[Openmp-dev] Mapping of non-trivial type support

[Alexey Bataev via Openmp-dev]

clang works in accordance with the standard. Standard says that mapping is performed as bitwise copy of the objects. You can perform the bitwise copy safely only for the trivial types.
You cannot simply map a vector. You need to convert it to C/C++ array at first.
OpenMP 5.0 introduced user-defined mappers to solve the problem of non-trivial types mapping, which are not supported by clang yet. We're working on this feature.

Best regards,
Alexey Bataev

> 4 авг. 2019 г., в 1:16, Itaru Kitayama via Openmp-dev <openmp-dev at lists.llvm.org> написал(а):
> 
> Hi,
> This simple code:
> 
> int main() {
>  
> std::vector<int> v(100, 0);
> #pragma omp target teams distribute parallel for map(tofrom: v)
>    for (int i=0;i<100;i++) {
>         v[i] =i;
>    }
> };
> 
> causes Clang to warn a message like:
> 
> vectormap.cpp:31:62: warning: Non-trivial type 'std::vector<int>' is mapped, only trivial types are guaranteed to be mapped correctly [-Wopenmp-target]
> #pragma omp target teams distribute parallel for map(tofrom: v)
>                           
>                                    ^
> 1 warning generated.
> 
> ... and encounters an issue at run time. How much non-trivial types are
> supported in trunk Clang?
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