From 1e28adfe7595da953b39fe091747e1553eab56e2 Mon Sep 17 00:00:00 2001
From: Greg Clayton <gclayton@apple.com>
Date: Wed, 25 Feb 2015 17:25:02 +0000
Subject: MacOSX symbol table change to combine the N_GSYM debug map entry with
 the "_OBJC_CLASS_$_", "_OBJC_METACLASS_$_", and "_OBJC_IVAR_$_" non debug
 symbols. This allows the symbol that represents the object file to contain
 the eSymbolTypeObjCClass and eSymbolTypeObjCMetaClass and will help us to be
 able to efficiently lookup the real definition of an objective C class
 without loading all .o files linearly to find the .o file that contains the
 true definition.

llvm-svn: 230509
---
 .../Plugins/ObjectFile/Mach-O/ObjectFileMachO.cpp  | 102 +++++++++++++++------
 1 file changed, 74 insertions(+), 28 deletions(-)

(limited to 'lldb/source/Plugins/ObjectFile')

diff --git a/lldb/source/Plugins/ObjectFile/Mach-O/ObjectFileMachO.cpp b/lldb/source/Plugins/ObjectFile/Mach-O/ObjectFileMachO.cpp
index 7b49daa59ab..682a1c27096 100644
--- a/lldb/source/Plugins/ObjectFile/Mach-O/ObjectFileMachO.cpp
+++ b/lldb/source/Plugins/ObjectFile/Mach-O/ObjectFileMachO.cpp
@@ -2142,6 +2142,9 @@ ObjectFileMachO::ParseSymtab ()
     uint32_t i;
     FileSpecList dylib_files;
     Log *log(lldb_private::GetLogIfAllCategoriesSet (LIBLLDB_LOG_SYMBOLS));
+    static const llvm::StringRef g_objc_v2_prefix_class ("_OBJC_CLASS_$_");
+    static const llvm::StringRef g_objc_v2_prefix_metaclass ("_OBJC_METACLASS_$_");
+    static const llvm::StringRef g_objc_v2_prefix_ivar ("_OBJC_IVAR_$_");
 
     for (i=0; i<m_header.ncmds; ++i)
     {
@@ -2821,15 +2824,37 @@ ObjectFileMachO::ParseSymtab ()
                                                         // correctly.  To do this right, we should coalesce all the GSYM & global symbols that have the
                                                         // same address.
 
-                                                        if (symbol_name && symbol_name[0] == '_' && symbol_name[1] ==  'O'
-                                                            && (strncmp (symbol_name, "_OBJC_IVAR_$_", strlen ("_OBJC_IVAR_$_")) == 0
-                                                                || strncmp (symbol_name, "_OBJC_CLASS_$_", strlen ("_OBJC_CLASS_$_")) == 0
-                                                                || strncmp (symbol_name, "_OBJC_METACLASS_$_", strlen ("_OBJC_METACLASS_$_")) == 0))
-                                                            add_nlist = false;
+                                                        is_gsym = true;
+                                                        sym[sym_idx].SetExternal(true);
+
+                                                        if (symbol_name && symbol_name[0] == '_' && symbol_name[1] ==  'O')
+                                                        {
+                                                            llvm::StringRef symbol_name_ref(symbol_name);
+                                                            if (symbol_name_ref.startswith(g_objc_v2_prefix_class))
+                                                            {
+                                                                symbol_name_non_abi_mangled = symbol_name + 1;
+                                                                symbol_name = symbol_name + g_objc_v2_prefix_class.size();
+                                                                type = eSymbolTypeObjCClass;
+                                                                demangled_is_synthesized = true;
+
+                                                            }
+                                                            else if (symbol_name_ref.startswith(g_objc_v2_prefix_metaclass))
+                                                            {
+                                                                symbol_name_non_abi_mangled = symbol_name + 1;
+                                                                symbol_name = symbol_name + g_objc_v2_prefix_metaclass.size();
+                                                                type = eSymbolTypeObjCMetaClass;
+                                                                demangled_is_synthesized = true;
+                                                            }
+                                                            else if (symbol_name_ref.startswith(g_objc_v2_prefix_ivar))
+                                                            {
+                                                                symbol_name_non_abi_mangled = symbol_name + 1;
+                                                                symbol_name = symbol_name + g_objc_v2_prefix_ivar.size();
+                                                                type = eSymbolTypeObjCIVar;
+                                                                demangled_is_synthesized = true;
+                                                            }
+                                                        }
                                                         else
                                                         {
-                                                            is_gsym = true;
-                                                            sym[sym_idx].SetExternal(true);
                                                             if (nlist.n_value != 0)
                                                                 symbol_section = section_info.GetSection (nlist.n_sect, nlist.n_value);
                                                             type = eSymbolTypeData;
@@ -3267,9 +3292,6 @@ ObjectFileMachO::ParseSymtab ()
                                                                                 symbol_name[2] == 'B')
                                                                             {
                                                                                 llvm::StringRef symbol_name_ref(symbol_name);
-                                                                                static const llvm::StringRef g_objc_v2_prefix_class ("_OBJC_CLASS_$_");
-                                                                                static const llvm::StringRef g_objc_v2_prefix_metaclass ("_OBJC_METACLASS_$_");
-                                                                                static const llvm::StringRef g_objc_v2_prefix_ivar ("_OBJC_IVAR_$_");
                                                                                 if (symbol_name_ref.startswith(g_objc_v2_prefix_class))
                                                                                 {
                                                                                     symbol_name_non_abi_mangled = symbol_name + 1;
@@ -3446,7 +3468,10 @@ ObjectFileMachO::ParseSymtab ()
                                                                 type = eSymbolTypeResolver;
                                                         }
                                                     }
-                                                    else if (type == eSymbolTypeData)
+                                                    else if (type == eSymbolTypeData          ||
+                                                             type == eSymbolTypeObjCClass     ||
+                                                             type == eSymbolTypeObjCMetaClass ||
+                                                             type == eSymbolTypeObjCIVar      )
                                                     {
                                                         // See if we can find a N_STSYM entry for any data symbols.
                                                         // If we do find a match, and the name matches, then we
@@ -3487,7 +3512,7 @@ ObjectFileMachO::ParseSymtab ()
                                                                 sym[GSYM_sym_idx].GetAddress().SetSection (symbol_section);
                                                                 sym[GSYM_sym_idx].GetAddress().SetOffset (symbol_value);
                                                                 // We just need the flags from the linker symbol, so put these flags
-                                                                // into the N_STSYM flags to avoid duplicate symbols in the symbol table
+                                                                // into the N_GSYM flags to avoid duplicate symbols in the symbol table
                                                                 sym[GSYM_sym_idx].SetFlags (nlist.n_type << 16 | nlist.n_desc);
                                                                 sym[sym_idx].Clear();
                                                                 continue;
@@ -3638,16 +3663,37 @@ ObjectFileMachO::ParseSymtab ()
                         // symbol type.  This is a temporary hack to make sure the ObjectiveC symbols get treated
                         // correctly.  To do this right, we should coalesce all the GSYM & global symbols that have the
                         // same address.
+                        is_gsym = true;
+                        sym[sym_idx].SetExternal(true);
 
-                        if (symbol_name && symbol_name[0] == '_' && symbol_name[1] ==  'O'
-                            && (strncmp (symbol_name, "_OBJC_IVAR_$_", strlen ("_OBJC_IVAR_$_")) == 0
-                                || strncmp (symbol_name, "_OBJC_CLASS_$_", strlen ("_OBJC_CLASS_$_")) == 0
-                                || strncmp (symbol_name, "_OBJC_METACLASS_$_", strlen ("_OBJC_METACLASS_$_")) == 0))
-                            add_nlist = false;
+                        if (symbol_name && symbol_name[0] == '_' && symbol_name[1] ==  'O')
+                        {
+                            llvm::StringRef symbol_name_ref(symbol_name);
+                            if (symbol_name_ref.startswith(g_objc_v2_prefix_class))
+                            {
+                                symbol_name_non_abi_mangled = symbol_name + 1;
+                                symbol_name = symbol_name + g_objc_v2_prefix_class.size();
+                                type = eSymbolTypeObjCClass;
+                                demangled_is_synthesized = true;
+                                
+                            }
+                            else if (symbol_name_ref.startswith(g_objc_v2_prefix_metaclass))
+                            {
+                                symbol_name_non_abi_mangled = symbol_name + 1;
+                                symbol_name = symbol_name + g_objc_v2_prefix_metaclass.size();
+                                type = eSymbolTypeObjCMetaClass;
+                                demangled_is_synthesized = true;
+                            }
+                            else if (symbol_name_ref.startswith(g_objc_v2_prefix_ivar))
+                            {
+                                symbol_name_non_abi_mangled = symbol_name + 1;
+                                symbol_name = symbol_name + g_objc_v2_prefix_ivar.size();
+                                type = eSymbolTypeObjCIVar;
+                                demangled_is_synthesized = true;
+                            }
+                        }
                         else
                         {
-                            is_gsym = true;
-                            sym[sym_idx].SetExternal(true);
                             if (nlist.n_value != 0)
                                 symbol_section = section_info.GetSection (nlist.n_sect, nlist.n_value);
                             type = eSymbolTypeData;
@@ -4087,9 +4133,6 @@ ObjectFileMachO::ParseSymtab ()
                                                 symbol_name[2] == 'B')
                                             {
                                                 llvm::StringRef symbol_name_ref(symbol_name);
-                                                static const llvm::StringRef g_objc_v2_prefix_class ("_OBJC_CLASS_$_");
-                                                static const llvm::StringRef g_objc_v2_prefix_metaclass ("_OBJC_METACLASS_$_");
-                                                static const llvm::StringRef g_objc_v2_prefix_ivar ("_OBJC_IVAR_$_");
                                                 if (symbol_name_ref.startswith(g_objc_v2_prefix_class))
                                                 {
                                                     symbol_name_non_abi_mangled = symbol_name + 1;
@@ -4175,12 +4218,12 @@ ObjectFileMachO::ParseSymtab ()
                         {
                             ConstString const_symbol_name(symbol_name);
                             sym[sym_idx].GetMangled().SetValue(const_symbol_name, symbol_name_is_mangled);
-                            if (is_gsym && is_debug)
-                            {
-                                N_GSYM_name_to_sym_idx[sym[sym_idx].GetMangled().GetName(Mangled::ePreferMangled).GetCString()] = sym_idx;
-                            }
                         }
                     }
+
+                    if (is_gsym)
+                        N_GSYM_name_to_sym_idx[sym[sym_idx].GetMangled().GetName(Mangled::ePreferMangled).GetCString()] = sym_idx;
+
                     if (symbol_section)
                     {
                         const addr_t section_file_addr = symbol_section->GetFileAddress();
@@ -4267,7 +4310,10 @@ ObjectFileMachO::ParseSymtab ()
                                     type = eSymbolTypeResolver;
                             }
                         }
-                        else if (type == eSymbolTypeData)
+                        else if (type == eSymbolTypeData          ||
+                                 type == eSymbolTypeObjCClass     ||
+                                 type == eSymbolTypeObjCMetaClass ||
+                                 type == eSymbolTypeObjCIVar      )
                         {
                             // See if we can find a N_STSYM entry for any data symbols.
                             // If we do find a match, and the name matches, then we
@@ -4308,7 +4354,7 @@ ObjectFileMachO::ParseSymtab ()
                                     sym[GSYM_sym_idx].GetAddress().SetSection (symbol_section);
                                     sym[GSYM_sym_idx].GetAddress().SetOffset (symbol_value);
                                     // We just need the flags from the linker symbol, so put these flags
-                                    // into the N_STSYM flags to avoid duplicate symbols in the symbol table
+                                    // into the N_GSYM flags to avoid duplicate symbols in the symbol table
                                     sym[GSYM_sym_idx].SetFlags (nlist.n_type << 16 | nlist.n_desc);
                                     sym[sym_idx].Clear();
                                     continue;
-- 
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