//===--- Builtins.h - Builtin function header -------------------*- 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
//
//===----------------------------------------------------------------------===//
///
/// \file
/// Defines enum values for all the target-independent builtin
/// functions.
///
//===----------------------------------------------------------------------===//
#ifndef LLVM_CLANG_BASIC_BUILTINS_H
#define LLVM_CLANG_BASIC_BUILTINS_H
#include "llvm/ADT/ArrayRef.h"
#include "llvm/ADT/StringMap.h"
#include "llvm/ADT/StringRef.h"
#include <cstring>
// VC++ defines 'alloca' as an object-like macro, which interferes with our
// builtins.
#undef alloca
namespace clang {
class TargetInfo;
class IdentifierTable;
class LangOptions;
enum LanguageID : uint16_t {
GNU_LANG = 0x1, // builtin requires GNU mode.
C_LANG = 0x2, // builtin for c only.
CXX_LANG = 0x4, // builtin for cplusplus only.
OBJC_LANG = 0x8, // builtin for objective-c and objective-c++
MS_LANG = 0x10, // builtin requires MS mode.
OMP_LANG = 0x20, // builtin requires OpenMP.
CUDA_LANG = 0x40, // builtin requires CUDA.
COR_LANG = 0x80, // builtin requires use of 'fcoroutine-ts' option.
OCL_GAS = 0x100, // builtin requires OpenCL generic address space.
OCL_PIPE = 0x200, // builtin requires OpenCL pipe.
OCL_DSE = 0x400, // builtin requires OpenCL device side enqueue.
ALL_OCL_LANGUAGES = 0x800, // builtin for OCL languages.
HLSL_LANG = 0x1000, // builtin requires HLSL.
ALL_LANGUAGES = C_LANG | CXX_LANG | OBJC_LANG, // builtin for all languages.
ALL_GNU_LANGUAGES = ALL_LANGUAGES | GNU_LANG, // builtin requires GNU mode.
ALL_MS_LANGUAGES = ALL_LANGUAGES | MS_LANG // builtin requires MS mode.
};
struct HeaderDesc {
enum HeaderID : uint16_t {
#define HEADER(ID, NAME) ID,
#include "clang/Basic/BuiltinHeaders.def"
#undef HEADER
} ID;
constexpr HeaderDesc(HeaderID ID) : ID(ID) {}
const char *getName() const;
};
namespace Builtin {
enum ID {
NotBuiltin = 0, // This is not a builtin function.
#define BUILTIN(ID, TYPE, ATTRS) BI##ID,
#include "clang/Basic/Builtins.def"
FirstTSBuiltin
};
struct Info {
llvm::StringLiteral Name;
const char *Type, *Attributes;
const char *Features;
HeaderDesc Header;
LanguageID Langs;
};
/// Holds information about both target-independent and
/// target-specific builtins, allowing easy queries by clients.
///
/// Builtins from an optional auxiliary target are stored in
/// AuxTSRecords. Their IDs are shifted up by TSRecords.size() and need to
/// be translated back with getAuxBuiltinID() before use.
class Context {
llvm::ArrayRef<Info> TSRecords;
llvm::ArrayRef<Info> AuxTSRecords;
public:
Context() = default;
/// Perform target-specific initialization
/// \param AuxTarget Target info to incorporate builtins from. May be nullptr.
void InitializeTarget(const TargetInfo &Target, const TargetInfo *AuxTarget);
/// Mark the identifiers for all the builtins with their
/// appropriate builtin ID # and mark any non-portable builtin identifiers as
/// such.
void initializeBuiltins(IdentifierTable &Table, const LangOptions& LangOpts);
/// Return the identifier name for the specified builtin,
/// e.g. "__builtin_abs".
llvm::StringRef getName(unsigned ID) const { return getRecord(ID).Name; }
/// Get the type descriptor string for the specified builtin.
const char *getTypeString(unsigned ID) const {
return getRecord(ID).Type;
}
/// Return true if this function is a target-specific builtin.
bool isTSBuiltin(unsigned ID) const {
return ID >= Builtin::FirstTSBuiltin;
}
/// Return true if this function has no side effects.
bool isPure(unsigned ID) const {
return strchr(getRecord(ID).Attributes, 'U') != nullptr;
}
/// Return true if this function has no side effects and doesn't
/// read memory.
bool isConst(unsigned ID) const {
return strchr(getRecord(ID).Attributes, 'c') != nullptr;
}
/// Return true if we know this builtin never throws an exception.
bool isNoThrow(unsigned ID) const {
return strchr(getRecord(ID).Attributes, 'n') != nullptr;
}
/// Return true if we know this builtin never returns.
bool isNoReturn(unsigned ID) const {
return strchr(getRecord(ID).Attributes, 'r') != nullptr;
}
/// Return true if we know this builtin can return twice.
bool isReturnsTwice(unsigned ID) const {
return strchr(getRecord(ID).Attributes, 'j') != nullptr;
}
/// Returns true if this builtin does not perform the side-effects
/// of its arguments.
bool isUnevaluated(unsigned ID) const {
return strchr(getRecord(ID).Attributes, 'u') != nullptr;
}
/// Return true if this is a builtin for a libc/libm function,
/// with a "__builtin_" prefix (e.g. __builtin_abs).
bool isLibFunction(unsigned ID) const {
return strchr(getRecord(ID).Attributes, 'F') != nullptr;
}
/// Determines whether this builtin is a predefined libc/libm
/// function, such as "malloc", where we know the signature a
/// priori.
/// In C, such functions behave as if they are predeclared,
/// possibly with a warning on first use. In Objective-C and C++,
/// they do not, but they are recognized as builtins once we see
/// a declaration.
bool isPredefinedLibFunction(unsigned ID) const {
return strchr(getRecord(ID).Attributes, 'f') != nullptr;
}
/// Returns true if this builtin requires appropriate header in other
/// compilers. In Clang it will work even without including it, but we can emit
/// a warning about missing header.
bool isHeaderDependentFunction(unsigned ID) const {
return strchr(getRecord(ID).Attributes, 'h') != nullptr;
}
/// Determines whether this builtin is a predefined compiler-rt/libgcc
/// function, such as "__clear_cache", where we know the signature a
/// priori.
bool isPredefinedRuntimeFunction(unsigned ID) const {
return strchr(getRecord(ID).Attributes, 'i') != nullptr;
}
/// Determines whether this builtin is a C++ standard library function
/// that lives in (possibly-versioned) namespace std, possibly a template
/// specialization, where the signature is determined by the standard library
/// declaration.
bool isInStdNamespace(unsigned ID) const {
return strchr(getRecord(ID).Attributes, 'z') != nullptr;
}
/// Determines whether this builtin can have its address taken with no
/// special action required.
bool isDirectlyAddressable(unsigned ID) const {
// Most standard library functions can have their addresses taken. C++
// standard library functions formally cannot in C++20 onwards, and when
// we allow it, we need to ensure we instantiate a definition.
return isPredefinedLibFunction(ID) && !isInStdNamespace(ID);
}
/// Determines whether this builtin has custom typechecking.
bool hasCustomTypechecking(unsigned ID) const {
return strchr(getRecord(ID).Attributes, 't') != nullptr;
}
/// Determines whether a declaration of this builtin should be recognized
/// even if the type doesn't match the specified signature.
bool allowTypeMismatch(unsigned ID) const {
return strchr(getRecord(ID).Attributes, 'T') != nullptr ||
hasCustomTypechecking(ID);
}
/// Determines whether this builtin has a result or any arguments which
/// are pointer types.
bool hasPtrArgsOrResult(unsigned ID) const {
return strchr(getRecord(ID).Type, '*') != nullptr;
}
/// Return true if this builtin has a result or any arguments which are
/// reference types.
bool hasReferenceArgsOrResult(unsigned ID) const {
return strchr(getRecord(ID).Type, '&') != nullptr ||
strchr(getRecord(ID).Type, 'A') != nullptr;
}
/// If this is a library function that comes from a specific
/// header, retrieve that header name.
const char *getHeaderName(unsigned ID) const {
return getRecord(ID).Header.getName();
}
/// Determine whether this builtin is like printf in its
/// formatting rules and, if so, set the index to the format string
/// argument and whether this function as a va_list argument.
bool isPrintfLike(unsigned ID, unsigned &FormatIdx, bool &HasVAListArg);
/// Determine whether this builtin is like scanf in its
/// formatting rules and, if so, set the index to the format string
/// argument and whether this function as a va_list argument.
bool isScanfLike(unsigned ID, unsigned &FormatIdx, bool &HasVAListArg);
/// Determine whether this builtin has callback behavior (see
/// llvm::AbstractCallSites for details). If so, add the index to the
/// callback callee argument and the callback payload arguments.
bool performsCallback(unsigned ID,
llvm::SmallVectorImpl<int> &Encoding) const;
/// Return true if this function has no side effects and doesn't
/// read memory, except for possibly errno or raising FP exceptions.
///
/// Such functions can be const when the MathErrno lang option and FP
/// exceptions are disabled.
bool isConstWithoutErrnoAndExceptions(unsigned ID) const {
return strchr(getRecord(ID).Attributes, 'e') != nullptr;
}
bool isConstWithoutExceptions(unsigned ID) const {
return strchr(getRecord(ID).Attributes, 'g') != nullptr;
}
const char *getRequiredFeatures(unsigned ID) const {
return getRecord(ID).Features;
}
unsigned getRequiredVectorWidth(unsigned ID) const;
/// Return true if builtin ID belongs to AuxTarget.
bool isAuxBuiltinID(unsigned ID) const {
return ID >= (Builtin::FirstTSBuiltin + TSRecords.size());
}
/// Return real builtin ID (i.e. ID it would have during compilation
/// for AuxTarget).
unsigned getAuxBuiltinID(unsigned ID) const { return ID - TSRecords.size(); }
/// Returns true if this is a libc/libm function without the '__builtin_'
/// prefix.
static bool isBuiltinFunc(llvm::StringRef Name);
/// Returns true if this is a builtin that can be redeclared. Returns true
/// for non-builtins.
bool canBeRedeclared(unsigned ID) const;
/// Return true if this function can be constant evaluated by Clang frontend.
bool isConstantEvaluated(unsigned ID) const {
return strchr(getRecord(ID).Attributes, 'E') != nullptr;
}
private:
const Info &getRecord(unsigned ID) const;
/// Helper function for isPrintfLike and isScanfLike.
bool isLike(unsigned ID, unsigned &FormatIdx, bool &HasVAListArg,
const char *Fmt) const;
};
/// Returns true if the required target features of a builtin function are
/// enabled.
/// \p TargetFeatureMap maps a target feature to true if it is enabled and
/// false if it is disabled.
bool evaluateRequiredTargetFeatures(
llvm::StringRef RequiredFatures,
const llvm::StringMap<bool> &TargetFetureMap);
} // namespace Builtin
/// Kinds of BuiltinTemplateDecl.
enum BuiltinTemplateKind : int {
/// This names the __make_integer_seq BuiltinTemplateDecl.
BTK__make_integer_seq,
/// This names the __type_pack_element BuiltinTemplateDecl.
BTK__type_pack_element
};
} // end namespace clang
#endif