[flang-commits] [flang] 1dd8da2 - [flang] Fix semantics check for RETURN statement

[Emil Kieri via flang-commits]

Author: Emil Kieri
Date: 2022-05-02T22:04:58+02:00
New Revision: 1dd8da2d7c75c2a34bf85a37a819755d60ddfb2b

URL: https://github.com/llvm/llvm-project/commit/1dd8da2d7c75c2a34bf85a37a819755d60ddfb2b
DIFF: https://github.com/llvm/llvm-project/commit/1dd8da2d7c75c2a34bf85a37a819755d60ddfb2b.diff

LOG: [flang] Fix semantics check for RETURN statement

The RETURN statement is allowed in functions and subroutines, but not
in main programs. It is however a common extension, which we also
implement, to allow RETURN from main programs -- we only issue a
portability warning when -pedantic or -std=f2018 are set.

This patch fixes false positives for this portability warning, where it
was triggered also when RETURN was present in functions or subroutines.

Fixexs #55080

Reviewed By: PeteSteinfeld

Differential Revision: https://reviews.llvm.org/D124732

Added: 
    flang/test/Semantics/altreturn07.f90

Modified: 
    flang/lib/Semantics/check-return.cpp
    flang/test/Semantics/altreturn02.f90

Removed: 
    


################################################################################
diff  --git a/flang/lib/Semantics/check-return.cpp b/flang/lib/Semantics/check-return.cpp
index b28c82b37bb84..ec2600bac3c68 100644
--- a/flang/lib/Semantics/check-return.cpp
+++ b/flang/lib/Semantics/check-return.cpp
@@ -36,7 +36,8 @@ void ReturnStmtChecker::Leave(const parser::ReturnStmt &returnStmt) {
             IsFunction(*subprogramScope->GetSymbol()))) {
       context_.Say(
           "RETURN with expression is only allowed in SUBROUTINE subprogram"_err_en_US);
-    } else if (context_.ShouldWarn(common::LanguageFeature::ProgramReturn)) {
+    } else if (subprogramScope->kind() == Scope::Kind::MainProgram &&
+        context_.ShouldWarn(common::LanguageFeature::ProgramReturn)) {
       context_.Say("RETURN should not appear in a main program"_port_en_US);
     }
   }

diff  --git a/flang/test/Semantics/altreturn02.f90 b/flang/test/Semantics/altreturn02.f90
index a142871732198..f17d173ccbbd8 100644
--- a/flang/test/Semantics/altreturn02.f90
+++ b/flang/test/Semantics/altreturn02.f90
@@ -1,4 +1,4 @@
-! RUN: %python %S/test_errors.py %s %flang_fc1
+! RUN: %flang_fc1 -fsyntax-only -pedantic %s  2>&1 | FileCheck %s --allow-empty
 ! Check subroutine with alt return
 
        SUBROUTINE TEST (N, *, *)
@@ -6,3 +6,5 @@ SUBROUTINE TEST (N, *, *)
        IF ( N .EQ. 1 ) RETURN 1
        RETURN 2
        END
+! CHECK-NOT: error:
+! CHECK-NOT: portability:

diff  --git a/flang/test/Semantics/altreturn07.f90 b/flang/test/Semantics/altreturn07.f90
new file mode 100644
index 0000000000000..b0cb60a98a328
--- /dev/null
+++ b/flang/test/Semantics/altreturn07.f90
@@ -0,0 +1,6 @@
+! RUN: %flang_fc1 -fsyntax-only -pedantic %s  2>&1 | FileCheck %s
+! Test extension: RETURN from main program
+
+return
+! CHECK: portability: RETURN should not appear in a main program
+end