Merge pull request #66 from a2/a2/compound-operators

Add support for compound operators

README.md

@@ -115,7 +115,7 @@ Use the Luacheck issue tracker on GitHub to submit bugs, suggestions and questio
 
 ## Building and testing
 
-After the Luacheck repo is cloned and changes are made, run `luarocks make` (using `sudo` if necessary) from its root directory to install dev version of Luacheck. To run Luacheck using sources in current directory without installing it, run `lua -e 'package.path="./src/?.lua;./src/?/init.lua;"..package.path' bin/luacheck.lua ...`. To test Luacheck, ensure that you have [busted](http://olivinelabs.com/busted/) and [luautf8](https://github.com/starwing/luautf8) installed and run `busted`.
+After the Luacheck repo is cloned and changes are made, run `luarocks make` (using `sudo` if necessary) from its root directory to install dev version of Luacheck. To run Luacheck using sources in current directory without installing it, run `lua -e 'package.path="./src/?.lua;./src/?/init.lua;"..package.path' bin/luacheck.lua ...`. To test Luacheck, ensure that you have [busted](http://olivinelabs.com/busted/), [luautf8](https://github.com/starwing/luautf8), and [luasocket](https://github.com/lunarmodules/luasocket) installed and run `busted`.
 
 ## Docker
 

docsrc/cli.rst

@@ -119,6 +119,7 @@ Option                                  Meaning
 ``--ignore | -i <patt> [<patt>] ...``   Filter out warnings matching patterns.
 ``--enable | -e <patt> [<patt>] ...``   Do not filter out warnings matching patterns.
 ``--only | -o <patt> [<patt>] ...``     Filter out warnings not matching patterns.
+``--operators <patt> [<patt>] ...``     Allow compound operators matching patterns. (Multiple assignment not supported, as this is specifically for the Playdate SDK.)
 ``--config <config>``                   Path to custom configuration file (default: ``.luacheckrc``).
 ``--no-config``                         Do not look up custom configuration file.
 ``--default-config <config>``           Default path to custom configuration file, to be used if ``--[no-]config`` is not used and ``.luacheckrc`` is not found.

docsrc/config.rst

@@ -42,6 +42,7 @@ Option                        Type                                     Default v
 ``read_globals``              Array of strings or field definition map ``{}``
 ``new_read_globals``          Array of strings or field definition map (Do not overwrite)
 ``not_globals``               Array of strings                         ``{}``
+``operators``                 Array of strings                         ``{}``
 ``compat``                    Boolean                                  ``false``
 ``allow_defined``             Boolean                                  ``false``
 ``allow_defined_top``         Boolean                                  ``false``

docsrc/warnings.rst

@@ -10,6 +10,7 @@ Code Description
 021  An invalid inline option.
 022  An unpaired inline push directive.
 023  An unpaired inline pop directive.
+033  Invalid use of a compound operator. (Lua doesn't support compound operator by default; if using an extension that does, please set the operators option.)
 111  Setting an undefined global variable.
 112  Mutating an undefined global variable.
 113  Accessing an undefined global variable.

luacheck-dev-1.rockspec

@@ -68,6 +68,7 @@ build = {
       ["luacheck.serializer"] = "src/luacheck/serializer.lua",
       ["luacheck.stages"] = "src/luacheck/stages/init.lua",
       ["luacheck.stages.detect_bad_whitespace"] = "src/luacheck/stages/detect_bad_whitespace.lua",
+      ["luacheck.stages.detect_compound_operators"] = "src/luacheck/stages/detect_compound_operators.lua",
       ["luacheck.stages.detect_cyclomatic_complexity"] = "src/luacheck/stages/detect_cyclomatic_complexity.lua",
       ["luacheck.stages.detect_empty_blocks"] = "src/luacheck/stages/detect_empty_blocks.lua",
       ["luacheck.stages.detect_empty_statements"] = "src/luacheck/stages/detect_empty_statements.lua",

spec/cli_spec.lua

@@ -295,6 +295,36 @@ Total: 5 warnings / 0 errors in 1 file
 ]], get_output "--std lua51+lua52+lua53 spec/samples/bad_code.lua --no-config")
    end)
 
+   it("raises critical errors on config without additional operators", function()
+      assert.equal([[Checking spec/samples/compound_operators.lua      4 errors
+
+    spec/samples/compound_operators.lua:2:1: assignment uses compound operator +=
+    spec/samples/compound_operators.lua:3:1: assignment uses compound operator -=
+    spec/samples/compound_operators.lua:4:1: assignment uses compound operator *=
+    spec/samples/compound_operators.lua:5:1: assignment uses compound operator /=
+
+Total: 0 warnings / 4 errors in 1 file
+]], get_output "spec/samples/compound_operators.lua --no-config")
+   end)
+
+   it("raises critical errors for unfiltered additional operators", function()
+      assert.equal([[Checking spec/samples/compound_operators.lua      3 errors
+
+    spec/samples/compound_operators.lua:3:1: assignment uses compound operator -=
+    spec/samples/compound_operators.lua:4:1: assignment uses compound operator *=
+    spec/samples/compound_operators.lua:5:1: assignment uses compound operator /=
+
+Total: 0 warnings / 3 errors in 1 file
+]], get_output "spec/samples/compound_operators.lua --no-config --operators +=")
+   end)
+
+   it("allows to define allowed compound operators", function()
+      assert.equal([[Checking spec/samples/compound_operators.lua      OK
+
+Total: 0 warnings / 0 errors in 1 file
+]], get_output "spec/samples/compound_operators.lua --config=spec/configs/compound_operators_config.luacheckrc")
+   end)
+
    it("allows to ignore some variables", function()
       assert.equal([[
 Checking spec/samples/bad_code.lua                3 warnings
@@ -993,7 +1023,7 @@ spec/samples/python_code.lua:1:6: (E011) expected '=' near '__future__'
    end)
 
    it("expands folders", function()
-      assert.matches("^Total: %d+ warnings / %d+ errors in 26 files\n$", get_output "spec/samples -qqq --no-config --exclude-files spec/samples/global_fields.lua")
+      assert.matches("^Total: %d+ warnings / %d+ errors in 27 files\n$", get_output "spec/samples -qqq --no-config --exclude-files spec/samples/global_fields.lua")
    end)
 
    it("uses --include-files when expanding folders", function()
@@ -1205,6 +1235,7 @@ Codes: true
             assert.equal(([[
 Checking spec/samples/argparse-0.2.0.lua          9 warnings
 Checking spec/samples/compat.lua                  4 warnings
+Checking spec/samples/compound_operators.lua      4 errors
 Checking spec/samples/custom_std_inline_options.lua 3 warnings / 1 error
 Checking spec/samples/global_inline_options.lua   3 warnings
 Checking spec/samples/globals.lua                 2 warnings
@@ -1221,7 +1252,7 @@ Checking spec/samples/unused_secondaries.lua      4 warnings
 Checking spec/samples/utf8.lua                    4 warnings
 Checking spec/samples/utf8_error.lua              1 error
 
-Total: 73 warnings / 5 errors in 19 files
+Total: 73 warnings / 9 errors in 20 files
 ]]):gsub("(spec/samples)/", "%1"..package.config:sub(1, 1)),
             get_output "spec/samples --config=spec/configs/exclude_files_config.luacheckrc -qq --exclude-files spec/samples/global_fields.lua")
          end)
@@ -1230,6 +1261,7 @@ Total: 73 warnings / 5 errors in 19 files
             assert.equal([[
 Checking argparse-0.2.0.lua                       9 warnings
 Checking compat.lua                               4 warnings
+Checking compound_operators.lua                   4 errors
 Checking custom_std_inline_options.lua            3 warnings / 1 error
 Checking global_inline_options.lua                3 warnings
 Checking globals.lua                              2 warnings
@@ -1246,14 +1278,15 @@ Checking unused_secondaries.lua                   4 warnings
 Checking utf8.lua                                 4 warnings
 Checking utf8_error.lua                           1 error
 
-Total: 73 warnings / 5 errors in 19 files
+Total: 73 warnings / 9 errors in 20 files
 ]], get_output(". --config=spec/configs/exclude_files_config.luacheckrc -qq --exclude-files global_fields.lua", "spec/samples/"))
          end)
 
          it("combines excluded files from config and cli", function()
             assert.equal([[
 Checking argparse-0.2.0.lua                       9 warnings
 Checking compat.lua                               4 warnings
+Checking compound_operators.lua                   4 errors
 Checking custom_std_inline_options.lua            3 warnings / 1 error
 Checking global_inline_options.lua                3 warnings
 Checking globals.lua                              2 warnings
@@ -1268,7 +1301,7 @@ Checking unused_secondaries.lua                   4 warnings
 Checking utf8.lua                                 4 warnings
 Checking utf8_error.lua                           1 error
 
-Total: 65 warnings / 5 errors in 17 files
+Total: 65 warnings / 9 errors in 18 files
 ]], get_output(". --config=spec/configs/exclude_files_config.luacheckrc -qq --exclude-files global_fields.lua --exclude-files " .. quote("./read*"), "spec/samples/"))
          end)
 

spec/configs/compound_operators_config.luacheckrc

@@ -0,0 +1 @@
+operators = {"+=", "-=", "*=", "/="}

spec/samples/compound_operators.lua

@@ -0,0 +1,6 @@
+local i = 0
+i += 10
+i -= 5
+i *= 2
+i /= 5
+return i

src/luacheck/builtin_standards/init.lua

@@ -311,7 +311,7 @@ builtin_standards.luacheckrc = {
       "allow_defined_top", "module", "globals", "read_globals", "new_globals", "new_read_globals", "not_globals",
       "ignore", "enable", "only", "std", "max_line_length", "max_code_line_length", "max_string_line_length",
       "max_comment_line_length", "max_cyclomatic_complexity", "quiet", "color", "codes", "ranges", "formatter",
-      "cache", "jobs", "files", "stds", "exclude_files", "include_files"
+      "cache", "jobs", "files", "stds", "exclude_files", "include_files", "operators"
    }
 }
 

src/luacheck/filter.lua

@@ -163,6 +163,15 @@ local function passes_filter(normalized_options, warning)
       end
 
       warning.max_complexity = max_complexity
+   elseif warning.code == "033" then
+      local operators = normalized_options.operators or {}
+      for _, op in ipairs(operators) do
+         if warning.operator == op then
+            return false
+         end
+      end
+
+      return true
    elseif warning.code:find("^[234]") and warning.name == "_" and not warning.useless then
       return false
    elseif warning.code:find("^1[14]") then

src/luacheck/main.lua

@@ -65,6 +65,12 @@ Links:
          :action "concat"
          :init(nil),
       parser:option("--only -o", "Filter out warnings not matching these patterns.")
+         :args "+"
+         :count "*"
+         :argname "<patt>"
+         :action "concat"
+         :init(nil),
+      parser:option("--operators", "Allow compound operators matching patterns")
          :args "+"
          :count "*"
          :argname "<patt>"

src/luacheck/options.lua

@@ -70,7 +70,7 @@ options.variadic_inline_options = {
    not_globals = array_of_strings,
    ignore = array_of_strings,
    enable = array_of_strings,
-   only = array_of_strings
+   only = array_of_strings,
 }
 
 options.all_options = {
@@ -79,7 +79,8 @@ options.all_options = {
    max_code_line_length = number_or_false,
    max_string_line_length = number_or_false,
    max_comment_line_length = number_or_false,
-   max_cyclomatic_complexity = number_or_false
+   max_cyclomatic_complexity = number_or_false,
+   operators = array_of_strings
 }
 
 utils.update(options.all_options, options.nullary_inline_options)
@@ -385,6 +386,26 @@ local function normalize_patterns(rules)
    return res
 end
 
+local function get_operators(opts_stack)
+   local operators, operatorsMap = nil, nil
+
+   for _, opts in ipairs(opts_stack) do
+      if opts.operators then
+         operators = operators or {}
+         operatorsMap = operatorsMap or {}
+
+         for _, op in ipairs(opts.operators) do
+            if not operatorsMap[op] then
+               table.insert(operators, op)
+               operatorsMap[op] = true
+            end
+         end
+      end
+   end
+
+   return operators
+end
+
 local scalar_options = {
    unused_secondaries = true,
    self = true,
@@ -404,6 +425,7 @@ function options.normalize(opts_stack, stds)
    local res = {}
    stds = stds or builtin_standards
    res.std = get_final_std(opts_stack, stds)
+   res.operators = get_operators(opts_stack)
 
    for option, default in pairs(scalar_options) do
       res[option] = get_scalar_opt(opts_stack, option, default)

src/luacheck/parser.lua

@@ -572,6 +572,16 @@ local binary_operators = {
    ["and"] = "and", ["or"] = "or"
 }
 
+local compound_operators = {
+   ["+"] = "add", ["-"] = "sub",
+   ["*"] = "mul", ["%"] = "mod",
+   ["^"] = "pow",
+   ["/"] = "div", ["//"] = "idiv",
+   ["&"] = "band", ["|"] = "bor", ["~"] = "bxor",
+   ["<<"] = "shl", [">>"] = "shr",
+   [".."] = "concat"
+}
+
 local left_priorities = {
    add = 10, sub = 10,
    mul = 11, mod = 11,
@@ -903,9 +913,31 @@ local function parse_expression_statement(state)
       lhs[#lhs + 1] = primary_expression
    until not test_and_skip_token(state, ",")
 
-   check_and_skip_token(state, "=")
-   local rhs = parse_expression_list(state)
-   return new_inner_node(start_range, rhs[#rhs], "Set", {lhs, rhs})
+   local compound_operator = compound_operators[state.token]
+   if compound_operator then
+      -- This is an assignment in the form `lhs op= rhs`.
+
+      if #lhs ~= 1 then
+         -- Multiple lhs values are not valid
+         parse_error(state, "compound assignment not allowed on tuples near " .. compound_operator .. "=")
+      end
+
+      -- Skip operator.
+      skip_token(state)
+      check_and_skip_token(state, "=")
+
+      local rhs = parse_expression_list(state)
+      if #rhs ~= 1 then
+         parse_error(state, "compound assignment not allowed on tuples near " .. compound_operator .. "=")
+      end
+
+      return new_inner_node(start_range, rhs[1], "OpSet", {compound_operator, lhs[1], rhs[1]})
+   else
+      -- This is an assignment in the form `lhs = rhs`.
+      check_and_skip_token(state, "=")
+      local rhs = parse_expression_list(state)
+      return new_inner_node(start_range, rhs[#rhs], "Set", {lhs, rhs})
+   end
 end
 
 local function parse_statement(state)

src/luacheck/serializer.lua

@@ -9,7 +9,7 @@ local option_fields = {
    "unused_secondaries", "allow_defined", "allow_defined_top", "module",
    "read_globals", "new_globals", "new_read_globals", "enable", "only", "not_globals",
    "max_line_length", "max_code_line_length", "max_string_line_length", "max_comment_line_length",
-   "max_cyclomatic_complexity"
+   "max_cyclomatic_complexity", "operators"
 }
 
 local function compress_table(t, fields)

src/luacheck/stages/detect_compound_operators.lua

@@ -0,0 +1,34 @@
+local core_utils = require "luacheck.core_utils"
+
+local stage = {}
+
+stage.warnings = {
+    ["033"] = {message_format = "assignment uses compound operator {operator}", fields = {"operator"}},
+}
+
+local reverse_compound_operators = {
+    add = "+=",
+    sub = "-=",
+    mul = "*=",
+    mod = "%=",
+    pow = "^=",
+    div = "/=",
+    idiv = "//=",
+    band = "&=",
+    bor = "|=",
+    bxor = "~=",
+    shl = "<<=",
+    shr = ">>=",
+    concat = "..="
+}
+
+local function check_node(chstate, node)
+    local operator = reverse_compound_operators[node[1]]
+    chstate:warn_range("033", node, {operator = operator})
+end
+
+function stage.run(chstate)
+    core_utils.each_statement(chstate, { "OpSet" }, check_node)
+end
+
+return stage

src/luacheck/stages/init.lua

@@ -16,6 +16,7 @@ stages.names = {
    "name_functions",
    "resolve_locals",
    "detect_bad_whitespace",
+   "detect_compound_operators",
    "detect_cyclomatic_complexity",
    "detect_empty_blocks",
    "detect_empty_statements",

src/luacheck/stages/linearize.lua

@@ -199,6 +199,19 @@ local function new_set_item(node)
    }
 end
 
+local function new_opset_item(node)
+   return {
+      tag = "OpSet",
+      node = node,
+      lhs = node[2],
+      rhs = node[3],
+      accesses = {},
+      mutations = {},
+      used_values = {},
+      lines = {}
+   }
+end
+
 local function is_unpacking(node)
    return node.tag == "Dots" or node.tag == "Call" or node.tag == "Invoke"
 end
@@ -515,6 +528,24 @@ function LinState:emit_stmt_Set(node)
    self:emit(item)
 end
 
+function LinState:emit_stmt_OpSet(node)
+   local item = new_opset_item(node)
+   self:scan_expr(item, node[3])
+
+   local lhs = node[2]
+   if lhs.tag == "Id" then
+      local var = self:check_var(lhs)
+
+      if var then
+         self:register_upvalue_action(item, var, "set_upvalues")
+      end
+   else
+      assert(lhs.tag == "Index")
+      self:scan_lhs_index(item, lhs)
+   end
+
+   self:emit(item)
+end
 
 function LinState:scan_expr(item, node)
    local scanner = self["scan_expr_" .. node.tag]
@@ -611,6 +642,8 @@ function LinState:scan_expr_Op(item, node)
    end
 end
 
+LinState.scan_expr_OpSet = LinState.scan_expr_Op
+
 -- Puts tables {var = value} into field `set_variables` of items in line which set values.
 -- Registers set values in field `values` of variables.
 function LinState:register_set_variables()