Java: Autoformat Overflow.qll and add comment about imprecise float.

aschackmull · aschackmull · commit 11279d4c8308 · 2018-10-12T13:40:32.000+02:00
diff --git a/java/ql/src/semmle/code/java/arithmetic/Overflow.qll b/java/ql/src/semmle/code/java/arithmetic/Overflow.qll
@@ -2,14 +2,9 @@ import java
 
 /** A subclass of `PrimitiveType` with width-based ordering methods. */
 class OrdPrimitiveType extends PrimitiveType {
+  predicate widerThan(OrdPrimitiveType that) { getWidthRank() > that.getWidthRank() }
 
-  predicate widerThan(OrdPrimitiveType that) {
-    getWidthRank() > that.getWidthRank()
-  }
-
-  predicate widerThanOrEqualTo(OrdPrimitiveType that) {
-    getWidthRank() >= that.getWidthRank()
-  }
+  predicate widerThanOrEqualTo(OrdPrimitiveType that) { getWidthRank() >= that.getWidthRank() }
 
   OrdPrimitiveType maxType(OrdPrimitiveType that) {
     (this.widerThan(that) and result = this)
@@ -38,7 +33,8 @@ class OrdPrimitiveType extends PrimitiveType {
     or
     (this.getName() = "int" and result = 2147483647.0)
     or
-    (this.getName() = "long" and result = 9223372036854775807.0)
+    // Long.MAX_VALUE is 9223372036854775807 but floating point only has 53 bits of precision.
+    (this.getName() = "long" and result = 9223372036854776000.0)
     // don't try for floats and doubles
   }
 
@@ -49,7 +45,8 @@ class OrdPrimitiveType extends PrimitiveType {
     or
     (this.getName() = "int" and result = -2147483648.0)
     or
-    (this.getName() = "long" and result = -9223372036854775808.0)
+    // Long.MIN_VALUE is -9223372036854775808 but floating point only has 53 bits of precision.
+    (this.getName() = "long" and result = -9223372036854776000.0)
     // don't try for floats and doubles
   }
 }
@@ -75,17 +72,17 @@ class NumType extends Type {
     this.getOrdPrimitiveType().widerThanOrEqualTo(that.getOrdPrimitiveType())
   }
 
-  int getWidthRank() {
-    result = this.getOrdPrimitiveType().getWidthRank()
-  }
+  int getWidthRank() { result = this.getOrdPrimitiveType().getWidthRank() }
 }
 
 class ArithExpr extends Expr {
   ArithExpr() {
     (
       this instanceof UnaryAssignExpr or
-      this instanceof AddExpr or this instanceof MulExpr or
-      this instanceof SubExpr or this instanceof DivExpr
+      this instanceof AddExpr or
+      this instanceof MulExpr or
+      this instanceof SubExpr or
+      this instanceof DivExpr
     ) and
     forall(Expr e | e = this.(BinaryExpr).getAnOperand() or e = this.(UnaryAssignExpr).getExpr() |
       e.getType() instanceof NumType
@@ -112,9 +109,7 @@ class ArithExpr extends Expr {
   /**
    * Gets the right-hand operand if this is a binary expression.
    */
-  Expr getRightOperand() {
-    result = this.(BinaryExpr).getRightOperand()
-  }
+  Expr getRightOperand() { result = this.(BinaryExpr).getRightOperand() }
 
   /** Gets an operand of this arithmetic expression. */
   Expr getAnOperand() {
