[Diagnostics] Update in_macro_expansion note for attached macros

Use the attached atttribute's location as the location of the macro,
rather than the location of the declaration it's attached to. Also add
the kind and name of that declaration to the note itself.

Author: bnbarham

include/swift/AST/DiagnosticsCommon.def

@@ -221,7 +221,7 @@ ERROR(unknown_attribute,none,
 // MARK: macro diagnostics
 //------------------------------------------------------------------------------
 NOTE(in_macro_expansion,none,
-     "in expansion of macro %0 here", (DeclName))
+     "in expansion of macro %0%select{| on %kind1}1 here", (DeclName, const Decl *))
 ERROR(macro_experimental,none,
       "%0 macros are an experimental feature that is not enabled %select{|(%1)}1",
       (StringRef, StringRef))

lib/AST/DiagnosticEngine.cpp

@@ -1406,11 +1406,25 @@ DiagnosticEngine::getGeneratedSourceBufferNotes(SourceLoc loc) {
     case GeneratedSourceInfo::PeerMacroExpansion:
     case GeneratedSourceInfo::ConformanceMacroExpansion:
     case GeneratedSourceInfo::ExtensionMacroExpansion: {
-      SourceRange origRange = expansionNode.getSourceRange();
       DeclName macroName = getGeneratedSourceInfoMacroName(*generatedInfo);
 
-      Diagnostic expansionNote(diag::in_macro_expansion, macroName);
-      expansionNote.setLoc(origRange.Start);
+      // If it was an expansion of an attached macro, increase the range to
+      // include the decl's attributes. Also add the name of the decl the macro
+      // is attached to.
+      CustomAttr *attachedAttr = generatedInfo->attachedMacroCustomAttr;
+      Decl *attachedDecl =
+          attachedAttr ? expansionNode.dyn_cast<Decl *>() : nullptr;
+      SourceRange origRange = attachedDecl
+                                  ? attachedDecl->getSourceRangeIncludingAttrs()
+                                  : expansionNode.getSourceRange();
+
+      Diagnostic expansionNote(diag::in_macro_expansion, macroName,
+                               attachedDecl);
+      if (attachedAttr) {
+        expansionNote.setLoc(attachedAttr->getLocation());
+      } else {
+        expansionNote.setLoc(origRange.Start);
+      }
       expansionNote.addRange(
           Lexer::getCharSourceRangeFromSourceRange(SourceMgr, origRange));
       expansionNote.setIsChildNote(true);

test/Macros/macro_expand.swift

@@ -76,7 +76,7 @@ macro Invalid() = #externalMacro(module: "MacroDefinition", type: "InvalidMacro"
 
 @Invalid
 struct Bad {}
-// expected-note@-1 18 {{in expansion of macro 'Invalid' here}}
+// expected-note@-2 18 {{in expansion of macro 'Invalid' on struct 'Bad' here}}
 
 // CHECK-DIAGS: error: macro expansion cannot introduce import
 // CHECK-DIAGS: error: macro expansion cannot introduce precedence group

test/Macros/macro_expand_extensions.swift

@@ -124,7 +124,7 @@ macro UndocumentedNamesInExtension() = #externalMacro(module: "MacroDefinition",
 
 @UndocumentedNamesInExtension
 struct S<Element> {}
-// expected-note@-1 {{in expansion of macro 'UndocumentedNamesInExtension' here}}
+// expected-note@-2 {{in expansion of macro 'UndocumentedNamesInExtension' on generic struct 'S' here}}
 
 // CHECK-DIAGS: error: declaration name 'requirement()' is not covered by macro 'UndocumentedNamesInExtension'
 
@@ -133,7 +133,7 @@ macro UndocumentedConformanceInExtension() = #externalMacro(module: "MacroDefini
 
 @UndocumentedConformanceInExtension
 struct InvalidConformance<Element> {}
-// expected-note@-1 {{in expansion of macro 'UndocumentedConformanceInExtension' here}}
+// expected-note@-2 {{in expansion of macro 'UndocumentedConformanceInExtension' on generic struct 'InvalidConformance' here}}
 
 // CHECK-DIAGS: error: conformance to 'P' is not covered by macro 'UndocumentedConformanceInExtension'
 
@@ -142,7 +142,7 @@ macro UndocumentedCodable() = #externalMacro(module: "MacroDefinition", type: "A
 
 @UndocumentedCodable
 struct TestUndocumentedCodable {}
-// expected-note@-1 {{in expansion of macro 'UndocumentedCodable' here}}
+// expected-note@-2 {{in expansion of macro 'UndocumentedCodable' on struct 'TestUndocumentedCodable' here}}
 
 // CHECK-DIAGS: error: conformance to 'Codable' (aka 'Decodable & Encodable') is not covered by macro 'UndocumentedCodable'
 
@@ -151,7 +151,7 @@ macro UndocumentedEncodable() = #externalMacro(module: "MacroDefinition", type:
 
 @UndocumentedEncodable
 struct TestUndocumentedEncodable {}
-// expected-note@-1 {{in expansion of macro 'UndocumentedEncodable' here}}
+// expected-note@-2 {{in expansion of macro 'UndocumentedEncodable' on struct 'TestUndocumentedEncodable' here}}
 
 // CHECK-DIAGS: error: conformance to 'Codable' (aka 'Decodable & Encodable') is not covered by macro 'UndocumentedEncodable'
 

test/Macros/macro_expand_synthesized_members.swift

@@ -104,7 +104,8 @@ print(ElementType.paper.unknown())
 
 #if TEST_DIAGNOSTICS
 @addMembersQuotedInit
-struct S2 { // expected-note{{in expansion of macro 'addMembersQuotedInit' here}}
+struct S2 {
+// expected-note@-2 {{in expansion of macro 'addMembersQuotedInit' on struct 'S2' here}}
   func useSynthesized() {
     S.method()
     print(type(of: getStorage()))