Merge pull request #14721 from aschackmull/shared/ssareadpos-share

Java/C++/RangeAnalysis: Move SsaReadPosition to shared qlpack.

Author: aschackmull

cpp/ql/lib/semmle/code/cpp/rangeanalysis/new/internal/semantic/SemanticExprSpecific.qll

@@ -198,75 +198,15 @@ module SemanticExprConfig {
     result = v.asOperand().getUse().getBlock()
   }
 
-  private newtype TReadPosition =
-    TReadPositionBlock(IR::IRBlock block) or
-    TReadPositionPhiInputEdge(IR::IRBlock pred, IR::IRBlock succ) {
-      exists(IR::PhiInputOperand input |
-        pred = input.getPredecessorBlock() and
-        succ = input.getUse().getBlock()
-      )
-    }
-
-  class SsaReadPosition extends TReadPosition {
-    string toString() { none() }
-
-    Location getLocation() { none() }
-
-    predicate hasRead(SsaVariable v) { none() }
-  }
-
-  private class SsaReadPositionBlock extends SsaReadPosition, TReadPositionBlock {
-    IR::IRBlock block;
-
-    SsaReadPositionBlock() { this = TReadPositionBlock(block) }
-
-    final override string toString() { result = block.toString() }
-
-    final override Location getLocation() { result = block.getLocation() }
-
-    final override predicate hasRead(SsaVariable v) {
-      exists(IR::Operand operand | operand.getDef() = v.asInstruction() |
-        not operand instanceof IR::PhiInputOperand and
-        operand.getUse().getBlock() = block
-      )
-    }
-  }
-
-  private class SsaReadPositionPhiInputEdge extends SsaReadPosition, TReadPositionPhiInputEdge {
-    IR::IRBlock pred;
-    IR::IRBlock succ;
-
-    SsaReadPositionPhiInputEdge() { this = TReadPositionPhiInputEdge(pred, succ) }
-
-    final override string toString() { result = pred.toString() + "->" + succ.toString() }
-
-    final override Location getLocation() { result = succ.getLocation() }
-
-    final override predicate hasRead(SsaVariable v) {
-      exists(IR::PhiInputOperand operand | operand.getDef() = v.asInstruction() |
-        operand.getPredecessorBlock() = pred and
-        operand.getUse().getBlock() = succ
-      )
-    }
-  }
-
-  predicate hasReadOfSsaVariable(SsaReadPosition pos, SsaVariable v) { pos.hasRead(v) }
-
-  predicate readBlock(SsaReadPosition pos, BasicBlock block) { pos = TReadPositionBlock(block) }
-
-  predicate phiInputEdge(SsaReadPosition pos, BasicBlock origBlock, BasicBlock phiBlock) {
-    pos = TReadPositionPhiInputEdge(origBlock, phiBlock)
-  }
-
-  predicate phiInput(SsaReadPosition pos, SsaVariable phi, SsaVariable input) {
+  /** Holds if `inp` is an input to the phi node along the edge originating in `bb`. */
+  predicate phiInputFromBlock(SsaVariable phi, SsaVariable inp, BasicBlock bb) {
     exists(IR::PhiInputOperand operand |
-      pos = TReadPositionPhiInputEdge(operand.getPredecessorBlock(), operand.getUse().getBlock())
-    |
+      bb = operand.getPredecessorBlock() and
       phi.asInstruction() = operand.getUse() and
       (
-        input.asInstruction() = operand.getDef()
+        inp.asInstruction() = operand.getDef()
         or
-        input.asOperand() = operand
+        inp.asOperand() = operand
       )
     )
   }

cpp/ql/lib/semmle/code/cpp/rangeanalysis/new/internal/semantic/SemanticSSA.qll

@@ -31,35 +31,8 @@ class SemSsaPhiNode extends SemSsaVariable {
   SemSsaPhiNode() { Specific::phi(this) }
 
   final SemSsaVariable getAPhiInput() { result = Specific::getAPhiInput(this) }
-}
-
-class SemSsaReadPosition instanceof Specific::SsaReadPosition {
-  final string toString() { result = super.toString() }
-
-  final Specific::Location getLocation() { result = super.getLocation() }
-
-  final predicate hasReadOfVar(SemSsaVariable var) { Specific::hasReadOfSsaVariable(this, var) }
-}
-
-class SemSsaReadPositionPhiInputEdge extends SemSsaReadPosition {
-  SemBasicBlock origBlock;
-  SemBasicBlock phiBlock;
-
-  SemSsaReadPositionPhiInputEdge() { Specific::phiInputEdge(this, origBlock, phiBlock) }
-
-  predicate phiInput(SemSsaPhiNode phi, SemSsaVariable inp) { Specific::phiInput(this, phi, inp) }
-
-  SemBasicBlock getOrigBlock() { result = origBlock }
-
-  SemBasicBlock getPhiBlock() { result = phiBlock }
-}
-
-class SemSsaReadPositionBlock extends SemSsaReadPosition {
-  SemBasicBlock block;
-
-  SemSsaReadPositionBlock() { Specific::readBlock(this, block) }
-
-  SemBasicBlock getBlock() { result = block }
 
-  SemExpr getAnExpr() { result = this.getBlock().getAnExpr() }
+  final predicate hasInputFromBlock(SemSsaVariable inp, SemBasicBlock bb) {
+    Specific::phiInputFromBlock(this, inp, bb)
+  }
 }

cpp/ql/lib/semmle/code/cpp/rangeanalysis/new/internal/semantic/analysis/RangeAnalysisImpl.qll

@@ -74,6 +74,8 @@ module Sem implements Semantic {
 
   BasicBlock getABasicBlockSuccessor(BasicBlock bb) { result = bb.getASuccessor() }
 
+  int getBlockId1(BasicBlock bb) { result = bb.getUniqueId() }
+
   class Guard = SemGuard;
 
   predicate implies_v2 = semImplies_v2/4;
@@ -92,12 +94,6 @@ module Sem implements Semantic {
 
   class SsaExplicitUpdate = SemSsaExplicitUpdate;
 
-  class SsaReadPosition = SemSsaReadPosition;
-
-  class SsaReadPositionPhiInputEdge = SemSsaReadPositionPhiInputEdge;
-
-  class SsaReadPositionBlock = SemSsaReadPositionBlock;
-
   predicate conversionCannotOverflow(Type fromType, Type toType) {
     SemanticType::conversionCannotOverflow(fromType, toType)
   }

cpp/ql/lib/semmle/code/cpp/rangeanalysis/new/internal/semantic/analysis/RangeUtils.qll

@@ -133,33 +133,4 @@ module RangeUtil<DeltaSig D, LangSig<Sem, D> Lang> implements UtilSig<Sem, D> {
     or
     not exists(Lang::getAlternateTypeForSsaVariable(var)) and result = var.getType()
   }
-
-  import Ranking
-}
-
-import Ranking
-
-module Ranking {
-  /**
-   * Holds if `rix` is the number of input edges to `phi`.
-   */
-  predicate maxPhiInputRank(SemSsaPhiNode phi, int rix) {
-    rix = max(int r | rankedPhiInput(phi, _, _, r))
-  }
-
-  /**
-   * Holds if `inp` is an input to `phi` along `edge` and this input has index `r`
-   * in an arbitrary 1-based numbering of the input edges to `phi`.
-   */
-  predicate rankedPhiInput(
-    SemSsaPhiNode phi, SemSsaVariable inp, SemSsaReadPositionPhiInputEdge edge, int r
-  ) {
-    edge.phiInput(phi, inp) and
-    edge =
-      rank[r](SemSsaReadPositionPhiInputEdge e |
-        e.phiInput(phi, _)
-      |
-        e order by e.getOrigBlock().getUniqueId()
-      )
-  }
 }

cpp/ql/lib/semmle/code/cpp/rangeanalysis/new/internal/semantic/analysis/SignAnalysisCommon.qll

@@ -45,7 +45,7 @@ module SignAnalysis<DeltaSig D, UtilSig<Sem, D> Utils> {
   /** An SSA Phi definition, whose sign is the union of the signs of its inputs. */
   private class PhiSignDef extends FlowSignDef instanceof SemSsaPhiNode {
     final override Sign getSign() {
-      exists(SemSsaVariable inp, SemSsaReadPositionPhiInputEdge edge |
+      exists(SemSsaVariable inp, SsaReadPositionPhiInputEdge edge |
         edge.phiInput(this, inp) and
         result = semSsaSign(inp, edge)
       )
@@ -170,11 +170,11 @@ module SignAnalysis<DeltaSig D, UtilSig<Sem, D> Utils> {
     override Sign getSignRestriction() {
       // Propagate via SSA
       // Propagate the sign from the def of `v`, incorporating any inference from guards.
-      result = semSsaSign(v, any(SemSsaReadPositionBlock bb | bb.getAnExpr() = this))
+      result = semSsaSign(v, any(SsaReadPositionBlock bb | bb.getBlock().getAnExpr() = this))
       or
       // No block for this read. Just use the sign of the def.
       // REVIEW: How can this happen?
-      not exists(SemSsaReadPositionBlock bb | bb.getAnExpr() = this) and
+      not exists(SsaReadPositionBlock bb | bb.getBlock().getAnExpr() = this) and
       result = semSsaDefSign(v)
     }
   }
@@ -290,7 +290,7 @@ module SignAnalysis<DeltaSig D, UtilSig<Sem, D> Utils> {
    * to only include bounds for which we might determine a sign.
    */
   private predicate lowerBound(
-    SemExpr lowerbound, SemSsaVariable v, SemSsaReadPosition pos, boolean isStrict
+    SemExpr lowerbound, SemSsaVariable v, SsaReadPosition pos, boolean isStrict
   ) {
     exists(boolean testIsTrue, SemRelationalExpr comp |
       pos.hasReadOfVar(v) and
@@ -314,7 +314,7 @@ module SignAnalysis<DeltaSig D, UtilSig<Sem, D> Utils> {
    * to only include bounds for which we might determine a sign.
    */
   private predicate upperBound(
-    SemExpr upperbound, SemSsaVariable v, SemSsaReadPosition pos, boolean isStrict
+    SemExpr upperbound, SemSsaVariable v, SsaReadPosition pos, boolean isStrict
   ) {
     exists(boolean testIsTrue, SemRelationalExpr comp |
       pos.hasReadOfVar(v) and
@@ -340,7 +340,7 @@ module SignAnalysis<DeltaSig D, UtilSig<Sem, D> Utils> {
    *  - `isEq = true` : `v = eqbound`
    *  - `isEq = false` : `v != eqbound`
    */
-  private predicate eqBound(SemExpr eqbound, SemSsaVariable v, SemSsaReadPosition pos, boolean isEq) {
+  private predicate eqBound(SemExpr eqbound, SemSsaVariable v, SsaReadPosition pos, boolean isEq) {
     exists(SemGuard guard, boolean testIsTrue, boolean polarity, SemExpr e |
       pos.hasReadOfVar(pragma[only_bind_into](v)) and
       guardControlsSsaRead(guard, pragma[only_bind_into](pos), testIsTrue) and
@@ -355,7 +355,7 @@ module SignAnalysis<DeltaSig D, UtilSig<Sem, D> Utils> {
    * Holds if `bound` is a bound for `v` at `pos` that needs to be positive in
    * order for `v` to be positive.
    */
-  private predicate posBound(SemExpr bound, SemSsaVariable v, SemSsaReadPosition pos) {
+  private predicate posBound(SemExpr bound, SemSsaVariable v, SsaReadPosition pos) {
     upperBound(bound, v, pos, _) or
     eqBound(bound, v, pos, true)
   }
@@ -364,7 +364,7 @@ module SignAnalysis<DeltaSig D, UtilSig<Sem, D> Utils> {
    * Holds if `bound` is a bound for `v` at `pos` that needs to be negative in
    * order for `v` to be negative.
    */
-  private predicate negBound(SemExpr bound, SemSsaVariable v, SemSsaReadPosition pos) {
+  private predicate negBound(SemExpr bound, SemSsaVariable v, SsaReadPosition pos) {
     lowerBound(bound, v, pos, _) or
     eqBound(bound, v, pos, true)
   }
@@ -373,24 +373,24 @@ module SignAnalysis<DeltaSig D, UtilSig<Sem, D> Utils> {
    * Holds if `bound` is a bound for `v` at `pos` that can restrict whether `v`
    * can be zero.
    */
-  private predicate zeroBound(SemExpr bound, SemSsaVariable v, SemSsaReadPosition pos) {
+  private predicate zeroBound(SemExpr bound, SemSsaVariable v, SsaReadPosition pos) {
     lowerBound(bound, v, pos, _) or
     upperBound(bound, v, pos, _) or
     eqBound(bound, v, pos, _)
   }
 
   /** Holds if `bound` allows `v` to be positive at `pos`. */
-  private predicate posBoundOk(SemExpr bound, SemSsaVariable v, SemSsaReadPosition pos) {
+  private predicate posBoundOk(SemExpr bound, SemSsaVariable v, SsaReadPosition pos) {
     posBound(bound, v, pos) and TPos() = semExprSign(bound)
   }
 
   /** Holds if `bound` allows `v` to be negative at `pos`. */
-  private predicate negBoundOk(SemExpr bound, SemSsaVariable v, SemSsaReadPosition pos) {
+  private predicate negBoundOk(SemExpr bound, SemSsaVariable v, SsaReadPosition pos) {
     negBound(bound, v, pos) and TNeg() = semExprSign(bound)
   }
 
   /** Holds if `bound` allows `v` to be zero at `pos`. */
-  private predicate zeroBoundOk(SemExpr bound, SemSsaVariable v, SemSsaReadPosition pos) {
+  private predicate zeroBoundOk(SemExpr bound, SemSsaVariable v, SsaReadPosition pos) {
     lowerBound(bound, v, pos, _) and TNeg() = semExprSign(bound)
     or
     lowerBound(bound, v, pos, false) and TZero() = semExprSign(bound)
@@ -408,7 +408,7 @@ module SignAnalysis<DeltaSig D, UtilSig<Sem, D> Utils> {
    * Holds if there is a bound that might restrict whether `v` has the sign `s`
    * at `pos`.
    */
-  private predicate hasGuard(SemSsaVariable v, SemSsaReadPosition pos, Sign s) {
+  private predicate hasGuard(SemSsaVariable v, SsaReadPosition pos, Sign s) {
     s = TPos() and posBound(_, v, pos)
     or
     s = TNeg() and negBound(_, v, pos)
@@ -421,7 +421,7 @@ module SignAnalysis<DeltaSig D, UtilSig<Sem, D> Utils> {
    * might be ruled out by a guard.
    */
   pragma[noinline]
-  private Sign guardedSsaSign(SemSsaVariable v, SemSsaReadPosition pos) {
+  private Sign guardedSsaSign(SemSsaVariable v, SsaReadPosition pos) {
     result = semSsaDefSign(v) and
     pos.hasReadOfVar(v) and
     hasGuard(v, pos, result)
@@ -432,7 +432,7 @@ module SignAnalysis<DeltaSig D, UtilSig<Sem, D> Utils> {
    * can rule it out.
    */
   pragma[noinline]
-  private Sign unguardedSsaSign(SemSsaVariable v, SemSsaReadPosition pos) {
+  private Sign unguardedSsaSign(SemSsaVariable v, SsaReadPosition pos) {
     result = semSsaDefSign(v) and
     pos.hasReadOfVar(v) and
     not hasGuard(v, pos, result)
@@ -443,7 +443,7 @@ module SignAnalysis<DeltaSig D, UtilSig<Sem, D> Utils> {
    * ruled out the sign but does not.
    * This does not check that the definition of `v` also allows the sign.
    */
-  private Sign guardedSsaSignOk(SemSsaVariable v, SemSsaReadPosition pos) {
+  private Sign guardedSsaSignOk(SemSsaVariable v, SsaReadPosition pos) {
     result = TPos() and
     forex(SemExpr bound | posBound(bound, v, pos) | posBoundOk(bound, v, pos))
     or
@@ -455,7 +455,7 @@ module SignAnalysis<DeltaSig D, UtilSig<Sem, D> Utils> {
   }
 
   /** Gets a possible sign for `v` at `pos`. */
-  private Sign semSsaSign(SemSsaVariable v, SemSsaReadPosition pos) {
+  private Sign semSsaSign(SemSsaVariable v, SsaReadPosition pos) {
     result = unguardedSsaSign(v, pos)
     or
     result = guardedSsaSign(v, pos) and