Refactor core check modules

* Move chstate methods for creating warnings into modules doing detection,
  to make them more isolated and easier to test.
* Minor refactoring and renaming.
* Fix a bug when reporting unused mutually recursive functions as
  unused values.

CHANGELOG.md

@@ -8,6 +8,11 @@
   functions with complexity higher than a configurable limit; disabled
   by default (#141).
 
+### Fixes
+
+* Fixed errors or incorrect reporting when unused mutually recursive functions
+  have other values assigned to their local variables.
+
 ## 0.21.2 (2017-11-13)
 
 ### Fixes

install.lua

@@ -94,42 +94,42 @@ end
 print("    Installing luacheck modules into " .. luacheck_src_dir)
 mkdir(luacheck_lib_dir)
 
-for _, filename in ipairs {
-      "main.lua",
+for _, filename in ipairs({
       "init.lua",
+      "argparse.lua",
+      "builtin_standards.lua",
+      "cache.lua",
+      "check.lua",
       "config.lua",
-      "linearize.lua",
-      "analyze.lua",
       "core_utils.lua",
-      "check.lua",
-      "parser.lua",
-      "lexer.lua",
-      "filter.lua",
-      "options.lua",
-      "inline_options.lua",
-      "builtin_standards.lua",
-      "love_standard.lua",
-      "ngx_standard.lua",
+      "detect_bad_whitespace.lua",
+      "detect_cyclomatic_complexity.lua",
+      "detect_globals.lua",
+      "detect_uninit_access.lua",
+      "detect_unreachable_code.lua",
+      "detect_unused_locals.lua",
+      "detect_unused_rec_funcs.lua",
       "expand_rockspec.lua",
-      "multithreading.lua",
-      "cache.lua",
+      "filter.lua",
       "format.lua",
-      "version.lua",
       "fs.lua",
       "globbing.lua",
-      "utils.lua",
-      "argparse.lua",
-      "whitespace.lua",
-      "detect_cyclomatic_complexity.lua",
-      "detect_globals.lua",
-      "standards.lua",
-      "lua_fs.lua",
+      "inline_options.lua",
+      "lexer.lua",
       "lfs_fs.lua",
-      "detect_unused_rec_funcs.lua",
-      "detect_unreachable_code.lua",
-      "detect_uninit_access.lua",
+      "linearize.lua",
+      "love_standard.lua",
+      "lua_fs.lua",
+      "main.lua",
       "name_functions.lua",
-      "detect_unused_locals.lua"} do
+      "multithreading.lua",
+      "ngx_standard.lua",
+      "options.lua",
+      "parser.lua",
+      "resolve_locals.lua",
+      "standards.lua",
+      "utils.lua",
+      "version.lua"}) do
    copy("src" .. dirsep .. "luacheck" .. dirsep .. filename, luacheck_lib_dir)
 end
 

luacheck-dev-1.rockspec

@@ -19,13 +19,13 @@ build = {
    type = "builtin",
    modules = {
       luacheck = "src/luacheck/init.lua",
-      ["luacheck.analyze"] = "src/luacheck/analyze.lua",
       ["luacheck.argparse"] = "src/luacheck/argparse.lua",
       ["luacheck.builtin_standards"] = "src/luacheck/builtin_standards.lua",
       ["luacheck.cache"] = "src/luacheck/cache.lua",
       ["luacheck.check"] = "src/luacheck/check.lua",
       ["luacheck.config"] = "src/luacheck/config.lua",
       ["luacheck.core_utils"] = "src/luacheck/core_utils.lua",
+      ["luacheck.detect_bad_whitespace"] = "src/luacheck/detect_bad_whitespace.lua",
       ["luacheck.detect_cyclomatic_complexity"] = "src/luacheck/detect_cyclomatic_complexity.lua",
       ["luacheck.detect_globals"] = "src/luacheck/detect_globals.lua",
       ["luacheck.detect_uninit_access"] = "src/luacheck/detect_uninit_access.lua",
@@ -49,10 +49,10 @@ build = {
       ["luacheck.ngx_standard"] = "src/luacheck/ngx_standard.lua",
       ["luacheck.options"] = "src/luacheck/options.lua",
       ["luacheck.parser"] = "src/luacheck/parser.lua",
+      ["luacheck.resolve_locals"] = "src/luacheck/resolve_locals.lua",
       ["luacheck.standards"] = "src/luacheck/standards.lua",
       ["luacheck.utils"] = "src/luacheck/utils.lua",
-      ["luacheck.version"] = "src/luacheck/version.lua",
-      ["luacheck.whitespace"] = "src/luacheck/whitespace.lua"
+      ["luacheck.version"] = "src/luacheck/version.lua"
    },
    install = {
       bin = {

spec/check_spec.lua

@@ -250,6 +250,25 @@ end
 ]])
    end)
 
+   it("detects unused mutually recursive functions as values", function()
+      assert.same({
+         {code = "311", name = "odd", line = 5, column = 10, end_column = 12},
+         {code = "311", name = "even", line = 9, column = 10, end_column = 13}
+      }, check[[
+local even = 2
+local odd = 3
+(...)(even, odd)
+
+function odd(x)
+   return x == 1 or even(x - 1)
+end
+
+function even(x)
+   return x == 0 or odd(x - 1) or even(x)
+end
+]])
+   end)
+
    it("does not incorrectly detect unused recursive functions inside unused functions", function()
       assert.same({
          {code = "211", name = "unused", func = true, line = 1, column = 16, end_column = 21}

spec/cli_spec.lua

@@ -915,7 +915,7 @@ spec/samples/bad_code.lua
 local A,B,C,D,E,F="package","711","helper","function","embrace","hepler";return {{{"112",A,1,1,7,[23]={A,"loaded",true}},{B,[3]=1,[4]=1,[5]=1,[27]=1,[29]="main_chunk"},{B,[3]=3,[4]=7,[5]=14,[27]=1,[28]=C,[29]=D},{"211",C,3,16,21,[10]=true},{"212","...",3,23,25},{B,[3]=7,[4]=1,[5]=8,[27]=2,[28]=E,[29]=D},{"111",E,7,10,16,[11]=true,[23]={E}},{"412","opt",8,10,12,7,18},{"113",F,9,11,16,[23]={F}}},{},{24,0,26,9,3,0,21,31,26,3,0},{[4]="comment"}}
 spec/samples/python_code.lua
 (%d+)
-return {{{"011",[3]=1,[4]=6,[5]=15,[12]="expected '=' near '__future__'"}},{},{}}
+return {{{"011",[3]=1,[4]=6,[5]=15,[12]="expected '=' near '__future__'"}},{},{},{}}
 ]]):gsub("[%[%]]", "%%%0")))
          -- luacheck: pop
 
@@ -934,10 +934,10 @@ return {{{"011",[3]=1,[4]=6,[5]=15,[12]="expected '=' near '__future__'"}},{},{}
 %s
 spec/samples/python_code.lua
 %s
-return {{{"111", "global", 1, 1, [23]={"global"}}, {"321", "uninit", 6, 8}},{},{}}
+return {{{"111", "global", 1, 1, [23]={"global"}}, {"321", "uninit", 6, 8}},{},{},{}}
 spec/samples/good_code.lua
 %s
-return {{{"011",[3]=5,[4]=7,[12]="this code is actually bad"}},{},{}}
+return {{{"011",[3]=5,[4]=7,[12]="this code is actually bad"}},{},{},{}}
 spec/samples/bad_code.lua
 %s
 return {{},{},{}}]]):format(version, python_mtime, good_mtime, tostring(tonumber(bad_mtime) - 1)))

spec/linearize_spec.lua

@@ -1,20 +1,11 @@
 local linearize = require "luacheck.linearize"
 local parser = require "luacheck.parser"
-local utils = require "luacheck.utils"
-
-local ChState = utils.class()
-
-function ChState.__init() end
-function ChState.warn_redefined() end
-function ChState.warn_global() end
-function ChState.warn_unused_label() end
-function ChState.warn_unbalanced() end
-function ChState.warn_empty_block() end
 
 local function get_line_(src)
    local ast = parser.parse(src)
-   local chstate = ChState()
-   return linearize(chstate, ast)
+   local chstate = {ast = ast, warnings = {}}
+   linearize(chstate)
+   return chstate.main_line
 end
 
 local function get_line(src)

spec/analyze_spec.lua → spec/resolve_locals_spec.lua

@@ -1,35 +1,6 @@
-local analyze = require "luacheck.analyze"
 local linearize = require "luacheck.linearize"
 local parser = require "luacheck.parser"
-local utils = require "luacheck.utils"
-
-local ChState = utils.class()
-
-function ChState.__init() end
-function ChState.warn_redefined() end
-function ChState.warn_global() end
-function ChState.warn_unused_label() end
-function ChState.warn_unused_variable() end
-function ChState.warn_unused_value() end
-function ChState.warn_unset() end
-
-local function get_line_(src)
-   local ast = parser.parse(src)
-   local chstate = ChState()
-   return linearize(chstate, ast)
-end
-
-local function get_line(src)
-   local ok, res = pcall(get_line_, src)
-
-   if ok then
-      return res
-   elseif type(res) == "table" then
-      return nil
-   else
-      error(res, 0)
-   end
-end
+local resolve_locals = require "luacheck.resolve_locals"
 
 local function used_variables_to_string(item)
    local buf = {}
@@ -49,12 +20,14 @@ local function used_variables_to_string(item)
 end
 
 local function get_used_variables_as_string(src)
-   local line = get_line(src)
-   analyze(line)
+   local ast = parser.parse(src)
+   local chstate = {ast = ast, warnings = {}}
+   linearize(chstate)
+   resolve_locals(chstate)
 
    local buf = {}
 
-   for _, item in ipairs(line.items) do
+   for _, item in ipairs(chstate.main_line.items) do
       if item.accesses and next(item.accesses) then
          assert.is_table(item.used_values)
          table.insert(buf, used_variables_to_string(item))
@@ -64,7 +37,7 @@ local function get_used_variables_as_string(src)
    return table.concat(buf, "\n")
 end
 
-describe("analyze", function()
+describe("resolve_locals", function()
    describe("when resolving values", function()
       it("resolves values in linear cases", function()
          assert.equal([[