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Ship the SwiftUI/UIKit guest at the embedded tier, and make it instantiable there #1

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Ship the SwiftUI/UIKit guest at the embedded tier, and make it instantiable there #1

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36 changes: 36 additions & 0 deletions cli/Package.resolved
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34 changes: 30 additions & 4 deletions cli/Sources/Compiler/BuildPipeline.swift
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Original file line number Diff line number Diff line change
Expand Up @@ -1264,7 +1264,12 @@ public struct BuildPipeline {
rejectedExports: rejectedExports.map { (name: $0.0, reason: $0.1) })
}

let candidates = wasmSources.map {
PATCH_SWIFTUI_ONLY=1 skips the default (function-thunk)
// module entirely. Its generated JSON-ABI wrappers force T2 (~11.7 MB); with
// no primary module the SwiftUI guest is promoted to be `module.wasm`.
let swiftUIOnly = ProcessInfo.processInfo.environment["PATCH_SWIFTUI_ONLY"] != nil
if swiftUIOnly { FileHandle.standardError.write(Data("PATCH_SWIFTUI_ONLY: skipping the default function module; shipping the SwiftUI guest only\n".utf8)) }
let candidates = swiftUIOnly ? [] : wasmSources.map {
WasmConvergence.Candidate(functionID: $0.lastPathComponent, sourceFile: $0,
exports: exportsBySource[$0] ?? [])
}
Expand Down Expand Up @@ -1375,7 +1380,7 @@ public struct BuildPipeline {
// Lowers a declarative UIKit cell's construction to a guest `uikit_configure`
// export + ships it. Gated by the SAME `swiftui` toggle (the UIKit path is part
// of the same view-patching feature) and skipped without the toolchain.
if swiftUIOn, !(outcome.toolchainUnavailable) {
if ProcessInfo.processInfo.environment["PATCH_UIKIT"] != "0", swiftUIOn, !(outcome.toolchainUnavailable) {
if let uk = try runUIKitLowering(
sourceDir: sourceDir, buildDir: buildDir,
compiler: compiler, defaultModule: moduleURL) {
Expand Down Expand Up @@ -1599,6 +1604,16 @@ public struct BuildPipeline {
/// module is reported but not promoted — never a regression, never a broken module).
/// Copies (not moves) so the original guest path stays valid for reporting.
@discardableResult
/read a packaging tier from an env var (`t0` | `t1` | `t2`).
static func envTier(_ name: String) -> PackagingTier? {
switch ProcessInfo.processInfo.environment[name]?.lowercased() {
case "t0", "t0embedded", "embedded": return .t0Embedded
case "t1", "t1stdlib", "stdlib": return .t1Stdlib
case "t2", "t2foundation", "foundation": return .t2Foundation
default: return nil
}
}

static func promoteGuestToPrimary(guest: URL, primary: URL) -> Bool {
let fm = FileManager.default
guard fm.fileExists(atPath: guest.path),
Expand Down Expand Up @@ -2019,8 +2034,16 @@ public struct BuildPipeline {
WasmConvergence.Candidate(functionID: $0.lastPathComponent, sourceFile: $0,
exports: exportsBySource[$0] ?? [])
}
the guest IR is Foundation-free by design (see
// SwiftUIGuestEmitter.irResourceNames), so start it at T0 and let the
// convergence loop escalate on a real compile failure. Upstream pins T2,
// which is the ~11.7 MB floor. PATCH_SWIFTUI_START_TIER / _MAX_TIER
// (t0|t1|t2) override per run for measurement.
let guestStart = Self.envTier("PATCH_SWIFTUI_START_TIER") ?? .t0Embedded
let guestMax = Self.envTier("PATCH_SWIFTUI_MAX_TIER")
log("guest module convergence: start=\(guestStart.rawValue) max=\(guestMax?.rawValue ?? "none")")
let outcome = try convergence.converge(candidates, outputModule: swModuleURL,
startTier: .t2Foundation)
startTier: guestStart, maxTier: guestMax)
lastOutcome = outcome
// SHIP iff a module compiled AND it actually carries view exports. A subtle
// trap: the convergence loop is FILE-level — on a wrapper compile error it
Expand Down Expand Up @@ -2175,8 +2198,11 @@ public struct BuildPipeline {
WasmConvergence.Candidate(functionID: $0.lastPathComponent, sourceFile: $0,
exports: exportsBySource[$0] ?? [])
}
same as the SwiftUI guest — start embedded, escalate on failure.
let outcome = try WasmConvergence(compiler: compiler).converge(
candidates, outputModule: ukModuleURL, startTier: .t2Foundation)
candidates, outputModule: ukModuleURL,
startTier: Self.envTier("PATCH_UIKIT_START_TIER") ?? .t0Embedded,
maxTier: Self.envTier("PATCH_UIKIT_MAX_TIER"))
let shippedExports = outcome.compiled.flatMap { $0.exports }
.filter { $0 != "patch_malloc" && $0 != "patch_free" }
guard outcome.moduleURL != nil, !shippedExports.isEmpty else {
Expand Down
35 changes: 35 additions & 0 deletions cli/Sources/Compiler/WasmCompiler.swift
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Expand Up @@ -177,6 +177,13 @@ public struct SwiftWasmCompiler: WasmCompiling {
try fm.createDirectory(at: dst.deletingLastPathComponent(), withIntermediateDirectories: true)
try file.contents.write(to: dst, atomically: true, encoding: .utf8)
}
embedded Swift on wasm leaves `_swift_stdlib_strtod_clocale`
// (what `Double(String)` lowers to) to the platform; the full runtime defines
// it at T1/T2, so the shim is written ONLY at T0 to avoid a duplicate symbol.
if tier == .t0Embedded {
let shim = work.appendingPathComponent("Sources/\(CHeaderBridge.cTargetName)/swift_stdlib_shims.c")
try Self.embeddedStdlibShimSource.write(to: shim, atomically: true, encoding: .utf8)
}

try packageManifest(exports: exportedSymbols).write(
to: work.appendingPathComponent("Package.swift"), atomically: true, encoding: .utf8)
Expand Down Expand Up @@ -427,6 +434,18 @@ public struct SwiftWasmCompiler: WasmCompiling {
/// treats nil as "no guard verdict" — the existing toolchain error handling wins).
/// Minimal hand-rolled parser: WASM is `\0asm` + version, then sections; the
/// import section (id 2) is a vec of (module: name, field: name, desc).
/C shim for the one Swift runtime hook embedded wasm needs
/// from the platform. wasi-libc's `strtod` is the C-locale parse.
static let embeddedStdlibShimSource = """
#include <stdlib.h>
const char *_swift_stdlib_strtod_clocale(const char *nptr, double *outResult) {
char *end = NULL;
*outResult = strtod(nptr, &end);
return end;
}

"""

static func unsatisfiableEnvImports(_ bytes: [UInt8]) -> [String]? {
guard bytes.count > 8,
bytes[0] == 0x00, bytes[1] == 0x61, bytes[2] == 0x73, bytes[3] == 0x6d else { return nil }
Expand Down Expand Up @@ -510,6 +529,7 @@ public struct SwiftWasmCompiler: WasmCompiling {
private func realSourceManifest(moduleName: String, exports: [String], fusion: Bool = false) -> String {
var flags = ["-Xclang-linker", "-mexec-model=reactor", "-Xlinker", "--allow-undefined"]
for symbol in exports { flags += ["-Xlinker", "--export-if-defined=\(symbol)"] }
if tier == .t0Embedded && !fusion { flags += ["-Xlinker", "-lswiftUnicodeDataTables"] }
let flagList = flags.map { "\"\($0)\"" }.joined(separator: ", ")
// BREAKTHROUGH #9 — T0 EMBEDDED real-source compile. When the tier is
// `.t0Embedded`, build the real-module target with the Embedded feature +
Expand Down Expand Up @@ -537,6 +557,11 @@ public struct SwiftWasmCompiler: WasmCompiling {
swiftSettings: [
.swiftLanguageMode(.v5),
.enableExperimentalFeature("Embedded"),
the guest IR guards its Codable conformances
// behind `#if !FRONTIER_EMBEDDED` (see Conformance.swift) but
// upstream never defined it, so every T0 compile failed on
// `Codable is unavailable in embedded Swift`.
.define("FRONTIER_EMBEDDED"),
.unsafeFlags(["-wmo"])
],
linkerSettings: [ .unsafeFlags([\(flagList)]) ]
Expand Down Expand Up @@ -608,6 +633,11 @@ public struct SwiftWasmCompiler: WasmCompiling {
for symbol in exports {
flags += ["-Xlinker", "--export-if-defined=\(symbol)"]
}
embedded Swift's String comparison/normalization calls
// `_swift_stdlib_getNormData` & co, which live in the SDK's static
// `libswiftUnicodeDataTables.a`. Without it `--allow-undefined` leaves them
// as `env.*` imports the SDK runtime cannot satisfy (instantiate fails).
if tier == .t0Embedded { flags += ["-Xlinker", "-lswiftUnicodeDataTables"] }
let flagList = flags.map { "\"\($0)\"" }.joined(separator: ", ")

if tier == .t0Embedded {
Expand All @@ -627,6 +657,11 @@ public struct SwiftWasmCompiler: WasmCompiling {
dependencies: ["\(CHeaderBridge.cTargetName)"],
swiftSettings: [
.enableExperimentalFeature("Embedded"),
the guest IR guards its Codable conformances
// behind `#if !FRONTIER_EMBEDDED` (see Conformance.swift) but
// upstream never defined it, so every T0 compile failed on
// `Codable is unavailable in embedded Swift`.
.define("FRONTIER_EMBEDDED"),
.unsafeFlags(["-wmo"])
],
linkerSettings: [ .unsafeFlags([\(flagList)]) ]
Expand Down