//=== AnyCall.h - Abstraction over different callables --------*- C++ -*--//
//
// 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
//
//===----------------------------------------------------------------------===//
//
// A utility class for performing generic operations over different callables.
//
//===----------------------------------------------------------------------===//
//
#ifndef LLVM_CLANG_ANALYSIS_ANYCALL_H
#define LLVM_CLANG_ANALYSIS_ANYCALL_H
#include "clang/AST/Decl.h"
#include "clang/AST/ExprCXX.h"
#include "clang/AST/ExprObjC.h"
#include <optional>
namespace clang {
/// An instance of this class corresponds to a call.
/// It might be a syntactically-concrete call, done as a part of evaluating an
/// expression, or it may be an abstract callee with no associated expression.
class AnyCall {
public:
enum Kind {
/// A function, function pointer, or a C++ method call
Function,
/// A call to an Objective-C method
ObjCMethod,
/// A call to an Objective-C block
Block,
/// An implicit C++ destructor call (called implicitly
/// or by operator 'delete')
Destructor,
/// An implicit or explicit C++ constructor call
Constructor,
/// A C++ inherited constructor produced by a "using T::T" directive
InheritedConstructor,
/// A C++ allocation function call (operator `new`), via C++ new-expression
Allocator,
/// A C++ deallocation function call (operator `delete`), via C++
/// delete-expression
Deallocator
};
private:
/// Either expression or declaration (but not both at the same time)
/// can be null.
/// Call expression, is null when is not known (then declaration is non-null),
/// or for implicit destructor calls (when no expression exists.)
const Expr *E = nullptr;
/// Corresponds to a statically known declaration of the called function,
/// or null if it is not known (e.g. for a function pointer).
const Decl *D = nullptr;
Kind K;
public:
AnyCall(const CallExpr *CE) : E(CE) {
D = CE->getCalleeDecl();
K = (CE->getCallee()->getType()->getAs<BlockPointerType>()) ? Block
: Function;
if (D && ((K == Function && !isa<FunctionDecl>(D)) ||
(K == Block && !isa<BlockDecl>(D))))
D = nullptr;
}
AnyCall(const ObjCMessageExpr *ME)
: E(ME), D(ME->getMethodDecl()), K(ObjCMethod) {}
AnyCall(const CXXNewExpr *NE)
: E(NE), D(NE->getOperatorNew()), K(Allocator) {}
AnyCall(const CXXDeleteExpr *NE)
: E(NE), D(NE->getOperatorDelete()), K(Deallocator) {}
AnyCall(const CXXConstructExpr *NE)
: E(NE), D(NE->getConstructor()), K(Constructor) {}
AnyCall(const CXXInheritedCtorInitExpr *CIE)
: E(CIE), D(CIE->getConstructor()), K(InheritedConstructor) {}
AnyCall(const CXXDestructorDecl *D) : E(nullptr), D(D), K(Destructor) {}
AnyCall(const CXXConstructorDecl *D) : E(nullptr), D(D), K(Constructor) {}
AnyCall(const ObjCMethodDecl *D) : E(nullptr), D(D), K(ObjCMethod) {}
AnyCall(const FunctionDecl *D) : E(nullptr), D(D) {
if (isa<CXXConstructorDecl>(D)) {
K = Constructor;
} else if (isa <CXXDestructorDecl>(D)) {
K = Destructor;
} else {
K = Function;
}
}
/// If @c E is a generic call (to ObjC method /function/block/etc),
/// return a constructed @c AnyCall object. Return std::nullopt otherwise.
static std::optional<AnyCall> forExpr(const Expr *E) {
if (const auto *ME = dyn_cast<ObjCMessageExpr>(E)) {
return AnyCall(ME);
} else if (const auto *CE = dyn_cast<CallExpr>(E)) {
return AnyCall(CE);
} else if (const auto *CXNE = dyn_cast<CXXNewExpr>(E)) {
return AnyCall(CXNE);
} else if (const auto *CXDE = dyn_cast<CXXDeleteExpr>(E)) {
return AnyCall(CXDE);
} else if (const auto *CXCE = dyn_cast<CXXConstructExpr>(E)) {
return AnyCall(CXCE);
} else if (const auto *CXCIE = dyn_cast<CXXInheritedCtorInitExpr>(E)) {
return AnyCall(CXCIE);
} else {
return std::nullopt;
}
}
/// If @c D is a callable (Objective-C method or a function), return
/// a constructed @c AnyCall object. Return std::nullopt otherwise.
// FIXME: block support.
static std::optional<AnyCall> forDecl(const Decl *D) {
if (const auto *FD = dyn_cast<FunctionDecl>(D)) {
return AnyCall(FD);
} else if (const auto *MD = dyn_cast<ObjCMethodDecl>(D)) {
return AnyCall(MD);
}
return std::nullopt;
}
/// \returns formal parameters for direct calls (including virtual calls)
ArrayRef<ParmVarDecl *> parameters() const {
if (!D)
return std::nullopt;
if (const auto *FD = dyn_cast<FunctionDecl>(D)) {
return FD->parameters();
} else if (const auto *MD = dyn_cast<ObjCMethodDecl>(D)) {
return MD->parameters();
} else if (const auto *BD = dyn_cast<BlockDecl>(D)) {
return BD->parameters();
} else {
return std::nullopt;
}
}
using param_const_iterator = ArrayRef<ParmVarDecl *>::const_iterator;
param_const_iterator param_begin() const { return parameters().begin(); }
param_const_iterator param_end() const { return parameters().end(); }
size_t param_size() const { return parameters().size(); }
bool param_empty() const { return parameters().empty(); }
QualType getReturnType(ASTContext &Ctx) const {
switch (K) {
case Function:
if (E)
return cast<CallExpr>(E)->getCallReturnType(Ctx);
return cast<FunctionDecl>(D)->getReturnType();
case ObjCMethod:
if (E)
return cast<ObjCMessageExpr>(E)->getCallReturnType(Ctx);
return cast<ObjCMethodDecl>(D)->getReturnType();
case Block:
// FIXME: BlockDecl does not know its return type,
// hence the asymmetry with the function and method cases above.
return cast<CallExpr>(E)->getCallReturnType(Ctx);
case Destructor:
case Constructor:
case InheritedConstructor:
case Allocator:
case Deallocator:
return cast<FunctionDecl>(D)->getReturnType();
}
llvm_unreachable("Unknown AnyCall::Kind");
}
/// \returns Function identifier if it is a named declaration,
/// @c nullptr otherwise.
const IdentifierInfo *getIdentifier() const {
if (const auto *ND = dyn_cast_or_null<NamedDecl>(D))
return ND->getIdentifier();
return nullptr;
}
const Decl *getDecl() const {
return D;
}
const Expr *getExpr() const {
return E;
}
Kind getKind() const {
return K;
}
void dump() const {
if (E)
E->dump();
if (D)
D->dump();
}
};
}
#endif // LLVM_CLANG_ANALYSIS_ANYCALL_H