使用antlr4获取预处理器行并解析C代码 [英] Get Preprocessor lines with antlr4 with parsing C Code
问题描述
我使用Antlr4解析C代码,我使用以下语法进行解析:
I am using Antlr4 to parse C code and I am using the following grammar to parse:
上述语法default没有提供任何解析规则来获取预处理器语句。
The above grammar by default does not provide any parsing rules to get preprocessor statements.
我通过添加以下行来稍微改变语法以获得预处理器行
I changed the grammar slightly to get the preprocessor lines by adding the following lines
externalDeclaration
: functionDefinition
| declaration
| ';' // stray ;
| preprocessorDeclaration
;
preprocessorDeclaration
: PreprocessorBlock
;
PreprocessorBlock
: '#' ~[\r\n]*
-> channel(HIDDEN)
;
在Java中我使用以下监听器来获取预处理器行
And in Java I am using the following listener to get the preprocessor lines
@Override
public void enterPreprocessorDeclaration(PreprocessorDeclarationContext ctx) {
System.out.println("Preprocessor Directive found");
System.out.println("Preprocessor: " + parser.getTokenStream().getText(ctx));
}
永远不会触发该方法。有人可以建议一种获取预处理器行的方法吗?
The method is never triggered. Can someone suggest a method to get the preprocessor lines?
输入:
#include <stdio.h>
int k = 10;
int f(int a, int b){
int i;
for(i = 0; i < 5; i++){
printf("%d", i);
}
}
推荐答案
实际上,使用频道(HIDDEN)
,规则 preprocessorDeclaration
不产生输出。
Actually, with channel(HIDDEN)
, the rule preprocessorDeclaration
produces no output.
如果我删除 - >频道(隐藏)
,它有效:
preprocessorDeclaration
@after {System.out.println("Preprocessor found : " + $text);}
: PreprocessorBlock
;
PreprocessorBlock
: '#' ~[\r\n]*
// -> channel(HIDDEN)
;
执行:
$ grun C compilationUnit -tokens -diagnostics t2.text
[@0,0:17='#include <stdio.h>',<PreprocessorBlock>,1:0]
[@1,18:18='\n',<Newline>,channel=1,1:18]
[@2,19:19='\n',<Newline>,channel=1,2:0]
[@3,20:22='int',<'int'>,3:0]
...
[@72,115:114='<EOF>',<EOF>,10:0]
C last update 1159
Preprocessor found : #include <stdio.h>
line 4:11 reportAttemptingFullContext d=83 (parameterDeclaration), input='int a,'
line 4:11 reportAmbiguity d=83 (parameterDeclaration): ambigAlts={1, 2}, input='int a,'
...
#include <stdio.h>
int k = 10;
int f(int a, int b) {
int i;
for(i = 0; i < 5; i++) {
printf("%d", i);
}
}
在文件 CMyListener.java中
(来自我之前的回答)我已添加:
In file CMyListener.java
(from my previous answer) I have added :
public void enterPreprocessorDeclaration(CParser.PreprocessorDeclarationContext ctx) {
System.out.println("Preprocessor Directive found");
System.out.println("Preprocessor: " + parser.getTokenStream().getText(ctx));
}
执行:
$ java test_c t2.text
...
parsing ended
>>>> about to walk
Preprocessor Directive found
Preprocessor: #include <stdio.h>
>>> in CMyListener
#include <stdio.h>
int k = 10;
...
}
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