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| author | John Hodge <tpg@mutabah.net> | 2017-01-01 15:35:45 +0800 |
|---|---|---|
| committer | John Hodge <tpg@mutabah.net> | 2017-01-01 15:35:45 +0800 |
| commit | 57d08b51b8f0a9aa87953feaef43530ff861c91b (patch) | |
| tree | e48d05860b6fae88a3d32484b5f718433645108e /src/trans | |
| parent | 4cd46a298c6611dd169eeae3ef7412f0c3af3289 (diff) | |
| download | mrust-57d08b51b8f0a9aa87953feaef43530ff861c91b.tar.gz | |
MIR/Trans - Fix DST field borrow hack
Diffstat (limited to 'src/trans')
| -rw-r--r-- | src/trans/codegen_c.cpp | 30 |
1 files changed, 23 insertions, 7 deletions
diff --git a/src/trans/codegen_c.cpp b/src/trans/codegen_c.cpp index 82b78dd8..7bdce493 100644 --- a/src/trans/codegen_c.cpp +++ b/src/trans/codegen_c.cpp @@ -953,22 +953,38 @@ namespace { } ), (Borrow, - emit_lvalue(e.dst); - m_of << " = "; + ::HIR::TypeRef tmp; + const auto& ty = mir_res.get_lvalue_type(tmp, ve.val); bool special = false; // If the inner value has type [T] or str, create DST based on inner pointer and existing metadata - TU_IFLET(::MIR::LValue, ve.val, Deref, e, - ::HIR::TypeRef tmp; - const auto& ty = mir_res.get_lvalue_type(tmp, ve.val); // NOTE: Checks the result of the deref + TU_IFLET(::MIR::LValue, ve.val, Deref, le, if( metadata_type(ty) != MetadataType::None ) { - emit_lvalue(*e.val); + emit_lvalue(e.dst); + m_of << " = "; + emit_lvalue(*le.val); special = true; } ) - // TODO: Magic for taking a &-ptr to unsized field of a struct. + // Magic for taking a &-ptr to unsized field of a struct. // - Needs to get metadata from bottom-level pointer. + else TU_IFLET(::MIR::LValue, ve.val, Field, le, + if( metadata_type(ty) != MetadataType::None ) { + const ::MIR::LValue* base_val = &*le.val; + while(base_val->is_Field()) + base_val = &*base_val->as_Field().val; + MIR_ASSERT(mir_res, base_val->is_Deref(), "DST access must be via a deref"); + const ::MIR::LValue& base_ptr = *base_val->as_Deref().val; + + // Construct the new DST + emit_lvalue(e.dst); m_of << ".META = "; emit_lvalue(base_ptr); m_of << ".META;\n\t"; + emit_lvalue(e.dst); m_of << ".PTR = &"; emit_lvalue(ve.val); + special = true; + } + ) if( !special ) { + emit_lvalue(e.dst); + m_of << " = "; m_of << "& "; emit_lvalue(ve.val); } ), |