[clang] c851d6c - When performing a substitution into a dependent alias template, mark the

[Richard Smith via cfe-commits]

Author: Richard Smith
Date: 2020-06-17T15:12:04-07:00
New Revision: c851d6cf4a4ab803d01d0059f4659f4f9f4435ea

URL: https://github.com/llvm/llvm-project/commit/c851d6cf4a4ab803d01d0059f4659f4f9f4435ea
DIFF: https://github.com/llvm/llvm-project/commit/c851d6cf4a4ab803d01d0059f4659f4f9f4435ea.diff

LOG: When performing a substitution into a dependent alias template, mark the
outer levels as retained rather than omitting their arguments.

This better reflects what's going on (we're performing a substitution
while still inside a template). In theory this is also more correct, but
I've not found a testcase where it matters in practice (largely because
we don't allow alias templates to be declared inside a function).

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 073b4e818a24..3292284d63ba 100644
--- a/clang/lib/Sema/SemaTemplate.cpp
+++ b/clang/lib/Sema/SemaTemplate.cpp
@@ -3558,9 +3558,8 @@ QualType Sema::CheckTemplateIdType(TemplateName Name,
     // Only substitute for the innermost template argument list.
     MultiLevelTemplateArgumentList TemplateArgLists;
     TemplateArgLists.addOuterTemplateArguments(&StackTemplateArgs);
-    unsigned Depth = AliasTemplate->getTemplateParameters()->getDepth();
-    for (unsigned I = 0; I < Depth; ++I)
-      TemplateArgLists.addOuterTemplateArguments(None);
+    TemplateArgLists.addOuterRetainedLevels(
+        AliasTemplate->getTemplateParameters()->getDepth());
 
     LocalInstantiationScope Scope(*this);
     InstantiatingTemplate Inst(*this, TemplateLoc, Template);