[PATCH] D11298: Convert a few classes over to use the new TrailingObjects helper.

[Richard Smith]

rsmith accepted this revision.
rsmith added a comment.
This revision is now accepted and ready to land.

Looks like a really nice cleanup, thanks!


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Comment at: include/clang/AST/DeclTemplate.h:47-49
@@ -45,3 +46,5 @@
 /// derived classes.
-class LLVM_ALIGNAS(/*alignof(void*)*/ LLVM_PTR_SIZE) TemplateParameterList {
+class LLVM_ALIGNAS(/*alignof(void*)*/ LLVM_PTR_SIZE) TemplateParameterList final
+    : private llvm::TrailingObjects<TemplateParameterList, NamedDecl *> {
+
   /// The location of the 'template' keyword.
----------------
I've used that trick in the past to work around the same bug in older versions of GCC; I think it should work OK (but we're getting into known-weird corners of MSVC record layout). Doing that in a follow-up change seems fine to me.

================
Comment at: lib/AST/Decl.cpp:3122
@@ +3121,3 @@
+  void *Buffer = Context.Allocate(
+      totalSizeToAlloc<TemplateArgumentLoc, FunctionTemplateDecl *>(
+          TArgs.size(), Ts.size()));
----------------
OK, I guessed that might be the reason. Seems like a reasonable safety measure. (Do you get an error if you specify the wrong types?)

================
Comment at: lib/AST/DeclTemplate.cpp:554-557
@@ -556,5 +553,6 @@
+        getTrailingObjects<std::pair<QualType, TypeSourceInfo *>>();
     for (unsigned I = 0; I != NumExpandedTypes; ++I) {
-      TypesAndInfos[2*I] = ExpandedTypes[I].getAsOpaquePtr();
-      TypesAndInfos[2*I + 1] = ExpandedTInfos[I];
+      TypesAndInfos[I].first = ExpandedTypes[I];
+      TypesAndInfos[I].second = ExpandedTInfos[I];
     }
   }
----------------
I'd prefer a placement new expression here rather than calling the assignment operator on an uninitialized `QualType` object.


http://reviews.llvm.org/D11298