unified: Sharpen set of candidates when measuring static name binding

Author: asgerf

unified/ql/lib/codeql/unified/internal/AnalysisQuality.qll

@@ -6,12 +6,45 @@ private import codeql.unified.internal.NameBindingPlugin
 
 /** Stats about identifiers that static name binding could resolve. */
 module StaticNameResolutionStats implements EntityStatsSig {
+  /**
+   * Holds if `name` has been positively identified as something that refer to a value, and static name binding
+   * is thus not expected to resolve its members.
+   */
+  private predicate resolvesToValue(Identifier name) {
+    exists(AstNode decl |
+      decl = getStaticBindingTarget(name).getDeclaration() and
+      not decl instanceof ClassLikeDeclaration and
+      not decl instanceof TypeAliasDeclaration and
+      not decl instanceof TypeParameter and
+      not decl instanceof AssociatedTypeDeclaration
+    )
+  }
+
+  /**
+   * Holds if name-binding for `expr` depends on type inference, and is thus not subject to static name binding.
+   *
+   * Usually this holds for qualified instance member accesses (`foo().x`) and leading-dot expressions (`.x`).
+   */
+  private predicate memberAccessDependsOnTypeInference(MemberAccessExpr expr) {
+    exists(Expr base | base = expr.getBase() |
+      // Base expression resolves to a value, e.g. a field, variable, or function (for languages where functions are values).
+      resolvesToValue(getIdentifierFromRef(base))
+      or
+      // Base expression is of a kind that is not subject to static name resolution, e.g. `foo().x`
+      not exists(getIdentifierFromRef(base))
+      or
+      // Base expression is a confirmed to depend on type inference
+      memberAccessDependsOnTypeInference(base)
+    )
+  }
+
   class Candidate extends Identifier {
     Candidate() {
-      this = getIdentifierFromRef(_) and
+      exists(AstNode ref |
+        this = getIdentifierFromRef(ref) and
+        not memberAccessDependsOnTypeInference(ref)
+      ) and
       not this instanceof NameDeclaration
-      // TODO: exclude names we know are not static references, e.g. unqualified instance-field access,
-      // currently blocked on getting static name binding to report this information.
     }
 
     NameBindingNode getTarget() {