[Macros] Ensure that we inherit imports from enclosing file for macro expansion files

Author: DougGregor

lib/Sema/TypeCheckMacros.cpp

@@ -477,6 +477,7 @@ Expr *swift::expandMacroExpr(
   auto macroSourceFile = new (ctx) SourceFile(
       *dc->getParentModule(), SourceFileKind::MacroExpansion, macroBufferID,
       /*parsingOpts=*/{}, /*isPrimary=*/false);
+  macroSourceFile->setImports(sourceFile->getImports());
 
   // Retrieve the parsed expression from the list of top-level items.
   auto topLevelItems = macroSourceFile->getTopLevelItems();
@@ -655,6 +656,7 @@ bool swift::expandFreestandingDeclarationMacro(
   auto macroSourceFile = new (ctx) SourceFile(
       *dc->getParentModule(), SourceFileKind::MacroExpansion, macroBufferID,
       /*parsingOpts=*/{}, /*isPrimary=*/false);
+  macroSourceFile->setImports(sourceFile->getImports());
 
   PrettyStackTraceDecl debugStack(
       "type checking expanded declaration macro", med);
@@ -832,6 +834,7 @@ void swift::expandAccessors(
   auto macroSourceFile = new (ctx) SourceFile(
       *dc->getParentModule(), SourceFileKind::MacroExpansion, macroBufferID,
       /*parsingOpts=*/{}, /*isPrimary=*/false);
+  macroSourceFile->setImports(declSourceFile->getImports());
 
   PrettyStackTraceDecl debugStack(
       "type checking expanded declaration macro", storage);
@@ -1014,6 +1017,7 @@ void swift::expandAttributes(CustomAttr *attr, MacroDecl *macro, Decl *member,
   auto macroSourceFile = new (ctx) SourceFile(
       *dc->getParentModule(), SourceFileKind::MacroExpansion, macroBufferID,
       /*parsingOpts=*/{}, /*isPrimary=*/false);
+  macroSourceFile->setImports(declSourceFile->getImports());
 
   PrettyStackTraceDecl debugStack(
       "type checking expanded declaration macro", member);

test/Macros/macro_expand.swift

@@ -101,6 +101,16 @@ func testAddBlocker(a: Int, b: Int, c: Int, oa: OnlyAdds) {
   // CHECK-DIAGS-NEXT: Original source range: {{.*}}macro_expand.swift:[[@LINE-6]]:7 - {{.*}}macro_expand.swift:[[@LINE-6]]:27
   // CHECK-DIAGS-NEXT: oa - oa
   // CHECK-DIAGS-NEXT: END CONTENTS OF FILE
+
+  _ = #addBlocker({ // expected-note{{in expansion of macro 'addBlocker' here}}
+
+      print("hello")
+      print(oa + oa) // expected-error{{blocked an add; did you mean to subtract? (from macro 'addBlocker')}}
+      // expected-note@-1{{use '-'}}
+      print(oa + oa) // expected-error{{blocked an add; did you mean to subtract? (from macro 'addBlocker')}}
+      // expected-note@-1{{use '-'}}
+    }())
+
   // Check recursion.
   #recurse(false) // okay
   #recurse(true) // expected-note{{in expansion of macro 'recurse' here}}