[flang-commits] [flang] e962718 - [flang] Fix non-deterministic line output function

[Ivan Zhechev via flang-commits]

Author: Ivan Zhechev
Date: 2021-09-02T15:13:45Z
New Revision: e962718dd5fc5e77d189729e3e1af34440450bdc

URL: https://github.com/llvm/llvm-project/commit/e962718dd5fc5e77d189729e3e1af34440450bdc
DIFF: https://github.com/llvm/llvm-project/commit/e962718dd5fc5e77d189729e3e1af34440450bdc.diff

LOG: [flang] Fix non-deterministic line output function

The evaluation order for the `|` operator is undefined
(in contrast to the short-circuiting `||` operator). The arguments are
stored in variables to force a specific evaluation order.

A test in D107575 relies on this change.

Reviewed By: kiranchandramohan, klausler

Differential Revision: https://reviews.llvm.org/D108623

Added: 
    

Modified: 
    flang/lib/Semantics/check-declarations.cpp

Removed: 
    


################################################################################
diff  --git a/flang/lib/Semantics/check-declarations.cpp b/flang/lib/Semantics/check-declarations.cpp
index 4468784c06a17..368c8a108a5b9 100644
--- a/flang/lib/Semantics/check-declarations.cpp
+++ b/flang/lib/Semantics/check-declarations.cpp
@@ -1152,6 +1152,12 @@ bool CheckHelper::CheckDefinedOperator(SourceName opName, GenericKind kind,
     return false;
   }
   std::optional<parser::MessageFixedText> msg;
+  auto checkDefinedOperatorArgs{
+      [&](SourceName opName, const Symbol &specific, const Procedure &proc) {
+        bool arg0Defined{CheckDefinedOperatorArg(opName, specific, proc, 0)};
+        bool arg1Defined{CheckDefinedOperatorArg(opName, specific, proc, 1)};
+        return arg0Defined && arg1Defined;
+      }};
   if (specific.attrs().test(Attr::NOPASS)) { // C774
     msg = "%s procedure '%s' may not have NOPASS attribute"_err_en_US;
   } else if (!proc.functionResult.has_value()) {
@@ -1161,8 +1167,7 @@ bool CheckHelper::CheckDefinedOperator(SourceName opName, GenericKind kind,
           " result"_err_en_US;
   } else if (auto m{CheckNumberOfArgs(kind, proc.dummyArguments.size())}) {
     msg = std::move(m);
-  } else if (!CheckDefinedOperatorArg(opName, specific, proc, 0) |
-      !CheckDefinedOperatorArg(opName, specific, proc, 1)) {
+  } else if (!checkDefinedOperatorArgs(opName, specific, proc)) {
     return false; // error was reported
   } else if (ConflictsWithIntrinsicOperator(kind, proc)) {
     msg = "%s function '%s' conflicts with intrinsic operator"_err_en_US;