[clang][ExprConst] Diagnose ptr subs with non-zero offset

[tbaederr]

The attached test case was missing the note.

[llvmbot]

@llvm/pr-subscribers-clang

Author: Timm Baeder (tbaederr)

Changes

The attached test case was missing the note.

Just checking the CI.

---

Full diff: https://github.com/llvm/llvm-project/pull/135938.diff

2 Files Affected:

• (modified) clang/lib/AST/ExprConstant.cpp (-3)
• (modified) clang/test/SemaCXX/constant-expression-cxx11.cpp (+4)

diff --git a/clang/lib/AST/ExprConstant.cpp b/clang/lib/AST/ExprConstant.cpp
index d1cc722fb7945..b14ff21a8ebc2 100644
--- a/clang/lib/AST/ExprConstant.cpp
+++ b/clang/lib/AST/ExprConstant.cpp
@@ -14764,9 +14764,6 @@ bool IntExprEvaluator::VisitBinaryOperator(const BinaryOperator *E) {
     // Reject differing bases from the normal codepath; we special-case
     // comparisons to null.
     if (!HasSameBase(LHSValue, RHSValue)) {
-      // Handle &&A - &&B.
-      if (!LHSValue.Offset.isZero() || !RHSValue.Offset.isZero())
-        return Error(E);
       const Expr *LHSExpr = LHSValue.Base.dyn_cast<const Expr *>();
       const Expr *RHSExpr = RHSValue.Base.dyn_cast<const Expr *>();
 
diff --git a/clang/test/SemaCXX/constant-expression-cxx11.cpp b/clang/test/SemaCXX/constant-expression-cxx11.cpp
index c35f3a5632a05..28016da925ef9 100644
--- a/clang/test/SemaCXX/constant-expression-cxx11.cpp
+++ b/clang/test/SemaCXX/constant-expression-cxx11.cpp
@@ -409,6 +409,10 @@ constexpr int a = 0;
 constexpr int b = 1;
 constexpr int n = &b - &a; // expected-error {{must be initialized by a constant expression}} \
                            // expected-note {{arithmetic involving unrelated objects '&b' and '&a' has unspecified value}}
+constexpr static int arrk[2] = {1,2};
+constexpr static int arrk2[2] = {3,4};
+constexpr int k2 = &arrk[1] - &arrk2[0]; // expected-error {{must be initialized by a constant expression}} \
+                                         // expected-note {{arithmetic involving unrelated objects}}
 
 namespace MaterializeTemporary {
 

[AaronBallman]

LGTM!