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| author | Björn Gustavsson <[email protected]> | 2018-11-21 05:55:12 +0100 |
|---|---|---|
| committer | Björn Gustavsson <[email protected]> | 2018-11-21 06:10:16 +0100 |
| commit | df0ce3328e4ac64c0bd82fb10a879d4f0732b261 (patch) | |
| tree | c94dcb451c6ce1490641a70a5d41fa0b411e804e | |
| parent | c0812d51fbb550d4a53df128e4ec322746f015ca (diff) | |
| download | otp-df0ce3328e4ac64c0bd82fb10a879d4f0732b261.tar.gz otp-df0ce3328e4ac64c0bd82fb10a879d4f0732b261.tar.bz2 otp-df0ce3328e4ac64c0bd82fb10a879d4f0732b261.zip | |
Fix inadvertently suppressed warning for unused variable
An external fun could inadvertently suppress warnings for
unused variables, such as in this example:
bug() ->
BugVar = foo(),
if true ->
fun m:f/1
end.
There would be no warning that `BugVar` was unused.
The bug was introduced in ff432e262e652, which was the commit
that extended external funs to allow variables.
https://bugs.erlang.org/browse/ERL-762
| -rw-r--r-- | lib/stdlib/src/erl_lint.erl | 3 | ||||
| -rw-r--r-- | lib/stdlib/test/erl_lint_SUITE.erl | 20 |
2 files changed, 19 insertions, 4 deletions
diff --git a/lib/stdlib/src/erl_lint.erl b/lib/stdlib/src/erl_lint.erl index e9ac2fcdff..e0cd68617b 100644 --- a/lib/stdlib/src/erl_lint.erl +++ b/lib/stdlib/src/erl_lint.erl @@ -2262,8 +2262,7 @@ expr({'fun',Line,Body}, Vt, St) -> {[],St}; {function,M,F,A} -> %% New in R15. - {Bvt, St1} = expr_list([M,F,A], Vt, St), - {vtupdate(Bvt, Vt),St1} + expr_list([M,F,A], Vt, St) end; expr({named_fun,_,'_',Cs}, Vt, St) -> fun_clauses(Cs, Vt, St); diff --git a/lib/stdlib/test/erl_lint_SUITE.erl b/lib/stdlib/test/erl_lint_SUITE.erl index f9ab83a120..d18c7c255c 100644 --- a/lib/stdlib/test/erl_lint_SUITE.erl +++ b/lib/stdlib/test/erl_lint_SUITE.erl @@ -67,7 +67,8 @@ record_errors/1, otp_11879_cont/1, non_latin1_module/1, otp_14323/1, stacktrace_syntax/1, - otp_14285/1, otp_14378/1]). + otp_14285/1, otp_14378/1, + external_funs/1]). suite() -> [{ct_hooks,[ts_install_cth]}, @@ -88,7 +89,7 @@ all() -> maps, maps_type, maps_parallel_match, otp_11851, otp_11879, otp_13230, record_errors, otp_11879_cont, non_latin1_module, otp_14323, - stacktrace_syntax, otp_14285, otp_14378]. + stacktrace_syntax, otp_14285, otp_14378, external_funs]. groups() -> [{unused_vars_warn, [], @@ -4134,6 +4135,21 @@ otp_14285(Config) -> run(Config, Ts), ok. +external_funs(Config) when is_list(Config) -> + Ts = [{external_funs_1, + %% ERL-762: Unused variable warning not being emitted. + <<"f() -> + BugVar = process_info(self()), + if true -> fun m:f/1 end. + f(M, F) -> + BugVar = process_info(self()), + if true -> fun M:F/1 end.">>, + [], + {warnings,[{2,erl_lint,{unused_var,'BugVar'}}, + {5,erl_lint,{unused_var,'BugVar'}}]}}], + run(Config, Ts), + ok. + format_error(E) -> lists:flatten(erl_lint:format_error(E)). |