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

[David Holmes]

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
>