xo-reader2/src/reader2/DGlobalEnv.cpp
Roland Conybeare 73b2561aa8 refactor: rename GCObject.shallow_copy -> shallow_move
resolve conflict since relying on move constructor in std_copy_for
2026-04-04 15:00:53 -04:00

145 lines
4.2 KiB
C++

/** @file DGlobalEnv.cpp
*
* @author Roland Conybeare, Feb 2026
**/
#include "GlobalEnv.hpp"
#include <xo/expression2/GlobalSymtab.hpp>
#include <xo/object2/Array.hpp>
namespace xo {
using xo::mm::AAllocator;
using xo::mm::AGCObject;
namespace scm {
DGlobalEnv::DGlobalEnv(DGlobalSymtab * symtab, DArray * values)
: symtab_{symtab}, values_{values}
{}
DGlobalEnv *
DGlobalEnv::_make(obj<AAllocator> mm,
DGlobalSymtab * symtab)
{
DArray * values = DArray::empty(mm, symtab->var_capacity());
void * mem = mm.alloc_for<DGlobalSymtab>();
return new (mem) DGlobalEnv(symtab, values);
}
obj<AGCObject>
DGlobalEnv::lookup_value(Binding ix) const noexcept
{
if (!ix.is_global()) {
assert(false);
return obj<AGCObject>();
}
if (ix.j_slot() >= static_cast<int32_t>(values_->size())) {
assert(false);
return obj<AGCObject>();
}
return (*values_)[ix.j_slot()];
}
void
DGlobalEnv::assign_value(obj<AAllocator> mm, Binding ix, obj<AGCObject> x)
{
scope log(XO_DEBUG(false),
xtag("ix.j_slot", ix.j_slot()),
xtag("values.cap", values_->capacity()));
assert(ix.is_global());
if (ix.j_slot() >= static_cast<int32_t>(values_->size())) {
// Control will come here in interpreter as new definitions are introduced.
// After seeing
// def foo = 1.2345;
// introducing new symbol foo:
// GlobalSymtab extends to include foo without this GlobalEnv
// knowing about it.
if (ix.j_slot() + 1 > static_cast<int32_t>(values_->capacity())) {
// realloc global array for more size
size_t cap_2x = 2 * values_->capacity();
while (cap_2x < static_cast<size_t>(ix.j_slot() + 1))
cap_2x = 2 * cap_2x;
DArray * values_2x = DArray::copy(mm, values_, cap_2x);
assert(values_2x);
if (values_2x) {
log && log("STUB: need write barrier for GC (also in GlobalSymtab!)");
this->values_ = values_2x;
} else {
return;
}
}
/** expand size sot that j_slot is valid **/
values_->resize(ix.j_slot() + 1);
}
log && log("STUB: need write barrier for GC here");
(*values_)[ix.j_slot()] = x;
}
DVariable *
DGlobalEnv::_upsert_value(obj<AAllocator> mm,
const DUniqueString * sym,
TypeDescr td,
obj<AGCObject> value)
{
DVariable * var
= DVariable::make(mm, sym, TypeRef::resolved(td));
assert(var);
symtab_->upsert_variable(mm, var);
this->assign_value(mm, var->path(), value);
return var;
}
// ----- AGCObject facet -----
std::size_t
DGlobalEnv::shallow_size() const noexcept
{
return sizeof(*this);
}
DGlobalEnv *
DGlobalEnv::shallow_move(obj<AAllocator> mm) noexcept
{
return mm.std_copy_for<DGlobalEnv>(this);
}
std::size_t
DGlobalEnv::forward_children(obj<ACollector> gc) noexcept
{
gc.forward_inplace(&symtab_);
gc.forward_inplace(&values_);
return this->shallow_size();
}
// ----- APrintable facet -----
bool
DGlobalEnv::pretty(const ppindentinfo & ppii) const
{
return ppii.pps()->pretty_struct
(ppii,
"DGlobalEnv",
refrtag("n_vars", symtab_->n_vars()));
}
} /*namespace scm*/
} /*namespace xo*/
/* end DGlobalEnv.cpp */