fixup! make mangled name last component in label; remove need for splitting helper

Author: Michael137

lldb/include/lldb/Expression/Expression.h

@@ -102,17 +102,11 @@ class Expression {
 ///
 /// The format being:
 ///
-///   <prefix>:<mangled name>:<module uid>:<symbol uid>
+///   <prefix>:<module uid>:<symbol uid>:<mangled name>
 ///
 /// The label string needs to stay valid for the entire lifetime
 /// of this object.
 struct FunctionCallLabel {
-  /// Name to use when searching for the function symbol in
-  /// \c module_id. For most function calls this will be a
-  /// mangled name. In cases where a mangled name can't be used,
-  /// this will be the function name.
-  llvm::StringRef lookup_name;
-
   /// Unique identifier of the lldb_private::Module
   /// which contains the symbol identified by \c symbol_id.
   lldb::user_id_t module_id;
@@ -122,14 +116,23 @@ struct FunctionCallLabel {
   /// be the DIE UID.
   lldb::user_id_t symbol_id;
 
+  /// Name to use when searching for the function symbol in
+  /// \c module_id. For most function calls this will be a
+  /// mangled name. In cases where a mangled name can't be used,
+  /// this will be the function name.
+  ///
+  /// NOTE: kept as last element so we don't have to worry about
+  /// ':' in the mangled name when parsing the label.
+  llvm::StringRef lookup_name;
+
   /// Decodes the specified function \c label into a \c FunctionCallLabel.
   static llvm::Expected<FunctionCallLabel> fromString(llvm::StringRef label);
 
   /// Encode this FunctionCallLabel into it's string representation.
   ///
   /// The representation roundtrips through \c fromString:
   /// \code{.cpp}
-  /// llvm::StringRef encoded = "$__lldb_func:_Z3foov:0x0:0x0";
+  /// llvm::StringRef encoded = "$__lldb_func:0x0:0x0:_Z3foov";
   /// FunctionCallLabel label = *fromString(label);
   ///
   /// assert (label.toString() == encoded);
@@ -142,13 +145,6 @@ struct FunctionCallLabel {
 /// from JITted expressions.
 inline constexpr llvm::StringRef FunctionCallLabelPrefix = "$__lldb_func";
 
-/// Returns the components of the specified function call label.
-///
-/// The format of \c label is described in \c FunctionCallLabel.
-/// The label prefix is not one of the components.
-llvm::Expected<llvm::SmallVector<llvm::StringRef, 3>>
-splitFunctionCallLabel(llvm::StringRef label);
-
 } // namespace lldb_private
 
 #endif // LLDB_EXPRESSION_EXPRESSION_H

lldb/source/Expression/Expression.cpp

@@ -31,8 +31,12 @@ Expression::Expression(ExecutionContextScope &exe_scope)
   assert(m_target_wp.lock());
 }
 
-llvm::Expected<llvm::SmallVector<llvm::StringRef, 3>>
-lldb_private::splitFunctionCallLabel(llvm::StringRef label) {
+/// Returns the components of the specified function call label.
+///
+/// The format of \c label is described in \c FunctionCallLabel.
+/// The label prefix is not one of the components.
+static llvm::Expected<llvm::SmallVector<llvm::StringRef, 3>>
+splitFunctionCallLabel(llvm::StringRef label) {
   if (!label.consume_front(FunctionCallLabelPrefix))
     return llvm::createStringError(
         "expected function call label prefix not found in %s", label.data());
@@ -60,25 +64,26 @@ lldb_private::FunctionCallLabel::fromString(llvm::StringRef label) {
 
   const auto &components = *components_or_err;
 
-  llvm::StringRef module_label = components[1];
-  llvm::StringRef die_label = components[2];
+  llvm::StringRef module_label = components[0];
+  llvm::StringRef die_label = components[1];
 
   lldb::user_id_t module_id = 0;
   if (module_label.consumeInteger(0, module_id))
     return llvm::createStringError(
-        llvm::formatv("failed to parse module ID from '{0}'.", components[1]));
+        llvm::formatv("failed to parse module ID from '{0}'.", components[0]));
 
   lldb::user_id_t die_id;
   if (die_label.consumeInteger(/*Radix=*/0, die_id))
     return llvm::createStringError(
-        llvm::formatv("failed to parse DIE ID from '{0}'.", components[2]));
+        llvm::formatv("failed to parse DIE ID from '{0}'.", components[1]));
 
-  return FunctionCallLabel{/*.lookup_name=*/components[0],
-                           /*.module_id=*/module_id, /*.symbol_id=*/die_id};
+  return FunctionCallLabel{/*.module_id=*/module_id,
+                           /*.symbol_id=*/die_id,
+                           /*.lookup_name=*/components[2]};
 }
 
 std::string lldb_private::FunctionCallLabel::toString() const {
-  return llvm::formatv("{0}:{1}:{2:x}:{3:x}", FunctionCallLabelPrefix,
-                       lookup_name, module_id, symbol_id)
+  return llvm::formatv("{0}:{1:x}:{2:x}:{3}", FunctionCallLabelPrefix,
+                       module_id, symbol_id, lookup_name)
       .str();
 }

lldb/source/Plugins/SymbolFile/DWARF/DWARFASTParserClang.cpp

@@ -267,9 +267,11 @@ static std::optional<std::string> MakeLLDBFuncAsmLabel(const DWARFDIE &die) {
   if (die_id == LLDB_INVALID_UID)
     return std::nullopt;
 
-  return FunctionCallLabel{/*.lookup_name=*/name,
-                           /*module_id=*/module_id,
-                           /*symbol_id=*/die_id}
+  return FunctionCallLabel{
+      /*module_id=*/module_id,
+      /*symbol_id=*/die_id,
+      /*.lookup_name=*/name
+  }
       .toString();
 }
 

lldb/source/Plugins/TypeSystem/Clang/TypeSystemClang.cpp

@@ -9044,13 +9044,13 @@ ConstString TypeSystemClang::DeclGetName(void *opaque_decl) {
 
 static ConstString
 ExtractMangledNameFromFunctionCallLabel(llvm::StringRef label) {
-  auto components_or_err = splitFunctionCallLabel(label);
-  if (!components_or_err) {
-    llvm::consumeError(components_or_err.takeError());
+  auto label_or_err = FunctionCallLabel::fromString(label);
+  if (!label_or_err) {
+    llvm::consumeError(label_or_err.takeError());
     return {};
   }
 
-  llvm::StringRef mangled = (*components_or_err)[0];
+  llvm::StringRef mangled = label_or_err->lookup_name;
   if (Mangled::IsMangledName(mangled))
     return ConstString(mangled);