diff --git a/src/librustc/middle/trans/controlflow.rs b/src/librustc/middle/trans/controlflow.rs index e9eb7ff086dd..81260428f241 100644 --- a/src/librustc/middle/trans/controlflow.rs +++ b/src/librustc/middle/trans/controlflow.rs @@ -67,13 +67,8 @@ pub fn trans_if(bcx: block, expr::trans_to_datum(bcx, cond).to_result(); let then_bcx_in = scope_block(bcx, thn.info(), "then"); - let else_bcx_in = scope_block(bcx, els.info(), "else"); let cond_val = bool_to_i1(bcx, cond_val); - CondBr(bcx, cond_val, then_bcx_in.llbb, else_bcx_in.llbb); - - debug!("then_bcx_in=%s, else_bcx_in=%s", - then_bcx_in.to_str(), else_bcx_in.to_str()); let then_bcx_out = trans_block(then_bcx_in, thn, dest); let then_bcx_out = trans_block_cleanups(then_bcx_out, @@ -83,9 +78,10 @@ pub fn trans_if(bcx: block, // because trans_expr will create another scope block // context for the block, but we've already got the // 'else' context - let else_bcx_out = match els { + let (else_bcx_in, next_bcx) = match els { Some(elexpr) => { - match elexpr.node { + let else_bcx_in = scope_block(bcx, els.info(), "else"); + let else_bcx_out = match elexpr.node { ast::expr_if(_, _, _) => { let elseif_blk = ast_util::block_from_expr(elexpr); trans_block(else_bcx_in, &elseif_blk, dest) @@ -95,14 +91,25 @@ pub fn trans_if(bcx: block, } // would be nice to have a constraint on ifs _ => bcx.tcx().sess.bug("strange alternative in if") - } - } - _ => else_bcx_in - }; - let else_bcx_out = trans_block_cleanups(else_bcx_out, - block_cleanups(else_bcx_in)); - return join_blocks(bcx, [then_bcx_out, else_bcx_out]); + }; + let else_bcx_out = trans_block_cleanups(else_bcx_out, + block_cleanups(else_bcx_in)); + (else_bcx_in, join_blocks(bcx, [then_bcx_out, else_bcx_out])) + } + _ => { + let next_bcx = sub_block(bcx, "next"); + Br(then_bcx_out, next_bcx.llbb); + + (next_bcx, next_bcx) + } + }; + + debug!("then_bcx_in=%s, else_bcx_in=%s", + then_bcx_in.to_str(), else_bcx_in.to_str()); + + CondBr(bcx, cond_val, then_bcx_in.llbb, else_bcx_in.llbb); + next_bcx } pub fn join_blocks(parent_bcx: block, in_cxs: &[block]) -> block {