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Diffstat (limited to 'src/rebar_xref.erl')
| -rw-r--r-- | src/rebar_xref.erl | 184 |
1 files changed, 184 insertions, 0 deletions
diff --git a/src/rebar_xref.erl b/src/rebar_xref.erl new file mode 100644 index 0000000..b5e6d8a --- /dev/null +++ b/src/rebar_xref.erl @@ -0,0 +1,184 @@ +%% -*- tab-width: 4;erlang-indent-level: 4;indent-tabs-mode: nil -*- +%% ex: ts=4 sw=4 et +%% ------------------------------------------------------------------- +%% +%% rebar: Erlang Build Tools +%% +%% Copyright (c) 2009 Dave Smith (dizzyd@dizzyd.com) +%% +%% Permission is hereby granted, free of charge, to any person obtaining a copy +%% of this software and associated documentation files (the "Software"), to deal +%% in the Software without restriction, including without limitation the rights +%% to use, copy, modify, merge, publish, distribute, sublicense, and/or sell +%% copies of the Software, and to permit persons to whom the Software is +%% furnished to do so, subject to the following conditions: +%% +%% The above copyright notice and this permission notice shall be included in +%% all copies or substantial portions of the Software. +%% +%% THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR +%% IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, +%% FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE +%% AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER +%% LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, +%% OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN +%% THE SOFTWARE. +%% +%% ------------------------------------------------------------------- + +%% ------------------------------------------------------------------- +%% This module borrows heavily from http://github.com/etnt/exrefcheck project as +%% written by Torbjorn Tornkvist <tobbe@kreditor.se>, Daniel Luna and others. +%% ------------------------------------------------------------------- +-module(rebar_xref). + +-include("rebar.hrl"). + +-export([xref/2]). + +%% =================================================================== +%% Public API +%% =================================================================== + +xref(Config, _) -> + %% Spin up xref + xref:start(xref), + ok = xref:set_library_path(xref, code_path()), + xref:set_default(xref, [{warnings, rebar_config:get(Config, xref_warnings, false)}, + {verbose, rebar_config:is_verbose()}]), + {ok, _} = xref:add_directory(xref, "ebin"), + + %% Get list of xref checks we want to run + XrefChecks = rebar_config:get(Config, xref_checks, [exports_not_used, + undefined_function_calls]), + + %% Look for exports that are unused by anything + case lists:member(exports_not_used, XrefChecks) of + true -> + check_exports_not_used(Config); + false -> + ok + end, + + %% Look for calls to undefined functions + case lists:member(undefined_function_calls, XrefChecks) of + true -> + check_undefined_function_calls(Config); + false -> + ok + end, + + ok. + +foobar() -> + ok. + +%% =================================================================== +%% Internal functions +%% =================================================================== + +check_exports_not_used(_Config) -> + {ok, UnusedExports0} = xref:analyze(xref, exports_not_used), + UnusedExports = filter_away_ignored(UnusedExports0), + + %% Report all the unused functions + display_mfas(UnusedExports, "is unused export (Xref)"), + ok. + +check_undefined_function_calls(_Config) -> + {ok, UndefinedCalls0} = xref:analyze(xref, undefined_function_calls), + + UndefinedCalls = [{find_mfa_source(Caller), format_fa(Caller), format_mfa(Target)} || + {Caller, Target} <- UndefinedCalls0], + [?CONSOLE("~s:~w: Warning ~s calls undefined function ~s\n", + [Source, Line, FunStr, Target]) || + {{Source, Line}, FunStr, Target} <- UndefinedCalls], + ok. + + +code_path() -> + [P || P <- code:get_path(), + filelib:is_dir(P)]. + +%% +%% Ignore behaviour functions, and explicitly marked functions +%% +filter_away_ignored(UnusedExports) -> + %% Functions can be ignored by using + %% -ignore_xref([{F, A}, ...]). + + %% Setup a filter function that build a list of behaviour callbacks and/or + %% any functions marked to ignore. We then use this list to mask any functions + %% marked as unused exports by xref + F = fun(Mod) -> + Attrs = ks(attributes, Mod:module_info()), + Ignore = ks(ignore_xref, Attrs), + Callbacks = [B:behaviour_info(callbacks) || B <- ks(behaviour, Attrs)], + [{Mod, F, A} || {F, A} <- Ignore ++ lists:flatten(Callbacks)] + end, + AttrIgnore = lists:flatten(lists:map(F, lists:usort([M || {M, _, _} <- UnusedExports]))), + [X || X <- UnusedExports, not(lists:member(X, AttrIgnore))]. + + + +ks(Key, List) -> + case lists:keysearch(Key, 1, List) of + {value, {Key, Value}} -> + Value; + false -> + [] + end. + +display_mfas([], _Message) -> + ok; +display_mfas([{Mod, Fun, Args} = MFA | Rest], Message) -> + {Source, Line} = find_mfa_source(MFA), + ?CONSOLE("~s:~w: Warning: function ~s/~w ~s\n", [Source, Line, Fun, Args, Message]), + display_mfas(Rest, Message). + +format_mfa({M, F, A}) -> + ?FMT("~s:~s/~w", [M, F, A]). + +format_fa({_M, F, A}) -> + ?FMT("~s/~w", [F, A]). + +%% +%% Extract an element from a tuple, or undefined if N > tuple size +safe_element(N, Tuple) -> + case catch(element(N, Tuple)) of + {'EXIT', {badarg, _}} -> + undefined; + Value -> + Value + end. + +%% +%% Extract the line number for a given function def +%% +abstract_code_function_line(Code, Name, Args) -> + [{function, Line, Name, _, _}] = [E || E <- Code, + safe_element(1, E) == function, + safe_element(3, E) == Name, + safe_element(4, E) == Args], + Line. + +%% +%% Extract the original source filename from the abstract code +%% +abstract_code_source_file(Code) -> + [{attribute, 1, file, {Name, _}} | _] = Code, + Name. + + +%% +%% Given a MFA, find the file and LOC where it's defined. Note that +%% xref doesn't work if there is no abstract_code, so we can avoid +%% being too paranoid here. +%% +find_mfa_source({M, F, A}) -> + {M, Bin, _} = code:get_object_code(M), + {ok, {M, [{abstract_code, AbstractCode}]}} = beam_lib:chunks(Bin, [abstract_code]), + {raw_abstract_v1, Code} = AbstractCode, + Source = abstract_code_source_file(Code), + Line = abstract_code_function_line(Code, F, A), + {Source, Line}. |