Added result type and stacktrace capabilities.

source/mijin/debug/stacktrace.cpp

@@ -0,0 +1,88 @@
+
+#include "./stacktrace.hpp"
+
+#include <cstdint>
+#include <optional>
+#include <string>
+#include <backtrace.h>
+
+namespace mijin
+{
+namespace
+{
+//
+// internal defines
+//
+
+//
+// internal constants
+//
+
+//
+// internal types
+//
+
+struct BacktraceData
+{
+    std::optional<std::string> error;
+    std::vector<Stackframe> stackframes;
+};
+
+//
+// internal variables
+//
+
+//
+// internal functions
+//
+
+int backtraceFullCallback(void* data, std::uintptr_t programCounter, const char* filename, int lineno, const char* function)
+{
+    BacktraceData& btData = *static_cast<BacktraceData*>(data);
+    btData.stackframes.push_back({
+        .address = reinterpret_cast<void*>(programCounter),
+        .filename = filename ? filename : "<unknown>",
+        .function = function ? function : "<unknown>",
+        .lineNumber = lineno
+    });
+    return 0;
+}
+
+void backtraceErrorCallback(void* data, const char* msg, int /* errnum */)
+{
+    BacktraceData& btData = *static_cast<BacktraceData*>(data);
+    btData.error = msg;
+}
+
+backtrace_state* gBacktraceState = nullptr;
+} // namespace
+
+//
+// public functions
+//
+
+Result<Stacktrace> captureStacktrace(unsigned skipFrames) noexcept
+{
+    BacktraceData btData;
+    if (gBacktraceState == nullptr)
+    {
+        gBacktraceState = backtrace_create_state(/*filename = */ nullptr, /* threaded = */ false, &backtraceErrorCallback, &btData);
+    }
+    if (btData.error.has_value())
+    {
+        return ResultError(std::move(*btData.error));
+    }
+    if (gBacktraceState == nullptr)
+    {
+        return ResultError("Error initializing libbacktrace.");
+    }
+    backtrace_full(gBacktraceState, static_cast<int>(skipFrames) + 1, &backtraceFullCallback, &backtraceErrorCallback, &btData);
+    if (btData.error.has_value())
+    {
+        return ResultError(std::move(*btData.error));
+    }
+
+    return Stacktrace(std::move(btData.stackframes));
+}
+
+} // namespace mijin