Merge pull request #72027 from DougGregor/top-level-closure-discriminators-in-macros

Ensure that we assign discriminators for closures from top-level macros

Author: DougGregor

lib/AST/ASTContext.cpp

@@ -2193,12 +2193,20 @@ unsigned ASTContext::getNextMacroDiscriminator(
 
 /// Get the next discriminator within the given declaration context.
 unsigned ASTContext::getNextDiscriminator(const DeclContext *dc) {
+  // Top-level code declarations don't have their own discriminators.
+  if (auto tlcd = dyn_cast<TopLevelCodeDecl>(dc))
+    dc = tlcd->getParent();
+
   return getImpl().NextDiscriminator[dc];
 }
 
 /// Set the maximum assigned discriminator within the given declaration context.
 void ASTContext::setMaxAssignedDiscriminator(
     const DeclContext *dc, unsigned discriminator) {
+  // Top-level code declarations don't have their own discriminators.
+  if (auto tlcd = dyn_cast<TopLevelCodeDecl>(dc))
+    dc = tlcd->getParent();
+
   assert(discriminator >= getImpl().NextDiscriminator[dc]);
   getImpl().NextDiscriminator[dc] = discriminator;
 }

test/Macros/macro_expand_toplevel.swift

@@ -0,0 +1,15 @@
+// REQUIRES: swift_swift_parser, executable_test
+
+// RUN: %empty-directory(%t)
+// RUN: %host-build-swift -swift-version 5 -emit-library -o %t/%target-library-name(MacroDefinition) -module-name=MacroDefinition %S/Inputs/syntax_macro_definitions.swift
+
+// RUN: %target-build-swift -swift-version 5 -g -load-plugin-library %t/%target-library-name(MacroDefinition) %s -o %t/main -module-name MacroUser -Xfrontend -emit-dependencies-path -Xfrontend %t/main.d -Xfrontend -emit-reference-dependencies-path -Xfrontend %t/main.swiftdeps
+// RUN: %target-codesign %t/main
+// RUN: %target-run %t/main | %FileCheck %s
+
+@freestanding(expression) macro stringify<T>(_ value: T) -> (T, String) = #externalMacro(module: "MacroDefinition", type: "StringifyMacro")
+
+// CHECK: 3
+// CHECK-NEXT: 7
+print(#stringify({ 1 + 2 }()))
+print(#stringify({ 3 + 4 }()))