`.stabd, .stabn, .stabs'
========================

   There are three directives that begin `.stab'.  All emit symbols
(see Symbols.), for use by symbolic debuggers.  The symbols are not
entered in the `as' hash table: they cannot be referenced elsewhere in
the source file.  Up to five fields are required:
STRING
     This is the symbol's name.  It may contain any character except
     `\000', so is more general than ordinary symbol names.  Some
     debuggers used to code arbitrarily complex structures into symbol
     names using this field.

TYPE
     An absolute expression.  The symbol's type is set to the low 8
     bits of this expression.  Any bit pattern is permitted, but `ld'
     and debuggers will choke on silly bit patterns.

OTHER
     An absolute expression.  The symbol's "other" attribute is set to
     the low 8 bits of this expression.

DESC
     An absolute expression.  The symbol's descriptor is set to the low
     16 bits of this expression.

VALUE
     An absolute expression which becomes the symbol's value.

   If a warning is detected while reading a `.stabd', `.stabn', or
`.stabs' statement, the symbol has probably already been created and
you will get a half-formed symbol in your object file.  This is
compatible with earlier assemblers!

`.stabd TYPE , OTHER , DESC'
     The "name" of the symbol generated is not even an empty string.
     It is a null pointer, for compatibility.  Older assemblers used a
     null pointer so they didn't waste space in object files with empty
     strings.

     The symbol's value is set to the location counter, relocatably.
     When your program is linked, the value of this symbol will be
     where the location counter was when the `.stabd' was assembled.

`.stabn TYPE , OTHER , DESC , VALUE'
     The name of the symbol is set to the empty string `""'.

`.stabs STRING ,  TYPE , OTHER , DESC , VALUE'
     All five fields are specified.