[PATCH] D69204: [OpenMP 5.0] - Extend defaultmap

[Chi Chun Chen via Phabricator via cfe-commits]

cchen marked an inline comment as done.
cchen added inline comments.


================
Comment at: clang/lib/Sema/SemaOpenMP.cpp:4374
+  case DMIB_unspecified:
+    return OMPC_MAP_tofrom;
+  }
----------------
ABataev wrote:
> cchen wrote:
> > ABataev wrote:
> > > cchen wrote:
> > > > ABataev wrote:
> > > > > `OMPC_MAP_tofrom` must be returned only for `DMIB_tofrom`, for others, it must be `llvm_unreachable(....)`
> > > > For DMIB_firstprivate, I think you are right, it should be unreachable, however, for DMIB_default and DMIB_unspecified, they are definitely reachable in `ActOnOpenMPExecutableDirective`.
> > > Then this function is not correct because for scalars default is not tofrom.
> > You are right, for scalar and pointer, the implicit behavior is firstprivate, so they are unreachable in this case, however, for aggregate, the implicit behavior is tofrom (I emit the .ll file for aggregate using the master branch and found that the maptype is 547).
> You need to add extra checks for scalars and pointers in this function.
In fact, it is possible for scalar or pointer to reach `DMIB_default` and `DMIB_unspecified` case. For this example:
```
extern int c;
#pragma omp declare target link(c)

void foo() {
  #pragma omp target defaultmap(default:scalar)
  {
    c++;
  }
}
```
`c` will be added into `ImplicitMap` since `Res` is not empty, therefore, `DMIB_default` and `DMIB_unspecified` is reachable.


Repository:
  rG LLVM Github Monorepo

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  https://reviews.llvm.org/D69204/new/

https://reviews.llvm.org/D69204