diff options
Diffstat (limited to 'gdb/doc')
| -rw-r--r-- | gdb/doc/ChangeLog | 5 | ||||
| -rw-r--r-- | gdb/doc/gdb.texinfo | 118 |
2 files changed, 123 insertions, 0 deletions
diff --git a/gdb/doc/ChangeLog b/gdb/doc/ChangeLog index 071a409..0525c5f 100644 --- a/gdb/doc/ChangeLog +++ b/gdb/doc/ChangeLog @@ -1,3 +1,8 @@ +2010-06-11 Stan Shebs <stan@codesourcery.com> + + * gdb.texinfo (Observer Mode): New section. + (General Query Packets): Document QAllow. + 2010-06-04 Doug Evans <dje@google.com> * gdb.texinfo (Python API): New node `Disabling Pretty-Printers'. diff --git a/gdb/doc/gdb.texinfo b/gdb/doc/gdb.texinfo index fa7a0ec..6ac7d16 100644 --- a/gdb/doc/gdb.texinfo +++ b/gdb/doc/gdb.texinfo @@ -4958,6 +4958,7 @@ you examine the stopped thread in the debugger. * Background Execution:: Running your program asynchronously * Thread-Specific Breakpoints:: Controlling breakpoints * Interrupted System Calls:: GDB may interfere with system calls +* Observer Mode:: GDB does not alter program behavior @end menu @node All-Stop Mode @@ -5318,6 +5319,103 @@ monitor certain events such as thread creation and thread destruction. When such an event happens, a system call in another thread may return prematurely, even though your program does not appear to stop. +@node Observer Mode +@subsection Observer Mode + +If you want to build on non-stop mode and observe program behavior +without any chance of disruption by @value{GDBN}, you can set +variables to disable all of the debugger's attempts to modify state, +whether by writing memory, inserting breakpoints, etc. These operate +at a low level, intercepting operations from all commands. + +When all of these are set to @code{off}, then @value{GDBN} is said to +be @dfn{observer mode}. As a convenience, the variable +@code{observer} can be set to disable these, plus enable non-stop +mode. + +Note that @value{GDBN} will not prevent you from making nonsensical +combinations of these settings. For instance, if you have enabled +@code{may-insert-breakpoints} but disabled @code{may-write-memory}, +then breakpoints that work by writing trap instructions into the code +stream will still not be able to be placed. + +@table @code + +@kindex observer +@item set observer on +@itemx set observer off +When set to @code{on}, this disables all the permission variables +below (except for @code{insert-fast-tracepoints}), plus enables +non-stop debugging. Setting this to @code{off} switches back to +normal debugging, though remaining in non-stop mode. + +@item show observer +Show whether observer mode is on or off. + +@kindex may-write-registers +@item set may-write-registers on +@itemx set may-write-registers off +This controls whether @value{GDBN} will attempt to alter the values of +registers, such as with assignment expressions in @code{print}, or the +@code{jump} command. It defaults to @code{on}. + +@item show may-write-registers +Show the current permission to write registers. + +@kindex may-write-memory +@item set may-write-memory on +@itemx set may-write-memory off +This controls whether @value{GDBN} will attempt to alter the contents +of memory, such as with assignment expressions in @code{print}. It +defaults to @code{on}. + +@item show may-write-memory +Show the current permission to write memory. + +@kindex may-insert-breakpoints +@item set may-insert-breakpoints on +@itemx set may-insert-breakpoints off +This controls whether @value{GDBN} will attempt to insert breakpoints. +This affects all breakpoints, including internal breakpoints defined +by @value{GDBN}. It defaults to @code{on}. + +@item show may-insert-breakpoints +Show the current permission to insert breakpoints. + +@kindex may-insert-tracepoints +@item set may-insert-tracepoints on +@itemx set may-insert-tracepoints off +This controls whether @value{GDBN} will attempt to insert (regular) +tracepoints at the beginning of a tracing experiment. It affects only +non-fast tracepoints, fast tracepoints being under the control of +@code{may-insert-fast-tracepoints}. It defaults to @code{on}. + +@item show may-insert-tracepoints +Show the current permission to insert tracepoints. + +@kindex may-insert-fast-tracepoints +@item set may-insert-fast-tracepoints on +@itemx set may-insert-fast-tracepoints off +This controls whether @value{GDBN} will attempt to insert fast +tracepoints at the beginning of a tracing experiment. It affects only +fast tracepoints, regular (non-fast) tracepoints being under the +control of @code{may-insert-tracepoints}. It defaults to @code{on}. + +@item show may-insert-fast-tracepoints +Show the current permission to insert fast tracepoints. + +@kindex may-interrupt +@item set may-interrupt on +@itemx set may-interrupt off +This controls whether @value{GDBN} will attempt to interrupt or stop +program execution. When this variable is @code{off}, the +@code{interrupt} command will have no effect, nor will +@kbd{Ctrl-c}. It defaults to @code{on}. + +@item show may-interrupt +Show the current permission to interrupt or stop the program. + +@end table @node Reverse Execution @chapter Running programs backward @@ -31190,6 +31288,18 @@ Here are the currently defined query and set packets: @table @samp +@item QAllow:@var{op}:@var{val}@dots{} +@cindex @samp{QAllow} packet +Specify which operations @value{GDBN} expects to request of the +target, as a semicolon-separated list of operation name and value +pairs. Possible values for @var{op} include @samp{WriteReg}, +@samp{WriteMem}, @samp{InsertBreak}, @samp{InsertTrace}, +@samp{InsertFastTrace}, and @samp{Stop}. @var{val} is either 0, +indicating that @value{GDBN} will not request the operation, or 1, +indicating that it may. (The target can then use this to set up its +own internals optimally, for instance if the debugger never expects to +insert breakpoints, it may not need to install its own trap handler.) + @item qC @cindex current thread, remote request @cindex @samp{qC} packet @@ -31711,6 +31821,11 @@ These are the currently defined stub features and their properties: @tab @samp{-} @tab No +@item @samp{QAllow} +@tab No +@tab @samp{-} +@tab No + @end multitable These are the currently defined stub features, in more detail: @@ -31808,6 +31923,9 @@ The remote stub accepts and implements the reverse step packet The remote stub understands the @samp{QTDPsrc} packet that supplies the source form of tracepoint definitions. +@item QAllow +The remote stub understands the @samp{QAllow} packet. + @end table @item qSymbol:: |