nixpkgs/pkgs/build-support/setup-hooks/wrap-gapps-hook.sh
Bruce Toll bbb2f93cee wrap-gapps-hook.sh: only wrap links when required
Unless dontWrapGapps is set, the wrap-gapps-hook.sh will currently
wrap all executables (and symbolic links to executables) found under
the target directories: bin and libexec.

As a result, if a symbolic link in a target directory points to an
executable in a target directory, both will get wrapped.  This
causes an extra shell/exec when following the symbolic link,
as well as increasing the size of the final executable's environment.

To avoid wrapping a link to an already wrapped executable, this
commit splits the determination of what gets wrapped into two phases:

1. All binaries under the target directories are wrapped and logged
   with "Wrapping program ..."

2. All links to executables under the target directories are
   identified and checked to see if they reference an executable
   under one of the target directories.

   If yes, the required wrapping has already been performed on
   the associated binary (in phase 1), so no wrapping is done
   and "Not wrapping link: ... (already wrapped)" is logged.

   If no, the link points at an executable that hasn't been
   wrapped, so the link is wrapped and "Wrapping link: ..." is logged.

As an example, the yelp package has a bin directory that contains
an executable "yelp" and a symbolic link "gnome-help" -> "yelp".

Prior to this commit, the bin directory would contain these files
after wrapping:

  gnome-help          -- wrapper to exec .gnome-help-wrapped
  .gnome-help-wrapped -- a symbolic link to yelp
  yelp                -- wrapper to exec .yelp-wrapped
  .yelp-wrapped       -- the original yelp binary

After this commit, the bin directory will instead contain:

  gnome-help          -- a symbolic link to yelp
  yelp                -- wrapper to exec .yelp-wrapped
  .yelp-wrapped       -- the original yelp binary

NOTE: The primary motivation for this commit is to avoid obscuring
the fact that two or more paths are simple aliases and expected to
behave identically. It also reduces the likelihood of hitting
limits related to environment variable size.

LIMITATION: The method used above is intended to be conservative
and will still wrap symbolic links to other symbolic links when
the ultimate target is outside of bin or libexec.
2019-01-31 20:14:30 -05:00

76 lines
2.5 KiB
Bash

gappsWrapperArgs=()
find_gio_modules() {
if [ -d "$1"/lib/gio/modules ] && [ -n "$(ls -A $1/lib/gio/modules)" ] ; then
gappsWrapperArgs+=(--prefix GIO_EXTRA_MODULES : "$1/lib/gio/modules")
fi
}
addEnvHooks "$targetOffset" find_gio_modules
# Note: $gappsWrapperArgs still gets defined even if $dontWrapGApps is set.
wrapGAppsHook() {
# guard against running multiple times (e.g. due to propagation)
[ -z "$wrapGAppsHookHasRun" ] || return 0
wrapGAppsHookHasRun=1
if [ -n "$GDK_PIXBUF_MODULE_FILE" ]; then
gappsWrapperArgs+=(--set GDK_PIXBUF_MODULE_FILE "$GDK_PIXBUF_MODULE_FILE")
fi
if [ -n "$XDG_ICON_DIRS" ]; then
gappsWrapperArgs+=(--prefix XDG_DATA_DIRS : "$XDG_ICON_DIRS")
fi
if [ -n "$GSETTINGS_SCHEMAS_PATH" ]; then
gappsWrapperArgs+=(--prefix XDG_DATA_DIRS : "$GSETTINGS_SCHEMAS_PATH")
fi
if [ -d "$prefix/share" ]; then
gappsWrapperArgs+=(--prefix XDG_DATA_DIRS : "$prefix/share")
fi
for v in $wrapPrefixVariables GST_PLUGIN_SYSTEM_PATH_1_0 GI_TYPELIB_PATH GRL_PLUGIN_PATH; do
eval local dummy="\$$v"
gappsWrapperArgs+=(--prefix $v : "$dummy")
done
if [[ -z "$dontWrapGApps" ]]; then
targetDirsThatExist=()
targetDirsRealPath=()
# wrap binaries
targetDirs=( "${prefix}/bin" "${prefix}/libexec" )
for targetDir in "${targetDirs[@]}"; do
if [[ -d "${targetDir}" ]]; then
targetDirsThatExist+=("${targetDir}")
targetDirsRealPath+=("$(realpath "${targetDir}")/")
find "${targetDir}" -type f -executable -print0 \
| while IFS= read -r -d '' file; do
echo "Wrapping program '${file}'"
wrapProgram "${file}" "${gappsWrapperArgs[@]}"
done
fi
done
# wrap links to binaries that point outside targetDirs
# Note: links to binaries within targetDirs do not need
# to be wrapped as the binaries have already been wrapped
if [[ ${#targetDirsThatExist[@]} -ne 0 ]]; then
find "${targetDirsThatExist[@]}" -type l -xtype f -executable -print0 \
| while IFS= read -r -d '' linkPath; do
linkPathReal=$(realpath "${linkPath}")
for targetPath in "${targetDirsRealPath[@]}"; do
if [[ "$linkPathReal" == "$targetPath"* ]]; then
echo "Not wrapping link: '$linkPath' (already wrapped)"
continue 2
fi
done
echo "Wrapping link: '$linkPath'"
wrapProgram "${linkPath}" "${gappsWrapperArgs[@]}"
done
fi
fi
}
fixupOutputHooks+=(wrapGAppsHook)