| ======================================== |
| 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:`` and the ``target=<target-triple>`` feature, typically with a regular |
| expression matching an appropriate substring of the 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 regular expressions may inadvertently match |
| more triples than expected. For example, ``XFAIL: target=mips{{.*}}`` matches |
| ``mips-linux-gnu``, ``mipsel-linux-gnu``, ``mips64-linux-gnu``, and |
| ``mips64el-linux-gnu``. Including a trailing ``-`` such as in |
| ``XFAIL: target=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: target=x86_64{{{.*}}`` |
| will mark both the x86_64 and i386 tests as an expected failure while |
| ``XFAIL: target=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. |