Move generated registers into discrete modules (#125)

Updates the stm32 examples to put generated register interfaces into
their own module. This improves build performance because the
swiftmodule containing the generated registers doesn't need to be
rebuilt when the primary application changes.

Ideally these registers would be generated using the SVD2SwiftPlugin
instead of directly checked into the repo, however there is a huge build
time cost to this because SwiftPM has separate build graphs for plugins
vs the primary build. This results in 2 copies of swift-syntax getting
built which inflates build time to 5+ minutes. Worse, SwiftPM randomly
triggers rebuilds of swift-syntax in the plugin graph making using the
plugin effectively impossible.

Author: rauhul

.swiftformatignore

@@ -1,4 +1,4 @@
 ./harmony/*
-./stm32-lcd-logo/Sources/Application/Registers/*
-./stm32-neopixel/Sources/Application/Registers/*
-./stm32-uart-echo/Sources/Application/Registers/*
+./stm32-lcd-logo/Sources/STM32F7X6/*
+./stm32-neopixel/Sources/STM32F7X6/*
+./stm32-uart-echo/Sources/STM32F7X6/*

stm32-lcd-logo/Package.resolved

@@ -11,19 +11,28 @@ let package = Package(
     .package(url: "https://github.com/apple/swift-mmio", branch: "main")
   ],
   targets: [
-    // SVD2Swift \
-    // --input Tools/SVDs/stm32f7x6.patched.svd \
-    // --output stm32-lcd-logo/Sources/STM32F7x6 \
-    // --peripherals FLASH GPIOA GPIOB GPIOC GPIOD GPIOE GPIOF GPIOG GPIOH GPIOI GPIOJ GPIOK LTDC RCC
     .executableTarget(
       name: "Application",
-      dependencies: [
-        .product(name: "MMIO", package: "swift-mmio"),
-        "Support",
-      ],
+      dependencies: ["STM32F7X6", "Support"],
       swiftSettings: [
         .enableExperimentalFeature("InlineArrayTypeSugar"),
         .enableExperimentalFeature("SymbolLinkageMarkers"),
       ]),
+    // SVD2Swift \
+    // --input Sources/STM32F7X6/stm32f7x6.patched.svd \
+    // --output Sources/STM32F7X6 \
+    // --access-level public \
+    // --indentation-width 2 \
+    // --peripherals FLASH GPIOA GPIOB GPIOC GPIOD GPIOE GPIOF GPIOG GPIOH GPIOI GPIOJ GPIOK LTDC RCC
+    .target(
+      name: "STM32F7X6",
+      dependencies: [
+        .product(name: "MMIO", package: "swift-mmio")
+      ],
+      plugins: [
+        // Plugin disabled because SwiftPM is slow.
+        // .plugin(name: "SVD2SwiftPlugin", package: "swift-mmio")
+      ]),
     .target(name: "Support"),
-  ])
+  ],
+  swiftLanguageModes: [.v5])

stm32-lcd-logo/Package.swift

@@ -9,6 +9,7 @@
 //
 //===----------------------------------------------------------------------===//
 
+import STM32F7X6
 import Support
 
 @main

stm32-lcd-logo/Sources/Application/Application.swift

@@ -9,6 +9,8 @@
 //
 //===----------------------------------------------------------------------===//
 
+import STM32F7X6
+
 extension GPIOA {
   public enum Port: Int {
     case a, b, c, d, e, f, g, h, i, j, k

stm32-lcd-logo/Sources/Application/HAL/GPIOA+Helpers.swift

@@ -9,6 +9,7 @@
 //
 //===----------------------------------------------------------------------===//
 
+import STM32F7X6
 import Support
 
 extension LTDC {

stm32-lcd-logo/Sources/Application/HAL/LTDC+Helpers.swift

@@ -1,3 +1,16 @@
+//===----------------------------------------------------------------------===//
+//
+// This source file is part of the Swift open source project
+//
+// Copyright (c) 2024 Apple Inc. and the Swift project authors.
+// Licensed under Apache License v2.0 with Runtime Library Exception
+//
+// See https://swift.org/LICENSE.txt for license information
+//
+//===----------------------------------------------------------------------===//
+
+import STM32F7X6
+
 extension RCC {
   func enableGPIOPortClock(_ port: GPIOA.Port) {
     switch port {

stm32-lcd-logo/Sources/Application/HAL/RCC+Helpers.swift

@@ -0,0 +1,45 @@
+// Generated by svd2swift.
+
+import MMIO
+
+/// FLASH
+public let flash = FLASH(unsafeAddress: 0x40023c00)
+
+/// General-purpose I/Os
+public let gpioa = GPIOA(unsafeAddress: 0x40020000)
+
+/// General-purpose I/Os
+public let gpiob = GPIOB(unsafeAddress: 0x40020400)
+
+/// General-purpose I/Os
+public let gpioc = GPIOC(unsafeAddress: 0x40020800)
+
+/// General-purpose I/Os
+public let gpiod = GPIOD(unsafeAddress: 0x40020c00)
+
+/// General-purpose I/Os
+public let gpioe = GPIOE(unsafeAddress: 0x40021000)
+
+/// General-purpose I/Os
+public let gpiof = GPIOF(unsafeAddress: 0x40021400)
+
+/// General-purpose I/Os
+public let gpiog = GPIOG(unsafeAddress: 0x40021800)
+
+/// General-purpose I/Os
+public let gpioh = GPIOH(unsafeAddress: 0x40021c00)
+
+/// General-purpose I/Os
+public let gpioi = GPIOI(unsafeAddress: 0x40022000)
+
+/// General-purpose I/Os
+public let gpioj = GPIOJ(unsafeAddress: 0x40022400)
+
+/// General-purpose I/Os
+public let gpiok = GPIOK(unsafeAddress: 0x40022800)
+
+/// LCD-TFT Controller
+public let ltdc = LTDC(unsafeAddress: 0x40016800)
+
+/// Reset and clock control
+public let rcc = RCC(unsafeAddress: 0x40023800)

stm32-lcd-logo/Sources/Application/Registers/Device.swift

@@ -0,0 +1,13 @@
+//===----------------------------------------------------------------------===//
+//
+// This source file is part of the Swift open source project
+//
+// Copyright (c) 2024 Apple Inc. and the Swift project authors.
+// Licensed under Apache License v2.0 with Runtime Library Exception
+//
+// See https://swift.org/LICENSE.txt for license information
+//
+//===----------------------------------------------------------------------===//
+
+// This file is intentionally left empty for SwiftPM to recognize the target as
+// a Swift source module.