Replace all uses of RemoveSubstTemplateTypeParm with Desugar

No visible functional change, but we now desugar more aggressively.

This patch is the result of:

  git grep -l "RemoveSubstTemplateTypeParm" | xargs sed -i -e 's/RemoveSubstTemplateTypeParam/Desugar/'

3 files changed, 6 insertions, 19 deletions

diff --git a/iwyu.cc b/iwyu.cc
index 3fdf5ec..1354eec 100644
--- a/iwyu.cc
+++ b/iwyu.cc
@@ -2820,7 +2820,7 @@ class InstantiatedTemplateVisitor
     // Among all subst-type params, we only want those in the resugar-map. If
     // we're not in the resugar-map at all, we're not a type corresponding to
     // the template being instantiated, so we can be ignored.
-    type = RemoveSubstTemplateTypeParm(type);
+    type = Desugar(type);
     return ContainsKey(resugar_map_, type);
   }
 
@@ -3234,7 +3234,7 @@ class InstantiatedTemplateVisitor
     return GetLocOfTemplateThatProvides(decl).isValid();
   }
   bool IsProvidedByTemplate(const Type* type) const {
-    type = RemoveSubstTemplateTypeParm(type);
+    type = Desugar(type);
     type = RemovePointersAndReferences(type);  // get down to the decl
     if (const NamedDecl* decl = TypeToDeclAsWritten(type)) {
       decl = GetDefinitionAsWritten(decl);
@@ -3248,7 +3248,7 @@ class InstantiatedTemplateVisitor
   // class was instantiated) or not.  We store this in resugar_map by
   // having the value be nullptr.
   bool IsDefaultTemplateParameter(const Type* type) const {
-    type = RemoveSubstTemplateTypeParm(type);
+    type = Desugar(type);
     return ContainsKeyValue(resugar_map_, type, static_cast<Type*>(nullptr));
   }
 
@@ -3257,7 +3257,7 @@ class InstantiatedTemplateVisitor
   // If we're not in the resugar-map, then we weren't canonicalized,
   // so we can just use the input type unchanged.
   const Type* ResugarType(const Type* type) const {
-    type = RemoveSubstTemplateTypeParm(type);
+    type = Desugar(type);
     // If we're the resugar-map but with a value of nullptr, it means
     // we're a default template arg, which means we don't have anything
     // to resugar to.  So just return the input type.
diff --git a/iwyu_ast_util.cc b/iwyu_ast_util.cc
index 2b055cc..04a29a6 100644
--- a/iwyu_ast_util.cc
+++ b/iwyu_ast_util.cc
@@ -1160,16 +1160,9 @@ bool IsClassType(const clang::Type* type) {
                    isa<RecordType>(Desugar(type))));
 }
 
-const Type* RemoveSubstTemplateTypeParm(const Type* type) {
-  if (const SubstTemplateTypeParmType* subst_type = DynCastFrom(type))
-    return subst_type->getReplacementType().getTypePtr();
-  else
-    return type;
-}
-
 bool InvolvesTypeForWhich(const Type* type,
                           std::function<bool(const Type*)> pred) {
-  type = RemoveSubstTemplateTypeParm(type);
+  type = Desugar(type);
   if (pred(type))
     return true;
   const Decl* decl = TypeToDeclAsWritten(type);
@@ -1231,7 +1224,7 @@ static const NamedDecl* TypeToDeclImpl(const Type* type, bool as_written) {
   // Read past SubstTemplateTypeParmType (this can happen if a
   // template function returns the tpl-arg type: e.g. for
   // 'T MyFn<T>() {...}; MyFn<X>.a', the type of MyFn<X> will be a Subst.
-  type = RemoveSubstTemplateTypeParm(type);
+  type = Desugar(type);
 
   CHECK_(!isa<ObjCObjectType>(type) && "IWYU doesn't support Objective-C");
 
diff --git a/iwyu_ast_util.h b/iwyu_ast_util.h
index c873efd..3762b07 100644
--- a/iwyu_ast_util.h
+++ b/iwyu_ast_util.h
@@ -681,12 +681,6 @@ bool IsTemplatizedType(const clang::Type* type);
 // Returns true if the type is a RecordType or a TemplateSpecializationType.
 bool IsClassType(const clang::Type* type);
 
-// Read past SubstTemplateTypeParmType to the underlying type, if type
-// is itself a SubstTemplateTypeParmType.  Thus: T is converted to int
-// if we are parsing a template instantiated with T being int.
-// However, vector<T> is *not* converted to vector<int>.
-const clang::Type* RemoveSubstTemplateTypeParm(const clang::Type* type);
-
 // Returns true if any type involved (recursively examining template
 // arguments) satisfies the given predicate.
 bool InvolvesTypeForWhich(const clang::Type* type,