Re: [Qemu-devel] [PATCH v3] configure: preserve various environment variables in config.status

[Thomas Huth]

On 2018-09-04 14:36, Daniel P. Berrangé wrote:
> The config.status script is auto-generated by configure upon
> completion. The intention is that config.status can be later invoked by
> the developer directly, or by make indirectly, to re-detect the same
> environment that configure originally used.
> 
> The current config.status script, however, only contains a record of the
> command line arguments to configure. Various environment variables have
> an effect on what configure will find. In particular PKG_CONFIG_LIBDIR &
> PKG_CONFIG_PATH vars will affect what libraries pkg-config finds. The
> PATH var will affect what toolchain binaries and XXXX-config scripts are
> found. The LD_LIBRARY_PATH var will affect what libraries are
> found. Most commands have env variables that will override the name/path
> of the default version configure finds.
> 
> All these key env variables should be recorded in the config.status script.
> 
> Autoconf would also preserve CFLAGS, LDFLAGS, LIBS, CPPFLAGS, but QEMU
> deals with those differently, expecting extra flags to be set using
> configure args, rather than env variables. At the end of the script we
> also don't have the original values of those env vars, as we modify them
> during configure.

It's a little bit inconsequent to ignore CFLAGS etc., but to save the CC
and CXX variable, since we've got a configure option for setting $CC and
$CXX, too ("--cc" and "--cxx"). Maybe we should clean that up one day,
but that's for another patch...

For this one here:

Reviewed-by: Thomas Huth <address@hidden>