[clang] 1b8125b - Don't assert if we find a dependently-typed variable in the

[Richard Smith via cfe-commits]

Author: Richard Smith
Date: 2020-06-16T19:41:13-07:00
New Revision: 1b8125b041e28a315e5c5fe64441a2fb07a2f5ea

URL: https://github.com/llvm/llvm-project/commit/1b8125b041e28a315e5c5fe64441a2fb07a2f5ea
DIFF: https://github.com/llvm/llvm-project/commit/1b8125b041e28a315e5c5fe64441a2fb07a2f5ea.diff

LOG: Don't assert if we find a dependently-typed variable in the
redeclaration chain for an array.

A prior attempt to fix this in r280330 didn't handle the case where the
old variable is dependent and the new one is not.

It is notable and worrying that the test case in this example forms a
redeclaration chain for a non-dependent variable that includes a
declaration with a dependent type. We should probably fix that too.

Added: 
    

Modified: 
    clang/lib/Sema/SemaDecl.cpp
    clang/test/SemaTemplate/array-redeclaration.cpp

Removed: 
    


################################################################################
diff  --git a/clang/lib/Sema/SemaDecl.cpp b/clang/lib/Sema/SemaDecl.cpp
index d5d946429e7d..2bf16d138d5a 100644
--- a/clang/lib/Sema/SemaDecl.cpp
+++ b/clang/lib/Sema/SemaDecl.cpp
@@ -3910,11 +3910,11 @@ void Sema::MergeVarDeclTypes(VarDecl *New, VarDecl *Old,
       if (!NewArray->isIncompleteArrayType() && !NewArray->isDependentType()) {
         for (VarDecl *PrevVD = Old->getMostRecentDecl(); PrevVD;
              PrevVD = PrevVD->getPreviousDecl()) {
-          const ArrayType *PrevVDTy = Context.getAsArrayType(PrevVD->getType());
+          QualType PrevVDTy = PrevVD->getType();
           if (PrevVDTy->isIncompleteArrayType() || PrevVDTy->isDependentType())
             continue;
 
-          if (!Context.hasSameType(NewArray, PrevVDTy))
+          if (!Context.hasSameType(New->getType(), PrevVDTy))
             return diagnoseVarDeclTypeMismatch(*this, New, PrevVD);
         }
       }

diff  --git a/clang/test/SemaTemplate/array-redeclaration.cpp b/clang/test/SemaTemplate/array-redeclaration.cpp
index 4edee701cfc4..af0a2770291c 100644
--- a/clang/test/SemaTemplate/array-redeclaration.cpp
+++ b/clang/test/SemaTemplate/array-redeclaration.cpp
@@ -31,3 +31,9 @@ void foo3() {
 void foo4() {
   foo3<5>();
 }
+
+namespace NS {
+  int f() { extern int arr[3]; { extern int arr[]; } return 0; }
+  template<typename T> void g() { extern int arr[3]; extern T arr; }
+  template void g<int[]>();
+}