Compilation options for different versions of Clang, GCC, MSVC, Emscripten, ICC and ICX. Provided a generator and different file formats (build system and compiler).

The output directory contains files for cmake, xmake, premake5, meson, bjam/b2, scons and command-line options for gcc/g++, clang/clang++ and msvc. If a version of the compiler is not present, then there is no difference compared to an older version.

Each build system also has a branch with only the files it needs.

Here is an example with gcc:

int main()
{
  int x;
  return x; // used but uninitialized
}

$ g++ main.cpp

No output

$ g++ main.cpp @cpp-compiler-options/output/cpp/gcc/gcc-6.1-warnings

main.cpp: In function ‘int main()’:
main.cpp:4:10: warning: ‘x’ is used uninitialized in this function [-Wuninitialized]
    4 |   return x; // used but not initialized
      |          ^

(@file is a special option of gcc and clang for read command-line options from file.)

Options
1. Recommended options
Use generated files
Generators
How to add or modify options?

Options

Supported options are (alphabetically in a category):

# Warning:

analyzer = default off on taint
analyzer_too_complex_warning = default off on
analyzer_verbosity = default 0 1 2 3
conversion_warnings = on default off sign conversion
covered_switch_default_warnings = on default off
fix_compiler_error = on default off
msvc_crt_secure_no_warnings = on default off
noexcept_warnings = default off on
reproducible_build_warnings = default off on
shadow_warnings = off default on local compatible_local all
suggestions = default off on
switch_warnings = on default off exhaustive_enum mandatory_default exhaustive_enum_and_mandatory_default
unsafe_buffer_usage_warnings = default on off
warnings = on default off strict very_strict
warnings_as_error = default off on basic
windows_abi_compatibility_warnings = off default on

# Pedantic:

msvc_conformance = all default all_without_throwing_new
pedantic = on default off as_error
stl_fix = on default off

# Debug:

debug = default off on line_tables_only gdb lldb sce
float_sanitizers = default off on
integer_sanitizers = default off on
ndebug = with_optimization_1_or_above default off on
other_sanitizers = default off thread pointer memory
sanitizers = default off on
stl_debug = default off on allow_broken_abi allow_broken_abi_and_bugs assert_as_exception
var_init = default uninitialized pattern zero

# Optimization:

cpu = default generic native
linker = default bfd gold lld native
lto = default off on normal fat thin
optimization = default 0 g 1 2 3 fast size z
whole_program = default off on strip_all

# C++:

exceptions = default off on
rtti = default off on

# Hardening:

control_flow = default off on branch return allow_bugs
relro = default off on full
stack_protector = default off on strong all

# Other:

color = default auto never always
coverage = default off on
diagnostics_format = default fixits patch print_source_range_info
diagnostics_show_template_tree = default off on
elide_type = default off on
msvc_diagnostics_format = caret default classic column
msvc_isystem = default anglebrackets include_and_caexcludepath external_as_include_system_flag
msvc_isystem_with_template_from_non_external = default off on
pie = default off on static fpic fPIC fpie fPIE
windows_bigobj = on default

The value default does nothing.

If not specified:

msvc_conformance is all
msvc_diagnostics_format is caret
ndebug is with_optimization_1_or_above
The following values are off:
- shadow_warnings
- windows_abi_compatibility_warnings
The following values are on:
- conversion_warnings
- covered_switch_default_warnings
- fix_compiler_error
- msvc_crt_secure_no_warnings
- pedantic
- stl_fix
- switch_warnings
- warnings
- windows_bigobj

control_flow=allow_bugs
- clang: Can crash programs with "illegal hardware instruction" on totally unlikely lines. It can also cause link errors and force -fvisibility=hidden and -flto.
stl_debug=allow_broken_abi_and_bugs
- clang: libc++ can crash on dynamic memory releases in the standard classes. This bug is fixed with the library associated with version 8.
msvc_isystem=external_as_include_system_flag is only available with cmake.

Recommended options

category	options
debug	`control_flow=on` `debug=on` `sanitizers=on` `stl_debug=allow_broken_abi` or `on`
release	`cpu=native` `linker=gold`, `lld` or `native` `lto=on` or `thin` `optimization=3` `rtti=off` `whole_program=strip_all`
security	`control_flow=on` `relro=full` `stack_protector=strong` `pie=PIE`
really strict warnings	`pedantic=as_error` `shadow_warnings=local` `suggestions=on` `warnings=very_strict`

Use generated files

This is what enabled of sanitizers looks like with the different build systems available:

$ cmake -DJLN_SANITIZERS=on

$ xmake f --jln-sanitizers=on

$ premake5 --jln-sanitizers=on

$ meson -Djln_sanitizers=on

$ bjam -s jln_sanitizers=on

$ scons jln_sanitizers=on

(jln is a parameterizable prefix: ./compiler-options.lua generators/cmake.lua [prefix])

CMake

# launch example: cmake -DJLN_SANITIZERS=on
include(output/cpp/cmake)

# init default values
# jln_init_flags(
#     [<jln-option> <default_value>]...
#     [AUTO_PROFILE on]
#     [VERBOSE on]
#     [BUILD_TYPE type [<jln-option> <default_value>]...]...
# )
# AUTO_PROFILE: enables options based on CMAKE_BUILD_TYPE
#               (assumes "Debug" if CMAKE_BUILD_TYPE is empty)
# BUILD_TYPE: enables following options only if ${CMAKE_BUILD_TYPE}
#             has the same value (CMAKE_BUILD_TYPE assumed to Debug if empty)
jln_init_flags(
  SUGGESTIONS on      # set SUGGESTIONS default value to "on"
  BUILD_TYPE debug
    SANITIZERS on     # set SANITIZERS default value to "on" only in Debug build
  BUILD_TYPE release
    LTO on            # set LTO default value to "on" only in Release build
)


# jln_target_interface(
#     <libname> {INTERFACE|PUBLIC|PRIVATE}
#     [<jln-option> <value>]...
#     [DISABLE_OTHERS {on|off}]
#     [BUILD_TYPE type [<jln-option> <value>]...]...
# )
jln_target_interface(mytarget1 INTERFACE WARNINGS very_strict) # set WARNINGS to "very_strict"


# jln_flags(
#     CXX_VAR <out-variable>
#     LINK_VAR <out-variable>
#     [<jln-option> <value>]...
#     [DISABLE_OTHERS {on|off}]
#     [BUILD_TYPE type [<jln-option> <value>]...]...
# )
jln_flags(CXX_VAR CXX_FLAGS LINK_VAR LINK_FLAGS WARNINGS very_strict)

target_link_libraries(mytarget2 INTERFACE ${LINK_FLAGS})
target_compile_options(mytarget2 INTERFACE ${CXX_FLAGS})

# NOTE: for C, jln_ prefix function becomes jln_c_ and CXX_VAR becomes C_VAR

xmake

Copy output/cpp/xmake_options.lua to myproj/cpp/xmake.lua and output/cpp/xmake to myproj/cpp/flags.lua. cpp is an arbitrary directory name, this can be changed.

-- launch example: xmake f --jln-sanitizers=on

includes'cpp'

-- Registers new command-line options and set default values
jln_cxx_init_options({warnings='very_strict', warnings_as_error='basic'})

-- Set options for a specific mode (see also jln_cxx_rule())
-- When the first parameter is nil or unspecified, a default configuration is used.
jln_cxx_init_modes({
  debug={
    stl_debug='on',
  },
  release={
    function() ... end, -- callback for release mode
    lto='on',
  },
  -- ...
})

target('hello1')
  set_kind('binary')
  add_files('src/hello.cpp')



-- Create a new rule. Options are added to the current configuration
jln_cxx_rule('custom_rule', {warnings_as_error='on'})

target('hello2')
  set_kind('binary')
  add_rules('custom_rule')
  add_files('src/hello.cpp')



target('hello3')
  set_kind('binary')
  -- Custom configuration when jln_cxx_rule() or jln_cxx_modes() are not enough
  on_load(function(target)
    import'cpp.flags'
    -- see also get_flags() and create_options()
    local flags = flags.set_flags(target, {elide_type='on'})
    print(flags)
  end)
  add_files('src/hello.cpp')


-- NOTE: for C, jln_cxx_ prefix become jln_c_

Meson

Copy output/cpp/meson_options.txt and rename output/cpp/meson to meson_jln_flags/meson.build.

# launch example: meson -Djln_sanitizers=on
# note: `meson --warnlevel=0` implies `--Djln_warnings=off`

project('test', 'cpp')

# default options (without prefix)
# optional
jln_default_flags = {'rtti': 'off'}

# options for specific buildtype (added to default options)
# optional.
jln_buildtype_flags = {
  'debug': {'rtti': 'on'},
}

# Use a default configuration when jln_buildtype_flags is unspecified.
# optional.
jln_use_profile_buildtype = true

# optional
jln_custom_flags = [
  {'rtti': 'off', 'optimization': '3'}, # (0) opti flags
  {'debug': 'on'}, # (1) debug flags
  # { ... } # (2)
  # etc
]

# declare jln_link_flags, jln_cpp_flags, jln_custom_cpp_flags and jln_custom_link_flags
subdir('meson_jln_flags')

my_opti_cpp_flags = jln_custom_cpp_flags[0] # (0) opti flags (see above)
my_opti_link_flags = jln_custom_link_flags[0]
my_debug_cpp_flags = jln_custom_cpp_flags[1] # (1) debug flags (see above)
my_debug_link_flags = jln_custom_link_flags[1]
# my_... = jln_custom_cpp_flags[2] # (2)
# my_... = jln_custom_link_flags[2]
# etc

executable('demo', 'main.cpp', link_args: jln_link_flags, cpp_args: jln_cpp_flags)

# NOTE: for C, jln_ prefix becomes jln_c_

Premake5

-- launch example: premake5 --jln-sanitizers=on

include "output/cpp/premake5"

-- Registers new command-line options and set default values
jln_newoptions({warnings='very_strict'})

    -- getoptions(values = {}, disable_others = false, print_compiler = false)
    -- `values`: table. ex: {warnings='on'}
    -- `values` can have 3 additional fields:
    --  - `cxx`: compiler name (otherwise deducted from --cxx and --toolchain)
    --  - `cxx_version` (otherwise deducted from cxx)
    --  - `ld`: linker name
    -- `disable_others`: boolean
    -- `print_compiler`: boolean
    -- return {cxxflags=table, ldflags=table}
    -- Note: with C language, cxxflags, cxx and cxx_version become cflags, cc and cc_version
    local options = flags.getoptions({elide_type='on'})
    for _,opt in ipairs(options.cxxflags) do target:add('cxxflags', opt, {force=true}) end
    for _,opt in ipairs(options.ldflags) do target:add('ldflags', opt, {force=true}) end

    -- or equivalent (return also options)
    flags.setoptions(target, {elide_type='on'})

    -- return the merge of the default values and new value table
    local values = flags.tovalues({elide_type='on'}, --[[disable_others:bool]])
    print(values)

-- jln_getoptions(values = {}, disable_others = false, print_compiler = false)
-- `values`: table. ex: {warnings='on'}
-- `values` can have 3 additional fields:
--  - `cxx`: compiler name
--  - `cxx_version` (otherwise deducted from cxx)
--  - `ld`: linker name
-- `disable_others`: boolean
-- `print_compiler`: boolean
-- return {buildoptions=table, linkoptions=table}
-- Note: with C language, cxx and cxx_version become cc and cc_version
local mylib_options = jln_getoptions({elide_type='on'})
buildoptions(mylib_options.buildoptions)
linkoptions(mylib_options.linkoptions)

-- or equivalent
jln_setoptions({elide_type='on'})

-- returns the merge of the default values and new value table
local values = jln_tovalues({elide_type='on'}, --[[disable_others:bool]])
print(values)

-- NOTE: for C, jln_ prefix function becomes jln_c_

Bjam/B2 (Boost.Build)

# launch example: bjam -s jln_sanitizers=on

include output/cpp/bjam ;

# rule jln_flags ( properties * )

project name : requirements
  <jln-lto-default>on # enable jln-lto
  <jln-relro-default>on
  <conditional>@jln_flags
: default-build release ;

exe test : test.cpp : <jln-relro-incidental>off # incidental version of <jln-relro>off

# NOTE: for C, jln_flags becomes jln_c_flags

SCons

# launch example: scons jln_sanitizers=on

import jln_options as jln

jln.set_global_flags({'rtti': 'off'})

vars = Variables(None, ARGUMENTS)
jln.add_variables(vars, {'debug':'on'}) # default value of debug to on

# get_flags(variables[, env]) -> {flags=[...], linkflags=[...]}
flags1 = jln.get_flags(vars)
flags2 = jln.get_flags({'debug':'on'})

Bash alias for gcc/clang

The scripts below add 4 aliases with warnings=on, pedantic=on and color=always.

gw++ for g++
cw++ for clang++

for comp in g++ clang++ ; do
  version=$($comp --version | sed -E '1!d;s/.*([0-9]\.[0-9]\.[0-9]).*/\1/g')
  echo "alias ${comp:0:1}w++='$comp "$(./compiler-options.lua generators/compiler.lua "$comp-$version" warnings pedantic color=always)\'
done >> ~/.bashrc

gwcc for gcc
cwcc for clang

for comp in gcc clang ; do
  version=$($comp --version | sed -E '1!d;s/.*([0-9]\.[0-9]\.[0-9]).*/\1/g')
  echo "alias ${comp:0:1}wcc='$comp "$(./compiler-options.lua -c generators/compiler.lua "$comp-$version" warnings pedantic color=always)\'
done >> ~/.bashrc

Generators

Usage:

./compiler-options.lua [-h] [-p] [-c] [-o outfilebase]
                       [-t [-]{platform|compiler|linker}=name[,...]]
                       [-f [-]{option_name[=value_name][,...]}]
                       [-d option_name=value_name[,...]]
                       {generator} [options...]

./compiler-options.lua -f debug,warning generators/cmake.lua # only with debug and warning
./compiler-options.lua -f -debug,warning generators/cmake.lua # without debug nor warning

-p Print an AST.
-c for C, default is C++.
-t Restrict to a list of platform, compiler or linker. When the list is prefixed with '-', values are removed from current AST.
-f Restrict to a list of option/value. When the list is prefixed with -, options/values are removed.
-d Set new default value. An empty string for value_name is equivalent to default.

generators/compiler.lua

See ./compiler-options.lua generators/compiler.lua -h for detailed usage information.

generators/list_options.lua

$ ./compiler-options.lua generators/list_options.lua [--profile] [--color]

Checks and displays options and their values.

generators/{cmake,xmake,meson,premake5,bjam,scons}.lua

Generators for different build system.

$ ./compiler-options.lua [-o filebase] {generator} [option-prefix]

How to add or modify options?

Edit compiler-options.lua file.

The MakeAST function contains the options tree.

_koptions of Vbase contains the list of available options. _opts_by_category a categorization of these options.

Flags

c, cxx, flag, link, fl

c'-Wall' -- C only
cxx'-Wall' -- C++ only
flag'-Wall' -- C and C++
link'-flto' -- Link option
fl'xxx' -- is a alias of {flag'xxx',link'xxx'}

Compilers and linkers

gcc for gcc or g++
clang for clang or clang++
clang_cl for clang-cl
clang_emcc refers to the version of clang used by emcc
clang_like refers to clang, clang_cl and clang_emcc
msvc for cl
icc
icl
lld_link for lld-link
ld64

icx, icpx, dpcpp are equivalent to clang.

With mingw, the compiler is gcc.

version can be specified with vers or a compiler name and a parameter of the form {operator}{major}.{minor}.

gcc { ... } -- for gcc only
gcc'>=5' { ... } -- for >= gcc-5
gcc'>=5.3' { ... } -- for >= gcc-5.3
gcc'<5.3' { ... } -- for < gcc-5.3

gcc'>=5.3' { ... } -- equivalent to `gcc { vers'>=5.3' { ... } }`

Platform

linux
windows
macos
mingw with gcc as compiler

Options and levels

opt'name' { ... }
lvl'name' { ... }

opt'warnings' { -- if warnings is enabled (not `warnings=default`)
  lvl'off' { cxx'-w' } -- for `warnings=off`
}

has_opt'name' { ... }

opt'warnings' {
  has_opt'debug' { -- if debug is enabled (not `debug=default`)
    lvl'off' { cxx'-w' } -- for `warnings=off`, not debug=off
  }
}

has_opt'debug':with('gdb', 'on') { -- if debug is 'on' or 'gdb'
  ...
}
has_opt'debug':without('gdb', 'on') { -- if debug is not 'default', 'on' or 'gdb'
  ...
}

reset_opt'name' for disabled an option

vers'<8' {
  reset_opt'lto' -- disable lto option when version < 8
}

Conditions

Or(...)
And(...)

Or(gcc, clang, msvc) { ... }
And(gcc, lvl'off') { ... }

if_mt

Compilers, linkers, platforms and condition returns a if_mt.

-xxx {...} for not xxx
xxx {...} / yyy {...} for xxx or else yyy

opt'warnings' { -lvl'on' { ... } } -- neither warnings=on nor warnings=default
lvl'on' { xxx } / { yyy } -- equivalent to `{ lvl'on' { xxx }, -lvl'on' { yyy } }`

Note: -opt'name' isn't allowed

Others

if_else(cond, f) = cond { f(true) } / f()
match(a,b,c,...) = a / b / c / ...
act(data) for a specific action hardcoded into a generator
- cmake: data must be a table which can contain the keys:
  - cxx: add the value in CMAKE_CXX_FLAGS / CMAKE_C_FLAGS
  - system_flag: add the value in CMAKE_INCLUDE_SYSTEM_FLAG_CXX / CMAKE_INCLUDE_SYSTEM_FLAG_C.

jonathanpoelen/cpp-compiler-options