LDC with ARM backend

[Claude via Digitalmars-d-learn]

On Friday, 15 July 2016 at 15:24:36 UTC, Kai Nacke wrote:
> There is a reason why we do not distribute a binary version of 
> LDC with all LLVM targets enabled. LDC still uses the real 
> format of the host. This is different on ARM (80bit on 
> Linux/x86 vs. 64bit on Linux/ARM). Do not expect that 
> applications using real type work correctly.
> (The Windows version of LDC uses 64bit reals. The binary build 
> has the ARM target enabled.)
>
> Regards,
> Kai

Hello Kai,

Thanks for your answer.

 From the link https://wiki.dlang.org/Build_LDC_for_Android , I 
did exactly the same steps described in section "Compile LLVM" 
(patch applied).

At section "Build ldc for Android/ARM", I did it quite the same. 
I applied the patch ldc_1.0.0_android_arm, but changed 
runtime/CMakeList.txt, instead of using Android specific stuff, I 
did:


Line 15:
set(D_FLAGS               -w;-mtriple=arm-none-linux-gnueabi      
   CACHE STRING  "Runtime build flags, separated by ;")

Line 505:
#
# Set up build targets.
#
set(RT_CFLAGS "-g")
set(CMAKE_SYSTEM_NAME Linux)
set(CMAKE_C_COMPILER 
/opt/arm-2009q1/bin/arm-none-linux-gnueabi-gcc)
set(CMAKE_CXX_COMPILER 
/opt/arm-2009q1/bin/arm-none-linux-gnueabi-c++)



On the command line, I aliased DMD to /usr/bin/dmd and runt cmake 
as described...

Afterwards, I ran make for ldc2, phobos2-ldc an druntime-ldc, but 
I did not apply the patches on phobos and runtime. It looked like 
the path introduced some static compilation towards Android, so I 
thought it would not apply to my needs.

So here' what I get if I do a "ldc2 -version":


LDC - the LLVM D compiler (1.0.0):
   based on DMD v2.070.2 and LLVM 3.8.1
   built with DMD64 D Compiler v2.071.1
   Default target: x86_64-unknown-linux-gnu
   Host CPU: westmere
   http://dlang.org - http://wiki.dlang.org/LDC

   Registered Targets:
     arm     - ARM
     armeb   - ARM (big endian)
     thumb   - Thumb
     thumbeb - Thumb (big endian)



I can strictly compile a "hello world" program:
./bin/ldc2 -mtriple=arm-none-linux-gnueabi test.d

I get the expected "test.o"

But I don't know how to link it. I don't have "clang". I tried to 
link it with the gcc from the gnu ARM toolchain with 
libdruntime-ldc.a, libldc.a and libphobos2-ldc.a, but it fails 
miserably: many undefined symbols (pthread, and some other os 
related stuff).