Re: LDC / BetterC / _d_run_main
On Saturday, 10 March 2018 at 10:57:05 UTC, Johan Engelen wrote: On Saturday, 10 March 2018 at 07:54:33 UTC, Mike Franklin wrote: On Saturday, 10 March 2018 at 02:25:38 UTC, Richard wrote: Hi, I've been trying to see if I can get an mbed project to work with Dlang basically compiling D code for use on a Cortex-M Proccessor You might be interested in the following, if you're not already aware: * https://github.com/JinShil/stm32f42_discovery_demo * https://bitbucket.org/timosi/minlibd There is also: https://github.com/kubo39/stm32f407discovery and its submodules. The STM32 demo only supports GDC right now, but I'll be updating it to support LDC when 2.079.0 lands there. Awesome. -Johan That's interesting I've uploaded by own setup over here if anyone's interested * https://github.com/grbd/GBD.Dlang.MbedBlinkyTest
Re: LDC / BetterC / _d_run_main
On Saturday, 10 March 2018 at 07:54:33 UTC, Mike Franklin wrote:
On Saturday, 10 March 2018 at 02:25:38 UTC, Richard wrote:
Hi,
I've been trying to see if I can get an mbed project to work
with Dlang
basically compiling D code for use on a Cortex-M Proccessor
You might be interested in the following, if you're not already
aware:
* https://github.com/JinShil/stm32f42_discovery_demo
* https://bitbucket.org/timosi/minlibd
The STM32 demo only supports GDC right now, but I'll be
updating it to support LDC when 2.079.0 lands there. 2.079.0
removes some coupling of the compiler to the runtime, so I
should be able to avoid the following bugs:
https://github.com/ldc-developers/ldc/issues/created_by/JinShil
so I tried this instead
```
extern (C) int _d_run_main(int argc, char **argv, void*
mainFunc) {
MainFuncType mFunc = cast(MainFuncType) mainFunc;
return mFunc(null);
}
```
but nope that didn't seem to work ether, compiles okay but the
code in main() (D space) isn't called
I'd imagine this should be a simple thing, anyone got any
ideas?
The following worked fine for me on my x64 Linux desktop with
LDC version 1.8.0 (DMD v2.078.3, LLVM 5.0.1)
``` main.d
import core.stdc.stdio;
private alias extern(C) int function(char[][] args)
MainFuncType;
extern (C) int _d_run_main(int argc, char **argv, void*
mainFunc)
{
MainFuncType mFunc = cast(MainFuncType) mainFunc;
return mFunc(null);
}
void main()
{
printf("Hello, World!\n");
}
```
Compile with: ldc2 -defaultlib= -debuglib= -betterC main.d
Mike
Based on the above this seems to work fine so I'll use this since
it's the simplest option.
```
extern(C) int main(int argc, char** argv) {
return d_main();
}
int d_main() {
// Do stuff
}
```
This compiles but main() is never called btw
```
import core.stdc.stdio;
private alias extern(C) int function(char[][] args) MainFuncType;
extern (C) int _d_run_main(int argc, char **argv, void* mainFunc)
{
MainFuncType mFunc = cast(MainFuncType) mainFunc;
return mFunc(null);
}
int main() {
// Do stuff
}
```
I tried compiling with
ldc2 -defaultlib= -debuglib= -mtriple=thumb-none-linux-eabi
-mcpu=cortex-m3 --od=. -c -betterC main.d
LDC / BetterC / _d_run_main
Hi,
I've been trying to see if I can get an mbed project to work with
Dlang
basically compiling D code for use on a Cortex-M Proccessor
So far I've been using the latest release of LDC with the
-BetterC Flag
From what I can gather, normally without -BetterC it works like
this:
* main() - C main generated by the compiler
* _d_run_main - called by C main to setup the runtime
* _Dmain - main function in D land, is called by _d_run_main
With -BetterC enabled, it instead works like this
* main() - C main generated by the compiler
* _d_run_main - needs to be written by the user since there's
no runtime
* _Dmain - main function in D land
so basically I need to write my own basic _d_run_main to call
_Dmain.
Code in github does something like this typically
```
private alias extern(C) int function(char[][] args) MainFunc;
private extern (C) int _d_run_main(int argc, char** argv,
MainFunc mainFunc)
{
return mainFunc(null);
}
```
However the LDC compiler doesn't like this as it expects the
mainFunc parameter to be a void pointer
so I tried this instead
```
extern (C) int _d_run_main(int argc, char **argv, void* mainFunc)
{
MainFuncType mFunc = cast(MainFuncType) mainFunc;
return mFunc(null);
}
```
but nope that didn't seem to work ether, compiles okay but the
code in main() (D space) isn't called
I'd imagine this should be a simple thing, anyone got any ideas?
Re: question about conditional operator (?:)
On Tuesday, 26 July 2016 at 13:19:54 UTC, ag0aep6g wrote: Operator precedence is different from what you think. `a ? b : c = d` means `(a ? b : c) = d`. But you want `a ? b : (c = d)`. So you need parentheses around `p+=1`. Or just go with `if` and `else`. It's clearer anyway. From http://wiki.dlang.org/Operator_precedence Priority(15 is highest) 3 Conditional operator ?: 2 Assignment operators= -= += <<= >>= >>>= = *= %= ^= ^^= ~= I was actually close to not needing parentheses :). But I see that your suggestion to stick with if else in this case is the sensible thing to do, especially since ?: seems to lead to more errors. Thanks for the answers.
question about conditional operator (?:)
Hello all,
I've got a program that correctly computes the largest factor in
the prime decomposition of a positive number:
*
import std.math std.stdio;
ulong largestPrimeFactor(ulong n) {
for(ulong p=2; p<=sqrt(cast(real)n); ) {
if(n%p==0)
n/=p;
else
p+=1;
}
return n;
}
void main() {
writeln(largestPrimeFactor(4));
}
*
However, if I replace the content of the for loop with the ?:
operator, the program is not
correct anymore (largestPrimeFactor(4) now returns 3):
*
import std.math std.stdio;
ulong largestPrimeFactor(ulong n) {
for(ulong p=2; p<=sqrt(cast(real)n); ) {
n%p==0 ? n/=p : p+=1 ;
}
return n;
}
void main() {
writeln(largestPrimeFactor(4));
}
*
What am I doing wrong here?
I'm using dmd version 2.071.1-0 on ubuntu.
