stdlib/public fixes for Windows support

stdlib/public/SwiftShims/LibcShims.h

@@ -124,16 +124,16 @@ typedef unsigned long __swift_pthread_key_t;
 #endif
 
 SWIFT_RUNTIME_STDLIB_INTERFACE
-int _swift_stdlib_pthread_key_create(
+int _swift_stdlib_tls_key_create(
   __swift_pthread_key_t * _Nonnull key, void
   (* _Nullable destructor)(void * _Nullable )
 );
 
 SWIFT_RUNTIME_STDLIB_INTERFACE
-void * _Nullable _swift_stdlib_pthread_getspecific(__swift_pthread_key_t key);
+void * _Nullable _swift_stdlib_tls_getspecific(__swift_pthread_key_t key);
 
 SWIFT_RUNTIME_STDLIB_INTERFACE
-int _swift_stdlib_pthread_setspecific(
+int _swift_stdlib_tls_setspecific(
   __swift_pthread_key_t key, const void * _Nullable value
 );
 

stdlib/public/SwiftShims/RefCount.h

@@ -733,7 +733,7 @@ class SideTableRefCountBits : public RefCountBitsT<RefCountNotInline>
 template <typename RefCountBits>
 class RefCounts {
   std::atomic<RefCountBits> refCounts;
-#if !__LP64__
+#if !__LP64__ && !defined(_WIN64)
   // FIXME: hack - something somewhere is assuming a 3-word header on 32-bit
   // See also other fixmes marked "small header for 32-bit"
   uintptr_t unused SWIFT_ATTRIBUTE_UNAVAILABLE;

stdlib/public/SwiftShims/Visibility.h

@@ -93,7 +93,7 @@
 
 #else
 # if defined(__CYGWIN__)
-#  define SWIFT_RUNTIME_EXPORT
+#  define SWIFT_EXPORT_ATTRIBUTE
 # else
 #  if defined(swiftCore_EXPORTS)
 #   define SWIFT_EXPORT_ATTRIBUTE __declspec(dllexport)

stdlib/public/core/ThreadLocalStorage.swift

@@ -64,7 +64,7 @@ internal struct _ThreadLocalStorage {
   static internal func getPointer()
     -> UnsafeMutablePointer<_ThreadLocalStorage>
   {
-    let tlsRawPtr = _swift_stdlib_pthread_getspecific(_tlsKey)
+    let tlsRawPtr = _swift_stdlib_tls_getspecific(_tlsKey)
     if _fastPath(tlsRawPtr != nil) {
       return tlsRawPtr._unsafelyUnwrappedUnchecked.assumingMemoryBound(
         to: _ThreadLocalStorage.self)
@@ -119,7 +119,7 @@ internal func _destroyTLS(_ ptr: UnsafeMutableRawPointer?) {
 internal let _tlsKey: __swift_pthread_key_t = {
   let sentinelValue = __swift_pthread_key_t.max
   var key: __swift_pthread_key_t = sentinelValue
-  let success = _swift_stdlib_pthread_key_create(&key, _destroyTLS)
+  let success = _swift_stdlib_tls_key_create(&key, _destroyTLS)
   _sanityCheck(success == 0, "somehow failed to create TLS key")
   _sanityCheck(key != sentinelValue, "Didn't make a new key")
   return key
@@ -129,7 +129,7 @@ internal let _tlsKey: __swift_pthread_key_t = {
 internal func _initializeThreadLocalStorage()
   -> UnsafeMutablePointer<_ThreadLocalStorage>
 {
-  _sanityCheck(_swift_stdlib_pthread_getspecific(_tlsKey) == nil,
+  _sanityCheck(_swift_stdlib_tls_getspecific(_tlsKey) == nil,
     "already initialized")
 
   // Create and initialize one.
@@ -146,7 +146,7 @@ internal func _initializeThreadLocalStorage()
   tlsPtr.initialize(
     to: _ThreadLocalStorage(_uBreakIterator: newUBreakIterator)
   )
-  let success = _swift_stdlib_pthread_setspecific(_tlsKey, tlsPtr)
+  let success = _swift_stdlib_tls_setspecific(_tlsKey, tlsPtr)
   _sanityCheck(success == 0, "setspecific failed")
   return tlsPtr
 }

stdlib/public/runtime/Errors.cpp

@@ -50,6 +50,8 @@
 #include <asl.h>
 #elif defined(__ANDROID__)
 #include <android/log.h>
+#elif defined(_WIN32)
+#include <Dbghelp.h>
 #endif
 
 namespace FatalErrorFlags {
@@ -78,17 +80,27 @@ static bool getSymbolNameAddr(llvm::StringRef libraryName, SymbolInfo syminfo,
   // demangle with swift. We are taking advantage of __cxa_demangle actually
   // providing failure status instead of just returning the original string like
   // swift demangle.
-  int status;
-  char *demangled = abi::__cxa_demangle(syminfo.symbolName, 0, 0, &status);
-  if (status == 0) {
-    assert(demangled != nullptr && "If __cxa_demangle succeeds, demangled "
-                                   "should never be nullptr");
-    symbolName += demangled;
-    free(demangled);
-    return true;
-  }
-  assert(demangled == nullptr && "If __cxa_demangle fails, demangled should "
-                                 "be a nullptr");
+
+#if defined(_WIN32)
+    char demangled[1024];
+    DWORD length = UnDecorateSymbolName(syminfo.symbolName, demangled, 1024, 0);
+    if (length > 0) {
+        symbolName += demangled;
+        return true;
+    }
+#else
+    int status;
+    char *demangled = abi::__cxa_demangle(syminfo.symbolName, 0, 0, &status);
+    if (status == 0) {
+        assert(demangled != nullptr && "If __cxa_demangle succeeds, demangled "
+               "should never be nullptr");
+        symbolName += demangled;
+        free(demangled);
+        return true;
+    }
+    assert(demangled == nullptr && "If __cxa_demangle fails, demangled should "
+           "be a nullptr");
+#endif
 
   // Otherwise, try to demangle with swift. If swift fails to demangle, it will
   // just pass through the original output.

stdlib/public/stubs/LibcShims.cpp

@@ -15,10 +15,14 @@
 #include <cmath>
 #if defined(_WIN32)
 #include <io.h>
+#define WIN32_LEAN_AND_MEAN
+#define VC_EXTRALEAN
+#define NOMINMAX
+#include <windows.h>
 #else
 #include <unistd.h>
-#endif
 #include <pthread.h>
+#endif
 
 #include <stdlib.h>
 #include <stdio.h>
@@ -98,33 +102,57 @@ int swift::_swift_stdlib_close(int fd) {
 #endif
 }
 
+#if !defined(_WIN32)
 // Guard compilation on the typedef for __swift_pthread_key_t in LibcShims.h
 // being identical to the platform's pthread_key_t
 static_assert(std::is_same<__swift_pthread_key_t, pthread_key_t>::value,
               "This platform's pthread_key_t differs. If you hit this assert, "
               "fix __swift_pthread_key_t's typedef in LibcShims.h by adding an "
               "#if guard and definition for your platform");
+#endif
 
 SWIFT_RUNTIME_STDLIB_INTERFACE
-int swift::_swift_stdlib_pthread_key_create(
+int swift::_swift_stdlib_tls_key_create(
   __swift_pthread_key_t * _Nonnull key,
   void (* _Nullable destructor)(void *)
 ) {
-  return pthread_key_create(key, destructor);
-}
-
-SWIFT_RUNTIME_STDLIB_INTERFACE
-void * _Nullable swift::_swift_stdlib_pthread_getspecific(
+  #if defined(_WIN32)
+    // We're using the Fls- (Fiber) instead of Tls- (Thread) functions since
+    // on Windows, "If no fiber switching occurs, FLS acts exactly the same 
+    // as thread local storage," and FlsAlloc takes a destructor while
+    // TlsAlloc doesn't.
+    // https://msdn.microsoft.com/en-us/library/windows/desktop/ms682661.aspx
+    __swift_pthread_key_t result = FlsAlloc(destructor);
+    if (result != FLS_OUT_OF_INDEXES) {
+      *key = result;
+      return 0;
+    }
+    return result;
+  #else
+    return pthread_key_create(key, destructor);
+  #endif
+}
+
+SWIFT_RUNTIME_STDLIB_INTERFACE
+void * _Nullable swift::_swift_stdlib_tls_getspecific(
   __swift_pthread_key_t key
 ) {
-  return pthread_getspecific(key);
+  #if defined(_WIN32)
+    return FlsGetValue(key);
+  #else
+    return pthread_getspecific(key);
+  #endif
 }
 
 SWIFT_RUNTIME_STDLIB_INTERFACE
-int swift::_swift_stdlib_pthread_setspecific(
+int swift::_swift_stdlib_tls_setspecific(
   __swift_pthread_key_t key, const void * _Nullable value
 ) {
-  return pthread_setspecific(key, value);
+  #if defined(_WIN32)
+    return FlsSetValue(key, const_cast<void*>(value));
+  #else
+    return pthread_setspecific(key, value);
+  #endif
 }
 
 #if defined(__APPLE__)