On Wed, Jul 29, 2015 at 10:43 AM, Sean Callanan <scallanan@apple.com> wrote:

LLDB’s module support (implemented here: http://llvm.org/svn/llvm-project/lldb/trunk/source/Expression/ClangModulesDeclVendor.cpp) sets up its own CompilerInstance and then loads modules into it.

The way we import macros from modules into expressions is by textual inclusion – we iterate across the macros like this:

–

if (m_compiler_instance->getPreprocessor().getExternalSource())

{

  m_compiler_instance->getPreprocessor().getExternalSource()->ReadDefinedMacros();

}

for (clang::Preprocessor::macro_iterator mi = m_compiler_instance->getPreprocessor().macro_begin(),

                                         me = m_compiler_instance->getPreprocessor().macro_end();

     mi != me; ++mi)

{

  // ...

  clang::MacroInfo *macro_info = nullptr;

        

  for (clang::ModuleMacro *module_macro : m_compiler_instance->getPreprocessor().getLeafModuleMacros(ii))

  {

    // pick the macro_info from the module we care most about; that might be NULL

  }

        

  if (macro_info)

  {

    // make a string from the macro

  }

}

–

What Im noticing is that a macro (say, “MAX”) doesn’t appear in the macro_begin() list at all.  Only later, after I’ve done a name lookup for “MAX" (on the assumption that it might be a variable, see ClangModulesDeclVendorImpl::FindDecls()), does it appear in the list.

Is there something else I need to tickle here, or is this a bug in the API?

Does this help:

Index: lib/Serialization/ASTReader.cpp

===================================================================

--- lib/Serialization/ASTReader.cpp     (revision 243368)

+++ lib/Serialization/ASTReader.cpp     (working copy)

@@ -1623,7 +1623,7 @@

         case PP_MACRO_OBJECT_LIKE:

         case PP_MACRO_FUNCTION_LIKE:

-          getLocalIdentifier(**I, Record[0]);

+          updateOutOfDateIdentifier(*getLocalIdentifier(**I, Record[0]));

           break;

         case PP_TOKEN: