[flang] Add [[maybe_unused]] to fix -Werror build

[klausler]

Add the [[maybe_unused]] attribute to a variable in lib/Lower/OpenMP/OpenMP.cpp to avoid a (possibly bogus) unused variable warning when building with GCC 9.3.0.

[llvmbot]

@llvm/pr-subscribers-flang-fir-hlfir

Author: Peter Klausler (klausler)

Changes

Add the [[maybe_unused]] attribute to a variable in lib/Lower/OpenMP/OpenMP.cpp to avoid a (possibly bogus) unused variable warning when building with GCC 9.3.0.

---

Full diff: https://github.com/llvm/llvm-project/pull/83456.diff

1 Files Affected:

• (modified) flang/lib/Lower/OpenMP/OpenMP.cpp (+1-1)

diff --git a/flang/lib/Lower/OpenMP/OpenMP.cpp b/flang/lib/Lower/OpenMP/OpenMP.cpp
index 21ad51c53d8742..b68976a4c765c3 100644
--- a/flang/lib/Lower/OpenMP/OpenMP.cpp
+++ b/flang/lib/Lower/OpenMP/OpenMP.cpp
@@ -840,7 +840,7 @@ genEnterExitUpdateDataOp(Fortran::lower::AbstractConverter &converter,
   llvm::SmallVector<mlir::Attribute> dependTypeOperands;
 
   Fortran::parser::OmpIfClause::DirectiveNameModifier directiveName;
-  llvm::omp::Directive directive;
+  [[maybe_unused]] llvm::omp::Directive directive;
   if constexpr (std::is_same_v<OpTy, mlir::omp::EnterDataOp>) {
     directiveName =
         Fortran::parser::OmpIfClause::DirectiveNameModifier::TargetEnterData;

[psteinfeld]

Looks good.

Note that this looks like a compiler bug to me. The variable directive is used on line 873, so this warning should not appear.

Thanks for fixing this!