• B Language grammar - here
• Language reference - here

---

The compiler works in 3 stages:

• The Lexer, Parser first-pass, built with an LALR(1) grammar and parser generator in python that interfaces with C++ via pybind11

• An IR I've called Instruction Tuple Abstraction or ITA - a linear 4-tuple set of platform-agnostic instructions that represent program flow, scope, and application runtime

• The target platforms - currently x86_64, arm64, and z80

---

There are a few differences between the compiler and B specification, namely:

• Support for C++ style comments (i.e. //)
• Boolean type coercion for all data types in conditionals
• Switch statement condition must always be enclosed with ( and ),
• Uses C operator precedence
• Constant literals must be exactly 1 byte
• Logical operators behave more like C (i.e. || and &&)
• Bitwise operators behave more like C (i.e. | and &)

Usage

Credence :: B Language Compiler
Usage:
  Credence [OPTION...] positional parameters

  -a, --ast-loader arg   AST Loader [json, python] (default: python)
  -t, --target arg       Target [ast, ir, arm64, x86_64, z80] (default: ir)
  -d, --debug            Enable debugging
  -h, --help             Print usage
      --source-code arg  B Source file

./credence --help

Targets

The default compile target is currently ITA:

Example:

B Code:

main() {
  auto x, y, z;
  x = 5;
  y = 1;
  z = add(x, y) * sub(x,y);
  while(z > x) {
    z = z - 1;
  }
  x = 0;
}

add(x,y) {
  return(x + y);
}

sub(x,y) {
  return(x - y);
}

ITA:

__main:
 BeginFunc ;
    x = (5:int:4);
    y = (1:int:4);
    PUSH y;
    PUSH x;
    CALL add;
    POP 16;
    _t1 = RET;
    PUSH y;
    PUSH x;
    CALL sub;
    POP 16;
    _t2 = RET;
    _t3 = _t1 * _t2;
    z = _t3;
    _t6 = z > x;
_L4:
    IF _t6 GOTO _L5;
    GOTO _L1;
_L1:
    x = (0:int:4);
_L8:
    LEAVE;
_L5:
    _t7 = z - (1:int:4);
    z = _t7;
    GOTO _L4;
 EndFunc ;
__add:
 BeginFunc ;
    _t1 = x + y;
    RET _t1;
    LEAVE;
 EndFunc ;
__sub:
 BeginFunc ;
    _t1 = x - y;
    RET _t1;
    LEAVE;
 EndFunc ;

---

Test suite

make test

---

Installation

Note: $PYTHONHOME must be set to an installation that has chakram installed.

Ubuntu

sudo apt-get update
sudo apt-get install -y gcc-10 llvm-20 valgrind clang-20 iwyu python3-dev cppcheck clang-tidy pipx
# Inside the repository:
echo 'eval "$(register-python-argcomplete pipx)"' >> ~/.profile
source ~/.profile
cmake -Bbuild -DCMAKE_BUILD_TYPE=Debug -DUSE_SANITIZER="Address;Undefined" -DCMAKE_EXPORT_COMPILE_COMMANDS=ON
cmake --build build

MacOS

brew update
brew install coreutils include-what-you-use llvm@20 cmake python3 pyenv
# Inside the repository:
cmake .. -DCMAKE_BUILD_TYPE=Debug -DUSE_SANITIZER="Address;Undefined" -DCMAKE_EXPORT_COMPILE_COMMANDS=ON
cmake --build build

Windows (mingw/msys)

pacman -S git wget mingw-w64-x86_64-clang mingw-w64-x86_64-gcc mingw-w64-x86_64-ninja mingw-w64-x86_64-cmake make mingw-w64-x86_64-python3 autoconf libtool
# Inside the repository:
# Note: iwyu and the -fsanitizers do not work in mingw
cmake -Bbuild -DCMAKE_BUILD_TYPE=Debug -DCMAKE_EXPORT_COMPILE_COMMANDS=ON
ninja

Installing chakram

git submodule update --init --recursive
cd python/chakram
pipx install poetry # or similar
poetry install
# Be sure to use pyenv or similar
make install

---

Dependencies

Note: These are installed automatically via CPM and cmake.

• simplejson++ - lightweight memory safe json library
• chakram - LALR(1) parser generator and Lexer
• cxxopts - lightweight commandline parser
• matchit - pattern matching
• eternal - constexpr lookup tables
• pybind11

License

Apache 2 License.