diff options
Diffstat (limited to 'src/librustc/middle/cfg/construct.rs')
| -rw-r--r-- | src/librustc/middle/cfg/construct.rs | 41 |
1 files changed, 39 insertions, 2 deletions
diff --git a/src/librustc/middle/cfg/construct.rs b/src/librustc/middle/cfg/construct.rs index 208a9d05716..4f6885f05ed 100644 --- a/src/librustc/middle/cfg/construct.rs +++ b/src/librustc/middle/cfg/construct.rs @@ -240,7 +240,7 @@ impl<'a> CFGBuilder<'a> { // v 3 // [expr] // - // Note that `break` and `loop` statements + // Note that `break` and `continue` statements // may cause additional edges. // Is the condition considered part of the loop? @@ -258,7 +258,44 @@ impl<'a> CFGBuilder<'a> { expr_exit } - ast::ExprForLoop(..) => fail!("non-desugared expr_for_loop"), + ast::ExprForLoop(ref pat, ref head, ref body, _) => { + // + // [pred] + // | + // v 1 + // [head] + // | + // v 2 + // [loopback] <--+ 7 + // | | + // v 3 | + // +------[cond] | + // | | | + // | v 5 | + // | [pat] | + // | | | + // | v 6 | + // v 4 [body] -----+ + // [expr] + // + // Note that `break` and `continue` statements + // may cause additional edges. + + let head = self.expr(head.clone(), pred); // 1 + let loopback = self.add_dummy_node([head]); // 2 + let cond = self.add_dummy_node([loopback]); // 3 + let expr_exit = self.add_node(expr.id, [cond]); // 4 + self.loop_scopes.push(LoopScope { + loop_id: expr.id, + continue_index: loopback, + break_index: expr_exit, + }); + let pat = self.pat(&**pat, cond); // 5 + let body = self.block(&**body, pat); // 6 + self.add_contained_edge(body, loopback); // 7 + self.loop_scopes.pop(); + expr_exit + } ast::ExprLoop(ref body, _) => { // |