OpenMP not supported on macOS and Windows
When compiling with OpenMP, there are various compilation errors on macOS, Windows and even on Linux
On macOS, the FindOpenMP.cmake module doesn't find any valid compile flag. When I set
-fopenmp, I got messages like:
clang: warning: argument unused during compilation: '-fopenmp' /Users/otbval/Dashboard/nightly/OTB-Release/src/Modules/Remote/DiapOTBModule/include/otbSARInterferogramImageFilter.txx:36:10: fatal error: 'omp.h' file not found
On Windows, there is a problem with SampleAugmentation filters (more information here )
modules\learning\sampling\include\otbSampleAugmentation.h(57): error C3016: 'j': index variable in OpenMP 'for' statement must have signed integral type
On Linux, I had a linking error with module DiapOTBModule, not finding the symbols
omp_set_num_threads. After a quick check, the
OpenMP_EXE_LINKER_FLAGS is never filled by FindOpenMP.
Steps to reproduce
Configure CMake with
OTB_USE_OPENMP=ON then build.
OTB 6.6 and later OS: macOS, Win, Linux