[lldb][swift] Filter Q funclets when setting breakpoints

lldb/source/Plugins/Language/Swift/SwiftLanguage.cpp

@@ -1814,6 +1814,17 @@ SwiftLanguage::GetDemangledFunctionNameWithoutArguments(Mangled mangled) const {
   return mangled_name;
 }
 
+bool SwiftLanguage::IgnoreForLineBreakpoints(const SymbolContext &sc) const {
+  // If we don't have a function, conservatively return false.
+  if (!sc.function)
+    return false;
+  StringRef name = sc.function->GetMangled().GetMangledName().GetStringRef();
+  // In async functions, ignore await resume ("Q") funclets, these only
+  // deallocate the async context and task_switch back to user code.
+  return SwiftLanguageRuntime::IsSwiftAsyncAwaitResumePartialFunctionSymbol(
+      name);
+}
+
 //------------------------------------------------------------------
 // Static Functions
 //------------------------------------------------------------------

lldb/source/Plugins/Language/Swift/SwiftLanguage.h

@@ -90,6 +90,9 @@ class SwiftLanguage : public Language {
 
   llvm::StringRef GetInstanceVariableName() override { return "self"; }
 
+  /// Override that skips breakpoints inside await resume ("Q") async funclets.
+  bool IgnoreForLineBreakpoints(const SymbolContext &sc) const override;
+
   //------------------------------------------------------------------
   // PluginInterface protocol
   //------------------------------------------------------------------

lldb/test/API/lang/swift/async_breakpoints/Makefile

@@ -0,0 +1,3 @@
+SWIFT_SOURCES := main.swift
+
+include Makefile.rules

lldb/test/API/lang/swift/async_breakpoints/TestSwiftAsyncBreakpoints.py

@@ -0,0 +1,54 @@
+import lldb
+from lldbsuite.test.decorators import *
+import lldbsuite.test.lldbtest as lldbtest
+import lldbsuite.test.lldbutil as lldbutil
+
+
+class TestSwiftAsyncBreakpoints(lldbtest.TestBase):
+    @swiftTest
+    @skipIfWindows
+    @skipIfLinux
+    @skipIf(archs=no_match(["arm64", "arm64e", "x86_64"]))
+    def test(self):
+        """Test async breakpoints"""
+        self.build()
+        filespec = lldb.SBFileSpec("main.swift")
+        target, process, thread, breakpoint1 = lldbutil.run_to_source_breakpoint(
+            self, "Breakpoint1", filespec
+        )
+        breakpoint2 = target.BreakpointCreateBySourceRegex("Breakpoint2", filespec)
+        breakpoint3 = target.BreakpointCreateBySourceRegex("Breakpoint3", filespec)
+        self.assertEquals(breakpoint1.GetNumLocations(), 2)
+        self.assertEquals(breakpoint2.GetNumLocations(), 1)
+        self.assertEquals(breakpoint3.GetNumLocations(), 2)
+
+        location11 = breakpoint1.GetLocationAtIndex(0)
+        location12 = breakpoint1.GetLocationAtIndex(1)
+        self.assertEquals(location11.GetHitCount(), 1)
+        self.assertEquals(location12.GetHitCount(), 0)
+
+        self.assertEquals(thread.GetStopDescription(128), "breakpoint 1.1")
+        process.Continue()
+        self.assertEquals(thread.GetStopDescription(128), "breakpoint 1.2")
+
+        thread.StepOver()
+        self.assertEquals(thread.GetStopDescription(128), "breakpoint 2.1")
+        self.expect("expr timestamp1", substrs=["42"])
+
+        thread.StepOver()
+        self.assertIn("breakpoint 3.1", thread.GetStopDescription(128))
+        self.expect("expr timestamp1", substrs=["42"])
+
+        process.Continue()
+        self.assertIn("breakpoint 3.2", thread.GetStopDescription(128))
+        self.expect("expr timestamp1", substrs=["42"])
+
+        thread.StepOver()
+        self.expect("expr timestamp1", substrs=["42"])
+        self.expect("expr timestamp2", substrs=["43"])
+
+        self.runCmd("settings set language.enable-filter-for-line-breakpoints false")
+        breakpoint1_no_filter = target.BreakpointCreateBySourceRegex(
+            "Breakpoint1", filespec
+        )
+        self.assertEquals(breakpoint1_no_filter.GetNumLocations(), 3)

lldb/test/API/lang/swift/async_breakpoints/main.swift

@@ -0,0 +1,15 @@
+func getTimestamp(i:Int) async -> Int {
+  return i
+}
+
+func work() {}
+
+func foo() async {
+  work()
+  let timestamp1 = await getTimestamp(i:42) // Breakpoint1
+  work() // Breakpoint2
+  let timestamp2 = await getTimestamp(i:43) // Breakpoint3
+  work()
+}
+
+await foo()