From: Hui Zhu Date: Thu, 30 Apr 2009 03:24:48 +0000 (+0000) Subject: * gdb.texinfo: Add documentation for process record and replay. X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=53cc454a92a4a4288c7172a7c3ed93186e3f8779;p=binutils-gdb.git * gdb.texinfo: Add documentation for process record and replay. --- diff --git a/gdb/doc/ChangeLog b/gdb/doc/ChangeLog index 2a0277d8440..f8fe13e46bf 100644 --- a/gdb/doc/ChangeLog +++ b/gdb/doc/ChangeLog @@ -1,3 +1,8 @@ +2009-04-30 Hui Zhu + Michael Snyder + + * gdb.texinfo: Add documentation for process record and replay. + 2009-04-29 Jan Kratochvil * gdb.texinfo (Macros): Note command-line for `info macro'. Append diff --git a/gdb/doc/gdb.texinfo b/gdb/doc/gdb.texinfo index 57bd0840fe6..ded394ea76e 100644 --- a/gdb/doc/gdb.texinfo +++ b/gdb/doc/gdb.texinfo @@ -134,6 +134,7 @@ software in general. We will miss him. * Running:: Running programs under @value{GDBN} * Stopping:: Stopping and continuing * Reverse Execution:: Running programs backward +* Process record and replay:: Recording inferior's execution and replaying it * Stack:: Examining the stack * Source:: Examining source files * Data:: Examining data @@ -5002,6 +5003,112 @@ This is the default. @end table +@node Process record and replay +@chapter Recording inferior's execution and replaying it +@cindex process record and replay +@cindex recording inferior's execution and replaying it + +In a architecture environment that supports process record and replay, +process record and replay target can record a log of the process execution, +and replay it with both forward and reverse execute commands. + +When this target is in use, if the execution log includes the record for +the next instruction, @value{GDBN} will debug in replay mode. So inferior +will not really execute and all the execution events are taken from the +execution log. Just the values of registers (include pc register) and +memory of the inferior will be changed. + +Otherwise, @value{GDBN} will debug in record mode. So inferior will +execute normally and @value{GDBN} will record the execution log. + +If you are debugging in a architecture environment that supports +process record and replay, @value{GDBN} provides the following commands. + +@table @code +@kindex target record +@kindex record +@kindex rec +@item target record +This a standard command to start process record and replay target. +Process record and replay target can only debug a process that already +running. Therefore you need to first start the process @code{run}, +and then start the recording @code{target record}. + +Both @code{record} and @code{rec} are the aliases of @code{target record}. + +Displaced stepping function will disable when process record and replay +target is opened. Because process record and replay target doesn't +support displaced stepping function. + +If inferior in non-stop mode (non-stop) or in asynchronous mode +(target-async), process record and replay target can't be open because +it doesn't support these two modes. + +@kindex record stop +@kindex rec s +@item record stop +Stop process record and replay target at once. When Process record and +replay target stops, all the execution log will be deleted and the inferior +will either be terminated, or remain in its final state. + +When you stop the process record and replay target in record mode (at the +end of the execution log), the inferior will be stopped at the next +instruction that would have been recorded. In other words, if you record +for a while and then stop recording, the inferior process will be left in +the same state as if recording never happened. + +On the other hand, if the process record and replay target is stopped while +in replay mode (that is, not at the end of the execution log but at some +earlier point), the inferior process will become ``live'' at that earlier state, +and it will then be possible to continue debugging the process ``live'' from +that state. + +When the inferior process exits, or @value{GDBN} detaches from it, process +record and replay target will automatically stop itself. + +@kindex set record insn-number-max +@item set record insn-number-max @var{limit} +Set the limit of instructions to be recorded. Default value is 200000. + +In this case, if record instructions number is bigger than @var{limit}, +@value{GDBN} will auto delete the earliest recorded instruction execute +log. + +If set to 0, @value{GDBN} will not delete the earliest recorded instruction +execute log. Record instructions number limit function will disable. + +@kindex show record insn-number-max +@item show record insn-number-max +Show the value of recorded instructions limit. + +@kindex set record stop-at-limit +@item set record stop-at-limit on +Set the behavior when record instructions limit is reached. +This is the default mode. Meaning that @value{GDBN} will stop ask user +want close @code{record stop-at-limit} or stop inferior. + +@item set record stop-at-limit off +This mean that @value{GDBN} will auto delete the oldest record to make +room for each new one. + +@kindex show record stop-at-limit +@item show record stop-at-limit +Show the value of record stop-at-limit. + +@kindex info record insn-number +@item info record insn-number +Show the current number of recorded instructions. + +@kindex record delete +@kindex rec del +@item record delete +When record target running in replay mode (``in the past''), delete the +subsequent execution log and begin to record a new execution log starting +from the current address. It means you will abandon the previously +recorded ``future'' and begin recording a new ``future''. +@end table + + @node Stack @chapter Examining the Stack