Add FindSymbol and update tests

Author: Leporacanthicus

flang/lib/Semantics/resolve-names.cpp

@@ -1643,9 +1643,28 @@ bool OmpVisitor::Pre(const parser::OpenMPDeclareMapperConstruct &x) {
 
 bool OmpVisitor::Pre(const parser::OmpMapClause &x) {
   const auto &mid{std::get<parser::OmpMapperIdentifier>(x.t)};
-  if (const auto &mapperName{mid.v})
-    mapperName->symbol =
-        &MakeSymbol(*mapperName, MiscDetails{MiscDetails::Kind::ConstructName});
+  if (const auto &mapperName{mid.v}) {
+    if (const auto symbol = FindSymbol(currScope(), *mapperName)) {
+      // TODO: Do we need a specific flag or type here, to distinghuish against
+      // other ConstructName things? Leaving this for the full implementation
+      // of mapper lowering.
+      auto *misc{symbol->detailsIf<MiscDetails>()};
+      if (!misc || misc->kind() != MiscDetails::Kind::ConstructName)
+        context().Say(mapperName->source,
+            "Name '%s' should be a mapper name"_err_en_US, mapperName->source);
+      else
+        mapperName->symbol = symbol;
+    } else {
+      mapperName->symbol = &MakeSymbol(
+          *mapperName, MiscDetails{MiscDetails::Kind::ConstructName});
+      // TODO: When completing the implementation, we probably want to error if
+      // the symbol is not declared, but right now, testing that the TODO for
+      // OmpMapclause happens is obscured by the TODO for declare mapper, so
+      // leaving this out. Remove the above line once the declare mapper is
+      // implemented. context().Say(mapperName->source, "'%s' not
+      // declared"_err_en_US, mapperName->source);
+    }
+  }
   return true;
 }
 

flang/test/Lower/OpenMP/Todo/map-mapper.f90

@@ -2,6 +2,11 @@
 program p
   integer, parameter :: n = 256
   real(8) :: a(256)
+  !! TODO: Add declare mapper, when it works to lower this construct 
+  !!type t1
+  !!   integer :: x
+  !!end type t1
+  !!!$omp declare mapper(xx : t1 :: nn) map(nn, nn%x)
   !$omp target map(mapper(xx), from:a)
 !CHECK: not yet implemented: OmpMapClause(MAPPER(...))
   do i=1,n

flang/test/Semantics/OpenMP/map-clause.f90

@@ -33,3 +33,11 @@ subroutine sb(arr)
    c = 2
  !$omp end target
 end subroutine
+
+subroutine sb1
+  integer :: xx
+  integer :: a
+  !ERROR: Name 'xx' should be a mapper name
+  !$omp target map(mapper(xx), from:a)
+  !$omp end target
+end subroutine sb1