Source-to-source compiler (trans-compiler or transpiler) using FLEX & BISON.

• General Info
• Installation
• Execution
• Acknowledgements

The input files (file .tc) is written in the fictional TeaC programming language and the generated code is in C. Each TeaC program is a set of word units, which are arranged according to syntax rules of a fictional language. We generate a compiler that recognizes .tc archives and generate the equivalent C code. The implementation is split to two parts:

• Lexical Analyzer
• Parser Generator
  • Convertion fictional code to C code using bison actions.

General form of description of a language programming. Scans words in text files in token format and corresponds them to grammatical rules (declared in .l file).
We specify the categories of rules:

• Keywords
• Identifiers
• Constants
  • Boolean
  • Real positive
  • Strings
• Operators
• Delimiters
• Specials (white space, comments)

In this version, we have set some specific words for TeaC as keywords:

The other categories have basic common programming language content (possibly with some shortcomings, check .l for clarifications).

For more information about Flex, see https://www.geeksforgeeks.org/flex-fast-lexical-analyzer-generator/.

Syntactic rules of a language define the correct syntax of its word units. Here, we have:

• Main
  • Declarations
  • Functions
  • Body
• Data Types
• Array (one dimension)
• Variables
• Functions
• Expressions
• Commands
• Constants

It builds <parser_name>.tab.c, <parser_name>.tab.h files.

For more information https://www.geeksforgeeks.org/bison-command-in-linux-with-examples/

• In linux terminal, run commands to install tools.

$ sudo apt-get install flex
$ sudo apt update
$ sudo apt install bison

For any help, see

$ bison --help

• GCC install to converter parser rules to a recognized programming language (C in this case)

$ sudo apt install build-essential
$ sudo apt-get update

• Verify correctly installation with the version of the GCC

 gcc --version

• Syntax analysis from parser

bison -d -v -r  <parser_name>.y

• Lexical analysis from lexer

flex <analyzer name>.l

• Build compiler using the extracted rules

gcc -o teac <parser_name>.tab.c <analyzer name>.yy.c cgen.c -lfl

• Convert the fictional input to a .c file

./teac < <TeaC_input>.tc> output.c

• Build and run

gcc -Wall -std=c99 -o out output.c
./out

In \scripts, there are a few script for testing code for different sample inputs. correct1.tc is a sample of source code of TeaC language.

cgen.c contains function for lex to handle string. In other words, uses buffers to handle the parser's tokens.
Error in stream => Error in syntax => No executable

• This project was created for the requirements of the lesson Theory of Computation