[flang-commits] [flang] 1c900ed - [flang] Catch error: COMMON block and implicit interface external subprogram with same name

[Peter Klausler via flang-commits]

Author: Peter Klausler
Date: 2023-06-27T13:18:30-07:00
New Revision: 1c900ed373983d52a230b6baf7bfb49eaec155a5

URL: https://github.com/llvm/llvm-project/commit/1c900ed373983d52a230b6baf7bfb49eaec155a5
DIFF: https://github.com/llvm/llvm-project/commit/1c900ed373983d52a230b6baf7bfb49eaec155a5.diff

LOG: [flang] Catch error: COMMON block and implicit interface external subprogram with same name

Declaration checking catches the error of a COMMON block and a subprogram
definition having the same name, but misses the case of a COMMON block
and an a reference to an external subprogram with an implicit interface.
Fix.  Fixes bug https://github.com/llvm/llvm-project/issues/63247.

Differential Revision: https://reviews.llvm.org/D153786

Added: 
    

Modified: 
    flang/lib/Semantics/check-declarations.cpp
    flang/test/Semantics/declarations04.f90

Removed: 
    


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diff  --git a/flang/lib/Semantics/check-declarations.cpp b/flang/lib/Semantics/check-declarations.cpp
index baf7af2b60611..24ee1b240115c 100644
--- a/flang/lib/Semantics/check-declarations.cpp
+++ b/flang/lib/Semantics/check-declarations.cpp
@@ -2552,7 +2552,8 @@ static std::optional<std::string> DefinesGlobalName(const Symbol &symbol) {
   } else {
     const std::string *bindC{symbol.GetBindName()};
     if (symbol.has<CommonBlockDetails>() ||
-        IsExternalProcedureDefinition(symbol)) {
+        IsExternalProcedureDefinition(symbol) ||
+        (symbol.owner().IsGlobal() && IsExternal(symbol))) {
       return bindC ? *bindC : symbol.name().ToString();
     } else if (bindC &&
         (symbol.has<ObjectEntityDetails>() || IsModuleProcedure(symbol))) {

diff  --git a/flang/test/Semantics/declarations04.f90 b/flang/test/Semantics/declarations04.f90
index f061cb9e5300f..6b33578ca9c05 100644
--- a/flang/test/Semantics/declarations04.f90
+++ b/flang/test/Semantics/declarations04.f90
@@ -23,3 +23,9 @@ block data ext3
   !PORTABILITY: Global name 'ext4' conflicts with a module
   common /ext4/ x
 end
+
+subroutine s
+  !ERROR: Two entities have the same global name 'foo'
+  common /foo/n
+  call foo
+end