add ccache completion

src/_ccache

@@ -0,0 +1,66 @@
+#compdef ccache
+# zsh completion script for ccache
+
+# Copyright 2018 CERN for the benefit of the LHCb Collaboration.
+
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions are met:
+# 
+# * Redistributions of source code must retain the above copyright notice, this
+#   list of conditions and the following disclaimer.
+# 
+# * Redistributions in binary form must reproduce the above copyright notice,
+#   this list of conditions and the following disclaimer in the documentation
+#   and/or other materials provided with the distribution.
+# 
+# * Neither the name of the copyright holder nor the names of its
+#   contributors may be used to endorse or promote products derived from
+#   this software without specific prior written permission.
+# 
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+# AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+# IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+# DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
+# FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+# DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+# SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+# CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+# OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+#
+# In applying this licence, CERN does not waive the privileges and immunities
+# granted to it by virtue of its status as an Intergovernmental Organization
+# or submit itself to any jurisdiction.
+
+# allow users to define their better compilers
+# inspired by _cmake_compilers
+# users could override with
+#
+# _ccache_compilers() {
+#   local -a _ccache_compilers
+#   _ccache_compilers=(gcc g++ clang clang++)
+#   _wanted compilers expl "compiler" compadd -- $_ccache_compilers
+# }
+(( $+functions[_ccache_compilers] )) ||
+_ccache_compilers() {
+  _command_names -e
+}
+
+if [[ $words[2] == -* ]]; then
+  # if the first argument starts with -, we are in configure-ccache mode
+  # for this, _gnu_generic is okayish:
+  #  * ccache --set-config=key=value won't complete beyond the first =
+  #  * ccache --set-config=foo=bar --<TAB> won't suggest "set-config" another time
+  if [[ $words[$CURRENT] == -* ]]; then
+    # only call _gnu_generic without hyphen (files are not useful)
+    _gnu_generic
+  fi
+elif [[ $CURRENT -eq 2 ]]; then
+  _ccache_compilers
+else
+  # the command line already looks like 'ccache <compiler> ...'
+  # forward to the completion function of the compiler
+  (( CURRENT-- ))
+  shift words
+  _normal
+fi