[flang][OpenMP] Fix common block missing symbol crash (#67330)

Fixes #65034 by skipping copy of host-association information if the
concerned symbol is missing from the inner construct

Author: NimishMishra

flang/include/flang/Lower/AbstractConverter.h

@@ -118,6 +118,10 @@ class AbstractConverter {
       const Fortran::semantics::Symbol &sym,
       mlir::OpBuilder::InsertPoint *copyAssignIP = nullptr) = 0;
 
+  /// For a given symbol, check if it is present in the inner-most
+  /// level of the symbol map.
+  virtual bool isPresentShallowLookup(Fortran::semantics::Symbol &sym) = 0;
+
   /// Collect the set of symbols with \p flag in \p eval
   /// region if \p collectSymbols is true. Likewise, collect the
   /// set of the host symbols with \p flag of the associated symbols in \p eval

flang/lib/Lower/Bridge.cpp

@@ -603,6 +603,10 @@ class FirConverter : public Fortran::lower::AbstractConverter {
         std::nullopt);
   }
 
+  bool isPresentShallowLookup(Fortran::semantics::Symbol &sym) override final {
+    return bool(shallowLookupSymbol(sym));
+  }
+
   bool createHostAssociateVarClone(
       const Fortran::semantics::Symbol &sym) override final {
     mlir::Location loc = genLocation(sym.name());

flang/lib/Lower/OpenMP.cpp

@@ -1592,7 +1592,8 @@ bool ClauseProcessor::processCopyin() const {
           mlir::OpBuilder::InsertPoint *copyAssignIP = nullptr) {
         assert(sym->has<Fortran::semantics::HostAssocDetails>() &&
                "No host-association found");
-        converter.copyHostAssociateVar(*sym, copyAssignIP);
+        if (converter.isPresentShallowLookup(*sym))
+          converter.copyHostAssociateVar(*sym, copyAssignIP);
       };
   bool hasCopyin = findRepeatableClause<ClauseTy::Copyin>(
       [&](const ClauseTy::Copyin *copyinClause,

flang/test/Lower/OpenMP/FIR/copyin.f90

@@ -310,3 +310,43 @@ subroutine common_2()
      end do
   !$omp end parallel do
 end subroutine
+
+!CHECK: func.func @_QPcommon_3() {
+!CHECK: %[[val_0:.*]] = fir.address_of(@blk_) : !fir.ref<!fir.array<8xi8>>
+!CHECK: %[[val_1:.*]] = omp.threadprivate %[[val_0]] : !fir.ref<!fir.array<8xi8>> -> !fir.ref<!fir.array<8xi8>>
+!CHECK: %[[val_2:.*]] = fir.convert %[[val_1]] : (!fir.ref<!fir.array<8xi8>>) -> !fir.ref<!fir.array<?xi8>>
+!CHECK: %[[val_c4:.*]] = arith.constant 4 : index
+!CHECK: %[[val_3:.*]] = fir.coordinate_of %[[val_2]], %[[val_c4]] : (!fir.ref<!fir.array<?xi8>>, index) -> !fir.ref<i8>
+!CHECK: %[[val_4:.*]] = fir.convert %[[val_3]] : (!fir.ref<i8>) -> !fir.ref<i32>
+!CHECK: omp.parallel {
+!CHECK: %[[val_5:.*]] = omp.threadprivate %[[val_0]] : !fir.ref<!fir.array<8xi8>> -> !fir.ref<!fir.array<8xi8>>
+!CHECK: %[[val_6:.*]] = fir.convert %[[val_5]] : (!fir.ref<!fir.array<8xi8>>) -> !fir.ref<!fir.array<?xi8>>
+!CHECK: %[[val_c4_0:.*]] = arith.constant 4 : index
+!CHECK: %[[val_7:.*]] = fir.coordinate_of %[[val_6]], %[[val_c4_0]] : (!fir.ref<!fir.array<?xi8>>, index) -> !fir.ref<i8>
+!CHECK: %[[val_8:.*]] = fir.convert %[[val_7]] : (!fir.ref<i8>) -> !fir.ref<i32>
+!CHECK: %[[val_9:.*]] = fir.load %[[val_4]] : !fir.ref<i32>
+!CHECK: fir.store %[[val_9]] to %[[val_8]] : !fir.ref<i32>
+!CHECK: omp.barrier
+!CHECK: omp.sections {
+!CHECK: omp.section {
+!CHECK: %[[val_10:.*]] = fir.load %[[val_8]] : !fir.ref<i32>
+!CHECK: %[[val_c3_i32:.*]] = arith.constant 3 : i32
+!CHECK: %[[val_11:.*]] = arith.addi %[[val_10]], %[[val_c3_i32]] : i32
+!CHECK: fir.store %[[val_11]] to %[[val_8]] : !fir.ref<i32>
+!CHECK: omp.terminator
+!CHECK: }
+!CHECK: omp.terminator
+!CHECK: }
+!CHECK: return
+!CHECK: }
+subroutine common_3()
+  integer :: x
+  integer :: y
+  common /blk/ x, y
+  !$omp threadprivate (/blk/)
+
+  !$omp parallel sections copyin(/blk/)
+        !$omp section
+            y = y + 3
+  !$omp end parallel sections
+end subroutine