Hi Alexey,
Below is a new patch content that removes JNICALL modifiers from the exported
functions of interest. This results in exported functions not to be name
decorated and use __cdecl calling convention.
Do you have any more suggestions, or would you please guide me on next steps?
Thanks,
Ali
# HG changeset patch
# User Ali Ince <ali.i...@gmail.com>
# Date 1542542415 0
# Sun Nov 18 12:00:15 2018 +0000
# Node ID a41df44e13e1b761f4b3f05a17ed18953067ae39
# Parent 16d5ec7dbbb49ef3f969e34be870e3f917ea89ff
Remove JNICALL modifiers to prevent name decoration on 32-bit windows builds
diff -r 16d5ec7dbbb4 -r a41df44e13e1
src/jdk.jdi/share/native/libdt_shmem/shmemBack.c
--- a/src/jdk.jdi/share/native/libdt_shmem/shmemBack.c Tue Aug 14 14:28:23
2018 +0200
+++ b/src/jdk.jdi/share/native/libdt_shmem/shmemBack.c Sun Nov 18 12:00:15
2018 +0000
@@ -339,7 +339,7 @@
return JDWPTRANSPORT_ERROR_NONE;
}
-JNIEXPORT jint JNICALL
+JNIEXPORT jint
jdwpTransport_OnLoad(JavaVM *vm, jdwpTransportCallback* cbTablePtr,
jint version, jdwpTransportEnv** result)
{
diff -r 16d5ec7dbbb4 -r a41df44e13e1
src/jdk.jdwp.agent/share/native/include/jdwpTransport.h
--- a/src/jdk.jdwp.agent/share/native/include/jdwpTransport.h Tue Aug 14
14:28:23 2018 +0200
+++ b/src/jdk.jdwp.agent/share/native/include/jdwpTransport.h Sun Nov 18
12:00:15 2018 +0000
@@ -140,7 +140,7 @@
void (*free)(void *buffer); /* Call this for all deallocations */
} jdwpTransportCallback;
-typedef jint (JNICALL *jdwpTransport_OnLoad_t)(JavaVM *jvm,
+typedef jint (*jdwpTransport_OnLoad_t)(JavaVM *jvm,
jdwpTransportCallback *callback,
jint version,
jdwpTransportEnv** env);
diff -r 16d5ec7dbbb4 -r a41df44e13e1
src/jdk.jdwp.agent/share/native/libdt_socket/socketTransport.c
--- a/src/jdk.jdwp.agent/share/native/libdt_socket/socketTransport.c Tue Aug
14 14:28:23 2018 +0200
+++ b/src/jdk.jdwp.agent/share/native/libdt_socket/socketTransport.c Sun Nov
18 12:00:15 2018 +0000
@@ -1019,7 +1019,7 @@
return JDWPTRANSPORT_ERROR_NONE;
}
-JNIEXPORT jint JNICALL
+JNIEXPORT jint
jdwpTransport_OnLoad(JavaVM *vm, jdwpTransportCallback* cbTablePtr,
jint version, jdwpTransportEnv** env)
{
> On 16 Nov 2018, at 23:03, Alexey Ivanov <alexey.iva...@oracle.com> wrote:
>
> Hi Ali,
>
> It's exactly what I referred to.
>
> Yes, it does change the calling convention.
> Yet it's not a (big) problem because both parties will use the same calling
> convention.
>
> Using a DLL from another build will not be possible. But it's not a good idea
> to do so anyway.
>
>
> Mapfiles and export options have been removed by
> https://bugs.openjdk.java.net/browse/JDK-8200178 to simplify managing
> exported functions. So that to add or remove an exported function, you don't
> have modify makefiles and/or mapfiles. You just edit the source files.
>
> Regards,
> Alexey
>
> On 16/11/2018 22:42, Ali İnce wrote:
>> Hi Alexey,
>>
>> Thanks for your reply.
>>
>> I will definitely give it a try though I’m not sure if that’ll be a breaking
>> change. This is because JNICALL modifier is defined to be __stdcall on
>> windows which is both specified on jdwpTransport_OnLoad exported functions
>> both for dt_socket.dll and dt_shmem.dll.
>>
>> The __stdcall is ignored on x64 platforms and also name decoration is not
>> applied
>> (https://docs.microsoft.com/en-gb/cpp/build/reference/decorated-names?view=vs-2017).
>> I believe that’s why we don’t experience any problems on x64 builds.
>>
>> Removing JNICALL (thus __stdcall) modifier (apparently only applies to x86
>> builds) will result in the calling convention to be changed, and thus will
>> change how parameters are ordered and also the stack cleanup rules. I think
>> this may result in problems in programs that are designed to load shared
>> libraries and its exported functions at runtime (not bound by link time
>> which probably won’t cause any issues - assuming that they use the shared
>> function signature) - as in
>> https://github.com/AdoptOpenJDK/openjdk-jdk11u/blob/5f01925b80ed851b133ee26fbcb07026ac04149e/src/jdk.jdwp.agent/share/native/libjdwp/transport.c#L99.
>>
>> Any thoughts?
>>
>> Regards,
>>
>> Ali
>>
>>> On 15 Nov 2018, at 22:14, Alexey Ivanov <alexey.iva...@oracle.com> wrote:
>>>
>>> Hi Ali,
>>>
>>> Can the issue be resolved by using different call modifiers on the affected
>>> functions?
>>>
>>> Some build / link issues were resolved by adding / removing JNICALL
>>> modifier, see
>>> https://bugs.openjdk.java.net/browse/JDK-8201226
>>> http://mail.openjdk.java.net/pipermail/build-dev/2018-April/021553.html
>>>
>>> https://bugs.openjdk.java.net/browse/JDK-8202476
>>> http://mail.openjdk.java.net/pipermail/build-dev/2018-May/021913.html
>>>
>>> Regards,
>>> Alexey
>>>
>>> On 15/11/2018 21:43, Ali İnce wrote:
>>>> Hi,
>>>>
>>>> An issue (https://github.com/AdoptOpenJDK/openjdk-build/issues/709) raised
>>>> against AdoptOpenJDK jdk11 32-bit windows builds led us to the name
>>>> decoration problem on built 32-bit dlls - specifically dt_socket.dll and
>>>> dt_shmem.dll. Whereas 64-bit MSVC builds don’t apply any name decorations
>>>> on exported functions, 32-bit builds apply them - which requires either
>>>> def files or /export flags to be specified on the linker arguments.
>>>>
>>>> Although the expected linker arguments were present on previous jdk
>>>> makefiles, they were removed in jdk11 makefiles.
>>>>
>>>> Below is the proposed patch, which can also be browsed at
>>>> https://github.com/AdoptOpenJDK/openjdk-jdk11u/pull/1.
>>>>
>>>> Would you please have a look and let me know of any points I may have
>>>> missed (I don’t have any background information about why the export flags
>>>> were removed in jdk11)?
>>>>
>>>> Regards,
>>>>
>>>> Ali
>>>>
>>>> diff --git a/make/lib/Lib-jdk.jdi.gmk b/make/lib/Lib-jdk.jdi.gmk
>>>> index 197b95c2e2..ac6ebf5591 100644
>>>> --- a/make/lib/Lib-jdk.jdi.gmk
>>>> +++ b/make/lib/Lib-jdk.jdi.gmk
>>>> @@ -37,6 +37,7 @@ ifeq ($(OPENJDK_TARGET_OS), windows)
>>>> jdk.jdwp.agent:include \
>>>> jdk.jdwp.agent:libjdwp/export, \
>>>> LDFLAGS := $(LDFLAGS_JDKLIB), \
>>>> + LDFLAGS_windows := -export:jdwpTransport_OnLoad, \
>>>> LIBS := $(JDKLIB_LIBS), \
>>>> ))
>>>>
>>>> diff --git a/make/lib/Lib-jdk.jdwp.agent.gmk
>>>> b/make/lib/Lib-jdk.jdwp.agent.gmk
>>>> index 0bc93e0d35..0382e55325 100644
>>>> --- a/make/lib/Lib-jdk.jdwp.agent.gmk
>>>> +++ b/make/lib/Lib-jdk.jdwp.agent.gmk
>>>> @@ -37,6 +37,7 @@ $(eval $(call SetupJdkLibrary, BUILD_LIBDT_SOCKET, \
>>>> libjdwp/export, \
>>>> LDFLAGS := $(LDFLAGS_JDKLIB) \
>>>> $(call SET_SHARED_LIBRARY_ORIGIN), \
>>>> + LDFLAGS_windows := -export:jdwpTransport_OnLoad, \
>>>> LIBS_linux := -lpthread, \
>>>> LIBS_solaris := -lnsl -lsocket, \
>>>> LIBS_windows := $(JDKLIB_LIBS) ws2_32.lib, \
>
