C#: Introduce Expr.getIntValue.

csharp/ql/examples/snippets/integer_literal.ql

@@ -9,5 +9,5 @@
 import csharp
 
 from IntegerLiteral literal
-where literal.getValue().toInt() = 0
+where literal.getIntValue() = 0
 select literal

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

@@ -713,7 +713,7 @@ private class SignedIntegralConstantExpr extends Expr {
 }
 
 private predicate convConstantIntExpr(SignedIntegralConstantExpr e, SimpleType toType) {
-  exists(int n | n = e.getValue().toInt() |
+  exists(int n | n = e.getIntValue() |
     toType = any(SByteType t | n in [t.minValue() .. t.maxValue()])
     or
     toType = any(ByteType t | n in [t.minValue() .. t.maxValue()])
@@ -730,7 +730,7 @@ private predicate convConstantIntExpr(SignedIntegralConstantExpr e, SimpleType t
 
 private predicate convConstantLongExpr(SignedIntegralConstantExpr e) {
   e.getType() instanceof LongType and
-  e.getValue().toInt() >= 0
+  e.getIntValue() >= 0
 }
 
 /** 6.1.10: Implicit reference conversions involving type parameters. */

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

@@ -161,7 +161,7 @@ private newtype TComparisonTest =
       compare.getComparisonKind().isCompare() and
       outerKind = outer.getComparisonKind() and
       outer.getAnArgument() = compare.getExpr() and
-      i = outer.getAnArgument().getValue().toInt()
+      i = outer.getAnArgument().getIntValue()
     |
       outerKind.isEquality() and
       (

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

@@ -32,13 +32,13 @@ private module ConstantComparisonOperation {
 
   private int maxValue(Expr expr) {
     if convertedType(expr) instanceof IntegralType and exists(expr.getValue())
-    then result = expr.getValue().toInt()
+    then result = expr.getIntValue()
     else result = convertedType(expr).maxValue()
   }
 
   private int minValue(Expr expr) {
     if convertedType(expr) instanceof IntegralType and exists(expr.getValue())
-    then result = expr.getValue().toInt()
+    then result = expr.getIntValue()
     else result = convertedType(expr).minValue()
   }
 

csharp/ql/lib/semmle/code/csharp/controlflow/Guards.qll

@@ -60,25 +60,16 @@ private module GuardsInput implements
     override boolean asBooleanValue() { boolConst(this, result) }
   }
 
-  private predicate intConst(Expr e, int i) {
-    e.getValue().toInt() = i and
-    (
-      e.getType() instanceof Enum
-      or
-      e.getType() instanceof IntegralType
-    )
-  }
-
   private class IntegerConstant extends ConstantExpr {
-    IntegerConstant() { intConst(this, _) }
+    IntegerConstant() { exists(this.getIntValue()) }
 
-    override int asIntegerValue() { intConst(this, result) }
+    override int asIntegerValue() { result = this.getIntValue() }
   }
 
   private class EnumConst extends ConstantExpr {
     EnumConst() { this.getType() instanceof Enum and this.hasValue() }
 
-    override int asIntegerValue() { result = this.getValue().toInt() }
+    override int asIntegerValue() { result = this.getIntValue() }
   }
 
   private class StringConstant extends ConstantExpr instanceof StringLiteral {
@@ -517,35 +508,35 @@ class EnumerableCollectionExpr extends Expr {
           |
             // x.Length == 0
             ct.getComparisonKind().isEquality() and
-            ct.getAnArgument().getValue().toInt() = 0 and
+            ct.getAnArgument().getIntValue() = 0 and
             branch = isEmpty
             or
             // x.Length == k, k > 0
             ct.getComparisonKind().isEquality() and
-            ct.getAnArgument().getValue().toInt() > 0 and
+            ct.getAnArgument().getIntValue() > 0 and
             branch = true and
             isEmpty = false
             or
             // x.Length != 0
             ct.getComparisonKind().isInequality() and
-            ct.getAnArgument().getValue().toInt() = 0 and
+            ct.getAnArgument().getIntValue() = 0 and
             branch = isEmpty.booleanNot()
             or
             // x.Length != k, k != 0
             ct.getComparisonKind().isInequality() and
-            ct.getAnArgument().getValue().toInt() != 0 and
+            ct.getAnArgument().getIntValue() != 0 and
             branch = false and
             isEmpty = false
             or
             // x.Length > k, k >= 0
             ct.getComparisonKind().isLessThan() and
-            ct.getFirstArgument().getValue().toInt() >= 0 and
+            ct.getFirstArgument().getIntValue() >= 0 and
             branch = true and
             isEmpty = false
             or
             // x.Length >= k, k > 0
             ct.getComparisonKind().isLessThanEquals() and
-            ct.getFirstArgument().getValue().toInt() > 0 and
+            ct.getFirstArgument().getIntValue() > 0 and
             branch = true and
             isEmpty = false
           )

csharp/ql/lib/semmle/code/csharp/dataflow/internal/rangeanalysis/ConstantUtils.qll

@@ -23,7 +23,7 @@ predicate systemArrayLengthAccess(PropertyAccess pa) {
  * - a read of the `Length` of an array with `val` lengths.
  */
 private predicate constantIntegerExpr(ExprNode e, int val) {
-  e.getValue().toInt() = val
+  e.getExpr().getIntValue() = val
   or
   exists(ExprNode src |
     e = getAnExplicitDefinitionRead(src) and

csharp/ql/lib/semmle/code/csharp/exprs/Expr.qll

@@ -57,6 +57,13 @@ class Expr extends ControlFlowElement, @expr {
   /** Gets the value of this expression, if any */
   string getValue() { expr_value(this, result) }
 
+  /** Gets the integer value of this expression, if any. */
+  cached
+  int getIntValue() {
+    result = this.getValue().toInt() and
+    (this.getType() instanceof IntegralType or this.getType() instanceof Enum)
+  }
+
   /** Holds if this expression has a value. */
   final predicate hasValue() { exists(this.getValue()) }
 

csharp/ql/lib/semmle/code/csharp/frameworks/system/runtime/CompilerServices.qll

@@ -81,7 +81,7 @@ class SystemRuntimeCompilerServicesInlineArrayAttribute extends Attribute {
   /**
    * Gets the length of the inline array.
    */
-  int getLength() { result = this.getConstructorArgument(0).getValue().toInt() }
+  int getLength() { result = this.getConstructorArgument(0).getIntValue() }
 }
 
 /** An attribute of type `System.Runtime.CompilerServices.OverloadResolutionPriority`. */
@@ -94,5 +94,5 @@ class SystemRuntimeCompilerServicesOverloadResolutionPriorityAttribute extends A
   /**
    * Gets the priority number.
    */
-  int getPriority() { result = this.getConstructorArgument(0).getValue().toInt() }
+  int getPriority() { result = this.getConstructorArgument(0).getIntValue() }
 }

csharp/ql/src/Likely Bugs/BadCheckOdd.ql

@@ -13,7 +13,7 @@
 import csharp
 
 predicate isDefinitelyPositive(Expr e) {
-  e.getValue().toInt() >= 0 or
+  e.getIntValue() >= 0 or
   e.(PropertyAccess).getTarget().hasName("Length") or
   e.(MethodCall).getTarget().hasUndecoratedName("Count")
 }
@@ -23,12 +23,12 @@ where
   t.getLeftOperand() = lhs and
   t.getRightOperand() = rhs and
   not isDefinitelyPositive(lhs.getLeftOperand().stripCasts()) and
-  lhs.getRightOperand().(IntegerLiteral).getValue() = "2" and
+  lhs.getRightOperand().(IntegerLiteral).getIntValue() = 2 and
   (
-    t instanceof EQExpr and rhs.getValue() = "1" and parity = "oddness"
+    t instanceof EQExpr and rhs.getIntValue() = 1 and parity = "oddness"
     or
-    t instanceof NEExpr and rhs.getValue() = "1" and parity = "evenness"
+    t instanceof NEExpr and rhs.getIntValue() = 1 and parity = "evenness"
     or
-    t instanceof GTExpr and rhs.getValue() = "0" and parity = "oddness"
+    t instanceof GTExpr and rhs.getIntValue() = 0 and parity = "oddness"
   )
 select t, "Possibly invalid test for " + parity + ". This will fail for negative numbers."

csharp/ql/src/Likely Bugs/MishandlingJapaneseEra.ql

@@ -27,8 +27,8 @@ predicate isExactEraStartDateCreation(ObjectCreation cr) {
     cr.getType().hasFullyQualifiedName("System", "DateTime") or
     cr.getType().hasFullyQualifiedName("System", "DateTimeOffset")
   ) and
-  isEraStart(cr.getArgument(0).getValue().toInt(), cr.getArgument(1).getValue().toInt(),
-    cr.getArgument(2).getValue().toInt())
+  isEraStart(cr.getArgument(0).getIntValue(), cr.getArgument(1).getIntValue(),
+    cr.getArgument(2).getIntValue())
 }
 
 predicate isDateFromJapaneseCalendarToDateTime(MethodCall mc) {
@@ -44,7 +44,7 @@ predicate isDateFromJapaneseCalendarToDateTime(MethodCall mc) {
     mc.getNumberOfArguments() = 7 // implicitly current era
     or
     mc.getNumberOfArguments() = 8 and
-    mc.getArgument(7).getValue() = "0"
+    mc.getArgument(7).getIntValue() = 0
   ) // explicitly current era
 }
 

csharp/ql/src/Likely Bugs/PossibleLossOfPrecision.ql

@@ -40,8 +40,8 @@ predicate convertedToFloatOrDecimal(Expr e, Type t) {
 /** Holds if `div` is an exact integer division. */
 predicate exactDivision(DivExpr div) {
   exists(int numerator, int denominator |
-    numerator = div.getNumerator().stripCasts().getValue().toInt() and
-    denominator = div.getDenominator().stripCasts().getValue().toInt() and
+    numerator = div.getNumerator().stripCasts().getIntValue() and
+    denominator = div.getDenominator().stripCasts().getIntValue() and
     numerator % denominator = 0
   )
 }

csharp/ql/src/Security Features/InsufficientKeySize.ql

@@ -20,23 +20,23 @@ predicate incorrectUseOfRC2(Assignment e, string msg) {
         .getDeclaringType()
         .hasFullyQualifiedName("System.Security.Cryptography", "RC2CryptoServiceProvider")
   ) and
-  e.getRightOperand().getValue().toInt() < 128 and
+  e.getRightOperand().getIntValue() < 128 and
   msg = "Key size should be at least 128 bits for RC2 encryption."
 }
 
 predicate incorrectUseOfDsa(ObjectCreation e, string msg) {
   e.getTarget()
       .getDeclaringType()
       .hasFullyQualifiedName("System.Security.Cryptography", "DSACryptoServiceProvider") and
-  exists(Expr i | e.getArgument(0) = i and i.getValue().toInt() < 2048) and
+  exists(Expr i | e.getArgument(0) = i and i.getIntValue() < 2048) and
   msg = "Key size should be at least 2048 bits for DSA encryption."
 }
 
 predicate incorrectUseOfRsa(ObjectCreation e, string msg) {
   e.getTarget()
       .getDeclaringType()
       .hasFullyQualifiedName("System.Security.Cryptography", "RSACryptoServiceProvider") and
-  exists(Expr i | e.getArgument(0) = i and i.getValue().toInt() < 2048) and
+  exists(Expr i | e.getArgument(0) = i and i.getIntValue() < 2048) and
   msg = "Key size should be at least 2048 bits for RSA encryption."
 }