Swift: Model swap.

Author: geoffw0

swift/ql/lib/codeql/swift/frameworks/StandardLibrary/ManualMemoryManagement.qll

@@ -0,0 +1,16 @@
+/**
+ * Provides models for Swift "Manual Memory Management" functions.
+ */
+
+import swift
+private import codeql.swift.dataflow.ExternalFlow
+
+private class ManualMemoryManagementSummaries extends SummaryModelCsv {
+  override predicate row(string row) {
+    row =
+      [
+        ";;false;swap(_:_:);;;Argument[0];Argument[1];value",
+        ";;false;swap(_:_:);;;Argument[1];Argument[0];value",
+      ]
+  }
+}

swift/ql/lib/codeql/swift/frameworks/StandardLibrary/StandardLibrary.qll

@@ -8,6 +8,7 @@ private import Data
 private import FileManager
 private import FilePath
 private import InputStream
+private import ManualMemoryManagement
 private import NsData
 private import NsObject
 private import NsString

swift/ql/test/library-tests/dataflow/dataflow/DataFlow.expected

@@ -270,7 +270,10 @@ edges
 | test.swift:593:13:593:13 | s2 [s, x] | test.swift:592:11:592:17 | enter #keyPath(...) [s, x] |
 | test.swift:593:13:593:13 | s2 [s, x] | test.swift:593:13:593:26 | \\...[...] |
 | test.swift:618:13:618:20 | call to source() | test.swift:626:15:626:15 | y |
+| test.swift:628:9:628:16 | call to source() | test.swift:630:10:630:11 | &... |
 | test.swift:628:9:628:16 | call to source() | test.swift:631:15:631:15 | x |
+| test.swift:630:10:630:11 | &... | test.swift:630:14:630:15 | [post] &... |
+| test.swift:630:14:630:15 | [post] &... | test.swift:632:15:632:15 | y |
 nodes
 | file://:0:0:0:0 | .a [x] | semmle.label | .a [x] |
 | file://:0:0:0:0 | .str | semmle.label | .str |
@@ -567,7 +570,10 @@ nodes
 | test.swift:618:13:618:20 | call to source() | semmle.label | call to source() |
 | test.swift:626:15:626:15 | y | semmle.label | y |
 | test.swift:628:9:628:16 | call to source() | semmle.label | call to source() |
+| test.swift:630:10:630:11 | &... | semmle.label | &... |
+| test.swift:630:14:630:15 | [post] &... | semmle.label | [post] &... |
 | test.swift:631:15:631:15 | x | semmle.label | x |
+| test.swift:632:15:632:15 | y | semmle.label | y |
 subpaths
 | test.swift:75:21:75:22 | &... | test.swift:65:16:65:28 | arg1 | test.swift:65:1:70:1 | arg2[return] | test.swift:75:31:75:32 | [post] &... |
 | test.swift:114:19:114:19 | arg | test.swift:109:9:109:14 | arg | test.swift:110:12:110:12 | arg | test.swift:114:12:114:22 | call to ... |
@@ -681,3 +687,4 @@ subpaths
 | test.swift:593:13:593:26 | \\...[...] | test.swift:590:16:590:23 | call to source() | test.swift:593:13:593:26 | \\...[...] | result |
 | test.swift:626:15:626:15 | y | test.swift:618:13:618:20 | call to source() | test.swift:626:15:626:15 | y | result |
 | test.swift:631:15:631:15 | x | test.swift:628:9:628:16 | call to source() | test.swift:631:15:631:15 | x | result |
+| test.swift:632:15:632:15 | y | test.swift:628:9:628:16 | call to source() | test.swift:632:15:632:15 | y | result |

swift/ql/test/library-tests/dataflow/dataflow/test.swift

@@ -629,5 +629,5 @@ func testSwap() {
     y = 0
     swap(&x, &y)
     sink(arg: x) // $ SPURIOUS: flow=628
-    sink(arg: y) // $ MISSING: flow=628
+    sink(arg: y) // $ flow=628
 }