[meta-virtualization] xen, xen-tools: pass prefix maps to fix buildpaths reproducible build issues

To fix warnings when the buildpaths QA test is enabled, pass the file
and debug prefix map options that were previously supplied only for
reproducible builds, adding them to the DEBUG_PREFIX_MAP variable
and supplying that to CC.

Testing indicates that passing the prefix maps needs to be via CC
rather than the EXTRA_CFLAGS_XEN_CORE/TOOLS variables.

Signed-off-by: Christopher Clark <christopher.w.clark@gmail.com>
---
 recipes-extended/xen/xen.inc | 21 ++++++++++-----------
 1 file changed, 10 insertions(+), 11 deletions(-)

Looks good to me, and better than what we had before.

I've fast tracked it into master, so we can see what the
next set of autobuilder runs uncover.

Many thanks for looking at this.

Bruce


In message: [meta-virtualization][PATCH] xen, xen-tools: pass prefix maps to fix buildpaths reproducible build issues
on 09/07/2022 Christopher Clark wrote:

> To fix warnings when the buildpaths QA test is enabled, pass the file
> and debug prefix map options that were previously supplied only for
> reproducible builds, adding them to the DEBUG_PREFIX_MAP variable
> and supplying that to CC.
> 
> Testing indicates that passing the prefix maps needs to be via CC
> rather than the EXTRA_CFLAGS_XEN_CORE/TOOLS variables.
> 
> Signed-off-by: Christopher Clark <christopher.w.clark@gmail.com>
> ---
>  recipes-extended/xen/xen.inc | 21 ++++++++++-----------
>  1 file changed, 10 insertions(+), 11 deletions(-)
> 
> diff --git a/recipes-extended/xen/xen.inc b/recipes-extended/xen/xen.inc
> index ed6e6a7..2bbf1e3 100644
> --- a/recipes-extended/xen/xen.inc
> +++ b/recipes-extended/xen/xen.inc
> @@ -88,12 +88,13 @@ export CROSS_COMPILE="${TARGET_PREFIX}"
>  # overide LDFLAGS to allow xen to build without: "x86_64-oe-linux-ld: unrecognized option '-Wl,-O1'"
>  export LDFLAGS=""
>  
> -# Pass through the Yocto distro compiler flags via the Xen-provided variables.
> -# Special handling:
> -# - The Yocto distro compiler flags are typically set to be appropriate for
> -#   user-space software rather than for generation of a hypervisor binary, so
> -#   only pass the debug prefix map to the hypervisor build:
> -EXTRA_CFLAGS_XEN_CORE="${DEBUG_PREFIX_MAP}"
> +# No additional C flags for the main hypervisor build
> +EXTRA_CFLAGS_XEN_CORE ?= ""
> +# Add prefix maps to support buildpaths QA test and reproducibility
> +DEBUG_PREFIX_MAP:append = " \
> +    -ffile-prefix-map=${S}=${PN}-source \
> +    -fdebug-prefix-map=${WORKDIR}=${PN} \
> +    "
>  
>  # - The Xen tools build for x86 systems with HVM-mode enabled includes hvmloader
>  #   which fails to build when "-m64" is included in flags set via the
> @@ -109,11 +110,11 @@ TUNE_CCARGS:x86-64=""
>  #   It must not be compiled with SSE compiler options enabled and the Xen build
>  #   explicitly clears CFLAGS to ensure that, so such options must not be passed
>  #   in via the tool variable. hvmloader is required to run HVM-mode guest VMs.
> -CC="${CCACHE}${HOST_PREFIX}gcc ${TOOLCHAIN_OPTIONS} ${CC_REPRODUCIBLE_OPTIONS}"
> +CC="${CCACHE}${HOST_PREFIX}gcc ${TOOLCHAIN_OPTIONS} ${DEBUG_PREFIX_MAP} ${CC_REPRODUCIBLE_OPTIONS}"
>  EXTRA_CFLAGS_XEN_TOOLS="${HOST_CC_ARCH} ${CFLAGS}"
>  # 32-bit ARM needs the TUNE_CCARGS component of HOST_CC_ARCH to be passed
>  # in CC to ensure that configure can compile binaries for the right arch.
> -CC:arm="${CCACHE}${HOST_PREFIX}gcc ${TUNE_CCARGS} ${TOOLCHAIN_OPTIONS} ${CC_REPRODUCIBLE_OPTIONS}"
> +CC:arm="${CCACHE}${HOST_PREFIX}gcc ${TUNE_CCARGS} ${TOOLCHAIN_OPTIONS} ${DEBUG_PREFIX_MAP} ${CC_REPRODUCIBLE_OPTIONS}"
>  
>  # There are no Xen-provided variables for C++, so append to the tool variables:
>  CPP:append = " ${CPPFLAGS}"
> @@ -158,9 +159,7 @@ EXTRA_OEMAKE += "${@['', 'XEN_WHOAMI=${PF} XEN_DOMAIN=${DISTRO} XEN_BUILD_HOST=$
>                      [d.getVar('BUILD_REPRODUCIBLE_BINARIES') == '1']}${@get_build_time_vars(d)}"
>  
>  # Improve build reproducibility: compiler flags to remove filesystem differences.
> -CC_REPRODUCIBLE_OPTIONS = "${@['', '-gno-record-gcc-switches ' + \
> -                                   '-ffile-prefix-map=${S}=${PN}-source ' + \
> -                                   '-fdebug-prefix-map=${WORKDIR}=${PN}'] \
> +CC_REPRODUCIBLE_OPTIONS = "${@['', '-gno-record-gcc-switches'] \
>                               [d.getVar('BUILD_REPRODUCIBLE_BINARIES') == '1']}"
>  
>  # check for XSM in package config to allow XSM_ENABLE to be set
> -- 
> 2.25.1
>