link error: unresolved external symbol "int __cdecl convert_to_unicode(char const *,wchar_t * *)

[David Holmes]

Hi Yasumasa,

On 17/06/2021 11:28 am, Yasumasa Suenaga wrote:
> Hi,
> 
> I can build current HEAD of upstream (02c9bf087e5) successfully both 
> fastdebug and release build.
> I use VS 2019 (16.10.1) on WSL 1 Ubuntu 20.04 .

We use 16.9.3 with no problem, but it does seem that the prototype is 
missing the static storage class modifier to match the definition 
(otherwise it is assumed externa).

I filed:

https://bugs.openjdk.java.net/browse/JDK-8268927

and am testing a trivial fix to add 'static' which will hopefully fix 
Vitaly's problem.

Thanks,
David

> 
> Thanks,
> 
> Yasumasa
> 
> 
> On 2021/06/17 10:04, David Holmes wrote:
>> Hi Vitaly,
>>
>> On 17/06/2021 9:47 am, Vitaly Provodin wrote:
>>> Hi all,
>>>
>>> Building OpenJDK on Windows I am faced with the following error
>>>
>>> ---------------------------8<---------------------------
>>> os_windows.obj : error LNK2019: unresolved external symbol "int 
>>> __cdecl convert_to_unicode(char const *,wchar_t * *)" 
>>> (?convert_to_unicode@@YAHPEBDPEAPEA_W at Z) referenced in function 
>>> "public: static void __cdecl os::set_native_thread_name(char const 
>>> *)" (?set_native_thread_name at os@@SAXPEBD at Z)
>>
>> That is strange. convert_to_unicode is a static function in 
>> os_windows.cpp so there is no reason for the linker to have any issue 
>> as far as I can see - and we have not seen any build issues locally. ???
>>
>> I wonder if the forward declaration / prototype also needs to state 
>> static? can you try this change:
>>
>> diff --git a/src/hotspot/os/windows/os_windows.cpp 
>> b/src/hotspot/os/windows/os_windows.cpp
>> index 6e996b11993..affe8a10265 100644
>> --- a/src/hotspot/os/windows/os_windows.cpp
>> +++ b/src/hotspot/os/windows/os_windows.cpp
>> @@ -892,7 +892,7 @@ static SetThreadDescriptionFnPtr 
>> _SetThreadDescription = NULL;
>>   DEBUG_ONLY(static GetThreadDescriptionFnPtr _GetThreadDescription = 
>> NULL;)
>>
>>   // forward decl.
>> -errno_t convert_to_unicode(char const* char_path, LPWSTR* unicode_path);
>> +static errno_t convert_to_unicode(char const* char_path, LPWSTR* 
>> unicode_path);
>>
>>   void os::set_native_thread_name(const char *name) {
>>
>> Otherwise the simple fix would be to move the definition of 
>> convert_to_unicode to be ahead of set_native_thread_name() and get rid 
>> of the prototype.
>>
>> But again I have no idea why we would not have seen this build problem 
>> locally. I will file a bug.
>>
>> Thanks,
>> David
>> -----
>>
>>> c:\buildagent\work\d0555747f6bd5c6\build\windows-x86_64-server-release\support\modules_libs\java.base\server\jvm.dll 
>>> : fatal error LNK1120: 1 unresolved externals
>>> make[3]: *** [lib/CompileJvm.gmk:144: 
>>> /cygdrive/c/buildagent/work/d0555747f6bd5c6/build/windows-x86_64-server-release/support/modules_libs/java.base/server/jvm.dll] 
>>> Error 1
>>> make[2]: *** [make/Main.gmk:252: hotspot-server-libs] Error 2
>>> make[2]: *** Waiting for unfinished jobs....
>>> ERROR: Build failed for targets 'clean images test-image' in 
>>> configuration 'windows-x86_64-server-release' (exit code 2)
>>> ---------------------------8<---------------------------
>>>
>>> The issue was integrated with the patch 
>>> https://github.com/openjdk/jdk/commit/9f3c7e74ff00a7550742ed8b9d6671c2d4bb6041 
>>> that fixes https://bugs.openjdk.java.net/browse/JDK-8238649 Call new 
>>> Win32 API SetThreadDescription in os::set_native_thread_name
>>> After reverting this commit the build completes successfully
>>>
>>> Note Visual Studio 2019 Developer Command Prompt v16.8.5 is used for 
>>> building
>>>
>>> Is this issue actual for me only? - could not find any mentions about 
>>> it (in maillists, JBS)
>>> Could you please advice how it can be resolved?
>>>
>>> Thanks in advance,
>>> Vitaly
>>>