======================================== Compiler-rt Testing Infrastructure Guide ======================================== .. contents:: :local: Overview ======== This document is the reference manual for the compiler-rt modifications to the testing infrastructure. Documentation for the infrastructure itself can be found at :ref:`llvm_testing_guide`. LLVM testing infrastructure organization ======================================== The compiler-rt testing infrastructure contains regression tests which are run as part of the usual ``make check-all`` and are expected to always pass -- they should be run before every commit. Quick start =========== The regressions tests are in the "compiler-rt" module and are normally checked out in the directory ``llvm/projects/compiler-rt/test``. Use ``make check-all`` to run the regression tests after building compiler-rt. REQUIRES, XFAIL, etc. --------------------- Sometimes it is necessary to restrict a test to a specific target or mark it as an "expected fail" or XFAIL. This is normally achieved using ``REQUIRES:`` or ``XFAIL:`` with a substring of LLVM's default target triple. Unfortunately, the behaviour of this is somewhat quirky in compiler-rt. There are two main pitfalls to avoid. The first pitfall is that these directives perform a substring match on the triple and as such ``XFAIL: mips`` affects more triples than expected. For example, ``mips-linux-gnu``, ``mipsel-linux-gnu``, ``mips64-linux-gnu``, and ``mips64el-linux-gnu`` will all match a ``XFAIL: mips`` directive. Including a trailing ``-`` such as in ``XFAIL: mips-`` can help to mitigate this quirk but even that has issues as described below. The second pitfall is that the default target triple is often inappropriate for compiler-rt tests since compiler-rt tests may be compiled for multiple targets. For example, a typical build on an ``x86_64-linux-gnu`` host will often run the tests for both x86_64 and i386. In this situation ``XFAIL: x86_64`` will mark both the x86_64 and i386 tests as an expected failure while ``XFAIL: i386`` will have no effect at all. To remedy both pitfalls, compiler-rt tests provide a feature string which can be used to specify a single target. This string is of the form ``target-is-${arch}`` where ``${arch}}`` is one of the values from the following lines of the CMake output:: -- Compiler-RT supported architectures: x86_64;i386 -- Builtin supported architectures: i386;x86_64 So for example ``XFAIL: target-is-x86_64`` will mark a test as expected to fail on x86_64 without also affecting the i386 test and ``XFAIL: target-is-i386`` will mark a test as expected to fail on i386 even if the default target triple is ``x86_64-linux-gnu``. Directives that use these ``target-is-${arch}`` string require exact matches so ``XFAIL: target-is-mips``, ``XFAIL: target-is-mipsel``, ``XFAIL: target-is-mips64``, and ``XFAIL: target-is-mips64el`` all refer to different MIPS targets.