[flang-commits] [flang] [mlir] [mlir][OpenACC] Error on external calls without acc routine info (PR #223815)

[Razvan Lupusoru via flang-commits]

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@@ -154,28 +155,42 @@ class ACCImplicitRoutine
       // regions, skip it
       if (!callee)
         return;
+      // Already a valid symbol for GPU regions (e.g. an existing routine or an
+      // LLVM intrinsic), skip it.
       if (accSupport.isValidSymbolUse(callOp.getOperation(), calleeSymbolRef))
         return;
+      // Without a definition in this compilation unit an implicit routine
+      // cannot be applied, so the call target needs explicit routine
+      // information.
+      if (callee.isExternal()) {
+        callOp->emitError()
+            << "Procedures called in a compute region must have acc routine "
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razvanlupusoru wrote:

nit: Avoid word "procedure" since it is Fortran specific. I would say: "Calls in an acc compute region must be marked with acc routine"

https://github.com/llvm/llvm-project/pull/223815