Dataflow/Go: Add getLocation to calls and callables for easier debugging.

Author: aschackmull

go/ql/lib/semmle/go/dataflow/internal/DataFlowPrivate.qll

@@ -311,6 +311,13 @@ class DataFlowCallable extends TDataFlowCallable {
         .hasLocationInfo(filepath, startline, startcolumn, endline, endcolumn)
   }
 
+  /** Gets the location of this callable. */
+  Location getLocation() {
+    result = getCallableLocation(this.asCallable()) or
+    result = this.asFileScope().getLocation() or
+    result = getCallableLocation(this.asSummarizedCallable())
+  }
+
   /** Gets a best-effort total ordering. */
   int totalorder() {
     this =
@@ -322,6 +329,13 @@ class DataFlowCallable extends TDataFlowCallable {
   }
 }
 
+private Location getCallableLocation(Callable c) {
+  exists(string filepath, int startline, int startcolumn, int endline, int endcolumn |
+    c.hasLocationInfo(filepath, startline, startcolumn, endline, endcolumn) and
+    result.hasLocationInfo(filepath, startline, startcolumn, endline, endcolumn)
+  )
+}
+
 /** A function call relevant for data flow. */
 class DataFlowCall extends Expr {
   DataFlow::CallNode call;
@@ -344,6 +358,9 @@ class DataFlowCall extends Expr {
     not exists(this.getEnclosingFunction()) and result.asFileScope() = this.getFile()
   }
 
+  /** Gets the location of this call. */
+  Location getLocation() { result = super.getLocation() }
+
   /** Gets a best-effort total ordering. */
   int totalorder() {
     this =

shared/dataflow/codeql/dataflow/DataFlow.qll

@@ -72,6 +72,9 @@ signature module InputSig<LocationSig Location> {
     /** Gets a textual representation of this element. */
     string toString();
 
+    /** Gets the location of this call. */
+    Location getLocation();
+
     DataFlowCallable getEnclosingCallable();
 
     /** Gets a best-effort total ordering. */
@@ -82,6 +85,9 @@ signature module InputSig<LocationSig Location> {
     /** Gets a textual representation of this element. */
     string toString();
 
+    /** Gets the location of this callable. */
+    Location getLocation();
+
     /** Gets a best-effort total ordering. */
     int totalorder();
   }