Author: rsmith
Date: Thu Mar 8 18:00:01 2018
New Revision: 327099
URL: http://llvm.org/viewvc/llvm-project?rev=327099&view=rev
Log:
PR36645: Go looking for an appropriate array bound when constant-evaluating a
name of an array object.
Modified:
cfe/trunk/lib/AST/ExprConstant.cpp
cfe/trunk/test/SemaCXX/constant-expression-cxx11.cpp
Modified: cfe/trunk/lib/AST/ExprConstant.cpp
URL:
http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/AST/ExprConstant.cpp?rev=327099&r1=327098&r2=327099&view=diff
==============================================================================
--- cfe/trunk/lib/AST/ExprConstant.cpp (original)
+++ cfe/trunk/lib/AST/ExprConstant.cpp Thu Mar 8 18:00:01 2018
@@ -63,14 +63,22 @@ namespace {
static QualType getType(APValue::LValueBase B) {
if (!B) return QualType();
- if (const ValueDecl *D = B.dyn_cast<const ValueDecl*>())
+ if (const ValueDecl *D = B.dyn_cast<const ValueDecl*>()) {
// FIXME: It's unclear where we're supposed to take the type from, and
- // this actually matters for arrays of unknown bound. Using the type of
- // the most recent declaration isn't clearly correct in general. Eg:
+ // this actually matters for arrays of unknown bound. Eg:
//
// extern int arr[]; void f() { extern int arr[3]; };
// constexpr int *p = &arr[1]; // valid?
- return cast<ValueDecl>(D->getMostRecentDecl())->getType();
+ //
+ // For now, we take the array bound from the most recent declaration.
+ for (auto *Redecl = cast<ValueDecl>(D->getMostRecentDecl()); Redecl;
+ Redecl = cast_or_null<ValueDecl>(Redecl->getPreviousDecl())) {
+ QualType T = Redecl->getType();
+ if (!T->isIncompleteArrayType())
+ return T;
+ }
+ return D->getType();
+ }
const Expr *Base = B.get<const Expr*>();
Modified: cfe/trunk/test/SemaCXX/constant-expression-cxx11.cpp
URL:
http://llvm.org/viewvc/llvm-project/cfe/trunk/test/SemaCXX/constant-expression-cxx11.cpp?rev=327099&r1=327098&r2=327099&view=diff
==============================================================================
--- cfe/trunk/test/SemaCXX/constant-expression-cxx11.cpp (original)
+++ cfe/trunk/test/SemaCXX/constant-expression-cxx11.cpp Thu Mar 8 18:00:01
2018
@@ -629,6 +629,10 @@ namespace ArrayOfUnknownBound {
extern const int carr[]; // expected-note {{here}}
constexpr int n = carr[0]; // expected-error {{constant}} expected-note
{{non-constexpr variable}}
+
+ constexpr int local_extern[] = {1, 2, 3};
+ void f() { extern const int local_extern[]; }
+ static_assert(local_extern[1] == 2, "");
}
namespace DependentValues {
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