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digitalmars.D.learn - Is it possible to set/override the name of the source file when piping

reply Siarhei Siamashka <siarhei.siamashka gmail.com> writes:
Example:

```D
import std;
void main() {
   deliberate syntax error here
}
```

```bash
$ cat example.d | dmd -run -
__stdin.d(3): Error: found `error` when expecting `;` or `=`, did 
you mean `deliberate syntax = here`?
__stdin.d(3): Error: found `}` when expecting `;` or `=`, did you 
mean `error here = End of File`?
```

Now I'm curious. Is it possible to somehow communicate the real 
source file name to `dmd`, so that it shows up in the error log 
instead of "__stdin.d"?
Dec 13 2023
next sibling parent reply Adam D Ruppe <destructionator gmail.com> writes:
On Wednesday, 13 December 2023 at 19:37:09 UTC, Siarhei Siamashka 
wrote:

 Now I'm curious. Is it possible to somehow communicate the real 
 source file name to `dmd`, so that it shows up in the error log 
 instead of "__stdin.d"?


the sequence `#line "filename.d" 1` at the top of the thing might 
do what you need.

https://dlang.org/spec/lex.html#special-token-sequence

might also suggest putting a `module` declaration in the file.
Dec 13 2023
parent Siarhei Siamashka <siarhei.siamashka gmail.com> writes:
On Wednesday, 13 December 2023 at 19:51:11 UTC, Adam D Ruppe 
wrote:

 On Wednesday, 13 December 2023 at 19:37:09 UTC, Siarhei 
 Siamashka wrote:

 Now I'm curious. Is it possible to somehow communicate the 
 real source file name to `dmd`, so that it shows up in the 
 error log instead of "__stdin.d"?


 the sequence `#line "filename.d" 1` at the top of the thing 
 might do what you need.

 https://dlang.org/spec/lex.html#special-token-sequence

 might also suggest putting a `module` declaration in the file.


Thanks a lot! Looks like it does the job:

```D
/+dub.sdl:+/ #line 2 "example.d"
import std;
void main() {
   deliberate syntax error here
}
```

At least this way there's no undesired line numbers mismatch 
between different ways to compile and run the same file:

```
$ dub example.d
example.d(4,14): Error: found `error` when expecting `;` or `=`, 
did you mean `deliberate syntax = here`?
example.d(4,27): Error: found `}` when expecting `;` or `=`, did 
you mean `error here = End of File`?

$ cat example.d | dmd -run -
example.d(4): Error: found `error` when expecting `;` or `=`, did 
you mean `deliberate syntax = here`?
example.d(4): Error: found `}` when expecting `;` or `=`, did you 
mean `error here = End of File`?
```

But the compiler command line doesn't provide any alternative 
solutions to override the "__stdin.d" placeholder, right? My 
primary concern is that the file name and the special token or 
module directive have to match each other. And unless this is 
reliably enforced, it may become an additional headache to worry 
about.
Dec 13 2023
prev sibling next sibling parent "H. S. Teoh" <hsteoh qfbox.info> writes:
On Wed, Dec 13, 2023 at 07:37:09PM +0000, Siarhei Siamashka via
Digitalmars-d-learn wrote:

 Example:
 
 ```D
 import std;
 void main() {
   deliberate syntax error here
 }
 ```
 
 ```bash
 $ cat example.d | dmd -run -
 __stdin.d(3): Error: found `error` when expecting `;` or `=`, did you mean
 `deliberate syntax = here`?
 __stdin.d(3): Error: found `}` when expecting `;` or `=`, did you mean
 `error here = End of File`?
 ```
 
 Now I'm curious. Is it possible to somehow communicate the real source
 file name to `dmd`, so that it shows up in the error log instead of
 "__stdin.d"?


Add a module declaration to your source file. For example:

	echo 'module abc; import std; void main(){writefln(__MODULE__);}' | dmd -run -

Output:
	abc

`__stdin` is used as a placeholder when no module declaration is
present, and dmd doesn't know the filename (which is what it would
normally have used for the module name in this case).


T

-- 
Век живи - век учись. А дураком помрёшь.
Dec 13 2023
prev sibling parent "H. S. Teoh" <hsteoh qfbox.info> writes:
On Wed, Dec 13, 2023 at 11:58:42AM -0800, H. S. Teoh via Digitalmars-d-learn
wrote:
[...]

 Add a module declaration to your source file. For example:
 
 	echo 'module abc; import std; void main(){writefln(__MODULE__);}' | dmd -run -
 
 Output:
 	abc
 
 `__stdin` is used as a placeholder when no module declaration is
 present, and dmd doesn't know the filename (which is what it would
 normally have used for the module name in this case).


[...]

Hmm, apparently the module declaration doesn't change the placeholder
filename. Using `#line 1 abc.d` does the trick, as Adam suggests.


T

-- 
People tell me I'm stubborn, but I refuse to accept it!
Dec 13 2023