Ctron

Application built from scratch that compiles a C file to an EXE of the same code. Ctron translates a simplified C-like language into a Windows executable (.exe). It uses Flex & Bison to generate LLVM IR, compiles it to assembly with llc.exe, and finally produces an executable using gcc.

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Writing C Code for Ctron

Ctron currently supports a restricted subset of C. Follow these rules when writing code:

Supported & Required Syntax

• "\d" is interpreted as "\n".
• The keyword global must appear before declaring any global variables.
• Use // to start a single-line comment.
• Only the int type is fully functional (and void for functions).

Functions

void functions must end with:

return;

Operators

Fully functional:

• ==, ||, &&, <, >, <=, >=

Not functional yet:

• !, !=
• +=, -=, ++, --, *=, /=

Use the expanded form instead, for example:

x = x + 1;   // instead of x++
x = x - 1;   // instead of x--
x = x * 2;   // instead of x *= 2
x = x / 2;   // instead of x /= 2

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Required Files & Environment

The following files must be located in the same folder as Ctron.exe (or Main.cpp during development):

• Flex_BisonV6.exe
• llc.exe

Additionally, the computer must have gcc installed (MinGW recommended).

• If gcc is missing, Ctron should produce an initial error indicating that the environment is not set up correctly.

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Running the Ctron Compiler (Ctron)

Open cmd in the folder that contains Ctron.exe (or the built binary).

Help

Type:

Ctron -help

or:

Ctron -h

Example output:

Usage:
  Ctron [options]
  Ctron [source_file] [command]

Options:
        -h                       Display this information.

Commands:
        -o <file>                Place the output into <file>.
        -o                       Place the output into [source_file.exe].

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Compiling a File with Ctron

To compile test.c and output an EXE with the same base name (test.exe):

Ctron test.c -o

To compile test.c and output an EXE with a custom file name:

Ctron test.c -o custom.exe

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Running Bison + Flex Manually

These steps show the internal pipeline when you want to run Flex/Bison and LLVM tools directly.

1. Generate out.ll (LLVM IR) using Flex + Bison:

   Flex_BisonV6.exe test.c

   This generates:

   out.ll
   

2. Convert out.ll to x86 assembly using llc.exe:

   llc.exe -march=x86 --x86-asm-syntax=intel out.ll

   This generates:

   out.s
   

3. Compile the assembly file to an executable using gcc:

   gcc out.s -o test.exe

4. Run the resulting executable:

   test.exe