cmd: refactor detection code and improve detection of project dir

3 files changed, 186 insertions, 171 deletions

diff --git a/src/luarocks/cmd.lua b/src/luarocks/cmd.lua
index 4397d43b..a46b0722 100644
--- a/src/luarocks/cmd.lua
+++ b/src/luarocks/cmd.lua
@@ -38,106 +38,6 @@ local function is_ownership_ok(directory)
    return false
 end
 
-local function exists(file)
-   local fd = io.open(file, "r")
-   if fd then
-      fd:close()
-      return true
-   end
-   return false
-end
-
-do
-   local function Q(pathname)
-      if pathname:match("^.:") then
-         return pathname:sub(1, 2) .. '"' .. pathname:sub(3) .. '"'
-      end
-      return '"' .. pathname .. '"'
-   end
-
-   local function check_lua_version(lua_exe, luaver)
-      if not exists(lua_exe) then
-         return nil
-      end
-      local lv, err = util.popen_read(Q(lua_exe) .. ' -e "io.write(_VERSION:sub(5))"')
-      if luaver and luaver ~= lv then
-         return nil
-      end
-      local ljv
-      if lv == "5.1" then
-         ljv = util.popen_read(Q(lua_exe) .. ' -e "io.write(tostring(jit and jit.version:sub(8)))"')
-         if ljv == "nil" then
-            ljv = nil
-         end
-      end
-      return lv, ljv
-   end
-
-   local find_lua_bindir
-   do
-      local exe_suffix = (package.config:sub(1, 1) == "\\" and ".exe" or "")
-
-      local function insert_lua_versions(names, luaver)
-         local variants = {
-            "lua" .. luaver .. exe_suffix,
-            "lua" .. luaver:gsub("%.", "") .. exe_suffix,
-            "lua-" .. luaver .. exe_suffix,
-            "lua-" .. luaver:gsub("%.", "") .. exe_suffix,
-         }
-         for _, name in ipairs(variants) do
-            names[name] = luaver
-            table.insert(names, name)
-         end
-      end
-
-      find_lua_bindir = function(prefix, luaver)
-         local names = {}
-         if luaver then
-            insert_lua_versions(names, luaver)
-         else
-            for v in util.lua_versions("descending") do
-               insert_lua_versions(names, v)
-            end
-         end
-         if luaver == "5.1" or not luaver then
-            table.insert(names, "luajit" .. exe_suffix)
-         end
-         table.insert(names, "lua" .. exe_suffix)
-
-         local bindirs = { prefix .. "/bin", prefix }
-         local tried = {}
-         for _, d in ipairs(bindirs) do
-            for _, name in ipairs(names) do
-               local lua_exe = dir.path(d, name)
-               table.insert(tried, lua_exe)
-               local lv, ljv = check_lua_version(lua_exe, luaver)
-               if lv then
-                  return name, d, lv, ljv
-               end
-            end
-         end
-         return nil, "Lua interpreter not found at " .. prefix .. "\n" ..
-                     "Tried:\t" .. table.concat(tried, "\n\t")
-      end
-   end
-
-   function cmd.find_lua(prefix, luaver)
-      local lua_interpreter, bindir, luajitver
-      lua_interpreter, bindir, luaver, luajitver = find_lua_bindir(prefix, luaver)
-      if not lua_interpreter then
-         return nil, bindir
-      end
-
-      return {
-         lua_version = luaver,
-         luajit_version = luajitver,
-         lua_interpreter = lua_interpreter,
-         lua_dir = prefix,
-         lua_bindir = bindir,
-      }
-   end
-end
-
 local function check_popen()
    local popen_ok, popen_result = pcall(io.popen, "")
    if popen_ok then
@@ -151,16 +51,17 @@ local function check_popen()
    end
 end
 
-local function find_project_dir()
-   local try = "."
-   for _ = 1, 10 do -- FIXME detect when root dir was hit instead
-      if exists(try .. "/.luarocks") and exists(try .. "/lua_modules") then
-         return try
-      elseif exists(try .. "/.luarocks-no-project") then
-         return nil
+local function check_if_config_is_present(detected, try)
+   local versions = detected.lua_version 
+                    and { detected.lua_version }
+                    or  util.lua_versions("descending")
+   return fun.find(versions, function(v)
+      if util.exists(dir.path(try, ".luarocks", "config-"..v..".lua")) then
+         detected.project_dir = try
+         detected.lua_version = v
+         return detected
       end
-      try = try .. "/.."
-   end
+   end)
 end
 
 local process_tree_flags
@@ -261,19 +162,6 @@ local function process_server_flags(flags)
    return true
 end
 
-local function find_lua_version_at(dirname)
-   local lua_version
-   for v in util.lua_versions("descending") do
-      if exists(dir.path(dirname, ".luarocks", "config-"..v..".lua")) then
-         lua_version = v
-         break
-      end
-   end
-   return {
-      lua_version = lua_version
-   }
-end
-
 --- Main command-line processor.
 -- Parses input arguments and calls the appropriate driver function
 -- to execute the action requested on the command-line, forwarding
@@ -375,47 +263,65 @@ function cmd.run_command(description, commands, external_namespace, ...)
       die("Invalid entry for --deps-mode.")
    end
 
-   local project_dir
-   if flags["project-tree"] then
-      project_dir = flags["project-tree"]:gsub("[/\\][^/\\]+$", "")
-   end
-
-   local lua_data
+   local detected
    if flags["lua-dir"] then
       local err
-      lua_data, err = cmd.find_lua(flags["lua-dir"], flags["lua-version"])
-      if not lua_data then
+      detected, err = util.find_lua(flags["lua-dir"], flags["lua-version"])
+      if not detected then
          die(err)
       end
+      assert(detected.lua_version)
+      assert(detected.lua_dir)
    elseif flags["lua-version"] then
       local path_sep = (package.config:sub(1, 1) == "\\" and ";" or ":")
       for bindir in os.getenv("PATH"):gmatch("[^"..path_sep.."]+") do
          local parentdir = bindir:gsub("[\\/][^\\/]+[\\/]?$", "")
-         lua_data = cmd.find_lua(dir.path(parentdir), flags["lua-version"])
-         if lua_data then
+         detected = util.find_lua(dir.path(parentdir), flags["lua-version"])
+         if detected then
             break
          end
-         lua_data = cmd.find_lua(bindir, flags["lua-version"])
-         if lua_data then
+         detected = util.find_lua(bindir, flags["lua-version"])
+         if detected then
             break
          end
       end
-      if not lua_data then
+      if not detected then
          util.warning("Could not find a Lua interpreter for version " ..
                       flags["lua-version"] .. " in your PATH. " ..
                       "Modules may not install with the correct configurations. " ..
                       "You may want to specify to the path prefix to your build " ..
                       "of Lua " .. flags["lua-version"] .. " using --lua-dir")
-         lua_data = {
+         detected = {
             lua_version = flags["lua-version"],
          }
       end
-   else
-      if not project_dir then
-         project_dir = find_project_dir()
+   end
+
+   if flags["project-tree"] then
+      local project_tree = flags["project-tree"]:gsub("[/\\][^/\\]+$", "")
+      detected = detected or {
+         project_dir = project_tree
+      }
+      local d = check_if_config_is_present(detected, project_tree)
+      if d then
+         detected = d
+      else
+         detected.project_dir = nil
       end
-      if project_dir then
-         lua_data = find_lua_version_at(project_dir)
+   else
+      detected = detected or {}
+      local try = "."
+      for _ = 1, 10 do -- FIXME detect when root dir was hit instead
+         if util.exists(try .. "/.luarocks") and util.exists(try .. "/lua_modules") then
+            local d = check_if_config_is_present(detected, try)
+            if d then
+               detected = d
+               break
+            end
+         elseif util.exists(try .. "/.luarocks-no-project") then
+            break
+         end
+         try = try .. "/.."
       end
    end
 
@@ -433,16 +339,16 @@ function cmd.run_command(description, commands, external_namespace, ...)
    end
 
    -----------------------------------------------------------------------------
-   local ok, err = cfg.init(lua_data, project_dir, util.warning)
+   local ok, err = cfg.init(detected, util.warning)
    if not ok then
       die(err)
    end
    -----------------------------------------------------------------------------
 
    fs.init()
-   
-   if project_dir then
-      project_dir = fs.absolute_name(project_dir)
+
+   if detected.project_dir then
+      detected.project_dir = fs.absolute_name(detected.project_dir)
    end
 
    if flags["version"] then
@@ -467,7 +373,7 @@ function cmd.run_command(description, commands, external_namespace, ...)
       die("Current directory does not exist. Please run LuaRocks from an existing directory.")
    end
 
-   ok, err = process_tree_flags(flags, project_dir)
+   ok, err = process_tree_flags(flags, detected.project_dir)
    if not ok then
       die(err)
    end
diff --git a/src/luarocks/core/cfg.lua b/src/luarocks/core/cfg.lua
index 5cfa10c3..670f04b2 100644
--- a/src/luarocks/core/cfg.lua
+++ b/src/luarocks/core/cfg.lua
@@ -535,8 +535,8 @@ local cfg = {}
 
 --- Initializes the LuaRocks configuration for variables, paths
 -- and OS detection.
--- @param lua_data table containing information pertaining the location
--- of Lua in the environment. All fields below are optional:
+-- @param detected table containing information detected about the 
+-- environment. All fields below are optional:
 -- * lua_version (in x.y format, e.g. "5.3")
 -- * luajit_version (complete, e.g. "2.1.0-beta3")
 -- * lua_bindir (e.g. "/usr/local/bin")
@@ -544,25 +544,25 @@ local cfg = {}
 -- * lua_libdir(e.g. "/usr/local/lib")
 -- * lua_dir (e.g. "/usr/local")
 -- * lua_interpreter (e.g. "lua-5.3")
--- @param project_dir a string with the path of the project directory
--- when using per-project environments, as created with `luarocks init`
+-- * project_dir (a string with the path of the project directory
+--   when using per-project environments, as created with `luarocks init`)
 -- @param warning a logging function for warnings that takes a string
 -- @return true on success; nil and an error message on failure.
-function cfg.init(lua_data, project_dir, warning)
-   lua_data = lua_data or {}
+function cfg.init(detected, warning)
+   detected = detected or {}
 
    local hc_ok, hardcoded = pcall(require, "luarocks.core.hardcoded")
    if not hc_ok then
       hardcoded = {}
    end
 
-   local lua_version = lua_data.lua_version or hardcoded.LUA_VERSION or _VERSION:sub(5)
-   local luajit_version = lua_data.luajit_version or hardcoded.LUAJIT_VERSION or (jit and jit.version:sub(8))
-   local lua_interpreter = lua_data.lua_interpreter or hardcoded.LUA_INTERPRETER or (arg and arg[-1] and arg[-1]:gsub(".*[\\/]", "")) or (is_windows and "lua.exe" or "lua")
-   local lua_bindir = lua_data.lua_bindir or hardcoded.LUA_BINDIR or (arg and arg[-1] and arg[-1]:gsub("[\\/][^\\/]+$", ""))
-   local lua_incdir = lua_data.lua_incdir or hardcoded.LUA_INCDIR
-   local lua_libdir = lua_data.lua_libdir or hardcoded.LUA_LIBDIR
-   local lua_dir = lua_data.lua_dir or hardcoded.LUA_DIR
+   local lua_version = detected.lua_version or hardcoded.LUA_VERSION or _VERSION:sub(5)
+   local luajit_version = detected.luajit_version or hardcoded.LUAJIT_VERSION or (jit and jit.version:sub(8))
+   local lua_interpreter = detected.lua_interpreter or hardcoded.LUA_INTERPRETER or (arg and arg[-1] and arg[-1]:gsub(".*[\\/]", "")) or (is_windows and "lua.exe" or "lua")
+   local lua_bindir = detected.lua_bindir or hardcoded.LUA_BINDIR or (arg and arg[-1] and arg[-1]:gsub("[\\/][^\\/]+$", ""))
+   local lua_incdir = detected.lua_incdir or hardcoded.LUA_INCDIR
+   local lua_libdir = detected.lua_libdir or hardcoded.LUA_LIBDIR
+   local lua_dir = detected.lua_dir or hardcoded.LUA_DIR
    
    local init = cfg.init
 
@@ -638,8 +638,8 @@ function cfg.init(lua_data, project_dir, warning)
       local name = "config-"..cfg.lua_version..".lua"
       sys_config_file = (cfg.sysconfdir .. "/" .. name):gsub("\\", "/")
       home_config_file = (cfg.homeconfdir .. "/" .. name):gsub("\\", "/")
-      if project_dir then
-         project_config_file = project_dir .. "/.luarocks/" .. name
+      if detected.project_dir then
+         project_config_file = detected.project_dir .. "/.luarocks/" .. name
       end
    end
 
@@ -682,7 +682,7 @@ function cfg.init(lua_data, project_dir, warning)
       end
 
       -- finally, use the project-specific config file if any
-      if project_dir then
+      if detected.project_dir then
          project_config_ok, err = load_config_file(cfg, platforms, project_config_file)
          if err then
             return nil, err, "config"
@@ -695,14 +695,14 @@ function cfg.init(lua_data, project_dir, warning)
    -- Let's finish up the cfg table.
    ----------------------------------------
 
-   -- Settings given via lua_data (i.e. --lua-dir) take precedence over config files:
-   cfg.lua_version = lua_data.lua_version or cfg.lua_version
-   cfg.luajit_version = lua_data.luajit_version or cfg.luajit_version
-   cfg.lua_interpreter = lua_data.lua_interpreter or cfg.lua_interpreter
-   cfg.variables.LUA_BINDIR = lua_data.lua_bindir or cfg.variables.LUA_BINDIR or lua_bindir
-   cfg.variables.LUA_INCDIR = lua_data.lua_incdir or cfg.variables.LUA_INCDIR or lua_incdir
-   cfg.variables.LUA_LIBDIR = lua_data.lua_libdir or cfg.variables.LUA_LIBDIR or lua_libdir
-   cfg.variables.LUA_DIR = lua_data.lua_dir or cfg.variables.LUA_DIR or lua_dir
+   -- Settings detected or given via the CLI (i.e. --lua-dir) take precedence over config files:
+   cfg.lua_version = detected.lua_version or cfg.lua_version
+   cfg.luajit_version = detected.luajit_version or cfg.luajit_version
+   cfg.lua_interpreter = detected.lua_interpreter or cfg.lua_interpreter
+   cfg.variables.LUA_BINDIR = detected.lua_bindir or cfg.variables.LUA_BINDIR or lua_bindir
+   cfg.variables.LUA_INCDIR = detected.lua_incdir or cfg.variables.LUA_INCDIR or lua_incdir
+   cfg.variables.LUA_LIBDIR = detected.lua_libdir or cfg.variables.LUA_LIBDIR or lua_libdir
+   cfg.variables.LUA_DIR = detected.lua_dir or cfg.variables.LUA_DIR or lua_dir
 
    -- Build a default list of rocks trees if not given
    if cfg.rocks_trees == nil then
@@ -739,7 +739,7 @@ function cfg.init(lua_data, project_dir, warning)
 
    function cfg.which_config()
       return {
-         project = project_dir and {
+         project = detected.project_dir and {
             file = project_config_file,
             ok = project_config_ok,
          },
diff --git a/src/luarocks/util.lua b/src/luarocks/util.lua
index 7d7ce921..25c521ea 100644
--- a/src/luarocks/util.lua
+++ b/src/luarocks/util.lua
@@ -548,4 +548,113 @@ function util.require_json()
    return nil, errmsg
 end
 
+-- A portable version of fs.exists that can be used at early startup,
+-- before the platform has been determined and luarocks.fs has been
+-- initialized.
+function util.exists(file)
+   local fd, _, code = io.open(file, "r")
+   if code == 13 then
+      -- code 13 means "Permission denied" on both Unix and Windows
+      -- io.open on folders always fails with code 13 on Windows
+      return true
+   end
+   if fd then
+      fd:close()
+      return true
+   end
+   return false
+end
+
+do
+   local function Q(pathname)
+      if pathname:match("^.:") then
+         return pathname:sub(1, 2) .. '"' .. pathname:sub(3) .. '"'
+      end
+      return '"' .. pathname .. '"'
+   end
+
+   function util.check_lua_version(lua_exe, luaver)
+      if not util.exists(lua_exe) then
+         return nil
+      end
+      local lv, err = util.popen_read(Q(lua_exe) .. ' -e "io.write(_VERSION:sub(5))"')
+      if luaver and luaver ~= lv then
+         return nil
+      end
+      local ljv
+      if lv == "5.1" then
+         ljv = util.popen_read(Q(lua_exe) .. ' -e "io.write(tostring(jit and jit.version:sub(8)))"')
+         if ljv == "nil" then
+            ljv = nil
+         end
+      end
+      return lv, ljv
+   end
+
+   local find_lua_bindir
+   do
+      local exe_suffix = (package.config:sub(1, 1) == "\\" and ".exe" or "")
+
+      local function insert_lua_variants(names, luaver)
+         local variants = {
+            "lua" .. luaver .. exe_suffix,
+            "lua" .. luaver:gsub("%.", "") .. exe_suffix,
+            "lua-" .. luaver .. exe_suffix,
+            "lua-" .. luaver:gsub("%.", "") .. exe_suffix,
+         }
+         for _, name in ipairs(variants) do
+            names[name] = luaver
+            table.insert(names, name)
+         end
+      end
+
+      find_lua_bindir = function(prefix, luaver)
+         local names = {}
+         if luaver then
+            insert_lua_variants(names, luaver)
+         else
+            for v in util.lua_variants("descending") do
+               insert_lua_variants(names, v)
+            end
+         end
+         if luaver == "5.1" or not luaver then
+            table.insert(names, "luajit" .. exe_suffix)
+         end
+         table.insert(names, "lua" .. exe_suffix)
+
+         local bindirs = { prefix .. "/bin", prefix }
+         local tried = {}
+         for _, d in ipairs(bindirs) do
+            for _, name in ipairs(names) do
+               local lua_exe = d .. "/" .. name
+               table.insert(tried, lua_exe)
+               local lv, ljv = util.check_lua_version(lua_exe, luaver)
+               if lv then
+                  return name, d, lv, ljv
+               end
+            end
+         end
+         return nil, "Lua interpreter not found at " .. prefix .. "\n" ..
+                     "Tried:\t" .. table.concat(tried, "\n\t")
+      end
+   end
+
+   function util.find_lua(prefix, luaver)
+      local lua_interpreter, bindir, luajitver
+      lua_interpreter, bindir, luaver, luajitver = find_lua_bindir(prefix, luaver)
+      if not lua_interpreter then
+         return nil, bindir
+      end
+
+      return {
+         lua_version = luaver,
+         luajit_version = luajitver,
+         lua_interpreter = lua_interpreter,
+         lua_dir = prefix,
+         lua_bindir = bindir,
+      }
+   end
+end
+
 return util
+