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Message-ID: <77fa61cf-0046-3f38-e782-2bb8b4be3fc3@harkless.org>
Date: Mon, 16 Jan 2023 15:42:55 -0800
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Subject: Re: GCC doesn't find relative includes when passed paths using
 backward-slashes
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To: cygwin AT cygwin DOT com
References: <c593e554-d8ac-a0e5-96c0-c54fe9db633e AT grundis DOT de>
In-Reply-To: <c593e554-d8ac-a0e5-96c0-c54fe9db633e@grundis.de>
From: Dan Harkless via Cygwin <cygwin AT cygwin DOT com>
Reply-To: Dan Harkless <cygwin-list21 AT harkless DOT org>
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Sender: "Cygwin" <cygwin-bounces+archive-cygwin=delorie DOT com AT cygwin DOT com>
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On 1/15/2023 4:38 AM, Alexander Grund via Cygwin wrote:
> Hi,
>
> consider the following MWE:
>
> |$ touch bar/foo.h $ cat bar/main.cpp #include "foo.h" int main(){} With this most simple setup calling GCC with `g++ "bar\main.cpp"` results in GCC failing to find the include file. However using `g++ "bar/main.cpp"` works as expected. |
> |So the compiler does find the CPP file and also is able to resolve others paths passed with backslashes (e.g. -I arguments) but basically disables resolving includes relative to the file including it. For context: This turned up on CI for Boost where "|C:\cygwin64\bin" is added to the PATH env variable to be able to use the Cygwin GCC with B2. The build system, finding it is running on Windows, will pass paths with backward slashes to the compiler. This happens on both CMD with the added PATH and using the bash. For reference I tried the same with MinGW and there either path separator worked. So it seems to be an issue in the Cygwin builds of GCC. I tried both 11.2 and 11.3, the latest currently available. Best Regards, Alexander Grund ||

Backslash has a special meaning in C/C++ strings (the quote/escape 
character).  There's some kind of special magic in Cygwin bash that lets 
you use most backslashes in paths without escaping them, but ordinarily 
(outside of '-quotes) on UNIX/Cygwin you need to. If you use:

     g++ bar\\main.cpp

or:

     g++ "bar\\main.cpp"

or:

     g++ 'bar\main.cpp'

it'll work.

--
Dan Harkless
http://harkless.org/dan/


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