[flang-commits] [flang] 8f41431 - [flang] Disallow BOZ literal constants as arguments of implicit interfaces

[Peter Steinfeld via flang-commits]

Author: Peter Steinfeld
Date: 2021-07-26T15:04:05-07:00
New Revision: 8f41431654fedac4a5ad2751056a611bfc7751f0

URL: https://github.com/llvm/llvm-project/commit/8f41431654fedac4a5ad2751056a611bfc7751f0
DIFF: https://github.com/llvm/llvm-project/commit/8f41431654fedac4a5ad2751056a611bfc7751f0.diff

LOG: [flang] Disallow BOZ literal constants as arguments of implicit interfaces

Since BOZ literal arguments are typeless, we cannot know how to pass them as
actual arguments to procedures with implicit interfaces.  This change avoids
the problem by emitting an error message in such situations.

This change stemmed from the following issue --
  https://github.com/flang-compiler/f18-llvm-project/issues/794

Differential Revision: https://reviews.llvm.org/D106831

Added: 
    

Modified: 
    flang/lib/Semantics/check-call.cpp
    flang/test/Semantics/boz-literal-constants.f90

Removed: 
    


################################################################################
diff  --git a/flang/lib/Semantics/check-call.cpp b/flang/lib/Semantics/check-call.cpp
index 5a358c46f31f6..77fc25b44f6e4 100644
--- a/flang/lib/Semantics/check-call.cpp
+++ b/flang/lib/Semantics/check-call.cpp
@@ -46,6 +46,9 @@ static void CheckImplicitInterfaceArg(
     }
   }
   if (const auto *expr{arg.UnwrapExpr()}) {
+    if (std::holds_alternative<evaluate::BOZLiteralConstant>(expr->u)) {
+      messages.Say("BOZ argument requires an explicit interface"_err_en_US);
+    }
     if (auto named{evaluate::ExtractNamedEntity(*expr)}) {
       const Symbol &symbol{named->GetLastSymbol()};
       if (symbol.Corank() > 0) {

diff  --git a/flang/test/Semantics/boz-literal-constants.f90 b/flang/test/Semantics/boz-literal-constants.f90
index 1de7c06fb4e2f..8636a31e705f1 100644
--- a/flang/test/Semantics/boz-literal-constants.f90
+++ b/flang/test/Semantics/boz-literal-constants.f90
@@ -77,4 +77,7 @@ subroutine bozchecks
   res = MERGE_BITS(B"1101",3,B"1011")
 
   res = REAL(B"1101")
+
+  !ERROR: BOZ argument requires an explicit interface
+  call implictSub(Z'12345')
 end subroutine