alloca.h

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#pragma once
 
#include "fl/stl/has_include.h"  // IWYU pragma: keep
 
// Conditional stack array support includes - must be before namespace
#ifndef FASTLED_VARIABLE_LENGTH_ARRAY_NEEDS_EMULATION
#if defined(FL_IS_CLANG) || defined(FL_IS_STM32_H7)
// Clang doesn't have variable length arrays. Therefore we need to emulate them
// using alloca. It's been found that Arduino Giga M7 also doesn't support
// variable length arrays for some reason so we force it to emulate them as well
// in this case.
#define FASTLED_VARIABLE_LENGTH_ARRAY_NEEDS_EMULATION 1
#else
// Else, assume the compiler is gcc, which has variable length arrays
#define FASTLED_VARIABLE_LENGTH_ARRAY_NEEDS_EMULATION 0
#endif
#endif // FASTLED_VARIABLE_LENGTH_ARRAY_NEEDS_EMULATION

#if !FASTLED_VARIABLE_LENGTH_ARRAY_NEEDS_EMULATION
#define FASTLED_STACK_ARRAY(TYPE, NAME, SIZE)                                  \
    TYPE NAME[SIZE];                                                           \
    fl::memset(NAME, 0, sizeof(TYPE) * (SIZE))
#elif FL_HAS_INCLUDE(<alloca.h>)
// IWYU pragma: begin_keep
#include <alloca.h>
// IWYU pragma: end_keep
#define FASTLED_STACK_ARRAY(TYPE, NAME, SIZE)                                  \
    TYPE *NAME = fl::bit_cast_ptr<TYPE>(alloca(sizeof(TYPE) * (SIZE)));      \
    fl::memset(NAME, 0, sizeof(TYPE) * (SIZE))
#elif FL_HAS_INCLUDE(<malloc.h>)
// IWYU pragma: begin_keep
#include <malloc.h>
// IWYU pragma: end_keep
#define FASTLED_STACK_ARRAY(TYPE, NAME, SIZE)                                  \
    TYPE *NAME = fl::bit_cast_ptr<TYPE>(alloca(sizeof(TYPE) * (SIZE)));      \
    fl::memset(NAME, 0, sizeof(TYPE) * (SIZE))
#else
#error "Compiler does not allow variable type arrays."
#endif