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digitalmars.D.ldc - Where is the arm-none-eabi target?

reply IGotD- <nise nise.com> writes:
I'm trying to compile druntime for a custom OS. When I try to 
compile for the target triple -target=arm-none-eabi, the compiler 
does nothing without any error messages and there is no object 
file output at all. However according to this guide.

https://wiki.dlang.org/Minimal_semihosted_ARM_Cortex-M_%22Hello_World%22

it uses the triple thumb-none-linux-eabi, which is kind odd of 
but it might work for that particular case.

The problem is when using thumb-none-linux-eabi, the compiler 
automatically inserts D version identifiers like Posix. There are 
ways around this like putting your desired target sooner in the 
version if-else statements but still for completeness shouldn't 
the non OS target be supported and why aren't there any warning 
messages when using the arm-none-eabi target?
Mar 13 2020
next sibling parent reply kinke <noone nowhere.com> writes:
On Friday, 13 March 2020 at 14:41:03 UTC, IGotD- wrote:

 The problem is when using thumb-none-linux-eabi, the compiler 
 automatically inserts D version identifiers like Posix.


Yes, Linux is a Posix target.


 but still for completeness shouldn't the non OS target be 
 supported


It is and doesn't predefine Posix etc. then; try 
`-mtriple=thumb--none-eabi` (or `thumb-unknown-eabi` etc.).


 and why aren't there any warning messages when using the 
 arm-none-eabi target?


Probably because it works just fine, at least it does for me with 
LDC v1.20 on Windows - `ldc2 -c -mtriple=arm-none-eabi hello.d -v 
&& ls -l hello.o`. `-v` shows the expanded triple (3rd line, => 
arm-none-unknown-eabi).
Mar 13 2020
next sibling parent reply IGotD- <nise nise.com> writes:
On Friday, 13 March 2020 at 17:06:03 UTC, kinke wrote:

 On Friday, 13 March 2020 at 14:41:03 UTC, IGotD- wrote:

 The problem is when using thumb-none-linux-eabi, the compiler 
 automatically inserts D version identifiers like Posix.


 Yes, Linux is a Posix target.


 but still for completeness shouldn't the non OS target be 
 supported


 It is and doesn't predefine Posix etc. then; try 
 `-mtriple=thumb--none-eabi` (or `thumb-unknown-eabi` etc.).


 and why aren't there any warning messages when using the 
 arm-none-eabi target?


 Probably because it works just fine, at least it does for me 
 with LDC v1.20 on Windows - `ldc2 -c -mtriple=arm-none-eabi 
 hello.d -v && ls -l hello.o`. `-v` shows the expanded triple 
 (3rd line, => arm-none-unknown-eabi).


You are right, any other file works with arm-none-eabi.

Actually this might be more related to druntime rather than 
arm-none-eabi.

Try.

cd ldc/runtime/druntime/src (where your druntime is located).
ldc2 -c --output-o -conf= -w -de -dip1000 -mtriple=arm-none-eabi 
-O3 -release -preview=fieldwise -od=/tmp/objects -op core/atomic.d

ls /tmp/objects/core, and there is no atomic.o file.

the compiler just gives a warning: Warning: Assuming critical 
section size = 40 bytes
not sure what this is about.

change -mtriple to arm-none-linux-eabi and the object file is 
created.

I've tried to find if some identifier is missing because of this 
but I haven't found any also atomic should only be CPU 
architecture dependent.
Mar 13 2020
parent reply kinke <noone nowhere.com> writes:
On Friday, 13 March 2020 at 21:47:02 UTC, IGotD- wrote:

 cd ldc/runtime/druntime/src (where your druntime is located).
 ldc2 -c --output-o -conf= -w -de -dip1000 
 -mtriple=arm-none-eabi -O3 -release -preview=fieldwise 
 -od=/tmp/objects -op core/atomic.d


Works fine for me, again with v1.20 on Windows, no warnings wrt. 
unknown section size (needs OS-specific compiler support for 
`synchronized`). I can only guess that you are using an older LDC 
version.
Mar 13 2020
parent reply kinke <noone nowhere.com> writes:
On Friday, 13 March 2020 at 22:11:57 UTC, kinke wrote:

 I can only guess that you are using an older LDC version.


Note that druntime and the compiler are tightly coupled because 
both depend on each other, so you should always use the 
corresponding LDC version to compile druntime. I.e., not trying 
to build our current druntime (branch `ldc`) with LDC v1.20, nor 
trying to build druntime v1.20/2.090 with older LDC versions. 
ldc-build-runtime usually handles that for you. - The atomic 
intrinsics have been reworked recently.
Mar 14 2020
parent IGotD- <nise nise.com> writes:
On Saturday, 14 March 2020 at 12:51:30 UTC, kinke wrote:

 Note that druntime and the compiler are tightly coupled because 
 both depend on each other, so you should always use the 
 corresponding LDC version to compile druntime. I.e., not trying 
 to build our current druntime (branch `ldc`) with LDC v1.20, 
 nor trying to build druntime v1.20/2.090 with older LDC 
 versions. ldc-build-runtime usually handles that for you. - The 
 atomic intrinsics have been reworked recently.


I'm using LDC 1.20.1. I cloned the entire LDC git for my changes 
in the runtime and the version for druntime in particular is 
e96b6f2.

Date:   Tue Feb 25 01:50:21 2020 +0100



Latest tag is ldc-v1.20.0 three commits earlier and I don't find 
any tag for 1.20.1 so my git might be a bit old.
Mar 14 2020
prev sibling parent reply IGotD- <nise nise.com> writes:
On Friday, 13 March 2020 at 17:06:03 UTC, kinke wrote:

 Probably because it works just fine, at least it does for me 
 with LDC v1.20 on Windows


I just tried with LDC 1.20.1 on Windows, there it compiles the to 
the object files just as you previously tested. We have a 
difference between Linux and Windows for the same command line.
Mar 18 2020
parent kinke <noone nowhere.com> writes:
On Wednesday, 18 March 2020 at 12:57:26 UTC, IGotD- wrote:

 On Friday, 13 March 2020 at 17:06:03 UTC, kinke wrote:

 Probably because it works just fine, at least it does for me 
 with LDC v1.20 on Windows


 I just tried with LDC 1.20.1 on Windows, there it compiles the 
 to the object files just as you previously tested. We have a 
 difference between Linux and Windows for the same command line.


The difference is that on Windows hosts, we don't have any 
fallback value for the critical section size for an unknown; the 
first time it is needed, an error is issued.

For Posix hosts, we use the native `pthread_mutex_t` size as 
fallback value, coupled with a one-time warning issued during 
initialization. The `-w` in your cmdline aborts on warnings; you 
can use `-wi` to have them printed but continue.

It might be better never to fall back to the native size, not 
just for consistency across hosts.
Mar 18 2020
prev sibling parent reply dangbinghoo <dangbinghoo gmail.com> writes:
On Friday, 13 March 2020 at 14:41:03 UTC, IGotD- wrote:

 I'm trying to compile druntime for a custom OS. When I try to 
 compile for the target triple -target=arm-none-eabi, the 
 compiler does nothing without any error messages and there is 
 no object file output at all. However according to this guide.

 https://wiki.dlang.org/Minimal_semihosted_ARM_Cortex-M_%22Hello_World%22

 it uses the triple thumb-none-linux-eabi, which is kind odd of 
 but it might work for that particular case.

 The problem is when using thumb-none-linux-eabi, the compiler 
 automatically inserts D version identifiers like Posix. There 
 are ways around this like putting your desired target sooner in 
 the version if-else statements but still for completeness 
 shouldn't the non OS target be supported and why aren't there 
 any warning messages when using the arm-none-eabi target?


IMO, ldc right now will not work without a real OS like 
windows/linux/macos, as druntime and phobos is built upon with 
clib. And none-eabi doesn't have the "standard C library".

it will only work with arm-none-eabi target when trying to build 
LDC a "betterC compiler".
Mar 31 2020
parent IGotD- <nise nise.com> writes:
On Tuesday, 31 March 2020 at 09:59:44 UTC, dangbinghoo wrote:

 On Friday, 13 March 2020 at 14:41:03 UTC, IGotD- wrote:

 IMO, ldc right now will not work without a real OS like 
 windows/linux/macos, as druntime and phobos is built upon with 
 clib. And none-eabi doesn't have the "standard C library".

 it will only work with arm-none-eabi target when trying to 
 build LDC a "betterC compiler".


I'm using arm-none-eabi so that the compiler doesn't pre-select 
any operating system. Then I just use the --d-version option to 
inject my own verison of my custom OS. This seems to be working
Mar 31 2020