mingw/info/stabs/Methods.html

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  12 Node:<a name="Methods">Methods</a>,
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  18
  19 <h3 class="section">Method Definition</h3>
  20
  21    <p>The class definition shown above declares Ameth.  The C++ source below
  22 defines Ameth:
  23
  24 <pre class="example">     int
  25      baseA::Ameth(int in, char other)
  26      {
  27              return in;
  28      };
  29      </pre>
  30
  31    <p>This method definition yields three stabs following the code of the
  32 method.  One stab describes the method itself and following two describe
  33 its parameters.  Although there is only one formal argument all methods
  34 have an implicit argument which is the <code>this</code> pointer.  The <code>this</code>
  35 pointer is a pointer to the object on which the method was called.  Note
  36 that the method name is mangled to encode the class name and argument
  37 types.  Name mangling is described in the <small>ARM</small> (<cite>The Annotated
  38 C++ Reference Manual</cite>, by Ellis and Stroustrup, <small>ISBN</small>
  39 0-201-51459-1); <code>gpcompare.texi</code> in Cygnus GCC distributions
  40 describes the differences between GNU mangling and <small>ARM</small>
  41 mangling.
  42
  43 <pre class="example">     .stabs "name:symbol_descriptor(global function)return_type(int)",
  44              N_FUN, NIL, NIL, code_addr_of_method_start
  45
  46      .stabs "Ameth__5baseAic:F1",36,0,0,_Ameth__5baseAic
  47      </pre>
  48
  49    <p>Here is the stab for the <code>this</code> pointer implicit argument.  The
  50 name of the <code>this</code> pointer is always <code>this</code>.  Type 19, the
  51 <code>this</code> pointer is defined as a pointer to type 20, <code>baseA</code>,
  52 but a stab defining <code>baseA</code> has not yet been emitted.  Since the
  53 compiler knows it will be emitted shortly, here it just outputs a cross
  54 reference to the undefined symbol, by prefixing the symbol name with
  55 <code>xs</code>.
  56
  57 <pre class="example">     .stabs "name:sym_desc(register param)type_def(19)=
  58              type_desc(ptr to)type_ref(baseA)=
  59              type_desc(cross-reference to)baseA:",N_RSYM,NIL,NIL,register_number
  60
  61      .stabs "this:P19=*20=xsbaseA:",64,0,0,8
  62      </pre>
  63
  64    <p>The stab for the explicit integer argument looks just like a parameter
  65 to a C function.  The last field of the stab is the offset from the
  66 argument pointer, which in most systems is the same as the frame
  67 pointer.
  68
  69 <pre class="example">     .stabs "name:sym_desc(value parameter)type_ref(int)",
  70              N_PSYM,NIL,NIL,offset_from_arg_ptr
  71
  72      .stabs "in:p1",160,0,0,72
  73      </pre>
  74
  75    <p>&lt;&lt; The examples that follow are based on A1.C &gt;&gt;
  76
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  78