c-semantics.c revision 256281
1/* This file contains the definitions and documentation for the common 2 tree codes used in the GNU C and C++ compilers (see c-common.def 3 for the standard codes). 4 Copyright (C) 2000, 2001, 2002, 2003, 2004, 2005 5 Free Software Foundation, Inc. 6 Written by Benjamin Chelf (chelf@codesourcery.com). 7 8This file is part of GCC. 9 10GCC is free software; you can redistribute it and/or modify it under 11the terms of the GNU General Public License as published by the Free 12Software Foundation; either version 2, or (at your option) any later 13version. 14 15GCC is distributed in the hope that it will be useful, but WITHOUT ANY 16WARRANTY; without even the implied warranty of MERCHANTABILITY or 17FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 18for more details. 19 20You should have received a copy of the GNU General Public License 21along with GCC; see the file COPYING. If not, write to the Free 22Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 2302110-1301, USA. */ 24 25#include "config.h" 26#include "system.h" 27#include "coretypes.h" 28#include "tm.h" 29#include "tree.h" 30#include "function.h" 31#include "splay-tree.h" 32#include "varray.h" 33#include "c-common.h" 34#include "except.h" 35/* In order for the format checking to accept the C frontend 36 diagnostic framework extensions, you must define this token before 37 including toplev.h. */ 38#define GCC_DIAG_STYLE __gcc_cdiag__ 39#include "toplev.h" 40#include "flags.h" 41#include "ggc.h" 42#include "rtl.h" 43#include "output.h" 44#include "timevar.h" 45#include "predict.h" 46#include "tree-inline.h" 47#include "tree-gimple.h" 48#include "langhooks.h" 49 50/* Create an empty statement tree rooted at T. */ 51 52tree 53push_stmt_list (void) 54{ 55 tree t; 56 t = alloc_stmt_list (); 57 TREE_CHAIN (t) = cur_stmt_list; 58 cur_stmt_list = t; 59 return t; 60} 61 62/* Finish the statement tree rooted at T. */ 63 64tree 65pop_stmt_list (tree t) 66{ 67 tree u = cur_stmt_list, chain; 68 69 /* Pop statement lists until we reach the target level. The extra 70 nestings will be due to outstanding cleanups. */ 71 while (1) 72 { 73 chain = TREE_CHAIN (u); 74 TREE_CHAIN (u) = NULL_TREE; 75 if (t == u) 76 break; 77 u = chain; 78 } 79 cur_stmt_list = chain; 80 81 /* If the statement list is completely empty, just return it. This is 82 just as good small as build_empty_stmt, with the advantage that 83 statement lists are merged when they appended to one another. So 84 using the STATEMENT_LIST avoids pathological buildup of EMPTY_STMT_P 85 statements. */ 86 if (TREE_SIDE_EFFECTS (t)) 87 { 88 tree_stmt_iterator i = tsi_start (t); 89 90 /* If the statement list contained exactly one statement, then 91 extract it immediately. */ 92 if (tsi_one_before_end_p (i)) 93 { 94 u = tsi_stmt (i); 95 tsi_delink (&i); 96 free_stmt_list (t); 97 t = u; 98 } 99 } 100 101 return t; 102} 103 104/* Build a generic statement based on the given type of node and 105 arguments. Similar to `build_nt', except that we set 106 EXPR_LOCATION to be the current source location. */ 107/* ??? This should be obsolete with the lineno_stmt productions 108 in the grammar. */ 109 110tree 111build_stmt (enum tree_code code, ...) 112{ 113 tree ret; 114 int length, i; 115 va_list p; 116 bool side_effects; 117 118 va_start (p, code); 119 120 ret = make_node (code); 121 TREE_TYPE (ret) = void_type_node; 122 length = TREE_CODE_LENGTH (code); 123 SET_EXPR_LOCATION (ret, input_location); 124 125 /* TREE_SIDE_EFFECTS will already be set for statements with 126 implicit side effects. Here we make sure it is set for other 127 expressions by checking whether the parameters have side 128 effects. */ 129 130 side_effects = false; 131 for (i = 0; i < length; i++) 132 { 133 tree t = va_arg (p, tree); 134 if (t && !TYPE_P (t)) 135 side_effects |= TREE_SIDE_EFFECTS (t); 136 TREE_OPERAND (ret, i) = t; 137 } 138 139 TREE_SIDE_EFFECTS (ret) |= side_effects; 140 141 va_end (p); 142 return ret; 143} 144 145/* Let the back-end know about DECL. */ 146 147void 148emit_local_var (tree decl) 149{ 150 /* Create RTL for this variable. */ 151 if (!DECL_RTL_SET_P (decl)) 152 { 153 if (DECL_HARD_REGISTER (decl)) 154 /* The user specified an assembler name for this variable. 155 Set that up now. */ 156 rest_of_decl_compilation (decl, 0, 0); 157 else 158 expand_decl (decl); 159 } 160} 161 162/* Create a CASE_LABEL_EXPR tree node and return it. */ 163 164tree 165build_case_label (tree low_value, tree high_value, tree label_decl) 166{ 167 return build_stmt (CASE_LABEL_EXPR, low_value, high_value, label_decl); 168} 169