CMake utilities to expose common compiler flags in a compiler-independent way. This works by exposing a CMake function get_compiler_flags that can
optionally take some arguments specifying what kind of flags to enable. It then tries to figure out the appropriate flags for the given compiler.
The available options are:
| Option | Description |
|---|---|
ENABLE_WARNINGS_AS_ERRORS |
Turns warnings into errors |
ENABLE_MOST_WARNINGS |
Enables most of the available compiler warnings. The choice of which exactly this includes, is arguably subjective. |
ENABLE_UNSAFE_MATH |
Enables unsafe (aka "fast") math mode |
DISABLE_ALL_WARNINGS |
Disables all warnings |
DISABLE_DEFAULT_FLAGS |
If this is given, the function omits adding some common default flags, which are normally returned in addition to the ones explicitly requested. |
ENSURE_DEFAULT_CHAR_IS_SIGNED |
Ensures that a plain char will be signed. |
ENSURE_DEFAULT_CHAR_IS_UNSIGNED |
Ensures that a plain char will be unsigned. |
OPTIMIZE_FOR_SPEED |
Tells the compiler to optimize for maximum performance |
OPTIMIZE_FOR_SIZE |
Tells the compiler to optimize for minimum binary size |
OPTIMIZE_FOR_DEBUG |
Tells the compiler to use an optimization level suitable for debug builds |
COMPILER_ID <id> |
Specifies the compiler ID of the compiler to obtain the flags for. The ID must be one of the possible values of CMAKE_<LANG>_COMPILER_ID. Note that currently only GNU (GCC), Clang, AppleClang and MSVC are supported. If not given, this option defaults to the currently used compiler for the chosen language. |
LANG <lang> |
The language for which to obtain compiler flags. Note, that currently only CXX (C++) is supported. If not given, this defaults to CXX. |
OUTPUT_VARIABLE |
The name of the variable the result shall be stored in. This is the only mandatory function argument. |
Thus, an example invocation could look like this:
get_compiler_flags(
ENABLE_MOST_WARNINGS
ENABLE_WARNINGS_AS_ERRORS
OUTPUT_VARIABLE MY_FLAGS
)
# Note: In general you should prefer per-target flag definitions
add_compile_options(${MY_FLAGS})For more examples, have a look at the tests.