xo-interpreter2/xo-expression2/src/expression2/DGlobalSymtab.cpp

169 lines
4.6 KiB
C++

/** @file DGlobalSymtab.cpp
*
* @author Roland Conybeare, Jan 2026
**/
#include "DGlobalSymtab.hpp"
#include "DUniqueString.hpp"
#include <xo/expression2/Expression.hpp>
#include <xo/expression2/Variable.hpp>
#include <xo/object2/Array.hpp>
#include <xo/gc/GCObject.hpp>
#include <xo/facet/FacetRegistry.hpp>
#include <xo/indentlog/scope.hpp>
namespace xo {
using xo::map::DArenaHashMap;
using xo::mm::AGCObject;
namespace scm {
DGlobalSymtab::DGlobalSymtab(repr_type * map,
DArray * vars)
: map_{map}, vars_{vars}
{
}
DGlobalSymtab *
DGlobalSymtab::make(obj<AAllocator> global_mm,
obj<AAllocator> mm,
const ArenaHashMapConfig & cfg)
{
repr_type * map = nullptr;
{
/** memory DGlobalSymtab::map_
* (but not counting the mmap()'s that map will make for itself)
**/
void * global_mem = global_mm.alloc_for<repr_type>();
map = new (global_mem) repr_type(cfg);
}
assert(map);
void * symtab_mem = mm.alloc_for<DGlobalSymtab>();
/* choosing same capacity for hash, vars */
DArray * vars = DArray::empty(mm, map->capacity());
assert(vars);
DGlobalSymtab * symtab = new (symtab_mem) DGlobalSymtab(map, vars);
assert(symtab);
return symtab;
}
void
DGlobalSymtab::visit_pools(const MemorySizeVisitor & visitor) const
{
if (map_)
map_->visit_pools(visitor);
}
DVariable *
DGlobalSymtab::lookup_variable(const DUniqueString * sym) const noexcept
{
Binding existing = this->lookup_binding(sym);
if (existing.is_null())
return nullptr;
auto var_gco = obj<AGCObject,DVariable>::from((*vars_)[existing.j_slot()]);
auto var = var_gco.to_facet<AExpression>();
assert(var.data());
return var.data();
}
DVariable *
DGlobalSymtab::establish_variable(obj<AAllocator> mm,
const DUniqueString * sym,
TypeRef typeref)
{
DVariable * var = this->lookup_variable(sym);
if (!var) {
assert(vars_);
DArray::size_type n = vars_->size();
// NOTE: expansion here is moot at present (Feb 2026).
// Not implemented in ArenaHashMap
/** make sure vars_ has room **/
if (n == vars_->capacity()) {
// reallocate with more capacity
DArray * vars_2x = DArray::copy(mm, vars_, vars_->capacity() * 2);
assert(vars_2x);
this->vars_ = vars_2x;
}
/** create new variable **/
Binding binding = Binding::global(n);
var = DVariable::make(mm, sym, typeref, binding);
if (!var) {
// something terribly wrong
assert(false);
return var;
}
assert(map_->size() < map_->capacity());
(*map_)[sym] = binding.j_slot();
bool ok = vars_->push_back(obj<AGCObject,DVariable>(var));
if (!ok)
assert(false);
}
return var;
}
Binding
DGlobalSymtab::lookup_binding(const DUniqueString * sym) const noexcept
{
assert(sym);
scope log(XO_DEBUG(true), "stub");
log && log(xtag("sym", std::string_view(*sym)));
auto ix = map_->find(sym);
if (ix == map_->end())
return Binding::null();
return Binding::global(ix->second);
}
// ----- gcobject facet -----
std::size_t
DGlobalSymtab::shallow_size() const noexcept
{
return sizeof(DGlobalSymtab);
}
DGlobalSymtab *
DGlobalSymtab::shallow_copy(obj<AAllocator> mm) const noexcept
{
return mm.std_copy_for<DGlobalSymtab>(this);
}
std::size_t
DGlobalSymtab::forward_children(obj<ACollector> gc) noexcept
{
// map_ doesn't contain any gc-owned data, can skip
gc.forward_inplace(&vars_);
return this->shallow_size();
}
} /*namespace scm*/
} /*namespace xo*/
/* end DGlobalSymtab.cpp */