annotate src/compiler.h @ 5608:4cffcc80b299

Fix Windows build by adding sequence.obj to the build list.
author Vin Shelton <acs@xemacs.org>
date Thu, 08 Dec 2011 10:05:14 -0500
parents 308d34e9f07d
children 574f0cded429
Ignore whitespace changes - Everywhere: Within whitespace: At end of lines:
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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
2367
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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 */