improved assert (#37)

- Improvement: Add file and line to ASSERT exceptions
- Improvement: Catch call stack when throwing assert exceptions and log/output call stack at important places to provide more context to caller

9 files changed, 427 insertions, 31 deletions

diff --git a/src/zencore/callstack.cpp b/src/zencore/callstack.cpp
new file mode 100644
index 000000000..905ab3d9e
--- /dev/null
+++ b/src/zencore/callstack.cpp
@@ -0,0 +1,221 @@
+// Copyright Epic Games, Inc. All Rights Reserved.
+
+#include <zencore/callstack.h>
+#include <zencore/thread.h>
+
+#if ZEN_PLATFORM_WINDOWS
+#	include <zencore/windows.h>
+#	include <Dbghelp.h>
+#endif
+
+#if ZEN_PLATFORM_LINUX || ZEN_PLATFORM_MAC
+#	include <execinfo.h>
+#endif
+
+#if ZEN_WITH_TESTS
+#	include <zencore/testing.h>
+#endif
+
+#include <fmt/format.h>
+
+namespace zen {
+#if ZEN_PLATFORM_WINDOWS
+
+class WinSymbolInit
+{
+public:
+	WinSymbolInit() {}
+	~WinSymbolInit()
+	{
+		m_CallstackLock.WithExclusiveLock([this]() {
+			if (m_Initialized)
+			{
+				SymCleanup(m_CurrentProcess);
+			}
+		});
+	}
+
+	bool GetSymbol(void* Frame, SYMBOL_INFO* OutSymbolInfo, DWORD64& OutDisplacement)
+	{
+		bool Result = false;
+		m_CallstackLock.WithExclusiveLock([&]() {
+			if (!m_Initialized)
+			{
+				m_CurrentProcess = GetCurrentProcess();
+				if (SymInitialize(m_CurrentProcess, NULL, TRUE) == TRUE)
+				{
+					m_Initialized = true;
+				}
+			}
+			if (m_Initialized)
+			{
+				if (SymFromAddr(m_CurrentProcess, (DWORD64)Frame, &OutDisplacement, OutSymbolInfo) == TRUE)
+				{
+					Result = true;
+				}
+			}
+		});
+		return Result;
+	}
+
+private:
+	HANDLE m_CurrentProcess = NULL;
+	BOOL   m_Initialized	= FALSE;
+	RwLock m_CallstackLock;
+};
+
+static WinSymbolInit WinSymbols;
+
+#endif
+
+CallstackFrames*
+CreateCallstack(uint32_t FrameCount, void** Frames) noexcept
+{
+	if (FrameCount == 0)
+	{
+		return nullptr;
+	}
+	CallstackFrames* Callstack = (CallstackFrames*)malloc(sizeof(CallstackFrames) + sizeof(void*) * FrameCount);
+	if (Callstack != nullptr)
+	{
+		Callstack->FrameCount = FrameCount;
+		if (FrameCount == 0)
+		{
+			Callstack->Frames = nullptr;
+		}
+		else
+		{
+			Callstack->Frames = (void**)&Callstack[1];
+			memcpy(Callstack->Frames, Frames, sizeof(void*) * FrameCount);
+		}
+	}
+	return Callstack;
+}
+
+CallstackFrames*
+CloneCallstack(const CallstackFrames* Callstack) noexcept
+{
+	if (Callstack == nullptr)
+	{
+		return nullptr;
+	}
+	return CreateCallstack(Callstack->FrameCount, Callstack->Frames);
+}
+
+void
+FreeCallstack(CallstackFrames* Callstack) noexcept
+{
+	if (Callstack != nullptr)
+	{
+		free(Callstack);
+	}
+}
+
+uint32_t
+GetCallstack(int FramesToSkip, int FramesToCapture, void* OutAddresses[])
+{
+#if ZEN_PLATFORM_WINDOWS
+	return (uint32_t)CaptureStackBackTrace(FramesToSkip, FramesToCapture, OutAddresses, 0);
+#endif
+#if ZEN_PLATFORM_LINUX || ZEN_PLATFORM_MAC
+	void* Frames[FramesToSkip + FramesToCapture];
+	int	  FrameCount = backtrace(Frames, FramesToSkip + FramesToCapture);
+	if (FrameCount > FramesToSkip)
+	{
+		for (int Index = FramesToSkip; Index < FrameCount; Index++)
+		{
+			OutAddresses[Index - FramesToSkip] = Frames[Index];
+		}
+		return (uint32_t)(FrameCount - FramesToSkip);
+	}
+	else
+	{
+		return 0;
+	}
+#endif
+}
+
+std::vector<std::string>
+GetFrameSymbols(uint32_t FrameCount, void** Frames)
+{
+	std::vector<std::string> FrameSymbols;
+	if (FrameCount > 0)
+	{
+		FrameSymbols.resize(FrameCount);
+#if ZEN_PLATFORM_WINDOWS
+		char		 SymbolBuffer[sizeof(SYMBOL_INFO) + 1024];
+		SYMBOL_INFO* SymbolInfo	 = (SYMBOL_INFO*)SymbolBuffer;
+		SymbolInfo->SizeOfStruct = sizeof(SYMBOL_INFO);
+		SymbolInfo->MaxNameLen	 = 1023;
+		DWORD64 Displacement	 = 0;
+		for (uint32_t FrameIndex = 0; FrameIndex < FrameCount; FrameIndex++)
+		{
+			if (WinSymbols.GetSymbol(Frames[FrameIndex], SymbolInfo, Displacement))
+			{
+				FrameSymbols[FrameIndex] = fmt::format("{}+{:#x} [{:#x}]", SymbolInfo->Name, Displacement, (uintptr_t)Frames[FrameIndex]);
+			}
+		}
+#endif
+#if ZEN_PLATFORM_LINUX || ZEN_PLATFORM_MAC
+		char** messages = backtrace_symbols(Frames, (int)FrameCount);
+		if (messages)
+		{
+			for (uint32_t FrameIndex = 0; FrameIndex < FrameCount; FrameIndex++)
+			{
+				FrameSymbols[FrameIndex] = messages[FrameIndex];
+			}
+			free(messages);
+		}
+#endif
+	}
+	return FrameSymbols;
+}
+
+void
+FormatCallstack(const CallstackFrames* Callstack, StringBuilderBase& SB)
+{
+	bool First = true;
+	for (const std::string& Symbol : GetFrameSymbols(Callstack))
+	{
+		if (!First)
+		{
+			SB.Append("\n");
+		}
+		else
+		{
+			First = false;
+		}
+		SB.Append(Symbol);
+	}
+}
+
+std::string
+CallstackToString(const CallstackFrames* Callstack)
+{
+	StringBuilder<2048> SB;
+	FormatCallstack(Callstack, SB);
+	return SB.ToString();
+}
+
+#if ZEN_WITH_TESTS
+
+TEST_CASE("Callstack.Basic")
+{
+	void*	 Addresses[4];
+	uint32_t FrameCount = GetCallstack(1, 4, Addresses);
+	CHECK(FrameCount > 0);
+	std::vector<std::string> Symbols = GetFrameSymbols(FrameCount, Addresses);
+	for (const std::string& Symbol : Symbols)
+	{
+		CHECK(!Symbol.empty());
+	}
+}
+
+void
+callstack_forcelink()
+{
+}
+
+#endif
+
+}  // namespace zen
diff --git a/src/zencore/filesystem.cpp b/src/zencore/filesystem.cpp
index 3e94b550f..ca2b3101f 100644
--- a/src/zencore/filesystem.cpp
+++ b/src/zencore/filesystem.cpp
@@ -730,7 +730,7 @@ CopyTree(std::filesystem::path FromPath, std::filesystem::path ToPath, const Cop
 						throw std::runtime_error("CopyFile failed in an unexpected way");
 					}
 				}
-				catch (std::exception& Ex)
+				catch (const std::exception& Ex)
 				{
 					++FailedFileCount;
 
diff --git a/src/zencore/include/zencore/callstack.h b/src/zencore/include/zencore/callstack.h
new file mode 100644
index 000000000..02ba8b3c3
--- /dev/null
+++ b/src/zencore/include/zencore/callstack.h
@@ -0,0 +1,37 @@
+// Copyright Epic Games, Inc. All Rights Reserved.
+
+#pragma once
+
+#include <zencore/zencore.h>
+
+#include <zencore/string.h>
+
+#include <string>
+#include <vector>
+
+namespace zen {
+
+struct CallstackFrames
+{
+	uint32_t FrameCount;
+	void**	 Frames;
+};
+
+CallstackFrames* CreateCallstack(uint32_t FrameCount, void** Frames) noexcept;
+CallstackFrames* CloneCallstack(const CallstackFrames* Callstack) noexcept;
+void			 FreeCallstack(CallstackFrames* Callstack) noexcept;
+
+uint32_t				 GetCallstack(int FramesToSkip, int FramesToCapture, void* OutAddresses[]);
+std::vector<std::string> GetFrameSymbols(uint32_t FrameCount, void** Frames);
+inline std::vector<std::string>
+GetFrameSymbols(const CallstackFrames* Callstack)
+{
+	return GetFrameSymbols(Callstack ? Callstack->FrameCount : 0, Callstack ? Callstack->Frames : nullptr);
+}
+
+void		FormatCallstack(const CallstackFrames* Callstack, StringBuilderBase& SB);
+std::string CallstackToString(const CallstackFrames* Callstack);
+
+void callstack_forcelink();	 // internal
+
+}  // namespace zen
diff --git a/src/zencore/include/zencore/scopeguard.h b/src/zencore/include/zencore/scopeguard.h
index d04c8ed9c..3fd0564f6 100644
--- a/src/zencore/include/zencore/scopeguard.h
+++ b/src/zencore/include/zencore/scopeguard.h
@@ -21,7 +21,11 @@ public:
 			{
 				m_guardFunc();
 			}
-			catch (std::exception& Ex)
+			catch (const AssertException& Ex)
+			{
+				ZEN_ERROR("Assert exception in scope guard: {}", Ex.FullDescription());
+			}
+			catch (const std::exception& Ex)
 			{
 				ZEN_ERROR("scope guard threw exception: '{}'", Ex.what());
 			}
diff --git a/src/zencore/include/zencore/zencore.h b/src/zencore/include/zencore/zencore.h
index 1a9060e29..cd1a34c7b 100644
--- a/src/zencore/include/zencore/zencore.h
+++ b/src/zencore/include/zencore/zencore.h
@@ -24,34 +24,63 @@
 #endif
 
 namespace zen {
+
+struct CallstackFrames;
+
 class AssertException : public std::logic_error
 {
 public:
-	inline explicit AssertException(const char* Msg) : std::logic_error(Msg) {}
+	using _Mybase = std::logic_error;
+
+	virtual ~AssertException() noexcept;
+
+	inline AssertException(const char* Msg, struct CallstackFrames* Callstack) noexcept : _Mybase(Msg), _Callstack(Callstack) {}
+
+	AssertException(const AssertException& Rhs) noexcept;
+
+	AssertException(AssertException&& Rhs) noexcept;
+
+	AssertException& operator=(const AssertException& Rhs) noexcept;
+
+	std::string FullDescription() const noexcept;
+
+	struct CallstackFrames* _Callstack = nullptr;
 };
 
 struct AssertImpl
 {
+	ZEN_FORCENOINLINE ZEN_DEBUG_SECTION AssertImpl() : PrevAssertImpl(CurrentAssertImpl) { CurrentAssertImpl = this; }
+	virtual ZEN_FORCENOINLINE			ZEN_DEBUG_SECTION ~AssertImpl() { CurrentAssertImpl = PrevAssertImpl; }
+
 	static void ZEN_FORCENOINLINE ZEN_DEBUG_SECTION ExecAssert
 		[[noreturn]] (const char* Filename, int LineNumber, const char* FunctionName, const char* Msg)
 	{
-		CurrentAssertImpl->OnAssert(Filename, LineNumber, FunctionName, Msg);
-		throw AssertException{Msg};
+		AssertImpl* AssertImpl = CurrentAssertImpl;
+		while (AssertImpl)
+		{
+			AssertImpl->OnAssert(Filename, LineNumber, FunctionName, Msg);
+			AssertImpl = AssertImpl->PrevAssertImpl;
+		}
+		ThrowAssertException(Filename, LineNumber, FunctionName, Msg);
 	}
 
-protected:
 	virtual void ZEN_FORCENOINLINE ZEN_DEBUG_SECTION OnAssert(const char* Filename,
 															  int		  LineNumber,
 															  const char* FunctionName,
 															  const char* Msg)
 	{
-		(void(Filename));
-		(void(LineNumber));
-		(void(FunctionName));
-		(void(Msg));
+		ZEN_UNUSED(Filename);
+		ZEN_UNUSED(LineNumber);
+		ZEN_UNUSED(FunctionName);
+		ZEN_UNUSED(Msg);
 	}
-	static AssertImpl  DefaultAssertImpl;
+
+protected:
+	static void ZEN_FORCENOINLINE ZEN_DEBUG_SECTION ThrowAssertException
+		[[noreturn]] (const char* Filename, int LineNumber, const char* FunctionName, const char* Msg);
 	static AssertImpl* CurrentAssertImpl;
+	static AssertImpl  DefaultAssertImpl;
+	AssertImpl*		   PrevAssertImpl = nullptr;
 };
 
 }  // namespace zen
diff --git a/src/zencore/jobqueue.cpp b/src/zencore/jobqueue.cpp
index 86c08cda9..d26d0dd1e 100644
--- a/src/zencore/jobqueue.cpp
+++ b/src/zencore/jobqueue.cpp
@@ -69,7 +69,7 @@ public:
 				Stop();
 			}
 		}
-		catch (std::exception& Ex)
+		catch (const std::exception& Ex)
 		{
 			ZEN_WARN("Failed shutting down jobqueue. Reason: '{}'", Ex.what());
 		}
@@ -106,7 +106,7 @@ public:
 			});
 			return {.Id = NewJobId};
 		}
-		catch (std::exception& Ex)
+		catch (const std::exception& Ex)
 		{
 			WorkerCounter.CountDown();
 			QueueLock.WithExclusiveLock([&]() {
@@ -359,7 +359,18 @@ public:
 				CompletedJobs.insert_or_assign(CurrentJob->Id.Id, std::move(CurrentJob));
 			});
 		}
-		catch (std::exception& Ex)
+		catch (const AssertException& Ex)
+		{
+			ZEN_DEBUG("Background job {}:'{}' asserted. Reason: {}", CurrentJob->Id.Id, CurrentJob->Name, Ex.FullDescription());
+			QueueLock.WithExclusiveLock([&]() {
+				CurrentJob->State.AbortReason = Ex.FullDescription();
+				CurrentJob->EndTick			  = JobClock::Now();
+				CurrentJob->WorkerThreadId	  = 0;
+				RunningJobs.erase(CurrentJob->Id.Id);
+				AbortedJobs.insert_or_assign(CurrentJob->Id.Id, std::move(CurrentJob));
+			});
+		}
+		catch (const std::exception& Ex)
 		{
 			ZEN_DEBUG("Background job {}:'{}' aborted. Reason: '{}'", CurrentJob->Id.Id, CurrentJob->Name, Ex.what());
 			QueueLock.WithExclusiveLock([&]() {
diff --git a/src/zencore/workthreadpool.cpp b/src/zencore/workthreadpool.cpp
index 16b2310ff..f41c13bf6 100644
--- a/src/zencore/workthreadpool.cpp
+++ b/src/zencore/workthreadpool.cpp
@@ -186,7 +186,13 @@ WorkerThreadPool::Impl::WorkerThreadFunction(ThreadStartInfo Info)
 				ZEN_TRACE_CPU_FLUSH("AsyncWork");
 				Work->Execute();
 			}
-			catch (std::exception& e)
+			catch (const AssertException& Ex)
+			{
+				Work->m_Exception = std::current_exception();
+
+				ZEN_WARN("Assert exception in worker thread: {}", Ex.FullDescription());
+			}
+			catch (const std::exception& e)
 			{
 				Work->m_Exception = std::current_exception();
 
@@ -234,7 +240,13 @@ WorkerThreadPool::ScheduleWork(Ref<IWork> Work)
 			ZEN_TRACE_CPU_FLUSH("SyncWork");
 			Work->Execute();
 		}
-		catch (std::exception& e)
+		catch (const AssertException& Ex)
+		{
+			Work->m_Exception = std::current_exception();
+
+			ZEN_WARN("Assert exception in worker thread: {}", Ex.FullDescription());
+		}
+		catch (const std::exception& e)
 		{
 			Work->m_Exception = std::current_exception();
 
diff --git a/src/zencore/xmake.lua b/src/zencore/xmake.lua
index e6102679d..5f2d95e16 100644
--- a/src/zencore/xmake.lua
+++ b/src/zencore/xmake.lua
@@ -53,6 +53,7 @@ target('zencore')
 
     if is_plat("windows") then
         add_syslinks("Advapi32")
+        add_syslinks("Dbghelp")
         add_syslinks("Shell32")
         add_syslinks("User32")
         add_syslinks("crypt32")
diff --git a/src/zencore/zencore.cpp b/src/zencore/zencore.cpp
index c97f5e5ca..c4fcc89de 100644
--- a/src/zencore/zencore.cpp
+++ b/src/zencore/zencore.cpp
@@ -6,12 +6,9 @@
 #	include <zencore/windows.h>
 #endif
 
-#if ZEN_PLATFORM_LINUX
-#	include <pthread.h>
-#endif
-
 #include <zencore/assertfmt.h>
 #include <zencore/blake3.h>
+#include <zencore/callstack.h>
 #include <zencore/compactbinary.h>
 #include <zencore/compactbinarybuilder.h>
 #include <zencore/compactbinarypackage.h>
@@ -55,10 +52,59 @@ ExecAssertFmt(const char* Filename, int LineNumber, const char* FunctionName, st
 
 namespace zen {
 
+AssertException::AssertException(const AssertException& Rhs) noexcept : _Mybase(Rhs), _Callstack(CloneCallstack(Rhs._Callstack))
+{
+}
+
+AssertException::AssertException(AssertException&& Rhs) noexcept : _Mybase(Rhs), _Callstack(Rhs._Callstack)
+{
+	Rhs._Callstack = nullptr;
+}
+
+AssertException::~AssertException() noexcept
+{
+	FreeCallstack(_Callstack);
+}
+
+AssertException&
+AssertException::operator=(const AssertException& Rhs) noexcept
+{
+	_Mybase::operator=(Rhs);
+
+	CallstackFrames* Callstack = CloneCallstack(Rhs._Callstack);
+	std::swap(_Callstack, Callstack);
+	FreeCallstack(Callstack);
+	return *this;
+}
+
+std::string
+AssertException::FullDescription() const noexcept
+{
+	if (_Callstack)
+	{
+		return fmt::format("'{}'\n{}", what(), CallstackToString(_Callstack));
+	}
+	return what();
+}
+
+void
+AssertImpl::ThrowAssertException(const char* Filename, int LineNumber, const char* FunctionName, const char* Msg)
+{
+	ZEN_UNUSED(FunctionName);
+	fmt::basic_memory_buffer<char, 2048> Message;
+	auto								 Appender = fmt::appender(Message);
+	fmt::format_to(Appender, "{}({}): {}", Filename, LineNumber, Msg);
+	Message.push_back('\0');
+
+	void*	 Frames[8];
+	uint32_t FrameCount = GetCallstack(3, 8, Frames);
+	throw AssertException(Message.data(), CreateCallstack(FrameCount, Frames));
+}
+
 void refcount_forcelink();
 
+AssertImpl* AssertImpl::CurrentAssertImpl = nullptr;
 AssertImpl	AssertImpl::DefaultAssertImpl;
-AssertImpl* AssertImpl::CurrentAssertImpl = &AssertImpl::DefaultAssertImpl;
 
 //////////////////////////////////////////////////////////////////////////
 
@@ -138,6 +184,7 @@ void
 zencore_forcelinktests()
 {
 	zen::blake3_forcelink();
+	zen::callstack_forcelink();
 	zen::compositebuffer_forcelink();
 	zen::compress_forcelink();
 	zen::crypto_forcelink();
@@ -174,24 +221,24 @@ TEST_SUITE_BEGIN("core.assert");
 
 TEST_CASE("Assert.Default")
 {
-	bool A = true;
-	bool B = false;
-	CHECK_THROWS_WITH(ZEN_ASSERT(A == B), "A == B");
+	bool		A		 = true;
+	bool		B		 = false;
+	std::string Expected = fmt::format("{}({}): {}", __FILE__, __LINE__ + 1, "A == B");
+	CHECK_THROWS_WITH(ZEN_ASSERT(A == B), Expected.c_str());
 }
 
 TEST_CASE("Assert.Format")
 {
-	bool A = true;
-	bool B = false;
-	CHECK_THROWS_WITH(ZEN_ASSERT_FORMAT(A == B, "{} == {}", A, B), "assert(A == B) failed: true == false");
+	bool		A		 = true;
+	bool		B		 = false;
+	std::string Expected = fmt::format("{}({}): {}", __FILE__, __LINE__ + 1, "assert(A == B) failed: true == false");
+	CHECK_THROWS_WITH(ZEN_ASSERT_FORMAT(A == B, "{} == {}", A, B), Expected.c_str());
 }
 
 TEST_CASE("Assert.Custom")
 {
 	struct MyAssertImpl : AssertImpl
 	{
-		ZEN_FORCENOINLINE ZEN_DEBUG_SECTION				 MyAssertImpl() : PrevAssertImpl(CurrentAssertImpl) { CurrentAssertImpl = this; }
-		virtual ZEN_FORCENOINLINE						 ZEN_DEBUG_SECTION ~MyAssertImpl() { CurrentAssertImpl = PrevAssertImpl; }
 		virtual void ZEN_FORCENOINLINE ZEN_DEBUG_SECTION OnAssert(const char* Filename,
 																  int		  LineNumber,
 																  const char* FunctionName,
@@ -202,7 +249,7 @@ TEST_CASE("Assert.Custom")
 			FuncName	   = FunctionName;
 			Message		   = Msg;
 		}
-		AssertImpl* PrevAssertImpl;
+		AssertImpl* PrevAssertImpl = nullptr;
 
 		const char* AssertFileName = nullptr;
 		int			Line		   = -1;
@@ -213,13 +260,47 @@ TEST_CASE("Assert.Custom")
 	MyAssertImpl MyAssert;
 	bool		 A = true;
 	bool		 B = false;
-	CHECK_THROWS_WITH(ZEN_ASSERT(A == B), "A == B");
+	CHECK_THROWS_WITH(ZEN_ASSERT(A == B), std::string(fmt::format("{}({}): {}", __FILE__, __LINE__, "A == B")).c_str());
 	CHECK(MyAssert.AssertFileName != nullptr);
 	CHECK(MyAssert.Line != -1);
 	CHECK(MyAssert.FuncName != nullptr);
 	CHECK(strcmp(MyAssert.Message, "A == B") == 0);
 }
 
+TEST_CASE("Assert.Callstack")
+{
+	try
+	{
+		ZEN_ASSERT(false);
+	}
+	catch (const AssertException& Assert)
+	{
+		ZEN_INFO("Assert failed: {}", Assert.what());
+		CHECK(Assert._Callstack->FrameCount > 0);
+		CHECK(Assert._Callstack->Frames != nullptr);
+		ZEN_INFO("Callstack:\n{}", CallstackToString(Assert._Callstack));
+	}
+
+	WorkerThreadPool Pool(1);
+	auto			 Task = Pool.EnqueueTask(std::packaged_task<int()>{[] {
+		ZEN_ASSERT(false);
+		return 1;
+	}});
+
+	try
+	{
+		(void)Task.get();
+		CHECK(false);
+	}
+	catch (const AssertException& Assert)
+	{
+		ZEN_INFO("Assert in future: {}", Assert.what());
+		CHECK(Assert._Callstack->FrameCount > 0);
+		CHECK(Assert._Callstack->Frames != nullptr);
+		ZEN_INFO("Callstack:\n{}", CallstackToString(Assert._Callstack));
+	}
+}
+
 TEST_SUITE_END();
 #endif