Refactor: reorder parameters of SsaDefinition.definesAt

Match the order used in the shared SSA library

Author: owen-mc

go/ql/lib/semmle/go/dataflow/SSA.qll

@@ -127,7 +127,7 @@ class SsaDefinition extends TSsaDefinition {
    * Phi nodes are considered to be at index `-1`, all other definitions at the index of
    * the control flow node they correspond to.
    */
-  abstract predicate definesAt(ReachableBasicBlock bb, int idx, SsaSourceVariable v);
+  abstract predicate definesAt(SsaSourceVariable v, ReachableBasicBlock bb, int idx);
 
   /**
    * INTERNAL: Use `toString()` instead.
@@ -187,13 +187,13 @@ class SsaExplicitDefinition extends SsaDefinition, TExplicitDef {
   /** Gets the right-hand side of the definition. */
   IR::Instruction getRhs() { this.getInstruction().writes(_, result) }
 
-  override predicate definesAt(ReachableBasicBlock bb, int i, SsaSourceVariable v) {
+  override predicate definesAt(SsaSourceVariable v, ReachableBasicBlock bb, int i) {
     this = TExplicitDef(bb, i, v)
   }
 
-  override ReachableBasicBlock getBasicBlock() { this.definesAt(result, _, _) }
+  override ReachableBasicBlock getBasicBlock() { this.definesAt(_, result, _) }
 
-  override SsaSourceVariable getSourceVariable() { this = TExplicitDef(_, _, result) }
+  override SsaSourceVariable getSourceVariable() { this.definesAt(result, _, _) }
 
   override string prettyPrintRef() {
     exists(Location loc | loc = this.getLocation() |
@@ -242,20 +242,20 @@ abstract class SsaImplicitDefinition extends SsaDefinition {
  * at any function call that may affect the value of the variable.
  */
 class SsaVariableCapture extends SsaImplicitDefinition, TCapture {
-  override predicate definesAt(ReachableBasicBlock bb, int i, SsaSourceVariable v) {
+  override predicate definesAt(SsaSourceVariable v, ReachableBasicBlock bb, int i) {
     this = TCapture(bb, i, v)
   }
 
-  override ReachableBasicBlock getBasicBlock() { this.definesAt(result, _, _) }
+  override ReachableBasicBlock getBasicBlock() { this.definesAt(_, result, _) }
 
-  override SsaSourceVariable getSourceVariable() { this.definesAt(_, _, result) }
+  override SsaSourceVariable getSourceVariable() { this.definesAt(result, _, _) }
 
   override string getKind() { result = "capture" }
 
   override string prettyPrintDef() { result = "capture variable " + this.getSourceVariable() }
 
   override Location getLocation() {
-    exists(ReachableBasicBlock bb, int i | this.definesAt(bb, i, _) |
+    exists(ReachableBasicBlock bb, int i | this.definesAt(_, bb, i) |
       result = bb.getNode(i).getLocation()
     )
   }
@@ -288,7 +288,7 @@ class SsaPhiNode extends SsaPseudoDefinition, TPhi {
     result = getDefReachingEndOf(this.getBasicBlock().getAPredecessor(), this.getSourceVariable())
   }
 
-  override predicate definesAt(ReachableBasicBlock bb, int i, SsaSourceVariable v) {
+  override predicate definesAt(SsaSourceVariable v, ReachableBasicBlock bb, int i) {
     bb = this.getBasicBlock() and v = this.getSourceVariable() and i = -1
   }
 

go/ql/lib/semmle/go/dataflow/SsaImpl.qll

@@ -71,7 +71,7 @@ private module Internal {
   pragma[noinline]
   private predicate inDefDominanceFrontier(ReachableJoinBlock bb, SsaSourceVariable v) {
     exists(ReachableBasicBlock defbb, SsaDefinition def |
-      def.definesAt(defbb, _, v) and
+      def.definesAt(v, defbb, _) and
       bb.inDominanceFrontierOf(defbb)
     )
   }
@@ -206,7 +206,7 @@ private module Internal {
   private predicate ssaRef(ReachableBasicBlock bb, int i, SsaSourceVariable v, RefKind k) {
     useAt(bb, i, v) and k = ReadRef()
     or
-    any(SsaDefinition def).definesAt(bb, i, v) and k = WriteRef()
+    any(SsaDefinition def).definesAt(v, bb, i) and k = WriteRef()
   }
 
   /**
@@ -248,7 +248,7 @@ private module Internal {
    */
   private SsaDefinition getLocalDefinition(ReachableBasicBlock bb, int i, SsaSourceVariable v) {
     exists(int r | r = rewindReads(bb, i, v) |
-      exists(int j | result.definesAt(bb, j, v) and ssaRefRank(bb, j, v, _) = r - 1)
+      exists(int j | result.definesAt(v, bb, j) and ssaRefRank(bb, j, v, _) = r - 1)
     )
   }
 
@@ -270,7 +270,7 @@ private module Internal {
     exists(int lastRef | lastRef = max(int i | ssaRef(bb, i, v, _)) |
       result = getLocalDefinition(bb, lastRef, v)
       or
-      result.definesAt(bb, lastRef, v) and
+      result.definesAt(v, bb, lastRef) and
       liveAtSuccEntry(bb, v)
     )
     or
@@ -279,7 +279,7 @@ private module Internal {
     // then one must dominate the other, so we can find the reaching definition
     // by following the idominance relation backwards.
     result = getDefReachingEndOfImmediateDominator(bb, v) and
-    not exists(SsaDefinition ssa | ssa.definesAt(bb, _, v)) and
+    not exists(SsaDefinition ssa | ssa.definesAt(v, bb, _)) and
     liveAtSuccEntry(bb, v)
   }
 
@@ -412,7 +412,7 @@ private module Internal {
   predicate firstUse(SsaDefinition def, IR::Instruction use) {
     exists(SsaSourceVariable v, ReachableBasicBlock b1, int i1, ReachableBasicBlock b2, int i2 |
       adjacentVarRefs(v, b1, i1, b2, i2) and
-      def.definesAt(b1, i1, v) and
+      def.definesAt(v, b1, i1) and
       variableUse(v, use, b2, i2)
     )
     or
@@ -421,8 +421,8 @@ private module Internal {
       int i2
     |
       adjacentVarRefs(v, b1, i1, b2, i2) and
-      def.definesAt(b1, i1, v) and
-      redef.definesAt(b2, i2, v) and
+      def.definesAt(v, b1, i1) and
+      redef.definesAt(v, b2, i2) and
       firstUse(redef, use)
     )
   }
@@ -457,7 +457,7 @@ private module Internal {
     |
       adjacentVarRefs(v, b1, i1, b2, i2) and
       variableUse(v, use1, b1, i1) and
-      def.definesAt(b2, i2, v) and
+      def.definesAt(v, b2, i2) and
       firstUse(def, use2)
     )
   }