8190217: Add a JS "static checker" sample for nashorn parser API
authorsundar
Thu, 26 Oct 2017 20:57:19 +0530
changeset 47457 217860329f71
parent 47456 9c1e4b0a4761
child 47458 945935416d7c
8190217: Add a JS "static checker" sample for nashorn parser API Reviewed-by: jlaskey
src/sample/nashorn/bad_patterns.js
src/sample/nashorn/staticchecker.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/sample/nashorn/bad_patterns.js	Thu Oct 26 20:57:19 2017 +0530
@@ -0,0 +1,68 @@
+/*
+ * Copyright (c) 2017, Oracle and/or its affiliates. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ *   - Redistributions of source code must retain the above copyright
+ *     notice, this list of conditions and the following disclaimer.
+ *
+ *   - Redistributions in binary form must reproduce the above copyright
+ *     notice, this list of conditions and the following disclaimer in the
+ *     documentation and/or other materials provided with the distribution.
+ *
+ *   - Neither the name of Oracle nor the names of its
+ *     contributors may be used to endorse or promote products derived
+ *     from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
+ * IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
+ * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE COPYRIGHT OWNER OR
+ * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+ * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+ * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
+ * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+ * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+/**
+ * This is a test script file for staticchecker.js.
+ *
+ * Usage:
+ *    jjs --language=es6 staticcheker.js -- bad_patterns.js
+ */
+var obj = {}
+obj.__proto__ = null;
+
+with(obj) {}
+
+delete obj;
+
+eval("print('hello')")
+
+Object = null
+JavaImporter = undefined
+
+function func() {}
+
+func.prototype.x = 44;
+
+Object.prototype.foo = "hello";
+
+String.prototype.bar = function() {}
+
+try {
+   eval("***");
+} catch(e) {}
+
+try {
+   eval("***");
+} catch(e) { ; }
+
+try {
+   eval("***");
+} catch(e) { print(e) }
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/sample/nashorn/staticchecker.js	Thu Oct 26 20:57:19 2017 +0530
@@ -0,0 +1,207 @@
+/*
+ * Copyright (c) 2017, Oracle and/or its affiliates. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ *   - Redistributions of source code must retain the above copyright
+ *     notice, this list of conditions and the following disclaimer.
+ *
+ *   - Redistributions in binary form must reproduce the above copyright
+ *     notice, this list of conditions and the following disclaimer in the
+ *     documentation and/or other materials provided with the distribution.
+ *
+ *   - Neither the name of Oracle nor the names of its
+ *     contributors may be used to endorse or promote products derived
+ *     from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
+ * IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
+ * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE COPYRIGHT OWNER OR
+ * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+ * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+ * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
+ * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+ * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+// Usage: jjs --language=es6 staticchecker.js -- <file>
+//    or  jjs --language=es6 staticchecker.js -- <directory>
+// default argument is the current directory
+
+if (arguments.length == 0) {
+    arguments[0] = ".";
+}
+
+const File = Java.type("java.io.File");
+const file = new File(arguments[0]);
+if (!file.exists()) {
+    print(arguments[0] + " is neither a file nor a directory");
+    exit(1);
+}
+
+// A simple static checker for javascript best practices.
+// static checks performed are:
+//
+// *  __proto__ magic property is bad (non-standard)
+// * 'with' statements are bad
+// * 'eval' calls are bad
+// * 'delete foo' (scope variable delete) is bad
+// * assignment to standard globals is bad (eg. Object = "hello")
+// * assignment to property on standard prototype is bad (eg. String.prototype.foo = 45)
+// * exception swallow (empty catch block in try-catch statements)
+
+const Files = Java.type("java.nio.file.Files");
+const EmptyStatementTree = Java.type("jdk.nashorn.api.tree.EmptyStatementTree");
+const IdentifierTree = Java.type("jdk.nashorn.api.tree.IdentifierTree");
+const MemberSelectTree = Java.type("jdk.nashorn.api.tree.MemberSelectTree");
+const Parser = Java.type("jdk.nashorn.api.tree.Parser");
+const SimpleTreeVisitor = Java.type("jdk.nashorn.api.tree.SimpleTreeVisitorES6");
+const Tree = Java.type("jdk.nashorn.api.tree.Tree");
+
+const parser = Parser.create("-scripting", "--language=es6");
+
+// capture standard global upfront
+const globals = new Set();
+for (let name of Object.getOwnPropertyNames(this)) {
+    globals.add(name);
+}
+
+const checkFile = function(file) {
+    print("Parsing " + file);
+    const ast = parser.parse(file, print);
+    if (!ast) {
+        print("FAILED to parse: " + file);
+        return;
+    }
+
+    const checker = new (Java.extend(SimpleTreeVisitor)) {
+        lineMap: null,
+
+        printWarning(node, msg) {
+            var pos = node.startPosition;
+            var line = this.lineMap.getLineNumber(pos);
+            var column = this.lineMap.getColumnNumber(pos);
+            print(`WARNING: ${msg} in ${file} @ ${line}:${column}`);
+        },
+        
+        printWithWarning(node) {
+            this.printWarning(node, "'with' usage");
+        },
+
+        printProtoWarning(node) {
+            this.printWarning(node, "__proto__ usage");
+        },
+
+        printScopeDeleteWarning(node, varName) {
+            this.printWarning(node, `delete ${varName}`);
+        },
+
+        hasOnlyEmptyStats(stats) {
+            const itr = stats.iterator();
+            while (itr.hasNext()) {
+                if (! (itr.next() instanceof EmptyStatementTree)) {
+                    return false;
+                }
+            }
+
+            return true;
+        },
+
+        checkProto(node, name) {
+            if (name == "__proto__") {
+                this.printProtoWarning(node);
+            }
+        },
+
+        checkAssignment(lhs) {
+            if (lhs instanceof IdentifierTree && globals.has(lhs.name)) {
+                this.printWarning(lhs, `assignment to standard global "${lhs.name}"`);
+            } else if (lhs instanceof MemberSelectTree) {
+                const expr = lhs.expression;
+                if (expr instanceof MemberSelectTree &&
+                    expr.expression instanceof IdentifierTree &&
+                    globals.has(expr.expression.name) && 
+                    "prototype" == expr.identifier) {
+                    this.printWarning(lhs, 
+                        `property set "${expr.expression.name}.prototype.${lhs.identifier}"`);
+                }
+            }
+        },
+
+        visitAssignment(node, extra) {
+            this.checkAssignment(node.variable);
+            Java.super(checker).visitAssignment(node, extra);
+        },
+
+        visitCatch(node, extra) {
+            var stats = node.block.statements;
+            if (stats.empty || this.hasOnlyEmptyStats(stats)) {
+                this.printWarning(node, "exception swallow");
+            }
+            Java.super(checker).visitCatch(node, extra);
+        },
+
+        visitCompilationUnit(node, extra) {
+            this.lineMap = node.lineMap;
+            Java.super(checker).visitCompilationUnit(node, extra);
+        },
+
+        visitFunctionCall(node, extra) {
+           var func = node.functionSelect;
+           if (func instanceof IdentifierTree && func.name == "eval") {
+               this.printWarning(node, "eval call found");
+           }
+           Java.super(checker).visitFunctionCall(node, extra);
+        },
+
+        visitIdentifier(node, extra) {
+            this.checkProto(node, node.name);
+            Java.super(checker).visitIdentifier(node, extra);
+        },
+
+        visitMemberSelect(node, extra) {
+            this.checkProto(node, node.identifier);
+            Java.super(checker).visitMemberSelect(node, extra);
+        },
+
+        visitProperty(node, extra) {
+            this.checkProto(node, node.key);
+            Java.super(checker).visitProperty(node, extra);
+        },
+
+        visitUnary(node, extra) {
+            if (node.kind == Tree.Kind.DELETE &&
+                node.expression instanceof IdentifierTree) {
+                this.printScopeDeleteWarning(node, node.expression.name);
+            }
+            Java.super(checker).visitUnary(node, extra);
+        },
+
+        visitWith(node, extra) {
+            this.printWithWarning(node);
+            Java.super(checker).visitWith(node, extra);
+        }
+    };
+
+    try {
+        ast.accept(checker, null);
+    } catch (e) {
+        print(e);
+        if (e.printStackTrace) e.printStackTrace();
+        if (e.stack) print(e.stack);
+    }
+}
+
+if (file.isDirectory()) {
+    Files.walk(file.toPath())
+        .filter(function(p) Files.isRegularFile(p))
+        .filter(function(p) p.toFile().name.endsWith('.js'))
+        .forEach(checkFile);
+} else {
+    checkFile(file);
+}