[flang] Fix bogus errors from SIZE/SHAPE/UBOUND on assumed-shape

[klausler]

Summary

While it is indeed an error to use SIZE, SHAPE, or UBOUND on an
assumed-shape dummy argument without also supplying a DIM= argument
to the intrinsic function, it is *not* an error to use these intrinsic
functions on sections or expressions of such arrays. Refine the test
used for the error message.

[clementval]

LGTM

flang/include/flang/Evaluate/tools.h

if (auto dataRef{ExtractDataRef(expr, intoSubstring)}) {
     }
   } else {
     return false;
   }
 }
 
 template <typename A>
 std::optional<NamedEntity> ExtractNamedEntity(const A &x) {
-  if (auto dataRef{ExtractDataRef(x, true)}) {
+  if (auto dataRef{ExtractDataRef(x)}) {
     return common::visit(
         common::visitors{
             [](SymbolRef &&symbol) -> std::optional<NamedEntity> {
               return NamedEntity{symbol};
             },
             [](Component &&component) -> std::optional<NamedEntity> {
               return NamedEntity{std::move(component)};
             },

flang/lib/Evaluate/intrinsics.cpp

if (const ActualArgument * arg{actualForDummy[j]}) {
         }
         argOk = rank == knownArg->Rank();
         break;
       case Rank::anyOrAssumedRank:
         if (!hasDimArg && rank > 0 && !isAssumedRank &&
             (std::strcmp(name, "shape") == 0 ||
                 std::strcmp(name, "size") == 0 ||
                 std::strcmp(name, "ubound") == 0)) {
-          // Check for an assumed-size array argument.
+          // Check for a whole assumed-size array argument.
           // These are disallowed for SHAPE, and require DIM= for
           // SIZE and UBOUND.
           // (A previous error message for UBOUND will take precedence
           // over this one, as this error is caught by the second entry
           // for UBOUND.)
-          if (const Symbol * argSym{GetLastSymbol(*arg)}) {
-            if (semantics::IsAssumedSizeArray(*argSym)) {
+          if (auto named{ExtractNamedEntity(*arg)}) {
+            if (semantics::IsAssumedSizeArray(named->GetLastSymbol())) {
               if (strcmp(name, "shape") == 0) {
                 messages.Say(arg->sourceLocation(),
                     "The '%s=' argument to the intrinsic function '%s' may not be assumed-size"_err_en_US,
                     d.keyword, name);
               } else {
                 messages.Say(arg->sourceLocation(),
                     "A dim= argument is required for '%s' when the array is assumed-size"_err_en_US,
                     name);

flang/test/Semantics/misc-intrinsics.f90

subroutine test(arg)
     print *, shape(arg)
     ! But these cases are fine:
     print *, size(arg, dim=1)
     print *, ubound(arg, dim=1)
     print *, lbound(arg)
     print *, size(array)
     print *, ubound(array)
     print *, lbound(array)
+    print *, size(arg(:,1))
+    print *, ubound(arg(:,1))
+    print *, shape(arg(:,1))
   end subroutine
 end