except: move posix/win32 exceptions to own units

posix/except.cpp

@@ -0,0 +1,99 @@
+/*
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ * Copyright 2010, 2017,
+ *     Danny Robson <danny@nerdcruft.net>
+ */
+
+#include "except.hpp"
+
+#include "../debug.hpp"
+
+#include <cstring>
+
+using util::posix::error;
+
+
+///////////////////////////////////////////////////////////////////////////////
+/// Construct an exception object from a given error value.
+///
+/// The error value MUST be an error at construction time.
+error::error (int _code):
+    std::runtime_error (::strerror (_code)),
+    m_code (_code)
+{
+    CHECK_NEQ (_code, 0);
+}
+
+
+///----------------------------------------------------------------------------
+/// Construct an exception object from the current value of errno.
+///
+/// errno MUST signal an error at construction time.
+error::error ():
+    error (last_code ())
+{
+    CHECK_NEQ (m_code, 0);
+}
+
+
+///////////////////////////////////////////////////////////////////////////////
+int
+error::last_code (void)
+{
+    return errno;
+}
+
+
+//-----------------------------------------------------------------------------
+int
+error::code (void) const
+{
+    return m_code;
+}
+
+
+///////////////////////////////////////////////////////////////////////////////
+/// Throw an exception object if errno currently signals an error.
+void
+error::try_code (void)
+{
+    try_code (last_code ());
+}
+
+
+///----------------------------------------------------------------------------
+/// Throw an exception object if 'code' represents an error.
+void
+error::try_code (int code)
+{
+    if (__builtin_expect (code != 0, false))
+        throw error (code);
+}
+
+
+///----------------------------------------------------------------------------
+void
+error::throw_code (void)
+{
+    throw_code (last_code ());
+}
+
+
+///----------------------------------------------------------------------------
+void
+error::throw_code (int code)
+{
+    CHECK_NEQ (code, 0);
+    throw error (code);
+}

posix/except.hpp

@@ -0,0 +1,55 @@
+/*
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ * Copyright 2010, 2017,
+ *     Danny Robson <danny@nerdcruft.net>
+ */
+
+#ifndef CRUFT_UTIL_POSIX_EXCEPT_HPP
+#define CRUFT_UTIL_POSIX_EXCEPT_HPP
+
+#include <stdexcept>
+
+namespace util::posix {
+    /// An exception class used for reporting errors signalled by errno.
+    ///
+    /// Ideally this would be named `errno' but that symbol is permitted to
+    /// be a macro and significantly complicates symbol resolution either way.
+    class error : public std::runtime_error {
+    public:
+        explicit error (int code);
+        error ();
+
+        int code (void) const;
+        static int last_code (void);
+
+        static void try_code (void);
+        static void try_code (int code);
+
+        static void throw_code [[gnu::noreturn]] (void);
+        static void throw_code [[gnu::noreturn]] (int code);
+
+        template <typename T>
+        static T try_value (T value)
+        {
+            if (value < 0)
+                throw_code ();
+            return value;
+        }
+
+    private:
+        int m_code;
+    };
+}
+
+#endif

win32/except.cpp

@@ -0,0 +1,119 @@
+/*
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ * Copyright 2010, 2017
+ *     Danny Robson <danny@nerdcruft.net>
+ */
+
+#include "except.hpp"
+
+#include "../debug.hpp"
+
+using util::win32::error;
+
+
+///////////////////////////////////////////////////////////////////////////////
+error::error (DWORD _code):
+    runtime_error (code_string (_code)),
+    m_code (_code)
+{
+    CHECK_NEQ (m_code, (DWORD)ERROR_SUCCESS);
+}
+
+
+//-----------------------------------------------------------------------------
+error::error (void):
+    error (last_code ())
+{ ; }
+
+
+///////////////////////////////////////////////////////////////////////////////
+DWORD
+error::code (void) const
+{
+    return m_code;
+}
+
+
+//-----------------------------------------------------------------------------
+DWORD
+error::last_code (void)
+{
+    return GetLastError ();
+}
+
+
+///////////////////////////////////////////////////////////////////////////////
+void
+error::try_code (void)
+{
+    try_code (last_code ());
+}
+
+
+//-----------------------------------------------------------------------------
+void
+error::try_code (DWORD id)
+{
+    if (__builtin_expect (id != ERROR_SUCCESS, false))
+        throw_code (id);
+}
+
+
+//-----------------------------------------------------------------------------
+void
+error::throw_code (void)
+{
+    throw_code (last_code ());
+}
+
+
+//-----------------------------------------------------------------------------
+void
+error::throw_code (DWORD code)
+{
+    CHECK_NEQ (code, (DWORD)ERROR_SUCCESS);
+    throw error (code);
+}
+
+
+//-----------------------------------------------------------------------------
+std::string
+error::code_string (void)
+{
+    return code_string (last_code ());
+}
+
+
+//-----------------------------------------------------------------------------
+std::string
+error::code_string (DWORD code)
+{
+    char message[256];
+
+    auto res = FormatMessage (
+        FORMAT_MESSAGE_FROM_SYSTEM,
+        NULL,
+        code,
+        MAKELANGID (LANG_NEUTRAL, SUBLANG_DEFAULT),
+        message,
+        std::size (message),
+        NULL
+    );
+
+    if (res == 0) {
+        error::throw_code ();
+    }
+
+    return std::string (message, message + res);
+}

win32/except.hpp

@@ -0,0 +1,47 @@
+/*
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ * Copyright 2010, 2017
+ *     Danny Robson <danny@nerdcruft.net>
+ */
+
+#ifndef CRUFT_UTIL_WIN32_EXCEPT_HPP
+#define CRUFT_UTIL_WIN32_EXCEPT_HPP
+
+#include <stdexcept>
+#include <windows.h>
+
+namespace util::win32 {
+    class error : public std::runtime_error {
+    public:
+        explicit error (DWORD _code);
+        error ();
+
+        DWORD code (void) const;
+        static DWORD last_code (void);
+
+        static void try_code (void);
+        static void try_code (DWORD);
+
+        static void throw_code [[gnu::noreturn]] (void);
+        static void throw_code [[gnu::noreturn]] (DWORD);
+
+        static std::string code_string (void);
+        static std::string code_string (DWORD);
+
+    private:
+        DWORD m_code;
+    };
+}
+
+#endif