Merge pull request #4489 from hvitved/csharp/cil-to-string

C#: Simplify `toString()` for CIL entities

Author: hvitved

csharp/change-notes/2020-10-28-cil-to-string.md

@@ -0,0 +1,3 @@
+lgtm,codescanning
+* The `toString()` predicate is now less verbose for CIL entities. The old `toString()` behavior
+  can be recovered by using `toStringExtra()` and `getQualifiedName()`, respectively.

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

@@ -14,7 +14,7 @@ class Attribute extends Element, @cil_attribute {
   /** Gets the type of this attribute. */
   Type getType() { result = getConstructor().getDeclaringType() }
 
-  override string toString() { result = "[" + getType().toString() + "(...)]" }
+  override string toString() { result = "[" + getType().getName() + "(...)]" }
 
   /** Gets the value of the `i`th argument of this attribute. */
   string getArgument(int i) { cil_attribute_positional_argument(this, i, result) }

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

@@ -477,7 +477,9 @@ class InvalidOverride extends MethodViolation {
   }
 
   override string getMessage() {
-    result = "Overridden method from " + base.getDeclaringType() + " is not in a base type"
+    result =
+      "Overridden method from " + base.getDeclaringType().getQualifiedName() +
+        " is not in a base type"
   }
 }
 

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

@@ -4,7 +4,10 @@ private import CIL
 
 /** An instruction. */
 class Instruction extends Element, ControlFlowNode, DataFlowNode, @cil_instruction {
-  override string toString() { result = getIndex() + ": " + getOpcodeName() + getExtraStr() }
+  override string toString() { result = getOpcodeName() }
+
+  /** Gets a more verbose textual representation of this instruction. */
+  string toStringExtra() { result = getIndex() + ": " + getOpcodeName() + getExtraStr() }
 
   /** Gets the method containing this instruction. */
   override MethodImplementation getImplementation() { cil_instruction(this, _, _, result) }

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

@@ -54,7 +54,11 @@ class MethodImplementation extends EntryPoint, @cil_method_implementation {
   /** Gets a string representing the disassembly of this implementation. */
   string getDisassembly() {
     result =
-      concat(Instruction i | i = this.getAnInstruction() | i.toString(), ", " order by i.getIndex())
+      concat(Instruction i |
+        i = this.getAnInstruction()
+      |
+        i.toStringExtra(), ", " order by i.getIndex()
+      )
   }
 }
 
@@ -76,7 +80,7 @@ class Method extends DotNet::Callable, Element, Member, TypeContainer, DataFlowN
 
   override string getName() { cil_method(this, result, _, _) }
 
-  override string toString() { result = this.getQualifiedName() }
+  override string toString() { result = this.getName() }
 
   override Type getDeclaringType() { cil_method(this, _, result, _) }
 

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

@@ -38,7 +38,7 @@ class Type extends DotNet::Type, Declaration, TypeContainer, @cil_type {
 
   override string getName() { cil_type(this, result, _, _, _) }
 
-  override string toString() { result = getQualifiedName() }
+  override string toString() { result = this.getName() }
 
   /** Gets the containing type of this type, if any. */
   override Type getDeclaringType() { result = getParent() }

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

@@ -39,7 +39,8 @@ class StackVariable extends Variable, @cil_stack_variable {
  */
 class LocalVariable extends StackVariable, @cil_local_variable {
   override string toString() {
-    result = "Local variable " + getIndex() + " of method " + getImplementation().getMethod()
+    result =
+      "Local variable " + getIndex() + " of method " + getImplementation().getMethod().getName()
   }
 
   /** Gets the method implementation defining this local variable. */
@@ -65,7 +66,7 @@ class Parameter extends DotNet::Parameter, StackVariable, @cil_parameter {
   /** Gets the index of this parameter. */
   int getIndex() { cil_parameter(this, _, result, _) }
 
-  override string toString() { result = "Parameter " + getIndex() + " of " + getMethod() }
+  override string toString() { result = "Parameter " + getIndex() + " of " + getMethod().getName() }
 
   override Type getType() { cil_parameter(this, _, _, result) }
 

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

@@ -89,7 +89,7 @@ class Attribute extends TopLevelExprParent, @attribute {
   override Location getALocation() { attribute_location(this, result) }
 
   override string toString() {
-    exists(string type, string name | type = getType().toString() |
+    exists(string type, string name | type = getType().getName() |
       (if type.matches("%Attribute") then name = type.prefix(type.length() - 9) else name = type) and
       result = "[" + name + "(...)]"
     )

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

@@ -227,7 +227,7 @@ class TypeParameterConstraints extends Element, @type_parameter_constraints {
   predicate hasNullableRefTypeConstraint() { general_type_parameter_constraints(this, 5) }
 
   /** Gets a textual representation of these constraints. */
-  override string toString() { result = "where " + this.getTypeParameter().toString() + ": ..." }
+  override string toString() { result = "where " + this.getTypeParameter().getName() + ": ..." }
 }
 
 /**

csharp/ql/src/semmle/code/csharp/dataflow/internal/DataFlowPrivate.qll

@@ -62,8 +62,10 @@ private class ExprNodeImpl extends ExprNode, NodeImpl {
   override string toStringImpl() {
     result = this.getControlFlowNode().toString()
     or
-    this = TCilExprNode(_) and
-    result = "CIL expression"
+    exists(CIL::Expr e |
+      this = TCilExprNode(e) and
+      result = e.toString()
+    )
   }
 }