Merge pull request #9219 from igfoo/igfoo/livelits

Improve LiveLiterals

Author: igfoo

java/ql/lib/semmle/code/java/frameworks/android/Compose.qll

@@ -14,14 +14,22 @@ class LiveLiteral extends MethodAccess {
     not this.getEnclosingCallable() instanceof LiveLiteralMethod
   }
 
-  /** Gets the constant value that backs this live literal. */
+  /**
+   * Live literal classes consist of the following:
+   * - A private field holding the constant value that backs this live literal.
+   * - A private getter to access the constant value.
+   * - A public getter that either calls the private getter and returns its result or,
+   * if live literals are activated, returns the value of a dynamic state object that is initialized with
+   * the constant value.
+   *
+   * This predicate gets the constant value held by the private field.
+   */
   CompileTimeConstantExpr getValue() {
-    result =
-      any(ReturnStmt r | this.getMethod().calls*(r.getEnclosingCallable()))
-          .getResult()
-          .(VarAccess)
-          .getVariable()
-          .getInitializer()
+    exists(MethodAccess getterCall, VarAccess va |
+      methodReturns(this.getMethod(), getterCall) and
+      methodReturns(getterCall.getMethod(), va) and
+      result = va.getVariable().getInitializer()
+    )
   }
 
   override string toString() { result = this.getValue().toString() }
@@ -31,3 +39,10 @@ class LiveLiteral extends MethodAccess {
 class LiveLiteralMethod extends Method {
   LiveLiteralMethod() { this.getDeclaringType().getName().matches("LiveLiterals$%") }
 }
+
+private predicate methodReturns(Method m, Expr res) {
+  exists(ReturnStmt r |
+    r.getResult() = res and
+    r.getEnclosingCallable() = m
+  )
+}