Add riscv64-linux support

.github/workflows/linux.yml

@@ -58,9 +58,11 @@ jobs:
         image:
           - build
           - build.cross
+          - build.cross-riscv64
           - gcc
           - xcb
           - xcb.cross
+          - xcb.cross-riscv64
     name: ${{ matrix.image }}
     runs-on: depot-ubuntu-22.04
     permissions:

ci-targets.yaml

@@ -143,6 +143,27 @@ linux:
           - freethreaded+lto
         minimum-python-version: "3.13"
 
+  riscv64-unknown-linux-gnu:
+    arch: riscv64
+    libc: gnu
+    python_versions:
+      - "3.9"
+      - "3.10"
+      - "3.11"
+      - "3.12"
+      - "3.13"
+      - "3.14"
+    build_options:
+      - debug
+      - noopt
+      - lto
+    build_options_conditional:
+      - options:
+          - freethreaded+debug
+          - freethreaded+noopt
+          - freethreaded+lto
+        minimum-python-version: "3.13"
+
   x86_64-unknown-linux-gnu:
     arch: x86_64
     libc: gnu

cpython-unix/build-cpython.sh

@@ -936,6 +936,9 @@ mips64el-unknown-linux-gnuabi64)
 ppc64le-unknown-linux-gnu)
     PYTHON_ARCH="powerpc64le-linux-gnu"
     ;;
+riscv64-unknown-linux-gnu)
+    PYTHON_ARCH="riscv64-linux-gnu"
+    ;;
 s390x-unknown-linux-gnu)
     PYTHON_ARCH="s390x-linux-gnu"
     ;;

cpython-unix/build-libX11.sh

@@ -69,6 +69,9 @@ if [ -n "${CROSS_COMPILING}" ]; then
     ppc64le-unknown-linux-gnu)
       EXTRA_FLAGS="${EXTRA_FLAGS} --enable-malloc0returnsnull"
       ;;
+    riscv64-unknown-linux-gnu)
+      EXTRA_FLAGS="${EXTRA_FLAGS} --enable-malloc0returnsnull"
+      ;;
     s390x-unknown-linux-gnu)
       EXTRA_FLAGS="${EXTRA_FLAGS} --enable-malloc0returnsnull"
       ;;

cpython-unix/build-main.py

@@ -103,9 +103,11 @@ def main():
             "toolchain",
             "toolchain-image-build",
             "toolchain-image-build.cross",
+            "toolchain-image-build.cross-riscv64",
             "toolchain-image-gcc",
             "toolchain-image-xcb",
             "toolchain-image-xcb.cross",
+            "toolchain-image-xcb.cross-riscv64",
         },
         default="default",
         help="The make target to evaluate",

cpython-unix/build.cross-riscv64.Dockerfile

@@ -0,0 +1,68 @@
+# Debian Buster.
+FROM debian@sha256:2a0c1b9175adf759420fe0fbd7f5b449038319171eb76554bb76cbe172b62b42
+MAINTAINER Gregory Szorc <[email protected]>
+
+RUN groupadd -g 1000 build && \
+    useradd -u 1000 -g 1000 -d /build -s /bin/bash -m build && \
+    mkdir /tools && \
+    chown -R build:build /build /tools
+
+ENV HOME=/build \
+    SHELL=/bin/bash \
+    USER=build \
+    LOGNAME=build \
+    HOSTNAME=builder \
+    DEBIAN_FRONTEND=noninteractive
+
+CMD ["/bin/bash", "--login"]
+WORKDIR '/build'
+
+RUN for s in debian_buster debian_buster-updates debian-security_buster/updates; do \
+      echo "deb http://snapshot.debian.org/archive/${s%_*}/20250109T084424Z/ ${s#*_} main"; \
+    done > /etc/apt/sources.list && \
+    ( echo 'quiet "true";'; \
+      echo 'APT::Get::Assume-Yes "true";'; \
+      echo 'APT::Install-Recommends "false";'; \
+      echo 'Acquire::Check-Valid-Until "false";'; \
+      echo 'Acquire::Retries "5";'; \
+    ) > /etc/apt/apt.conf.d/99cpython-portable
+
+RUN apt-get update
+
+# Host building.
+RUN apt-get install \
+    bzip2 \
+    gcc \
+    g++ \
+    libc6-dev \
+    libffi-dev \
+    make \
+    patch \
+    perl \
+    pkg-config \
+    tar \
+    xz-utils \
+    unzip \
+    zip \
+    zlib1g-dev
+
+# Cross-building.
+RUN apt-get install \
+    gcc-aarch64-linux-gnu \
+    gcc-arm-linux-gnueabi \
+    gcc-arm-linux-gnueabihf \
+    gcc-mips-linux-gnu \
+    gcc-mips64el-linux-gnuabi64 \
+    gcc-mipsel-linux-gnu \
+    gcc-powerpc64le-linux-gnu \
+    gcc-riscv64-linux-gnu \
+    gcc-s390x-linux-gnu \
+    libc6-dev-arm64-cross \
+    libc6-dev-armel-cross \
+    libc6-dev-armhf-cross \
+    libc6-dev-mips-cross \
+    libc6-dev-mips64el-cross \
+    libc6-dev-mipsel-cross \
+    libc6-dev-ppc64el-cross \
+    libc6-dev-riscv64-cross \
+    libc6-dev-s390x-cross

cpython-unix/build.py

@@ -550,6 +550,13 @@ def python_build_info(
     if mips and version == "3.13":
         # See https://github.com/indygreg/python-build-standalone/issues/410
         linux_allowed_system_libraries.add("atomic")
+    riscv = target_triple.split("-")[0] in {"riscv64"}
+    if riscv:
+        # RISC-V binary often comes with libatomic on old GCC versions
+        # See https://github.com/riscvarchive/riscv-gcc/issues/12
+        # https://github.com/riscvarchive/riscv-gcc/issues/337
+        # https://gcc.gnu.org/bugzilla/show_bug.cgi?id=86005
+        linux_allowed_system_libraries.add("atomic")
 
     # Add in core linking annotations.
     libs = extra_metadata["python_config_vars"].get("LIBS", "").split()

cpython-unix/extension-modules.yml

@@ -259,6 +259,7 @@ _decimal:
       targets:
         - aarch64-.*
         - ppc64le-unknown-linux.*
+        - riscv64-unknown-linux.*
         - s390x-unknown-linux-.*
         - x86_64.*
   links:

cpython-unix/targets.yml

@@ -470,6 +470,46 @@ ppc64le-unknown-linux-gnu:
     - zlib
   openssl_target: linux-ppc64le
 
+riscv64-unknown-linux-gnu:
+  host_platforms:
+    - linux64
+  pythons_supported:
+    - '3.9'
+    - '3.10'
+    - '3.11'
+    - '3.12'
+    - '3.13'
+    - '3.14'
+  docker_image_suffix: .cross-riscv64
+  host_cc: /usr/bin/x86_64-linux-gnu-gcc
+  host_cxx: /usr/bin/x86_64-linux-gnu-g++
+  target_cc: /usr/bin/riscv64-linux-gnu-gcc
+  needs:
+    - autoconf
+    - bdb
+    - binutils
+    - bzip2
+    - expat
+    - libedit
+    - libffi
+    - libX11
+    - libXau
+    - libxcb
+    - m4
+    - mpdecimal
+    - ncurses
+    - openssl-3.0
+    - patchelf
+    - sqlite
+    - tcl
+    - tk
+    - tix
+    - uuid
+    - xorgproto
+    - xz
+    - zlib
+  openssl_target: linux64-riscv64
+
 s390x-unknown-linux-gnu:
   host_platforms:
     - linux64

cpython-unix/xcb.cross-riscv64.Dockerfile

@@ -0,0 +1,3 @@
+{% include 'build.cross-riscv64.Dockerfile' %}
+RUN apt-get install \
+    python

docs/building.rst

@@ -42,6 +42,7 @@ As are various other targets::
     $ ./build-linux.py --target mips-unknown-linux-gnu
     $ ./build-linux.py --target mipsel-unknown-linux-gnu
     $ ./build-linux.py --target ppc64le-unknown-linux-gnu
+    $ ./build-linux.py --target riscv64-unknown-linux-gnu
     $ ./build-linux.py --target s390x-unknown-linux-gnu
 
 macOS

src/release.rs

@@ -194,6 +194,19 @@ pub static RELEASE_TRIPLES: Lazy<BTreeMap<&'static str, TripleRelease>> = Lazy::
         },
     );
 
+    h.insert(
+        "riscv64-unknown-linux-gnu",
+        TripleRelease {
+            suffixes: linux_suffixes_nopgo.clone(),
+            install_only_suffix: "lto",
+            python_version_requirement: Some(VersionSpecifier::from_str(">=3.9").unwrap()),
+            conditional_suffixes: vec![ConditionalSuffixes {
+                python_version_requirement: VersionSpecifier::from_str(">=3.13").unwrap(),
+                suffixes: linux_suffixes_nopgo_freethreaded.clone(),
+            }],
+        },
+    );
+
     h.insert(
         "s390x-unknown-linux-gnu",
         TripleRelease {

src/validation.rs

@@ -45,6 +45,7 @@ const RECOGNIZED_TRIPLES: &[&str] = &[
     "mipsel-unknown-linux-gnu",
     "mips64el-unknown-linux-gnuabi64",
     "ppc64le-unknown-linux-gnu",
+    "riscv64-unknown-linux-gnu",
     "s390x-unknown-linux-gnu",
     "thumbv7k-apple-watchos",
     "x86_64-apple-darwin",
@@ -172,6 +173,10 @@ static GLIBC_MAX_VERSION_BY_TRIPLE: Lazy<HashMap<&'static str, version_compare::
             "ppc64le-unknown-linux-gnu",
             version_compare::Version::from("2.17").unwrap(),
         );
+        versions.insert(
+            "riscv64-unknown-linux-gnu",
+            version_compare::Version::from("2.28").unwrap(),
+        );
         versions.insert(
             "s390x-unknown-linux-gnu",
             version_compare::Version::from("2.17").unwrap(),
@@ -233,6 +238,7 @@ static ELF_ALLOWED_LIBRARIES_BY_TRIPLE: Lazy<HashMap<&'static str, Vec<&'static
             ),
             ("mips64el-unknown-linux-gnuabi64", vec![]),
             ("ppc64le-unknown-linux-gnu", vec!["ld64.so.1", "ld64.so.2"]),
+            ("riscv64-unknown-linux-gnu", vec!["ld-linux-riscv64-lp64d.so.1", "libatomic.so.1"]),
             ("s390x-unknown-linux-gnu", vec!["ld64.so.1"]),
             ("x86_64-unknown-linux-gnu", vec!["ld-linux-x86-64.so.2"]),
             ("x86_64_v2-unknown-linux-gnu", vec!["ld-linux-x86-64.so.2"]),
@@ -488,6 +494,7 @@ static PLATFORM_TAG_BY_TRIPLE: Lazy<HashMap<&'static str, &'static str>> = Lazy:
         ("mipsel-unknown-linux-gnu", "linux-mipsel"),
         ("mips64el-unknown-linux-gnuabi64", "todo"),
         ("ppc64le-unknown-linux-gnu", "linux-powerpc64le"),
+        ("riscv64-unknown-linux-gnu", "linux-riscv64"),
         ("s390x-unknown-linux-gnu", "linux-s390x"),
         ("x86_64-apple-darwin", "macosx-10.15-x86_64"),
         ("x86_64-apple-ios", "iOS-x86_64"),
@@ -866,6 +873,7 @@ fn validate_elf<Elf: FileHeader<Endian = Endianness>>(
         "mipsel-unknown-linux-gnu" => object::elf::EM_MIPS,
         "mips64el-unknown-linux-gnuabi64" => 0,
         "ppc64le-unknown-linux-gnu" => object::elf::EM_PPC64,
+        "riscv64-unknown-linux-gnu" => object::elf::EM_RISCV,
         "s390x-unknown-linux-gnu" => object::elf::EM_S390,
         "x86_64-unknown-linux-gnu" => object::elf::EM_X86_64,
         "x86_64_v2-unknown-linux-gnu" => object::elf::EM_X86_64,