[flang][cuda] Emit error when trying to print device data

Author: clementval

flang/lib/Semantics/check-cuda.cpp

@@ -774,4 +774,24 @@ void CUDAChecker::Enter(const parser::AssignmentStmt &x) {
   }
 }
 
+void CUDAChecker::Enter(const parser::PrintStmt &x) {
+  CHECK(context_.location());
+  const Scope &scope{context_.FindScope(*context_.location())};
+  if (IsCUDADeviceContext(&scope) || deviceConstructDepth_ > 0) {
+    return;
+  }
+
+  auto &outputItemList{std::get<std::list<Fortran::parser::OutputItem>>(x.t)};
+  for (const auto &item : outputItemList) {
+    if (const auto *x{std::get_if<parser::Expr>(&item.u)}) {
+      if (const auto *expr{GetExpr(context_, *x)}) {
+        if (Fortran::evaluate::HasCUDADeviceAttrs(*expr)) {
+          context_.Say(parser::FindSourceLocation(*x),
+              "device data not allowed in I/O statements"_err_en_US);
+        }
+      }
+    }
+  }
+}
+
 } // namespace Fortran::semantics

flang/lib/Semantics/check-cuda.h

@@ -49,6 +49,7 @@ class CUDAChecker : public virtual BaseChecker {
   void Leave(const parser::OpenACCLoopConstruct &);
   void Enter(const parser::DoConstruct &);
   void Leave(const parser::DoConstruct &);
+  void Enter(const parser::PrintStmt &);
 
 private:
   SemanticsContext &context_;

flang/test/Semantics/cuf23.cuf

@@ -0,0 +1,34 @@
+! RUN: %python %S/test_errors.py %s %flang_fc1 -fopenacc
+
+program test
+  real, device :: a(10)
+  a = 1.0
+!ERROR: device data not allowed in I/O statements
+  print *, a(1)
+!ERROR: device data not allowed in I/O statements
+  print *, a
+end
+
+subroutine host()
+  integer :: i
+  real, device :: a(10)
+  !$acc parallel loop
+  do i = 1, 10
+    print*, a(i) ! ok
+  end do
+
+  !$cuf kernel do
+  do i = 1, 10
+    print*, a(i) ! ok
+  end do
+end subroutine
+
+attributes(global) subroutine global1()
+  real, device :: a(10)
+  print*, a ! ok
+end subroutine
+
+attributes(device) subroutine device1()
+  real, device :: a(10)
+  print*, a ! ok
+end subroutine