Rust: Implement path resolution in QL

rust/ql/lib/codeql/rust/AstConsistency.qll

@@ -73,6 +73,14 @@ query predicate multiplePositions(Element parent, int pos1, int pos2, string acc
   pos1 != pos2
 }
 
+private import codeql.rust.elements.internal.PathResolution
+
+/** Holds if `p` may resolve to multiple items including `i`. */
+query predicate multiplePathResolutions(Path p, ItemNode i) {
+  i = resolvePath(p) and
+  strictcount(resolvePath(p)) > 1
+}
+
 /**
  * Gets counts of abstract syntax tree inconsistencies of each type.
  */
@@ -98,4 +106,7 @@ int getAstInconsistencyCounts(string type) {
   or
   type = "Multiple positions" and
   result = count(Element e | multiplePositions(_, _, _, _, e) | e)
+  or
+  type = "Multiple path resolutions" and
+  result = count(Path p | multiplePathResolutions(p, _) | p)
 }

rust/ql/lib/codeql/rust/elements/internal/CallExprBaseImpl.qll

@@ -16,6 +16,7 @@ module Impl {
   private import codeql.rust.elements.internal.MethodCallExprImpl::Impl
   private import codeql.rust.elements.internal.CallExprImpl::Impl
   private import codeql.rust.elements.internal.PathExprImpl::Impl
+  private import codeql.rust.elements.internal.PathResolution
 
   pragma[nomagic]
   Resolvable getCallResolvable(CallExprBase call) {
@@ -33,6 +34,10 @@ module Impl {
      * Gets the target callable of this call, if a unique such target can
      * be statically resolved.
      */
-    Callable getStaticTarget() { getCallResolvable(this).resolvesAsItem(result) }
+    Callable getStaticTarget() {
+      getCallResolvable(this).resolvesAsItem(result)
+      or
+      result = resolvePath(this.(CallExpr).getFunction().(PathExpr).getPath())
+    }
   }
 }

rust/ql/lib/codeql/rust/elements/internal/PathImpl.qll

@@ -27,5 +27,11 @@ module Impl {
       then result = "...::" + this.getPart().toAbbreviatedString()
       else result = this.getPart().toAbbreviatedString()
     }
+
+    /**
+     * Gets the text of this path, if it exists.
+     */
+    pragma[nomagic]
+    string getText() { result = this.getPart().getNameRef().getText() }
   }
 }