LDC 1.11.0 beta2

[Joakim]

On Sunday, 15 July 2018 at 19:46:24 UTC, kinke wrote:
> Glad to announce the second beta for LDC 1.11.
>
> * Based on D 2.081.1+ (today's DMD stable).
> * Prebuilt packages now using LLVM 6.0.1 and including 
> additional cross-compilation targets (MIPS, MSP430, RISC-V and 
> WebAssembly).
> * Rudimentary support for compiling & linking directly to 
> WebAssembly. See the dedicated Wiki page [1] for how to get 
> started.
> * Some support for classes without TypeInfos, for -betterC 
> and/or a minimal (d)runtime.
>
> Full release log and downloads: 
> https://github.com/ldc-developers/ldc/releases/tag/v1.11.0-beta2
>
> Thanks to all contributors!
>
> [1] https://wiki.dlang.org/Generating_WebAssembly_with_LDC

Ldc 1.11 beta 2 is also the first ldc release with a mostly 
working Android/AArch64 port.

In order to cross-compile the stdlib for 64-bit ARM, follow these 
instructions for linux/x64, adapted from the wiki page for 
Android/ARM (https://wiki.dlang.org/Build_D_for_Android), which 
require the same build tools- CMake, the Android NDK, and either 
Make or Ninja:

export 
CC=/path/to/your/android-ndk-r17b/toolchains/llvm/prebuilt/linux-x86_64/bin/clang

/path/to/your/ldc2-1.11.0-beta2-linux-x86_64/bin/ldc-build-runtime --ninja --targetPreset=Android-aarch64

Leave off the --ninja flag if you're using Make instead, and 
adjust the paths in all the commands, replacing /path/to/your/ 
with the correct paths on your system. This will download the ldc 
source into a temporary directory called ldc-build-runtime.tmp 
and attempt to cross-compile the stdlib for Android/AArch64, but 
fail with the following error:

std/math.d(4320): Error: static assert:  `infL > 2.00000L && 
(infL <= 4.00000L)` is false

Download and apply a small workaround patch for Phobos 
(https://gist.github.com/joakim-noah/7b997a7f8c49ff8f9d93658f78ec3cbe) to get it to work:

curl -L -O 
https://gist.githubusercontent.com/joakim-noah/7b997a7f8c49ff8f9d93658f78ec3cbe/raw/a7c7a2d46a679e34236f00fa9a5dee19e3b50667/compile_phobos_aarch64

git apply compile_phobos_aarch64

/path/to/your/ldc2-1.11.0-beta2-linux-x86_64/bin/ldc-build-runtime --ninja --targetPreset=Android-aarch64 --reset

You can now cross-compile command-line binaries for 
Android/AArch64, similar to Android/ARM as shown on the wiki:

export NDK=/path/to/your/android-ndk-r17b

/path/to/your/ldc2-1.11.0-beta2-linux-x86_64/bin/ldc2 
-mtriple=aarch64-none-linux-android 
-L-L/path/to/your/ldc-build-runtime.tmp/lib 
-Xcc=--sysroot=$NDK/platforms/android-21/arch-arm64 
-Xcc=-fuse-ld=bfd -Xcc=-gcc-toolchain 
-Xcc=$NDK/toolchains/aarch64-linux-android-4.9/prebuilt/linux-x86_64 -Xcc=-target -Xcc=aarch64-none-linux-android -Xcc=-fpie -Xcc=-pie sieve.d

The Phobos patch shows the remaining pieces that need to be 
ported, support for 128-bit real floating-point at compile-time 
(as that static assert tripping is likely because the 128-bit 
`real.max` is slightly larger than the 80-bit one and overflows 
to Inf) and core.stdc.stdarg.va_arg for AArch64.

You can also build the stdlib test runners, after applying this 
druntime patch to disable a few tests that cannot be compiled 
(https://gist.github.com/joakim-noah/417ffbac4d6041242d3091001595981d):

curl -L -O 
https://gist.githubusercontent.com/joakim-noah/417ffbac4d6041242d3091001595981d/raw/555d5c85f9055fe63d7c2c6a0493425a9c21edd2/disable_druntime_tests_aarch64

git apply disable_druntime_tests_aarch64

/path/to/your/ldc2-1.11.0-beta2-linux-x86_64/bin/ldc-build-runtime --ninja --targetPreset=Android-aarch64 --testrunners

You can then copy the druntime-test-runner and 
phobos2-test-runner binaries from the ldc-build-runtime.tmp 
directory to the Termux app on an Android/AArch64 device to see 
what tests fail. In my experience, all the druntime tests pass 
and tests only fail for 6-7 Phobos modules, mostly related to 
CTFE not supporting 128-bit floating point:

https://github.com/ldc-developers/ldc/issues/2153#issuecomment-379847985

The debug versions of the above test binaries (which are also 
built with the above command) hang when run, tripping an assert 
in the GC on startup, though they work fine when natively 
compiled with an older ldc 0.17 on an Android/AArch64 device.

If you'd like to chip in on any of these remaining issues, here's 
a straightforward way to get started on porting D to the most 
widely-deployed CPU architecture used for personal computing on 
the planet, with almost all iOS devices and about half of Android 
devices now running on AArch64, billions of devices.

I'll get those last few druntime tests ported next.