[20/30] meson: prepare move of QEMU_CFLAGS to meson

Clean up the handling of compiler flags in meson.build, splitting
the general flags that should be included in subprojects as well,
from warning flags that only apply to QEMU itself.  The two were
mixed in both configure tests and meson tests.

This split makes it easier to move the compiler tests piecewise
from configure to Meson.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
 meson.build | 53 +++++++++++++++++++++++++++++------------------------
 1 file changed, 29 insertions(+), 24 deletions(-)

On Fri, Dec 9, 2022 at 3:34 PM Paolo Bonzini <pbonzini@redhat.com> wrote:
>
> Clean up the handling of compiler flags in meson.build, splitting
> the general flags that should be included in subprojects as well,
> from warning flags that only apply to QEMU itself.  The two were
> mixed in both configure tests and meson tests.
>
> This split makes it easier to move the compiler tests piecewise
> from configure to Meson.
>
> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>

> ---
>  meson.build | 53 +++++++++++++++++++++++++++++------------------------
>  1 file changed, 29 insertions(+), 24 deletions(-)
>
> diff --git a/meson.build b/meson.build
> index 99c1bde4d154..dac343d14797 100644
> --- a/meson.build
> +++ b/meson.build
> @@ -190,10 +190,23 @@ endif
>  # Compiler flags #
>  ##################
>
> -qemu_cflags = config_host['QEMU_CFLAGS'].split()
> +qemu_common_flags = []
> +qemu_cflags = []
> +foreach arg : config_host['QEMU_CFLAGS'].split()
> +  if arg.startswith('-W')
> +    qemu_cflags += arg
> +  else
> +    qemu_common_flags += arg
> +  endif
> +endforeach
>  qemu_objcflags = config_host['QEMU_OBJCFLAGS'].split()
>  qemu_ldflags = config_host['QEMU_LDFLAGS'].split()
>
> +if get_option('gprof')
> +  qemu_common_flags += ['-p']
> +  qemu_ldflags += ['-p']
> +endif
> +
>  if get_option('prefer_static')
>    qemu_ldflags += get_option('b_pie') ? '-static-pie' : '-static'
>  endif
> @@ -207,10 +220,9 @@ if targetos == 'windows'
>    qemu_ldflags += cc.get_supported_link_arguments('-Wl,--dynamicbase', '-Wl,--high-entropy-va')
>  endif
>
> -if get_option('gprof')
> -  qemu_cflags += ['-p']
> -  qemu_objcflags += ['-p']
> -  qemu_ldflags += ['-p']
> +# Exclude --warn-common with TSan to suppress warnings from the TSan libraries.
> +if targetos != 'sunos' and not config_host.has_key('CONFIG_TSAN')
> +  qemu_ldflags += cc.get_supported_link_arguments('-Wl,--warn-common')
>  endif
>
>  # Specify linker-script with add_project_link_arguments so that it is not placed
> @@ -230,8 +242,7 @@ if get_option('fuzzing')
>                    name: '-fsanitize-coverage-allowlist=/dev/null',
>                   args: ['-fsanitize-coverage-allowlist=/dev/null',
>                          '-fsanitize-coverage=trace-pc'] )
> -    add_global_arguments('-fsanitize-coverage-allowlist=instrumentation-filter',
> -                         native: false, language: all_languages)
> +    qemu_common_flags += ['-fsanitize-coverage-allowlist=instrumentation-filter']
>    endif
>
>    if get_option('fuzzing_engine') == ''
> @@ -239,10 +250,8 @@ if get_option('fuzzing')
>      # compiled code.  To build non-fuzzer binaries with --enable-fuzzing, link
>      # everything with fsanitize=fuzzer-no-link. Otherwise, the linker will be
>      # unable to bind the fuzzer-related callbacks added by instrumentation.
> -    add_global_arguments('-fsanitize=fuzzer-no-link',
> -                         native: false, language: all_languages)
> -    add_global_link_arguments('-fsanitize=fuzzer-no-link',
> -                              native: false, language: all_languages)
> +    qemu_common_flags += ['-fsanitize=fuzzer-no-link']
> +    qemu_ldflags += ['-fsanitize=fuzzer-no-link']
>      # For the actual fuzzer binaries, we need to link against the libfuzzer
>      # library. They need to be configurable, to support OSS-Fuzz
>      fuzz_exe_ldflags = ['-fsanitize=fuzzer']
> @@ -253,6 +262,9 @@ if get_option('fuzzing')
>    endif
>  endif
>
> +add_global_arguments(qemu_common_flags, native: false, language: all_languages)
> +add_global_link_arguments(qemu_ldflags, native: false, language: all_languages)
> +
>  # Check that the C++ compiler exists and works with the C compiler.
>  link_language = 'c'
>  linker = cc
> @@ -276,16 +288,9 @@ if 'cpp' in all_languages
>    endif
>  endif
>
> -# Exclude --warn-common with TSan to suppress warnings from the TSan libraries.
> -if targetos != 'sunos' and not config_host.has_key('CONFIG_TSAN')
> -  qemu_ldflags += linker.get_supported_link_arguments('-Wl,--warn-common')
> -endif
> -
> -add_global_link_arguments(qemu_ldflags, native: false, language: all_languages)
> -
> -add_global_arguments(qemu_cflags, native: false, language: 'c')
> -add_global_arguments(qemu_cxxflags, native: false, language: 'cpp')
> -add_global_arguments(qemu_objcflags, native: false, language: 'objc')
> +add_project_arguments(qemu_cflags, native: false, language: 'c')
> +add_project_arguments(qemu_cxxflags, native: false, language: 'cpp')
> +add_project_arguments(qemu_objcflags, native: false, language: 'objc')
>  if targetos == 'linux'
>    add_project_arguments('-isystem', meson.current_source_dir() / 'linux-headers',
>                          '-isystem', 'linux-headers',
> @@ -3778,12 +3783,12 @@ link_args = get_option(link_language + '_link_args')
>  if link_args.length() > 0
>    summary_info += {'LDFLAGS':         ' '.join(link_args)}
>  endif
> -summary_info += {'QEMU_CFLAGS':       ' '.join(qemu_cflags)}
> +summary_info += {'QEMU_CFLAGS':       ' '.join(qemu_common_flags + qemu_cflags)}
>  if 'cpp' in all_languages
> -  summary_info += {'QEMU_CXXFLAGS':     ' '.join(qemu_cxxflags)}
> +  summary_info += {'QEMU_CXXFLAGS':     ' '.join(qemu_common_flags + qemu_cxxflags)}
>  endif
>  if 'objc' in all_languages
> -  summary_info += {'QEMU_OBJCFLAGS':    ' '.join(qemu_objcflags)}
> +  summary_info += {'QEMU_OBJCFLAGS':    ' '.join(qemu_common_flags + qemu_objcflags)}
>  endif
>  summary_info += {'QEMU_LDFLAGS':      ' '.join(qemu_ldflags)}
>  summary_info += {'profiler':          get_option('profiler')}
> --
> 2.38.1
>
>

On Fri, Dec 09, 2022 at 12:23:59PM +0100, Paolo Bonzini wrote:
> Clean up the handling of compiler flags in meson.build, splitting
> the general flags that should be included in subprojects as well,
> from warning flags that only apply to QEMU itself.  The two were
> mixed in both configure tests and meson tests.
> 
> This split makes it easier to move the compiler tests piecewise
> from configure to Meson.
> 
> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
> ---
>  meson.build | 53 +++++++++++++++++++++++++++++------------------------
>  1 file changed, 29 insertions(+), 24 deletions(-)

Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>


With regards,
Daniel