QL: Merge pull request #14 from github/predicate-expr-resolution

Resolve predicate expressions

Author: hvitved

ql/consistency-queries/PredicateResolution.ql

@@ -0,0 +1 @@
+import codeql_ql.ast.internal.Predicate::PredConsistency

ql/src/codeql_ql/ast/Ast.qll

@@ -1,6 +1,7 @@
 import ql
 private import codeql_ql.ast.internal.AstNodes
 private import codeql_ql.ast.internal.Module
+private import codeql_ql.ast.internal.Predicate
 private import codeql_ql.ast.internal.Type
 
 /** An AST node of a QL program */
@@ -82,13 +83,30 @@ class PredicateExpr extends TPredicateExpr, AstNode {
 
   override string toString() { result = "predicate" }
 
+  string getName() {
+    exists(Generated::AritylessPredicateExpr ape, Generated::LiteralId id |
+      ape.getParent() = pe and
+      id.getParent() = ape and
+      result = id.getValue()
+    )
+  }
+
+  int getArity() {
+    exists(Generated::Integer i |
+      i.getParent() = pe and
+      result = i.getValue().toInt()
+    )
+  }
+
   ModuleExpr getQualifier() {
     exists(Generated::AritylessPredicateExpr ape |
       ape.getParent() = pe and
       toGenerated(result).getParent() = ape
     )
   }
 
+  Predicate getResolvedPredicate() { resolvePredicateExpr(this, result) }
+
   override AstNode getParent() {
     this in [result.(ClasslessPredicate).getAlias(), result.(HigherOrderFormula).getInput(_)]
   }
@@ -99,7 +117,7 @@ class PredicateExpr extends TPredicateExpr, AstNode {
 /**
  * A classless predicate.
  */
-class ClasslessPredicate extends TClasslessPredicate, Predicate, ModuleMember {
+class ClasslessPredicate extends TClasslessPredicate, Predicate, ModuleDeclaration {
   Generated::ModuleMember member;
   Generated::ClasslessPredicate pred;
 
@@ -253,7 +271,7 @@ class TypeExpr extends TType, AstNode {
 /**
  * A QL module.
  */
-class Module extends TModule, AstNode, ModuleMember {
+class Module extends TModule, ModuleDeclaration {
   Generated::Module mod;
 
   Module() { this = TModule(mod) }
@@ -267,10 +285,7 @@ class Module extends TModule, AstNode, ModuleMember {
     )
   }
 
-  /**
-   * Gets the name of the module.
-   */
-  string getName() { result = mod.getName().(Generated::ModuleName).getChild().getValue() }
+  override string getName() { result = mod.getName().(Generated::ModuleName).getChild().getValue() }
 
   /**
    * Gets a member of the module.
@@ -297,10 +312,22 @@ class ModuleMember extends TModuleMember, AstNode {
   predicate isPrivate() { none() } // TODO: Implement.
 }
 
+/** A declaration. */
+class Declaration extends TDeclaration, AstNode {
+  /** Gets the name of this declaration. */
+  string getName() { none() }
+}
+
+/** An entity that can be declared in a module. */
+class ModuleDeclaration extends TModuleDeclaration, Declaration, ModuleMember { }
+
+/** An type declaration. Either a `class` or a `newtype`. */
+class TypeDeclaration extends TTypeDeclaration, Declaration { }
+
 /**
  * A QL class.
  */
-class Class extends TClass, AstNode, ModuleMember {
+class Class extends TClass, TypeDeclaration, ModuleDeclaration {
   Generated::Dataclass cls;
 
   Class() { this = TClass(cls) }
@@ -314,10 +341,7 @@ class Class extends TClass, AstNode, ModuleMember {
     )
   }
 
-  /**
-   * Gets the name of the class.
-   */
-  string getName() { result = cls.getName().getValue() }
+  override string getName() { result = cls.getName().getValue() }
 
   /**
    * Gets the charateristic predicate for this class.
@@ -365,12 +389,12 @@ class Class extends TClass, AstNode, ModuleMember {
 /**
  * A `newtype Foo` declaration.
  */
-class NewType extends TNewType, ModuleMember {
+class NewType extends TNewType, TypeDeclaration, ModuleDeclaration {
   Generated::Datatype type;
 
   NewType() { this = TNewType(type) }
 
-  string getName() { result = type.getName().getValue() }
+  override string getName() { result = type.getName().getValue() }
 
   override string getAPrimaryQlClass() { result = "NewType" }
 
@@ -390,15 +414,14 @@ class NewType extends TNewType, ModuleMember {
 /**
  * A branch in a `newtype`.
  */
-class NewTypeBranch extends TNewTypeBranch, AstNode {
+class NewTypeBranch extends TNewTypeBranch, TypeDeclaration {
   Generated::DatatypeBranch branch;
 
   NewTypeBranch() { this = TNewTypeBranch(branch) }
 
   override string getAPrimaryQlClass() { result = "NewTypeBranch" }
 
-  /** Gets the name of this branch. */
-  string getName() { result = branch.getName().getValue() }
+  override string getName() { result = branch.getName().getValue() }
 
   /** Gets a field in this branch. */
   VarDecl getField(int i) {

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

@@ -154,4 +154,10 @@ Generated::AstNode toGenerated(AST::AstNode n) {
 
 class TPredicate = TCharPred or TClasslessPredicate or TClassPredicate;
 
-class TModuleMember = TClasslessPredicate or TClass or TModule or TNewType or TImport or TSelect;
+class TModuleMember = TModuleDeclaration or TImport or TSelect;
+
+class TDeclaration = TTypeDeclaration or TModuleDeclaration;
+
+class TTypeDeclaration = TClass or TNewType or TNewTypeBranch;
+
+class TModuleDeclaration = TClasslessPredicate or TModule or TClass or TNewType;

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

@@ -121,7 +121,7 @@ private predicate resolveQualifiedName(Import imp, ContainerOrModule m, int i) {
         m = TFolder(c)
       )
       or
-      defines(getEnclosingModule(imp).getEnclosing*(), q, m, _)
+      definesModule(getEnclosingModule(imp).getEnclosing*(), q, m, _)
     )
     or
     exists(Folder_ mid |
@@ -142,7 +142,7 @@ private predicate resolveSelectionName(Import imp, ContainerOrModule m, int i) {
   or
   exists(ContainerOrModule mid |
     resolveSelectionName(imp, mid, i - 1) and
-    defines(mid, imp.getSelectionName(i), m, true)
+    definesModule(mid, imp.getSelectionName(i), m, true)
   )
 }
 
@@ -158,20 +158,22 @@ predicate resolve(Import imp, FileOrModule m) {
 predicate resolveModuleExpr(ModuleExpr me, FileOrModule m) {
   not m = TFile(any(File f | f.getExtension() = "ql")) and
   not exists(me.getQualifier()) and
-  defines(getEnclosingModule(me).getEnclosing*(), me.getName(), m, _)
+  definesModule(getEnclosingModule(me).getEnclosing*(), me.getName(), m, _)
   or
   exists(FileOrModule mid |
     resolveModuleExpr(me.getQualifier(), mid) and
-    defines(mid, me.getName(), m, true)
+    definesModule(mid, me.getName(), m, true)
   )
 }
 
-private boolean getPublicBool(ModuleMember m) {
-  if m.isPrivate() then result = false else result = true
-}
+boolean getPublicBool(ModuleMember m) { if m.isPrivate() then result = false else result = true }
 
-/** Holds if `container` defines module `m` with name `name`. */
-private predicate defines(
+/**
+ * Holds if `container` defines module `m` with name `name`.
+ *
+ * `m` may be defined either directly or through `import`s.
+ */
+private predicate definesModule(
   ContainerOrModule container, string name, ContainerOrModule m, boolean public
 ) {
   container = m.getEnclosing() and
@@ -188,7 +190,7 @@ private predicate defines(
     container = getEnclosingModule(imp) and
     resolve(imp, m0) and
     not exists(imp.importedAs()) and
-    defines(m0, name, m, true) and
+    definesModule(m0, name, m, true) and
     public = getPublicBool(imp)
   )
   or

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

@@ -0,0 +1,52 @@
+import ql
+private import codeql_ql.ast.internal.Module
+
+private predicate definesPredicate(FileOrModule m, string name, ClasslessPredicate p, boolean public) {
+  m = getEnclosingModule(p) and
+  name = p.getName() and
+  public = getPublicBool(p)
+  or
+  // import X
+  exists(Import imp, FileOrModule m0 |
+    m = getEnclosingModule(imp) and
+    m0 = imp.getResolvedModule() and
+    not exists(imp.importedAs()) and
+    definesPredicate(m0, name, p, true) and
+    public = getPublicBool(imp)
+  )
+  or
+  // predicate X = Y
+  exists(ClasslessPredicate alias |
+    m = getEnclosingModule(alias) and
+    name = alias.getName() and
+    resolvePredicateExpr(alias.getAlias(), p) and
+    public = getPublicBool(alias)
+  )
+}
+
+predicate resolvePredicateExpr(PredicateExpr pe, ClasslessPredicate p) {
+  exists(FileOrModule m, boolean public |
+    not exists(pe.getQualifier()) and
+    m = getEnclosingModule(pe).getEnclosing*() and
+    public = [false, true]
+    or
+    m = pe.getQualifier().getResolvedModule() and
+    public = true
+  |
+    definesPredicate(m, pe.getName(), p, public) and
+    count(p.getParameter(_)) = pe.getArity()
+  )
+}
+
+module PredConsistency {
+  query predicate noResolvePredicateExpr(PredicateExpr pe) {
+    not resolvePredicateExpr(pe, _) and
+    not pe.getLocation().getFile().getAbsolutePath().regexpMatch(".*/(test|examples)/.*")
+  }
+
+  query predicate multipleResolvePredicateExpr(PredicateExpr pe, int c, ClasslessPredicate p) {
+    c = strictcount(ClasslessPredicate p0 | resolvePredicateExpr(pe, p0)) and
+    c > 1 and
+    resolvePredicateExpr(pe, p)
+  }
+}

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

@@ -207,10 +207,6 @@ private predicate qualifier(TypeExpr te, FileOrModule m, boolean public) {
   )
 }
 
-private boolean getPublicBool(ModuleMember m) {
-  if m.isPrivate() then result = false else result = true
-}
-
 private predicate defines(FileOrModule m, string name, Type t, boolean public) {
   exists(Class ty | t = TClass(ty) |
     getEnclosingModule(ty) = m and

ql/src/ide-contextual-queries/localDefinitions.ql

@@ -50,10 +50,18 @@ predicate resolveType(TypeExpr ref, AstNode target, string kind) {
   ref.getLocation().getFile() = getFileBySourceArchiveName(selectedSourceFile())
 }
 
+predicate resolvePredicate(PredicateExpr ref, Predicate target, string kind) {
+  target = ref.getResolvedPredicate() and
+  kind = "predicate" and
+  ref.getLocation().getFile() = getFileBySourceArchiveName(selectedSourceFile())
+}
+
 predicate resolve(Loc ref, Loc target, string kind) {
   resolveModule(ref.asAst(), target.asMod(), kind)
   or
   resolveType(ref.asAst(), target.asAst(), kind)
+  or
+  resolvePredicate(ref.asAst(), target.asAst(), kind)
 }
 
 from Loc ref, Loc target, string kind

ql/src/ide-contextual-queries/localReferences.ql

@@ -49,10 +49,18 @@ predicate resolveType(TypeExpr ref, AstNode target, string kind) {
   ref.getLocation().getFile() = getFileBySourceArchiveName(selectedSourceFile())
 }
 
+predicate resolvePredicate(PredicateExpr ref, Predicate target, string kind) {
+  target = ref.getResolvedPredicate() and
+  kind = "predicate" and
+  ref.getLocation().getFile() = getFileBySourceArchiveName(selectedSourceFile())
+}
+
 predicate resolve(Loc ref, Loc target, string kind) {
   resolveModule(ref.asAst(), target.asMod(), kind)
   or
   resolveType(ref.asAst(), target.asAst(), kind)
+  or
+  resolvePredicate(ref.asAst(), target.asAst(), kind)
 }
 
 from Loc ref, Loc target, string kind