Add a zig cc-based image.

Uses cargo-zigbuild as a backend, and adds configuration options for zig under `[build.zig]` and `[target.(...).zig]`. If enabled, and an image override is not provided, `cross` will always use the `zig` image.

It supports custom `glibc` versions by parsing the libc portion of the target, and extracting a the libc version if present. The target, if built-in, is then the triple/libc pair, otherwise, it's just the triple.

The image does not provide runners, `bindgen` Clang args, or `pkg-config` paths, since `zig cc` does not provide the dynamic library loader (`ld-linux*.so`) required, meaning none of the binaries can be run. For `bindgen`, `zig cc` has an unusual directory structure, so there is no traditional sysroot with `usr`, `lib`, and `include` subdirectories. Finally, since we don't have system packages we can work with, exporting a `pkg-config` path makes little sense.

Closes cross-rs#860.

.github/workflows/ci.yml

@@ -207,6 +207,7 @@ jobs:
             - { target: thumbv7em-none-eabi,              os: ubuntu-latest,                    std: 1 }
             - { target: thumbv7em-none-eabihf,            os: ubuntu-latest,                    std: 1 }
             - { target: thumbv7m-none-eabi,               os: ubuntu-latest,                    std: 1 }
+            - { target: zig,                              os: ubuntu-latest }
 
   build:
     name: target (${{ matrix.pretty }},${{ matrix.os }})
@@ -283,7 +284,7 @@ jobs:
           IMAGE: ${{ steps.build-docker-image.outputs.image }}
         shell: bash
       - name: Test Image
-        if: steps.prepare-meta.outputs.has-image
+        if: steps.prepare-meta.outputs.has-image && matrix.target != 'zig'
         run: ./ci/test.sh
         env:
           TARGET: ${{ matrix.target }}
@@ -294,6 +295,12 @@ jobs:
           RUN: ${{ matrix.run }}
           RUNNERS: ${{ matrix.runners }}
         shell: bash
+
+      - name: Test Zig Image
+        if: steps.prepare-meta.outputs.has-image && matrix.target == 'zig'
+        run: ./ci/test-zig.sh
+        shell: bash
+
       - uses: ./.github/actions/cargo-install-upload-artifacts
         if: matrix.deploy
         with:

CHANGELOG.md

@@ -7,6 +7,10 @@ This project adheres to [Semantic Versioning](http://semver.org/).
 
 ## [Unreleased] - ReleaseDate
 
+### Added
+
+- #880 - added a zig-based image, allowing multiple targets to be built from the same image.
+
 ### Changed
 
 - #869 - ensure cargo configuration environment variable flags are passed to the docker container.

ci/shared.sh

@@ -0,0 +1,23 @@
+#!/usr/bin/env bash
+
+function retry {
+  local tries="${TRIES-5}"
+  local timeout="${TIMEOUT-1}"
+  local try=0
+  local exit_code=0
+
+  while (( try < tries )); do
+    if "${@}"; then
+      return 0
+    else
+      exit_code=$?
+    fi
+
+    sleep "${timeout}"
+    echo "Retrying ..." 1>&2
+    try=$(( try + 1 ))
+    timeout=$(( timeout * 2 ))
+  done
+
+  return ${exit_code}
+}

ci/test-zig.sh

@@ -0,0 +1,48 @@
+#!/usr/bin/env bash
+# shellcheck disable=SC2086,SC1091,SC1090
+
+set -x
+set -euo pipefail
+
+# NOTE: "${@}" is an unbound variable for bash 3.2, which is the
+# installed version on macOS. likewise, "${var[@]}" is an unbound
+# error if var is an empty array.
+
+ci_dir=$(dirname "${BASH_SOURCE[0]}")
+ci_dir=$(realpath "${ci_dir}")
+project_home=$(dirname "${ci_dir}")
+. "${ci_dir}"/shared.sh
+
+# zig cc is very slow: only use a few targets.
+TARGETS=(
+    "aarch64-unknown-linux-gnu"
+    "aarch64-unknown-linux-musl"
+    "i586-unknown-linux-gnu"
+    "i586-unknown-linux-musl"
+)
+
+main() {
+    export CROSS_BUILD_ZIG=1
+
+    local td=
+    local target=
+
+    retry cargo fetch
+    cargo build
+    export CROSS="${project_home}/target/debug/cross"
+
+    td="$(mktemp -d)"
+    git clone --depth 1 https://github.com/cross-rs/rust-cpp-hello-word "${td}"
+    pushd "${td}"
+
+    for target in "${TARGETS[@]}"; do
+        "${CROSS}" build --target "${target}"
+        # note: ensure #724 doesn't replicate during CI.
+        cargo clean
+    done
+
+    popd
+    rm -rf "${td}"
+}
+
+main "${@}"

ci/test.sh

@@ -1,5 +1,5 @@
 #!/usr/bin/env bash
-# shellcheck disable=SC2086
+# shellcheck disable=SC2086,SC1091,SC1090
 
 set -x
 set -euo pipefail
@@ -8,27 +8,9 @@ set -euo pipefail
 # installed version on macOS. likewise, "${var[@]}" is an unbound
 # error if var is an empty array.
 
-function retry {
-  local tries="${TRIES-5}"
-  local timeout="${TIMEOUT-1}"
-  local try=0
-  local exit_code=0
-
-  while (( try < tries )); do
-    if "${@}"; then
-      return 0
-    else
-      exit_code=$?
-    fi
-
-    sleep "${timeout}"
-    echo "Retrying ..." 1>&2
-    try=$(( try + 1 ))
-    timeout=$(( timeout * 2 ))
-  done
-
-  return ${exit_code}
-}
+ci_dir=$(dirname "${BASH_SOURCE[0]}")
+ci_dir=$(realpath "${ci_dir}")
+. "${ci_dir}"/shared.sh
 
 workspace_test() {
   "${CROSS[@]}" build --target "${TARGET}" --workspace "$@" ${CROSS_FLAGS}

docker/Dockerfile.zig

@@ -0,0 +1,30 @@
+FROM ubuntu:20.04
+ARG DEBIAN_FRONTEND=noninteractive
+
+COPY common.sh lib.sh /
+RUN /common.sh
+
+COPY cmake.sh /
+RUN /cmake.sh
+
+COPY xargo.sh /
+RUN /xargo.sh
+
+COPY zig.sh /
+RUN /zig.sh
+
+# needed for the zig cache, which tries to install a cache dir
+# in the current users directory, relative to $HOME. if the user
+# doesn't exist, it will try to install in the root directory,
+# getting permission errors
+RUN adduser --uid 1000 --disabled-password --gecos "" cross
+
+RUN apt-get update && apt-get install --assume-yes --no-install-recommends \
+    qemu-system \
+    qemu-user
+
+# we don't export `BINDGEN_EXTRA_CLANG_ARGS`, `QEMU_LD_PREFIX`, or
+# `PKG_CONFIG_PATH` since zig doesn't have a traditional sysroot structure,
+# and we're not using standard, shared packages. none of the packages
+# have runners either, since they do not ship with the required
+# dynamic linker (`ld-linux-${arch}.so`).

docker/zig.sh

@@ -0,0 +1,62 @@
+#!/usr/bin/env bash
+
+set -x
+set -euo pipefail
+
+# shellcheck disable=SC1091
+. lib.sh
+
+main() {
+    install_packages ca-certificates curl xz-utils
+
+    install_zig
+    install_zigbuild
+
+    purge_packages
+    rm "${0}"
+}
+
+install_zig() {
+    local version="0.9.1"
+    local filename="zig-linux-x86_64-${version}.tar.xz"
+    local dst="/opt/zig"
+
+    local td
+    td="$(mktemp -d)"
+
+    pushd "${td}"
+
+    curl --retry 3 -sSfL "https://ziglang.org/download/${version}/${filename}" -O
+    mkdir -p "${dst}"
+    tar --strip-components=1 -xJf "${filename}" --directory "${dst}"
+
+    popd
+
+    rm -rf "${td}"
+}
+
+install_zigbuild() {
+    local version=0.10.3
+
+    local td
+    td="$(mktemp -d)"
+
+    pushd "${td}"
+
+    export RUSTUP_HOME="${td}/rustup"
+    export CARGO_HOME="${td}/cargo"
+
+    curl --retry 3 -sSfL https://sh.rustup.rs -o rustup-init.sh
+    sh rustup-init.sh -y --no-modify-path --profile minimal
+
+    PATH="${CARGO_HOME}/bin:${PATH}" \
+        cargo install cargo-zigbuild \
+        --version "${version}" \
+        --root /usr/local
+
+    popd
+
+    rm -rf "${td}"
+}
+
+main "${@}"

docs/cross_toml.md

@@ -10,6 +10,7 @@ The `build` key allows you to set global variables, e.g.:
 [build]
 xargo = true
 build-std = true
+zig = false
 default-target = "x86_64-unknown-linux-gnu"
 ```
 
@@ -33,6 +34,7 @@ The `target` key allows you to specify parameters for specific compilation targe
 [target.aarch64-unknown-linux-gnu]
 xargo = false
 build-std = false
+zig = true
 image = "test-image"
 pre-build = ["apt-get update"]
 runner = "custom-runner"

src/config.rs

@@ -65,6 +65,10 @@ impl Environment {
         self.get_values_for("BUILD_STD", target, bool_from_envvar)
     }
 
+    fn zig(&self, target: &Target) -> (Option<bool>, Option<bool>) {
+        self.get_values_for("ZIG", target, bool_from_envvar)
+    }
+
     fn image(&self, target: &Target) -> Option<String> {
         self.get_target_var(target, "IMAGE")
     }
@@ -244,6 +248,10 @@ impl Config {
         self.bool_from_config(target, Environment::build_std, CrossToml::build_std)
     }
 
+    pub fn zig(&self, target: &Target) -> Option<bool> {
+        self.bool_from_config(target, Environment::zig, CrossToml::zig)
+    }
+
     pub fn image(&self, target: &Target) -> Result<Option<String>> {
         self.string_from_config(target, Environment::image, CrossToml::image)
     }
@@ -382,16 +390,19 @@ mod tests {
             let env = Environment::new(Some(map));
             assert_eq!(env.xargo(&target()), (Some(true), None));
             assert_eq!(env.build_std(&target()), (Some(false), None));
+            assert_eq!(env.zig(&target()), (None, None));
         }
 
         #[test]
         pub fn build_and_target_set_returns_tuple() {
             let mut map = std::collections::HashMap::new();
             map.insert("CROSS_BUILD_XARGO", "true");
+            map.insert("CROSS_BUILD_ZIG", "false");
             map.insert("CROSS_TARGET_AARCH64_UNKNOWN_LINUX_GNU_XARGO", "false");
 
             let env = Environment::new(Some(map));
             assert_eq!(env.xargo(&target()), (Some(true), Some(false)));
+            assert_eq!(env.zig(&target()), (Some(false), None));
         }
 
         #[test]
@@ -527,7 +538,6 @@ mod tests {
                 config.env_volumes(&target())?,
                 Some(vec![s!("VOLUME3"), s!("VOLUME4")])
             );
-            // TODO(ahuszagh) Need volumes
 
             Ok(())
         }