[clang-tools-extra] [clang-doc] Add helpers for Template config (PR #138062)

[Erick Velez via cfe-commits]

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@@ -74,7 +75,51 @@ static std::unique_ptr<MustacheTemplateFile> NamespaceTemplate = nullptr;
 
 static std::unique_ptr<MustacheTemplateFile> RecordTemplate = nullptr;
 
+static Error
+setupTemplate(std::unique_ptr<MustacheTemplateFile> &Template,
+              StringRef TemplatePath,
+              std::vector<std::pair<StringRef, StringRef>> Partials) {
+  auto T = MustacheTemplateFile::createMustacheFile(TemplatePath);
+  if (Error Err = T.takeError())
+    return Err;
+  Template = std::move(T.get());
+  for (const auto [Name, FileName] : Partials) {
+    if (auto Err = Template->registerPartialFile(Name, FileName))
+      return Err;
+  }
+  return Error::success();
+}
+
 static Error setupTemplateFiles(const clang::doc::ClangDocContext &CDCtx) {
+  // Template files need to use the native path when they're opened,
+  // but have to be used in Posix style when used in HTML.
+  auto ConvertToNative = [](std::string &&Path) -> std::string {
+    SmallString<128> PathBuf(Path);
+    llvm::sys::path::native(PathBuf);
+    return PathBuf.str().str();
+  };
+
+  std::string NamespaceFilePath =
+      ConvertToNative(CDCtx.MustacheTemplates.lookup("namespace-template"));
+  std::string ClassFilePath =
+      ConvertToNative(CDCtx.MustacheTemplates.lookup("class-template"));
+  std::string CommentFilePath =
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evelez7 wrote:

possible mega-nit: This is also referred to as `CommentTemplate` in Utils.cpp but its key is plural ("comments-template"). Then the first type is plural below in the pair ("Comments"). It's the only one like this.

https://github.com/llvm/llvm-project/pull/138062