function RegisterExtractorPack(id)

local extractorDirectory = GetPlatformToolsDirectory()

local relativeSwiftExtractor = extractorDirectory .. 'extractor'

local swiftExtractor = AbsolutifyExtractorPath(id, relativeSwiftExtractor)

local resourceDirectory = AbsolutifyExtractorPath(id, 'resource-dir' .. PathSep .. PlatformDirectory)

function indexOf(array, value)

for i, v in ipairs(array) do

if v == value then

return i

end

end

return nil

end

function startswith(text, prefix)

return string.find(text, prefix, 1, true) == 1

end

-- removes unsupported CLI arg including the following how_many args

function strip_unsupported_arg(args, arg, how_many)

local index = indexOf(args, arg)

if index then

table.remove(args, index)

while (how_many > 0)

do

table.remove(args, index)

how_many = how_many - 1

end

end

end

-- removes unsupported -Xcc flag, e.g, calling strip_unsupported_xcc_arg('-foo', 2) against

-- swift -Xcc -foo -Xcc -bar main.swift

-- will only leave 'swift main.swift' removing both -Xcc -foo, and also -Xcc -bar

-- removes unsupported CLI arg passed to clang via -Xcc together with the following how_many args

function strip_unsupported_clang_arg(args, arg, how_many)

local index = indexOf(args, arg)

if index and index > 0 and args[index - 1] == '-Xcc' then

index = index - 1 -- start from -Xcc

how_many = 2 * (how_many + 1) -- need to remove initial -Xcc <arg> as well as following -Xcc prefixed flags

while (how_many > 0)

do

table.remove(args, index)

how_many = how_many - 1

end

end

end

function strip_unsupported_args(args)

strip_unsupported_arg(args, '-emit-localized-strings', 0)

strip_unsupported_arg(args, '-emit-localized-strings-path', 1)

strip_unsupported_arg(args, '-stack-check', 0)

strip_unsupported_arg(args, '-experimental-skip-non-inlinable-function-bodies-without-types', 0)

strip_unsupported_clang_arg(args, '-ivfsstatcache', 1)

strip_unsupported_clang_arg(args, '-fno-odr-hash-protocols', 0)

strip_unsupported_clang_arg(args, '-clang-vendor-feature=+disableNonDependentMemberExprInCurrentInstantiation', 0)

strip_unsupported_clang_arg(args, '-clang-vendor-feature=+enableAggressiveVLAFolding', 0)

strip_unsupported_clang_arg(args, '-clang-vendor-feature=+revert09abecef7bbf', 0)

strip_unsupported_clang_arg(args, '-clang-vendor-feature=+thisNoAlignAttr', 0)

strip_unsupported_clang_arg(args, '-clang-vendor-feature=+thisNoNullAttr', 0)

strip_unsupported_clang_arg(args, '-clang-vendor-feature=+disableAtImportPrivateFrameworkInImplementationError', 0)

-- The four args below are removed to workaround version mismatches due to recent versions

-- of Xcode defaulting to explicit modules:

strip_unsupported_arg(args, '-disable-implicit-swift-modules', 0)

strip_unsupported_clang_arg(args, '-fno-implicit-modules', 0)

strip_unsupported_clang_arg(args, '-fno-implicit-module-maps', 0)

strip_unsupported_arg(args, '-explicit-swift-module-map-file', 1)

end

-- xcodebuild does not always specify the -resource-dir in which case the compiler falls back

-- to a resource-dir based on its path. We want to know what is the original resource-dir in

-- all cases so that we can patch it with out own. When we see a -resource-dir preceded by

-- -Xcc this will be a resource-dir that is passed to clang. We can still obtain the swift

-- resource-dir in this case by skipping over the -Xcc that follows it and stripping off the

-- clang suffix from the path.

function find_original_resource_dir(compilerPath, args)

local found = indexOf(args, '-resource-dir')

if found and args[found + 1] then

if args[found - 1] ~= '-Xcc' then

return args[found + 1]

elseif args[found + 1] == '-Xcc' and args[found + 2] then

local clang_index = string.find(args[found + 2], "/clang$")

if clang_index and clang_index - 1 > 0 then

return string.sub(args[found + 2], 1, clang_index - 1)

end

end

end

-- derive -resource-dir based on the compilerPath

-- e.g.: /usr/bin/swift-frontend -> /usr/bin/../lib/swift

local second_last_slash_index = string.find(compilerPath, "/[^/]*/[^/]*$")

local usr_dir = string.sub(compilerPath, 1, second_last_slash_index)

return usr_dir .. 'lib/swift'

end

-- replace or add our own resource directory

function replace_resource_dir(compilerPath, args)

local originalResourceDir = find_original_resource_dir(compilerPath, args)

for index, value in ipairs(args) do

if startswith(value, originalResourceDir) then

args[index] = resourceDirectory .. string.sub(value, #originalResourceDir + 1, -1)

end

end

if not indexOf(args, '-resource-dir') then

table.insert(args, '-resource-dir')

table.insert(args, resourceDirectory)

end

end

function SwiftMatcher(compilerName, compilerPath, compilerArguments, lang)

-- Only match binaries names `swift-frontend`

if compilerName ~= 'swift-frontend' then

return nil

end

-- Skip the invocation in case it's not called in `-frontend` mode

if compilerArguments.argv[1] ~= '-frontend' then

return nil

end

-- Drop the `-frontend` argument

table.remove(compilerArguments.argv, 1)

-- Skip "info" queries in case there is nothing to extract

if compilerArguments.argv[1] == '-print-target-info' then

return nil

end

if compilerArguments.argv[1] == '-emit-supported-features' then

return nil

end

if compilerArguments.argv[1] == '-scan-dependencies' then

return nil

end

strip_unsupported_args(compilerArguments.argv)

replace_resource_dir(compilerPath, compilerArguments.argv)

return {

trace = true,

replace = false,

order = ORDER_AFTER,

invocation = { path = swiftExtractor, arguments = compilerArguments }

}

end

return {

SwiftMatcher,

CreatePatternMatcher({ '^lsregister$' }, MatchCompilerName, nil,

{ trace = false }),

CreatePatternMatcher({ '^codesign$' }, MatchCompilerName, nil,

{ trace = false }),

CreatePatternMatcher({ '^sandbox%-exec$' }, MatchCompilerName, nil,

{ trace = false }),

}

end

-- Return a list of minimum supported versions of the configuration file format

-- return one entry per supported major version.

function GetCompatibleVersions()

return { '1.0.0' }

end