Replace TypeLoc llvm::cast support to be well-defined.

The TypeLoc hierarchy used the llvm::cast machinery to perform undefined
behavior by casting pointers/references to TypeLoc objects to derived types
and then using the derived copy constructors (or even returning pointers to
derived types that actually point to the original TypeLoc object).

Some context is in this thread:
http://lists.cs.uiuc.edu/pipermail/llvmdev/2012-December/056804.html
Though it's spread over a few months which can be hard to read in the mail
archive.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@175462 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 8 insertions, 8 deletions

diff --git a/lib/Sema/SemaTemplate.cpp b/lib/Sema/SemaTemplate.cpp
index 86af8c3a23..74a6da1947 100644
--- a/lib/Sema/SemaTemplate.cpp
+++ b/lib/Sema/SemaTemplate.cpp
@@ -6956,15 +6956,15 @@ Sema::ActOnTypenameType(Scope *S, SourceLocation TypenameLoc,
 
   TypeSourceInfo *TSI = Context.CreateTypeSourceInfo(T);
   if (isa<DependentNameType>(T)) {
-    DependentNameTypeLoc TL = cast<DependentNameTypeLoc>(TSI->getTypeLoc());
+    DependentNameTypeLoc TL = TSI->getTypeLoc().castAs<DependentNameTypeLoc>();
     TL.setElaboratedKeywordLoc(TypenameLoc);
     TL.setQualifierLoc(QualifierLoc);
     TL.setNameLoc(IdLoc);
   } else {
-    ElaboratedTypeLoc TL = cast<ElaboratedTypeLoc>(TSI->getTypeLoc());
+    ElaboratedTypeLoc TL = TSI->getTypeLoc().castAs<ElaboratedTypeLoc>();
     TL.setElaboratedKeywordLoc(TypenameLoc);
     TL.setQualifierLoc(QualifierLoc);
-    cast<TypeSpecTypeLoc>(TL.getNamedTypeLoc()).setNameLoc(IdLoc);
+    TL.getNamedTypeLoc().castAs<TypeSpecTypeLoc>().setNameLoc(IdLoc);
   }
 
   return CreateParsedType(T, TSI);
@@ -7054,12 +7054,12 @@ static bool isEnableIf(NestedNameSpecifierLoc NNS, const IdentifierInfo &II,
   if (!NNS || !NNS.getNestedNameSpecifier()->getAsType())
     return false;
   TypeLoc EnableIfTy = NNS.getTypeLoc();
-  TemplateSpecializationTypeLoc *EnableIfTSTLoc =
-    dyn_cast<TemplateSpecializationTypeLoc>(&EnableIfTy);
-  if (!EnableIfTSTLoc || EnableIfTSTLoc->getNumArgs() == 0)
+  TemplateSpecializationTypeLoc EnableIfTSTLoc =
+      EnableIfTy.getAs<TemplateSpecializationTypeLoc>();
+  if (!EnableIfTSTLoc || EnableIfTSTLoc.getNumArgs() == 0)
     return false;
   const TemplateSpecializationType *EnableIfTST =
-    cast<TemplateSpecializationType>(EnableIfTSTLoc->getTypePtr());
+    cast<TemplateSpecializationType>(EnableIfTSTLoc.getTypePtr());
 
   // ... which names a complete class template declaration...
   const TemplateDecl *EnableIfDecl =
@@ -7074,7 +7074,7 @@ static bool isEnableIf(NestedNameSpecifierLoc NNS, const IdentifierInfo &II,
     return false;
 
   // Assume the first template argument is the condition.
-  CondRange = EnableIfTSTLoc->getArgLoc(0).getSourceRange();
+  CondRange = EnableIfTSTLoc.getArgLoc(0).getSourceRange();
   return true;
 }