Testing libc++ using LIT
libc++ uses LIT to configure and run its tests. The primary way to run the
libc++ tests is by using make check-libcxx. However since libc++
can be used in any number of possible configurations it is important to
customize the way LIT builds and runs the tests. This guide provides
information on how to use LIT directly to test libc++.
Documentation for LIT can be found here.
Getting Started
After building libc++ use the following commands before you start using LIT to test.
alias lit='python path/to/llvm/utils/lit/lit.py'export LIBCXX_SITE_CONFIG=path/to/build-libcxx/test/lit.site.cfg
You can now run the libc++ tests by running:
cd path/to/libcxxlit -sv ./test
To only run a subsection of the tests use:
lit -sv test/std/numerics # Run only the numeric tests
Customization Options
libc++'s testsuite provides multiple options to configure the way the tests
are build and run. To use these options you pass them on the LIT command line
as --param NAME or --param NAME=VALUE. Some options
have default values specified during CMake's configuration. Passing the option
on the command line will override the default.
libcxx_site_config=<path/to/lit.site.cfg>
Specify the site configuration to use when running the tests. This option
overrides the enviroment variable LIBCXX_SITE_CONFIG
libcxx_headers=<path/to/headers>
Specify the libc++ headers that are tested. By default the headers in the source tree are used.
libcxx_library=<path/to/libc++.so>
Specify the libc++ library that is tested. By default the library in the build
directory is used. This option cannot be used when use_system_lib
is provided.
use_system_lib=<bool>
Default: False
Enable or disable testing against the installed version of libc++ library.
Note: This does not use the installed headers.
use_lit_shell=<bool>
Enable or disable the use of LIT's internal shell in ShTests. If the enviroment variableLIT_USE_INTERNAL_SHELLis present then that is used as the default value. Otherwise the default value isTrueon Windows andFalseon every other platform.
no_default_flags=<bool>
Default:FalseDisable all default compile and link flags from being added. When this option is used only flags specified using thecompile_flagsandlink_flagswill be used.
compile_flags="<list-of-args>"
Specify additional compile flags as a space delimited string. Note: This options should not be used to change the standard version used.
link_flags="<list-of-args>"
Specify additional link flags as a space delimited string.
std=<standard version>
Values: c++98, c++03, c++11, c++14, c++1z
Change the standard version used when building the tests.
debug_level=<level>
Values: 0, 1
Enable the use of debug mode. Level 0 enables assertions and level 1 enables
assertions and debugging of iterator misuse.
use_sanitizer=<sanitizer name>
Values:Memory, MemoryWithOrigins, Address, UndefinedRun the tests using the given sanitizer. IfLLVM_USE_SANITIZERwas given when building libc++ then that sanitizer will be used by default.
color_diagnostics
Enable the use of colorized compile diagnostics. If thecolor_diagnosticsoption is specified or the enviroment variableLIBCXX_COLOR_DIAGNOSTICSis present then color diagnostics will be enabled.