Commit 338f21a4 authored by peter klausler's avatar peter klausler
Browse files

[flang] Enforce specification function rules on callee, not call 

A function can't be a specification function if it has a dummy procedure
argument, even if it's optional and unused.  So don't check the reference
for actual procedure arguments, but rather the characteristics of the
function.

Differential Revision: https://reviews.llvm.org/D109935
parent f6ddfac4

flang/lib/Evaluate/check-expression.cpp

+14 −3
Original line number Diff line number Diff line
@@ -460,9 +460,6 @@ public: 
      : Base{*this}, scope_{s}, context_{context} {}

  using Base::operator();



  Result operator()(const ProcedureDesignator &) const {

    return "dummy procedure argument";

  }

  Result operator()(const CoarrayRef &) const { return "coindexed reference"; }



  Result operator()(const semantics::Symbol &symbol) const {
@@ -541,6 +538,20 @@ public: 
            "' not allowed for derived type components or type parameter"

            " values";

      }

      if (auto procChars{

              characteristics::Procedure::Characterize(x.proc(), context_)}) {

        const auto iter{std::find_if(procChars->dummyArguments.begin(),

            procChars->dummyArguments.end(),

            [](const characteristics::DummyArgument &dummy) {

              return std::holds_alternative<characteristics::DummyProcedure>(

                  dummy.u);

            })};

        if (iter != procChars->dummyArguments.end()) {

          return "reference to function '"s + ultimate.name().ToString() +

              "' with dummy procedure argument '" + iter->name + '\'';

        }

      }

      // References to internal functions are caught in expression semantics.

      // TODO: other checks for standard module procedures

    } else {

      const SpecificIntrinsic &intrin{DEREF(x.proc().GetSpecificIntrinsic())};

flang/test/Semantics/expr-errors02.f90

+3 −2
Original line number Diff line number Diff line
@@ -15,6 +15,7 @@ module m 
    pure integer function hasProcArg(p)

      import realfunc

      procedure(realfunc) :: p

      optional :: p

    end function

  end interface

  integer :: coarray[*]
@@ -37,8 +38,8 @@ module m 
    integer, intent(in), optional :: optional

    !ERROR: Invalid specification expression: reference to OPTIONAL dummy argument 'optional'

    type(t(optional)) :: x5

    !ERROR: Invalid specification expression: dummy procedure argument

    type(t(hasProcArg(realfunc))) :: x6

    !ERROR: Invalid specification expression: reference to function 'hasprocarg' with dummy procedure argument 'p'

    type(t(hasProcArg())) :: x6

    !ERROR: Invalid specification expression: coindexed reference

    type(t(coarray[1])) :: x7

    type(t(kind(foo()))) :: x101 ! ok