[cfe-commits] [patch] Trying to fix __va_list_tag serialization issue (bug 13189)

[Meador Inge]

On Jun 29, 2012, at 1:49 AM, Jean-Daniel Dupas wrote:

> 
> Le 29 juin 2012 à 07:57, Meador Inge a écrit :
> 
>> Moving to cfe-commits...
>> 
>> On Jun 28, 2012, at 6:06 PM, Jean-Daniel Dupas wrote:
>> 
>>> Hello (and please ignore previous mail to cfe-dev),
>>> 
>>> I'm trying to fix a regression with va_list handling in precompiled headers.
>>> 
>>> http://llvm.org/bugs/show_bug.cgi?id=13189
>>> 
>>> Can someone tell me if the attached patch is the right approach to solve this type serialization issue.
>> 
>> 
>> I was working on something slightly more simplified where a reference to the __va_list_tag type is just saved when building the decls.  Something like the attached. 
>> 
> 
> +    case PREDEF_TYPE_VA_LIST_TAG:
> +      T = Context.VaListTagTy;
> +      break;
> 
> Is there any guarantee the type will be already built at this point ? 


When the AST reader is created a Sema object is initialized that insures that type will be available by nature of Sema::Initialize calling ASTContext::getBuiltinVaListDecl.  If this makes folks nervous we could add a wrapper ASTContext::getVaTagType (similar to what you proposed, but takes advantage of the fact that ASTContext::getBuiltinVaListDecl saves the tag type) to ensure the construction and then call the wrapper instead.

--
Meador Inge
CodeSourcery / Mentor Embedded
http://www.mentor.com/embedded-software