Add support for live literals

atorralba · igfoo · commit 3920b64d62fa · 2022-05-10T19:51:25.000+01:00
diff --git a/java/ql/lib/semmle/code/java/Expr.qll b/java/ql/lib/semmle/code/java/Expr.qll
@@ -2,10 +2,8 @@
  * Provides classes for working with Java expressions.
  */
 
-import Member
-import Type
-import Variable
-import Statement
+import java
+import semmle.code.java.frameworks.android.Compose
 
 /** A common super-class that represents all kinds of expressions. */
 class Expr extends ExprParent, @expr {
@@ -161,6 +159,8 @@ class CompileTimeConstantExpr extends Expr {
         v.isFinal() and
         v.getInitializer().isCompileTimeConstant()
       )
+      or
+      this instanceof LiveLiteral
     )
   }
 
@@ -185,6 +185,8 @@ class CompileTimeConstantExpr extends Expr {
     exists(Variable v | this = v.getAnAccess() |
       result = v.getInitializer().(CompileTimeConstantExpr).getStringValue()
     )
+    or
+    result = this.(LiveLiteral).getValue().getStringValue()
   }
 
   /**
@@ -297,6 +299,8 @@ class CompileTimeConstantExpr extends Expr {
     exists(Variable v | this = v.getAnAccess() |
       result = v.getInitializer().(CompileTimeConstantExpr).getBooleanValue()
     )
+    or
+    result = this.(LiveLiteral).getValue().getBooleanValue()
   }
 
   /**
@@ -377,6 +381,8 @@ class CompileTimeConstantExpr extends Expr {
         result = v.getInitializer().(CompileTimeConstantExpr).getIntValue()
       )
     )
+    or
+    result = this.(LiveLiteral).getValue().getIntValue()
   }
 }
 
diff --git a/java/ql/lib/semmle/code/java/frameworks/android/Compose.qll b/java/ql/lib/semmle/code/java/frameworks/android/Compose.qll
@@ -0,0 +1,35 @@
+/**
+ * Provides classes and predicates for working with components generated by the Android's Jetpack Compose compiler.
+ */
+
+import java
+
+/**
+ * A call to a live literal method.
+ * This always returns a constant expression and can be considered as such.
+ */
+class LiveLiteral extends MethodAccess {
+  CompileTimeConstantExpr value;
+
+  LiveLiteral() {
+    this.getMethod() instanceof LiveLiteralMethod and
+    not this.getEnclosingCallable() instanceof LiveLiteralMethod
+  }
+
+  /** Gets the constant value that backs this live literal. */
+  CompileTimeConstantExpr getValue() {
+    result =
+      any(ReturnStmt r | this.getMethod().calls*(r.getEnclosingCallable()))
+          .getResult()
+          .(VarAccess)
+          .getVariable()
+          .getInitializer()
+  }
+
+  override string toString() { result = this.getValue().toString() }
+}
+
+/** A live literal method. */
+class LiveLiteralMethod extends Method {
+  LiveLiteralMethod() { this.getDeclaringType().getName().matches("LiveLiterals$%") }
+}

Original file line number	Diff line number	Diff line change
`@@ -2,10 +2,8 @@`
`2`	`2`	`* Provides classes for working with Java expressions.`
`3`	`3`	`*/`
`4`	`4`
`5`		`-import Member`
`6`		`-import Type`
`7`		`-import Variable`
`8`		`-import Statement`
	`5`	`+import java`
	`6`	`+import semmle.code.java.frameworks.android.Compose`
`9`	`7`
`10`	`8`	`/** A common super-class that represents all kinds of expressions. */`
`11`	`9`	`class Expr extends ExprParent, @expr {`
`@@ -161,6 +159,8 @@ class CompileTimeConstantExpr extends Expr {`
`161`	`159`	`v.isFinal() and`
`162`	`160`	`v.getInitializer().isCompileTimeConstant()`
`163`	`161`	`)`
	`162`	`+ or`
	`163`	`+ this instanceof LiveLiteral`
`164`	`164`	`)`
`165`	`165`	`}`
`166`	`166`
`@@ -185,6 +185,8 @@ class CompileTimeConstantExpr extends Expr {`
`185`	`185`	`exists(Variable v \| this = v.getAnAccess() \|`
`186`	`186`	`result = v.getInitializer().(CompileTimeConstantExpr).getStringValue()`
`187`	`187`	`)`
	`188`	`+ or`
	`189`	`+ result = this.(LiveLiteral).getValue().getStringValue()`
`188`	`190`	`}`
`189`	`191`
`190`	`192`	`/**`
`@@ -297,6 +299,8 @@ class CompileTimeConstantExpr extends Expr {`
`297`	`299`	`exists(Variable v \| this = v.getAnAccess() \|`
`298`	`300`	`result = v.getInitializer().(CompileTimeConstantExpr).getBooleanValue()`
`299`	`301`	`)`
	`302`	`+ or`
	`303`	`+ result = this.(LiveLiteral).getValue().getBooleanValue()`
`300`	`304`	`}`
`301`	`305`
`302`	`306`	`/**`
`@@ -377,6 +381,8 @@ class CompileTimeConstantExpr extends Expr {`
`377`	`381`	`result = v.getInitializer().(CompileTimeConstantExpr).getIntValue()`
`378`	`382`	`)`
`379`	`383`	`)`
	`384`	`+ or`
	`385`	`+ result = this.(LiveLiteral).getValue().getIntValue()`
`380`	`386`	`}`
`381`	`387`	`}`
`382`	`388`