//===--- CheckerBase.td - Checker TableGen classes ------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
//
//  This file defines the TableGen core definitions for checkers
//
//===----------------------------------------------------------------------===//

/// Describes a checker or package option type. This is important for validating
/// user supplied inputs.
/// New option types can be added by modifying this enum. Note that this
/// requires changes in the TableGen emitter file ClangSACheckersEmitter.cpp.
class CmdLineOptionTypeEnum<bits<2> val> {
  bits<2> Type = val;
}
def Integer : CmdLineOptionTypeEnum<0>;
def String : CmdLineOptionTypeEnum<1>;
def Boolean : CmdLineOptionTypeEnum<2>;

/// Describes the state of the entry. We wouldn't like to display, for example,
/// developer only entries for a list meant for end users.
class DevelopmentStageEnum<bits<1> val> {
  bits<1> Val = val;
}

/// Alpha entries are under development, might be incomplet, inkorrekt and
/// unstable.
def InAlpha : DevelopmentStageEnum<0>;

/// Released entries are stable, produce minimal, if any false positives,
/// and emits reports that explain the occurance of the bug understandably and
/// thoroughly.
def Released : DevelopmentStageEnum<1>;

/// Marks the entry hidden. Hidden entries won't be displayed in
/// -analyzer-checker-option-help.
class HiddenEnum<bit val> {
  bit Val = val;
}
def DontHide : HiddenEnum<0>;
def Hide : HiddenEnum<1>;

/// Describes an option for a checker or a package.
class CmdLineOption<CmdLineOptionTypeEnum type, string cmdFlag, string desc,
                    string defaultVal, DevelopmentStageEnum stage,
                    HiddenEnum isHidden = DontHide> {
  bits<2> Type = type.Type;
  string  CmdFlag = cmdFlag;
  string  Desc = desc;
  string  DefaultVal = defaultVal;
  bits<1> DevelopmentStage = stage.Val;
  bit     Hidden = isHidden.Val;
}

/// Describes a list of package options.
class PackageOptions<list<CmdLineOption> opts> {
  list<CmdLineOption> PackageOptions = opts;
}

/// Describes a package. Every checker is a part of a package, for example,
/// 'NullDereference' is part of the 'core' package, hence it's full name is
/// 'core.NullDereference'.
/// Example:
///   def Core : Package<"core">;
class Package<string name> {
  string              PackageName = name;
  // This field is optional.
  list<CmdLineOption> PackageOptions;
  Package             ParentPackage;
  bit                 Hidden = 0;
}

/// Describes a 'super' package that holds another package inside it. This is
/// used to nest packages in one another. One may, for example, create the
/// 'builtin' package inside 'core', thus creating the package 'core.builtin'.
/// Example:
///   def CoreBuiltin : Package<"builtin">, ParentPackage<Core>;
class ParentPackage<Package P> { Package ParentPackage = P; }

/// A description. May be displayed to the user when clang is invoked with
/// a '-help'-like command line option.
class HelpText<string text> { string HelpText = text; }

/// Describes what kind of documentation exists for the checker.
class DocumentationEnum<bits<1> val> {
  bits<1> Documentation = val;
}
def NotDocumented : DocumentationEnum<0>;
def HasDocumentation : DocumentationEnum<1>;

class Documentation<DocumentationEnum val> {
  bits<1> Documentation = val.Documentation;
}

/// Describes a checker. Every builtin checker has to be registered with the use
/// of this class (out-of-trunk checkers loaded from plugins obviously don't).
/// Note that a checker has a name (e.g.: 'NullDereference'), and a fullname,
/// that is autogenerated with the help of the ParentPackage field, that also
/// includes package names (e.g.: 'core.NullDereference').
/// Example:
///   def DereferenceChecker : Checker<"NullDereference">,
///     HelpText<"Check for dereferences of null pointers">;
class Checker<string name = ""> {
  string              CheckerName = name;
  string              HelpText;
  // This field is optional.
  list<CmdLineOption> CheckerOptions;
  // This field is optional.
  list<Checker>       Dependencies;
  // This field is optional.
  list<Checker>       WeakDependencies;
  bits<1>             Documentation;
  Package             ParentPackage;
  bit                 Hidden = 0;
}

/// Describes a list of checker options.
class CheckerOptions<list<CmdLineOption> opts> {
  list<CmdLineOption> CheckerOptions = opts;
}

/// Describes (strong) dependencies in between checkers. This is important for
/// modeling checkers, for example, MallocBase depends on the proper modeling of
/// string operations, so it depends on CStringBase. A checker may only be
/// enabled if none of its dependencies (transitively) is disabled. Dependencies
/// are always registered before the dependent checker, and its checker
/// callbacks are also evaluated sooner.
/// One may only depend on a purely modeling checker (that emits no diagnostis).
/// Example:
///   def InnerPointerChecker : Checker<"InnerPointer">,
///     HelpText<"Check for inner pointers of C++ containers used after "
///              "re/deallocation">,
///     Dependencies<[MallocBase]>;
class Dependencies<list<Checker> Deps = []> {
  list<Checker> Dependencies = Deps;
}

/// Describes preferred registration and evaluation order in between checkers.
/// Unlike strong dependencies, this expresses dependencies in between
/// diagnostics, and *not* modeling. In the case of an unsatisfied (disabled)
/// weak dependency, the dependent checker might still be registered. If the
/// weak dependency is satisfied, it'll be registered, and its checker
/// callbacks will be evaluated before the dependent checker. This can be used
/// to ensure that a more specific warning would be displayed in place of a
/// generic one, should multiple checkers detect the same bug. For example,
/// non-null parameter bugs are detected by NonNullParamChecker due to the
/// nonnull attribute, and StdLibraryFunctionsChecker as it models standard
/// functions, and the former is the more specific one. While freeing a
/// dangling pointer is a bug, if it is also a double free, we would like to
/// recognize it as such first and foremost. This works best for fatal error
/// node generation, otherwise both warnings may be present and in any order.
class WeakDependencies<list<Checker> Deps = []> {
  list<Checker> WeakDependencies = Deps;
}

/// Marks a checker or a package hidden. Hidden entries are meant for developers
/// only, and aren't exposed to end users.
class Hidden { bit Hidden = 1; }