[embedded] Fix calling convention on embedded runtime APIs (switch @_silgen_name for @_cdecl)

stdlib/public/core/EmbeddedRuntime.swift

@@ -48,10 +48,10 @@ public struct HeapObject {
 
 /// Forward declarations of C functions
 
-@_silgen_name("posix_memalign")
+@_extern(c, "posix_memalign")
 func posix_memalign(_: UnsafeMutablePointer<UnsafeMutableRawPointer?>, _: Int, _: Int) -> CInt
 
-@_silgen_name("free")
+@_extern(c, "free")
 func free(_ p: Builtin.RawPointer)
 
 
@@ -81,8 +81,12 @@ public func swift_slowDealloc(_ ptr: UnsafeMutableRawPointer, _ size: Int, _ ali
   free(ptr._rawValue)
 }
 
-@_silgen_name("swift_allocObject")
-public func swift_allocObject(metadata: UnsafeMutablePointer<ClassMetadata>, requiredSize: Int, requiredAlignmentMask: Int) -> UnsafeMutablePointer<HeapObject> {
+@_cdecl("swift_allocObject")
+public func swift_allocObject(metadata: Builtin.RawPointer, requiredSize: Int, requiredAlignmentMask: Int) -> Builtin.RawPointer {
+  return swift_allocObject(metadata: UnsafeMutablePointer<ClassMetadata>(metadata), requiredSize: requiredSize, requiredAlignmentMask: requiredAlignmentMask)._rawValue
+}
+
+func swift_allocObject(metadata: UnsafeMutablePointer<ClassMetadata>, requiredSize: Int, requiredAlignmentMask: Int) -> UnsafeMutablePointer<HeapObject> {
   let p = swift_slowAlloc(requiredSize, requiredAlignmentMask)!
   let object = p.assumingMemoryBound(to: HeapObject.self)
   _swift_embedded_set_heap_object_metadata_pointer(object, metadata)
@@ -90,13 +94,21 @@ public func swift_allocObject(metadata: UnsafeMutablePointer<ClassMetadata>, req
   return object
 }
 
-@_silgen_name("swift_deallocObject")
-public func swift_deallocObject(object: UnsafeMutablePointer<HeapObject>, allocatedSize: Int, allocatedAlignMask: Int) {
+@_cdecl("swift_deallocObject")
+public func swift_deallocObject(object: Builtin.RawPointer, allocatedSize: Int, allocatedAlignMask: Int) {
+  swift_deallocObject(object: UnsafeMutablePointer<HeapObject>(object), allocatedSize: allocatedSize, allocatedAlignMask: allocatedAlignMask)
+}
+
+func swift_deallocObject(object: UnsafeMutablePointer<HeapObject>, allocatedSize: Int, allocatedAlignMask: Int) {
   free(object._rawValue)
 }
 
-@_silgen_name("swift_deallocClassInstance")
-public func swift_deallocClassInstance(object: UnsafeMutablePointer<HeapObject>, allocatedSize: Int, allocatedAlignMask: Int) {
+@_cdecl("swift_deallocClassInstance")
+public func swift_deallocClassInstance(object: Builtin.RawPointer, allocatedSize: Int, allocatedAlignMask: Int) {
+  swift_deallocClassInstance(object: UnsafeMutablePointer<HeapObject>(object), allocatedSize: allocatedSize, allocatedAlignMask: allocatedAlignMask)
+}
+
+func swift_deallocClassInstance(object: UnsafeMutablePointer<HeapObject>, allocatedSize: Int, allocatedAlignMask: Int) {
   if (object.pointee.refcount & HeapObject.doNotFreeBit) != 0 {
     return
   }
@@ -104,15 +116,23 @@ public func swift_deallocClassInstance(object: UnsafeMutablePointer<HeapObject>,
   free(object._rawValue)
 }
 
-@_silgen_name("swift_initStaticObject")
-public func swift_initStaticObject(metadata: UnsafeMutablePointer<ClassMetadata>, object: UnsafeMutablePointer<HeapObject>) -> UnsafeMutablePointer<HeapObject> {
+@_cdecl("swift_initStaticObject")
+public func swift_initStaticObject(metadata: Builtin.RawPointer, object: Builtin.RawPointer) -> Builtin.RawPointer {
+  return swift_initStaticObject(metadata: UnsafeMutablePointer<ClassMetadata>(metadata), object: UnsafeMutablePointer<HeapObject>(object))._rawValue
+}
+
+func swift_initStaticObject(metadata: UnsafeMutablePointer<ClassMetadata>, object: UnsafeMutablePointer<HeapObject>) -> UnsafeMutablePointer<HeapObject> {
   _swift_embedded_set_heap_object_metadata_pointer(object, metadata)
   object.pointee.refcount = HeapObject.immortalRefCount
   return object
 }
 
-@_silgen_name("swift_initStackObject")
-public func swift_initStackObject(metadata: UnsafeMutablePointer<ClassMetadata>, object: UnsafeMutablePointer<HeapObject>) -> UnsafeMutablePointer<HeapObject> {
+@_cdecl("swift_initStackObject")
+public func swift_initStackObject(metadata: Builtin.RawPointer, object: Builtin.RawPointer) -> Builtin.RawPointer {
+  return swift_initStackObject(metadata: UnsafeMutablePointer<ClassMetadata>(metadata), object: UnsafeMutablePointer<HeapObject>(object))._rawValue
+}
+
+func swift_initStackObject(metadata: UnsafeMutablePointer<ClassMetadata>, object: UnsafeMutablePointer<HeapObject>) -> UnsafeMutablePointer<HeapObject> {
   _swift_embedded_set_heap_object_metadata_pointer(object, metadata)
   object.pointee.refcount = 1 | HeapObject.doNotFreeBit
   return object
@@ -122,17 +142,21 @@ public func swift_initStackObject(metadata: UnsafeMutablePointer<ClassMetadata>,
 
 /// Refcounting
 
-@_silgen_name("swift_setDeallocating")
-public func swift_setDeallocating(object: UnsafeMutablePointer<HeapObject>) {
+@_cdecl("swift_setDeallocating")
+public func swift_setDeallocating(object: Builtin.RawPointer) {
 }
 
-@_silgen_name("swift_isUniquelyReferenced_nonNull_native")
-public func swift_isUniquelyReferenced_nonNull_native(object: UnsafeMutablePointer<HeapObject>) -> Bool {
+@_cdecl("swift_isUniquelyReferenced_nonNull_native")
+public func swift_isUniquelyReferenced_nonNull_native(object: Builtin.RawPointer) -> Bool {
+  return swift_isUniquelyReferenced_nonNull_native(object: UnsafeMutablePointer<HeapObject>(object))
+}
+
+func swift_isUniquelyReferenced_nonNull_native(object: UnsafeMutablePointer<HeapObject>) -> Bool {
   let refcount = refcountPointer(for: object)
   return loadAcquire(refcount) == 1
 }
 
-@_silgen_name("swift_retain")
+@_cdecl("swift_retain")
 public func swift_retain(object: Builtin.RawPointer) -> Builtin.RawPointer {
   if Int(Builtin.ptrtoint_Word(object)) == 0 { return object }
   let o = UnsafeMutablePointer<HeapObject>(object)
@@ -140,7 +164,7 @@ public func swift_retain(object: Builtin.RawPointer) -> Builtin.RawPointer {
 }
 
 // Cannot use UnsafeMutablePointer<HeapObject>? directly in the function argument or return value as it causes IRGen crashes
-@_silgen_name("swift_retain_n")
+@_cdecl("swift_retain_n")
 public func swift_retain_n(object: Builtin.RawPointer, n: UInt32) -> Builtin.RawPointer {
   if Int(Builtin.ptrtoint_Word(object)) == 0 { return object }
   let o = UnsafeMutablePointer<HeapObject>(object)
@@ -158,21 +182,21 @@ func swift_retain_n_(object: UnsafeMutablePointer<HeapObject>, n: UInt32) -> Uns
   return object
 }
 
-@_silgen_name("swift_release")
+@_cdecl("swift_release")
 public func swift_release(object: Builtin.RawPointer) {
   if Int(Builtin.ptrtoint_Word(object)) == 0 { return }
   let o = UnsafeMutablePointer<HeapObject>(object)
   swift_release_n_(object: o, n: 1)
 }
 
-@_silgen_name("swift_release_n")
+@_cdecl("swift_release_n")
 public func swift_release_n(object: Builtin.RawPointer, n: UInt32) {
   if Int(Builtin.ptrtoint_Word(object)) == 0 { return }
   let o = UnsafeMutablePointer<HeapObject>(object)
   swift_release_n_(object: o, n: n)
 }
 
-public func swift_release_n_(object: UnsafeMutablePointer<HeapObject>?, n: UInt32) {
+func swift_release_n_(object: UnsafeMutablePointer<HeapObject>?, n: UInt32) {
   guard let object else {
     return
   }
@@ -228,12 +252,12 @@ fileprivate func storeRelease(_ atomic: UnsafeMutablePointer<Int>, newValue: Int
 
 /// Exclusivity checking
 
-@_silgen_name("swift_beginAccess")
+@_cdecl("swift_beginAccess")
 public func swift_beginAccess(pointer: UnsafeMutableRawPointer, buffer: UnsafeMutableRawPointer, flags: UInt, pc: UnsafeMutableRawPointer) {
   // TODO: Add actual exclusivity checking.
 }
 
-@_silgen_name("swift_endAccess")
+@_cdecl("swift_endAccess")
 public func swift_endAccess(buffer: UnsafeMutableRawPointer) {
   // TODO: Add actual exclusivity checking.
 }
@@ -242,7 +266,7 @@ public func swift_endAccess(buffer: UnsafeMutableRawPointer) {
 
 // Once
 
-@_silgen_name("swift_once")
+@_cdecl("swift_once")
 public func swift_once(predicate: UnsafeMutablePointer<Int>, fn: (@convention(c) (UnsafeMutableRawPointer)->()), context: UnsafeMutableRawPointer) {
   let checkedLoadAcquire = { predicate in
     let value = loadAcquire(predicate)
@@ -269,12 +293,12 @@ public func swift_once(predicate: UnsafeMutablePointer<Int>, fn: (@convention(c)
 
 // Misc
 
-@_silgen_name("swift_deletedMethodError")
+@_cdecl("swift_deletedMethodError")
 public func swift_deletedMethodError() -> Never {
   Builtin.int_trap()
 }
 
-@_silgen_name("swift_willThrow")
+@_silgen_name("swift_willThrow") // This is actually expected to be swiftcc (@_silgen_name and not @_cdecl).
 public func swift_willThrow() throws {
 }
 

test/embedded/lto-multiple-object-files.swift

@@ -0,0 +1,56 @@
+// Regression test for a runtime failure that used to happen under some very specific conditions: (1) LTO, (2) Swift
+// compiler is used with -num-threads to emit multiple .o files even in WMO mode, (3) the first listed source file
+// contains no code that would trigger the use of swift_initStaticObject runtime function (e.g. no array literals), (4)
+// another source file does use swift_initStaticObject that doesn't get optimized away (e.g. an array literal in a
+// never-inline function, but not an empty array). In that case, we used to have a mismatching calling convention on
+// swift_initStaticObject that the LTO pipeline would conclude is invalid IR and replace it with an unconditional trap.
+
+// RUN: %empty-directory(%t)
+// RUN: %{python} %utils/split_file.py -o %t %s
+
+// RUN: %target-swift-frontend -Osize -lto=llvm-full %t/MyFile1.swift %t/MyFile2.swift -enable-experimental-feature Embedded -emit-bc -num-threads 2 -o %t/MyFile1.o -o %t/MyFile2.o
+// RUN: %target-clang -Oz %t/MyFile1.o %t/MyFile2.o -o %t/a.out
+// RUN: %target-run %t/a.out | %FileCheck %s
+
+// REQUIRES: swift_in_compiler
+// REQUIRES: executable_test
+// REQUIRES: OS=macosx
+
+// For LTO, the linker dlopen()'s the libLTO library, which is a scenario that
+// ASan cannot work in ("Interceptors are not working, AddressSanitizer is
+// loaded too late").
+// REQUIRES: no_asan
+
+// BEGIN MyFile1.swift
+
+public func foo() {
+  print("foo")
+}
+
+// BEGIN MyFile2.swift
+
+public func bar() {
+  print("bar")
+}
+
+@inline(never)
+public func baz(array: [Int]) -> ([Int], [Int]) {
+  let x = [1, 2, 3]
+  let y = [3, 4, 5]
+  return (x, y)
+}
+
+@main
+struct Main {
+  static func main() {
+    foo()
+    let (x, y) = baz(array: Array<Int>.init(repeating: 0, count: 8))
+    let c = x.count + y.count
+    print(c)
+    bar()
+  }
+}
+
+// CHECK: foo
+// CHECK-NEXT: 6
+// CHECK-NEXT: bar