[clang] 3c67c22 - [clang][Interp] Test non-active union access

[Timm Bäder via cfe-commits]

Author: Timm Bäder
Date: 2024-05-22T17:31:34+02:00
New Revision: 3c67c227f2e16accd3cdb3aeb4c845edabd2f6c4

URL: https://github.com/llvm/llvm-project/commit/3c67c227f2e16accd3cdb3aeb4c845edabd2f6c4
DIFF: https://github.com/llvm/llvm-project/commit/3c67c227f2e16accd3cdb3aeb4c845edabd2f6c4.diff

LOG: [clang][Interp] Test non-active union access

Added: 
    

Modified: 
    clang/lib/AST/Interp/Interp.cpp
    clang/test/AST/Interp/unions.cpp

Removed: 
    


################################################################################
diff  --git a/clang/lib/AST/Interp/Interp.cpp b/clang/lib/AST/Interp/Interp.cpp
index 1ed2ff30bdd05..cac678352e2ce 100644
--- a/clang/lib/AST/Interp/Interp.cpp
+++ b/clang/lib/AST/Interp/Interp.cpp
@@ -457,10 +457,10 @@ bool CheckLoad(InterpState &S, CodePtr OpPC, const Pointer &Ptr) {
     return false;
   if (!CheckRange(S, OpPC, Ptr, AK_Read))
     return false;
-  if (!CheckInitialized(S, OpPC, Ptr, AK_Read))
-    return false;
   if (!CheckActive(S, OpPC, Ptr, AK_Read))
     return false;
+  if (!CheckInitialized(S, OpPC, Ptr, AK_Read))
+    return false;
   if (!CheckTemporary(S, OpPC, Ptr, AK_Read))
     return false;
   if (!CheckMutable(S, OpPC, Ptr))

diff  --git a/clang/test/AST/Interp/unions.cpp b/clang/test/AST/Interp/unions.cpp
index 08ca39c3cb089..004e500de064f 100644
--- a/clang/test/AST/Interp/unions.cpp
+++ b/clang/test/AST/Interp/unions.cpp
@@ -1,8 +1,6 @@
 // RUN: %clang_cc1 -fexperimental-new-constant-interpreter -verify=expected,both %s
 // RUN: %clang_cc1 -verify=ref,both %s
 
-// both-no-diagnostics
-
 union U {
   int a;
   int b;
@@ -10,5 +8,5 @@ union U {
 
 constexpr U a = {12};
 static_assert(a.a == 12, "");
-
-
+static_assert(a.b == 0, ""); // both-error {{not an integral constant expression}} \
+                             // both-note {{read of member 'b' of union with active member 'a'}}