tree e26f639d38098fca8a62f64a513287c067a9a7b3
parent 337585e3d881c2c2c9099888b09902119dc05bf8
author Even Rouault <even.rouault@spatialys.com> 1570359151 +0200
committer Even Rouault <even.rouault@spatialys.com> 1570359151 +0200
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Do not override user-defined CMAKE_C[XX]_FLAGS for clang

337585e3d881c2c2c9099888b09902119dc05bf8 unconditionnaly
overrides any potential user-defined CMAKE_C[XX]_FLAGS.
This for example breaks the GDAL oss-fuzz builds which build Poppler
from source (see https://github.com/OSGeo/gdal/blob/master/gdal/fuzzers/build.sh#L54)

So do the same as the GCC path where we save input CMAKE_C[XX]_FLAGS
and reinject them in custom CMAKE_C{XX}_FLAGS_{build_configuration}
The values are identical to GCC, execpt for the _DEBUG configuration
where we remove '-O2 -fno-reorder-blocks -fno-schedule-insns -fno-inline'
since clang does not support -fno-reorder-blocks and -fno-schedule-insns,
so it is likely better to disable any optimization for proper debugging.