Add a Swift backend for LibertyXDR

This commit is contained in:
Přemysl Eric Janouch 2023-06-15 09:42:06 +02:00
parent 8466d0d850
commit 53197b51e5
Signed by: p
GPG Key ID: A0420B94F92B9493
5 changed files with 298 additions and 12 deletions

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@ -72,7 +72,7 @@ add_test (test-cmake-parser
# Test protocol code generation # Test protocol code generation
set (lxdrgen_outputs) set (lxdrgen_outputs)
set (lxdrgen_base "${PROJECT_BINARY_DIR}/lxdrgen.lxdr") set (lxdrgen_base "${PROJECT_BINARY_DIR}/lxdrgen.lxdr")
foreach (backend c go mjs) foreach (backend c go mjs swift)
list (APPEND lxdrgen_outputs ${lxdrgen_base}.${backend}) list (APPEND lxdrgen_outputs ${lxdrgen_base}.${backend})
add_custom_command (OUTPUT ${lxdrgen_base}.${backend} add_custom_command (OUTPUT ${lxdrgen_base}.${backend}
COMMAND env LC_ALL=C awk COMMAND env LC_ALL=C awk
@ -108,3 +108,11 @@ if (NODE_EXECUTABLE)
else () else ()
message (WARNING "Cannot test generated protocol code for Javascript") message (WARNING "Cannot test generated protocol code for Javascript")
endif () endif ()
find_program (SWIFTC_EXECUTABLE swiftc)
if (SWIFTC_EXECUTABLE)
add_test (test-lxdrgen-swift
${SWIFTC_EXECUTABLE} -typecheck ${lxdrgen_base}.swift)
else ()
message (WARNING "Cannot test generated protocol code for Swift")
endif ()

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@ -54,6 +54,9 @@ lxdrgen-mjs.awk::
LibertyXDR backend for Javascript, currently for decoding only. LibertyXDR backend for Javascript, currently for decoding only.
It cuts a corner by not using BigInts, on par with `JSON.parse()`. It cuts a corner by not using BigInts, on par with `JSON.parse()`.
lxdrgen-swift.awk::
LibertyXDR backend for the Swift programming language.
Contributing and Support Contributing and Support
------------------------ ------------------------
Use https://git.janouch.name/p/liberty to report any bugs, request features, Use https://git.janouch.name/p/liberty to report any bugs, request features,

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@ -441,7 +441,7 @@ function codegen_struct(name, cg, gotype) {
function codegen_union_tag(d, cg) { function codegen_union_tag(d, cg) {
cg["tagtype"] = d["type"] cg["tagtype"] = d["type"]
cg["tagname"] = d["name"] cg["tagname"] = snaketocamel(d["name"])
# The tag is implied from the type of struct stored in the interface. # The tag is implied from the type of struct stored in the interface.
} }
@ -450,8 +450,8 @@ function codegen_union_struct(name, casename, cg, scg, structname, init) {
structname = name snaketocamel(casename) structname = name snaketocamel(casename)
codegen_struct(structname, scg) codegen_struct(structname, scg)
init = CodegenGoType[structname] "{" snaketocamel(cg["tagname"]) \ init = CodegenGoType[structname] "{" cg["tagname"] \
": " decapitalize(snaketocamel(cg["tagname"])) "}" ": " decapitalize(cg["tagname"]) "}"
append(cg, "unmarshal", append(cg, "unmarshal",
"\tcase " CodegenGoType[cg["tagtype"]] snaketocamel(casename) ":\n" \ "\tcase " CodegenGoType[cg["tagtype"]] snaketocamel(casename) ":\n" \
"\t\ts := " init "\n" \ "\t\ts := " init "\n" \
@ -467,7 +467,7 @@ function codegen_union_struct(name, casename, cg, scg, structname, init) {
"\t\tu.Interface = &s\n") "\t\tu.Interface = &s\n")
} }
function codegen_union(name, cg, gotype, tagfield, tagvar) { function codegen_union(name, cg, gotype, tagvar) {
gotype = PrefixCamel name gotype = PrefixCamel name
print "type " gotype " struct {" print "type " gotype " struct {"
print "\tInterface any" print "\tInterface any"
@ -481,18 +481,17 @@ function codegen_union(name, cg, gotype, tagfield, tagvar) {
print "}" print "}"
print "" print ""
tagfield = snaketocamel(cg["tagname"]) tagvar = decapitalize(cg["tagname"])
tagvar = decapitalize(tagfield)
print "func (u *" gotype ") UnmarshalJSON(data []byte) (err error) {" print "func (u *" gotype ") UnmarshalJSON(data []byte) (err error) {"
print "\tvar t struct {" print "\tvar t struct {"
print "\t\t" tagfield " " CodegenGoType[cg["tagtype"]] \ print "\t\t" cg["tagname"] " " CodegenGoType[cg["tagtype"]] \
" `json:\"" tagvar "\"`" " `json:\"" tagvar "\"`"
print "\t}" print "\t}"
print "\tif err := json.Unmarshal(data, &t); err != nil {" print "\tif err := json.Unmarshal(data, &t); err != nil {"
print "\t\treturn err" print "\t\treturn err"
print "\t}" print "\t}"
print "" print ""
print "\tswitch " tagvar " := t." tagfield "; " tagvar " {" print "\tswitch " tagvar " := t." cg["tagname"] "; " tagvar " {"
print cg["unmarshal"] "\tdefault:" print cg["unmarshal"] "\tdefault:"
print "\t\terr = errors.New(`unsupported value: ` + " tagvar ".String())" print "\t\terr = errors.New(`unsupported value: ` + " tagvar ".String())"
print "\t}" print "\t}"

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@ -185,14 +185,14 @@ function codegen_struct(name, cg) {
function codegen_union_tag(d, cg) { function codegen_union_tag(d, cg) {
cg["tagtype"] = d["type"] cg["tagtype"] = d["type"]
cg["tagname"] = d["name"] cg["tagname"] = decapitalize(snaketocamel(d["name"]))
} }
function codegen_union_struct(name, casename, cg, scg, structname) { function codegen_union_struct(name, casename, cg, scg, structname) {
append(scg, "methods", append(scg, "methods",
"\n" \ "\n" \
"\tconstructor() {\n" \ "\tconstructor() {\n" \
"\t\tthis." decapitalize(snaketocamel(cg["tagname"])) \ "\t\tthis." cg["tagname"] \
" = " cg["tagtype"] "." snaketocamel(casename) "\n" \ " = " cg["tagtype"] "." snaketocamel(casename) "\n" \
"\t}\n") "\t}\n")
@ -209,7 +209,7 @@ function codegen_union_struct(name, casename, cg, scg, structname) {
} }
function codegen_union(name, cg, tagvar) { function codegen_union(name, cg, tagvar) {
tagvar = decapitalize(snaketocamel(cg["tagname"])) tagvar = cg["tagname"]
print "" print ""
print "export function deserialize" name "(r) {" print "export function deserialize" name "(r) {"

276
tools/lxdrgen-swift.awk Normal file
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@ -0,0 +1,276 @@
# lxdrgen-swift.awk: Swift backend for lxdrgen.awk.
#
# Copyright (c) 2023, Přemysl Eric Janouch <p@janouch.name>
# SPDX-License-Identifier: 0BSD
function define_internal(name, swifttype) {
Types[name] = "internal"
CodegenSwiftType[name] = swifttype
CodegenDeserialize[name] = "%s.read()"
}
function define_sint(size, shortname, swifttype) {
shortname = "i" size
swifttype = "Int" size
define_internal(shortname, swifttype)
}
function define_uint(size, shortname, swifttype) {
shortname = "u" size
swifttype = "UInt" size
define_internal(shortname, swifttype)
}
function codegen_begin() {
define_sint("8")
define_sint("16")
define_sint("32")
define_sint("64")
define_uint("8")
define_uint("16")
define_uint("32")
define_uint("64")
define_internal("bool", "Bool")
define_internal("string", "String")
print "// Code generated from " FILENAME ". DO NOT EDIT."
print "import Foundation"
print ""
print "public struct RelayReader {"
print "\tpublic var data: Data"
print ""
print "\tpublic enum ReadError: Error {"
print "\t\tcase unexpectedEOF"
print "\t\tcase invalidEncoding"
print "\t\tcase overflow"
print "\t\tcase unexpectedValue"
print "\t}"
print ""
print "\tpublic mutating func read<T: FixedWidthInteger>() throws -> T {"
print "\t\tlet size = MemoryLayout<T>.size"
print "\t\tguard data.count >= size else {"
print "\t\t\tthrow ReadError.unexpectedEOF"
print "\t\t}"
print "\t\tvar acc: T = 0"
print "\t\tdata.prefix(size).forEach { acc = acc << 8 | T($0) }"
print "\t\tdata = data.dropFirst(size)"
print "\t\treturn acc"
print "\t}"
print ""
print "\tpublic mutating func read() throws -> Bool {"
print "\t\ttry read() != UInt8(0)"
print "\t}"
print ""
print "\tpublic mutating func read() throws -> String {"
print "\t\tlet size: UInt32 = try self.read()"
print "\t\tguard let count = Int(exactly: size) else {"
print "\t\t\tthrow ReadError.overflow"
print "\t\t}"
print "\t\tguard data.count >= count else {"
print "\t\t\tthrow ReadError.unexpectedEOF"
print "\t\t}"
print "\t\tdefer {"
print "\t\t\tdata = data.dropFirst(count)"
print "\t\t}"
print "\t\tif let s = String(data: data.prefix(count), encoding: .utf8) {"
print "\t\t\treturn s"
print "\t\t} else {"
print "\t\t\tthrow ReadError.invalidEncoding"
print "\t\t}"
print "\t}"
print ""
print "\tpublic mutating func read<" \
"T: RawRepresentable<Int8>>() throws -> T {"
print "\t\tguard let value = T(rawValue: try read()) else {"
print "\t\t\tthrow ReadError.unexpectedValue"
print "\t\t}"
print "\t\treturn value"
print "\t}"
print ""
print "\tpublic mutating func read<T>("
print "\t\t\t_ read: (inout Self) throws -> T) throws -> [T] {"
print "\t\tlet size: UInt32 = try self.read()"
print "\t\tguard let count = Int(exactly: size) else {"
print "\t\t\tthrow ReadError.overflow"
print "\t\t}"
print "\t\tvar array = [T]()"
print "\t\tarray.reserveCapacity(count)"
print "\t\tfor _ in 0..<count {"
print "\t\t\tarray.append(try read(&self))"
print "\t\t}"
print "\t\treturn array"
print "\t}"
print "}"
print ""
print "public struct RelayWriter {"
print "\tpublic var data = Data()"
print ""
print "\tpublic mutating func append<T: FixedWidthInteger>(_ number: T) {"
print "\t\tvar n = number.byteSwapped"
print "\t\tfor _ in 0..<MemoryLayout<T>.size {"
print "\t\t\tdata.append(UInt8(truncatingIfNeeded: n))"
print "\t\t\tn >>= 8"
print "\t\t}"
print "\t}"
print ""
print "\tpublic mutating func append(_ bool: Bool) {"
print "\t\tappend(UInt8(bool ? 1 : 0))"
print "\t}"
print ""
print "\tpublic mutating func append(_ string: String) {"
print "\t\tlet bytes = string.data(using: .utf8)!"
print "\t\tappend(UInt32(bytes.count))"
print "\t\tdata.append(bytes)"
print "\t}"
print ""
print "\tpublic mutating func append<" \
"T: RawRepresentable<Int8>>(_ value: T) {"
print "\t\tappend(value.rawValue)"
print "\t}"
print ""
print "\tpublic mutating func append<T>("
print "\t\t\t_ array: Array<T>, _ write: (inout Self, T) -> ()) {"
print "\t\tappend(UInt32(array.count))"
print "\t\tfor i in 0..<array.count {"
print "\t\t\twrite(&self, array[i])"
print "\t\t}"
print "\t}"
print ""
print "\tpublic mutating func append<T: RelayEncodable>(_ value: T) {"
print "\t\tvalue.encode(to: &self)"
print "\t}"
print "}"
print ""
print "public protocol RelayEncodable { " \
"func encode(to: inout RelayWriter) }"
}
function codegen_constant(name, value) {
print ""
print "public let " decapitalize(PrefixCamel snaketocamel(name)) " = " value
}
function codegen_enum_value(name, subname, value, cg) {
append(cg, "fields",
"\tcase " decapitalize(snaketocamel(subname)) " = " value "\n")
}
function codegen_enum(name, cg, swifttype) {
swifttype = PrefixCamel name
print ""
print "public enum " swifttype ": Int8 {"
print cg["fields"] "}"
CodegenSwiftType[name] = swifttype
CodegenDeserialize[name] = "%s.read()"
for (i in cg)
delete cg[i]
}
function codegen_struct_field(d, cg, camel) {
camel = decapitalize(snaketocamel(d["name"]))
if (!d["isarray"]) {
append(cg, "fields",
"\tpublic var " camel ": " CodegenSwiftType[d["type"]] "\n")
append(cg, "deserialize",
"\t\tself." camel " = try " \
sprintf(CodegenDeserialize[d["type"]], "from") "\n")
append(cg, "serialize",
"\t\tto.append(self." camel ")\n")
return
}
append(cg, "fields",
"\tpublic var " camel ": [" CodegenSwiftType[d["type"]] "]\n")
append(cg, "deserialize",
"\t\tself." camel " = try from.read() { r in try " \
sprintf(CodegenDeserialize[d["type"]], "r") " }\n")
append(cg, "serialize",
"\t\tto.append(self." camel ") { (w, value) in w.append(value) }\n")
}
function codegen_struct_tag(d, cg, camel) {
camel = decapitalize(snaketocamel(d["name"]))
append(cg, "serialize",
"\t\tto.append(self." camel ")\n")
}
function codegen_struct(name, cg, swifttype) {
swifttype = PrefixCamel name
print ""
print "public struct " swifttype " {\n" cg["fields"] "}"
print ""
print "extension " swifttype ": " PrefixCamel "Encodable {"
print "\tpublic init(from: inout RelayReader) throws {"
print cg["deserialize"] "\t}"
print ""
print "\tpublic func encode(to: inout RelayWriter) {"
print cg["serialize"] "\t}"
print "}"
CodegenSwiftType[name] = swifttype
CodegenDeserialize[name] = "%s.read()"
for (i in cg)
delete cg[i]
}
function codegen_union_tag(d, cg) {
cg["tagtype"] = d["type"]
cg["tagname"] = decapitalize(snaketocamel(d["name"]))
}
function codegen_union_struct(name, casename, cg, scg, swifttype) {
# And thus not all generated structs are present in Types.
swifttype = PrefixCamel name snaketocamel(casename)
casename = decapitalize(snaketocamel(casename))
print ""
print "public struct " swifttype ": " PrefixCamel name " {"
print "\tpublic var " cg["tagname"] \
": " CodegenSwiftType[cg["tagtype"]] " { ." casename " }"
print scg["fields"] "}"
print ""
print "extension " swifttype ": " PrefixCamel "Encodable {"
print "\tfileprivate init(from: inout RelayReader) throws {"
print scg["deserialize"] "\t}"
print ""
print "\tpublic func encode(to: inout RelayWriter) {"
print scg["serialize"] "\t}"
print "}"
append(cg, "cases", "\tcase ." casename ":\n" \
"\t\treturn try " swifttype "(from: &from)\n")
CodegenSwiftType[name] = swifttype
CodegenDeserialize[name] = "%s.read()"
for (i in scg)
delete scg[i]
}
function codegen_union(name, cg, swifttype, init) {
# Classes don't have automatic member-wise initializers,
# thus using structs and protocols.
swifttype = PrefixCamel name
print ""
print "public protocol " swifttype ": " PrefixCamel "Encodable {"
print "\tvar " cg["tagname"] ": " CodegenSwiftType[cg["tagtype"]] " { get }"
print "}"
init = decapitalize(swifttype)
print ""
print "public func " init \
"(from: inout RelayReader) throws -> " swifttype " {"
print "\tlet " cg["tagname"] ": " CodegenSwiftType[cg["tagtype"]] \
" = try from.read()"
print "\tswitch " cg["tagname"] " {"
# TODO: Only generate the default if there are remaining values,
# so that swiftc doesn't produce warnings.
print cg["cases"] "\tdefault:"
print "\t\tthrow RelayReader.ReadError.unexpectedValue"
print"\t}"
print "}"
CodegenSwiftType[name] = swifttype
CodegenDeserialize[name] = init "(from: &%s)"
for (i in cg)
delete cg[i]
}