MetaCG

MetaCG provides a common whole-program call-graph representation to exchange information between different tools built on top of LLVM/Clang. It uses the JSON file format and separates structure from information, i.e., caller/callee relation and meta information.

The MetaCG graph library is the fundamental component, together with, e.g., I/O facilities. The repository also contains an experimental Clang-based tool for call-graph construction at the source-code level. As an example tool, the repository contains the PGIS analysis tool, which is used as the analysis backend in PIRA. PGIS has been deprecated and may be removed in a future version.

The current default file format is MetaCG format version 4. More info on the different formats can be found in the graph README.

The MetaCG project includes pymetacg, a set of bindings that allows to parse MetaCG files from Python. Refer to the pymetacg README for more information how to build and use pymetacg.

Requirements and Building

MetaCG consists of the graph library, a CG construction tool, and an example analysis tool. The graph library is always built, while the CGCollector and the PGIS tool can be disabled at configure time.

We test MetaCG internally using GCC 11 for Clang/LLVM 13, 14, 15, 16, 17 and 18. Other version combinations may work.

Build Requirements (for graph lib) - nlohmann/json library github - spdlog github

Additional Build Requirements (for full build) - Clang/LLVM version 10 (and above) - Cube 4.5 scalasca.org - Extra-P 3.0 .tar.gz - cxxopts github - PyQt5 - matplotlib

Building

Graph Library Only

The default is to build only the graph library. The build requirements are downloaded at configure time. While CMake looks for nlohmann-json version 3.12., MetaCG should work starting from version 3.9.2. For spdlog, we rely on version 1.15.3 -- other versions may work. If you do not want to download at configure time, please use the respective CMake options listed below.

```{.sh}

To build the MetaCG library w/o PGIS or CGCollector

$> cmake -S . -B build -G Ninja -DCMAKEINSTALLPREFIX=/where/to/install $> cmake --build build --parallel $> cmake --install build ```

Build Graph Library and Tools (CGCollector, PGIS, ...)

You can configure MetaCG to also build CGCollector, PGIS and other tools based on the graphlib (cgconvert, cgformat, cgmerge2). This requires additional dependencies. Clang/LLVM (in a supported version) are assumed to be available on the system. Extra-P and Cube library can be built using the build_submodules.sh script provided in the repository, though the script is not tested outside of our CI system. It builds and installs the dependencies into ./extern.

{.sh} $> ./build_submodules.sh

Thereafter, the package can be configured and built from the top-level CMake. Change the CMAKE_INSTALL_PREFIX to where you want your MetaCG installation to live.

```{.sh}

To build the MetaCG library w/ PGIS and CGCollector

$> extinstalldir=./extern/install $> cmake -S . -B build \ -DCMAKEINSTALLPREFIX=/where/to/install \ -DCUBEDIR="$extinstalldir/cubelib" \ -DEXTRAPINCLUDE="$extinstalldir/extrap/include" \ -DEXTRAPLIB="$extinstalldir/extrap/lib" \ -DMETACGBUILDCGCOLLECTOR=ON \ -DMETACGBUILDPGIS=ON \ -DMETACGBUILDGRAPHTOOLS=ON $> cmake --build build --parallel

Installation installs CGCollector, CGMerge, CGValidate, PGIS

$> cmake --install build ```

General CMake Options

These options are common for the MetaCG package.

• Bool METACG_BUILD_CGCOLLECTOR: Whether to build call-graph construction tool
• Bool METACG_BUILD_PGIS: Whether to build demo-analysis tool
• Bool METACG_USE_EXTERNAL_JSON: Search for installed version of nlohmann-json

PGIS CMake Options

These options are required when building with METACG_BUILD_PGIS=ON.

• Path CUBE_DIR: Path to the libcube installation
• Path EXTRAP_LIB: Path to the Extra-P library directory
• Path EXTRAP_INCLUDE: Path to the Extra-P include directory

Usage

Graph Library

Provides the basic data structures and its means to read and write the call graph with the metadata to a JSON file. To include MetaCG as library in your project, you can simply install, find the package and link the library. This pulls in all required dependencies and compile flags.

```

In your project's CMake

findpackage(MetaCG <VERSIONSTR> REQUIRED)

Assuming you have a target MainApp

targetlinklibrary(MainApp metacg::metacg) ```

CGCollector

Clang-based call-graph generation tool for MetaCG. It has the components CGCollector, CGMerge and CGValidate to construct the partial MCG per translation unit, merge the partial MCGs into the final whole-program MCG and validate edges against a full Score-P profile, respectively.

See its README for details.

PGIS (The PIRA Analyzer)

This tool is part of the PIRA toolchain. It is used as analysis engine and constructs instrumentation selections guided by both static and dynamic information from a target application.

See its README for details.