LangOptions.h

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//===- LangOptions.h - C Language Family Language Options -------*- 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 the clang::LangOptions interface.
//
//===----------------------------------------------------------------------===//
 
#ifndef LLVM_CLANG_BASIC_LANGOPTIONS_H
#define LLVM_CLANG_BASIC_LANGOPTIONS_H
 
#include "clang/Basic/CFProtectionOptions.h"
#include "clang/Basic/CommentOptions.h"
#include "clang/Basic/LLVM.h"
#include "clang/Basic/LangStandard.h"
#include "clang/Basic/ObjCRuntime.h"
#include "clang/Basic/Sanitizers.h"
#include "clang/Basic/TargetCXXABI.h"
#include "clang/Basic/Visibility.h"
#include "llvm/ADT/FloatingPointMode.h"
#include "llvm/ADT/StringRef.h"
#include "llvm/TargetParser/Triple.h"
#include <optional>
#include <string>
#include <vector>
 
namespace clang {
 
/// In the Microsoft ABI, this controls the placement of virtual displacement
/// members used to implement virtual inheritance.
enum class MSVtorDispMode { Never, ForVBaseOverride, ForVFTable };
 
/// Shader programs run in specific pipeline stages.
/// The order of these values matters, and must be kept in sync with the
/// Triple Environment enum in llvm::Triple. The ordering is enforced in
///  static_asserts in Triple.cpp and in clang/Basic/HLSLRuntime.h.
enum class ShaderStage {
  Pixel = 0,
  Vertex,
  Geometry,
  Hull,
  Domain,
  Compute,
  Library,
  RayGeneration,
  Intersection,
  AnyHit,
  ClosestHit,
  Miss,
  Callable,
  Mesh,
  Amplification,
  Invalid,
};
 
enum class PointerAuthenticationMode : unsigned {
  None,
  Strip,
  SignAndStrip,
  SignAndAuth
};
 
/// Bitfields of LangOptions, split out from LangOptions in order to ensure that
/// this large collection of bitfields is a trivial class type.
class LangOptionsBase {
  friend class CompilerInvocation;
  friend class CompilerInvocationBase;
 
public:
  using Visibility = clang::Visibility;
  using RoundingMode = llvm::RoundingMode;
  using CFBranchLabelSchemeKind = clang::CFBranchLabelSchemeKind;
 
  enum GCMode { NonGC, GCOnly, HybridGC };
  enum StackProtectorMode { SSPOff, SSPOn, SSPStrong, SSPReq };
 
  // Automatic variables live on the stack, and when trivial they're usually
  // uninitialized because it's undefined behavior to use them without
  // initializing them.
  enum class TrivialAutoVarInitKind { Uninitialized, Zero, Pattern };
 
  enum SignedOverflowBehaviorTy {
    // Default C standard behavior.
    SOB_Undefined,
 
    // -fwrapv
    SOB_Defined,
 
    // -ftrapv
    SOB_Trapping
  };
 
  // FIXME: Unify with TUKind.
  enum CompilingModuleKind {
    /// Not compiling a module interface at all.
    CMK_None,
 
    /// Compiling a module from a module map.
    CMK_ModuleMap,
 
    /// Compiling a module header unit.
    CMK_HeaderUnit,
 
    /// Compiling a C++ modules interface unit.
    CMK_ModuleInterface,
  };
 
  enum PragmaMSPointersToMembersKind {
    PPTMK_BestCase,
    PPTMK_FullGeneralitySingleInheritance,
    PPTMK_FullGeneralityMultipleInheritance,
    PPTMK_FullGeneralityVirtualInheritance
  };
 
  using MSVtorDispMode = clang::MSVtorDispMode;
 
  enum DefaultCallingConvention {
    DCC_None,
    DCC_CDecl,
    DCC_FastCall,
    DCC_StdCall,
    DCC_VectorCall,
    DCC_RegCall,
    DCC_RtdCall
  };
 
  enum AddrSpaceMapMangling { ASMM_Target, ASMM_On, ASMM_Off };
 
  // Corresponds to _MSC_VER
  enum MSVCMajorVersion {
    MSVC2010 = 1600,
    MSVC2012 = 1700,
    MSVC2013 = 1800,
    MSVC2015 = 1900,
    MSVC2017 = 1910,
    MSVC2017_5 = 1912,
    MSVC2017_7 = 1914,
    MSVC2019 = 1920,
    MSVC2019_5 = 1925,
    MSVC2019_8 = 1928,
    MSVC2022_3 = 1933,
  };
 
  enum SYCLMajorVersion {
    SYCL_None,
    SYCL_2017,
    SYCL_2020,
    // The "default" SYCL version to be used when none is specified on the
    // frontend command line.
    SYCL_Default = SYCL_2020
  };
 
  enum HLSLLangStd {
    HLSL_Unset = 0,
    HLSL_2015 = 2015,
    HLSL_2016 = 2016,
    HLSL_2017 = 2017,
    HLSL_2018 = 2018,
    HLSL_2021 = 2021,
    HLSL_202x = 2028,
    HLSL_202y = 2029,
  };
 
  /// Clang versions with different platform ABI conformance.
  enum class ClangABI {
    /// Attempt to be ABI-compatible with code generated by Clang 3.8.x
    /// (SVN r257626). This causes <1 x long long> to be passed in an
    /// integer register instead of an SSE register on x64_64.
    Ver3_8,
 
    /// Attempt to be ABI-compatible with code generated by Clang 4.0.x
    /// (SVN r291814). This causes move operations to be ignored when
    /// determining whether a class type can be passed or returned directly.
    Ver4,
 
    /// Attempt to be ABI-compatible with code generated by Clang 6.0.x
    /// (SVN r321711). This causes determination of whether a type is
    /// standard-layout to ignore collisions between empty base classes
    /// and between base classes and member subobjects, which affects
    /// whether we reuse base class tail padding in some ABIs.
    Ver6,
 
    /// Attempt to be ABI-compatible with code generated by Clang 7.0.x
    /// (SVN r338536). This causes alignof (C++) and _Alignof (C11) to be
    /// compatible with __alignof (i.e., return the preferred alignment)
    /// rather than returning the required alignment.
    Ver7,
 
    /// Attempt to be ABI-compatible with code generated by Clang 9.0.x
    /// (SVN r351319). This causes vectors of __int128 to be passed in memory
    /// instead of passing in multiple scalar registers on x86_64 on Linux and
    /// NetBSD.
    Ver9,
 
    /// Attempt to be ABI-compatible with code generated by Clang 11.0.x
    /// (git 2e10b7a39b93). This causes clang to pass unions with a 256-bit
    /// vector member on the stack instead of using registers, to not properly
    /// mangle substitutions for template names in some cases, and to mangle
    /// declaration template arguments without a cast to the parameter type
    /// even when that can lead to mangling collisions.
    Ver11,
 
    /// Attempt to be ABI-compatible with code generated by Clang 12.0.x
    /// (git 8e464dd76bef). This causes clang to mangle lambdas within
    /// global-scope inline variables incorrectly.
    Ver12,
 
    /// Attempt to be ABI-compatible with code generated by Clang 14.0.x.
    /// This causes clang to:
    ///   - mangle dependent nested names incorrectly.
    ///   - make trivial only those defaulted copy constructors with a
    ///     parameter-type-list equivalent to the parameter-type-list of an
    ///     implicit declaration.
    Ver14,
 
    /// Attempt to be ABI-compatible with code generated by Clang 15.0.x.
    /// This causes clang to:
    ///   - Reverse the implementation for DR692, DR1395 and DR1432.
    ///   - pack non-POD members of packed structs.
    ///   - consider classes with defaulted special member functions non-pod.
    Ver15,
 
    /// Attempt to be ABI-compatible with code generated by Clang 17.0.x.
    /// This causes clang to revert some fixes to its implementation of the
    /// Itanium name mangling scheme, with the consequence that overloaded
    /// function templates are mangled the same if they differ only by:
    ///   - constraints
    ///   - whether a non-type template parameter has a deduced type
    ///   - the parameter list of a template template parameter
    Ver17,
 
    /// Attempt to be ABI-compatible with code generated by Clang 18.0.x.
    /// This causes clang to revert some fixes to the mangling of lambdas
    /// in the initializers of members of local classes.
    Ver18,
 
    /// Attempt to be ABI-compatible with code generated by Clang 19.0.x.
    /// This causes clang to:
    ///   - Incorrectly mangle the 'base type' substitutions of the CXX
    ///   construction vtable because it hasn't added 'type' as a substitution.
    ///   - Skip mangling enclosing class templates of member-like friend
    ///   function templates.
    Ver19,
 
    /// Conform to the underlying platform's C and C++ ABIs as closely
    /// as we can.
    Latest
  };
 
  enum class CoreFoundationABI {
    /// No interoperability ABI has been specified
    Unspecified,
    /// CoreFoundation does not have any language interoperability
    Standalone,
    /// Interoperability with the ObjectiveC runtime
    ObjectiveC,
    /// Interoperability with the latest known version of the Swift runtime
    Swift,
    /// Interoperability with the Swift 5.0 runtime
    Swift5_0,
    /// Interoperability with the Swift 4.2 runtime
    Swift4_2,
    /// Interoperability with the Swift 4.1 runtime
    Swift4_1,
  };
 
  enum FPModeKind {
    // Disable the floating point pragma
    FPM_Off,
 
    // Enable the floating point pragma
    FPM_On,
 
    // Aggressively fuse FP ops (E.g. FMA) disregarding pragmas.
    FPM_Fast,
 
    // Aggressively fuse FP ops and honor pragmas.
    FPM_FastHonorPragmas
  };
 
  /// Possible floating point exception behavior.
  enum FPExceptionModeKind {
    /// Assume that floating-point exceptions are masked.
    FPE_Ignore,
    /// Transformations do not cause new exceptions but may hide some.
    FPE_MayTrap,
    /// Strictly preserve the floating-point exception semantics.
    FPE_Strict,
    /// Used internally to represent initial unspecified value.
    FPE_Default
  };
 
  /// Possible float expression evaluation method choices.
  enum FPEvalMethodKind {
    /// The evaluation method cannot be determined or is inconsistent for this
    /// target.
    FEM_Indeterminable = -1,
    /// Use the declared type for fp arithmetic.
    FEM_Source = 0,
    /// Use the type double for fp arithmetic.
    FEM_Double = 1,
    /// Use extended type for fp arithmetic.
    FEM_Extended = 2,
    /// Used only for FE option processing; this is only used to indicate that
    /// the user did not specify an explicit evaluation method on the command
    /// line and so the target should be queried for its default evaluation
    /// method instead.
    FEM_UnsetOnCommandLine = 3
  };
 
  enum ExcessPrecisionKind { FPP_Standard, FPP_Fast, FPP_None };
 
  /// Possible exception handling behavior.
  enum class ExceptionHandlingKind { None, SjLj, WinEH, DwarfCFI, Wasm };
 
  enum class LaxVectorConversionKind {
    /// Permit no implicit vector bitcasts.
    None,
    /// Permit vector bitcasts between integer vectors with different numbers
    /// of elements but the same total bit-width.
    Integer,
    /// Permit vector bitcasts between all vectors with the same total
    /// bit-width.
    All,
  };
 
  enum class AltivecSrcCompatKind {
    // All vector compares produce scalars except vector pixel and vector bool.
    // The types vector pixel and vector bool return vector results.
    Mixed,
    // All vector compares produce vector results as in GCC.
    GCC,
    // All vector compares produce scalars as in XL.
    XL,
    // Default clang behaviour.
    Default = Mixed,
  };
 
  enum class SignReturnAddressScopeKind {
    /// No signing for any function.
    None,
    /// Sign the return address of functions that spill LR.
    NonLeaf,
    /// Sign the return address of all functions,
    All
  };
 
  enum class SignReturnAddressKeyKind {
    /// Return address signing uses APIA key.
    AKey,
    /// Return address signing uses APIB key.
    BKey
  };
 
  enum class ThreadModelKind {
    /// POSIX Threads.
    POSIX,
    /// Single Threaded Environment.
    Single
  };
 
  enum class ExtendArgsKind {
    /// Integer arguments are sign or zero extended to 32/64 bits
    /// during default argument promotions.
    ExtendTo32,
    ExtendTo64
  };
 
  enum class GPUDefaultStreamKind {
    /// Legacy default stream
    Legacy,
    /// Per-thread default stream
    PerThread,
  };
 
  /// Exclude certain code patterns from being instrumented by arithmetic
  /// overflow sanitizers
  enum OverflowPatternExclusionKind {
    /// Don't exclude any overflow patterns from sanitizers
    None = 1 << 0,
    /// Exclude all overflow patterns (below)
    All = 1 << 1,
    /// if (a + b < a)
    AddSignedOverflowTest = 1 << 2,
    /// if (a + b < a)
    AddUnsignedOverflowTest = 1 << 3,
    /// -1UL
    NegUnsignedConst = 1 << 4,
    /// while (count--)
    PostDecrInWhile = 1 << 5,
  };
 
  enum class DefaultVisiblityExportMapping {
    None,
    /// map only explicit default visibilities to exported
    Explicit,
    /// map all default visibilities to exported
    All,
  };
 
  enum class VisibilityForcedKinds {
    /// Force hidden visibility
    ForceHidden,
    /// Force protected visibility
    ForceProtected,
    /// Force default visibility
    ForceDefault,
    /// Don't alter the visibility
    Source,
  };
 
  enum class VisibilityFromDLLStorageClassKinds {
    /// Keep the IR-gen assigned visibility.
    Keep,
    /// Override the IR-gen assigned visibility with default visibility.
    Default,
    /// Override the IR-gen assigned visibility with hidden visibility.
    Hidden,
    /// Override the IR-gen assigned visibility with protected visibility.
    Protected,
  };
 
  enum class StrictFlexArraysLevelKind {
    /// Any trailing array member is a FAM.
    Default = 0,
    /// Any trailing array member of undefined, 0, or 1 size is a FAM.
    OneZeroOrIncomplete = 1,
    /// Any trailing array member of undefined or 0 size is a FAM.
    ZeroOrIncomplete = 2,
    /// Any trailing array member of undefined size is a FAM.
    IncompleteOnly = 3,
  };
 
  /// Controls the various implementations for complex multiplication and
  // division.
  enum ComplexRangeKind {
    /// Implementation of complex division and multiplication using a call to
    ///  runtime library functions(generally the case, but the BE might
    /// sometimes replace the library call if it knows enough about the
    /// potential range of the inputs). Overflow and non-finite values are
    /// handled by the library implementation. This is the default value.
    CX_Full,
 
    /// Implementation of complex division offering an improved handling
    /// for overflow in intermediate calculations with no special handling for
    /// NaN and infinite values.
    CX_Improved,
 
    /// Implementation of complex division using algebraic formulas at
    /// higher precision. Overflow is handled. Non-finite values are handled in
    /// some cases. If the target hardware does not have native support for a
    /// higher precision data type, an implementation for the complex operation
    /// will be used to provide improved guards against intermediate overflow,
    /// but overflow and underflow may still occur in some cases. NaN and
    /// infinite values are not handled.
    CX_Promoted,
 
    /// Implementation of complex division and multiplication using
    /// algebraic formulas at source precision. No special handling to avoid
    /// overflow. NaN and infinite values are not handled.
    CX_Basic,
 
    /// No range rule is enabled.
    CX_None
  };
 
  /// Controls which variables have static destructors registered.
  enum class RegisterStaticDestructorsKind {
    /// Register static destructors for all variables.
    All,
    /// Register static destructors only for thread-local variables.
    ThreadLocal,
    /// Don't register static destructors for any variables.
    None,
  };
 
  // Define simple language options (with no accessors).
#define LANGOPT(Name, Bits, Default, Description) unsigned Name : Bits;
#define ENUM_LANGOPT(Name, Type, Bits, Default, Description)
#include "clang/Basic/LangOptions.def"
 
protected:
  // Define language options of enumeration type. These are private, and will
  // have accessors (below).
#define LANGOPT(Name, Bits, Default, Description)
#define ENUM_LANGOPT(Name, Type, Bits, Default, Description) \
  LLVM_PREFERRED_TYPE(Type) \
  unsigned Name : Bits;
#include "clang/Basic/LangOptions.def"
};
 
/// Keeps track of the various options that can be
/// enabled, which controls the dialect of C or C++ that is accepted.
class LangOptions : public LangOptionsBase {
public:
  /// The used language standard.
  LangStandard::Kind LangStd;
 
  /// Set of enabled sanitizers.
  SanitizerSet Sanitize;
  /// Is at least one coverage instrumentation type enabled.
  bool SanitizeCoverage = false;
 
  /// Paths to files specifying which objects
  /// (files, functions, variables) should not be instrumented.
  std::vector<std::string> NoSanitizeFiles;
 
  /// Paths to the XRay "always instrument" files specifying which
  /// objects (files, functions, variables) should be imbued with the XRay
  /// "always instrument" attribute.
  /// WARNING: This is a deprecated field and will go away in the future.
  std::vector<std::string> XRayAlwaysInstrumentFiles;
 
  /// Paths to the XRay "never instrument" files specifying which
  /// objects (files, functions, variables) should be imbued with the XRay
  /// "never instrument" attribute.
  /// WARNING: This is a deprecated field and will go away in the future.
  std::vector<std::string> XRayNeverInstrumentFiles;
 
  /// Paths to the XRay attribute list files, specifying which objects
  /// (files, functions, variables) should be imbued with the appropriate XRay
  /// attribute(s).
  std::vector<std::string> XRayAttrListFiles;
 
  /// Paths to special case list files specifying which entities
  /// (files, functions) should or should not be instrumented.
  std::vector<std::string> ProfileListFiles;
 
  clang::ObjCRuntime ObjCRuntime;
 
  CoreFoundationABI CFRuntime = CoreFoundationABI::Unspecified;
 
  std::string ObjCConstantStringClass;
 
  /// The name of the handler function to be called when -ftrapv is
  /// specified.
  ///
  /// If none is specified, abort (GCC-compatible behaviour).
  std::string OverflowHandler;
 
  /// The module currently being compiled as specified by -fmodule-name.
  std::string ModuleName;
 
  /// The name of the current module, of which the main source file
  /// is a part. If CompilingModule is set, we are compiling the interface
  /// of this module, otherwise we are compiling an implementation file of
  /// it. This starts as ModuleName in case -fmodule-name is provided and
  /// changes during compilation to reflect the current module.
  std::string CurrentModule;
 
  /// The names of any features to enable in module 'requires' decls
  /// in addition to the hard-coded list in Module.cpp and the target features.
  ///
  /// This list is sorted.
  std::vector<std::string> ModuleFeatures;
 
  /// Options for parsing comments.
  CommentOptions CommentOpts;
 
  /// A list of all -fno-builtin-* function names (e.g., memset).
  std::vector<std::string> NoBuiltinFuncs;
 
  /// A prefix map for __FILE__, __BASE_FILE__ and __builtin_FILE().
  std::map<std::string, std::string, std::greater<std::string>> MacroPrefixMap;
 
  /// Triples of the OpenMP targets that the host code codegen should
  /// take into account in order to generate accurate offloading descriptors.
  std::vector<llvm::Triple> OMPTargetTriples;
 
  /// Name of the IR file that contains the result of the OpenMP target
  /// host code generation.
  std::string OMPHostIRFile;
 
  /// The user provided compilation unit ID, if non-empty. This is used to
  /// externalize static variables which is needed to support accessing static
  /// device variables in host code for single source offloading languages
  /// like CUDA/HIP.
  std::string CUID;
 
  /// C++ ABI to compile with, if specified by the frontend through -fc++-abi=.
  /// This overrides the default ABI used by the target.
  std::optional<TargetCXXABI::Kind> CXXABI;
 
  /// Indicates whether the front-end is explicitly told that the
  /// input is a header file (i.e. -x c-header).
  bool IsHeaderFile = false;
 
  /// The default stream kind used for HIP kernel launching.
  GPUDefaultStreamKind GPUDefaultStream;
 
  /// Which overflow patterns should be excluded from sanitizer instrumentation
  unsigned OverflowPatternExclusionMask = 0;
 
  std::vector<std::string> OverflowPatternExclusionValues;
 
  /// The seed used by the randomize structure layout feature.
  std::string RandstructSeed;
 
  /// Indicates whether to use target's platform-specific file separator when
  /// __FILE__ macro is used and when concatenating filename with directory or
  /// to use build environment environment's platform-specific file separator.
  ///
  /// The plaform-specific path separator is the backslash(\‍) for Windows and
  /// forward slash (/) elsewhere.
  bool UseTargetPathSeparator = false;
 
  // Indicates whether we should keep all nullptr checks for pointers
  // received as a result of a standard operator new (-fcheck-new)
  bool CheckNew = false;
 
  // In OpenACC mode, contains a user provided override for the _OPENACC macro.
  // This exists so that we can override the macro value and test our incomplete
  // implementation on real-world examples.
  std::string OpenACCMacroOverride;
 
  // Indicates if the wasm-opt binary must be ignored in the case of a
  // WebAssembly target.
  bool NoWasmOpt = false;
 
  LangOptions();
 
  /// Set language defaults for the given input language and
  /// language standard in the given LangOptions object.
  ///
  /// \param Opts - The LangOptions object to set up.
  /// \param Lang - The input language.
  /// \param T - The target triple.
  /// \param Includes - If the language requires extra headers to be implicitly
  ///                   included, they will be appended to this list.
  /// \param LangStd - The input language standard.
  static void
  setLangDefaults(LangOptions &Opts, Language Lang, const llvm::Triple &