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|
defmodule Module.ParallelChecker do
@moduledoc false
import Kernel, except: [spawn: 3]
@type cache() :: {pid(), :ets.tid()}
@type warning() :: term()
@type kind() :: :def | :defmacro
@type mode() :: :elixir | :erlang
@doc """
Initializes the parallel checker process.
"""
def start_link(schedulers \\ nil) do
:gen_server.start_link(__MODULE__, schedulers, [])
end
@doc """
Stops the parallel checker process.
"""
def stop(checker) do
send(checker, {__MODULE__, :stop})
:ok
end
@doc """
Gets the parallel checker data from pdict.
"""
def get do
case :erlang.get(:elixir_checker_info) do
{parent, nil} ->
{:ok, checker} = start_link()
put(parent, checker)
{parent, checker}
{parent, checker} ->
{parent, checker}
end
end
@doc """
Stores the parallel checker information.
"""
def put(pid, checker) when is_pid(pid) and is_pid(checker) do
:erlang.put(:elixir_checker_info, {pid, checker})
end
@doc """
Spawns a process that runs the parallel checker.
"""
def spawn({pid, checker}, module, info) do
ref = make_ref()
spawned =
spawn(fn ->
mon_ref = Process.monitor(pid)
receive do
{^ref, :cache, ets} ->
Process.link(pid)
module_map =
if is_map(info) do
info
else
case File.read(info) do
{:ok, binary} -> maybe_module_map(binary, module)
{:error, _} -> nil
end
end
module_map && cache_from_module_map(ets, module_map)
send(checker, {ref, :cached})
receive do
{^ref, :check} ->
# Set the compiler info so we can collect warnings
:erlang.put(:elixir_compiler_info, {pid, self()})
warnings =
if module_map do
check_module(module_map, {checker, ets})
else
[]
end
send(pid, {__MODULE__, module, warnings})
send(checker, {__MODULE__, :done})
end
{:DOWN, ^mon_ref, _, _, _} ->
:ok
end
end)
register(checker, spawned, ref)
:ok
end
@doc """
Verifies the given compilation function
by starting a checker if one does not exist.
See `verify/3`.
"""
def verify(fun) do
case :erlang.get(:elixir_compiler_info) do
:undefined ->
previous = :erlang.put(:elixir_checker_info, {self(), nil})
try do
result = fun.()
case :erlang.get(:elixir_checker_info) do
{_, nil} -> :ok
{_, checker} -> verify(checker, [])
end
result
after
{_, checker} = :erlang.get(:elixir_checker_info)
if previous != :undefined do
:erlang.put(:elixir_checker_info, previous)
else
:erlang.erase(:elixir_checker_info)
end
checker && stop(checker)
end
_ ->
# If we are during compilation, then they will be
# reported to the compiler, which will validate them.
fun.()
end
end
@doc """
Receives pairs of module maps and BEAM binaries. In parallel it verifies
the modules and adds the ExCk chunk to the binaries. Returns the updated
list of warnings from the verification.
"""
@spec verify(pid(), [{module(), Path.t()}]) :: [warning()]
def verify(checker, runtime_files) do
for {module, file} <- runtime_files do
spawn({self(), checker}, module, file)
end
count = :gen_server.call(checker, :start, :infinity)
collect_results(count, [])
end
defp collect_results(0, diagnostics) do
diagnostics
end
defp collect_results(count, diagnostics) do
receive do
{:diagnostic, diagnostic} ->
collect_results(count, [diagnostic | diagnostics])
{__MODULE__, _module, new_diagnostics} ->
collect_results(count - 1, new_diagnostics ++ diagnostics)
end
end
@doc """
Test cache.
"""
def test_cache do
{:ok, checker} = start_link()
{checker, :gen_server.call(checker, :ets, :infinity)}
end
@doc """
Preloads a module into the cache. Call this function before any other
cache lookups for the module.
"""
@spec preload_module(cache(), module()) :: :ok
def preload_module({server, ets}, module) do
case :ets.lookup(ets, {:cached, module}) do
[{_key, _}] -> :ok
[] -> cache_module({server, ets}, module)
end
end
@doc """
Returns the export kind and deprecation reason for the given MFA from
the cache. If the module does not exist return `{:error, :module}`,
or if the function does not exist return `{:error, :function}`.
"""
@spec fetch_export(cache(), module(), atom(), arity()) ::
{:ok, mode(), kind(), binary() | nil} | {:error, :function | :module}
def fetch_export({_server, ets}, module, fun, arity) do
case :ets.lookup(ets, {:cached, module}) do
[{_key, false}] ->
{:error, :module}
[{_key, mode}] ->
case :ets.lookup(ets, {:export, module, {fun, arity}}) do
[{_key, kind, reason}] -> {:ok, mode, kind, reason}
[] -> {:error, :function}
end
end
end
@doc """
Returns all exported functions and macros for the given module from
the cache.
"""
@spec all_exports(cache(), module()) :: [{atom(), arity()}]
def all_exports({_server, ets}, module) do
# This is only called after we get a deprecation notice
# so we can assume it's a cached module
ets
|> :ets.match({{:export, module, :"$1"}, :_, :_})
|> Enum.flat_map(& &1)
|> Enum.sort()
end
## Module checking
defp check_module(module_map, cache) do
%{
module: module,
file: file,
line: line,
compile_opts: compile_opts,
definitions: definitions,
uses_behaviours: uses_behaviours,
impls: impls
} = module_map
no_warn_undefined =
compile_opts
|> extract_no_warn_undefined()
|> merge_compiler_no_warn_undefined()
behaviour_warnings =
Module.Types.Behaviour.check_behaviours_and_impls(
module,
file,
line,
uses_behaviours,
impls,
definitions
)
warnings =
module
|> Module.Types.warnings(file, definitions, no_warn_undefined, cache)
|> Kernel.++(behaviour_warnings)
|> group_warnings()
|> emit_warnings()
module_map
|> Map.get(:after_verify, [])
|> Enum.each(fn {verify_mod, verify_fun} -> apply(verify_mod, verify_fun, [module]) end)
warnings
end
defp extract_no_warn_undefined(compile_opts) do
for(
{:no_warn_undefined, values} <- compile_opts,
value <- List.wrap(values),
do: value
)
end
defp merge_compiler_no_warn_undefined(no_warn_undefined) do
case Code.get_compiler_option(:no_warn_undefined) do
:all -> :all
list when is_list(list) -> no_warn_undefined ++ list
end
end
## Warning helpers
def group_warnings(warnings) do
warnings
|> Enum.reduce(%{}, fn {module, warning, location}, acc ->
locations = MapSet.new([location])
Map.update(acc, {module, warning}, locations, &MapSet.put(&1, location))
end)
|> Enum.map(fn {{module, warning}, locations} -> {module, warning, Enum.sort(locations)} end)
|> Enum.sort()
end
def emit_warnings(warnings) do
Enum.flat_map(warnings, fn {module, warning, locations} ->
message = module.format_warning(warning)
diagnostics = Enum.map(locations, &to_diagnostic(message, &1))
:elixir_errors.print_warning([message, ?\n, format_stacktraces(diagnostics)])
diagnostics
end)
end
defp format_stacktraces([diagnostic]) do
format_diagnostic_stacktrace(diagnostic)
end
defp format_stacktraces(diagnostics) do
[
"Invalid call found at #{length(diagnostics)} locations:\n",
Enum.map(diagnostics, &format_diagnostic_stacktrace/1)
]
end
defp format_diagnostic_stacktrace(%{stacktrace: [stacktrace]}) do
[" ", Exception.format_stacktrace_entry(stacktrace), ?\n]
end
defp to_diagnostic(message, {file, line, mfa}) do
%{
severity: :warning,
file: file,
position: line,
message: message,
stacktrace: [to_stacktrace(file, line, mfa)]
}
end
defp to_stacktrace(file, line, {module, fun, arity}),
do: {module, fun, arity, location(file, line)}
defp to_stacktrace(file, line, nil),
do: {:elixir_compiler, :__FILE__, 1, location(file, line)}
defp to_stacktrace(file, line, module),
do: {module, :__MODULE__, 0, location(file, line)}
defp location(file, line) do
[file: String.to_charlist(Path.relative_to_cwd(file)), line: line]
end
## Cache
defp cache_module({server, ets}, module) do
if lock(server, module) do
cache_from_chunk(ets, module) || cache_from_info(ets, module)
unlock(server, module)
end
end
defp cache_from_chunk(ets, module) do
with {^module, binary, _filename} <- :code.get_object_code(module),
{:ok, {^module, [{~c"ExCk", chunk}]}} <- :beam_lib.chunks(binary, [~c"ExCk"]),
{:elixir_checker_v1, contents} <- :erlang.binary_to_term(chunk) do
cache_chunk(ets, module, contents.exports)
true
else
_ -> false
end
end
defp cache_from_info(ets, module) do
if Code.ensure_loaded?(module) do
{mode, exports} = info_exports(module)
deprecated = info_deprecated(module)
cache_info(ets, module, exports, deprecated, mode)
else
:ets.insert(ets, {{:cached, module}, false})
end
end
defp info_exports(module) do
map =
Map.new(
[{{:__info__, 1}, :def}] ++
behaviour_exports(module) ++
Enum.map(module.__info__(:macros), &{&1, :defmacro}) ++
Enum.map(module.__info__(:functions), &{&1, :def})
)
{:elixir, map}
rescue
_ -> {:erlang, Map.new(Enum.map(module.module_info(:exports), &{&1, :def}))}
end
defp info_deprecated(module) do
Map.new(module.__info__(:deprecated))
rescue
_ -> %{}
end
defp maybe_module_map(binary, module) when is_binary(binary) do
# If a module was compiled without debug_info,
# then there is no module_map for further verification.
with {:ok, {_, [debug_info: chunk]}} <- :beam_lib.chunks(binary, [:debug_info]),
{:debug_info_v1, backend, data} = chunk,
{:ok, module_map} <- backend.debug_info(:elixir_v1, module, data, []) do
module_map
else
_ -> nil
end
end
defp cache_from_module_map(ets, map) do
exports =
[{{:__info__, 1}, :def}] ++
behaviour_exports(map) ++
definitions_to_exports(map.definitions)
deprecated = Map.new(map.deprecated)
cache_info(ets, map.module, exports, deprecated, :elixir)
end
defp cache_info(ets, module, exports, deprecated, mode) do
Enum.each(exports, fn {{fun, arity}, kind} ->
reason = Map.get(deprecated, {fun, arity})
:ets.insert(ets, {{:export, module, {fun, arity}}, kind, reason})
{{fun, arity}, kind}
end)
:ets.insert(ets, {{:cached, module}, mode})
end
defp cache_chunk(ets, module, exports) do
Enum.each(exports, fn {{fun, arity}, %{kind: kind, deprecated_reason: reason}} ->
:ets.insert(ets, {{:export, module, {fun, arity}}, kind, reason})
{{fun, arity}, kind}
end)
:ets.insert(ets, {{:export, module, {:__info__, 1}}, :def, nil})
:ets.insert(ets, {{:cached, module}, :elixir})
end
defp behaviour_exports(%{defines_behaviour: true}), do: [{{:behaviour_info, 1}, :def}]
defp behaviour_exports(%{defines_behaviour: false}), do: []
defp behaviour_exports(module) when is_atom(module) do
if function_exported?(module, :behaviour_info, 1) do
[{{:behaviour_info, 1}, :def}]
else
[]
end
end
defp definitions_to_exports(definitions) do
Enum.flat_map(definitions, fn {function, kind, _meta, _clauses} ->
if kind in [:def, :defmacro] do
[{function, kind}]
else
[]
end
end)
end
defp lock(server, module) do
:gen_server.call(server, {:lock, module}, :infinity)
end
defp unlock(server, module) do
:gen_server.call(server, {:unlock, module}, :infinity)
end
defp register(server, pid, ref) do
:gen_server.cast(server, {:register, pid, ref})
end
## Server callbacks
def init(schedulers) do
ets = :ets.new(__MODULE__, [:set, :public, {:read_concurrency, true}])
state = %{
ets: ets,
waiting: %{},
modules: [],
spawned: 0,
schedulers: schedulers || max(:erlang.system_info(:schedulers_online), 2)
}
{:ok, state}
end
def handle_call(:start, _from, %{ets: ets, modules: modules} = state) do
for {pid, ref} <- modules do
send(pid, {ref, :cache, ets})
end
for {_pid, ref} <- modules do
receive do
{^ref, :cached} -> :ok
end
end
{:reply, length(modules), run_checkers(state)}
end
def handle_call(:ets, _from, state) do
{:reply, state.ets, state}
end
def handle_call({:lock, module}, from, %{waiting: waiting} = state) do
case waiting do
%{^module => froms} ->
waiting = Map.put(state.waiting, module, [from | froms])
{:noreply, %{state | waiting: waiting}}
%{} ->
waiting = Map.put(state.waiting, module, [])
{:reply, true, %{state | waiting: waiting}}
end
end
def handle_call({:unlock, module}, _from, %{waiting: waiting} = state) do
froms = Map.fetch!(waiting, module)
Enum.each(froms, &:gen_server.reply(&1, false))
waiting = Map.delete(waiting, module)
{:reply, :ok, %{state | waiting: waiting}}
end
def handle_info({__MODULE__, :done}, state) do
state = %{state | spawned: state.spawned - 1}
{:noreply, run_checkers(state)}
end
def handle_info({__MODULE__, :stop}, state) do
{:stop, :normal, state}
end
def handle_cast({:register, pid, ref}, %{modules: modules} = state) do
{:noreply, %{state | modules: [{pid, ref} | modules]}}
end
defp run_checkers(%{modules: []} = state) do
state
end
defp run_checkers(%{spawned: spawned, schedulers: schedulers} = state)
when spawned >= schedulers do
state
end
defp run_checkers(%{modules: [{pid, ref} | modules]} = state) do
send(pid, {ref, :check})
run_checkers(%{state | modules: modules, spawned: state.spawned + 1})
end
end
|