1 // Copyright 2012 The Rust Project Developers. See the COPYRIGHT
2 // file at the top-level directory of this distribution and at
3 // http://rust-lang.org/COPYRIGHT.
5 // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
6 // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
7 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
8 // option. This file may not be copied, modified, or distributed
9 // except according to those terms.
13 use middle::lang_items::{PanicFnLangItem, PanicBoundsCheckFnLangItem};
15 use trans::basic_block::BasicBlock;
18 use trans::cleanup::CleanupMethods;
23 use trans::debuginfo::{DebugLoc, ToDebugLoc};
29 use rustc_front::util as ast_util;
32 use syntax::parse::token::InternedString;
33 use syntax::parse::token;
35 pub fn trans_stmt<'blk, 'tcx>(cx: Block<'blk, 'tcx>,
37 -> Block<'blk, 'tcx> {
38 let _icx = push_ctxt("trans_stmt");
40 debug!("trans_stmt({:?})", s);
42 if cx.unreachable.get() {
46 if cx.sess().asm_comments() {
47 add_span_comment(cx, s.span, &format!("{:?}", s));
52 let id = ast_util::stmt_id(s);
53 let cleanup_debug_loc =
54 debuginfo::get_cleanup_debug_loc_for_ast_node(bcx.ccx(), id, s.span, false);
55 fcx.push_ast_cleanup_scope(cleanup_debug_loc);
58 hir::StmtExpr(ref e, _) | hir::StmtSemi(ref e, _) => {
59 bcx = trans_stmt_semi(bcx, &**e);
61 hir::StmtDecl(ref d, _) => {
63 hir::DeclLocal(ref local) => {
64 bcx = init_local(bcx, &**local);
65 debuginfo::create_local_var_metadata(bcx, &**local);
67 // Inner items are visited by `trans_item`/`trans_meth`.
68 hir::DeclItem(_) => {},
73 bcx = fcx.pop_and_trans_ast_cleanup_scope(bcx, ast_util::stmt_id(s));
78 pub fn trans_stmt_semi<'blk, 'tcx>(cx: Block<'blk, 'tcx>, e: &hir::Expr)
79 -> Block<'blk, 'tcx> {
80 let _icx = push_ctxt("trans_stmt_semi");
82 if cx.unreachable.get() {
86 let ty = expr_ty(cx, e);
87 if cx.fcx.type_needs_drop(ty) {
88 expr::trans_to_lvalue(cx, e, "stmt").bcx
90 expr::trans_into(cx, e, expr::Ignore)
94 pub fn trans_block<'blk, 'tcx>(bcx: Block<'blk, 'tcx>,
97 -> Block<'blk, 'tcx> {
98 let _icx = push_ctxt("trans_block");
100 if bcx.unreachable.get() {
107 let cleanup_debug_loc =
108 debuginfo::get_cleanup_debug_loc_for_ast_node(bcx.ccx(), b.id, b.span, true);
109 fcx.push_ast_cleanup_scope(cleanup_debug_loc);
112 bcx = trans_stmt(bcx, &**s);
115 if dest != expr::Ignore {
116 let block_ty = node_id_type(bcx, b.id);
118 if b.expr.is_none() || type_is_zero_size(bcx.ccx(), block_ty) {
120 } else if b.expr.is_some() {
121 // If the block has an expression, but that expression isn't reachable,
122 // don't save into the destination given, ignore it.
123 if let Some(ref cfg) = bcx.fcx.cfg {
124 if !cfg.node_is_reachable(b.expr.as_ref().unwrap().id) {
133 if !bcx.unreachable.get() {
134 bcx = expr::trans_into(bcx, &**e, dest);
138 assert!(dest == expr::Ignore || bcx.unreachable.get());
142 bcx = fcx.pop_and_trans_ast_cleanup_scope(bcx, b.id);
147 pub fn trans_if<'blk, 'tcx>(bcx: Block<'blk, 'tcx>,
151 els: Option<&hir::Expr>,
153 -> Block<'blk, 'tcx> {
154 debug!("trans_if(bcx={}, if_id={}, cond={:?}, thn={}, dest={})",
155 bcx.to_str(), if_id, cond, thn.id,
156 dest.to_string(bcx.ccx()));
157 let _icx = push_ctxt("trans_if");
159 if bcx.unreachable.get() {
165 let cond_val = unpack_result!(bcx, expr::trans(bcx, cond).to_llbool());
167 // Drop branches that are known to be impossible
168 if let Some(cv) = const_to_opt_uint(cond_val) {
170 // if true { .. } [else { .. }]
171 bcx = trans_block(bcx, &*thn, dest);
172 trans::debuginfo::clear_source_location(bcx.fcx);
174 if let Some(elexpr) = els {
175 bcx = expr::trans_into(bcx, &*elexpr, dest);
176 trans::debuginfo::clear_source_location(bcx.fcx);
183 let name = format!("then-block-{}-", thn.id);
184 let then_bcx_in = bcx.fcx.new_id_block(&name[..], thn.id);
185 let then_bcx_out = trans_block(then_bcx_in, &*thn, dest);
186 trans::debuginfo::clear_source_location(bcx.fcx);
188 let cond_source_loc = cond.debug_loc();
193 let else_bcx_in = bcx.fcx.new_id_block("else-block", elexpr.id);
194 let else_bcx_out = expr::trans_into(else_bcx_in, &*elexpr, dest);
195 next_bcx = bcx.fcx.join_blocks(if_id,
196 &[then_bcx_out, else_bcx_out]);
197 CondBr(bcx, cond_val, then_bcx_in.llbb, else_bcx_in.llbb, cond_source_loc);
201 next_bcx = bcx.fcx.new_id_block("next-block", if_id);
202 Br(then_bcx_out, next_bcx.llbb, DebugLoc::None);
203 CondBr(bcx, cond_val, then_bcx_in.llbb, next_bcx.llbb, cond_source_loc);
207 // Clear the source location because it is still set to whatever has been translated
209 trans::debuginfo::clear_source_location(next_bcx.fcx);
214 pub fn trans_while<'blk, 'tcx>(bcx: Block<'blk, 'tcx>,
215 loop_expr: &hir::Expr,
218 -> Block<'blk, 'tcx> {
219 let _icx = push_ctxt("trans_while");
221 if bcx.unreachable.get() {
229 // cond_bcx_in <--------+
235 // | body_bcx_out --+
238 let next_bcx_in = fcx.new_id_block("while_exit", loop_expr.id);
239 let cond_bcx_in = fcx.new_id_block("while_cond", cond.id);
240 let body_bcx_in = fcx.new_id_block("while_body", body.id);
242 fcx.push_loop_cleanup_scope(loop_expr.id, [next_bcx_in, cond_bcx_in]);
244 Br(bcx, cond_bcx_in.llbb, loop_expr.debug_loc());
246 // compile the block where we will handle loop cleanups
247 let cleanup_llbb = fcx.normal_exit_block(loop_expr.id, cleanup::EXIT_BREAK);
249 // compile the condition
250 let Result {bcx: cond_bcx_out, val: cond_val} =
251 expr::trans(cond_bcx_in, cond).to_llbool();
253 CondBr(cond_bcx_out, cond_val, body_bcx_in.llbb, cleanup_llbb, cond.debug_loc());
256 let body_bcx_out = trans_block(body_bcx_in, body, expr::Ignore);
257 Br(body_bcx_out, cond_bcx_in.llbb, DebugLoc::None);
259 fcx.pop_loop_cleanup_scope(loop_expr.id);
263 pub fn trans_loop<'blk, 'tcx>(bcx: Block<'blk, 'tcx>,
264 loop_expr: &hir::Expr,
266 -> Block<'blk, 'tcx> {
267 let _icx = push_ctxt("trans_loop");
269 if bcx.unreachable.get() {
283 // Links between body_bcx_in and next_bcx are created by
286 let next_bcx_in = bcx.fcx.new_id_block("loop_exit", loop_expr.id);
287 let body_bcx_in = bcx.fcx.new_id_block("loop_body", body.id);
289 fcx.push_loop_cleanup_scope(loop_expr.id, [next_bcx_in, body_bcx_in]);
291 Br(bcx, body_bcx_in.llbb, loop_expr.debug_loc());
292 let body_bcx_out = trans_block(body_bcx_in, body, expr::Ignore);
293 Br(body_bcx_out, body_bcx_in.llbb, DebugLoc::None);
295 fcx.pop_loop_cleanup_scope(loop_expr.id);
297 // If there are no predecessors for the next block, we just translated an endless loop and the
298 // next block is unreachable
299 if BasicBlock(next_bcx_in.llbb).pred_iter().next().is_none() {
300 Unreachable(next_bcx_in);
306 pub fn trans_break_cont<'blk, 'tcx>(bcx: Block<'blk, 'tcx>,
308 opt_label: Option<ast::Ident>,
310 -> Block<'blk, 'tcx> {
311 let _icx = push_ctxt("trans_break_cont");
313 if bcx.unreachable.get() {
319 // Locate loop that we will break to
320 let loop_id = match opt_label {
321 None => fcx.top_loop_scope(),
323 match bcx.tcx().def_map.borrow().get(&expr.id).map(|d| d.full_def()) {
324 Some(def::DefLabel(loop_id)) => loop_id,
326 bcx.tcx().sess.bug(&format!("{:?} in def-map for label", r))
332 // Generate appropriate cleanup code and branch
333 let cleanup_llbb = fcx.normal_exit_block(loop_id, exit);
334 Br(bcx, cleanup_llbb, expr.debug_loc());
335 Unreachable(bcx); // anything afterwards should be ignored
339 pub fn trans_break<'blk, 'tcx>(bcx: Block<'blk, 'tcx>,
341 label_opt: Option<ast::Ident>)
342 -> Block<'blk, 'tcx> {
343 return trans_break_cont(bcx, expr, label_opt, cleanup::EXIT_BREAK);
346 pub fn trans_cont<'blk, 'tcx>(bcx: Block<'blk, 'tcx>,
348 label_opt: Option<ast::Ident>)
349 -> Block<'blk, 'tcx> {
350 return trans_break_cont(bcx, expr, label_opt, cleanup::EXIT_LOOP);
353 pub fn trans_ret<'blk, 'tcx>(bcx: Block<'blk, 'tcx>,
354 return_expr: &hir::Expr,
355 retval_expr: Option<&hir::Expr>)
356 -> Block<'blk, 'tcx> {
357 let _icx = push_ctxt("trans_ret");
359 if bcx.unreachable.get() {
365 let dest = match (fcx.llretslotptr.get(), retval_expr) {
366 (Some(_), Some(retval_expr)) => {
367 let ret_ty = expr_ty_adjusted(bcx, &*retval_expr);
368 expr::SaveIn(fcx.get_ret_slot(bcx, ty::FnConverging(ret_ty), "ret_slot"))
372 if let Some(x) = retval_expr {
373 bcx = expr::trans_into(bcx, &*x, dest);
375 expr::SaveIn(slot) if fcx.needs_ret_allocas => {
376 Store(bcx, slot, fcx.llretslotptr.get().unwrap());
381 let cleanup_llbb = fcx.return_exit_block();
382 Br(bcx, cleanup_llbb, return_expr.debug_loc());
387 pub fn trans_fail<'blk, 'tcx>(bcx: Block<'blk, 'tcx>,
388 call_info: NodeIdAndSpan,
389 fail_str: InternedString)
390 -> Block<'blk, 'tcx> {
392 let _icx = push_ctxt("trans_fail_value");
394 if bcx.unreachable.get() {
398 let v_str = C_str_slice(ccx, fail_str);
399 let loc = bcx.sess().codemap().lookup_char_pos(call_info.span.lo);
400 let filename = token::intern_and_get_ident(&loc.file.name);
401 let filename = C_str_slice(ccx, filename);
402 let line = C_u32(ccx, loc.line as u32);
403 let expr_file_line_const = C_struct(ccx, &[v_str, filename, line], false);
404 let expr_file_line = consts::addr_of(ccx, expr_file_line_const, "panic_loc");
405 let args = vec!(expr_file_line);
406 let did = langcall(bcx, Some(call_info.span), "", PanicFnLangItem);
407 let bcx = callee::trans_lang_call(bcx,
411 call_info.debug_loc()).bcx;
416 pub fn trans_fail_bounds_check<'blk, 'tcx>(bcx: Block<'blk, 'tcx>,
417 call_info: NodeIdAndSpan,
420 -> Block<'blk, 'tcx> {
422 let _icx = push_ctxt("trans_fail_bounds_check");
424 if bcx.unreachable.get() {
428 // Extract the file/line from the span
429 let loc = bcx.sess().codemap().lookup_char_pos(call_info.span.lo);
430 let filename = token::intern_and_get_ident(&loc.file.name);
432 // Invoke the lang item
433 let filename = C_str_slice(ccx, filename);
434 let line = C_u32(ccx, loc.line as u32);
435 let file_line_const = C_struct(ccx, &[filename, line], false);
436 let file_line = consts::addr_of(ccx, file_line_const, "panic_bounds_check_loc");
437 let args = vec!(file_line, index, len);
438 let did = langcall(bcx, Some(call_info.span), "", PanicBoundsCheckFnLangItem);
439 let bcx = callee::trans_lang_call(bcx,
443 call_info.debug_loc()).bcx;