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};
27 use util::ppaux::Repr;
31 use syntax::parse::token::InternedString;
32 use syntax::parse::token;
33 use syntax::visit::Visitor;
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.repr(cx.tcx()));
42 if cx.unreachable.get() {
46 if cx.sess().asm_comments() {
47 add_span_comment(cx, s.span, &s.repr(cx.tcx()));
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 ast::StmtExpr(ref e, _) | ast::StmtSemi(ref e, _) => {
59 bcx = trans_stmt_semi(bcx, &**e);
61 ast::StmtDecl(ref d, _) => {
63 ast::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 ast::DeclItem(_) => {},
71 ast::StmtMac(..) => cx.tcx().sess.bug("unexpanded macro")
74 bcx = fcx.pop_and_trans_ast_cleanup_scope(bcx, ast_util::stmt_id(s));
79 pub fn trans_stmt_semi<'blk, 'tcx>(cx: Block<'blk, 'tcx>, e: &ast::Expr)
80 -> Block<'blk, 'tcx> {
81 let _icx = push_ctxt("trans_stmt_semi");
83 if cx.unreachable.get() {
87 let ty = expr_ty(cx, e);
88 if cx.fcx.type_needs_drop(ty) {
89 expr::trans_to_lvalue(cx, e, "stmt").bcx
91 expr::trans_into(cx, e, expr::Ignore)
95 pub fn trans_block<'blk, 'tcx>(bcx: Block<'blk, 'tcx>,
98 -> Block<'blk, 'tcx> {
99 let _icx = push_ctxt("trans_block");
101 if bcx.unreachable.get() {
108 let cleanup_debug_loc =
109 debuginfo::get_cleanup_debug_loc_for_ast_node(bcx.ccx(), b.id, b.span, true);
110 fcx.push_ast_cleanup_scope(cleanup_debug_loc);
113 bcx = trans_stmt(bcx, &**s);
116 if dest != expr::Ignore {
117 let block_ty = node_id_type(bcx, b.id);
119 if b.expr.is_none() || type_is_zero_size(bcx.ccx(), block_ty) {
121 } else if b.expr.is_some() {
122 // If the block has an expression, but that expression isn't reachable,
123 // don't save into the destination given, ignore it.
124 if let Some(ref cfg) = bcx.fcx.cfg {
125 if !cfg.node_is_reachable(b.expr.as_ref().unwrap().id) {
134 bcx = expr::trans_into(bcx, &**e, dest);
137 assert!(dest == expr::Ignore || bcx.unreachable.get());
141 bcx = fcx.pop_and_trans_ast_cleanup_scope(bcx, b.id);
146 pub fn trans_if<'blk, 'tcx>(bcx: Block<'blk, 'tcx>,
150 els: Option<&ast::Expr>,
152 -> Block<'blk, 'tcx> {
153 debug!("trans_if(bcx={}, if_id={}, cond={}, thn={}, dest={})",
154 bcx.to_str(), if_id, bcx.expr_to_string(cond), thn.id,
155 dest.to_string(bcx.ccx()));
156 let _icx = push_ctxt("trans_if");
158 if bcx.unreachable.get() {
164 let cond_val = unpack_result!(bcx, expr::trans(bcx, cond).to_llbool());
166 // Drop branches that are known to be impossible
167 if is_const(cond_val) && !is_undef(cond_val) {
168 if const_to_uint(cond_val) == 1 {
171 let mut trans = TransItemVisitor { ccx: bcx.fcx.ccx };
172 trans.visit_expr(&*elexpr);
176 // if true { .. } [else { .. }]
177 bcx = trans_block(bcx, &*thn, dest);
178 trans::debuginfo::clear_source_location(bcx.fcx);
180 let mut trans = TransItemVisitor { ccx: bcx.fcx.ccx } ;
181 trans.visit_block(&*thn);
184 // if false { .. } else { .. }
186 bcx = expr::trans_into(bcx, &*elexpr, dest);
187 trans::debuginfo::clear_source_location(bcx.fcx);
198 let name = format!("then-block-{}-", thn.id);
199 let then_bcx_in = bcx.fcx.new_id_block(&name[..], thn.id);
200 let then_bcx_out = trans_block(then_bcx_in, &*thn, dest);
201 trans::debuginfo::clear_source_location(bcx.fcx);
203 let cond_source_loc = cond.debug_loc();
208 let else_bcx_in = bcx.fcx.new_id_block("else-block", elexpr.id);
209 let else_bcx_out = expr::trans_into(else_bcx_in, &*elexpr, dest);
210 next_bcx = bcx.fcx.join_blocks(if_id,
211 &[then_bcx_out, else_bcx_out]);
212 CondBr(bcx, cond_val, then_bcx_in.llbb, else_bcx_in.llbb, cond_source_loc);
216 next_bcx = bcx.fcx.new_id_block("next-block", if_id);
217 Br(then_bcx_out, next_bcx.llbb, DebugLoc::None);
218 CondBr(bcx, cond_val, then_bcx_in.llbb, next_bcx.llbb, cond_source_loc);
222 // Clear the source location because it is still set to whatever has been translated
224 trans::debuginfo::clear_source_location(next_bcx.fcx);
229 pub fn trans_while<'blk, 'tcx>(bcx: Block<'blk, 'tcx>,
230 loop_expr: &ast::Expr,
233 -> Block<'blk, 'tcx> {
234 let _icx = push_ctxt("trans_while");
236 if bcx.unreachable.get() {
244 // cond_bcx_in <--------+
250 // | body_bcx_out --+
253 let next_bcx_in = fcx.new_id_block("while_exit", loop_expr.id);
254 let cond_bcx_in = fcx.new_id_block("while_cond", cond.id);
255 let body_bcx_in = fcx.new_id_block("while_body", body.id);
257 fcx.push_loop_cleanup_scope(loop_expr.id, [next_bcx_in, cond_bcx_in]);
259 Br(bcx, cond_bcx_in.llbb, loop_expr.debug_loc());
261 // compile the block where we will handle loop cleanups
262 let cleanup_llbb = fcx.normal_exit_block(loop_expr.id, cleanup::EXIT_BREAK);
264 // compile the condition
265 let Result {bcx: cond_bcx_out, val: cond_val} =
266 expr::trans(cond_bcx_in, cond).to_llbool();
268 CondBr(cond_bcx_out, cond_val, body_bcx_in.llbb, cleanup_llbb, cond.debug_loc());
271 let body_bcx_out = trans_block(body_bcx_in, body, expr::Ignore);
272 Br(body_bcx_out, cond_bcx_in.llbb, DebugLoc::None);
274 fcx.pop_loop_cleanup_scope(loop_expr.id);
278 pub fn trans_loop<'blk, 'tcx>(bcx: Block<'blk, 'tcx>,
279 loop_expr: &ast::Expr,
281 -> Block<'blk, 'tcx> {
282 let _icx = push_ctxt("trans_loop");
284 if bcx.unreachable.get() {
298 // Links between body_bcx_in and next_bcx are created by
301 let next_bcx_in = bcx.fcx.new_id_block("loop_exit", loop_expr.id);
302 let body_bcx_in = bcx.fcx.new_id_block("loop_body", body.id);
304 fcx.push_loop_cleanup_scope(loop_expr.id, [next_bcx_in, body_bcx_in]);
306 Br(bcx, body_bcx_in.llbb, loop_expr.debug_loc());
307 let body_bcx_out = trans_block(body_bcx_in, body, expr::Ignore);
308 Br(body_bcx_out, body_bcx_in.llbb, DebugLoc::None);
310 fcx.pop_loop_cleanup_scope(loop_expr.id);
312 // If there are no predecessors for the next block, we just translated an endless loop and the
313 // next block is unreachable
314 if BasicBlock(next_bcx_in.llbb).pred_iter().next().is_none() {
315 Unreachable(next_bcx_in);
321 pub fn trans_break_cont<'blk, 'tcx>(bcx: Block<'blk, 'tcx>,
323 opt_label: Option<ast::Ident>,
325 -> Block<'blk, 'tcx> {
326 let _icx = push_ctxt("trans_break_cont");
328 if bcx.unreachable.get() {
334 // Locate loop that we will break to
335 let loop_id = match opt_label {
336 None => fcx.top_loop_scope(),
338 match bcx.tcx().def_map.borrow().get(&expr.id).map(|d| d.full_def()) {
339 Some(def::DefLabel(loop_id)) => loop_id,
341 bcx.tcx().sess.bug(&format!("{:?} in def-map for label", r))
347 // Generate appropriate cleanup code and branch
348 let cleanup_llbb = fcx.normal_exit_block(loop_id, exit);
349 Br(bcx, cleanup_llbb, expr.debug_loc());
350 Unreachable(bcx); // anything afterwards should be ignored
354 pub fn trans_break<'blk, 'tcx>(bcx: Block<'blk, 'tcx>,
356 label_opt: Option<ast::Ident>)
357 -> Block<'blk, 'tcx> {
358 return trans_break_cont(bcx, expr, label_opt, cleanup::EXIT_BREAK);
361 pub fn trans_cont<'blk, 'tcx>(bcx: Block<'blk, 'tcx>,
363 label_opt: Option<ast::Ident>)
364 -> Block<'blk, 'tcx> {
365 return trans_break_cont(bcx, expr, label_opt, cleanup::EXIT_LOOP);
368 pub fn trans_ret<'blk, 'tcx>(bcx: Block<'blk, 'tcx>,
369 return_expr: &ast::Expr,
370 retval_expr: Option<&ast::Expr>)
371 -> Block<'blk, 'tcx> {
372 let _icx = push_ctxt("trans_ret");
374 if bcx.unreachable.get() {
380 let dest = match (fcx.llretslotptr.get(), retval_expr) {
381 (Some(_), Some(retval_expr)) => {
382 let ret_ty = expr_ty_adjusted(bcx, &*retval_expr);
383 expr::SaveIn(fcx.get_ret_slot(bcx, ty::FnConverging(ret_ty), "ret_slot"))
387 if let Some(x) = retval_expr {
388 bcx = expr::trans_into(bcx, &*x, dest);
390 expr::SaveIn(slot) if fcx.needs_ret_allocas => {
391 Store(bcx, slot, fcx.llretslotptr.get().unwrap());
396 let cleanup_llbb = fcx.return_exit_block();
397 Br(bcx, cleanup_llbb, return_expr.debug_loc());
402 pub fn trans_fail<'blk, 'tcx>(bcx: Block<'blk, 'tcx>,
403 call_info: NodeIdAndSpan,
404 fail_str: InternedString)
405 -> Block<'blk, 'tcx> {
407 let _icx = push_ctxt("trans_fail_value");
409 if bcx.unreachable.get() {
413 let v_str = C_str_slice(ccx, fail_str);
414 let loc = bcx.sess().codemap().lookup_char_pos(call_info.span.lo);
415 let filename = token::intern_and_get_ident(&loc.file.name);
416 let filename = C_str_slice(ccx, filename);
417 let line = C_u32(ccx, loc.line as u32);
418 let expr_file_line_const = C_struct(ccx, &[v_str, filename, line], false);
419 let expr_file_line = consts::addr_of(ccx, expr_file_line_const, "panic_loc");
420 let args = vec!(expr_file_line);
421 let did = langcall(bcx, Some(call_info.span), "", PanicFnLangItem);
422 let bcx = callee::trans_lang_call(bcx,
426 call_info.debug_loc()).bcx;
431 pub fn trans_fail_bounds_check<'blk, 'tcx>(bcx: Block<'blk, 'tcx>,
432 call_info: NodeIdAndSpan,
435 -> Block<'blk, 'tcx> {
437 let _icx = push_ctxt("trans_fail_bounds_check");
439 if bcx.unreachable.get() {
443 // Extract the file/line from the span
444 let loc = bcx.sess().codemap().lookup_char_pos(call_info.span.lo);
445 let filename = token::intern_and_get_ident(&loc.file.name);
447 // Invoke the lang item
448 let filename = C_str_slice(ccx, filename);
449 let line = C_u32(ccx, loc.line as u32);
450 let file_line_const = C_struct(ccx, &[filename, line], false);
451 let file_line = consts::addr_of(ccx, file_line_const, "panic_bounds_check_loc");
452 let args = vec!(file_line, index, len);
453 let did = langcall(bcx, Some(call_info.span), "", PanicBoundsCheckFnLangItem);
454 let bcx = callee::trans_lang_call(bcx,
458 call_info.debug_loc()).bcx;