InterpBuiltin.cpp | Explore in Territory

//===--- InterpBuiltin.cpp - Interpreter for the constexpr VM ---*- 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
//
//===----------------------------------------------------------------------===//
#include "../ExprConstShared.h"
#include "Boolean.h"
#include "Compiler.h"
#include "EvalEmitter.h"
#include "Interp.h"
#include "PrimType.h"
#include "clang/AST/OSLog.h"
#include "clang/AST/RecordLayout.h"
#include "clang/Basic/Builtins.h"
#include "clang/Basic/TargetBuiltins.h"
#include "clang/Basic/TargetInfo.h"
#include "llvm/Support/SipHash.h"

namespace clang {
namespace interp {

static unsigned callArgSize(const InterpState &S, const CallExpr *C) { … }

template <typename T>
static T getParam(const InterpFrame *Frame, unsigned Index) { … }

static APSInt getAPSIntParam(const InterpFrame *Frame, unsigned Index) { … }

PrimType getIntPrimType(const InterpState &S) { … }

PrimType getLongPrimType(const InterpState &S) { … }

/// Peek an integer value from the stack into an APSInt.
static APSInt peekToAPSInt(InterpStack &Stk, PrimType T, size_t Offset = 0) { … }

/// Pushes \p Val on the stack as the type given by \p QT.
static void pushInteger(InterpState &S, const APSInt &Val, QualType QT) { … }

template <typename T>
static void pushInteger(InterpState &S, T Val, QualType QT) { … }

static void assignInteger(Pointer &Dest, PrimType ValueT, const APSInt &Value) { … }

static bool retPrimValue(InterpState &S, CodePtr OpPC, APValue &Result,
                         std::optional<PrimType> &T) { … }

static bool interp__builtin_is_constant_evaluated(InterpState &S, CodePtr OpPC,
                                                  const InterpFrame *Frame,
                                                  const CallExpr *Call) { … }

static bool interp__builtin_strcmp(InterpState &S, CodePtr OpPC,
                                   const InterpFrame *Frame,
                                   const CallExpr *Call) { … }

static bool interp__builtin_strlen(InterpState &S, CodePtr OpPC,
                                   const InterpFrame *Frame,
                                   const CallExpr *Call) { … }

static bool interp__builtin_nan(InterpState &S, CodePtr OpPC,
                                const InterpFrame *Frame, const Function *F,
                                bool Signaling) { … }

static bool interp__builtin_inf(InterpState &S, CodePtr OpPC,
                                const InterpFrame *Frame, const Function *F) { … }

static bool interp__builtin_copysign(InterpState &S, CodePtr OpPC,
                                     const InterpFrame *Frame,
                                     const Function *F) { … }

static bool interp__builtin_fmin(InterpState &S, CodePtr OpPC,
                                 const InterpFrame *Frame, const Function *F) { … }

static bool interp__builtin_fmax(InterpState &S, CodePtr OpPC,
                                 const InterpFrame *Frame,
                                 const Function *Func) { … }

/// Defined as __builtin_isnan(...), to accommodate the fact that it can
/// take a float, double, long double, etc.
/// But for us, that's all a Floating anyway.
static bool interp__builtin_isnan(InterpState &S, CodePtr OpPC,
                                  const InterpFrame *Frame, const Function *F,
                                  const CallExpr *Call) { … }

static bool interp__builtin_issignaling(InterpState &S, CodePtr OpPC,
                                        const InterpFrame *Frame,
                                        const Function *F,
                                        const CallExpr *Call) { … }

static bool interp__builtin_isinf(InterpState &S, CodePtr OpPC,
                                  const InterpFrame *Frame, const Function *F,
                                  bool CheckSign, const CallExpr *Call) { … }

static bool interp__builtin_isfinite(InterpState &S, CodePtr OpPC,
                                     const InterpFrame *Frame,
                                     const Function *F, const CallExpr *Call) { … }

static bool interp__builtin_isnormal(InterpState &S, CodePtr OpPC,
                                     const InterpFrame *Frame,
                                     const Function *F, const CallExpr *Call) { … }

static bool interp__builtin_issubnormal(InterpState &S, CodePtr OpPC,
                                        const InterpFrame *Frame,
                                        const Function *F,
                                        const CallExpr *Call) { … }

static bool interp__builtin_iszero(InterpState &S, CodePtr OpPC,
                                   const InterpFrame *Frame, const Function *F,
                                   const CallExpr *Call) { … }

static bool interp__builtin_signbit(InterpState &S, CodePtr OpPC,
                                    const InterpFrame *Frame, const Function *F,
                                    const CallExpr *Call) { … }

static bool interp_floating_comparison(InterpState &S, CodePtr OpPC,
                                       const InterpFrame *Frame,
                                       const Function *F,
                                       const CallExpr *Call) { … }

/// First parameter to __builtin_isfpclass is the floating value, the
/// second one is an integral value.
static bool interp__builtin_isfpclass(InterpState &S, CodePtr OpPC,
                                      const InterpFrame *Frame,
                                      const Function *Func,
                                      const CallExpr *Call) { … }

/// Five int values followed by one floating value.
static bool interp__builtin_fpclassify(InterpState &S, CodePtr OpPC,
                                       const InterpFrame *Frame,
                                       const Function *Func,
                                       const CallExpr *Call) { … }

// The C standard says "fabs raises no floating-point exceptions,
// even if x is a signaling NaN. The returned value is independent of
// the current rounding direction mode."  Therefore constant folding can
// proceed without regard to the floating point settings.
// Reference, WG14 N2478 F.10.4.3
static bool interp__builtin_fabs(InterpState &S, CodePtr OpPC,
                                 const InterpFrame *Frame,
                                 const Function *Func) { … }

static bool interp__builtin_popcount(InterpState &S, CodePtr OpPC,
                                     const InterpFrame *Frame,
                                     const Function *Func,
                                     const CallExpr *Call) { … }

static bool interp__builtin_parity(InterpState &S, CodePtr OpPC,
                                   const InterpFrame *Frame,
                                   const Function *Func, const CallExpr *Call) { … }

static bool interp__builtin_clrsb(InterpState &S, CodePtr OpPC,
                                  const InterpFrame *Frame,
                                  const Function *Func, const CallExpr *Call) { … }

static bool interp__builtin_bitreverse(InterpState &S, CodePtr OpPC,
                                       const InterpFrame *Frame,
                                       const Function *Func,
                                       const CallExpr *Call) { … }

static bool interp__builtin_classify_type(InterpState &S, CodePtr OpPC,
                                          const InterpFrame *Frame,
                                          const Function *Func,
                                          const CallExpr *Call) { … }

// __builtin_expect(long, long)
// __builtin_expect_with_probability(long, long, double)
static bool interp__builtin_expect(InterpState &S, CodePtr OpPC,
                                   const InterpFrame *Frame,
                                   const Function *Func, const CallExpr *Call) { … }

/// rotateleft(value, amount)
static bool interp__builtin_rotate(InterpState &S, CodePtr OpPC,
                                   const InterpFrame *Frame,
                                   const Function *Func, const CallExpr *Call,
                                   bool Right) { … }

static bool interp__builtin_ffs(InterpState &S, CodePtr OpPC,
                                const InterpFrame *Frame, const Function *Func,
                                const CallExpr *Call) { … }

static bool interp__builtin_addressof(InterpState &S, CodePtr OpPC,
                                      const InterpFrame *Frame,
                                      const Function *Func,
                                      const CallExpr *Call) { … }

static bool interp__builtin_move(InterpState &S, CodePtr OpPC,
                                 const InterpFrame *Frame, const Function *Func,
                                 const CallExpr *Call) { … }

static bool interp__builtin_eh_return_data_regno(InterpState &S, CodePtr OpPC,
                                                 const InterpFrame *Frame,
                                                 const Function *Func,
                                                 const CallExpr *Call) { … }

/// Just takes the first Argument to the call and puts it on the stack.
static bool noopPointer(InterpState &S, CodePtr OpPC, const InterpFrame *Frame,
                        const Function *Func, const CallExpr *Call) { … }

// Two integral values followed by a pointer (lhs, rhs, resultOut)
static bool interp__builtin_overflowop(InterpState &S, CodePtr OpPC,
                                       const InterpFrame *Frame,
                                       const Function *Func,
                                       const CallExpr *Call) { … }

/// Three integral values followed by a pointer (lhs, rhs, carry, carryOut).
static bool interp__builtin_carryop(InterpState &S, CodePtr OpPC,
                                    const InterpFrame *Frame,
                                    const Function *Func,
                                    const CallExpr *Call) { … }

static bool interp__builtin_clz(InterpState &S, CodePtr OpPC,
                                const InterpFrame *Frame, const Function *Func,
                                const CallExpr *Call) { … }

static bool interp__builtin_ctz(InterpState &S, CodePtr OpPC,
                                const InterpFrame *Frame, const Function *Func,
                                const CallExpr *Call) { … }

static bool interp__builtin_bswap(InterpState &S, CodePtr OpPC,
                                  const InterpFrame *Frame,
                                  const Function *Func, const CallExpr *Call) { … }

/// bool __atomic_always_lock_free(size_t, void const volatile*)
/// bool __atomic_is_lock_free(size_t, void const volatile*)
/// bool __c11_atomic_is_lock_free(size_t)
static bool interp__builtin_atomic_lock_free(InterpState &S, CodePtr OpPC,
                                             const InterpFrame *Frame,
                                             const Function *Func,
                                             const CallExpr *Call) { … }

/// __builtin_complex(Float A, float B);
static bool interp__builtin_complex(InterpState &S, CodePtr OpPC,
                                    const InterpFrame *Frame,
                                    const Function *Func,
                                    const CallExpr *Call) { … }

/// __builtin_is_aligned()
/// __builtin_align_up()
/// __builtin_align_down()
/// The first parameter is either an integer or a pointer.
/// The second parameter is the requested alignment as an integer.
static bool interp__builtin_is_aligned_up_down(InterpState &S, CodePtr OpPC,
                                               const InterpFrame *Frame,
                                               const Function *Func,
                                               const CallExpr *Call) { … }

/// __builtin_assume_aligned(Ptr, Alignment[, ExtraOffset])
static bool interp__builtin_assume_aligned(InterpState &S, CodePtr OpPC,
                                           const InterpFrame *Frame,
                                           const Function *Func,
                                           const CallExpr *Call) { … }

static bool interp__builtin_ia32_bextr(InterpState &S, CodePtr OpPC,
                                       const InterpFrame *Frame,
                                       const Function *Func,
                                       const CallExpr *Call) { … }

static bool interp__builtin_ia32_bzhi(InterpState &S, CodePtr OpPC,
                                      const InterpFrame *Frame,
                                      const Function *Func,
                                      const CallExpr *Call) { … }

static bool interp__builtin_ia32_lzcnt(InterpState &S, CodePtr OpPC,
                                       const InterpFrame *Frame,
                                       const Function *Func,
                                       const CallExpr *Call) { … }

static bool interp__builtin_ia32_tzcnt(InterpState &S, CodePtr OpPC,
                                       const InterpFrame *Frame,
                                       const Function *Func,
                                       const CallExpr *Call) { … }

static bool interp__builtin_ia32_pdep(InterpState &S, CodePtr OpPC,
                                      const InterpFrame *Frame,
                                      const Function *Func,
                                      const CallExpr *Call) { … }

static bool interp__builtin_ia32_pext(InterpState &S, CodePtr OpPC,
                                      const InterpFrame *Frame,
                                      const Function *Func,
                                      const CallExpr *Call) { … }

static bool interp__builtin_ia32_addcarry_subborrow(InterpState &S,
                                                    CodePtr OpPC,
                                                    const InterpFrame *Frame,
                                                    const Function *Func,
                                                    const CallExpr *Call) { … }

static bool interp__builtin_os_log_format_buffer_size(InterpState &S,
                                                      CodePtr OpPC,
                                                      const InterpFrame *Frame,
                                                      const Function *Func,
                                                      const CallExpr *Call) { … }

static bool interp__builtin_ptrauth_string_discriminator(
    InterpState &S, CodePtr OpPC, const InterpFrame *Frame,
    const Function *Func, const CallExpr *Call) { … }

// FIXME: This implementation is not complete.
// The Compiler instance we create cannot access the current stack frame, local
// variables, function parameters, etc. We also need protection from
// side-effects, fatal errors, etc.
static bool interp__builtin_constant_p(InterpState &S, CodePtr OpPC,
                                       const InterpFrame *Frame,
                                       const Function *Func,
                                       const CallExpr *Call) { … }

static bool interp__builtin_operator_new(InterpState &S, CodePtr OpPC,
                                         const InterpFrame *Frame,
                                         const Function *Func,
                                         const CallExpr *Call) { … }

static bool interp__builtin_operator_delete(InterpState &S, CodePtr OpPC,
                                            const InterpFrame *Frame,
                                            const Function *Func,
                                            const CallExpr *Call) { … }

bool InterpretBuiltin(InterpState &S, CodePtr OpPC, const Function *F,
                      const CallExpr *Call, uint32_t BuiltinID) { … }

bool InterpretOffsetOf(InterpState &S, CodePtr OpPC, const OffsetOfExpr *E,
                       llvm::ArrayRef<int64_t> ArrayIndices,
                       int64_t &IntResult) { … }

bool SetThreeWayComparisonField(InterpState &S, CodePtr OpPC,
                                const Pointer &Ptr, const APSInt &IntValue) { … }

static bool copyComposite(InterpState &S, CodePtr OpPC, const Pointer &Src,
                          Pointer &Dest, bool Activate);
static bool copyRecord(InterpState &S, CodePtr OpPC, const Pointer &Src,
                       Pointer &Dest, bool Activate = false) { … }

static bool copyComposite(InterpState &S, CodePtr OpPC, const Pointer &Src,
                          Pointer &Dest, bool Activate = false) { … }

bool DoMemcpy(InterpState &S, CodePtr OpPC, const Pointer &Src, Pointer &Dest) { … }

} // namespace interp
} // namespace clang
llvm/clang/lib/AST/ByteCode/InterpBuiltin.cpp
