Add -I command line flag

4 files changed, 40 insertions, 13 deletions

diff --git a/Main.hs b/Main.hs
index 492c82b..48f2b5a 100644
--- a/Main.hs
+++ b/Main.hs
@@ -3,7 +3,7 @@ module Main where
 
 import           Control.Applicative (empty)
 import           Control.Exception.Base (throwIO,Exception)
-import           Control.Monad (void,foldM,join)
+import           Control.Monad (void,foldM,join,filterM)
 import qualified Data.Array as A
 import           Data.Char (isSpace)
 import           Data.HashMap.Strict (HashMap)
@@ -12,6 +12,7 @@ import           Data.Semigroup ((<>))
 import           Data.Void
 import           Options.Applicative hiding (Parser,  ParseError)
 import           System.Directory
+import           System.FilePath
 import           System.IO (hPutStrLn,stderr)
 import           System.IO.Error (tryIOError)
 import           System.Process
@@ -173,6 +174,7 @@ data Error
   | MacroNoNeedsBlock String
   | MacroNeedsBlock String
   | IncludeArg
+  | IncludeNotFound String
   | IncludeParse (ParseError (Token String) Void)
   | IncludeRecurse
   | SetArg
@@ -198,6 +200,7 @@ instance Show Error where
   show (MacroNoNeedsBlock n) = "Macro '"++n++"' does not accept a block argument"
   show (MacroNeedsBlock n) = "Macro '"++n++"' requires a block argument, but none given"
   show IncludeArg = "Invalid argument(s) to 'pre_include'"
+  show (IncludeNotFound f) = "Can't find include file '"++f++"'"
   show (IncludeParse e) = parseErrorPretty e
   show IncludeRecurse = "Recursion depth exceeded with 'pre_include'"
   show SetArg = "Invalid argument(s) to 'pre_set'"
@@ -377,8 +380,24 @@ ifExpand st arg conf = do
 
 
 
+includeExpand :: PState -> Int -> String -> IO (PState, [Directive])
+includeExpand st n fn = do
+  fns <- filterM doesFileExist $ map (</>fn) $ stIncDir st
+  f <- case fns of
+    [] -> throwIO (IncludeNotFound fn)
+    f:_ -> return f
+  contents <- readFile f
+  ast <- case parse parser fn contents of
+    Left e  -> throwIO (IncludeParse e)
+    Right r -> return r
+  (nst, conf) <- procConf (st { stIncludes = n-1 }) ast
+  return (nst { stIncludes = n+1 }, conf)
+
+
+
 data PState = PState
-  { stVars     :: HashMap String [ArgComponent]
+  { stIncDir   :: [String]
+  , stVars     :: HashMap String [ArgComponent]
   , stMacros   :: HashMap String Macro
   , stArgs     :: HashMap String [ArgComponent] -- shadows stVars
     -- Max 1, but Prelude's 'lookup' isn't generic to work on Maybe, so this'll do
@@ -431,13 +450,7 @@ procConf gst gconf = foldM p (gst, []) gconf
   stmt st (Directive "pre_include" a b) =
     case (stIncludes st, a, b) of
       (0, _, _) -> throwIO IncludeRecurse
-      (i, ArgString [Literal n]:[], Nothing) -> do
-        contents <- readFile n
-        ast <- case parse parser n contents of
-          Left e  -> throwIO (IncludeParse e)
-          Right r -> return r
-        (nst, conf) <- procConf (st { stIncludes = i-1 }) ast
-        return (nst { stIncludes = i+1 }, conf)
+      (i, ArgString [Literal n]:[], Nothing) -> includeExpand st i n
       _ -> throwIO IncludeArg
 
   stmt st (Directive "pre_set" a b) =
@@ -486,6 +499,7 @@ data Options = Options
   { optVersion :: Bool
   , optInput   :: String
   , optOutput  :: String
+  , optInclude :: [String]
   }
 
 main :: IO ()
@@ -504,8 +518,11 @@ main = do
     <$> switch    (short 'V' <> long "version" <> hidden <> help "Show program version")
     <*> strOption (short 'i' <> metavar "FILE" <> value "-" <> showDefault <> help "Input file")
     <*> strOption (short 'o' <> metavar "FILE" <> value "-" <> showDefault <> help "Output file")
+    <*> many (strOption (short 'I' <> metavar "DIR" <> help "Add search path for pre_include directives"))
 
   prog o = do
+    let inc = if null (optInclude o) then ["."] else optInclude o
+
     input <- if optInput o == "-"
       then getContents
       else readFile (optInput o)
@@ -513,7 +530,7 @@ main = do
     case parse parser (optInput o) input of
       Left e -> hPutStrLn stderr $ parseErrorPretty e
       Right r -> do
-        output <- fmt <$> procConf' (PState mempty mempty mempty mempty mempty 15) r
+        output <- fmt <$> procConf' (PState inc mempty mempty mempty mempty mempty 15) r
         if optOutput o == "-"
           then putStr output
           else writeFile (optOutput o) output
diff --git a/nginx-confgen.cabal b/nginx-confgen.cabal
index 8ebb227..5df1bf7 100644
--- a/nginx-confgen.cabal
+++ b/nginx-confgen.cabal
@@ -20,6 +20,7 @@ executable nginx-confgen
       array
     , base
     , directory
+    , filepath
     , megaparsec
     , optparse-applicative
     , process
diff --git a/nginx-confgen.pod b/nginx-confgen.pod
index 2bc0176..d4efeb5 100644
--- a/nginx-confgen.pod
+++ b/nginx-confgen.pod
@@ -54,6 +54,13 @@ C<->, then the file will be read from standard input.
 Write the output to the given file. If this option is not given or set to C<->,
 then the file will be written to standard output.
 
+=item -I I<DIR>
+
+Set the search path for I<pre_include> directives. This option can be given
+multiple times to search several directories in order. If this option is not
+given, then include files are resolved relative to the directory that
+nginx-confgen is run from (i.e. C<-I .>).
+
 =back
 
 
@@ -68,8 +75,7 @@ during preprocessing. The included file may contain any preprocessing
 directives supported by nginx-confgen. Variables and macros defined in the
 included file will be available in the parent file.
 
-Beware that relative paths are resolved from the working directory that
-nginx-confgen is run from.
+Relative paths are searched for in the directories given with the C<-I> flag.
 
 =head2 pre_set
 
diff --git a/test/main.conf b/test/main.conf
index 249d7ad..09cda5b 100644
--- a/test/main.conf
+++ b/test/main.conf
@@ -24,7 +24,10 @@ pre_exec $nameserver "grep nameserver /etc/resolv.conf \\
                       | head -n 1 | sed 's/^nameserver //'";
 resolver $nameserver;
 
-pre_include test/macros.conf;
+# This needs -Itest to resolve
+pre_include macros.conf;
+
+pre_include /dev/null;
 
 http {
     types {