1#*************************************************************************** 2# _ _ ____ _ 3# Project ___| | | | _ \| | 4# / __| | | | |_) | | 5# | (__| |_| | _ <| |___ 6# \___|\___/|_| \_\_____| 7# 8# Copyright (C) Daniel Stenberg, <daniel@haxx.se>, et al. 9# 10# This software is licensed as described in the file COPYING, which 11# you should have received as part of this distribution. The terms 12# are also available at https://curl.se/docs/copyright.html. 13# 14# You may opt to use, copy, modify, merge, publish, distribute and/or sell 15# copies of the Software, and permit persons to whom the Software is 16# furnished to do so, under the terms of the COPYING file. 17# 18# This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY 19# KIND, either express or implied. 20# 21# SPDX-License-Identifier: curl 22# 23########################################################################### 24include(CheckCCompilerFlag) 25 26set(_picky "") 27 28if(CURL_WERROR AND 29 ((CMAKE_COMPILER_IS_GNUCC AND 30 NOT DOS AND # Watt-32 headers use the '#include_next' GCC extension 31 NOT CMAKE_C_COMPILER_VERSION VERSION_LESS 5.0 AND 32 NOT CMAKE_VERSION VERSION_LESS 3.23.0) OR # to avoid check_symbol_exists() conflicting with GCC -pedantic-errors 33 CMAKE_C_COMPILER_ID MATCHES "Clang")) 34 list(APPEND _picky "-pedantic-errors") 35endif() 36 37if(APPLE AND 38 (CMAKE_C_COMPILER_ID STREQUAL "Clang" AND NOT CMAKE_C_COMPILER_VERSION VERSION_LESS 3.6) OR 39 (CMAKE_C_COMPILER_ID STREQUAL "AppleClang" AND NOT CMAKE_C_COMPILER_VERSION VERSION_LESS 6.3)) 40 list(APPEND _picky "-Werror=partial-availability") # clang 3.6 appleclang 6.3 41endif() 42 43if(CMAKE_COMPILER_IS_GNUCC OR CMAKE_C_COMPILER_ID MATCHES "Clang") 44 list(APPEND _picky "-Werror-implicit-function-declaration") # clang 1.0 gcc 2.95 45endif() 46 47if(PICKY_COMPILER) 48 if(CMAKE_COMPILER_IS_GNUCC OR CMAKE_C_COMPILER_ID MATCHES "Clang") 49 50 # https://clang.llvm.org/docs/DiagnosticsReference.html 51 # https://gcc.gnu.org/onlinedocs/gcc/Warning-Options.html 52 53 # _picky_enable = Options we want to enable as-is. 54 # _picky_detect = Options we want to test first and enable if available. 55 56 # Prefer the -Wextra alias with clang. 57 if(CMAKE_C_COMPILER_ID MATCHES "Clang") 58 set(_picky_enable "-Wextra") 59 else() 60 set(_picky_enable "-W") 61 endif() 62 63 list(APPEND _picky_enable 64 -Wall -pedantic 65 ) 66 67 # ---------------------------------- 68 # Add new options here, if in doubt: 69 # ---------------------------------- 70 set(_picky_detect 71 ) 72 73 # Assume these options always exist with both clang and gcc. 74 # Require clang 3.0 / gcc 2.95 or later. 75 list(APPEND _picky_enable 76 -Wbad-function-cast # clang 2.7 gcc 2.95 77 -Wconversion # clang 2.7 gcc 2.95 78 -Wmissing-declarations # clang 1.0 gcc 2.7 79 -Wmissing-prototypes # clang 1.0 gcc 1.0 80 -Wnested-externs # clang 1.0 gcc 2.7 81 -Wno-long-long # clang 1.0 gcc 2.95 82 -Wno-multichar # clang 1.0 gcc 2.95 83 -Wpointer-arith # clang 1.0 gcc 1.4 84 -Wshadow # clang 1.0 gcc 2.95 85 -Wsign-compare # clang 1.0 gcc 2.95 86 -Wundef # clang 1.0 gcc 2.95 87 -Wunused # clang 1.1 gcc 2.95 88 -Wwrite-strings # clang 1.0 gcc 1.4 89 ) 90 91 # Always enable with clang, version dependent with gcc 92 set(_picky_common_old 93 -Waddress # clang 2.7 gcc 4.3 94 -Wattributes # clang 2.7 gcc 4.1 95 -Wcast-align # clang 1.0 gcc 4.2 96 -Wdeclaration-after-statement # clang 1.0 gcc 3.4 97 -Wdiv-by-zero # clang 2.7 gcc 4.1 98 -Wempty-body # clang 2.7 gcc 4.3 99 -Wendif-labels # clang 1.0 gcc 3.3 100 -Wfloat-equal # clang 1.0 gcc 2.96 (3.0) 101 -Wformat-security # clang 2.7 gcc 4.1 102 -Wignored-qualifiers # clang 2.8 gcc 4.3 103 -Wmissing-field-initializers # clang 2.7 gcc 4.1 104 -Wmissing-noreturn # clang 2.7 gcc 4.1 105 -Wno-format-nonliteral # clang 1.0 gcc 2.96 (3.0) 106 -Wno-sign-conversion # clang 2.9 gcc 4.3 107 -Wno-system-headers # clang 1.0 gcc 3.0 108 # -Wpadded # clang 2.9 gcc 4.1 # Not used: We cannot change public structs 109 -Wold-style-definition # clang 2.7 gcc 3.4 110 -Wredundant-decls # clang 2.7 gcc 4.1 111 -Wstrict-prototypes # clang 1.0 gcc 3.3 112 # -Wswitch-enum # clang 2.7 gcc 4.1 # Not used: It basically disallows default case 113 -Wtype-limits # clang 2.7 gcc 4.3 114 -Wunreachable-code # clang 2.7 gcc 4.1 115 # -Wunused-macros # clang 2.7 gcc 4.1 # Not practical 116 -Wunused-parameter # clang 2.7 gcc 4.1 117 -Wvla # clang 2.8 gcc 4.3 118 ) 119 120 if(CMAKE_C_COMPILER_ID MATCHES "Clang") 121 list(APPEND _picky_enable 122 ${_picky_common_old} 123 -Wshift-sign-overflow # clang 2.9 124 -Wshorten-64-to-32 # clang 1.0 125 -Wformat=2 # clang 3.0 gcc 4.8 126 ) 127 if(NOT MSVC) 128 list(APPEND _picky_enable 129 -Wlanguage-extension-token # clang 3.0 130 ) 131 endif() 132 # Enable based on compiler version 133 if((CMAKE_C_COMPILER_ID STREQUAL "Clang" AND NOT CMAKE_C_COMPILER_VERSION VERSION_LESS 3.6) OR 134 (CMAKE_C_COMPILER_ID STREQUAL "AppleClang" AND NOT CMAKE_C_COMPILER_VERSION VERSION_LESS 6.3)) 135 list(APPEND _picky_enable 136 -Wdouble-promotion # clang 3.6 gcc 4.6 appleclang 6.3 137 -Wenum-conversion # clang 3.2 gcc 10.0 appleclang 4.6 g++ 11.0 138 -Wheader-guard # clang 3.4 appleclang 5.1 139 -Wpragmas # clang 3.5 gcc 4.1 appleclang 6.0 140 -Wsometimes-uninitialized # clang 3.2 appleclang 4.6 141 # -Wunreachable-code-break # clang 3.5 appleclang 6.0 # Not used: Silent in "unity" builds 142 -Wunused-const-variable # clang 3.4 gcc 6.0 appleclang 5.1 143 ) 144 endif() 145 if((CMAKE_C_COMPILER_ID STREQUAL "Clang" AND NOT CMAKE_C_COMPILER_VERSION VERSION_LESS 3.9) OR 146 (CMAKE_C_COMPILER_ID STREQUAL "AppleClang" AND NOT CMAKE_C_COMPILER_VERSION VERSION_LESS 8.3)) 147 list(APPEND _picky_enable 148 -Wcomma # clang 3.9 appleclang 8.3 149 -Wmissing-variable-declarations # clang 3.2 appleclang 4.6 150 ) 151 endif() 152 if((CMAKE_C_COMPILER_ID STREQUAL "Clang" AND NOT CMAKE_C_COMPILER_VERSION VERSION_LESS 7.0) OR 153 (CMAKE_C_COMPILER_ID STREQUAL "AppleClang" AND NOT CMAKE_C_COMPILER_VERSION VERSION_LESS 10.3)) 154 list(APPEND _picky_enable 155 -Wassign-enum # clang 7.0 appleclang 10.3 156 -Wextra-semi-stmt # clang 7.0 appleclang 10.3 157 ) 158 endif() 159 if((CMAKE_C_COMPILER_ID STREQUAL "Clang" AND NOT CMAKE_C_COMPILER_VERSION VERSION_LESS 10.0) OR 160 (CMAKE_C_COMPILER_ID STREQUAL "AppleClang" AND NOT CMAKE_C_COMPILER_VERSION VERSION_LESS 12.4)) 161 list(APPEND _picky_enable 162 -Wimplicit-fallthrough # clang 4.0 gcc 7.0 appleclang 12.4 # We do silencing for clang 10.0 and above only 163 ) 164 endif() 165 else() # gcc 166 # Enable based on compiler version 167 if(NOT CMAKE_C_COMPILER_VERSION VERSION_LESS 4.3) 168 list(APPEND _picky_enable 169 ${_picky_common_old} 170 -Wclobbered # gcc 4.3 171 -Wmissing-parameter-type # gcc 4.3 172 -Wold-style-declaration # gcc 4.3 173 -Wpragmas # clang 3.5 gcc 4.1 appleclang 6.0 174 -Wstrict-aliasing=3 # gcc 4.0 175 ) 176 endif() 177 if(NOT CMAKE_C_COMPILER_VERSION VERSION_LESS 4.5 AND MINGW) 178 list(APPEND _picky_enable 179 -Wno-pedantic-ms-format # gcc 4.5 (MinGW-only) 180 ) 181 endif() 182 if(NOT CMAKE_C_COMPILER_VERSION VERSION_LESS 4.8) 183 list(APPEND _picky_enable 184 -Wdouble-promotion # clang 3.6 gcc 4.6 appleclang 6.3 185 -Wformat=2 # clang 3.0 gcc 4.8 186 -Wtrampolines # gcc 4.6 187 ) 188 endif() 189 if(NOT CMAKE_C_COMPILER_VERSION VERSION_LESS 5.0) 190 list(APPEND _picky_enable 191 -Warray-bounds=2 -ftree-vrp # clang 3.0 gcc 5.0 (clang default: -Warray-bounds) 192 ) 193 endif() 194 if(NOT CMAKE_C_COMPILER_VERSION VERSION_LESS 6.0) 195 list(APPEND _picky_enable 196 -Wduplicated-cond # gcc 6.0 197 -Wnull-dereference # clang 3.0 gcc 6.0 (clang default) 198 -fdelete-null-pointer-checks 199 -Wshift-negative-value # clang 3.7 gcc 6.0 (clang default) 200 -Wshift-overflow=2 # clang 3.0 gcc 6.0 (clang default: -Wshift-overflow) 201 -Wunused-const-variable # clang 3.4 gcc 6.0 appleclang 5.1 202 ) 203 endif() 204 if(NOT CMAKE_C_COMPILER_VERSION VERSION_LESS 7.0) 205 list(APPEND _picky_enable 206 -Walloc-zero # gcc 7.0 207 -Wduplicated-branches # gcc 7.0 208 -Wformat-truncation=2 # gcc 7.0 209 -Wimplicit-fallthrough # clang 4.0 gcc 7.0 210 -Wrestrict # gcc 7.0 211 ) 212 endif() 213 if(NOT CMAKE_C_COMPILER_VERSION VERSION_LESS 10.0) 214 list(APPEND _picky_enable 215 -Warith-conversion # gcc 10.0 216 -Wenum-conversion # clang 3.2 gcc 10.0 appleclang 4.6 g++ 11.0 217 ) 218 endif() 219 endif() 220 221 # 222 223 foreach(_ccopt IN LISTS _picky_enable) 224 list(APPEND _picky "${_ccopt}") 225 endforeach() 226 227 foreach(_ccopt IN LISTS _picky_detect) 228 # Use a unique variable name 1. for meaningful log output 2. to have a fresh, undefined variable for each detection 229 string(MAKE_C_IDENTIFIER "OPT${_ccopt}" _optvarname) 230 # GCC only warns about unknown -Wno- options if there are also other diagnostic messages, 231 # so test for the positive form instead 232 string(REPLACE "-Wno-" "-W" _ccopt_on "${_ccopt}") 233 check_c_compiler_flag(${_ccopt_on} ${_optvarname}) 234 if(${_optvarname}) 235 list(APPEND _picky "${_ccopt}") 236 endif() 237 endforeach() 238 239 if(CMAKE_COMPILER_IS_GNUCC) 240 if(CMAKE_C_COMPILER_VERSION VERSION_LESS 4.5) 241 # Avoid false positives 242 list(APPEND _picky "-Wno-shadow") 243 list(APPEND _picky "-Wno-unreachable-code") 244 endif() 245 if(NOT CMAKE_C_COMPILER_VERSION VERSION_LESS 4.2 AND CMAKE_C_COMPILER_VERSION VERSION_LESS 4.6) 246 # GCC <4.6 do not support #pragma to suppress warnings locally. Disable them globally instead. 247 list(APPEND _picky "-Wno-overlength-strings") 248 endif() 249 if(NOT CMAKE_C_COMPILER_VERSION VERSION_LESS 4.0 AND CMAKE_C_COMPILER_VERSION VERSION_LESS 4.7) 250 list(APPEND _picky "-Wno-missing-field-initializers") # https://gcc.gnu.org/bugzilla/show_bug.cgi?id=36750 251 endif() 252 if(NOT CMAKE_C_COMPILER_VERSION VERSION_LESS 4.3 AND CMAKE_C_COMPILER_VERSION VERSION_LESS 4.8) 253 list(APPEND _picky "-Wno-type-limits") # Avoid false positives 254 endif() 255 endif() 256 endif() 257endif() 258 259# clang-cl 260if(CMAKE_C_COMPILER_ID STREQUAL "Clang" AND MSVC) 261 list(APPEND _picky "-Wno-language-extension-token") # Allow __int64 262 263 set(_picky_tmp "") 264 foreach(_ccopt IN LISTS _picky) 265 # Prefix -Wall, otherwise clang-cl interprets it as an MSVC option and translates it to -Weverything 266 if(_ccopt MATCHES "^-W" AND NOT _ccopt STREQUAL "-Wall") 267 list(APPEND _picky_tmp ${_ccopt}) 268 else() 269 list(APPEND _picky_tmp "-clang:${_ccopt}") 270 endif() 271 endforeach() 272 set(_picky ${_picky_tmp}) 273endif() 274 275if(_picky) 276 string(REPLACE ";" " " _picky "${_picky}") 277 set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} ${_picky}") 278 message(STATUS "Picky compiler options: ${_picky}") 279endif() 280