Get non completion clang output into a buffer when completing

rc/clang.kak

@@ -1,24 +1,32 @@
 decl str clang_options
 
-decl -hidden str clang_filename
+decl -hidden str clang_tmp_dir
 decl -hidden str-list clang_completions
 
 def clang-complete %{
     %sh{
-        filename=$(mktemp -d -t kak-clang.XXXXXXXX)/buffer.cpp
-        echo "set buffer clang_filename $filename"
-        echo "write $filename"
+        dir=$(mktemp -d -t kak-clang.XXXXXXXX)
+        mkfifo ${dir}/fifo
+        echo "set buffer clang_tmp_dir ${dir}"
+        echo "write ${dir}/buffer.cpp"
     }
     # end the previous %sh{} so that its output gets interpreted by kakoune
     # before launching the following as a background task.
     %sh{
+        dir=${kak_opt_clang_tmp_dir}
+        echo "eval -draft %{
+                  edit! -fifo ${dir}/fifo *clang-output*
+                  set buffer filetype make
+                  set buffer _make_current_error_line 0
+                  hook buffer BufCloseFifo .* %{ nop %sh{ rm -r ${dir} } }
+              }"
         # this runs in a detached shell, asynchronously, so that kakoune does not hang while clang is running.
         # As completions references a cursor position and a buffer timestamp, only valid completions should be
         # displayed.
         (
             pos=-:${kak_cursor_line}:${kak_cursor_column}
             cd $(dirname ${kak_buffile})
-            clang++ -x c++ -fsyntax-only ${kak_opt_clang_options} -Xclang -code-completion-at=${pos} - < ${kak_opt_clang_filename} 2>&1 | awk -e '
+            clang++ -x c++ -fsyntax-only ${kak_opt_clang_options} -Xclang -code-completion-at=${pos} - < ${dir}/buffer.cpp 2>&1 | awk -e '
               function rmblocks(opening, closing, val, res) {
                   while (match(val, opening)) {
                       res = res substr(val, 1, RSTART-1)
@@ -35,11 +43,11 @@ def clang-complete %{
                   gsub("\\((, )+\\)", "(", c); gsub("<(, )+>", "<", c)
                   out = out ":" c
               }
+              ! /^COMPLETION:[^:]+:/ { print $0 }
               END {
                   cmd = "kak -p " ENVIRON["kak_session"]
                   print "eval -client " ENVIRON["kak_client"] " %[ echo completed; set buffer clang_completions %[" out "] ]" | cmd
-              }'
-            rm -r $(dirname ${kak_opt_clang_filename})
+              }' 2>&1 > ${dir}/fifo
         ) > /dev/null 2>&1 < /dev/null &
     }
 }