RFR: 8309880: Add support for linking libffi on Windows and Mac

[Jorn Vernee]

On Tue, 13 Jun 2023 16:05:07 GMT, Erik Joelsson <erikj at openjdk.org> wrote:

>> Update the make/autoconf/lib-ffi.m4 script to support using libffi on Windows and Mac.
>> 
>> For Windows I had to tweak `fallbackLinker.c` to be able to build: there was an import of `stdint.h` missing, and since it was using `WSAGetLastError` it needed to link against `ws2_32.lib`.
>> 
>> This PR also contains a fix originally made by @shipilev as part  of: https://github.com/openjdk/jdk/pull/13827 (with a minor tweak), in order to be able to build the fallback linker on mac correctly. I also disabled 3 failing tests in the jdk_foreign suite on that platform.
>> 
>> ---
>> 
>> I've updated the `createLibffiBundle.sh` script for Mac, since I got it to work with a devkit, but I didn't manage to do the same for Windows. The steps I took to make my Windows libffi bundle were as follows:
>> 1. run 'x64 Native Tools Command Prompt for VS 2022'. cl.exe and link.exe should be on path
>> 2. run `ucrt64` (this is one of the shell environments that comes with MSYS2). This should carry over the environment set up by the VS dev prompt.
>> 3. then, in the libffi repo root folder:
>>   3.a run `autogen.sh`
>>   3.b run:
>> 
>> bash configure \
>>   CC="/path/to/libffi/msvcc.sh -m64" \
>>   CXX="/path/to/libffi/msvcc.sh -m64" \
>>   CPPFLAGS="-DFFI_BUILDING_DLL" \
>>   --disable-docs \
>>   --prefix=<install dest>
>> 
>> (`<install dest>` can be whatever you like. That's what you point `--with-libffi` to).
>> 
>> 4. run `make install`. This should create the `<intstall dest>` directory with the files: `include/ffi.h`, `include/ffitarget.h`, `lib/libffi.dll`. It also creates a `lib/libffi.lib` file, but it is of the wrong file type, `DLL` rather than `LIBRARY`.
>> 5. Manually create a working `.lib` file:
>>   5.a use `dumpbin /exports libffi.dll` to get a list of exported symbols
>>   5.b put them in a `libffi.def` file: `EXPORTS` on the first line, then a symbol on each line following
>>   5.c run `lib /def:libffi.def /machine:x64 /out:libffi.lib` to create the right `.lib` file (`lib` is a visual studio tool)
>> 
>> ---
>> 
>> Testing:
>> - manual testing on Windows/x64 and Mac/AArch64, by running the `jdk_foreign` test suite with `-Djdk.internal.foreign.CABI=FALLBACK` (i.e. using the fallback linker).
>> - Linux/x64 Zero test run of the `jdk_foreign` suite
>> - Linux/AArch64 Zero build
>
> make/modules/java.base/Lib.gmk line 231:
> 
>> 229:                  $(call SET_SHARED_LIBRARY_ORIGIN), \
>> 230:       LIBS := $(LIBFFI_LIBS), \
>> 231: 	  LIBS_windows := $(LIBFFI_LIBS) ws2_32.lib, \
> 
> Indentation looks off. Make sure you aren't mixing in tabs here.

Good catch, I indeed had a tab in there (I have github set to show tabs as 4 spaces, so didn't notice this).

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PR Review Comment: https://git.openjdk.org/jdk/pull/14446#discussion_r1228422332