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digitalmars.D.ldc - Dlang LLVM ERROR: Program used external function which could not be

reply BARRE KEVIN <ikelive hotmail.fr> writes:
https://stackoverflow.com/questions/44550353/dlang-llvm-error-program-used-external-function-which-could-not-be-resolved

I try to compile d code to llvm IR but when i compile or execute 
.ll i have error

LLVM ERROR: Program used external function '_d_throw_exception' 
which could not be resolved!

Why in c or c++ with

clang -S -emit-llvm foo.c
lli foo.ll

It is work normaly.
Jun 14 2017
next sibling parent reply David Nadlinger via digitalmars-d-ldc <digitalmars-d-ldc puremagic.com> writes:
Hi Kevin,

On 14 Jun 2017, at 17:48, BARRE KEVIN via digitalmars-d-ldc wrote:

 LLVM ERROR: Program used external function '_d_throw_exception' which 
 could not be resolved!

 Why in c or c++ with

 clang -S -emit-llvm foo.c
 lli foo.ll


`_d_throw_exception` is a function in the D standard library (druntime, 
to be precise). As such, even though the LLVM IR produced by LDC is 
well-formed (i.e. LDC is not at fault here), when lli tries to interpret 
the IR in question, it isn't able to find the address of the function 
("could not be resolved"), because it doesn't know anything about 
druntime or how to load it.

lli has the necessary provisions for C/C++, so it works there (I don't 
remember off the top of my head whether they hardcode the C runtime 
functions or simply use the symbols from the lli executable itself, 
which is of course written in C++).

You could, for instance, work around this by compiling druntime into 
bitcode and linking that with your .ll files before trying to execute 
them. Why do you want to use lli in the first place, though?

Best,
David
Jun 14 2017
parent reply BARRE KEVIN <ikelive hotmail.fr> writes:
On Wednesday, 14 June 2017 at 17:05:00 UTC, David Nadlinger wrote:

 Hi Kevin,

 On 14 Jun 2017, at 17:48, BARRE KEVIN via digitalmars-d-ldc 
 wrote:

 [...]


 [...]


I want try llvm tools :)

for example compile D source in llvm source (.bc, .ll) and 
compile later with llc or execute with lli.

it is possible ??

Thanks
Jun 15 2017
parent David Nadlinger via digitalmars-d-ldc <digitalmars-d-ldc puremagic.com> writes:
Hi Kevin,

On 15 Jun 2017, at 16:17, BARRE KEVIN via digitalmars-d-ldc wrote:

 I want try llvm tools :)

 for example compile D source in llvm source (.bc, .ll) and compile 
 later with llc or execute with lli.

 it is possible ??


Using the LLVM tools is definitely possible – in fact, this is a large 
part of what makes LLVM development so much easier than for the DMD 
backend (and to some extent, also than GCC). Using llc should always 
work just fine. What LDC does to produce an executable is more or less 
equivalent to "llc -filetype=obj …", followed by a call to the system 
linker which you can see using "ldc2 -v". I also regularly use the opt 
tool to look at what individual optimizer passes do to a given piece of 
code, and bugpoint for debugging LLVM crashes/miscompilations.

lli is a bit different to the usual compilation workflow in that it 
literally executes the IR inside an interpreter. Thus, all the code that 
relies on the program image (executable file)/globals/… as a concept 
won't work. This includes the central druntime mechanics for module 
registration and (probably) also garbage collection. Thus, lli might not 
be the easiest thing to get started with, although it can definitely be 
made to work if you work without druntime.

Best,
David
Jun 15 2017
prev sibling next sibling parent Kagamin <spam here.lot> writes:
Try this:
---
import core.stdc.stdio;
int main()
{
     puts("Hello World !!!");
     return 0;
}
---
Jun 15 2017
prev sibling parent reply BARRE KEVIN <ikelive hotmail.fr> writes:
On Wednesday, 14 June 2017 at 16:48:31 UTC, BARRE KEVIN wrote:

 https://stackoverflow.com/questions/44550353/dlang-llvm-error-program-used-external-function-which-could-not-be-resolved

 I try to compile d code to llvm IR but when i compile or 
 execute .ll i have error

 LLVM ERROR: Program used external function '_d_throw_exception' 
 which could not be resolved!

 Why in c or c++ with

 clang -S -emit-llvm foo.c
 lli foo.ll

 It is work normaly.


lli -load /usr/lib/libphobos2.so foo.ll

I forgot link the library
Jun 15 2017
parent reply BARRE KEVIN <ikelive hotmail.fr> writes:
On Thursday, 15 June 2017 at 13:30:21 UTC, BARRE KEVIN wrote:

 On Wednesday, 14 June 2017 at 16:48:31 UTC, BARRE KEVIN wrote:

 https://stackoverflow.com/questions/44550353/dlang-llvm-error-program-used-external-function-which-could-not-be-resolved

 I try to compile d code to llvm IR but when i compile or 
 execute .ll i have error

 LLVM ERROR: Program used external function 
 '_d_throw_exception' which could not be resolved!

 Why in c or c++ with

 clang -S -emit-llvm foo.c
 lli foo.ll

 It is work normaly.


 lli -load /usr/lib/libphobos2.so foo.ll

 I forgot link the library


lli -load /usr/lib/libdruntime-ldc-debug.so.72 -load 
/usr/lib/libphobos2-ldc-debug.so.72 main.ll

no work :(

i forgot something ?
Jun 15 2017
parent reply BARRE KEVIN <ikelive hotmail.fr> writes:
 lli -load /usr/lib/libdruntime-ldc-debug.so.72 -load 
 /usr/lib/libphobos2-ldc-debug.so.72 main.ll

 no work :(

 i forgot something ?


LLVM ERROR: Program used external function '__start___minfo' 
which could not be resolved!
Jun 15 2017
parent reply David Nadlinger via digitalmars-d-ldc <digitalmars-d-ldc puremagic.com> writes:
On 15 Jun 2017, at 15:50, BARRE KEVIN via digitalmars-d-ldc wrote:

 LLVM ERROR: Program used external function '__start___minfo' which 
 could not be resolved!


lli's error message is slightly misleading; __start___minfo is not a 
function, but a special symbol usually "created" by the linker while 
producing the main executable. It is used to register the D modules from 
your executable with druntime, so that static constructors, etc. can be 
invoked.

You'd need to disable all the functionality requiring runtime support to 
make D code work within lli, for example using `-betterC` or 
`pragma(LDC_no_moduleinfo)`/…. Still not sure why you would want to 
use `lli` with LDC-compiled code in the first place, though.

  — David
Jun 15 2017
parent BARRE KEVIN <ikelive hotmail.fr> writes:
On Thursday, 15 June 2017 at 14:59:48 UTC, David Nadlinger wrote:

 On 15 Jun 2017, at 15:50, BARRE KEVIN via digitalmars-d-ldc 
 wrote:

 LLVM ERROR: Program used external function '__start___minfo' 
 which could not be resolved!


 lli's error message is slightly misleading; __start___minfo is 
 not a function, but a special symbol usually "created" by the 
 linker while producing the main executable. It is used to 
 register the D modules from your executable with druntime, so 
 that static constructors, etc. can be invoked.

 You'd need to disable all the functionality requiring runtime 
 support to make D code work within lli, for example using 
 `-betterC` or `pragma(LDC_no_moduleinfo)`/…. Still not sure why 
 you would want to use `lli` with LDC-compiled code in the first 
 place, though.

  — David


ldc2 -output-ll -betterC main.d
lli -load /usr/lib/libphobos2-ldc.so.72 main.ll

output -> Hello World !!!

Thanks David

You are ninja
Jun 15 2017