1 files changed, 70 insertions, 0 deletions
diff --git a/src/ci/scripts/install-clang.sh b/src/ci/scripts/install-clang.sh
new file mode 100755
index 000000000..0bc8a0389
--- /dev/null
+++ b/src/ci/scripts/install-clang.sh
@@ -0,0 +1,70 @@
+#!/bin/bash
+# ignore-tidy-linelength
+# This script installs clang on the local machine. Note that we don't install
+# clang on Linux since its compiler story is just so different. Each container
+# has its own toolchain configured appropriately already.
+
+set -euo pipefail
+IFS=$'\n\t'
+
+source "$(cd "$(dirname "$0")" && pwd)/../shared.sh"
+
+# Update both macOS's and Windows's tarballs when bumping the version here.
+LLVM_VERSION="14.0.5"
+
+if isMacOS; then
+    # If the job selects a specific Xcode version, use that instead of
+    # downloading our own version.
+    if [[ ${USE_XCODE_CLANG-0} -eq 1 ]]; then
+        bindir="$(xcode-select --print-path)/Toolchains/XcodeDefault.xctoolchain/usr/bin"
+    else
+        file="${MIRRORS_BASE}/clang%2Bllvm-${LLVM_VERSION}-x86_64-apple-darwin.tar.xz"
+        retry curl -f "${file}" -o "clang+llvm-${LLVM_VERSION}-x86_64-apple-darwin.tar.xz"
+        tar xJf "clang+llvm-${LLVM_VERSION}-x86_64-apple-darwin.tar.xz"
+        bindir="$(pwd)/clang+llvm-${LLVM_VERSION}-x86_64-apple-darwin/bin"
+    fi
+
+    ciCommandSetEnv CC "${bindir}/clang"
+    ciCommandSetEnv CXX "${bindir}/clang++"
+
+    # macOS 10.15 onwards doesn't have libraries in /usr/include anymore: those
+    # are now located deep into the filesystem, under Xcode's own files. The
+    # native clang is configured to use the correct path, but our custom one
+    # doesn't. This sets the SDKROOT environment variable to the SDK so that
+    # our own clang can figure out the correct include path on its own.
+    ciCommandSetEnv SDKROOT "$(xcrun --sdk macosx --show-sdk-path)"
+
+    # Configure `AR` specifically so rustbuild doesn't try to infer it as
+    # `clang-ar` by accident.
+    ciCommandSetEnv AR "ar"
+elif isWindows && [[ ${CUSTOM_MINGW-0} -ne 1 ]]; then
+
+    if [[ ${WINDOWS_SDK_20348_HACK-0} -eq 1 ]]; then
+        rm -rf '/c/Program Files (x86)/Windows Kits/10/include/10.0.20348.0'
+        mv '/c/Program Files (x86)/Windows Kits/10/include/'10.0.{19041,20348}.0
+    fi
+
+    # If we're compiling for MSVC then we, like most other distribution builders,
+    # switch to clang as the compiler. This'll allow us eventually to enable LTO
+    # amongst LLVM and rustc. Note that we only do this on MSVC as I don't think
+    # clang has an output mode compatible with MinGW that we need. If it does we
+    # should switch to clang for MinGW as well!
+    #
+    # The LLVM installer is an NSIS installer, which we can extract with 7z. We
+    # don't want to run the installer directly; extracting it is more reliable
+    # in CI environments.
+
+    mkdir -p citools/clang-rust
+    cd citools
+    retry curl -f "${MIRRORS_BASE}/LLVM-${LLVM_VERSION}-win64.exe" \
+        -o "LLVM-${LLVM_VERSION}-win64.exe"
+    7z x -oclang-rust/ "LLVM-${LLVM_VERSION}-win64.exe"
+    ciCommandSetEnv RUST_CONFIGURE_ARGS \
+        "${RUST_CONFIGURE_ARGS} --set llvm.clang-cl=$(pwd)/clang-rust/bin/clang-cl.exe"
+fi
+
+if isWindows; then
+    # GitHub image 20210928.2 added LLVM, but it is broken (and we don't want
+    # to use it anyways).
+    rm -rf /c/Program\ Files/LLVM
+fi