[clang] [Clang][AST] Store injected template arguments in TemplateParameterList (PR #113579)

[Erich Keane via cfe-commits]

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@@ -51,14 +51,15 @@ DefaultTemplateArgumentContainsUnexpandedPack(const TemplateParam &P) {
          P.getDefaultArgument().getArgument().containsUnexpandedParameterPack();
 }
 
-TemplateParameterList::TemplateParameterList(const ASTContext& C,
+TemplateParameterList::TemplateParameterList(const ASTContext &C,
                                              SourceLocation TemplateLoc,
                                              SourceLocation LAngleLoc,
                                              ArrayRef<NamedDecl *> Params,
                                              SourceLocation RAngleLoc,
                                              Expr *RequiresClause)
-    : TemplateLoc(TemplateLoc), LAngleLoc(LAngleLoc), RAngleLoc(RAngleLoc),
-      NumParams(Params.size()), ContainsUnexpandedParameterPack(false),
+    : InjectedArgs(&C), TemplateLoc(TemplateLoc), LAngleLoc(LAngleLoc),
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erichkeane wrote:

> > Could you do that (add it as a parm to the `getInjectedTemplateArgs`, and see how rough it is for the callers to get the ASTContext), and put it somewhere I can take a look?
> 
> @erichkeane See [3fd8326](https://github.com/llvm/llvm-project/commit/3fd8326e222877bce474010481a459b5db0c8be2)
> 
> This _will_ break tools that use `getInjectedTemplateArgs` though (e.g. the tool I'm working on [MrDocs] uses `getInjectedTemplateArgs`).

Thanks for doing that!  I'll note that looks way nicer IMO.  I'd hope that downstream users would have access to the ASTContext/Sema in a way that they could use that?  Is it REALLY troublesome/not really possible, or is it just a code change?

https://github.com/llvm/llvm-project/pull/113579