[Sema] Don't check for array bounds when the types in the base expression are dependent
Bail-out of CheckArrayAccess when the types of the base expression before
and after eventual casts are dependent. We will get another chance to check
for array bounds during instantiation. Fixes PR41087.
Differential Revision: https://reviews.llvm.org/D59776
Reviewed By: efriedma
llvm-svn: 356957
diff --git a/clang/lib/Sema/SemaChecking.cpp b/clang/lib/Sema/SemaChecking.cpp
index 8f710ca..b9b14a0 100644
--- a/clang/lib/Sema/SemaChecking.cpp
+++ b/clang/lib/Sema/SemaChecking.cpp
@@ -12522,6 +12522,8 @@
return;
const Type *BaseType = ArrayTy->getElementType().getTypePtr();
+ if (EffectiveType->isDependentType() || BaseType->isDependentType())
+ return;
Expr::EvalResult Result;
if (!IndexExpr->EvaluateAsInt(Result, Context, Expr::SE_AllowSideEffects))
diff --git a/clang/test/SemaCXX/array-bounds.cpp b/clang/test/SemaCXX/array-bounds.cpp
index 6ebff8c..495ccaf 100644
--- a/clang/test/SemaCXX/array-bounds.cpp
+++ b/clang/test/SemaCXX/array-bounds.cpp
@@ -296,3 +296,16 @@
// We can still diagnose this.
C &h() { return reinterpret_cast<C *>(xxx)[-1]; } // expected-warning {{array index -1 is before the beginning of the array}}
}
+
+namespace PR41087 {
+ template <typename Ty> void foo() {
+ Ty buffer[2]; // expected-note 3{{array 'buffer' declared here}}
+ ((char *)buffer)[2] = 'A'; // expected-warning 1{{array index 2 is past the end of the array (which contains 2 elements)}}
+ ((char *)buffer)[-1] = 'A'; // expected-warning 2{{array index -1 is before the beginning of the array}}
+ }
+
+ void f() {
+ foo<char>(); // expected-note 1{{in instantiation of function template specialization}}
+ foo<int>(); // expected-note 1{{in instantiation of function template specialization}}
+ };
+}