make an advanced topics section, move symtab to it

llvm-svn: 21473
This commit is contained in:
Chris Lattner 2005-04-23 16:10:52 +00:00
parent cab989c0a9
commit 420674160a

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@ -82,6 +82,12 @@ with another <tt>Value</tt></a> </li>
-->
</ul>
</li>
<li><a href="#advanced">Advanced Topics</a>
<ul>
<li><a href="#SymbolTable">The <tt>SymbolTable</tt> class </a></li>
</ul></li>
<li><a href="#coreclasses">The Core LLVM Class Hierarchy Reference</a>
<ul>
<li><a href="#Value">The <tt>Value</tt> class</a>
@ -113,13 +119,6 @@ with another <tt>Value</tt></a> </li>
</li>
</ul>
</li>
<li><a href="#SymbolTable">The <tt>SymbolTable</tt> class </a></li>
<li>The <tt>ilist</tt> and <tt>iplist</tt> classes
<ul>
<li>Creating, inserting, moving and deleting from LLVM lists </li>
</ul>
</li>
<li>Important iterator invalidation semantics to be aware of.</li>
</ol>
<div class="doc_author">
@ -924,6 +923,241 @@ ReplaceInstWithValue, ReplaceInstWithInst -->
</div>
<!-- *********************************************************************** -->
<div class="doc_section">
<a name="advanced">Advanced Topics</a>
</div>
<!-- *********************************************************************** -->
<div class="doc_text">
</div>
<!-- ======================================================================= -->
<div class="doc_subsection">
<a name="SymbolTable">The <tt>SymbolTable</tt> class</a>
</div>
<div class="doc_text">
<p>This class provides a symbol table that the <a
href="#Function"><tt>Function</tt></a> and <a href="#Module">
<tt>Module</tt></a> classes use for naming definitions. The symbol table can
provide a name for any <a href="#Value"><tt>Value</tt></a> or <a
href="#Type"><tt>Type</tt></a>. <tt>SymbolTable</tt> is an abstract data
type. It hides the data it contains and provides access to it through a
controlled interface.</p>
<p>Note that the symbol table class is should not be directly accessed by most
clients. It should only be used when iteration over the symbol table names
themselves are required, which is very special purpose. Note that not all LLVM
<a href="#Value">Value</a>s have names, and those without names (i.e. they have
an empty name) do not exist in the symbol table.
</p>
<p>To use the <tt>SymbolTable</tt> well, you need to understand the
structure of the information it holds. The class contains two
<tt>std::map</tt> objects. The first, <tt>pmap</tt>, is a map of
<tt>Type*</tt> to maps of name (<tt>std::string</tt>) to <tt>Value*</tt>.
The second, <tt>tmap</tt>, is a map of names to <tt>Type*</tt>. Thus, Values
are stored in two-dimensions and accessed by <tt>Type</tt> and name. Types,
however, are stored in a single dimension and accessed only by name.</p>
<p>The interface of this class provides three basic types of operations:
<ol>
<li><em>Accessors</em>. Accessors provide read-only access to information
such as finding a value for a name with the
<a href="#SymbolTable_lookup">lookup</a> method.</li>
<li><em>Mutators</em>. Mutators allow the user to add information to the
<tt>SymbolTable</tt> with methods like
<a href="#SymbolTable_insert"><tt>insert</tt></a>.</li>
<li><em>Iterators</em>. Iterators allow the user to traverse the content
of the symbol table in well defined ways, such as the method
<a href="#SymbolTable_type_begin"><tt>type_begin</tt></a>.</li>
</ol>
<h3>Accessors</h3>
<dl>
<dt><tt>Value* lookup(const Type* Ty, const std::string&amp; name) const</tt>:
</dt>
<dd>The <tt>lookup</tt> method searches the type plane given by the
<tt>Ty</tt> parameter for a <tt>Value</tt> with the provided <tt>name</tt>.
If a suitable <tt>Value</tt> is not found, null is returned.</dd>
<dt><tt>Type* lookupType( const std::string&amp; name) const</tt>:</dt>
<dd>The <tt>lookupType</tt> method searches through the types for a
<tt>Type</tt> with the provided <tt>name</tt>. If a suitable <tt>Type</tt>
is not found, null is returned.</dd>
<dt><tt>bool hasTypes() const</tt>:</dt>
<dd>This function returns true if an entry has been made into the type
map.</dd>
<dt><tt>bool isEmpty() const</tt>:</dt>
<dd>This function returns true if both the value and types maps are
empty</dd>
</dl>
<h3>Mutators</h3>
<dl>
<dt><tt>void insert(Value *Val)</tt>:</dt>
<dd>This method adds the provided value to the symbol table. The Value must
have both a name and a type which are extracted and used to place the value
in the correct type plane under the value's name.</dd>
<dt><tt>void insert(const std::string&amp; Name, Value *Val)</tt>:</dt>
<dd> Inserts a constant or type into the symbol table with the specified
name. There can be a many to one mapping between names and constants
or types.</dd>
<dt><tt>void insert(const std::string&amp; Name, Type *Typ)</tt>:</dt>
<dd> Inserts a type into the symbol table with the specified name. There
can be a many-to-one mapping between names and types. This method
allows a type with an existing entry in the symbol table to get
a new name.</dd>
<dt><tt>void remove(Value* Val)</tt>:</dt>
<dd> This method removes a named value from the symbol table. The
type and name of the Value are extracted from \p N and used to
lookup the Value in the correct type plane. If the Value is
not in the symbol table, this method silently ignores the
request.</dd>
<dt><tt>void remove(Type* Typ)</tt>:</dt>
<dd> This method removes a named type from the symbol table. The
name of the type is extracted from \P T and used to look up
the Type in the type map. If the Type is not in the symbol
table, this method silently ignores the request.</dd>
<dt><tt>Value* remove(const std::string&amp; Name, Value *Val)</tt>:</dt>
<dd> Remove a constant or type with the specified name from the
symbol table.</dd>
<dt><tt>Type* remove(const std::string&amp; Name, Type* T)</tt>:</dt>
<dd> Remove a type with the specified name from the symbol table.
Returns the removed Type.</dd>
<dt><tt>Value *value_remove(const value_iterator&amp; It)</tt>:</dt>
<dd> Removes a specific value from the symbol table.
Returns the removed value.</dd>
<dt><tt>bool strip()</tt>:</dt>
<dd> This method will strip the symbol table of its names leaving
the type and values. </dd>
<dt><tt>void clear()</tt>:</dt>
<dd>Empty the symbol table completely.</dd>
</dl>
<h3>Iteration</h3>
<p>The following functions describe three types of iterators you can obtain
the beginning or end of the sequence for both const and non-const. It is
important to keep track of the different kinds of iterators. There are
three idioms worth pointing out:</p>
<table>
<tr><th>Units</th><th>Iterator</th><th>Idiom</th></tr>
<tr>
<td align="left">Planes Of name/Value maps</td><td>PI</td>
<td align="left"><pre><tt>
for (SymbolTable::plane_const_iterator PI = ST.plane_begin(),
PE = ST.plane_end(); PI != PE; ++PI ) {
PI-&gt;first // This is the Type* of the plane
PI-&gt;second // This is the SymbolTable::ValueMap of name/Value pairs
</tt></pre></td>
</tr>
<tr>
<td align="left">All name/Type Pairs</td><td>TI</td>
<td align="left"><pre><tt>
for (SymbolTable::type_const_iterator TI = ST.type_begin(),
TE = ST.type_end(); TI != TE; ++TI )
TI-&gt;first // This is the name of the type
TI-&gt;second // This is the Type* value associated with the name
</tt></pre></td>
</tr>
<tr>
<td align="left">name/Value pairs in a plane</td><td>VI</td>
<td align="left"><pre><tt>
for (SymbolTable::value_const_iterator VI = ST.value_begin(SomeType),
VE = ST.value_end(SomeType); VI != VE; ++VI )
VI-&gt;first // This is the name of the Value
VI-&gt;second // This is the Value* value associated with the name
</tt></pre></td>
</tr>
</table>
<p>Using the recommended iterator names and idioms will help you avoid
making mistakes. Of particular note, make sure that whenever you use
value_begin(SomeType) that you always compare the resulting iterator
with value_end(SomeType) not value_end(SomeOtherType) or else you
will loop infinitely.</p>
<dl>
<dt><tt>plane_iterator plane_begin()</tt>:</dt>
<dd>Get an iterator that starts at the beginning of the type planes.
The iterator will iterate over the Type/ValueMap pairs in the
type planes. </dd>
<dt><tt>plane_const_iterator plane_begin() const</tt>:</dt>
<dd>Get a const_iterator that starts at the beginning of the type
planes. The iterator will iterate over the Type/ValueMap pairs
in the type planes. </dd>
<dt><tt>plane_iterator plane_end()</tt>:</dt>
<dd>Get an iterator at the end of the type planes. This serves as
the marker for end of iteration over the type planes.</dd>
<dt><tt>plane_const_iterator plane_end() const</tt>:</dt>
<dd>Get a const_iterator at the end of the type planes. This serves as
the marker for end of iteration over the type planes.</dd>
<dt><tt>value_iterator value_begin(const Type *Typ)</tt>:</dt>
<dd>Get an iterator that starts at the beginning of a type plane.
The iterator will iterate over the name/value pairs in the type plane.
Note: The type plane must already exist before using this.</dd>
<dt><tt>value_const_iterator value_begin(const Type *Typ) const</tt>:</dt>
<dd>Get a const_iterator that starts at the beginning of a type plane.
The iterator will iterate over the name/value pairs in the type plane.
Note: The type plane must already exist before using this.</dd>
<dt><tt>value_iterator value_end(const Type *Typ)</tt>:</dt>
<dd>Get an iterator to the end of a type plane. This serves as the marker
for end of iteration of the type plane.
Note: The type plane must already exist before using this.</dd>
<dt><tt>value_const_iterator value_end(const Type *Typ) const</tt>:</dt>
<dd>Get a const_iterator to the end of a type plane. This serves as the
marker for end of iteration of the type plane.
Note: the type plane must already exist before using this.</dd>
<dt><tt>type_iterator type_begin()</tt>:</dt>
<dd>Get an iterator to the start of the name/Type map.</dd>
<dt><tt>type_const_iterator type_begin() cons</tt>:</dt>
<dd> Get a const_iterator to the start of the name/Type map.</dd>
<dt><tt>type_iterator type_end()</tt>:</dt>
<dd>Get an iterator to the end of the name/Type map. This serves as the
marker for end of iteration of the types.</dd>
<dt><tt>type_const_iterator type_end() const</tt>:</dt>
<dd>Get a const-iterator to the end of the name/Type map. This serves
as the marker for end of iteration of the types.</dd>
<dt><tt>plane_const_iterator find(const Type* Typ ) const</tt>:</dt>
<dd>This method returns a plane_const_iterator for iteration over
the type planes starting at a specific plane, given by \p Ty.</dd>
<dt><tt>plane_iterator find( const Type* Typ </tt>:</dt>
<dd>This method returns a plane_iterator for iteration over the
type planes starting at a specific plane, given by \p Ty.</dd>
</dl>
</div>
<!-- *********************************************************************** -->
<div class="doc_section">
<a name="coreclasses">The Core LLVM Class Hierarchy Reference </a>
@ -1816,220 +2050,6 @@ arguments. An argument has a pointer to the parent Function.</p>
</div>
<!-- ======================================================================= -->
<div class="doc_subsection">
<a name="SymbolTable">The <tt>SymbolTable</tt> class</a>
</div>
<div class="doc_text">
<p>This class provides a symbol table that the
<a href="#Function"><tt>Function</tt></a> and <a href="#Module">
<tt>Module</tt></a> classes use for naming definitions. The symbol table can
provide a name for any <a href="#Value"><tt>Value</tt></a> or
<a href="#Type"><tt>Type</tt></a>. <tt>SymbolTable</tt> is an abstract data
type. It hides the data it contains and provides access to it through a
controlled interface.</p>
<p>To use the <tt>SymbolTable</tt> well, you need to understand the
structure of the information it holds. The class contains two
<tt>std::map</tt> objects. The first, <tt>pmap</tt>, is a map of
<tt>Type*</tt> to maps of name (<tt>std::string</tt>) to <tt>Value*</tt>.
The second, <tt>tmap</tt>, is a map of names to <tt>Type*</tt>. Thus, Values
are stored in two-dimensions and accessed by <tt>Type</tt> and name. Types,
however, are stored in a single dimension and accessed only by name.</p>
<p>The interface of this class provides three basic types of operations:
<ol>
<li><em>Accessors</em>. Accessors provide read-only access to information
such as finding a value for a name with the
<a href="#SymbolTable_lookup">lookup</a> method.</li>
<li><em>Mutators</em>. Mutators allow the user to add information to the
<tt>SymbolTable</tt> with methods like
<a href="#SymbolTable_insert"><tt>insert</tt></a>.</li>
<li><em>Iterators</em>. Iterators allow the user to traverse the content
of the symbol table in well defined ways, such as the method
<a href="#SymbolTable_type_begin"><tt>type_begin</tt></a>.</li>
</ol>
<h3>Accessors</h3>
<dl>
<dt><tt>Value* lookup(const Type* Ty, const std::string&amp; name) const</tt>:
</dt>
<dd>The <tt>lookup</tt> method searches the type plane given by the
<tt>Ty</tt> parameter for a <tt>Value</tt> with the provided <tt>name</tt>.
If a suitable <tt>Value</tt> is not found, null is returned.</dd>
<dt><tt>Type* lookupType( const std::string&amp; name) const</tt>:</dt>
<dd>The <tt>lookupType</tt> method searches through the types for a
<tt>Type</tt> with the provided <tt>name</tt>. If a suitable <tt>Type</tt>
is not found, null is returned.</dd>
<dt><tt>bool hasTypes() const</tt>:</dt>
<dd>This function returns true if an entry has been made into the type
map.</dd>
<dt><tt>bool isEmpty() const</tt>:</dt>
<dd>This function returns true if both the value and types maps are
empty</dd>
</dl>
<h3>Mutators</h3>
<dl>
<dt><tt>void insert(Value *Val)</tt>:</dt>
<dd>This method adds the provided value to the symbol table. The Value must
have both a name and a type which are extracted and used to place the value
in the correct type plane under the value's name.</dd>
<dt><tt>void insert(const std::string&amp; Name, Value *Val)</tt>:</dt>
<dd> Inserts a constant or type into the symbol table with the specified
name. There can be a many to one mapping between names and constants
or types.</dd>
<dt><tt>void insert(const std::string&amp; Name, Type *Typ)</tt>:</dt>
<dd> Inserts a type into the symbol table with the specified name. There
can be a many-to-one mapping between names and types. This method
allows a type with an existing entry in the symbol table to get
a new name.</dd>
<dt><tt>void remove(Value* Val)</tt>:</dt>
<dd> This method removes a named value from the symbol table. The
type and name of the Value are extracted from \p N and used to
lookup the Value in the correct type plane. If the Value is
not in the symbol table, this method silently ignores the
request.</dd>
<dt><tt>void remove(Type* Typ)</tt>:</dt>
<dd> This method removes a named type from the symbol table. The
name of the type is extracted from \P T and used to look up
the Type in the type map. If the Type is not in the symbol
table, this method silently ignores the request.</dd>
<dt><tt>Value* remove(const std::string&amp; Name, Value *Val)</tt>:</dt>
<dd> Remove a constant or type with the specified name from the
symbol table.</dd>
<dt><tt>Type* remove(const std::string&amp; Name, Type* T)</tt>:</dt>
<dd> Remove a type with the specified name from the symbol table.
Returns the removed Type.</dd>
<dt><tt>Value *value_remove(const value_iterator&amp; It)</tt>:</dt>
<dd> Removes a specific value from the symbol table.
Returns the removed value.</dd>
<dt><tt>bool strip()</tt>:</dt>
<dd> This method will strip the symbol table of its names leaving
the type and values. </dd>
<dt><tt>void clear()</tt>:</dt>
<dd>Empty the symbol table completely.</dd>
</dl>
<h3>Iteration</h3>
<p>The following functions describe three types of iterators you can obtain
the beginning or end of the sequence for both const and non-const. It is
important to keep track of the different kinds of iterators. There are
three idioms worth pointing out:</p>
<table>
<tr><th>Units</th><th>Iterator</th><th>Idiom</th></tr>
<tr>
<td align="left">Planes Of name/Value maps</td><td>PI</td>
<td align="left"><pre><tt>
for (SymbolTable::plane_const_iterator PI = ST.plane_begin(),
PE = ST.plane_end(); PI != PE; ++PI ) {
PI-&gt;first // This is the Type* of the plane
PI-&gt;second // This is the SymbolTable::ValueMap of name/Value pairs
</tt></pre></td>
</tr>
<tr>
<td align="left">All name/Type Pairs</td><td>TI</td>
<td align="left"><pre><tt>
for (SymbolTable::type_const_iterator TI = ST.type_begin(),
TE = ST.type_end(); TI != TE; ++TI )
TI-&gt;first // This is the name of the type
TI-&gt;second // This is the Type* value associated with the name
</tt></pre></td>
</tr>
<tr>
<td align="left">name/Value pairs in a plane</td><td>VI</td>
<td align="left"><pre><tt>
for (SymbolTable::value_const_iterator VI = ST.value_begin(SomeType),
VE = ST.value_end(SomeType); VI != VE; ++VI )
VI-&gt;first // This is the name of the Value
VI-&gt;second // This is the Value* value associated with the name
</tt></pre></td>
</tr>
</table>
<p>Using the recommended iterator names and idioms will help you avoid
making mistakes. Of particular note, make sure that whenever you use
value_begin(SomeType) that you always compare the resulting iterator
with value_end(SomeType) not value_end(SomeOtherType) or else you
will loop infinitely.</p>
<dl>
<dt><tt>plane_iterator plane_begin()</tt>:</dt>
<dd>Get an iterator that starts at the beginning of the type planes.
The iterator will iterate over the Type/ValueMap pairs in the
type planes. </dd>
<dt><tt>plane_const_iterator plane_begin() const</tt>:</dt>
<dd>Get a const_iterator that starts at the beginning of the type
planes. The iterator will iterate over the Type/ValueMap pairs
in the type planes. </dd>
<dt><tt>plane_iterator plane_end()</tt>:</dt>
<dd>Get an iterator at the end of the type planes. This serves as
the marker for end of iteration over the type planes.</dd>
<dt><tt>plane_const_iterator plane_end() const</tt>:</dt>
<dd>Get a const_iterator at the end of the type planes. This serves as
the marker for end of iteration over the type planes.</dd>
<dt><tt>value_iterator value_begin(const Type *Typ)</tt>:</dt>
<dd>Get an iterator that starts at the beginning of a type plane.
The iterator will iterate over the name/value pairs in the type plane.
Note: The type plane must already exist before using this.</dd>
<dt><tt>value_const_iterator value_begin(const Type *Typ) const</tt>:</dt>
<dd>Get a const_iterator that starts at the beginning of a type plane.
The iterator will iterate over the name/value pairs in the type plane.
Note: The type plane must already exist before using this.</dd>
<dt><tt>value_iterator value_end(const Type *Typ)</tt>:</dt>
<dd>Get an iterator to the end of a type plane. This serves as the marker
for end of iteration of the type plane.
Note: The type plane must already exist before using this.</dd>
<dt><tt>value_const_iterator value_end(const Type *Typ) const</tt>:</dt>
<dd>Get a const_iterator to the end of a type plane. This serves as the
marker for end of iteration of the type plane.
Note: the type plane must already exist before using this.</dd>
<dt><tt>type_iterator type_begin()</tt>:</dt>
<dd>Get an iterator to the start of the name/Type map.</dd>
<dt><tt>type_const_iterator type_begin() cons</tt>:</dt>
<dd> Get a const_iterator to the start of the name/Type map.</dd>
<dt><tt>type_iterator type_end()</tt>:</dt>
<dd>Get an iterator to the end of the name/Type map. This serves as the
marker for end of iteration of the types.</dd>
<dt><tt>type_const_iterator type_end() const</tt>:</dt>
<dd>Get a const-iterator to the end of the name/Type map. This serves
as the marker for end of iteration of the types.</dd>
<dt><tt>plane_const_iterator find(const Type* Typ ) const</tt>:</dt>
<dd>This method returns a plane_const_iterator for iteration over
the type planes starting at a specific plane, given by \p Ty.</dd>
<dt><tt>plane_iterator find( const Type* Typ </tt>:</dt>
<dd>This method returns a plane_iterator for iteration over the
type planes starting at a specific plane, given by \p Ty.</dd>
</dl>
</div>
<!-- *********************************************************************** -->
<hr>
<address>