1、詞法分析程序?qū)嶒?yàn)報(bào)告 班級(jí)：xxxx211305姓名：戈策學(xué)號(hào)：xxxx211221詞法分析程序?qū)嶒?yàn)報(bào)告實(shí)驗(yàn)內(nèi)容設(shè)計(jì)并實(shí)現(xiàn)C語言的詞法分析程序，要求如下：可以識(shí)別C語言編寫的源程序中的每個(gè)單詞符號(hào)，并以記號(hào)的形式輸出每個(gè)單詞?？梢越y(tǒng)計(jì)并讀取源程序中的注釋。可以統(tǒng)計(jì)源程序中的語句行數(shù)、單詞個(gè)數(shù)和字符個(gè)數(shù)，并輸出統(tǒng)計(jì)結(jié)果。其中回車換行不計(jì)入字符個(gè)數(shù)，空格不計(jì)算為單詞。檢查源程序中存在的錯(cuò)誤，并可以報(bào)告錯(cuò)誤所在的行列位置。發(fā)現(xiàn)源程序中存在錯(cuò)誤后，進(jìn)行適當(dāng)?shù)幕謴?fù)，使詞法分析可以繼續(xù)進(jìn)行，通過一次詞法分析處理，可以檢查并報(bào)告源程序中存在的所有錯(cuò)誤。程序特色全部實(shí)現(xiàn)上述實(shí)驗(yàn)要求標(biāo)識(shí)符規(guī)則符合標(biāo)準(zhǔn)C語言要求

2、，允許以下劃線開頭，并包含下劃線可識(shí)別C語言允許的所有無符號(hào)實(shí)數(shù)形式，包括整數(shù)和浮點(diǎn)數(shù)。其中浮點(diǎn)數(shù)可包含指數(shù)e或E，并遵循C語言允許省略整數(shù)部分（如.5表示0.5）或省略小數(shù)部分（如2.E2表示2.0*102）可識(shí)別幾乎C語言所有標(biāo)點(diǎn)符號(hào)和運(yùn)算符，共計(jì)50個(gè)可正確識(shí)別字符和字符串中的轉(zhuǎn)義字符，如和“abcd”均可識(shí)別為單詞不完整，并指出錯(cuò)誤的行和列可識(shí)別C語言的兩種注釋，/和/*/，其中/*/按照C語言要求允許跨越多行語言說明標(biāo)識(shí)符：以字母或下劃線開頭，后跟字母、數(shù)字或下劃線組成的字符串關(guān)鍵字：C語言所有32個(gè)關(guān)鍵字無符號(hào)數(shù)：C語言所允許的所有十進(jìn)制實(shí)數(shù)形式，包括整數(shù)和浮點(diǎn)數(shù)。其中浮點(diǎn)數(shù)包括C

3、語言允許的省略整數(shù)部分（如.5表示0.5）和省略小數(shù)部分（如2.E2表示2.0*102）算數(shù)運(yùn)算符：+、+、-、-、*、/、%賦值運(yùn)算符：=、+=、-=、*=、/=、%=、&=輸入形式命令行界面，指定C語言源文件作為輸入輸出形式所有標(biāo)識(shí)符寫入指定的符號(hào)表文件分離出一個(gè)單詞后，對(duì)識(shí)別出的記號(hào)以二元式的形式輸出到用戶指定文件，其形式為記號(hào)屬性記號(hào)屬性IDkeykeykeykeykeykeykeykeykeykeykeykeykeykeykeykeykeykeykeykeykeykeykeykeykeykeykeykeykeykeykeykeynumarith-oparith-oparith-opa

4、rith-oparith-oparith-oparith-op符號(hào)表序號(hào)autodoubleintstructbreakelselongswitchcaseenumregistertypedefcharexternreturnunionconstfloatshortunsignedcontinueforsignedvoiddefaultgotosizeofvolatiledoifstaticwhile實(shí)數(shù)值+-*/%asgn-opasgn-opasgn-opasgn-opasgn-opasgn-opasgn-opasgn-opasgn-oprel-oprel-oprel-oprel-oprel

5、-oprel-oplog-oplog-oplog-opbit-opbit-opbit-opbit-opbit-opbit-opothersothersothersothersothersothersothersothers others othersothers others others others charstringcomments=+=-=*=/=string token; /字符串，存放當(dāng)前單詞string:iterator forward; /字符串buffer的迭代器，向前掃描字符核心算法識(shí)別無符號(hào)數(shù)的有限狀態(tài)自動(dòng)機(jī)ss0s23starts1s4s5s6Errordigite/

6、Edigitdigitothers.digitothersdigitdigitdigit+/-/* 由上圖構(gòu)造相應(yīng)的無符號(hào)數(shù)識(shí)別子程序 */void get_digits() while(forward != buffer.end() & notEnd) switch(state) case 1: if(*forward = .) state = 23; else if(*forward = E|e) state = 4; else if(isdigit(*forward) state = 1; else notEnd = fasle; break; case 23: if(*forward

7、= E|e) state = 4; else if(isdigit(*forward) state =23; else notEnd = false; break; case 4: if(*forward = +|-) state = 6; else if(isdigit(*forward) state = 5; else Error;notEnd = false; break; case 5: if(isdigit(*forward) state = 5; else notEnd = false; break; case 6: if(isdigit(*forward) state = 5;

8、elseError;notEnd = false; break; default:break; /* 讀取一個(gè)字符后，如果是語言所定義的單詞符號(hào)的開始字符，則轉(zhuǎn)移到相應(yīng)的識(shí)別識(shí)別過程，否則進(jìn)入錯(cuò)誤處理狀態(tài) */int main() init; open infile, outfile, tablefile; while (true) if (getline(infile, buffer, n) = true) +line; cnt_char += column; column = 0;forward = buffer.begin(); else cnt_char += column; writ

9、e table to tablefile; close infile, outfile, tablefile; output to console; get_nbc; switch (C) case a.z,A.Z,_: token.append; while(digit | letter | _) token.append; if(iskey) table_insert(); outfile : token.append; +forward; if(*forward = =) token.append; outfile rel-op; else if(*forward = *(forward

10、-1) token.append; outfile bit-op; else outfile rel-op; break; case =: token.append; +forward; if(*forward = =) outfile rel-op; else outfile asgn-op; break; case !: token.append; +forward; if(*forward = =) outfile rel-op; else outfile log-op; break; case : token.append; +forward; while(*forward != )

11、token.append; +forward; if(*(forward-1) = ) token.append; +forward; if(forward = buffer.end() Error; else outfile string; break; case : token.append; +forward; while(*forward != ) token.append; +forward; if(*(forward-1) = ) token.append; +forward; if(forward = buffer.end() Error; else outfile char; break; case .: token.append; +forward; if(isdigit) get_digits(); outfile num; break