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lib/JavaScript/Embedded/C/lib/duk_config.h  view on Meta::CPAN

 * issues, see test-bug-mingw-math-issues.js.  Enable pow() workarounds
 * for these targets.
 */
#undef DUK_USE_POW_WORKAROUNDS
#if defined(DUK_F_NETBSD) || defined(DUK_F_MINGW)
#define DUK_USE_POW_WORKAROUNDS
#endif

/* Similar workarounds for atan2() semantics issues.  MinGW issues are
 * documented in test-bug-mingw-math-issues.js.
 */
#undef DUK_USE_ATAN2_WORKAROUNDS
#if defined(DUK_F_MINGW)
#define DUK_USE_ATAN2_WORKAROUNDS
#endif

/* Rely as little as possible on compiler behavior for NaN comparison,
 * signed zero handling, etc.  Currently never activated but may be needed
 * for broken compilers.
 */
#undef DUK_USE_PARANOID_MATH

/* There was a curious bug where test-bi-date-canceling.js would fail e.g.
 * on 64-bit Ubuntu, gcc-4.8.1, -m32, and no -std=c99.  Some date computations
 * using doubles would be optimized which then broke some corner case tests.
 * The problem goes away by adding 'volatile' to the datetime computations.
 * Not sure what the actual triggering conditions are, but using this on
 * non-C99 systems solves the known issues and has relatively little cost
 * on other platforms.
 */
#undef DUK_USE_PARANOID_DATE_COMPUTATION
#if !defined(DUK_F_C99)
#define DUK_USE_PARANOID_DATE_COMPUTATION
#endif

/*
 *  Byte order and double memory layout detection
 *
 *  Endianness detection is a major portability hassle because the macros
 *  and headers are not standardized.  There's even variance across UNIX
 *  platforms.  Even with "standard" headers, details like underscore count
 *  varies between platforms, e.g. both __BYTE_ORDER and _BYTE_ORDER are used
 *  (Crossbridge has a single underscore, for instance).
 *
 *  The checks below are structured with this in mind: several approaches are
 *  used, and at the end we check if any of them worked.  This allows generic
 *  approaches to be tried first, and platform/compiler specific hacks tried
 *  last.  As a last resort, the user can force a specific endianness, as it's
 *  not likely that automatic detection will work on the most exotic platforms.
 *
 *  Duktape supports little and big endian machines.  There's also support
 *  for a hybrid used by some ARM machines where integers are little endian
 *  but IEEE double values use a mixed order (12345678 -> 43218765).  This
 *  byte order for doubles is referred to as "mixed endian".
 */

/* GCC and Clang provide endianness defines as built-in predefines, with
 * leading and trailing double underscores (e.g. __BYTE_ORDER__).  See
 * output of "make gccpredefs" and "make clangpredefs".  Clang doesn't
 * seem to provide __FLOAT_WORD_ORDER__; assume not mixed endian for clang.
 * http://gcc.gnu.org/onlinedocs/cpp/Common-Predefined-Macros.html
 */
#if !defined(DUK_USE_BYTEORDER) && defined(__BYTE_ORDER__)
#if defined(__ORDER_LITTLE_ENDIAN__) && (__BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__)
#if defined(__FLOAT_WORD_ORDER__) && defined(__ORDER_LITTLE_ENDIAN__) && (__FLOAT_WORD_ORDER__ == __ORDER_LITTLE_ENDIAN__)
#define DUK_USE_BYTEORDER 1
#elif defined(__FLOAT_WORD_ORDER__) && defined(__ORDER_BIG_ENDIAN__) && (__FLOAT_WORD_ORDER__ == __ORDER_BIG_ENDIAN__)
#define DUK_USE_BYTEORDER 2
#elif !defined(__FLOAT_WORD_ORDER__)
/* Float word order not known, assume not a hybrid. */
#define DUK_USE_BYTEORDER 1
#else
/* Byte order is little endian but cannot determine IEEE double word order. */
#endif  /* float word order */
#elif defined(__ORDER_BIG_ENDIAN__) && (__BYTE_ORDER__ == __ORDER_BIG_ENDIAN__)
#if defined(__FLOAT_WORD_ORDER__) && defined(__ORDER_BIG_ENDIAN__) && (__FLOAT_WORD_ORDER__ == __ORDER_BIG_ENDIAN__)
#define DUK_USE_BYTEORDER 3
#elif !defined(__FLOAT_WORD_ORDER__)
/* Float word order not known, assume not a hybrid. */
#define DUK_USE_BYTEORDER 3
#else
/* Byte order is big endian but cannot determine IEEE double word order. */
#endif  /* float word order */
#else
/* Cannot determine byte order; __ORDER_PDP_ENDIAN__ is related to 32-bit
 * integer ordering and is not relevant.
 */
#endif  /* integer byte order */
#endif  /* !defined(DUK_USE_BYTEORDER) && defined(__BYTE_ORDER__) */

/* More or less standard endianness predefines provided by header files.
 * The ARM hybrid case is detected by assuming that __FLOAT_WORD_ORDER
 * will be big endian, see: http://lists.mysql.com/internals/443.
 * On some platforms some defines may be present with an empty value which
 * causes comparisons to fail: https://github.com/svaarala/duktape/issues/453.
 */
#if !defined(DUK_USE_BYTEORDER)
#if defined(__BYTE_ORDER) && defined(__LITTLE_ENDIAN) && (__BYTE_ORDER == __LITTLE_ENDIAN) || \
    defined(_BYTE_ORDER) && defined(_LITTLE_ENDIAN) && (_BYTE_ORDER == _LITTLE_ENDIAN) || \
    defined(__LITTLE_ENDIAN__)
#if defined(__FLOAT_WORD_ORDER) && defined(__LITTLE_ENDIAN) && (__FLOAT_WORD_ORDER == __LITTLE_ENDIAN) || \
    defined(_FLOAT_WORD_ORDER) && defined(_LITTLE_ENDIAN) && (_FLOAT_WORD_ORDER == _LITTLE_ENDIAN)
#define DUK_USE_BYTEORDER 1
#elif defined(__FLOAT_WORD_ORDER) && defined(__BIG_ENDIAN) && (__FLOAT_WORD_ORDER == __BIG_ENDIAN) || \
      defined(_FLOAT_WORD_ORDER) && defined(_BIG_ENDIAN) && (_FLOAT_WORD_ORDER == _BIG_ENDIAN)
#define DUK_USE_BYTEORDER 2
#elif !defined(__FLOAT_WORD_ORDER) && !defined(_FLOAT_WORD_ORDER)
/* Float word order not known, assume not a hybrid. */
#define DUK_USE_BYTEORDER 1
#else
/* Byte order is little endian but cannot determine IEEE double word order. */
#endif  /* float word order */
#elif defined(__BYTE_ORDER) && defined(__BIG_ENDIAN) && (__BYTE_ORDER == __BIG_ENDIAN) || \
      defined(_BYTE_ORDER) && defined(_BIG_ENDIAN) && (_BYTE_ORDER == _BIG_ENDIAN) || \
      defined(__BIG_ENDIAN__)
#if defined(__FLOAT_WORD_ORDER) && defined(__BIG_ENDIAN) && (__FLOAT_WORD_ORDER == __BIG_ENDIAN) || \
    defined(_FLOAT_WORD_ORDER) && defined(_BIG_ENDIAN) && (_FLOAT_WORD_ORDER == _BIG_ENDIAN)
#define DUK_USE_BYTEORDER 3
#elif !defined(__FLOAT_WORD_ORDER) && !defined(_FLOAT_WORD_ORDER)
/* Float word order not known, assume not a hybrid. */
#define DUK_USE_BYTEORDER 3

lib/JavaScript/Embedded/C/lib/duk_config.h  view on Meta::CPAN

#endif
#endif

/*
 *  Alignment requirement and support for unaligned accesses
 *
 *  Assume unaligned accesses are not supported unless specifically allowed
 *  in the target platform.  Some platforms may support unaligned accesses
 *  but alignment to 4 or 8 may still be desirable.  Note that unaligned
 *  accesses (and even pointers) relative to natural alignment (regardless
 *  of target alignment) are technically undefined behavior and thus
 *  compiler/architecture specific.
 */

/* If not forced, use safe default for alignment. */
#if !defined(DUK_USE_ALIGN_BY)
#define DUK_USE_ALIGN_BY 8
#endif

/* Compiler specific hackery needed to force struct size to match alignment,
 * see e.g. duk_hbuffer.h.
 *
 * http://stackoverflow.com/questions/11130109/c-struct-size-alignment
 * http://stackoverflow.com/questions/10951039/specifying-64-bit-alignment
 */
#if !(defined(DUK_USE_PACK_MSVC_PRAGMA) || defined(DUK_USE_PACK_GCC_ATTR) || \
      defined(DUK_USE_PACK_CLANG_ATTR) || defined(DUK_USE_PACK_DUMMY_MEMBER))
#define DUK_USE_PACK_DUMMY_MEMBER
#endif

#if !defined(DUK_U64_CONSTANT)
#define DUK_U64_CONSTANT(x) x##ULL
#endif
#if !defined(DUK_I64_CONSTANT)
#define DUK_I64_CONSTANT(x) x##LL
#endif

#if !defined(DUK_VA_COPY)
/* We need va_copy() which is defined in C99 / C++11, so an awkward
 * replacement is needed for pre-C99 / pre-C++11 environments.  This
 * will quite likely need portability hacks for some non-C99
 * environments.
 */
#if defined(DUK_F_C99) || defined(DUK_F_CPP11)
/* C99 / C++11 and above: rely on va_copy() which is required.
 * Omit parenthesis on macro right side on purpose to minimize differences
 * to direct use.
 */
#define DUK_VA_COPY(dest,src) va_copy(dest,src)
#else
/* Pre-C99: va_list type is implementation dependent.  This replacement
 * assumes it is a plain value so that a simple assignment will work.
 * This is not the case on all platforms (it may be a single-array element,
 * for instance).
 */
#define DUK_VA_COPY(dest,src) do { (dest) = (src); } while (0)
#endif
#endif

#if !defined(DUK_MACRO_STRINGIFY)
/* Macro hackery to convert e.g. __LINE__ to a string without formatting,
 * see: http://stackoverflow.com/questions/240353/convert-a-preprocessor-token-to-a-string
 */
#define DUK_MACRO_STRINGIFY_HELPER(x)  #x
#define DUK_MACRO_STRINGIFY(x)  DUK_MACRO_STRINGIFY_HELPER(x)
#endif

#if !defined(DUK_CAUSE_SEGFAULT)
/* This can be used for testing; valgrind will then indicate the C call stack
 * leading to the call site.
 */
#define DUK_CAUSE_SEGFAULT()  do { *((volatile duk_uint32_t *) NULL) = (duk_uint32_t) 0xdeadbeefUL; } while (0)
#endif

#if !defined(DUK_UNREF)
/* Macro for suppressing warnings for potentially unreferenced variables.
 * The variables can be actually unreferenced or unreferenced in some
 * specific cases only; for instance, if a variable is only debug printed,
 * it is unreferenced when debug printing is disabled.  May cause warnings
 * for volatile arguments.
 */
#define DUK_UNREF(x)  do { (void) (x); } while (0)
#endif

/* Fillin for DUK_NORETURN; DUK_WO_NORETURN() is used to insert dummy
 * dummy statements after noreturn calls to silence harmless compiler
 * warnings, e.g.:
 *
 *   DUK_ERROR_TYPE(thr, "aiee");
 *   DUK_WO_NORETURN(return 0;);
 *
 * Statements inside DUK_WO_NORETURN() must NEVER be actually reachable,
 * and they're only included to satisfy the compiler.
 */
#if defined(DUK_NORETURN)
#define DUK_WO_NORETURN(stmt) do { } while (0)
#else
#define DUK_NORETURN(decl)  decl
#define DUK_WO_NORETURN(stmt) do { stmt } while (0)
#endif

#if defined(DUK_UNREACHABLE)
#define DUK_WO_UNREACHABLE(stmt) do { } while (0)
#else
/* Don't know how to declare unreachable point, so don't do it; this
 * may cause some spurious compilation warnings (e.g. "variable used
 * uninitialized").
 */
#define DUK_UNREACHABLE()  do { } while (0)
#define DUK_WO_UNREACHABLE(stmt) do { stmt } while (0)
#endif

#if !defined(DUK_LOSE_CONST)
/* Convert any input pointer into a "void *", losing a const qualifier.
 * This is not fully portable because casting through duk_uintptr_t may
 * not work on all architectures (e.g. those with long, segmented pointers).
 */
#define DUK_LOSE_CONST(src) ((void *) (duk_uintptr_t) (src))
#endif

#if !defined(DUK_LIKELY)
#define DUK_LIKELY(x)    (x)
#endif
#if !defined(DUK_UNLIKELY)
#define DUK_UNLIKELY(x)  (x)
#endif
#if !defined(DUK_UNPREDICTABLE)
#define DUK_UNPREDICTABLE(x)  (x)
#endif

#if !defined(DUK_NOINLINE)
#define DUK_NOINLINE       /*nop*/
#endif
#if !defined(DUK_INLINE)
#define DUK_INLINE         /*nop*/
#endif