C++: Allow getInstructionFunction to yield a declaration

cpp/ql/lib/semmle/code/cpp/ir/dataflow/internal/DataFlowNodes.qll

@@ -878,7 +878,11 @@ module Public {
 
     /** Gets the parameter through which this value is assigned. */
     Parameter getParameter() {
-      result = this.getCallInstruction().getStaticCallTarget().getParameter(this.getArgumentIndex())
+      result =
+        this.getCallInstruction()
+            .getStaticCallTarget()
+            .(Function)
+            .getParameter(this.getArgumentIndex())
     }
   }
 

cpp/ql/lib/semmle/code/cpp/ir/dataflow/internal/SsaImplCommon.qll

@@ -175,7 +175,8 @@ private class PointerWrapperTypeIndirection extends Indirection instanceof Point
   override predicate isAdditionalDereference(Instruction deref, Operand address) {
     exists(CallInstruction call |
       operandForFullyConvertedCall(getAUse(deref), call) and
-      this = call.getStaticCallTarget().getClassAndName(["operator*", "operator->", "get"]) and
+      this =
+        call.getStaticCallTarget().(Function).getClassAndName(["operator*", "operator->", "get"]) and
       address = call.getThisArgumentOperand()
     )
   }
@@ -194,7 +195,7 @@ private module IteratorIndirections {
 
     override predicate isAdditionalWrite(Node0Impl value, Operand address, boolean certain) {
       exists(CallInstruction call | call.getArgumentOperand(0) = value.asOperand() |
-        this = call.getStaticCallTarget().getClassAndName("operator=") and
+        this = call.getStaticCallTarget().(Function).getClassAndName("operator=") and
         address = call.getThisArgumentOperand() and
         certain = false
       )

cpp/ql/lib/semmle/code/cpp/ir/implementation/aliased_ssa/Instruction.qll

@@ -495,7 +495,7 @@ class FieldInstruction extends Instruction {
  * `FunctionAddress` instruction.
  */
 class FunctionInstruction extends Instruction {
-  Language::Function funcSymbol;
+  Language::Declaration funcSymbol;
 
   FunctionInstruction() { funcSymbol = Raw::getInstructionFunction(this) }
 
@@ -504,7 +504,7 @@ class FunctionInstruction extends Instruction {
   /**
    * Gets the function that this instruction references.
    */
-  final Language::Function getFunctionSymbol() { result = funcSymbol }
+  final Language::Declaration getFunctionSymbol() { result = funcSymbol }
 }
 
 /**
@@ -1678,7 +1678,7 @@ class CallInstruction extends Instruction {
   /**
    * Gets the `Function` that the call targets, if this is statically known.
    */
-  final Language::Function getStaticCallTarget() {
+  final Language::Declaration getStaticCallTarget() {
     result = this.getCallTarget().(FunctionAddressInstruction).getFunctionSymbol()
   }
 

cpp/ql/lib/semmle/code/cpp/ir/implementation/raw/Instruction.qll

@@ -495,7 +495,7 @@ class FieldInstruction extends Instruction {
  * `FunctionAddress` instruction.
  */
 class FunctionInstruction extends Instruction {
-  Language::Function funcSymbol;
+  Language::Declaration funcSymbol;
 
   FunctionInstruction() { funcSymbol = Raw::getInstructionFunction(this) }
 
@@ -504,7 +504,7 @@ class FunctionInstruction extends Instruction {
   /**
    * Gets the function that this instruction references.
    */
-  final Language::Function getFunctionSymbol() { result = funcSymbol }
+  final Language::Declaration getFunctionSymbol() { result = funcSymbol }
 }
 
 /**
@@ -1678,7 +1678,7 @@ class CallInstruction extends Instruction {
   /**
    * Gets the `Function` that the call targets, if this is statically known.
    */
-  final Language::Function getStaticCallTarget() {
+  final Language::Declaration getStaticCallTarget() {
     result = this.getCallTarget().(FunctionAddressInstruction).getFunctionSymbol()
   }
 

cpp/ql/lib/semmle/code/cpp/ir/implementation/raw/internal/IRConstruction.qll

@@ -115,7 +115,7 @@ module Raw {
   }
 
   cached
-  Function getInstructionFunction(Instruction instruction) {
+  Declaration getInstructionFunction(Instruction instruction) {
     result =
       getInstructionTranslatedElement(instruction)
           .getInstructionFunction(getInstructionTag(instruction))

cpp/ql/lib/semmle/code/cpp/ir/implementation/raw/internal/TranslatedCall.qll

@@ -348,7 +348,7 @@ class TranslatedExprCall extends TranslatedCallExpr {
 class TranslatedFunctionCall extends TranslatedCallExpr, TranslatedDirectCall {
   override FunctionCall expr;
 
-  override Function getInstructionFunction(InstructionTag tag) {
+  override Declaration getInstructionFunction(InstructionTag tag) {
     tag = CallTargetTag() and result = expr.getTarget()
   }
 

cpp/ql/lib/semmle/code/cpp/ir/implementation/raw/internal/TranslatedElement.qll

@@ -1182,7 +1182,7 @@ abstract class TranslatedElement extends TTranslatedElement {
    * If the instruction specified by `tag` is a `FunctionInstruction`, gets the
    * `Function` for that instruction.
    */
-  Function getInstructionFunction(InstructionTag tag) { none() }
+  Declaration getInstructionFunction(InstructionTag tag) { none() }
 
   /**
    * If the instruction specified by `tag` is a `VariableInstruction`, gets the

cpp/ql/lib/semmle/code/cpp/ir/implementation/raw/internal/TranslatedExpr.qll

@@ -1264,7 +1264,7 @@ class TranslatedFunctionAccess extends TranslatedNonConstantExpr {
     resultType = this.getResultType()
   }
 
-  override Function getInstructionFunction(InstructionTag tag) {
+  override Declaration getInstructionFunction(InstructionTag tag) {
     tag = OnlyInstructionTag() and
     result = expr.getTarget()
   }
@@ -2547,7 +2547,7 @@ class TranslatedAllocatorCall extends TTranslatedAllocatorCall, TranslatedDirect
     any()
   }
 
-  override Function getInstructionFunction(InstructionTag tag) {
+  override Declaration getInstructionFunction(InstructionTag tag) {
     tag = CallTargetTag() and result = expr.getAllocator()
   }
 
@@ -2630,7 +2630,7 @@ class TranslatedDeleteOrDeleteArrayExpr extends TranslatedNonConstantExpr, Trans
     result = this.getFirstArgumentOrCallInstruction(kind)
   }
 
-  override Function getInstructionFunction(InstructionTag tag) {
+  override Declaration getInstructionFunction(InstructionTag tag) {
     tag = CallTargetTag() and result = expr.getDeallocator()
   }
 

cpp/ql/lib/semmle/code/cpp/ir/implementation/unaliased_ssa/Instruction.qll

@@ -495,7 +495,7 @@ class FieldInstruction extends Instruction {
  * `FunctionAddress` instruction.
  */
 class FunctionInstruction extends Instruction {
-  Language::Function funcSymbol;
+  Language::Declaration funcSymbol;
 
   FunctionInstruction() { funcSymbol = Raw::getInstructionFunction(this) }
 
@@ -504,7 +504,7 @@ class FunctionInstruction extends Instruction {
   /**
    * Gets the function that this instruction references.
    */
-  final Language::Function getFunctionSymbol() { result = funcSymbol }
+  final Language::Declaration getFunctionSymbol() { result = funcSymbol }
 }
 
 /**
@@ -1678,7 +1678,7 @@ class CallInstruction extends Instruction {
   /**
    * Gets the `Function` that the call targets, if this is statically known.
    */
-  final Language::Function getStaticCallTarget() {
+  final Language::Declaration getStaticCallTarget() {
     result = this.getCallTarget().(FunctionAddressInstruction).getFunctionSymbol()
   }