Merge branch 'master' into csharp/autoformat/tests

Author: hvitved

csharp/ql/src/CSI/NullMaybe.ql

@@ -2,7 +2,7 @@
  * @name Dereferenced variable may be null
  * @description Dereferencing a variable whose value may be 'null' may cause a
  *              'NullReferenceException'.
- * @kind problem
+ * @kind path-problem
  * @problem.severity warning
  * @precision high
  * @id cs/dereferenced-value-may-be-null
@@ -14,7 +14,8 @@
 
 import csharp
 import semmle.code.csharp.dataflow.Nullness
+import PathGraph
 
-from Dereference d, Ssa::SourceVariable v, string msg, Element reason
-where d.isFirstMaybeNull(v.getAnSsaDefinition(), msg, reason)
-select d, "Variable $@ may be null here " + msg + ".", v, v.toString(), reason, "this"
+from Dereference d, PathNode source, PathNode sink, Ssa::SourceVariable v, string msg, Element reason
+where d.isFirstMaybeNull(v.getAnSsaDefinition(), source, sink, msg, reason)
+select d, source, sink, "Variable $@ may be null here " + msg + ".", v, v.toString(), reason, "this"

csharp/ql/src/Useless code/DefaultToString.ql

@@ -58,7 +58,34 @@ predicate alwaysDefaultToString(ValueOrRefType t) {
   )
 }
 
-from Expr e, ValueOrRefType t
-where invokesToString(e, t)
-  and alwaysDefaultToString(t)
-select e, "Default 'ToString()': $@ inherits 'ToString()' from 'Object', and so is not suitable for printing.", t, t.getName()
+newtype TDefaultToStringType =
+  TDefaultToStringType0(ValueOrRefType t) { alwaysDefaultToString(t) }
+
+class DefaultToStringType extends TDefaultToStringType {
+  ValueOrRefType t;
+
+  DefaultToStringType() { this = TDefaultToStringType0(t) }
+
+  ValueOrRefType getType() { result = t }
+
+  string toString() { result = t.toString() }
+
+  // A workaround for generating empty URLs for non-source locations, because qltest
+  // does not support non-source locations
+  string getURL() {
+    exists(Location l |
+      l = t.getLocation() |
+      if l instanceof SourceLocation then
+        exists(string path, int a, int b, int c, int d |
+          l.hasLocationInfo(path, a, b, c, d) |
+          toUrl(path, a, b, c, d, result)
+        )
+      else
+        result = ""
+    )
+  }
+}
+
+from Expr e, DefaultToStringType t
+where invokesToString(e, t.getType())
+select e, "Default 'ToString()': $@ inherits 'ToString()' from 'Object', and so is not suitable for printing.", t, t.getType().getName()

csharp/ql/src/semmle/code/cil/Type.qll

@@ -23,7 +23,6 @@ class Namespace extends DotNet::Namespace, TypeContainer, @namespace {
   override Namespace getParent() { result = this.getParentNamespace() }
   override Namespace getParentNamespace() { parent_namespace(this, result) }
   override string getName() { namespaces(this,result) }
-  string getUrl() { result="" }
   override Location getLocation() { none() }
 }
 

csharp/ql/src/semmle/code/csharp/Assignable.qll

@@ -441,6 +441,12 @@ class AssignableDefinition extends TAssignableDefinition {
    */
   Expr getExpr() { none() }
 
+  /**
+   * Gets the underlying element associated with this definition. This is either
+   * an expression or a parameter.
+   */
+  Element getElement() { result = this.getExpr() }
+
   /** Gets the enclosing callable of this definition. */
   Callable getEnclosingCallable() { result = this.getExpr().getEnclosingCallable() }
 
@@ -703,6 +709,8 @@ module AssignableDefinitions {
       result = p.getCallable().getEntryPoint()
     }
 
+    override Parameter getElement() { result = p }
+
     override Callable getEnclosingCallable() {
       result = p.getCallable()
     }

csharp/ql/src/semmle/code/csharp/Element.qll

@@ -22,7 +22,10 @@ class Element extends DotNet::Element, @element {
    * Where an element has multiple locations (for example a source file and an assembly),
    * gets only the source location.
    */
-  override Location getLocation() { result = bestLocation(this) }
+  override Location getLocation() { result = ExprOrStmtParentCached::bestLocation(this) }
+
+  /** Gets the URL of this element. */
+  string getURL() { result = ExprOrStmtParentCached::getURL(this) }
 
   /** Gets a location of this element, including sources and assemblies. */
   override Location getALocation() { none() }

csharp/ql/src/semmle/code/csharp/ExprOrStmtParent.qll

@@ -346,7 +346,7 @@ private int getImplementationSize(ValueOrRefType t, File f) {
     result = getImplementationSize1(t, f)
 }
 
-private cached module Cached {
+cached module ExprOrStmtParentCached {
   cached
   ControlFlowElement getTopLevelChild(ExprOrStmtParent p, int i) {
     result = p.(MultiImplementationsParent).getBestChild(i)
@@ -363,7 +363,7 @@ private cached module Cached {
    * in `f`.
    */
   cached
-  predicate mustHaveLocationInFileCached(Declaration d, File f) {
+  predicate mustHaveLocationInFile(Declaration d, File f) {
     exists(MultiImplementationsParent p, ValueOrRefType t |
       t = getTopLevelDeclaringType(p) and
       f = p.getBestFile() |
@@ -381,7 +381,7 @@ private cached module Cached {
    * locations, choose only one.
    */
   cached
-  Location bestLocationCached(Element e) {
+  Location bestLocation(Element e) {
     result = e.getALocation().(SourceLocation) and
     (mustHaveLocationInFile(e, _) implies mustHaveLocationInFile(e, result.getFile()))
     or
@@ -391,8 +391,17 @@ private cached module Cached {
       result = min(Location l | l = e.getALocation() | l order by l.getFile().toString())
     )
   }
-}
-private import Cached
 
-predicate mustHaveLocationInFile = mustHaveLocationInFileCached/2;
-predicate bestLocation = bestLocationCached/1;
+  cached
+  string getURL(Element e) {
+    exists(Location l, string path, int a, int b, int c, int d |
+      l = bestLocation(e) |
+      l.hasLocationInfo(path, a, b, c, d) and
+      toUrl(path, a, b, c, d, result)
+    )
+    or
+    not exists(bestLocation(e)) and
+    result = ""
+  }
+}
+private import ExprOrStmtParentCached

csharp/ql/src/semmle/code/csharp/Location.qll

@@ -37,24 +37,16 @@ class Location extends @location
   string toString() { none() }
 
   /** Gets the start line of this location. */
-  int getStartLine() {
-     locations_default(this,_,result,_,_,_)
-  }
+  final int getStartLine() { this.hasLocationInfo(_, result, _, _, _) }
 
   /** Gets the end line of this location. */
-  int getEndLine() {
-     locations_default(this,_,_,_,result,_)
-  }
+  final int getEndLine() { this.hasLocationInfo(_, _, _, result, _) }
 
   /** Gets the start column of this location. */
-  int getStartColumn() {
-     locations_default(this,_,_,result,_,_)
-  }
+  final int getStartColumn() { this.hasLocationInfo(_, _, result, _, _) }
 
   /** Gets the end column of this location. */
-  int getEndColumn() {
-     locations_default(this,_,_,_,_,result)
-  }
+  final int getEndColumn() { this.hasLocationInfo(_, _, _, _, result) }
 }
 
 /**

csharp/ql/src/semmle/code/csharp/Member.qll

@@ -36,17 +36,6 @@ class Declaration extends DotNet::Declaration, Element, @declaration {
     result = this.getDeclaringType().getQualifiedName() + "." + this.toStringWithTypes()
   }
 
-  /** Define URL for declarations with no location. */
-  string getURL() {
-    if exists(this.getLocation()) then
-      exists(string path, int a, int b, int c, int d |
-        this.getLocation().hasLocationInfo(path, a, b, c, d) |
-        toUrl(path, a, b, c, d, result)
-      )
-    else
-      result = ""
-  }
-
   /**
    * Holds if this declaration has been generated by the compiler, for example
    * implicit constructors or accessors.

csharp/ql/src/semmle/code/csharp/Namespace.qll

@@ -112,8 +112,12 @@ class Namespace extends DotNet::Namespace, TypeContainer, @namespace {
 
   override predicate fromLibrary() { not this.fromSource() }
 
-  /** Gets the URL of this namespace (which is empty in this case). */
-  string getURL() { result = "" }
+  /** Gets a declaration of this namespace, if any. */
+  NamespaceDeclaration getADeclaration() { result.getNamespace() = this }
+
+  override Location getALocation() {
+    result = this.getADeclaration().getALocation()
+  }
 }
 
 /**
@@ -193,7 +197,7 @@ class NamespaceDeclaration extends Element, @namespace_declaration {
    */
   ValueOrRefType getATypeDeclaration() { parent_namespace_declaration(result, this) }
 
-  override Location getALocation() { none() }
+  override Location getALocation() { namespace_declaration_location(this, result) }
 
   override string toString() { result = "namespace ... { ... }" }
 }

csharp/ql/src/semmle/code/csharp/Type.qll

@@ -729,7 +729,6 @@ class Class extends RefType, @class_type {
  * ```
  */
 class AnonymousClass extends Class {
-
   AnonymousClass() { this.getName().matches("<%") }
 }
 
@@ -787,8 +786,7 @@ class DelegateType extends RefType, Parameterizable, @delegate_type {
 /**
  * The `null` type. The type of the `null` literal.
  */
-class NullType extends RefType, @null_type {
-}
+class NullType extends RefType, @null_type { }
 
 /**
  * A nullable type, for example `int?`.
@@ -869,6 +867,13 @@ class ArrayType extends DotNet::ArrayType, RefType, @array_type {
   }
 
   override Type getChild(int n) { result = getElementType() and n = 0 }
+
+  override Location getALocation() {
+    type_location(this, result)
+    or
+    not type_location(this, _) and
+    result = this.getElementType().getALocation()
+  }
 }
 
 /**