annotate src/compiler.h @ 5697:40fbceabaafd

menubar-items.el (default-menubar): Reorganize. Add PROBLEMS to toplevel. New "More about XEmacs" submenu for NEWS, licensing, etc. New "Recent History" menu for messages, lossage, etc. Get rid of ugly and unexpressive ellipses.
author Stephen J. Turnbull <stephen@xemacs.org>
date Mon, 24 Dec 2012 03:08:33 +0900
parents 308d34e9f07d
children 574f0cded429
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1 /* Compiler-specific definitions for XEmacs.
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2 Copyright (C) 1998-1999, 2003 Free Software Foundation, Inc.
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3 Copyright (C) 1994 Richard Mlynarik.
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4 Copyright (C) 1995, 1996, 2000-2004, 2010 Ben Wing.
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5
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6 This file is part of XEmacs.
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7
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8 XEmacs is free software: you can redistribute it and/or modify it
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9 under the terms of the GNU General Public License as published by the
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10 Free Software Foundation, either version 3 of the License, or (at your
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11 option) any later version.
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12
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13 XEmacs is distributed in the hope that it will be useful, but WITHOUT
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14 ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
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15 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
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16 for more details.
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17
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18 You should have received a copy of the GNU General Public License
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19 along with XEmacs. If not, see <http://www.gnu.org/licenses/>. */
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20
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21 /* Synched up with: not in FSF. */
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22
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23 /* Authorship:
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24
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25 NOT_REACHED, DOESNT_RETURN, PRINTF_ARGS by Richard Mlynarik, c. 1994.
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26 RETURN_SANS_WARNING by Martin buchholz, 1998 or 1999.
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27 Many changes and improvements by Jerry James, 2003.
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28 Split out of lisp.h, reorganized, and modernized.
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29 {BEGIN,END}_C_DECLS, NEED_GCC, GCC_VERSION
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30 ATTRIBUTE_MALLOC, ATTRIBUTE_CONST, ATTRIBUTE_PURE, UNUSED
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31 */
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32
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33 #ifndef INCLUDED_compiler_h
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34 #define INCLUDED_compiler_h
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35
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36 /* Define min() and max(). (Some compilers put them in strange places that
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37 won't be referenced by include files used by XEmacs, such as `macros.h'
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38 under Solaris.) */
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39
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40 #ifndef min
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41 # define min(a,b) (((a) <= (b)) ? (a) : (b))
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42 #endif
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43 #ifndef max
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44 # define max(a,b) (((a) > (b)) ? (a) : (b))
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45 #endif
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46
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47 /* Regular C complains about possible clobbering of local vars NOT declared
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48 as volatile if there's a longjmp() in a function. C++ complains if such
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49 vars ARE volatile; or more correctly, sans volatile no problem even when
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50 you longjmp, avec volatile you get unfixable compile errors like
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51
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52 /src/xemacs/lilfix/src/process-unix.c: In function `void
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53 unix_send_process(Lisp_Object, lstream*)':
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54 /src/xemacs/lilfix/src/process-unix.c:1577: no matching function for call to `
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55 Lisp_Object::Lisp_Object(volatile Lisp_Object&)'
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56 /src/xemacs/lilfix/src/lisp-union.h:32: candidates are:
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57 Lisp_Object::Lisp_Object(const Lisp_Object&)
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58 */
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59
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60 #ifdef __cplusplus
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61 # define VOLATILE_IF_NOT_CPP
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62 #else
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63 # define VOLATILE_IF_NOT_CPP volatile
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64 #endif
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65
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66 /* Avoid indentation problems when XEmacs sees the curly braces */
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67 #ifndef BEGIN_C_DECLS
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68 # ifdef __cplusplus
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69 # define BEGIN_C_DECLS extern "C" {
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70 # define END_C_DECLS }
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71 # else
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72 # define BEGIN_C_DECLS
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73 # define END_C_DECLS
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74 # endif
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75 #endif
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76
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77 /* Guard against older gccs that did not define all of these symbols */
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78 #ifdef __GNUC__
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79 # ifndef __GNUC_MINOR__
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80 # define __GNUC_MINOR__ 0
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81 # endif
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82 # ifndef __GNUC_PATCHLEVEL__
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83 # define __GNUC_PATCHLEVEL__ 0
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84 # endif
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85 #endif /* __GNUC__ */
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86
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87 /* Simplify testing for specific GCC versions. For non-GNU compilers,
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88 GCC_VERSION evaluates to zero. */
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89 #ifndef NEED_GCC
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90 # define NEED_GCC(major,minor,patch) (major * 1000000 + minor * 1000 + patch)
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91 #endif /* NEED_GCC */
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92 #ifndef GCC_VERSION
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93 # ifdef __GNUC__
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94 # define GCC_VERSION NEED_GCC (__GNUC__, __GNUC_MINOR__, __GNUC_PATCHLEVEL__)
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95 # else
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96 # define GCC_VERSION 0
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97 # endif /* __GNUC__ */
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98 #endif /* GCC_VERSION */
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99
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100 #ifdef _MSC_VER
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101 #define MSC_VERSION _MSC_VER
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102 #else
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103 #define MSC_VERSION 0
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104 #endif
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105
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106 /* GCC < 2.6.0 could only declare one attribute per function. In that case,
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107 we define DOESNT_RETURN in preference to PRINTF_ARGS, which is only used
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108 for checking args against the string spec. */
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109 #ifndef PRINTF_ARGS
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110 # if (GCC_VERSION >= NEED_GCC (2, 6, 0))
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111 # define PRINTF_ARGS(string_index,first_to_check) \
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112 __attribute__ ((format (printf, string_index, first_to_check)))
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113 # else
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114 # define PRINTF_ARGS(string_index,first_to_check)
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115 # endif /* GNUC */
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116 #endif
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117
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118 #ifndef DOESNT_RETURN_TYPE
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119 # if (GCC_VERSION > NEED_GCC (0, 0, 0))
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120 # if (GCC_VERSION >= NEED_GCC (2, 5, 0))
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121 # ifndef __INTEL_COMPILER
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122 # define RETURN_NOT_REACHED(value) DO_NOTHING
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123 # endif
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124 # define DOESNT_RETURN_TYPE(rettype) rettype
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125 # define DECLARE_DOESNT_RETURN_TYPE(rettype,decl) rettype decl \
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126 __attribute__ ((noreturn))
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127 # else /* GCC_VERSION < NEED_GCC (2, 5, 0) */
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128 # define DOESNT_RETURN_TYPE(rettype) rettype volatile
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129 # define DECLARE_DOESNT_RETURN_TYPE(rettype,decl) rettype volatile decl
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130 # endif /* GCC_VERSION >= NEED_GCC (2, 5, 0) */
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131 # elif (MSC_VERSION >= 1200)
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132 /* MSVC 6.0 has a mechanism to declare functions which never return */
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133 # define DOESNT_RETURN_TYPE(rettype) __declspec(noreturn) rettype
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134 # define DECLARE_DOESNT_RETURN_TYPE(rettype,decl) \
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135 __declspec(noreturn) rettype XCDECL decl
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136 # if (MSC_VERSION >= 1300)
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137 /* VC++ 7 issues warnings about return statements in __declspec(noreturn)
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138 functions; this problem didn't exist under VC++ 6 */
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139 # define RETURN_NOT_REACHED(value) DO_NOTHING
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140 # endif
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141 # else /* not gcc, VC++ */
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142 # define DOESNT_RETURN_TYPE(rettype) rettype
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143 # define DECLARE_DOESNT_RETURN_TYPE(rettype,decl) rettype decl
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144 # endif /* GCC_VERSION > NEED_GCC (0, 0, 0) */
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145 #endif /* DOESNT_RETURN_TYPE */
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146 #ifndef DOESNT_RETURN
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147 # define DOESNT_RETURN DOESNT_RETURN_TYPE (void)
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148 # define DECLARE_DOESNT_RETURN(decl) DECLARE_DOESNT_RETURN_TYPE (void, decl)
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149 #endif /* DOESNT_RETURN */
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150
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151 /* Another try to fix SunPro C compiler warnings */
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152 /* "end-of-loop code not reached" */
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153 /* "statement not reached */
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154 #if defined __SUNPRO_C || defined __USLC__
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155 # define RETURN_SANS_WARNINGS if (1) return
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156 # define RETURN_NOT_REACHED(value) DO_NOTHING
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157 #endif
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158
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159 /* More ways to shut up compiler. This works in Fcommand_loop_1(),
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160 where there's an infinite loop in a function returning a Lisp object.
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161 */
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162 #if (defined (_MSC_VER) && MSC_VERSION < 1300) || defined (__SUNPRO_C) || \
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163 defined (__SUNPRO_CC)
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164 # define DO_NOTHING_DISABLING_NO_RETURN_WARNINGS if (0) return Qnil
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165 #else
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166 # define DO_NOTHING_DISABLING_NO_RETURN_WARNINGS DO_NOTHING
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167 #endif
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168
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169 #ifndef RETURN_NOT_REACHED
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170 # define RETURN_NOT_REACHED(value) return (value)
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171 #endif
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172
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173 #ifndef RETURN_SANS_WARNINGS
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174 # define RETURN_SANS_WARNINGS return
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175 #endif
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176
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177 #ifndef DO_NOTHING
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178 # define DO_NOTHING do {} while (0)
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179 #endif
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180
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181 #ifndef DECLARE_NOTHING
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182 # define DECLARE_NOTHING struct nosuchstruct
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183 #endif
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184
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185 #ifndef ATTRIBUTE_MALLOC
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186 # if (GCC_VERSION >= NEED_GCC (2, 96, 0))
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187 # define ATTRIBUTE_MALLOC __attribute__ ((__malloc__))
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188 # else
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189 # define ATTRIBUTE_MALLOC
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190 # endif /* GCC_VERSION >= NEED_GCC (2, 96, 0) */
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191 #endif /* ATTRIBUTE_MALLOC */
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192
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193 #ifndef ATTRIBUTE_PURE
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194 # if (GCC_VERSION >= NEED_GCC (2, 96, 0))
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195 # define ATTRIBUTE_PURE __attribute__ ((pure))
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196 # else
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197 # define ATTRIBUTE_PURE
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198 # endif /* GCC_VERSION >= NEED_GCC (2, 96, 0) */
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199 #endif /* ATTRIBUTE_PURE */
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200
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201 #ifndef ATTRIBUTE_CONST
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202 # if (GCC_VERSION >= NEED_GCC (2, 5, 0))
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203 # define ATTRIBUTE_CONST __attribute__ ((const))
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204 # define CONST_FUNC
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205 # else
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206 # define ATTRIBUTE_CONST
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207 # define CONST_FUNC const
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208 # endif /* GCC_VERSION >= NEED_GCC (2, 5, 0) */
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209 #endif /* ATTRIBUTE_CONST */
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210
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211 /*
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212 NOTE: These macros MUST be named UNUSED (exactly) or something
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213 prefixed with USED_IF_, or DEFUN docstrings will be parsed incorrectly.
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214 See comments in make_docfile.c (write_c_args). You'd think that this
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215 wouldn't happen, but unfortunately we do indeed have some arguments
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216 of DEFUNs unused for GNU compatibility or because features are missing.
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217
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218 #### At one time, __attribute__ ((unused)) confused G++. We don't know
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219 which versions. Please report problems and fix conditionals.
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220 #### A similar issue arose with the Intel CC. We know that v7 didn't
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221 work and v9 does. Let us know if v8 works or not, please.
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222 See <m34plsmh88.fsf@jerrypc.cs.usu.edu>.
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223 */
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224 #ifndef UNUSED_ARG
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225 # define UNUSED_ARG(decl) unused_##decl
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226 #endif
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227 #ifndef UNUSED
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228 # if defined(__GNUC__) && (!defined(__INTEL_COMPILER) || __INTEL_COMPILER >= 800)
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229 # define ATTRIBUTE_UNUSED __attribute__ ((unused))
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230 # else
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231 # define ATTRIBUTE_UNUSED
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232 # endif
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233 # define UNUSED(decl) UNUSED_ARG (decl) ATTRIBUTE_UNUSED
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234 #endif /* UNUSED */
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235
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236 /* Various macros for params/variables used or unused depending on
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237 config flags. */
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238
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239 #ifdef MULE
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240 # define USED_IF_MULE(decl) decl
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241 #else
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242 # define USED_IF_MULE(decl) UNUSED (decl)
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243 #endif
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244 #ifdef HAVE_XFT
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245 # define USED_IF_XFT(decl) decl
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246 #else
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247 # define USED_IF_XFT(decl) UNUSED (decl)
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248 #endif
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249 #ifdef HAVE_SCROLLBARS
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250 # define USED_IF_SCROLLBARS(decl) decl
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251 #else
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252 # define USED_IF_SCROLLBARS(decl) UNUSED (decl)
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253 #endif
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254 #ifdef NEW_GC
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255 # define USED_IF_NEW_GC(decl) decl
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256 # define UNUSED_IF_NEW_GC(decl) UNUSED (decl)
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257 #else
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258 # define USED_IF_NEW_GC(decl) UNUSED (decl)
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259 # define UNUSED_IF_NEW_GC(decl) decl
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260 #endif
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261 #ifdef HAVE_TTY
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262 #define USED_IF_TTY(decl) decl
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263 #else
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264 #define USED_IF_TTY(decl) UNUSED (decl)
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265 #endif
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266 #ifdef HAVE_TOOLBARS
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267 #define USED_IF_TOOLBARS(decl) decl
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268 #else
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269 #define USED_IF_TOOLBARS(decl) UNUSED (decl)
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270 #endif
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271
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272 /* Declaration that variable or expression X is "used" to defeat
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273 "unused variable" warnings. DON'T DO THIS FOR PARAMETERS IF IT ALL
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274 POSSIBLE. Use an UNUSED() or USED_IF_*() declaration on the parameter
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275 instead. Don't do this for unused local variables that should really
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276 just be deleted. */
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277 #define USED(x) ((void) (x))
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278
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279 #ifdef DEBUG_XEMACS
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280 # define REGISTER
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281 # define register
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282 #else
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283 # define REGISTER register
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284 #endif
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285
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286 #if defined(HAVE_MS_WINDOWS) && defined(HAVE_SHLIB)
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287 # ifdef EMACS_MODULE
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288 # define MODULE_API __declspec(dllimport)
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289 # else
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290 # define MODULE_API __declspec(dllexport)
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291 # endif
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292 #else
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293 # define MODULE_API
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294 #endif
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295
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296 /* Under "strict-aliasing" assumptions, you're not necessarily allowed to
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297 access the same memory address as two different types. The proper way
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298 around that is with a union. The macros below help out, e.g. the
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299 definition of XE_MAKEPOINTS(val) is
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300
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301 ANSI_ALIASING_TYPEDEF (POINTS, POINTS);
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302 #define XE_MAKEPOINTS(l) ANSI_ALIASING_CAST (POINTS, l)
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303
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304 replacing
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305
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306 BAD!!! #define XE_MAKEPOINTS(l) (* (POINTS *) &(l))
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307
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308 On the other hand, if you are just casting from one pointer to the other
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309 in order to pass a pointer to another function, it's probably OK to just
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310 trick GCC by inserting an intermediate cast to (void *), to avoid
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311 warnings about "dereferencing type-punned pointer". #### I don't know
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312 how kosher this is, but do strict-aliasing rules really apply across
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313 functions?
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314
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315 Note that the input to e.g. VOIDP_CAST must be an lvalue (i.e. not
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316 &(something)), but the value of the macro is also an lvalue, so in place
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317 of `(void **) &foo' you could write `& VOIDP_CAST (foo)' if you are
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318 subsequently dereferencing the value or don't feel comfortable doing a
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319 trick like `(void **) (void *) &foo'.
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320
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321 Unfortunately, it does not work to just define the union type on the fly in
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322 the cast -- otherwise, we could avoid the need for a typedef. Or rather,
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323 it does work under gcc but not under Visual C++.
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324
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325 --ben
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326 */
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327
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328 #define ANSI_ALIASING_TYPEDEF(name, type) typedef union { char c; type p; } *ANSI_ALIASING_##name
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329 #define ANSI_ALIASING_CAST(name, val) (((ANSI_ALIASING_##name) &(val))->p)
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330 ANSI_ALIASING_TYPEDEF (voidp, void *);
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331 /* VOIDP_CAST: Cast an lvalue to (void *) in a way that is ANSI-aliasing
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332 safe and will not result in GCC warnings. The result is still an
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333 lvalue, so you can assign to it or take its address. */
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334 #define VOIDP_CAST(l) ANSI_ALIASING_CAST (voidp, l)
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335
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336 #endif /* INCLUDED_compiler_h */