More PR fixes

Author: AndreiDiaconu1

csharp/ql/src/semmle/code/csharp/ir/implementation/raw/internal/TranslatedElement.qll

@@ -11,6 +11,9 @@ private import TranslatedStmt
 private import IRConstruction
 private import semmle.code.csharp.ir.Util
 private import semmle.code.csharp.ir.internal.IRCSharpLanguage as Language
+private import desugar.Foreach
+private import desugar.Delegate
+private import desugar.Lock
 
 /**
  * Gets the built-in `int` type.
@@ -23,14 +26,14 @@ ArrayType getArrayOfDim(int dim, Type type) {
 }
 
 private predicate canCreateCompilerGeneratedElement(Element generatedBy, int nth) {
-  (
-    generatedBy instanceof ForeachStmt or
-    generatedBy instanceof LockStmt or
-    generatedBy instanceof DelegateCreation or
-    generatedBy instanceof DelegateCall
-  ) and
-  // For now we allow a max of 15 compiler generated elements
-  nth in [0 .. 14]
+  generatedBy instanceof ForeachStmt and nth in [0 .. ForeachElements::noGeneratedElements()]
+  or
+  generatedBy instanceof LockStmt and nth in [0 .. LockElements::noGeneratedElements()]
+  or
+  generatedBy instanceof DelegateCreation and
+  nth in [0 .. DelegateElements::noGeneratedElements(generatedBy)]
+  or
+  generatedBy instanceof DelegateCall and nth in [0 .. DelegateElements::noGeneratedElements(generatedBy)]
 }
 
 /**

csharp/ql/src/semmle/code/csharp/ir/implementation/raw/internal/TranslatedFunction.qll

@@ -165,7 +165,7 @@ class TranslatedFunction extends TranslatedElement, TTranslatedFunction {
       isLValue = false and
       (
         // Only generate the `Unwind` instruction if there is any exception
-        // handling present in the function.
+        // handling present in the function (compiler generated or not).
         exists(TryStmt try | try.getEnclosingCallable() = callable) or
         exists(ThrowStmt throw | throw.getEnclosingCallable() = callable)
       )

csharp/ql/src/semmle/code/csharp/ir/implementation/raw/internal/common/TranslatedDeclarationBase.qll

@@ -113,7 +113,7 @@ abstract class LocalVariableDeclarationBase extends TranslatedElement {
   abstract TranslatedElement getInitialization();
 
   /**
-   * Predicate that holds if a declaration is not explicitly initialized,
+   * Holds if a declaration is not explicitly initialized,
    * but will be implicitly initialized by an element.
    */
   abstract predicate isInitializedByElement();

csharp/ql/src/semmle/code/csharp/ir/implementation/raw/internal/desugar/Delegate.qll

@@ -31,6 +31,12 @@ module DelegateElements {
   }
 
   TranslatedDelegateInvokeCall getInvoke(DelegateCall generatedBy) { result.getAST() = generatedBy }
+
+  int noGeneratedElements(Element generatedBy) {
+    generatedBy instanceof DelegateCreation and result = 1
+    or
+    generatedBy instanceof DelegateCall and result = 1
+  }
 }
 
 /**

csharp/ql/src/semmle/code/csharp/ir/implementation/raw/internal/desugar/Foreach.qll

@@ -58,6 +58,8 @@ module ForeachElements {
   TranslatedForeachTry getTry(ForeachStmt generatedBy) { result.getAST() = generatedBy }
 
   TranslatedForeachEnumerator getEnumDecl(ForeachStmt generatedBy) { result.getAST() = generatedBy }
+
+  int noGeneratedElements() { result = 12 }
 }
 
 private class TranslatedForeachTry extends TranslatedCompilerGeneratedTry,
@@ -206,17 +208,14 @@ private class TranslatedForeachGetEnumerator extends TranslatedCompilerGenerated
 
   override Callable getInstructionFunction(InstructionTag tag) {
     tag = CallTargetTag() and
-    exists(Callable internal |
-      internal.getName() = "GetEnumerator" and
-      // TODO: For now ignore the possibility that the
-      //       foreach variable can have a generic type.
-      //       The type of the callable will need to be fabricated,
-      //       since we might not find the correct callable in the DB.
-      //       Probably will have change the way the immediate
-      //       operand of `FunctionAddress` is calculated.
-      internal.getReturnType().getName() = "IEnumerator" and
-      result = internal
-    )
+    result.getName() = "GetEnumerator" and
+    // TODO: For now ignore the possibility that the
+    //       foreach variable can have a generic type.
+    //       The type of the callable will need to be fabricated,
+    //       since we might not find the correct callable in the DB.
+    //       Probably will have change the way the immediate
+    //       operand of `FunctionAddress` is calculated.
+    result.getReturnType().getName() = "IEnumerator"
   }
 
   override TranslatedExpr getArgument(int id) { none() }

csharp/ql/src/semmle/code/csharp/ir/implementation/raw/internal/desugar/Lock.qll

@@ -48,6 +48,8 @@ module LockElements {
   TranslatedLockWasTakenDecl getLockWasTakenDecl(LockStmt generatedBy) {
     result.getAST() = generatedBy
   }
+
+  int noGeneratedElements() { result = 13 }
 }
 
 /**

csharp/ql/src/semmle/code/csharp/ir/implementation/raw/internal/desugar/internal/TranslatedCompilerGeneratedElement.qll

@@ -3,7 +3,6 @@
  * which represents the element that generated the compiler generated element.
  */
 
-import csharp
 private import semmle.code.csharp.ir.implementation.raw.internal.TranslatedElement
 private import semmle.code.csharp.ir.internal.IRCSharpLanguage as Language
 

csharp/ql/src/semmle/code/csharp/ir/internal/IRUtilities.qll

@@ -1,16 +1,5 @@
 private import csharp
 
-/**
- * Given a type, get the type that would result by applying "pointer decay".
- * A function type becomes a pointer to that function type, and an array type
- * becomes a pointer to the element type of the array. If the specified type
- * is not subject to pointer decay, this predicate does not hold.
- */
-// TODO: Only pointer to array decay in C#?
-private Type getDecayedType(Type type) {
-  result.(PointerType).getReferentType() = type.(ArrayType).getElementType()
-}
-
 /**
  * Get the actual type of the specified variable, as opposed to the declared type.
  * This returns the type of the variable after any pointer decay is applied, and
@@ -21,9 +10,7 @@ Type getVariableType(Variable v) {
     declaredType = v.getType() and
     if v instanceof Parameter
     then
-      result = getDecayedType(declaredType)
-      or
-      not exists(getDecayedType(declaredType)) and result = declaredType
+      result = declaredType
     else
       if declaredType instanceof ArrayType
       then

csharp/ql/test/library-tests/ir/ir/lock.cs

@@ -4,10 +4,10 @@ class LockTest
 {
     static void A()    
     {
-        object _object = new object();
-        lock (_object)
+        object @object = new object();
+        lock (@object)
         {
-            Console.WriteLine(_object.ToString());
+            Console.WriteLine(@object.ToString());
         }
     }
 }

csharp/ql/test/library-tests/ir/ir/raw_ir.expected

@@ -609,14 +609,14 @@ lock.cs:
 #    5|     v0_0(Void)            = EnterFunction              : 
 #    5|     mu0_1(null)           = AliasedDefinition          : 
 #    5|     mu0_2(null)           = UnmodeledDefinition        : 
-#    7|     r0_3(glval<Object>)   = VariableAddress[_object]   : 
+#    7|     r0_3(glval<Object>)   = VariableAddress[object]    : 
 #    7|     r0_4(Object)          = NewObj                     : 
 #    7|     r0_5(glval<null>)     = FunctionAddress[Object]    : 
 #    7|     v0_6(Void)            = Call                       : func:r0_5, this:r0_4
 #    7|     mu0_7(null)           = ^CallSideEffect            : ~mu0_2
 #    7|     mu0_8(Object)         = Store                      : &:r0_3, r0_4
 #    8|     r0_9(glval<Object>)   = VariableAddress[#temp8:9]  : 
-#    8|     r0_10(glval<Object>)  = VariableAddress[_object]   : 
+#    8|     r0_10(glval<Object>)  = VariableAddress[object]    : 
 #    8|     r0_11(Object)         = Load                       : &:r0_10, ~mu0_2
 #    8|     mu0_12(Object)        = Store                      : &:r0_9, r0_11
 #    8|     r0_13(glval<Boolean>) = VariableAddress[#temp8:9]  : 
@@ -629,7 +629,7 @@ lock.cs:
 #    8|     v0_20(Void)           = Call                       : func:r0_16, 0:r0_18, 1:r0_19
 #    8|     mu0_21(null)          = ^CallSideEffect            : ~mu0_2
 #   10|     r0_22(glval<null>)    = FunctionAddress[WriteLine] : 
-#   10|     r0_23(glval<Object>)  = VariableAddress[_object]   : 
+#   10|     r0_23(glval<Object>)  = VariableAddress[object]    : 
 #   10|     r0_24(Object)         = Load                       : &:r0_23, ~mu0_2
 #   10|     r0_25(glval<null>)    = FunctionAddress[ToString]  : 
 #   10|     r0_26(String)         = Call                       : func:r0_25, this:r0_24