[Qemu-devel] [PATCH 0/2 v3] Fix static linking for cURL and SDL

["Yann E. MORIN" <yann.morin.1998@free.fr>]

Hello All!

Currently, configure checks for cURL and SDL with either pkg-config (the
default), or with {curl,sdl}-config (as a fallback).

But pkg-config and {curl,sdl}-config do not have the same set of options:
  - to check for shared libs, both use the option: --libs
  - to check for static libs:
    - pkg-config uses      : --static --libs
    - {curl,sdl}-config use: --static-libs

To add to the complexity, pkg-config is called through the querry_pkg_config
wrapper, that already passes --static when static linking is required, but
there is no such wrapper for {curl,sdl}-config, so we miss the occasion to
pass --static-libs.

To fix this:
  - introduce a new variable QEMU_XXX_CONFIG_LIBS_FLAGS that mirrors the
    behavior of QEMU_PKG_CONFIG_FLAGS; this variable can be used by all
    xxx-config scripts (eg. curl-config, but later sdl-config too).
    Default it to '--libs', which is for shared linking.
  - properly use either --libs for pkg-config (--static is already taken
    care of in the wrapper), or $QEMU_XXX_CONFIG_LIBS_FLAGS for
    {curl,sdl}-config.


Changes since v2:
  - remove trailing reference to cURL in the SDL patch (Stefan Hajnoczi)
  - sent to qemu-devel and cc qemu-trivial (Peter Maydell, Stefan)
  - fix type in the name of the new variable

Changes since v1:
  - drop the spice fix, it is not needed (bad env locally)
  - drop the added --static to calls to pkg-config, as it's already in the
    wrapper (Stefan Hajnoczi)

Regards,
Yann E. MORIN.