Swift SIL: add Function.isPossiblyUsedExternally and Function.isAvailableExternally

Author: eeckstein

SwiftCompilerSources/Sources/SIL/Function.swift

@@ -74,6 +74,22 @@ final public class Function : CustomStringConvertible, HasShortDescription, Hash
     return nil
   }
 
+  /// True, if the linkage of the function indicates that it is visible outside the current
+  /// compilation unit and therefore not all of its uses are known.
+  ///
+  /// For example, `public` linkage.
+  public var isPossiblyUsedExternally: Bool {
+    return SILFunction_isPossiblyUsedExternally(bridged) != 0
+  }
+
+  /// True, if the linkage of the function indicates that it has a definition outside the
+  /// current compilation unit.
+  ///
+  /// For example, `public_external` linkage.
+  public var isAvailableExternally: Bool {
+    return SILFunction_isAvailableExternally(bridged) != 0
+  }
+
   public func hasSemanticsAttribute(_ attr: StaticString) -> Bool {
     attr.withUTF8Buffer { (buffer: UnsafeBufferPointer<UInt8>) in
       SILFunction_hasSemanticsAttr(bridged, llvm.StringRef(buffer.baseAddress!, buffer.count)) != 0

include/swift/SIL/SILBridging.h

@@ -224,6 +224,8 @@ SwiftInt SILFunction_getNumSILArguments(BridgedFunction function);
 BridgedType SILFunction_getSILArgumentType(BridgedFunction function, SwiftInt idx);
 BridgedType SILFunction_getSILResultType(BridgedFunction function);
 SwiftInt SILFunction_isSwift51RuntimeAvailable(BridgedFunction function);
+SwiftInt SILFunction_isPossiblyUsedExternally(BridgedFunction function);
+SwiftInt SILFunction_isAvailableExternally(BridgedFunction function);
 SwiftInt SILFunction_hasSemanticsAttr(BridgedFunction function,
                                       llvm::StringRef attrName);
 

lib/SIL/Utils/SILBridging.cpp

@@ -217,6 +217,14 @@ SwiftInt SILFunction_isSwift51RuntimeAvailable(BridgedFunction function) {
     ctxt.getSwift51Availability());
 }
 
+SwiftInt SILFunction_isPossiblyUsedExternally(BridgedFunction function) {
+  return castToFunction(function)->isPossiblyUsedExternally() ? 1 : 0;
+}
+
+SwiftInt SILFunction_isAvailableExternally(BridgedFunction function) {
+  return castToFunction(function)->isAvailableExternally() ? 1 : 0;
+}
+
 SwiftInt SILFunction_hasSemanticsAttr(BridgedFunction function,
                                       StringRef attrName) {
   SILFunction *f = castToFunction(function);