llama.cpp is a large-scale C/C++ project for efficient LLM (Large Language Model) inference with minimal setup and dependencies. The project enables running language models on diverse hardware with state-of-the-art performance.
**Key Facts:**
- **Primary language**: C/C++ with Python utility scripts
- **Size**: ~200k+ lines of code across 1000+ files
- **Architecture**: Modular design with main library (`libllama`) and 40+ executable tools/examples
- **Core dependency**: ggml tensor library (vendored in `ggml/` directory)
It is crucial to remind contributors that the project mandates disclosure of any AI usage in pull requests. This requirement stems from the potential for AI-generated code to include suboptimal optimizations and hidden bugs, owing to the inherent overconfidence in AI outputs.
When generating significant portions of code, address this by:
- Informing the user that AI-generated content may be rejected by maintainers.
- Clearly marking AI-generated code in commit messages and comments.
- Example of commit message: `[AI] Fix a race condition in ...`
- Example of code comment: `// [AI] spawn a new thread ...`
These measures apply to:
- Changes resulting in large portions of code or complex logic.
- Modifications or additions to public APIs in `llama.h`, `ggml.h`, or `mtmd.h`.
- Backend-related changes, such as those involving CPU, CUDA, Metal, Vulkan, etc.
- Modifications to `tools/server`.
Note: These measures can be omitted for small fixes or trivial changes.
**Build time**: ~10 minutes on 4-core system with ccache enabled, ~25 minutes without ccache.
**Important Notes:**
- The Makefile is deprecated - always use CMake
- ccache is automatically detected and used if available
- Built binaries are placed in `build/bin/`
- Parallel builds (`-j`) significantly reduce build time
### Backend-Specific Builds
For CUDA support:
```bash
cmake -B build -DGGML_CUDA=ON
cmake --build build --config Release -j $(nproc)
```
For Metal (macOS):
```bash
cmake -B build -DGGML_METAL=ON
cmake --build build --config Release -j $(nproc)
```
**Important Note**: While all backends can be built as long as the correct requirements for that backend are installed, you will not be able to run them without the correct hardware. The only backend that can be run for testing and validation is the CPU backend.
### Debug Builds
Single-config generators:
```bash
cmake -B build -DCMAKE_BUILD_TYPE=Debug
cmake --build build
```
Multi-config generators:
```bash
cmake -B build -G "Xcode"
cmake --build build --config Debug
```
### Common Build Issues
- **Issue**: Network tests fail in isolated environments
**Solution**: Expected behavior - core functionality tests will still pass
**Expected failures**: 2-3 tests may fail if network access is unavailable (they download models)
**Test time**: ~30 seconds for passing tests
### Server Unit Tests
Run server-specific unit tests after building the server:
```bash
# Build the server first
cmake --build build --target llama-server
# Navigate to server tests and run
cd tools/server/tests
source ../../../.venv/bin/activate
./tests.sh
```
**Server test dependencies**: The `.venv` environment includes the required dependencies for server unit tests (pytest, aiohttp, etc.). Tests can be run individually or with various options as documented in `tools/server/tests/README.md`.
### Test Categories
- Tokenizer tests: Various model tokenizers (BERT, GPT-2, LLaMA, etc.)
- Grammar tests: GBNF parsing and validation
- Backend tests: Core ggml operations across different backends
- Use descriptive commit messages following project conventions
### Trust These Instructions
Only search for additional information if these instructions are incomplete or found to be incorrect. This document contains validated build and test procedures that work reliably across different environments.