Use the swift calling convention for swift functions

Use the generic type lowering algorithm described in
"docs/CallingConvention.rst#physical-lowering" to map from IRGen's explosion
type to the type expected by the ABI.

Change IRGen to use the swift calling convention (swiftcc) for native swift
functions.

Use the 'swiftself' attribute on self parameters and for closures contexts.

Use the 'swifterror' parameter for swift error parameters.

Change functions in the runtime that are called as native swift functions to use
the swift calling convention.

rdar://19978563

Author: aschwaighofer

include/swift/Runtime/Config.h

@@ -36,7 +36,7 @@
 #ifdef __s390x__
 #define SWIFT_USE_SWIFTCALL 1
 #else
-#define SWIFT_USE_SWIFTCALL 0
+#define SWIFT_USE_SWIFTCALL 1
 #endif
 #endif
 

include/swift/Runtime/HeapObject.h

@@ -155,12 +155,10 @@ using BoxPair = TwoWordPair<HeapObject *, OpaqueValue *>;
 /// The heap object has an initial retain count of 1, and its metadata is set
 /// such that destroying the heap object destroys the contained value.
 SWIFT_RUNTIME_EXPORT
-BoxPair::Return swift_allocBox(Metadata const *type)
-           SWIFT_CC(swift);
+BoxPair::Return swift_allocBox(Metadata const *type);
 
 SWIFT_RUNTIME_EXPORT
-BoxPair::Return (*_swift_allocBox)(Metadata const *type)
-           SWIFT_CC(swift);
+BoxPair::Return (*_swift_allocBox)(Metadata const *type);
 
 
 // Allocate plain old memory. This is the generalized entry point

include/swift/Runtime/Metadata.h

@@ -1331,7 +1331,7 @@ const FullOpaqueMetadata METADATA_SYM(BO);        // Builtin.UnknownObject
 struct HeapMetadataHeaderPrefix {
   /// Destroy the object, returning the allocated size of the object
   /// or 0 if the object shouldn't be deallocated.
-  void (*destroy)(HeapObject *);
+  SWIFT_CC(swift) void (*destroy)(SWIFT_CONTEXT HeapObject *);
 };
 
 /// The header present on all heap metadata.
@@ -1548,7 +1548,7 @@ struct TargetNominalTypeDescriptor {
 };
 using NominalTypeDescriptor = TargetNominalTypeDescriptor<InProcess>;
 
-typedef void (*ClassIVarDestroyer)(HeapObject *);
+typedef SWIFT_CC(swift) void (*ClassIVarDestroyer)(SWIFT_CONTEXT HeapObject *);
 
 /// The structure of all class metadata.  This structure is embedded
 /// directly within the class's heap metadata structure and therefore
@@ -3488,6 +3488,7 @@ std::string nameForMetadata(const Metadata *type,
 
 /// Return the superclass, if any.  The result is nullptr for root
 /// classes and class protocol types.
+SWIFT_CC(swift)
 SWIFT_RUNTIME_STDLIB_INTERFACE
 const Metadata *_swift_class_getSuperclass(const Metadata *theClass);
 

include/swift/Runtime/Reflection.h

@@ -46,6 +46,7 @@ struct MirrorReturn {
 ///
 /// Produce a mirror for any value.  The runtime produces a mirror that
 /// structurally reflects values of any type.
+SWIFT_CC(swift)
 SWIFT_RUNTIME_EXPORT
 MirrorReturn
 swift_reflectAny(OpaqueValue *value, const Metadata *T);

include/swift/Serialization/ModuleFormat.h

@@ -54,7 +54,7 @@ const uint16_t VERSION_MAJOR = 0;
 /// in source control, you should also update the comment to briefly
 /// describe what change you made. The content of this comment isn't important;
 /// it just ensures a conflict if two people change the module format.
-const uint16_t VERSION_MINOR = 315; // Last change: uniquely identify extensions
+const uint16_t VERSION_MINOR = 316; // Last change: Swift calling convention
 
 using DeclID = PointerEmbeddedInt<unsigned, 31>;
 using DeclIDField = BCFixed<31>;

lib/IRGen/Explosion.h

@@ -233,9 +233,6 @@ class ExplosionSchema {
     return Elements[index];
   }
 
-  bool requiresIndirectParameter(IRGenModule &IGM) const;
-  bool requiresIndirectResult(IRGenModule &IGM) const;
-
   typedef SmallVectorImpl<Element>::iterator iterator;
   typedef SmallVectorImpl<Element>::const_iterator const_iterator;
 
@@ -255,13 +252,6 @@ class ExplosionSchema {
   ///   - the element type, if the schema contains exactly one element;
   ///   - an anonymous struct type concatenating those types, otherwise.
   llvm::Type *getScalarResultType(IRGenModule &IGM) const;
-
-  /// Treating the types in this schema as potential arguments to a
-  /// function call, add them to the end of the given vector of types.
-  void addToArgTypes(IRGenModule &IGM,
-                     const TypeInfo &TI,
-                     llvm::AttributeSet &Attrs,
-                     SmallVectorImpl<llvm::Type*> &types) const;
 };
 
 } // end namespace irgen