词汇分析

Question

My target is to make a very simple and basic C syntax checker. (Not a full Compiler but just a basic Program which take a source code as Input and would print out the code back showing the errors). I want to use C++ as the language for this.

Can anyone guide me to write regular expression in 'c++' language for the following:

1. Assignment
2. For
3. switch

Any details/suggestions/guidance further would be much appreciated.

Answer 1

I don't think you can parse C with regular expressions alone. You'll need to start looking into lexers, parsers, grammars, etc...

A good starting point could be this: Quick Starter on Parser Grammars - No Past Experience Required .

You can find C grammars online for yacc / lex .

Answer 2

Checking the syntax of C code requires a lot more than regular expressions. You'll need a tool that supports parsing algebraic gammars instead, I'd suggest looking at http://www.gnu.org/software/bison/ which will generate the "skeleton" of a parser in C++ so you can edit it and add your syntax-checking code.

Answer 3

Use the clang libraries. A tutorial can be found on GitHub .

Answer 4

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Answer 5

To recognize C statements, lexical analysis is not sufficient, because lexers work at the character level. What you need, in addition to a C lexer, is a C parser which will do syntax analysis of the source code. The LRSTAR Parser Generator supplies a C project which will get you up and running.