I want to run simple analysis on C files (such as if you call foo
macro with INT_TYPE
as argument, then cast the response to int*
), I do not want to prerprocess the file, I just want to parse it (so that, for instance, I'll have correct line numbers).
Ie, I want to get from
#include <a.h>
#define FOO(f)
int f() {FOO(1);}
an list of tokens like
<include_directive value="a.h"/>
<macro name="FOO"><param name="f"/><result/></macro>
<function name="f">
<return>int</return>
<body>
<macro_call name="FOO"><param>1</param></macro_call>
</body>
</function>
with no need to set include path, etc.
Is there any preexisting parser that does it? All parsers I know assume C is preprocessed. I want to have access to the macros and actual include instructions.
Our C Front End can parse code containing preprocesser elements can do this to fair extent and still build a usable AST. (Yes, the parse tree has precise file/line/column number information).
There are a number of restrictions, which allows it to handle most code. In those few cases it cannot handle, often a small, easy change to the source file giving equivalent code solves the problem.
Here's a rough set of rules and restrictions:
In our experience, one can revise a code base of 50,000 lines in a few hours to get around these issues. While that seems annoying (and it is), the alternative is to not be able to parse the source code at all, which is far worse than annoying.
You also want more than just a parser. See Life After Parsing , to know what happens after you succeed in getting a parse tree. We've done some additional work in building symbol tables in which the declarations are recorded with the preprocessor context in which they are embedded, enabling type checking to include the preprocessor conditions.
You can have a look at this ANTLR grammar . You will have to add rules for preprocessor tokens, though.
Your specific example can be handled by writing your own parsing and ignore macro expansion.
Because FOO(1)
itself can be interpreted as a function call.
When more cases are considered however, the parser is much more difficult. You can refer PDF Link to find more information.
The technical post webpages of this site follow the CC BY-SA 4.0 protocol. If you need to reprint, please indicate the site URL or the original address.Any question please contact:yoyou2525@163.com.