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digitalmars.D.learn - Import C under Windows 10

reply DLearner <bmqazwsx123 gmail.com> writes:
This relates to:

```
DMD64 D Compiler v2.112.0
Copyright (C) 1999-2025 by The D Language Foundation, All Rights 
Reserved written by Walter Bright

```

While trying to compile and run hello.c (ie trying out Import C):

```
#include <stdio.h>
int main()
{
    printf("Hello world.\n");
    return 0;
}

```

I got

```
Error: cl.exe not found. Please ensure that Visual Studio Build 
Tools are installed and properly configured.
```
despite repeatedly downloading everything I could find relating 
to Visual Studio 2019.

FWIW, isn't 'cl.exe' MS's _own_ C compiler - I wanted to use the 
C compiler within DMD.

Ideas?
Apr 14
next sibling parent Serg Gini <kornburn yandex.ru> writes:
On Tuesday, 14 April 2026 at 14:25:29 UTC, DLearner wrote:

 Ideas?


I don't... just wanted to say that I admire your passion of 
trying to make ImportC working on "hello world" example..

First try in 2023: 
https://forum.dlang.org/post/tq76ke$2s28$1 digitalmars.com
Then in 2024: 
https://forum.dlang.org/thread/azwhxaopahmquhbcczku forum.dlang.org

Hopefully 2026 will become the year when ImportC will start 
working for you!
Never give up! Never surrender!
Apr 14
prev sibling next sibling parent drug007 <drug2004 bk.ru> writes:
On 4/14/26 17:25, DLearner wrote:

 This relates to:
 
 ```
 DMD64 D Compiler v2.112.0
 Copyright (C) 1999-2025 by The D Language Foundation, All Rights 
 Reserved written by Walter Bright
 
 ```
 
 While trying to compile and run hello.c (ie trying out Import C):
 
 ```
 #include <stdio.h>
 int main()
 {
     printf("Hello world.\n");
     return 0;
 }
 
 ```
 
 I got
 
 ```
 Error: cl.exe not found. Please ensure that Visual Studio Build Tools 
 are installed and properly configured.
 ```
 despite repeatedly downloading everything I could find relating to 
 Visual Studio 2019.
 
 FWIW, isn't 'cl.exe' MS's _own_ C compiler - I wanted to use the C 
 compiler within DMD.
 
 Ideas?


I don't use Windows so I can't help you but despite the fact that 
cl.exe is MS's own C compiler, dmd uses C compiler just to call the 
corresponding preprocessor. You can call it yourself and feed 
preprocessed files to dmd directly. You don't need any C compiler but 
you need a C preprocessor
Apr 14
prev sibling parent reply Ferhat =?UTF-8?B?S3VydHVsbXXFnw==?= <aferust gmail.com> writes:
On Tuesday, 14 April 2026 at 14:25:29 UTC, DLearner wrote:

 This relates to:

 ```
 DMD64 D Compiler v2.112.0
 Copyright (C) 1999-2025 by The D Language Foundation, All 
 Rights Reserved written by Walter Bright

 ```

 While trying to compile and run hello.c (ie trying out Import 
 C):

 ```
 #include <stdio.h>
 int main()
 {
    printf("Hello world.\n");
    return 0;
 }

 ```

 I got

 ```
 Error: cl.exe not found. Please ensure that Visual Studio Build 
 Tools are installed and properly configured.
 ```
 despite repeatedly downloading everything I could find relating 
 to Visual Studio 2019.

 FWIW, isn't 'cl.exe' MS's _own_ C compiler - I wanted to use 
 the C compiler within DMD.

 Ideas?


Usually, Windows Command Prompt does not automatically recognize 
VS compilers (due to PATH issues). Just run everything in a x64 
Native Tools Command Prompt for VS 2019 (or 32 bit).
Apr 15
parent reply drug007 <drug2004 bk.ru> writes:
On 4/15/26 10:20, Ferhat Kurtulmuş wrote:

 
 Usually, Windows Command Prompt does not automatically recognize VS 
 compilers (due to PATH issues). Just run everything in a x64 Native 
 Tools Command Prompt for VS 2019 (or 32 bit).


Exactly! This link can be useful - 
https://learn.microsoft.com/en-us/visualstudio/ide/reference/command-prompt-powershell?view=visualstudio
Apr 15
parent reply DLearner <bmqazwsx123 gmail.com> writes:
On Wednesday, 15 April 2026 at 10:49:14 UTC, drug007 wrote:

 On 4/15/26 10:20, Ferhat Kurtulmuş wrote:

 
 Usually, Windows Command Prompt does not automatically 
 recognize VS compilers (due to PATH issues). Just run 
 everything in a x64 Native Tools Command Prompt for VS 2019 
 (or 32 bit).


 Exactly! This link can be useful - 
 https://learn.microsoft.com/en-us/visualstudio/ide/reference/command-prompt-powershell?view=visualstudio


Thanks!

For the record, by clearing out all earlier Visual Studio's and 
downloading Visual Studio 2026, and using 'Developer Powershell', 
I _finally_ made it work.

However, would it not be better if the Windows DMD download was 
'battery included', in the sense that the built-in C compiler did 
it's own preprocessing?
Apr 15
parent reply drug007 <drug2004 bk.ru> writes:
On 4/15/26 21:54, DLearner wrote:

 On Wednesday, 15 April 2026 at 10:49:14 UTC, drug007 wrote:

 On 4/15/26 10:20, Ferhat Kurtulmuş wrote:

 Usually, Windows Command Prompt does not automatically recognize VS 
 compilers (due to PATH issues). Just run everything in a x64 Native 
 Tools Command Prompt for VS 2019 (or 32 bit).


 Exactly! This link can be useful - https://learn.microsoft.com/en-us/ 
 visualstudio/ide/reference/command-prompt-powershell?view=visualstudio


 
 Thanks!
 
 For the record, by clearing out all earlier Visual Studio's and 
 downloading Visual Studio 2026, and using 'Developer Powershell', I 
 _finally_ made it work.
 
 However, would it not be better if the Windows DMD download was 'battery 
 included', in the sense that the built-in C compiler did it's own 
 preprocessing?


I don't think it's worth it. Too much efforts for nothing. dmd does not 
contain an internal C compiler, not at all, dmd translates C to D AST. 
And dmd does not contain a preprocessor in any form. So you need to 
write C preprocessor from scratch.
Apr 15
parent reply DLearner <bmqazwsx123 gmail.com> writes:
On Wednesday, 15 April 2026 at 19:28:33 UTC, drug007 wrote:

 On 4/15/26 21:54, DLearner wrote:


[...]

 
 However, would it not be better if the Windows DMD download 
 was 'battery included', in the sense that the built-in C 
 compiler did it's own preprocessing?


 I don't think it's worth it. Too much efforts for nothing. dmd 
 does not contain an internal C compiler, not at all, dmd 
 translates C to D AST. And dmd does not contain a preprocessor 
 in any form. So you need to write C preprocessor from scratch.


If the maintainers of DMD don't wish to write a new preprocessor, 
could not one of the four or five preprocessors mentioned in 
42.4.2 be somehow incorporated?

It's just that cl.exe is less than 1Mb, yet the Visual Studio 
download to be able to use it is over 10Gb!
And one seems to be forced to use the 'Developer Powershell', 
which is very sluggish compared to the normal terminal window (if 
you run DMD in the normal terminal window it can't find cl.exe).
Apr 16
next sibling parent reply Dennis <dkorpel gmail.com> writes:
On Thursday, 16 April 2026 at 19:30:48 UTC, DLearner wrote:

 It's just that cl.exe is less than 1Mb, yet the Visual Studio 
 download to be able to use it is over 10Gb!


Unfortunately, Microsoft doesn't allow redistributing Visual 
Studio Build Tools.


 And one seems to be forced to use the 'Developer Powershell', 
 which is very sluggish compared to the normal terminal window 
 (if you run DMD in the normal terminal window it can't find 
 cl.exe).


DMD has a bunch of logic trying to find the Visual Studio 
installation path:

https://github.com/dlang/dmd/blob/2a47bdaafa58a90af9d6ce621f561ef9eb0bc5fd/compiler/src/dmd/vsoptions.d#L213

Did you install it in a special way, or modify your registry / 
environment variables in any way?
Apr 16
parent DLearner <bmqazwsx123 gmail.com> writes:
On Thursday, 16 April 2026 at 19:46:48 UTC, Dennis wrote:

 On Thursday, 16 April 2026 at 19:30:48 UTC, DLearner wrote:


[...]

 DMD has a bunch of logic trying to find the Visual Studio 
 installation path:

 https://github.com/dlang/dmd/blob/2a47bdaafa58a90af9d6ce621f561ef9eb0bc5fd/compiler/src/dmd/vsoptions.d#L213

 Did you install it in a special way, or modify your registry / 
 environment variables in any way?


Installed using Windows installer from the Dlang website.
Registry not modified.
Over time, some of the user (not system) paths were added to.
The system paths are unmodified in any way (by me).

FWIW: I noticed that there FOUR different locations for cl.exe - 
I thought this bizarre.

Has anyone tested inputC using VS2026 - maybe MS changed paths?
Apr 16
prev sibling parent "Richard (Rikki) Andrew Cattermole" <richard cattermole.co.nz> writes:
On 17/04/2026 7:30 AM, DLearner wrote:

 If the maintainers of DMD don't wish to write a new preprocessor, could 
 not one of the four or five preprocessors mentioned in 42.4.2 be somehow 
 incorporated?


The issue isn't the preprocessor itself.

Its all the variables it sets, and the headers (can just throw mingw at it).
Apr 16