[AVR] standard library support for AVR

cmake/modules/SwiftHandleGybSources.cmake

@@ -109,6 +109,7 @@ function(handle_gyb_sources dependency_out_var_name sources_var_name)
   if (GYB_ARCH)
     set_if_arch_bitness(ptr_size
       ARCH "${GYB_ARCH}"
+      CASE_16_BIT "2"
       CASE_32_BIT "4"
       CASE_64_BIT "8")
     set(extra_gyb_flags "-DCMAKE_SIZEOF_VOID_P=${ptr_size}")

cmake/modules/SwiftSetIfArchBitness.cmake

@@ -2,11 +2,13 @@ function(set_if_arch_bitness var_name)
   cmake_parse_arguments(
       SIA # prefix
       "" # options
-      "ARCH;CASE_32_BIT;CASE_64_BIT" # single-value args
+      "ARCH;CASE_16_BIT;CASE_32_BIT;CASE_64_BIT" # single-value args
       "" # multi-value args
       ${ARGN})
 
-  if("${SIA_ARCH}" STREQUAL "i386" OR
+  if("${SIA_ARCH}" STREQUAL "avr")
+      set("${var_name}" "${SIA_CASE_16_BIT}" PARENT_SCOPE)
+  elseif("${SIA_ARCH}" STREQUAL "i386" OR
      "${SIA_ARCH}" STREQUAL "i686" OR
      "${SIA_ARCH}" STREQUAL "x86" OR
      "${SIA_ARCH}" STREQUAL "armv4t" OR

lib/Basic/LangOptions.cpp

@@ -110,6 +110,7 @@ static const SupportedConditionalValue SupportedConditionalCompilationEndianness
 };
 
 static const SupportedConditionalValue SupportedConditionalCompilationPointerBitWidths[] = {
+  "_16",
   "_32",
   "_64"
 };
@@ -568,7 +569,9 @@ std::pair<bool, bool> LangOptions::setTarget(llvm::Triple triple) {
   }
 
   // Set the "_pointerBitWidth" platform condition.
-  if (Target.isArch32Bit()) {
+  if (Target.isArch16Bit()) {
+    addPlatformConditionValue(PlatformConditionKind::PointerBitWidth, "_16");
+  } else if (Target.isArch32Bit()) {
     addPlatformConditionValue(PlatformConditionKind::PointerBitWidth, "_32");
   } else if (Target.isArch64Bit()) {
     addPlatformConditionValue(PlatformConditionKind::PointerBitWidth, "_64");

lib/ClangImporter/ImportDecl.cpp

@@ -290,14 +290,14 @@ getSwiftStdlibType(const clang::TypedefNameDecl *D,
     break;
 
   case MappedCTypeKind::UnsignedWord:
-    if (ClangTypeSize != 64 && ClangTypeSize != 32)
+    if (ClangTypeSize != 64 && ClangTypeSize != 32 && ClangTypeSize != 16)
       return std::make_pair(Type(), "");
     if (!ClangType->isUnsignedIntegerType())
       return std::make_pair(Type(), "");
     break;
 
   case MappedCTypeKind::SignedWord:
-    if (ClangTypeSize != 64 && ClangTypeSize != 32)
+    if (ClangTypeSize != 64 && ClangTypeSize != 32 && ClangTypeSize != 16)
       return std::make_pair(Type(), "");
     if (!ClangType->isSignedIntegerType())
       return std::make_pair(Type(), "");

stdlib/public/CMakeLists.txt

@@ -214,6 +214,12 @@ if(SWIFT_SHOULD_BUILD_EMBEDDED_STDLIB_CROSS_COMPILING)
       "wasm64    wasm64-unknown-none-wasm    wasm64-unknown-none-wasm"
     )
   endif()
+
+  if("AVR" IN_LIST LLVM_TARGETS_TO_BUILD)
+    list(APPEND EMBEDDED_STDLIB_TARGET_TRIPLES
+      "avr  avr-none-none-elf    avr-none-none-elf"
+    )
+  endif()  
 endif()
 
 if(SWIFT_SHOULD_BUILD_EMBEDDED_STDLIB)

stdlib/public/Synchronization/CMakeLists.txt

@@ -142,6 +142,11 @@ if(SWIFT_SHOULD_BUILD_EMBEDDED_STDLIB)
     list(GET list 0 arch)
     list(GET list 1 mod)
     list(GET list 2 triple)
+
+    # Disable the Synchronization library on AVR for now.
+    if("${arch}" MATCHES "avr")
+      continue()
+    endif()
 
     set(SWIFT_SDK_embedded_ARCH_${arch}_MODULE "${mod}")
     set(SWIFT_SDK_embedded_LIB_SUBDIR "embedded")

stdlib/public/core/Builtin.swift

@@ -429,6 +429,8 @@ internal var _objectPointerIsObjCBit: UInt {
     return 0x4000_0000_0000_0000
 #elseif _pointerBitWidth(_32)
     return 0x0000_0002
+#elseif _pointerBitWidth(_16)
+    return 0x0000
 #else
 #error("Unknown platform")
 #endif

stdlib/public/core/CTypes.swift

@@ -25,10 +25,14 @@ public typealias CUnsignedChar = UInt8
 public typealias CUnsignedShort = UInt16
 
 /// The C 'unsigned int' type.
+#if  _pointerBitWidth(_16)
+public typealias CUnsignedInt = UInt
+#else
 public typealias CUnsignedInt = UInt32
+#endif
 
 /// The C 'unsigned long' type.
-#if os(Windows) && (arch(x86_64) || arch(arm64))
+#if (os(Windows) && (arch(x86_64) || arch(arm64))) || _pointerBitWidth(_16)
 public typealias CUnsignedLong = UInt32
 #else
 public typealias CUnsignedLong = UInt
@@ -44,10 +48,14 @@ public typealias CSignedChar = Int8
 public typealias CShort = Int16
 
 /// The C 'int' type.
+#if  _pointerBitWidth(_16)
+public typealias CInt = Int
+#else
 public typealias CInt = Int32
+#endif
 
 /// The C 'long' type.
-#if os(Windows) && (arch(x86_64) || arch(arm64))
+#if (os(Windows) && (arch(x86_64) || arch(arm64))) || _pointerBitWidth(_16)
 public typealias CLong = Int32
 #else
 public typealias CLong = Int

stdlib/public/core/EmbeddedRuntime.swift

@@ -41,9 +41,12 @@ public struct HeapObject {
 #if _pointerBitWidth(_64)
   static let doNotFreeBit = Int(bitPattern: 0x8000_0000_0000_0000)
   static let refcountMask = Int(bitPattern: 0x7fff_ffff_ffff_ffff)
-#else
+#elseif _pointerBitWidth(_32)
   static let doNotFreeBit = Int(bitPattern: 0x8000_0000)
   static let refcountMask = Int(bitPattern: 0x7fff_ffff)
+#elseif _pointerBitWidth(_16)
+  static let doNotFreeBit = Int(bitPattern: 0x8000)
+  static let refcountMask = Int(bitPattern: 0x7fff)
 #endif
 
   // Note: The immortalRefCount value of -1 is also hard-coded in IRGen in `irgen::emitConstantObject`.
@@ -55,8 +58,10 @@ public struct HeapObject {
 
 #if _pointerBitWidth(_64)
   static let bridgeObjectToPlainObjectMask = UInt(0x8fff_ffff_ffff_fff8)
-#else
+#elseif _pointerBitWidth(_32)
   static let bridgeObjectToPlainObjectMask = UInt(0xffff_ffff)
+#elseif _pointerBitWidth(_16)
+  static let bridgeObjectToPlainObjectMask = UInt(0xffff)
 #endif
 }
 

stdlib/public/core/Hasher.swift

@@ -164,6 +164,8 @@ extension Hasher {
       combine(UInt64(truncatingIfNeeded: value))
 #elseif _pointerBitWidth(_32)
       combine(UInt32(truncatingIfNeeded: value))
+#elseif _pointerBitWidth(_16)
+      combine(UInt16(truncatingIfNeeded: value))
 #else
 #error("Unknown platform")
 #endif
@@ -439,7 +441,7 @@ public struct Hasher {
     _internalInvariant(UInt.bitWidth == UInt64.bitWidth)
     state.compress(UInt64(truncatingIfNeeded: value))
     let tbc = _TailBuffer(tail: 0, byteCount: 8)
-#elseif _pointerBitWidth(_32)
+#elseif _pointerBitWidth(_32) || _pointerBitWidth(_16)
     _internalInvariant(UInt.bitWidth < UInt64.bitWidth)
     let tbc = _TailBuffer(
       tail: UInt64(truncatingIfNeeded: value),

stdlib/public/core/Int128.swift

@@ -456,6 +456,8 @@ extension Int128: BinaryInteger {
     UInt(Builtin.trunc_Int128_Int64(_value))
 #elseif _pointerBitWidth(_32)
     UInt(Builtin.trunc_Int128_Int32(_value))
+#elseif _pointerBitWidth(_16)
+    UInt(Builtin.trunc_Int128_Int16(_value))
 #else
 #error("Unsupported platform")
 #endif

stdlib/public/core/IntegerTypes.swift.gyb

@@ -1659,7 +1659,9 @@ ${assignmentOperatorComment(x.operator, True)}
   @_transparent
   public // @testable
   init(_ _v: Builtin.Word) {
-% if BuiltinName == 'Int32':
+% if BuiltinName == 'Int16':
+    self._value = Builtin.truncOrBitCast_Word_Int16(_v)
+% elif BuiltinName == 'Int32':
     self._value = Builtin.truncOrBitCast_Word_Int32(_v)
 % elif BuiltinName == 'Int64':
     self._value = Builtin.${z}extOrBitCast_Word_Int64(_v)
@@ -1669,7 +1671,9 @@ ${assignmentOperatorComment(x.operator, True)}
   @_transparent
   public // @testable
   var _builtinWordValue: Builtin.Word {
-% if BuiltinName == 'Int32':
+% if BuiltinName == 'Int16':
+    return Builtin.${z}extOrBitCast_Int16_Word(_value)
+% elif BuiltinName == 'Int32':
     return Builtin.${z}extOrBitCast_Int32_Word(_value)
 % elif BuiltinName == 'Int64':
     return Builtin.truncOrBitCast_Int64_Word(_value)

stdlib/public/core/SmallString.swift

@@ -79,7 +79,7 @@ internal struct _SmallString {
 extension _SmallString {
   @inlinable @inline(__always)
   internal static var capacity: Int {
-#if _pointerBitWidth(_32)
+#if _pointerBitWidth(_32) || _pointerBitWidth(_16)
     return 10
 #elseif os(Android) && arch(arm64)
     return 14

stdlib/public/core/StringGuts.swift

@@ -201,7 +201,7 @@ extension _StringGuts {
     the runtime is depending on this, update Reflection.mm and \
     this if you change it
     """)
-    #elseif _pointerBitWidth(_32)
+    #elseif _pointerBitWidth(_32) || _pointerBitWidth(_16)
     _internalInvariant(MemoryLayout<String>.size == 12, """
     the runtime is depending on this, update Reflection.mm and \
     this if you change it