mingw/info/stabs/Questions.html

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  12 Node:<a name="Questions">Questions</a>
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  15
  16 <h2 class="appendix">Questions and Anomalies</h2>
  17
  18      <ul>
  19 <li>For GNU C stabs defining local and global variables (<code>N_LSYM</code> and
  20 <code>N_GSYM</code>), the desc field is supposed to contain the source
  21 line number on which the variable is defined.  In reality the desc
  22 field is always 0.  (This behavior is defined in <code>dbxout.c</code> and
  23 putting a line number in desc is controlled by <code>#ifdef
  24 WINNING_GDB</code>, which defaults to false). GDB supposedly uses this
  25 information if you say <code>list </code><var>var</var><code></code>.  In reality, <var>var</var> can
  26 be a variable defined in the program and GDB says <code>function
  27 </code><var>var</var><code> not defined</code>.
  28
  29      <li>In GNU C stabs, there seems to be no way to differentiate tag types:
  30 structures, unions, and enums (symbol descriptor <code>T</code>) and typedefs
  31 (symbol descriptor <code>t</code>) defined at file scope from types defined locally
  32 to a procedure or other more local scope.  They all use the <code>N_LSYM</code>
  33 stab type.  Types defined at procedure scope are emitted after the
  34 <code>N_RBRAC</code> of the preceding function and before the code of the
  35 procedure in which they are defined.  This is exactly the same as
  36 types defined in the source file between the two procedure bodies.
  37 GDB over-compensates by placing all types in block #1, the block for
  38 symbols of file scope.  This is true for default, <code>-ansi</code> and
  39 <code>-traditional</code> compiler options. (Bugs gcc/1063, gdb/1066.)
  40
  41      <li>What ends the procedure scope?  Is it the proc block's <code>N_RBRAC</code> or the
  42 next <code>N_FUN</code>?  (I believe its the first.)
  43 </ul>
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