Merge pull request swiftlang#63359 from DougGregor/more-macro-fixes

More macro fixes

Author: DougGregor

lib/ASTGen/Sources/ASTGen/Macros.swift

@@ -199,11 +199,11 @@ func expandFreestandingMacro(
         print("not on a macro expansion node: \(token.recursiveDescription)")
         return -1
       }
+      macroName = parentExpansion.macro.text
       let decls = try declMacro.expansion(
         of: sourceManager.detach(parentExpansion, in: context),
         in: context
       )
-      macroName = parentExpansion.macro.text
       evaluatedSyntax = Syntax(CodeBlockItemListSyntax(
         decls.map { CodeBlockItemSyntax(item: .decl($0)) }))
 
@@ -213,11 +213,12 @@ func expandFreestandingMacro(
     }
   } catch {
     // Record the error
-    context.diagnose(
-      Diagnostic(
+    sourceManager.diagnose(
+      diagnostic: Diagnostic(
         node: parentSyntax,
         message: ThrownErrorDiagnostic(message: String(describing: error))
-      )
+      ),
+      messageSuffix: " (from macro '\(macroName)')"
     )
     return -1
   }
@@ -426,11 +427,12 @@ func expandAttachedMacro(
   } catch {
     // Record the error
     // FIXME: Need to decide where to diagnose the error:
-    context.diagnose(
-      Diagnostic(
+    sourceManager.diagnose(
+      diagnostic: Diagnostic(
         node: Syntax(declarationNode),
         message: ThrownErrorDiagnostic(message: String(describing: error))
-      )
+      ),
+      messageSuffix: " (from macro '\(macroName)')"
     )
 
     return 1

lib/ASTGen/Sources/ASTGen/SourceManager.swift

@@ -76,13 +76,17 @@ extension SourceManager {
       return nil
     }
 
-    // Recursively find the root and its offset. This also must succeed.
+    // Recursively find the root and its offset.
     guard let (rootSF, parentOffset) = rootSourceFile(of: parent) else {
       return nil
     }
 
-    // Add our offset to our parent's offset, and we're done.
-    return (rootSF, parentOffset + SourceLength(utf8Length: offset))
+    // The position of our node is...
+    let finalPosition =
+      node.position                      // Our position relative to its root
+      + SourceLength(utf8Length: offset) // and that root's offset in its parent
+      + SourceLength(utf8Length: parentOffset.utf8Offset)
+    return (rootSF, finalPosition)
   }
 
   /// Produce the C++ source location for a given position based on a
@@ -106,7 +110,7 @@ extension SourceManager {
     // node.
     let position = position ?? node.position
     let offsetWithinSyntaxNode =
-       position.utf8Offset - node.root.position.utf8Offset
+       position.utf8Offset - node.position.utf8Offset
     let offsetFromSourceFile = rootPosition.utf8Offset + offsetWithinSyntaxNode
 
     // Compute the resulting address.

test/Macros/Inputs/syntax_macro_definitions.swift

@@ -147,15 +147,6 @@ public enum AddBlocker: ExpressionMacro {
     of node: some FreestandingMacroExpansionSyntax,
     in context: some MacroExpansionContext
   ) -> ExprSyntax {
-    let opTable = OperatorTable.standardOperators
-    let node = opTable.foldAll(node) { error in
-      context.diagnose(error.asDiagnostic)
-    }.asProtocol(FreestandingMacroExpansionSyntax.self)!
-
-    guard let argument = node.argumentList.first?.expression else {
-      fatalError("boom")
-    }
-
     let visitor = AddVisitor()
     let result = visitor.visit(Syntax(node))
 
@@ -242,6 +233,35 @@ public struct DefineBitwidthNumberedStructsMacro: DeclarationMacro {
   }
 }
 
+public struct WarningMacro: ExpressionMacro {
+   public static func expansion(
+     of macro: some FreestandingMacroExpansionSyntax,
+     in context: some MacroExpansionContext
+   ) throws -> ExprSyntax {
+     guard let firstElement = macro.argumentList.first,
+       let stringLiteral = firstElement.expression
+         .as(StringLiteralExprSyntax.self),
+       stringLiteral.segments.count == 1,
+       case let .stringSegment(messageString)? = stringLiteral.segments.first
+     else {
+       throw CustomError.message("#myWarning macro requires a string literal")
+     }
+
+     context.diagnose(
+       Diagnostic(
+         node: Syntax(macro),
+         message: SimpleDiagnosticMessage(
+           message: messageString.content.description,
+           diagnosticID: MessageID(domain: "test", id: "error"),
+           severity: .warning
+         )
+       )
+     )
+
+     return "()"
+  }
+}
+
 public struct PropertyWrapperMacro {}
 
 extension PropertyWrapperMacro: AccessorMacro, Macro {

test/Macros/macro_expand.swift

@@ -11,6 +11,8 @@
 // Debug info SIL testing
 // RUN: %target-swift-frontend -emit-sil -enable-experimental-feature Macros -enable-experimental-feature Macros -load-plugin-library %t/%target-library-name(MacroDefinition) -I %swift-host-lib-dir %s -module-name MacroUser -o - -g | %FileCheck --check-prefix CHECK-SIL %s
 
+// RUN: %target-swift-frontend -emit-sil -enable-experimental-feature Macros -enable-experimental-feature Macros -load-plugin-library %t/%target-library-name(MacroDefinition) -I %swift-host-lib-dir %s -module-name MacroUser -o - -g | %FileCheck --check-prefix CHECK-SIL %s
+
 // Execution testing
 // RUN: %target-build-swift -g -enable-experimental-feature Macros -enable-experimental-feature Macros -load-plugin-library %t/%target-library-name(MacroDefinition) -I %swift-host-lib-dir -L %swift-host-lib-dir %s -o %t/main -module-name MacroUser
 // RUN: %target-run %t/main | %FileCheck %s

test/Macros/macro_expand_throwing.swift

@@ -0,0 +1,20 @@
+// RUN: %empty-directory(%t)
+// RUN: %target-build-swift -I %swift-host-lib-dir -L %swift-host-lib-dir -emit-library -o %t/%target-library-name(MacroDefinition) -module-name=MacroDefinition %S/Inputs/syntax_macro_definitions.swift -g -no-toolchain-stdlib-rpath -swift-version 5
+
+// Make sure the diagnostic comes through...
+// RUN: %target-typecheck-verify-swift -enable-experimental-feature Macros -load-plugin-library %t/%target-library-name(MacroDefinition) -I %swift-host-lib-dir -module-name MacroUser
+
+// Make sure the diagnostic doesn't crash in SILGen
+// RUN: not %target-swift-frontend -emit-sil -enable-experimental-feature Macros -enable-experimental-feature Macros -load-plugin-library %t/%target-library-name(MacroDefinition) -I %swift-host-lib-dir %s -module-name MacroUser -o - -g
+
+// FIXME: Swift parser is not enabled on Linux CI yet.
+// REQUIRES: OS=macosx
+
+@freestanding(expression) macro myWarning(_ message: String) = #externalMacro(module: "MacroDefinition", type: "WarningMacro")
+
+func testThrownError() {
+  let name = "hello"
+  #myWarning(name) // expected-error{{#myWarning macro requires a string literal (from macro 'myWarning')}}
+
+  #myWarning("experimental features ahead") // expected-warning{{experimental features ahead}}
+}