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<title>STABS: Basic Cplusplus Types</title>
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<a name="Basic-Cplusplus-Types"></a>
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<p>
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Next: <a href="Simple-Classes.html#Simple-Classes" accesskey="n" rel="next">Simple Classes</a>, Previous: <a href="Nested-Symbols.html#Nested-Symbols" accesskey="p" rel="previous">Nested Symbols</a>, Up: <a href="Cplusplus.html#Cplusplus" accesskey="u" rel="up">Cplusplus</a> [<a href="index.html#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="Symbol-Types-Index.html#Symbol-Types-Index" title="Index" rel="index">Index</a>]</p>
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<hr>
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<a name="Basic-Types-For-C_002b_002b"></a>
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<h3 class="section">8.3 Basic Types For C<tt>++</tt></h3>
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<p><< the examples that follow are based on a01.C >>
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</p>
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<p>C<tt>++</tt> adds two more builtin types to the set defined for C. These are
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the unknown type and the vtable record type. The unknown type, type
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16, is defined in terms of itself like the void type.
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</p>
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<p>The vtable record type, type 17, is defined as a structure type and
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then as a structure tag. The structure has four fields: delta, index,
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pfn, and delta2. pfn is the function pointer.
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</p>
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<p><< In boilerplate $vtbl_ptr_type, what are the fields delta,
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index, and delta2 used for? >>
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</p>
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<p>This basic type is present in all C<tt>++</tt> programs even if there are no
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virtual methods defined.
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</p>
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<div class="display">
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<pre class="display">.stabs "struct_name:sym_desc(type)type_def(17)=type_desc(struct)struct_bytes(8)
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elem_name(delta):type_ref(short int),bit_offset(0),field_bits(16);
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elem_name(index):type_ref(short int),bit_offset(16),field_bits(16);
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elem_name(pfn):type_def(18)=type_desc(ptr to)type_ref(void),
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bit_offset(32),field_bits(32);
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elem_name(delta2):type_def(short int);bit_offset(32),field_bits(16);;"
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N_LSYM, NIL, NIL
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</pre></div>
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<div class="smallexample">
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<pre class="smallexample">.stabs "$vtbl_ptr_type:t17=s8
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delta:6,0,16;index:6,16,16;pfn:18=*15,32,32;delta2:6,32,16;;"
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,128,0,0,0
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</pre></div>
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<div class="display">
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<pre class="display">.stabs "name:sym_dec(struct tag)type_ref($vtbl_ptr_type)",N_LSYM,NIL,NIL,NIL
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</pre></div>
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<div class="example">
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<pre class="example">.stabs "$vtbl_ptr_type:T17",128,0,0,0
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</pre></div>
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