Merge pull request github#8728 from asgerf/ql/library-coverage

QL: Add facilities for data flow

Author: asgerf

config/identical-files.json

@@ -383,7 +383,8 @@
     "csharp/ql/test/TestUtilities/InlineExpectationsTest.qll",
     "java/ql/test/TestUtilities/InlineExpectationsTest.qll",
     "python/ql/test/TestUtilities/InlineExpectationsTest.qll",
-    "ruby/ql/test/TestUtilities/InlineExpectationsTest.qll"
+    "ruby/ql/test/TestUtilities/InlineExpectationsTest.qll",
+    "ql/ql/test/TestUtilities/InlineExpectationsTest.qll"
   ],
   "C++ ExternalAPIs": [
     "cpp/ql/src/Security/CWE/CWE-020/ExternalAPIs.qll",

ql/ql/src/codeql_ql/ast/Ast.qll

@@ -79,6 +79,7 @@ class AstNode extends TAstNode {
 
   /** Gets an annotation of this AST node. */
   Annotation getAnAnnotation() {
+    not this instanceof Annotation and // avoid cyclic parent-child relationship
     toQL(this).getParent() = pragma[only_bind_out](toQL(result)).getParent()
   }
 
@@ -125,6 +126,9 @@ class TopLevel extends TTopLevel, AstNode {
   /** Gets a `newtype` defined at the top-level of this module. */
   NewType getANewType() { result = this.getAMember() }
 
+  /** Gets a `select` clause in the top-level of this module. */
+  Select getASelect() { result = this.getAMember() }
+
   override ModuleMember getAChild(string pred) {
     pred = directMember("getAnImport") and result = this.getAnImport()
     or
@@ -137,6 +141,8 @@ class TopLevel extends TTopLevel, AstNode {
     pred = directMember("getANewType") and result = this.getANewType()
     or
     pred = directMember("getQLDoc") and result = this.getQLDoc()
+    or
+    pred = directMember("getASelect") and result = this.getASelect()
   }
 
   QLDoc getQLDocFor(ModuleMember m) {
@@ -547,6 +553,9 @@ class VarDef extends TVarDef, AstNode {
 
   Type getType() { none() }
 
+  /** Gets a variable access to this `VarDef` */
+  VarAccess getAnAccess() { result.getDeclaration() = this }
+
   override string getAPrimaryQlClass() { result = "VarDef" }
 
   override string toString() { result = this.getName() }

ql/ql/src/codeql_ql/ast/internal/AstNodeNumbering.qll

@@ -0,0 +1,38 @@
+private import codeql_ql.ast.Ast
+
+pragma[inline]
+private predicate isNumberedNode(AstNode node) {
+  // these are not nested in the location of the parent node, so we can't use their location to order them
+  not node instanceof Annotation and
+  not node instanceof QLDoc
+}
+
+private int getNodeDepth(AstNode node) {
+  node instanceof TopLevel and
+  result = 0
+  or
+  isNumberedNode(node) and
+  result = 1 + getNodeDepth(node.getParent())
+}
+
+/**
+ * Gets the pre-order ID for the given `node`, that is, its visit position
+ * in a pre-order traversal of all nodes.
+ *
+ * The children of a node are ordered left-to-right as they appear in the source code.
+ *
+ * The ID is globally unique for this AST node, also across files.
+ *
+ * At the moment this predicate is only defined for node which are:
+ * - reachable via `getAChild` edges from a `TopLevel`, and
+ * - is not a comment or annotation
+ */
+cached
+int getPreOrderId(AstNode node) {
+  node =
+    rank[result](AstNode n, Location loc, int depth |
+      depth = getNodeDepth(n) and loc = n.getLocation()
+    |
+      n order by loc.getFile().getAbsolutePath(), loc.getStartLine(), loc.getStartColumn(), depth
+    )
+}

ql/ql/src/codeql_ql/ast/internal/AstNodes.qll

@@ -204,7 +204,7 @@ QL::AstNode toQL(AST::AstNode n) {
 class TPredicate =
   TCharPred or TClasslessPredicate or TClassPredicate or TDBRelation or TNewTypeBranch;
 
-class TPredOrBuiltin = TPredicate or TNewTypeBranch or TBuiltin;
+class TPredOrBuiltin = TPredicate or TBuiltin;
 
 class TBuiltin = TBuiltinClassless or TBuiltinMember;