clang: new completion

completions/clang

@@ -0,0 +1,81 @@
+_clang_filedir()
+{
+    # _filedir function provided by recent versions of bash-completion package is
+    # better than "compgen -f" because the former honors spaces in pathnames while
+    # the latter doesn't. So we use compgen only when _filedir is not provided.
+    _filedir 2> /dev/null || COMPREPLY=( $( compgen -f ) )
+}
+
+_clang()
+{
+    local cur prev words cword arg flags w1 w2
+    # If latest bash-completion is not supported just initialize COMPREPLY and
+    # initialize variables by setting manualy.
+    _init_completion -n 2> /dev/null
+    if [[ "$?" != 0 ]]; then
+        COMPREPLY=()
+        cword=$COMP_CWORD
+        cur="${COMP_WORDS[$cword]}"
+    fi
+
+    w1="${COMP_WORDS[$cword - 1]}"
+    if [[ $cword > 1 ]]; then
+        w2="${COMP_WORDS[$cword - 2]}"
+    fi
+
+    # Clang want to know if -cc1 or -Xclang option is specified or not, because we don't want to show
+    # cc1 options otherwise.
+    if [[ "${COMP_WORDS[1]}" == "-cc1" || "$w1" == "-Xclang" ]]; then
+        arg="#"
+    fi
+
+    # bash always separates '=' as a token even if there's no space before/after '='.
+    # On the other hand, '=' is just a regular character for clang options that
+    # contain '='. For example, "-stdlib=" is defined as is, instead of "-stdlib" and "=".
+    # So, we need to partially undo bash tokenization here for integrity.
+    if [[ "$cur" == -* ]]; then
+        # -foo<tab>
+        arg="$arg$cur"
+    elif [[ "$w1" == -*  && "$cur" == '=' ]]; then
+        # -foo=<tab>
+        arg="$arg$w1=,"
+    elif [[ "$cur" == -*= ]]; then
+        # -foo=<tab>
+        arg="$arg$cur,"
+    elif [[ "$w1" == -* ]]; then
+        # -foo <tab> or -foo bar<tab>
+        arg="$arg$w1,$cur"
+    elif [[ "$w2" == -* && "$w1" == '=' ]]; then
+        # -foo=bar<tab>
+        arg="$arg$w2=,$cur"
+    elif [[ ${cur: -1} != '=' && ${cur/=} != $cur ]]; then
+        # -foo=bar<tab>
+        arg="$arg${cur%=*}=,${cur#*=}"
+    fi
+
+    # expand ~ to $HOME
+    eval local path=${COMP_WORDS[0]}
+    flags=$( "$path" --autocomplete="$arg" 2>/dev/null | sed -e 's/\t.*//' )
+    # If clang is old that it does not support --autocomplete,
+    # fall back to the filename completion.
+    if [[ "$?" != 0 ]]; then
+        _clang_filedir
+        return
+    fi
+
+    # When clang does not emit any possible autocompletion, or user pushed tab after " ",
+    # just autocomplete files.
+    if [[ "$flags" == "$(echo -e '\n')" || "$arg" == "" ]]; then
+        # If -foo=<tab> and there was no possible values, autocomplete files.
+        [[ "$cur" == '=' || "$cur" == -*= ]] && cur=""
+        _clang_filedir
+    elif [[ "$cur" == '=' ]]; then
+        COMPREPLY=( $( compgen -W "$flags" -- "") )
+    else
+        # Bash automatically appends a space after '=' by default.
+        # Disable it so that it works nicely for options in the form of -foo=bar.
+        [[ "${flags: -1}" == '=' ]] && compopt -o nospace 2> /dev/null
+        COMPREPLY=( $( compgen -W "$flags" -- "$cur" ) )
+    fi
+}
+complete -F _clang clang