Merge pull request #70685 from kubamracek/embedded-print-stopgap

[embedded] Add a stop-gap print() for embedded Swift

Author: kubamracek

include/swift/Runtime/RuntimeFunctions.def

@@ -193,7 +193,7 @@ FUNCTION(UnexpectedError, swift_unexpectedError, SwiftCC, AlwaysAvailable,
          RETURNS(VoidTy),
          ARGS(ErrorPtrTy),
          ATTRS(NoUnwind, NoReturn),
-         EFFECT(NoEffect),
+         EFFECT(NoEffect, Deallocating),
          UNKNOWN_MEMEFFECTS)
 
 // void *swift_copyPOD(void *dest, void *src, Metadata *self);

stdlib/public/core/CMakeLists.txt

@@ -263,6 +263,7 @@ endif()
 list(APPEND SWIFTLIB_EMBEDDED_SOURCES
   EmbeddedRuntime.swift
   EmbeddedStubs.swift
+  EmbeddedPrint.swift
   )
 
 set(GROUP_INFO_JSON_FILE ${CMAKE_CURRENT_SOURCE_DIR}/GroupInfo.json)

stdlib/public/core/EmbeddedPrint.swift

@@ -0,0 +1,101 @@
+//===----------------------------------------------------------------------===//
+//
+// This source file is part of the Swift.org open source project
+//
+// Copyright (c) 2014 - 2017 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
+// See https://swift.org/CONTRIBUTORS.txt for the list of Swift project authors
+//
+//===----------------------------------------------------------------------===//
+
+import SwiftShims
+
+// TODO: This is all a stop-gap so that at least some types are printable in
+// embedded Swift, in an embedded-programming friendly way (we mainly need
+// printing to not need to heap allocate).
+
+@_silgen_name("putchar")
+@discardableResult
+func putchar(_: CInt) -> CInt
+
+public func print(_ string: StaticString, terminator: StaticString = "\n") {
+  var p = string.utf8Start
+  while p.pointee != 0 {
+    putchar(CInt(p.pointee))
+    p += 1
+  }
+  p = terminator.utf8Start
+  while p.pointee != 0 {
+    putchar(CInt(p.pointee))
+    p += 1
+  }
+}
+
+func printCharacters(_ buf: UnsafeRawBufferPointer) {
+  for c in buf {
+    putchar(CInt(c))
+  }
+}
+
+func printCharacters(_ buf: UnsafeBufferPointer<UInt8>) {
+  printCharacters(UnsafeRawBufferPointer(buf))
+}
+
+extension BinaryInteger {
+  func writeToStdout() {
+    if self == (0 as Self) {
+      print("0", terminator: "")
+      return
+    }
+
+    func _ascii(_ digit: UInt8) -> UInt8 {
+      UInt8(("0" as Unicode.Scalar).value) + digit
+    }
+    let isNegative = Self.isSigned && self < (0 as Self)
+    var value = magnitude
+
+    // Avoid withUnsafeTemporaryAllocation which is not typed-throws ready yet
+    let byteCount = 64
+    let stackBuffer = Builtin.stackAlloc(byteCount._builtinWordValue,
+         1._builtinWordValue, 1._builtinWordValue)
+    let buffer = UnsafeMutableRawBufferPointer(start: .init(stackBuffer),
+        count: byteCount)
+
+    var index = buffer.count - 1
+    while value != 0 {
+      let (quotient, remainder) =
+          value.quotientAndRemainder(dividingBy: Magnitude(10))
+      buffer[index] = _ascii(UInt8(truncatingIfNeeded: remainder))
+      index -= 1
+      value = quotient
+    }
+    if isNegative {
+      buffer[index] = UInt8(("-" as Unicode.Scalar).value)
+      index -= 1
+    }
+    let start = index + 1
+    let end = buffer.count - 1
+    let count = end - start + 1
+
+    let pointerToPrint = buffer.baseAddress?.advanced(by: start)
+        .assumingMemoryBound(to: UInt8.self)
+    printCharacters(UnsafeBufferPointer(start: pointerToPrint, count: count))
+
+    Builtin.stackDealloc(stackBuffer)
+  }
+}
+
+public func print(_ integer: some BinaryInteger, terminator: StaticString = "\n") {
+  integer.writeToStdout()
+  print("", terminator: terminator)
+}
+
+public func print(_ boolean: Bool, terminator: StaticString = "\n") {
+  if boolean {
+    print("true", terminator: terminator)
+  } else {
+    print("false", terminator: terminator)
+  }
+}

stdlib/public/core/GroupInfo.json

@@ -248,7 +248,8 @@
     "DurationProtocol.swift",
     "Instant.swift",
     "EmbeddedRuntime.swift",
-    "EmbeddedStubs.swift"
+    "EmbeddedStubs.swift",
+    "EmbeddedPrint.swift"
   ],
   "Result": [
     "Result.swift"

stdlib/public/core/LifetimeManager.swift

@@ -99,6 +99,7 @@ public func _withUnprotectedUnsafeMutablePointer<T, Result>(
 #endif
 }
 
+#if !$Embedded
 /// Invokes the given closure with a pointer to the given argument.
 ///
 /// The `withUnsafePointer(to:_:)` function is useful for calling Objective-C
@@ -127,6 +128,17 @@ public func withUnsafePointer<T, Result>(
 {
   return try body(UnsafePointer<T>(Builtin.addressOfBorrow(value)))
 }
+#else
+// TODO: This should be unified with non-embedded Swift.
+@inlinable
+public func withUnsafePointer<T, E, Result>(
+  to value: T,
+  _ body: (UnsafePointer<T>) throws(E) -> Result
+) throws(E) -> Result
+{
+  return try body(UnsafePointer<T>(Builtin.addressOfBorrow(value)))
+}
+#endif
 
 /// Invokes the given closure with a pointer to the given argument.
 ///

test/SILOptimizer/devirt_deinits.swift

@@ -4,7 +4,7 @@
 // RUN: %target-run-simple-swift(-Xllvm -enable-deinit-devirtualizer -parse-as-library) | %FileCheck -check-prefix CHECK-OUTPUT %s
 
 // Check if it works in embedded mode.
-// RUN: %target-run-simple-swift(%S/../embedded/Inputs/print.swift -enable-experimental-feature Embedded -parse-as-library -runtime-compatibility-version none -wmo -Xfrontend -disable-objc-interop) | %FileCheck -check-prefix CHECK-OUTPUT %s
+// RUN: %target-run-simple-swift(-enable-experimental-feature Embedded -parse-as-library -runtime-compatibility-version none -wmo -Xfrontend -disable-objc-interop) | %FileCheck -check-prefix CHECK-OUTPUT %s
 
 // Run without the deinit-devirtualizer to verify that our CHECK-OUTPUT lines are correct.
 // TODO: currently disabled because of rdar://118449507

test/embedded/FixedArray.swift

@@ -1,11 +1,11 @@
 
-// RUN: %target-run-simple-swift(%S/Inputs/ExperimentalFixedArray.swift %S/Inputs/print.swift -enable-experimental-feature Embedded -enable-experimental-feature FixedArrays -parse-as-library -runtime-compatibility-version none -wmo -Xfrontend -disable-objc-interop) | %FileCheck %s
-// RUN: %target-run-simple-swift(-O %S/Inputs/ExperimentalFixedArray.swift %S/Inputs/print.swift -enable-experimental-feature Embedded -enable-experimental-feature FixedArrays -parse-as-library -runtime-compatibility-version none -wmo -Xfrontend -disable-objc-interop) | %FileCheck %s
+// RUN: %target-run-simple-swift(%S/Inputs/ExperimentalFixedArray.swift -enable-experimental-feature Embedded -enable-experimental-feature FixedArrays -parse-as-library -runtime-compatibility-version none -wmo -Xfrontend -disable-objc-interop) | %FileCheck %s
+// RUN: %target-run-simple-swift(-O %S/Inputs/ExperimentalFixedArray.swift -enable-experimental-feature Embedded -enable-experimental-feature FixedArrays -parse-as-library -runtime-compatibility-version none -wmo -Xfrontend -disable-objc-interop) | %FileCheck %s
 
 // Also test in non-embedded mode
 
-// RUN: %target-run-simple-swift(%S/Inputs/ExperimentalFixedArray.swift %S/Inputs/print.swift -enable-experimental-feature FixedArrays -parse-as-library -wmo) | %FileCheck %s
-// RUN: %target-run-simple-swift(-O %S/Inputs/ExperimentalFixedArray.swift %S/Inputs/print.swift -enable-experimental-feature FixedArrays -parse-as-library -wmo) | %FileCheck %s
+// RUN: %target-run-simple-swift(%S/Inputs/ExperimentalFixedArray.swift -enable-experimental-feature FixedArrays -parse-as-library -wmo) | %FileCheck %s
+// RUN: %target-run-simple-swift(-O %S/Inputs/ExperimentalFixedArray.swift -enable-experimental-feature FixedArrays -parse-as-library -wmo) | %FileCheck %s
 
 // REQUIRES: executable_test
 // REQUIRES: optimized_stdlib
@@ -37,18 +37,18 @@ struct IntByte: Printable {
   let b: Int8
 
   func print() {
-    main.print(i, terminator: "")
-    main.print(",", terminator: "")
-    main.print(b, terminator: "")
+    Swift.print(i, terminator: "")
+    Swift.print(",", terminator: "")
+    Swift.print(b, terminator: "")
   }
 }
 
 extension Optional: Printable where Wrapped == Int64 {
   func print() {
     if let x = self {
-      main.print(x, terminator: "")
+      Swift.print(x, terminator: "")
     } else {
-      main.print("nil", terminator: "")
+      Swift.print("nil", terminator: "")
     }
   }
 }
@@ -151,13 +151,13 @@ struct Matrix<T: Printable>: ~Copyable {
 
   func print() {
     for r in 0..<rows {
-      main.print("(", terminator: "")
+      Swift.print("(", terminator: "")
       for c in 0..<columns {
         self[r, c].print()
         if c < columns - 1 {
-          main.print(",", terminator: "")
+          Swift.print(",", terminator: "")
         } else {
-          main.print(")")
+          Swift.print(")")
         }
       }
     }
@@ -271,7 +271,7 @@ protocol Printable {
 
 extension Int: Printable {
   func print() {
-    main.print(self, terminator: "")
+    Swift.print(self, terminator: "")
   }
 }
 
@@ -290,13 +290,13 @@ final class CheckLifetime: Printable {
   }
 
   deinit {
-    main.print("deinit ", terminator: "")
-    main.print(x)
+    Swift.print("deinit ", terminator: "")
+    Swift.print(x)
   }
 
   func print() {
-    main.print("CheckLifetime(", terminator: "")
-    main.print(x, terminator: ")")
+    Swift.print("CheckLifetime(", terminator: "")
+    Swift.print(x, terminator: ")")
   }
 }
 

test/embedded/Inputs/print.swift

@@ -1,5 +1,5 @@
 // RUN: %empty-directory(%t)
-// RUN: %target-swift-frontend %s %S/Inputs/print.swift -enable-experimental-feature Embedded -enable-builtin-module -c -o %t/main.o
+// RUN: %target-swift-frontend %s -parse-as-library -enable-experimental-feature Embedded -enable-builtin-module -c -o %t/main.o
 // RUN: %target-clang %t/main.o -o %t/a.out -dead_strip
 // RUN: %target-run %t/a.out | %FileCheck %s
 

test/embedded/array-builtins-exec.swift

@@ -10,17 +10,18 @@
 // REQUIRES: OS=macosx || OS=linux-gnu
 
 @_silgen_name("putchar")
-func putchar(_: UInt8)
+@discardableResult
+func putchar(_: CInt) -> CInt
 
 public func print(_ s: StaticString, terminator: StaticString = "\n") {
   var p = s.utf8Start
   while p.pointee != 0 {
-    putchar(p.pointee)
+    putchar(CInt(p.pointee))
     p += 1
   }
   p = terminator.utf8Start
   while p.pointee != 0 {
-    putchar(p.pointee)
+    putchar(CInt(p.pointee))
     p += 1
   }
 }