Simplify representation of calls that use scope resolution operator.

Now, `Foo::bar` is a call where the receiver expr is `Foo`.

ql/src/codeql_ruby/ast/Call.qll

@@ -11,12 +11,16 @@ class Call extends Expr {
 
   /**
    * Gets the receiver of this call, if any. For example:
+   *
    * ```rb
    * foo.bar
-   * baz()
+   * Baz::qux
+   * corge()
    * ```
-   * The result for the call to `bar` is the `Expr` for `foo`, while the call
-   * to `baz` has no result.
+   *
+   * The result for the call to `bar` is the `Expr` for `foo`; the result for
+   * the call to `qux` is the `Expr` for `Baz`; for the call to `corge` there
+   * is no result.
    */
   final Expr getReceiver() { result = range.getReceiver() }
 
@@ -26,47 +30,11 @@ class Call extends Expr {
    * ```rb
    * foo.bar x, y
    * ```
+   *
    * the result is `"bar"`.
-   *
-   * N.B. in the following example, where the method name uses the scope
-   * resolution operator, the result is the name being resolved, i.e. `"bar"`.
-   * Use `getMethodNameScopeExpr` to get the expression for `Foo`.
-   *
-   * ```rb
-   * Foo::bar x, y
-   * ```
    */
   final string getMethodName() { result = range.getMethodName() }
 
-  /**
-   * Gets the scope expression used in the method name's scope resolution
-   * operation, if any.
-   *
-   * In the following example, the result is the `Expr` for `Foo`.
-   *
-   * ```rb
-   * Foo::bar()
-   * ```
-   *
-   * However, there is no result for the following example, since there is no
-   * scope resolution operation.
-   *
-   * ```rb
-   * baz()
-   * ```
-   */
-  final Expr getMethodNameScopeExpr() { result = range.getMethodNameScopeExpr() }
-
-  /**
-   * Holds if the method name uses the scope resolution operator to access the
-   * global scope, as in this example:
-   *
-   * ```rb
-   * ::foo
-   * ```
-   */
-  final predicate methodNameHasGlobalScope() { range.methodNameHasGlobalScope() }
-
   /**
    * Gets the `n`th argument of this method call. In the following example, the
    * result for n=0 is the `IntegerLiteral` 0, while for n=1 the result is a

ql/src/codeql_ruby/ast/internal/Call.qll

@@ -9,10 +9,6 @@ module Call {
 
     abstract string getMethodName();
 
-    abstract Expr getMethodNameScopeExpr();
-
-    abstract predicate methodNameHasGlobalScope();
-
     abstract Expr getArgument(int n);
 
     abstract Block getBlock();
@@ -29,10 +25,6 @@ module Call {
 
     final override string getMethodName() { result = generated.getValue() }
 
-    final override Expr getMethodNameScopeExpr() { none() }
-
-    final override predicate methodNameHasGlobalScope() { none() }
-
     final override Expr getArgument(int n) { none() }
 
     final override Block getBlock() { none() }
@@ -48,14 +40,10 @@ module Call {
       not access(identifier, _)
     }
 
-    final override Expr getReceiver() { none() }
+    final override Expr getReceiver() { result = generated.getScope() }
 
     final override string getMethodName() { result = identifier.getValue() }
 
-    final override Expr getMethodNameScopeExpr() { result = generated.getScope() }
-
-    final override predicate methodNameHasGlobalScope() { not exists(generated.getScope()) }
-
     final override Expr getArgument(int n) { none() }
 
     final override Block getBlock() { none() }
@@ -64,7 +52,11 @@ module Call {
   private class RegularCallRange extends Call::Range, @call {
     final override Generated::Call generated;
 
-    final override Expr getReceiver() { result = generated.getReceiver() }
+    final override Expr getReceiver() {
+      if exists(generated.getReceiver())
+      then result = generated.getReceiver()
+      else result = generated.getMethod().(Generated::ScopeResolution).getScope()
+    }
 
     final override string getMethodName() {
       result = generated.getMethod().(Generated::Token).getValue() or
@@ -72,17 +64,6 @@ module Call {
         generated.getMethod().(Generated::ScopeResolution).getName().(Generated::Token).getValue()
     }
 
-    final override Expr getMethodNameScopeExpr() {
-      result = generated.getMethod().(Generated::ScopeResolution).getScope()
-    }
-
-    final override predicate methodNameHasGlobalScope() {
-      exists(Generated::ScopeResolution sr |
-        sr = generated.getMethod() and
-        not exists(sr.getScope())
-      )
-    }
-
     final override Expr getArgument(int n) { result = generated.getArguments().getChild(n) }
 
     final override Block getBlock() { result = generated.getBlock() }
@@ -97,10 +78,6 @@ module YieldCall {
 
     final override string getMethodName() { result = "yield" }
 
-    final override Expr getMethodNameScopeExpr() { none() }
-
-    final override predicate methodNameHasGlobalScope() { none() }
-
     final override Expr getArgument(int n) { result = generated.getChild().getChild(n) }
 
     final override Block getBlock() { none() }
@@ -121,10 +98,6 @@ module SuperCall {
 
     final override string getMethodName() { result = generated.getValue() }
 
-    final override Expr getMethodNameScopeExpr() { none() }
-
-    final override predicate methodNameHasGlobalScope() { none() }
-
     final override Expr getArgument(int n) { none() }
 
     final override Block getBlock() { none() }
@@ -141,10 +114,6 @@ module SuperCall {
       result = generated.getMethod().(Generated::Super).getValue()
     }
 
-    final override Expr getMethodNameScopeExpr() { none() }
-
-    final override predicate methodNameHasGlobalScope() { none() }
-
     final override Expr getArgument(int n) { result = generated.getArguments().getChild(n) }
 
     final override Block getBlock() { result = generated.getBlock() }