Can`t access pthread API

[Jorn Vernee]

It looks like a clang error. See the

Cannot write source file unix.pthread.bits.thread_shared_types_h, cause: 
jdk.internal.clang.TypeLayoutError: InvalidFieldName. type: Type{ 
spelling=struct __pthread_cond_s, kind=Record }, fieldName: __low
Tree causing above exception is: __pthread_cond_s

And then later on during compilation that type is missing:

error: cannot find symbol
         public unix.pthread.bits.thread_shared_types_h.__pthread_cond_s 
__data$get();
                                                       ^
   symbol:   class __pthread_cond_s

Definition of the struct per [1] is:

struct __pthread_cond_s
{
   __extension__ union
   {
     __extension__ unsigned long long int __wseq;
     struct
     {
       unsigned int __low;
       unsigned int __high;
     } __wseq32;
   };
   __extension__ union
   {
     __extension__ unsigned long long int __g1_start;
     struct
     {
       unsigned int __low;
       unsigned int __high;
     } __g1_start32;
   };
   unsigned int __g_refs[2] __LOCK_ALIGNMENT;
   unsigned int __g_size[2];
   unsigned int __g1_orig_size;
   unsigned int __wrefs;
   unsigned int __g_signals[2];
};

So, I'm guessing the __low field is incorrectly being flattened into 
__pthread_cond_s.

This looks suspiciously like the LLVM8 problem where the behavior of 
isAnonymous was changed. And trying to jextract just this struct locally 
with an LLVM7 build seems to work fine. So, at this point it's 
reasonable to ask: which LLVM version is being used? Note that only 
LLVM7 is currently officially supported, 8-9 are known to cause 
problems. (if this is from a Shipilev nightly, those seem to be using 
LLVM7, so that shouldn't be a problem).

Jorn

[1] : 
https://code.woboq.org/qt5/include/bits/thread-shared-types.h.html#__pthread_cond_s

On 2019-06-17 02:05, Maurizio Cimadamore wrote:
> Thanks for the report - Sundar, can you take a look? Seems like a
> regression with the new compile-from-source strategy - the jextract
> command line is here:
> 
> https://pastebin.com/5RrEwNGU
> 
> Cheers
> Maurizio
> 
> On 16/06/2019 17:45, Thiago Moura wrote:
>> Hi,
>> 
>> I'm interested on experiment the early builds of Panama to interact 
>> with
>> the IoTivity lib (https://github.com/iotivity/iotivity-lite). But 
>> first,
>> I'm trying to access the pthread API to get familiar with the Foreign 
>> APIs.
>> 
>> Unfortunately, I`m unable to do that. More details on what I've tried 
>> so
>> far is on my SO post:
>> https://stackoverflow.com/questions/56517514/how-to-access-pthread-api-with-project-panama
>> 
>> Regards