add JS support for static initializers

Author: erik-krogh

javascript/change-notes/2021-09-07-static-initializer.md

@@ -0,0 +1,2 @@
+lgtm,codescanning
+* Support for the ECMAScript proposed feature "class static initialization blocks" has been added.

javascript/extractor/src/com/semmle/jcorn/Parser.java

@@ -83,6 +83,7 @@
 import com.semmle.js.ast.SourceLocation;
 import com.semmle.js.ast.SpreadElement;
 import com.semmle.js.ast.Statement;
+import com.semmle.js.ast.StaticInitializer;
 import com.semmle.js.ast.Super;
 import com.semmle.js.ast.SwitchCase;
 import com.semmle.js.ast.SwitchStatement;
@@ -3244,6 +3245,10 @@ protected MemberDefinition<?> parseClassMember(boolean hadConstructor) {
     PropertyInfo pi = new PropertyInfo(false, isGenerator, methodStartLoc);
     this.parsePropertyName(pi);
     boolean isStatic = isMaybeStatic && this.type != TokenType.parenL;
+    if (isStatic && this.type == TokenType.braceL) {
+      BlockStatement block = parseBlock(false);
+      return new StaticInitializer(block.getLoc(), block);
+    }
     if (isStatic) {
       if (isGenerator) this.unexpected();
       isGenerator = this.eat(TokenType.star);

javascript/ql/test/library-tests/Classes/staticInitializer.js

@@ -0,0 +1,18 @@
+class MyClass {
+  static x = 1;
+  constructor() {
+    this.y = 2;
+  }
+  static {
+    MyClass.z = 3;
+  }
+  foo() {
+    this.t = 4;
+  }
+  static bar() {
+    this.u = 5;
+  }
+  static {
+    this.v = 6;
+  }
+}

javascript/ql/test/library-tests/Classes/tests.expected

@@ -4,27 +4,31 @@ test_FieldInits
 | privateFields.js:2:2:2:15 | #privDecl = 3; | privateFields.js:2:14:2:14 | 3 |
 | privateFields.js:3:2:3:12 | #if = "if"; | privateFields.js:3:8:3:11 | "if" |
 | privateFields.js:21:2:21:22 | ["#publ ... "] = 6; | privateFields.js:21:21:21:21 | 6 |
+| staticInitializer.js:2:3:2:15 | static x = 1; | staticInitializer.js:2:14:2:14 | 1 |
 test_ComputedMethods
 | tst.js:3:3:3:56 | ["const ... r. */ } |
 | tst.js:13:3:13:10 | [m]() {} |
 test_StaticMethods
 | points.js:15:3:17:3 | static  ... t";\\n  } |
 | points.js:30:3:32:3 | static  ... t";\\n  } |
 | staticConstructor.js:2:3:2:59 | static  ... tor"; } |
+| staticInitializer.js:12:3:14:3 | static  ...  5;\\n  } |
 test_ClassDefinition_getSuperClass
 | points.js:20:1:33:1 | class C ... ;\\n  }\\n} | points.js:20:29:20:33 | Point |
 | tst.js:6:1:8:1 | class B ... t); }\\n} | tst.js:6:17:6:17 | A |
 test_ClassNodeStaticMethod
 | points.js:1:1:18:1 | class P ... ;\\n  }\\n} | className | points.js:15:19:17:3 | () {\\n   ... t";\\n  } |
 | points.js:20:1:33:1 | class C ... ;\\n  }\\n} | className | points.js:30:19:32:3 | () {\\n   ... t";\\n  } |
 | staticConstructor.js:1:1:3:1 | class M ... r"; }\\n} | constructor | staticConstructor.js:2:21:2:59 | () { re ... tor"; } |
+| staticInitializer.js:1:1:18:1 | class M ... ;\\n  }\\n} | bar | staticInitializer.js:12:13:14:3 | () {\\n   ...  5;\\n  } |
 test_ClassDefinitions
 | dataflow.js:4:2:13:2 | class F ... \\n\\t\\t}\\n\\t} |
 | fields.js:1:1:4:1 | class C ...  = 42\\n} |
 | points.js:1:1:18:1 | class P ... ;\\n  }\\n} |
 | points.js:20:1:33:1 | class C ... ;\\n  }\\n} |
 | privateFields.js:1:1:27:1 | class F ... );\\n\\t}\\n} |
 | staticConstructor.js:1:1:3:1 | class M ... r"; }\\n} |
+| staticInitializer.js:1:1:18:1 | class M ... ;\\n  }\\n} |
 | tst.js:1:9:4:1 | class { ...  */ }\\n} |
 | tst.js:6:1:8:1 | class B ... t); }\\n} |
 | tst.js:11:1:14:1 | class C ... () {}\\n} |
@@ -38,13 +42,15 @@ test_Fields
 | privateFields.js:3:2:3:12 | #if = "if"; | privateFields.js:3:2:3:4 | #if |
 | privateFields.js:19:2:19:13 | #privSecond; | privateFields.js:19:2:19:12 | #privSecond |
 | privateFields.js:21:2:21:22 | ["#publ ... "] = 6; | privateFields.js:21:3:21:16 | "#publicField" |
+| staticInitializer.js:2:3:2:15 | static x = 1; | staticInitializer.js:2:10:2:10 | x |
 test_ClassDefinition_getName
 | dataflow.js:4:2:13:2 | class F ... \\n\\t\\t}\\n\\t} | Foo |
 | fields.js:1:1:4:1 | class C ...  = 42\\n} | C |
 | points.js:1:1:18:1 | class P ... ;\\n  }\\n} | Point |
 | points.js:20:1:33:1 | class C ... ;\\n  }\\n} | ColouredPoint |
 | privateFields.js:1:1:27:1 | class F ... );\\n\\t}\\n} | Foo |
 | staticConstructor.js:1:1:3:1 | class M ... r"; }\\n} | MyClass |
+| staticInitializer.js:1:1:18:1 | class M ... ;\\n  }\\n} | MyClass |
 | tst.js:1:9:4:1 | class { ...  */ }\\n} | A |
 | tst.js:6:1:8:1 | class B ... t); }\\n} | B |
 | tst.js:11:1:14:1 | class C ... () {}\\n} | C |
@@ -67,6 +73,9 @@ test_MethodDefinitions
 | privateFields.js:23:2:26:2 | calls() ... l();\\n\\t} | privateFields.js:23:2:23:6 | calls | privateFields.js:23:7:26:2 | () {\\n\\t\\t ... l();\\n\\t} | privateFields.js:1:1:27:1 | class F ... );\\n\\t}\\n} |
 | staticConstructor.js:1:15:1:14 | constructor() {} | staticConstructor.js:1:15:1:14 | constructor | staticConstructor.js:1:15:1:14 | () {} | staticConstructor.js:1:1:3:1 | class M ... r"; }\\n} |
 | staticConstructor.js:2:3:2:59 | static  ... tor"; } | staticConstructor.js:2:10:2:20 | constructor | staticConstructor.js:2:21:2:59 | () { re ... tor"; } | staticConstructor.js:1:1:3:1 | class M ... r"; }\\n} |
+| staticInitializer.js:3:3:5:3 | constru ...  2;\\n  } | staticInitializer.js:3:3:3:13 | constructor | staticInitializer.js:3:14:5:3 | () {\\n   ...  2;\\n  } | staticInitializer.js:1:1:18:1 | class M ... ;\\n  }\\n} |
+| staticInitializer.js:9:3:11:3 | foo() { ...  4;\\n  } | staticInitializer.js:9:3:9:5 | foo | staticInitializer.js:9:6:11:3 | () {\\n   ...  4;\\n  } | staticInitializer.js:1:1:18:1 | class M ... ;\\n  }\\n} |
+| staticInitializer.js:12:3:14:3 | static  ...  5;\\n  } | staticInitializer.js:12:10:12:12 | bar | staticInitializer.js:12:13:14:3 | () {\\n   ...  5;\\n  } | staticInitializer.js:1:1:18:1 | class M ... ;\\n  }\\n} |
 | tst.js:2:3:2:50 | "constr ... r. */ } | tst.js:2:3:2:15 | "constructor" | tst.js:2:16:2:50 | () { /* ... r. */ } | tst.js:1:9:4:1 | class { ...  */ }\\n} |
 | tst.js:3:3:3:56 | ["const ... r. */ } | tst.js:3:4:3:16 | "constructor" | tst.js:3:18:3:56 | () { /* ... r. */ } | tst.js:1:9:4:1 | class { ...  */ }\\n} |
 | tst.js:7:3:7:38 | constru ... get); } | tst.js:7:3:7:13 | constructor | tst.js:7:14:7:38 | () { su ... get); } | tst.js:6:1:8:1 | class B ... t); }\\n} |
@@ -99,6 +108,12 @@ test_getAMember
 | privateFields.js:1:1:27:1 | class F ... );\\n\\t}\\n} | privateFields.js:23:2:26:2 | calls() ... l();\\n\\t} |
 | staticConstructor.js:1:1:3:1 | class M ... r"; }\\n} | staticConstructor.js:1:15:1:14 | constructor() {} |
 | staticConstructor.js:1:1:3:1 | class M ... r"; }\\n} | staticConstructor.js:2:3:2:59 | static  ... tor"; } |
+| staticInitializer.js:1:1:18:1 | class M ... ;\\n  }\\n} | staticInitializer.js:2:3:2:15 | static x = 1; |
+| staticInitializer.js:1:1:18:1 | class M ... ;\\n  }\\n} | staticInitializer.js:3:3:5:3 | constru ...  2;\\n  } |
+| staticInitializer.js:1:1:18:1 | class M ... ;\\n  }\\n} | staticInitializer.js:6:10:8:3 | {\\n    M ...  3;\\n  } |
+| staticInitializer.js:1:1:18:1 | class M ... ;\\n  }\\n} | staticInitializer.js:9:3:11:3 | foo() { ...  4;\\n  } |
+| staticInitializer.js:1:1:18:1 | class M ... ;\\n  }\\n} | staticInitializer.js:12:3:14:3 | static  ...  5;\\n  } |
+| staticInitializer.js:1:1:18:1 | class M ... ;\\n  }\\n} | staticInitializer.js:15:10:17:3 | {\\n    t ...  6;\\n  } |
 | tst.js:1:9:4:1 | class { ...  */ }\\n} | tst.js:2:3:2:50 | "constr ... r. */ } |
 | tst.js:1:9:4:1 | class { ...  */ }\\n} | tst.js:3:3:3:56 | ["const ... r. */ } |
 | tst.js:6:1:8:1 | class B ... t); }\\n} | tst.js:7:3:7:38 | constru ... get); } |
@@ -124,6 +139,9 @@ test_MethodNames
 | privateFields.js:23:2:26:2 | calls() ... l();\\n\\t} | calls |
 | staticConstructor.js:1:15:1:14 | constructor() {} | constructor |
 | staticConstructor.js:2:3:2:59 | static  ... tor"; } | constructor |
+| staticInitializer.js:3:3:5:3 | constru ...  2;\\n  } | constructor |
+| staticInitializer.js:9:3:11:3 | foo() { ...  4;\\n  } | foo |
+| staticInitializer.js:12:3:14:3 | static  ...  5;\\n  } | bar |
 | tst.js:2:3:2:50 | "constr ... r. */ } | constructor |
 | tst.js:3:3:3:56 | ["const ... r. */ } | constructor |
 | tst.js:7:3:7:38 | constru ... get); } | constructor |
@@ -148,6 +166,7 @@ test_ConstructorDefinitions
 | points.js:21:3:24:3 | constru ...  c;\\n  } |
 | privateFields.js:1:11:1:10 | constructor() {} |
 | staticConstructor.js:1:15:1:14 | constructor() {} |
+| staticInitializer.js:3:3:5:3 | constru ...  2;\\n  } |
 | tst.js:2:3:2:50 | "constr ... r. */ } |
 | tst.js:7:3:7:38 | constru ... get); } |
 | tst.js:11:9:11:8 | constructor() {} |
@@ -158,6 +177,7 @@ test_ClassNodeConstructor
 | points.js:20:1:33:1 | class C ... ;\\n  }\\n} | points.js:21:14:24:3 | (x, y,  ...  c;\\n  } |
 | privateFields.js:1:1:27:1 | class F ... );\\n\\t}\\n} | privateFields.js:1:11:1:10 | () {} |
 | staticConstructor.js:1:1:3:1 | class M ... r"; }\\n} | staticConstructor.js:1:15:1:14 | () {} |
+| staticInitializer.js:1:1:18:1 | class M ... ;\\n  }\\n} | staticInitializer.js:3:14:5:3 | () {\\n   ...  2;\\n  } |
 | tst.js:1:9:4:1 | class { ...  */ }\\n} | tst.js:2:16:2:50 | () { /* ... r. */ } |
 | tst.js:6:1:8:1 | class B ... t); }\\n} | tst.js:7:14:7:38 | () { su ... get); } |
 | tst.js:11:1:14:1 | class C ... () {}\\n} | tst.js:11:9:11:8 | () {} |
@@ -170,6 +190,7 @@ test_ClassNodeInstanceMethod
 | privateFields.js:1:1:27:1 | class F ... );\\n\\t}\\n} | equals | privateFields.js:10:8:12:2 | (o) {\\n\\t ... ecl;\\n\\t} |
 | privateFields.js:1:1:27:1 | class F ... );\\n\\t}\\n} | reads | privateFields.js:4:7:8:2 | () {\\n\\t\\t ... #if;\\n\\t} |
 | privateFields.js:1:1:27:1 | class F ... );\\n\\t}\\n} | writes | privateFields.js:14:8:17:2 | () {\\n\\t\\t ... = 5;\\n\\t} |
+| staticInitializer.js:1:1:18:1 | class M ... ;\\n  }\\n} | foo | staticInitializer.js:9:6:11:3 | () {\\n   ...  4;\\n  } |
 | tst.js:1:9:4:1 | class { ...  */ }\\n} | constructor | tst.js:3:18:3:56 | () { /* ... r. */ } |
 | tst.js:11:1:14:1 | class C ... () {}\\n} | m | tst.js:12:4:12:8 | () {} |
 getAccessModifier
@@ -223,6 +244,15 @@ getAccessModifier
 | staticConstructor.js:2:3:2:59 | static  ... tor"; } | staticConstructor.js:2:10:2:20 | constructor | Public |
 | staticConstructor.js:4:1:4:11 | console.log | staticConstructor.js:4:9:4:11 | log | Public |
 | staticConstructor.js:4:13:4:31 | MyClass.constructor | staticConstructor.js:4:21:4:31 | constructor | Public |
+| staticInitializer.js:2:3:2:15 | static x = 1; | staticInitializer.js:2:10:2:10 | x | Public |
+| staticInitializer.js:3:3:5:3 | constru ...  2;\\n  } | staticInitializer.js:3:3:3:13 | constructor | Public |
+| staticInitializer.js:4:5:4:10 | this.y | staticInitializer.js:4:10:4:10 | y | Public |
+| staticInitializer.js:7:5:7:13 | MyClass.z | staticInitializer.js:7:13:7:13 | z | Public |
+| staticInitializer.js:9:3:11:3 | foo() { ...  4;\\n  } | staticInitializer.js:9:3:9:5 | foo | Public |
+| staticInitializer.js:10:5:10:10 | this.t | staticInitializer.js:10:10:10:10 | t | Public |
+| staticInitializer.js:12:3:14:3 | static  ...  5;\\n  } | staticInitializer.js:12:10:12:12 | bar | Public |
+| staticInitializer.js:13:5:13:10 | this.u | staticInitializer.js:13:10:13:10 | u | Public |
+| staticInitializer.js:16:5:16:10 | this.v | staticInitializer.js:16:10:16:10 | v | Public |
 | tst.js:2:3:2:50 | "constr ... r. */ } | tst.js:2:3:2:15 | "constructor" | Public |
 | tst.js:3:3:3:56 | ["const ... r. */ } | tst.js:3:4:3:16 | "constructor" | Public |
 | tst.js:7:3:7:38 | constru ... get); } | tst.js:7:3:7:13 | constructor | Public |
@@ -233,3 +263,6 @@ getAccessModifier
 dataflow
 | dataflow.js:2:15:2:22 | "source" | dataflow.js:14:7:14:25 | new Foo().getPriv() |
 | dataflow.js:2:15:2:22 | "source" | dataflow.js:16:7:16:33 | new Foo ... ivate() |
+staticInitializer
+| staticInitializer.js:1:1:18:1 | class M ... ;\\n  }\\n} | staticInitializer.js:6:10:8:3 | {\\n    M ...  3;\\n  } |
+| staticInitializer.js:1:1:18:1 | class M ... ;\\n  }\\n} | staticInitializer.js:15:10:17:3 | {\\n    t ...  6;\\n  } |

javascript/ql/test/library-tests/Classes/tests.ql

@@ -1,20 +1,76 @@
-import FieldInits
-import ComputedMethods
-import StaticMethods
-import ClassDefinition_getSuperClass
-import ClassNodeStaticMethod
-import ClassDefinitions
-import AccessorMethods
-import Fields
-import ClassDefinition_getName
-import MethodDefinitions
-import getAMember
-import MethodNames
-import NewTargetExpr
-import SuperExpr
-import SyntheticConstructors
-import ConstructorDefinitions
-import ClassNodeConstructor
-import ClassNodeInstanceMethod
-import PrivateField
-import ClassFlow
+import javascript
+
+query predicate test_FieldInits(FieldDefinition field, Expr res) { res = field.getInit() }
+
+query predicate test_ComputedMethods(MethodDefinition md) { md.isComputed() }
+
+query predicate test_StaticMethods(MethodDefinition md) { md.isStatic() }
+
+query predicate test_ClassDefinition_getSuperClass(ClassDefinition cd, Expr res) {
+  res = cd.getSuperClass()
+}
+
+query predicate test_ClassNodeStaticMethod(
+  DataFlow::ClassNode class_, string name, DataFlow::FunctionNode res
+) {
+  res = class_.getStaticMethod(name)
+}
+
+query predicate test_ClassDefinitions(ClassDefinition cd) { any() }
+
+query predicate test_AccessorMethods(AccessorMethodDefinition amd) { any() }
+
+query predicate test_Fields(FieldDefinition field, Expr res) { res = field.getNameExpr() }
+
+query predicate test_ClassDefinition_getName(ClassDefinition cd, string res) { res = cd.getName() }
+
+query predicate test_MethodDefinitions(
+  MethodDefinition md, Expr res0, FunctionExpr res1, ClassDefinition res2
+) {
+  res0 = md.getNameExpr() and res1 = md.getBody() and res2 = md.getDeclaringClass()
+}
+
+query predicate test_getAMember(ClassDefinition c, MemberDeclaration res) { res = c.getAMember() }
+
+query predicate test_MethodNames(MethodDefinition md, string res) { res = md.getName() }
+
+query predicate test_NewTargetExpr(NewTargetExpr e) { any() }
+
+query predicate test_SuperExpr(SuperExpr s) { any() }
+
+query predicate test_SyntheticConstructors(ConstructorDefinition cd) { cd.isSynthetic() }
+
+query predicate test_ConstructorDefinitions(ConstructorDefinition cd) { any() }
+
+query predicate test_ClassNodeConstructor(DataFlow::ClassNode class_, DataFlow::FunctionNode res) {
+  res = class_.getConstructor()
+}
+
+query predicate test_ClassNodeInstanceMethod(
+  DataFlow::ClassNode class_, string name, DataFlow::FunctionNode res
+) {
+  res = class_.getInstanceMethod(name)
+}
+
+query string getAccessModifier(DataFlow::PropRef ref, Expr prop) {
+  prop = ref.getPropertyNameExpr() and
+  if ref.isPrivateField() then result = "Private" else result = "Public"
+}
+
+class Configuration extends DataFlow::Configuration {
+  Configuration() { this = "ClassDataFlowTestingConfig" }
+
+  override predicate isSource(DataFlow::Node source) {
+    source.getEnclosingExpr().(StringLiteral).getValue().toLowerCase() = "source"
+  }
+
+  override predicate isSink(DataFlow::Node sink) {
+    any(DataFlow::CallNode call | call.getCalleeName() = "sink").getAnArgument() = sink
+  }
+}
+
+query predicate dataflow(DataFlow::Node pred, DataFlow::Node succ) {
+  any(Configuration c).hasFlow(pred, succ)
+}
+
+query BlockStmt staticInitializer(ClassDefinition cd) { result = cd.getAStaticInitializerBlock() }