c-pragma.c revision 18334
1/* Handle #pragma, system V.4 style. Supports #pragma weak and #pragma pack. 2 Copyright (C) 1992 Free Software Foundation, Inc. 3 4This file is part of GNU CC. 5 6GNU CC is free software; you can redistribute it and/or modify 7it under the terms of the GNU General Public License as published by 8the Free Software Foundation; either version 2, or (at your option) 9any later version. 10 11GNU CC is distributed in the hope that it will be useful, 12but WITHOUT ANY WARRANTY; without even the implied warranty of 13MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 14GNU General Public License for more details. 15 16You should have received a copy of the GNU General Public License 17along with GNU CC; see the file COPYING. If not, write to 18the Free Software Foundation, 59 Temple Place - Suite 330, 19Boston, MA 02111-1307, USA. */ 20 21#include <stdio.h> 22#include "config.h" 23#include "tree.h" 24#include "function.h" 25#include "defaults.h" 26#include "c-pragma.h" 27 28#ifdef HANDLE_SYSV_PRAGMA 29 30/* When structure field packing is in effect, this variable is the 31 number of bits to use as the maximum alignment. When packing is not 32 in effect, this is zero. */ 33 34extern int maximum_field_alignment; 35 36/* File used for outputting assembler code. */ 37extern FILE *asm_out_file; 38 39/* Handle one token of a pragma directive. TOKEN is the 40 current token, and STRING is its printable form. */ 41 42void 43handle_pragma_token (string, token) 44 char *string; 45 tree token; 46{ 47 static enum pragma_state state = ps_start, type; 48 static char *name; 49 static char *value; 50 static int align; 51 52 if (string == 0) 53 { 54 if (type == ps_pack) 55 { 56 if (state == ps_right) 57 maximum_field_alignment = align * 8; 58 else 59 warning ("malformed `#pragma pack'"); 60 } 61 else if (type == ps_weak) 62 { 63#ifdef HANDLE_PRAGMA_WEAK 64 if (HANDLE_PRAGMA_WEAK) 65 handle_pragma_weak (state, name, value); 66 67#endif /* HANDLE_PRAMA_WEAK */ 68 } 69 70 type = state = ps_start; 71 return; 72 } 73 74 switch (state) 75 { 76 case ps_start: 77 if (token && TREE_CODE (token) == IDENTIFIER_NODE) 78 { 79 if (strcmp (IDENTIFIER_POINTER (token), "pack") == 0) 80 type = state = ps_pack; 81 else if (strcmp (IDENTIFIER_POINTER (token), "weak") == 0) 82 type = state = ps_weak; 83 else 84 type = state = ps_done; 85 } 86 else 87 type = state = ps_done; 88 break; 89 90 case ps_weak: 91 if (token && TREE_CODE (token) == IDENTIFIER_NODE) 92 { 93 name = IDENTIFIER_POINTER (token); 94 state = ps_name; 95 } 96 else 97 state = ps_bad; 98 break; 99 100 case ps_name: 101 state = (strcmp (string, "=") ? ps_bad : ps_equals); 102 break; 103 104 case ps_equals: 105 if (token && TREE_CODE (token) == IDENTIFIER_NODE) 106 { 107 value = IDENTIFIER_POINTER (token); 108 state = ps_value; 109 } 110 else 111 state = ps_bad; 112 break; 113 114 case ps_value: 115 state = ps_bad; 116 break; 117 118 case ps_pack: 119 if (strcmp (string, "(") == 0) 120 state = ps_left; 121 else 122 state = ps_bad; 123 break; 124 125 case ps_left: 126 if (token && TREE_CODE (token) == INTEGER_CST 127 && TREE_INT_CST_HIGH (token) == 0) 128 switch (TREE_INT_CST_LOW (token)) 129 { 130 case 1: 131 case 2: 132 case 4: 133 align = TREE_INT_CST_LOW (token); 134 state = ps_align; 135 break; 136 137 default: 138 state = ps_bad; 139 } 140 else if (! token && strcmp (string, ")") == 0) 141 { 142 align = 0; 143 state = ps_right; 144 } 145 else 146 state = ps_bad; 147 break; 148 149 case ps_align: 150 if (strcmp (string, ")") == 0) 151 state = ps_right; 152 else 153 state = ps_bad; 154 break; 155 156 case ps_right: 157 state = ps_bad; 158 break; 159 160 case ps_bad: 161 case ps_done: 162 break; 163 164 default: 165 abort (); 166 } 167} 168#endif /* HANDLE_SYSV_PRAGMA */ 169