zeek/src/Func.h

401 lines
11 KiB
C++

// See the file "COPYING" in the main distribution directory for copyright.
#pragma once
#include <utility>
#include <memory>
#include <string>
#include <vector>
#include <tuple>
#include <type_traits>
#include "zeek/ZeekList.h"
#include "zeek/Stmt.h"
#include "zeek/Obj.h"
#include "zeek/IntrusivePtr.h"
#include "zeek/Type.h" /* for function_flavor */
#include "zeek/TraverseTypes.h"
#include "zeek/ZeekArgs.h"
#include "zeek/BifReturnVal.h"
ZEEK_FORWARD_DECLARE_NAMESPACED(Scope, zeek::detail);
ZEEK_FORWARD_DECLARE_NAMESPACED(Val, zeek);
ZEEK_FORWARD_DECLARE_NAMESPACED(Stmt, zeek::detail);
ZEEK_FORWARD_DECLARE_NAMESPACED(CallExpr, zeek::detail);
ZEEK_FORWARD_DECLARE_NAMESPACED(ID, zeek::detail);
ZEEK_FORWARD_DECLARE_NAMESPACED(FuncType, zeek);
ZEEK_FORWARD_DECLARE_NAMESPACED(Frame, zeek::detail);
namespace caf {
template <class> class expected;
}
namespace broker {
class data;
using vector = std::vector<data>;
using caf::expected;
}
namespace zeek {
namespace detail {
using ScopePtr = IntrusivePtr<Scope>;
using IDPtr = IntrusivePtr<ID>;
using StmtPtr = IntrusivePtr<Stmt>;
class ScriptFunc;
} // namespace detail
class Func;
using FuncPtr = IntrusivePtr<Func>;
class Func : public Obj {
public:
static inline const FuncPtr nil;
enum Kind { SCRIPT_FUNC, BUILTIN_FUNC };
static constexpr auto BRO_FUNC [[deprecated("Remove in v4.1. Use Func::SCRIPT_FUNC instead.")]] = SCRIPT_FUNC;
explicit Func(Kind arg_kind);
~Func() override;
virtual bool IsPure() const = 0;
FunctionFlavor Flavor() const { return GetType()->Flavor(); }
struct Body {
detail::StmtPtr stmts;
int priority;
bool operator<(const Body& other) const
{ return priority > other.priority; } // reverse sort
};
const std::vector<Body>& GetBodies() const { return bodies; }
bool HasBodies() const { return bodies.size(); }
[[deprecated("Remove in v4.1. Use Invoke() instead.")]]
Val* Call(ValPList* args, detail::Frame* parent = nullptr) const;
/**
* Calls a Zeek function.
* @param args the list of arguments to the function call.
* @param parent the frame from which the function is being called.
* @return the return value of the function call.
*/
virtual ValPtr Invoke(
zeek::Args* args, detail::Frame* parent = nullptr) const = 0;
/**
* A version of Invoke() taking a variable number of individual arguments.
*/
template <class... Args>
std::enable_if_t<
std::is_convertible_v<std::tuple_element_t<0, std::tuple<Args...>>, ValPtr>,
ValPtr>
Invoke(Args&&... args) const
{
auto zargs = zeek::Args{std::forward<Args>(args)...};
return Invoke(&zargs);
}
// Add a new event handler to an existing function (event).
virtual void AddBody(detail::StmtPtr new_body,
const std::vector<detail::IDPtr>& new_inits,
size_t new_frame_size, int priority = 0);
virtual void SetScope(detail::ScopePtr newscope);
virtual detail::Scope* GetScope() const { return scope.get(); }
[[deprecated("Remove in v4.1. Use GetType().")]]
virtual FuncType* FType() const { return type.get(); }
const FuncTypePtr& GetType() const
{ return type; }
Kind GetKind() const { return kind; }
const char* Name() const { return name.c_str(); }
void SetName(const char* arg_name) { name = arg_name; }
void Describe(ODesc* d) const override = 0;
virtual void DescribeDebug(ODesc* d, const zeek::Args* args) const;
virtual FuncPtr DoClone();
virtual detail::TraversalCode Traverse(detail::TraversalCallback* cb) const;
uint32_t GetUniqueFuncID() const { return unique_id; }
static const FuncPtr& GetFuncPtrByID(uint32_t id)
{ return id >= unique_ids.size() ? Func::nil : unique_ids[id]; }
protected:
Func();
// Copies this function's state into other.
void CopyStateInto(Func* other) const;
// Helper function for checking result of plugin hook.
void CheckPluginResult(bool handled, const ValPtr& hook_result,
FunctionFlavor flavor) const;
std::vector<Body> bodies;
detail::ScopePtr scope;
Kind kind;
uint32_t unique_id;
FuncTypePtr type;
std::string name;
static inline std::vector<FuncPtr> unique_ids;
};
namespace detail {
class ScriptFunc final : public Func {
public:
ScriptFunc(const IDPtr& id, StmtPtr body,
const std::vector<IDPtr>& inits,
size_t frame_size, int priority);
~ScriptFunc() override;
bool IsPure() const override;
ValPtr Invoke(zeek::Args* args, Frame* parent) const override;
/**
* Creates a separate frame for captures and initializes its
* elements. The list of captures comes from the ScriptFunc's
* type, so doesn't need to be passed in, just the frame to
* use in evaluating the identifiers.
*
* @param f the frame used for evaluating the captured identifiers
*/
void CreateCaptures(Frame* f);
/**
* Returns the frame associated with this function for tracking
* captures, or nil if there isn't one.
*
* @return internal frame kept by the function for persisting captures
*/
Frame* GetCapturesFrame() const { return captures_frame; }
// Same definition as in Frame.h.
using OffsetMap = std::unordered_map<std::string, int>;
/**
* Returns the mapping of captures to slots in the captures frame.
*
* @return pointer to mapping of captures to slots
*/
const OffsetMap* GetCapturesOffsetMap() const
{ return captures_offset_mapping; }
// The following "Closure" methods implement the deprecated
// capture-by-reference functionality.
/**
* Adds a closure to the function. Closures are cloned and
* future calls to ScriptFunc methods will not modify *f*.
*
* @param ids IDs that are captured by the closure.
* @param f the closure to be captured.
*/
void AddClosure(IDPList ids, Frame* f);
/**
* Replaces the current closure with one built from *data*
*
* @param data a serialized closure
*/
bool UpdateClosure(const broker::vector& data);
/**
* If the function's closure is a weak reference to the given frame,
* upgrade to a strong reference of a shallow clone of that frame.
*/
bool StrengthenClosureReference(Frame* f);
/**
* Serializes this function's closure or capture frame.
*
* @return a serialized version of the function's closure/capture frame.
*/
broker::expected<broker::data> SerializeClosure() const;
/**
* Sets the captures frame to one built from *data*.
*
* @param data a serialized frame
*/
bool DeserializeCaptures(const broker::vector& data);
void AddBody(StmtPtr new_body,
const std::vector<IDPtr>& new_inits,
size_t new_frame_size, int priority) override;
StmtPtr CurrentBody() const { return current_body; }
/**
* Returns the function's frame size.
* @return The number of ValPtr slots in the function's frame.
*/
int FrameSize() const { return frame_size; }
/**
* Changes the function's frame size to a new size - used for
* script optimization/compilation.
*
* @param new_size The frame size the function should use.
*/
void SetFrameSize(int new_size) { frame_size = new_size; }
/** Sets this function's outer_id list. */
void SetOuterIDs(IDPList ids)
{ outer_ids = std::move(ids); }
void Describe(ODesc* d) const override;
protected:
ScriptFunc() : Func(SCRIPT_FUNC) {}
StmtPtr AddInits(
StmtPtr body,
const std::vector<IDPtr>& inits);
/**
* Clones this function along with its closures.
*/
FuncPtr DoClone() override;
/**
* Performs a selective clone of *f* using the IDs that were
* captured in the function's closure.
*
* @param f the frame to be cloned.
*/
void SetClosureFrame(Frame* f);
/**
* Uses the given frame for captures, and generates the
* mapping from captured variables to offsets in the frame.
*
* @param f the frame holding the values of capture variables
*/
void SetCaptures(Frame* f);
private:
size_t frame_size;
// List of the outer IDs used in the function.
IDPList outer_ids;
// The following is used for deprecated capture-by-reference
// closures:
// The frame the ScriptFunc was initialized in.
Frame* closure = nullptr;
bool weak_closure_ref = false;
// Used for capture-by-copy closures. These persist over the
// function's lifetime, providing quasi-globals that maintain
// state across individual calls to the function.
Frame* captures_frame = nullptr;
OffsetMap* captures_offset_mapping = nullptr;
// The most recently added/updated body.
StmtPtr current_body;
};
using built_in_func = BifReturnVal (*)(Frame* frame, const Args* args);
class BuiltinFunc final : public Func {
public:
BuiltinFunc(built_in_func func, const char* name, bool is_pure);
~BuiltinFunc() override;
bool IsPure() const override;
ValPtr Invoke(zeek::Args* args, Frame* parent) const override;
built_in_func TheFunc() const { return func; }
void Describe(ODesc* d) const override;
protected:
BuiltinFunc() { func = nullptr; is_pure = 0; }
built_in_func func;
bool is_pure;
};
extern bool check_built_in_call(BuiltinFunc* f, CallExpr* call);
struct CallInfo {
const CallExpr* call;
const Func* func;
const zeek::Args& args;
};
// Struct that collects all the specifics defining a Func. Used for ScriptFuncs
// with closures.
struct function_ingredients {
// Gathers all of the information from a scope and a function body needed
// to build a function.
function_ingredients(ScopePtr scope, StmtPtr body);
IDPtr id;
StmtPtr body;
std::vector<IDPtr> inits;
int frame_size;
int priority;
ScopePtr scope;
};
extern std::vector<CallInfo> call_stack;
// This is set to true after the built-in functions have been initialized.
extern bool did_builtin_init;
extern std::vector<void (*)()> bif_initializers;
extern void init_primary_bifs();
inline void run_bif_initializers()
{
for ( const auto& bi : bif_initializers )
bi();
bif_initializers = {};
}
extern void emit_builtin_exception(const char* msg);
extern void emit_builtin_exception(const char* msg, const ValPtr& arg);
extern void emit_builtin_exception(const char* msg, Obj* arg);
} // namespace detail
extern std::string render_call_stack();
// These methods are used by BIFs, so they're in the public namespace.
extern void emit_builtin_error(const char* msg);
extern void emit_builtin_error(const char* msg, const ValPtr&);
extern void emit_builtin_error(const char* msg, Obj* arg);
} // namespace zeek
using Func [[deprecated("Remove in v4.1. Use zeek::Func.")]] = zeek::Func;
using BroFunc [[deprecated("Remove in v4.1. Use zeek::detail::ScriptFunc.")]] = zeek::detail::ScriptFunc;
using BuiltinFunc [[deprecated("Remove in v4.1. Use zeek::detail::BuiltinFunc.")]] = zeek::detail::BuiltinFunc;
using CallInfo [[deprecated("Remove in v4.1. Use zeek::detail::CallInfo.")]] = zeek::detail::CallInfo;
using function_ingredients [[deprecated("Remove in v4.1. Use zeek::detail::function_ingredients.")]] = zeek::detail::function_ingredients;
constexpr auto check_built_in_call [[deprecated("Remove in v4.1. Use zeek::detail::check_built_in_call.")]] = zeek::detail::check_built_in_call;
constexpr auto render_call_stack [[deprecated("Remove in v4.1. Use zeek::render_call_stack.")]] = zeek::render_call_stack;
// TODO: do call_stack and did_builtin_init need to be aliased?
// These have to be implemented as actual methods due to function overloading breaking the use of aliases.
[[deprecated("Remove in v4.1. Use zeek::emit_builtin_error.")]]
extern void builtin_error(const char* msg);
[[deprecated("Remove in v4.1. Use zeek::emit_builtin_error.")]]
extern void builtin_error(const char* msg, zeek::ValPtr);
[[deprecated("Remove in v4.1. Use zeek::emit_builtin_error.")]]
extern void builtin_error(const char* msg, zeek::Obj* arg);