[clang] a8d096a - [Concepts] Add missing null check to transformConstructor

[Saar Raz via cfe-commits]

Author: Saar Raz
Date: 2020-01-27T00:15:42+02:00
New Revision: a8d096aff6b1930ad57bd0c30077d2b4920b5025

URL: https://github.com/llvm/llvm-project/commit/a8d096aff6b1930ad57bd0c30077d2b4920b5025
DIFF: https://github.com/llvm/llvm-project/commit/a8d096aff6b1930ad57bd0c30077d2b4920b5025.diff

LOG: [Concepts] Add missing null check to transformConstructor

Caused bug 44671 when transforming a constructor with a type-constraint with no explicit template args.

Added: 
    

Modified: 
    clang/lib/Sema/SemaTemplate.cpp

Removed: 
    


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diff  --git a/clang/lib/Sema/SemaTemplate.cpp b/clang/lib/Sema/SemaTemplate.cpp
index ba4cd7632f3c..4d38d07a6213 100755
--- a/clang/lib/Sema/SemaTemplate.cpp
+++ b/clang/lib/Sema/SemaTemplate.cpp
@@ -2047,12 +2047,14 @@ struct ConvertConstructorToDeductionGuideTransform {
       if (const auto *TC = TTP->getTypeConstraint()) {
         TemplateArgumentListInfo TransformedArgs;
         const auto *ArgsAsWritten = TC->getTemplateArgsAsWritten();
-        if (SemaRef.Subst(ArgsAsWritten->getTemplateArgs(),
+        if (!ArgsAsWritten ||
+            SemaRef.Subst(ArgsAsWritten->getTemplateArgs(),
                           ArgsAsWritten->NumTemplateArgs, TransformedArgs,
                           Args))
           SemaRef.AttachTypeConstraint(
               TC->getNestedNameSpecifierLoc(), TC->getConceptNameInfo(),
-              TC->getNamedConcept(), &TransformedArgs, NewTTP,
+              TC->getNamedConcept(), ArgsAsWritten ? &TransformedArgs : nullptr,
+              NewTTP,
               NewTTP->isParameterPack()
                  ? cast<CXXFoldExpr>(TC->getImmediatelyDeclaredConstraint())
                      ->getEllipsisLoc()