module builtin

#flag -DGC_THREADS=1

$if dynamic_boehm ? {
    $if windows {
        $if tinyc {
            #flag -I @VEXEROOT/thirdparty/libgc/include
            #flag -L @VEXEROOT/thirdparty/tcc/lib
            #flag -lgc
        } $else $if msvc {
            #flag -DGC_BUILTIN_ATOMIC=1
            #flag -I @VEXEROOT/thirdparty/libgc/include
        } $else {
            #flag -DGC_WIN32_THREADS=1
            #flag -DGC_BUILTIN_ATOMIC=1
            #flag -I @VEXEROOT/thirdparty/libgc
            #flag @VEXEROOT/thirdparty/libgc/gc.o
        }
    } $else {
        $if $pkgconfig('bdw-gc') {
            #pkgconfig bdw-gc
        } $else {
            $if openbsd || freebsd {
                #flag -I/usr/local/include
                #flag -L/usr/local/lib
            }
            $if freebsd {
                #flag -lgc-threaded
            } $else {
                #flag -lgc
            }
        }
    }
} $else {
    $if macos || linux {
        #flag -DGC_BUILTIN_ATOMIC=1
        #flag -I @VEXEROOT/thirdparty/libgc/include
        $if (prod && !tinyc && !debug) || !(amd64 || arm64 || i386 || arm32) {
            // TODO: replace the architecture check with a `!$exists("@VEXEROOT/thirdparty/tcc/lib/libgc.a")` comptime call
            #flag @VEXEROOT/thirdparty/libgc/gc.o
        } $else {
            #flag @VEXEROOT/thirdparty/tcc/lib/libgc.a
        }
        $if macos {
            #flag -DMPROTECT_VDB=1
        }
        #flag -ldl
        #flag -lpthread
    } $else $if freebsd {
        // Tested on FreeBSD 13.0-RELEASE-p3, with clang, gcc and tcc:
        #flag -DGC_BUILTIN_ATOMIC=1
        #flag -DBUS_PAGE_FAULT=T_PAGEFLT
        $if !tinyc {
            #flag -I @VEXEROOT/thirdparty/libgc/include
            #flag @VEXEROOT/thirdparty/libgc/gc.o
        }
        $if tinyc {
            #flag -I/usr/local/include
            #flag $first_existing("/usr/local/lib/libgc-threaded.a", "/usr/lib/libgc-threaded.a")
            #flag -lgc-threaded
        }
        #flag -lpthread
    } $else $if openbsd {
        #flag -DGC_BUILTIN_ATOMIC=1
        #flag -I/usr/local/include
        #flag $first_existing("/usr/local/lib/libgc.a", "/usr/lib/libgc.a")
        #flag -lpthread
    } $else $if windows {
        #flag -DGC_NOT_DLL=1
        #flag -DGC_WIN32_THREADS=1
        $if tinyc {
            #flag -DGC_BUILTIN_ATOMIC=1
            #flag -I @VEXEROOT/thirdparty/libgc/include
            #flag @VEXEROOT/thirdparty/tcc/lib/libgc.a
            #flag -luser32
        } $else $if msvc {
            // Build libatomic_ops
            #flag @VEXEROOT/thirdparty/libatomic_ops/atomic_ops.o
            #flag -I  @VEXEROOT/thirdparty/libatomic_ops

            #flag -I @VEXEROOT/thirdparty/libgc/include
            #flag @VEXEROOT/thirdparty/libgc/gc.o
        } $else {
            #flag -DGC_BUILTIN_ATOMIC=1
            #flag -I @VEXEROOT/thirdparty/libgc/include
            #flag @VEXEROOT/thirdparty/libgc/gc.o
        }
    } $else $if $pkgconfig('bdw-gc') {
        #flag -DGC_BUILTIN_ATOMIC=1
        #pkgconfig bdw-gc
    } $else {
        #flag -DGC_BUILTIN_ATOMIC=1
        #flag -lgc
    }
}

$if gcboehm_leak ? {
    #flag -DGC_DEBUG=1
}

#include <gc.h>

// replacements for `malloc()/calloc()`, `realloc()` and `free()`
// for use with Boehm-GC
// Do not use them manually. They are automatically chosen when
// compiled with `-gc boehm` or `-gc boehm_leak`.
fn C.GC_MALLOC(n usize) voidptr

fn C.GC_MALLOC_ATOMIC(n usize) voidptr

fn C.GC_MALLOC_UNCOLLECTABLE(n usize) voidptr

fn C.GC_REALLOC(ptr voidptr, n usize) voidptr

fn C.GC_FREE(ptr voidptr)

// explicitly perform garbage collection now! Garbage collections
// are done automatically when needed, so this function is hardly needed
fn C.GC_gcollect()

// functions to temporarily suspend/resume garbage collection
fn C.GC_disable()

fn C.GC_enable()

// returns non-zero if GC is disabled
fn C.GC_is_disabled() int

// protect memory block from being freed before this call
fn C.GC_reachable_here(voidptr)

// for leak detection it is advisable to do explicit garbage collections
pub fn gc_check_leaks() {
    $if gcboehm_leak ? {
        C.GC_gcollect()
    }
}

fn C.GC_get_heap_usage_safe(pheap_size &usize, pfree_bytes &usize, punmapped_bytes &usize, pbytes_since_gc &usize, ptotal_bytes &usize)
fn C.GC_get_memory_use() usize