DBG: use undocumented __unDNameEx function to significantly speed up symbol loading

Before:
Loaded 313534 line infos in 47.406
Loaded 140366 symbols in 171.640

After:
Loaded 313534 line infos in 4.187
Loaded 140366 symbols in 9.391

src/dbg/pdbdiafile.cpp

@@ -1,3 +1,4 @@
+#include "_global.h"
 #include <comutil.h>
 #include <windows.h>
 #include <thread>
@@ -10,6 +11,7 @@
 
 #include "pdbdiafile.h"
 #include "stringutils.h"
+#include "console.h"
 
 volatile LONG PDBDiaFile::m_sbInitialized = 0;
 
@@ -802,6 +804,50 @@ bool PDBDiaFile::resolveSymbolSize(IDiaSymbol* symbol, uint64_t & size, uint32_t
     return res;
 }
 
+typedef char* pchar_t;
+typedef const char* pcchar_t;
+typedef char* (*GetParameter_t)(long n);
+using Alloc_t = decltype(malloc);
+using Free_t = decltype(free);
+
+enum
+{
+    UNDNAME_COMPLETE = 0x0, //Enables full undecoration.
+    UNDNAME_NO_LEADING_UNDERSCORES = 0x1, //Removes leading underscores from Microsoft extended keywords.
+    UNDNAME_NO_MS_KEYWORDS = 0x2, //Disables expansion of Microsoft extended keywords.
+    UNDNAME_NO_FUNCTION_RETURNS = 0x4, //Disables expansion of return type for primary declaration.
+    UNDNAME_NO_ALLOCATION_MODEL = 0x8, //Disables expansion of the declaration model.
+    UNDNAME_NO_ALLOCATION_LANGUAGE = 0x10, //Disables expansion of the declaration language specifier.
+    UNDNAME_NO_MS_THISTYPE = 0x20, //NYI Disable expansion of MS keywords on the 'this' type for primary declaration.
+    UNDNAME_NO_CV_THISTYPE = 0x40, //NYI Disable expansion of CV modifiers on the 'this' type for primary declaration/
+    UNDNAME_NO_THISTYPE = 0x60, //Disables all modifiers on the this type.
+    UNDNAME_NO_ACCESS_SPECIFIERS = 0x80, //Disables expansion of access specifiers for members.
+    UNDNAME_NO_THROW_SIGNATURES = 0x100, //Disables expansion of "throw-signatures" for functions and pointers to functions.
+    UNDNAME_NO_MEMBER_TYPE = 0x200, //Disables expansion of static or virtual members.
+    UNDNAME_NO_RETURN_UDT_MODEL = 0x400, //Disables expansion of the Microsoft model for UDT returns.
+    UNDNAME_32_BIT_DECODE = 0x800, //Undecorates 32-bit decorated names.
+    UNDNAME_NAME_ONLY = 0x1000, //Gets only the name for primary declaration; returns just [scope::]name. Expands template params.
+    UNDNAME_TYPE_ONLY = 0x2000, //Input is just a type encoding; composes an abstract declarator.
+    UNDNAME_HAVE_PARAMETERS = 0x4000, //The real template parameters are available.
+    UNDNAME_NO_ECSU = 0x8000, //Suppresses enum/class/struct/union.
+    UNDNAME_NO_IDENT_CHAR_CHECK = 0x10000, //Suppresses check for valid identifier characters.
+    UNDNAME_NO_PTR64 = 0x20000, //Does not include ptr64 in output.
+};
+
+#if _MSC_VER != 1800
+#error unDNameEx is undocumented and possibly unsupported on your runtime! Uncomment this line if you understand the risks and want continue regardless...
+#endif //_MSC_VER
+
+//undname.cxx
+extern "C" pchar_t __cdecl __unDNameEx(_Out_opt_z_cap_(maxStringLength) pchar_t outputString,
+                                       pcchar_t name,
+                                       int maxStringLength,    // Note, COMMA is leading following optional arguments
+                                       Alloc_t pAlloc,
+                                       Free_t pFree,
+                                       GetParameter_t pGetParameter,
+                                       unsigned long disableFlags
+                                      );
+
 bool PDBDiaFile::convertSymbolInfo(IDiaSymbol* symbol, DiaSymbol_t & symbolInfo, const bool collectUndecoratedNames)
 {
     HRESULT hr;
@@ -825,9 +871,38 @@ bool PDBDiaFile::convertSymbolInfo(IDiaSymbol* symbol, DiaSymbol_t & symbolInfo,
 
     symbolInfo.name = getSymbolNameString(symbol);
 
-    if(collectUndecoratedNames)
+    if(collectUndecoratedNames && !symbolInfo.name.empty() && symbolInfo.name.at(0) == '?')
     {
-        symbolInfo.undecoratedName = getSymbolUndecoratedNameString(symbol);
+        //TODO: undocumented hack to have some kind of performance while undecorating names
+        auto mymalloc = [](size_t size) { return emalloc(size, "convertSymbolInfo::undecoratedName"); };
+        auto myfree = [](void* ptr) { return efree(ptr, "convertSymbolInfo::undecoratedName"); };
+        symbolInfo.undecoratedName.resize(max(512, symbolInfo.name.length() * 2));
+        if(!__unDNameEx((char*)symbolInfo.undecoratedName.data(),
+                        symbolInfo.name.c_str(),
+                        symbolInfo.undecoratedName.size(),
+                        mymalloc,
+                        myfree,
+                        nullptr,
+                        UNDNAME_COMPLETE))
+        {
+            symbolInfo.undecoratedName.clear();
+        }
+        else
+        {
+            symbolInfo.undecoratedName.resize(strlen(symbolInfo.undecoratedName.c_str()));
+            if(symbolInfo.name == symbolInfo.undecoratedName)
+                symbolInfo.undecoratedName = ""; //https://stackoverflow.com/a/18299315
+            /*auto test = getSymbolUndecoratedNameString(symbol); //TODO: this does not appear to work very well
+            if(!symbolInfo.undecoratedName.empty())
+            {
+                if(test != symbolInfo.undecoratedName)
+                {
+                    dprintf("undecoration mismatch, msvcrt: \"%s\", DIA: \"%s\"\n",
+                        symbolInfo.undecoratedName.c_str(),
+                        test.c_str());
+                }
+            }*/
+        }
     }
 
     hr = symbol->get_addressSection((DWORD*)&symbolInfo.segment);

src/dbg/symbolinfo.cpp

@@ -79,10 +79,9 @@ void SymEnum(duint Base, CBSYMBOLENUM EnumCallback, void* UserData)
                         return true;
                 }
 
-                // Convert a mangled/decorated C++ name to a readable format
+                // Don't show duplicated decorated/undecorated names
-                if(info.decoratedName == info.undecoratedName)
+                if(info.undecoratedName.empty() || info.decoratedName == info.undecoratedName)
                 {
-                    curSymbol.decoratedSymbol = curSymbol.undecoratedSymbol;
                     curSymbol.undecoratedSymbol = nullptr;
                 }
 

src/gui/Src/Gui/SymbolView.cpp

@@ -305,10 +305,18 @@ void SymbolView::cbSymbolEnum(SYMBOLINFO* symbol, void* user)
     {
         symbolList->setCellContent(index, 2, symbol->decoratedSymbol);
     }
+    else
+    {
+        symbolList->setCellContent(index, 2, QString());
+    }
     if(symbol->undecoratedSymbol)
     {
         symbolList->setCellContent(index, 3, symbol->undecoratedSymbol);
     }
+    else
+    {
+        symbolList->setCellContent(index, 3, QString());
+    }
 
     if(symbol->isImported)
     {