🌸[6.1] Correct newline emission in generated headers

lib/PrintAsClang/ModuleContentsWriter.cpp

@@ -488,7 +488,6 @@ class ModuleWriter {
         (inserted || !it->second.second))
       ClangValueTypePrinter::forwardDeclType(os, CD, printer);
     it->second = {EmissionState::Defined, true};
-    os << '\n';
     printer.print(CD);
     return true;
   }
@@ -507,7 +506,6 @@ class ModuleWriter {
           forwardDeclareType(TD);
         });
 
-    os << '\n';
     printer.print(FD);
     return true;
   }
@@ -550,7 +548,6 @@ class ModuleWriter {
       return false;
 
     seenTypes[PD] = { EmissionState::Defined, true };
-    os << '\n';
     printer.print(PD);
     return true;
   }
@@ -576,7 +573,6 @@ class ModuleWriter {
     if (!forwardDeclareMemberTypes(ED->getAllMembers(), ED))
       return false;
 
-    os << '\n';
     printer.print(ED);
     return true;
   }
@@ -840,6 +836,7 @@ class ModuleWriter {
     while (!declsToWrite.empty()) {
       const Decl *D = declsToWrite.back();
       bool success = true;
+      auto posBefore = os.tell();
 
       if (auto ED = dyn_cast<EnumDecl>(D)) {
         success = writeEnum(ED);
@@ -870,7 +867,10 @@ class ModuleWriter {
 
       if (success) {
         assert(declsToWrite.back() == D);
-        os << "\n";
+        // If we actually wrote something to the file, add a newline after it.
+        // (As opposed to, for instance, an extension we decided to skip.)
+        if (posBefore != os.tell())
+          os << "\n";
         declsToWrite.pop_back();
       }
     }

lib/PrintAsClang/PrintAsClang.cpp

@@ -589,7 +589,7 @@ bool swift::printAsClangHeader(raw_ostream &os, ModuleDecl *M,
                  clangHeaderSearchInfo, exposedModuleHeaderNames);
   });
   writePostImportPrologue(os, *M);
-  emitObjCConditional(os, [&] { os << objcModuleContents.str(); });
+  emitObjCConditional(os, [&] { os << "\n" << objcModuleContents.str(); });
   writeObjCEpilogue(os);
   emitCxxConditional(os, [&] {
     // FIXME: Expose Swift with @expose by default.

test/Interop/CxxToSwiftToCxx/bridge-cxx-struct-back-to-cxx.swift

@@ -269,7 +269,6 @@ public struct Strct {
 // CHECK-NEXT: } // namespace swift
 // CHECK-EMPTY:
 // CHECK-NEXT: namespace UseCxxTy SWIFT_PRIVATE_ATTR SWIFT_SYMBOL_MODULE("UseCxxTy") {
-// CHECK-EMPTY:
 // CHECK-NEXT: SWIFT_INLINE_THUNK ns::NonTrivialTemplate<ns::TrivialinNS> retNonTrivial2() noexcept SWIFT_SYMBOL({{.*}}) SWIFT_WARN_UNUSED_RESULT {
 // CHECK-NEXT: alignas(alignof(ns::NonTrivialTemplate<ns::TrivialinNS>)) char storage[sizeof(ns::NonTrivialTemplate<ns::TrivialinNS>)];
 // CHECK-NEXT: auto * _Nonnull storageObjectPtr = reinterpret_cast<ns::NonTrivialTemplate<ns::TrivialinNS> *>(storage);

test/Interop/SwiftToCxx/expose-attr/expose-swift-decls-to-cxx.swift

@@ -98,12 +98,10 @@ public final class ExposedClass {
 // CHECK-NEXT:   _impl::$s6Expose8exposed1yyF();
 // CHECK-NEXT: }
 // CHECK-EMPTY:
-// CHECK-EMPTY:
 // CHECK-NEXT: SWIFT_INLINE_THUNK void exposed3() noexcept SWIFT_SYMBOL("{{.*}}") {
 // CHECK-NEXT:   _impl::$s6Expose8exposed3yyF();
 // CHECK-NEXT: }
 // CHECK-EMPTY:
-// CHECK-EMPTY:
 // CHECK-NEXT: SWIFT_INLINE_THUNK void exposed4() noexcept SWIFT_SYMBOL("{{.*}}") {
 // CHECK-NEXT:   _impl::$s6Expose15exposed4RenamedyyF();
 // CHECK-NEXT: }

test/PrintAsCxx/empty.swift

@@ -94,6 +94,7 @@
 // CHECK-NEXT:  #if __has_feature(objc_modules)
 
 // CHECK-LABEL: #if defined(__OBJC__)
+// CHECK-EMPTY:
 // CHECK-NEXT:  #endif
 // CHECK-NEXT:  #if __has_attribute(external_source_symbol)
 // CHECK-NEXT:  # pragma clang attribute pop

test/PrintAsObjC/Inputs/comments-expected-output.h

@@ -2,7 +2,6 @@ SWIFT_CLASS("_TtC8comments4A000")
 @interface A000
 @end
 
-
 /// Aaa.  A010.  Bbb.
 SWIFT_CLASS("_TtC8comments21A010_AttachToEntities")
 @interface A010_AttachToEntities
@@ -17,37 +16,32 @@ SWIFT_CLASS_PROPERTY(@property (nonatomic, class, readonly) NSInteger v2;)
 + (NSInteger)v2 SWIFT_WARN_UNUSED_RESULT;
 @end
 
-
 /// Aaa.  A013.
 SWIFT_PROTOCOL("_TtP8comments21A013_AttachToEntities_")
 @protocol A013_AttachToEntities
 @end
 
-
 SWIFT_CLASS("_TtC8comments10ATXHeaders")
 @interface ATXHeaders
 /// <h1>LEVEL ONE</h1>
 /// <h2>LEVEL TWO</h2>
 - (void)f0;
 @end
 
-
 SWIFT_CLASS("_TtC8comments10Attributes")
 @interface Attributes
 /// Here is an attribute:
 /// Attribute text
 - (void)f0;
 @end
 
-
 SWIFT_CLASS("_TtC8comments13AutomaticLink")
 @interface AutomaticLink
 /// And now for a URL.
 /// <a href="http://developer.apple.com/swift/">http://developer.apple.com/swift/</a>
 - (void)f0;
 @end
 
-
 SWIFT_CLASS("_TtC8comments10BlockQuote")
 @interface BlockQuote
 /// Aaa.
@@ -62,7 +56,6 @@ SWIFT_CLASS("_TtC8comments10BlockQuote")
 - (void)f0;
 @end
 
-
 SWIFT_CLASS("_TtC8comments5Brief")
 @interface Brief
 /// Aaa.
@@ -81,14 +74,12 @@ SWIFT_CLASS("_TtC8comments5Brief")
 - (void)f3;
 @end
 
-
 SWIFT_CLASS("_TtC8comments15ClosingComments")
 @interface ClosingComments
 /// Some comment. */
 - (void)closingComment;
 @end
 
-
 SWIFT_CLASS("_TtC8comments16ClosureContainer")
 @interface ClosureContainer
 /// Partially applies a binary operator.
@@ -156,7 +147,6 @@ SWIFT_CLASS("_TtC8comments16ClosureContainer")
 - (void)closureParameterOutlineOutlineWithA:(NSInteger)a combine:(SWIFT_NOESCAPE NSInteger (^ _Nonnull)(NSInteger, NSInteger))combine;
 @end
 
-
 SWIFT_CLASS("_TtC8comments9CodeBlock")
 @interface CodeBlock
 /// This is how you use this code.
@@ -169,15 +159,13 @@ SWIFT_CLASS("_TtC8comments9CodeBlock")
 - (void)f0;
 @end
 
-
 SWIFT_CLASS("_TtC8comments8Emphasis")
 @interface Emphasis
 /// Aaa <em>bbb</em> ccc.
 /// Aaa <em>bbb</em> ccc.
 - (void)f0;
 @end
 
-
 SWIFT_CLASS("_TtC8comments13EmptyComments")
 @interface EmptyComments
 ///
@@ -192,7 +180,6 @@ SWIFT_CLASS("_TtC8comments13EmptyComments")
 - (void)f4;
 @end
 
-
 SWIFT_CLASS("_TtC8comments9Footnotes")
 @interface Footnotes
 /// Has some footnotes.
@@ -202,7 +189,6 @@ SWIFT_CLASS("_TtC8comments9Footnotes")
 - (void)f0;
 @end
 
-
 SWIFT_CLASS("_TtC8comments19HasThrowingFunction")
 @interface HasThrowingFunction
 /// Might throw something.
@@ -214,7 +200,6 @@ SWIFT_CLASS("_TtC8comments19HasThrowingFunction")
 - (void)f1:(NSInteger)x;
 @end
 
-
 SWIFT_CLASS("_TtC8comments15HorizontalRules")
 @interface HorizontalRules
 /// Briefly.
@@ -223,14 +208,12 @@ SWIFT_CLASS("_TtC8comments15HorizontalRules")
 - (void)f0;
 @end
 
-
 SWIFT_CLASS("_TtC8comments16ImplicitNameLink")
 @interface ImplicitNameLink
 /// <a href="https://www.apple.com/">Apple</a>
 - (void)f0;
 @end
 
-
 SWIFT_CLASS("_TtC8comments20IndentedBlockComment")
 @interface IndentedBlockComment
 /// Brief.
@@ -257,21 +240,18 @@ SWIFT_CLASS("_TtC8comments20IndentedBlockComment")
 - (void)f2;
 @end
 
-
 SWIFT_CLASS("_TtC8comments10InlineCode")
 @interface InlineCode
 /// Aaa <code>bbb</code> ccc.
 - (void)f0;
 @end
 
-
 SWIFT_CLASS("_TtC8comments10InlineLink")
 @interface InlineLink
 /// Aaa <a href="/path/to/something">bbb</a> ccc.
 - (void)f0;
 @end
 
-
 SWIFT_CLASS("_TtC8comments14MultiLineBrief")
 @interface MultiLineBrief
 /// Brief first line.
@@ -280,7 +260,6 @@ SWIFT_CLASS("_TtC8comments14MultiLineBrief")
 - (void)f0;
 @end
 
-
 SWIFT_CLASS("_TtC8comments11OrderedList")
 @interface OrderedList
 /// <ol>
@@ -295,7 +274,6 @@ SWIFT_CLASS("_TtC8comments11OrderedList")
 - (void)f0;
 @end
 
-
 /// \param x A number
 ///
 SWIFT_CLASS("_TtC8comments15ParamAndReturns")
@@ -340,7 +318,6 @@ SWIFT_CLASS("_TtC8comments15ParamAndReturns")
 - (void)f4;
 @end
 
-
 SWIFT_CLASS("_TtC8comments16ParameterOutline")
 @interface ParameterOutline
 /// \param x A number
@@ -352,7 +329,6 @@ SWIFT_CLASS("_TtC8comments16ParameterOutline")
 - (void)f0:(NSInteger)x y:(NSInteger)y z:(NSInteger)z;
 @end
 
-
 SWIFT_CLASS("_TtC8comments22ParameterOutlineMiddle")
 @interface ParameterOutlineMiddle
 /// <ul>
@@ -372,12 +348,10 @@ SWIFT_CLASS("_TtC8comments22ParameterOutlineMiddle")
 - (void)f0:(NSInteger)x y:(NSInteger)y z:(NSInteger)z;
 @end
 
-
 SWIFT_CLASS("_TtC8comments13ReferenceLink")
 @interface ReferenceLink
 @end
 
-
 SWIFT_CLASS("_TtC8comments7Returns")
 @interface Returns
 ///
@@ -386,15 +360,13 @@ SWIFT_CLASS("_TtC8comments7Returns")
 - (NSInteger)f0 SWIFT_WARN_UNUSED_RESULT;
 @end
 
-
 SWIFT_CLASS("_TtC8comments18SeparateParameters")
 @interface SeparateParameters
 /// \param x A number
 ///
 - (void)f0:(NSInteger)x y:(NSInteger)y;
 @end
 
-
 SWIFT_CLASS("_TtC8comments13SetextHeaders")
 @interface SetextHeaders
 /// <h1>LEVEL ONE</h1>
@@ -406,15 +378,13 @@ SWIFT_CLASS("_TtC8comments13SetextHeaders")
 - (void)f0;
 @end
 
-
 SWIFT_CLASS("_TtC8comments14StrongEmphasis")
 @interface StrongEmphasis
 /// Aaa <em>bbb</em> ccc.
 /// Aaa <em>bbb</em> ccc.
 - (void)f0;
 @end
 
-
 SWIFT_CLASS("_TtC8comments13UnorderedList")
 @interface UnorderedList
 /// <ul>