From: jjenista <jjenista>
Date: Thu, 22 Sep 2011 18:19:01 +0000 (+0000)
Subject: getting definite reach analysis set up as a fixed point piggy-back to disjoint
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=b0ba28b34bd7c794e028160701044aeb263b790e;p=IRC.git

getting definite reach analysis set up as a fixed point piggy-back to disjoint
---

diff --git a/Robust/src/Analysis/Disjoint/DefiniteReachAnalysis.java b/Robust/src/Analysis/Disjoint/DefiniteReachAnalysis.java
index 6987a3bd..098fc9ca 100644
--- a/Robust/src/Analysis/Disjoint/DefiniteReachAnalysis.java
+++ b/Robust/src/Analysis/Disjoint/DefiniteReachAnalysis.java
@@ -8,101 +8,84 @@ import Util.*;
 
 
 public class DefiniteReachAnalysis {
-
-  // R
-  //
-  // Maps variables and an edge (x, y, e) to an unused value when the
-  // object of x is already reachable from the object of y, and the
-  // set of edges conservatively gives the path.
-  // NOTE: Use EdgeKey instead of edges because this analysis's
-  // scope is beyond the scope of a single reach graph.
-
-  // Fs
-  // Just a hashmap of variable to enum (unknown, new).
-
-  // Fu
-
-  // Fd
-
+  
+  // keep a state of definite reachability analysis for
+  // every program point
+  private Map<FlatNode, DefiniteReachState> fn2state;
+  
   public DefiniteReachAnalysis() {
+    fn2state = new HashMap<FlatNode, DefiniteReachState>();
   }
 
-  // what are the transfer functions that are relevant for this analyis?
-
-  public void methodEntry(Set<TempDescriptor> parameters) {
-    // R' := {}
-    // R.clear();
 
-    // Rs' := P x {unknown}
+  public void methodEntry( FlatNode fn, 
+                           Set<TempDescriptor> parameters ) {
+    DefiniteReachState state = get( fn );
+    state.methodEntry( parameters );
+    fn2state.put( fn, state );
   }
 
-  public void copy(TempDescriptor x,
-                   TempDescriptor y) {
-    // R' := (R - <x,*> - <*,x>)        U
-    //       {<x,z>->e | <y,z>->e in R} U
-    //       {<z,x>->e | <z,y>->e in R}
-    // R' = new Map(R)
-    // R'.remove(view0, x);
-    // R'.remove(view1, x);
-    // setYs = R.get(view0, y);
-    // for each <y,z>->e: R'.put(<x,z>, e);
-    // setYs = R.get(view1, y);
-    // for each <z,y>->e: R'.put(<z,x>, e);
-
-    // Rs' := (Rs - <x,*>) U {<x,v> | <y,v> in Rs}
+  public void copy( FlatNode fn, 
+                    TempDescriptor x,
+                    TempDescriptor y ) {
+    DefiniteReachState state = makeIn( fn );
+    state.copy( x, y );
+    fn2state.put( fn, state ); 
   }
 
-  public void load(TempDescriptor x,
-                   TempDescriptor y,
-                   FieldDescriptor f) {
-    // R' := (R - <x,*> - <*,x>) U
-    //       ({<x,y>} x Eo(y,f)) U
-    //       U        {<x,z>} x (Eo(y,f)U{e})
-    //   <y,z>->e in R
-    // R' = new Map(R)
-    // R'.remove(view0, x);
-    // R'.remove(view1, x);
-    // R'.put(<x,y>, eee!);
-    // setYs = R.get(view0, y);
-    // for each <y,z>->e: R'.put(<x,z>, eee!Ue);
-
-    // Rs' := (Rs - <x,*>) U {<x, unknown>}
+  public void load( FlatNode fn, 
+                    TempDescriptor  x,
+                    TempDescriptor  y,
+                    FieldDescriptor f ) {
+    DefiniteReachState state = makeIn( fn );
+    state.load( x, y, f );
+    fn2state.put( fn, state ); 
   }
 
-  public void store(TempDescriptor x,
-                   FieldDescriptor f,
-                   TempDescriptor y) {
-    // I think this should be if there is ANY <w,z>->e' IN Eremove, then kill all <w,z>
-    // R' := (R - {<w,z>->e | <w,z>->e in R, A<w,z>->e' in R, e' notin Eremove}) U
-    //       {<y,x>->e | e in E(x) x {f} x E(y)}
-    // R' = new Map(R)
-    // R'.remove(?); some e's...
-    // R'.put(<y,x>, E(x) x {f} x E(y));
-
-    // Rs' := Rs
+  public void store( FlatNode fn, 
+                     TempDescriptor  x,
+                     FieldDescriptor f,
+                     TempDescriptor  y ) {
+    DefiniteReachState state = makeIn( fn );
+    state.store( x, f, y );
+    fn2state.put( fn, state ); 
   }
 
-  public void newObject(TempDescriptor x) {
-    // R' := (R - <x,*> - <*,x>)
-    // R' = new Map(R)
-    // R'.remove(view0, x);
-    // R'.remove(view1, x);
+  public void newObject( FlatNode fn, 
+                         TempDescriptor x ) {
+    DefiniteReachState state = makeIn( fn );
+    state.newObject( x );
+    fn2state.put( fn, state ); 
+  }
 
-    // Rs' := (Rs - <x,*>) U {<x, new>}
+  // x is the return value, x = foo(...);
+  public void methodCall( FlatNode fn, 
+                          TempDescriptor x ) {
+    DefiniteReachState state = makeIn( fn );
+    state.methodCall( x );
+    fn2state.put( fn, state ); 
   }
 
-  public void methodCall(TempDescriptor x) {
-    // R' := (R - <x,*> - <*,x>)
-    // R' = new Map(R)
-    // R'.remove(view0, x);
-    // R'.remove(view1, x);
 
-    // Rs' := (Rs - <x,*>) U {<x, unknown>}
+  // get the current state for just after the given
+  // program point
+  private DefiniteReachState get( FlatNode fn ) {
+    DefiniteReachState state = fn2state.get( fn );
+    if( state == null ) {
+      state = new DefiniteReachState();
+      fn2state.put( fn, state );
+    }
+    return state;
   }
 
-  public void merge() {
-    // R' := <x,y>->e iff its in all incoming edges
-
-    // Rs' := <x, new> iff in all incoming edges, otherwie <x, unknown>
+  // get the current state for the program point just
+  // before the given program point by merging the out
+  // states of the predecessor statements
+  private DefiniteReachState makeIn( FlatNode fn ) {
+    DefiniteReachState stateIn = new DefiniteReachState();
+    for( int i = 0; i < fn.numPrev(); ++i ) {
+      stateIn.merge( get( fn.getPrev( i ) ) );
+    }
+    return stateIn;
   }
 }
diff --git a/Robust/src/Analysis/Disjoint/DefiniteReachState.java b/Robust/src/Analysis/Disjoint/DefiniteReachState.java
new file mode 100644
index 00000000..06525ffb
--- /dev/null
+++ b/Robust/src/Analysis/Disjoint/DefiniteReachState.java
@@ -0,0 +1,159 @@
+package Analysis.Disjoint;
+
+import java.util.*;
+
+import IR.*;
+import IR.Flat.*;
+import Util.*;
+
+
+public class DefiniteReachState {
+
+  // R
+  //
+  // Maps variables and an edge (x, y, e) to an unused value when the
+  // object of x is already reachable from the object of y, and the
+  // set of edges conservatively gives the path.
+  // NOTE: Use EdgeKey instead of edges because this analysis's
+  // scope is beyond the scope of a single reach graph.
+
+
+  // Rs
+  // Tracks whether the analysis must know the definite reachability
+  // information of a given variable.
+  private enum DefReachKnown {
+    UNKNOWN,
+    KNOWN,
+  }
+  private Map<TempDescriptor, DefReachKnown> rs;
+  
+  
+
+  // Fu
+
+  // Fd
+
+  public DefiniteReachState() {
+    rs = new HashMap<TempDescriptor, DefReachKnown>();
+  }
+
+  // what are the transfer functions that are relevant for this analyis?
+
+  public void methodEntry(Set<TempDescriptor> parameters) {
+    // R' := {}
+    // R.clear();
+
+    rs.clear();
+
+    for( TempDescriptor p : parameters ) {
+      rs.put( p, DefReachKnown.UNKNOWN );
+    }
+
+  }
+
+  public void copy(TempDescriptor x,
+                   TempDescriptor y) {
+    // R' := (R - <x,*> - <*,x>)        U
+    //       {<x,z>->e | <y,z>->e in R} U
+    //       {<z,x>->e | <z,y>->e in R}
+    // R' = new Map(R)
+    // R'.remove(view0, x);
+    // R'.remove(view1, x);
+    // setYs = R.get(view0, y);
+    // for each <y,z>->e: R'.put(<x,z>, e);
+    // setYs = R.get(view1, y);
+    // for each <z,y>->e: R'.put(<z,x>, e);
+
+    // Rs' := (Rs - <x,*>) U {<x,v> | <y,v> in Rs}
+    DefReachKnown v = rs.get( y );
+    assert( v != null );
+    rs.put( x, v );
+  }
+
+  public void load(TempDescriptor x,
+                   TempDescriptor y,
+                   FieldDescriptor f) {
+    // R' := (R - <x,*> - <*,x>) U
+    //       ({<x,y>} x Eo(y,f)) U
+    //       U        {<x,z>} x (Eo(y,f)U{e})
+    //   <y,z>->e in R
+    // R' = new Map(R)
+    // R'.remove(view0, x);
+    // R'.remove(view1, x);
+    // R'.put(<x,y>, eee!);
+    // setYs = R.get(view0, y);
+    // for each <y,z>->e: R'.put(<x,z>, eee!Ue);
+
+    // Rs' := (Rs - <x,*>) U {<x, unknown>}
+    rs.put( x, DefReachKnown.UNKNOWN );
+  }
+
+  public void store(TempDescriptor x,
+                   FieldDescriptor f,
+                   TempDescriptor y) {
+    // I think this should be if there is ANY <w,z>->e' IN Eremove, then kill all <w,z>
+    // R' := (R - {<w,z>->e | <w,z>->e in R, A<w,z>->e' in R, e' notin Eremove}) U
+    //       {<y,x>->e | e in E(x) x {f} x E(y)}
+    // R' = new Map(R)
+    // R'.remove(?); some e's...
+    // R'.put(<y,x>, E(x) x {f} x E(y));
+
+    // Rs' := Rs
+  }
+
+  public void newObject(TempDescriptor x) {
+    // R' := (R - <x,*> - <*,x>)
+    // R' = new Map(R)
+    // R'.remove(view0, x);
+    // R'.remove(view1, x);
+
+    // Rs' := (Rs - <x,*>) U {<x, new>}
+    rs.put( x, DefReachKnown.KNOWN );
+    
+  }
+
+  // x is the return value, x = foo(...);
+  public void methodCall(TempDescriptor x) {
+    // R' := (R - <x,*> - <*,x>)
+    // R' = new Map(R)
+    // R'.remove(view0, x);
+    // R'.remove(view1, x);
+
+    // Rs' := (Rs - <x,*>) U {<x, unknown>}
+    rs.put( x, DefReachKnown.UNKNOWN );
+  }
+
+  public void merge( DefiniteReachState that ) {
+    // R' := <x,y>->e iff its in all incoming edges
+
+    // Rs' := <x, new> iff in all incoming edges, otherwie <x, unknown>
+    mergeRs( that );
+  }
+
+  private void mergeRs( DefiniteReachState that ) {
+    // merge "that" into "this" and leave "that" unchanged
+    Set<TempDescriptor> allVars = new HashSet<TempDescriptor>();
+    allVars.addAll( this.rs.keySet() );
+    allVars.addAll( that.rs.keySet() );
+    for( TempDescriptor x : allVars ) {
+      DefReachKnown vThis = this.rs.get( x );
+      DefReachKnown vThat = that.rs.get( x );
+      if( vThis != null && vThis.equals( DefReachKnown.KNOWN ) &&
+          vThat != null && vThat.equals( DefReachKnown.KNOWN ) ) {
+        this.rs.put( x, DefReachKnown.KNOWN );
+      } else {
+        this.rs.put( x, DefReachKnown.UNKNOWN );
+      }
+    }
+  }
+
+
+  public String toString() {
+    StringBuilder s = new StringBuilder( "R_s = {" );
+    for( TempDescriptor x : rs.keySet() ) {
+      s.append( "  "+x+"->"+rs.get( x ) );
+    }
+    s.append( "}" );
+    return s.toString();
+  }
+}