mingw/info/stabs/Symbol-Table-Format.html

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  12 Node:<a name="Symbol%20Table%20Format">Symbol Table Format</a>,
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  18 <h3 class="section">Symbol Table Format</h3>
  19
  20    <p>Each time the assembler encounters a stab directive, it puts
  21 each field of the stab into a corresponding field in a symbol table
  22 entry of its output file.  If the stab contains a string field, the
  23 symbol table entry for that stab points to a string table entry
  24 containing the string data from the stab.  Assembler labels become
  25 relocatable addresses.  Symbol table entries in a.out have the format:
  26
  27 <pre class="example">     struct internal_nlist {
  28        unsigned long n_strx;         /* index into string table of name */
  29        unsigned char n_type;         /* type of symbol */
  30        unsigned char n_other;        /* misc info (usually empty) */
  31        unsigned short n_desc;        /* description field */
  32        bfd_vma n_value;              /* value of symbol */
  33      };
  34      </pre>
  35
  36    <p>If the stab has a string, the <code>n_strx</code> field holds the offset in
  37 bytes of the string within the string table.  The string is terminated
  38 by a NUL character.  If the stab lacks a string (for example, it was
  39 produced by a <code>.stabn</code> or <code>.stabd</code> directive), the
  40 <code>n_strx</code> field is zero.
  41
  42    <p>Symbol table entries with <code>n_type</code> field values greater than 0x1f
  43 originated as stabs generated by the compiler (with one random
  44 exception).  The other entries were placed in the symbol table of the
  45 executable by the assembler or the linker.
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