[flang-commits] [PATCH] D143835: [flang] Associate entities are variables

[Peter Klausler via Phabricator via flang-commits]

klausler created this revision.
klausler added a reviewer: clementval.
klausler added a project: Flang.
Herald added subscribers: sunshaoce, jdoerfert.
Herald added a project: All.
klausler requested review of this revision.

A more precise reading of the standard for associate entities, like "x"
in ASSOCIATE(x => selector), shows that the utility predicates used for
determining their status as variables should treat them as variables
(not necessarily definable), whatever the selector is.  Currently
the cases where the selector is an expression or a designator with a
vector subscript are not properly considered to be variables.
(See Fortran 2018, 11.1.3.3 paragraph 5.)


https://reviews.llvm.org/D143835

Files:
  flang/lib/Evaluate/tools.cpp


Index: flang/lib/Evaluate/tools.cpp
===================================================================
--- flang/lib/Evaluate/tools.cpp
+++ flang/lib/Evaluate/tools.cpp
@@ -78,8 +78,11 @@
 // IsVariable()
 
 auto IsVariableHelper::operator()(const Symbol &symbol) const -> Result {
-  const Symbol &root{GetAssociationRoot(symbol)};
-  return !IsNamedConstant(root) && root.has<semantics::ObjectEntityDetails>();
+  // ASSOCIATE(x => expr) -- x counts as a variable, but undefinable
+  const Symbol &ultimate{symbol.GetUltimate()};
+  return !IsNamedConstant(ultimate) &&
+      (ultimate.has<semantics::ObjectEntityDetails>() ||
+          ultimate.has<semantics::AssocEntityDetails>());
 }
 auto IsVariableHelper::operator()(const Component &x) const -> Result {
   const Symbol &comp{x.GetLastSymbol()};
@@ -1251,15 +1254,10 @@
 }
 
 bool IsVariableName(const Symbol &original) {
-  const Symbol &symbol{ResolveAssociations(original)};
-  if (symbol.has<ObjectEntityDetails>()) {
-    return !IsNamedConstant(symbol);
-  } else if (const auto *assoc{symbol.detailsIf<AssocEntityDetails>()}) {
-    const auto &expr{assoc->expr()};
-    return expr && IsVariable(*expr) && !HasVectorSubscript(*expr);
-  } else {
-    return false;
-  }
+  const Symbol &ultimate{original.GetUltimate()};
+  return !IsNamedConstant(ultimate) &&
+      (ultimate.has<ObjectEntityDetails>() ||
+          ultimate.has<AssocEntityDetails>());
 }
 
 bool IsPureProcedure(const Symbol &original) {


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