Re: [PATCH] meson: remove -no-pie linker flag

[Richard Henderson]

On 5/22/23 01:08, Paolo Bonzini wrote:
> The large comment in the patch says it all; the -no-pie flag is broken and
> this is why it was not included in QEMU_LDFLAGS before commit a988b4c5614
> ("build: move remaining compiler flag tests to meson", 2023-05-18).
>
> Resolves: https://gitlab.com/qemu-project/qemu/-/issues/1664
> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
> ---
>   meson.build | 13 +++++++++----
>   1 file changed, 9 insertions(+), 4 deletions(-)
>
> diff --git a/meson.build b/meson.build
> index 0a5cdefd4d3d..6733b2917081 100644
> --- a/meson.build
> +++ b/meson.build
> @@ -267,10 +267,15 @@ endif
>   # has explicitly disabled PIE we need to extend our cflags.
>   if not get_option('b_pie')
>     qemu_common_flags += cc.get_supported_arguments('-fno-pie')
> -  if not get_option('prefer_static')
> -    # No PIE is implied by -static which we added above.
> -    qemu_ldflags += cc.get_supported_link_arguments('-no-pie')
> -  endif
> +  # What about linker flags?  For a static build, no PIE is implied by -static
> +  # which we added above.

Is it though?  That was the major problem at the time: it wasn't.

IIRC, debian has enabled link-pie-by-default, so '-static' meant '-static-pie'.  Moreover, 
not all of their static libraries were built -fpie, which led to link errors.

Trying both now, e.g. '--static --disable-system --disable-tools 
--disable-docs',
a link line contains

... -Wl,--as-needed -Wl,--no-undefined -pie -Wl,--whole-archive libhwcore.fa ...
                                       ^^^^

Where does that come from, and why isn't -no-pie the antidote?


r~