[lldb][nfc] Adjust language plugin to changes in FilterForLineBreakpoints

lldb/include/lldb/Target/Language.h

@@ -356,14 +356,13 @@ class Language : public PluginInterface {
 
   virtual llvm::StringRef GetInstanceVariableName() { return {}; }
 
-  /// Returns true if this SymbolContext should be ignored when setting
-  /// breakpoints by line (number or regex). Helpful for languages that create
-  /// artificial functions without meaningful user code associated with them
-  /// (e.g. code that gets expanded in late compilation stages, like by
-  /// CoroSplitter).
-  virtual bool IgnoreForLineBreakpoints(const SymbolContext &) const {
-    return false;
-  }
+  /// Given a symbol context list of matches which supposedly represent the
+  /// same file and line number in a CU, erases those that should be ignored
+  /// when setting breakpoints by line (number or regex). Helpful for languages
+  /// that create split a single source-line into many functions (e.g. call
+  /// sites transformed by CoroSplitter).
+  virtual void
+  FilterForLineBreakpoints(llvm::SmallVectorImpl<SymbolContext> &) const {}
 
   /// Returns a boolean indicating whether two symbol contexts are equal for the
   /// purposes of frame comparison. If the plugin has no opinion, it should

lldb/source/Breakpoint/BreakpointResolver.cpp

@@ -207,16 +207,15 @@ bool operator<(const SourceLoc lhs, const SourceLoc rhs) {
 void BreakpointResolver::SetSCMatchesByLine(
     SearchFilter &filter, SymbolContextList &sc_list, bool skip_prologue,
     llvm::StringRef log_ident, uint32_t line, std::optional<uint16_t> column) {
-  llvm::SmallVector<SymbolContext, 16> all_scs;
-
-  for (const auto &sc : sc_list) {
-    if (Language::GetGlobalLanguageProperties()
-            .GetEnableFilterForLineBreakpoints())
-      if (Language *lang = Language::FindPlugin(sc.GetLanguage());
-          lang && lang->IgnoreForLineBreakpoints(sc))
-        continue;
-    all_scs.push_back(sc);
-  }
+  llvm::SmallVector<SymbolContext, 16> all_scs(sc_list.begin(), sc_list.end());
+
+  // Let the language plugin filter `sc_list`. Because all symbol contexts in
+  // sc_list are assumed to belong to the same File, Line and CU, the code below
+  // assumes they have the same language.
+  if (!sc_list.IsEmpty() && Language::GetGlobalLanguageProperties()
+                                .GetEnableFilterForLineBreakpoints())
+    if (Language *lang = Language::FindPlugin(sc_list[0].GetLanguage()))
+      lang->FilterForLineBreakpoints(all_scs);
 
   while (all_scs.size()) {
     uint32_t closest_line = UINT32_MAX;

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

@@ -1832,16 +1832,20 @@ 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;
-  llvm::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);
+void SwiftLanguage::FilterForLineBreakpoints(
+    llvm::SmallVectorImpl<SymbolContext> &sc_list) const {
+  llvm::erase_if(sc_list, [](const SymbolContext &sc) {
+    // If we don't have a function, conservatively keep this sc.
+    if (!sc.function)
+      return false;
+
+    // In async functions, ignore await resume ("Q") funclets, these only
+    // deallocate the async context and task_switch back to user code.
+    llvm::StringRef name =
+        sc.function->GetMangled().GetMangledName().GetStringRef();
+    return SwiftLanguageRuntime::IsSwiftAsyncAwaitResumePartialFunctionSymbol(
+        name);
+  });
 }
 
 std::optional<bool>

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

@@ -97,7 +97,8 @@ 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;
+  void FilterForLineBreakpoints(
+      llvm::SmallVectorImpl<SymbolContext> &) const override;
 
   //------------------------------------------------------------------
   // PluginInterface protocol