depot/third_party/nixpkgs/pkgs/build-support/fetchpatch/default.nix

121 lines
3.5 KiB
Nix

# This function downloads and normalizes a patch/diff file.
# This is primarily useful for dynamically generated patches,
# such as GitHub's or cgit's, where the non-significant content parts
# often change with updating of git or cgit.
# stripLen acts as the -p parameter when applying a patch.
{
lib,
fetchurl,
patchutils,
}:
{
relative ? null,
stripLen ? 0,
decode ? "cat", # custom command to decode patch e.g. base64 -d
extraPrefix ? null,
excludes ? [ ],
includes ? [ ],
revert ? false,
postFetch ? "",
nativeBuildInputs ? [ ],
...
}@args:
let
args' =
if relative != null then
{
stripLen = 1 + lib.length (lib.splitString "/" relative) + stripLen;
extraPrefix = lib.optionalString (extraPrefix != null) extraPrefix;
}
else
{
inherit stripLen extraPrefix;
};
in
let
inherit (args') stripLen extraPrefix;
in
lib.throwIfNot (excludes == [ ] || includes == [ ])
"fetchpatch: cannot use excludes and includes simultaneously"
fetchurl
(
{
nativeBuildInputs = [ patchutils ] ++ nativeBuildInputs;
postFetch =
''
tmpfile="$TMPDIR/patch"
if [ ! -s "$out" ]; then
echo "error: Fetched patch file '$out' is empty!" 1>&2
exit 1
fi
set +e
${decode} < "$out" > "$tmpfile"
if [ $? -ne 0 ] || [ ! -s "$tmpfile" ]; then
echo 'Failed to decode patch with command "'${lib.escapeShellArg decode}'"' >&2
echo 'Fetched file was (limited to 128 bytes):' >&2
od -A x -t x1z -v -N 128 "$out" >&2
exit 1
fi
set -e
mv "$tmpfile" "$out"
lsdiff \
${lib.optionalString (relative != null) "-p1 -i ${lib.escapeShellArg relative}/'*'"} \
"$out" \
| sort -u | sed -e 's/[*?]/\\&/g' \
| xargs -I{} \
filterdiff \
--include={} \
--strip=${toString stripLen} \
${
lib.optionalString (extraPrefix != null) ''
--addoldprefix=a/${lib.escapeShellArg extraPrefix} \
--addnewprefix=b/${lib.escapeShellArg extraPrefix} \
''
} \
--clean "$out" > "$tmpfile"
if [ ! -s "$tmpfile" ]; then
echo "error: Normalized patch '$tmpfile' is empty (while the fetched file was not)!" 1>&2
echo "Did you maybe fetch a HTML representation of a patch instead of a raw patch?" 1>&2
echo "Fetched file was:" 1>&2
cat "$out" 1>&2
exit 1
fi
filterdiff \
-p1 \
${builtins.toString (builtins.map (x: "-x ${lib.escapeShellArg x}") excludes)} \
${builtins.toString (builtins.map (x: "-i ${lib.escapeShellArg x}") includes)} \
"$tmpfile" > "$out"
if [ ! -s "$out" ]; then
echo "error: Filtered patch '$out' is empty (while the original patch file was not)!" 1>&2
echo "Check your includes and excludes." 1>&2
echo "Normalized patch file was:" 1>&2
cat "$tmpfile" 1>&2
exit 1
fi
''
+ lib.optionalString revert ''
interdiff "$out" /dev/null > "$tmpfile"
mv "$tmpfile" "$out"
''
+ postFetch;
}
// builtins.removeAttrs args [
"relative"
"stripLen"
"decode"
"extraPrefix"
"excludes"
"includes"
"revert"
"postFetch"
"nativeBuildInputs"
]
)