Re: is this a bug ? mixin template static function missing!
On Friday, 10 August 2018 at 12:05:52 UTC, Simen Kjærås wrote:
On Friday, 10 August 2018 at 11:17:10 UTC, learnfirst1 wrote:
If you try the same without the mixin template, you'll see that
it doesn't work:
struct Test {
extern(C) pragma(crt_constructor) static void init(){ // work
int i = 3;
}
}
void main(){
extern(C) pragma(crt_constructor) static void init(){ // not
work
int i = 3;
}
}
--
It not work make no sense, since it can work on struct.
I am not be able to search the related spec docs, only this
link:
https://dlang.org/blog/2018/01/04/dmd-2-078-0-has-been-released/
Based on my understand, nested static extern(C) function is all
about visibility. It just like put private before it, there is
really no reason to treat them in diff way.
Re: is this a bug ? mixin template static function missing!
On Friday, 10 August 2018 at 11:17:10 UTC, learnfirst1 wrote:
I think the static extern(C) nested function should just work
like global extern(C) function. DMD still report missing
symbols. Or I am wrong about this ?
template G(){
static extern(C) pragma(crt_constructor) void init(){}
}
void main(){
mixin G!(); // Line 5
init();
}
If you try the same without the mixin template, you'll see that
it doesn't work:
void main() {
static extern(C) pragma(crt_constructor) void init();
init();
}
Depending on the order of static, extern(C) and
pragma(crt_constructor), you can get at least two different error
messages, but either way - it doesn't work.
It would be possible to make this work by changing the compiler,
but according to spec, it shouldn't.
--
Simen
Re: is this a bug ? mixin template static function missing!
On Friday, 10 August 2018 at 10:24:55 UTC, Simen Kjærås wrote:
On Friday, 10 August 2018 at 08:31:21 UTC, learnfirst1 wrote:
Filed a bug:
https://issues.dlang.org/show_bug.cgi?id=19153
template G(){
pragma(crt_constructor) static extern(C) void init(){}
}
void main(){
mixin G!(); // Line 5
init();
}
same missing symbols.
Re: is this a bug ? mixin template static function missing!
On Friday, 10 August 2018 at 10:24:55 UTC, Simen Kjærås wrote:
On Friday, 10 August 2018 at 08:31:21 UTC, learnfirst1 wrote:
The correct behavior would be for the compiler to show the
latter error message for a mixin'd function as well.
Filed a bug:
https://issues.dlang.org/show_bug.cgi?id=19153
--
Simen
I think the static extern(C) nested function should just work
like global extern(C) function. DMD still report missing
symbols. Or I am wrong about this ?
template G(){
static extern(C) pragma(crt_constructor) void init(){}
}
void main(){
mixin G!(); // Line 5
init();
}
Re: is this a bug ? mixin template static function missing!
On Friday, 10 August 2018 at 08:31:21 UTC, learnfirst1 wrote:
#!/usr/bin/env rdmd
import core.stdc.stdio;
template G(size_t line = __LINE__, A...){
int i = 3;
static extern(C) pragma(crt_constructor) void init2(){
printf("init: %d\n", line);
}
}
pragma(crt_constructor) extern(C) void init1(){
printf("init from global\n");
}
struct A {
mixin G!();
}
extern(C) void main(){
mixin G!() g;
printf("g.i=%d\n", g.i);
g.init2(); // remove this can build, but g.init2 not get
called!
}
-
build error:
Undefined symbols for architecture x86_64:
"__D4test4mainUZ1g5init2UNbNiZv", referenced from:
It is indeed. Reduced example:
template G(){
extern(C) pragma(crt_constructor) void init(){}
}
void main(){
mixin G!();
init();
}
For nested functions, extern(C) is simply ignored[0]. Since
pragma(crt_constructor) requires that the symbol it's applied to
uses C linkage (and an error message to that effect is shown if
you write pragma(crt_constructor) void fun() {} in module scope:
Error: function `fun` must be extern(C) for
pragma(crt_constructor)
In addition, if you try to apply pragma(crt_constructor) to a
nested function, you get this error message, showing further that
nested functions can't be crt_constructors:
Error: unrecognized pragma(crt_constructor)
The correct behavior would be for the compiler to show the latter
error message for a mixin'd function as well.
Filed a bug:
https://issues.dlang.org/show_bug.cgi?id=19153
--
Simen
[0]: from https://dlang.org/spec/attribute.html#linkage:
Note that extern(C) can be provided for all types of
declarations, including struct or class, even though there is no
corresponding match on the C side. In that case, the attribute is
ignored. This behavior applies for nested functions and nested
variables as well.
