Fix Bugzilla issue 24111 - [ImportC] fatal error C1034: stdio.h: no include path set

[shoo]

I have attempted a fix for this problem: https://issues.dlang.org/show_bug.cgi?id=24111
#15780 is the predecessor's approach to this problem.
My implementation is based on how it is used in LDC ( https://github.com/ldc-developers/ldc/blob/8399e47ceb4dfbbcf1ca0b7cf934c04a864387b7/driver/tool.cpp#L297-L312 )
Also, I refer to a part of std.process to pass environment variables to CreateProcess. ( https://github.com/dlang/phobos/blob/dcbfbd43ac321e81af60afd795bd0f3c3f47cfa0/std/process.d#L412-L440 , https://github.com/dlang/phobos/blob/dcbfbd43ac321e81af60afd795bd0f3c3f47cfa0/std/process.d#L1450-L1482 )

I have very little experience with dmd code, so my coding style may be incorrect or inefficiently implemented. Please point out any problems.

[dlang-bot]

Thanks for your pull request and interest in making D better, @shoo! We are looking forward to reviewing it, and you should be hearing from a maintainer soon.
Please verify that your PR follows this checklist:

• My PR is fully covered with tests (you can see the coverage diff by visiting the details link of the codecov check)
• My PR is as minimal as possible (smaller, focused PRs are easier to review than big ones)
• I have provided a detailed rationale explaining my changes
• New or modified functions have Ddoc comments (with Params: and Returns:)

Please see CONTRIBUTING.md for more information.

---

If you have addressed all reviews or aren't sure how to proceed, don't hesitate to ping us with a simple comment.

Bugzilla references

Auto-close	Bugzilla	Severity	Description
✓	24111	enhancement	[ImportC] fatal error C1034: stdio.h: no include path set

Testing this PR locally

If you don't have a local development environment setup, you can use Digger to test this PR:

dub run digger -- build "master + dmd#16248"

[rikkimax]

This seems quite a bit more complex than is required.

I suggest setting the environment variable into the process state instead and then resetting it to the old value afterward.
This is what LDC appears to be doing.

[shoo]

This seems quite a bit more complex than is required.

I suggest setting the environment variable into the process state instead and then resetting it to the old value afterward. This is what LDC appears to be doing.

Fix it.
The process of checking for duplication with existing paths was also removed as it was not very useful.

[rikkimax]

Okay, that looks a lot cleaner.

The failures for OSX are currently known and are unrelated to you.
@ibuclaw has a plan for it.

[thewilsonator]

are you able to add a test case for this issue?

[shoo]

are you able to add a test case for this issue?

I would like to be able to add a test case similar to or minimized from the dub test case and run it on Windows with the INCLUDE environment variable forced to be empty.

@REM In the Windows *.bat file:
cd .\test\use-c-sources\
set INCLUDE=
dub build

However, I could not understand how to properly add the test case.
Can you tell me a good way to do this?

[thewilsonator]

run dub build -v and extract the compiler command and use that in place of dub build, as for how to do windows batch file tests, not sure. We definitely have.sh shell tests for posix systems.

[shoo]

@thewilsonator How about this?

[shoo]

Can anyone review this PR?