diff options
| -rw-r--r-- | src/mir/from_hir.hpp | 5 | ||||
| -rw-r--r-- | src/mir/mir_builder.cpp | 59 |
2 files changed, 58 insertions, 6 deletions
diff --git a/src/mir/from_hir.hpp b/src/mir/from_hir.hpp index 475087c7..c5d770af 100644 --- a/src/mir/from_hir.hpp +++ b/src/mir/from_hir.hpp @@ -42,7 +42,9 @@ enum class VarState { Uninit, // No value assigned yet Init, // Initialised and valid at this point MaybeMoved, // Possibly has been moved + //MaybeMovedInner, // Inner possibly has been moved Moved, // Definitely moved + InnerMoved, // The inner has been moved, but the container needs to be dropped Dropped, // Dropped (out of scope) }; extern ::std::ostream& operator<<(::std::ostream& os, VarState x); @@ -86,6 +88,7 @@ class MirBuilder ::MIR::RValue m_result; bool m_result_valid; + //::std::vector<VarState> m_arg_states; ::std::vector<VarState> m_variable_states; ::std::vector<VarState> m_temporary_states; @@ -140,6 +143,8 @@ public: void push_stmt_assign(const Span& sp, ::MIR::LValue dst, ::MIR::RValue val); // Push a drop (likely only used by scope cleanup) void push_stmt_drop(const Span& sp, ::MIR::LValue val); + // Push a shallow drop (for Box) + void push_stmt_drop_shallow(const Span& sp, ::MIR::LValue val); // - Block management bool block_active() const { diff --git a/src/mir/mir_builder.cpp b/src/mir/mir_builder.cpp index b53a9356..f4f9db7e 100644 --- a/src/mir/mir_builder.cpp +++ b/src/mir/mir_builder.cpp @@ -259,6 +259,9 @@ void MirBuilder::push_stmt_assign(const Span& sp, ::MIR::LValue dst, ::MIR::RVal case VarState::MaybeMoved: // ERROR? Temporaries shouldn't be resassigned after becoming valid break; + case VarState::InnerMoved: + BUG(sp, "Reassigning inner-moved temporary - " << dst); + break; case VarState::Init: // ERROR. Temporaries are single-assignment break; @@ -270,6 +273,7 @@ void MirBuilder::push_stmt_assign(const Span& sp, ::MIR::LValue dst, ::MIR::RVal //m_return_valid = true; ), (Variable, + // TODO: Ensure that slot is mutable (information is lost, assume true) switch( get_variable_state(sp, e) ) { case VarState::Uninit: @@ -279,10 +283,12 @@ void MirBuilder::push_stmt_assign(const Span& sp, ::MIR::LValue dst, ::MIR::RVal // TODO: Is this an error? The variable has descoped. break; case VarState::Init: - // 1. Must be mut - // 2. Drop (if not Copy) + // Drop (if not Copy) - Copy check is done within push_stmt_drop push_stmt_drop( sp, dst.clone() ); break; + case VarState::InnerMoved: + push_stmt_drop_shallow( sp, dst.clone() ); + break; case VarState::MaybeMoved: // TODO: Conditional drop break; @@ -304,6 +310,19 @@ void MirBuilder::push_stmt_drop(const Span& sp, ::MIR::LValue val) m_output.blocks.at(m_current_block).statements.push_back( ::MIR::Statement::make_Drop({ ::MIR::eDropKind::DEEP, mv$(val) }) ); } +void MirBuilder::push_stmt_drop_shallow(const Span& sp, ::MIR::LValue val) +{ + ASSERT_BUG(sp, m_block_active, "Pushing statement with no active block"); + ASSERT_BUG(sp, val.tag() != ::MIR::LValue::TAGDEAD, ""); + + // TODO: Ensure that the type is a Box + //if( lvalue_is_copy(sp, val) ) { + // // Don't emit a drop for Copy values + // return ; + //} + + m_output.blocks.at(m_current_block).statements.push_back( ::MIR::Statement::make_Drop({ ::MIR::eDropKind::SHALLOW, mv$(val) }) ); +} void MirBuilder::set_cur_block(unsigned int new_block) { @@ -518,6 +537,9 @@ void MirBuilder::complete_scope(ScopeDef& sd) case VarState::Moved: new_states[i] = VarState::MaybeMoved; break; + case VarState::InnerMoved: + TODO(sd.span, "Handle InnerMoved in Split scope (Init:arm.var_states)"); + break; case VarState::Dropped: BUG(sd.span, "Dropped value in arm"); break; @@ -527,6 +549,9 @@ void MirBuilder::complete_scope(ScopeDef& sd) new_states[i] = VarState::MaybeMoved; // MaybeInit? } break; + case VarState::InnerMoved: + TODO(sd.span, "Handle InnerMoved in Split scope (new_states)"); + break; case VarState::MaybeMoved: // Already optional, don't change break; @@ -547,6 +572,9 @@ void MirBuilder::complete_scope(ScopeDef& sd) case VarState::Moved: // No change break; + case VarState::InnerMoved: + TODO(sd.span, "Handle InnerMoved in Split scope (Moved:arm.var_states)"); + break; case VarState::Dropped: BUG(sd.span, "Dropped value in arm"); break; @@ -881,9 +909,22 @@ void MirBuilder::drop_scope_values(const ScopeDef& sd) (Temporaries, for(auto tmp_idx : ::reverse(e.temporaries)) { - if( get_temp_state(sd.span, tmp_idx) == VarState::Init ) { + switch( get_temp_state(sd.span, tmp_idx) ) + { + case VarState::Uninit: + case VarState::Dropped: + case VarState::Moved: + break; + case VarState::Init: push_stmt_drop( sd.span, ::MIR::LValue::make_Temporary({ tmp_idx }) ); set_temp_state(sd.span, tmp_idx, VarState::Dropped); + break; + case VarState::InnerMoved: + push_stmt_drop_shallow( sd.span, ::MIR::LValue::make_Temporary({ tmp_idx }) ); + set_temp_state(sd.span, tmp_idx, VarState::Dropped); + break; + case VarState::MaybeMoved: + BUG(sd.span, "Optionally moved temporary? - " << tmp_idx); } } ), @@ -899,8 +940,11 @@ void MirBuilder::drop_scope_values(const ScopeDef& sd) case VarState::Init: push_stmt_drop( sd.span, ::MIR::LValue::make_Variable(var_idx) ); break; + case VarState::InnerMoved: + push_stmt_drop_shallow( sd.span, ::MIR::LValue::make_Variable(var_idx) ); + break; case VarState::MaybeMoved: - //TODO(Span(), "MaybeMoved"); + //TODO(sd.span, "Include drop flags"); // TODO: Drop flags break; } @@ -981,15 +1025,17 @@ void MirBuilder::moved_lvalue(const Span& sp, const ::MIR::LValue& lv) BUG(sp, "Box move out of invalid LValue " << inner_lv << " - should have been moved"); ), (Variable, - TODO(sp, "Mark var " << ei << " for shallow drop"); + set_variable_state(sp, ei, VarState::InnerMoved); ), (Temporary, - TODO(sp, "Mark temp " << ei.idx << " for shallow drop"); + set_temp_state(sp, ei.idx, VarState::InnerMoved); ), (Argument, TODO(sp, "Mark arg " << ei.idx << " for shallow drop"); ) ) + // Early return! + return ; } } BUG(sp, "Move out of deref with non-Copy values - &move? - " << lv); @@ -1032,6 +1078,7 @@ ScopeHandle::~ScopeHandle() _(Init) _(MaybeMoved) _(Moved) + _(InnerMoved) _(Dropped) #undef _ } |