dotnet-installer/eng/common/native/init-compiler.sh

#!/usr/bin/env bash
#
# This file detects the C/C++ compiler and exports it to the CC/CXX environment variables
#

if [[ "$#" -lt 3 ]]; then
  echo "Usage..."
  echo "init-compiler.sh <script directory> <Architecture> <compiler> <compiler major version> <compiler minor version>"
  echo "Specify the script directory."
  echo "Specify the target architecture."
  echo "Specify the name of compiler (clang or gcc)."
  echo "Specify the major version of compiler."
  echo "Specify the minor version of compiler."
  exit 1
fi

nativescriptroot="$1"
build_arch="$2"
compiler="$3"
cxxCompiler="$compiler++"
majorVersion="$4"
minorVersion="$5"

. "$nativescriptroot"/../pipeline-logging-functions.sh

# clear the existing CC and CXX from environment
CC=
CXX=
LDFLAGS=

if [[ "$compiler" == "gcc" ]]; then cxxCompiler="g++"; fi

check_version_exists() {
    desired_version=-1

    # Set up the environment to be used for building with the desired compiler.
    if command -v "$compiler-$1.$2" > /dev/null; then
        desired_version="-$1.$2"
    elif command -v "$compiler$1$2" > /dev/null; then
        desired_version="$1$2"
    elif command -v "$compiler-$1$2" > /dev/null; then
        desired_version="-$1$2"
    fi

    echo "$desired_version"
}

if [[ -z "$CLR_CC" ]]; then

    # Set default versions
    if [[ -z "$majorVersion" ]]; then
        # note: gcc (all versions) and clang versions higher than 6 do not have minor version in file name, if it is zero.
        if [[ "$compiler" == "clang" ]]; then versions=( 13 12 11 10 9 8 7 6.0 5.0 4.0 3.9 3.8 3.7 3.6 3.5 )
        elif [[ "$compiler" == "gcc" ]]; then versions=( 12 11 10 9 8 7 6 5 4.9 ); fi

        for version in "${versions[@]}"; do
            parts=(${version//./ })
            desired_version="$(check_version_exists "${parts[0]}" "${parts[1]}")"
            if [[ "$desired_version" != "-1" ]]; then majorVersion="${parts[0]}"; break; fi
        done

        if [[ -z "$majorVersion" ]]; then
            if command -v "$compiler" > /dev/null; then
                if [[ "$(uname)" != "Darwin" ]]; then
                    Write-PipelineTelemetryError -category "Build" -type "warning" "Specific version of $compiler not found, falling back to use the one in PATH."
                fi
                CC="$(command -v "$compiler")"
                CXX="$(command -v "$cxxCompiler")"
            else
                Write-PipelineTelemetryError -category "Build" "No usable version of $compiler found."
                exit 1
            fi
        else
            if [[ "$compiler" == "clang" && "$majorVersion" -lt 5 ]]; then
                if [[ "$build_arch" == "arm" || "$build_arch" == "armel" ]]; then
                    if command -v "$compiler" > /dev/null; then
                        Write-PipelineTelemetryError -category "Build" -type "warning" "Found clang version $majorVersion which is not supported on arm/armel architectures, falling back to use clang from PATH."
                        CC="$(command -v "$compiler")"
                        CXX="$(command -v "$cxxCompiler")"
                    else
                        Write-PipelineTelemetryError -category "Build" "Found clang version $majorVersion which is not supported on arm/armel architectures, and there is no clang in PATH."
                        exit 1
                    fi
                fi
            fi
        fi
    else
        desired_version="$(check_version_exists "$majorVersion" "$minorVersion")"
        if [[ "$desired_version" == "-1" ]]; then
            Write-PipelineTelemetryError -category "Build" "Could not find specific version of $compiler: $majorVersion $minorVersion."
            exit 1
        fi
    fi

    if [[ -z "$CC" ]]; then
        CC="$(command -v "$compiler$desired_version")"
        CXX="$(command -v "$cxxCompiler$desired_version")"
        if [[ -z "$CXX" ]]; then CXX="$(command -v "$cxxCompiler")"; fi
    fi
else
    if [[ ! -f "$CLR_CC" ]]; then
        Write-PipelineTelemetryError -category "Build" "CLR_CC is set but path '$CLR_CC' does not exist"
        exit 1
    fi
    CC="$CLR_CC"
    CXX="$CLR_CXX"
fi

if [[ -z "$CC" ]]; then
    Write-PipelineTelemetryError -category "Build" "Unable to find $compiler."
    exit 1
fi

if [[ "$compiler" == "clang" ]]; then
    if "$CC" -fuse-ld=lld -Wl,--version 2>&1; then
        # Only lld version >= 9 can be considered stable
        if [[ "$majorVersion" -ge 9 ]]; then
            LDFLAGS="-fuse-ld=lld"
        fi
    fi
fi

SCAN_BUILD_COMMAND="$(command -v "scan-build$desired_version")"

export CC CXX LDFLAGS SCAN_BUILD_COMMAND