[llvm-branch-commits] [flang] f24c642 - [flang] Fix bogus message on interface procedure argument names

[Peter Steinfeld via llvm-branch-commits]

Author: Peter Steinfeld
Date: 2020-12-03T12:08:55-08:00
New Revision: f24c642178a5a31aa1c44585537c08fdfc3fdfd5

URL: https://github.com/llvm/llvm-project/commit/f24c642178a5a31aa1c44585537c08fdfc3fdfd5
DIFF: https://github.com/llvm/llvm-project/commit/f24c642178a5a31aa1c44585537c08fdfc3fdfd5.diff

LOG: [flang] Fix bogus message on interface procedure argument names

We were keeping the state of parsed equivalence sets in the class
DeclarationVisitor.  A problem happened when  analyzing the the specification
part of a declaration that contained an EQUIVALENCE statement followed by an
interface block.  The same DeclarationVisitor object that was created for the
outer declaration was being used to analyze the specification part
of a procedure body in the interface block.  When analyzing the specification
part of the procedure in the interface block, the names in the outer
declaration's EQUIVALENCE statement were erroneously compared with the names in
the arguments of the interface procedure.  This resulted in a bogus error
message.

I fixed this by not checking equivalence sets when we're in an interface
block.  I also added a test that will produce an error message without
this change.

Differential Revision: https://reviews.llvm.org/D92501

Added: 
    

Modified: 
    flang/lib/Semantics/resolve-names.cpp
    flang/test/Semantics/equivalence01.f90

Removed: 
    


################################################################################
diff  --git a/flang/lib/Semantics/resolve-names.cpp b/flang/lib/Semantics/resolve-names.cpp
index ad5fc734c776..78ce019ec4b8 100644
--- a/flang/lib/Semantics/resolve-names.cpp
+++ b/flang/lib/Semantics/resolve-names.cpp
@@ -6194,7 +6194,11 @@ void ResolveNamesVisitor::FinishSpecificationPart(
   // TODO: what about instantiations in BLOCK?
   CheckSaveStmts();
   CheckCommonBlocks();
-  CheckEquivalenceSets();
+  if (!inInterfaceBlock()) {
+    // TODO: warn for the case where the EQUIVALENCE statement is in a
+    // procedure declaration in an interface block
+    CheckEquivalenceSets();
+  }
 }
 
 // Analyze the bodies of statement functions now that the symbols in this

diff  --git a/flang/test/Semantics/equivalence01.f90 b/flang/test/Semantics/equivalence01.f90
index 404be570d657..234c42744ee9 100644
--- a/flang/test/Semantics/equivalence01.f90
+++ b/flang/test/Semantics/equivalence01.f90
@@ -1,4 +1,4 @@
-! RUN: %S/test_errors.sh %s %t %f18
+!RUN: %S/test_errors.sh %s %t %f18
 subroutine s1
   integer i, j
   real r(2)
@@ -182,3 +182,18 @@ module s15
   !ERROR: 'a(3_8)' and 'a(1_8)' cannot have the same first storage unit
   equivalence(b(2),a(1))
 end module
+
+subroutine s16
+
+  integer var, dupName
+
+  ! There should be no error message for the following
+  equivalence (dupName, var)
+
+  interface
+    subroutine interfaceSub (dupName)
+      integer dupName
+    end subroutine interfaceSub
+  end interface
+
+end subroutine s16