[flang-commits] [flang] [flang][openacc] Check trip count invariance with other IVs (PR #79906)

[Slava Zakharin via flang-commits]

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@@ -1250,10 +1256,41 @@ void AccAttributeVisitor::CheckAssociatedLoopIndex(
     return nullptr;
   };
 
-  const auto &outer{std::get<std::optional<parser::DoConstruct>>(x.t)};
-  for (const parser::DoConstruct *loop{&*outer}; loop && level > 0;) {
+  auto checkExprHasSymbols = [&](llvm::SmallVector<Symbol *> &ivs,
+                                 semantics::UnorderedSymbolSet &symbols) {
+    for (auto iv : ivs) {
+      if (symbols.count(*iv) != 0) {
+        context_.Say(GetContext().directiveSource,
+            "Trip count must be computable and invariant"_err_en_US);
+      }
+    }
+  };
+
+  Symbol::Flag flag;
+  llvm::SmallVector<Symbol *> ivs;
+  using Bounds = parser::LoopControl::Bounds;
+  for (const parser::DoConstruct *loop{&outerDoConstruct}; loop && level > 0;) {
     // Go through all nested loops to ensure index variable exists.
-    GetLoopIndex(*loop);
+    if (const parser::Name * ivName{GetLoopIndex(*loop)}) {
+      if (auto *symbol{ResolveAcc(*ivName, flag, currScope())}) {
+        if (auto &control = loop->GetLoopControl()) {
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vzakhari wrote:

nit: I see a mix of var initialization styles (via `{}` and `=`).  You may consider sticking to one :)

https://github.com/llvm/llvm-project/pull/79906