[flang-commits] [flang] [flang][cuda] Reapply restriction on kernel subprogram but not device (PR #91764)

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llvmbot wrote:


<!--LLVM PR SUMMARY COMMENT-->

@llvm/pr-subscribers-flang-semantics

Author: Valentin Clement (バレンタイン クレメン) (clementval)

<details>
<summary>Changes</summary>

The restriction was completely removed in #<!-- -->89677. This was a bit too much. Reapply the restriction on elemental, pure and recursive but only for kernel subprogram (`grid_global` and `global` attributes).

---
Full diff: https://github.com/llvm/llvm-project/pull/91764.diff


2 Files Affected:

- (modified) flang/lib/Semantics/check-declarations.cpp (+7) 
- (modified) flang/test/Semantics/cuf02.cuf (+15-3) 


``````````diff
diff --git a/flang/lib/Semantics/check-declarations.cpp b/flang/lib/Semantics/check-declarations.cpp
index 26efa288b5aee..ce7870b8d54e4 100644
--- a/flang/lib/Semantics/check-declarations.cpp
+++ b/flang/lib/Semantics/check-declarations.cpp
@@ -1470,6 +1470,13 @@ void CheckHelper::CheckSubprogram(
     messages_.Say(symbol.name(),
         "A function may not have ATTRIBUTES(GLOBAL) or ATTRIBUTES(GRID_GLOBAL)"_err_en_US);
   }
+  if (cudaAttrs &&
+      (*cudaAttrs == common::CUDASubprogramAttrs::Global ||
+          *cudaAttrs == common::CUDASubprogramAttrs::Grid_Global) &&
+      symbol.attrs().HasAny({Attr::RECURSIVE, Attr::PURE, Attr::ELEMENTAL})) {
+    messages_.Say(symbol.name(),
+        "A kernel subprogram may not be RECURSIVE, PURE, or ELEMENTAL"_err_en_US);
+  }
   if (cudaAttrs && *cudaAttrs != common::CUDASubprogramAttrs::Host) {
     // CUDA device subprogram checks
     if (ClassifyProcedure(symbol) == ProcedureDefinitionClass::Internal) {
diff --git a/flang/test/Semantics/cuf02.cuf b/flang/test/Semantics/cuf02.cuf
index a4a229565a3e8..58cb3cf490115 100644
--- a/flang/test/Semantics/cuf02.cuf
+++ b/flang/test/Semantics/cuf02.cuf
@@ -29,11 +29,23 @@ module m
   !ERROR: A function may not have ATTRIBUTES(GLOBAL) or ATTRIBUTES(GRID_GLOBAL)
   attributes(global) real function f1
   end
-  recursive attributes(global) subroutine s7 ! ok
+  !ERROR: A kernel subprogram may not be RECURSIVE, PURE, or ELEMENTAL
+  recursive attributes(global) subroutine s7
   end
-  pure attributes(global) subroutine s8 ! ok
+  !ERROR: A kernel subprogram may not be RECURSIVE, PURE, or ELEMENTAL
+  pure attributes(global) subroutine s8
   end
-  elemental attributes(global) subroutine s9 ! ok
+  !ERROR: A kernel subprogram may not be RECURSIVE, PURE, or ELEMENTAL
+  elemental attributes(global) subroutine s9
+  end
+  !ERROR: A kernel subprogram may not be RECURSIVE, PURE, or ELEMENTAL
+  recursive attributes(grid_global) subroutine s10
+  end
+  !ERROR: A kernel subprogram may not be RECURSIVE, PURE, or ELEMENTAL
+  pure attributes(grid_global) subroutine s11
+  end
+  !ERROR: A kernel subprogram may not be RECURSIVE, PURE, or ELEMENTAL
+  elemental attributes(grid_global) subroutine s12
   end
 end
 

``````````

</details>


https://github.com/llvm/llvm-project/pull/91764