From 26ef33212de6699a2f559cf3de87aac7a2f9e1f5 Mon Sep 17 00:00:00 2001
From: Owen Mansel-Chan <owen-mc@github.com>
Date: Wed, 21 Jan 2026 12:07:59 +0000
Subject: [PATCH] Test builtins like standard library

---
 .../go/frameworks/StdlibTaintFlow/Builtin.go  | 104 ++++++++++++++++++
 1 file changed, 104 insertions(+)
 create mode 100644 go/ql/test/library-tests/semmle/go/frameworks/StdlibTaintFlow/Builtin.go

diff --git a/go/ql/test/library-tests/semmle/go/frameworks/StdlibTaintFlow/Builtin.go b/go/ql/test/library-tests/semmle/go/frameworks/StdlibTaintFlow/Builtin.go
new file mode 100644
index 00000000000..ca1ea9c932e
--- /dev/null
+++ b/go/ql/test/library-tests/semmle/go/frameworks/StdlibTaintFlow/Builtin.go
@@ -0,0 +1,104 @@
+package main
+
+// Also tested in go/ql/test/library-tests/semmle/go/dataflow/ExternalValueFlow
+// and go/ql/test/library-tests/semmle/go/dataflow/ExternalTaintFlow.
+
+func TaintStepTest_Append1(sourceCQL interface{}) interface{} {
+	from := sourceCQL.([]byte)
+	var intoInterface interface{}
+	intoInterface = append(from, "a string"...)
+	return intoInterface
+}
+
+func TaintStepTest_Append2(sourceCQL interface{}) interface{} {
+	from := sourceCQL.(int)
+	slice := []int{from}
+	var intoInterface []int
+	intoInterface = append(slice, 0)
+	return intoInterface[0]
+}
+
+func TaintStepTest_Append3(sourceCQL interface{}) interface{} {
+	from := sourceCQL.(string)
+	var intoInterface interface{}
+	intoInterface = append([]byte{}, from...)
+	return intoInterface
+}
+
+func TaintStepTest_Append4(sourceCQL interface{}) interface{} {
+	from := sourceCQL.(int)
+	var intoInterface []int
+	intoInterface = append([]int{}, 0, from, 1)
+	return intoInterface[0]
+}
+
+func TaintStepTest_Copy1(sourceCQL interface{}) interface{} {
+	from := sourceCQL.(string)
+	var intoInterface []byte
+	copy(intoInterface, from)
+	return intoInterface
+}
+
+func TaintStepTest_Copy2(sourceCQL interface{}) interface{} {
+	from := []int{sourceCQL.(int)}
+	var intoInterface []int
+	copy(intoInterface, from)
+	return intoInterface[0]
+}
+
+func TaintStepTest_Max(sourceCQL interface{}) interface{} {
+	from := sourceCQL.(int)
+	var intoInterface int
+	intoInterface = max(0, 1, from, 2, 3)
+	return intoInterface
+}
+
+func TaintStepTest_Min(sourceCQL interface{}) interface{} {
+	from := sourceCQL.(int)
+	var intoInterface int
+	intoInterface = min(0, 1, from, 2, 3)
+	return intoInterface
+}
+
+func RunAllTaints_Builtin() {
+	{
+		source := newSource(0)
+		out := TaintStepTest_Append1(source)
+		sink(0, out)
+	}
+	{
+		source := newSource(1)
+		out := TaintStepTest_Append2(source)
+		sink(1, out)
+	}
+	{
+		source := newSource(2)
+		out := TaintStepTest_Append3(source)
+		sink(2, out)
+	}
+	{
+		source := newSource(3)
+		out := TaintStepTest_Append4(source)
+		sink(3, out)
+	}
+	{
+		source := newSource(4)
+		out := TaintStepTest_Copy1(source)
+		sink(4, out)
+	}
+	{
+		source := newSource(5)
+		out := TaintStepTest_Copy2(source)
+		sink(5, out)
+	}
+	{
+		source := newSource(3)
+		out := TaintStepTest_Max(source)
+		sink(3, out)
+	}
+	{
+		source := newSource(4)
+		out := TaintStepTest_Min(source)
+		sink(4, out)
+	}
+}