From d272dce4f855a1819eec4f47e3899a32a8adae67 Mon Sep 17 00:00:00 2001
From: Gary Talent <gtalent2@gmail.com>
Date: Sun, 2 Sep 2018 21:10:32 -0500
Subject: [PATCH] [ox/std] Make asserts generate stack traces

(synced from 0ba964a475331f6d648a3bf93f64a11a971c9c9a)
---
 src/ox/std/CMakeLists.txt |  2 ++
 src/ox/std/assert.cpp     |  4 +++-
 src/ox/std/stacktrace.cpp | 31 +++++++++++++++++++++++++++++++
 src/ox/std/stacktrace.hpp | 20 ++++++++++++++++++++
 src/ox/std/std.hpp        |  1 +
 5 files changed, 57 insertions(+), 1 deletion(-)
 create mode 100644 src/ox/std/stacktrace.cpp
 create mode 100644 src/ox/std/stacktrace.hpp

diff --git a/src/ox/std/CMakeLists.txt b/src/ox/std/CMakeLists.txt
index 7674b732f..b0c3140bb 100644
--- a/src/ox/std/CMakeLists.txt
+++ b/src/ox/std/CMakeLists.txt
@@ -6,6 +6,7 @@ add_library(
 		byteswap.cpp
 		memops.cpp
 		random.cpp
+		stacktrace.cpp
 		strops.cpp
 )
 
@@ -26,6 +27,7 @@ install(
 		memops.hpp
 		new.hpp
 		random.hpp
+		stacktrace.hpp
 		string.hpp
 		strops.hpp
 		std.hpp
diff --git a/src/ox/std/assert.cpp b/src/ox/std/assert.cpp
index 5785a0ec1..b52f8fba9 100644
--- a/src/ox/std/assert.cpp
+++ b/src/ox/std/assert.cpp
@@ -13,6 +13,7 @@
 
 #include <ox/__buildinfo/defines.hpp>
 
+#include "stacktrace.hpp"
 #include "assert.hpp"
 
 namespace ox {
@@ -22,6 +23,7 @@ void _assert<bool>([[maybe_unused]]const char *file, [[maybe_unused]]int line, [
 #if defined(OX_USE_STDLIB)
 	if (!pass) {
 		std::cerr << "\033[31;1;1mASSERT FAILURE:\033[0m (" << file << ':' << line << "): " << msg << std::endl;
+		printStackTrace(2);
 		std::abort();
 	}
 #endif
@@ -37,7 +39,7 @@ void _assert<Error>([[maybe_unused]]const char *file, [[maybe_unused]]int line,
 		if (ei.file != nullptr) {
 			std::cerr << "\tError Location:\t" << reinterpret_cast<const char*>(ei.file) << ':' << ei.line << '\n';
 		}
-		std::cerr << std::flush;
+		printStackTrace(2);
 		std::abort();
 	}
 #endif
diff --git a/src/ox/std/stacktrace.cpp b/src/ox/std/stacktrace.cpp
new file mode 100644
index 000000000..7657ea6e5
--- /dev/null
+++ b/src/ox/std/stacktrace.cpp
@@ -0,0 +1,31 @@
+/*
+ * Copyright 2015 - 2018 gtalent2@gmail.com
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ */
+
+#if defined(OX_USE_STDLIB)
+#include <array>
+#include <execinfo.h>
+#include <iostream>
+#include <unistd.h>
+#endif
+
+#include "stacktrace.hpp"
+
+namespace ox {
+
+void printStackTrace([[maybe_unused]]int shave) {
+#if defined(OX_USE_STDLIB)
+	std::array<void*, 100> frames;
+	auto size = backtrace(frames.data(), frames.size());
+	if (size > shave) {
+		std::cout << "\nStacktrace:\n";
+		backtrace_symbols_fd(frames.data() + shave, size - shave, STDERR_FILENO);
+	}
+#endif
+}
+
+}
diff --git a/src/ox/std/stacktrace.hpp b/src/ox/std/stacktrace.hpp
new file mode 100644
index 000000000..d101c842c
--- /dev/null
+++ b/src/ox/std/stacktrace.hpp
@@ -0,0 +1,20 @@
+/*
+ * Copyright 2015 - 2018 gtalent2@gmail.com
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ */
+
+#pragma once
+
+namespace ox {
+
+/**
+ * Prints a stack trace to stderr.
+ *
+ * @param shave number of call levels to shave off the top
+ */
+void printStackTrace(int shave = 1);
+
+}
diff --git a/src/ox/std/std.hpp b/src/ox/std/std.hpp
index d69184f39..1da4226bf 100644
--- a/src/ox/std/std.hpp
+++ b/src/ox/std/std.hpp
@@ -16,6 +16,7 @@
 #include "memops.hpp"
 #include "new.hpp"
 #include "random.hpp"
+#include "stacktrace.hpp"
 #include "stddef.hpp"
 #include "strops.hpp"
 #include "string.hpp"