[LLDB] Refactored CPlusPlusLanguage::MethodName to break lldb-server dependencies (#132274)

This patch addresses the issue #129543.
After this patch the size of lldb-server is reduced by 9MB.

Co-authored-by: @bulbazord Alex Langford

Author: slydiman

lldb/include/lldb/Core/Mangled.h

@@ -246,6 +246,8 @@ class Mangled {
   ///     for s, otherwise the enumerator for the mangling scheme detected.
   static Mangled::ManglingScheme GetManglingScheme(llvm::StringRef const name);
 
+  static bool IsMangledName(llvm::StringRef name);
+
   /// Decode a serialized version of this object from data.
   ///
   /// \param data

lldb/include/lldb/Core/RichManglingContext.h

@@ -12,6 +12,7 @@
 #include "lldb/lldb-forward.h"
 #include "lldb/lldb-private.h"
 
+#include "lldb/Target/Language.h"
 #include "lldb/Utility/ConstString.h"
 
 #include "llvm/ADT/Any.h"
@@ -67,11 +68,7 @@ class RichManglingContext {
   char *m_ipd_buf;
   size_t m_ipd_buf_size = 2048;
 
-  /// Members for PluginCxxLanguage
-  /// Cannot forward declare inner class CPlusPlusLanguage::MethodName. The
-  /// respective header is in Plugins and including it from here causes cyclic
-  /// dependency. Instead keep a llvm::Any and cast it on-access in the cpp.
-  llvm::Any m_cxx_method_parser;
+  std::unique_ptr<Language::MethodName> m_cxx_method_parser;
 
   /// Clean up memory when using PluginCxxLanguage
   void ResetCxxMethodParser();
@@ -81,15 +78,6 @@ class RichManglingContext {
 
   /// Uniform handling of string buffers for ItaniumPartialDemangler.
   llvm::StringRef processIPDStrResult(char *ipd_res, size_t res_len);
-
-  /// Cast the given parser to the given type. Ideally we would have a type
-  /// trait to deduce \a ParserT from a given InfoProvider, but unfortunately we
-  /// can't access CPlusPlusLanguage::MethodName from within the header.
-  template <class ParserT> static ParserT *get(llvm::Any parser) {
-    assert(parser.has_value());
-    assert(llvm::any_cast<ParserT *>(&parser));
-    return *llvm::any_cast<ParserT *>(&parser);
-  }
 };
 
 } // namespace lldb_private

lldb/include/lldb/Target/Language.h

@@ -214,6 +214,104 @@ class Language : public PluginInterface {
     return std::vector<Language::MethodNameVariant>();
   };
 
+  class MethodName {
+  public:
+    MethodName() {}
+
+    MethodName(ConstString full)
+        : m_full(full), m_basename(), m_context(), m_arguments(),
+          m_qualifiers(), m_return_type(), m_scope_qualified(), m_parsed(false),
+          m_parse_error(false) {}
+
+    virtual ~MethodName() {};
+
+    void Clear() {
+      m_full.Clear();
+      m_basename = llvm::StringRef();
+      m_context = llvm::StringRef();
+      m_arguments = llvm::StringRef();
+      m_qualifiers = llvm::StringRef();
+      m_return_type = llvm::StringRef();
+      m_scope_qualified.clear();
+      m_parsed = false;
+      m_parse_error = false;
+    }
+
+    bool IsValid() {
+      if (!m_parsed)
+        Parse();
+      if (m_parse_error)
+        return false;
+      return (bool)m_full;
+    }
+
+    ConstString GetFullName() const { return m_full; }
+
+    llvm::StringRef GetBasename() {
+      if (!m_parsed)
+        Parse();
+      return m_basename;
+    }
+
+    llvm::StringRef GetContext() {
+      if (!m_parsed)
+        Parse();
+      return m_context;
+    }
+
+    llvm::StringRef GetArguments() {
+      if (!m_parsed)
+        Parse();
+      return m_arguments;
+    }
+
+    llvm::StringRef GetQualifiers() {
+      if (!m_parsed)
+        Parse();
+      return m_qualifiers;
+    }
+
+    llvm::StringRef GetReturnType() {
+      if (!m_parsed)
+        Parse();
+      return m_return_type;
+    }
+
+    std::string GetScopeQualifiedName() {
+      if (!m_parsed)
+        Parse();
+      return m_scope_qualified;
+    }
+
+  protected:
+    virtual void Parse() {
+      m_parsed = true;
+      m_parse_error = true;
+    }
+
+    ConstString m_full; // Full name:
+                        // "size_t lldb::SBTarget::GetBreakpointAtIndex(unsigned
+                        // int) const"
+    llvm::StringRef m_basename;    // Basename:     "GetBreakpointAtIndex"
+    llvm::StringRef m_context;     // Decl context: "lldb::SBTarget"
+    llvm::StringRef m_arguments;   // Arguments:    "(unsigned int)"
+    llvm::StringRef m_qualifiers;  // Qualifiers:   "const"
+    llvm::StringRef m_return_type; // Return type:  "size_t"
+    std::string m_scope_qualified;
+    bool m_parsed = false;
+    bool m_parse_error = false;
+  };
+
+  virtual std::unique_ptr<Language::MethodName>
+  GetMethodName(ConstString name) const {
+    return std::make_unique<Language::MethodName>(name);
+  };
+
+  virtual std::pair<lldb::FunctionNameType, llvm::StringRef>
+  GetFunctionNameInfo(ConstString name) const {
+    return std::pair{lldb::eFunctionNameTypeNone, llvm::StringRef()};
+  };
+
   /// Returns true iff the given symbol name is compatible with the mangling
   /// scheme of this language.
   ///

lldb/source/Core/CMakeLists.txt

@@ -16,8 +16,7 @@ if (LLDB_ENABLE_CURSES)
   endif()
 endif()
 
-# TODO: Add property `NO_PLUGIN_DEPENDENCIES` to lldbCore
-add_lldb_library(lldbCore
+add_lldb_library(lldbCore NO_PLUGIN_DEPENDENCIES
   Address.cpp
   AddressRange.cpp
   AddressRangeListImpl.cpp
@@ -71,8 +70,6 @@ add_lldb_library(lldbCore
     lldbUtility
     lldbValueObject
     lldbVersion
-    lldbPluginCPlusPlusLanguage
-    lldbPluginObjCLanguage
     ${LLDB_CURSES_LIBS}
 
   CLANG_LIBS

lldb/source/Core/Mangled.cpp

@@ -33,12 +33,12 @@
 #include <cstring>
 using namespace lldb_private;
 
-static inline bool cstring_is_mangled(llvm::StringRef s) {
-  return Mangled::GetManglingScheme(s) != Mangled::eManglingSchemeNone;
-}
-
 #pragma mark Mangled
 
+bool Mangled::IsMangledName(llvm::StringRef name) {
+  return Mangled::GetManglingScheme(name) != Mangled::eManglingSchemeNone;
+}
+
 Mangled::ManglingScheme Mangled::GetManglingScheme(llvm::StringRef const name) {
   if (name.empty())
     return Mangled::eManglingSchemeNone;
@@ -121,7 +121,7 @@ int Mangled::Compare(const Mangled &a, const Mangled &b) {
 
 void Mangled::SetValue(ConstString name) {
   if (name) {
-    if (cstring_is_mangled(name.GetStringRef())) {
+    if (IsMangledName(name.GetStringRef())) {
       m_demangled.Clear();
       m_mangled = name;
     } else {