Tree-sitter: Emit empty_location relation to avoid scan

Author: hvitved

config/dbscheme-fragments.json

@@ -28,6 +28,7 @@
     "/*- Yaml dbscheme -*/",
     "/*- Blame dbscheme -*/",
     "/*- JSON dbscheme -*/",
-    "/*- Python dbscheme -*/"
+    "/*- Python dbscheme -*/",
+    "/*- Empty location -*/"
   ]
 }

ql/ql/src/ql.dbscheme

@@ -36,6 +36,12 @@ containerparent(
   unique int child: @container ref
 );
 
+/*- Empty location -*/
+
+empty_location(
+  int location: @location_default ref
+);
+
 /*- Source location prefix -*/
 
 /**

ruby/ql/lib/codeql/Locations.qll

@@ -64,5 +64,5 @@ class Location extends @location_default {
 
 /** An entity representing an empty location. */
 class EmptyLocation extends Location {
-  EmptyLocation() { this.hasLocationInfo("", 0, 0, 0, 0) }
+  EmptyLocation() { empty_location(this) }
 }

ruby/ql/lib/ruby.dbscheme

@@ -36,6 +36,12 @@ containerparent(
   unique int child: @container ref
 );
 
+/*- Empty location -*/
+
+empty_location(
+  int location: @location_default ref
+);
+
 /*- Source location prefix -*/
 
 /**

shared/tree-sitter-extractor/src/extractor/mod.rs

@@ -75,7 +75,7 @@ fn populate_empty_file(writer: &mut trap::Writer) -> trap::Label {
 
 pub fn populate_empty_location(writer: &mut trap::Writer) {
     let file_label = populate_empty_file(writer);
-    global_location(
+    let loc_label = global_location(
         writer,
         file_label,
         trap::Location {
@@ -85,6 +85,7 @@ pub fn populate_empty_location(writer: &mut trap::Writer) {
             end_column: 0,
         },
     );
+    writer.add_tuple("empty_location", vec![trap::Arg::Label(loc_label)]);
 }
 
 pub fn populate_parent_folders(

shared/tree-sitter-extractor/src/generator/prefix.dbscheme

@@ -33,6 +33,12 @@ containerparent(
   unique int child: @container ref
 );
 
+/*- Empty location -*/
+
+empty_location(
+  int location: @location_default ref
+);
+
 /*- Source location prefix -*/
 
 /**