Add an exception class to cover backend creation and opening

2 files changed, 48 insertions, 0 deletions

diff --git a/common/alexcpt.cpp b/common/alexcpt.cpp
new file mode 100644
index 00000000..21508b13
--- /dev/null
+++ b/common/alexcpt.cpp
@@ -0,0 +1,30 @@
+
+#include "config.h"
+
+#include "alexcpt.h"
+
+#include <cstdio>
+#include <cstdarg>
+
+#include "opthelpers.h"
+
+
+namespace al {
+
+backend_exception::backend_exception(ALCenum code, const char *msg, ...) : mErrorCode{code}
+{
+    va_list args, args2;
+    va_start(args, msg);
+    va_copy(args2, args);
+    int msglen{std::vsnprintf(nullptr, 0, msg, args)};
+    if(UNLIKELY(msglen > 0))
+    {
+        mMessage.resize(static_cast<size_t>(msglen)+1);
+        std::vsnprintf(&mMessage[0], mMessage.length(), msg, args2);
+        mMessage.pop_back();
+    }
+    va_end(args2);
+    va_end(args);
+}
+
+} // namespace al
diff --git a/common/alexcpt.h b/common/alexcpt.h
index 3e31667e..b4f6f55e 100644
--- a/common/alexcpt.h
+++ b/common/alexcpt.h
@@ -2,7 +2,25 @@
 #define ALEXCPT_H
 
 #include <exception>
+#include <string>
 
+#include "AL/alc.h"
+
+
+namespace al {
+
+class backend_exception final : public std::exception {
+    std::string mMessage;
+    ALCenum mErrorCode;
+
+public:
+    backend_exception(ALCenum code, const char *msg, ...);
+
+    const char *what() const noexcept override { return mMessage.c_str(); }
+    ALCenum errorCode() const noexcept { return mErrorCode; }
+};
+
+} // namespace al
 
 #define START_API_FUNC try