diff --git a/csharp/ql/lib/semmle/code/csharp/dataflow/internal/DataFlowDispatch.qll b/csharp/ql/lib/semmle/code/csharp/dataflow/internal/DataFlowDispatch.qll
index aa3fad909c5d7..8c15a3279e278 100644
--- a/csharp/ql/lib/semmle/code/csharp/dataflow/internal/DataFlowDispatch.qll
+++ b/csharp/ql/lib/semmle/code/csharp/dataflow/internal/DataFlowDispatch.qll
@@ -8,6 +8,7 @@ private import semmle.code.csharp.dispatch.Dispatch
 private import semmle.code.csharp.dispatch.RuntimeCallable
 private import semmle.code.csharp.frameworks.system.Collections
 private import semmle.code.csharp.frameworks.system.collections.Generic
+private import semmle.code.csharp.internal.Location
 
 /**
  * Gets a source declaration of callable `c` that has a body and is
@@ -24,6 +25,21 @@ newtype TReturnKind =
   TOutReturnKind(int i) { i = any(Parameter p | p.isOut()).getPosition() } or
   TRefReturnKind(int i) { i = any(Parameter p | p.isRef()).getPosition() }
 
+private predicate hasMultipleSourceLocations(Callable c) { strictcount(getASourceLocation(c)) > 1 }
+
+private module NearestBodyLocationInput implements NearestLocationInputSig {
+  class C = ControlFlowElement;
+
+  predicate relevantLocations(ControlFlowElement body, Location l1, Location l2) {
+    exists(Callable c |
+      hasMultipleSourceLocations(c) and
+      l1 = getASourceLocation(c) and
+      body = c.getBody() and
+      l2 = body.getLocation()
+    )
+  }
+}
+
 cached
 private module Cached {
   /**
@@ -33,7 +49,18 @@ private module Cached {
    */
   cached
   newtype TDataFlowCallable =
-    TCallable(Callable c) { c.isUnboundDeclaration() } or
+    TCallable(Callable c, Location l) {
+      c.isUnboundDeclaration() and
+      l = [c.getLocation(), getASourceLocation(c)] and
+      (
+        not hasMultipleSourceLocations(c)
+        or
+        // when `c` has multiple source locations, only use those with a body;
+        // for example, `partial` methods may have multiple source locations but
+        // we are only interested in the one with a body
+        NearestLocation<NearestBodyLocationInput>::nearestLocation(_, l, _)
+      )
+    } or
     TSummarizedCallable(FlowSummary::SummarizedCallable sc) or
     TFieldOrPropertyCallable(FieldOrProperty f) or
     TCapturedVariableCallable(LocalScopeVariable v) { v.isCaptured() }
@@ -82,17 +109,23 @@ private module DispatchImpl {
    */
   predicate mayBenefitFromCallContext(DataFlowCall call) { mayBenefitFromCallContext(call, _) }
 
+  bindingset[dc, result]
+  pragma[inline_late]
+  private Callable viableImplInCallContext0(DispatchCall dc, NonDelegateDataFlowCall ctx) {
+    result = dc.getADynamicTargetInCallContext(ctx.getDispatchCall()).getUnboundDeclaration()
+  }
+
   /**
    * Gets a viable dispatch target of `call` in the context `ctx`. This is
    * restricted to those `call`s for which a context might make a difference.
    */
   DataFlowCallable viableImplInCallContext(DataFlowCall call, DataFlowCall ctx) {
-    exists(DispatchCall dc | dc = call.(NonDelegateDataFlowCall).getDispatchCall() |
-      result.getUnderlyingCallable() =
-        getCallableForDataFlow(dc.getADynamicTargetInCallContext(ctx.(NonDelegateDataFlowCall)
-                .getDispatchCall()).getUnboundDeclaration())
+    exists(DispatchCall dc, Callable c | dc = call.(NonDelegateDataFlowCall).getDispatchCall() |
+      result = call.getARuntimeTarget() and
+      getCallableForDataFlow(c) = result.asCallable(_) and
+      c = viableImplInCallContext0(dc, ctx)
       or
-      exists(Callable c, DataFlowCallable encl |
+      exists(DataFlowCallable encl |
         result.asSummarizedCallable() = c and
         mayBenefitFromCallContext(call, encl) and
         encl = ctx.getARuntimeTarget() and
@@ -159,7 +192,51 @@ class RefReturnKind extends OutRefReturnKind, TRefReturnKind {
 /** A callable used for data flow. */
 class DataFlowCallable extends TDataFlowCallable {
   /** Gets the underlying source code callable, if any. */
-  Callable asCallable() { this = TCallable(result) }
+  Callable asCallable(Location l) { this = TCallable(result, l) }
+
+  /** Holds if this callable is multi-bodied. */
+  pragma[nomagic]
+  predicate isMultiBodied() { hasMultipleSourceLocations(this.asCallable(_)) }
+
+  private ControlFlow::Nodes::ElementNode getAMultiBodyEntryNode() {
+    exists(ControlFlowElement body, Location l |
+      body = this.asCallable(l).getBody() and
+      NearestLocation<NearestBodyLocationInput>::nearestLocation(body, l, _) and
+      result = body.getAControlFlowEntryNode()
+    )
+  }
+
+  pragma[nomagic]
+  private ControlFlow::Nodes::ElementNode getAMultiBodyControlFlowNodePred() {
+    result = this.getAMultiBodyEntryNode().getAPredecessor()
+    or
+    result = this.getAMultiBodyControlFlowNodePred().getAPredecessor()
+  }
+
+  pragma[nomagic]
+  private ControlFlow::Nodes::ElementNode getAMultiBodyControlFlowNodeSucc() {
+    result = this.getAMultiBodyEntryNode().getASuccessor()
+    or
+    result = this.getAMultiBodyControlFlowNodeSucc().getASuccessor()
+  }
+
+  pragma[nomagic]
+  private ControlFlow::Nodes::ElementNode getAMultiBodyControlFlowNode() {
+    result =
+      [
+        this.getAMultiBodyEntryNode(), this.getAMultiBodyControlFlowNodePred(),
+        this.getAMultiBodyControlFlowNodeSucc()
+      ]
+  }
+
+  /** Gets a control flow node belonging to this callable. */
+  pragma[inline]
+  ControlFlow::Node getAControlFlowNode() {
+    result = this.getAMultiBodyControlFlowNode()
+    or
+    not this.isMultiBodied() and
+    result.getEnclosingCallable() = this.asCallable(_)
+  }
 
   /** Gets the underlying summarized callable, if any. */
   FlowSummary::SummarizedCallable asSummarizedCallable() { this = TSummarizedCallable(result) }
@@ -171,7 +248,7 @@ class DataFlowCallable extends TDataFlowCallable {
 
   /** Gets the underlying callable. */
   Callable getUnderlyingCallable() {
-    result = this.asCallable() or result = this.asSummarizedCallable()
+    result = this.asCallable(_) or result = this.asSummarizedCallable()
   }
 
   /** Gets a textual representation of this dataflow callable. */
@@ -185,7 +262,9 @@ class DataFlowCallable extends TDataFlowCallable {
 
   /** Get the location of this dataflow callable. */
   Location getLocation() {
-    result = this.getUnderlyingCallable().getLocation()
+    this = TCallable(_, result)
+    or
+    result = this.asSummarizedCallable().getLocation()
     or
     result = this.asFieldOrProperty().getLocation()
     or
@@ -256,6 +335,26 @@ abstract class DataFlowCall extends TDataFlowCall {
   }
 }
 
+private predicate relevantFolder(Folder f) {
+  exists(NonDelegateDataFlowCall call, Location l | f = l.getFile().getParentContainer() |
+    l = call.getLocation() and
+    call.getARuntimeTargetCandidate(_, _).isMultiBodied()
+    or
+    call.getARuntimeTargetCandidate(l, _).isMultiBodied()
+  )
+}
+
+private predicate adjacentFolders(Folder f1, Folder f2) {
+  f1 = f2.getParentContainer()
+  or
+  f2 = f1.getParentContainer()
+}
+
+bindingset[f1, f2]
+pragma[inline_late]
+private predicate folderDist(Folder f1, Folder f2, int i) =
+  shortestDistances(relevantFolder/1, adjacentFolders/2)(f1, f2, i)
+
 /** A non-delegate C# call relevant for data flow. */
 class NonDelegateDataFlowCall extends DataFlowCall, TNonDelegateCall {
   private ControlFlow::Nodes::ElementNode cfn;
@@ -266,25 +365,63 @@ class NonDelegateDataFlowCall extends DataFlowCall, TNonDelegateCall {
   /** Gets the underlying call. */
   DispatchCall getDispatchCall() { result = dc }
 
-  override DataFlowCallable getARuntimeTarget() {
-    result.asCallable() = getCallableForDataFlow(dc.getADynamicTarget())
-    or
+  pragma[nomagic]
+  private predicate hasSourceTarget() { dc.getADynamicTarget().fromSource() }
+
+  pragma[nomagic]
+  private FlowSummary::SummarizedCallable getASummarizedCallableTarget() {
     // Only use summarized callables with generated summaries in case
     // we are not able to dispatch to a source declaration.
-    exists(FlowSummary::SummarizedCallable sc, boolean static |
-      result.asSummarizedCallable() = sc and
-      sc = this.getATarget(static) and
+    exists(boolean static |
+      result = this.getATarget(static) and
       not (
-        sc.applyGeneratedModel() and
-        dc.getADynamicTarget().getUnboundDeclaration().getFile().fromSource()
+        result.applyGeneratedModel() and
+        this.hasSourceTarget()
       )
     |
       static = false
       or
-      static = true and not sc instanceof RuntimeCallable
+      static = true and not result instanceof RuntimeCallable
     )
   }
 
+  pragma[nomagic]
+  DataFlowCallable getARuntimeTargetCandidate(Location l, Callable c) {
+    c = result.asCallable(l) and
+    c = getCallableForDataFlow(dc.getADynamicTarget())
+  }
+
+  pragma[nomagic]
+  private DataFlowCallable getAMultiBodiedRuntimeTargetCandidate(Callable c, int distance) {
+    result.isMultiBodied() and
+    exists(Location l | result = this.getARuntimeTargetCandidate(l, c) |
+      inSameFile(l, this.getLocation()) and
+      distance = -1
+      or
+      folderDist(l.getFile().getParentContainer(),
+        this.getLocation().getFile().getParentContainer(), distance)
+    )
+  }
+
+  pragma[nomagic]
+  override DataFlowCallable getARuntimeTarget() {
+    // For calls to multi-bodied methods, we restrict the viable targets to those
+    // that are closest to the callsite, measured by file-system distance.
+    exists(Callable c |
+      result =
+        min(DataFlowCallable cand, int distance |
+          cand = this.getAMultiBodiedRuntimeTargetCandidate(c, distance)
+        |
+          cand order by distance
+        )
+    )
+    or
+    result = this.getARuntimeTargetCandidate(_, _) and
+    not result.isMultiBodied()
+    or
+    result.asSummarizedCallable() = this.getASummarizedCallableTarget()
+  }
+
   /** Gets a static or dynamic target of this call. */
   Callable getATarget(boolean static) {
     result = dc.getADynamicTarget().getUnboundDeclaration() and static = false
@@ -296,9 +433,7 @@ class NonDelegateDataFlowCall extends DataFlowCall, TNonDelegateCall {
 
   override DataFlow::ExprNode getNode() { result.getControlFlowNode() = cfn }
 
-  override DataFlowCallable getEnclosingCallable() {
-    result.asCallable() = cfn.getEnclosingCallable()
-  }
+  override DataFlowCallable getEnclosingCallable() { result.getAControlFlowNode() = cfn }
 
   override string toString() { result = cfn.toString() }
 
@@ -326,9 +461,7 @@ class ExplicitDelegateLikeDataFlowCall extends DelegateDataFlowCall, TExplicitDe
 
   override DataFlow::ExprNode getNode() { result.getControlFlowNode() = cfn }
 
-  override DataFlowCallable getEnclosingCallable() {
-    result.asCallable() = cfn.getEnclosingCallable()
-  }
+  override DataFlowCallable getEnclosingCallable() { result.getAControlFlowNode() = cfn }
 
   override string toString() { result = cfn.toString() }
 
diff --git a/csharp/ql/lib/semmle/code/csharp/dataflow/internal/DataFlowPrivate.qll b/csharp/ql/lib/semmle/code/csharp/dataflow/internal/DataFlowPrivate.qll
index b32fb5ffb38df..040ce64467fc8 100644
--- a/csharp/ql/lib/semmle/code/csharp/dataflow/internal/DataFlowPrivate.qll
+++ b/csharp/ql/lib/semmle/code/csharp/dataflow/internal/DataFlowPrivate.qll
@@ -17,6 +17,7 @@ private import semmle.code.csharp.frameworks.NHibernate
 private import semmle.code.csharp.frameworks.Razor
 private import semmle.code.csharp.frameworks.system.Collections
 private import semmle.code.csharp.frameworks.system.threading.Tasks
+private import semmle.code.csharp.internal.Location
 private import codeql.util.Unit
 private import codeql.util.Boolean
 
@@ -94,7 +95,7 @@ private DataFlowCallable getEnclosingStaticFieldOrProperty(Expr e) {
 
 private class ExprNodeImpl extends ExprNode, NodeImpl {
   override DataFlowCallable getEnclosingCallableImpl() {
-    result.asCallable() = this.getControlFlowNodeImpl().getEnclosingCallable()
+    result.getAControlFlowNode() = this.getControlFlowNodeImpl()
     or
     result = getEnclosingStaticFieldOrProperty(this.asExpr())
   }
@@ -143,9 +144,7 @@ abstract private class LocalFunctionCreationNode extends NodeImpl, TLocalFunctio
     else inSameCallable = false
   }
 
-  override DataFlowCallable getEnclosingCallableImpl() {
-    result.asCallable() = cfn.getEnclosingCallable()
-  }
+  override DataFlowCallable getEnclosingCallableImpl() { result.getAControlFlowNode() = cfn }
 
   override Type getTypeImpl() { none() }
 
@@ -173,8 +172,6 @@ private module ThisFlow {
 
   /** Holds if `n` is a `this` access at control flow node `cfn`. */
   private predicate thisAccess(Node n, ControlFlow::Node cfn) {
-    n.(InstanceParameterNode).getCallable() = cfn.(ControlFlow::Nodes::EntryNode).getCallable()
-    or
     thisAccessExpr(n.asExprAtNode(cfn))
     or
     cfn = n.(InstanceParameterAccessPreNode).getUnderlyingControlFlowNode()
@@ -187,6 +184,20 @@ private module ThisFlow {
       bb.getCallable() = p.getCallable() and
       i = p.getPosition() + 1
     )
+    or
+    exists(DataFlowCallable c, ControlFlow::BasicBlocks::EntryBlock entry |
+      n.(InstanceParameterNode).isParameterOf(c, _) and
+      exists(ControlFlow::Node succ |
+        succ = c.getAControlFlowNode() and
+        succ = entry.getFirstNode().getASuccessor() and
+        // In case `c` has multiple bodies, we want each body to gets its own implicit
+        // entry definition. In case `c` doesn't have multiple bodies, the line below
+        // is simply the same as `bb = entry`, because `entry.getFirstNode().getASuccessor()`
+        // will be in the entry block.
+        bb = succ.getBasicBlock() and
+        i = -1
+      )
+    )
   }
 
   private predicate thisRank(Node n, BasicBlock bb, int rankix) {
@@ -339,7 +350,7 @@ module VariableCapture {
 
     private class CapturedThisParameter extends CapturedParameter, TCapturedThis {
       override InstanceParameterNode getParameterNode() {
-        result = TInstanceParameterNode(this.asThis())
+        result = TInstanceParameterNode(this.asThis(), _)
       }
     }
 
@@ -772,11 +783,12 @@ module LocalFlow {
    * Holds if the value of `node2` is given by `node1`.
    */
   predicate localMustFlowStep(Node node1, Node node2) {
-    exists(Callable c, Expr e |
-      node1.(InstanceParameterNode).getCallable() = c and
-      node2.asExpr() = e and
-      (e instanceof ThisAccess or e instanceof BaseAccess) and
-      c = e.getEnclosingCallable()
+    exists(DataFlowCallable c, Expr e |
+      node1.(InstanceParameterNode).getEnclosingCallableImpl() = c and
+      node2.getControlFlowNode() = c.getAControlFlowNode() and
+      node2.asExpr() = e
+    |
+      e instanceof ThisAccess or e instanceof BaseAccess
     )
     or
     hasNodePath(any(LocalExprStepConfiguration x), node1, node2) and
@@ -1066,14 +1078,18 @@ private Gvn::GvnType getANonTypeParameterSubTypeRestricted(RelevantGvnType t) {
 
 /** A callable with an implicit `this` parameter. */
 private class InstanceCallable extends Callable {
+  private Location l;
+
   InstanceCallable() {
-    this = any(DataFlowCallable dfc).asCallable() and
+    this = any(DataFlowCallable dfc).asCallable(l) and
     not this.(Modifiable).isStatic() and
     // local functions and delegate capture `this` and should therefore
     // not have a `this` parameter
     not this instanceof LocalFunction and
     not this instanceof AnonymousFunctionExpr
   }
+
+  Location getARelevantLocation() { result = l }
 }
 
 /** A collection of cached types and predicates to be evaluated in the same stage. */
@@ -1097,15 +1113,14 @@ private module Cached {
     TExprNode(ControlFlow::Nodes::ElementNode cfn) { cfn.getAstNode() instanceof Expr } or
     TSsaDefinitionExtNode(SsaImpl::DefinitionExt def) {
       // Handled by `TExplicitParameterNode` below
-      not def instanceof Ssa::ImplicitParameterDefinition
+      not def instanceof Ssa::ImplicitParameterDefinition and
+      def.getBasicBlock() = any(DataFlowCallable c).getAControlFlowNode().getBasicBlock()
     } or
     TAssignableDefinitionNode(AssignableDefinition def, ControlFlow::Node cfn) {
       cfn = def.getExpr().getAControlFlowNode()
     } or
-    TExplicitParameterNode(Parameter p) {
-      p = any(DataFlowCallable dfc).asCallable().getAParameter()
-    } or
-    TInstanceParameterNode(InstanceCallable c) or
+    TExplicitParameterNode(Parameter p, DataFlowCallable c) { p = c.asCallable(_).getAParameter() } or
+    TInstanceParameterNode(InstanceCallable c, Location l) { l = c.getARelevantLocation() } or
     TDelegateSelfReferenceNode(Callable c) { lambdaCreationExpr(_, c) } or
     TLocalFunctionCreationNode(ControlFlow::Nodes::ElementNode cfn, Boolean isPostUpdate) {
       cfn.getAstNode() instanceof LocalFunctionStmt
@@ -1150,8 +1165,8 @@ private module Cached {
     TInstanceParameterAccessNode(ControlFlow::Node cfn, Boolean isPostUpdate) {
       cfn = getAPrimaryConstructorParameterCfn(_)
     } or
-    TPrimaryConstructorThisAccessNode(Parameter p, Boolean isPostUpdate) {
-      p.getCallable() instanceof PrimaryConstructor
+    TPrimaryConstructorThisAccessNode(Parameter p, Boolean isPostUpdate, DataFlowCallable c) {
+      p = c.asCallable(_).(PrimaryConstructor).getAParameter()
     } or
     TCaptureNode(VariableCapture::Flow::SynthesizedCaptureNode cn)
 
@@ -1244,7 +1259,7 @@ predicate nodeIsHidden(Node n) {
   n =
     TInstanceParameterNode(any(Callable c |
         not c.fromSource() or c instanceof FlowSummary::SummarizedCallable
-      ))
+      ), _)
   or
   n instanceof YieldReturnNode
   or
@@ -1281,7 +1296,7 @@ class SsaDefinitionExtNode extends NodeImpl, TSsaDefinitionExtNode {
   SsaImpl::DefinitionExt getDefinitionExt() { result = def }
 
   override DataFlowCallable getEnclosingCallableImpl() {
-    result.asCallable() = def.getEnclosingCallable()
+    result.getAControlFlowNode().getBasicBlock() = def.getBasicBlock()
   }
 
   override Type getTypeImpl() { result = def.getSourceVariable().getType() }
@@ -1311,9 +1326,7 @@ class AssignableDefinitionNodeImpl extends NodeImpl, TAssignableDefinitionNode {
     cfn = cfn_
   }
 
-  override DataFlowCallable getEnclosingCallableImpl() {
-    result.asCallable() = cfn_.getEnclosingCallable()
-  }
+  override DataFlowCallable getEnclosingCallableImpl() { result.getAControlFlowNode() = cfn_ }
 
   override Type getTypeImpl() { result = def.getTarget().getType() }
 
@@ -1336,32 +1349,93 @@ abstract class ParameterNodeImpl extends NodeImpl {
   abstract predicate isParameterOf(DataFlowCallable c, ParameterPosition pos);
 }
 
+private module NearestLocationInputParamAfterCallable implements NearestLocationInputSig {
+  class C = Parameter;
+
+  predicate relevantLocations(Parameter p, Location l1, Location l2) {
+    exists(DataFlowCallable c |
+      c.asCallable(l1).getParameter(_) = p and
+      l2 = [p.getLocation(), getASourceLocation(p)]
+    )
+  }
+}
+
 private module ParameterNodes {
+  pragma[nomagic]
+  private predicate ssaParamDef(Ssa::ImplicitParameterDefinition ssaDef, Parameter p, Location l) {
+    p = ssaDef.getParameter() and
+    l = ssaDef.getLocation()
+  }
+
+  private module NearestLocationInputParamBeforeCallable implements NearestLocationInputSig {
+    class C = Parameter;
+
+    predicate relevantLocations(Parameter p, Location l1, Location l2) {
+      exists(DataFlowCallable c |
+        c.asCallable(l2).getParameter(_) = p and
+        l1 = [p.getLocation(), getASourceLocation(p)]
+      )
+    }
+  }
+
   /**
    * The value of an explicit parameter at function entry, viewed as a node in a data
    * flow graph.
    */
   class ExplicitParameterNode extends ParameterNodeImpl, TExplicitParameterNode {
     private Parameter parameter;
+    private DataFlowCallable callable;
+
+    ExplicitParameterNode() { this = TExplicitParameterNode(parameter, callable) }
 
-    ExplicitParameterNode() { this = TExplicitParameterNode(parameter) }
+    Parameter getParameter() { result = parameter }
+
+    pragma[nomagic]
+    private Location getNearestParameterLocation() {
+      exists(Location cloc | exists(callable.asCallable(cloc)) |
+        // typical scenario: parameter is syntactically after the callable
+        NearestLocation<NearestLocationInputParamAfterCallable>::nearestLocation(parameter, cloc,
+          result)
+        or
+        // atypical scenario: parameter is syntactically before the callable, for example
+        // `int this[int x] { get => x }`, where the parameter `x` is syntactically
+        // before the the callable `get_Item`
+        NearestLocation<NearestLocationInputParamBeforeCallable>::nearestLocation(parameter, result,
+          cloc)
+      )
+    }
+
+    pragma[nomagic]
+    private Location getParameterLocation(Parameter p) {
+      p = parameter and
+      (
+        result = this.getNearestParameterLocation()
+        or
+        not exists(this.getNearestParameterLocation()) and
+        result = parameter.getLocation()
+      )
+    }
 
     /** Gets the SSA definition corresponding to this parameter, if any. */
-    Ssa::ImplicitParameterDefinition getSsaDefinition() { result.getParameter() = parameter }
+    Ssa::ImplicitParameterDefinition getSsaDefinition() {
+      exists(Parameter p, Location l |
+        l = this.getParameterLocation(p) and
+        ssaParamDef(result, p, l)
+      )
+    }
 
     override predicate isParameterOf(DataFlowCallable c, ParameterPosition pos) {
-      c.asCallable().getParameter(pos.getPosition()) = parameter
+      c = callable and
+      c.asCallable(_).getParameter(pos.getPosition()) = parameter
     }
 
-    override DataFlowCallable getEnclosingCallableImpl() {
-      result.asCallable() = parameter.getCallable()
-    }
+    override DataFlowCallable getEnclosingCallableImpl() { this.isParameterOf(result, _) }
 
     override Type getTypeImpl() { result = parameter.getType() }
 
     override ControlFlow::Node getControlFlowNodeImpl() { none() }
 
-    override Location getLocationImpl() { result = parameter.getLocation() }
+    override Location getLocationImpl() { result = this.getParameterLocation(_) }
 
     override string toStringImpl() { result = parameter.toString() }
   }
@@ -1369,23 +1443,24 @@ private module ParameterNodes {
   /** An implicit instance (`this`) parameter. */
   class InstanceParameterNode extends ParameterNodeImpl, TInstanceParameterNode {
     private Callable callable;
+    private Location location;
 
-    InstanceParameterNode() { this = TInstanceParameterNode(callable) }
+    InstanceParameterNode() { this = TInstanceParameterNode(callable, location) }
 
     /** Gets the callable containing this implicit instance parameter. */
-    Callable getCallable() { result = callable }
+    Callable getCallable(Location loc) { result = callable and location = loc }
 
     override predicate isParameterOf(DataFlowCallable c, ParameterPosition pos) {
-      callable = c.asCallable() and pos.isThisParameter()
+      callable = c.asCallable(location) and pos.isThisParameter()
     }
 
-    override DataFlowCallable getEnclosingCallableImpl() { result.asCallable() = callable }
+    override DataFlowCallable getEnclosingCallableImpl() { result.asCallable(location) = callable }
 
     override Type getTypeImpl() { result = callable.getDeclaringType() }
 
     override ControlFlow::Node getControlFlowNodeImpl() { none() }
 
-    override Location getLocationImpl() { result = callable.getLocation() }
+    override Location getLocationImpl() { result = location }
 
     override string toStringImpl() { result = "this" }
   }
@@ -1405,12 +1480,12 @@ private module ParameterNodes {
     final Callable getCallable() { result = callable }
 
     override predicate isParameterOf(DataFlowCallable c, ParameterPosition pos) {
-      callable = c.asCallable() and pos.isDelegateSelf()
+      callable = c.asCallable(_) and pos.isDelegateSelf()
     }
 
     override ControlFlow::Node getControlFlowNodeImpl() { none() }
 
-    override DataFlowCallable getEnclosingCallableImpl() { result.asCallable() = callable }
+    override DataFlowCallable getEnclosingCallableImpl() { result.asCallable(_) = callable }
 
     override Location getLocationImpl() { result = callable.getLocation() }
 
@@ -1524,7 +1599,7 @@ private module ArgumentNodes {
     override ControlFlow::Node getControlFlowNodeImpl() { result = cfn }
 
     override DataFlowCallable getEnclosingCallableImpl() {
-      result.asCallable() = cfn.getEnclosingCallable()
+      result.getAControlFlowNode() = cfn
       or
       result = getEnclosingStaticFieldOrProperty(cfn.getAstNode())
     }
@@ -1565,7 +1640,7 @@ private module ArgumentNodes {
     }
 
     override DataFlowCallable getEnclosingCallableImpl() {
-      result.asCallable() = callCfn.getEnclosingCallable()
+      result.getAControlFlowNode() = callCfn
       or
       result = getEnclosingStaticFieldOrProperty(callCfn.getAstNode())
     }
@@ -1652,9 +1727,7 @@ private module ReturnNodes {
 
     override NormalReturnKind getKind() { any() }
 
-    override DataFlowCallable getEnclosingCallableImpl() {
-      result.asCallable() = yrs.getEnclosingCallable()
-    }
+    override DataFlowCallable getEnclosingCallableImpl() { result.getAControlFlowNode() = cfn }
 
     override Type getTypeImpl() { result = yrs.getEnclosingCallable().getReturnType() }
 
@@ -1678,9 +1751,7 @@ private module ReturnNodes {
 
     override NormalReturnKind getKind() { any() }
 
-    override DataFlowCallable getEnclosingCallableImpl() {
-      result.asCallable() = expr.getEnclosingCallable()
-    }
+    override DataFlowCallable getEnclosingCallableImpl() { result.getAControlFlowNode() = cfn }
 
     override Type getTypeImpl() { result = expr.getEnclosingCallable().getReturnType() }
 
@@ -1865,9 +1936,7 @@ abstract private class InstanceParameterAccessNode extends NodeImpl, TInstancePa
     exists(ParameterAccess pa | cfn = getAPrimaryConstructorParameterCfn(pa) and pa.getTarget() = p)
   }
 
-  override DataFlowCallable getEnclosingCallableImpl() {
-    result.asCallable() = cfn.getEnclosingCallable()
-  }
+  override DataFlowCallable getEnclosingCallableImpl() { result.getAControlFlowNode() = cfn }
 
   override Type getTypeImpl() { result = cfn.getEnclosingCallable().getDeclaringType() }
 
@@ -1910,16 +1979,22 @@ abstract private class PrimaryConstructorThisAccessNode extends NodeImpl,
 {
   Parameter p;
   boolean isPostUpdate;
+  DataFlowCallable callable;
 
-  PrimaryConstructorThisAccessNode() { this = TPrimaryConstructorThisAccessNode(p, isPostUpdate) }
+  PrimaryConstructorThisAccessNode() {
+    this = TPrimaryConstructorThisAccessNode(p, isPostUpdate, callable)
+  }
 
-  override DataFlowCallable getEnclosingCallableImpl() { result.asCallable() = p.getCallable() }
+  override DataFlowCallable getEnclosingCallableImpl() { result = callable }
 
   override Type getTypeImpl() { result = p.getCallable().getDeclaringType() }
 
   override ControlFlow::Nodes::ElementNode getControlFlowNodeImpl() { none() }
 
-  override Location getLocationImpl() { result = p.getLocation() }
+  override Location getLocationImpl() {
+    NearestLocation<NearestLocationInputParamAfterCallable>::nearestLocation(p,
+      callable.getLocation(), result)
+  }
 
   override string toStringImpl() { result = "this" }
 
@@ -1952,7 +2027,7 @@ class CaptureNode extends NodeImpl, TCaptureNode {
   VariableCapture::Flow::SynthesizedCaptureNode getSynthesizedCaptureNode() { result = cn }
 
   override DataFlowCallable getEnclosingCallableImpl() {
-    result.asCallable() = cn.getEnclosingCallable()
+    result.getAControlFlowNode().getBasicBlock() = cn.getBasicBlock()
   }
 
   override Type getTypeImpl() {
@@ -2186,9 +2261,9 @@ predicate storeStep(Node node1, ContentSet c, Node node2) {
   or
   primaryConstructorParameterStore(node1, c, node2)
   or
-  exists(Parameter p |
-    node1 = TExplicitParameterNode(p) and
-    node2 = TPrimaryConstructorThisAccessNode(p, true) and
+  exists(Parameter p, DataFlowCallable callable |
+    node1 = TExplicitParameterNode(p, callable) and
+    node2 = TPrimaryConstructorThisAccessNode(p, true, callable) and
     if p.getCallable().getDeclaringType() instanceof RecordType
     then c.(PropertyContent).getProperty().getName() = p.getName()
     else c.(PrimaryConstructorParameterContent).getParameter() = p
@@ -2603,7 +2678,7 @@ module PostUpdateNodes {
     }
 
     override DataFlowCallable getEnclosingCallableImpl() {
-      result.asCallable() = cfn.getEnclosingCallable()
+      result.getAControlFlowNode() = cfn
       or
       result = getEnclosingStaticFieldOrProperty(oc)
     }
@@ -2636,7 +2711,7 @@ module PostUpdateNodes {
     }
 
     override DataFlowCallable getEnclosingCallableImpl() {
-      result.asCallable() = cfn.getEnclosingCallable()
+      result.getAControlFlowNode() = cfn
       or
       result = getEnclosingStaticFieldOrProperty(cfn.getAstNode())
     }
@@ -2679,7 +2754,7 @@ module PostUpdateNodes {
     PrimaryConstructorThisAccessPostUpdateNode() { isPostUpdate = true }
 
     override PrimaryConstructorThisAccessPreNode getPreUpdateNode() {
-      result = TPrimaryConstructorThisAccessNode(p, false)
+      result = TPrimaryConstructorThisAccessNode(p, false, callable)
     }
 
     override string toStringImpl() { result = "[post] this" }
@@ -2774,7 +2849,7 @@ class LambdaCallKind = Unit;
 
 /** Holds if `creation` is an expression that creates a delegate for `c`. */
 predicate lambdaCreation(Node creation, LambdaCallKind kind, DataFlowCallable c) {
-  lambdaCreationExpr(creation.asExpr(), c.asCallable()) and
+  lambdaCreationExpr(creation.asExpr(), c.asCallable(_)) and
   exists(kind)
 }
 
diff --git a/csharp/ql/lib/semmle/code/csharp/dataflow/internal/DataFlowPublic.qll b/csharp/ql/lib/semmle/code/csharp/dataflow/internal/DataFlowPublic.qll
index 20e3dd8eb7d00..4d1dc25f6e995 100644
--- a/csharp/ql/lib/semmle/code/csharp/dataflow/internal/DataFlowPublic.qll
+++ b/csharp/ql/lib/semmle/code/csharp/dataflow/internal/DataFlowPublic.qll
@@ -39,7 +39,7 @@ class Node extends TNode {
 
   /** Gets the enclosing callable of this node. */
   final Callable getEnclosingCallable() {
-    result = this.(NodeImpl).getEnclosingCallableImpl().asCallable()
+    result = this.(NodeImpl).getEnclosingCallableImpl().asCallable(_)
   }
 
   /** Gets the control flow node corresponding to this node, if any. */
@@ -88,7 +88,7 @@ class ExprNode extends Node, TExprNode {
 
 pragma[nomagic]
 private predicate isParameterOf0(DataFlowCallable c, ParameterPosition ppos, Parameter p) {
-  p.getCallable() = c.asCallable() and
+  p.getCallable() = c.asCallable(_) and
   p.getPosition() = ppos.getPosition()
 }
 
diff --git a/csharp/ql/lib/semmle/code/csharp/exprs/Call.qll b/csharp/ql/lib/semmle/code/csharp/exprs/Call.qll
index 7a3cf0ea8d935..be4577d760eb1 100644
--- a/csharp/ql/lib/semmle/code/csharp/exprs/Call.qll
+++ b/csharp/ql/lib/semmle/code/csharp/exprs/Call.qll
@@ -528,7 +528,7 @@ class DelegateLikeCall extends Call, DelegateLikeCall_ {
   final override Callable getARuntimeTarget() {
     exists(ExplicitDelegateLikeDataFlowCall call |
       this = call.getCall() and
-      result = viableCallableLambda(call, _).asCallable()
+      result = viableCallableLambda(call, _).asCallable(_)
     )
   }
 
diff --git a/csharp/ql/src/utils/modelgenerator/internal/CaptureModelsSpecific.qll b/csharp/ql/src/utils/modelgenerator/internal/CaptureModelsSpecific.qll
index 29df13ccbd79a..9d13666816658 100644
--- a/csharp/ql/src/utils/modelgenerator/internal/CaptureModelsSpecific.qll
+++ b/csharp/ql/src/utils/modelgenerator/internal/CaptureModelsSpecific.qll
@@ -238,7 +238,7 @@ string paramReturnNodeAsOutput(CS::Callable c, ParameterPosition pos) {
  * Gets the enclosing callable of `ret`.
  */
 Callable returnNodeEnclosingCallable(DataFlow::Node ret) {
-  result = DataFlowImplCommon::getNodeEnclosingCallable(ret).asCallable()
+  result = DataFlowImplCommon::getNodeEnclosingCallable(ret).asCallable(_)
 }
 
 /**
diff --git a/csharp/ql/test/library-tests/dataflow/global/DataFlowPath.expected b/csharp/ql/test/library-tests/dataflow/global/DataFlowPath.expected
index 9b8f7aa390a82..096865964efa8 100644
--- a/csharp/ql/test/library-tests/dataflow/global/DataFlowPath.expected
+++ b/csharp/ql/test/library-tests/dataflow/global/DataFlowPath.expected
@@ -453,8 +453,8 @@ edges
 | GlobalDataFlow.cs:558:46:558:46 | access to local variable x : String | GlobalDataFlow.cs:558:44:558:47 | delegate call : String | provenance |  |
 | MultiImplementationA.cs:5:28:5:41 | "taint source" : String | MultiImplementationA.cs:7:27:7:27 | x : String | provenance |  |
 | MultiImplementationA.cs:7:27:7:27 | x : String | MultiImplementationA.cs:7:39:7:39 | access to parameter x | provenance |  |
-| MultiImplementationA.cs:7:27:7:27 | x : String | MultiImplementationB.cs:5:39:5:39 | access to parameter x | provenance |  |
-| MultiImplementationB.cs:3:28:3:41 | "taint source" : String | MultiImplementationA.cs:7:27:7:27 | x : String | provenance |  |
+| MultiImplementationB.cs:3:28:3:41 | "taint source" : String | MultiImplementationB.cs:5:27:5:27 | x : String | provenance |  |
+| MultiImplementationB.cs:5:27:5:27 | x : String | MultiImplementationB.cs:5:39:5:39 | access to parameter x | provenance |  |
 | Splitting.cs:3:28:3:34 | tainted : String | Splitting.cs:8:24:8:30 | [b (line 3): false] access to parameter tainted : String | provenance |  |
 | Splitting.cs:3:28:3:34 | tainted : String | Splitting.cs:8:24:8:30 | [b (line 3): true] access to parameter tainted : String | provenance |  |
 | Splitting.cs:8:13:8:13 | access to local variable x : String | Splitting.cs:9:15:9:15 | [b (line 3): false] access to local variable x | provenance |  |
@@ -912,6 +912,7 @@ nodes
 | MultiImplementationA.cs:7:27:7:27 | x : String | semmle.label | x : String |
 | MultiImplementationA.cs:7:39:7:39 | access to parameter x | semmle.label | access to parameter x |
 | MultiImplementationB.cs:3:28:3:41 | "taint source" : String | semmle.label | "taint source" : String |
+| MultiImplementationB.cs:5:27:5:27 | x : String | semmle.label | x : String |
 | MultiImplementationB.cs:5:39:5:39 | access to parameter x | semmle.label | access to parameter x |
 | Splitting.cs:3:28:3:34 | tainted : String | semmle.label | tainted : String |
 | Splitting.cs:8:13:8:13 | access to local variable x : String | semmle.label | access to local variable x : String |
@@ -1085,8 +1086,6 @@ subpaths
 | GlobalDataFlow.cs:323:15:323:24 | access to parameter sinkParam9 | GlobalDataFlow.cs:211:46:211:59 | "taint source" : String | GlobalDataFlow.cs:323:15:323:24 | access to parameter sinkParam9 | access to parameter sinkParam9 |
 | Capture.cs:273:30:273:30 | access to parameter x | Capture.cs:273:34:273:47 | "taint source" : String | Capture.cs:273:30:273:30 | access to parameter x | access to parameter x |
 | MultiImplementationA.cs:7:39:7:39 | access to parameter x | MultiImplementationA.cs:5:28:5:41 | "taint source" : String | MultiImplementationA.cs:7:39:7:39 | access to parameter x | access to parameter x |
-| MultiImplementationA.cs:7:39:7:39 | access to parameter x | MultiImplementationB.cs:3:28:3:41 | "taint source" : String | MultiImplementationA.cs:7:39:7:39 | access to parameter x | access to parameter x |
-| MultiImplementationB.cs:5:39:5:39 | access to parameter x | MultiImplementationA.cs:5:28:5:41 | "taint source" : String | MultiImplementationB.cs:5:39:5:39 | access to parameter x | access to parameter x |
 | MultiImplementationB.cs:5:39:5:39 | access to parameter x | MultiImplementationB.cs:3:28:3:41 | "taint source" : String | MultiImplementationB.cs:5:39:5:39 | access to parameter x | access to parameter x |
 | GlobalDataFlow.cs:27:15:27:32 | access to property SinkProperty0 | GlobalDataFlow.cs:18:27:18:40 | "taint source" : String | GlobalDataFlow.cs:27:15:27:32 | access to property SinkProperty0 | access to property SinkProperty0 |
 | Splitting.cs:21:21:21:33 | call to method Return<String> | Splitting.cs:24:28:24:34 | tainted : String | Splitting.cs:21:21:21:33 | call to method Return<String> | call to method Return<String> |
diff --git a/csharp/ql/test/library-tests/dataflow/global/TaintTrackingPath.expected b/csharp/ql/test/library-tests/dataflow/global/TaintTrackingPath.expected
index 6a317ec46cf90..bb21ba40806b6 100644
--- a/csharp/ql/test/library-tests/dataflow/global/TaintTrackingPath.expected
+++ b/csharp/ql/test/library-tests/dataflow/global/TaintTrackingPath.expected
@@ -505,8 +505,8 @@ edges
 | GlobalDataFlowStringBuilder.cs:49:21:49:33 | call to method ToString : String | GlobalDataFlowStringBuilder.cs:49:13:49:17 | access to local variable sink3 : String | provenance |  |
 | MultiImplementationA.cs:5:28:5:41 | "taint source" : String | MultiImplementationA.cs:7:27:7:27 | x : String | provenance |  |
 | MultiImplementationA.cs:7:27:7:27 | x : String | MultiImplementationA.cs:7:39:7:39 | access to parameter x | provenance |  |
-| MultiImplementationA.cs:7:27:7:27 | x : String | MultiImplementationB.cs:5:39:5:39 | access to parameter x | provenance |  |
-| MultiImplementationB.cs:3:28:3:41 | "taint source" : String | MultiImplementationA.cs:7:27:7:27 | x : String | provenance |  |
+| MultiImplementationB.cs:3:28:3:41 | "taint source" : String | MultiImplementationB.cs:5:27:5:27 | x : String | provenance |  |
+| MultiImplementationB.cs:5:27:5:27 | x : String | MultiImplementationB.cs:5:39:5:39 | access to parameter x | provenance |  |
 | Splitting.cs:3:28:3:34 | tainted : String | Splitting.cs:8:24:8:30 | [b (line 3): false] access to parameter tainted : String | provenance |  |
 | Splitting.cs:3:28:3:34 | tainted : String | Splitting.cs:8:24:8:30 | [b (line 3): true] access to parameter tainted : String | provenance |  |
 | Splitting.cs:8:13:8:13 | access to local variable x : String | Splitting.cs:9:15:9:15 | [b (line 3): false] access to local variable x | provenance |  |
@@ -1019,6 +1019,7 @@ nodes
 | MultiImplementationA.cs:7:27:7:27 | x : String | semmle.label | x : String |
 | MultiImplementationA.cs:7:39:7:39 | access to parameter x | semmle.label | access to parameter x |
 | MultiImplementationB.cs:3:28:3:41 | "taint source" : String | semmle.label | "taint source" : String |
+| MultiImplementationB.cs:5:27:5:27 | x : String | semmle.label | x : String |
 | MultiImplementationB.cs:5:39:5:39 | access to parameter x | semmle.label | access to parameter x |
 | Splitting.cs:3:28:3:34 | tainted : String | semmle.label | tainted : String |
 | Splitting.cs:8:13:8:13 | access to local variable x : String | semmle.label | access to local variable x : String |
@@ -1196,8 +1197,6 @@ subpaths
 | GlobalDataFlowStringBuilder.cs:42:15:42:19 | access to local variable sink2 | GlobalDataFlowStringBuilder.cs:30:35:30:48 | "taint source" : String | GlobalDataFlowStringBuilder.cs:42:15:42:19 | access to local variable sink2 | access to local variable sink2 |
 | GlobalDataFlowStringBuilder.cs:50:15:50:19 | access to local variable sink3 | GlobalDataFlowStringBuilder.cs:48:47:48:60 | "taint source" : String | GlobalDataFlowStringBuilder.cs:50:15:50:19 | access to local variable sink3 | access to local variable sink3 |
 | MultiImplementationA.cs:7:39:7:39 | access to parameter x | MultiImplementationA.cs:5:28:5:41 | "taint source" : String | MultiImplementationA.cs:7:39:7:39 | access to parameter x | access to parameter x |
-| MultiImplementationA.cs:7:39:7:39 | access to parameter x | MultiImplementationB.cs:3:28:3:41 | "taint source" : String | MultiImplementationA.cs:7:39:7:39 | access to parameter x | access to parameter x |
-| MultiImplementationB.cs:5:39:5:39 | access to parameter x | MultiImplementationA.cs:5:28:5:41 | "taint source" : String | MultiImplementationB.cs:5:39:5:39 | access to parameter x | access to parameter x |
 | MultiImplementationB.cs:5:39:5:39 | access to parameter x | MultiImplementationB.cs:3:28:3:41 | "taint source" : String | MultiImplementationB.cs:5:39:5:39 | access to parameter x | access to parameter x |
 | Splitting.cs:9:15:9:15 | [b (line 3): false] access to local variable x | Splitting.cs:3:28:3:34 | tainted : String | Splitting.cs:9:15:9:15 | [b (line 3): false] access to local variable x | [b (line 3): false] access to local variable x |
 | Splitting.cs:9:15:9:15 | [b (line 3): true] access to local variable x | Splitting.cs:3:28:3:34 | tainted : String | Splitting.cs:9:15:9:15 | [b (line 3): true] access to local variable x | [b (line 3): true] access to local variable x |
diff --git a/shared/dataflow/codeql/dataflow/VariableCapture.qll b/shared/dataflow/codeql/dataflow/VariableCapture.qll
index c48b46e8a7ba0..309809f5761ff 100644
--- a/shared/dataflow/codeql/dataflow/VariableCapture.qll
+++ b/shared/dataflow/codeql/dataflow/VariableCapture.qll
@@ -793,18 +793,18 @@ module Flow<LocationSig Location, InputSig<Location> Input> implements OutputSig
   private class TSynthesizedCaptureNode = TSynthRead or TSynthThisQualifier or TSynthPhi;
 
   class SynthesizedCaptureNode extends ClosureNode, TSynthesizedCaptureNode {
-    Callable getEnclosingCallable() {
-      exists(BasicBlock bb | this = TSynthRead(_, bb, _, _) and result = bb.getEnclosingCallable())
+    BasicBlock getBasicBlock() {
+      this = TSynthRead(_, result, _, _)
       or
-      exists(BasicBlock bb |
-        this = TSynthThisQualifier(bb, _, _) and result = bb.getEnclosingCallable()
-      )
+      this = TSynthThisQualifier(result, _, _)
       or
-      exists(CaptureSsa::DefinitionExt phi, BasicBlock bb |
-        this = TSynthPhi(phi) and phi.definesAt(_, bb, _, _) and result = bb.getEnclosingCallable()
+      exists(CaptureSsa::DefinitionExt phi |
+        this = TSynthPhi(phi) and phi.definesAt(_, result, _, _)
       )
     }
 
+    Callable getEnclosingCallable() { result = this.getBasicBlock().getEnclosingCallable() }
+
     predicate isVariableAccess(CapturedVariable v) {
       this = TSynthRead(v, _, _, _)
       or