| 1 |
|
-module(safely). |
| 2 |
|
%% This module preserves the return types of a `catch' statement, |
| 3 |
|
%% but doesn't silently convert `throw's to normal values. |
| 4 |
|
%% The issue is that throws have different semantics than errors: |
| 5 |
|
%% https://erlang.org/doc/reference_manual/expressions.html#catch-and-throw, |
| 6 |
|
%% so a throw is actually a control flow escape, while an error is an actual crash. |
| 7 |
|
%% If it is an error, we want the stacktrace, if not, we don't. |
| 8 |
|
%% For more information, see usage in test/safely_SUITE.erl |
| 9 |
|
|
| 10 |
|
-include_lib("kernel/include/logger.hrl"). |
| 11 |
|
|
| 12 |
|
-export([apply/2, apply/3]). |
| 13 |
|
-export([apply_and_log/3, apply_and_log/4]). |
| 14 |
|
-compile({no_auto_import, [apply/2, apply/3]}). |
| 15 |
|
-ignore_xref([apply/3, apply_and_log/4]). |
| 16 |
|
|
| 17 |
|
-type error_class() :: error | exit | throw. |
| 18 |
|
-type catch_result(A) :: A | {error_class(), term()}. |
| 19 |
|
|
| 20 |
|
-define(MATCH_EXCEPTIONS_DO_LOG(F, Context), |
| 21 |
|
try F catch |
| 22 |
|
error:R:S -> |
| 23 |
|
?LOG_ERROR(Context#{class => error, reason => R, stacktrace => S}), |
| 24 |
|
{error, {R, S}}; |
| 25 |
|
throw:R -> |
| 26 |
|
?LOG_ERROR(Context#{class => throw, reason => R}), |
| 27 |
|
{throw, R}; |
| 28 |
|
exit:R:S -> |
| 29 |
|
?LOG_ERROR(Context#{class => exit, reason => R, stacktrace => S}), |
| 30 |
|
{exit, {R, S}} |
| 31 |
|
end). |
| 32 |
|
|
| 33 |
|
-define(MATCH_EXCEPTIONS(F), |
| 34 |
|
try F catch |
| 35 |
|
error:R:S -> {error, {R, S}}; |
| 36 |
|
throw:R -> {throw, R}; |
| 37 |
|
exit:R:S -> {exit, {R, S}} |
| 38 |
|
end). |
| 39 |
|
|
| 40 |
|
-spec apply(fun((...) -> A), [term()]) -> catch_result(A). |
| 41 |
|
apply(Function, Args) when is_function(Function), is_list(Args) -> |
| 42 |
153619 |
?MATCH_EXCEPTIONS(erlang:apply(Function, Args)). |
| 43 |
|
|
| 44 |
|
-spec apply(atom(), atom(), [term()]) -> catch_result(any()). |
| 45 |
|
apply(Module, Function, Args) when is_atom(Function), is_list(Args) -> |
| 46 |
:-( |
?MATCH_EXCEPTIONS(erlang:apply(Module, Function, Args)). |
| 47 |
|
|
| 48 |
|
-spec apply_and_log(fun((...) -> A), [term()], map()) -> catch_result(A). |
| 49 |
|
apply_and_log(Function, Args, Context) |
| 50 |
|
when is_function(Function), is_list(Args), is_map(Context) -> |
| 51 |
344 |
?MATCH_EXCEPTIONS_DO_LOG(erlang:apply(Function, Args), Context). |
| 52 |
|
|
| 53 |
|
-spec apply_and_log(atom(), atom(), [term()], map()) -> catch_result(any()). |
| 54 |
|
apply_and_log(Module, Function, Args, Context) |
| 55 |
|
when is_atom(Function), is_list(Args), is_map(Context) -> |
| 56 |
:-( |
?MATCH_EXCEPTIONS_DO_LOG(erlang:apply(Module, Function, Args), Context). |