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| author | John Hodge <tpg@mutabah.net> | 2016-12-24 12:07:55 +1100 |
|---|---|---|
| committer | John Hodge <tpg@mutabah.net> | 2016-12-24 12:07:55 +1100 |
| commit | 3c557d2413f1c6f7c1229ea351cce44014d3078b (patch) | |
| tree | d6acb60f67573b5ed552ad34cafd34a33c4eaf9e | |
| parent | 07e150e9d7d638977ba3a1561d2687950a2a4668 (diff) | |
| download | mrust-3c557d2413f1c6f7c1229ea351cce44014d3078b.tar.gz | |
MIR Gen - Better scoping for single-arm matches
| -rw-r--r-- | src/mir/from_hir.cpp | 24 |
1 files changed, 19 insertions, 5 deletions
diff --git a/src/mir/from_hir.cpp b/src/mir/from_hir.cpp index 655591a5..7218563b 100644 --- a/src/mir/from_hir.cpp +++ b/src/mir/from_hir.cpp @@ -529,15 +529,29 @@ namespace { } else if( node.m_arms.size() == 1 && node.m_arms[0].m_patterns.size() == 1 && ! node.m_arms[0].m_cond ) { // - Shortcut: Single-arm match - auto scope = m_builder.new_scope_var( node.span() ); - this->define_vars_from(node.span(), node.m_arms[0].m_patterns[0]); - this->destructure_from(node.span(), node.m_arms[0].m_patterns[0], mv$(match_val)); - this->visit_node_ptr(node.m_arms[0].m_code); + auto& arm = node.m_arms[0]; + const auto& pat = arm.m_patterns[0]; + + auto scope = m_builder.new_scope_var(arm.m_code->span()); + auto tmp_scope = m_builder.new_scope_temp(arm.m_code->span()); + this->define_vars_from(node.span(), pat); + // TODO: Do the same shortcut as _Let? + this->destructure_from(node.span(), pat, mv$(match_val)); + + // Temp scope. + this->visit_node_ptr(arm.m_code); + if( m_builder.block_active() ) { + auto res = m_builder.get_result(arm.m_code->span()); + m_builder.raise_variables( arm.m_code->span(), res ); + m_builder.set_result(arm.m_code->span(), mv$(res)); + + m_builder.terminate_scope( node.span(), mv$(tmp_scope) ); m_builder.terminate_scope( node.span(), mv$(scope) ); } else { - auto _ = mv$(scope); + { auto _ = mv$(tmp_scope); } + { auto _ = mv$(scope); } } } else { |