mingw/info/gdb/GDB-MI-Breakpoint-Table-Commands.html

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  12 Node:<a name="GDB%2fMI%20Breakpoint%20Table%20Commands">GDB/MI Breakpoint Table Commands</a>,
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  18
  19 <h3 class="section"><small>GDB/MI</small> Breakpoint table commands</h3>
  20
  21    <p>This section documents <small>GDB/MI</small> commands for manipulating
  22 breakpoints.
  23
  24 <h4 class="subheading">The <code>-break-after</code> Command</h4>
  25
  26 <h5 class="subsubheading">Synopsis</h5>
  27
  28 <pre class="example">      -break-after <var>number</var> <var>count</var>
  29      </pre>
  30
  31    <p>The breakpoint number <var>number</var> is not in effect until it has been
  32 hit <var>count</var> times.  To see how this is reflected in the output of
  33 the <code>-break-list</code> command, see the description of the
  34 <code>-break-list</code> command below.
  35
  36 <h5 class="subsubheading">GDB Command</h5>
  37
  38    <p>The corresponding GDB command is <code>ignore</code>.
  39
  40 <h5 class="subsubheading">Example</h5>
  41
  42 <pre class="smallexample">     (gdb)
  43      -break-insert main
  44      ^done,bkpt={number="1",addr="0x000100d0",file="hello.c",line="5"}
  45      (gdb)
  46      -break-after 1 3
  47      ~
  48      ^done
  49      (gdb)
  50      -break-list
  51      ^done,BreakpointTable={nr_rows="1",nr_cols="6",
  52      hdr=[{width="3",alignment="-1",col_name="number",colhdr="Num"},
  53      {width="14",alignment="-1",col_name="type",colhdr="Type"},
  54      {width="4",alignment="-1",col_name="disp",colhdr="Disp"},
  55      {width="3",alignment="-1",col_name="enabled",colhdr="Enb"},
  56      {width="10",alignment="-1",col_name="addr",colhdr="Address"},
  57      {width="40",alignment="2",col_name="what",colhdr="What"}],
  58      body=[bkpt={number="1",type="breakpoint",disp="keep",enabled="y",
  59      addr="0x000100d0",func="main",file="hello.c",line="5",times="0",
  60      ignore="3"}]}
  61      (gdb)
  62      </pre>
  63
  64 <h4 class="subheading">The <code>-break-condition</code> Command</h4>
  65
  66 <h5 class="subsubheading">Synopsis</h5>
  67
  68 <pre class="example">      -break-condition <var>number</var> <var>expr</var>
  69      </pre>
  70
  71    <p>Breakpoint <var>number</var> will stop the program only if the condition in
  72 <var>expr</var> is true.  The condition becomes part of the
  73 <code>-break-list</code> output (see the description of the <code>-break-list</code>
  74 command below).
  75
  76 <h5 class="subsubheading">GDB Command</h5>
  77
  78    <p>The corresponding GDB command is <code>condition</code>.
  79
  80 <h5 class="subsubheading">Example</h5>
  81
  82 <pre class="smallexample">     (gdb)
  83      -break-condition 1 1
  84      ^done
  85      (gdb)
  86      -break-list
  87      ^done,BreakpointTable={nr_rows="1",nr_cols="6",
  88      hdr=[{width="3",alignment="-1",col_name="number",colhdr="Num"},
  89      {width="14",alignment="-1",col_name="type",colhdr="Type"},
  90      {width="4",alignment="-1",col_name="disp",colhdr="Disp"},
  91      {width="3",alignment="-1",col_name="enabled",colhdr="Enb"},
  92      {width="10",alignment="-1",col_name="addr",colhdr="Address"},
  93      {width="40",alignment="2",col_name="what",colhdr="What"}],
  94      body=[bkpt={number="1",type="breakpoint",disp="keep",enabled="y",
  95      addr="0x000100d0",func="main",file="hello.c",line="5",cond="1",
  96      times="0",ignore="3"}]}
  97      (gdb)
  98      </pre>
  99
 100 <h4 class="subheading">The <code>-break-delete</code> Command</h4>
 101
 102 <h5 class="subsubheading">Synopsis</h5>
 103
 104 <pre class="example">      -break-delete ( <var>breakpoint</var> )+
 105      </pre>
 106
 107    <p>Delete the breakpoint(s) whose number(s) are specified in the argument
 108 list.  This is obviously reflected in the breakpoint list.
 109
 110 <h5 class="subsubheading">GDB command</h5>
 111
 112    <p>The corresponding GDB command is <code>delete</code>.
 113
 114 <h5 class="subsubheading">Example</h5>
 115
 116 <pre class="example">     (gdb)
 117      -break-delete 1
 118      ^done
 119      (gdb)
 120      -break-list
 121      ^done,BreakpointTable={nr_rows="0",nr_cols="6",
 122      hdr=[{width="3",alignment="-1",col_name="number",colhdr="Num"},
 123      {width="14",alignment="-1",col_name="type",colhdr="Type"},
 124      {width="4",alignment="-1",col_name="disp",colhdr="Disp"},
 125      {width="3",alignment="-1",col_name="enabled",colhdr="Enb"},
 126      {width="10",alignment="-1",col_name="addr",colhdr="Address"},
 127      {width="40",alignment="2",col_name="what",colhdr="What"}],
 128      body=[]}
 129      (gdb)
 130      </pre>
 131
 132 <h4 class="subheading">The <code>-break-disable</code> Command</h4>
 133
 134 <h5 class="subsubheading">Synopsis</h5>
 135
 136 <pre class="example">      -break-disable ( <var>breakpoint</var> )+
 137      </pre>
 138
 139    <p>Disable the named <var>breakpoint</var>(s).  The field <code>enabled</code> in the
 140 break list is now set to <code>n</code> for the named <var>breakpoint</var>(s).
 141
 142 <h5 class="subsubheading">GDB Command</h5>
 143
 144    <p>The corresponding GDB command is <code>disable</code>.
 145
 146 <h5 class="subsubheading">Example</h5>
 147
 148 <pre class="smallexample">     (gdb)
 149      -break-disable 2
 150      ^done
 151      (gdb)
 152      -break-list
 153      ^done,BreakpointTable={nr_rows="1",nr_cols="6",
 154      hdr=[{width="3",alignment="-1",col_name="number",colhdr="Num"},
 155      {width="14",alignment="-1",col_name="type",colhdr="Type"},
 156      {width="4",alignment="-1",col_name="disp",colhdr="Disp"},
 157      {width="3",alignment="-1",col_name="enabled",colhdr="Enb"},
 158      {width="10",alignment="-1",col_name="addr",colhdr="Address"},
 159      {width="40",alignment="2",col_name="what",colhdr="What"}],
 160      body=[bkpt={number="2",type="breakpoint",disp="keep",enabled="n",
 161      addr="0x000100d0",func="main",file="hello.c",line="5",times="0"}]}
 162      (gdb)
 163      </pre>
 164
 165 <h4 class="subheading">The <code>-break-enable</code> Command</h4>
 166
 167 <h5 class="subsubheading">Synopsis</h5>
 168
 169 <pre class="example">      -break-enable ( <var>breakpoint</var> )+
 170      </pre>
 171
 172    <p>Enable (previously disabled) <var>breakpoint</var>(s).
 173
 174 <h5 class="subsubheading">GDB Command</h5>
 175
 176    <p>The corresponding GDB command is <code>enable</code>.
 177
 178 <h5 class="subsubheading">Example</h5>
 179
 180 <pre class="smallexample">     (gdb)
 181      -break-enable 2
 182      ^done
 183      (gdb)
 184      -break-list
 185      ^done,BreakpointTable={nr_rows="1",nr_cols="6",
 186      hdr=[{width="3",alignment="-1",col_name="number",colhdr="Num"},
 187      {width="14",alignment="-1",col_name="type",colhdr="Type"},
 188      {width="4",alignment="-1",col_name="disp",colhdr="Disp"},
 189      {width="3",alignment="-1",col_name="enabled",colhdr="Enb"},
 190      {width="10",alignment="-1",col_name="addr",colhdr="Address"},
 191      {width="40",alignment="2",col_name="what",colhdr="What"}],
 192      body=[bkpt={number="2",type="breakpoint",disp="keep",enabled="y",
 193      addr="0x000100d0",func="main",file="hello.c",line="5",times="0"}]}
 194      (gdb)
 195      </pre>
 196
 197 <h4 class="subheading">The <code>-break-info</code> Command</h4>
 198
 199 <h5 class="subsubheading">Synopsis</h5>
 200
 201 <pre class="example">      -break-info <var>breakpoint</var>
 202      </pre>
 203
 204    <p>Get information about a single breakpoint.
 205
 206 <h5 class="subsubheading">GDB command</h5>
 207
 208    <p>The corresponding GDB command is <code>info break </code><var>breakpoint</var><code></code>.
 209
 210 <h5 class="subsubheading">Example</h5>
 211
 212    <p>N.A.
 213
 214 <h4 class="subheading">The <code>-break-insert</code> Command</h4>
 215
 216 <h5 class="subsubheading">Synopsis</h5>
 217
 218 <pre class="example">      -break-insert [ -t ] [ -h ] [ -r ]
 219          [ -c <var>condition</var> ] [ -i <var>ignore-count</var> ]
 220          [ -p <var>thread</var> ] [ <var>line</var> | <var>addr</var> ]
 221      </pre>
 222
 223 <p>If specified, <var>line</var>, can be one of:
 224
 225      <ul>
 226 <li>function
 227 <li>filename:linenum
 228 <li>filename:function
 229 <li>*address
 230 </ul>
 231
 232    <p>The possible optional parameters of this command are:
 233
 234      <dl>
 235 <dt><code>-t</code>
 236      <dd>Insert a tempoary breakpoint.
 237 <br><dt><code>-h</code>
 238      <dd>Insert a hardware breakpoint.
 239 <br><dt><code>-c </code><var>condition</var><code></code>
 240      <dd>Make the breakpoint conditional on <var>condition</var>.
 241 <br><dt><code>-i </code><var>ignore-count</var><code></code>
 242      <dd>Initialize the <var>ignore-count</var>.
 243 <br><dt><code>-r</code>
 244      <dd>Insert a regular breakpoint in all the functions whose names match the
 245 given regular expression.  Other flags are not applicable to regular
 246 expresson.
 247 </dl>
 248
 249 <h5 class="subsubheading">Result</h5>
 250
 251    <p>The result is in the form:
 252
 253 <pre class="example">      ^done,bkptno="<var>number</var>",func="<var>funcname</var>",
 254        file="<var>filename</var>",line="<var>lineno</var>"
 255      </pre>
 256
 257 <p>where <var>number</var> is the GDB number for this breakpoint, <var>funcname</var>
 258 is the name of the function where the breakpoint was inserted,
 259 <var>filename</var> is the name of the source file which contains this
 260 function, and <var>lineno</var> is the source line number within that file.
 261
 262    <p>Note: this format is open to change.
 263
 264 <h5 class="subsubheading">GDB Command</h5>
 265
 266    <p>The corresponding GDB commands are <code>break</code>, <code>tbreak</code>,
 267 <code>hbreak</code>, <code>thbreak</code>, and <code>rbreak</code>.
 268
 269 <h5 class="subsubheading">Example</h5>
 270
 271 <pre class="smallexample">     (gdb)
 272      -break-insert main
 273      ^done,bkpt={number="1",addr="0x0001072c",file="recursive2.c",line="4"}
 274      (gdb)
 275      -break-insert -t foo
 276      ^done,bkpt={number="2",addr="0x00010774",file="recursive2.c",line="11"}
 277      (gdb)
 278      -break-list
 279      ^done,BreakpointTable={nr_rows="2",nr_cols="6",
 280      hdr=[{width="3",alignment="-1",col_name="number",colhdr="Num"},
 281      {width="14",alignment="-1",col_name="type",colhdr="Type"},
 282      {width="4",alignment="-1",col_name="disp",colhdr="Disp"},
 283      {width="3",alignment="-1",col_name="enabled",colhdr="Enb"},
 284      {width="10",alignment="-1",col_name="addr",colhdr="Address"},
 285      {width="40",alignment="2",col_name="what",colhdr="What"}],
 286      body=[bkpt={number="1",type="breakpoint",disp="keep",enabled="y",
 287      addr="0x0001072c", func="main",file="recursive2.c",line="4",times="0"},
 288      bkpt={number="2",type="breakpoint",disp="del",enabled="y",
 289      addr="0x00010774",func="foo",file="recursive2.c",line="11",times="0"}]}
 290      (gdb)
 291      -break-insert -r foo.*
 292      ~int foo(int, int);
 293      ^done,bkpt={number="3",addr="0x00010774",file="recursive2.c",line="11"}
 294      (gdb)
 295      </pre>
 296
 297 <h4 class="subheading">The <code>-break-list</code> Command</h4>
 298
 299 <h5 class="subsubheading">Synopsis</h5>
 300
 301 <pre class="example">      -break-list
 302      </pre>
 303
 304    <p>Displays the list of inserted breakpoints, showing the following fields:
 305
 306      <dl>
 307 <dt><code>Number</code>
 308      <dd>number of the breakpoint
 309 <br><dt><code>Type</code>
 310      <dd>type of the breakpoint: <code>breakpoint</code> or <code>watchpoint</code>
 311 <br><dt><code>Disposition</code>
 312      <dd>should the breakpoint be deleted or disabled when it is hit: <code>keep</code>
 313 or <code>nokeep</code>
 314 <br><dt><code>Enabled</code>
 315      <dd>is the breakpoint enabled or no: <code>y</code> or <code>n</code>
 316 <br><dt><code>Address</code>
 317      <dd>memory location at which the breakpoint is set
 318 <br><dt><code>What</code>
 319      <dd>logical location of the breakpoint, expressed by function name, file
 320 name, line number
 321 <br><dt><code>Times</code>
 322      <dd>number of times the breakpoint has been hit
 323 </dl>
 324
 325    <p>If there are no breakpoints or watchpoints, the <code>BreakpointTable</code>
 326 <code>body</code> field is an empty list.
 327
 328 <h5 class="subsubheading">GDB Command</h5>
 329
 330    <p>The corresponding GDB command is <code>info break</code>.
 331
 332 <h5 class="subsubheading">Example</h5>
 333
 334 <pre class="smallexample">     (gdb)
 335      -break-list
 336      ^done,BreakpointTable={nr_rows="2",nr_cols="6",
 337      hdr=[{width="3",alignment="-1",col_name="number",colhdr="Num"},
 338      {width="14",alignment="-1",col_name="type",colhdr="Type"},
 339      {width="4",alignment="-1",col_name="disp",colhdr="Disp"},
 340      {width="3",alignment="-1",col_name="enabled",colhdr="Enb"},
 341      {width="10",alignment="-1",col_name="addr",colhdr="Address"},
 342      {width="40",alignment="2",col_name="what",colhdr="What"}],
 343      body=[bkpt={number="1",type="breakpoint",disp="keep",enabled="y",
 344      addr="0x000100d0",func="main",file="hello.c",line="5",times="0"},
 345      bkpt={number="2",type="breakpoint",disp="keep",enabled="y",
 346      addr="0x00010114",func="foo",file="hello.c",line="13",times="0"}]}
 347      (gdb)
 348      </pre>
 349
 350    <p>Here's an example of the result when there are no breakpoints:
 351
 352 <pre class="smallexample">     (gdb)
 353      -break-list
 354      ^done,BreakpointTable={nr_rows="0",nr_cols="6",
 355      hdr=[{width="3",alignment="-1",col_name="number",colhdr="Num"},
 356      {width="14",alignment="-1",col_name="type",colhdr="Type"},
 357      {width="4",alignment="-1",col_name="disp",colhdr="Disp"},
 358      {width="3",alignment="-1",col_name="enabled",colhdr="Enb"},
 359      {width="10",alignment="-1",col_name="addr",colhdr="Address"},
 360      {width="40",alignment="2",col_name="what",colhdr="What"}],
 361      body=[]}
 362      (gdb)
 363      </pre>
 364
 365 <h4 class="subheading">The <code>-break-watch</code> Command</h4>
 366
 367 <h5 class="subsubheading">Synopsis</h5>
 368
 369 <pre class="example">      -break-watch [ -a | -r ]
 370      </pre>
 371
 372    <p>Create a watchpoint.  With the <code>-a</code> option it will create an
 373 <dfn>access</dfn> watchpoint, i.e. a watchpoint that triggers either on a
 374 read from or on a write to the memory location.  With the <code>-r</code>
 375 option, the watchpoint created is a <dfn>read</dfn> watchpoint, i.e. it will
 376 trigger only when the memory location is accessed for reading.  Without
 377 either of the options, the watchpoint created is a regular watchpoint,
 378 i.e. it will trigger when the memory location is accessed for writing.
 379 See <a href="Set-Watchpoints.html#Set%20Watchpoints">Setting watchpoints</a>.
 380
 381    <p>Note that <code>-break-list</code> will report a single list of watchpoints and
 382 breakpoints inserted.
 383
 384 <h5 class="subsubheading">GDB Command</h5>
 385
 386    <p>The corresponding GDB commands are <code>watch</code>, <code>awatch</code>, and
 387 <code>rwatch</code>.
 388
 389 <h5 class="subsubheading">Example</h5>
 390
 391    <p>Setting a watchpoint on a variable in the <code>main</code> function:
 392
 393 <pre class="smallexample">     (gdb)
 394      -break-watch x
 395      ^done,wpt={number="2",exp="x"}
 396      (gdb)
 397      -exec-continue
 398      ^running
 399      ^done,reason="watchpoint-trigger",wpt={number="2",exp="x"},
 400      value={old="-268439212",new="55"},
 401      frame={func="main",args=[],file="recursive2.c",line="5"}
 402      (gdb)
 403      </pre>
 404
 405    <p>Setting a watchpoint on a variable local to a function.  GDB will stop
 406 the program execution twice: first for the variable changing value, then
 407 for the watchpoint going out of scope.
 408
 409 <pre class="smallexample">     (gdb)
 410      -break-watch C
 411      ^done,wpt={number="5",exp="C"}
 412      (gdb)
 413      -exec-continue
 414      ^running
 415      ^done,reason="watchpoint-trigger",
 416      wpt={number="5",exp="C"},value={old="-276895068",new="3"},
 417      frame={func="callee4",args=[],
 418      file="../../../devo/gdb/testsuite/gdb.mi/basics.c",line="13"}
 419      (gdb)
 420      -exec-continue
 421      ^running
 422      ^done,reason="watchpoint-scope",wpnum="5",
 423      frame={func="callee3",args=[{name="strarg",
 424      value="0x11940 \"A string argument.\""}],
 425      file="../../../devo/gdb/testsuite/gdb.mi/basics.c",line="18"}
 426      (gdb)
 427      </pre>
 428
 429    <p>Listing breakpoints and watchpoints, at different points in the program
 430 execution.  Note that once the watchpoint goes out of scope, it is
 431 deleted.
 432
 433 <pre class="smallexample">     (gdb)
 434      -break-watch C
 435      ^done,wpt={number="2",exp="C"}
 436      (gdb)
 437      -break-list
 438      ^done,BreakpointTable={nr_rows="2",nr_cols="6",
 439      hdr=[{width="3",alignment="-1",col_name="number",colhdr="Num"},
 440      {width="14",alignment="-1",col_name="type",colhdr="Type"},
 441      {width="4",alignment="-1",col_name="disp",colhdr="Disp"},
 442      {width="3",alignment="-1",col_name="enabled",colhdr="Enb"},
 443      {width="10",alignment="-1",col_name="addr",colhdr="Address"},
 444      {width="40",alignment="2",col_name="what",colhdr="What"}],
 445      body=[bkpt={number="1",type="breakpoint",disp="keep",enabled="y",
 446      addr="0x00010734",func="callee4",
 447      file="../../../devo/gdb/testsuite/gdb.mi/basics.c",line="8",times="1"},
 448      bkpt={number="2",type="watchpoint",disp="keep",
 449      enabled="y",addr="",what="C",times="0"}]}
 450      (gdb)
 451      -exec-continue
 452      ^running
 453      ^done,reason="watchpoint-trigger",wpt={number="2",exp="C"},
 454      value={old="-276895068",new="3"},
 455      frame={func="callee4",args=[],
 456      file="../../../devo/gdb/testsuite/gdb.mi/basics.c",line="13"}
 457      (gdb)
 458      -break-list
 459      ^done,BreakpointTable={nr_rows="2",nr_cols="6",
 460      hdr=[{width="3",alignment="-1",col_name="number",colhdr="Num"},
 461      {width="14",alignment="-1",col_name="type",colhdr="Type"},
 462      {width="4",alignment="-1",col_name="disp",colhdr="Disp"},
 463      {width="3",alignment="-1",col_name="enabled",colhdr="Enb"},
 464      {width="10",alignment="-1",col_name="addr",colhdr="Address"},
 465      {width="40",alignment="2",col_name="what",colhdr="What"}],
 466      body=[bkpt={number="1",type="breakpoint",disp="keep",enabled="y",
 467      addr="0x00010734",func="callee4",
 468      file="../../../devo/gdb/testsuite/gdb.mi/basics.c",line="8",times="1"},
 469      bkpt={number="2",type="watchpoint",disp="keep",
 470      enabled="y",addr="",what="C",times="-5"}]}
 471      (gdb)
 472      -exec-continue
 473      ^running
 474      ^done,reason="watchpoint-scope",wpnum="2",
 475      frame={func="callee3",args=[{name="strarg",
 476      value="0x11940 \"A string argument.\""}],
 477      file="../../../devo/gdb/testsuite/gdb.mi/basics.c",line="18"}
 478      (gdb)
 479      -break-list
 480      ^done,BreakpointTable={nr_rows="1",nr_cols="6",
 481      hdr=[{width="3",alignment="-1",col_name="number",colhdr="Num"},
 482      {width="14",alignment="-1",col_name="type",colhdr="Type"},
 483      {width="4",alignment="-1",col_name="disp",colhdr="Disp"},
 484      {width="3",alignment="-1",col_name="enabled",colhdr="Enb"},
 485      {width="10",alignment="-1",col_name="addr",colhdr="Address"},
 486      {width="40",alignment="2",col_name="what",colhdr="What"}],
 487      body=[bkpt={number="1",type="breakpoint",disp="keep",enabled="y",
 488      addr="0x00010734",func="callee4",
 489      file="../../../devo/gdb/testsuite/gdb.mi/basics.c",line="8",times="1"}]}
 490      (gdb)
 491      </pre>
 492
 493    </body></html>
 494