The limited compiler for C language.

This is a litimed compiler for C language, we only consider "int"(exclude array) and some basic logical statement like if else while, this compiler cannot deal with complicated situation.

How to use :

1. make
2. ./CMinusMinus <Filename>

Steps of the compiler :

###lexer

• parsing the input file (EX. main.c), determine the types of all symbols in it.

###Syntax_Analyzer (use LL(0) parsing)

• check if there is any syntax error in the input file (by grammar.txt).
• Steps of Syntax_Analyzer
• 1. find the nullable, first, and follow sets of each symbol
• 2. create LLTable
• 3. create parse tree
• If you got an error in the console, you can go check the Set.txt, Table.txt, Parse_Tree.txt,
• and go check anything wrong.

###Semantic_Analyzer

• We didn't create semantic rule here(Don't know how), and we check invalid variable only. (replicated declared)
• The Semantic Analyzer only created symbol table here, the table will show scope, type, token, of each identifier.
• If you want to check the Semantic Analyzer is right or not, you can check the Symbol_Table.txt

###Quadruple

###Tiny Machine

Vaild tokens

• Keywords: int char return if else while break
• Operators: = ! + - * / == != < > <= >= && ||
• Special Symbols: [ ] { } ( ) ; ,
• Identifier: [A-Za-z_][A-Za-z0-9_]*
• Number: [0-9]+
• Char: '[.|\n|\t| ]'
• Comment: //

Coding Style

The input file(Ex. main.c) must contain at least one space between two tokens.

Grammar

The grammar can be switched to anything else, but note that all the indention in the grammar should be "space", do not use "tab".