[flang-commits] [flang] 5be7f8a - [flang] Catch attempt to misuse an abstract procedure in a generic interface

[Peter Klausler via flang-commits]

Author: Peter Klausler
Date: 2023-03-02T09:43:00-08:00
New Revision: 5be7f8a666daee086042da0650b595a0938e3da2

URL: https://github.com/llvm/llvm-project/commit/5be7f8a666daee086042da0650b595a0938e3da2
DIFF: https://github.com/llvm/llvm-project/commit/5be7f8a666daee086042da0650b595a0938e3da2.diff

LOG: [flang] Catch attempt to misuse an abstract procedure in a generic interface

A procedure defined in an ABSTRACT INTERFACE may not appear as
a specific procedure in a generic interface.

Differential Revision: https://reviews.llvm.org/D145102

Added: 
    

Modified: 
    flang/lib/Semantics/check-declarations.cpp
    flang/test/Semantics/generic02.f90

Removed: 
    


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diff  --git a/flang/lib/Semantics/check-declarations.cpp b/flang/lib/Semantics/check-declarations.cpp
index 8321bbc08b7a..8c38d0f59b6e 100644
--- a/flang/lib/Semantics/check-declarations.cpp
+++ b/flang/lib/Semantics/check-declarations.cpp
@@ -1374,6 +1374,14 @@ void CheckHelper::CheckSpecificsAreDistinguishable(
   GenericKind kind{details.kind()};
   DistinguishabilityHelper helper{context_};
   for (const Symbol &specific : details.specificProcs()) {
+    if (specific.attrs().test(Attr::ABSTRACT)) {
+      if (auto *msg{messages_.Say(generic.name(),
+              "Generic interface '%s' must not use abstract interface '%s' as a specific procedure"_err_en_US,
+              generic.name(), specific.name())}) {
+        msg->Attach(
+            specific.name(), "Definition of '%s'"_en_US, specific.name());
+      }
+    }
     if (const Procedure *procedure{Characterize(specific)}) {
       if (procedure->HasExplicitInterface()) {
         helper.Add(generic, kind, specific, *procedure);

diff  --git a/flang/test/Semantics/generic02.f90 b/flang/test/Semantics/generic02.f90
index e4f7fe671aae..551b897470ce 100644
--- a/flang/test/Semantics/generic02.f90
+++ b/flang/test/Semantics/generic02.f90
@@ -1,10 +1,16 @@
 ! RUN: %python %S/test_errors.py %s %flang_fc1
 program test
+  !ERROR: Generic interface 'generic' must not use abstract interface 'abstract' as a specific procedure
   interface generic
     subroutine explicit(n)
       integer, intent(in) :: n
     end subroutine
     procedure implicit
+    procedure abstract
+  end interface
+  abstract interface
+    subroutine abstract
+    end subroutine
   end interface
 !ERROR: Specific procedure 'implicit' of generic interface 'generic' must have an explicit interface
   external implicit