From 2ae8c8e7ce51bf38de54147e6f33bb847a3b6506 Mon Sep 17 00:00:00 2001 From: Markus Metzger Date: Mon, 11 Mar 2013 08:36:57 +0000 Subject: [PATCH] Document the branch tracing extensions to the remote serial protocol. doc/ * gdb.texinfo (Requirements): List qXfer:btrace:read requiring expat. (General Query Packets): Describe Qbtrace:bts, Qbtrace:off, and qXfer:btrace:read. --- gdb/doc/ChangeLog | 6 +++ gdb/doc/gdb.texinfo | 119 ++++++++++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 125 insertions(+) diff --git a/gdb/doc/ChangeLog b/gdb/doc/ChangeLog index f6df82a..6e3e1df 100644 --- a/gdb/doc/ChangeLog +++ b/gdb/doc/ChangeLog @@ -1,3 +1,9 @@ +2013-03-11 Markus Metzger + + * gdb.texinfo (Requirements): List qXfer:btrace:read requiring expat. + (General Query Packets): Describe Qbtrace:bts, Qbtrace:off, and + qXfer:btrace:read. + 2013-03-09 Eli Zaretskii * gdb.texinfo (General Query Packets, Tracepoint Packets): Don't diff --git a/gdb/doc/gdb.texinfo b/gdb/doc/gdb.texinfo index a607166..55929f6 100644 --- a/gdb/doc/gdb.texinfo +++ b/gdb/doc/gdb.texinfo @@ -34783,6 +34783,8 @@ or alternatively @pxref{Library List Format for SVR4 Targets}) MS-Windows shared libraries (@pxref{Shared Libraries}) @item Traceframe info (@pxref{Traceframe Info Format}) +@item +Branch trace (@pxref{Branch Trace Format}) @end itemize @item zlib @@ -35644,6 +35646,7 @@ Show the current setting of the target wait timeout. * Memory Map Format:: * Thread List Format:: * Traceframe Info Format:: +* Branch Trace Format:: @end menu @node Overview @@ -37267,6 +37270,11 @@ These are the currently defined stub features and their properties: @tab @samp{-} @tab Yes +@item @samp{qXfer:btrace:read} +@tab No +@tab @samp{-} +@tab Yes + @item @samp{qXfer:features:read} @tab No @tab @samp{-} @@ -37327,6 +37335,16 @@ These are the currently defined stub features and their properties: @tab @samp{-} @tab Yes +@item @samp{Qbtrace:off} +@tab Yes +@tab @samp{-} +@tab Yes + +@item @samp{Qbtrace:bts} +@tab Yes +@tab @samp{-} +@tab Yes + @item @samp{QNonStop} @tab No @tab @samp{-} @@ -37427,6 +37445,10 @@ byte in its buffer for the NUL. If this stub feature is not supported, The remote stub understands the @samp{qXfer:auxv:read} packet (@pxref{qXfer auxiliary vector read}). +@item qXfer:btrace:read +The remote stub understands the @samp{qXfer:btrace:read} +packet (@pxref{qXfer btrace read}). + @item qXfer:features:read The remote stub understands the @samp{qXfer:features:read} packet (@pxref{qXfer target description read}). @@ -37565,6 +37587,12 @@ See @ref{Bytecode Descriptions} for details about the bytecode. The remote stub supports running a breakpoint's command list itself, rather than reporting the hit to @value{GDBN}. +@item Qbtrace:off +The remote stub understands the @samp{Qbtrace:off} packet. + +@item Qbtrace:bts +The remote stub understands the @samp{Qbtrace:bts} packet. + @end table @item qSymbol:: @@ -37683,6 +37711,25 @@ auxiliary vector}. Note @var{annex} must be empty. This packet is not probed by default; the remote stub must request it, by supplying an appropriate @samp{qSupported} response (@pxref{qSupported}). +@item qXfer:btrace:read:@var{annex}:@var{offset},@var{length} +@anchor{qXfer btrace read} + +Return a description of the current branch trace. +@xref{Branch Trace Format}. The annex part of the generic @samp{qXfer} +packet may have one of the following values: + +@table @code +@item all +Returns all available branch trace. + +@item new +Returns all available branch trace if the branch trace changed since +the last read request. +@end table + +This packet is not probed by default; the remote stub must request it +by supplying an appropriate @samp{qSupported} response (@pxref{qSupported}). + @item qXfer:features:read:@var{annex}:@var{offset},@var{length} @anchor{qXfer target description read} Access the @dfn{target description}. @xref{Target Descriptions}. The @@ -37919,6 +37966,28 @@ The remote server created a new process. A badly formed request or an error was encountered. @end table +@item Qbtrace:bts +Enable branch tracing for the current thread using bts tracing. + +Reply: +@table @samp +@item OK +Branch tracing has been enabled. +@item E.errtext +A badly formed request or an error was encountered. +@end table + +@item Qbtrace:off +Disable branch tracing for the current thread. + +Reply: +@table @samp +@item OK +Branch tracing has been disabled. +@item E.errtext +A badly formed request or an error was encountered. +@end table + @end table @node Architecture-Specific Protocol Details @@ -40377,6 +40446,56 @@ The formal DTD for the traceframe info format is given below: length CDATA #REQUIRED> @end smallexample +@node Branch Trace Format +@section Branch Trace Format +@cindex branch trace format + +In order to display the branch trace of an inferior thread, +@value{GDBN} needs to obtain the list of branches. This list is +represented as list of sequential code blocks that are connected via +branches. The code in each block has been executed sequentially. + +This list is obtained using the @samp{qXfer:btrace:read} +(@pxref{qXfer btrace read}) packet and is an XML document. + +@value{GDBN} must be linked with the Expat library to support XML +traceframe info discovery. @xref{Expat}. + +The top-level structure of the document is shown below: + +@smallexample + + + + block... + +@end smallexample + +@itemize + +@item +A block of sequentially executed instructions starting at @var{begin} +and ending at @var{end}: + +@smallexample + +@end smallexample + +@end itemize + +The formal DTD for the branch trace format is given below: + +@smallexample + + + + + +@end smallexample + @include agentexpr.texi @node Target Descriptions -- 2.7.4