From f5a8e38e040f3425eab6136aa15e7b670acca851 Mon Sep 17 00:00:00 2001
From: Owen Mansel-Chan <owen-mc@github.com>
Date: Thu, 26 Feb 2026 12:40:28 +0000
Subject: [PATCH] Add overlay test

---
 .../library-tests/semmle/go/overlay/base/a.go |  37 ++++
 .../semmle/go/overlay/base/test.expected      |  90 ++++++++++
 .../semmle/go/overlay/base/test.qlref         |   1 +
 .../semmle/go/overlay/codeql-test.yml         |   3 +
 .../semmle/go/overlay/overlay/a.go            |  35 ++++
 .../semmle/go/overlay/overlay/test.expected   |  78 +++++++++
 .../semmle/go/overlay/overlay/test.qlref      |   1 +
 .../semmle/go/overlay/test.expected           | 159 ++++++++++++++++++
 .../library-tests/semmle/go/overlay/test.ql   |  19 +++
 .../semmle/go/overlay/testlocations.expected  |   6 +
 .../semmle/go/overlay/testlocations.ql        |  22 +++
 11 files changed, 451 insertions(+)
 create mode 100644 go/ql/test/library-tests/semmle/go/overlay/base/a.go
 create mode 100644 go/ql/test/library-tests/semmle/go/overlay/base/test.expected
 create mode 100644 go/ql/test/library-tests/semmle/go/overlay/base/test.qlref
 create mode 100644 go/ql/test/library-tests/semmle/go/overlay/codeql-test.yml
 create mode 100644 go/ql/test/library-tests/semmle/go/overlay/overlay/a.go
 create mode 100644 go/ql/test/library-tests/semmle/go/overlay/overlay/test.expected
 create mode 100644 go/ql/test/library-tests/semmle/go/overlay/overlay/test.qlref
 create mode 100644 go/ql/test/library-tests/semmle/go/overlay/test.expected
 create mode 100644 go/ql/test/library-tests/semmle/go/overlay/test.ql
 create mode 100644 go/ql/test/library-tests/semmle/go/overlay/testlocations.expected
 create mode 100644 go/ql/test/library-tests/semmle/go/overlay/testlocations.ql

diff --git a/go/ql/test/library-tests/semmle/go/overlay/base/a.go b/go/ql/test/library-tests/semmle/go/overlay/base/a.go
new file mode 100644
index 000000000000..63d4b36b034e
--- /dev/null
+++ b/go/ql/test/library-tests/semmle/go/overlay/base/a.go
@@ -0,0 +1,37 @@
+package base
+
+import "strings"
+
+type A struct {
+	name string
+}
+
+/*
+ * A block comment.
+ * With multiple lines.
+ */
+func (a *A) GetNameLength() int {
+	// A line comment.
+	return len(a.name)
+}
+
+/*
+ * A block comment.
+ * With multiple lines.
+ */
+func (a *A) GetNameUpper() string {
+	// A line comment.
+	return strings.ToUpper(a.name)
+}
+
+func FuncA(name string) *A {
+	return &A{name: name}
+}
+
+func Id(name string) string {
+	return name
+}
+
+type B interface {
+	GetName() string
+}
diff --git a/go/ql/test/library-tests/semmle/go/overlay/base/test.expected b/go/ql/test/library-tests/semmle/go/overlay/base/test.expected
new file mode 100644
index 000000000000..d6e14f69e8e4
--- /dev/null
+++ b/go/ql/test/library-tests/semmle/go/overlay/base/test.expected
@@ -0,0 +1,90 @@
+expressions
+| a.go:1:9:1:12 | base |
+| a.go:3:8:3:16 | "strings" |
+| a.go:5:6:5:6 | A |
+| a.go:5:8:7:1 | struct type |
+| a.go:6:2:6:5 | name |
+| a.go:6:7:6:12 | string |
+| a.go:13:1:13:31 | function type |
+| a.go:13:7:13:7 | a |
+| a.go:13:9:13:10 | star expression |
+| a.go:13:10:13:10 | A |
+| a.go:13:13:13:25 | GetNameLength |
+| a.go:13:29:13:31 | int |
+| a.go:15:9:15:11 | len |
+| a.go:15:9:15:19 | call to len |
+| a.go:15:13:15:13 | a |
+| a.go:15:13:15:18 | selection of name |
+| a.go:15:15:15:18 | name |
+| a.go:22:1:22:33 | function type |
+| a.go:22:7:22:7 | a |
+| a.go:22:9:22:10 | star expression |
+| a.go:22:10:22:10 | A |
+| a.go:22:13:22:24 | GetNameUpper |
+| a.go:22:28:22:33 | string |
+| a.go:24:9:24:15 | strings |
+| a.go:24:9:24:23 | selection of ToUpper |
+| a.go:24:9:24:31 | call to ToUpper |
+| a.go:24:17:24:23 | ToUpper |
+| a.go:24:25:24:25 | a |
+| a.go:24:25:24:30 | selection of name |
+| a.go:24:27:24:30 | name |
+| a.go:27:1:27:26 | function type |
+| a.go:27:6:27:10 | FuncA |
+| a.go:27:12:27:15 | name |
+| a.go:27:17:27:22 | string |
+| a.go:27:25:27:26 | star expression |
+| a.go:27:26:27:26 | A |
+| a.go:28:9:28:22 | &... |
+| a.go:28:10:28:10 | A |
+| a.go:28:10:28:22 | struct literal |
+| a.go:28:12:28:15 | name |
+| a.go:28:12:28:21 | key-value pair |
+| a.go:28:18:28:21 | name |
+| a.go:31:1:31:27 | function type |
+| a.go:31:6:31:7 | Id |
+| a.go:31:9:31:12 | name |
+| a.go:31:14:31:19 | string |
+| a.go:31:22:31:27 | string |
+| a.go:32:9:32:12 | name |
+| a.go:35:6:35:6 | B |
+| a.go:35:8:37:1 | interface type |
+| a.go:36:2:36:8 | GetName |
+| a.go:36:9:36:17 | function type |
+| a.go:36:12:36:17 | string |
+statements
+| a.go:13:33:16:1 | block statement |
+| a.go:15:2:15:19 | return statement |
+| a.go:22:35:25:1 | block statement |
+| a.go:24:2:24:31 | return statement |
+| a.go:27:28:29:1 | block statement |
+| a.go:28:2:28:22 | return statement |
+| a.go:31:29:33:1 | block statement |
+| a.go:32:2:32:12 | return statement |
+functions
+| a.go:13:13:13:25 | GetNameLength |
+| a.go:22:13:22:24 | GetNameUpper |
+| a.go:27:6:27:10 | FuncA |
+| a.go:31:6:31:7 | Id |
+| a.go:36:2:36:8 | GetName |
+types
+| a.go:5:6:5:6 | A |
+| a.go:35:6:35:6 | B |
+parameters
+| a.go:13:7:13:7 | a |
+| a.go:22:7:22:7 | a |
+| a.go:27:12:27:15 | name |
+| a.go:31:9:31:12 | name |
+fields
+| a.go:6:2:6:5 | name |
+commentLines
+| a.go:9:1:12:3 | comment |
+| a.go:14:2:14:19 | comment |
+| a.go:18:1:21:3 | comment |
+| a.go:23:2:23:19 | comment |
+commentBlocks
+| a.go:9:1:12:3 | comment group |
+| a.go:14:2:14:19 | comment group |
+| a.go:18:1:21:3 | comment group |
+| a.go:23:2:23:19 | comment group |
+htmlElements
diff --git a/go/ql/test/library-tests/semmle/go/overlay/base/test.qlref b/go/ql/test/library-tests/semmle/go/overlay/base/test.qlref
new file mode 100644
index 000000000000..bbce8f8b98d3
--- /dev/null
+++ b/go/ql/test/library-tests/semmle/go/overlay/base/test.qlref
@@ -0,0 +1 @@
+query: ../test.ql
diff --git a/go/ql/test/library-tests/semmle/go/overlay/codeql-test.yml b/go/ql/test/library-tests/semmle/go/overlay/codeql-test.yml
new file mode 100644
index 000000000000..59ca317af6f0
--- /dev/null
+++ b/go/ql/test/library-tests/semmle/go/overlay/codeql-test.yml
@@ -0,0 +1,3 @@
+overlay:
+  base: "base/"
+  overlay: "overlay/"
diff --git a/go/ql/test/library-tests/semmle/go/overlay/overlay/a.go b/go/ql/test/library-tests/semmle/go/overlay/overlay/a.go
new file mode 100644
index 000000000000..c9264fa82507
--- /dev/null
+++ b/go/ql/test/library-tests/semmle/go/overlay/overlay/a.go
@@ -0,0 +1,35 @@
+package base
+
+import "strings"
+
+type C struct{}
+
+type A struct {
+	name string
+}
+
+func (a *A) GetNameUpper() string {
+	return strings.ToUpper(a.name)
+}
+
+/*
+ * A block comment.
+ * With multiple lines.
+ */
+func (a *A) GetName() string {
+	// A line comment.
+	return a.name
+}
+
+func Id(name string) string {
+	return name
+}
+
+/*
+ * A block comment.
+ * With multiple lines.
+ */
+func FuncC() *C {
+	// A line comment.
+	return &C{}
+}
diff --git a/go/ql/test/library-tests/semmle/go/overlay/overlay/test.expected b/go/ql/test/library-tests/semmle/go/overlay/overlay/test.expected
new file mode 100644
index 000000000000..efc812bef0b8
--- /dev/null
+++ b/go/ql/test/library-tests/semmle/go/overlay/overlay/test.expected
@@ -0,0 +1,78 @@
+expressions
+| a.go:1:9:1:12 | base |
+| a.go:3:8:3:16 | "strings" |
+| a.go:5:6:5:6 | C |
+| a.go:5:8:5:15 | struct type |
+| a.go:7:6:7:6 | A |
+| a.go:7:8:9:1 | struct type |
+| a.go:8:2:8:5 | name |
+| a.go:8:7:8:12 | string |
+| a.go:11:1:11:33 | function type |
+| a.go:11:7:11:7 | a |
+| a.go:11:9:11:10 | star expression |
+| a.go:11:10:11:10 | A |
+| a.go:11:13:11:24 | GetNameUpper |
+| a.go:11:28:11:33 | string |
+| a.go:12:9:12:15 | strings |
+| a.go:12:9:12:23 | selection of ToUpper |
+| a.go:12:9:12:31 | call to ToUpper |
+| a.go:12:17:12:23 | ToUpper |
+| a.go:12:25:12:25 | a |
+| a.go:12:25:12:30 | selection of name |
+| a.go:12:27:12:30 | name |
+| a.go:19:1:19:28 | function type |
+| a.go:19:7:19:7 | a |
+| a.go:19:9:19:10 | star expression |
+| a.go:19:10:19:10 | A |
+| a.go:19:13:19:19 | GetName |
+| a.go:19:23:19:28 | string |
+| a.go:21:9:21:9 | a |
+| a.go:21:9:21:14 | selection of name |
+| a.go:21:11:21:14 | name |
+| a.go:24:1:24:27 | function type |
+| a.go:24:6:24:7 | Id |
+| a.go:24:9:24:12 | name |
+| a.go:24:14:24:19 | string |
+| a.go:24:22:24:27 | string |
+| a.go:25:9:25:12 | name |
+| a.go:32:1:32:15 | function type |
+| a.go:32:6:32:10 | FuncC |
+| a.go:32:14:32:15 | star expression |
+| a.go:32:15:32:15 | C |
+| a.go:34:9:34:12 | &... |
+| a.go:34:10:34:10 | C |
+| a.go:34:10:34:12 | struct literal |
+statements
+| a.go:11:35:13:1 | block statement |
+| a.go:12:2:12:31 | return statement |
+| a.go:19:30:22:1 | block statement |
+| a.go:21:2:21:14 | return statement |
+| a.go:24:29:26:1 | block statement |
+| a.go:25:2:25:12 | return statement |
+| a.go:32:17:35:1 | block statement |
+| a.go:34:2:34:12 | return statement |
+functions
+| a.go:11:13:11:24 | GetNameUpper |
+| a.go:19:13:19:19 | GetName |
+| a.go:24:6:24:7 | Id |
+| a.go:32:6:32:10 | FuncC |
+types
+| a.go:5:6:5:6 | C |
+| a.go:7:6:7:6 | A |
+parameters
+| a.go:11:7:11:7 | a |
+| a.go:19:7:19:7 | a |
+| a.go:24:9:24:12 | name |
+fields
+| a.go:8:2:8:5 | name |
+commentLines
+| a.go:15:1:18:3 | comment |
+| a.go:20:2:20:19 | comment |
+| a.go:28:1:31:3 | comment |
+| a.go:33:2:33:19 | comment |
+commentBlocks
+| a.go:15:1:18:3 | comment group |
+| a.go:20:2:20:19 | comment group |
+| a.go:28:1:31:3 | comment group |
+| a.go:33:2:33:19 | comment group |
+htmlElements
diff --git a/go/ql/test/library-tests/semmle/go/overlay/overlay/test.qlref b/go/ql/test/library-tests/semmle/go/overlay/overlay/test.qlref
new file mode 100644
index 000000000000..bbce8f8b98d3
--- /dev/null
+++ b/go/ql/test/library-tests/semmle/go/overlay/overlay/test.qlref
@@ -0,0 +1 @@
+query: ../test.ql
diff --git a/go/ql/test/library-tests/semmle/go/overlay/test.expected b/go/ql/test/library-tests/semmle/go/overlay/test.expected
new file mode 100644
index 000000000000..66c5f1ab9380
--- /dev/null
+++ b/go/ql/test/library-tests/semmle/go/overlay/test.expected
@@ -0,0 +1,159 @@
+expressions
+| base/a.go:1:9:1:12 | base |
+| base/a.go:3:8:3:16 | "strings" |
+| base/a.go:5:6:5:6 | A |
+| base/a.go:5:8:7:1 | struct type |
+| base/a.go:6:2:6:5 | name |
+| base/a.go:6:7:6:12 | string |
+| base/a.go:13:1:13:31 | function type |
+| base/a.go:13:7:13:7 | a |
+| base/a.go:13:9:13:10 | star expression |
+| base/a.go:13:10:13:10 | A |
+| base/a.go:13:13:13:25 | GetNameLength |
+| base/a.go:13:29:13:31 | int |
+| base/a.go:15:9:15:11 | len |
+| base/a.go:15:9:15:19 | call to len |
+| base/a.go:15:13:15:13 | a |
+| base/a.go:15:13:15:18 | selection of name |
+| base/a.go:15:15:15:18 | name |
+| base/a.go:22:1:22:33 | function type |
+| base/a.go:22:7:22:7 | a |
+| base/a.go:22:9:22:10 | star expression |
+| base/a.go:22:10:22:10 | A |
+| base/a.go:22:13:22:24 | GetNameUpper |
+| base/a.go:22:28:22:33 | string |
+| base/a.go:24:9:24:15 | strings |
+| base/a.go:24:9:24:23 | selection of ToUpper |
+| base/a.go:24:9:24:31 | call to ToUpper |
+| base/a.go:24:17:24:23 | ToUpper |
+| base/a.go:24:25:24:25 | a |
+| base/a.go:24:25:24:30 | selection of name |
+| base/a.go:24:27:24:30 | name |
+| base/a.go:27:1:27:26 | function type |
+| base/a.go:27:6:27:10 | FuncA |
+| base/a.go:27:12:27:15 | name |
+| base/a.go:27:17:27:22 | string |
+| base/a.go:27:25:27:26 | star expression |
+| base/a.go:27:26:27:26 | A |
+| base/a.go:28:9:28:22 | &... |
+| base/a.go:28:10:28:10 | A |
+| base/a.go:28:10:28:22 | struct literal |
+| base/a.go:28:12:28:15 | name |
+| base/a.go:28:12:28:21 | key-value pair |
+| base/a.go:28:18:28:21 | name |
+| base/a.go:31:1:31:27 | function type |
+| base/a.go:31:6:31:7 | Id |
+| base/a.go:31:9:31:12 | name |
+| base/a.go:31:14:31:19 | string |
+| base/a.go:31:22:31:27 | string |
+| base/a.go:32:9:32:12 | name |
+| base/a.go:35:6:35:6 | B |
+| base/a.go:35:8:37:1 | interface type |
+| base/a.go:36:2:36:8 | GetName |
+| base/a.go:36:9:36:17 | function type |
+| base/a.go:36:12:36:17 | string |
+| overlay/a.go:1:9:1:12 | base |
+| overlay/a.go:3:8:3:16 | "strings" |
+| overlay/a.go:5:6:5:6 | C |
+| overlay/a.go:5:8:5:15 | struct type |
+| overlay/a.go:7:6:7:6 | A |
+| overlay/a.go:7:8:9:1 | struct type |
+| overlay/a.go:8:2:8:5 | name |
+| overlay/a.go:8:7:8:12 | string |
+| overlay/a.go:11:1:11:33 | function type |
+| overlay/a.go:11:7:11:7 | a |
+| overlay/a.go:11:9:11:10 | star expression |
+| overlay/a.go:11:10:11:10 | A |
+| overlay/a.go:11:13:11:24 | GetNameUpper |
+| overlay/a.go:11:28:11:33 | string |
+| overlay/a.go:12:9:12:15 | strings |
+| overlay/a.go:12:9:12:23 | selection of ToUpper |
+| overlay/a.go:12:9:12:31 | call to ToUpper |
+| overlay/a.go:12:17:12:23 | ToUpper |
+| overlay/a.go:12:25:12:25 | a |
+| overlay/a.go:12:25:12:30 | selection of name |
+| overlay/a.go:12:27:12:30 | name |
+| overlay/a.go:19:1:19:28 | function type |
+| overlay/a.go:19:7:19:7 | a |
+| overlay/a.go:19:9:19:10 | star expression |
+| overlay/a.go:19:10:19:10 | A |
+| overlay/a.go:19:13:19:19 | GetName |
+| overlay/a.go:19:23:19:28 | string |
+| overlay/a.go:21:9:21:9 | a |
+| overlay/a.go:21:9:21:14 | selection of name |
+| overlay/a.go:21:11:21:14 | name |
+| overlay/a.go:24:1:24:27 | function type |
+| overlay/a.go:24:6:24:7 | Id |
+| overlay/a.go:24:9:24:12 | name |
+| overlay/a.go:24:14:24:19 | string |
+| overlay/a.go:24:22:24:27 | string |
+| overlay/a.go:25:9:25:12 | name |
+| overlay/a.go:32:1:32:15 | function type |
+| overlay/a.go:32:6:32:10 | FuncC |
+| overlay/a.go:32:14:32:15 | star expression |
+| overlay/a.go:32:15:32:15 | C |
+| overlay/a.go:34:9:34:12 | &... |
+| overlay/a.go:34:10:34:10 | C |
+| overlay/a.go:34:10:34:12 | struct literal |
+statements
+| base/a.go:13:33:16:1 | block statement |
+| base/a.go:15:2:15:19 | return statement |
+| base/a.go:22:35:25:1 | block statement |
+| base/a.go:24:2:24:31 | return statement |
+| base/a.go:27:28:29:1 | block statement |
+| base/a.go:28:2:28:22 | return statement |
+| base/a.go:31:29:33:1 | block statement |
+| base/a.go:32:2:32:12 | return statement |
+| overlay/a.go:11:35:13:1 | block statement |
+| overlay/a.go:12:2:12:31 | return statement |
+| overlay/a.go:19:30:22:1 | block statement |
+| overlay/a.go:21:2:21:14 | return statement |
+| overlay/a.go:24:29:26:1 | block statement |
+| overlay/a.go:25:2:25:12 | return statement |
+| overlay/a.go:32:17:35:1 | block statement |
+| overlay/a.go:34:2:34:12 | return statement |
+functions
+| base/a.go:13:13:13:25 | GetNameLength |
+| base/a.go:22:13:22:24 | GetNameUpper |
+| base/a.go:27:6:27:10 | FuncA |
+| base/a.go:31:6:31:7 | Id |
+| base/a.go:36:2:36:8 | GetName |
+| overlay/a.go:11:13:11:24 | GetNameUpper |
+| overlay/a.go:19:13:19:19 | GetName |
+| overlay/a.go:24:6:24:7 | Id |
+| overlay/a.go:32:6:32:10 | FuncC |
+types
+| base/a.go:5:6:5:6 | A |
+| base/a.go:35:6:35:6 | B |
+| overlay/a.go:5:6:5:6 | C |
+| overlay/a.go:7:6:7:6 | A |
+parameters
+| base/a.go:13:7:13:7 | a |
+| base/a.go:22:7:22:7 | a |
+| base/a.go:27:12:27:15 | name |
+| base/a.go:31:9:31:12 | name |
+| overlay/a.go:11:7:11:7 | a |
+| overlay/a.go:19:7:19:7 | a |
+| overlay/a.go:24:9:24:12 | name |
+fields
+| base/a.go:6:2:6:5 | name |
+| overlay/a.go:8:2:8:5 | name |
+commentLines
+| base/a.go:9:1:12:3 | comment |
+| base/a.go:14:2:14:19 | comment |
+| base/a.go:18:1:21:3 | comment |
+| base/a.go:23:2:23:19 | comment |
+| overlay/a.go:15:1:18:3 | comment |
+| overlay/a.go:20:2:20:19 | comment |
+| overlay/a.go:28:1:31:3 | comment |
+| overlay/a.go:33:2:33:19 | comment |
+commentBlocks
+| base/a.go:9:1:12:3 | comment group |
+| base/a.go:14:2:14:19 | comment group |
+| base/a.go:18:1:21:3 | comment group |
+| base/a.go:23:2:23:19 | comment group |
+| overlay/a.go:15:1:18:3 | comment group |
+| overlay/a.go:20:2:20:19 | comment group |
+| overlay/a.go:28:1:31:3 | comment group |
+| overlay/a.go:33:2:33:19 | comment group |
+htmlElements
diff --git a/go/ql/test/library-tests/semmle/go/overlay/test.ql b/go/ql/test/library-tests/semmle/go/overlay/test.ql
new file mode 100644
index 000000000000..63ba7877e84e
--- /dev/null
+++ b/go/ql/test/library-tests/semmle/go/overlay/test.ql
@@ -0,0 +1,19 @@
+import go
+
+query predicate expressions(Expr e) { any() }
+
+query predicate statements(Stmt s) { any() }
+
+query predicate functions(Function f) { exists(f.getLocation()) }
+
+query predicate types(Type t) { exists(t.getLocation()) }
+
+query predicate parameters(Parameter p) { any() }
+
+query predicate fields(Field f) { exists(f.getLocation()) }
+
+query predicate commentLines(Comment c) { any() }
+
+query predicate commentBlocks(CommentGroup cg) { any() }
+
+query predicate htmlElements(HTML::Element xl) { any() }
diff --git a/go/ql/test/library-tests/semmle/go/overlay/testlocations.expected b/go/ql/test/library-tests/semmle/go/overlay/testlocations.expected
new file mode 100644
index 000000000000..f5df161919f6
--- /dev/null
+++ b/go/ql/test/library-tests/semmle/go/overlay/testlocations.expected
@@ -0,0 +1,6 @@
+elementsWithMultipleLocations
+commentLinesWithMultipleLocations
+commentBlocksWithMultipleLocations
+removedEntities
+| base/a.go:13:13:13:25 | GetNameLength |
+| base/a.go:27:6:27:10 | FuncA |
diff --git a/go/ql/test/library-tests/semmle/go/overlay/testlocations.ql b/go/ql/test/library-tests/semmle/go/overlay/testlocations.ql
new file mode 100644
index 000000000000..9f7fa2f354f8
--- /dev/null
+++ b/go/ql/test/library-tests/semmle/go/overlay/testlocations.ql
@@ -0,0 +1,22 @@
+import go
+
+// This is a consistency check that the overlay mechanism for cleaning up locations
+// works correctly.
+query predicate elementsWithMultipleLocations(AstNode an, Location loc) {
+  strictcount(Location l0 | l0 = an.getLocation()) > 1 and
+  loc = an.getLocation()
+}
+
+query predicate commentLinesWithMultipleLocations(Comment cl, Location loc) {
+  strictcount(Location l0 | l0 = cl.getLocation()) > 1 and
+  loc = cl.getLocation()
+}
+
+query predicate commentBlocksWithMultipleLocations(CommentGroup cb, Location loc) {
+  strictcount(Location l0 | l0 = cb.getLocation()) > 1 and
+  loc = cb.getLocation()
+}
+
+// This is a consistency check that the entities that are removed as a part of
+// the changes in the overlay are indeed removed from the database.
+query predicate removedEntities(Function f) { f.getName() = ["FuncA", "GetNameLength"] }