[flang] Add a test case for `fir.dt_entry`

[awarzynski]

Summary

This complements https://reviews.llvm.org/D113662

[kiranchandramohan]

flang/test/Fir/convert-to-llvm-invalid.fir

37

I think @clementval was suggesting that dt_entry should always. come inside a dispatch_table. The fact that dt_entry can be written in module scope shows that it is missing some constraints.

I think dt_entry operation should have the HasParent constraint where the parent is the dispatch_table.

https://mlir.llvm.org/docs/Traits/#hasparent
https://github.com/llvm/llvm-project/blob/9534e361ea12aaecde52b8ac4c947f9a301d0c9b/mlir/include/mlir/Dialect/OpenMP/OpenMPOps.td#L155

I was thinking that the test was skipped because if it has the constraint maybe we never reach the conversion of dt_entry and hence the error is never produced.

[clementval]

flang/test/Fir/convert-to-llvm-invalid.fir

37

Cannot summarized it better than @kiranchandramohan. Doesn't really makes sense to have a fir.dt_entry alone in the wild.

[awarzynski]

Abandon in favor of https://reviews.llvm.org/D113674.

flang/test/Fir/convert-to-llvm-invalid.fir

37

I was thinking that the test was skipped because if it has the constraint maybe we never reach the conversion of dt_entry and hence the error is never produced.

The conversion *is hit*, so clearly something is missing somewhere :) I added this test so have something that documents the current behavior. If that conversion is never hit (nor it should be), then perhaps it ought to be deleted?

Anyway, thanks for the context and for clarifying! Let's try ttps://reviews.llvm.org/D113674 instead.

flang/test/Fir/convert-to-llvm-invalid.fir

 func @dispatch(%arg0: !fir.box<!fir.type<derived3{f:f32}>>) {
   // expected-error@+1{{failed to legalize operation 'fir.dispatch'}}
   %0 = fir.dispatch "method"(%arg0) : (!fir.box<!fir.type<derived3{f:f32}>>) -> i32
   return
 }
 
 // -----
 
-// Test that `fir.dispatch_table`/`fir.dt_entry` fails to be legalized.
+// Test that `fir.dispatch_table` fails to be legalized.
 // Not implemented yet.
 
 // expected-error@+1{{failed to legalize operation 'fir.dispatch_table'}}
 fir.dispatch_table @dispatch_tbl {
   fir.dt_entry "method", @method_impl
 }
+
+// -----
+
+// Test that `fir.dt_entry` fails to be legalized.
+// Not implemented yet.
+
+// expected-error@+1{{failed to legalize operation 'fir.dt_entry'}}
+fir.dt_entry "method", @method_impl