Swift SIL: add some Builder APIs

* `createStructExtract`
* `createStructElementAddr`
* `createTupleExtract`
* `createTupleElementAddr`

Author: eeckstein

SwiftCompilerSources/Sources/SIL/Builder.swift

@@ -250,13 +250,29 @@ public struct Builder {
     return notifyNew(structInst.getAs(StructInst.self))
   }
 
+  public func createStructExtract(struct: Value, fieldIndex: Int) -> StructExtractInst {
+    return notifyNew(bridged.createStructExtract(`struct`.bridged, fieldIndex).getAs(StructExtractInst.self))
+  }
+
+  public func createStructElementAddr(structAddress: Value, fieldIndex: Int) -> StructElementAddrInst {
+    return notifyNew(bridged.createStructElementAddr(structAddress.bridged, fieldIndex).getAs(StructElementAddrInst.self))
+  }
+
   public func createTuple(type: Type, elements: [Value]) -> TupleInst {
     let tuple = elements.withBridgedValues { valuesRef in
       return bridged.createTuple(type.bridged, valuesRef)
     }
     return notifyNew(tuple.getAs(TupleInst.self))
   }
 
+  public func createTupleExtract(tuple: Value, elementIndex: Int) -> TupleExtractInst {
+    return notifyNew(bridged.createTupleExtract(tuple.bridged, elementIndex).getAs(TupleExtractInst.self))
+  }
+
+  public func createTupleElementAddr(tupleAddress: Value, elementIndex: Int) -> TupleElementAddrInst {
+    return notifyNew(bridged.createTupleElementAddr(tupleAddress.bridged, elementIndex).getAs(TupleElementAddrInst.self))
+  }
+
   @discardableResult
   public func createStore(source: Value, destination: Value, ownership: StoreInst.Ownership) -> StoreInst {
     let store = bridged.createStore(source.bridged, destination.bridged, ownership.rawValue)

include/swift/SIL/SILBridging.h

@@ -1268,12 +1268,36 @@ struct BridgedBuilder{
     return {builder().createStruct(regularLoc(), type, elements.getValues(elementValues))};
   }
 
+  SWIFT_IMPORT_UNSAFE
+  BridgedInstruction createStructExtract(BridgedValue str, SwiftInt fieldIndex) const {
+    swift::SILValue v = str.getSILValue();
+    return {builder().createStructExtract(regularLoc(), v, v->getType().getFieldDecl(fieldIndex))};
+  }
+
+  SWIFT_IMPORT_UNSAFE
+  BridgedInstruction createStructElementAddr(BridgedValue addr, SwiftInt fieldIndex) const {
+    swift::SILValue v = addr.getSILValue();
+    return {builder().createStructElementAddr(regularLoc(), v, v->getType().getFieldDecl(fieldIndex))};
+  }
+
   SWIFT_IMPORT_UNSAFE
   BridgedInstruction createTuple(swift::SILType type, BridgedValueArray elements) const {
     llvm::SmallVector<swift::SILValue, 16> elementValues;
     return {builder().createTuple(regularLoc(), type, elements.getValues(elementValues))};
   }
 
+  SWIFT_IMPORT_UNSAFE
+  BridgedInstruction createTupleExtract(BridgedValue str, SwiftInt elementIndex) const {
+    swift::SILValue v = str.getSILValue();
+    return {builder().createTupleExtract(regularLoc(), v, elementIndex)};
+  }
+
+  SWIFT_IMPORT_UNSAFE
+  BridgedInstruction createTupleElementAddr(BridgedValue addr, SwiftInt elementIndex) const {
+    swift::SILValue v = addr.getSILValue();
+    return {builder().createTupleElementAddr(regularLoc(), v, elementIndex)};
+  }
+
   SWIFT_IMPORT_UNSAFE
   BridgedInstruction createStore(BridgedValue src, BridgedValue dst,
                                  SwiftInt ownership) const {

include/swift/SIL/SILType.h

@@ -564,6 +564,8 @@ class SILType {
   bool isFunction() const { return is<SILFunctionType>(); }
   bool isMetatype() const { return is<MetatypeType>(); }
 
+  VarDecl *getFieldDecl(intptr_t fieldIndex) const;
+
   /// Given that this is a nominal type, return the lowered type of
   /// the given field.  Applies substitutions as necessary.  The
   /// result will be an address type if the base type is an address

lib/SIL/IR/SILType.cpp

@@ -320,6 +320,12 @@ static void addFieldSubstitutionsIfNeeded(TypeConverter &TC, SILType ty,
   }
 }
 
+VarDecl *SILType::getFieldDecl(intptr_t fieldIndex) const {
+  NominalTypeDecl *decl = getNominalOrBoundGenericNominal();
+  assert(decl && "expected nominal type");
+  return getIndexedField(decl, fieldIndex);
+}
+
 SILType SILType::getFieldType(VarDecl *field, TypeConverter &TC,
                               TypeExpansionContext context) const {
   AbstractionPattern origFieldTy = TC.getAbstractionPattern(field);
@@ -361,9 +367,7 @@ SILType SILType::getFieldType(VarDecl *field, SILFunction *fn) const {
 }
 
 SILType SILType::getFieldType(intptr_t fieldIndex, SILFunction *function) const {
-  NominalTypeDecl *decl = getNominalOrBoundGenericNominal();
-  assert(decl && "expected nominal type");
-  VarDecl *field = getIndexedField(decl, fieldIndex);
+  VarDecl *field = getFieldDecl(fieldIndex);
   return getFieldType(field, function->getModule(), function->getTypeExpansionContext());
 }