An embeddable, thread-safe implementation of the cubescript language
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#include "cs_bcode.hh"
#include "cs_state.hh"
#include "cs_vm.hh"
namespace cubescript {
/* public API impls */
LIBCUBESCRIPT_EXPORT bcode_ref::bcode_ref(bcode *v): p_code(v) {
bcode_addref(v->raw());
}
LIBCUBESCRIPT_EXPORT bcode_ref::bcode_ref(bcode_ref const &v):
p_code(v.p_code)
{
bcode_addref(p_code->raw());
}
LIBCUBESCRIPT_EXPORT bcode_ref::~bcode_ref() {
bcode_unref(p_code->raw());
}
LIBCUBESCRIPT_EXPORT bcode_ref &bcode_ref::operator=(
bcode_ref const &v
) {
bcode_unref(p_code->raw());
p_code = v.p_code;
bcode_addref(p_code->raw());
return *this;
}
LIBCUBESCRIPT_EXPORT bcode_ref &bcode_ref::operator=(bcode_ref &&v) {
bcode_unref(p_code->raw());
p_code = v.p_code;
v.p_code = nullptr;
return *this;
}
LIBCUBESCRIPT_EXPORT bool bcode_ref::empty() const {
if (!p_code) {
return true;
}
return (*p_code->raw() & BC_INST_OP_MASK) == BC_INST_EXIT;
}
LIBCUBESCRIPT_EXPORT bcode_ref::operator bool() const {
return p_code != nullptr;
}
LIBCUBESCRIPT_EXPORT any_value bcode_ref::call(state &cs) const {
any_value ret{};
vm_exec(state_p{cs}.ts(), p_code->raw(), ret);
return ret;
}
LIBCUBESCRIPT_EXPORT loop_state bcode_ref::call_loop(
state &cs, any_value &ret
) const {
auto &ts = state_p{cs}.ts();
++ts.loop_level;
try {
ret = call(cs);
} catch (break_exception) {
--ts.loop_level;
return loop_state::BREAK;
} catch (continue_exception) {
--ts.loop_level;
return loop_state::CONTINUE;
} catch (...) {
--ts.loop_level;
throw;
}
return loop_state::NORMAL;
}
LIBCUBESCRIPT_EXPORT loop_state bcode_ref::call_loop(state &cs) const {
any_value ret{};
return call_loop(cs, ret);
}
/* private funcs */
struct bcode_hdr {
internal_state *cs; /* needed to construct the allocator */
std::size_t asize; /* alloc size of the bytecode block */
bcode bc; /* BC_INST_START + refcount */
};
/* returned address is the 'init' member of the header */
std::uint32_t *bcode_alloc(internal_state *cs, std::size_t sz) {
auto a = std_allocator<std::uint32_t>{cs};
std::size_t hdrs = sizeof(bcode_hdr) / sizeof(std::uint32_t);
auto p = a.allocate(sz + hdrs - 1);
bcode_hdr *hdr = reinterpret_cast<bcode_hdr *>(p);
hdr->cs = cs;
hdr->asize = sz + hdrs - 1;
return p + hdrs - 1;
}
/* bc's address must be the 'init' member of the header */
static inline void bcode_free(std::uint32_t *bc) {
auto *rp = bc + 1 - (sizeof(bcode_hdr) / sizeof(std::uint32_t));
bcode_hdr *hdr = reinterpret_cast<bcode_hdr *>(rp);
std_allocator<std::uint32_t>{hdr->cs}.deallocate(rp, hdr->asize);
}
static inline void bcode_incr(std::uint32_t *bc) {
*bc += 0x100;
}
static inline void bcode_decr(std::uint32_t *bc) {
*bc -= 0x100;
if (std::int32_t(*bc) < 0x100) {
bcode_free(bc);
}
}
void bcode_addref(std::uint32_t *code) {
if (!code) {
return;
}
if ((*code & BC_INST_OP_MASK) == BC_INST_START) {
bcode_incr(code);
return;
}
switch (code[-1]&BC_INST_OP_MASK) {
case BC_INST_START:
bcode_incr(&code[-1]);
break;
case BC_INST_OFFSET:
code -= std::ptrdiff_t(code[-1] >> 8);
bcode_incr(code);
break;
}
}
void bcode_unref(std::uint32_t *code) {
if (!code) {
return;
}
if ((*code & BC_INST_OP_MASK) == BC_INST_START) {
bcode_decr(code);
return;
}
switch (code[-1]&BC_INST_OP_MASK) {
case BC_INST_START:
bcode_decr(&code[-1]);
break;
case BC_INST_OFFSET:
code -= std::ptrdiff_t(code[-1] >> 8);
bcode_decr(code);
break;
}
}
/* empty fallbacks */
static std::uint32_t emptyrets[VAL_ANY] = {
BC_RET_NULL, BC_RET_INT, BC_RET_FLOAT, BC_RET_STRING
};
empty_block *bcode_init_empty(internal_state *cs) {
auto a = std_allocator<empty_block>{cs};
auto *p = a.allocate(VAL_ANY);
for (std::size_t i = 0; i < VAL_ANY; ++i) {
p[i].init.init = BC_INST_START + 0x100;
p[i].code = BC_INST_EXIT | emptyrets[i];
}
return p;
}
void bcode_free_empty(internal_state *cs, empty_block *empty) {
std_allocator<empty_block>{cs}.deallocate(empty, VAL_ANY);
}
bcode *bcode_get_empty(empty_block *empty, std::size_t val) {
return &empty[val].init + 1;
}
} /* namespace cubescript */