[IDE] Avoid printing some Swift extensions twice in mixed source fram…

[xedin]

…eworks

printModuleInterfaceDecl printes extensions right after the type they are associated with is printed. Extensions associated with a type that appears in the "target" module shouldn't be added to SwiftDecls because that would lead to double printing them.

[xedin]

@swift-ci please test

[bnbarham]

There's already a check in printModuleInterfaceDecl for extensions, which seems like dead code after this change? It currently skips printing extensions if they don't have a clang node and are part of the same module:

  if (auto Ext = dyn_cast<ExtensionDecl>(D)) {
    // Clang extensions (categories) are always printed in source order.
    // Swift extensions are printed with their associated type unless it's
    // a cross-module extension.
    if (!extensionHasClangNode(Ext)) {
      auto ExtendedNominal = Ext->getExtendedNominal();
      if (!ExtendedNominal ||
          Ext->getModuleContext() == ExtendedNominal->getModuleContext())
        return false;
    }
  }

Though that also means we're skipping more than before. Does this change prevent printing of categories for pure ObjC imports (no Swift)?

[xedin]

Yeah, I forgot to remove this condition which is not no-op and for ObjC categories - they are added to clang decls and would be printed.

[xedin]

Removed the old check.

[hamishknight]

Does this change prevent printing of categories for pure ObjC imports (no Swift)?

Note the check above this means we're only looking at Swift extensions specifically here

[bnbarham]

Note the check above this means we're only looking at Swift extensions specifically here

Which check 🤔?

[hamishknight]

      if (extensionHasClangNode(Ext)) {
        addToClangDecls(Ext, extensionGetClangNode(Ext));
        continue;
      }

[hamishknight]

Thanks!

[xedin]

@swift-ci please test