Have attached macro requests return an array of expansion buffer IDs.

DougGregor · DougGregor · commit 7ebc86e584bb · 2023-02-11T11:21:43.000-08:00
The result values of the expansion requests for attached macros tended
to be useless, because most of their operation is via side effects on
the nodes they are attached to. Replace the result values with an
array of expansion buffer IDs, so clients can see what effect the
macro expansion had.
diff --git a/include/swift/AST/TypeCheckRequests.h b/include/swift/AST/TypeCheckRequests.h
@@ -3827,34 +3827,38 @@ class ExpandMacroExpansionDeclRequest
 
 /// Expand all member attribute macros attached to the given
 /// declaration.
+///
+/// Produces the set of macro expansion buffer IDs.
 class ExpandMemberAttributeMacros
     : public SimpleRequest<ExpandMemberAttributeMacros,
-                           bool(Decl *),
+                           ArrayRef<unsigned>(Decl *),
                            RequestFlags::Cached> {
 public:
   using SimpleRequest::SimpleRequest;
 
 private:
   friend SimpleRequest;
 
-  bool evaluate(Evaluator &evaluator, Decl *decl) const;
+  ArrayRef<unsigned> evaluate(Evaluator &evaluator, Decl *decl) const;
 
 public:
   bool isCached() const { return true; }
 };
 
 /// Expand synthesized member macros attached to the given declaration.
+///
+/// Produces the set of macro expansion buffer IDs.
 class ExpandSynthesizedMemberMacroRequest
     : public SimpleRequest<ExpandSynthesizedMemberMacroRequest,
-                           bool(Decl *),
+                           ArrayRef<unsigned>(Decl *),
                            RequestFlags::Cached> {
 public:
   using SimpleRequest::SimpleRequest;
 
 private:
   friend SimpleRequest;
 
-  bool evaluate(Evaluator &evaluator, Decl *decl) const;
+  ArrayRef<unsigned> evaluate(Evaluator &evaluator, Decl *decl) const;
 
 public:
   bool isCached() const { return true; }
diff --git a/include/swift/AST/TypeCheckerTypeIDZone.def b/include/swift/AST/TypeCheckerTypeIDZone.def
@@ -432,10 +432,10 @@ SWIFT_REQUEST(TypeChecker, ExpandMacroExpansionDeclRequest,
               ArrayRef<Decl *>(MacroExpansionDecl *),
               Cached, NoLocationInfo)
 SWIFT_REQUEST(TypeChecker, ExpandMemberAttributeMacros,
-              bool(Decl *),
+              ArrayRef<unsigned>(Decl *),
               Cached, NoLocationInfo)
-SWIFT_REQUEST(TypeCHecker, ExpandSynthesizedMemberMacroRequest,
-              bool(Decl *),
+SWIFT_REQUEST(TypeChecker, ExpandSynthesizedMemberMacroRequest,
+              ArrayRef<unsigned>(Decl *),
               Cached, NoLocationInfo)
 SWIFT_REQUEST(TypeChecker, ExpandPeerMacroRequest,
               bool(Decl *),
diff --git a/lib/AST/Decl.cpp b/lib/AST/Decl.cpp
@@ -369,9 +369,9 @@ StringRef Decl::getDescriptiveKindName(DescriptiveDeclKind K) {
 
 DeclAttributes Decl::getSemanticAttrs() const {
   auto mutableThis = const_cast<Decl *>(this);
-  evaluateOrDefault(getASTContext().evaluator,
-                    ExpandMemberAttributeMacros{mutableThis},
-                    false);
+  (void)evaluateOrDefault(getASTContext().evaluator,
+                          ExpandMemberAttributeMacros{mutableThis},
+                          { });
 
   return getAttrs();
 }
diff --git a/lib/AST/NameLookup.cpp b/lib/AST/NameLookup.cpp
@@ -2082,9 +2082,9 @@ QualifiedLookupRequest::evaluate(Evaluator &eval, const DeclContext *DC,
 
     // Expand synthesized member macros.
     auto &ctx = current->getASTContext();
-    evaluateOrDefault(ctx.evaluator,
-                      ExpandSynthesizedMemberMacroRequest{current},
-                      false);
+    (void)evaluateOrDefault(ctx.evaluator,
+                            ExpandSynthesizedMemberMacroRequest{current},
+                            false);
 
     // Look for results within the current nominal type and its extensions.
     bool currentIsProtocol = isa<ProtocolDecl>(current);
diff --git a/lib/Sema/LookupVisibleDecls.cpp b/lib/Sema/LookupVisibleDecls.cpp
@@ -607,9 +607,9 @@ static void synthesizeMemberDeclsForLookup(NominalTypeDecl *NTD,
 
   // Expand synthesized member macros.
   auto &ctx = NTD->getASTContext();
-  evaluateOrDefault(ctx.evaluator,
-                    ExpandSynthesizedMemberMacroRequest{NTD},
-                    false);
+  (void)evaluateOrDefault(ctx.evaluator,
+                          ExpandSynthesizedMemberMacroRequest{NTD},
+                          false);
 
   // Expand peer macros.
   for (auto *member : NTD->getMembers()) {
diff --git a/lib/Sema/TypeCheckMacros.cpp b/lib/Sema/TypeCheckMacros.cpp
@@ -388,36 +388,39 @@ static std::string adjustMacroExpansionBufferName(StringRef name) {
   return result;
 }
 
-bool ExpandMemberAttributeMacros::evaluate(Evaluator &evaluator,
-                                           Decl *decl) const {
+ArrayRef<unsigned> ExpandMemberAttributeMacros::evaluate(Evaluator &evaluator,
+                                                         Decl *decl) const {
   if (decl->isImplicit())
-    return false;
+    return { }};
 
   auto *parentDecl = decl->getDeclContext()->getAsDecl();
   if (!parentDecl)
-    return false;
+    return { };
 
   if (isa<PatternBindingDecl>(decl))
-    return false;
+    return { };
 
-  bool addedAttributes = false;
+  SmallVector<unsigned, 2> bufferIDs;
   parentDecl->forEachAttachedMacro(MacroRole::MemberAttribute,
       [&](CustomAttr *attr, MacroDecl *macro) {
-        addedAttributes |= expandAttributes(attr, macro, decl);
+        if (auto bufferID = expandAttributes(attr, macro, decl))
+          bufferIDs.push_back(*bufferID);
       });
 
-  return addedAttributes;
+  return parentDecl->getASTContext().AllocateCopy(bufferIDs);
 }
 
-bool ExpandSynthesizedMemberMacroRequest::evaluate(Evaluator &evaluator,
-                                                   Decl *decl) const {
-  bool synthesizedMembers = false;
+ArrayRef<unsigned> ExpandSynthesizedMemberMacroRequest::evaluate(
+    Evaluator &evaluator, Decl *decl
+) const {
+  SmallVector<unsigned, 2> bufferIDs;
   decl->forEachAttachedMacro(MacroRole::Member,
       [&](CustomAttr *attr, MacroDecl *macro) {
-        synthesizedMembers |= expandMembers(attr, macro, decl);
+        if (auto bufferID = expandMembers(attr, macro, decl))
+          bufferIDs.push_back(*bufferID);
       });
 
-  return synthesizedMembers;
+  return decl->getASTContext().AllocateCopy(bufferIDs);
 }
 
 bool ExpandPeerMacroRequest::evaluate(Evaluator &evaluator, Decl *decl) const {
@@ -1025,44 +1028,43 @@ void swift::expandAccessors(
   }
 }
 
-bool swift::expandAttributes(CustomAttr *attr, MacroDecl *macro, Decl *member) {
+Optional<unsigned>
+swift::expandAttributes(CustomAttr *attr, MacroDecl *macro, Decl *member) {
   // Evaluate the macro.
   auto macroSourceFile = evaluateAttachedMacro(macro, member, attr,
                                                /*passParentContext*/true,
                                                MacroRole::MemberAttribute);
   if (!macroSourceFile)
-    return false;
+    return None;
 
   PrettyStackTraceDecl debugStack(
       "type checking expanded declaration macro", member);
 
-  bool addedAttributes = false;
   auto topLevelDecls = macroSourceFile->getTopLevelDecls();
   for (auto decl : topLevelDecls) {
     // Add the new attributes to the semantic attribute list.
     SmallVector<DeclAttribute *, 2> attrs(decl->getAttrs().begin(),
                                           decl->getAttrs().end());
     for (auto *attr : attrs) {
-      addedAttributes = true;
       member->getAttrs().add(attr);
     }
   }
 
-  return addedAttributes;
+  return macroSourceFile->getBufferID();
 }
 
-bool swift::expandMembers(CustomAttr *attr, MacroDecl *macro, Decl *decl) {
+Optional<unsigned>
+swift::expandMembers(CustomAttr *attr, MacroDecl *macro, Decl *decl) {
   // Evaluate the macro.
   auto macroSourceFile = evaluateAttachedMacro(macro, decl, attr,
                                                /*passParentContext*/false,
                                                MacroRole::Member);
   if (!macroSourceFile)
-    return false;
+    return None;
 
   PrettyStackTraceDecl debugStack(
       "type checking expanded declaration macro", decl);
 
-  bool synthesizedMembers = false;
   auto topLevelDecls = macroSourceFile->getTopLevelDecls();
   for (auto member : topLevelDecls) {
     // Note that synthesized members are not considered implicit. They have
@@ -1074,11 +1076,9 @@ bool swift::expandMembers(CustomAttr *attr, MacroDecl *macro, Decl *decl) {
     } else if (auto *extension = dyn_cast<ExtensionDecl>(decl)) {
       extension->addMember(member);
     }
-
-    synthesizedMembers = true;
   }
 
-  return synthesizedMembers;
+  return macroSourceFile->getBufferID();
 }
 
 bool swift::expandPeers(CustomAttr *attr, MacroDecl *macro, Decl *decl) {
diff --git a/lib/Sema/TypeCheckMacros.h b/lib/Sema/TypeCheckMacros.h
@@ -55,14 +55,17 @@ void expandAccessors(
 
 /// Expand the attributes for the given member declaration based
 /// on the custom attribute that references the given macro.
-bool expandAttributes(CustomAttr *attr, MacroDecl *macro, Decl *member);
+///
+/// If expansion occurred, returns the macro expansion buffer ID.
+Optional<unsigned>
+expandAttributes(CustomAttr *attr, MacroDecl *macro, Decl *member);
 
 /// Expand the synthesized members for the given declaration based on
 /// the custom attribute that references the given macro.
 ///
-/// Returns \c true if the macro added new synthesized members, \c false
-/// otherwise.
-bool expandMembers(CustomAttr *attr, MacroDecl *macro, Decl *decl);
+/// If expansion occurred, returns the macro expansion buffer ID.
+Optional<unsigned>
+expandMembers(CustomAttr *attr, MacroDecl *macro, Decl *decl);
 
 /// Expand the peer declarations for the given declaration based on
 /// the custom attribute that references the given macro.
diff --git a/lib/Sema/TypeCheckStorage.cpp b/lib/Sema/TypeCheckStorage.cpp
@@ -110,9 +110,9 @@ static void computeLoweredStoredProperties(NominalTypeDecl *decl,
                                            IterableDeclContext *implDecl) {
   // Expand synthesized member macros.
   auto &ctx = decl->getASTContext();
-  evaluateOrDefault(ctx.evaluator,
-                    ExpandSynthesizedMemberMacroRequest{decl},
-                    false);
+  (void)evaluateOrDefault(ctx.evaluator,
+                          ExpandSynthesizedMemberMacroRequest{decl},
+                          false);
 
   // Just walk over the members of the type, forcing backing storage
   // for lazy properties and property wrappers to be synthesized.
