Re: [PATCH v2 10/10] detect-compiler: detect clang even if it found CUDA

From: Jeff King <peff@peff.net>
Date: Mar 26, 2025, 17:41 UTC
Message-ID: <20250326174127.GA2508080@coredump.intra.peff.net>
In-Reply-To: <2f6f31240fe6ce5f8efab662af477540a0f966ca.1742945534.git.gitgitgadget@gmail.com>

On Tue, Mar 25, 2025 at 11:32:14PM +0000, Johannes Schindelin via GitGitGadget wrote:

Show 14 quoted lines

> In my setup, clang finds `/usr/local/cuda` and hence the output of
> `clang -v` ends with this line:
> 
> 	Found CUDA installation: /usr/local/cuda, version
> 
> This confuses the `detect-compiler` script because it matches _all_
> lines that contain the needle "version" surrounded by spaces. As a
> consequence, the `get_family` function returns two lines: "Ubuntu clang"
> and above-mentioned line, which the `case` statement does not handle
> well and hence reports "unknown compiler family" instead of the expected
> set of "clang14", "clang13", ..., "clang1" output.
> 
> Let's unconfuse the script by letting it parse the first matching line
> and ignore the rest.

Makes sense. I wondered if this:

>  get_version_line() {
> -	LANG=C LC_ALL=C $CC -v 2>&1 | grep ' version '
> +	LANG=C LC_ALL=C $CC -v 2>&1 | sed -n '/ version /{p;q}'

might be more readable with "grep -m1", but it looks like "-m" is not in POSIX. So what you wrote is probably safer.

-Peff