diff --git a/src/librustc/middle/cfg/mod.rs b/src/librustc/middle/cfg/mod.rs index bc512a73a4bd..0e9bd42a23a1 100644 --- a/src/librustc/middle/cfg/mod.rs +++ b/src/librustc/middle/cfg/mod.rs @@ -49,4 +49,11 @@ impl CFG { blk: &ast::Block) -> CFG { construct::construct(tcx, blk) } + + pub fn node_is_reachable(&self, id: ast::NodeId) -> bool { + for node in self.graph.depth_traverse(self.entry) { + if node.id == id { return true } + } + return false; + } } diff --git a/src/librustc/middle/graph.rs b/src/librustc/middle/graph.rs index 4c03ed2a480e..4397f03a6428 100644 --- a/src/librustc/middle/graph.rs +++ b/src/librustc/middle/graph.rs @@ -34,6 +34,7 @@ use std::fmt::{Formatter, Error, Show}; use std::uint; +use std::collections::BitvSet; pub struct Graph { nodes: Vec> , @@ -294,6 +295,42 @@ impl Graph { } } } + + pub fn depth_traverse<'a>(&'a self, start: NodeIndex) -> DepthFirstTraversal<'a, N, E> { + DepthFirstTraversal { + graph: self, + stack: vec![start], + visited: BitvSet::new() + } + } +} + +pub struct DepthFirstTraversal<'g, N:'g, E:'g> { + graph: &'g Graph, + stack: Vec, + visited: BitvSet +} + +impl<'g, N, E> Iterator<&'g N> for DepthFirstTraversal<'g, N, E> { + fn next(&mut self) -> Option<&'g N> { + while self.stack.len() > 0 { + let idx = self.stack.pop().unwrap(); + if self.visited.contains(&idx.node_id()) { + continue; + } + self.visited.insert(idx.node_id()); + self.graph.each_outgoing_edge(idx, |_, e| -> bool { + if !self.visited.contains(&e.target().node_id()) { + self.stack.push(e.target()); + } + true + }); + + return Some(self.graph.node_data(idx)); + } + + return None; + } } pub fn each_edge_index(max_edge_index: EdgeIndex, mut f: F) where diff --git a/src/librustc_driver/lib.rs b/src/librustc_driver/lib.rs index b0f8b3bdbe7d..82d3edfa5e04 100644 --- a/src/librustc_driver/lib.rs +++ b/src/librustc_driver/lib.rs @@ -472,7 +472,7 @@ pub fn list_metadata(sess: &Session, path: &Path, /// The diagnostic emitter yielded to the procedure should be used for reporting /// errors of the compiler. pub fn monitor(f: F) { - static STACK_SIZE: uint = 32000000; // 32MB + static STACK_SIZE: uint = 8 * 1024 * 1024; // 8MB let (tx, rx) = channel(); let w = io::ChanWriter::new(tx); diff --git a/src/librustc_trans/trans/base.rs b/src/librustc_trans/trans/base.rs index 83779ffbe161..1a82a7131a77 100644 --- a/src/librustc_trans/trans/base.rs +++ b/src/librustc_trans/trans/base.rs @@ -38,6 +38,7 @@ use llvm::{BasicBlockRef, Linkage, ValueRef, Vector, get_param}; use llvm; use metadata::{csearch, encoder, loader}; use middle::astencode; +use middle::cfg; use middle::lang_items::{LangItem, ExchangeMallocFnLangItem, StartFnLangItem}; use middle::subst; use middle::weak_lang_items; @@ -1305,47 +1306,33 @@ pub fn make_return_slot_pointer<'a, 'tcx>(fcx: &FunctionContext<'a, 'tcx>, } } -struct CheckForNestedReturnsVisitor { +struct FindNestedReturn { found: bool, - in_return: bool } -impl CheckForNestedReturnsVisitor { - fn explicit() -> CheckForNestedReturnsVisitor { - CheckForNestedReturnsVisitor { found: false, in_return: false } - } - fn implicit() -> CheckForNestedReturnsVisitor { - CheckForNestedReturnsVisitor { found: false, in_return: true } +impl FindNestedReturn { + fn new() -> FindNestedReturn { + FindNestedReturn { found: false } } } -impl<'v> Visitor<'v> for CheckForNestedReturnsVisitor { +impl<'v> Visitor<'v> for FindNestedReturn { fn visit_expr(&mut self, e: &ast::Expr) { match e.node { ast::ExprRet(..) => { - if self.in_return { - self.found = true; - } else { - self.in_return = true; - visit::walk_expr(self, e); - self.in_return = false; - } + self.found = true; } _ => visit::walk_expr(self, e) } } } -fn has_nested_returns(tcx: &ty::ctxt, id: ast::NodeId) -> bool { - match tcx.map.find(id) { +fn build_cfg(tcx: &ty::ctxt, id: ast::NodeId) -> (ast::NodeId, Option) { + let blk = match tcx.map.find(id) { Some(ast_map::NodeItem(i)) => { match i.node { ast::ItemFn(_, _, _, _, ref blk) => { - let mut explicit = CheckForNestedReturnsVisitor::explicit(); - let mut implicit = CheckForNestedReturnsVisitor::implicit(); - visit::walk_item(&mut explicit, &*i); - visit::walk_expr_opt(&mut implicit, &blk.expr); - explicit.found || implicit.found + blk } _ => tcx.sess.bug("unexpected item variant in has_nested_returns") } @@ -1355,11 +1342,7 @@ fn has_nested_returns(tcx: &ty::ctxt, id: ast::NodeId) -> bool { ast::ProvidedMethod(ref m) => { match m.node { ast::MethDecl(_, _, _, _, _, _, ref blk, _) => { - let mut explicit = CheckForNestedReturnsVisitor::explicit(); - let mut implicit = CheckForNestedReturnsVisitor::implicit(); - visit::walk_method_helper(&mut explicit, &**m); - visit::walk_expr_opt(&mut implicit, &blk.expr); - explicit.found || implicit.found + blk } ast::MethMac(_) => tcx.sess.bug("unexpanded macro") } @@ -1379,11 +1362,7 @@ fn has_nested_returns(tcx: &ty::ctxt, id: ast::NodeId) -> bool { ast::MethodImplItem(ref m) => { match m.node { ast::MethDecl(_, _, _, _, _, _, ref blk, _) => { - let mut explicit = CheckForNestedReturnsVisitor::explicit(); - let mut implicit = CheckForNestedReturnsVisitor::implicit(); - visit::walk_method_helper(&mut explicit, &**m); - visit::walk_expr_opt(&mut implicit, &blk.expr); - explicit.found || implicit.found + blk } ast::MethMac(_) => tcx.sess.bug("unexpanded macro") } @@ -1397,24 +1376,47 @@ fn has_nested_returns(tcx: &ty::ctxt, id: ast::NodeId) -> bool { Some(ast_map::NodeExpr(e)) => { match e.node { ast::ExprClosure(_, _, _, ref blk) => { - let mut explicit = CheckForNestedReturnsVisitor::explicit(); - let mut implicit = CheckForNestedReturnsVisitor::implicit(); - visit::walk_expr(&mut explicit, e); - visit::walk_expr_opt(&mut implicit, &blk.expr); - explicit.found || implicit.found + blk } _ => tcx.sess.bug("unexpected expr variant in has_nested_returns") } } - - Some(ast_map::NodeVariant(..)) | Some(ast_map::NodeStructCtor(..)) => false, + Some(ast_map::NodeVariant(..)) | Some(ast_map::NodeStructCtor(..)) => return (ast::DUMMY_NODE_ID, None), // glue, shims, etc - None if id == ast::DUMMY_NODE_ID => false, + None if id == ast::DUMMY_NODE_ID => return (ast::DUMMY_NODE_ID, None), _ => tcx.sess.bug(format!("unexpected variant in has_nested_returns: {}", tcx.map.path_to_string(id)).as_slice()) + }; + + (blk.id, Some(cfg::CFG::new(tcx, &**blk))) +} + +fn has_nested_returns(tcx: &ty::ctxt, cfg: &cfg::CFG, blk_id: ast::NodeId) -> bool { + for n in cfg.graph.depth_traverse(cfg.entry) { + match tcx.map.find(n.id) { + Some(ast_map::NodeExpr(ex)) => { + if let ast::ExprRet(Some(ref ret_expr)) = ex.node { + let mut visitor = FindNestedReturn::new(); + visit::walk_expr(&mut visitor, &**ret_expr); + if visitor.found { + return true; + } + } + } + Some(ast_map::NodeBlock(blk)) if blk.id == blk_id => { + let mut visitor = FindNestedReturn::new(); + visit::walk_expr_opt(&mut visitor, &blk.expr); + if visitor.found { + return true; + } + } + _ => {} + } } + + return false; } // NB: must keep 4 fns in sync: @@ -1453,7 +1455,12 @@ pub fn new_fn_ctxt<'a, 'tcx>(ccx: &'a CrateContext<'a, 'tcx>, ty::FnDiverging => false }; let debug_context = debuginfo::create_function_debug_context(ccx, id, param_substs, llfndecl); - let nested_returns = has_nested_returns(ccx.tcx(), id); + let (blk_id, cfg) = build_cfg(ccx.tcx(), id); + let nested_returns = if let Some(ref cfg) = cfg { + has_nested_returns(ccx.tcx(), cfg, blk_id) + } else { + false + }; let mut fcx = FunctionContext { llfn: llfndecl, @@ -1472,7 +1479,8 @@ pub fn new_fn_ctxt<'a, 'tcx>(ccx: &'a CrateContext<'a, 'tcx>, block_arena: block_arena, ccx: ccx, debug_context: debug_context, - scopes: RefCell::new(Vec::new()) + scopes: RefCell::new(Vec::new()), + cfg: cfg }; if has_env { diff --git a/src/librustc_trans/trans/common.rs b/src/librustc_trans/trans/common.rs index 83938fa33570..c8a628a33e7a 100644 --- a/src/librustc_trans/trans/common.rs +++ b/src/librustc_trans/trans/common.rs @@ -18,6 +18,7 @@ use session::Session; use llvm; use llvm::{ValueRef, BasicBlockRef, BuilderRef, ContextRef}; use llvm::{True, False, Bool}; +use middle::cfg; use middle::def; use middle::infer; use middle::lang_items::LangItem; @@ -264,6 +265,8 @@ pub struct FunctionContext<'a, 'tcx: 'a> { // Cleanup scopes. pub scopes: RefCell>>, + + pub cfg: Option, } impl<'a, 'tcx> FunctionContext<'a, 'tcx> {