Hello!

I have the following assebly:
```C
__asm__ __volatile__ (
	"990: nop\n"                                                 \
	".pushsection .note.stapsdt,\"?\",\"note\"\n"                \
	".balign 4\n"                                                \
	".4byte 992f-991f, 994f-993f, 3\n"                           \
	"991: .asciz \"stapsdt\"\n"                                  \
	"992: .balign 4\n"                                           \
	"993: .8byte 990b\n"                                         \
	".8byte _.stapsdt.base\n"                                    \
	".8byte 0\n"                                                 \
	".asciz \"myapp\"\n"                                         \
	".asciz \"func_call\"\n"                                     \
	".asciz \"%n[_SDT_S1]@%[_SDT_A1] %n[_SDT_S2]@%[_SDT_A2]\"\n" \
	"994: .balign 4\n"                                           \
	".popsection\n"
	:: [_SDT_S1] "n" (4),
	   [_SDT_A1] "nor" ((a)),
	   [_SDT_S2] "n" (4),
	   [_SDT_A2] "nor" ((b))
);
```
this code compiles by gcc but gdc ((Debian 6.3.0-18+deb9u1) 6.3.0 20170516) fails. It doesn't like __volatile__ keyword and :: syntax

```D
__asm__  (
	"990: nop"
	".pushsection .note.stapsdt,\"?\",\"note\""
	".balign 4"
	".4byte 992f-991f, 994f-993f, 3"
	"991: .asciz \"stapsdt\""
	"992: .balign 4"
	"993: .8byte 990b"
	".8byte _.stapsdt.base"
	".8byte 0"
	".asciz \"myapp\""
	".asciz \"func_call\""
	".asciz \"%n[_SDT_S1]@%[_SDT_A1] %n[_SDT_S2]@%[_SDT_A2]\""
	"994: .balign 4"
	".popsection\n"
	:: [_SDT_S1] "n" (4),
	   [_SDT_A1] "nor" ((a)),
	   [_SDT_S2] "n" (4),
	   [_SDT_A2] "nor" ((b))
);
```

On Thu, 24 Oct 2019 at 12:05, drug via D.gnu <d.gnu@puremagic.com> wrote:
>
> Hello!
>
> I have the following assebly:
> ```C
> __asm__ __volatile__ (
>         "990: nop\n"                                                 \
>         ".pushsection .note.stapsdt,\"?\",\"note\"\n"                \
>         ".balign 4\n"                                                \
>         ".4byte 992f-991f, 994f-993f, 3\n"                           \
>         "991: .asciz \"stapsdt\"\n"                                  \
>         "992: .balign 4\n"                                           \
>         "993: .8byte 990b\n"                                         \
>         ".8byte _.stapsdt.base\n"                                    \
>         ".8byte 0\n"                                                 \
>         ".asciz \"myapp\"\n"                                         \
>         ".asciz \"func_call\"\n"                                     \
>         ".asciz \"%n[_SDT_S1]@%[_SDT_A1] %n[_SDT_S2]@%[_SDT_A2]\"\n" \
>         "994: .balign 4\n"                                           \
>         ".popsection\n"
>         :: [_SDT_S1] "n" (4),
>            [_SDT_A1] "nor" ((a)),
>            [_SDT_S2] "n" (4),
>            [_SDT_A2] "nor" ((b))
> );
> ```
> this code compiles by gcc but gdc ((Debian 6.3.0-18+deb9u1) 6.3.0
> 20170516) fails. It doesn't like __volatile__ keyword and :: syntax
>
> ```D
> __asm__  (
>         "990: nop"
>         ".pushsection .note.stapsdt,\"?\",\"note\""
>         ".balign 4"
>         ".4byte 992f-991f, 994f-993f, 3"
>         "991: .asciz \"stapsdt\""
>         "992: .balign 4"
>         "993: .8byte 990b"
>         ".8byte _.stapsdt.base"
>         ".8byte 0"
>         ".asciz \"myapp\""
>         ".asciz \"func_call\""
>         ".asciz \"%n[_SDT_S1]@%[_SDT_A1] %n[_SDT_S2]@%[_SDT_A2]\""
>         "994: .balign 4"
>         ".popsection\n"
>         :: [_SDT_S1] "n" (4),
>            [_SDT_A1] "nor" ((a)),
>            [_SDT_S2] "n" (4),
>            [_SDT_A2] "nor" ((b))
> );
> ```

It looks like this is a top-level inline asslembler declaration?  D doesn't support top-level inline assembler, however I think this would be a useful feature to allow.

As for the syntax, it's `asm { ... }`

-- 
Iain

On 10/24/19 5:41 PM, Iain Buclaw wrote:
> 
> It looks like this is a top-level inline asslembler declaration?  D
> doesn't support top-level inline assembler, however I think this would
> be a useful feature to allow.
> 
> As for the syntax, it's `asm { ... }`
> 

This is in fact DTrace probe generated by using
```
DTRACE_PROBE2(myapp, func_call, a, b);
```
I would like to generate this code by myself without C macros by obvious reason. I need ability to insert nop operation (that is trivial) and then add a note to specific section with the description of this probe (the address of this nop operation first of all and some other information)

But as I understand it is impossible?

On Thu, 24 Oct 2019 at 16:50, drug via D.gnu <d.gnu@puremagic.com> wrote:
>
> On 10/24/19 5:41 PM, Iain Buclaw wrote:
> >
> > It looks like this is a top-level inline asslembler declaration?  D doesn't support top-level inline assembler, however I think this would be a useful feature to allow.
> >
> > As for the syntax, it's `asm { ... }`
> >
>
> This is in fact DTrace probe generated by using
> ```
> DTRACE_PROBE2(myapp, func_call, a, b);
> ```
> I would like to generate this code by myself without C macros by obvious
> reason. I need ability to insert nop operation (that is trivial) and
> then add a note to specific section with the description of this probe
> (the address of this nop operation first of all and some other information)
>
> But as I understand it is impossible?

You can do the following:

void somefunc()
{
  asm {
        "990: nop" ~
        ".pushsection .note.stapsdt,\"?\",\"note\"" ~
        ".balign 4" ~
        ".4byte 992f-991f, 994f-993f, 3" ~
        "991: .asciz \"stapsdt\"" ~
        "992: .balign 4" ~
        "993: .8byte 990b" ~
        ".8byte _.stapsdt.base" ~
        ".8byte 0" ~
        ".asciz \"myapp\"" ~
        ".asciz \"func_call\"" ~
        ".asciz \"%n[_SDT_S1]@%[_SDT_A1] %n[_SDT_S2]@%[_SDT_A2]\"" ~
        "994: .balign 4" ~
        ".popsection\n"
        :: [_SDT_S1] "n" (4),
           [_SDT_A1] "nor" ((a)),
           [_SDT_S2] "n" (4),
           [_SDT_A2] "nor" ((b))
  }
}

The instruction string can be generated at CTFE.

-- 
Iain

On 10/24/19 8:01 PM, Iain Buclaw wrote:
> You can do the following:
> 
> void somefunc()
> {
>    asm {
>          "990: nop" ~
>          ".pushsection .note.stapsdt,\"?\",\"note\"" ~
>          ".balign 4" ~
>          ".4byte 992f-991f, 994f-993f, 3" ~
>          "991: .asciz \"stapsdt\"" ~
>          "992: .balign 4" ~
>          "993: .8byte 990b" ~
>          ".8byte _.stapsdt.base" ~
>          ".8byte 0" ~
>          ".asciz \"myapp\"" ~
>          ".asciz \"func_call\"" ~
>          ".asciz \"%n[_SDT_S1]@%[_SDT_A1] %n[_SDT_S2]@%[_SDT_A2]\"" ~
>          "994: .balign 4" ~
>          ".popsection\n"
>          :: [_SDT_S1] "n" (4),
>             [_SDT_A1] "nor" ((a)),
>             [_SDT_S2] "n" (4),
>             [_SDT_A2] "nor" ((b))
>    } // <= line 26
> }
> 
> The instruction string can be generated at CTFE.
> 
Unfortunately I doesn't work https://godbolt.org/z/ly2yBT
```
source/app.d:26:3: error: expression expected, not '}'
```

On Thu, 24 Oct 2019 at 19:20, drug via D.gnu <d.gnu@puremagic.com> wrote:
>
> On 10/24/19 8:01 PM, Iain Buclaw wrote:
> > You can do the following:
> >
> > void somefunc()
> > {
> >    asm {
> >          "990: nop" ~
> >          ".pushsection .note.stapsdt,\"?\",\"note\"" ~
> >          ".balign 4" ~
> >          ".4byte 992f-991f, 994f-993f, 3" ~
> >          "991: .asciz \"stapsdt\"" ~
> >          "992: .balign 4" ~
> >          "993: .8byte 990b" ~
> >          ".8byte _.stapsdt.base" ~
> >          ".8byte 0" ~
> >          ".asciz \"myapp\"" ~
> >          ".asciz \"func_call\"" ~
> >          ".asciz \"%n[_SDT_S1]@%[_SDT_A1] %n[_SDT_S2]@%[_SDT_A2]\"" ~
> >          "994: .balign 4" ~
> >          ".popsection\n"
> >          :: [_SDT_S1] "n" (4),
> >             [_SDT_A1] "nor" ((a)),
> >             [_SDT_S2] "n" (4),
> >             [_SDT_A2] "nor" ((b))
> >    } // <= line 26
> > }
> >
> > The instruction string can be generated at CTFE.
> >
> Unfortunately I doesn't work https://godbolt.org/z/ly2yBT
> ```
> source/app.d:26:3: error: expression expected, not '}'
> ```
>

That's correct, because I forgot the semicolon (the hint is in the latter message: found 'EOF' when expecting ';').

>From what little information I'm going off on that macro, it seems
that you want it to do something like the following: https://explore.dgnu.org/z/TtTcij

-- 
Iain

24.10.2019 22:51, Iain Buclaw пишет:
> On Thu, 24 Oct 2019 at 19:20, drug via D.gnu <d.gnu@puremagic.com> wrote:
>>
>> On 10/24/19 8:01 PM, Iain Buclaw wrote:
>>> You can do the following:
>>>
>>> void somefunc()
>>> {
>>>     asm {
>>>           "990: nop" ~
>>>           ".pushsection .note.stapsdt,\"?\",\"note\"" ~
>>>           ".balign 4" ~
>>>           ".4byte 992f-991f, 994f-993f, 3" ~
>>>           "991: .asciz \"stapsdt\"" ~
>>>           "992: .balign 4" ~
>>>           "993: .8byte 990b" ~
>>>           ".8byte _.stapsdt.base" ~
>>>           ".8byte 0" ~
>>>           ".asciz \"myapp\"" ~
>>>           ".asciz \"func_call\"" ~
>>>           ".asciz \"%n[_SDT_S1]@%[_SDT_A1] %n[_SDT_S2]@%[_SDT_A2]\"" ~
>>>           "994: .balign 4" ~
>>>           ".popsection\n"
>>>           :: [_SDT_S1] "n" (4),
>>>              [_SDT_A1] "nor" ((a)),
>>>              [_SDT_S2] "n" (4),
>>>              [_SDT_A2] "nor" ((b))
>>>     } // <= line 26
>>> }
>>>
>>> The instruction string can be generated at CTFE.
>>>
>> Unfortunately I doesn't work https://godbolt.org/z/ly2yBT
>> ```
>> source/app.d:26:3: error: expression expected, not '}'
>> ```
>>
> 
> That's correct, because I forgot the semicolon (the hint is in the
> latter message: found 'EOF' when expecting ';').
> 
>>From what little information I'm going off on that macro, it seems
> that you want it to do something like the following:
> https://explore.dgnu.org/z/TtTcij
> 

That's it! Thank you very much!