Move ConstantStringExpr to RangeUtils.qll

Author: atorralba

java/ql/lib/semmle/code/java/dataflow/RangeUtils.qll

@@ -104,6 +104,17 @@ private predicate constantBooleanExpr(Expr e, boolean val) {
   CalcConstants::calculateBooleanValue(e) = val
 }
 
+pragma[nomagic]
+private predicate constantStringExpr(Expr e, string val) {
+  e.(CompileTimeConstantExpr).getStringValue() = val
+  or
+  exists(SsaExplicitUpdate v, Expr src |
+    e = v.getAUse() and
+    src = v.getDefiningExpr().(VariableAssign).getSource() and
+    constantStringExpr(src, val)
+  )
+}
+
 private boolean getBoolValue(Expr e) { constantBooleanExpr(e, result) }
 
 private int getIntValue(Expr e) { constantIntegerExpr(e, result) }
@@ -126,6 +137,14 @@ class ConstantBooleanExpr extends Expr {
   boolean getBooleanValue() { constantBooleanExpr(this, result) }
 }
 
+/** An expression that always has the same string value. */
+class ConstantStringExpr extends Expr {
+  ConstantStringExpr() { constantStringExpr(this, _) }
+
+  /** Get the string value of this expression. */
+  string getStringValue() { constantStringExpr(this, result) }
+}
+
 /**
  * Gets an expression that equals `v - d`.
  */

java/ql/lib/semmle/code/java/security/XmlParsers.qll

@@ -4,9 +4,7 @@ import java
 import semmle.code.java.dataflow.DataFlow
 import semmle.code.java.dataflow.DataFlow2
 import semmle.code.java.dataflow.DataFlow3
-import semmle.code.java.dataflow.DataFlow4
-import semmle.code.java.dataflow.DataFlow5
-private import semmle.code.java.dataflow.SSA
+private import semmle.code.java.dataflow.RangeUtils
 
 /*
  * Various XML parsers in Java.
@@ -130,26 +128,6 @@ class DocumentBuilderFactoryConfig extends ParserConfig {
   }
 }
 
-private predicate constantStringExpr(Expr e, string val) {
-  e.(CompileTimeConstantExpr).getStringValue() = val
-  or
-  exists(SsaExplicitUpdate v, Expr src |
-    e = v.getAUse() and
-    src = v.getDefiningExpr().(VariableAssign).getSource() and
-    constantStringExpr(src, val)
-  )
-}
-
-/** An expression that always has the same string value. */
-private class ConstantStringExpr extends Expr {
-  string value;
-
-  ConstantStringExpr() { constantStringExpr(this, value) }
-
-  /** Get the string value of this expression. */
-  string getStringValue() { result = value }
-}
-
 /**
  * A general configuration that is safe when enabled.
  */