Introduce a SFINAE "trap" that keeps track of the number of errors
that were suppressed due to SFINAE. By checking whether any errors
occur at the end of template argument deduction, we avoid the
possibility of suppressing an error (due to SFINAE) and then
recovering so well that template argument deduction never detects that
there was a problem. Thanks to Eli for the push in this direction.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@73336 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Sema/SemaTemplateDeduction.cpp b/lib/Sema/SemaTemplateDeduction.cpp
index 2cab07e..84d802d 100644
--- a/lib/Sema/SemaTemplateDeduction.cpp
+++ b/lib/Sema/SemaTemplateDeduction.cpp
@@ -632,6 +632,7 @@
// argument list if the template arguments of the partial
// specialization can be deduced from the actual template argument
// list (14.8.2).
+ SFINAETrap Trap(*this);
llvm::SmallVector<TemplateArgument, 4> Deduced;
Deduced.resize(Partial->getTemplateParameters()->size());
if (TemplateDeductionResult Result
@@ -735,6 +736,9 @@
// FIXME: Check template template arguments?
}
+ if (Trap.hasErrorOccurred())
+ return TDK_SubstitutionFailure;
+
return TDK_Success;
}