D-Kompilierer

A compiler for a German-keyword programming language (.d files) built with Flex/Bison. Generates LLVM IR for further compilation to native code.

University Project — This was a compiler construction course project. The codebase is complete and serves as an educational reference implementation. No further development is expected.

Prerequisites

• Bison ≥ 3.8.2 (macOS: install via Homebrew, system version is too old)
• Flex
• CMake ≥ 3.28
• C++17 compiler (GCC or Clang)
• LLVM (for IR generation and native compilation)

Building

mkdir build && cd build
cmake ..
make

macOS users: Homebrew Bison is required:

cmake -DBISON_EXECUTABLE=$(brew --prefix bison)/bin/bison ..

Usage & LLVM Workflow

The compiler parses .d source files and generates LLVM IR (.ll files). To produce an executable binary, you need to compile the IR and link it with a C/C++ wrapper.

Basic Usage

./build/compiler program.d

This generates output.ll in the current directory.

Full Compilation Workflow

# Step 1: Compile D source to LLVM IR
./build/compiler program.d

# Step 2: Compile IR to object file
llc -filetype=obj output.ll -o program.o

# Step 3: Link with C/C++ wrapper
clang wrapper.cc program.o -o program

# Step 4: Run
./program

See src/llvm/ for example C++ wrapper files and test IR.

Command-Line Flags

• -p — Trace parsing (Flex/Bison parser only)
• -s — Trace scanning (Flex/Bison parser only)

Project Structure

Directory	Purpose
src/parser/	Flex/Bison parser + Driver
src/manual/	Hand-written recursive-descent parser (⚠️ no longer maintained)
src/ast/	AST node types, Visitor pattern, ASTPrinter, AST→Symboltable
src/symboltable/	Symbol table implementation and printer
src/semantic/	Semantic analysis passes (GlobalDeclPass, SemanticChecker)
src/ir-generator/	LLVM IR code generation (CodegenVisitor)
src/llvm/	Example C++ wrappers and test IR files
src/common/	Shared types: SourceLocation, Token, Types
tests/	Test suite with correct/incorrect programs

Testing

cd tests && bash parser_test.sh

The test script:

• Rebuilds the compiler from scratch
• Runs all .d files in tests/correct/ (expects exit code 0)
• Runs all .d files in tests/incorrect/ (expects exit code 1)
• Automatically detects Homebrew Bison on macOS

Manual Parser Note

The manual parser in src/manual/ is no longer maintained. Use the default Flex/Bison parser for all compilation tasks. See src/manual/README.md for architectural documentation.

Language Features

The source language uses German keywords such as:

• funk (function)
• leer (void)
• zurück (return)
• and others

See test files in tests/correct/ for example programs.