gcc 6 has added a diagnostic under `-pedantic` that emits a warning
whenever an enumerator value is not a constant integer
expression. This applies to the expression "1 << 31", too, as [1]
explains: that shifts the bit into the sign bit, and therefore it's
not constant.
This warning combined with `-Werror` means that compilation of the
test program fails.
This patch implements the workaround mentioned in [1].
Actual error message:
```
'x86_64-w64-mingw32.static-gcc' -W -Wall -Werror -std=c99 -pedantic '/home/mosu/prog/video/mingw/cross/src/sdl_sound-test.c' -o '/home/mosu/prog/video/mingw/cross/usr/x86_64-w64-mingw32.static/bin/test-sdl_sound.exe' `'x86_64-w64-mingw32.static-pkg-config' SDL_sound --cflags --libs`
In file included from /home/mosu/prog/video/mingw/cross/src/sdl_sound-test.c:11:0:
/home/mosu/prog/video/mingw/cross/usr/x86_64-w64-mingw32.static/include/SDL/SDL_sound.h:117:32:
error: enumerator value for 'SOUND_SAMPLEFLAG_EAGAIN' is not an integer constant expression [-Werror=pedantic] SOUND_SAMPLEFLAG_EAGAIN = 1 << 31 /**< Function would block, or temp error. */
```
[1] https://gcc.gnu.org/bugzilla/show_bug.cgi?id=71803
g++ 6 is stricter regarding narrowing conversions in initializer
lists. This causes errors similar to the following during compilation
with the gcc6 or gcc7 overlays:
locationinfo.cpp:163:21: error: narrowing conversion of '237'
from 'int' to 'char' inside { } [-Wnarrowing]
This has already been fixed upstream in several consecutive patches,
but there's no release including those fixes yet. This patch consists
of the essence of said fixes.
Perl v5.26.0 has removed the current directory from the include
path. This breaks the `run_test.pl` script which tries to load modules
from the build directory and fails if the system Perl is 5.26.0 or
newer.
Error message: `Can't locate ompts_parserFunctions.pm in @INC`
gcc 7 has -Wimplicit-fallthrough on by default. On systems where the
build gcc is v7 or newer building gendef will therefore fail with the
following error:
src/gendef.c: In function ‘getMemonic’:
src/gendef.c:1034:15: error: this statement may fall through [-Werror=implicit-fallthrough=]
case c_4: sz++;
Fixes#1786.
Normally pkg-config would remove the system library path from
--libs output. Defining PKG_CONFIG_SYSTEM_LIBRARY_PATH helps
it do so. The extra mentions of system library path in the
linking commands is unsightly but probabaly harmless.
PKG_CONFIG_SYSROOT should not be set because MXE uses fully
qualified paths. However, to satisfy the Qt build system's
cross-compiling "sanity check", qtbase.mk defines
PKG_CONFIG_SYSROOT_DIR=/
This causes pkg-config to prefix the system include and library
paths with an extra /. Pkg-config does not strip these prefixed
paths from --cflags and --libs output. The workaround here is
to remove the PKG_CONFIG_SYSROOT_DIR definition in the wrapper
script for pkg-config.
Moritz Bunkus
Tony Theodore
MXEBot as Travis CI
Lukasz Taczuk
Mark Brand
darealshinji
Boris Nagaev