Merge pull request swiftlang#75308 from kubamracek/embedded-indexing-non-wmo

[embedded] Don't produce PerfDiags when in non-WMO mode (e.g. when building during indexing)

Author: kubamracek

include/swift/AST/SILOptions.h

@@ -150,6 +150,10 @@ class SILOptions {
   /// Enables SIL-level diagnostics for NonescapableTypes.
   bool EnableLifetimeDependenceDiagnostics = true;
 
+  /// Enables SIL-level performance diagnostics (for @noLocks, @noAllocation
+  /// annotations and for Embedded Swift).
+  bool EnablePerformanceDiagnostics = true;
+
   /// Controls whether or not paranoid verification checks are run.
   bool VerifyAll = false;
 

lib/SILOptimizer/Mandatory/PerformanceDiagnostics.cpp

@@ -805,6 +805,11 @@ class PerformanceDiagnosticsPass : public SILModuleTransform {
   void run() override {
     SILModule *module = getModule();
 
+    // Skip all performance/embedded diagnostics if asked. This is used from
+    // SourceKit to avoid reporting false positives when WMO is turned off for
+    // indexing purposes.
+    if (!module->getOptions().EnablePerformanceDiagnostics) return;
+
     PerformanceDiagnostics diagnoser(*module, getAnalysis<BasicCalleeAnalysis>());
 
     // Check that @_section, @_silgen_name is only on constant globals

test/SourceKit/Diagnostics/embedded_non_wmo.swift

@@ -0,0 +1,34 @@
+// Check that when emitting diagnostics in SourceKit, we don't report false positives in PerformanceDiagnostics (because WMO is disabled).
+
+// RUN: %empty-directory(%t)
+// RUN: split-file %s %t
+
+// RUN: %sourcekitd-test -req=diags %t/file1.swift -- %t/file1.swift %t/file2.swift -enable-experimental-feature Embedded -target %target-cpu-apple-macos14 | %FileCheck %s
+
+// REQUIRES: swift_in_compiler
+// REQUIRES: embedded_stdlib
+// REQUIRES: OS=macosx
+
+//--- file1.swift
+
+func foo() {
+    bar(Int.self)
+}
+
+@main
+struct Main {
+    static func main() {
+        foo()
+    }
+}
+
+//--- file2.swift
+
+func bar<T>(_ T: T.Type) {
+    
+}
+
+// CHECK:      {
+// CHECK-NEXT:   key.diagnostics: [
+// CHECK-NEXT:   ]
+// CHECK-NEXT: }

tools/SourceKit/lib/SwiftLang/SwiftASTManager.cpp

@@ -1217,6 +1217,11 @@ ASTUnitRef ASTBuildOperation::buildASTUnit(std::string &Error) {
       // flag and might thus fail, which SILGen cannot handle.
       llvm::SaveAndRestore<std::shared_ptr<std::atomic<bool>>> DisableCancellationDuringSILGen(CompIns.getASTContext().CancellationFlag, nullptr);
       SILOptions SILOpts = Invocation.getSILOptions();
+
+      // Disable PerformanceDiagnostics SIL pass, which in some cases requires
+      // WMO (e.g. for Embedded Swift diags) but SourceKit compiles without WMO.
+      SILOpts.EnablePerformanceDiagnostics = false;
+
       auto &TC = CompIns.getSILTypes();
       std::unique_ptr<SILModule> SILMod = performASTLowering(*SF, TC, SILOpts);
       if (CancellationFlag->load(std::memory_order_relaxed)) {