Generalized custom path configuration/build support.

Makefile

@@ -25,7 +25,7 @@ doc-local: all
 .PHONY: system-install gentoo-install finish-configure
 
 finish-configure:
-ifneq ($(OS_TYPE),Win32)
+ifneq ($(CUSTOM_PATH),yes)
 	@echo let tts_program = \"$(libdir)/liquidsoap/$(libs_dir_version)/liquidtts\" >> src/configure.ml
 	@echo let rundir = \"$(localstatedir)/run/liquidsoap\" >> src/configure.ml
 	@echo let logdir = \"$(localstatedir)/log/liquidsoap\" >> src/configure.ml
@@ -34,11 +34,11 @@ ifneq ($(OS_TYPE),Win32)
 	@echo let \(\) = add_subst \"\<sysrundir\>\" \"$(localstatedir)/run/liquidsoap\" >> src/configure.ml
 	@echo let \(\) = add_subst \"\<syslogdir\>\" \"$(localstatedir)/log/liquidsoap\" >> src/configure.ml
 else
-	@echo let tts_program = \"liquidtts\" >> src/configure.ml
-	@echo let rundir = \"run\" >> src/configure.ml
-	@echo let logdir = \"logs\" >> src/configure.ml
-	@echo let plugins_dir = \"plugins\" >> src/configure.ml
-	@echo let libs_dir = \"libs\" >> src/configure.ml
+	@echo let tts_program = get_dir \"liquidtts\" >> src/configure.ml
+	@echo let rundir = get_dir \"run\" >> src/configure.ml
+	@echo let logdir = get_dir \"logs\" >> src/configure.ml
+	@echo let plugins_dir = get_dir \"plugins\" >> src/configure.ml
+	@echo let libs_dir = get_dir \"libs\" >> src/configure.ml
 	@echo let \(\) = add_subst \"\<sysrundir\>\" \".\" >> src/configure.ml
 	@echo let \(\) = add_subst \"\<syslogdir\>\" \".\" >> src/configure.ml
 endif

Makefile.defs.in

@@ -27,6 +27,7 @@ CPPFLAGS = @CPPFLAGS@
 LIBS = @LIBS@
 LDFLAGS = @LDFLAGS@
 OS_TYPE = @OS_TYPE@
+CUSTOM_PATH = @W_CUSTOM_PATH@
 EXEEXT = @EXEEXT@
 CAMLP4O = @CAMLP4O@
 

configure.ac

@@ -259,6 +259,30 @@ AC_SUBST(TCP_NODELAY_VALUE)
 
 AC_SUBST(BYTE)
 
+AC_ARG_ENABLE([custom-path],
+   AS_HELP_STRING([--enable-custom-path],[Enable custom path support for loading liquidsoap's dependencies (always enable for win32 builds).]))
+
+if test "$OS_TYPE" = "Win32" -o "x$enable_custom_path" = "xyes"; then
+  W_CUSTOM_PATH="yes"
+  w_CUSTOM_PATH="ok"
+cat >> src/configure.ml <<__BLAH__
+let get_dir d = 
+  let dir =
+    Utils.resolve_path (Filename.dirname Sys.executable_name)
+  in
+  let cwd =
+    match Utils.getenv_opt "LIQUIDSOAP_BASE_DIR" with
+      | None      -> dir
+      | Some path -> Utils.resolve_path ~cwd:dir path
+  in 
+  Utils.resolve_path ~cwd d
+__BLAH__
+else
+  W_CUSTOM_PATH="no"
+  w_CUSTOM_PATH=""
+fi
+AC_SUBST(W_CUSTOM_PATH)
+
 #
 # Libs
 #
@@ -536,11 +560,25 @@ let file_mime = None
 let data_mime = None
 EOCONF
 else
+  if text =z "$w_CUSTOM_PATH"; then
     cat >> src/configure.ml <<EOCONF
 let magic_cookie = Magic.create ~flags:[[Magic.Mime; Magic.Symlink]] [[]]
 let file_mime = Some (Magic.file magic_cookie)
 let data_mime = Some (Magic.buffer magic_cookie)
 EOCONF
+  else
+    cat >> src/configure.ml <<EOCONF
+let magic_file  =
+  let cwd = Filename.dirname Sys.executable_name in
+  let magic = 
+    Utils.getenv ~default:(get_dir "magic/magic.mgc") "MAGIC"
+  in
+  Utils.resolve_path ~cwd magic
+let magic_cookie = Magic.create ~flags:[[Magic.Mime; Magic.Symlink]] [[magic_file]]
+let file_mime = Some (Magic.file magic_cookie)
+let data_mime = Some (Magic.buffer magic_cookie)
+EOCONF
+  fi
 fi
 
 #
@@ -565,23 +603,24 @@ else
     # Use Camomile with environment variables if
     # available
     if test -f $camdir/camomileLibraryDyn.cmi ; then
-      if test "$OS_TYPE" \!= "Win32" ; then
+      if test -z "$w_CUSTOM_PATH"; then
         camencoding=CamomileLibraryDyn.$camencoding
       else
-        # For win32, we use the functorial version 
-        # with our own config.
         camencoding="CamomileLibrary.CharEncoding.Configure(CamomileConfig)"
         cat >> src/configure.ml <<EOCONF
 module CamomileConfig = 
 struct
-  let datadir = Filename.concat "camomile" "database"
-  let localedir = Filename.concat "camomile" "locales"
-  let charmapdir = Filename.concat "camomile" "charmaps"
-  let unimapdir = Filename.concat "camomile" "mappings"
+  let datadir = Filename.concat (get_dir "camomile") "database"
+  let localedir = Filename.concat (get_dir "camomile") "locales"
+  let charmapdir = Filename.concat (get_dir "camomile") "charmaps"
+  let unimapdir = Filename.concat (get_dir "camomile") "mappings"
 end
 EOCONF
       fi
     else
+      if test -n "$w_CUSTOM_PATH"; then
+        AC_MSG_ERROR([Your camomile module is too old to support loading from a custom path.. Please upgrade it or disable custom path loading.])
+      fi
       if test -f $camdir/camomileLibrary.cmi ; then
         camencoding=CamomileLibrary.Default.$camencoding
       fi
@@ -834,6 +873,7 @@ cat <<EOMSG
  Version        : $OCAML_MAJOR.$OCAML_MINOR.$OCAML_REVISION
  OS             : $OS_TYPE
  Plugins        :$PLUGINS
+ Custom path    : $W_CUSTOM_PATH
  OCAML_CFLAGS   : $liquidsoap_ocamlcflags
  OCAML_LFLAGS   : $liquidsoap_ocamllflags
  CFLAGS         : $CFLAGS

doc/content/custom-path.txt

@@ -0,0 +1,80 @@
+title: Custom loading path
+
+h3. Basics
+
+Starting with version @1.0.1@, it is possible to build a liquidsoap binary that can load
+all its dependencies from any arbitrary path. This is very useful to distribute a liquidsoap
+bundled binary, independent of the distribution used.
+
+A custom loading path is a directory that contains the following file/directories:
+* @./camomile@: Camomile shared data. They are usually located in @/usr/(local/)share/camomile@
+* @./libs@: pervasive scripts. Their are located in @liquidsoap/scripts@ in liquidsoap's sources
+* @./log@: default log directories
+* @./magic@: directory for magic files. See below for more details.
+* @./plugins@: default plugins directory (most likely empty)
+* @./run@: default runtime files directory
+* @liquidtts@: @liquidtts@ script.
+
+h3. Adding liquidsoap binary
+
+In order to ship a liquidsoap binary which is independent of the distribution it will
+be run on, one need to also include its dynamic libraries, except for the most common.
+The following command may be used to list them:
+
+%%
+ldd ./liquidsoap | grep usr | cut -d' ' -f 3
+%%
+
+Those libraries are usually copied into a @./ld@ directory. Then, the @LD_LIBRARY_PATH@
+is used to point the dynamic loader to this directory.
+
+Finally, the @liquidsoap@ library is usually added in @./bin/liquidsoap@
+
+h3. Configuration variables
+
+In the following, configuration variables may refer to either absolute or relative paths. If referring to
+a relative path, the path is resolved relatively to the directory where the @liquidsoap@ binary
+is located at.
+
+In order to tell liquidsoap where its custom path is located, you need to set the 
+@LIQUIDSOAP_BASE_DIR@.
+
+Another important variable is @MAGIC@. It tells liquidsoap where to load the libmagic's
+definitions and defaults to @../magic/magic.mgc@. Older versions of libmagic may
+require to use @magic/magic.mime@ instead.
+
+h3. Full example
+
+For a fully-functional example, you can check our "heroku buildpack":https://github.com/savonet/heroku-buildpack-liquidsoap. 
+Its layout is:
+
+%%
+./bin
+./bin/liquidsoap
+./camomile
+./camomile/charmaps
+(...)
+./ld
+./ld/libao.so.2
+(...)
+./libs
+./libs/externals.liq
+(...)
+./liquidtts
+./log
+./magic
+./magic/magic.mime
+./plugins
+./run
+%%
+
+Its configuration variables are set to:
+
+%%
+LD_LIBRARY_PATH=/path/to/ld
+LIQUIDSOAP_BASE_DIR=..
+MAGIC=../magic/magic.mime
+%%
+
+As you can see, we use an old version of @libmagic@ so we need to load @magic.mime@ instead of @magic.mgc@.
+

doc/content/documentation.txt

@@ -13,6 +13,9 @@ just browse the "reference":reference.html and compose your dream stream.
 If you downloaded a source tarball of liquidsoap, you may first read the
 "build instructions":build.html.
 
+If you are looking for a way to build a distribution-independant bundle of
+liquidsoap, you may want to read the "custom path":custom-path.html page.
+
 h4@general. General tutorials
 
 * "Quickstart":quick_start.html: where anyone should start.

src/lang/lang_builtins.ml

@@ -1324,7 +1324,7 @@ let () =
             is not set."
     ["",Lang.string_t,None,None] Lang.string_t
     (fun p ->
-      Lang.string (Unix.getenv (Lang.to_string (List.assoc "" p))))
+      Lang.string (Utils.getenv ~default:"" (Lang.to_string (List.assoc "" p))))
 
 let () =
   add_builtin "setenv" ~cat:Sys

src/lang/lang_types.ml

@@ -20,12 +20,7 @@
 
  *****************************************************************************)
 
-let debug =
-  try
-    ignore (Sys.getenv "LIQUIDSOAP_DEBUG_LANG") ;
-    true
-  with
-    | Not_found -> false
+let debug = Utils.getenv_opt "LIQUIDSOAP_DEBUG_LANG" <> None
 
 (* Type information comes attached to the AST from the parsing,
  * with appropriate sharing of the type variables. Then the type inference

src/tools/utils.ml

@@ -28,6 +28,34 @@ external force_locale : unit -> unit = "liquidsoap_set_locale"
 let () = 
   force_locale ()
 
+(* Resolve a path. *)
+let resolve_path ?cwd path =
+  let cwd = 
+    match cwd with
+      | None     -> Sys.getcwd()
+      | Some cwd -> cwd
+  in
+  if Filename.is_relative path then
+   begin
+     Filename.concat cwd path
+   end
+  else
+    path
+
+(* Getenv with default value. *)
+let getenv ~default value =
+  try
+    Sys.getenv value
+  with
+    | Not_found -> default
+
+(* Getenv with option result. *)
+let getenv_opt value =
+  try
+    Some (Sys.getenv value)
+  with
+    | Not_found -> None
+
 (* Several list utilities *)
 
 let rec make_list n v = if n = 0 then [] else v::(make_list (n-1) v)
@@ -483,9 +511,7 @@ let rec mkdir ~perm dir =
 
 (** Expand ~ notation in filenames. *)
 let home_unrelate =
-  let home =
-    try Some (Sys.getenv "HOME") with Not_found -> None
-  in
+  let home = getenv_opt "HOME" in
   let unrel s =
     let len = String.length s in
       if len < 2 then
@@ -511,9 +537,9 @@ let home_unrelate =
 
 let get_tempdir () =
   if Sys.os_type = "Win32" then
-    (try Sys.getenv "TEMP" with Not_found -> "C:\temp")
+    getenv ~default:"C:\\temp" "TEMP"
   else
-    (try Sys.getenv "TMPDIR" with Not_found -> "/tmp")
+    getenv ~default:"/tmp" "TMPDIR"
 
 (** Decode Base64-encoded data *)
 let decode64 s =

src/tools/wav.ml

@@ -59,11 +59,7 @@ let () = Utils.register_error_translator error_translator
 
 (* open file and verify it has the right format *)  
 
-let debug =
-  try
-    ignore (Sys.getenv "LIQUIDSOAP_DEBUG_WAV") ; true
-  with
-    | Not_found -> false
+let debug = Utils.getenv_opt "LIQUIDSOAP_DEBUG_WAV" <> None
 
 let read_header read_ops ic =
   let really_input = read_ops.really_input in