// SPDX-FileCopyrightText: Copyright (c) 2013-2014 Damien P. George

// SPDX-FileCopyrightText: 2014 MicroPython & CircuitPython contributors (https://github.com/adafruit/circuitpython/graphs/contributors)

//

// SPDX-License-Identifier: MIT

#include <stdio.h>

#include "py/mpstate.h"

#include "py/gc.h"

#if MICROPY_ENABLE_GC

// Even if we have specific support for an architecture, it is

// possible to force use of setjmp-based implementation.

#if !MICROPY_GCREGS_SETJMP

// We capture here callee-save registers, i.e. ones which may contain

// interesting values held there by our callers. It doesn't make sense

// to capture caller-saved registers, because they, well, put on the

// stack already by the caller.

#if defined(__x86_64__)

typedef mp_uint_t regs_t[6];

STATIC void gc_helper_get_regs(regs_t arr) {

register long rbx asm ("rbx");

register long rbp asm ("rbp");

register long r12 asm ("r12");

register long r13 asm ("r13");

register long r14 asm ("r14");

register long r15 asm ("r15");

#ifdef __clang__

// TODO:

// This is dirty workaround for Clang. It tries to get around

// uncompliant (wrt to GCC) behavior of handling register variables.

// Application of this patch here is random, and done only to unbreak

// MacOS build. Better, cross-arch ways to deal with Clang issues should

// be found.

asm("" : "=r"(rbx));

asm("" : "=r"(rbp));

asm("" : "=r"(r12));

asm("" : "=r"(r13));

asm("" : "=r"(r14));

asm("" : "=r"(r15));

#endif

arr[0] = rbx;

arr[1] = rbp;

arr[2] = r12;

arr[3] = r13;

arr[4] = r14;

arr[5] = r15;

}

#elif defined(__i386__)

typedef mp_uint_t regs_t[4];

STATIC void gc_helper_get_regs(regs_t arr) {

register long ebx asm ("ebx");

register long esi asm ("esi");

register long edi asm ("edi");

register long ebp asm ("ebp");

arr[0] = ebx;

arr[1] = esi;

arr[2] = edi;

arr[3] = ebp;

}

#elif defined(__thumb2__) || defined(__thumb__) || defined(__arm__)

typedef mp_uint_t regs_t[10];

STATIC void gc_helper_get_regs(regs_t arr) {

register long r4 asm ("r4");

register long r5 asm ("r5");

register long r6 asm ("r6");

register long r7 asm ("r7");

register long r8 asm ("r8");

register long r9 asm ("r9");

register long r10 asm ("r10");

register long r11 asm ("r11");

register long r12 asm ("r12");

register long r13 asm ("r13");

arr[0] = r4;

arr[1] = r5;

arr[2] = r6;

arr[3] = r7;

arr[4] = r8;

arr[5] = r9;

arr[6] = r10;

arr[7] = r11;

arr[8] = r12;

arr[9] = r13;

}

#else

// If we don't have architecture-specific optimized support,

// just fall back to setjmp-based implementation.

#undef MICROPY_GCREGS_SETJMP

#define MICROPY_GCREGS_SETJMP (1)

#endif // Arch-specific selection

#endif // !MICROPY_GCREGS_SETJMP

// If MICROPY_GCREGS_SETJMP was requested explicitly, or if

// we enabled it as a fallback above.

#if MICROPY_GCREGS_SETJMP

#include <setjmp.h>

typedef jmp_buf regs_t;

STATIC void gc_helper_get_regs(regs_t arr) {

setjmp(arr);

}

#endif // MICROPY_GCREGS_SETJMP

void gc_collect(void) {

gc_collect_start();

regs_t regs;

gc_helper_get_regs(regs);

// GC stack (and regs because we captured them)

void **regs_ptr = (void**)(void*)&regs;

gc_collect_root(regs_ptr, ((mp_uint_t)MP_STATE_THREAD(stack_top) - (mp_uint_t)&regs) / sizeof(mp_uint_t));

#if MICROPY_EMIT_NATIVE

mp_unix_mark_exec();

#endif

gc_collect_end();

}

#endif //MICROPY_ENABLE_GC