rustBuildCrate: properly handle cargo env pragmas with spaces

There are two problems: first that we end up splitting on spaces in the
loop. Even when that is fixed, we still would split on spaces in the
`export` inside the loop. We need to guard against both.

Fixes #199298

Confirmed that it fixes the case mentioned in the ticket:

```console
[nix-develop]$ $(nix-build -I nixpkgs=/home/shana/programming/nixpkgs Cargo.nix -A rootCrate.build  --no-out-link)/bin/nix-rustc-env-escape-repro
Expecting three words, got: first second third
```

I think this is going to cause a rebuild of every Rust package even if
they were unaffected, not much we can do here.
This commit is contained in:
Mateusz Kowalczyk 2022-11-03 14:49:24 +09:00
parent 1f1ed641de
commit 233205c464
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View file

@ -189,9 +189,21 @@ in ''
EXTRA_LINK=$(sed -n "s/^cargo:rustc-link-lib=\(.*\)/\1/p" target/build/${crateName}.opt | tr '\n' ' ')
EXTRA_LINK_SEARCH=$(sed -n "s/^cargo:rustc-link-search=\(.*\)/\1/p" target/build/${crateName}.opt | tr '\n' ' ' | sort -u)
# We want to read part of every line that has cargo:rustc-env= prefix and
# export it as environment variables. This turns out tricky if the lines
# have spaces: we can't wrap the command in double quotes as that captures
# all the lines in single output. We can't use while read loop because
# exporting from inside of it doesn't make it to the outside scope. We
# can't use xargs as export is a built-in and does not work from it. As a
# last resort then, we change the IFS so that the for loop does not split
# on spaces and reset it after we are done. See ticket #199298.
#
_OLDIFS="$IFS"
IFS=$'\n'
for env in $(sed -n "s/^cargo:rustc-env=\(.*\)/\1/p" target/build/${crateName}.opt); do
export $env
export "$env"
done
IFS="$_OLDIFS"
CRATENAME=$(echo ${crateName} | sed -e "s/\(.*\)-sys$/\U\1/" -e "s/-/_/g")
grep -P "^cargo:(?!(rustc-|warning=|rerun-if-changed=|rerun-if-env-changed))" target/build/${crateName}.opt \