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| <html><head><title>LLVM Programmer's Manual</title></head> |
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| <table width="100%" bgcolor="#330077" border=0 cellpadding=4 cellspacing=0> |
| <tr><td> <font size=+3 color="#EEEEFF" face="Georgia,Palatino,Times,Roman"><b>LLVM Programmer's Manual</b></font></td> |
| </tr></table> |
| |
| <ol> |
| <li><a href="#introduction">Introduction</a> |
| <li><a href="#general">General Information</a> |
| <ul> |
| <li><a href="#stl">The C++ Standard Template Library</a> |
| <li>The isa<>, cast<> and dyn_cast<> templates |
| </ul> |
| <li><a href="#common">Helpful Hints for Common Operations</a> |
| <ul> |
| <li><a href="#inspection">Basic Inspection and Traversal Routines</a> |
| <ul> |
| <li><a href="#iterate_function">Iterating over the <tt>BasicBlock</tt>s |
| in a <tt>Function</tt></a> |
| <li><a href="#iterate_basicblock">Iterating over the <tt>Instruction</tt>s |
| in a <tt>BasicBlock</tt></a> |
| <li><a href="#iterate_convert">Turning an iterator into a class |
| pointer</a> |
| </ul> |
| <li><a href="#simplechanges">Making simple changes</a> |
| <ul> |
| <li>Creating and inserting new <tt>Instruction</tt>s |
| <li>Deleting <tt>Instruction</tt>s |
| <li>Replacing an <tt>Instruction</tt> with another <tt>Value</tt> |
| </ul> |
| <!-- |
| <li>Working with the Control Flow Graph |
| <ul> |
| <li>Accessing predecessors and successors of a <tt>BasicBlock</tt> |
| <li> |
| <li> |
| </ul> |
| --> |
| <li>Useful LLVM APIs |
| <ul> |
| <li>isa<>, cast<>, and dyn_cast<> templates |
| <!-- |
| <li>The general graph API |
| <li>The <tt>InstVisitor</tt> template |
| <li>The DEBUG() macro |
| <li>The <tt>Statistic</tt> template |
| --> |
| </ul> |
| <!-- |
| <li>Useful related topics |
| <ul> |
| <li>The <tt>-time-passes</tt> option |
| <li>How to use the LLVM Makefile system |
| <li>How to write a regression test |
| <li> |
| </ul> |
| --> |
| </ul> |
| <li><a href="#coreclasses">The Core LLVM Class Heirarchy Reference</a> |
| <ul> |
| <li><a href="#Value">The <tt>Value</tt> class</a> |
| <ul> |
| <li><a href="#User">The <tt>User</tt> class</a> |
| <ul> |
| <li><a href="#Instruction">The <tt>Instruction</tt> class</a> |
| <ul> |
| <li> |
| <li> |
| </ul> |
| <li><a href="#GlobalValue">The <tt>GlobalValue</tt> class</a> |
| <ul> |
| <li><a href="#BasicBlock">The <tt>BasicBlock</tt> class</a> |
| <li><a href="#Function">The <tt>Function</tt> class</a> |
| <li><a href="#GlobalVariable">The <tt>GlobalVariable</tt> class</a> |
| </ul> |
| <li><a href="#Module">The <tt>Module</tt> class</a> |
| <li><a href="#Constant">The <tt>Constant</tt> class</a> |
| <ul> |
| <li> |
| <li> |
| </ul> |
| </ul> |
| <li><a href="#Type">The <tt>Type</tt> class</a> |
| <li><a href="#Argument">The <tt>Argument</tt> class</a> |
| </ul> |
| <li>The <tt>SymbolTable</tt> class |
| <li>The <tt>ilist</tt> and <tt>iplist</tt> classes |
| <ul> |
| <li>Creating, inserting, moving and deleting from LLVM lists |
| </ul> |
| <li>Important iterator invalidation semantics to be aware of |
| </ul> |
| |
| <p><b>Written by <a href="mailto:dhurjati@cs.uiuc.edu">Dinakar Dhurjati</a> |
| and <a href="mailto:sabre@nondot.org">Chris Lattner</a></b><p> |
| </ol> |
| |
| |
| <!-- *********************************************************************** --> |
| <table width="100%" bgcolor="#330077" border=0 cellpadding=4 cellspacing=0> |
| <tr><td align=center><font color="#EEEEFF" size=+2 face="Georgia,Palatino"><b> |
| <a name="introduction">Introduction |
| </b></font></td></tr></table><ul> |
| <!-- *********************************************************************** --> |
| |
| This document is meant to hi-light some of the important classes and interfaces |
| available in the LLVM source-base. This manual is not indended to explain what |
| LLVM is, how it works, and what LLVM code looks like. It assumes that you know |
| the basics of LLVM and are interested in writing transformations or otherwise |
| analyzing or manipulating the code.<p> |
| |
| This document should get you oriented so that you can find your way in the |
| continuously growing source code that makes up the LLVM infrastructure. Note |
| that this manual is not intended to serve as a replacement for reading the |
| source code, so if you think there should be a method in one of these classes to |
| do something, but it's not listed, check the source. Links to the <a |
| href="/doxygen/">doxygen</a> sources are provided to make this as easy as |
| possible.<p> |
| |
| The first section of this document describes general information that is useful |
| to know when working in the LLVM infrastructure, and the second describes the |
| Core LLVM classes. In the future this manual will be extended with information |
| describing how to use extension libraries, such as dominator information, CFG |
| traversal routines, and useful utilities like the <tt><a |
| href="/doxygen/InstVisitor_8h-source.html">InstVisitor</a></tt> template.<p> |
| |
| |
| <!-- *********************************************************************** --> |
| </ul><table width="100%" bgcolor="#330077" border=0 cellpadding=4 cellspacing=0> |
| <tr><td align=center><font color="#EEEEFF" size=+2 face="Georgia,Palatino"><b> |
| <a name="general">General Information |
| </b></font></td></tr></table><ul> |
| <!-- *********************************************************************** --> |
| |
| This section contains general information that is useful if you are working in |
| the LLVM source-base, but that isn't specific to any particular API.<p> |
| |
| |
| <!-- ======================================================================= --> |
| </ul><table width="100%" bgcolor="#441188" border=0 cellpadding=4 cellspacing=0> |
| <tr><td> </td><td width="100%"> |
| <font color="#EEEEFF" face="Georgia,Palatino"><b> |
| <a name="stl">The C++ Standard Template Library</a> |
| </b></font></td></tr></table><ul> |
| |
| LLVM makes heavy use of the C++ Standard Template Library (STL), perhaps much |
| more than you are used to, or have seen before. Because of this, you might want |
| to do a little background reading in the techniques used and capabilities of the |
| library. There are many good pages that discuss the STL, and several books on |
| the subject that you can get, so it will not be discussed in this document.<p> |
| |
| Here are some useful links:<p> |
| <ol> |
| <li><a href="http://www.dinkumware.com/htm_cpl/index.html">Dinkumware C++ |
| Library reference</a> - an excellent reference for the STL and other parts of |
| the standard C++ library.<br> |
| |
| <li><a href="http://www.parashift.com/c++-faq-lite/">C++ Frequently Asked |
| Questions</a> |
| |
| <li><a href="http://www.sgi.com/tech/stl/">SGI's STL Programmer's Guide</a> - |
| Contains a useful <a |
| href="http://www.sgi.com/tech/stl/stl_introduction.html">Introduction to the |
| STL</a>. |
| |
| <li><a href="http://www.research.att.com/~bs/C++.html">Bjarne Stroustrup's C++ |
| Page</a> |
| |
| </ol><p> |
| |
| You are also encouraged to take a look at the <a |
| href="CodingStandards.html">LLVM Coding Standards</a> guide which focuses on how |
| to write maintainable code more than where to put your curly braces.<p> |
| |
| |
| |
| <!-- *********************************************************************** --> |
| </ul><table width="100%" bgcolor="#330077" border=0 cellpadding=4 cellspacing=0> |
| <tr><td align=center><font color="#EEEEFF" size=+2 face="Georgia,Palatino"><b> |
| <a name="common">Helpful Hints for Common Operations |
| </b></font></td></tr></table><ul> |
| <!-- *********************************************************************** --> |
| |
| This section describes how to perform some very simple transformations of LLVM |
| code. This is meant to give examples of common idioms used, showing the |
| practical side of LLVM transformations.<p> |
| |
| Because this is a "howto" section, you should also read about the main classes |
| that you will be working with. The <a href="#coreclasses">Core LLVM Class |
| Heirarchy Reference</a> contains details and descriptions of the main classes |
| that you should know about.<p> |
| |
| <!-- NOTE: this section should be heavy on example code --> |
| |
| |
| <!-- ======================================================================= --> |
| </ul><table width="100%" bgcolor="#441188" border=0 cellpadding=4 cellspacing=0> |
| <tr><td> </td><td width="100%"> |
| <font color="#EEEEFF" face="Georgia,Palatino"><b> |
| <a name="inspection">Basic Inspection and Traversal Routines</a> |
| </b></font></td></tr></table><ul> |
| |
| |
| <!-- LLVM has heirarchical representation: Module, Function, BasicBlock, |
| Instruction. Common patterns for all levels. --> |
| |
| <!-- _______________________________________________________________________ --> |
| </ul><h4><a name="iterate_function"><hr size=0>Iterating over the |
| <tt>BasicBlock</tt>s in a <tt>Function</tt> </h4><ul> |
| |
| |
| |
| <!-- _______________________________________________________________________ --> |
| </ul><h4><a name="iterate_basicblock"><hr size=0>Iterating over the |
| <tt>Instruction</tt>s in a <tt>BasicBlock</tt> </h4><ul> |
| |
| |
| |
| <!-- _______________________________________________________________________ --> |
| </ul><h4><a name="iterate_convert"><hr size=0>Turning an iterator into a class |
| pointer </h4><ul> |
| |
| <!-- dereferenced iterator = Class & |
| iterators have converting constructor for 'Class *' |
| iterators automatically convert to 'Class *' except in dyn_cast<> case |
| --> |
| |
| |
| |
| <!-- ======================================================================= --> |
| </ul><table width="100%" bgcolor="#441188" border=0 cellpadding=4 cellspacing=0> |
| <tr><td> </td><td width="100%"> |
| <font color="#EEEEFF" face="Georgia,Palatino"><b> |
| <a name="simplechanges">Making simple changes</a> |
| </b></font></td></tr></table><ul> |
| |
| <!-- Value::replaceAllUsesWith |
| User::replaceUsesOfWith |
| Point out: include/llvm/Transforms/Utils/ |
| especially BasicBlockUtils.h with: |
| ReplaceInstWithValue, ReplaceInstWithInst |
| |
| --> |
| |
| |
| <!-- *********************************************************************** --> |
| </ul><table width="100%" bgcolor="#330077" border=0 cellpadding=4 cellspacing=0> |
| <tr><td align=center><font color="#EEEEFF" size=+2 face="Georgia,Palatino"><b> |
| <a name="coreclasses">The Core LLVM Class Heirarchy Reference |
| </b></font></td></tr></table><ul> |
| <!-- *********************************************************************** --> |
| |
| The Core LLVM classes are the primary means of representing the program being |
| inspected or transformed. The core LLVM classes are defined in header files in |
| the <tt>include/llvm/</tt> directory, and implemented in the <tt>lib/VMCore</tt> |
| directory.<p> |
| |
| |
| <!-- ======================================================================= --> |
| </ul><table width="100%" bgcolor="#441188" border=0 cellpadding=4 cellspacing=0> |
| <tr><td> </td><td width="100%"> |
| <font color="#EEEEFF" face="Georgia,Palatino"><b> |
| <a name="Value">The <tt>Value</tt> class</a> |
| </b></font></td></tr></table><ul> |
| |
| <tt>#include "<a href="/doxygen/Value_8h-source.html">llvm/Value.h</a>"</tt></b><br> |
| doxygen info: <a href="/doxygen/classValue.html">Value Class</a><p> |
| |
| |
| The <tt>Value</tt> class is the most important class in LLVM Source base. It |
| represents a typed value that may be used (among other things) as an operand to |
| an instruction. There are many different types of <tt>Value</tt>s, such as <a |
| href="#Constant"><tt>Constant</tt></a>s, <a |
| href="#Argument"><tt>Argument</tt></a>s, and even <a |
| href="#Instruction"><tt>Instruction</tt></a>s and <a |
| href="#Function"><tt>Function</tt></a>s are <tt>Value</tt>s.<p> |
| |
| A particular <tt>Value</tt> may be used many times in the LLVM representation |
| for a program. For example, an incoming argument to a function (represented |
| with an instance of the <a href="#Argument">Argument</a> class) is "used" by |
| every instruction in the function that references the argument. To keep track |
| of this relationship, the <tt>Value</tt> class keeps a list of all of the <a |
| href="#User"><tt>User</tt></a>s that is using it (the <a |
| href="#User"><tt>User</tt></a> class is a base class for all nodes in the LLVM |
| graph that can refer to <tt>Value</tt>s). This use list is how LLVM represents |
| def-use information in the program, and is accessable through the <tt>use_</tt>* |
| methods, shown below.<p> |
| |
| Because LLVM is a typed representation, every LLVM <tt>Value</tt> is typed, and |
| this <a href="#Type">Type</a> is available through the <tt>getType()</tt> |
| method. <a name="#nameWarning">In addition, all LLVM values can be named. The |
| "name" of the <tt>Value</tt> is symbolic string printed in the LLVM code:<p> |
| |
| <pre> |
| %<b>foo</b> = add int 1, 2 |
| </pre> |
| |
| The name of this instruction is "foo". <b>NOTE</b> that the name of any value |
| may be missing (an empty string), so names should <b>ONLY</b> be used for |
| debugging (making the source code easier to read, debugging printouts), they |
| should not be used to keep track of values or map between them. For this |
| purpose, use a <tt>std::map</tt> of pointers to the <tt>Value</tt> itself |
| instead.<p> |
| |
| One important aspect of LLVM is that there is no distinction between an SSA |
| variable and the operation that produces it. Because of this, any reference to |
| the value produced by an instruction (or the value available as an incoming |
| argument, for example) is represented as a direct pointer to the class that |
| represents this value. Although this may take some getting used to, it |
| simplifies the representation and makes it easier to manipulate.<p> |
| |
| |
| <!-- _______________________________________________________________________ --> |
| </ul><h4><a name="m_Value"><hr size=0>Important Public Members of |
| the <tt>Value</tt> class</h4><ul> |
| |
| <li><tt>Value::use_iterator</tt> - Typedef for iterator over the use-list<br> |
| <tt>Value::use_const_iterator</tt> |
| - Typedef for const_iterator over the use-list<br> |
| <tt>unsigned use_size()</tt> - Returns the number of users of the value.<br> |
| <tt>bool use_empty()</tt> - Returns true if there are no users.<br> |
| <tt>use_iterator use_begin()</tt> |
| - Get an iterator to the start of the use-list.<br> |
| <tt>use_iterator use_end()</tt> |
| - Get an iterator to the end of the use-list.<br> |
| <tt><a href="#User">User</a> *use_back()</tt> |
| - Returns the last element in the list.<p> |
| |
| These methods are the interface to access the def-use information in LLVM. As with all other iterators in LLVM, the naming conventions follow the conventions defined by the <a href="#stl">STL</a>.<p> |
| |
| <li><tt><a href="#Type">Type</a> *getType() const</tt><p> |
| This method returns the Type of the Value. |
| |
| <li><tt>bool hasName() const</tt><br> |
| <tt>std::string getName() const</tt><br> |
| <tt>void setName(const std::string &Name)</tt><p> |
| |
| This family of methods is used to access and assign a name to a <tt>Value</tt>, |
| be aware of the <a href="#nameWarning">precaution above</a>.<p> |
| |
| |
| <li><tt>void replaceAllUsesWith(Value *V)</tt><p> |
| |
| This method traverses the use list of a <tt>Value</tt> changing all <a |
| href="#User"><tt>User</tt>'s</a> of the current value to refer to "<tt>V</tt>" |
| instead. For example, if you detect that an instruction always produces a |
| constant value (for example through constant folding), you can replace all uses |
| of the instruction with the constant like this:<p> |
| |
| <pre> |
| Inst->replaceAllUsesWith(ConstVal); |
| </pre><p> |
| |
| |
| |
| <!-- ======================================================================= --> |
| </ul><table width="100%" bgcolor="#441188" border=0 cellpadding=4 cellspacing=0> |
| <tr><td> </td><td width="100%"> |
| <font color="#EEEEFF" face="Georgia,Palatino"><b> |
| <a name="User">The <tt>User</tt> class</a> |
| </b></font></td></tr></table><ul> |
| |
| <tt>#include "<a href="/doxygen/User_8h-source.html">llvm/User.h</a>"</tt></b><br> |
| doxygen info: <a href="/doxygen/classUser.html">User Class</a><br> |
| Superclass: <a href="#Value"><tt>Value</tt></a><p> |
| |
| |
| The <tt>User</tt> class is the common base class of all LLVM nodes that may |
| refer to <a href="#Value"><tt>Value</tt></a>s. It exposes a list of "Operands" |
| that are all of the <a href="#Value"><tt>Value</tt></a>s that the User is |
| referring to. The <tt>User</tt> class itself is a subclass of |
| <tt>Value</tt>.<p> |
| |
| The operands of a <tt>User</tt> point directly to the LLVM <a |
| href="#Value"><tt>Value</tt></a> that it refers to. Because LLVM uses Static |
| Single Assignment (SSA) form, there can only be one definition referred to, |
| allowing this direct connection. This connection provides the use-def |
| information in LLVM.<p> |
| |
| <!-- _______________________________________________________________________ --> |
| </ul><h4><a name="m_User"><hr size=0>Important Public Members of |
| the <tt>User</tt> class</h4><ul> |
| |
| The <tt>User</tt> class exposes the operand list in two ways: through an index |
| access interface and through an iterator based interface.<p> |
| |
| <li><tt>Value *getOperand(unsigned i)</tt><br> |
| <tt>unsigned getNumOperands()</tt><p> |
| |
| These two methods expose the operands of the <tt>User</tt> in a convenient form |
| for direct access.<p> |
| |
| <li><tt>User::op_iterator</tt> - Typedef for iterator over the operand list<br> |
| <tt>User::op_const_iterator</tt> |
| <tt>use_iterator op_begin()</tt> |
| - Get an iterator to the start of the operand list.<br> |
| <tt>use_iterator op_end()</tt> |
| - Get an iterator to the end of the operand list.<p> |
| |
| Together, these methods make up the iterator based interface to the operands of |
| a <tt>User</tt>.<p> |
| |
| |
| |
| <!-- ======================================================================= --> |
| </ul><table width="100%" bgcolor="#441188" border=0 cellpadding=4 cellspacing=0> |
| <tr><td> </td><td width="100%"> |
| <font color="#EEEEFF" face="Georgia,Palatino"><b> |
| <a name="Instruction">The <tt>Instruction</tt> class</a> |
| </b></font></td></tr></table><ul> |
| |
| <tt>#include "<a |
| href="/doxygen/Instruction_8h-source.html">llvm/Instruction.h</a>"</tt></b><br> |
| doxygen info: <a href="/doxygen/classInstruction.html">Instruction Class</a><br> |
| Superclasses: <a href="#User"><tt>User</tt></a>, <a |
| href="#Value"><tt>Value</tt></a><p> |
| |
| The <tt>Instruction</tt> class is the common base class for all LLVM |
| instructions. It provides only a few methods, but is a very commonly used |
| class. The primary data tracked by the <tt>Instruction</tt> class itself is the |
| opcode (instruction type) and the parent <a |
| href="#BasicBlock"><tt>BasicBlock</tt></a> the <tt>Instruction</tt> is embedded |
| into. To represent a specific type of instruction, one of many subclasses of |
| <tt>Instruction</tt> are used.<p> |
| |
| Because the <tt>Instruction</tt> class subclasses the <a |
| href="#User"><tt>User</tt></a> class, its operands can be accessed in the same |
| way as for other <a href="#User"><tt>User</tt></a>s (with the |
| <tt>getOperand()</tt>/<tt>getNumOperands()</tt> and |
| <tt>op_begin()</tt>/<tt>op_end()</tt> methods).<p> |
| |
| |
| <!-- _______________________________________________________________________ --> |
| </ul><h4><a name="m_Instruction"><hr size=0>Important Public Members of |
| the <tt>Instruction</tt> class</h4><ul> |
| |
| <li><tt><a href="#BasicBlock">BasicBlock</a> *getParent()</tt><p> |
| |
| Returns the <a href="#BasicBlock"><tt>BasicBlock</tt></a> that this |
| <tt>Instruction</tt> is embedded into.<p> |
| |
| <li><tt>bool hasSideEffects()</tt><p> |
| |
| Returns true if the instruction has side effects, i.e. it is a <tt>call</tt>, |
| <tt>free</tt>, <tt>invoke</tt>, or <tt>store</tt>.<p> |
| |
| <li><tt>unsigned getOpcode()</tt><p> |
| |
| Returns the opcode for the <tt>Instruction</tt>.<p> |
| |
| <!-- |
| |
| \subsection{Subclasses of Instruction :} |
| \begin{itemize} |
| <li>BinaryOperator : This subclass of Instruction defines a general interface to the all the instructions involvong binary operators in LLVM. |
| \begin{itemize} |
| <li><tt>bool swapOperands()</tt>: Exchange the two operands to this instruction. If the instruction cannot be reversed (i.e. if it's a Div), it returns true. |
| \end{itemize} |
| <li>TerminatorInst : This subclass of Instructions defines an interface for all instructions that can terminate a BasicBlock. |
| \begin{itemize} |
| <li> <tt>unsigned getNumSuccessors()</tt>: Returns the number of successors for this terminator instruction. |
| <li><tt>BasicBlock *getSuccessor(unsigned i)</tt>: As the name suggests returns the ith successor BasicBlock. |
| <li><tt>void setSuccessor(unsigned i, BasicBlock *B)</tt>: sets BasicBlock B as the ith succesor to this terminator instruction. |
| \end{itemize} |
| |
| <li>PHINode : This represents the PHI instructions in the SSA form. |
| \begin{itemize} |
| <li><tt> unsigned getNumIncomingValues()</tt>: Returns the number of incoming edges to this PHI node. |
| <li><tt> Value *getIncomingValue(unsigned i)</tt>: Returns the ith incoming Value. |
| <li><tt>void setIncomingValue(unsigned i, Value *V)</tt>: Sets the ith incoming Value as V |
| <li><tt>BasicBlock *getIncomingBlock(unsigned i)</tt>: Returns the Basic Block corresponding to the ith incoming Value. |
| <li><tt> void addIncoming(Value *D, BasicBlock *BB)</tt>: |
| Add an incoming value to the end of the PHI list |
| <li><tt> int getBasicBlockIndex(const BasicBlock *BB) const</tt>: |
| Returns the first index of the specified basic block in the value list for this PHI. Returns -1 if no instance. |
| \end{itemize} |
| <li>CastInst : In LLVM all casts have to be done through explicit cast instructions. CastInst defines the interface to the cast instructions. |
| <li>CallInst : This defines an interface to the call instruction in LLVM. ARguments to the function are nothing but operands of the instruction. |
| \begin{itemize} |
| <li>: <tt>Function *getCalledFunction()</tt>: Returns a handle to the function that is being called by this Function. |
| \end{itemize} |
| <li>LoadInst, StoreInst, GetElemPtrInst : These subclasses represent load, store and getelementptr instructions in LLVM. |
| \begin{itemize} |
| <li><tt>Value * getPointerOperand ()</tt>: Returns the Pointer Operand which is typically the 0th operand. |
| \end{itemize} |
| <li>BranchInst : This is a subclass of TerminatorInst and defines the interface for conditional and unconditional branches in LLVM. |
| \begin{itemize} |
| <li><tt>bool isConditional()</tt>: Returns true if the branch is a conditional branch else returns false |
| <li> <tt>Value *getCondition()</tt>: Returns the condition if it is a conditional branch else returns null. |
| <li> <tt>void setUnconditionalDest(BasicBlock *Dest)</tt>: Changes the current branch to an unconditional one targetting the specified block. |
| \end{itemize} |
| |
| \end{itemize} |
| |
| --> |
| |
| |
| <!-- ======================================================================= --> |
| </ul><table width="100%" bgcolor="#441188" border=0 cellpadding=4 cellspacing=0> |
| <tr><td> </td><td width="100%"> |
| <font color="#EEEEFF" face="Georgia,Palatino"><b> |
| <a name="BasicBlock">The <tt>BasicBlock</tt> class</a> |
| </b></font></td></tr></table><ul> |
| |
| <tt>#include "<a |
| href="/doxygen/BasicBlock_8h-source.html">llvm/BasicBlock.h</a>"</tt></b><br> |
| doxygen info: <a href="/doxygen/classBasicBlock.html">BasicBlock Class</a><br> |
| Superclass: <a href="#Value"><tt>Value</tt></a><p> |
| |
| |
| This class represents a single entry multiple exit section of the code, commonly |
| known as a basic block by the compiler community. The <tt>BasicBlock</tt> class |
| maintains a list of <a href="#Instruction"><tt>Instruction</tt></a>s, which form |
| the body of the block. Matching the language definition, the last element of |
| this list of instructions is always a terminator instruction (a subclass of the |
| <a href="#TerminatorInst"><tt>TerminatorInst</tt></a> class).<p> |
| |
| In addition to tracking the list of instructions that make up the block, the |
| <tt>BasicBlock</tt> class also keeps track of the <a |
| href="#Function"><tt>Function</tt></a> that it is embedded into.<p> |
| |
| Note that <tt>BasicBlock</tt>s themselves are <a |
| href="#Value"><tt>Value</tt></a>s, because they are referenced by instructions |
| like branches and can go in the switch tables. <tt>BasicBlock</tt>s have type |
| <tt>label</tt>.<p> |
| |
| |
| <!-- _______________________________________________________________________ --> |
| </ul><h4><a name="m_BasicBlock"><hr size=0>Important Public Members of |
| the <tt>BasicBlock</tt> class</h4><ul> |
| |
| <li><tt>BasicBlock(const std::string &Name = "", <a |
| href="#Function">Function</a> *Parent = 0)</tt><p> |
| |
| The <tt>BasicBlock</tt> constructor is used to create new basic blocks for |
| insertion into a function. The constructor simply takes a name for the new |
| block, and optionally a <a href="#Function"><tt>Function</tt></a> to insert it |
| into. If the <tt>Parent</tt> parameter is specified, the new |
| <tt>BasicBlock</tt> is automatically inserted at the end of the specified <a |
| href="#Function"><tt>Function</tt></a>, if not specified, the BasicBlock must be |
| manually inserted into the <a href="#Function"><tt>Function</tt></a>.<p> |
| |
| <li><tt>BasicBlock::iterator</tt> - Typedef for instruction list iterator<br> |
| <tt>BasicBlock::const_iterator</tt> - Typedef for const_iterator.<br> |
| <tt>begin()</tt>, <tt>end()</tt>, <tt>front()</tt>, <tt>back()</tt>, |
| <tt>size()</tt>, <tt>empty()</tt>, <tt>rbegin()</tt>, <tt>rend()</tt><p> |
| |
| These methods and typedefs are forwarding functions that have the same semantics |
| as the standard library methods of the same names. These methods expose the |
| underlying instruction list of a basic block in a way that is easy to |
| manipulate. To get the full complement of container operations (including |
| operations to update the list), you must use the <tt>getInstList()</tt> |
| method.<p> |
| |
| <li><tt>BasicBlock::InstListType &getInstList()</tt><p> |
| |
| This method is used to get access to the underlying container that actually |
| holds the Instructions. This method must be used when there isn't a forwarding |
| function in the <tt>BasicBlock</tt> class for the operation that you would like |
| to perform. Because there are no forwarding functions for "updating" |
| operations, you need to use this if you want to update the contents of a |
| <tt>BasicBlock</tt>.<p> |
| |
| <li><tt><A href="#Function">Function</a> *getParent()</tt><p> |
| |
| Returns a pointer to <a href="#Function"><tt>Function</tt></a> the block is |
| embedded into, or a null pointer if it is homeless.<p> |
| |
| <li><tt><a href="#TerminatorInst">TerminatorInst</a> *getTerminator()</tt><p> |
| |
| Returns a pointer to the terminator instruction that appears at the end of the |
| <tt>BasicBlock</tt>. If there is no terminator instruction, or if the last |
| instruction in the block is not a terminator, then a null pointer is |
| returned.<p> |
| |
| |
| <!-- ======================================================================= --> |
| </ul><table width="100%" bgcolor="#441188" border=0 cellpadding=4 cellspacing=0> |
| <tr><td> </td><td width="100%"> |
| <font color="#EEEEFF" face="Georgia,Palatino"><b> |
| <a name="GlobalValue">The <tt>GlobalValue</tt> class</a> |
| </b></font></td></tr></table><ul> |
| |
| <tt>#include "<a |
| href="/doxygen/GlobalValue_8h-source.html">llvm/GlobalValue.h</a>"</tt></b><br> |
| doxygen info: <a href="/doxygen/classGlobalValue.html">GlobalValue Class</a><br> |
| Superclasses: <a href="#User"><tt>User</tt></a>, <a |
| href="#Value"><tt>Value</tt></a><p> |
| |
| Global values (<A href="#GlobalVariable"><tt>GlobalVariable</tt></a>s or <a |
| href="#Function"><tt>Function</tt></a>s) are the only LLVM values that are |
| visible in the bodies of all <a href="#Function"><tt>Function</tt></a>s. |
| Because they are visible at global scope, they are also subject to linking with |
| other globals defined in different translation units. To control the linking |
| process, <tt>GlobalValue</tt>s know their linkage rules. Specifically, |
| <tt>GlobalValue</tt>s know whether they have internal or external linkage.<p> |
| |
| If a <tt>GlobalValue</tt> has internal linkage (equivalent to being |
| <tt>static</tt> in C), it is not visible to code outside the current translation |
| unit, and does not participate in linking. If it has external linkage, it is |
| visible to external code, and does participate in linking. In addition to |
| linkage information, <tt>GlobalValue</tt>s keep track of which <a |
| href="#Module"><tt>Module</tt></a> they are currently part of.<p> |
| |
| Because <tt>GlobalValue</tt>s are memory objects, they are always referred to by |
| their address. As such, the <a href="#Type"><tt>Type</tt></a> of a global is |
| always a pointer to its contents. This is explained in the LLVM Language |
| Reference Manual.<p> |
| |
| |
| <!-- _______________________________________________________________________ --> |
| </ul><h4><a name="m_GlobalValue"><hr size=0>Important Public Members of |
| the <tt>GlobalValue</tt> class</h4><ul> |
| |
| <li><tt>bool hasInternalLinkage() const</tt><br> |
| <tt>bool hasExternalLinkage() const</tt><br> |
| <tt>void setInternalLinkage(bool HasInternalLinkage)</tt><p> |
| |
| These methods manipulate the linkage characteristics of the |
| <tt>GlobalValue</tt>.<p> |
| |
| <li><tt><a href="#Module">Module</a> *getParent()</tt><p> |
| |
| This returns the <a href="#Module"><tt>Module</tt></a> that the GlobalValue is |
| currently embedded into.<p> |
| |
| |
| |
| <!-- ======================================================================= --> |
| </ul><table width="100%" bgcolor="#441188" border=0 cellpadding=4 cellspacing=0> |
| <tr><td> </td><td width="100%"> |
| <font color="#EEEEFF" face="Georgia,Palatino"><b> |
| <a name="Function">The <tt>Function</tt> class</a> |
| </b></font></td></tr></table><ul> |
| |
| <tt>#include "<a |
| href="/doxygen/Function_8h-source.html">llvm/Function.h</a>"</tt></b><br> |
| doxygen info: <a href="/doxygen/classFunction.html">Function Class</a><br> |
| Superclasses: <a href="#GlobalValue"><tt>GlobalValue</tt></a>, <a |
| href="#User"><tt>User</tt></a>, <a href="#Value"><tt>Value</tt></a><p> |
| |
| The <tt>Function</tt> class represents a single procedure in LLVM. It is |
| actually one of the more complex classes in the LLVM heirarchy because it must |
| keep track of a large amount of data. The <tt>Function</tt> class keeps track |
| of a list of <a href="#BasicBlock"><tt>BasicBlock</tt></a>s, a list of formal <a |
| href="#Argument"><tt>Argument</tt></a>s, and a <a |
| href="#SymbolTable"><tt>SymbolTable</tt></a>.<p> |
| |
| The list of <a href="#BasicBlock"><tt>BasicBlock</tt></a>s is the most commonly |
| used part of <tt>Function</tt> objects. The list imposes an implicit ordering |
| of the blocks in the function, which indicate how the code will be layed out by |
| the backend. Additionally, the first <a |
| href="#BasicBlock"><tt>BasicBlock</tt></a> is the implicit entry node for the |
| <tt>Function</tt>. It is not legal in LLVM explicitly branch to this initial |
| block. There are no implicit exit nodes, and in fact there may be multiple exit |
| nodes from a single <tt>Function</tt>. If the <a |
| href="#BasicBlock"><tt>BasicBlock</tt></a> list is empty, this indicates that |
| the <tt>Function</tt> is actually a function declaration: the actual body of the |
| function hasn't been linked in yet.<p> |
| |
| In addition to a list of <a href="#BasicBlock"><tt>BasicBlock</tt></a>s, the |
| <tt>Function</tt> class also keeps track of the list of formal <a |
| href="#Argument"><tt>Argument</tt></a>s that the function receives. This |
| container manages the lifetime of the <a href="#Argument"><tt>Argument</tt></a> |
| nodes, just like the <a href="#BasicBlock"><tt>BasicBlock</tt></a> list does for |
| the <a href="#BasicBlock"><tt>BasicBlock</tt></a>s.<p> |
| |
| The <a href="#SymbolTable"><tt>SymbolTable</tt></a> is a very rarely used LLVM |
| feature that is only used when you have to look up a value by name. Aside from |
| that, the <a href="#SymbolTable"><tt>SymbolTable</tt></a> is used internally to |
| make sure that there are not conflicts between the names of <a |
| href="#Instruction"><tt>Instruction</tt></a>s, <a |
| href="#BasicBlock"><tt>BasicBlock</tt></a>s, or <a |
| href="#Argument"><tt>Argument</tt></a>s in the function body.<p> |
| |
| |
| <!-- _______________________________________________________________________ --> |
| </ul><h4><a name="m_Function"><hr size=0>Important Public Members of |
| the <tt>Function</tt> class</h4><ul> |
| |
| <li><tt>Function(const <a href="#FunctionType">FunctionType</a> *Ty, bool isInternal, const std::string &N = "")</tt><p> |
| |
| Constructor used when you need to create new <tt>Function</tt>s to add the the |
| program. The constructor must specify the type of the function to create and |
| whether or not it should start out with internal or external linkage.<p> |
| |
| <li><tt>bool isExternal()</tt><p> |
| |
| Return whether or not the <tt>Function</tt> has a body defined. If the function |
| is "external", it does not have a body, and thus must be resolved by linking |
| with a function defined in a different translation unit.<p> |
| |
| |
| <li><tt>Function::iterator</tt> - Typedef for basic block list iterator<br> |
| <tt>Function::const_iterator</tt> - Typedef for const_iterator.<br> |
| <tt>begin()</tt>, <tt>end()</tt>, <tt>front()</tt>, <tt>back()</tt>, |
| <tt>size()</tt>, <tt>empty()</tt>, <tt>rbegin()</tt>, <tt>rend()</tt><p> |
| |
| These are forwarding methods that make it easy to access the contents of a |
| <tt>Function</tt> object's <a href="#BasicBlock"><tt>BasicBlock</tt></a> |
| list.<p> |
| |
| <li><tt>Function::BasicBlockListType &getBasicBlockList()</tt><p> |
| |
| Returns the list of <a href="#BasicBlock"><tt>BasicBlock</tt></a>s. This is |
| neccesary to use when you need to update the list or perform a complex action |
| that doesn't have a forwarding method.<p> |
| |
| |
| <li><tt>Function::aiterator</tt> - Typedef for the argument list iterator<br> |
| <tt>Function::const_aiterator</tt> - Typedef for const_iterator.<br> |
| <tt>abegin()</tt>, <tt>aend()</tt>, <tt>afront()</tt>, <tt>aback()</tt>, |
| <tt>asize()</tt>, <tt>aempty()</tt>, <tt>arbegin()</tt>, <tt>arend()</tt><p> |
| |
| These are forwarding methods that make it easy to access the contents of a |
| <tt>Function</tt> object's <a href="#Argument"><tt>Argument</tt></a> list.<p> |
| |
| <li><tt>Function::ArgumentListType &getArgumentList()</tt><p> |
| |
| Returns the list of <a href="#Argument"><tt>Argument</tt></a>s. This is |
| neccesary to use when you need to update the list or perform a complex action |
| that doesn't have a forwarding method.<p> |
| |
| |
| |
| <li><tt><a href="#BasicBlock">BasicBlock</a> &getEntryNode()</tt><p> |
| |
| Returns the entry <a href="#BasicBlock"><tt>BasicBlock</tt></a> for the |
| function. Because the entry block for the function is always the first block, |
| this returns the first block of the <tt>Function</tt>.<p> |
| |
| <li><tt><a href="#Type">Type</a> *getReturnType()</tt><br> |
| <tt><a href="#FunctionType">FunctionType</a> *getFunctionType()</tt><p> |
| |
| This traverses the <a href="#Type"><tt>Type</tt></a> of the <tt>Function</tt> |
| and returns the return type of the function, or the <a |
| href="#FunctionType"><tt>FunctionType</tt></a> of the actual function.<p> |
| |
| |
| <li><tt>bool hasSymbolTable() const</tt><p> |
| |
| Return true if the <tt>Function</tt> has a symbol table allocated to it and if |
| there is at least one entry in it.<p> |
| |
| <li><tt><a href="#SymbolTable">SymbolTable</a> *getSymbolTable()</tt><p> |
| |
| Return a pointer to the <a href="#SymbolTable"><tt>SymbolTable</tt></a> for this |
| <tt>Function</tt> or a null pointer if one has not been allocated (because there |
| are no named values in the function).<p> |
| |
| <li><tt><a href="#SymbolTable">SymbolTable</a> *getSymbolTableSure()</tt><p> |
| |
| Return a pointer to the <a href="#SymbolTable"><tt>SymbolTable</tt></a> for this |
| <tt>Function</tt> or allocate a new <a |
| href="#SymbolTable"><tt>SymbolTable</tt></a> if one is not already around. This |
| should only be used when adding elements to the <a |
| href="#SymbolTable"><tt>SymbolTable</tt></a>, so that empty symbol tables are |
| not left laying around.<p> |
| |
| |
| |
| <!-- ======================================================================= --> |
| </ul><table width="100%" bgcolor="#441188" border=0 cellpadding=4 cellspacing=0> |
| <tr><td> </td><td width="100%"> |
| <font color="#EEEEFF" face="Georgia,Palatino"><b> |
| <a name="GlobalVariable">The <tt>GlobalVariable</tt> class</a> |
| </b></font></td></tr></table><ul> |
| |
| <tt>#include "<a |
| href="/doxygen/GlobalVariable_8h-source.html">llvm/GlobalVariable.h</a>"</tt></b><br> |
| doxygen info: <a href="/doxygen/classGlobalVariable.html">GlobalVariable Class</a><br> |
| Superclasses: <a href="#GlobalValue"><tt>GlobalValue</tt></a>, <a |
| href="#User"><tt>User</tt></a>, <a href="#Value"><tt>Value</tt></a><p> |
| |
| Global variables are represented with the (suprise suprise) |
| <tt>GlobalVariable</tt> class. Like functions, <tt>GlobalVariable</tt>s are |
| also subclasses of <a href="#GlobalValue"><tt>GlobalValue</tt></a>, and as such |
| are always referenced by their address (global values must live in memory, so |
| their "name" refers to their address). Global variables may have an initial |
| value (which must be a <a href="#Constant"><tt>Constant</tt></a>), and if they |
| have an initializer, they may be marked as "constant" themselves (indicating |
| that their contents never change at runtime).<p> |
| |
| |
| <!-- _______________________________________________________________________ --> |
| </ul><h4><a name="m_GlobalVariable"><hr size=0>Important Public Members of the |
| <tt>GlobalVariable</tt> class</h4><ul> |
| |
| <li><tt>GlobalVariable(const <a href="#Type">Type</a> *Ty, bool isConstant, bool |
| isInternal, <a href="#Constant">Constant</a> *Initializer = 0, const std::string |
| &Name = "")</tt><p> |
| |
| Create a new global variable of the specified type. If <tt>isConstant</tt> is |
| true then the global variable will be marked as unchanging for the program, and |
| if <tt>isInternal</tt> is true the resultant global variable will have internal |
| linkage. Optionally an initializer and name may be specified for the global variable as well.<p> |
| |
| |
| <li><tt>bool isConstant() const</tt><p> |
| |
| Returns true if this is a global variable is known not to be modified at |
| runtime.<p> |
| |
| |
| <li><tt>bool hasInitializer()</tt><p> |
| |
| Returns true if this <tt>GlobalVariable</tt> has an intializer.<p> |
| |
| |
| <li><tt><a href="#Constant">Constant</a> *getInitializer()</tt><p> |
| |
| Returns the intial value for a <tt>GlobalVariable</tt>. It is not legal to call |
| this method if there is no initializer.<p> |
| |
| |
| <!-- ======================================================================= --> |
| </ul><table width="100%" bgcolor="#441188" border=0 cellpadding=4 cellspacing=0> |
| <tr><td> </td><td width="100%"> |
| <font color="#EEEEFF" face="Georgia,Palatino"><b> |
| <a name="Module">The <tt>Module</tt> class</a> |
| </b></font></td></tr></table><ul> |
| |
| <tt>#include "<a |
| href="/doxygen/Module_8h-source.html">llvm/Module.h</a>"</tt></b><br> |
| doxygen info: <a href="/doxygen/classModule.html">Module Class</a><p> |
| |
| The <tt>Module</tt> class represents the top level structure present in LLVM |
| programs. An LLVM module is effectively either a translation unit of the |
| original program or a combination of several translation units merged by the |
| linker. The <tt>Module</tt> class keeps track of a list of <a |
| href="#Function"><tt>Function</tt></a>s, a list of <a |
| href="#GlobalVariable"><tt>GlobalVariable</tt></a>s, and a <a |
| href="#SymbolTable"><tt>SymbolTable</tt></a>. Additionally, it contains a few |
| helpful member functions that try to make common operations easy.<p> |
| |
| |
| <!-- _______________________________________________________________________ --> |
| </ul><h4><a name="m_Module"><hr size=0>Important Public Members of the |
| <tt>Module</tt> class</h4><ul> |
| |
| <li><tt>Module::iterator</tt> - Typedef for function list iterator<br> |
| <tt>Module::const_iterator</tt> - Typedef for const_iterator.<br> |
| <tt>begin()</tt>, <tt>end()</tt>, <tt>front()</tt>, <tt>back()</tt>, |
| <tt>size()</tt>, <tt>empty()</tt>, <tt>rbegin()</tt>, <tt>rend()</tt><p> |
| |
| These are forwarding methods that make it easy to access the contents of a |
| <tt>Module</tt> object's <a href="#Function"><tt>Function</tt></a> |
| list.<p> |
| |
| <li><tt>Module::FunctionListType &getFunctionList()</tt><p> |
| |
| Returns the list of <a href="#Function"><tt>Function</tt></a>s. This is |
| neccesary to use when you need to update the list or perform a complex action |
| that doesn't have a forwarding method.<p> |
| |
| <!-- Global Variable --> |
| <hr size=0> |
| |
| <li><tt>Module::giterator</tt> - Typedef for global variable list iterator<br> |
| <tt>Module::const_giterator</tt> - Typedef for const_iterator.<br> |
| <tt>gbegin()</tt>, <tt>gend()</tt>, <tt>gfront()</tt>, <tt>gback()</tt>, |
| <tt>gsize()</tt>, <tt>gempty()</tt>, <tt>grbegin()</tt>, <tt>grend()</tt><p> |
| |
| These are forwarding methods that make it easy to access the contents of a |
| <tt>Module</tt> object's <a href="#GlobalVariable"><tt>GlobalVariable</tt></a> |
| list.<p> |
| |
| <li><tt>Module::GlobalListType &getGlobalList()</tt><p> |
| |
| Returns the list of <a href="#GlobalVariable"><tt>GlobalVariable</tt></a>s. |
| This is neccesary to use when you need to update the list or perform a complex |
| action that doesn't have a forwarding method.<p> |
| |
| |
| <!-- Symbol table stuff --> |
| <hr size=0> |
| |
| <li><tt>bool hasSymbolTable() const</tt><p> |
| |
| Return true if the <tt>Module</tt> has a symbol table allocated to it and if |
| there is at least one entry in it.<p> |
| |
| <li><tt><a href="#SymbolTable">SymbolTable</a> *getSymbolTable()</tt><p> |
| |
| Return a pointer to the <a href="#SymbolTable"><tt>SymbolTable</tt></a> for this |
| <tt>Module</tt> or a null pointer if one has not been allocated (because there |
| are no named values in the function).<p> |
| |
| <li><tt><a href="#SymbolTable">SymbolTable</a> *getSymbolTableSure()</tt><p> |
| |
| Return a pointer to the <a href="#SymbolTable"><tt>SymbolTable</tt></a> for this |
| <tt>Module</tt> or allocate a new <a |
| href="#SymbolTable"><tt>SymbolTable</tt></a> if one is not already around. This |
| should only be used when adding elements to the <a |
| href="#SymbolTable"><tt>SymbolTable</tt></a>, so that empty symbol tables are |
| not left laying around.<p> |
| |
| |
| <!-- Convenience methods --> |
| <hr size=0> |
| |
| <li><tt><a href="#Function">Function</a> *getFunction(const std::string &Name, const <a href="#FunctionType">FunctionType</a> *Ty)</tt><p> |
| |
| Look up the specified function in the <tt>Module</tt> <a |
| href="#SymbolTable"><tt>SymbolTable</tt></a>. If it does not exist, return |
| <tt>null</tt>.<p> |
| |
| |
| <li><tt><a href="#Function">Function</a> *getOrInsertFunction(const std::string |
| &Name, const <a href="#FunctionType">FunctionType</a> *T)</tt><p> |
| |
| Look up the specified function in the <tt>Module</tt> <a |
| href="#SymbolTable"><tt>SymbolTable</tt></a>. If it does not exist, add an |
| external declaration for the function and return it.<p> |
| |
| |
| <li><tt>std::string getTypeName(const <a href="#Type">Type</a> *Ty)</tt><p> |
| |
| If there is at least one entry in the <a |
| href="#SymbolTable"><tt>SymbolTable</tt></a> for the specified <a |
| href="#Type"><tt>Type</tt></a>, return it. Otherwise return the empty |
| string.<p> |
| |
| |
| <li><tt>bool addTypeName(const std::string &Name, const <a href="#Type">Type</a> |
| *Ty)</tt><p> |
| |
| Insert an entry in the <a href="#SymbolTable"><tt>SymbolTable</tt></a> mapping |
| <tt>Name</tt> to <tt>Ty</tt>. If there is already an entry for this name, true |
| is returned and the <a href="#SymbolTable"><tt>SymbolTable</tt></a> is not |
| modified.<p> |
| |
| |
| <!-- ======================================================================= --> |
| </ul><table width="100%" bgcolor="#441188" border=0 cellpadding=4 cellspacing=0> |
| <tr><td> </td><td width="100%"> |
| <font color="#EEEEFF" face="Georgia,Palatino"><b> |
| <a name="Constant">The <tt>Constant</tt> class and subclasses</a> |
| </b></font></td></tr></table><ul> |
| |
| Constant represents a base class for different types of constants. It is |
| subclassed by ConstantBool, ConstantInt, ConstantSInt, ConstantUInt, |
| ConstantArray etc for representing the various types of Constants.<p> |
| |
| |
| <!-- _______________________________________________________________________ --> |
| </ul><h4><a name="m_Value"><hr size=0>Important Public Methods</h4><ul> |
| |
| <li><tt>bool isConstantExpr()</tt>: Returns true if it is a ConstantExpr |
| |
| |
| |
| |
| \subsection{Important Subclasses of Constant} |
| \begin{itemize} |
| <li>ConstantSInt : This subclass of Constant represents a signed integer constant. |
| \begin{itemize} |
| <li><tt>int64_t getValue () const</tt>: Returns the underlying value of this constant. |
| \end{itemize} |
| <li>ConstantUInt : This class represents an unsigned integer. |
| \begin{itemize} |
| <li><tt>uint64_t getValue () const</tt>: Returns the underlying value of this constant. |
| \end{itemize} |
| <li>ConstantFP : This class represents a floating point constant. |
| \begin{itemize} |
| <li><tt>double getValue () const</tt>: Returns the underlying value of this constant. |
| \end{itemize} |
| <li>ConstantBool : This represents a boolean constant. |
| \begin{itemize} |
| <li><tt>bool getValue () const</tt>: Returns the underlying value of this constant. |
| \end{itemize} |
| <li>ConstantArray : This represents a constant array. |
| \begin{itemize} |
| <li><tt>const std::vector<Use> &getValues() const</tt>: Returns a Vecotr of component constants that makeup this array. |
| \end{itemize} |
| <li>ConstantStruct : This represents a constant struct. |
| \begin{itemize} |
| <li><tt>const std::vector<Use> &getValues() const</tt>: Returns a Vecotr of component constants that makeup this array. |
| \end{itemize} |
| <li>ConstantPointerRef : This represents a constant pointer value that is initialized to point to a global value, which lies at a constant fixed address. |
| \begin{itemize} |
| <li><tt>GlobalValue *getValue()</tt>: Returns the global value to which this pointer is pointing to. |
| \end{itemize} |
| \end{itemize} |
| |
| |
| <!-- ======================================================================= --> |
| </ul><table width="100%" bgcolor="#441188" border=0 cellpadding=4 cellspacing=0> |
| <tr><td> </td><td width="100%"> |
| <font color="#EEEEFF" face="Georgia,Palatino"><b> |
| <a name="Type">The <tt>Type</tt> class and Derived Types</a> |
| </b></font></td></tr></table><ul> |
| |
| Type as noted earlier is also a subclass of a Value class. Any primitive |
| type (like int, short etc) in LLVM is an instance of Type Class. All |
| other types are instances of subclasses of type like FunctionType, |
| ArrayType etc. DerivedType is the interface for all such dervied types |
| including FunctionType, ArrayType, PointerType, StructType. Types can have |
| names. They can be recursive (StructType). There exists exactly one instance |
| of any type structure at a time. This allows using pointer equality of Type *s for comparing types. |
| |
| <!-- _______________________________________________________________________ --> |
| </ul><h4><a name="m_Value"><hr size=0>Important Public Methods</h4><ul> |
| |
| <li><tt>PrimitiveID getPrimitiveID () const</tt>: Returns the base type of the type. |
| <li><tt> bool isSigned () const</tt>: Returns whether an integral numeric type is signed. This is true for SByteTy, ShortTy, IntTy, LongTy. Note that this is not true for Float and Double. |
| <li><tt>bool isUnsigned () const</tt>: Returns whether a numeric type is unsigned. This is not quite the complement of isSigned... nonnumeric types return false as they do with isSigned. This returns true for UByteTy, UShortTy, UIntTy, and ULongTy. |
| <li><tt> bool isInteger () const</tt>: Equilivent to isSigned() || isUnsigned(), but with only a single virtual function invocation. |
| <li><tt>bool isIntegral () const</tt>: Returns true if this is an integral type, which is either Bool type or one of the Integer types. |
| |
| <li><tt>bool isFloatingPoint ()</tt>: Return true if this is one of the two floating point types. |
| <li><tt>bool isRecursive () const</tt>: Returns rue if the type graph contains a cycle. |
| <li><tt>isLosslesslyConvertableTo (const Type *Ty) const</tt>: Return true if this type can be converted to 'Ty' without any reinterpretation of bits. For example, uint to int. |
| <li><tt>bool isPrimitiveType () const</tt>: Returns true if it is a primitive type. |
| <li><tt>bool isDerivedType () const</tt>: Returns true if it is a derived type. |
| <li><tt>const Type * getContainedType (unsigned i) const</tt>: |
| This method is used to implement the type iterator. For derived types, this returns the types 'contained' in the derived type, returning 0 when 'i' becomes invalid. This allows the user to iterate over the types in a struct, for example, really easily. |
| <li><tt>unsigned getNumContainedTypes () const</tt>: Return the number of types in the derived type. |
| |
| |
| |
| \subsection{Derived Types} |
| \begin{itemize} |
| <li>SequentialType : This is subclassed by ArrayType and PointerType |
| \begin{itemize} |
| <li><tt>const Type * getElementType () const</tt>: Returns the type of each of the elements in the sequential type. |
| \end{itemize} |
| <li>ArrayType : This is a subclass of SequentialType and defines interface for array types. |
| \begin{itemize} |
| <li><tt>unsigned getNumElements () const</tt>: Returns the number of elements in the array. |
| \end{itemize} |
| <li>PointerType : Subclass of SequentialType for pointer types. |
| <li>StructType : subclass of DerivedTypes for struct types |
| <li>FunctionType : subclass of DerivedTypes for function types. |
| \begin{itemize} |
| |
| <li><tt>bool isVarArg () const</tt>: Returns true if its a vararg function |
| <li><tt> const Type * getReturnType () const</tt>: Returns the return type of the function. |
| <li><tt> const ParamTypes &getParamTypes () const</tt>: Returns a vector of parameter types. |
| <li><tt>const Type * getParamType (unsigned i)</tt>: Returns the type of the ith parameter. |
| <li><tt> const unsigned getNumParams () const</tt>: Returns the number of formal parameters. |
| \end{itemize} |
| \end{itemize} |
| |
| |
| |
| |
| <!-- ======================================================================= --> |
| </ul><table width="100%" bgcolor="#441188" border=0 cellpadding=4 cellspacing=0> |
| <tr><td> </td><td width="100%"> |
| <font color="#EEEEFF" face="Georgia,Palatino"><b> |
| <a name="Argument">The <tt>Argument</tt> class</a> |
| </b></font></td></tr></table><ul> |
| |
| This subclass of Value defines the interface for incoming formal arguments to a |
| function. A Function maitanis a list of its formal arguments. An argument has a |
| pointer to the parent Function. |
| |
| |
| |
| |
| <!-- *********************************************************************** --> |
| </ul> |
| <!-- *********************************************************************** --> |
| |
| <hr><font size-1> |
| <address>By: <a href="mailto:dhurjati@cs.uiuc.edu">Dinakar Dhurjati</a> and |
| <a href="mailto:sabre@nondot.org">Chris Lattner</a></address> |
| <!-- Created: Tue Aug 6 15:00:33 CDT 2002 --> |
| <!-- hhmts start --> |
| Last modified: Fri Sep 6 13:30:36 CDT 2002 |
| <!-- hhmts end --> |
| </font></body></html> |