/* An abort()-like primitive is needed by the default fatal error handler. */
#if !defined(DUK_ABORT)
#define DUK_ABORT             abort
#endif

#if !defined(DUK_SETJMP)
#define DUK_JMPBUF_TYPE       jmp_buf
#define DUK_SETJMP(jb)        setjmp((jb))
#define DUK_LONGJMP(jb)       longjmp((jb), 1)
#endif

#if 0
/* sigsetjmp() alternative */
#define DUK_JMPBUF_TYPE       sigjmp_buf
#define DUK_SETJMP(jb)        sigsetjmp((jb))
#define DUK_LONGJMP(jb)       siglongjmp((jb), 1)
#endif

/* Special naming to avoid conflict with e.g. DUK_FREE() in duk_heap.h
 * (which is unfortunately named).  May sometimes need replacement, e.g.
 * some compilers don't handle zero length or NULL correctly in realloc().
 */
#if !defined(DUK_ANSI_MALLOC)
#define DUK_ANSI_MALLOC      malloc
#endif
#if !defined(DUK_ANSI_REALLOC)
#define DUK_ANSI_REALLOC     realloc
#endif
#if !defined(DUK_ANSI_CALLOC)
#define DUK_ANSI_CALLOC      calloc
#endif
#if !defined(DUK_ANSI_FREE)
#define DUK_ANSI_FREE        free
#endif

/* ANSI C (various versions) and some implementations require that the
 * pointer arguments to memset(), memcpy(), and memmove() be valid values
 * even when byte size is 0 (even a NULL pointer is considered invalid in
 * this context).  Zero-size operations as such are allowed, as long as their
 * pointer arguments point to a valid memory area.  The DUK_MEMSET(),
 * DUK_MEMCPY(), and DUK_MEMMOVE() macros require this same behavior, i.e.:
 * (1) pointers must be valid and non-NULL, (2) zero size must otherwise be
 * allowed.  If these are not fulfilled, a macro wrapper is needed.
 *
 *   http://stackoverflow.com/questions/5243012/is-it-guaranteed-to-be-safe-to-perform-memcpy0-0-0
 *   http://lists.cs.uiuc.edu/pipermail/llvmdev/2007-October/011065.html
 *
 * Not sure what's the required behavior when a pointer points just past the
 * end of a buffer, which often happens in practice (e.g. zero size memmoves).
 * For example, if allocation size is 3, the following pointer would not
 * technically point to a valid memory byte:
 *
 *   <-- alloc -->
 *   | 0 | 1 | 2 | .....
 *                 ^-- p=3, points after last valid byte (2)
 */
#if !defined(DUK_MEMCPY)
#if defined(DUK_F_UCLIBC)
/* Old uclibcs have a broken memcpy so use memmove instead (this is overly wide
 * now on purpose): http://lists.uclibc.org/pipermail/uclibc-cvs/2008-October/025511.html
 */
#define DUK_MEMCPY       memmove
#else
#define DUK_MEMCPY       memcpy
#endif
#endif
#if !defined(DUK_MEMMOVE)
#define DUK_MEMMOVE      memmove
#endif
#if !defined(DUK_MEMCMP)
#define DUK_MEMCMP       memcmp
#endif
#if !defined(DUK_MEMSET)
#define DUK_MEMSET       memset
#endif
#if !defined(DUK_STRLEN)
#define DUK_STRLEN       strlen
#endif
#if !defined(DUK_STRCMP)
#define DUK_STRCMP       strcmp
#endif
#if !defined(DUK_STRNCMP)
#define DUK_STRNCMP      strncmp
#endif
#if !defined(DUK_SPRINTF)
#define DUK_SPRINTF      sprintf
#endif
#if !defined(DUK_SNPRINTF)
/* snprintf() is technically not part of C89 but usually available. */
#define DUK_SNPRINTF     snprintf
#endif
#if !defined(DUK_VSPRINTF)
#define DUK_VSPRINTF     vsprintf
#endif
#if !defined(DUK_VSNPRINTF)
/* vsnprintf() is technically not part of C89 but usually available. */
#define DUK_VSNPRINTF    vsnprintf
#endif
#if !defined(DUK_SSCANF)
#define DUK_SSCANF       sscanf
#endif
#if !defined(DUK_VSSCANF)
#define DUK_VSSCANF      vsscanf
#endif
#if !defined(DUK_MEMZERO)
#define DUK_MEMZERO(p,n) DUK_MEMSET((p), 0, (n))
#endif

#if !defined(DUK_DOUBLE_INFINITY)
#undef DUK_USE_COMPUTED_INFINITY
#if defined(DUK_F_GCC_VERSION) && (DUK_F_GCC_VERSION < 40600)
/* GCC older than 4.6: avoid overflow warnings related to using INFINITY */
#define DUK_DOUBLE_INFINITY  (__builtin_inf())
#elif defined(INFINITY)
#define DUK_DOUBLE_INFINITY  ((double) INFINITY)
#elif !defined(DUK_F_VBCC) && !defined(DUK_F_MSVC) && !defined(DUK_F_BCC) && \
      !defined(DUK_F_OLD_SOLARIS) && !defined(DUK_F_AIX)
#define DUK_DOUBLE_INFINITY  (1.0 / 0.0)
#else
/* In VBCC (1.0 / 0.0) results in a warning and 0.0 instead of infinity.
 * Use a computed infinity (initialized when a heap is created at the
 * latest).
 */
#define DUK_USE_COMPUTED_INFINITY
#define DUK_DOUBLE_INFINITY  duk_computed_infinity
#endif
#endif

#if !defined(DUK_DOUBLE_NAN)
#undef DUK_USE_COMPUTED_NAN
#if defined(NAN)
#define DUK_DOUBLE_NAN       NAN
#elif !defined(DUK_F_VBCC) && !defined(DUK_F_MSVC) && !defined(DUK_F_BCC) && \
      !defined(DUK_F_OLD_SOLARIS) && !defined(DUK_F_AIX)
#define DUK_DOUBLE_NAN       (0.0 / 0.0)
#else
/* In VBCC (0.0 / 0.0) results in a warning and 0.0 instead of NaN.
 * In MSVC (VS2010 Express) (0.0 / 0.0) results in a compile error.
 * Use a computed NaN (initialized when a heap is created at the
 * latest).
 */
#define DUK_USE_COMPUTED_NAN
#define DUK_DOUBLE_NAN       duk_computed_nan
#endif
#endif

/* Many platforms are missing fpclassify() and friends, so use replacements
 * if necessary.  The replacement constants (FP_NAN etc) can be anything but
 * match Linux constants now.
 */
#undef DUK_USE_REPL_FPCLASSIFY
#undef DUK_USE_REPL_SIGNBIT
#undef DUK_USE_REPL_ISFINITE
#undef DUK_USE_REPL_ISNAN
#undef DUK_USE_REPL_ISINF

/* Complex condition broken into separate parts. */
#undef DUK_F_USE_REPL_ALL
#if !(defined(FP_NAN) && defined(FP_INFINITE) && defined(FP_ZERO) && \
      defined(FP_SUBNORMAL) && defined(FP_NORMAL))
/* Missing some obvious constants. */
#define DUK_F_USE_REPL_ALL
#elif defined(DUK_F_AMIGAOS) && defined(DUK_F_VBCC)
/* VBCC is missing the built-ins even in C99 mode (perhaps a header issue). */
#define DUK_F_USE_REPL_ALL
#elif defined(DUK_F_AMIGAOS) && defined(DUK_F_M68K)
/* AmigaOS + M68K seems to have math issues even when using GCC cross
 * compilation.  Use replacements for all AmigaOS versions on M68K
 * regardless of compiler.
 */
#define DUK_F_USE_REPL_ALL
#elif defined(DUK_F_FREEBSD) && defined(DUK_F_CLANG)
/* Placeholder fix for (detection is wider than necessary):
 * http://llvm.org/bugs/show_bug.cgi?id=17788
 */
#define DUK_F_USE_REPL_ALL
#elif defined(DUK_F_UCLIBC)
/* At least some uclibc versions have broken floating point math.  For
 * example, fpclassify() can incorrectly classify certain NaN formats.
 * To be safe, use replacements.
 */
#define DUK_F_USE_REPL_ALL
#elif defined(DUK_F_AIX)
/* Older versions may be missing isnan(), etc. */
#define DUK_F_USE_REPL_ALL
#endif

#if defined(DUK_F_USE_REPL_ALL)
#define DUK_USE_REPL_FPCLASSIFY
#define DUK_USE_REPL_SIGNBIT
#define DUK_USE_REPL_ISFINITE
#define DUK_USE_REPL_ISNAN
#define DUK_USE_REPL_ISINF
#define DUK_FPCLASSIFY       duk_repl_fpclassify
#define DUK_SIGNBIT          duk_repl_signbit
#define DUK_ISFINITE         duk_repl_isfinite
#define DUK_ISNAN            duk_repl_isnan
#define DUK_ISINF            duk_repl_isinf
#define DUK_FP_NAN           0
#define DUK_FP_INFINITE      1
#define DUK_FP_ZERO          2
#define DUK_FP_SUBNORMAL     3
#define DUK_FP_NORMAL        4
#else
#define DUK_FPCLASSIFY       fpclassify
#define DUK_SIGNBIT          signbit
#define DUK_ISFINITE         isfinite
#define DUK_ISNAN            isnan
#define DUK_ISINF            isinf
#define DUK_FP_NAN           FP_NAN
#define DUK_FP_INFINITE      FP_INFINITE
#define DUK_FP_ZERO          FP_ZERO
#define DUK_FP_SUBNORMAL     FP_SUBNORMAL
#define DUK_FP_NORMAL        FP_NORMAL
#endif

#if defined(DUK_F_USE_REPL_ALL)
#undef DUK_F_USE_REPL_ALL
#endif

/* These functions don't currently need replacement but are wrapped for
 * completeness.  Because these are used as function pointers, they need
 * to be defined as concrete C functions (not macros).
 */
#if !defined(DUK_FABS)
#define DUK_FABS             fabs
#endif
#if !defined(DUK_FLOOR)
#define DUK_FLOOR            floor
#endif
#if !defined(DUK_CEIL)
#define DUK_CEIL             ceil
#endif
#if !defined(DUK_FMOD)
#define DUK_FMOD             fmod
#endif
#if !defined(DUK_POW)
#define DUK_POW              pow
#endif
#if !defined(DUK_ACOS)
#define DUK_ACOS             acos
#endif
#if !defined(DUK_ASIN)
#define DUK_ASIN             asin
#endif
#if !defined(DUK_ATAN)
#define DUK_ATAN             atan
#endif
#if !defined(DUK_ATAN2)
#define DUK_ATAN2            atan2
#endif
#if !defined(DUK_SIN)
#define DUK_SIN              sin
#endif
#if !defined(DUK_COS)
#define DUK_COS              cos
#endif
#if !defined(DUK_TAN)
#define DUK_TAN              tan
#endif
#if !defined(DUK_EXP)
#define DUK_EXP              exp
#endif
#if !defined(DUK_LOG)
#define DUK_LOG              log
#endif
#if !defined(DUK_SQRT)
#define DUK_SQRT             sqrt
#endif

/* The functions below exist only in C99/C++11 or later and need a workaround
 * for platforms that don't include them.  MSVC isn't detected as C99, but
 * these functions also exist in MSVC 2013 and later so include a clause for
 * that too.  Android doesn't have log2; disable all of these for Android.
 */
#if (defined(DUK_F_C99) || defined(DUK_F_CPP11) || (defined(_MSC_VER) && (_MSC_VER >= 1800))) && \
    !defined(DUK_F_ANDROID) && !defined(DUK_F_MINT)
#if !defined(DUK_CBRT)
#define DUK_CBRT             cbrt
#endif
#if !defined(DUK_LOG2)
#define DUK_LOG2             log2
#endif
#if !defined(DUK_LOG10)
#define DUK_LOG10            log10
#endif
#if !defined(DUK_TRUNC)
#define DUK_TRUNC            trunc
#endif
#endif  /* DUK_F_C99 etc */

/* NetBSD 6.0 x86 (at least) has a few problems with pow() semantics,
 * see test-bug-netbsd-math-pow.js.  MinGW has similar (but different)
 * 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