[WIP] Delayed privatization.

flang/include/flang/Lower/AbstractConverter.h

@@ -16,6 +16,7 @@
 #include "flang/Common/Fortran.h"
 #include "flang/Lower/LoweringOptions.h"
 #include "flang/Lower/PFTDefs.h"
+#include "flang/Lower/SymbolMap.h"
 #include "flang/Optimizer/Builder/BoxValue.h"
 #include "flang/Semantics/symbol.h"
 #include "mlir/IR/Builders.h"
@@ -296,6 +297,9 @@ class AbstractConverter {
     return loweringOptions;
   }
 
+  virtual Fortran::lower::SymbolBox
+  lookupOneLevelUpSymbol(const Fortran::semantics::Symbol &sym) = 0;
+
 private:
   /// Options controlling lowering behavior.
   const Fortran::lower::LoweringOptions &loweringOptions;

flang/include/flang/Lower/SymbolMap.h

@@ -312,6 +312,7 @@ class SymMap {
   lookupVariableDefinition(semantics::SymbolRef sym) {
     if (auto symBox = lookupSymbol(sym))
       return symBox.getIfFortranVariableOpInterface();
+
     return std::nullopt;
   }
 

flang/lib/Lower/Bridge.cpp

@@ -1052,7 +1052,10 @@ class FirConverter : public Fortran::lower::AbstractConverter {
       if (sym.detailsIf<Fortran::semantics::CommonBlockDetails>())
         return symMap->lookupSymbol(sym);
 
-      return {};
+      // With delayed privatization, Fortran symbols might now be mapped to
+      // simple `mlir::Value`s (arguments to the `omp.private` ops in this
+      // case). Therefore, it is possible that none of the above cases applies.
+      // return {};
     }
     if (Fortran::lower::SymbolBox v = symMap->lookupSymbol(sym))
       return v;
@@ -1070,7 +1073,7 @@ class FirConverter : public Fortran::lower::AbstractConverter {
   /// Find the symbol in one level up of symbol map such as for host-association
   /// in OpenMP code or return null.
   Fortran::lower::SymbolBox
-  lookupOneLevelUpSymbol(const Fortran::semantics::Symbol &sym) {
+  lookupOneLevelUpSymbol(const Fortran::semantics::Symbol &sym) override {
     if (Fortran::lower::SymbolBox v = localSymbols.lookupOneLevelUpSymbol(sym))
       return v;
     return {};