summaryrefslogtreecommitdiff
path: root/cmake/CompileFlags.cmake
blob: 659a9ca724dff04fcdd42720a50794b23314c355 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
# Macro which contains all bits to setup the compile flags correctly.
#
# compile_flags()
#
macro(compile_flags)
    if(MSVC)
        if(VCPKG_TARGET_TRIPLET MATCHES "-static" AND NOT VCPKG_TARGET_TRIPLET MATCHES "-md")
            # Switch to MT (static) instead of MD (dynamic) binary

            # For MSVC two generators are available
            # - a command line generator (Ninja) using CMAKE_BUILD_TYPE to specify the
            #   configuration of the build tree
            # - an IDE generator (Visual Studio) using CMAKE_CONFIGURATION_TYPES to
            #   specify all configurations that will be available in the generated solution
            list(APPEND MSVC_CONFIGS "${CMAKE_BUILD_TYPE}" "${CMAKE_CONFIGURATION_TYPES}")

            # Set usage of static runtime for all configurations
            foreach(MSVC_CONFIG ${MSVC_CONFIGS})
                string(TOUPPER "CMAKE_CXX_FLAGS_${MSVC_CONFIG}" MSVC_FLAGS)
                string(REPLACE "/MD" "/MT" ${MSVC_FLAGS} "${${MSVC_FLAGS}}")
            endforeach()
        endif()

        # "If /Zc:rvalueCast is specified, the compiler follows section 5.4 of the
        # C++11 standard". We need C++11 for the way we use threads.
        add_compile_options(/Zc:rvalueCast)

        if(NOT CMAKE_CXX_COMPILER_ID STREQUAL "Clang")
            add_compile_options(
                /MP # Enable multi-threaded compilation.
                /FC # Display the full path of source code files passed to the compiler in diagnostics.
            )
        endif()
    endif()

    # Add some -D flags for Debug builds. We cannot use add_definitions(), because
    # it does not appear to support the $<> tags.
    add_compile_options(
        "$<$<CONFIG:Debug>:-D_DEBUG>"
        "$<$<NOT:$<CONFIG:Debug>>:-D_FORTIFY_SOURCE=2>" # FORTIFY_SOURCE should only be used in non-debug builds (requires -O1+)
    )
    if(MINGW)
        add_link_options(
            "$<$<NOT:$<CONFIG:Debug>>:-fstack-protector>" # Prevent undefined references when _FORTIFY_SOURCE > 0
        )
    endif()

    # Prepare a generator that checks if we are not a debug, and don't have asserts
    # on. We need this later on to set some compile options for stable releases.
    set(IS_STABLE_RELEASE "$<AND:$<NOT:$<CONFIG:Debug>>,$<NOT:$<BOOL:${OPTION_USE_ASSERTS}>>>")

    if(MSVC)
        add_compile_options(/W3)
    elseif(CMAKE_CXX_COMPILER_ID STREQUAL "GNU" OR CMAKE_CXX_COMPILER_ID STREQUAL "Clang" OR CMAKE_CXX_COMPILER_ID STREQUAL "AppleClang")
        add_compile_options(
            -W
            -Wall
            -Wcast-qual
            -Wextra
            -Wsign-compare
            -Wundef
            -Wpointer-arith
            -Wwrite-strings
            -Wredundant-decls
            -Wformat-security
            -Wformat=2
            -Winit-self
            -Wnon-virtual-dtor

            # Often parameters are unused, which is fine.
            -Wno-unused-parameter
            # We use 'ABCD' multichar for SaveLoad chunks identifiers
            -Wno-multichar

            # Compilers complains about that we break strict-aliasing.
            #  On most places we don't see how to fix it, and it doesn't
            #  break anything. So disable strict-aliasing to make the
            #  compiler all happy.
            -fno-strict-aliasing
        )

        # When we are a stable release (Release build + USE_ASSERTS not set),
        # assertations are off, which trigger a lot of warnings. We disable
        # these warnings for these releases.
        if(CMAKE_CXX_COMPILER_ID STREQUAL "GNU")
            add_compile_options(
                "$<${IS_STABLE_RELEASE}:-Wno-unused-variable>"
                "$<${IS_STABLE_RELEASE}:-Wno-unused-but-set-parameter>"
                "$<${IS_STABLE_RELEASE}:-Wno-unused-but-set-variable>"
            )
        else()
            add_compile_options(
                "$<${IS_STABLE_RELEASE}:-Wno-unused-variable>"
                "$<${IS_STABLE_RELEASE}:-Wno-unused-parameter>"
            )
        endif()

        # Ninja processes the output so the output from the compiler
        # isn't directly to a terminal; hence, the default is
        # non-coloured output. We can override this to get nicely
        # coloured output, but since that might yield odd results with
        # IDEs, we extract it to an option.
        if(OPTION_FORCE_COLORED_OUTPUT)
            if("${CMAKE_CXX_COMPILER_ID}" STREQUAL "GNU")
                add_compile_options (-fdiagnostics-color=always)
            elseif("${CMAKE_CXX_COMPILER_ID}" STREQUAL "Clang" OR CMAKE_CXX_COMPILER_ID STREQUAL "AppleClang")
                add_compile_options (-fcolor-diagnostics)
            endif()
        endif()

        if(CMAKE_CXX_COMPILER_ID STREQUAL "GNU")
            include(CheckCXXCompilerFlag)
            check_cxx_compiler_flag("-flifetime-dse=1" LIFETIME_DSE_FOUND)

            add_compile_options(
                # GCC 4.2+ automatically assumes that signed overflows do
                # not occur in signed arithmetics, whereas we are not
                # sure that they will not happen. It furthermore complains
                # about its own optimized code in some places.
                "-fno-strict-overflow"

                # Prevent optimisation supposing enums are in a range specified by the standard
                # For details, see http://gcc.gnu.org/PR43680
                "-fno-tree-vrp"

                # -flifetime-dse=2 (default since GCC 6) doesn't play
                # well with our custom pool item allocator
                "$<$<BOOL:${LIFETIME_DSE_FOUND}>:-flifetime-dse=1>"
            )
        endif()

        if(CMAKE_CXX_COMPILER_ID STREQUAL "AppleClang")
            if (NOT CMAKE_OSX_ARCHITECTURES STREQUAL "arm64")
                include(CheckCXXCompilerFlag)
                check_cxx_compiler_flag("-mno-sse4" NO_SSE4_FOUND)

                if(NO_SSE4_FOUND)
                    add_compile_options(
                        # Don't use SSE4 for general sources to increase compatibility.
                        -mno-sse4
                    )
                endif()
            endif()
        endif()
    elseif(CMAKE_CXX_COMPILER_ID STREQUAL "Intel")
        add_compile_options(
            -Wall
            # warning #873: function ... ::operator new ... has no corresponding operator delete ...
            -wd873
            # warning #1292: unknown attribute "fallthrough"
            -wd1292
            # warning #1899: multicharacter character literal (potential portability problem)
            -wd1899
            # warning #2160: anonymous union qualifier is ignored
            -wd2160
        )
    else()
        message(FATAL_ERROR "No warning flags are set for this compiler yet; please consider creating a Pull Request to add support for this compiler.")
    endif()

    if(NOT WIN32 AND NOT HAIKU)
        # rdynamic is used to get useful stack traces from crash reports.
        set(CMAKE_EXE_LINKER_FLAGS "${CMAKE_EXE_LINKER_FLAGS} -rdynamic")
    endif()
endmacro()