diff options
| -rw-r--r-- | gdb/ChangeLog | 18 | ||||
| -rw-r--r-- | gdb/NEWS | 6 | ||||
| -rw-r--r-- | gdb/ax-gdb.c | 119 | ||||
| -rw-r--r-- | gdb/ax-gdb.h | 2 | ||||
| -rw-r--r-- | gdb/doc/ChangeLog | 8 | ||||
| -rw-r--r-- | gdb/doc/agentexpr.texi | 20 | ||||
| -rw-r--r-- | gdb/doc/gdb.texinfo | 73 | ||||
| -rw-r--r-- | gdb/remote.c | 25 | ||||
| -rw-r--r-- | gdb/testsuite/ChangeLog | 4 | ||||
| -rw-r--r-- | gdb/testsuite/gdb.trace/tracecmd.exp | 7 | ||||
| -rw-r--r-- | gdb/tracepoint.c | 20 |
11 files changed, 292 insertions, 10 deletions
diff --git a/gdb/ChangeLog b/gdb/ChangeLog index 690f76a..11e2241 100644 --- a/gdb/ChangeLog +++ b/gdb/ChangeLog @@ -1,3 +1,21 @@ +2009-07-14 Stan Shebs <stan@codesourcery.com> + + Conditional tracepoints. + * ax-gdb.h (gen_eval_for_expr): Declare. + * ax-gdb.c (gen_expr): Generate bytecodes for BINOP_EQUAL + and other comparisons. + (gen_eval_for_expr): New function. + (agent_eval_command): New maintenance command. + (_initialize_ax_gdb): Define the command. + * remote.c (struct remote_state): New field cond_tracepoints. + (PACKET_ConditionalTracepoints): New packet config type. + (remote_cond_tracepoint_feature): New function. + (remote_protocol_features): Add ConditionalTracepoints. + (remote_supports_cond_tracepoints): New function. + (_initialize_remote): Add ConditionalTracepoints. + * tracepoint.c (download_tracepoint): Add conditional. + * NEWS: Mention conditional tracepoints. + 2009-07-14 Ulrich Weigand <uweigand@de.ibm.com> * objfiles.c (objfile_relocate): Do not relocate the same @@ -3,6 +3,12 @@ *** Changes since GDB 6.8 +* Tracepoints may now be conditional. The syntax is as for +breakpoints; either an "if" clause appended to the "trace" command, +or the "condition" command is available. GDB sends the condition to +the target for evaluation using the same bytecode format as is used +for tracepoint actions. + * "disassemble" command with a /r modifier, print the raw instructions in hex as well as in symbolic form." diff --git a/gdb/ax-gdb.c b/gdb/ax-gdb.c index 4edf8f2..999b27c 100644 --- a/gdb/ax-gdb.c +++ b/gdb/ax-gdb.c @@ -1468,6 +1468,12 @@ gen_expr (struct expression *exp, union exp_element **pc, case BINOP_BITWISE_AND: case BINOP_BITWISE_IOR: case BINOP_BITWISE_XOR: + case BINOP_EQUAL: + case BINOP_NOTEQUAL: + case BINOP_LESS: + case BINOP_GTR: + case BINOP_LEQ: + case BINOP_GEQ: (*pc)++; gen_expr (exp, pc, ax, &value1); gen_usual_unary (exp, ax, &value1); @@ -1537,6 +1543,47 @@ gen_expr (struct expression *exp, union exp_element **pc, aop_bit_xor, aop_bit_xor, 0, "bitwise exclusive-or"); break; + case BINOP_EQUAL: + gen_binop (ax, value, &value1, &value2, + aop_equal, aop_equal, 0, "equal"); + break; + + case BINOP_NOTEQUAL: + gen_binop (ax, value, &value1, &value2, + aop_equal, aop_equal, 0, "equal"); + gen_logical_not (ax, value, + language_bool_type (exp->language_defn, + exp->gdbarch)); + break; + + case BINOP_LESS: + gen_binop (ax, value, &value1, &value2, + aop_less_signed, aop_less_unsigned, 0, "less than"); + break; + + case BINOP_GTR: + ax_simple (ax, aop_swap); + gen_binop (ax, value, &value1, &value2, + aop_less_signed, aop_less_unsigned, 0, "less than"); + break; + + case BINOP_LEQ: + ax_simple (ax, aop_swap); + gen_binop (ax, value, &value1, &value2, + aop_less_signed, aop_less_unsigned, 0, "less than"); + gen_logical_not (ax, value, + language_bool_type (exp->language_defn, + exp->gdbarch)); + break; + + case BINOP_GEQ: + gen_binop (ax, value, &value1, &value2, + aop_less_signed, aop_less_unsigned, 0, "less than"); + gen_logical_not (ax, value, + language_bool_type (exp->language_defn, + exp->gdbarch)); + break; + default: /* We should only list operators in the outer case statement that we actually handle in the inner case statement. */ @@ -1756,6 +1803,37 @@ gen_trace_for_expr (CORE_ADDR scope, struct expression *expr) return ax; } +/* Given a GDB expression EXPR, return a bytecode sequence that will + evaluate and return a result. The bytecodes will do a direct + evaluation, using the current data on the target, rather than + recording blocks of memory and registers for later use, as + gen_trace_for_expr does. The generated bytecode sequence leaves + the result of expression evaluation on the top of the stack. */ + +struct agent_expr * +gen_eval_for_expr (CORE_ADDR scope, struct expression *expr) +{ + struct cleanup *old_chain = 0; + struct agent_expr *ax = new_agent_expr (scope); + union exp_element *pc; + struct axs_value value; + + old_chain = make_cleanup_free_agent_expr (ax); + + pc = expr->elts; + trace_kludge = 0; + gen_expr (expr, &pc, ax, &value); + + /* Oh, and terminate. */ + ax_simple (ax, aop_end); + + /* We have successfully built the agent expr, so cancel the cleanup + request. If we add more cleanups that we always want done, this + will have to get more complicated. */ + discard_cleanups (old_chain); + return ax; +} + static void agent_command (char *exp, int from_tty) { @@ -1786,6 +1864,41 @@ agent_command (char *exp, int from_tty) do_cleanups (old_chain); dont_repeat (); } + +/* Parse the given expression, compile it into an agent expression + that does direct evaluation, and display the resulting + expression. */ + +static void +agent_eval_command (char *exp, int from_tty) +{ + struct cleanup *old_chain = 0; + struct expression *expr; + struct agent_expr *agent; + struct frame_info *fi = get_current_frame (); /* need current scope */ + + /* We don't deal with overlay debugging at the moment. We need to + think more carefully about this. If you copy this code into + another command, change the error message; the user shouldn't + have to know anything about agent expressions. */ + if (overlay_debugging) + error (_("GDB can't do agent expression translation with overlays.")); + + if (exp == 0) + error_no_arg (_("expression to translate")); + + expr = parse_expression (exp); + old_chain = make_cleanup (free_current_contents, &expr); + agent = gen_eval_for_expr (get_frame_pc (fi), expr); + make_cleanup_free_agent_expr (agent); + ax_print (gdb_stdout, agent); + + /* It would be nice to call ax_reqs here to gather some general info + about the expression, and then print out the result. */ + + do_cleanups (old_chain); + dont_repeat (); +} /* Initialization code. */ @@ -1795,6 +1908,10 @@ void _initialize_ax_gdb (void) { add_cmd ("agent", class_maintenance, agent_command, - _("Translate an expression into remote agent bytecode."), + _("Translate an expression into remote agent bytecode for tracing."), + &maintenancelist); + + add_cmd ("agent-eval", class_maintenance, agent_eval_command, + _("Translate an expression into remote agent bytecode for evaluation."), &maintenancelist); } diff --git a/gdb/ax-gdb.h b/gdb/ax-gdb.h index 57e889e..5d03c18 100644 --- a/gdb/ax-gdb.h +++ b/gdb/ax-gdb.h @@ -99,4 +99,6 @@ struct axs_value function to discover which registers the expression uses. */ extern struct agent_expr *gen_trace_for_expr (CORE_ADDR, struct expression *); +extern struct agent_expr *gen_eval_for_expr (CORE_ADDR, struct expression *); + #endif /* AX_GDB_H */ diff --git a/gdb/doc/ChangeLog b/gdb/doc/ChangeLog index cea168c..01fb199 100644 --- a/gdb/doc/ChangeLog +++ b/gdb/doc/ChangeLog @@ -1,3 +1,11 @@ +2009-07-14 Stan Shebs <stan@codesourcery.com> + + * gdb.texinfo (Tracepoint Conditions): New section. + (General Query Packets): Describe ConditionalTracepoints. + (Tracepoint Packets): Describe condition field. + (Maintenance Commands): Describe maint agent-eval. + * agentexpr.texi (Using Agent Expressions): Mention eval usage. + 2009-07-11 Hui Zhu <teawater@gmail.com> * gdb.texinfo (disassemble): Add a new modifier /r diff --git a/gdb/doc/agentexpr.texi b/gdb/doc/agentexpr.texi index 1b893d5..3066319 100644 --- a/gdb/doc/agentexpr.texi +++ b/gdb/doc/agentexpr.texi @@ -7,13 +7,11 @@ @c This file is part of the GDB manual. @c -@c Copyright (C) 2003, 2004, 2005, 2006 +@c Copyright (C) 2003, 2004, 2005, 2006, 2009 @c Free Software Foundation, Inc. @c @c See the file gdb.texinfo for copying conditions. -@c Revision: $Id$ - @node Agent Expressions @appendix The GDB Agent Expression Mechanism @@ -473,8 +471,20 @@ address, and the top of the stack is the lvalue's size, in bytes. @node Using Agent Expressions @section Using Agent Expressions -Here is a sketch of a full non-stop debugging cycle, showing how agent -expressions fit into the process. +Agent expressions can be used in several different ways by @value{GDBN}, +and the debugger can generate different bytecode sequences as appropriate. + +One possibility is to do expression evaluation on the target rather +than the host, such as for the conditional of a conditional +tracepoint. In such a case, @value{GDBN} compiles the source +expression into a bytecode sequence that simply gets values from +registers or memory, does arithmetic, and returns a result. + +Another way to use agent expressions is for tracepoint data +collection. @value{GDBN} generates a different bytecode sequence for +collection; in addition to bytecodes that do the calculation, +@value{GDBN} adds @code{trace} bytecodes to save the pieces of +memory that were used. @itemize @bullet diff --git a/gdb/doc/gdb.texinfo b/gdb/doc/gdb.texinfo index fc5e60f..71ae4b5 100644 --- a/gdb/doc/gdb.texinfo +++ b/gdb/doc/gdb.texinfo @@ -8932,6 +8932,7 @@ conditions and actions. * Create and Delete Tracepoints:: * Enable and Disable Tracepoints:: * Tracepoint Passcounts:: +* Tracepoint Conditions:: * Tracepoint Actions:: * Listing Tracepoints:: * Starting and Stopping Trace Experiments:: @@ -8971,6 +8972,13 @@ Here are some examples of using the @code{trace} command: @noindent You can abbreviate @code{trace} as @code{tr}. +@item trace @var{location} if @var{cond} +Set a tracepoint with condition @var{cond}; evaluate the expression +@var{cond} each time the tracepoint is reached, and collect data only +if the value is nonzero---that is, if @var{cond} evaluates as true. +@xref{Tracepoint Conditions, ,Tracepoint Conditions}, for more +information on tracepoint conditions. + @vindex $tpnum @cindex last tracepoint number @cindex recent tracepoint number @@ -9053,6 +9061,44 @@ Examples: @end smallexample @end table +@node Tracepoint Conditions +@subsection Tracepoint Conditions +@cindex conditional tracepoints +@cindex tracepoint conditions + +The simplest sort of tracepoint collects data every time your program +reaches a specified place. You can also specify a @dfn{condition} for +a tracepoint. A condition is just a Boolean expression in your +programming language (@pxref{Expressions, ,Expressions}). A +tracepoint with a condition evaluates the expression each time your +program reaches it, and data collection happens only if the condition +is true. + +Tracepoint conditions can be specified when a tracepoint is set, by +using @samp{if} in the arguments to the @code{trace} command. +@xref{Create and Delete Tracepoints, ,Setting Tracepoints}. They can +also be set or changed at any time with the @code{condition} command, +just as with breakpoints. + +Unlike breakpoint conditions, @value{GDBN} does not actually evaluate +the conditional expression itself. Instead, @value{GDBN} encodes the +expression into an agent expression (@pxref{Agent Expressions} +suitable for execution on the target, independently of @value{GDBN}. +Global variables become raw memory locations, locals become stack +accesses, and so forth. + +For instance, suppose you have a function that is usually called +frequently, but should not be called after an error has occurred. You +could use the following tracepoint command to collect data about calls +of that function that happen while the error code is propagating +through the program; an unconditional tracepoint could end up +collecting thousands of useless trace frames that you would have to +search through. + +@smallexample +(@value{GDBP}) @kbd{trace normal_operation if errcode > 0} +@end smallexample + @node Tracepoint Actions @subsection Tracepoint Action Lists @@ -26534,10 +26580,19 @@ messages, see @ref{Debugging Output}.) @table @code @kindex maint agent +@kindex maint agent-eval @item maint agent @var{expression} +@itemx maint agent-eval @var{expression} Translate the given @var{expression} into remote agent bytecodes. This command is useful for debugging the Agent Expression mechanism -(@pxref{Agent Expressions}). +(@pxref{Agent Expressions}). The @samp{agent} version produces an +expression useful for data collection, such as by tracepoints, while +@samp{maint agent-eval} produces an expression that evaluates directly +to a result. For instance, a collection expression for @code{globa + +globb} will include bytecodes to record four bytes of memory at each +of the addresses of @code{globa} and @code{globb}, while discarding +the result of the addition, while an evaluation expression will do the +addition and return the sum. @kindex maint info breakpoints @item @anchor{maint info breakpoints}maint info breakpoints @@ -28415,6 +28470,11 @@ These are the currently defined stub features and their properties: @tab @samp{-} @tab No +@item @samp{ConditionalTracepoints} +@tab No +@tab @samp{-} +@tab No + @end multitable These are the currently defined stub features, in more detail: @@ -28492,6 +28552,10 @@ indicated it supports them in its @samp{qSupported} request. The remote stub understands the @samp{qXfer:osdata:read} packet ((@pxref{qXfer osdata read}). +@item ConditionalTracepoints +The remote stub accepts and implements conditional expressions defined +for tracepoints (@pxref{Tracepoint Conditions}). + @end table @item qSymbol:: @@ -28804,11 +28868,14 @@ tracepoints (@pxref{Tracepoints}). @table @samp -@item QTDP:@var{n}:@var{addr}:@var{ena}:@var{step}:@var{pass}@r{[}-@r{]} +@item QTDP:@var{n}:@var{addr}:@var{ena}:@var{step}:@var{pass}[:X@var{len},@var{bytes}]@r{[}-@r{]} Create a new tracepoint, number @var{n}, at @var{addr}. If @var{ena} is @samp{E}, then the tracepoint is enabled; if it is @samp{D}, then the tracepoint is disabled. @var{step} is the tracepoint's step -count, and @var{pass} is its pass count. If the trailing @samp{-} is +count, and @var{pass} is its pass count. If an @samp{X} is present, +it introduces a tracepoint condition, which consists of a hexadecimal +length, followed by a comma and hex-encoded bytes, in a manner similar +to action encodings as described below. If the trailing @samp{-} is present, further @samp{QTDP} packets will follow to specify this tracepoint's actions. diff --git a/gdb/remote.c b/gdb/remote.c index 0a03fc7..ba5c346 100644 --- a/gdb/remote.c +++ b/gdb/remote.c @@ -294,6 +294,9 @@ struct remote_state /* True if the stub reports support for vCont;t. */ int support_vCont_t; + + /* True if the stub reports support for conditional tracepoints. */ + int cond_tracepoints; }; /* Returns true if the multi-process extensions are in effect. */ @@ -993,6 +996,7 @@ enum { PACKET_qXfer_siginfo_read, PACKET_qXfer_siginfo_write, PACKET_qAttached, + PACKET_ConditionalTracepoints, PACKET_MAX }; @@ -3015,6 +3019,15 @@ remote_non_stop_feature (const struct protocol_feature *feature, rs->non_stop_aware = (support == PACKET_ENABLE); } +static void +remote_cond_tracepoint_feature (const struct protocol_feature *feature, + enum packet_support support, + const char *value) +{ + struct remote_state *rs = get_remote_state (); + rs->cond_tracepoints = (support == PACKET_ENABLE); +} + static struct protocol_feature remote_protocol_features[] = { { "PacketSize", PACKET_DISABLE, remote_packet_size, -1 }, { "qXfer:auxv:read", PACKET_DISABLE, remote_supported_packet, @@ -3041,6 +3054,8 @@ static struct protocol_feature remote_protocol_features[] = { PACKET_qXfer_siginfo_read }, { "qXfer:siginfo:write", PACKET_DISABLE, remote_supported_packet, PACKET_qXfer_siginfo_write }, + { "ConditionalTracepoints", PACKET_DISABLE, remote_cond_tracepoint_feature, + PACKET_ConditionalTracepoints }, }; static void @@ -8740,6 +8755,13 @@ remote_supports_multi_process (void) return remote_multi_process_p (rs); } +int +remote_supports_cond_tracepoints (void) +{ + struct remote_state *rs = get_remote_state (); + return rs->cond_tracepoints; +} + static void init_remote_ops (void) { @@ -9183,6 +9205,9 @@ Show the maximum size of the address (in bits) in a memory packet."), NULL, add_packet_config_cmd (&remote_protocol_packets[PACKET_qAttached], "qAttached", "query-attached", 0); + add_packet_config_cmd (&remote_protocol_packets[PACKET_ConditionalTracepoints], + "ConditionalTracepoints", "conditional-tracepoints", 0); + /* Keep the old ``set remote Z-packet ...'' working. Each individual Z sub-packet has its own set and show commands, but users may have sets to this variable in their .gdbinit files (or in their diff --git a/gdb/testsuite/ChangeLog b/gdb/testsuite/ChangeLog index 763a12f..ad57d81 100644 --- a/gdb/testsuite/ChangeLog +++ b/gdb/testsuite/ChangeLog @@ -1,3 +1,7 @@ +2009-07-14 Stan Shebs <stan@codesourcery.com> + + * gdb.trace/tracecmd.exp: Add basic test of tracepoint conditions. + 2009-07-14 Michael Snyder <msnyder@vmware.com> * gdb.reverse/step-reverse.exp (stepi into function call): diff --git a/gdb/testsuite/gdb.trace/tracecmd.exp b/gdb/testsuite/gdb.trace/tracecmd.exp index edfc1e2..968088b 100644 --- a/gdb/testsuite/gdb.trace/tracecmd.exp +++ b/gdb/testsuite/gdb.trace/tracecmd.exp @@ -153,7 +153,12 @@ gdb_test "trace" "No default breakpoint address now." \ # deferred to limits test module # 1.11 tracepoint conditions -# conditions on tracepoints not implemented +gdb_delete_tracepoints +gdb_test "trace gdb_recursion_test if q1 > 0" \ + "Tracepoint $decimal at $hex: file.*$srcfile, line $testline1." \ + "1.11a: conditional tracepoint" +gdb_test "info trace" "in gdb_recursion_test.*$srcfile:$testline1.*trace only if q1 > 0" \ + "1.11b: verify conditional tracepoint" # 1.12 set tracepoint in prologue # [see tfind.exp] diff --git a/gdb/tracepoint.c b/gdb/tracepoint.c index 232c9e9..0d439ef 100644 --- a/gdb/tracepoint.c +++ b/gdb/tracepoint.c @@ -33,6 +33,7 @@ #include "breakpoint.h" #include "tracepoint.h" #include "remote.h" +extern int remote_supports_cond_tracepoints (void); #include "linespec.h" #include "regcache.h" #include "completer.h" @@ -1311,12 +1312,31 @@ download_tracepoint (struct breakpoint *t) char **stepping_actions; int ndx; struct cleanup *old_chain = NULL; + struct agent_expr *aexpr; + struct cleanup *aexpr_chain = NULL; sprintf_vma (tmp, (t->loc ? t->loc->address : 0)); sprintf (buf, "QTDP:%x:%s:%c:%lx:%x", t->number, tmp, /* address */ (t->enable_state == bp_enabled ? 'E' : 'D'), t->step_count, t->pass_count); + /* If the tracepoint has a conditional, make it into an agent + expression and append to the definition. */ + if (t->loc->cond) + { + /* Only test support at download time, we may not know target + capabilities at definition time. */ + if (remote_supports_cond_tracepoints ()) + { + aexpr = gen_eval_for_expr (t->loc->address, t->loc->cond); + aexpr_chain = make_cleanup_free_agent_expr (aexpr); + sprintf (buf + strlen (buf), ":X%x,", aexpr->len); + mem2hex (aexpr->buf, buf + strlen (buf), aexpr->len); + do_cleanups (aexpr_chain); + } + else + warning (_("Target does not support conditional tracepoints, ignoring tp %d cond"), t->number); + } if (t->actions) strcat (buf, "-"); |