Initial restructure

The `raw/internal` folder has been restructured to better enhance code sharing between compiler generated elements and AST generated elements.
The translated calls classes have been refactored to better fit the C# library.
A new folder has been added, `common` that provides blueprints for the classes that deal with translations of calls, declarations, exprs and conditions.
Several `TranslatedX.qll` files have been modified so that they use those blueprint classes.

Author: AndreiDiaconu1

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

@@ -54,6 +54,7 @@ newtype TInstructionTag =
   BoolConversionConstantTag() or
   BoolConversionCompareTag() or
   LoadTag() or // Implicit load due to lvalue-to-rvalue conversion
+  AddressTag() or
   CatchTag() or
   ThrowTag() or
   UnwindTag() or
@@ -192,16 +193,8 @@ string getInstructionTagId(TInstructionTag tag) {
   or
   tag = GeneratedBranchTag() and result = "GeneratedBranchTag"
   or
-  // TODO: Reread
-  //  exists(Field field, Class cls, int index, string tagName |
-  //    field = cls.getCanonicalMember(index) and
-  //    (
-  //      tag = InitializerFieldAddressTag(field) and tagName = "InitFieldAddr" or
-  //      tag = InitializerFieldDefaultValueTag(field) and tagName = "InitFieldDefVal" or
-  //      tag = InitializerFieldDefaultValueStoreTag(field) and tagName = "InitFieldDefValStore"
-  //    ) and
-  //    result = tagName + "(" + index + ")"
-  //  ) or
+  tag = AddressTag() and result = "AddressTag"
+  or
   exists(int index, string tagName |
     (
       tag = InitializerElementIndexTag(index) and tagName = "InitElemIndex"

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

@@ -5,267 +5,67 @@ private import InstructionTag
 private import TranslatedElement
 private import TranslatedExpr
 private import semmle.code.csharp.ir.Util
+private import semmle.code.csharp.ir.implementation.raw.internal.common.TranslatedCallBlueprint
 private import semmle.code.csharp.ir.internal.IRCSharpLanguage as Language
 
 /**
- * The IR translation of a call to a function. The call may be from an actual
- * call in the source code, or could be a call that is part of the translation
- * of a higher-level constructor (e.g. the allocator call in a `NewExpr`).
+ * The IR translation of a call to a function. The function can be a normal function
+ * (eg. `MethodCall`) or a constructor call (eg. `ObjectCreation`). Notice that the 
+ * AST generated translated calls are tied to an expression (unlike compiler generated ones,
+ * which can be attached to either a statement or an expression).
  */
-abstract class TranslatedCall extends TranslatedExpr {
-  final override TranslatedElement getChild(int id) {
-    // We choose the child's id in the order of evaluation.
-    // The qualifier is evaluated before the call target, because the value of
-    // the call target may depend on the value of the qualifier for virtual
-    // calls.
-    id = -2 and result = this.getQualifier()
-    or
-    id = -1 and result = this.getCallTarget()
-    or
-    result = this.getArgument(id)
-  }
-
-  final override Instruction getFirstInstruction() {
-    if exists(this.getQualifier())
-    then result = this.getQualifier().getFirstInstruction()
-    else result = this.getFirstCallTargetInstruction()
-  }
-
-  override predicate hasInstruction(
-    Opcode opcode, InstructionTag tag, Type resultType, boolean isLValue
-  ) {
-    tag = CallTag() and
-    opcode instanceof Opcode::Call and
-    resultType = getCallResultType() and
-    isLValue = false
-    or
-    hasSideEffect() and
-    tag = CallSideEffectTag() and
-    (
-      if hasWriteSideEffect()
-      then (
-        opcode instanceof Opcode::CallSideEffect and
-        resultType instanceof Language::UnknownType
-      ) else (
-        opcode instanceof Opcode::CallReadSideEffect and
-        resultType instanceof Language::UnknownType
-      )
-    ) and
-    isLValue = false
-  }
 
-  override Instruction getChildSuccessor(TranslatedElement child) {
-    child = this.getQualifier() and
-    result = this.getFirstCallTargetInstruction()
-    or
-    child = this.getCallTarget() and
-    result = this.getFirstArgumentOrCallInstruction()
-    or
-    exists(int argIndex |
-      child = this.getArgument(argIndex) and
-      if exists(this.getArgument(argIndex + 1))
-      then result = this.getArgument(argIndex + 1).getFirstInstruction()
-      else result = this.getInstruction(CallTag())
-    )
-  }
-
-  override Instruction getInstructionSuccessor(InstructionTag tag, EdgeKind kind) {
-    kind instanceof GotoEdge and
-    (
-      (
-        tag = CallTag() and
-        if this.hasSideEffect()
-        then result = this.getInstruction(CallSideEffectTag())
-        else result = this.getParent().getChildSuccessor(this)
-      )
-      or
-      this.hasSideEffect() and
-      tag = CallSideEffectTag() and
-      result = this.getParent().getChildSuccessor(this)
-    )
+abstract class TranslatedCall extends TranslatedExpr, TranslatedCallBlueprint {
+  final override Instruction getResult() {
+    result = TranslatedCallBlueprint.super.getResult()
   }
-
-  override Instruction getInstructionOperand(InstructionTag tag, OperandTag operandTag) {
-    tag = CallTag() and
-    (
-      tag = CallTag() and
-      (
-        operandTag instanceof CallTargetOperandTag and
-        result = this.getCallTargetResult()
-        or
-        operandTag instanceof ThisArgumentOperandTag and
-        result = this.getQualifierResult()
-        or
-        exists(PositionalArgumentOperandTag argTag |
-          argTag = operandTag and
-          result = this.getArgument(argTag.getArgIndex()).getResult()
-        )
-      )
-    )
-    or
-    tag = CallSideEffectTag() and
-    this.hasSideEffect() and
-    operandTag instanceof SideEffectOperandTag and
+  
+  override Instruction getUnmodeledDefinitionInstruction() {
     result = this.getEnclosingFunction().getUnmodeledDefinitionInstruction()
-    or
-    tag = CallSideEffectTag() and
-    hasSideEffect() and
-    operandTag instanceof SideEffectOperandTag and
-    result = getEnclosingFunction().getUnmodeledDefinitionInstruction()
-  }
-
-  final override Type getInstructionOperandType(InstructionTag tag, TypedOperandTag operandTag) {
-    tag = CallSideEffectTag() and
-    this.hasSideEffect() and
-    operandTag instanceof SideEffectOperandTag and
-    result instanceof Language::UnknownType
-  }
-
-  final override Instruction getResult() { result = this.getInstruction(CallTag()) }
-
-  /**
-   * Gets the result type of the call.
-   */
-  abstract Type getCallResultType();
-
-  /**
-   * Holds if the call has a `this` argument.
-   */
-  predicate hasQualifier() { exists(this.getQualifier()) }
-
-  /**
-   * Gets the `TranslatedExpr` for the indirect target of the call, if any.
-   */
-  TranslatedExpr getCallTarget() { none() }
-
-  /**
-   * Gets the first instruction of the sequence to evaluate the call target.
-   * By default, this is just the first instruction of `getCallTarget()`, but
-   * it can be overridden by a subclass for cases where there is a call target
-   * that is not computed from an expression (e.g. a direct call).
-   */
-  Instruction getFirstCallTargetInstruction() {
-    result = this.getCallTarget().getFirstInstruction()
-  }
-
-  /**
-   * Gets the instruction whose result value is the target of the call. By
-   * default, this is just the result of `getCallTarget()`, but it can be
-   * overridden by a subclass for cases where there is a call target that is not
-   * computed from an expression (e.g. a direct call).
-   */
-  Instruction getCallTargetResult() { result = this.getCallTarget().getResult() }
-
-  /**
-   * Gets the `TranslatedExpr` for the qualifier of the call (i.e. the value
-   * that is passed as the `this` argument.
-   */
-  abstract TranslatedExpr getQualifier();
-
-  /**
-   * Gets the instruction whose result value is the `this` argument of the call.
-   * By default, this is just the result of `getQualifier()`, but it can be
-   * overridden by a subclass for cases where there is a `this` argument that is
-   * not computed from a child expression (e.g. a constructor call).
-   */
-  Instruction getQualifierResult() { result = this.getQualifier().getResult() }
-
-  /**
-   * Gets the argument with the specified `index`. Does not include the `this`
-   * argument.
-   */
-  abstract TranslatedExpr getArgument(int index);
-
-  /**
-   * If there are any arguments, gets the first instruction of the first
-   * argument. Otherwise, returns the call instruction.
-   */
-  final Instruction getFirstArgumentOrCallInstruction() {
-    if this.hasArguments()
-    then result = this.getArgument(0).getFirstInstruction()
-    else result = this.getInstruction(CallTag())
-  }
-
-  /**
-   * Holds if the call has any arguments, not counting the `this` argument.
-   */
-  abstract predicate hasArguments();
-
-  // TODO: Fix side effects
-  predicate hasReadSideEffect() { any() }
-
-  predicate hasWriteSideEffect() { any() }
-
-  private predicate hasSideEffect() { hasReadSideEffect() or hasWriteSideEffect() }
-
-  override Instruction getPrimaryInstructionForSideEffect(InstructionTag tag) {
-    this.hasSideEffect() and
-    tag = CallSideEffectTag() and
-    result = this.getResult()
   }
 }
 
 /**
- * IR translation of a direct call to a specific function. Used for both
- * explicit calls and implicit calls.
+ * Represents the IR translation of a direct function call. The call can be one of the following:
+ * `MethodCall`, `LocalFunctionCall`, `AccessorCall`, `OperatorCall`.
+ * Note that `DelegateCall`s are not treated here since they need
  */
-abstract class TranslatedDirectCall extends TranslatedCall {
-  final override Instruction getFirstCallTargetInstruction() {
-    result = this.getInstruction(CallTargetTag())
-  }
-
-  final override Instruction getCallTargetResult() { result = this.getInstruction(CallTargetTag()) }
 
-  override predicate hasInstruction(
-    Opcode opcode, InstructionTag tag, Type resultType, boolean isLValue
-  ) {
-    TranslatedCall.super.hasInstruction(opcode, tag, resultType, isLValue)
-    or
-    tag = CallTargetTag() and
-    opcode instanceof Opcode::FunctionAddress and
-    resultType = expr.getType() and
-    isLValue = true
+class TranslatedFunctionCall extends TranslatedNonConstantExpr, TranslatedCall {
+  override Call expr;
+  
+  TranslatedFunctionCall() { 
+    expr instanceof MethodCall or
+    expr instanceof LocalFunctionCall or
+    expr instanceof AccessorCall or
+    expr instanceof OperatorCall
   }
 
-  override Instruction getInstructionSuccessor(InstructionTag tag, EdgeKind kind) {
-    result = TranslatedCall.super.getInstructionSuccessor(tag, kind)
-    or
-    tag = CallTargetTag() and
-    kind instanceof GotoEdge and
-    result = this.getFirstArgumentOrCallInstruction()
+  override Callable getInstructionFunction(InstructionTag tag) {
+    tag = CallTargetTag() and result = expr.getTarget()
   }
-}
 
-/**
- * The IR translation of a call to a function.
- */
-abstract class TranslatedCallExpr extends TranslatedNonConstantExpr, TranslatedCall {
-  override Call expr;
-
-  override Type getCallResultType() { result = this.getResultType() }
-
-  final override predicate hasArguments() { exists(expr.getArgument(0)) }
-
-  final override TranslatedExpr getQualifier() {
+  override predicate hasArguments() { 
+    exists(expr.getArgument(0)) 
+  }
+  
+  override TranslatedExpr getArgument(int index) {
+    result = getTranslatedExpr(expr.getArgument(index))
+  }
+  
+  override TranslatedExpr getQualifier() {
     expr instanceof QualifiableExpr and
     result = getTranslatedExpr(expr.(QualifiableExpr).getQualifier())
   }
-
-  final override TranslatedExpr getArgument(int index) {
-    result = getTranslatedExpr(expr.getArgument(index))
+  
+  override Instruction getQualifierResult() {
+    result = this.getQualifier().getResult()
   }
-}
-
-/**
- * Represents the IR translation of a direct function call.
- */
-class TranslatedFunctionCall extends TranslatedCallExpr, TranslatedDirectCall {
-  override Call expr;
-
-  override Callable getInstructionFunction(InstructionTag tag) {
-    tag = CallTargetTag() and result = expr.getTarget()
+  
+  override Type getCallResultType() { 
+    result = expr.getTarget().getReturnType()
   }
-
+  
   override predicate hasReadSideEffect() {
     not expr.getTarget().(SideEffectFunction).neverReadsMemory()
   }
@@ -276,26 +76,45 @@ class TranslatedFunctionCall extends TranslatedCallExpr, TranslatedDirectCall {
 }
 
 /**
- * Represents the IR translation of a call to a constructor.
- * The target of the call is a newly allocated object whose address, after
- * the constructor call, address will be passed to a variable declaration.
+ * Represents the IR translation of a call to a constructor or to a constructor initializer.
+ * The qualifier of the call is obtained from the constructor call context.
+ * Note that `DelegateCreation` is not present here, since the call to a delegate constructor is
+ * compiler generated.
  */
-class TranslatedConstructorCall extends TranslatedFunctionCall {
-  TranslatedConstructorCall() {
+class TranslatedConstructorCall extends TranslatedNonConstantExpr, TranslatedCall {
+  override Call expr;
+  
+  TranslatedConstructorCall() { 
     expr instanceof ObjectCreation or
     expr instanceof ConstructorInitializer
   }
 
+  override Callable getInstructionFunction(InstructionTag tag) {
+    tag = CallTargetTag() and result = expr.getTarget()
+  }
+  
+  override predicate hasArguments() { 
+    exists(expr.getArgument(0)) 
+  }
+  
+  override TranslatedExpr getArgument(int index) {
+    result = getTranslatedExpr(expr.getArgument(index))
+  }
+  
+  // The qualifier for a constructor call has already been generated
+  // (the `NewObj` instruction)
+  override TranslatedExpr getQualifier() {
+    none()
+  }
+  
+  override Type getCallResultType() { 
+    result instanceof VoidType
+  }
+  
   override Instruction getQualifierResult() {
-    // We must retrieve the qualifier from the context the
-    // constructor call happened
-    exists(StructorCallContext context |
+    exists(ConstructorCallContext context |
       context = this.getParent() and
       result = context.getReceiver()
     )
   }
-
-  override Type getCallResultType() { result instanceof VoidType }
-
-  override predicate hasQualifier() { any() }
 }