mattd created this revision.
In the case of ill-formed templates, a value dependent name can reach the
integral constant expression (ICE) check. After an error occurs following an
ill-formed template, an ICE check can be performed on a template definition.
That definition might contain an expression, such as "const a = sizeof(T);"
where T is a template type argument. In this case, the latter expression is
ValueDependent, T is type dependent, and the sizeof expression is therefore
considered Value Dependent.
The assertions will trigger, if the implementation of a templated member
function occurs in a separate namespace from its definition (bad code). If such
a case occurs, an ODR marking of a variable decl is performed, which happens to
check that a particular variable is constant.
Additionally, ValueDependent items can be ICEs, but we never check that case,
and the assertions assume we never see them in the first place. In general, I
don't like removing assertions, for obvious reasons. But in this case, I am
not sure they are necessary, and can be problematic as seen by the included
test case.
https://reviews.llvm.org/D40398
Files:
lib/AST/Decl.cpp
lib/AST/ExprConstant.cpp
test/SemaTemplate/illformed-template-ice.cpp
Index: test/SemaTemplate/illformed-template-ice.cpp
===================================================================
--- test/SemaTemplate/illformed-template-ice.cpp
+++ test/SemaTemplate/illformed-template-ice.cpp
@@ -0,0 +1,13 @@
+// RUN: %clang_cc1 -fsyntax-only -verify %s
+
+class A {
+public:
+ template <typename T> void B();
+};
+
+namespace {
+ template <typename T> void A::B() { // expected-error {{cannot define or
redeclare 'B' here because namespace '' does not enclose namespace 'A'}}
+ const int a = sizeof(T);
+ int b = a;
+ }
+}
Index: lib/AST/ExprConstant.cpp
===================================================================
--- lib/AST/ExprConstant.cpp
+++ lib/AST/ExprConstant.cpp
@@ -10250,7 +10250,6 @@
}
static ICEDiag CheckICE(const Expr* E, const ASTContext &Ctx) {
- assert(!E->isValueDependent() && "Should not see value dependent exprs!");
if (!E->getType()->isIntegralOrEnumerationType())
return ICEDiag(IK_NotICE, E->getLocStart());
Index: lib/AST/Decl.cpp
===================================================================
--- lib/AST/Decl.cpp
+++ lib/AST/Decl.cpp
@@ -2216,7 +2216,6 @@
return Eval->Evaluated.isUninit() ? nullptr : &Eval->Evaluated;
const auto *Init = cast<Expr>(Eval->Value);
- assert(!Init->isValueDependent());
if (Eval->IsEvaluating) {
// FIXME: Produce a diagnostic for self-initialization.
@@ -2284,7 +2283,6 @@
return Eval->IsICE;
const auto *Init = cast<Expr>(Eval->Value);
- assert(!Init->isValueDependent());
// In C++11, evaluate the initializer to check whether it's a constant
// expression.
Index: test/SemaTemplate/illformed-template-ice.cpp
===================================================================
--- test/SemaTemplate/illformed-template-ice.cpp
+++ test/SemaTemplate/illformed-template-ice.cpp
@@ -0,0 +1,13 @@
+// RUN: %clang_cc1 -fsyntax-only -verify %s
+
+class A {
+public:
+ template <typename T> void B();
+};
+
+namespace {
+ template <typename T> void A::B() { // expected-error {{cannot define or redeclare 'B' here because namespace '' does not enclose namespace 'A'}}
+ const int a = sizeof(T);
+ int b = a;
+ }
+}
Index: lib/AST/ExprConstant.cpp
===================================================================
--- lib/AST/ExprConstant.cpp
+++ lib/AST/ExprConstant.cpp
@@ -10250,7 +10250,6 @@
}
static ICEDiag CheckICE(const Expr* E, const ASTContext &Ctx) {
- assert(!E->isValueDependent() && "Should not see value dependent exprs!");
if (!E->getType()->isIntegralOrEnumerationType())
return ICEDiag(IK_NotICE, E->getLocStart());
Index: lib/AST/Decl.cpp
===================================================================
--- lib/AST/Decl.cpp
+++ lib/AST/Decl.cpp
@@ -2216,7 +2216,6 @@
return Eval->Evaluated.isUninit() ? nullptr : &Eval->Evaluated;
const auto *Init = cast<Expr>(Eval->Value);
- assert(!Init->isValueDependent());
if (Eval->IsEvaluating) {
// FIXME: Produce a diagnostic for self-initialization.
@@ -2284,7 +2283,6 @@
return Eval->IsICE;
const auto *Init = cast<Expr>(Eval->Value);
- assert(!Init->isValueDependent());
// In C++11, evaluate the initializer to check whether it's a constant
// expression.
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