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| <a name="Types-In-Guile"></a> |
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| Next: <a href="Guile-Pretty-Printing-API.html#Guile-Pretty-Printing-API" accesskey="n" rel="next">Guile Pretty Printing API</a>, Previous: <a href="Arithmetic-In-Guile.html#Arithmetic-In-Guile" accesskey="p" rel="prev">Arithmetic In Guile</a>, Up: <a href="Guile-API.html#Guile-API" accesskey="u" rel="up">Guile API</a> [<a href="index.html#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="Concept-Index.html#Concept-Index" title="Index" rel="index">Index</a>]</p> |
| </div> |
| <hr> |
| <a name="Types-In-Guile-1"></a> |
| <h4 class="subsubsection">23.3.3.7 Types In Guile</h4> |
| <a name="index-types-in-guile"></a> |
| <a name="index-guile_002c-working-with-types"></a> |
| |
| <a name="index-_003cgdb_003atype_003e"></a> |
| <p><small>GDB</small> represents types from the inferior in objects of type |
| <code><gdb:type></code>. |
| </p> |
| <p>The following type-related procedures are provided by the |
| <code>(gdb)</code> module. |
| </p> |
| <dl> |
| <dt><a name="index-type_003f"></a>Scheme Procedure: <strong>type?</strong> <em>object</em></dt> |
| <dd><p>Return <code>#t</code> if <var>object</var> is an object of type <code><gdb:type></code>. |
| Otherwise return <code>#f</code>. |
| </p></dd></dl> |
| |
| <dl> |
| <dt><a name="index-lookup_002dtype"></a>Scheme Procedure: <strong>lookup-type</strong> <em>name <span class="roman">[</span>#:block block<span class="roman">]</span></em></dt> |
| <dd><p>This function looks up a type by its <var>name</var>, which must be a string. |
| </p> |
| <p>If <var>block</var> is given, it is an object of type <code><gdb:block></code>, |
| and <var>name</var> is looked up in that scope. |
| Otherwise, it is searched for globally. |
| </p> |
| <p>Ordinarily, this function will return an instance of <code><gdb:type></code>. |
| If the named type cannot be found, it will throw an exception. |
| </p></dd></dl> |
| |
| <dl> |
| <dt><a name="index-type_002dcode"></a>Scheme Procedure: <strong>type-code</strong> <em>type</em></dt> |
| <dd><p>Return the type code of <var>type</var>. The type code will be one of the |
| <code>TYPE_CODE_</code> constants defined below. |
| </p></dd></dl> |
| |
| <dl> |
| <dt><a name="index-type_002dtag"></a>Scheme Procedure: <strong>type-tag</strong> <em>type</em></dt> |
| <dd><p>Return the tag name of <var>type</var>. The tag name is the name after |
| <code>struct</code>, <code>union</code>, or <code>enum</code> in C and C<tt>++</tt>; not all |
| languages have this concept. If this type has no tag name, then |
| <code>#f</code> is returned. |
| </p></dd></dl> |
| |
| <dl> |
| <dt><a name="index-type_002dname"></a>Scheme Procedure: <strong>type-name</strong> <em>type</em></dt> |
| <dd><p>Return the name of <var>type</var>. |
| If this type has no name, then <code>#f</code> is returned. |
| </p></dd></dl> |
| |
| <dl> |
| <dt><a name="index-type_002dprint_002dname"></a>Scheme Procedure: <strong>type-print-name</strong> <em>type</em></dt> |
| <dd><p>Return the print name of <var>type</var>. |
| This returns something even for anonymous types. |
| For example, for an anonymous C struct <code>"struct {...}"</code> is returned. |
| </p></dd></dl> |
| |
| <dl> |
| <dt><a name="index-type_002dsizeof"></a>Scheme Procedure: <strong>type-sizeof</strong> <em>type</em></dt> |
| <dd><p>Return the size of this type, in target <code>char</code> units. Usually, a |
| target’s <code>char</code> type will be an 8-bit byte. However, on some |
| unusual platforms, this type may have a different size. |
| </p></dd></dl> |
| |
| <dl> |
| <dt><a name="index-type_002dstrip_002dtypedefs"></a>Scheme Procedure: <strong>type-strip-typedefs</strong> <em>type</em></dt> |
| <dd><p>Return a new <code><gdb:type></code> that represents the real type of <var>type</var>, |
| after removing all layers of typedefs. |
| </p></dd></dl> |
| |
| <dl> |
| <dt><a name="index-type_002darray"></a>Scheme Procedure: <strong>type-array</strong> <em>type n1 <span class="roman">[</span>n2<span class="roman">]</span></em></dt> |
| <dd><p>Return a new <code><gdb:type></code> object which represents an array of this |
| type. If one argument is given, it is the inclusive upper bound of |
| the array; in this case the lower bound is zero. If two arguments are |
| given, the first argument is the lower bound of the array, and the |
| second argument is the upper bound of the array. An array’s length |
| must not be negative, but the bounds can be. |
| </p></dd></dl> |
| |
| <dl> |
| <dt><a name="index-type_002dvector"></a>Scheme Procedure: <strong>type-vector</strong> <em>type n1 <span class="roman">[</span>n2<span class="roman">]</span></em></dt> |
| <dd><p>Return a new <code><gdb:type></code> object which represents a vector of this |
| type. If one argument is given, it is the inclusive upper bound of |
| the vector; in this case the lower bound is zero. If two arguments are |
| given, the first argument is the lower bound of the vector, and the |
| second argument is the upper bound of the vector. A vector’s length |
| must not be negative, but the bounds can be. |
| </p> |
| <p>The difference between an <code>array</code> and a <code>vector</code> is that |
| arrays behave like in C: when used in expressions they decay to a pointer |
| to the first element whereas vectors are treated as first class values. |
| </p></dd></dl> |
| |
| <dl> |
| <dt><a name="index-type_002dpointer"></a>Scheme Procedure: <strong>type-pointer</strong> <em>type</em></dt> |
| <dd><p>Return a new <code><gdb:type></code> object which represents a pointer to |
| <var>type</var>. |
| </p></dd></dl> |
| |
| <dl> |
| <dt><a name="index-type_002drange"></a>Scheme Procedure: <strong>type-range</strong> <em>type</em></dt> |
| <dd><p>Return a list of two elements: the low bound and high bound of <var>type</var>. |
| If <var>type</var> does not have a range, an exception is thrown. |
| </p></dd></dl> |
| |
| <dl> |
| <dt><a name="index-type_002dreference"></a>Scheme Procedure: <strong>type-reference</strong> <em>type</em></dt> |
| <dd><p>Return a new <code><gdb:type></code> object which represents a reference to |
| <var>type</var>. |
| </p></dd></dl> |
| |
| <dl> |
| <dt><a name="index-type_002dtarget"></a>Scheme Procedure: <strong>type-target</strong> <em>type</em></dt> |
| <dd><p>Return a new <code><gdb:type></code> object which represents the target type |
| of <var>type</var>. |
| </p> |
| <p>For a pointer type, the target type is the type of the pointed-to |
| object. For an array type (meaning C-like arrays), the target type is |
| the type of the elements of the array. For a function or method type, |
| the target type is the type of the return value. For a complex type, |
| the target type is the type of the elements. For a typedef, the |
| target type is the aliased type. |
| </p> |
| <p>If the type does not have a target, this method will throw an |
| exception. |
| </p></dd></dl> |
| |
| <dl> |
| <dt><a name="index-type_002dconst"></a>Scheme Procedure: <strong>type-const</strong> <em>type</em></dt> |
| <dd><p>Return a new <code><gdb:type></code> object which represents a |
| <code>const</code>-qualified variant of <var>type</var>. |
| </p></dd></dl> |
| |
| <dl> |
| <dt><a name="index-type_002dvolatile"></a>Scheme Procedure: <strong>type-volatile</strong> <em>type</em></dt> |
| <dd><p>Return a new <code><gdb:type></code> object which represents a |
| <code>volatile</code>-qualified variant of <var>type</var>. |
| </p></dd></dl> |
| |
| <dl> |
| <dt><a name="index-type_002dunqualified"></a>Scheme Procedure: <strong>type-unqualified</strong> <em>type</em></dt> |
| <dd><p>Return a new <code><gdb:type></code> object which represents an unqualified |
| variant of <var>type</var>. That is, the result is neither <code>const</code> nor |
| <code>volatile</code>. |
| </p></dd></dl> |
| |
| <dl> |
| <dt><a name="index-type_002dnum_002dfields"></a>Scheme Procedure: <strong>type-num-fields</strong></dt> |
| <dd><p>Return the number of fields of <code><gdb:type></code> <var>type</var>. |
| </p></dd></dl> |
| |
| <dl> |
| <dt><a name="index-type_002dfields"></a>Scheme Procedure: <strong>type-fields</strong> <em>type</em></dt> |
| <dd><p>Return the fields of <var>type</var> as a list. |
| For structure and union types, <code>fields</code> has the usual meaning. |
| Range types have two fields, the minimum and maximum values. Enum types |
| have one field per enum constant. Function and method types have one |
| field per parameter. The base types of C<tt>++</tt> classes are also |
| represented as fields. If the type has no fields, or does not fit |
| into one of these categories, an empty list will be returned. |
| See <a href="#Fields-of-a-type-in-Guile">Fields of a type in Guile</a>. |
| </p></dd></dl> |
| |
| <dl> |
| <dt><a name="index-make_002dfield_002diterator"></a>Scheme Procedure: <strong>make-field-iterator</strong> <em>type</em></dt> |
| <dd><p>Return the fields of <var>type</var> as a <gdb:iterator> object. |
| See <a href="Iterators-In-Guile.html#Iterators-In-Guile">Iterators In Guile</a>. |
| </p></dd></dl> |
| |
| <dl> |
| <dt><a name="index-type_002dfield"></a>Scheme Procedure: <strong>type-field</strong> <em>type field-name</em></dt> |
| <dd><p>Return field named <var>field-name</var> in <var>type</var>. |
| The result is an object of type <code><gdb:field></code>. |
| See <a href="#Fields-of-a-type-in-Guile">Fields of a type in Guile</a>. |
| If the type does not have fields, or <var>field-name</var> is not a field |
| of <var>type</var>, an exception is thrown. |
| </p> |
| <p>For example, if <code>some-type</code> is a <code><gdb:type></code> instance holding |
| a structure type, you can access its <code>foo</code> field with: |
| </p> |
| <div class="smallexample"> |
| <pre class="smallexample">(define bar (type-field some-type "foo")) |
| </pre></div> |
| |
| <p><code>bar</code> will be a <code><gdb:field></code> object. |
| </p></dd></dl> |
| |
| <dl> |
| <dt><a name="index-type_002dhas_002dfield_003f"></a>Scheme Procedure: <strong>type-has-field?</strong> <em>type name</em></dt> |
| <dd><p>Return <code>#t</code> if <code><gdb:type></code> <var>type</var> has field named <var>name</var>. |
| Otherwise return <code>#f</code>. |
| </p></dd></dl> |
| |
| <p>Each type has a code, which indicates what category this type falls |
| into. The available type categories are represented by constants |
| defined in the <code>(gdb)</code> module: |
| </p> |
| <dl compact="compact"> |
| <dt><code>TYPE_CODE_PTR</code> |
| <a name="index-TYPE_005fCODE_005fPTR-1"></a> |
| </dt> |
| <dd><p>The type is a pointer. |
| </p> |
| </dd> |
| <dt><code>TYPE_CODE_ARRAY</code> |
| <a name="index-TYPE_005fCODE_005fARRAY-1"></a> |
| </dt> |
| <dd><p>The type is an array. |
| </p> |
| </dd> |
| <dt><code>TYPE_CODE_STRUCT</code> |
| <a name="index-TYPE_005fCODE_005fSTRUCT-1"></a> |
| </dt> |
| <dd><p>The type is a structure. |
| </p> |
| </dd> |
| <dt><code>TYPE_CODE_UNION</code> |
| <a name="index-TYPE_005fCODE_005fUNION-1"></a> |
| </dt> |
| <dd><p>The type is a union. |
| </p> |
| </dd> |
| <dt><code>TYPE_CODE_ENUM</code> |
| <a name="index-TYPE_005fCODE_005fENUM-1"></a> |
| </dt> |
| <dd><p>The type is an enum. |
| </p> |
| </dd> |
| <dt><code>TYPE_CODE_FLAGS</code> |
| <a name="index-TYPE_005fCODE_005fFLAGS-1"></a> |
| </dt> |
| <dd><p>A bit flags type, used for things such as status registers. |
| </p> |
| </dd> |
| <dt><code>TYPE_CODE_FUNC</code> |
| <a name="index-TYPE_005fCODE_005fFUNC-1"></a> |
| </dt> |
| <dd><p>The type is a function. |
| </p> |
| </dd> |
| <dt><code>TYPE_CODE_INT</code> |
| <a name="index-TYPE_005fCODE_005fINT-1"></a> |
| </dt> |
| <dd><p>The type is an integer type. |
| </p> |
| </dd> |
| <dt><code>TYPE_CODE_FLT</code> |
| <a name="index-TYPE_005fCODE_005fFLT-1"></a> |
| </dt> |
| <dd><p>A floating point type. |
| </p> |
| </dd> |
| <dt><code>TYPE_CODE_VOID</code> |
| <a name="index-TYPE_005fCODE_005fVOID-1"></a> |
| </dt> |
| <dd><p>The special type <code>void</code>. |
| </p> |
| </dd> |
| <dt><code>TYPE_CODE_SET</code> |
| <a name="index-TYPE_005fCODE_005fSET-1"></a> |
| </dt> |
| <dd><p>A Pascal set type. |
| </p> |
| </dd> |
| <dt><code>TYPE_CODE_RANGE</code> |
| <a name="index-TYPE_005fCODE_005fRANGE-1"></a> |
| </dt> |
| <dd><p>A range type, that is, an integer type with bounds. |
| </p> |
| </dd> |
| <dt><code>TYPE_CODE_STRING</code> |
| <a name="index-TYPE_005fCODE_005fSTRING-1"></a> |
| </dt> |
| <dd><p>A string type. Note that this is only used for certain languages with |
| language-defined string types; C strings are not represented this way. |
| </p> |
| </dd> |
| <dt><code>TYPE_CODE_BITSTRING</code> |
| <a name="index-TYPE_005fCODE_005fBITSTRING-1"></a> |
| </dt> |
| <dd><p>A string of bits. It is deprecated. |
| </p> |
| </dd> |
| <dt><code>TYPE_CODE_ERROR</code> |
| <a name="index-TYPE_005fCODE_005fERROR-1"></a> |
| </dt> |
| <dd><p>An unknown or erroneous type. |
| </p> |
| </dd> |
| <dt><code>TYPE_CODE_METHOD</code> |
| <a name="index-TYPE_005fCODE_005fMETHOD-1"></a> |
| </dt> |
| <dd><p>A method type, as found in C<tt>++</tt> or Java. |
| </p> |
| </dd> |
| <dt><code>TYPE_CODE_METHODPTR</code> |
| <a name="index-TYPE_005fCODE_005fMETHODPTR-1"></a> |
| </dt> |
| <dd><p>A pointer-to-member-function. |
| </p> |
| </dd> |
| <dt><code>TYPE_CODE_MEMBERPTR</code> |
| <a name="index-TYPE_005fCODE_005fMEMBERPTR-1"></a> |
| </dt> |
| <dd><p>A pointer-to-member. |
| </p> |
| </dd> |
| <dt><code>TYPE_CODE_REF</code> |
| <a name="index-TYPE_005fCODE_005fREF-1"></a> |
| </dt> |
| <dd><p>A reference type. |
| </p> |
| </dd> |
| <dt><code>TYPE_CODE_CHAR</code> |
| <a name="index-TYPE_005fCODE_005fCHAR-1"></a> |
| </dt> |
| <dd><p>A character type. |
| </p> |
| </dd> |
| <dt><code>TYPE_CODE_BOOL</code> |
| <a name="index-TYPE_005fCODE_005fBOOL-1"></a> |
| </dt> |
| <dd><p>A boolean type. |
| </p> |
| </dd> |
| <dt><code>TYPE_CODE_COMPLEX</code> |
| <a name="index-TYPE_005fCODE_005fCOMPLEX-1"></a> |
| </dt> |
| <dd><p>A complex float type. |
| </p> |
| </dd> |
| <dt><code>TYPE_CODE_TYPEDEF</code> |
| <a name="index-TYPE_005fCODE_005fTYPEDEF-1"></a> |
| </dt> |
| <dd><p>A typedef to some other type. |
| </p> |
| </dd> |
| <dt><code>TYPE_CODE_NAMESPACE</code> |
| <a name="index-TYPE_005fCODE_005fNAMESPACE-1"></a> |
| </dt> |
| <dd><p>A C<tt>++</tt> namespace. |
| </p> |
| </dd> |
| <dt><code>TYPE_CODE_DECFLOAT</code> |
| <a name="index-TYPE_005fCODE_005fDECFLOAT-1"></a> |
| </dt> |
| <dd><p>A decimal floating point type. |
| </p> |
| </dd> |
| <dt><code>TYPE_CODE_INTERNAL_FUNCTION</code> |
| <a name="index-TYPE_005fCODE_005fINTERNAL_005fFUNCTION-1"></a> |
| </dt> |
| <dd><p>A function internal to <small>GDB</small>. This is the type used to represent |
| convenience functions (see <a href="Convenience-Funs.html#Convenience-Funs">Convenience Funs</a>). |
| </p></dd> |
| </dl> |
| |
| <p>Further support for types is provided in the <code>(gdb types)</code> |
| Guile module (see <a href="Guile-Types-Module.html#Guile-Types-Module">Guile Types Module</a>). |
| </p> |
| <a name="Fields-of-a-type-in-Guile"></a><p>Each field is represented as an object of type <code><gdb:field></code>. |
| </p> |
| <p>The following field-related procedures are provided by the |
| <code>(gdb)</code> module: |
| </p> |
| <dl> |
| <dt><a name="index-field_003f"></a>Scheme Procedure: <strong>field?</strong> <em>object</em></dt> |
| <dd><p>Return <code>#t</code> if <var>object</var> is an object of type <code><gdb:field></code>. |
| Otherwise return <code>#f</code>. |
| </p></dd></dl> |
| |
| <dl> |
| <dt><a name="index-field_002dname"></a>Scheme Procedure: <strong>field-name</strong> <em>field</em></dt> |
| <dd><p>Return the name of the field, or <code>#f</code> for anonymous fields. |
| </p></dd></dl> |
| |
| <dl> |
| <dt><a name="index-field_002dtype"></a>Scheme Procedure: <strong>field-type</strong> <em>field</em></dt> |
| <dd><p>Return the type of the field. This is usually an instance of |
| <code><gdb:type></code>, but it can be <code>#f</code> in some situations. |
| </p></dd></dl> |
| |
| <dl> |
| <dt><a name="index-field_002denumval"></a>Scheme Procedure: <strong>field-enumval</strong> <em>field</em></dt> |
| <dd><p>Return the enum value represented by <code><gdb:field></code> <var>field</var>. |
| </p></dd></dl> |
| |
| <dl> |
| <dt><a name="index-field_002dbitpos"></a>Scheme Procedure: <strong>field-bitpos</strong> <em>field</em></dt> |
| <dd><p>Return the bit position of <code><gdb:field></code> <var>field</var>. |
| This attribute is not available for <code>static</code> fields (as in |
| C<tt>++</tt> or Java). |
| </p></dd></dl> |
| |
| <dl> |
| <dt><a name="index-field_002dbitsize"></a>Scheme Procedure: <strong>field-bitsize</strong> <em>field</em></dt> |
| <dd><p>If the field is packed, or is a bitfield, return the size of |
| <code><gdb:field></code> <var>field</var> in bits. Otherwise, zero is returned; |
| in which case the field’s size is given by its type. |
| </p></dd></dl> |
| |
| <dl> |
| <dt><a name="index-field_002dartificial_003f"></a>Scheme Procedure: <strong>field-artificial?</strong> <em>field</em></dt> |
| <dd><p>Return <code>#t</code> if the field is artificial, usually meaning that |
| it was provided by the compiler and not the user. |
| Otherwise return <code>#f</code>. |
| </p></dd></dl> |
| |
| <dl> |
| <dt><a name="index-field_002dbase_002dclass_003f"></a>Scheme Procedure: <strong>field-base-class?</strong> <em>field</em></dt> |
| <dd><p>Return <code>#t</code> if the field represents a base class of a C<tt>++</tt> |
| structure. |
| Otherwise return <code>#f</code>. |
| </p></dd></dl> |
| |
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