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ruikangliu / diy_compiler

编译课设-词法分析+LR1语法分析+语法制导翻译(生成四元式)

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  • 详细介绍可以查看我的博客

程序使用方法

使用前注意

  • 注意：在使用之前要先把存放文法的文件 grammer.txt 以及所有源文件 xxx.txt 放入一个文件夹中，同时一定要更改文件夹路径；即修改 main 函数中的 path_prefix，例如我现在的源文件 code.txt 放在 E:\\Workspace\\diy_compiler\\compiler\\Debug\\ 目录下，那修改 path_prefix 为该路径即可

UI 界面

  • 我制作了一个简单的 UI 界面，可以在命令行窗口里输入 lianli xxx.txt 来编译相应的源文件，命令末尾加上 -v 命令可以输出归约时使用的产生式，输出顺序为最右推导的逆序，效果如下图所示： 在这里插入图片描述

扩充文法

  • 我在程序中留有的接口可以方便的对源语言文法进行扩充：
    • 首先在 grammer.txt 中添加相应的产生式 (最好添加在最后，这样不会改变其他产生式的序号)
    • 再根据新添加的产生式对应的序号，在 LR1Processor::production_action 函数的相应 case 分支下添加语义动作即可
    • 其余的工作均由程序自动完成

测试样例

  • 所有样例文件都和程序打包在一起了

样例一

  • 样例一为正确的源程序
// code.txt
{
	int a, b;
	real c, d;
	int e, g, h;
	a = 1.3e3;
	
	if !(a * -b >= c + d)
	then
	{
		e = g + h;
	}
	else
		e = g * h;

	do{
		a = 1;
	}while (true);
	{
		int a;
		a = 1;
	}
	if (1)
	then a = 3;

	while a >= 10
	do
	{
		if (a == a * b)
		then
			a = a - 1;
	}
}

output:

  • 首先输出的是词法分析结果，输出每一个词法单元以及它们的行数
  • 如果在输入命令时后面加上 -v，还会输出语法分析时所使用的产生式，即输出最右推导的逆序列，但是因为输出信息太多，所以这里没加
  • 然后输出 Warning 信息，因为是正确的源程序，所以没有 Warning
  • 最后输出四元式
>>> lianli code.txt
line1: <{>
line2: <KEY_WORD,int>
line2: <ID,a>
line2: <,>
line2: <ID,b>
line2: <;>
line3: <KEY_WORD,real>
line3: <ID,c>
line3: <,>
line3: <ID,d>
line3: <;>
line4: <KEY_WORD,int>
line4: <ID,e>
line4: <,>
line4: <ID,g>
line4: <,>
line4: <ID,h>
line4: <;>
line5: <ID,a>
line5: <=>
line5: <NUM,1300>
line5: <;>
line7: <KEY_WORD,if>
line7: <!>
line7: <(>
line7: <ID,a>
line7: <*>
line7: <->
line7: <ID,b>
line7: <RELOPT,>=>
line7: <ID,c>
line7: <+>
line7: <ID,d>
line7: <)>
line8: <KEY_WORD,then>
line9: <{>
line10: <ID,e>
line10: <=>
line10: <ID,g>
line10: <+>
line10: <ID,h>
line10: <;>
line11: <}>
line12: <KEY_WORD,else>
line13: <ID,e>
line13: <=>
line13: <ID,g>
line13: <*>
line13: <ID,h>
line13: <;>
line15: <KEY_WORD,do>
line15: <{>
line16: <ID,a>
line16: <=>
line16: <NUM,1>
line16: <;>
line17: <}>
line17: <KEY_WORD,while>
line17: <(>
line17: <KEY_WORD,true>
line17: <)>
line17: <;>
line18: <{>
line19: <KEY_WORD,int>
line19: <ID,a>
line19: <;>
line20: <ID,a>
line20: <=>
line20: <NUM,1>
line20: <;>
line21: <}>
line22: <KEY_WORD,if>
line22: <(>
line22: <NUM,1>
line22: <)>
line23: <KEY_WORD,then>
line23: <ID,a>
line23: <=>
line23: <NUM,3>
line23: <;>
line25: <KEY_WORD,while>
line25: <ID,a>
line25: <RELOPT,>=>
line25: <NUM,10>
line26: <KEY_WORD,do>
line27: <{>
line28: <KEY_WORD,if>
line28: <(>
line28: <ID,a>
line28: <RELOPT,==>
line28: <ID,a>
line28: <*>
line28: <ID,b>
line28: <)>
line29: <KEY_WORD,then>
line30: <ID,a>
line30: <=>
line30: <ID,a>
line30: <->
line30: <NUM,1>
line30: <;>
line31: <}>
line32: <}>
***********************************
No Warning!

************************************

四元式:
1: ( rtoi, 1300.000000, _, t0 )
2: ( =, t0, _, ENTRY(a) )
3: ( @, ENTRY(b), _, t1 )
4: ( *, ENTRY(a), t1, t2 )
5: ( +, ENTRY(c), ENTRY(d), t3 )
6: ( >=, t2, t3, t4 )
7: ( jtrue, t4, _, 9 )
8: ( j, _, _, 9 )
9: ( !, t4, _, t5 )
10: ( jtrue, t5, _, 12 )
11: ( j, _, _, 15 )
12: ( +, ENTRY(g), ENTRY(h), t6 )
13: ( =, t6, _, ENTRY(e) )
14: ( j, _, _, 17 )
15: ( *, ENTRY(g), ENTRY(h), t7 )
16: ( =, t7, _, ENTRY(e) )
17: ( rtoi, 1.000000, _, t8 )
18: ( =, t8, _, ENTRY(a) )
19: ( jtrue, true, _, 21 )
20: ( j, _, _, 21 )
21: ( jtrue, true, _, 17 )
22: ( j, _, _, 23 )
23: ( rtoi, 1.000000, _, t9 )
24: ( =, t9, _, ENTRY(a) )
25: ( jtrue, 1.000000, _, 27 )
26: ( j, _, _, 27 )
27: ( jtrue, 1.000000, _, 29 )
28: ( j, _, _, 31 )
29: ( rtoi, 3.000000, _, t10 )
30: ( =, t10, _, ENTRY(a) )
31: ( >=, ENTRY(a), 10.000000, t11 )
32: ( jtrue, t11, _, 34 )
33: ( j, _, _, 45 )
34: ( *, ENTRY(a), ENTRY(b), t12 )
35: ( ==, ENTRY(a), t12, t13 )
36: ( jtrue, t13, _, 38 )
37: ( j, _, _, 38 )
38: ( jtrue, t13, _, 40 )
39: ( j, _, _, 31 )
40: ( itor, ENTRY(a), _, t14 )
41: ( -, t14, 1.000000, t15 )
42: ( rtoi, t15, _, t16 )
43: ( =, t16, _, ENTRY(a) )
44: ( j, _, _, 31 )
45: ( End, _, _, _ )

样例二

  • 样例二中科学计数法的表示存在错误，e 后面必须跟一个数字
// code1.txt
{
	int a, b;
	real c, d;
	int e, g, h;
	a = 1.3e;	// 词法分析阶段报错
	
	if !(a * -b >= c + d)
	then
	{
		e = g + h;
	}
	else
		e = g * h;

	while a >= 10
	do
	{
		if (a == a * b)
		then
			a = a - 1;
		b = b + 1
	}
	{
		int a;
		a = 1;
	}
	do{
		a = 1;
	}while (true);

	if (1
	then a = 3
}

output:

>>> lianli code1.txt
line1: <{>
line2: <KEY_WORD,int>
line2: <ID,a>
line2: <,>
line2: <ID,b>
line2: <;>
line3: <KEY_WORD,real>
line3: <ID,c>
line3: <,>
line3: <ID,d>
line3: <;>
line4: <KEY_WORD,int>
line4: <ID,e>
line4: <,>
line4: <ID,g>
line4: <,>
line4: <ID,h>
line4: <;>
line5: <ID,a>
line5: <=>
************************************
ERROR!
Line5: No number after 'e' !
************************************
>>>

样例三

  • 样例三中存在多重定义的错误，该错误将在语义分析阶段报错
// code2.txt
{
	int a, b;
	real c, d;
    real a;     // 多重定义
	int e, g, h;
	a = 1.3e3;
	
	if !(a * -b >= c + d)
	then
	{
		e = g + h;
	}
	else
		e = g * h;

	while a >= 10
	do
	{
		if (a == a * b)
		then
			a = a - 1;
		b = b + 1
	}
	{
		int a;
		a = 1;
	}
	do{
		a = 1;
	}while (true);

	if (1
	then a = 3
}

output:

>>> lianli code2.txt
line1: <{>
// 省略了部分词法分析输出
line34: <}>
************************************
ERROR!
Line4: multiple definition!
************************************
>>>

样例四

  • 样例四中使用了变量 a，但却没有定义，因此存在无定义错误
// code3.txt
{
	int b;  // 无定义
	real c, d;
	int e, g, h;
	a = 1.3e3;
	
	if !(a * -b >= c + d)
	then
	{
		e = g + h;
	}
	else
		e = g * h;

	while a >= 10
	do
	{
		if (a == a * b)
		then
			a = a - 1;
		b = b + 1
	}
	{
		int a;
		a = 1;
	}
	do{
		a = 1;
	}while (true);

	if (1
	then a = 3
}

output:

>>> lianli code3.txt
line1: <{>
// 省略了部分词法分析输出
line33: <}>
************************************
ERROR!
Line5: Undefined variant a !
************************************

样例五

  • 样例五在程序中除以了0，会产生除以0的报错，该报错在语义分析阶段完成
// code4.txt
{
	int a, b;
	real c, d;
	int e, g, h;
	a = 1.3e3 / 0;  // 除以0
	
	if !(a * -b >= c + d)
	then
	{
		e = g + h;
	}
	else
		e = g * h;

	while a >= 10
	do
	{
		if (a == a * b)
		then
			a = a - 1;
		b = b + 1
	}
	{
		int a;
		a = 1;
	}
	do{
		a = 1;
	}while (true);

	if (1
	then a = 3
}

output:

>>> lianli code4.txt
line1: <{>
// 省略了部分词法分析输出
line33: <}>
************************************
ERROR!
Line5: Err: Divided by zero!
************************************

样例六

  • 样例六中的错误为部分语句缺少 ) / ; / } 这样的分界符，在这种情况下会在语法分析阶段报错。但我使用了错误恢复，因此会自动在程序输入流程中插入缺少的分界符，最后依然能够生成正确的四元式，但会产生相应的 Warning，提示哪一行没有加分界符
// code5.txt
{
	int a, b;
	real c, d;
	int e, g, h;
	a = 1.3e3;
	
	if !(a * -b >= c + d    // 缺少右圆括号
	then
	{
		e = g + h;
	}
	else
		e = g * h;

	do{
		a = 1;
	}while (true)   // 缺少分号
	{
		int a;
		a = 1;      // 缺少右大括号
            
	if (1)
	then a = 3;

	while a >= 10
	do
	{
		if (a == a * b)
		then
			a = a - 1;  // 缺少右大括号
    
}

output:

  • 可以看到，最后输出的四元式与样例一中生成的四元式相同
>>> lianli code5.txt
line1: <{>
// 省略了部分词法分析输出
line32: <}>
***********************************

Line7:
Warning 0: Lack of )

Line17:
Warning 1: Lack of ;

Line32:
Warning 2: Lack of }

Line32:
Warning 3: Lack of }

4 Warning(s)!
************************************

四元式:
1: ( rtoi, 1300.000000, _, t0 )
2: ( =, t0, _, ENTRY(a) )
3: ( @, ENTRY(b), _, t1 )
4: ( *, ENTRY(a), t1, t2 )
5: ( +, ENTRY(c), ENTRY(d), t3 )
6: ( >=, t2, t3, t4 )
7: ( jtrue, t4, _, 9 )
8: ( j, _, _, 9 )
9: ( !, t4, _, t5 )
10: ( jtrue, t5, _, 12 )
11: ( j, _, _, 15 )
12: ( +, ENTRY(g), ENTRY(h), t6 )
13: ( =, t6, _, ENTRY(e) )
14: ( j, _, _, 17 )
15: ( *, ENTRY(g), ENTRY(h), t7 )
16: ( =, t7, _, ENTRY(e) )
17: ( rtoi, 1.000000, _, t8 )
18: ( =, t8, _, ENTRY(a) )
19: ( jtrue, true, _, 21 )
20: ( j, _, _, 21 )
21: ( jtrue, true, _, 17 )
22: ( j, _, _, 23 )
23: ( rtoi, 1.000000, _, t9 )
24: ( =, t9, _, ENTRY(a) )
25: ( jtrue, 1.000000, _, 27 )
26: ( j, _, _, 27 )
27: ( jtrue, 1.000000, _, 29 )
28: ( j, _, _, 31 )
29: ( rtoi, 3.000000, _, t10 )
30: ( =, t10, _, ENTRY(a) )
31: ( >=, ENTRY(a), 10.000000, t11 )
32: ( jtrue, t11, _, 34 )
33: ( j, _, _, 45 )
34: ( *, ENTRY(a), ENTRY(b), t12 )
35: ( ==, ENTRY(a), t12, t13 )
36: ( jtrue, t13, _, 38 )
37: ( j, _, _, 38 )
38: ( jtrue, t13, _, 40 )
39: ( j, _, _, 31 )
40: ( itor, ENTRY(a), _, t14 )
41: ( -, t14, 1.000000, t15 )
42: ( rtoi, t15, _, t16 )
43: ( =, t16, _, ENTRY(a) )
44: ( j, _, _, 31 )
45: ( End, _, _, _ )

样例七

  • 样例七展示了一般错误的处理情况：输出错误的行数、表明在读入哪一个符号时出错、以及可能的正确输入符号
  • 源程序中的错误为缺少一个运算符
// code6.txt
{
	int a, b;
	real c, d;
	int e, g, h;
	a = 1.3e3;
	
	if !(a * -b >= c + d)
	then
	{
		e = g + h;
	}
	else
		e = g * h;

	do{
		a = 1;
	}while (true);
	{
		int a;
		a = 1;
	}
	if (1)
	then a = 3;

	while a >= 10
	do
	{
		if a == a  b	// 缺少运算符
		then
			a = a - 1;
	}
}

output:

  • 可以看到，提供的可能正确输入符号中包含了各种算逻运算符以及结束 if 语句的 then
>>> lianli code6.txt
line1: <{>
// 省略了部分词法分析输出
line32: <}>
************************************
ERROR!
Line28:
state 32 can't accept id !
possible symbols are:
<= / then >= + - * or and == != < >
************************************

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编译课设-词法分析+LR1语法分析+语法制导翻译(生成四元式)

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