MIR Gen - Fix codegen issue with use of moved LValue

2 files changed, 35 insertions, 6 deletions

diff --git a/src/mir/from_hir.cpp b/src/mir/from_hir.cpp
index f54ead5a..001fe62e 100644
--- a/src/mir/from_hir.cpp
+++ b/src/mir/from_hir.cpp
@@ -443,7 +443,6 @@ namespace {
                 ASSERT_BUG(sp, ty_slot.m_data.is_Primitive(), "Assignment operator overloads are only valid on primitives - ty_slot="<<ty_slot);
                 ASSERT_BUG(sp, ty_val.m_data.is_Primitive(), "Assignment operator overloads are only valid on primitives - ty_val="<<ty_val);
                 
-                ::MIR::RValue res;
                 #define _(v)    ::HIR::ExprNode_Assign::Op::v
                 ::MIR::eBinOp   op;
                 switch(node.m_op)
@@ -470,8 +469,6 @@ namespace {
                     break;
                 }
                 #undef _
-                
-                m_builder.push_stmt_assign(mv$(dst), mv$(res));
             }
             else
             {
@@ -1335,11 +1332,14 @@ void MirBuilder::set_result(const Span& sp, ::MIR::RValue val)
 void MirBuilder::push_stmt_assign(::MIR::LValue dst, ::MIR::RValue val)
 {
     ASSERT_BUG(Span(), m_block_active, "Pushing statement with no active block");
+    ASSERT_BUG(Span(), dst.tag() != ::MIR::LValue::TAGDEAD, "");
+    ASSERT_BUG(Span(), val.tag() != ::MIR::RValue::TAGDEAD, "");
     m_output.blocks.at(m_current_block).statements.push_back( ::MIR::Statement::make_Assign({ mv$(dst), mv$(val) }) );
 }
 void MirBuilder::push_stmt_drop(::MIR::LValue val)
 {
     ASSERT_BUG(Span(), m_block_active, "Pushing statement with no active block");
+    ASSERT_BUG(Span(), val.tag() != ::MIR::LValue::TAGDEAD, "");
     m_output.blocks.at(m_current_block).statements.push_back( ::MIR::Statement::make_Drop({ ::MIR::eDropKind::DEEP, mv$(val) }) );
 }
 
diff --git a/src/mir/mir.cpp b/src/mir/mir.cpp
index df6e1cde..7a201f46 100644
--- a/src/mir/mir.cpp
+++ b/src/mir/mir.cpp
@@ -38,6 +38,35 @@ namespace MIR {
     
     ::std::ostream& operator<<(::std::ostream& os, const LValue& x)
     {
+        TU_MATCHA( (x), (e),
+        (Variable,
+            os << "Variable(" << e << ")";
+            ),
+        (Temporary,
+            os << "Temporary(" << e.idx << ")";
+            ),
+        (Argument,
+            os << "Argument(" << e.idx << ")";
+            ),
+        (Static,
+            os << "Static(" << e << ")";
+            ),
+        (Return,
+            os << "Return";
+            ),
+        (Field,
+            os << "Field(" << e.field_index << ", " << *e.val << ")";
+            ),
+        (Deref,
+            os << "Deref(" << *e.val << ")";
+            ),
+        (Index,
+            os << "Deref(" << *e.val << ", " << *e.idx << ")";
+            ),
+        (Downcast,
+            os << "Downcast(" << e.variant_index << ", " << *e.val << ")";
+            )
+        )
         return os;
     }
     
@@ -60,16 +89,16 @@ namespace MIR {
             os << "Panic(" << e.dst << ";)";
             ),
         (If,
-            os << "If( ? : " << e.bb0 << ", " << e.bb1 << ")";
+            os << "If( " << e.cond << " : " << e.bb0 << ", " << e.bb1 << ")";
             ),
         (Switch,
-            os << "Switch( ? : ";
+            os << "Switch( " << e.val << " : ";
             for(unsigned int j = 0; j < e.targets.size(); j ++)
                 os << j << " => bb" << e.targets[j] << ", ";
             os << ")";
             ),
         (Call,
-            os << "Call( ? = ?( ";
+            os << "Call( " << e.ret_val << " = " << e.fcn_val << "( ";
             for(const auto& arg : e.args)
                 os << arg << ", ";
             os << "), bb" << e.ret_block << ", bb" << e.panic_block << ")";