Merge pull request github#3528 from hvitved/csharp/cfg/cs6-initializers

C#: Fix CFG for C# 6 initializers

Author: calumgrant

csharp/ql/src/semmle/code/csharp/controlflow/ControlFlowGraph.qll

@@ -501,7 +501,7 @@ module ControlFlow {
       private class WriteAccessNoNodeExpr extends WriteAccess, NoNodeExpr {
         WriteAccessNoNodeExpr() {
           // For example a write to a static field, `Foo.Bar = 0`.
-          forall(Expr e | e = this.(QualifiableExpr).getQualifier() | e instanceof NoNodeExpr)
+          forall(Expr e | e = this.getAChildExpr() | e instanceof NoNodeExpr)
         }
       }
 
@@ -553,7 +553,17 @@ module ControlFlow {
        * not evaluated, only the qualifier and the indexer arguments (if any).
        */
       private class QualifiedWriteAccess extends WriteAccess, QualifiableExpr {
-        QualifiedWriteAccess() { this.hasQualifier() }
+        QualifiedWriteAccess() {
+          this.hasQualifier()
+          or
+          // Member initializers like
+          // ```
+          // new Dictionary<int, string>() { [0] = "Zero", [1] = "One", [2] = "Two" }
+          // ```
+          // need special treatment, because the the accesses `[0]`, `[1]`, and `[2]`
+          // have no qualifier.
+          this = any(MemberInitializer mi).getLValue()
+        }
       }
 
       /** A normal or a (potential) dynamic call to an accessor. */

csharp/ql/test/library-tests/controlflow/graph/BasicBlock.expected

@@ -400,14 +400,15 @@
 | Foreach.cs:36:10:36:11 | exit M6 | Foreach.cs:36:10:36:11 | exit M6 | 1 |
 | Foreach.cs:38:9:39:11 | foreach (... ... in ...) ... | Foreach.cs:38:9:39:11 | foreach (... ... in ...) ... | 1 |
 | Foreach.cs:38:26:38:26 | String x | Foreach.cs:39:11:39:11 | ; | 4 |
-| Initializers.cs:6:5:6:16 | enter Initializers | Initializers.cs:6:5:6:16 | exit Initializers | 14 |
 | Initializers.cs:8:5:8:16 | enter Initializers | Initializers.cs:8:5:8:16 | exit Initializers | 14 |
-| Initializers.cs:10:10:10:10 | enter M | Initializers.cs:10:10:10:10 | exit M | 20 |
-| Initializers.cs:16:20:16:20 | 1 | Initializers.cs:16:16:16:20 | ... = ... | 2 |
-| Initializers.cs:18:11:18:23 | enter NoConstructor | Initializers.cs:18:11:18:23 | exit NoConstructor | 8 |
-| Initializers.cs:29:9:29:11 | enter Sub | Initializers.cs:29:9:29:11 | exit Sub | 11 |
-| Initializers.cs:31:9:31:11 | enter Sub | Initializers.cs:31:9:31:11 | exit Sub | 8 |
-| Initializers.cs:33:9:33:11 | enter Sub | Initializers.cs:33:9:33:11 | exit Sub | 18 |
+| Initializers.cs:10:5:10:16 | enter Initializers | Initializers.cs:10:5:10:16 | exit Initializers | 14 |
+| Initializers.cs:12:10:12:10 | enter M | Initializers.cs:12:10:12:10 | exit M | 20 |
+| Initializers.cs:18:20:18:20 | 1 | Initializers.cs:18:16:18:20 | ... = ... | 2 |
+| Initializers.cs:20:11:20:23 | enter NoConstructor | Initializers.cs:20:11:20:23 | exit NoConstructor | 8 |
+| Initializers.cs:31:9:31:11 | enter Sub | Initializers.cs:31:9:31:11 | exit Sub | 11 |
+| Initializers.cs:33:9:33:11 | enter Sub | Initializers.cs:33:9:33:11 | exit Sub | 8 |
+| Initializers.cs:35:9:35:11 | enter Sub | Initializers.cs:35:9:35:11 | exit Sub | 18 |
+| Initializers.cs:51:10:51:13 | enter Test | Initializers.cs:51:10:51:13 | exit Test | 104 |
 | LoopUnrolling.cs:7:10:7:11 | enter M1 | LoopUnrolling.cs:9:13:9:28 | ... == ... | 7 |
 | LoopUnrolling.cs:7:10:7:11 | exit M1 | LoopUnrolling.cs:7:10:7:11 | exit M1 | 1 |
 | LoopUnrolling.cs:10:13:10:19 | return ...; | LoopUnrolling.cs:10:13:10:19 | return ...; | 1 |

csharp/ql/test/library-tests/controlflow/graph/Dominance.expected

@@ -1,3 +1,5 @@
+using System.Collections.Generic;
+
 class Initializers
 {
     int F = H + 1;
@@ -33,3 +35,33 @@ class Sub : NoConstructor
         Sub(int i, int j) { I = i + j; }
     }
 }
+
+class IndexInitializers
+{
+    class Compound
+    {
+        public Dictionary<int, string> DictionaryField;
+        public Dictionary<int, string> DictionaryProperty { get; set; }
+        public string[] ArrayField;
+        public string[] ArrayProperty { get; set; }
+        public string[,] ArrayField2;
+        public string[,] ArrayProperty2 { get; set; }
+    }
+
+    void Test(int i)
+    {
+        // Collection initializer
+        var dict = new Dictionary<int, string>() { [0] = "Zero", [1] = "One", [i + 2] = "Two" };
+
+        // Indexed initializer
+        var compound = new Compound()
+        {
+            DictionaryField = { [0] = "Zero", [1] = "One", [i + 2] = "Two" },
+            DictionaryProperty = { [3] = "Three", [2] = "Two", [i + 1] = "One" },
+            ArrayField = { [0] = "Zero", [i + 1] = "One" },
+            ArrayField2 = { [0, 1] = "i", [1, i + 0] = "1" },
+            ArrayProperty = { [1] = "One", [i + 2] = "Two" },
+            ArrayProperty2 = { [0, 1] = "i", [1, i + 0] = "1" },
+        };
+    }
+}

csharp/ql/test/library-tests/controlflow/graph/EnclosingCallable.expected

@@ -717,13 +717,14 @@ entryPoint
 | Foreach.cs:24:10:24:11 | M4 | Foreach.cs:25:5:28:5 | {...} |
 | Foreach.cs:30:10:30:11 | M5 | Foreach.cs:31:5:34:5 | {...} |
 | Foreach.cs:36:10:36:11 | M6 | Foreach.cs:37:5:40:5 | {...} |
-| Initializers.cs:6:5:6:16 | Initializers | Initializers.cs:3:9:3:9 | this access |
-| Initializers.cs:8:5:8:16 | Initializers | Initializers.cs:3:9:3:9 | this access |
-| Initializers.cs:10:10:10:10 | M | Initializers.cs:11:5:14:5 | {...} |
-| Initializers.cs:18:11:18:23 | NoConstructor | Initializers.cs:20:23:20:23 | this access |
-| Initializers.cs:29:9:29:11 | Sub | Initializers.cs:29:17:29:20 | call to constructor NoConstructor |
-| Initializers.cs:31:9:31:11 | Sub | Initializers.cs:31:22:31:25 | call to constructor Sub |
-| Initializers.cs:33:9:33:11 | Sub | Initializers.cs:20:23:20:23 | this access |
+| Initializers.cs:8:5:8:16 | Initializers | Initializers.cs:5:9:5:9 | this access |
+| Initializers.cs:10:5:10:16 | Initializers | Initializers.cs:5:9:5:9 | this access |
+| Initializers.cs:12:10:12:10 | M | Initializers.cs:13:5:16:5 | {...} |
+| Initializers.cs:20:11:20:23 | NoConstructor | Initializers.cs:22:23:22:23 | this access |
+| Initializers.cs:31:9:31:11 | Sub | Initializers.cs:31:17:31:20 | call to constructor NoConstructor |
+| Initializers.cs:33:9:33:11 | Sub | Initializers.cs:33:22:33:25 | call to constructor Sub |
+| Initializers.cs:35:9:35:11 | Sub | Initializers.cs:22:23:22:23 | this access |
+| Initializers.cs:51:10:51:13 | Test | Initializers.cs:52:5:66:5 | {...} |
 | LoopUnrolling.cs:7:10:7:11 | M1 | LoopUnrolling.cs:8:5:13:5 | {...} |
 | LoopUnrolling.cs:15:10:15:11 | M2 | LoopUnrolling.cs:16:5:20:5 | {...} |
 | LoopUnrolling.cs:22:10:22:11 | M3 | LoopUnrolling.cs:23:5:27:5 | {...} |