Merge pull request swiftlang#76364 from DougGregor/apply-macro-to-imported

Allow attached macros to be applied to imported C declarations

Author: DougGregor

include/swift/Basic/Features.def

@@ -230,6 +230,7 @@ EXPERIMENTAL_FEATURE(NamedOpaqueTypes, false)
 EXPERIMENTAL_FEATURE(FlowSensitiveConcurrencyCaptures, false)
 EXPERIMENTAL_FEATURE(CodeItemMacros, false)
 EXPERIMENTAL_FEATURE(PreambleMacros, false)
+EXPERIMENTAL_FEATURE(MacrosOnImports, true)
 EXPERIMENTAL_FEATURE(TupleConformances, false)
 EXPERIMENTAL_FEATURE(FullTypedThrows, false)
 EXPERIMENTAL_FEATURE(SameElementRequirements, false)

include/swift/Frontend/FrontendOptions.h

@@ -38,12 +38,12 @@ enum class IntermoduleDepTrackingMode;
 /// Options for controlling the behavior of the frontend.
 class FrontendOptions {
   friend class ArgsToFrontendOptionsConverter;
+public:
 
   /// A list of arbitrary modules to import and make implicitly visible.
   std::vector<std::pair<std::string, bool /*testable*/>>
       ImplicitImportModuleNames;
 
-public:
   FrontendInputsAndOutputs InputsAndOutputs;
 
   void forAllOutputPaths(const InputFile &input,

lib/AST/FeatureSet.cpp

@@ -121,6 +121,7 @@ UNINTERESTING_FEATURE(Embedded)
 UNINTERESTING_FEATURE(Volatile)
 UNINTERESTING_FEATURE(SuppressedAssociatedTypes)
 UNINTERESTING_FEATURE(StructLetDestructuring)
+UNINTERESTING_FEATURE(MacrosOnImports)
 
 static bool usesFeatureNonescapableTypes(Decl *decl) {
   auto containsNonEscapable =

lib/AST/NameLookup.cpp

@@ -40,6 +40,7 @@
 #include "swift/Basic/SourceManager.h"
 #include "swift/Basic/Statistic.h"
 #include "swift/ClangImporter/ClangImporterRequests.h"
+#include "swift/ClangImporter/ClangModule.h"
 #include "swift/Parse/Lexer.h"
 #include "swift/Strings.h"
 #include "clang/AST/DeclObjC.h"
@@ -1718,6 +1719,15 @@ SmallVector<MacroDecl *, 1> namelookup::lookupMacros(DeclContext *dc,
         ctx.evaluator, UnqualifiedLookupRequest{moduleLookupDesc}, {});
     auto foundTypeDecl = moduleLookup.getSingleTypeResult();
     auto *moduleDecl = dyn_cast_or_null<ModuleDecl>(foundTypeDecl);
+
+    // When resolving macro names for imported entities, we look for any
+    // loaded module.
+    if (!moduleDecl && isa<ClangModuleUnit>(moduleScopeDC) &&
+        ctx.LangOpts.hasFeature(Feature::MacrosOnImports)) {
+      moduleDecl = ctx.getLoadedModule(moduleName.getBaseIdentifier());
+      moduleScopeDC = moduleDecl;
+    }
+
     if (!moduleDecl)
       return {};
 

lib/ClangImporter/ClangImporter.cpp

@@ -683,6 +683,11 @@ void importer::getNormalInvocationArguments(
   if (LangOpts.hasFeature(Feature::SendingArgsAndResults))
     invocationArgStrs.push_back("-D__SWIFT_ATTR_SUPPORTS_SENDING=1");
 
+  // Indicate that the compiler will respect macros applied to imported
+  // declarations via '__attribute__((swift_attr("@...")))'.
+  if (LangOpts.hasFeature(Feature::MacrosOnImports))
+    invocationArgStrs.push_back("-D__SWIFT_ATTR_SUPPORTS_MACROS=1");
+
   if (searchPathOpts.getSDKPath().empty()) {
     invocationArgStrs.push_back("-Xclang");
     invocationArgStrs.push_back("-nostdsysteminc");
@@ -4717,6 +4722,17 @@ bool ClangImporter::Implementation::lookupValue(SwiftLookupTable &table,
       }
     }
 
+    // Visit auxiliary declarations to check for name matches.
+    decl->visitAuxiliaryDecls([&](Decl *aux) {
+      if (auto auxValue = dyn_cast<ValueDecl>(aux)) {
+        if (auxValue->getName().matchesRef(name) &&
+            auxValue->getDeclContext()->isModuleScopeContext()) {
+          consumer.foundDecl(auxValue, DeclVisibilityKind::VisibleAtTopLevel);
+          anyMatching = true;
+        }
+      }
+    });
+
     // If we have a declaration and nothing matched so far, try the names used
     // in other versions of Swift.
     if (auto clangDecl = entry.dyn_cast<clang::NamedDecl *>()) {

lib/ClangImporter/ImportDecl.cpp

@@ -9669,6 +9669,13 @@ bool ClangImporter::Implementation::addMemberAndAlternatesToExtension(
       if (!isa<AccessorDecl>(alternate))
         ext->addMember(alternate);
   }
+
+  member->visitAuxiliaryDecls([&](Decl *aux) {
+    if (auto auxValue = dyn_cast<ValueDecl>(aux)) {
+      ext->addMember(auxValue);
+    }
+  });
+
   return true;
 }
 
@@ -9741,6 +9748,16 @@ void ClangImporter::Implementation::insertMembersAndAlternates(
       }
     }
 
+    // If there are auxiliary declarations (e.g., produced by macros), load
+    // those.
+    member->visitAuxiliaryDecls([&](Decl *aux) {
+      if (auto auxValue = dyn_cast<ValueDecl>(aux)) {
+        if (auxValue->getDeclContext() == expectedDC &&
+            knownAlternateMembers.insert(auxValue).second)
+          members.push_back(auxValue);
+      }
+    });
+
     // If this declaration shouldn't be visible, don't add it to
     // the list.
     if (shouldSuppressDeclImport(nd))

lib/Sema/TypeCheckDecl.cpp

@@ -3350,6 +3350,7 @@ SourceLoc PrettyPrintDeclRequest::evaluate(Evaluator &eval, const Decl *decl) co
         getBufferAccessLevel(decl),
         ctx.TypeCheckerOpts.PrintFullConvention);
     decl->print(printer, options);
+
     // Close all of the enclosing types.
     for (const auto & enclosingType: enclosingTypes) {
       (void)enclosingType;
@@ -3381,5 +3382,11 @@ SourceLoc PrettyPrintDeclRequest::evaluate(Evaluator &eval, const Decl *decl) co
       }
   );
 
+  // Add a source file for the buffer.
+  auto moduleDecl = decl->getDeclContext()->getParentModule();
+  auto sourceFile = new (ctx) SourceFile(
+      *moduleDecl, SourceFileKind::Library, bufferID);
+  sourceFile->setImports({ });
+
   return memBufferStartLoc.getAdvancedLoc(targetDeclOffsetInBuffer);
 }

lib/Sema/TypeCheckMacros.cpp

@@ -23,6 +23,7 @@
 #include "swift/AST/ASTContext.h"
 #include "swift/AST/ASTMangler.h"
 #include "swift/AST/ASTNode.h"
+#include "swift/AST/ASTPrinter.h"
 #include "swift/AST/DiagnosticsFrontend.h"
 #include "swift/AST/Expr.h"
 #include "swift/AST/FreestandingMacroExpansion.h"
@@ -39,6 +40,7 @@
 #include "swift/Basic/Lazy.h"
 #include "swift/Basic/SourceManager.h"
 #include "swift/Basic/StringExtras.h"
+#include "swift/ClangImporter/ClangModule.h"
 #include "swift/Bridging/ASTGen.h"
 #include "swift/Bridging/Macros.h"
 #include "swift/Demangling/Demangler.h"
@@ -1021,7 +1023,10 @@ createMacroSourceFile(std::unique_ptr<llvm::MemoryBuffer> buffer,
   auto macroSourceFile = new (ctx) SourceFile(
       *dc->getParentModule(), SourceFileKind::MacroExpansion, macroBufferID,
       /*parsingOpts=*/{}, /*isPrimary=*/false);
-  macroSourceFile->setImports(dc->getParentSourceFile()->getImports());
+  if (auto parentSourceFile = dc->getParentSourceFile())
+    macroSourceFile->setImports(parentSourceFile->getImports());
+  else if (isa<ClangModuleUnit>(dc->getModuleScopeContext()))
+    macroSourceFile->setImports({});
   return macroSourceFile;
 }
 
@@ -1346,8 +1351,17 @@ static SourceFile *evaluateAttachedMacro(MacroDecl *macro, Decl *attachedTo,
   if (!attrSourceFile)
     return nullptr;
 
-  auto declSourceFile =
-      moduleDecl->getSourceFileContainingLocation(attachedTo->getStartLoc());
+  // If the declaration has no source location and comes from a Clang module,
+  // pretty-print the declaration and use that location.
+  SourceLoc attachedToLoc = attachedTo->getLoc();
+  if (attachedToLoc.isInvalid() &&
+      isa<ClangModuleUnit>(dc->getModuleScopeContext())) {
+    attachedToLoc = evaluateOrDefault(
+        ctx.evaluator, PrettyPrintDeclRequest{attachedTo}, SourceLoc());
+  }
+
+  SourceFile *declSourceFile =
+      moduleDecl->getSourceFileContainingLocation(attachedToLoc);
   if (!declSourceFile)
     return nullptr;
 
@@ -1486,13 +1500,18 @@ static SourceFile *evaluateAttachedMacro(MacroDecl *macro, Decl *attachedTo,
     if (auto var = dyn_cast<VarDecl>(attachedTo))
       searchDecl = var->getParentPatternBinding();
 
+    auto startLoc = searchDecl->getStartLoc();
+    if (startLoc.isInvalid() && isa<ClangModuleUnit>(dc->getModuleScopeContext())) {
+      startLoc = attachedToLoc;
+    }
+
     BridgedStringRef evaluatedSourceOut{nullptr, 0};
     assert(!externalDef.isError());
     swift_Macros_expandAttachedMacro(
         &ctx.Diags, externalDef.get(), discriminator->c_str(),
         extendedType.c_str(), conformanceList.c_str(), getRawMacroRole(role),
         astGenAttrSourceFile, attr->AtLoc.getOpaquePointerValue(),
-        astGenDeclSourceFile, searchDecl->getStartLoc().getOpaquePointerValue(),
+        astGenDeclSourceFile, startLoc.getOpaquePointerValue(),
         astGenParentDeclSourceFile, parentDeclLoc, &evaluatedSourceOut);
     if (!evaluatedSourceOut.unbridged().data())
       return nullptr;

test/Inputs/clang-importer-sdk/usr/include/completion_handler_globals.h

@@ -0,0 +1,25 @@
+#if __SWIFT_ATTR_SUPPORTS_MACROS
+#define ADD_ASYNC __attribute__((swift_attr("@macro_library.AddAsync")))
+#else
+#define ADD_ASYNC
+#endif
+
+void async_divide(double x, double y, void (* _Nonnull completionHandler)(double x)) ADD_ASYNC;
+
+typedef struct SlowComputer {
+} SlowComputer;
+
+void computer_divide(const SlowComputer *computer, double x, double y, void (* _Nonnull completionHandler)(double x))
+  ADD_ASYNC
+  __attribute__((swift_name("SlowComputer.divide(self:_:_:completionHandler:)")));
+
+
+#if __OBJC__
+@import Foundation;
+
+@interface Computer: NSObject
+-(void)multiply:(double)x by:(double)y afterDone:(void (^ _Nonnull)(double x))afterDone
+  ADD_ASYNC
+  __attribute__((swift_async(none)));
+@end
+#endif

test/Inputs/clang-importer-sdk/usr/include/module.modulemap

@@ -153,3 +153,7 @@ module IncompleteTypes {
   header "IncompleteTypes.h"
   export *
 }
+
+module CompletionHandlerGlobals {
+  header "completion_handler_globals.h"
+}