Improve documentation of logger and error_logger

4 files changed, 41 insertions, 22 deletions

diff --git a/lib/stdlib/doc/src/gen_event.xml b/lib/stdlib/doc/src/gen_event.xml
index 012737c390..51378a6b73 100644
--- a/lib/stdlib/doc/src/gen_event.xml
+++ b/lib/stdlib/doc/src/gen_event.xml
@@ -458,8 +458,7 @@ gen_event:stop             ----->  Module:terminate/2
           with the expected reason. Any other reason than <c>normal</c>,
           <c>shutdown</c>, or <c>{shutdown,Term}</c> causes an
           error report to be issued using
-          <seealso marker="kernel:error_logger#format/2">
-          <c>error_logger:format/2</c></seealso>.
+          <seealso marker="kernel:logger"><c>logger(3)</c></seealso>.
           The default <c>Reason</c> is <c>normal</c>.</p>
         <p><c>Timeout</c> is an integer greater than zero that
           specifies how many milliseconds to wait for the event manager to
diff --git a/lib/stdlib/doc/src/gen_server.xml b/lib/stdlib/doc/src/gen_server.xml
index da74e793e6..27edbc8de7 100644
--- a/lib/stdlib/doc/src/gen_server.xml
+++ b/lib/stdlib/doc/src/gen_server.xml
@@ -486,8 +486,7 @@ gen_server:abcast     -----> Module:handle_cast/2
           with the expected reason. Any other reason than <c>normal</c>,
           <c>shutdown</c>, or <c>{shutdown,Term}</c> causes an
           error report to be issued using
-          <seealso marker="kernel:error_logger#format/2">
-          <c>error_logger:format/2</c></seealso>.
+          <seealso marker="kernel:logger"><c>logger(3)</c></seealso>.
           The default <c>Reason</c> is <c>normal</c>.</p>
         <p><c>Timeout</c> is an integer greater than zero that
           specifies how many milliseconds to wait for the server to
@@ -861,8 +860,7 @@ gen_server:abcast     -----> Module:handle_cast/2
           <c>shutdown</c>, or <c>{shutdown,Term}</c>, the <c>gen_server</c>
           process is assumed to terminate because of an error and
           an error report is issued using
-          <seealso marker="kernel:error_logger#format/2">
-          <c>error_logger:format/2</c></seealso>.</p>
+          <seealso marker="kernel:logger"><c>logger(3)</c></seealso>.</p>
       </desc>
     </func>
   </funcs>
diff --git a/lib/stdlib/doc/src/gen_statem.xml b/lib/stdlib/doc/src/gen_statem.xml
index e918e83df7..a808d3af55 100644
--- a/lib/stdlib/doc/src/gen_statem.xml
+++ b/lib/stdlib/doc/src/gen_statem.xml
@@ -1778,7 +1778,7 @@ handle_event(_, _, State, Data) ->
 	  with the expected reason. Any other reason than <c>normal</c>,
 	  <c>shutdown</c>, or <c>{shutdown,Term}</c> causes an
 	  error report to be issued through
-	  <seealso marker="kernel:error_logger#format/2"><c>error_logger:format/2</c></seealso>.
+	  <seealso marker="kernel:logger"><c>logger(3)</c></seealso>.
 	  The default <c><anno>Reason</anno></c> is <c>normal</c>.
 	</p>
 	<p>
@@ -2286,7 +2286,7 @@ init(Args) -> erlang:error(not_implemented, [Args]).</pre>
           <c>shutdown</c>, or <c>{shutdown,Term}</c>,
 	  the <c>gen_statem</c> is assumed to terminate because of an error
 	  and an error report is issued using
-          <seealso marker="kernel:error_logger#format/2"><c>error_logger:format/2</c></seealso>.
+          <seealso marker="kernel:logger"><c>logger(3)</c></seealso>.
 	</p>
       </desc>
     </func>
diff --git a/lib/stdlib/doc/src/proc_lib.xml b/lib/stdlib/doc/src/proc_lib.xml
index cb152d1935..c4fdf972e4 100644
--- a/lib/stdlib/doc/src/proc_lib.xml
+++ b/lib/stdlib/doc/src/proc_lib.xml
@@ -59,18 +59,16 @@
     <p>When a process that is started using <c>proc_lib</c> terminates
       abnormally (that is, with another exit reason than <c>normal</c>,
       <c>shutdown</c>, or <c>{shutdown,Term}</c>), a <em>crash report</em>
-      is generated, which is written to terminal by the default SASL
-      event handler. That is, the crash report is normally only visible
-      if the SASL application is started; see
-      <seealso marker="sasl:sasl_app"><c>sasl(6)</c></seealso> and section
-      <seealso marker="sasl:error_logging">SASL Error Logging</seealso>
-      in the SASL User's Guide.</p>
+      is generated, which is written to terminal by the default logger
+      handler setup by Kernel. For more information about how crash reports
+      were logged before OTP-21, see <seealso marker="sasl:error_logging">
+      SASL Error Logging</seealso> in the SASL User's Guide.</p>
 
     <p>Unlike in "plain Erlang", <c>proc_lib</c> processes will not generate
       <em>error reports</em>, which are written to the terminal by the
-      emulator and do not require SASL to be started. All exceptions are
+      emulator. All exceptions are
       converted to <em>exits</em> which are ignored by the default
-      <c>error_logger</c> handler.</p>
+      <c>logger</c> handler.</p>
 
     <p>The crash report contains the previously stored information, such
       as ancestors and initial function, the termination reason, and
@@ -115,12 +113,22 @@
       <name name="format" arity="2"/>
       <fsummary>Format a crash report.</fsummary>
       <desc>
-        <p>This function can be used by a user-defined event handler to
+	<note>
+	  <p>This function is deprecated in the sense that
+	    the <c>error_logger</c> is no longer the preferred
+	    interface for logging in Erlang/OTP. A
+	    new <seealso marker="kernel:logger_chapter">logging
+	    API</seealso> was added in OTP-21, but
+	    legacy <c>error_logger</c> handlers may still be used. New
+	    logger handlers do not need to used this function, since
+	    the formatting callback (<c>report_cb</c>) is included as
+	    metadata in the log event.</p>
+	</note>
+        <p>This function can be used by a user-defined legacy
+	  <c>error_logger</c> event handler to
           format a crash report. The crash report is sent using
-          <seealso marker="kernel:error_logger#error_report/2">
-          <c>error_logger:error_report(crash_report,
-          <anno>CrashReport</anno>)</c></seealso>.
-          That is, the event to be handled is of the format
+          <seealso marker="kernel:logger">
+          <c>logger(3)</c></seealso>, and the event to be handled is of the format
           <c>{error_report, GL, {Pid, crash_report,
           <anno>CrashReport</anno>}}</c>,
           where <c>GL</c> is the group leader pid of process
@@ -132,7 +140,19 @@
       <name name="format" arity="3"/>
       <fsummary>Format a crash report.</fsummary>
       <desc>
-        <p>This function can be used by a user-defined event handler to
+	<note>
+	  <p>This function is deprecated in the sense that
+	    the <c>error_logger</c> is no longer the preferred
+	    interface for logging in Erlang/OTP. A
+	    new <seealso marker="kernel:logger_chapter">logging
+	    API</seealso> was added in OTP-21, but
+	    legacy <c>error_logger</c> handlers may still be used. New
+	    logger handlers do not need to used this function, since
+	    the formatting callback (<c>report_cb</c>) is included as
+	    metadata in the log event.</p>
+	</note>
+        <p>This function can be used by a user-defined legacy
+	  <c>error_logger</c> event handler to
           format a crash report. When <anno>Depth</anno> is specified as a
           positive integer, it is used in the format string to
           limit the output as follows: <c>io_lib:format("~P",
@@ -395,6 +415,8 @@ init(Parent) ->
     <title>See Also</title>
     <p><seealso marker="kernel:error_logger">
       <c>error_logger(3)</c></seealso></p>
+    <p><seealso marker="kernel:logger">
+      <c>logger(3)</c></seealso></p>
   </section>
 </erlref>