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MSVC support #17
Description
Output of cargo run --release in a project using md5-asm via md-5:
Compiling md5-asm v0.4.3
The following warnings were emitted during compilation:
warning: cl : Command line warning D9024 : unrecognized source file type 'src/x64.S', object file assumed
warning: cl : Command line warning D9027 : source file 'src/x64.S' ignored
error: failed to run custom build command for `md5-asm v0.4.3`
Caused by:
process didn't exit successfully: `K:\Code\project\target\release\build\md5-asm-2f85d6e6f786c14b\build-script-build` (exit code: 1)
--- stdout
TARGET = Some("x86_64-pc-windows-msvc")
OPT_LEVEL = Some("3")
HOST = Some("x86_64-pc-windows-msvc")
CC_x86_64-pc-windows-msvc = None
CC_x86_64_pc_windows_msvc = None
HOST_CC = None
CC = None
CFLAGS_x86_64-pc-windows-msvc = None
CFLAGS_x86_64_pc_windows_msvc = None
HOST_CFLAGS = None
CFLAGS = None
CRATE_CC_NO_DEFAULTS = None
CARGO_CFG_TARGET_FEATURE = Some("fxsr,sse,sse2")
DEBUG = Some("false")
running: "K:\\Code\\Microsoft Visual Studio\\2019\\Community\\VC\\Tools\\MSVC\\14.27.29110\\bin\\HostX64\\x64\\cl.exe" "-nologo" "-MD" "-O2" "-Brepro" "-W4" "-c" "-FoK:\\Code\\project\\target\\release\\build\\md5-asm-86902935336c4579\\out\\src/x64.o" "-c" "src/x64.S"
cargo:warning=cl : Command line warning D9024 : unrecognized source file type 'src/x64.S', object file assumed
cargo:warning=cl : Command line warning D9027 : source file 'src/x64.S' ignored
cl : Command line warning D9021 : no action performed
exit code: 0
AR_x86_64-pc-windows-msvc = None
AR_x86_64_pc_windows_msvc = None
HOST_AR = None
AR = None
running: "K:\\Code\\Microsoft Visual Studio\\2019\\Community\\VC\\Tools\\MSVC\\14.27.29110\\bin\\HostX64\\x64\\lib.exe" "-out:K:\\Code\\project\\target\\release\\build\\md5-asm-86902935336c4579\\out\\libmd5.a" "-nologo" "K:\\Code\\project\\target\\release\\build\\md5-asm-86902935336c4579\\out\\src/x64.o"
LINK : fatal error LNK1181: cannot open input file 'K:\Code\project\target\release\build\md5-asm-86902935336c4579\out\src\x64.o'
exit code: 1181
--- stderr
error occurred: Command "K:\\Code\\Microsoft Visual Studio\\2019\\Community\\VC\\Tools\\MSVC\\14.27.29110\\bin\\HostX64\\x64\\lib.exe" "-out:K:\\Code\\project\\target\\release\\build\\md5-asm-86902935336c4579\\out\\libmd5.a" "-nologo" "K:\\Code\\project\\target\\release\\build\\md5-asm-86902935336c4579\\out\\src/x64.o" with args "lib.exe" did not execute successfully (status code exit code: 1181).
Based on the .S files I don't think this project intends to support Windows. In that case it'd be nice if the project just gave a compile error saying Windows isn't supported rather than a confusing MSVC failure log.
Activity
newpavlov commentedon Oct 19, 2020
Hm, I am not familiar with the MSVC build system, but I would expect it should be able to compile
Sfiles. Have you tried the GNU toolchain?tarcieri commentedon Oct 19, 2020
@newpavlov it might be good to move this repo over to GitHub Actions and test on the
windows-latestplatformtarcieri commentedon Oct 20, 2020
After doing a GitHub Actions conversion, I opened this PR to test Windows w\ MSVC: #19
It appears to have reproduced the issue:
https://github.com/RustCrypto/asm-hashes/pull/19/checks?check_run_id=1281176873
tarcieri commentedon Oct 20, 2020
We merged #19 which adds Windows 64-bit tests for MinGW.
If anyone would like to work on MSVC support, it should be easy to modify to test on that as well.
[-]Compilation of md5-asm fails on Windows[/-][+]MSVC support[/+]not-an-aardvark commentedon Sep 9, 2021
I looked into this a bit while investigating the best approach for RustCrypto/hashes#315. My understanding is that there are two reasons MSVC builds are currently failing:
cccrate, which ostensibly invokes a C/C++ compiler, to compile an assembly file, even though the assembly file is not C/C++. This happens to work on other platforms, but apparently not on MSVC.extern "C". In other words, even if the assembly file was built correctly, the output would presumably be incorrect because all the arguments would start out in the wrong registers. I think maybe this could be fixed by usingextern "sysv64"instead, but this purported fix would be difficult to verify until the build script issue is addressed.not-an-aardvark commentedon Sep 9, 2021
Based on the
ccdocumentation, it seems like it does support assembly files, but it expects them to have the file extension.asmrather than.Son MSVC. So maybe having the build script copyx64.Stox64.asmwould address the issue.I don't have a windows or MSVC machine to test this on. I suppose I can try testing it on GitHub Actions.
not-an-aardvark commentedon Sep 9, 2021
Sadly, this still doesn't work because the assembler on MSVC accepts an assembly file using MASM syntax rather than GAS syntax, so it's necessary to rewrite the whole assembly file to convert it to the other syntax. I think I got maybe 70% of the way there manually, for the sha1 implementation, but there are still some assembler errors and I'm out of time to work on this for now.
It's also possible that there are other alternatives than rewriting all of the assembly, such as using a different assembler or auto-converting things, but I'm not sure.
tarcieri commentedon Sep 10, 2021
One of the main alternatives we're looking at here is Rust intrinsics:
#41 (comment)
It seems like intrinsics can provide mostly equivalent performance but in a much more portable way.
It'd be great if MSVC users could chime in with reports about how the new intrinsics implementation is working out for them.
not-an-aardvark commentedon Sep 10, 2021
That sounds great, although IIUC the portability of the intrinsics will also be limited because the relevant x64 intrinsics are only present on intel processors manufactured in the last five years or so.
tarcieri commentedon Sep 10, 2021
We do runtime detection to detect if CPUs are compatible, and fall back on a portable reference implementaton
newpavlov commentedon Sep 10, 2021
@not-an-aardvark
They are also present on relatively resent AMD CPUs as well.
tarcieri commentedon Sep 10, 2021
RustCrypto/hashes#312 added an AVX2-based backend using stdarch intrinsics. It doesn't rely on "SHA-NI" and is as fast as the assembly version.