t) {
int nextIndex = t.dot + 1;//下一个要识别的符号的索引
//存在下一个符号
if (nextIndex < t.right.size()) {
//终结符号
if (isVt(t.right[nextIndex]) && t.right[nextIndex] != "#") {
return 1;
}
else if(t.right[nextIndex] == "#"){
return 2;
}
else {
return 3;//待约项目
}
}
else {
return 2;//为归约项目
}
}
//初始化一个LR1项目为其核心项目Ino:Term1、Term2...
void SyntaxAnalysis::initialTermCollection(int no, vector<Term> v) {
int i;
for (i = 0; i < v.size(); i++) {
v[i].type = setTermType(v[i]);//设置类型信息
v[i].is_core = true;//标注为核心项目
LR1_collection[no].push_back(v[i]);
flags.insert(pair<int, bool>(no, false));//该状态未派生
}
//LR1_collection[name].insert(v.begin(), v.end());
}
bool SyntaxAnalysis::isTermExist(Term t, vector<Term> v) {
bool flag = false;
int m;
for (m = 0; m < v.size(); m++) {
if (t.termEqual(v[m])) {
flag = true;
break;
}
}
return flag;
}
//计算待约项目term的闭包
vector<Term> SyntaxAnalysis::closure(Term term) {
vector<Term> s;
int nextSymbolIndex = term.dot + 1;
string nextSymbol = term.right[nextSymbolIndex];
Term tmp;
int i;
string str;
set<string> first;
set<string> forward_set;//向前搜索符集合
//nextSymbol为term的右部最后一个符号
if (nextSymbolIndex + 1 == term.right.size()) {
forward_set.insert(term.forward);
}
else {
for (i = nextSymbolIndex + 1; i < term.right.size(); i++) {
str = term.right[i];
first = allFirst[str];
forward_set.insert(first.begin(), first.end());
//当前符号str的First集不含空#,则向前搜索符计算完成
if (!first.count("#")) {
forward_set.erase("#");
break;
}
}
if (forward_set.count("#")) {
forward_set.erase("#");
forward_set.insert(term.forward);
}
}
//遍历产生式集,寻找左部为nextSymbol的产生式
for (i = 0; i < grammar.size(); i++) {
if (grammar[i].pleft != nextSymbol)
continue;
tmp.pleft = grammar[i].pleft;
tmp.pright = grammar[i].pright;
tmp.right = grammar[i].right;
for (auto j = forward_set.begin(); j != forward_set.end(); j++) {
tmp.forward = (*j);
s.push_back(tmp);
}
}
return s;
}
void SyntaxAnalysis::extendTerm(int no) {
vector<Term> v;
v = LR1_collection[no];//获取核心项目
int i, j;
Term t;
queue<Term> q;//待约项目队列
vector<Term> temp;//存储核心项目求闭包所得的派生项目
for (i = 0; i < v.size(); i++) {
//若为归约项目或移进项目,不用派生
if (v[i].type != 3)
continue;
q.push(v[i]);
}
//BFS求每一层的待约项目
while (!q.empty()) {
t = q.front();//取队首
q.pop();//出队
temp = closure(t);
for (j = 0; j < temp.size(); j++) {
if (isTermExist(temp[j], LR1_collection[no]))
continue;
else {
temp[j].type = setTermType(temp[j]);
LR1_collection[no].push_back(temp[j]);
if (temp[j].type == 3)
q.push(temp[j]);
}
}
}
flags[no] = true;//派生完成
}
bool SyntaxAnalysis::isCoreTermExist(vector<Term> v) {
int i;
int nowIndex;
bool flag = false;
vector<Term> collection;//当前状态的核心项目
vector<Term> nowCollection;//当前状态的全部项目
//遍历当前已有的状态
for (auto it = LR1_collection.begin(); it != LR1_collection.end(); it++) {
nowIndex = (*it).first;
nowCollection = (*it).second;
//将状态的核心项目加入collection
if (flags[nowIndex]) {
for (i = 0; i < nowCollection.size(); i++) {
//若为核心项目
if (nowCollection[i].is_core)
collection.push_back(nowCollection[i]);
}
}
else
collection = nowCollection;
if (collection.size() >= v.size()) {
for (i = 0; i < v.size(); i++) {
//有一项不存在,则项目集必然不一样,找下一个已有的状态
if (!isTermExist(v[i], collection))
break;
}
if (i == v.size()) {//之前均未跳出,则说明v和collection完全匹配上,v已存在
flag = true;
pre = nowIndex;
break;
}
}
}
return flag;
}
bool SyntaxAnalysis::isFlagsAllT() {
bool myflag;
for (auto it = flags.begin(); it != flags.end(); it++) {
myflag = (*it).second;
//若有一个为false,直接返回false
if (!myflag)
return false;
}
return true;
}
void SyntaxAnalysis::getNewCollection(int no) {
unordered_map<string, vector<Term>> new_collections;//从当前状态no接收string后到达新状态的核心项目
vector<Term> v = LR1_collection[no];//获得状态no经过派生后的全部项目
int i;
int index;
string nextSym;
vector<Term> tmp;
Reflection r;
for (i = 0; i < v.size(); i++) {
if (v[i].type == 2)//归约项目不用移动活前缀
continue;
else {//待约或移进项目
index = v[i].dot;
nextSym = v[i].right[index + 1];//活前缀要识别的下一个符号
v[i].dot = index + 1;//活前缀移进一位
new_collections[nextSym].push_back(v[i]);
}
}
for (auto it = new_collections.begin(); it != new_collections.end(); it++) {
nextSym = (*it).first;
tmp = (*it).second;
//核心项目已经出现过
if (isCoreTermExist(tmp)) {
r.start = no;
r.end = pre;
r.received_symbol = nextSym;
if (isVt(nextSym))
r.type = 1;
else
r.type = 2;
reach.push_back(r);
continue;
}
else {
num = num + 1;
initialTermCollection(num, tmp);
r.start = no;
r.end = num;
r.received_symbol = nextSym;
if (isVt(nextSym))
r.type = 1;
else
r.type = 2;
reach.push_back(r);
}
}
}
//根据开始符号产生式的LR项目,构造LR(1)项目规范簇
void SyntaxAnalysis::buildLR1Collections(Term start) {
vector<Term> st;
int i = 0;
st.push_back(start);
initialTermCollection(i, st);
do {
extendTerm(i);
getNewCollection(i);
i++;
} while (!isFlagsAllT());
}
void SyntaxAnalysis::writeLR1ResultFile(string path) {
ofstream file;
file.open(path, ios::out);
int num, i, j;
vector<Term> v;
Term t;
for (auto it = LR1_collection.begin(); it != LR1_collection.end(); it++) {
num = (*it).first;
v = (*it).second;
file << "I" << num << ":" << endl;
for (i = 0; i < v.size(); i++) {
t = v[i];
if (t.dot + 1 < t.right.size()) {
file << "[ " << t.pleft << "-> ";
for (j = 0; j < t.right.size(); j++) {
if (j == t.dot + 1)
file << ".";
file << t.right[j];
}
file<< " , " << t.forward << " ]" << " ";
}
else
file << "[ " << t.pleft << "-> " << t.pright.append(".") << " , " << t.forward << " ]" << " ";
}
file << endl;
}
file << endl;
Reflection r;
//写入状态间的映射关系
for (i = 0; i < reach.size(); i++) {
r = reach[i];
file << "t( " << r.start << " , " << r.received_symbol << " )=" << r.end << endl;
}
file.close();
}
int SyntaxAnalysis::vt2int(string s) {
int i;
for (i = 0; i < vt_num; i++) {
if (s == Vt[i])
return i;
}
return -1;//不存在该终结符号
}
int SyntaxAnalysis::vn2int(string s) {
int i;
for (i = 0; i < vn_num; i++) {
if (myVn[i] == s)
return i;
}
return -1;//不存在该非终结符号
}
//进行归约时获取产生式下标
int SyntaxAnalysis::getProductionIndex(Term t) {
int i;
for (i = 0; i < grammar.size(); i++) {
if (grammar[i].pleft == t.pleft && grammar[i].pright == t.pright)
return i;
}
return -1;//未找到
}
void SyntaxAnalysis::buildLR1Table() {
int i, k, m, index;
int j = 0;
vector<Term> v;
Reflection r;
for (auto it = LR1_collection.begin(); it != LR1_collection.end(); it++) {
i = (*it).first;
v = (*it).second;
while (j < reach.size()) {
r = reach[j];
if (r.start == i) {
if (r.type == 1) {
k = vt2int(r.received_symbol);//在数组Vt的下标
ACTION[i][k] = "S" + to_string(r.end);//移进
}
else {
k = vn2int(r.received_symbol);//在数组myVn的下标
GOTO[i][k] = r.end;
}
}
else {
break;//reach每一项按其start值从小到大排列,遇到不相同的说明其start大于i,等外层到达start值时再循环
}
j++;
}
//填写归约项目,归约项目(除推出空#)一定在状态的核心项目中,而一个状态的核心项目排在其项目集的前面
for (m = 0; m < v.size(); m++) {
////若能推出空
//if (v[m].pright == "#") {
// index = getProductionIndex(v[m]);
// k = vt2int(v[m].forward);//在数组Vt中的下标
// ACTION[i][k]= "r" + to_string(index);//空产生式归约
// continue;
//}
//if (!v[m].is_core)//不是核心项目,说明已经查询过该状态所有的核心项目
// break;
if (v[m].type == 2) {
//查询对应的产生式索引
index = getProductionIndex(v[m]);
k = vt2int(v[m].forward);//在数组Vt中的下标
if (v[m].pleft=="S\'") {
ACTION[i][k] = "acc";
}
else
ACTION[i][k] = "r" + to_string(index);//归约
}
}
//未填充的地方为出错
for (m = 0; m < vt_num; m++) {
if (ACTION[i][m].empty())
ACTION[i][m] = "ER";//出错
}
}
}
void SyntaxAnalysis::writeLR1TableFile(string path) {
ofstream file;
file.open(path, ios::out);
int i, j;
for (i = 0; i < 300; i++) {
//file << i << ": ";
for (j = 0; j < vt_num; j++) {
file << ACTION[i][j] << " ";
}
for (j = 0; j < vn_num; j++) {
file << GOTO[i][j] << " ";
}
file << endl;
}
file.close();
}
string SyntaxAnalysis::tranSymbol(Word w) {
string symbol;
//标识符
if (w.type == 1)
symbol = "id";
//数字常量
else if (w.type == 2)
symbol = "num";
//字符常量
else if (w.type == 3)
symbol = "character";
//关键字、运算符、分界符等
else
symbol = w.value;
return symbol;
}
void SyntaxAnalysis::error(Word w) {
if (w.value != "$")
cout << "第" << w.line << "行,第" << w.column << "列出现语法错误!请检查源代码!" << endl;
else
cout << "源代码结尾出错!" << endl;
}
char SyntaxAnalysis::analyse(int status, string symbol, Word now_word) {
int index;//symbol对应的索引
index = vt2int(symbol);
string action;
action = ACTION[status][index];
int number;//ACTION表的元素的数字
if (action == "ER") {
//出错
//cout << "发生错误!" << endl;
showStack();
error(now_word);
return 'E';
}
//移进
else if (action.find("S") != string::npos) {
number = atoi(action.substr(1).c_str());//移进的状态
statusStack.push(number);
symbolStack.push(symbol);
cout << "移进" << action << endl;
showStack();
return 'S';
}
//归约
else if (action.find("r") != string::npos) {
int go;//GOTO表中对应的状态
int vnindex;//产生式左部符号的索引
int l;//产生式右部的长度
int tmp;//当前栈顶状态
number = atoi(action.substr(1).c_str());//产生式的索引
if (grammar[number].pright != "#")
l = grammar[number].right.size();
else
l = 0;
for (int i = 0; i < l; i++) {
statusStack.pop();
symbolStack.pop();
}
symbolStack.push(grammar[number].pleft);//产生式左部压入符号栈中
vnindex = vn2int(grammar[number].pleft);
tmp = statusStack.top();
go = GOTO[tmp][vnindex];
statusStack.push(go);//压入状态栈
showStack();
cout << "下个要接受的符号:" << symbol << endl;
cout << "使用的产生式为:" << grammar[number].pleft << "->" << grammar[number].pright << " ";
cout << "在状态" << tmp << "时面对" << grammar[number].pleft << "转移至状态" << go << " ";
cout << "归约" << action << endl;
return 'r';
}
//分析成功,退出
else if (action == "acc") {
showStack();
cout << "接收acc,语法分析成功!" << endl;
return 'A';
}
}
void SyntaxAnalysis::showStack() {
string s;
int i;
stack<string> s1;
stack<int> s2;
s1 = symbolStack;
s2 = statusStack;
cout << "符号栈:";
//输出符号栈内容
while (!s1.empty()) {
s = s1.top();
s1.pop();
cout << s << " ";
}
cout << endl;
cout << "状态栈:";
//输出状态栈
while (!s2.empty()) {
i = s2.top();
s2.pop();
cout << i << " ";
}
cout << endl;
}
void SyntaxAnalysis::LRAnalyse(list<Word> words) {
Word tempword;
string vtsymbol;//下一个要接受的符号
int status;//状态栈栈顶
char c;
statusStack.push(0);//初始状态0压入栈中
/*set<string> s;
s = Vn;
s.insert("id");
s.insert("num");
s.insert("character");
s.insert("int");
s.insert("char");
s.insert("bool");
s.insert("true");
s.insert("false");
mySemantic.buildAttributeGrammar(s);*/
for (auto it = words.begin(); it != words.end(); it++) {
tempword = *it;
vtsymbol = tranSymbol(tempword);
do {
status = statusStack.top();
c = analyse(status, vtsymbol, tempword);
cout << endl;
if (c == 'E')
break;
} while (c == 'r');
if (c == 'E')
break;
}
}
vector<string> SyntaxAnalysis::msplit(string st, char sign) {
vector<string> str;
for (int i = 0; i < st.length(); i++) {
string temp = "";
while (st[i] != sign && i < st.length()) {
temp += st[i];
i++;
}
str.push_back(temp);
}
return str;
}
void SyntaxAnalysis::readLR1Table(string path) {
ifstream file;
file.open(path, ios::in);
if (!file.is_open()) {
cout << "无法打开文件,请重试!" << endl;
}
string str;
int i, line;
vector<string> v;
line = 0;
while (getline(file, str)) {
v = msplit(str, ' ');
for (i = 0; i < vt_num; i++)
ACTION[line][i] = v[i];
for (i = 0; i < vn_num; i++)
GOTO[line][i] = atoi(v[i + vt_num].c_str());
line++;
}
}