diff options
Diffstat (limited to 'src/mir/cleanup.cpp')
| -rw-r--r-- | src/mir/cleanup.cpp | 96 |
1 files changed, 96 insertions, 0 deletions
diff --git a/src/mir/cleanup.cpp b/src/mir/cleanup.cpp new file mode 100644 index 00000000..9948a3b3 --- /dev/null +++ b/src/mir/cleanup.cpp @@ -0,0 +1,96 @@ +/* + * MRustC - Rust Compiler + * - By John Hodge (Mutabah/thePowersGang) + * + * mir/cleanup.cpp + * - MIR Cleanup + * + * Removes artefacts left after monomorphisation + * - Converts <Trait as Trait>::method() into a vtable call + * - Replaces constants by their value + */ +#include "main_bindings.hpp" +#include "mir.hpp" +#include <hir/visitor.hpp> +#include <hir_typeck/static.hpp> +#include <mir/helpers.hpp> + +void MIR_Cleanup(const StaticTraitResolve& resolve, const ::HIR::ItemPath& path, ::MIR::Function& fcn, const ::HIR::Function::args_t& args, const ::HIR::TypeRef& ret_type) +{ + Span sp; + ::MIR::TypeResolve state { sp, resolve, FMT_CB(ss, ss << path;), ret_type, args, fcn }; + + for(auto& block : fcn.blocks) + { + for(auto& stmt : block.statements) + { + if( stmt.is_Assign() ) + { + auto& se = stmt.as_Assign(); + + TU_IFLET( ::MIR::RValue, se.src, Constant, e, + // TODO: Replace `Const` with actual values + ) + } + } + + TU_IFLET( ::MIR::Terminator, block.terminator, CallPath, e, + + // Detect calling `<Trait as Trait>::method()` and replace with vtable call + if( e.fcn_path.m_data.is_UfcsKnown() && e.fcn_path.m_data.as_UfcsKnown().type->m_data.is_TraitObject() ) + { + const auto& pe = e.fcn_path.m_data.as_UfcsKnown(); + const auto& te = pe.type->m_data.as_TraitObject(); + // TODO: What if the method is from a supertrait? + if( pe.trait == te.m_trait.m_path ) + { + assert( te.m_trait.m_trait_ptr ); + const auto& trait = *te.m_trait.m_trait_ptr; + + // 1. Get the vtable index for this function + if( trait.m_value_indexes.count(pe.item) == 0 ) + BUG(sp, "Calling method '" << pe.item << "' of " << pe.trait << " which isn't in the vtable"); + unsigned int vtable_idx = trait.m_value_indexes.at( pe.item ); + + // 2. Load from the vtable + auto vtable_ty_spath = pe.trait.m_path; + vtable_ty_spath.m_components.back() += "#vtable"; + const auto& vtable_ref = resolve.m_crate.get_struct_by_path(sp, vtable_ty_spath); + // Copy the param set from the trait in the trait object + ::HIR::PathParams vtable_params = te.m_trait.m_path.m_params.clone(); + // - Include associated types on bound + for(const auto& ty_b : te.m_trait.m_type_bounds) { + auto idx = trait.m_type_indexes.at(ty_b.first); + if(vtable_params.m_types.size() <= idx) + vtable_params.m_types.resize(idx+1); + vtable_params.m_types[idx] = ty_b.second.clone(); + } + auto vtable_ty = ::HIR::TypeRef::new_pointer( + ::HIR::BorrowType::Shared, + ::HIR::TypeRef( ::HIR::GenericPath(vtable_ty_spath, mv$(vtable_params)), &vtable_ref ) + ); + + // Allocate a temporary for the vtable pointer itself + auto vtable_lv = ::MIR::LValue::make_Temporary({ static_cast<unsigned int>(fcn.temporaries.size()) }); + fcn.temporaries.push_back( mv$(vtable_ty) ); + // - Load the vtable and store it + auto vtable_rval = ::MIR::RValue::make_DstMeta({ + ::MIR::LValue::make_Deref({ box$(e.args.front().clone()) }) + }); + block.statements.push_back( ::MIR::Statement::make_Assign({ vtable_lv.clone(), mv$(vtable_rval) }) ); + + // Update the terminator with the new information. + auto vtable_fcn = ::MIR::LValue::make_Field({ box$(::MIR::LValue::make_Deref({ box$(vtable_lv) })), vtable_idx }); + auto new_term = ::MIR::Terminator::make_CallValue({ + e.ret_block, e.panic_block, + mv$(e.ret_val), mv$(vtable_fcn), + mv$(e.args) + }); + + block.terminator = mv$(new_term); + } + } + ) + } +} + |