Merge pull request #14086 from hvitved/csharp/perf-fixes

C#: Various performance fixes

Author: hvitved

csharp/ql/lib/semmle/code/csharp/Unification.qll

@@ -538,23 +538,26 @@ module Unification {
      *
      * Note: This predicate is inlined.
      */
-    bindingset[t]
+    bindingset[this]
+    pragma[inline_late]
     predicate unifiable(Type t) { none() }
 
     /**
      * Holds if this type parameter subsumes type `t`
      *
      * Note: This predicate is inlined.
      */
-    bindingset[t]
+    bindingset[this]
+    pragma[inline_late]
     predicate subsumes(Type t) { none() }
   }
 
   /** A type parameter that has a single constraint. */
   private class SingleConstraintTypeParameter extends ConstrainedTypeParameter {
     SingleConstraintTypeParameter() { constraintCount = 1 }
 
-    bindingset[t]
+    bindingset[this]
+    pragma[inline_late]
     override predicate unifiable(Type t) {
       exists(TTypeParameterConstraint ttc | ttc = getATypeConstraint(this) |
         ttc = TRefTypeConstraint() and
@@ -567,7 +570,8 @@ module Unification {
       )
     }
 
-    bindingset[t]
+    bindingset[this]
+    pragma[inline_late]
     override predicate subsumes(Type t) {
       exists(TTypeParameterConstraint ttc | ttc = getATypeConstraint(this) |
         ttc = TRefTypeConstraint() and
@@ -585,9 +589,13 @@ module Unification {
   private class MultiConstraintTypeParameter extends ConstrainedTypeParameter {
     MultiConstraintTypeParameter() { constraintCount > 1 }
 
-    bindingset[t]
+    pragma[nomagic]
+    TTypeParameterConstraint getATypeConstraint() { result = getATypeConstraint(this) }
+
+    bindingset[this]
+    pragma[inline_late]
     override predicate unifiable(Type t) {
-      forex(TTypeParameterConstraint ttc | ttc = getATypeConstraint(this) |
+      forex(TTypeParameterConstraint ttc | ttc = this.getATypeConstraint() |
         ttc = TRefTypeConstraint() and
         t.isRefType()
         or
@@ -598,9 +606,10 @@ module Unification {
       )
     }
 
-    bindingset[t]
+    bindingset[this]
+    pragma[inline_late]
     override predicate subsumes(Type t) {
-      forex(TTypeParameterConstraint ttc | ttc = getATypeConstraint(this) |
+      forex(TTypeParameterConstraint ttc | ttc = this.getATypeConstraint() |
         ttc = TRefTypeConstraint() and
         t.isRefType()
         or

csharp/ql/lib/semmle/code/csharp/commons/Assertions.qll

@@ -299,6 +299,12 @@ class NUnitAssertNonNullMethod extends NullnessAssertMethod, NUnitAssertMethod {
   override int getAnAssertionIndex(boolean b) { result = this.getAnAssertionIndex() and b = false }
 }
 
+pragma[nomagic]
+private predicate parameterAssertion(Assertion a, int index, Parameter p) {
+  strictcount(AssignableDefinition def | def.getTarget() = p) = 1 and
+  a.getExpr(index) = p.getAnAccess()
+}
+
 /** A method that forwards to another assertion method. */
 class ForwarderAssertMethod extends AssertMethod {
   private Assertion a;
@@ -307,10 +313,9 @@ class ForwarderAssertMethod extends AssertMethod {
 
   ForwarderAssertMethod() {
     p = this.getAParameter() and
-    strictcount(AssignableDefinition def | def.getTarget() = p) = 1 and
     forex(ControlFlowElement body | body = this.getBody() |
       bodyAsserts(this, body, a) and
-      a.getExpr(forwarderIndex) = p.getAnAccess()
+      parameterAssertion(a, forwarderIndex, p)
     )
   }
 

csharp/ql/lib/semmle/code/csharp/dataflow/internal/SsaImpl.qll

@@ -1159,6 +1159,7 @@ private predicate adjacentDefReachesUncertainRead(
   )
 }
 
+pragma[nomagic]
 private predicate adjacentDefReachesUncertainReadExt(
   DefinitionExt def, SsaInput::BasicBlock bb1, int i1, SsaInput::BasicBlock bb2, int i2
 ) {

csharp/ql/lib/semmle/code/csharp/dispatch/Dispatch.qll

@@ -862,9 +862,7 @@ private module Internal {
         or
         Unification::subsumes(t, qualifierType)
         or
-        t.(Unification::ConstrainedTypeParameter).unifiable(qualifierType)
-        or
-        qualifierType = t.(Unification::UnconstrainedTypeParameter).getAnUltimatelySuppliedType()
+        qualifierType = t.(TypeParameter).getAnUltimatelySuppliedType()
       )
     }
 

shared/controlflow/codeql/controlflow/Cfg.qll

@@ -399,13 +399,20 @@ module Make<LocationSig Location, InputSig<Location> Input> {
     }
   }
 
+  private predicate isFullyConstructedSplits(Splits splits) { exists(TAstNode(_, _, splits)) }
+
   /**
    * A set of control flow node splits. The set is represented by a list of splits,
    * ordered by ascending rank.
    */
   class Splits extends TSplits {
     /** Gets a textual representation of this set of splits. */
-    string toString() { result = splitsToString(this) }
+    string toString() {
+      result = splitsToString(this)
+      or
+      not isFullyConstructedSplits(this) and
+      result = "<partial split set>"
+    }
 
     /** Gets a split belonging to this set of splits. */
     SplitImpl getASplit() {
@@ -857,23 +864,27 @@ module Make<LocationSig Location, InputSig<Location> Input> {
         succEntrySplitsCons(_, _, head, tail, _)
       }
 
+    private string getSplitStringAt(Splits split, int index) {
+      exists(SplitImpl head, Splits tail | split = TSplitsCons(head, tail) |
+        index = 0 and result = head.toString() and result != ""
+        or
+        index > 0 and result = getSplitStringAt(tail, index - 1)
+      )
+    }
+
+    private string getSplitsStringPart(Splits splits, int index) {
+      isFullyConstructedSplits(splits) and
+      result = getSplitStringAt(splits, index)
+    }
+
     cached
     string splitsToString(Splits splits) {
-      splits = TSplitsNil() and
-      result = ""
-      or
-      exists(SplitImpl head, Splits tail, string headString, string tailString |
-        splits = TSplitsCons(head, tail)
-      |
-        headString = head.toString() and
-        tailString = tail.toString() and
-        if tailString = ""
-        then result = headString
-        else
-          if headString = ""
-          then result = tailString
-          else result = headString + ", " + tailString
-      )
+      result =
+        concat(string child, int index |
+          child = getSplitsStringPart(splits, index)
+        |
+          child, ", " order by index
+        )
     }
 
     /**