Re: [Qemu-devel] [PATCH v3 03/46] configure: add support for --cross-cc-FOO

[Murilo Opsfelder Araujo <muriloo@linux.ibm.com>]

On 04/24/2018 12:23 PM, Alex Bennée wrote:
> This allows us to specify cross compilers for our guests. This is
> useful for building test images/programs. Currently we re-run the
> compile test for each target. I couldn't think of a way to cache the
> value for a given arch without getting messier configure code.
> 
> The cross compiler for the guest is visible to each target as
> CROSS_CC_GUEST in config-target.mak.
> 
> Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
> 
> ---
> v3
>   - --cross-cc-*[!a-zA-Z0-9_-]*=*) error_exit...
>   - --cross-cc-*) cc_arch=${opt#--cross-cc-}; cc_arch=${cc_arch%%=*}
>   - add remaining target_compiler definitions
> ---
>  configure | 79 +++++++++++++++++++++++++++++++++++++++++++++++++++++++
>  1 file changed, 79 insertions(+)
> 
> diff --git a/configure b/configure
> index b0ae632ee4..caa838a0d0 100755
> --- a/configure
> +++ b/configure
> @@ -453,6 +453,13 @@ vxhs=""
>  libxml2=""
>  docker="no"
>  
> +# cross compilers defaults, can be overridden with --cross-cc-ARCH
> +cross_cc_aarch64="aarch64-linux-gnu-gcc"
> +cross_cc_arm="arm-linux-gnueabihf-gcc"
> +cross_cc_powerpc="powerpc-linux-gnu-gcc"

Do we need to have default values for all targets?

> +
> +enabled_cross_compilers=""
> +
>  supported_cpu="no"
>  supported_os="no"
>  bogus_os="no"
> @@ -483,6 +490,11 @@ for opt do
>    ;;
>    --disable-debug-info) debug_info="no"
>    ;;
> +  --cross-cc-*[!a-zA-Z0-9_-]*=*) error_exit "Passed bad --cross-cc-FOO option"
> +  ;;
> +  --cross-cc-*) cc_arch=${opt#--cross-cc-}; cc_arch=${cc_arch%%=*}
> +                eval "cross_cc_${cc_arch}=\$optarg"
> +  ;;

Do we need to verify if a valid --cross-cc-FOO was passed, in case of a
typo?

>    esac
>  done
>  # OS specific
> @@ -675,10 +687,12 @@ case "$cpu" in
>    i386|i486|i586|i686|i86pc|BePC)
>      cpu="i386"
>      supported_cpu="yes"
> +    cross_cc_i386=gcc
>    ;;
>    x86_64|amd64)
>      cpu="x86_64"
>      supported_cpu="yes"
> +    cross_cc_x86_64=gcc
>    ;;
>    armv*b|armv*l|arm)
>      cpu="arm"
> @@ -912,6 +926,8 @@ for opt do
>    ;;
>    --disable-debug-info)
>    ;;
> +  --cross-cc-*)
> +  ;;
>    --enable-modules)
>        modules="yes"
>    ;;
> @@ -6777,6 +6793,8 @@ case "$target" in
>      ;;
>  esac
>  
> +target_compiler=""
> +
>  mkdir -p $target_dir
>  echo "# Automatically generated by configure - do not modify" > $config_target_mak
>  
> @@ -6792,19 +6810,23 @@ TARGET_ABI_DIR=""
>  case "$target_name" in
>    i386)
>      gdb_xml_files="i386-32bit.xml i386-32bit-core.xml i386-32bit-sse.xml"
> +    target_compiler=$cross_cc_i386
>    ;;
>    x86_64)
>      TARGET_BASE_ARCH=i386
>      gdb_xml_files="i386-64bit.xml i386-64bit-core.xml i386-64bit-sse.xml"
> +    target_compiler=$cross_cc_x86_64
>    ;;
>    alpha)
>      mttcg="yes"
> +    target_compiler=$cross_cc_alpha
>    ;;
>    arm|armeb)
>      TARGET_ARCH=arm
>      bflt="yes"
>      mttcg="yes"
>      gdb_xml_files="arm-core.xml arm-vfp.xml arm-vfp3.xml arm-neon.xml"
> +    target_compiler=$cross_cc_arm
>    ;;
>    aarch64|aarch64_be)
>      TARGET_ARCH=aarch64
> @@ -6812,58 +6834,73 @@ case "$target_name" in
>      bflt="yes"
>      mttcg="yes"
>      gdb_xml_files="aarch64-core.xml aarch64-fpu.xml arm-core.xml arm-vfp.xml arm-vfp3.xml arm-neon.xml"
> +    target_compiler=$cross_cc_aarch64
>    ;;
>    cris)
> +    target_compiler=$cross_cc_cris
>    ;;
>    hppa)
>      mttcg="yes"
> +    target_compiler=$cross_cc_hppa
>    ;;
>    lm32)
> +    target_compiler=$cross_cc_lm32
>    ;;
>    m68k)
>      bflt="yes"
>      gdb_xml_files="cf-core.xml cf-fp.xml m68k-fp.xml"
> +    target_compiler=$cross_cc_m68k
>    ;;
>    microblaze|microblazeel)
>      TARGET_ARCH=microblaze
>      bflt="yes"
> +    target_compiler=$cross_cc_microblaze
>    ;;
>    mips|mipsel)
>      TARGET_ARCH=mips
> +    target_compiler=$cross_cc_mips
>      echo "TARGET_ABI_MIPSO32=y" >> $config_target_mak
>    ;;
>    mipsn32|mipsn32el)
>      TARGET_ARCH=mips64
>      TARGET_BASE_ARCH=mips
> +    target_compiler=$cross_cc_mipsn32
>      echo "TARGET_ABI_MIPSN32=y" >> $config_target_mak
>      echo "TARGET_ABI32=y" >> $config_target_mak
>    ;;
>    mips64|mips64el)
>      TARGET_ARCH=mips64
>      TARGET_BASE_ARCH=mips
> +    target_compiler=$cross_cc_mips64
>      echo "TARGET_ABI_MIPSN64=y" >> $config_target_mak
>    ;;
>    moxie)
> +    target_compiler=$cross_cc_moxie
>    ;;
>    nios2)
> +    target_compiler=$cross_cc_nios2
>    ;;
>    or1k)
> +    target_compiler=$cross_cc_or1k
>      TARGET_ARCH=openrisc
>      TARGET_BASE_ARCH=openrisc
>    ;;
>    ppc)
>      gdb_xml_files="power-core.xml power-fpu.xml power-altivec.xml power-spe.xml"
> +    target_compiler=$cross_cc_powerpc
>    ;;
>    ppcemb)
>      TARGET_BASE_ARCH=ppc
>      TARGET_ABI_DIR=ppc
>      gdb_xml_files="power-core.xml power-fpu.xml power-altivec.xml power-spe.xml"
> +    target_compiler=$cross_cc_ppcemb
>    ;;
>    ppc64)
>      TARGET_BASE_ARCH=ppc
>      TARGET_ABI_DIR=ppc
>      mttcg=yes
>      gdb_xml_files="power64-core.xml power-fpu.xml power-altivec.xml power-spe.xml power-vsx.xml"
> +    target_compiler=$cross_cc_ppc64
>    ;;
>    ppc64le)
>      TARGET_ARCH=ppc64
> @@ -6871,6 +6908,7 @@ case "$target_name" in
>      TARGET_ABI_DIR=ppc
>      mttcg=yes
>      gdb_xml_files="power64-core.xml power-fpu.xml power-altivec.xml power-spe.xml power-vsx.xml"
> +    target_compiler=$cross_cc_ppc64le
>    ;;
>    ppc64abi32)
>      TARGET_ARCH=ppc64
> @@ -6878,45 +6916,57 @@ case "$target_name" in
>      TARGET_ABI_DIR=ppc
>      echo "TARGET_ABI32=y" >> $config_target_mak
>      gdb_xml_files="power64-core.xml power-fpu.xml power-altivec.xml power-spe.xml power-vsx.xml"
> +    target_compiler=$cross_cc_ppc64abi32
>    ;;
>    riscv32)
>      TARGET_BASE_ARCH=riscv
>      TARGET_ABI_DIR=riscv
>      mttcg=yes
> +    target_compiler=$cross_cc_riscv32
>    ;;
>    riscv64)
>      TARGET_BASE_ARCH=riscv
>      TARGET_ABI_DIR=riscv
>      mttcg=yes
> +    target_compiler=$cross_cc_riscv64
>    ;;
>    sh4|sh4eb)
>      TARGET_ARCH=sh4
>      bflt="yes"
> +    target_compiler=$cross_cc_sh4
>    ;;
>    sparc)
> +    target_compiler=$cross_cc_sparc
>    ;;
>    sparc64)
>      TARGET_BASE_ARCH=sparc
> +    target_compiler=$cross_cc_sparc64
>    ;;
>    sparc32plus)
>      TARGET_ARCH=sparc64
>      TARGET_BASE_ARCH=sparc
>      TARGET_ABI_DIR=sparc
> +    target_compiler=$cross_cc_sparc32plus
>      echo "TARGET_ABI32=y" >> $config_target_mak
>    ;;
>    s390x)
>      mttcg=yes
>      gdb_xml_files="s390x-core64.xml s390-acr.xml s390-fpr.xml s390-vx.xml s390-cr.xml s390-virt.xml s390-gs.xml"
> +    target_compiler=$cross_cc_s390x
>    ;;
>    tilegx)
> +    target_compiler=$cross_cc_tilegx
>    ;;
>    tricore)
> +    target_compiler=$cross_cc_tricore
>    ;;
>    unicore32)
> +    target_compiler=$cross_cc_unicore32
>    ;;
>    xtensa|xtensaeb)
>      TARGET_ARCH=xtensa
>      mttcg="yes"
> +    target_compiler=$cross_cc_xtensa
>    ;;
>    *)
>      error_exit "Unsupported target CPU"
> @@ -6927,6 +6977,25 @@ if [ "$TARGET_BASE_ARCH" = "" ]; then
>    TARGET_BASE_ARCH=$TARGET_ARCH
>  fi
>  
> +# Do we have a cross compiler for this target?
> +if has $target_compiler; then
> +
> +    cat > $TMPC << EOF
> +#include <stdio.h>
> +int main(void) {
> +    printf("Hello World!\n");
> +}
> +EOF

Can this be replaced by write_c_skeleton?

> +
> +    if ! do_compiler $target_compiler -o $TMPE $TMPC -static ; then
> +        target_compiler=""
> +    else
> +        enabled_cross_compilers="${enabled_cross_compilers} ${target_compiler}"
> +    fi
> +else
> +    target_compiler=""
> +fi
> +
>  symlink "$source_path/Makefile.target" "$target_dir/Makefile"
>  
>  upper() {
> @@ -7000,6 +7069,10 @@ if test "$target_bsd_user" = "yes" ; then
>    echo "CONFIG_BSD_USER=y" >> $config_target_mak
>  fi
>  
> +if test -n "$target_compiler"; then
> +  echo "CROSS_CC_GUEST=$target_compiler" >> $config_target_mak
> +fi
> +
>  # generate QEMU_CFLAGS/LDFLAGS for targets
>  
>  cflags=""
> @@ -7122,6 +7195,12 @@ echo "QEMU_CFLAGS+=$cflags" >> $config_target_mak
>  
>  done # for target in $targets
>  
> +if test -n "$enabled_cross_compilers"; then
> +    echo
> +    echo "NOTE: cross-compilers enabled:"
> +    printf '%s\n' $enabled_cross_compilers | sort -u
> +fi
> +
>  if [ "$dtc_internal" = "yes" ]; then
>    echo "config-host.h: subdir-dtc" >> $config_host_mak
>  fi
>