[PATCH] D88695: [flang][msvc] Rework a MSVC work-around to avoid clang warning

[Peter Klausler via Phabricator via llvm-commits]

klausler created this revision.
klausler added reviewers: Meinersbur, tskeith.
klausler added a project: Flang.
Herald added a reviewer: jdoerfert.
Herald added a project: LLVM.
Herald added a subscriber: llvm-commits.
klausler requested review of this revision.

A recent MSVC work-around patch is eliciting unused variable
warnings from clang; package the lambda reference arguments
into a struct to avoid the warning.

I don't know whether this new patch still avoids the bugs in MSVC.

(Original work-around patch: https://reviews.llvm.org/D88504)


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D88695

Files:
  flang/lib/Evaluate/fold-implementation.h


Index: flang/lib/Evaluate/fold-implementation.h
===================================================================
--- flang/lib/Evaluate/fold-implementation.h
+++ flang/lib/Evaluate/fold-implementation.h
@@ -1154,14 +1154,20 @@
   if (auto array{ApplyElementwise(context, convert)}) {
     return *array;
   }
+  struct {
+    FoldingContext &context;
+    Convert<TO, FROMCAT> &convert;
+  } msvcWorkaround{context, convert};
   return std::visit(
-      [&context, &convert](auto &kindExpr) -> Expr<TO> {
+      [&msvcWorkaround](auto &kindExpr) -> Expr<TO> {
         using Operand = ResultType<decltype(kindExpr)>;
         // This variable is a workaround for msvc which emits an error when
         // using the FROMCAT template parameter below.
         TypeCategory constexpr FromCat{FROMCAT};
+        auto &convert{msvcWorkaround.convert};
         char buffer[64];
         if (auto value{GetScalarConstantValue<Operand>(kindExpr)}) {
+          FoldingContext &context{msvcWorkaround.context};
           if constexpr (TO::category == TypeCategory::Integer) {
             if constexpr (Operand::category == TypeCategory::Integer) {
               auto converted{Scalar<TO>::ConvertSigned(*value)};


-------------- next part --------------
A non-text attachment was scrubbed...
Name: D88695.295652.patch
Type: text/x-patch
Size: 1213 bytes
Desc: not available
URL: <http://lists.llvm.org/pipermail/llvm-commits/attachments/20201001/cfd09a8c/attachment.bin>