1 files changed, 162 insertions, 0 deletions
diff --git a/include/flatcc/portable/pstdalign.h b/include/flatcc/portable/pstdalign.h
new file mode 100644
index 0000000..169fe27
--- /dev/null
+++ b/include/flatcc/portable/pstdalign.h
@@ -0,0 +1,162 @@
+#ifndef PSTDALIGN_H
+#define PSTDALIGN_H
+
+/*
+ * NOTE: aligned_alloc is defined via paligned_alloc.h
+ * and requires aligned_free to be fully portable although
+ * free also works on C11 and platforms with posix_memalign.
+ *
+ * NOTE: C++11 defines alignas as a keyword but then also defines
+ * __alignas_is_defined.
+ *
+ * C++14 does not define __alignas_is_defined, at least sometimes.
+ *
+ * GCC 8.3 reverts on this and makes C++11 behave the same as C++14
+ * preventing a simple __cplusplus version check from working.
+ *
+ * Clang C++ without std=c++11 or std=c++14 does define alignas
+ * but does so incorrectly wrt. C11 and C++11 semantics because
+ * `alignas(4) float x;` is not recognized.
+ * To fix such issues, either move to a std version, or
+ * include a working stdalign.h for the given compiler before
+ * this file.
+ *
+ * newlib defines _Alignas and _Alignof in sys/cdefs but rely on
+ * gcc version for <stdaligh.h> which can lead to conflicts if
+ * stdalign is not included.
+ *
+ * newlibs need for <stdalign.h> conflicts with broken C++ stdalign
+ * but this can be fixed be using std=C++11 or newer.
+ *
+ * MSVC does not support <stdalign.h> at least up to MSVC 2015,
+ * but does appear to support alignas and alignof keywords in
+ * recent standard C++.
+ *
+ * TCC only supports alignas with a numeric argument like
+ * `alignas(4)`, but not `alignas(float)`.
+ *
+ * If stdalign.h is supported but heuristics in this file are
+ * insufficient to detect this, try including <stdaligh.h> manually
+ * or define HAVE_STDALIGN_H.
+ */
+
+/* https://github.com/dvidelabs/flatcc/issues/130 */
+#ifndef __alignas_is_defined
+#if defined(__cplusplus)
+#if __cplusplus == 201103 && !defined(__clang__) && ((__GNUC__ > 8) || (__GNUC__ == 8 && __GNUC_MINOR__ >= 3))
+#define __alignas_is_defined 1
+#define __alignof_is_defined 1
+#include <stdalign.h>
+#endif
+#endif
+#endif
+
+/* Allow for alternative solution to be included first. */
+#ifndef __alignas_is_defined
+
+#ifdef __cplusplus
+#if defined(PORTABLE_PATCH_CPLUSPLUS_STDALIGN)
+#include <stdalign.h>
+#undef alignas
+#define alignas(t) __attribute__((__aligned__(t)))
+#endif
+#endif
+
+#if !defined(PORTABLE_HAS_INCLUDE_STDALIGN)
+#if defined(__has_include)
+#if __has_include(<stdalign.h>)
+#define PORTABLE_HAS_INCLUDE_STDALIGN 1
+#else
+#define PORTABLE_HAS_INCLUDE_STDALIGN 0
+#endif
+#endif
+#endif
+
+ /* https://lists.gnu.org/archive/html/bug-gnulib/2015-08/msg00003.html */
+#if defined(__cplusplus)
+#if !defined(_MSC_VER)
+#include <stdalign.h>
+#endif
+#if __cplusplus > 201103
+#define __alignas_is_defined 1
+#define __alignof_is_defined 1
+#endif
+#elif PORTABLE_HAS_INCLUDE_STDALIGN
+#include <stdalign.h>
+#elif !defined(__clang__) && ((__GNUC__ > 4) || (__GNUC__ == 4 && __GNUC_MINOR__ >= 7))
+#include <stdalign.h>
+#elif defined(HAVE_STDALIGN_H)
+#include <stdaligh.h>
+#endif
+
+#endif /* __alignas_is_defined */
+
+#ifndef __alignas_is_defined
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#if (!defined(__clang__) && defined(__GNUC__) && \
+        ((__GNUC__ < 4) || (__GNUC__ == 4 && __GNUC_MINOR__ < 7)))
+#undef PORTABLE_C11_STDALIGN_MISSING
+#define PORTABLE_C11_STDALIGN_MISSING
+#endif
+
+#if defined(__IBMC__)
+#undef PORTABLE_C11_STDALIGN_MISSING
+#define PORTABLE_C11_STDALIGN_MISSING
+#endif
+
+#if ((defined(__STDC__) && __STDC__ && defined(__STDC_VERSION__) && __STDC_VERSION__ >= 201112L) && \
+    !defined(PORTABLE_C11_STDALIGN_MISSING))
+/* C11 or newer */
+#include <stdalign.h>
+#else
+#if defined(__GNUC__) || defined(__IBM_ALIGNOF__) || defined(__clang__)
+
+#ifndef _Alignas
+#define _Alignas(t) __attribute__((__aligned__(t)))
+#endif
+
+#ifndef _Alignof
+#define _Alignof(t) __alignof__(t)
+#endif
+
+#elif defined(_MSC_VER)
+
+#define _Alignas(t) __declspec (align(t))
+#define _Alignof(t) __alignof(t)
+
+#elif defined(__TINYC__)
+
+/* Supports `_Alignas(integer-expression)`, but not `_Alignas(type)`. */
+#define _Alignas(t) __attribute__(aligned(t))
+#define _Alignof(t) __alignof__(t)
+
+#else
+#error please update pstdalign.h with support for current compiler and library
+#endif
+
+#endif /* __STDC__ */
+
+#ifndef alignas
+#define alignas _Alignas
+#endif
+
+#ifndef alignof
+#define alignof _Alignof
+#endif
+
+#define __alignas_is_defined 1
+#define __alignof_is_defined 1
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* __alignas__is_defined */
+
+#include "paligned_alloc.h"
+
+#endif /* PSTDALIGN_H */