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mangled-name ::= '_S' global
All Swift-mangled names begin with this prefix.
The basic mangling scheme is a list of 'operators' where the operators are structured in a post-fix order. For example the mangling may start with an identifier but only later in the mangling a type-like operator defines how this identifier has to be interpreted:
4Test3FooC // The trailing 'C' says that 'Foo' is a class in module 'Test'
Operators are either identifiers or a sequence of one or more characters,
like C for class.
All operators share the same name-space. Important operators are a single
character, which means that no other operator may start with the same
character.
Some less important operators are longer and may also contain one or more
natural numbers. But it's always important that the demangler can identify the
end (the last character) of an operator. For example, it's not possible to
determine the last character if there are two operators M and Ma:
a could belong to M or it could be the first character of the next
operator.
The intention of the post-fix order is to optimize for common pre-fixes.
Regardless, if it's the mangling for a metatype or a function in a module, the
mangled name will start with the module name (after the _S).
In the following, productions which are only _part_ of an operator, are named with uppercase letters.
global ::= type 'N' // type metadata (address point)
// -- type starts with [BCOSTV]
global ::= type 'Mf' // 'full' type metadata (start of object)
global ::= type 'MP' // type metadata pattern
global ::= type 'Ma' // type metadata access function
global ::= type 'ML' // type metadata lazy cache variable
global ::= nominal-type 'Mr' // generic type completion function
global ::= nominal-type 'Mi' // generic type instantiation function
global ::= nominal-type 'MI' // generic type instantiation cache
global ::= nominal-type 'Mm' // class metaclass
global ::= nominal-type 'Mn' // nominal type descriptor
global ::= module 'MXM' // module descriptor
global ::= context 'MXE' // extension descriptor
global ::= context 'MXX' // anonymous context descriptor
global ::= context identifier 'MXY' // anonymous context descriptor
global ::= type assoc_type_path 'MXA' // generic parameter ref
global ::= protocol 'Mp' // protocol descriptor
global ::= protocol 'WR' // protocol requirement table
global ::= nominal-type 'Mo' // class metadata immediate member base offset
global ::= type 'MF' // metadata for remote mirrors: field descriptor
global ::= type 'MB' // metadata for remote mirrors: builtin type descriptor
global ::= protocol-conformance 'MA' // metadata for remote mirrors: associated type descriptor
global ::= nominal-type 'MC' // metadata for remote mirrors: superclass descriptor
// TODO check this::
global ::= mangled-name 'TA' // partial application forwarder
global ::= mangled-name 'Ta' // ObjC partial application forwarder
global ::= type 'w' VALUE-WITNESS-KIND // value witness
global ::= protocol-conformance 'Mc' // protocol conformance descriptor
global ::= protocol-conformance 'WP' // protocol witness table
global ::= protocol-conformance 'Wa' // protocol witness table accessor
global ::= protocol-conformance 'WG' // generic protocol witness table
global ::= protocol-conformance 'Wp' // protocol witness table pattern
global ::= protocol-conformance 'Wr' // resilient witness table
global ::= protocol-conformance 'WI' // generic protocol witness table instantiation function
global ::= type protocol-conformance 'WL' // lazy protocol witness table cache variable
global ::= protocol-conformance identifier 'Wt' // associated type metadata accessor
global ::= protocol-conformance assoc_type_path nominal-type 'WT' // associated type witness table accessor
global ::= type protocol-conformance 'Wl' // lazy protocol witness table accessor
global ::= type 'WV' // value witness table
global ::= entity 'Wvd' // field offset
global ::= entity 'WC' // resilient enum tag index
assoc_type_path ::= identifier '_' identifier*
A direct symbol resolves directly to the address of an object. An indirect symbol resolves to the address of a pointer to the object. They are distinct manglings to make a certain class of bugs immediately obvious.
The terminology is slightly overloaded when discussing offsets. A direct offset resolves to a variable holding the true offset. An indirect offset resolves to a variable holding an offset to be applied to type metadata to get the address of the true offset. (Offset variables are required when the object being accessed lies within a resilient structure. When the layout of the object may depend on generic arguments, these offsets must be kept in metadata. Indirect field offsets are therefore required when accessing fields in generic types where the metadata itself has unknown layout.)
global ::= global 'TO' // ObjC-as-swift thunk
global ::= global 'To' // swift-as-ObjC thunk
global ::= global 'TD' // dynamic dispatch thunk
global ::= global 'Td' // direct method reference thunk
global ::= entity entity 'TV' // vtable override thunk, derived followed by base
global ::= type label-list? 'D' // type mangling for the debugger with label list for function types.
global ::= type 'TC' // continuation prototype (not actually used for real symbols)
global ::= protocol-conformance entity 'TW' // protocol witness thunk
global ::= context identifier identifier 'TB' // property behavior initializer thunk (not used currently)
global ::= context identifier identifier 'Tb' // property behavior setter thunk (not used currently)
global ::= global specialization // function specialization
global ::= global 'Tm' // merged function
global ::= entity // some identifiable thing
global ::= type type generic-signature? 'T' REABSTRACT-THUNK-TYPE // reabstraction thunk helper function
global ::= entity generic-signature? type type* 'TK' // key path getter
global ::= entity generic-signature? type type* 'Tk' // key path setter
global ::= type generic-signature 'TH' // key path equality
global ::= type generic-signature 'Th' // key path hasher
REABSTRACT-THUNK-TYPE ::= 'R' // reabstraction thunk helper function
REABSTRACT-THUNK-TYPE ::= 'r' // reabstraction thunk
The types in a reabstraction thunk helper function are always non-polymorphic
<impl-function-type> types.
VALUE-WITNESS-KIND ::= 'al' // allocateBuffer
VALUE-WITNESS-KIND ::= 'ca' // assignWithCopy
VALUE-WITNESS-KIND ::= 'ta' // assignWithTake
VALUE-WITNESS-KIND ::= 'de' // deallocateBuffer
VALUE-WITNESS-KIND ::= 'xx' // destroy
VALUE-WITNESS-KIND ::= 'XX' // destroyBuffer
VALUE-WITNESS-KIND ::= 'Xx' // destroyArray
VALUE-WITNESS-KIND ::= 'CP' // initializeBufferWithCopyOfBuffer
VALUE-WITNESS-KIND ::= 'Cp' // initializeBufferWithCopy
VALUE-WITNESS-KIND ::= 'cp' // initializeWithCopy
VALUE-WITNESS-KIND ::= 'TK' // initializeBufferWithTakeOfBuffer
VALUE-WITNESS-KIND ::= 'Tk' // initializeBufferWithTake
VALUE-WITNESS-KIND ::= 'tk' // initializeWithTake
VALUE-WITNESS-KIND ::= 'pr' // projectBuffer
VALUE-WITNESS-KIND ::= 'xs' // storeExtraInhabitant
VALUE-WITNESS-KIND ::= 'xg' // getExtraInhabitantIndex
VALUE-WITNESS-KIND ::= 'Cc' // initializeArrayWithCopy
VALUE-WITNESS-KIND ::= 'Tt' // initializeArrayWithTakeFrontToBack
VALUE-WITNESS-KIND ::= 'tT' // initializeArrayWithTakeBackToFront
VALUE-WITNESS-KIND ::= 'ug' // getEnumTag
VALUE-WITNESS-KIND ::= 'up' // destructiveProjectEnumData
VALUE-WITNESS-KIND ::= 'ui' // destructiveInjectEnumTag
<VALUE-WITNESS-KIND> differentiates the kinds of value
witness functions for a type.
global ::= generic-signature? type 'WOy' // Outlined copy
global ::= generic-signature? type 'WOe' // Outlined consume
global ::= generic-signature? type 'WOr' // Outlined retain
global ::= generic-signature? type 'WOs' // Outlined release
global ::= generic-signature? type 'WOb' // Outlined initializeWithTake
global ::= generic-signature? type 'WOc' // Outlined initializeWithCopy
global ::= generic-signature? type 'WOd' // Outlined assignWithTake
global ::= generic-signature? type 'WOf' // Outlined assignWithCopy
global ::= generic-signature? type 'WOh' // Outlined destroy
entity ::= nominal-type // named type declaration
entity ::= context entity-spec static? curry-thunk?
static ::= 'Z'
curry-thunk ::= 'Tc'
label-list ::= empty-list // represents complete absence of parameter labels
label-list ::= ('_' | identifier)* // '_' is inserted as placeholder for empty label,
// since the number of labels should match the number of parameters
// The leading type is the function type
entity-spec ::= label-list type file-discriminator? 'fC' // allocating constructor
entity-spec ::= label-list type file-discriminator? 'fc' // non-allocating constructor
entity-spec ::= type 'fU' INDEX // explicit anonymous closure expression
entity-spec ::= type 'fu' INDEX // implicit anonymous closure
entity-spec ::= 'fA' INDEX // default argument N+1 generator
entity-spec ::= 'fi' // non-local variable initializer
entity-spec ::= 'fD' // deallocating destructor; untyped
entity-spec ::= 'fd' // non-deallocating destructor; untyped
entity-spec ::= 'fE' // ivar destroyer; untyped
entity-spec ::= 'fe' // ivar initializer; untyped
entity-spec ::= 'Tv' NATURAL // outlined global variable (from context function)
entity-spec ::= 'Te' bridge-spec // outlined objective c method call
entity-spec ::= decl-name label-list function-signature generic-signature? 'F' // function
entity-spec ::= label-list type file-discriminator? 'i' ACCESSOR // subscript
entity-spec ::= decl-name label-list? type 'v' ACCESSOR // variable
entity-spec ::= decl-name type 'fp' // generic type parameter
entity-spec ::= decl-name type 'fo' // enum element (currently not used)
entity-spec ::= identifier 'Qa' // associated type declaration
ACCESSOR ::= 'm' // materializeForSet
ACCESSOR ::= 's' // setter
ACCESSOR ::= 'g' // getter
ACCESSOR ::= 'G' // global getter
ACCESSOR ::= 'w' // willSet
ACCESSOR ::= 'W' // didSet
ACCESSOR ::= 'a' ADDRESSOR-KIND // mutable addressor
ACCESSOR ::= 'l' ADDRESSOR-KIND // non-mutable addressor
ACCESSOR ::= 'p' // pseudo accessor referring to the storage itself
ADDRESSOR-KIND ::= 'u' // unsafe addressor (no owner)
ADDRESSOR-KIND ::= 'O' // owning addressor (non-native owner)
ADDRESSOR-KIND ::= 'o' // owning addressor (native owner)
ADDRESSOR-KIND ::= 'p' // pinning addressor (native owner)
decl-name ::= identifier
decl-name ::= identifier 'L' INDEX // locally-discriminated declaration
decl-name ::= identifier identifier 'LL' // file-discriminated declaration
decl-name ::= identifier 'L' RELATED-DISCRIMINATOR // related declaration
RELATED-DISCRIMINATOR ::= [a-j]
RELATED-DISCRIMINATOR ::= [A-J]
file-discriminator ::= identifier 'Ll' // anonymous file-discriminated declaration
The identifier in a <file-discriminator> and the second identifier in a
file-discriminated <decl-name> is a string that represents the file the
original declaration came from. It should be considered unique within the
enclosing module. The first identifier is the name of the entity. Not all
declarations marked private declarations will use this mangling; if the
entity's context is enough to uniquely identify the entity, the simple
identifier form is preferred.
Twenty operators of the form 'LA', 'LB', etc. are reserved to described entities related to the entity whose name is provided. For example, 'LE' and 'Le' in the "SC" module are used to represent the structs synthesized by the Clang importer for various "error code" enums.
Outlined bridged Objective C method call mangling includes which parameters and return value are bridged and the type of pattern outlined.
bridge-spec := bridged-kind bridged-param* bridged-return '_'
bridged-param := 'n' // not bridged parameter
bridged-param := 'b' // bridged parameter
bridged-return := 'n' // not bridged return
bridged-return := 'b' // bridged return
bridged-kind := 'm' // bridged method
bridged-kind := 'a' // bridged property (by address)
bridged-kind := 'p' // bridged property (by value)
These manglings identify the enclosing context in which an entity was declared, such as its enclosing module, function, or nominal type.
context ::= module
context ::= entity
context ::= entity module generic-signature? 'E'
An extension mangling is used whenever an entity's declaration context is
an extension and the entity being extended is in a different module. In this
case the extension's module is mangled first, followed by the entity being
extended. If the extension and the extended entity are in the same module, the
plain entity mangling is preferred. If the extension is constrained, the
constraints on the extension are mangled in its generic signature.
When mangling the context of a local entity within a constructor or destructor, the non-allocating or non-deallocating variant is used.
module ::= identifier // module name
module ::= known-module // abbreviation
context ::= entity identifier type-list 'XZ' // unknown runtime context
The runtime produces manglings of unknown runtime contexts when a declaration context has no preserved runtime information, or when a declaration is encoded in runtime in a way that the current runtime does not understand. These manglings are unstable and may change between runs of the process.
known-module ::= 's' // Swift
known-module ::= 'SC' // Clang-importer-synthesized
known-module ::= 'So' // C and Objective-C
The Objective-C module is used as the context for mangling Objective-C
classes as <type>s.
any-generic-type ::= substitution
any-generic-type ::= context decl-name 'C' // nominal class type
any-generic-type ::= context decl-name 'O' // nominal enum type
any-generic-type ::= context decl-name 'V' // nominal struct type
any-generic-type ::= context decl-name 'XY' // unknown nominal type
any-generic-type ::= protocol 'P' // nominal protocol type
any-generic-type ::= context decl-name 'a' // typealias type (used in DWARF and USRs)
any-generic-type ::= 'S' KNOWN-TYPE-KIND // known nominal type substitution
any-generic-type ::= 'S' NATURAL KNOWN-TYPE-KIND // repeated known type substitutions of the same kind
KNOWN-TYPE-KIND ::= 'a' // Swift.Array
KNOWN-TYPE-KIND ::= 'b' // Swift.Bool
KNOWN-TYPE-KIND ::= 'c' // Swift.UnicodeScalar
KNOWN-TYPE-KIND ::= 'd' // Swift.Float64
KNOWN-TYPE-KIND ::= 'f' // Swift.Float32
KNOWN-TYPE-KIND ::= 'i' // Swift.Int
KNOWN-TYPE-KIND ::= 'V' // Swift.UnsafeRawPointer
KNOWN-TYPE-KIND ::= 'v' // Swift.UnsafeMutableRawPointer
KNOWN-TYPE-KIND ::= 'P' // Swift.UnsafePointer
KNOWN-TYPE-KIND ::= 'p' // Swift.UnsafeMutablePointer
KNOWN-TYPE-KIND ::= 'Q' // Swift.ImplicitlyUnwrappedOptional
KNOWN-TYPE-KIND ::= 'q' // Swift.Optional
KNOWN-TYPE-KIND ::= 'R' // Swift.UnsafeBufferPointer
KNOWN-TYPE-KIND ::= 'r' // Swift.UnsafeMutableBufferPointer
KNOWN-TYPE-KIND ::= 'S' // Swift.String
KNOWN-TYPE-KIND ::= 'u' // Swift.UInt
protocol ::= context decl-name
type ::= 'Bb' // Builtin.BridgeObject
type ::= 'BB' // Builtin.UnsafeValueBuffer
type ::= 'Bf' NATURAL '_' // Builtin.Float<n>
type ::= 'Bi' NATURAL '_' // Builtin.Int<n>
type ::= 'BO' // Builtin.UnknownObject
type ::= 'Bo' // Builtin.NativeObject
type ::= 'Bp' // Builtin.RawPointer
type ::= 'Bt' // Builtin.SILToken
type ::= type 'Bv' NATURAL '_' // Builtin.Vec<n>x<type>
type ::= 'Bw' // Builtin.Word
type ::= function-signature 'c' // function type (escaping)
type ::= function-signature 'X' FUNCTION-KIND // special function type
type ::= bound-generic-type
type ::= type 'Sg' // optional type, shortcut for: type 'ySqG'
type ::= type 'Xo' // @unowned type
type ::= type 'Xu' // @unowned(unsafe) type
type ::= type 'Xw' // @weak type
type ::= impl-function-type 'XF' // function implementation type (currently unused)
type ::= type 'Xb' // SIL @box type (deprecated)
type ::= type-list 'Xx' // SIL box type
type ::= type-list type-list generic-signature 'XX'
// Generic SIL box type
type ::= type 'XD' // dynamic self type
type ::= type 'm' // metatype without representation
type ::= type 'XM' METATYPE-REPR // metatype with representation
type ::= type 'Xp' // existential metatype without representation
type ::= type 'Xm' METATYPE-REPR // existential metatype with representation
type ::= 'Xe' // error or unresolved type
bound-generic-type ::= type 'y' (type* '_')* type* retroactive-conformance* 'G' // one type-list per nesting level of type
bound-generic-type ::= substitution
FUNCTION-KIND ::= 'f' // @thin function type
FUNCTION-KIND ::= 'U' // uncurried function type (currently not used)
FUNCTION-KIND ::= 'K' // @auto_closure function type (noescape)
FUNCTION-KIND ::= 'B' // objc block function type
FUNCTION-KIND ::= 'C' // C function pointer type
FUNCTION-KIND ::= 'A' // @auto_closure function type (escaping)
FUNCTION-KIND ::= 'E' // function type (noescape)
function-signature ::= params-type params-type throws? // results and parameters
params-type := type 'z'? 'h'? // tuple in case of multiple parameters or a single parameter with a single tuple type
// with optional inout convention, shared convention. parameters don't have labels,
// they are mangled separately as part of the entity.
params-type := empty-list // shortcut for no parameters
throws ::= 'K' // 'throws' annotation on function types
type-list ::= list-type '_' list-type* // list of types
type-list ::= empty-list
// FIXME: Consider replacing 'h' with a two-char code
list-type ::= type identifier? 'z'? 'h'? 'n'? 'd'? // type with optional label, inout convention, shared convention, owned convention, and variadic specifier
METATYPE-REPR ::= 't' // Thin metatype representation
METATYPE-REPR ::= 'T' // Thick metatype representation
METATYPE-REPR ::= 'o' // ObjC metatype representation
type ::= archetype
type ::= associated-type
type ::= any-generic-type
type ::= protocol-list 'p' // existential type
type ::= protocol-list superclass 'Xc' // existential type with superclass
type ::= protocol-list 'Xl' // existential type with AnyObject
type ::= type-list 't' // tuple
type ::= type generic-signature 'u' // generic type
type ::= 'x' // generic param, depth=0, idx=0
type ::= 'q' GENERIC-PARAM-INDEX // dependent generic parameter
type ::= type assoc-type-name 'qa' // associated type of non-generic param
type ::= assoc-type-name 'Qy' GENERIC-PARAM-INDEX // associated type
type ::= assoc-type-name 'Qz' // shortcut for 'Qyz'
type ::= assoc-type-list 'QY' GENERIC-PARAM-INDEX // associated type at depth
type ::= assoc-type-list 'QZ' // shortcut for 'QYz'
protocol-list ::= protocol '_' protocol*
protocol-list ::= empty-list
assoc-type-list ::= assoc-type-name '_' assoc-type-name*
archetype ::= context 'Qq' INDEX // archetype+context (DWARF only)
archetype ::= associated-type
associated-type ::= substitution
associated-type ::= protocol 'QP' // self type of protocol
associated-type ::= archetype identifier 'Qa' // associated type
assoc-type-name ::= identifier // associated type name without protocol
assoc-type-name ::= identifier protocol 'P' //
empty-list ::= 'y'
Associated types use an abbreviated mangling when the base generic parameter or associated type is constrained by a single protocol requirement. The associated type in this case can be referenced unambiguously by name alone. If the base has multiple conformance constraints, then the protocol name is mangled in to disambiguate.
impl-function-type ::= type* 'I' FUNC-ATTRIBUTES '_'
impl-function-type ::= type* generic-signature 'I' PSEUDO-GENERIC? FUNC-ATTRIBUTES '_'
FUNC-ATTRIBUTES ::= CALLEE-ESCAPE? CALLEE-CONVENTION FUNC-REPRESENTATION? PARAM-CONVENTION* RESULT-CONVENTION* ('z' RESULT-CONVENTION)
PSEUDO-GENERIC ::= 'P'
CALLEE-ESCAPE ::= 'e' // @escaping (inverse of SIL @noescape)
CALLEE-CONVENTION ::= 'y' // @callee_unowned
CALLEE-CONVENTION ::= 'g' // @callee_guaranteed
CALLEE-CONVENTION ::= 'x' // @callee_owned
CALLEE-CONVENTION ::= 't' // thin
FUNC-REPRESENTATION ::= 'B' // C block invocation function
FUNC-REPRESENTATION ::= 'C' // C global function
FUNC-REPRESENTATION ::= 'M' // Swift method
FUNC-REPRESENTATION ::= 'J' // ObjC method
FUNC-REPRESENTATION ::= 'K' // closure
FUNC-REPRESENTATION ::= 'W' // protocol witness
PARAM-CONVENTION ::= 'i' // indirect in
PARAM-CONVENTION ::= 'c' // indirect in constant
PARAM-CONVENTION ::= 'l' // indirect inout
PARAM-CONVENTION ::= 'b' // indirect inout aliasable
PARAM-CONVENTION ::= 'n' // indirect in guaranteed
PARAM-CONVENTION ::= 'x' // direct owned
PARAM-CONVENTION ::= 'y' // direct unowned
PARAM-CONVENTION ::= 'g' // direct guaranteed
PARAM-CONVENTION ::= 'e' // direct deallocating
RESULT-CONVENTION ::= 'r' // indirect
RESULT-CONVENTION ::= 'o' // owned
RESULT-CONVENTION ::= 'd' // unowned
RESULT-CONVENTION ::= 'u' // unowned inner pointer
RESULT-CONVENTION ::= 'a' // auto-released
For the most part, manglings follow the structure of formal language types. However, in some cases it is more useful to encode the exact implementation details of a function type.
The type* list contains parameter and return types (including the error
result), in that order.
The number of parameters and results must match with the number of
<PARAM-CONVENTION> and <RESULT-CONVENTION> characters after the
<FUNC-REPRESENTATION>.
The <generic-signature> is used if the function is polymorphic.
protocol-conformance ::= type protocol module generic-signature?
<protocol-conformance> refers to a type's conformance to a protocol. The
named module is the one containing the extension or type declaration that
declared the conformance.
protocol-conformance ::= context identifier protocol identifier generic-signature? // Property behavior conformance
Property behaviors are implemented using private protocol conformances.
generic-signature ::= requirement* 'l' // one generic parameter
generic-signature ::= requirement* 'r' GENERIC-PARAM-COUNT* 'l'
GENERIC-PARAM-COUNT ::= 'z' // zero parameters
GENERIC-PARAM-COUNT ::= INDEX // N+1 parameters
requirement ::= protocol 'R' GENERIC-PARAM-INDEX // protocol requirement
requirement ::= protocol assoc-type-name 'Rp' GENERIC-PARAM-INDEX // protocol requirement on associated type
requirement ::= protocol assoc-type-list 'RP' GENERIC-PARAM-INDEX // protocol requirement on associated type at depth
requirement ::= protocol substitution 'RQ' // protocol requirement with substitution
requirement ::= type 'Rb' GENERIC-PARAM-INDEX // base class requirement
requirement ::= type assoc-type-name 'Rc' GENERIC-PARAM-INDEX // base class requirement on associated type
requirement ::= type assoc-type-list 'RC' GENERIC-PARAM-INDEX // base class requirement on associated type at depth
requirement ::= type substitution 'RB' // base class requirement with substitution
requirement ::= type 'Rs' GENERIC-PARAM-INDEX // same-type requirement
requirement ::= type assoc-type-name 'Rt' GENERIC-PARAM-INDEX // same-type requirement on associated type
requirement ::= type assoc-type-list 'RT' GENERIC-PARAM-INDEX // same-type requirement on associated type at depth
requirement ::= type substitution 'RS' // same-type requirement with substitution
requirement ::= type 'Rl' GENERIC-PARAM-INDEX LAYOUT-CONSTRAINT // layout requirement
requirement ::= type assoc-type-name 'Rm' GENERIC-PARAM-INDEX LAYOUT-CONSTRAINT // layout requirement on associated type
requirement ::= type assoc-type-list 'RM' GENERIC-PARAM-INDEX LAYOUT-CONSTRAINT // layout requirement on associated type at depth
requirement ::= type substitution 'RM' LAYOUT-CONSTRAINT // layout requirement with substitution
GENERIC-PARAM-INDEX ::= 'z' // depth = 0, idx = 0
GENERIC-PARAM-INDEX ::= INDEX // depth = 0, idx = N+1
GENERIC-PARAM-INDEX ::= 'd' INDEX INDEX // depth = M+1, idx = N
LAYOUT-CONSTRAINT ::= 'N' // NativeRefCountedObject
LAYOUT-CONSTRAINT ::= 'R' // RefCountedObject
LAYOUT-CONSTRAINT ::= 'T' // Trivial
LAYOUT-CONSTRAINT ::= 'C' // Class
LAYOUT-CONSTRAINT ::= 'D' // NativeClass
LAYOUT-CONSTRAINT ::= 'E' LAYOUT-SIZE-AND-ALIGNMENT // Trivial of exact size
LAYOUT-CONSTRAINT ::= 'e' LAYOUT-SIZE // Trivial of exact size
LAYOUT-CONSTRAINT ::= 'M' LAYOUT-SIZE-AND-ALIGNMENT // Trivial of size at most N bits
LAYOUT-CONSTRAINT ::= 'm' LAYOUT-SIZE // Trivial of size at most N bits
LAYOUT-CONSTRAINT ::= 'U' // Unknown layout
LAYOUT-SIZE ::= INDEX // Size only
LAYOUT-SIZE-AND-ALIGNMENT ::= INDEX INDEX // Size followed by alignment
A generic signature begins with an optional list of requirements.
The <GENERIC-PARAM-COUNT> describes the number of generic parameters at
each depth of the signature. As a special case, no <GENERIC-PARAM-COUNT>
values indicates a single generic parameter at the outermost depth:
x_xCru // <T_0_0> T_0_0 -> T_0_0
d_0__xCr_0_u // <T_0_0><T_1_0, T_1_1> T_0_0 -> T_1_1
A generic signature must only precede an operator character which is different
from any character in a <GENERIC-PARAM-COUNT>.
retroactive-conformance ::= protocol-conformance 'g' INDEX
When a protocol conformance used to satisfy one of a bound generic type's generic requirements is retroactive (i.e., it is specified in a module other than the module of the conforming type or the conformed-to protocol), it is mangled with its offset into the set of conformance requirements, the root protocol conformance, and the suffix 'g'.
identifier ::= substitution
identifier ::= NATURAL IDENTIFIER-STRING // identifier without word substitutions
identifier ::= '0' IDENTIFIER-PART // identifier with word substitutions
IDENTIFIER-PART ::= NATURAL IDENTIFIER-STRING
IDENTIFIER-PART ::= [a-z] // word substitution (except the last one)
IDENTIFIER-PART ::= [A-Z] // last word substitution in identifier
IDENTIFIER-STRING ::= IDENTIFIER-START-CHAR IDENTIFIER-CHAR*
IDENTIFIER-START-CHAR ::= [_a-zA-Z]
IDENTIFIER-CHAR ::= [_$a-zA-Z0-9]
<identifier> is run-length encoded: the natural indicates how many
characters follow. Operator characters are mapped to letter characters as
given. In neither case can an identifier start with a digit, so
there's no ambiguity with the run-length.
If the run-length start with a 0 the identifier string contains
word substitutions. A word is a sub-string of an identifier which contains
letters and digits [A-Za-z0-9]. Words are separated by underscores
_. In addition a new word begins with an uppercase letter [A-Z]
if the previous character is not an uppercase letter:
Abc1DefG2HI // contains four words 'Abc1', 'Def' and 'G2' and 'HI'
_abc1_def_G2hi // contains three words 'abc1', 'def' and G2hi
The words of all identifiers, which are encoded in the current mangling are enumerated and assigned to a letter: a = first word, b = second word, etc.
An identifier containing word substitutions is a sequence of run-length encoded
sub-strings and references to previously mangled words.
All but the last word-references are lowercase letters and the last one is an
uppercase letter. If there is no literal sub-string after the last
word-reference, the last word-reference is followed by a 0.
Let's assume the current mangling already encoded the identifier AbcDefGHI:
02Myac1_B // expands to: MyAbcGHI_Def
A maximum of 26 words in a mangling can be used for substitutions.
identifier ::= '00' natural '_'? IDENTIFIER-CHAR+ // '_' is inserted if the identifier starts with a digit or '_'.
Identifiers that contain non-ASCII characters are encoded using the Punycode
algorithm specified in RFC 3492, with the modifications that _ is used
as the encoding delimiter, and uppercase letters A through J are used in place
of digits 0 through 9 in the encoding character set. The mangling then
consists of an 00 followed by the run length of the encoded string and the
encoded string itself. For example, the identifier vergüenza is mangled
to 0012vergenza_JFa. (The encoding in standard Punycode would be
vergenza-95a)
If the encoded string starts with a digit or an _, an additional _ is
inserted between the run length and the encoded string.
identifier ::= identifier 'o' OPERATOR-FIXITY
OPERATOR-FIXITY ::= 'p' // prefix operator
OPERATOR-FIXITY ::= 'P' // postfix operator
OPERATOR-FIXITY ::= 'i' // infix operator
OPERATOR-CHAR ::= 'a' // & 'and'
OPERATOR-CHAR ::= 'c' // @ 'commercial at'
OPERATOR-CHAR ::= 'd' // / 'divide'
OPERATOR-CHAR ::= 'e' // = 'equals'
OPERATOR-CHAR ::= 'g' // > 'greater'
OPERATOR-CHAR ::= 'l' // < 'less'
OPERATOR-CHAR ::= 'm' // * 'multiply'
OPERATOR-CHAR ::= 'n' // ! 'not'
OPERATOR-CHAR ::= 'o' // | 'or'
OPERATOR-CHAR ::= 'p' // + 'plus'
OPERATOR-CHAR ::= 'q' // ? 'question'
OPERATOR-CHAR ::= 'r' // % 'remainder'
OPERATOR-CHAR ::= 's' // - 'subtract'
OPERATOR-CHAR ::= 't' // ~ 'tilde'
OPERATOR-CHAR ::= 'x' // ^ 'xor'
OPERATOR-CHAR ::= 'z' // . 'zperiod'
If an identifier is followed by an o its text is interpreted as an
operator. Each lowercase character maps to an operator character
(OPERATOR-CHAR).
Operators that contain non-ASCII characters are mangled by first mapping the
ASCII operator characters to letters as for pure ASCII operator names, then
Punycode-encoding the substituted string.
For example, the infix operator «+» is mangled to
007p_qcaDcoi (p_qcaDc being the encoding of the substituted
string «p»).
substitution ::= 'A' INDEX // substitution of N+26
substitution ::= 'A' SUBST_IDX* LAST-SUBST-IDX // One or more consecutive substitutions of N < 26
SUBST-IDX ::= [a-z]
SUBST-IDX ::= NATURAL [a-z]
LAST-SUBST-IDX ::= [A-Z]
LAST-SUBST-IDX ::= NATURAL [A-Z]
<substitution> is a back-reference to a previously mangled entity. The mangling
algorithm maintains a mapping of entities to substitution indices as it runs.
When an entity that can be represented by a substitution (a module, nominal
type, or protocol) is mangled, a substitution is first looked for in the
substitution map, and if it is present, the entity is mangled using the
associated substitution index. Otherwise, the entity is mangled normally, and
it is then added to the substitution map and associated with the next
available substitution index.
For example, in mangling a function type
(zim.zang.zung, zim.zang.zung, zim.zippity) -> zim.zang.zoo (with module
zim and class zim.zang),
the recurring contexts zim, zim.zang, and zim.zang.zung
will be mangled using substitutions after being mangled
for the first time. The first argument type will mangle in long form,
3zim4zang4zung, and in doing so, zim will acquire substitution AA,
zim.zang will acquire substitution AB, and zim.zang.zung will
acquire AC. The second argument is the same as the first and will mangle
using its substitution, AC. The
third argument type will mangle using the substitution for zim,
AA7zippity. (It also acquires substitution AD which would be used
if it mangled again.) The result type will mangle using the substitution for
zim.zang, AB3zoo (and acquire substitution AE).
There are some pre-defined substitutions, see KNOWN-TYPE-KIND.
If the mangling contains two or more consecutive substitutions, it can be
abbreviated with the A substitution. Similar to word-substitutions the
index is encoded as letters, whereas the last letter is uppercase:
AaeB // equivalent to A_A4_A0_
Repeated substitutions are encoded with a natural prefix number:
A3a2B // equivalent to AaaabB
INDEX ::= '_' // 0
INDEX ::= NATURAL '_' // N+1
NATURAL ::= [1-9] [0-9]*
NATURAL_ZERO ::= [0-9]+
<INDEX> is a production for encoding numbers in contexts that can't
end in a digit; it's optimized for encoding smaller numbers.
specialization ::= type '_' type* 'Tg' SPEC-INFO // Generic re-abstracted specialization
specialization ::= type '_' type* 'TG' SPEC-INFO // Generic not re-abstracted specialization
The types are the replacement types of the substitution list.
specialization ::= type 'Tp' SPEC-INFO // Partial generic specialization
specialization ::= type 'TP' SPEC-INFO // Partial generic specialization, not re-abstracted
The type is the function type of the specialized function.
specialization ::= spec-arg* 'Tf' SPEC-INFO UNIQUE-ID? ARG-SPEC-KIND* '_' ARG-SPEC-KIND // Function signature specialization kind
The <ARG-SPEC-KIND> describes how arguments are specialized.
Some kinds need arguments, which precede Tf.
spec-arg ::= identifier
spec-arg ::= type
SPEC-INFO ::= FRAGILE? PASSID
PASSID ::= '0' // AllocBoxToStack,
PASSID ::= '1' // ClosureSpecializer,
PASSID ::= '2' // CapturePromotion,
PASSID ::= '3' // CapturePropagation,
PASSID ::= '4' // FunctionSignatureOpts,
PASSID ::= '5' // GenericSpecializer,
FRAGILE ::= 'q'
UNIQUE-ID ::= NATURAL // Used to make unique function names
ARG-SPEC-KIND ::= 'n' // Unmodified argument
ARG-SPEC-KIND ::= 'c' // Consumes n 'type' arguments which are closed over types in argument order
// and one 'identifier' argument which is the closure symbol name
ARG-SPEC-KIND ::= 'p' CONST-PROP // Constant propagated argument
ARG-SPEC-KIND ::= 'd' 'G'? 'X'? // Dead argument, with optional owned=>guaranteed or exploded-specifier
ARG-SPEC-KIND ::= 'g' 'X'? // Owned => Guaranteed,, with optional exploded-specifier
ARG-SPEC-KIND ::= 'x' // Exploded
ARG-SPEC-KIND ::= 'i' // Box to value
ARG-SPEC-KIND ::= 's' // Box to stack
CONST-PROP ::= 'f' // Consumes one identifier argument which is a function symbol name
CONST-PROP ::= 'g' // Consumes one identifier argument which is a global symbol name
CONST-PROP ::= 'i' NATURAL_ZERO // 64-bit-integer
CONST-PROP ::= 'd' NATURAL_ZERO // float-as-64-bit-integer
CONST-PROP ::= 's' ENCODING // string literal. Consumes one identifier argument.
ENCODING ::= 'b' // utf8
ENCODING ::= 'w' // utf16
ENCODING ::= 'c' // utf16
If the first character of the string literal is a digit [0-9] or an
underscore _, the identifier for the string literal is prefixed with an
additional underscore _.