Compiler ABI Extractor

How to ensure that object files from two compilers are ABI compatible?

This tool is capable of extracting ABI properties for a compiler. This human readable summary can be compared to another version, be it a reference version or one created for a different compiler or with different options, exposing where compatibility problems can pop up.

Prerequisites

Compiler ABI Extractor

Ensure Python is installed on the system:

$ sudo apt-get install python3

Installing Prebuilt Binaries

RISC-V GCC GNU Toolchain

Prebuilt binaries for the toolchain are available in the releases section of the riscv-gnu-toolchain repository.

Find the RISC-V 32-bit ELF GCC file. For example: riscv32-elf-ubuntu-22.04-gcc-nightly-2025.01.20-nightly.tar.xz

$ cd $HOME
# Replace `2025.01.20` with the latest version if necessary.
$ wget https://github.com/riscv-collab/riscv-gnu-toolchain/releases/download/2025.01.20/riscv32-elf-ubuntu-22.04-gcc-nightly-2025.01.20-nightly.tar.xz
$ tar -xvf riscv32-elf-ubuntu-22.04-gcc-nightly-2025.01.20-nightly.tar.xz

# Configure the environment:
$ export PATH=$HOME/riscv/bin:$PATH
$ export LD_LIBRARY_PATH=$HOME/riscv/lib:$LD_LIBRARY_PATH
$ which riscv32-unknown-elf-gcc

These binaries support only the ilp32d ABI.

QEMU

To install QEMU for riscv32, run:

$ sudo apt-get install qemu-user
$ which qemu-riscv32

Building from Source

To set up quickly, run the clone-build-toolchain-qemu.sh script:

$ source abi-extract-info/scripts/clone-build-toolchain-qemu.sh

This script will clone the RISC-V GNU Toolchain repository, which will then clone (via git submodules) and build the following tools:

• GCC (GNU Compiler Collection): https://gcc.gnu.org/git/gcc.git
• Binutils (Assembler, linker, and related tools): https://sourceware.org/git/binutils-gdb.git
• GDB (GNU Debugger): https://sourceware.org/git/binutils-gdb.git
• Newlib (C library for embedded systems): https://sourceware.org/git/newlib-cygwin.git
• QEMU (Emulator for running RISC-V binaries): https://gitlab.com/qemu-project/qemu.git

Examine the script for detailed steps.

Check the riscv-gnu-toolchain and qemu repositories for package dependencies.

Quick Start

To run the tool with default settings, use:

$ python3 abi-extract-info
Running gcc-riscv32 with qemu-riscv32...
Report file generated at gcc-riscv32_qemu-riscv32.report

By default, the tool expects a RISC-V 32-bit GCC compiler (riscv32-unknown-elf-gcc) and a QEMU emulator (qemu-riscv32) to be available on the system. It generates a summary report named after the compiler and simulator wrappers used.

For more options, refer to the helper manual with --help:

Usage python3 abi-extract-info [options]
Options:
  -cc <compiler wrapper>        Select the compiler.
  -sim <simulator wrapper>      Select the simulator.
  -v | --verbose                Print execution commands.
  --print-report                Print summary report upon conclusion.
  --save-temps                  Do not delete the temporary files from "tmp/" directory.
  --help                        Display this information.
  --help=cc                     Display available compiler options.
  --help=sim                    Display available simulator options.

To list available configurations, run:

$ python3 abi-extract-info --help=cc --help=sim
Available configurations for CC:
- gcc-riscv32
- clang-riscv32
Available configurations for SIM:
- qemu-riscv32

Documentation

For additional resources, see the docs/ folder.