From d0713f94af4d2dbd97ab251a43e3d290a13e860e Mon Sep 17 00:00:00 2001
From: Chris Lattner <sabre@nondot.org>
Date: Thu, 12 Sep 2002 17:06:43 +0000
Subject: [PATCH] Add a new
 BasicBlockPass::doInitialization/Finalization(Function &) pair of methods
 that may be useful for BasicBlockPasses.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@3689 91177308-0d34-0410-b5e6-96231b3b80d8
---
 docs/WritingAnLLVMPass.html | 67 +++++++++++++++++++++++++++++--------
 include/llvm/Pass.h         | 27 +++++++++++++--
 2 files changed, 77 insertions(+), 17 deletions(-)

diff --git a/docs/WritingAnLLVMPass.html b/docs/WritingAnLLVMPass.html
index 353fe6e366f..aee16631bf6 100644
--- a/docs/WritingAnLLVMPass.html
+++ b/docs/WritingAnLLVMPass.html
@@ -25,13 +25,19 @@
         </ul>
      <li><a href="#FunctionPass">The <tt>FunctionPass</tt> class</a>
         <ul>
-        <li><a href="#doInitialization">The <tt>doInitialization</tt> method</a>
+        <li><a href="#doInitialization_mod">The <tt>doInitialization(Module
+                                            &amp;)</tt> method</a>
         <li><a href="#runOnFunction">The <tt>runOnFunction</tt> method</a>
-        <li><a href="#doFinalization">The <tt>doFinalization</tt> method</a>
+        <li><a href="#doFinalization_mod">The <tt>doFinalization(Module
+                                            &amp;)</tt> method</a>
         </ul>
      <li><a href="#BasicBlockPass">The <tt>BasicBlockPass</tt> class</a>
         <ul>
+        <li><a href="#doInitialization_fn">The <tt>doInitialization(Function
+                                             &amp;)</tt> method</a>
         <li><a href="#runOnBasicBlock">The <tt>runOnBasicBlock</tt> method</a>
+        <li><a href="#doFinalization_fn">The <tt>doFinalization(Function
+                                             &amp;)</tt> method</a>
         </ul>
      </ul>
   <li><a href="#registration">Pass Registration</a>
@@ -424,8 +430,8 @@ may overload three virtual methods to do their work.  All of these methods
 should return true if they modified the program, or false if they didn't.<p>
 
 <!-- _______________________________________________________________________ -->
-</ul><h4><a name="doInitialization"><hr size=0>The <tt>doInitialization</tt>
-method</h4><ul>
+</ul><h4><a name="doInitialization_mod"><hr size=0>The
+<tt>doInitialization(Module &amp;)</tt> method</h4><ul>
 
 <pre>
   <b>virtual bool</b> doInitialization(Module &amp;M);
@@ -433,10 +439,11 @@ method</h4><ul>
 
 The <tt>doIninitialize</tt> method is allowed to do most of the things that
 <tt>FunctionPass</tt>'s are not allowed to do.  They can add and remove
-functions, get pointers to functions, etc.  The <tt>doInitialize</tt> method is
-designed to do simple initialization type of stuff that does not depend on the
-functions being processed.  The <tt>doInitialization</tt> function call is not
-scheduled to overlap with any other pass executions.<p>
+functions, get pointers to functions, etc.  The <tt>doInitialization</tt> method
+is designed to do simple initialization type of stuff that does not depend on
+the functions being processed.  The <tt>doInitialization</tt> method call is not
+scheduled to overlap with any other pass executions (thus it should be very
+fast).<p>
 
 A good example of how this method should be used is the <a
 href="http://llvm.cs.uiuc.edu/doxygen/LowerAllocations_8cpp-source.html">LowerAllocations</a>
@@ -457,7 +464,7 @@ transformation or analysis work of your pass.  As usual, a true value should be
 returned if the function is modified.<p>
 
 <!-- _______________________________________________________________________ -->
-</ul><h4><a name="doFinalization"><hr size=0>The <tt>doFinalization</tt> method</h4><ul>
+</ul><h4><a name="doFinalization_mod"><hr size=0>The <tt>doFinalization(Module &amp;)</tt> method</h4><ul>
 
 <pre>
   <b>virtual bool</b> doFinalization(Module &amp;M);
@@ -493,10 +500,26 @@ As such, they are <b>not</b> allowed to do any of the following:<p>
 
 <tt>BasicBlockPass</tt>'s are useful for traditional local and "peephole"
 optimizations.  They may override the same <a
-href="#doInitialization"><tt>doInitialization</tt></a> and <a
-href="#doFinalization"><tt>doFinalization</tt></a> methods that <a
-href="#FunctionPass"><tt>FunctionPass</tt></a>'s have, but also have a
-<tt>runOnBasicBlock</tt> method:<p>
+href="#doInitialization_mod"><tt>doInitialization(Module &amp;)</tt></a> and <a
+href="#doFinalization_mod"><tt>doFinalization(Module &amp;)</tt></a> methods that <a
+href="#FunctionPass"><tt>FunctionPass</tt></a>'s have, but also have the following virtual methods that may also be implemented:<p>
+
+<!-- _______________________________________________________________________ -->
+</ul><h4><a name="doInitialization_fn"><hr size=0>The
+<tt>doInitialization(Function &amp;)</tt> method</h4><ul>
+
+<pre>
+  <b>virtual bool</b> doInitialization(Function &amp;F);
+</pre><p>
+
+The <tt>doIninitialize</tt> method is allowed to do most of the things that
+<tt>BasicBlockPass</tt>'s are not allowed to do, but that
+<tt>FunctionPass</tt>'s can.  The <tt>doInitialization</tt> method is designed
+to do simple initialization type of stuff that does not depend on the
+BasicBlocks being processed.  The <tt>doInitialization</tt> method call is not
+scheduled to overlap with any other pass executions (thus it should be very
+fast).<p>
+
 
 <!-- _______________________________________________________________________ -->
 </ul><h4><a name="runOnBasicBlock"><hr size=0>The <tt>runOnBasicBlock</tt> method</h4><ul>
@@ -511,6 +534,22 @@ parameter, and are not allowed to modify the CFG.  A true value must be returned
 if the basic block is modified.<p>
 
 
+<!-- _______________________________________________________________________ -->
+</ul><h4><a name="doFinalization_fn"><hr size=0>The <tt>doFinalization(Function
+&amp;)</tt> method</h4><ul>
+
+<pre>
+  <b>virtual bool</b> doFinalization(Function &amp;F);
+</pre</p>
+
+The <tt>doFinalization</tt> method is an infrequently used method that is called
+when the pass framework has finished calling <a
+href="#runOnBasicBlock"><tt>runOnBasicBlock</tt></a> for every BasicBlock in the
+program being compiled.  This can be used to perform per-function
+finalization.<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>
@@ -1164,6 +1203,6 @@ href="#Pass"><tt>Pass</tt></a>, only the other way around.<p>
 <address><a href="mailto:sabre@nondot.org">Chris Lattner</a></address>
 <!-- Created: Tue Aug  6 15:00:33 CDT 2002 -->
 <!-- hhmts start -->
-Last modified: Thu Sep  5 15:06:01 CDT 2002
+Last modified: Thu Sep 12 11:46:40 CDT 2002
 <!-- hhmts end -->
 </font></body></html>
diff --git a/include/llvm/Pass.h b/include/llvm/Pass.h
index cdd00300183..d2cbb7e3cb2 100644
--- a/include/llvm/Pass.h
+++ b/include/llvm/Pass.h
@@ -250,15 +250,36 @@ private:
 ///   3. Optimizations conform to all of the contstraints of FunctionPass's.
 ///
 struct BasicBlockPass : public FunctionPass {
+  /// doInitialization - Virtual method overridden by subclasses to do
+  /// any neccesary per-module initialization.
+  ///
+  virtual bool doInitialization(Module &M) { return false; }
+
+  /// doInitialization - Virtual method overridden by BasicBlockPass subclasses
+  /// to do any neccesary per-function initialization.
+  ///
+  virtual bool doInitialization(Function &F) { return false; }
+
   /// runOnBasicBlock - Virtual method overriden by subclasses to do the
   /// per-basicblock processing of the pass.
   ///
   virtual bool runOnBasicBlock(BasicBlock &BB) = 0;
 
-  /// To run this pass on a function, we simply call runOnBasicBlock once for
-  /// each function.
+  /// doFinalization - Virtual method overriden by BasicBlockPass subclasses to
+  /// do any post processing needed after all passes have run.
   ///
-  virtual bool runOnFunction(Function &F);
+  virtual bool doFinalization(Function &F) { return false; }
+
+  /// doFinalization - Virtual method overriden by subclasses to do any post
+  /// processing needed after all passes have run.
+  ///
+  virtual bool doFinalization(Module &M) { return false; }
+
+
+  // To run this pass on a function, we simply call runOnBasicBlock once for
+  // each function.
+  //
+  bool runOnFunction(Function &F);
 
   /// To run directly on the basic block, we initialize, runOnBasicBlock, then
   /// finalize.