CI: Install rust and grcov

The Rust toolchain is so that we can build and install grcov, which is
Mozilla's tool to aggregate test coverage data into a report.

.gitlab-ci.yml

@@ -16,7 +16,7 @@ workflow:
 variables:
   FDO_UPSTREAM_REPO: 'cairo/cairo'
   FDO_DISTRIBUTION_VERSION: '40'
-  FDO_DISTRIBUTION_TAG: '2024-07-24-coverage.0'
+  FDO_DISTRIBUTION_TAG: '2024-07-26-coverage.0'
 
   # TODO: should probably get its own image at some point instead of reusing the GStreamer one
   # See https://gitlab.freedesktop.org/gstreamer/gstreamer/-/blob/main/.gitlab-image-tags.yml for latest
@@ -26,6 +26,9 @@ variables:
   DEFAULT_MESON_ARGS: >
     --default-library=both
 
+  RUST_STABLE: "1.80.0"
+  RUSTUP_VERSION: "1.27.1"
+
 stages:
   - prep
   - build
@@ -103,6 +106,14 @@ fedora image:
       libasan
       libubsan
       llvm
+      wget
+    FDO_DISTRIBUTION_EXEC: >-
+      bash .gitlab-ci/install-rust.sh --rustup-version ${RUSTUP_VERSION} \
+                              --stable ${RUST_STABLE} \
+                              --arch x86_64-unknown-linux-gnu &&
+      bash .gitlab-ci/install-rust-tools.sh &&
+      bash .gitlab-ci/install-grcov.sh &&
+      rm -rf /root/.cargo /root/.cache    # cleanup compilation dirs; binaries are installed now
 
 .build fedora:
   extends:

.gitlab-ci/env.sh

@@ -0,0 +1,2 @@
+export RUSTUP_HOME='/usr/local/rustup'
+export PATH=$PATH:/usr/local/cargo/bin

.gitlab-ci/install-grcov.sh

@@ -0,0 +1,8 @@
+source ./.gitlab-ci/env.sh
+
+set -eu
+export CARGO_HOME='/usr/local/cargo'
+
+# Coverage tools
+cargo install grcov
+rustup component add llvm-tools-preview

.gitlab-ci/install-rust-tools.sh

@@ -0,0 +1,11 @@
+source ./.gitlab-ci/env.sh
+
+set -eu
+export CARGO_HOME='/usr/local/cargo'
+
+rustup component add clippy
+rustup component add rustfmt
+# cargo install --force cargo-c
+cargo install --version ^1.0 gitlab_clippy
+cargo install --force cargo-deny
+# cargo install --force cargo-outdated

.gitlab-ci/install-rust.sh

@@ -0,0 +1,92 @@
+#!/bin/bash
+
+set -o errexit -o pipefail -o noclobber -o nounset
+
+source ./.gitlab-ci/env.sh
+
+export CARGO_HOME='/usr/local/cargo'
+
+PARSED=$(getopt --options '' --longoptions 'rustup-version:,stable:,minimum:,nightly,arch:' --name "$0" -- "$@")
+if [ $? -ne 0 ]; then
+	echo 'Terminating...' >&2
+	exit 1
+fi
+
+eval set -- "$PARSED"
+unset PARSED
+
+RUSTUP_VERSION=
+STABLE=
+MINIMUM=
+NIGHTLY=
+ARCH=
+
+while true; do
+    case "$1" in
+        '--rustup-version')
+            RUSTUP_VERSION=$2
+            shift 2
+            ;;
+
+        '--stable')
+            STABLE=$2
+            shift 2
+            ;;
+
+        '--minimum')
+            MINIMUM=$2
+            shift 2
+            ;;
+
+        '--nightly')
+            NIGHTLY=1
+            shift 1
+            ;;
+
+        '--arch')
+            ARCH=$2
+            shift 2
+            ;;
+
+        '--')
+            shift
+            break
+            ;;
+
+        *)
+            echo "Programming error"
+            exit 3
+            ;;
+    esac
+done
+
+if [ -z "$RUSTUP_VERSION" ]; then
+    echo "missing --rustup-version argument"
+    exit 1
+fi
+
+if [ -z "$STABLE" ]; then
+    echo "missing --stable argument, please pass the stable version of rustc you want"
+    exit 1
+fi
+    
+if [ -z "$ARCH" ]; then
+    echo "missing --arch argument, please pass an architecture triple like x86_64-unknown-linux-gnu"
+    exit 1
+fi
+
+RUSTUP_URL=https://static.rust-lang.org/rustup/archive/$RUSTUP_VERSION/$ARCH/rustup-init
+wget $RUSTUP_URL
+
+chmod +x rustup-init
+./rustup-init -y --no-modify-path --profile minimal --default-toolchain $STABLE
+rm rustup-init
+chmod -R a+w $RUSTUP_HOME $CARGO_HOME
+
+if [ -n "$MINIMUM" ]; then
+    rustup toolchain install $MINIMUM
+fi
+
+if [ -n "$NIGHTLY" ]; then
+    rustup toolchain install nightly
+fi