Print the macro's concrete decl ref for any macro expansions.

This gives us the macro's USR, letting us match it up to its
declaration elsewhere.

Author: allevato

lib/AST/ASTDumper.cpp

@@ -28,6 +28,7 @@
 #include "swift/AST/ParameterList.h"
 #include "swift/AST/ProtocolConformance.h"
 #include "swift/AST/SourceFile.h"
+#include "swift/AST/TypeCheckRequests.h"
 #include "swift/AST/TypeVisitor.h"
 #include "swift/AST/USRGeneration.h"
 #include "swift/Basic/Assertions.h"
@@ -2731,7 +2732,11 @@ namespace {
 
     void visitMacroExpansionDecl(MacroExpansionDecl *MED, Label label) {
       printCommon(MED, "macro_expansion_decl", label);
-      printName(MED->getMacroName().getFullName(), Label::optional("name"));
+      if (MemberLoading == ASTDumpMemberLoading::TypeChecked) {
+        printDeclRefField(MED->getMacroRef(), Label::always("macro"));
+      } else {
+        printName(MED->getMacroName().getFullName(), Label::optional("name"));
+      }
       printRec(MED->getArgs(), Label::optional("args"));
       printFoot();
     }
@@ -4931,10 +4936,21 @@ class PrintAttribute : public AttributeVisitor<PrintAttribute, void, Label>,
   }
   void visitCustomAttr(CustomAttr *Attr, Label label) {
     printCommon(Attr, "custom_attr", label);
-    printTypeField(Attr->getType(), Label::always("type"));
+    if (Attr->getType()) {
+      printTypeField(Attr->getType(), Label::always("type"));
+    } else if (MemberLoading == ASTDumpMemberLoading::TypeChecked) {
+      // If the type is null, it might be a macro reference. Try that if we're
+      // dumping the fully type-checked AST.
+      auto macroRef =
+          evaluateOrDefault(const_cast<ASTContext *>(Ctx)->evaluator,
+                            ResolveMacroRequest{Attr, DC}, ConcreteDeclRef());
+      if (macroRef) {
+        printDeclRefField(macroRef, Label::always("macro"));
+      }
+    }
     if (!Writer.isParsable()) {
       // The type has the semantic information we want for parsable outputs, so
-      // omit the `TypeRepr` there.
+      // omit the `TypeRepr` there. This also works for macro references.
       printRec(Attr->getTypeRepr(), Label::optional("type_repr"));
     }
     if (Attr->getArgs())

test/Frontend/ast-dump-json-macros.swift

@@ -6,16 +6,19 @@
 // RUN: %empty-directory(%t)
 // RUN: %host-build-swift -swift-version 5 -emit-library -o %t/%target-library-name(MacroDefinition) -module-name=MacroDefinition %S/Inputs/json_ast_macro_definitions.swift -g -no-toolchain-stdlib-rpath
 // RUN: %target-swift-frontend -swift-version 5 -emit-module -o %t/json_ast_macro_library.swiftmodule %S/Inputs/json_ast_macro_library.swift -module-name json_ast_macro_library -load-plugin-library %t/%target-library-name(MacroDefinition)
-// RUN: %target-swift-frontend -target %target-swift-5.9-abi-triple -I %t -load-plugin-library %t/%target-library-name(MacroDefinition) -parse-as-library -dump-ast -dump-ast-format json %s -module-name main -o -
-// | %FileCheck %s
+// RUN: %target-swift-frontend -target %target-swift-5.9-abi-triple -I %t -load-plugin-library %t/%target-library-name(MacroDefinition) -parse-as-library -dump-ast -dump-ast-format json %s -module-name main -o - | %FileCheck %s
 
 import json_ast_macro_library
 
 @InjectMember
 struct X {
     var y: Int
 }
-// CHECK:      "_kind":"pattern_binding_decl"
+// CHECK:      "_kind":"struct_decl",
+// CHECK-SAME: "usr":"s:4main1XV",
+// CHECK-SAME: "_kind":"custom_attr",
+// CHECK-SAME: "macro":{"_kind":"decl_ref","base_name":"InjectMember","decl_usr":"s:22json_ast_macro_library12InjectMemberyycfm","type_usr":"$syycD"}
+// CHECK-SAME: "_kind":"pattern_binding_decl"
 // CHECK-SAME: "buffer_id":"@__swiftmacro_4main1X12InjectMemberfMm_.swift"
 // CHECK-SAME: "name":"_macroInjectedMember"
 
@@ -26,22 +29,26 @@ struct Z {
 // decl before we see the MacroExpansionDecl.
 // CHECK-SAME: "_kind":"struct_decl",
 // CHECK-SAME: "usr":"s:4main1ZV20FixedNameFreestanderV",
-// CHECK-SAME: "buffer_id":"@__swiftmacro_4main0033astdumpjsonmacrosswift_GwAFheaeGafMX{{\d+}}_{{\d+}}_33_{{[0-9A-F]+}}Ll18injectFreestandingfMf_.swift"
-// CHECK-SAME: "_kind": "macro_expansion_decl",
+// CHECK-SAME: "buffer_id":"@__swiftmacro_4main0033astdumpjsonmacrosswift_GwAFheaeGafMX{{[0-9]+}}_{{[0-9]+}}_33_{{[0-9A-F]+}}Ll18injectFreestandingfMf_.swift"
+// CHECK-SAME: "_kind":"macro_expansion_decl",
 // CHECK-SAME: "auxiliary_decl_usrs":["s:4main1ZV20FixedNameFreestanderV"]
+// CHECK-SAME: "macro":{"_kind":"decl_ref","base_name":"injectFreestanding","decl_usr":"s:22json_ast_macro_library18injectFreestandingyycfm","type_usr":"$syycD"}
 
 @InjectPeer
 struct ThisWillBePeered {}
 // CHECK-SAME: "_kind":"struct_decl",
 // CHECK-SAME: "usr":"s:4main16ThisWillBePeeredV",
 // CHECK-SAME: "auxiliary_decl_usrs":["s:4main13FixedNamePeerV"],
+// CHECK-SAME: "_kind":"custom_attr",
+// CHECK-SAME: "macro":{"_kind":"decl_ref","base_name":"InjectPeer","decl_usr":"s:22json_ast_macro_library10InjectPeeryycfm","type_usr":"$syycD"}
 // CHECK-SAME: "_kind":"struct_decl",
 // CHECK-SAME: "usr":"s:4main13FixedNamePeerV",
 // CHECK-SAME: "buffer_id":"@__swiftmacro_4main16ThisWillBePeered10InjectPeerfMp_.swift"
 
 #injectFreestanding
 // CHECK-SAME: "_kind":"macro_expansion_decl",
 // CHECK-SAME: "auxiliary_decl_usrs":["s:4main20FixedNameFreestanderV"],
+// CHECK-SAME: "macro":{"_kind":"decl_ref","base_name":"injectFreestanding","decl_usr":"s:22json_ast_macro_library18injectFreestandingyycfm","type_usr":"$syycD"}
 // CHECK-SAME: "_kind":"struct_decl",
 // CHECK-SAME: "usr":"s:4main20FixedNameFreestanderV",
-// CHECK-SAME: "buffer_id":"@__swiftmacro_4main0033astdumpjsonmacrosswift_GwAFheaeGafMX{{\d+}}_{{\d+}}_33_{{[0-9A-F]+}}Ll18injectFreestandingfMf_.swift"
+// CHECK-SAME: "buffer_id":"@__swiftmacro_4main0033astdumpjsonmacrosswift_GwAFheaeGafMX{{[0-9]+}}_{{[0-9]+}}_33_{{[0-9A-F]+}}Ll18injectFreestandingfMf_.swift"