When tree-transforming an expression sequence, always flag expanded
variadic argument pack expansions as having changed, rather than doing
it for each changed expansion, which leaves out zero-argument packs
with catastrophic consequences.
Fixes PR10260.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@134483 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Sema/TreeTransform.h b/lib/Sema/TreeTransform.h
index edbf1fb..66ea7df 100644
--- a/lib/Sema/TreeTransform.h
+++ b/lib/Sema/TreeTransform.h
@@ -1547,9 +1547,9 @@
/// By default, performs semantic analysis to build the new expression.
/// Subclasses may override this routine to provide different behavior.
ExprResult RebuildInitList(SourceLocation LBraceLoc,
- MultiExprArg Inits,
- SourceLocation RBraceLoc,
- QualType ResultTy) {
+ MultiExprArg Inits,
+ SourceLocation RBraceLoc,
+ QualType ResultTy) {
ExprResult Result
= SemaRef.ActOnInitList(LBraceLoc, move(Inits), RBraceLoc);
if (Result.isInvalid() || ResultTy->isDependentType())
@@ -2476,6 +2476,10 @@
Outputs.push_back(Out.get());
continue;
}
+
+ // Record right away that the argument was changed. This needs
+ // to happen even if the array expands to nothing.
+ if (ArgChanged) *ArgChanged = true;
// The transform has determined that we should perform an elementwise
// expansion of the pattern. Do so.
@@ -2492,8 +2496,6 @@
return true;
}
- if (ArgChanged)
- *ArgChanged = true;
Outputs.push_back(Out.get());
}
diff --git a/test/CodeGenCXX/variadic-templates.cpp b/test/CodeGenCXX/variadic-templates.cpp
index 4f3cf1f..90c8370 100644
--- a/test/CodeGenCXX/variadic-templates.cpp
+++ b/test/CodeGenCXX/variadic-templates.cpp
@@ -9,4 +9,15 @@
// CHECK: ret i32 3
template int get_num_types(int, float, double);
+// PR10260 - argument packs that expand to nothing
+namespace test1 {
+ template <class... T> void foo() {
+ int values[sizeof...(T)+1] = { T::value... };
+ // CHECK: define linkonce_odr void @_ZN5test13fooIJEEEvv()
+ // CHECK: alloca [1 x i32], align 4
+ }
+ void test() {
+ foo<>();
+ }
+}