curl/CMake/PickyWarnings.cmake
Viktor Szakats 8a266ac488
build: delete -Wsign-conversion related FIXMEs
We decided last year not to pursue avoiding this warning, because it
adds noise and friction, while in most cases not revealing actual code
issues. We fixed the interesting portion of them throughout mid-2024.

Conclude this effort by deleting related FIXMEs and temporary comments.

Follow-up to 3829759bd0 #12489
Closes #15939
2025-01-09 02:12:52 +01:00

263 lines
12 KiB
CMake

#***************************************************************************
# _ _ ____ _
# Project ___| | | | _ \| |
# / __| | | | |_) | |
# | (__| |_| | _ <| |___
# \___|\___/|_| \_\_____|
#
# Copyright (C) Daniel Stenberg, <daniel@haxx.se>, et al.
#
# This software is licensed as described in the file COPYING, which
# you should have received as part of this distribution. The terms
# are also available at https://curl.se/docs/copyright.html.
#
# You may opt to use, copy, modify, merge, publish, distribute and/or sell
# copies of the Software, and permit persons to whom the Software is
# furnished to do so, under the terms of the COPYING file.
#
# This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
# KIND, either express or implied.
#
# SPDX-License-Identifier: curl
#
###########################################################################
include(CheckCCompilerFlag)
set(_picky "")
if(CURL_WERROR AND
((CMAKE_COMPILER_IS_GNUCC AND
NOT DOS AND # Watt-32 headers use the '#include_next' GCC extension
NOT CMAKE_C_COMPILER_VERSION VERSION_LESS 5.0 AND
NOT CMAKE_VERSION VERSION_LESS 3.23.0) OR # to avoid check_symbol_exists() conflicting with GCC -pedantic-errors
CMAKE_C_COMPILER_ID MATCHES "Clang"))
list(APPEND _picky "-pedantic-errors")
endif()
if(APPLE AND
(CMAKE_C_COMPILER_ID STREQUAL "Clang" AND NOT CMAKE_C_COMPILER_VERSION VERSION_LESS 3.6) OR
(CMAKE_C_COMPILER_ID STREQUAL "AppleClang" AND NOT CMAKE_C_COMPILER_VERSION VERSION_LESS 6.3))
list(APPEND _picky "-Werror=partial-availability") # clang 3.6 appleclang 6.3
endif()
if(CMAKE_COMPILER_IS_GNUCC OR CMAKE_C_COMPILER_ID MATCHES "Clang")
list(APPEND _picky "-Werror-implicit-function-declaration") # clang 1.0 gcc 2.95
endif()
if(PICKY_COMPILER)
if(CMAKE_COMPILER_IS_GNUCC OR CMAKE_C_COMPILER_ID MATCHES "Clang")
# https://clang.llvm.org/docs/DiagnosticsReference.html
# https://gcc.gnu.org/onlinedocs/gcc/Warning-Options.html
# _picky_enable = Options we want to enable as-is.
# _picky_detect = Options we want to test first and enable if available.
# Prefer the -Wextra alias with clang.
if(CMAKE_C_COMPILER_ID MATCHES "Clang")
set(_picky_enable "-Wextra")
else()
set(_picky_enable "-W")
endif()
list(APPEND _picky_enable
-Wall -pedantic
)
# ----------------------------------
# Add new options here, if in doubt:
# ----------------------------------
set(_picky_detect
)
# Assume these options always exist with both clang and gcc.
# Require clang 3.0 / gcc 2.95 or later.
list(APPEND _picky_enable
-Wbad-function-cast # clang 2.7 gcc 2.95
-Wconversion # clang 2.7 gcc 2.95
-Wmissing-declarations # clang 1.0 gcc 2.7
-Wmissing-prototypes # clang 1.0 gcc 1.0
-Wnested-externs # clang 1.0 gcc 2.7
-Wno-long-long # clang 1.0 gcc 2.95
-Wno-multichar # clang 1.0 gcc 2.95
-Wpointer-arith # clang 1.0 gcc 1.4
-Wshadow # clang 1.0 gcc 2.95
-Wsign-compare # clang 1.0 gcc 2.95
-Wundef # clang 1.0 gcc 2.95
-Wunused # clang 1.1 gcc 2.95
-Wwrite-strings # clang 1.0 gcc 1.4
)
# Always enable with clang, version dependent with gcc
set(_picky_common_old
-Waddress # clang 2.7 gcc 4.3
-Wattributes # clang 2.7 gcc 4.1
-Wcast-align # clang 1.0 gcc 4.2
-Wdeclaration-after-statement # clang 1.0 gcc 3.4
-Wdiv-by-zero # clang 2.7 gcc 4.1
-Wempty-body # clang 2.7 gcc 4.3
-Wendif-labels # clang 1.0 gcc 3.3
-Wfloat-equal # clang 1.0 gcc 2.96 (3.0)
-Wformat-security # clang 2.7 gcc 4.1
-Wignored-qualifiers # clang 2.8 gcc 4.3
-Wmissing-field-initializers # clang 2.7 gcc 4.1
-Wmissing-noreturn # clang 2.7 gcc 4.1
-Wno-format-nonliteral # clang 1.0 gcc 2.96 (3.0)
-Wno-system-headers # clang 1.0 gcc 3.0
# -Wpadded # clang 2.9 gcc 4.1 # Not used: We cannot change public structs
-Wold-style-definition # clang 2.7 gcc 3.4
-Wredundant-decls # clang 2.7 gcc 4.1
-Wsign-conversion # clang 2.9 gcc 4.3
-Wno-error=sign-conversion
-Wstrict-prototypes # clang 1.0 gcc 3.3
# -Wswitch-enum # clang 2.7 gcc 4.1 # Not used: It basically disallows default case
-Wtype-limits # clang 2.7 gcc 4.3
-Wunreachable-code # clang 2.7 gcc 4.1
# -Wunused-macros # clang 2.7 gcc 4.1 # Not practical
-Wunused-parameter # clang 2.7 gcc 4.1
-Wvla # clang 2.8 gcc 4.3
)
if(CMAKE_C_COMPILER_ID MATCHES "Clang")
list(APPEND _picky_enable
${_picky_common_old}
-Wshift-sign-overflow # clang 2.9
-Wshorten-64-to-32 # clang 1.0
-Wformat=2 # clang 3.0 gcc 4.8
)
if(NOT MSVC)
list(APPEND _picky_enable
-Wlanguage-extension-token # clang 3.0
)
endif()
# Enable based on compiler version
if((CMAKE_C_COMPILER_ID STREQUAL "Clang" AND NOT CMAKE_C_COMPILER_VERSION VERSION_LESS 3.6) OR
(CMAKE_C_COMPILER_ID STREQUAL "AppleClang" AND NOT CMAKE_C_COMPILER_VERSION VERSION_LESS 6.3))
list(APPEND _picky_enable
-Wdouble-promotion # clang 3.6 gcc 4.6 appleclang 6.3
-Wenum-conversion # clang 3.2 gcc 10.0 appleclang 4.6 g++ 11.0
-Wheader-guard # clang 3.4 appleclang 5.1
-Wpragmas # clang 3.5 gcc 4.1 appleclang 6.0
-Wsometimes-uninitialized # clang 3.2 appleclang 4.6
# -Wunreachable-code-break # clang 3.5 appleclang 6.0 # Not used: Silent in "unity" builds
-Wunused-const-variable # clang 3.4 gcc 6.0 appleclang 5.1
)
endif()
if((CMAKE_C_COMPILER_ID STREQUAL "Clang" AND NOT CMAKE_C_COMPILER_VERSION VERSION_LESS 3.9) OR
(CMAKE_C_COMPILER_ID STREQUAL "AppleClang" AND NOT CMAKE_C_COMPILER_VERSION VERSION_LESS 8.3))
list(APPEND _picky_enable
-Wcomma # clang 3.9 appleclang 8.3
-Wmissing-variable-declarations # clang 3.2 appleclang 4.6
)
endif()
if((CMAKE_C_COMPILER_ID STREQUAL "Clang" AND NOT CMAKE_C_COMPILER_VERSION VERSION_LESS 7.0) OR
(CMAKE_C_COMPILER_ID STREQUAL "AppleClang" AND NOT CMAKE_C_COMPILER_VERSION VERSION_LESS 10.3))
list(APPEND _picky_enable
-Wassign-enum # clang 7.0 appleclang 10.3
-Wextra-semi-stmt # clang 7.0 appleclang 10.3
)
endif()
if((CMAKE_C_COMPILER_ID STREQUAL "Clang" AND NOT CMAKE_C_COMPILER_VERSION VERSION_LESS 10.0) OR
(CMAKE_C_COMPILER_ID STREQUAL "AppleClang" AND NOT CMAKE_C_COMPILER_VERSION VERSION_LESS 12.4))
list(APPEND _picky_enable
-Wimplicit-fallthrough # clang 4.0 gcc 7.0 appleclang 12.4 # We do silencing for clang 10.0 and above only
)
endif()
else() # gcc
# Enable based on compiler version
if(NOT CMAKE_C_COMPILER_VERSION VERSION_LESS 4.3)
list(APPEND _picky_enable
${_picky_common_old}
-Wclobbered # gcc 4.3
-Wmissing-parameter-type # gcc 4.3
-Wold-style-declaration # gcc 4.3
-Wpragmas # clang 3.5 gcc 4.1 appleclang 6.0
-Wstrict-aliasing=3 # gcc 4.0
-Wtrampolines # gcc 4.3
)
endif()
if(NOT CMAKE_C_COMPILER_VERSION VERSION_LESS 4.5 AND MINGW)
list(APPEND _picky_enable
-Wno-pedantic-ms-format # gcc 4.5 (MinGW-only)
)
endif()
if(NOT CMAKE_C_COMPILER_VERSION VERSION_LESS 4.8)
list(APPEND _picky_enable
-Wdouble-promotion # clang 3.6 gcc 4.6 appleclang 6.3
-Wformat=2 # clang 3.0 gcc 4.8
)
endif()
if(NOT CMAKE_C_COMPILER_VERSION VERSION_LESS 5.0)
list(APPEND _picky_enable
-Warray-bounds=2 -ftree-vrp # clang 3.0 gcc 5.0 (clang default: -Warray-bounds)
)
endif()
if(NOT CMAKE_C_COMPILER_VERSION VERSION_LESS 6.0)
list(APPEND _picky_enable
-Wduplicated-cond # gcc 6.0
-Wnull-dereference # clang 3.0 gcc 6.0 (clang default)
-fdelete-null-pointer-checks
-Wshift-negative-value # clang 3.7 gcc 6.0 (clang default)
-Wshift-overflow=2 # clang 3.0 gcc 6.0 (clang default: -Wshift-overflow)
-Wunused-const-variable # clang 3.4 gcc 6.0 appleclang 5.1
)
endif()
if(NOT CMAKE_C_COMPILER_VERSION VERSION_LESS 7.0)
list(APPEND _picky_enable
-Walloc-zero # gcc 7.0
-Wduplicated-branches # gcc 7.0
-Wformat-truncation=2 # gcc 7.0
-Wimplicit-fallthrough # clang 4.0 gcc 7.0
-Wrestrict # gcc 7.0
)
endif()
if(NOT CMAKE_C_COMPILER_VERSION VERSION_LESS 10.0)
list(APPEND _picky_enable
-Warith-conversion # gcc 10.0
-Wenum-conversion # clang 3.2 gcc 10.0 appleclang 4.6 g++ 11.0
)
endif()
endif()
#
foreach(_ccopt IN LISTS _picky_enable)
list(APPEND _picky "${_ccopt}")
endforeach()
foreach(_ccopt IN LISTS _picky_detect)
# Use a unique variable name 1. for meaningful log output 2. to have a fresh, undefined variable for each detection
string(MAKE_C_IDENTIFIER "OPT${_ccopt}" _optvarname)
# GCC only warns about unknown -Wno- options if there are also other diagnostic messages,
# so test for the positive form instead
string(REPLACE "-Wno-" "-W" _ccopt_on "${_ccopt}")
check_c_compiler_flag(${_ccopt_on} ${_optvarname})
if(${_optvarname})
list(APPEND _picky "${_ccopt}")
endif()
endforeach()
endif()
endif()
# clang-cl
if(CMAKE_C_COMPILER_ID STREQUAL "Clang" AND MSVC)
list(APPEND _picky "-Wno-language-extension-token") # Allow __int64
set(_picky_tmp "")
foreach(_ccopt IN LISTS _picky)
# Prefix -Wall, otherwise clang-cl interprets it as an MSVC option and translates it to -Weverything
if(_ccopt MATCHES "^-W" AND NOT _ccopt STREQUAL "-Wall")
list(APPEND _picky_tmp ${_ccopt})
else()
list(APPEND _picky_tmp "/clang:${_ccopt}")
endif()
endforeach()
set(_picky ${_picky_tmp})
endif()
if(_picky)
string(REPLACE ";" " " _picky "${_picky}")
set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} ${_picky}")
message(STATUS "Picky compiler options: ${_picky}")
endif()