From 4e190c2e3c3e0c6045bb915537cd70b7be8e98d3 Mon Sep 17 00:00:00 2001
From: Wojtek Figat <wojtek@figat.pl>
Date: Sun, 19 Nov 2023 18:04:24 +0100
Subject: [PATCH] Add decoding stack trace function names on Apple platforms

---
 Source/Engine/Core/Types/StringBuilder.h      |  6 ++++
 .../Engine/Platform/Apple/ApplePlatform.cpp   | 33 ++++++++++++++++---
 Source/Engine/Platform/Base/PlatformBase.cpp  | 11 +++++--
 3 files changed, 43 insertions(+), 7 deletions(-)

diff --git a/Source/Engine/Core/Types/StringBuilder.h b/Source/Engine/Core/Types/StringBuilder.h
index 051554a23..068f245d0 100644
--- a/Source/Engine/Core/Types/StringBuilder.h
+++ b/Source/Engine/Core/Types/StringBuilder.h
@@ -3,6 +3,7 @@
 #pragma once
 
 #include "String.h"
+#include "StringView.h"
 #include "Engine/Core/Collections/Array.h"
 
 /// <summary>
@@ -138,6 +139,11 @@ public:
         _data.Add(*str, str.Length());
         return *this;
     }
+    StringBuilder& Append(const StringView& str)
+    {
+        _data.Add(*str, str.Length());
+        return *this;
+    }
 
     // Append int to the string
     // @param val Value to append
diff --git a/Source/Engine/Platform/Apple/ApplePlatform.cpp b/Source/Engine/Platform/Apple/ApplePlatform.cpp
index c939c1af2..8a2e1d7ef 100644
--- a/Source/Engine/Platform/Apple/ApplePlatform.cpp
+++ b/Source/Engine/Platform/Apple/ApplePlatform.cpp
@@ -43,6 +43,7 @@
 #include <dlfcn.h>
 #if CRASH_LOG_ENABLE
 #include <execinfo.h>
+#include <cxxabi.h>
 #endif
 
 CPUInfo Cpu;
@@ -502,20 +503,42 @@ Array<ApplePlatform::StackFrame> ApplePlatform::GetStackFrames(int32 skipCount,
     {
         char** names = backtrace_symbols(callstack + skipCount, useCount);
         result.Resize(useCount);
+        Array<StringAnsi> parts;
+        int32 len;
+#define COPY_STR(str, dst) \
+    len = Math::Min<int32>(str.Length(), ARRAY_COUNT(frame.dst) - 1); \
+    Platform::MemoryCopy(frame.dst, str.Get(), len); \
+    frame.dst[len] = 0
         for (int32 i = 0; i < useCount; i++)
         {
-            char* name = names[i];
+            const StringAnsi name(names[i]);
             StackFrame& frame = result[i];
             frame.ProgramCounter = callstack[skipCount + i];
             frame.ModuleName[0] = 0;
             frame.FileName[0] = 0;
             frame.LineNumber = 0;
-            int32 nameLen = Math::Min<int32>(StringUtils::Length(name), ARRAY_COUNT(frame.FunctionName) - 1);
-            Platform::MemoryCopy(frame.FunctionName, name, nameLen);
-            frame.FunctionName[nameLen] = 0;
-            
+
+            // Decode name
+            parts.Clear();
+            name.Split(' ', parts);
+            if (parts.Count() == 6)
+            {
+                COPY_STR(parts[1], ModuleName);
+                const StringAnsiView toDemangle(parts[3]);
+                int status = 0;
+                char* demangled = __cxxabiv1::__cxa_demangle(*toDemangle, 0, 0, &status);
+                const StringAnsiView toCopy = demangled && status == 0 ? StringAnsiView(demangled) : StringAnsiView(toDemangle);
+                COPY_STR(toCopy, FunctionName);
+                if (demangled)
+                    free(demangled);
+            }
+            else
+            {
+                COPY_STR(name, FunctionName);
+            }
         }
         free(names);
+#undef COPY_STR
     }
 #endif
     return result;
diff --git a/Source/Engine/Platform/Base/PlatformBase.cpp b/Source/Engine/Platform/Base/PlatformBase.cpp
index d15bec61c..9a6b1b9dc 100644
--- a/Source/Engine/Platform/Base/PlatformBase.cpp
+++ b/Source/Engine/Platform/Base/PlatformBase.cpp
@@ -633,14 +633,21 @@ String PlatformBase::GetStackTrace(int32 skipCount, int32 maxDepth, void* contex
     for (const auto& frame : stackFrames)
     {
         StringAsUTF16<ARRAY_COUNT(StackFrame::FunctionName)> functionName(frame.FunctionName);
+        const StringView functionNameStr(functionName.Get());
         if (StringUtils::Length(frame.FileName) != 0)
         {
             StringAsUTF16<ARRAY_COUNT(StackFrame::FileName)> fileName(frame.FileName);
-            result.AppendFormat(TEXT("   at {0}() in {1}:line {2}\n"), functionName.Get(), fileName.Get(), frame.LineNumber);
+            result.Append(TEXT("   at ")).Append(functionNameStr);
+            if (!functionNameStr.EndsWith(')'))
+                result.Append(TEXT("()"));
+            result.AppendFormat(TEXT("in {0}:line {1}\n"),fileName.Get(), frame.LineNumber);
         }
         else if (StringUtils::Length(frame.FunctionName) != 0)
         {
-            result.AppendFormat(TEXT("   at {0}()\n"), functionName.Get());
+            result.Append(TEXT("   at ")).Append(functionNameStr);
+            if (!functionNameStr.EndsWith(')'))
+                result.Append(TEXT("()"));
+            result.Append('\n');
         }
         else
         {