AC_CHECK_HEADER() emits warnings when configuring for non-x86, because
the preprocessor check is OK but the compile check is not:
configure: WARNING: immintrin.h: present but cannot be compiled
configure: WARNING: immintrin.h: check for missing prerequisite headers?
configure: WARNING: immintrin.h: see the Autoconf documentation
configure: WARNING: immintrin.h: section "Present But Cannot Be Compiled"
configure: WARNING: immintrin.h: proceeding with the compiler's result
.. by adding DBUS_CFLAGS and IBUS_CFLAGS to CPPFLAGS:
configure: WARNING: dbus/dbus.h: accepted by the compiler, rejected by the preprocessor!
configure: WARNING: dbus/dbus.h: proceeding with the compiler's result
configure: WARNING: ibus-1.0/ibus.h: accepted by the compiler, rejected by the preprocessor!
configure: WARNING: ibus-1.0/ibus.h: proceeding with the compiler's result
Patch from Matt Whitlock:
There are actually two distinct classes of problems at play here.
On the one hand, libsdl2's configure.ac has some POSIX conformance
issues - namely, the use of 'echo -n' and the passage of arguments
containing embedded backslashes to 'echo', neither of which is
defined by POSIX. The attached patch takes care of these issues.
Cameron Cawley
stdlib: Added SDL_round, SDL_roundf, SDL_lround and SDL_lroundf
The default implementation is based on the one used in the Windows RT video driver.
Specifically this patch which does not invoke _AC_PATH_X_XMKMF and
_AC_PATH_X_DIRECT internal autoconf routines when cross-compiling:
http://git.savannah.gnu.org/gitweb/?p=autoconf.git;a=commitdiff;h=33c3a47c04ab70a4dd54963fe433a171bc03747f
Without this, CFLAGS would brokenly have system include paths like
-I/usr/include/X11 when cross-compiling e.g. for windows. (And it
also resulted in annoying imake crashes for my setup...)
Substring
I was trying the KMSDRM video backend with some very simple programs that were working ok on 2.0.12. The same code won?t work on the current dev branch and I get:
DEBUG: check_modesetting: probing ?/dev/dri/card0?
DEBUG: /dev/dri/card0 connector, encoder and CRTC counts are: 4 5 6
DEBUG: check_modesetting: probing ?/dev/dri/card0?
DEBUG: /dev/dri/card0 connector, encoder and CRTC counts are: 4 5 6
DEBUG: KMSDRM_VideoInit()
DEBUG: Opening device /dev/dri/card0
DEBUG: Opened DRM FD (3)
DEBUG: no atomic modesetting support.
DEBUG: Video subsystem has not been initialized
INFO: Using SDL video driver: (null)
DEBUG: Video subsystem has not been initialized
After carefully checking, the radeon driver doesn?t support atomic modesetting. That?s not the only problem : the same happens with the amdgpu driver if we disable Display Core (kernel parameter amdgpu.dc=0, which is required to get analogue outputs working).
This is a major regression in the KMSDRM driver.
Using atomic mode setting is great, but having no fallback to the "standard KMS" is bad.