Build compiler and runtimes without Swift

Remove dependency on macros from compiler and stdlib build when
bootstrapping the compiler without Swift available.

Author: DougGregor

lib/AST/ASTScope.cpp

@@ -148,6 +148,7 @@ void ASTScope::unqualifiedLookup(
   if (auto *s = SF->getASTContext().Stats)
     ++s->getFrontendCounters().NumASTScopeLookups;
 
+#if SWIFT_BUILD_SWIFT_SYNTAX
   // Perform validation of SwiftLexicalLookup if option
   // Feature::UnqualifiedLookupValidation is enabled and lookup was not
   // performed in a macro.
@@ -171,6 +172,9 @@ void ASTScope::unqualifiedLookup(
   } else {
     ASTScopeImpl::unqualifiedLookup(SF, loc, consumer);
   }
+#else
+    ASTScopeImpl::unqualifiedLookup(SF, loc, consumer);
+#endif
 }
 
 llvm::SmallVector<LabeledStmt *, 4> ASTScope::lookupLabeledStmts(

lib/Parse/ParseExpr.cpp

@@ -3473,6 +3473,20 @@ ParserResult<Expr> Parser::parseExprMacroExpansion(bool isExprBasic) {
   if (!macroNameRef)
     return status;
 
+#if !SWIFT_BUILD_SWIFT_SYNTAX
+  // If we don't have swift-syntax and therefore have no support for macros,
+  // recognize #isolation as special and route it through
+  // CurrentContextIsolationExpr.
+  if (macroNameRef.getBaseName().userFacingName() == "isolation" &&
+      genericArgs.empty() &&
+      (!argList || argList->empty())) {
+    return makeParserResult(
+      status,
+      new (Context) CurrentContextIsolationExpr(
+          macroNameLoc.getStartLoc(), Type()));
+  }
+#endif
+
   return makeParserResult(
       status,
       MacroExpansionExpr::create(

lib/Sema/TypeChecker.cpp

@@ -755,6 +755,7 @@ std::pair<bool, bool> EvaluateIfConditionRequest::evaluate(
     Evaluator &evaluator, SourceFile *sourceFile, SourceRange conditionRange,
     bool shouldEvaluate
 ) const {
+#if SWIFT_BUILD_SWIFT_SYNTAX
   // FIXME: When we migrate to SwiftParser, use the parsed syntax tree.
   ASTContext &ctx = sourceFile->getASTContext();
   auto &sourceMgr = ctx.SourceMgr;
@@ -775,4 +776,7 @@ std::pair<bool, bool> EvaluateIfConditionRequest::evaluate(
   bool isActive = (evalResult & 0x01) != 0;
   bool allowSyntaxErrors = (evalResult & 0x02) != 0;
   return std::pair(isActive, allowSyntaxErrors);
+#else
+  llvm_unreachable("Must not be used in C++-only build");
+#endif
 }

stdlib/public/core/Availability.swift

@@ -52,7 +52,9 @@ public func _stdlib_isOSVersionAtLeast(
 @_semantics("availability.osversion")
 @_effects(readnone)
 @_unavailableInEmbedded
+#if hasFeature(Macros)
 @_noLocks
+#endif
 public func _stdlib_isOSVersionAtLeast(
   _ major: Builtin.Word,
   _ minor: Builtin.Word,
@@ -65,7 +67,9 @@ public func _stdlib_isOSVersionAtLeast(
 @_semantics("availability.osversion")
 @_effects(readnone)
 @_alwaysEmitIntoClient
+#if hasFeature(Macros)
 @_noLocks
+#endif
 public func _stdlib_isOSVersionAtLeast_AEIC(
   _ major: Builtin.Word,
   _ minor: Builtin.Word,
@@ -110,7 +114,9 @@ public func _stdlib_isOSVersionAtLeast_AEIC(
 @_semantics("availability.osversion")
 @_effects(readnone)
 @available(macOS 10.15, iOS 13.0, *)
+#if hasFeature(Macros)
 @_noLocks
+#endif
 public func _stdlib_isVariantOSVersionAtLeast(
   _ major: Builtin.Word,
   _ minor: Builtin.Word,
@@ -153,7 +159,9 @@ public func _stdlib_isVariantOSVersionAtLeast(
 @_semantics("availability.osversion")
 @_effects(readnone)
 @_unavailableInEmbedded
+#if hasFeature(Macros)
 @_noLocks
+#endif
 public func _stdlib_isOSVersionAtLeastOrVariantVersionAtLeast(
   _ major: Builtin.Word,
   _ minor: Builtin.Word,

stdlib/public/core/ObjectIdentifier+DebugDescription.swift

@@ -10,7 +10,7 @@
 //
 //===----------------------------------------------------------------------===//
 
-#if !$Embedded
+#if !$Embedded && hasFeature(Macros)
 @DebugDescription
 extension ObjectIdentifier {
   var lldbDescription: String {

stdlib/public/core/StringBridge.swift

@@ -752,6 +752,7 @@ extension StringProtocol {
 
   public // SPI(Foundation)
   func _toUTF16Indices(_ range: Range<Int>) -> Range<Index> {
+#if hasFeature(Macros)
     if Self.self == String.self {
       let s = unsafe unsafeBitCast(self, to: String.self)
       return s.utf16._indexRange(for: range, from: s.startIndex)
@@ -760,6 +761,7 @@ extension StringProtocol {
       let s = unsafe unsafeBitCast(self, to: Substring.self)
       return s._slice._base.utf16._indexRange(for: range, from: s.startIndex)
     }
+#endif
     let lowerbound = _toUTF16Index(range.lowerBound)
     let upperbound = _toUTF16Index(range.upperBound)
     return unsafe Range(uncheckedBounds: (lower: lowerbound, upper: upperbound))

stdlib/public/core/SwiftifyImport.swift

@@ -58,6 +58,8 @@ public enum _SwiftifyInfo {
 ///
 /// Parameter paramInfo: information about how the function uses the pointer passed to it. The
 /// safety of the generated wrapper function depends on this info being extensive and accurate.
+#if hasFeature(Macros)
 @attached(peer, names: overloaded)
 public macro _SwiftifyImport(_ paramInfo: _SwiftifyInfo..., typeMappings: [String: String] = [:]) =
     #externalMacro(module: "SwiftMacros", type: "SwiftifyImportMacro")
+#endif