curl/CMake/PickyWarnings.cmake
Viktor Szakats 3829759bd0
build: enable missing OpenSSF-recommended warnings, with fixes
https://best.openssf.org/Compiler-Hardening-Guides/Compiler-Options-Hardening-Guide-for-C-and-C++.html
as of 2023-11-29 [1].

Enable new recommended warnings (except `-Wsign-conversion`):

- enable `-Wformat=2` for clang (in both cmake and autotools).
- add `CURL_PRINTF()` internal attribute and mark functions accepting
  printf arguments with it. This is a copy of existing
  `CURL_TEMP_PRINTF()` but using `__printf__` to make it compatible
  with redefinting the `printf` symbol:
  https://gcc.gnu.org/onlinedocs/gcc-3.0.4/gcc_5.html#SEC94
- fix `CURL_PRINTF()` and existing `CURL_TEMP_PRINTF()` for
  mingw-w64 and enable it on this platform.
- enable `-Wimplicit-fallthrough`.
- enable `-Wtrampolines`.
- add `-Wsign-conversion` commented with a FIXME.
- cmake: enable `-pedantic-errors` the way we do it with autotools.
  Follow-up to d5c0351055 #2747
- lib/curl_trc.h: use `CURL_FORMAT()`, this also fixes it to enable format
  checks. Previously it was always disabled due to the internal `printf`
  macro.

Fix them:

- fix bug where an `set_ipv6_v6only()` call was missed in builds with
  `--disable-verbose` / `CURL_DISABLE_VERBOSE_STRINGS=ON`.
- add internal `FALLTHROUGH()` macro.
- replace obsolete fall-through comments with `FALLTHROUGH()`.
- fix fallthrough markups: Delete redundant ones (showing up as
  warnings in most cases). Add missing ones. Fix indentation.
- silence `-Wformat-nonliteral` warnings with llvm/clang.
- fix one `-Wformat-nonliteral` warning.
- fix new `-Wformat` and `-Wformat-security` warnings.
- fix `CURL_FORMAT_SOCKET_T` value for mingw-w64. Also move its
  definition to `lib/curl_setup.h` allowing use in `tests/server`.
- lib: fix two wrongly passed string arguments in log outputs.
  Co-authored-by: Jay Satiro
- fix new `-Wformat` warnings on mingw-w64.

[1] 56c0fde389/docs/Compiler-Hardening-Guides/Compiler-Options-Hardening-Guide-for-C-and-C%2B%2B.md

Closes #12489
2023-12-16 13:12:37 +00:00

234 lines
11 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)
unset(WPICKY)
if(CURL_WERROR AND CMAKE_COMPILER_IS_GNUCC AND NOT CMAKE_C_COMPILER_VERSION VERSION_LESS 5.0)
set(WPICKY "${WPICKY} -pedantic-errors")
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
# WPICKY_ENABLE = Options we want to enable as-is.
# WPICKY_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(WPICKY_ENABLE "-Wextra")
else()
set(WPICKY_ENABLE "-W")
endif()
list(APPEND WPICKY_ENABLE
-Wall -pedantic
)
# ----------------------------------
# Add new options here, if in doubt:
# ----------------------------------
set(WPICKY_DETECT
)
# Assume these options always exist with both clang and gcc.
# Require clang 3.0 / gcc 2.95 or later.
list(APPEND WPICKY_ENABLE
-Wbad-function-cast # clang 2.7 gcc 2.95
-Wconversion # clang 2.7 gcc 2.95
-Winline # clang 1.0 gcc 1.0
-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(WPICKY_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-sign-conversion # clang 2.9 gcc 4.3
-Wno-system-headers # clang 1.0 gcc 3.0
# -Wpadded # clang 2.9 gcc 4.1 # Not used because 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 # FIXME
# -Wno-error=sign-conversion # FIXME
-Wstrict-prototypes # clang 1.0 gcc 3.3
# -Wswitch-enum # clang 2.7 gcc 4.1 # Not used because this 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
)
set(WPICKY_COMMON
-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
-Wpragmas # clang 3.5 gcc 4.1 appleclang 6.0
-Wunused-const-variable # clang 3.4 gcc 6.0 appleclang 5.1
)
if(CMAKE_C_COMPILER_ID MATCHES "Clang")
list(APPEND WPICKY_ENABLE
${WPICKY_COMMON_OLD}
-Wshift-sign-overflow # clang 2.9
-Wshorten-64-to-32 # clang 1.0
-Wlanguage-extension-token # clang 3.0
-Wformat=2 # clang 3.0 gcc 4.8
)
# 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 WPICKY_ENABLE
${WPICKY_COMMON}
-Wunreachable-code-break # clang 3.5 appleclang 6.0
-Wheader-guard # clang 3.4 appleclang 5.1
-Wsometimes-uninitialized # clang 3.2 appleclang 4.6
)
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 WPICKY_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 WPICKY_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 WPICKY_ENABLE
-Wimplicit-fallthrough # clang 4.0 gcc 7.0 appleclang 12.4 # we have silencing markup for clang 10.0 and above only
)
endif()
else() # gcc
list(APPEND WPICKY_DETECT
${WPICKY_COMMON}
)
# Enable based on compiler version
if(NOT CMAKE_C_COMPILER_VERSION VERSION_LESS 4.3)
list(APPEND WPICKY_ENABLE
${WPICKY_COMMON_OLD}
-Wclobbered # gcc 4.3
-Wmissing-parameter-type # gcc 4.3
-Wold-style-declaration # gcc 4.3
-Wstrict-aliasing=3 # gcc 4.0
-Wtrampolines # gcc 4.3
)
endif()
if(NOT CMAKE_C_COMPILER_VERSION VERSION_LESS 4.5 AND MINGW)
list(APPEND WPICKY_ENABLE
-Wno-pedantic-ms-format # gcc 4.5 (mingw-only)
)
endif()
if(NOT CMAKE_C_COMPILER_VERSION VERSION_LESS 4.8)
list(APPEND WPICKY_ENABLE
-Wformat=2 # clang 3.0 gcc 4.8
)
endif()
if(NOT CMAKE_C_COMPILER_VERSION VERSION_LESS 5.0)
list(APPEND WPICKY_ENABLE
-Warray-bounds=2 -ftree-vrp # clang 3.0 gcc 5.0 (clang default: -Warray-bounds)
)
endif()
if(NOT CMAKE_C_COMPILER_VERSION VERSION_LESS 6.0)
list(APPEND WPICKY_ENABLE
-Wduplicated-cond # gcc 6.0
-Wnull-dereference # clang 3.0 gcc 6.0 (clang default)
-fdelete-null-pointer-checks
-Wshift-negative-value # clang 3.7 gcc 6.0 (clang default)
-Wshift-overflow=2 # clang 3.0 gcc 6.0 (clang default: -Wshift-overflow)
)
endif()
if(NOT CMAKE_C_COMPILER_VERSION VERSION_LESS 7.0)
list(APPEND WPICKY_ENABLE
-Walloc-zero # gcc 7.0
-Wduplicated-branches # gcc 7.0
-Wformat-overflow=2 # gcc 7.0
-Wformat-truncation=2 # gcc 7.0
-Wimplicit-fallthrough # clang 4.0 gcc 7.0
-Wrestrict # gcc 7.0
)
endif()
if(NOT CMAKE_C_COMPILER_VERSION VERSION_LESS 10.0)
list(APPEND WPICKY_ENABLE
-Warith-conversion # gcc 10.0
)
endif()
endif()
#
foreach(_CCOPT IN LISTS WPICKY_ENABLE)
set(WPICKY "${WPICKY} ${_CCOPT}")
endforeach()
foreach(_CCOPT IN LISTS WPICKY_DETECT)
# surprisingly, CHECK_C_COMPILER_FLAG needs a new variable to store each new
# test result in.
string(MAKE_C_IDENTIFIER "OPT${_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})
set(WPICKY "${WPICKY} ${_CCOPT}")
endif()
endforeach()
endif()
endif()
if(WPICKY)
set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} ${WPICKY}")
message(STATUS "Picky compiler options:${WPICKY}")
endif()