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author | Björn Gustavsson <[email protected]> | 2017-11-16 06:10:12 +0100 |
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committer | Björn Gustavsson <[email protected]> | 2017-11-30 12:46:51 +0100 |
commit | 01f96ee6197a7b5a2c64353a3b38260994ce5ad5 (patch) | |
tree | 97f5feee2f1277d83d9287dd922b03104307c7c4 /erts/doc/src | |
parent | 38e4dfbd281cae0fb58211b63861b037ad121231 (diff) | |
download | otp-01f96ee6197a7b5a2c64353a3b38260994ce5ad5.tar.gz otp-01f96ee6197a7b5a2c64353a3b38260994ce5ad5.tar.bz2 otp-01f96ee6197a7b5a2c64353a3b38260994ce5ad5.zip |
Add documentation for the new stacktrace syntax
Diffstat (limited to 'erts/doc/src')
-rw-r--r-- | erts/doc/src/erlang.xml | 45 |
1 files changed, 16 insertions, 29 deletions
diff --git a/erts/doc/src/erlang.xml b/erts/doc/src/erlang.xml index daf3002ec7..d7404fa3ce 100644 --- a/erts/doc/src/erlang.xml +++ b/erts/doc/src/erlang.xml @@ -1985,39 +1985,26 @@ true</pre> <fsummary>Get the call stack back-trace of the last exception.</fsummary> <type name="stack_item"/> <desc> - <p>Gets the call stack back-trace (<em>stacktrace</em>) for an - exception that has just been caught - in the calling process as a list of - <c>{<anno>Module</anno>,<anno>Function</anno>,<anno>Arity</anno>,<anno>Location</anno>}</c> - tuples. Field <c><anno>Arity</anno></c> in the first tuple can be the - argument list of that function call instead of an arity integer, - depending on the exception.</p> - <p>If there has not been any exceptions in a process, the - stacktrace is <c>[]</c>. After a code change for the process, - the stacktrace can also be reset to <c>[]</c>.</p> - <p><c>erlang:get_stacktrace/0</c> is only guaranteed to return - a stacktrace if called (directly or indirectly) from within the - scope of a <c>try</c> expression. That is, the following call works:</p> + <warning><p><c>erlang:get_stacktrace/0</c> is deprecated and will stop working + in a future release.</p></warning> + <p>Instead of using <c>erlang:get_stacktrace/0</c> to retrieve + the call stack back-trace, use the following syntax:</p> <pre> try Expr catch - C:R -> - {C,R,erlang:get_stacktrace()} + Class:Reason:Stacktrace -> + {Class,Reason,Stacktrace} end</pre> - <p>As does this call:</p> -<pre> -try Expr -catch - C:R -> - {C,R,helper()} -end - -helper() -> - erlang:get_stacktrace().</pre> - - <warning><p>In a future release, - <c>erlang:get_stacktrace/0</c> will return <c>[]</c> if called - from outside a <c>try</c> expression.</p></warning> + <p><c>erlang:get_stacktrace/0</c> retrieves the call stack back-trace + (<em>stacktrace</em>) for an exception that has just been + caught in the calling process as a list of + <c>{<anno>Module</anno>,<anno>Function</anno>,<anno>Arity</anno>,<anno>Location</anno>}</c> + tuples. Field <c><anno>Arity</anno></c> in the first tuple can + be the argument list of that function call instead of an arity + integer, depending on the exception.</p> + <p>If there has not been any exceptions in a process, the + stacktrace is <c>[]</c>. After a code change for the process, + the stacktrace can also be reset to <c>[]</c>.</p> <p>The stacktrace is the same data as operator <c>catch</c> returns, for example:</p> <pre> |