[flang-commits] [flang] [mlir] [Flang][OpenMP] Support conditional lastprivate on host (PR #200086)

[Tom Eccles via flang-commits]

================
@@ -2671,13 +2743,58 @@ genSectionsOp(lower::AbstractConverter &converter, lower::SymMap &symTable,
                            /*useDelayedPrivatization=*/false, symTable);
   dsp.processStep1();
 
+  // Detect conditional lastprivate symbols for sections.
+  auto &condLpSyms = dsp.getConditionalLastprivateSymbols();
+  fir::RecordType lpType;
+  mlir::Value lpAlloca;
+  if (!condLpSyms.empty()) {
+    lpType = buildConditionalLpType(converter, condLpSyms, loc);
+    mlir::omp::DeclareReductionOp declRedOp =
+        buildConditionalLastPrivateReduction(converter, lpType, condLpSyms);
+
+    // Create the struct alloca outside the parent parallel (if any).
+    // In the orphaned case (no enclosing ParallelOp), use a
+    // module-scope global so that all threads share one reduction target.
+    auto enclosingParallel = findEnclosingParallelOp(builder);
+    bool isOrphaned = !enclosingParallel;
+
+    // Guard against nested parallelism in the orphaned case.
+    // Emit this BEFORE touching the global to avoid racing on it.
+    if (isOrphaned)
+      emitNestedParallelGuardForCondLp(converter, loc);
+
+    if (!isOrphaned) {
----------------
tblah wrote:

```suggestion
    if (enclosingParallel) {
```
Super nitpick on readablility. Feel free to ignore

https://github.com/llvm/llvm-project/pull/200086