[flang-commits] [flang] 5a0b91f - [flang][openacc] Fix false positive error in common block resolution

[Valentin Clement via flang-commits]

Author: Valentin Clement
Date: 2023-07-10T08:39:35-07:00
New Revision: 5a0b91fc28212f105c9b49a62444f7b92a54b1ed

URL: https://github.com/llvm/llvm-project/commit/5a0b91fc28212f105c9b49a62444f7b92a54b1ed
DIFF: https://github.com/llvm/llvm-project/commit/5a0b91fc28212f105c9b49a62444f7b92a54b1ed.diff

LOG: [flang][openacc] Fix false positive error in common block resolution

The following error was triggered in the added test case.
This is a false positive.

COMMON block must be declared in the same scoping unit in which the OpenACC directive or clause appears

Reviewed By: kiranchandramohan

Differential Revision: https://reviews.llvm.org/D154742

Added: 
    

Modified: 
    flang/lib/Semantics/resolve-directives.cpp
    flang/test/Semantics/OpenACC/acc-resolve04.f90

Removed: 
    


################################################################################
diff  --git a/flang/lib/Semantics/resolve-directives.cpp b/flang/lib/Semantics/resolve-directives.cpp
index 3692a4fcd87588..d96871b2965c11 100644
--- a/flang/lib/Semantics/resolve-directives.cpp
+++ b/flang/lib/Semantics/resolve-directives.cpp
@@ -1064,15 +1064,19 @@ void AccAttributeVisitor::Post(const parser::Name &name) {
 
 Symbol *AccAttributeVisitor::ResolveAccCommonBlockName(
     const parser::Name *name) {
-  if (!name) {
-    return nullptr;
-  } else if (auto *prev{
-                 GetContext().scope.parent().FindCommonBlock(name->source)}) {
+  if (auto *prev{name
+              ? GetContext().scope.parent().FindCommonBlock(name->source)
+              : nullptr}) {
     name->symbol = prev;
     return prev;
-  } else {
-    return nullptr;
   }
+  // Check if the Common Block is declared in the current scope
+  if (auto *commonBlockSymbol{
+          name ? GetContext().scope.FindCommonBlock(name->source) : nullptr}) {
+    name->symbol = commonBlockSymbol;
+    return commonBlockSymbol;
+  }
+  return nullptr;
 }
 
 void AccAttributeVisitor::ResolveAccObjectList(

diff  --git a/flang/test/Semantics/OpenACC/acc-resolve04.f90 b/flang/test/Semantics/OpenACC/acc-resolve04.f90
index ee5e21adcb5e8c..8a72630a2ec9ff 100644
--- a/flang/test/Semantics/OpenACC/acc-resolve04.f90
+++ b/flang/test/Semantics/OpenACC/acc-resolve04.f90
@@ -1,7 +1,22 @@
 ! RUN: %flang_fc1 -fopenacc %s
 
+! Check common block resolution.
 ! Check that symbol are correctly resolved in device, host and self clause.
 
+subroutine sub(a)
+ implicit none
+ real :: a(10)
+ real :: b(10), c(10), d
+ common/foo/ b, d, c
+ integer :: i, n
+
+ !$acc declare present(/foo/)
+ !$acc parallel loop gang vector
+  do i = 1, n
+	  b(i) = a(i) + c(i) * d
+  end do
+end subroutine
+
 program test_resolve04
   real :: a(10), b(10)
   common /foo/ b, c