On Wed, 13 Oct 2021 13:55:04 GMT, Andrew Haley <a...@openjdk.org> wrote:
>> This patch expands the newly added system for hsdis backends to include LLVM. >> >> The actual code in hsdis-llvm.cpp is based heavily on the work by @luhenry, >> as published in the never integrated PR >> https://github.com/openjdk/jdk/pull/392. (I have basically just ripped out >> the binutils-based part of it.) >> >> Unfortunately I have not been able to make this work properly on Windows. >> With some additional flags I made it compile without complaints, but it >> caused hotspot to segfault in `LoadLibrary` (!) in `os::dll_load` when I >> tried to load the library. This is somewhat ironic, since the initial >> implementation was created by Ludovic for the very purpose of using it on >> Windows. >> >> The lack of Windows support in this patch does not mean it is impossible to >> get it to work, just that I need to co-operate with someone who has more >> experience of compiling LLVM on Windows, and/or are more eager to get this >> combination to work. > >> This patch expands the newly added system for hsdis backends to include LLVM. >> >> The actual code in hsdis-llvm.cpp is based heavily on the work by @luhenry, >> as published in the never integrated PR #392. (I have basically just ripped >> out the binutils-based part of it.) >> >> Unfortunately I have not been able to make this work properly on Windows. > > What is it for, then? > > hsdis builds on AArch64-MacOS-LLVM with > > > cd src/utils/hsdis > mkdir build > cd build > git clone https://github.com/bminor/binutils-gdb > ln -s binutils-gdb binutils > cd .. > make @theRealAph As you might be aware, the licensing criteria for binutils makes it impossible to distribute a binutils-based hsdis with the JDK. While IANAL, my understanding is that the LLVM license is less problematic in that way. Also, this is to allow a bit of freedom of choice. If you prefer the LLVM backend (I've been told that it generates better disassembly in some case) you should be able to select it. And finally, I do think that the LLVM backend should be able to work on Windows, too. It's just that this is tricky enough to motivate doing this in a separate, later, step. ------------- PR: https://git.openjdk.java.net/jdk/pull/5920
