From f7c4c403ebb2460e056bdb80463d75a32174bafa Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Fran=C3=A7ois-Xavier=20Carton?= <fx.carton91@gmail.com>
Date: Sat, 29 Dec 2018 01:11:35 +0100
Subject: [PATCH] Fix CFLAGS parsing

Split by space instead of dash.
This prevents incorrect parsing where space-separated arguments are
merged (in particular, .c or .o files were appended to -I or -D
arguments).

Handle shell escape: quotes and escaped quotes \" and shell
substitutions are recognised. This is done by verifying that no special
character (" ' ` ()) has not a matching character.

Fixes #2049
---
 autoload/ale/c.vim | 32 ++++++++++++++++++++++----------
 1 file changed, 22 insertions(+), 10 deletions(-)

diff --git a/autoload/ale/c.vim b/autoload/ale/c.vim
index ce5105b6..617e81f6 100644
--- a/autoload/ale/c.vim
+++ b/autoload/ale/c.vim
@@ -48,26 +48,38 @@ endfunction
 
 function! ale#c#ParseCFlags(path_prefix, cflag_line) abort
     let l:cflags_list = []
-    let l:previous_options = []
+    let l:previous_options = ''
 
-    let l:split_lines = split(a:cflag_line, '-')
+    let l:split_lines = split(a:cflag_line, ' ')
     let l:option_index = 0
 
     while l:option_index < len(l:split_lines)
-        let l:option = l:split_lines[l:option_index]
+        let l:option = l:previous_options . l:split_lines[l:option_index]
         let l:option_index = l:option_index + 1
-        call add(l:previous_options, l:option)
-        " Check if cflag contained a '-' and should not have been splitted
-        let l:option_list = split(l:option, '\zs')
 
-        if len(l:option_list) > 0 && l:option_list[-1] isnot# ' ' && l:option_index < len(l:split_lines)
+        " Check if cflag contained an unmatched characters and should not have been splitted
+        let l:option_special = substitute(l:option, '\\"', '', 'g')
+        let l:option_special = substitute(l:option_special, '[^"''()`]', '', 'g')
+        let l:option_special = substitute(l:option_special, '""', '', 'g')
+        let l:option_special = substitute(l:option_special, '''''', '', 'g')
+        let l:option_special = substitute(l:option_special, '``', '', 'g')
+        let l:option_special = substitute(l:option_special, '((', '(', 'g')
+        let l:option_special = substitute(l:option_special, '))', ')', 'g')
+        let l:option_special = substitute(l:option_special, '()', '', 'g')
+
+        if len(l:option_special) > 0 && l:option_index < len(l:split_lines)
+            let l:previous_options = l:option . ' '
             continue
         endif
 
-        let l:option = join(l:previous_options, '-')
-        let l:previous_options = []
+        " Check if there was spaces after -D/-I and the flag should not have been splitted
+        if l:option is# '-D' || l:option is# '-I'
+            let l:previous_options = l:option
+            continue
+        endif
+
+        let l:previous_options = ''
 
-        let l:option = '-' . substitute(l:option, '^\s*\(.\{-}\)\s*$', '\1', '')
 
         " Fix relative paths if needed
         if stridx(l:option, '-I') >= 0 &&