[libc-commits] [libc] [libc][test] Condition out tests that can't work on bare metal (PR #215830)

[Simon Tatham via libc-commits]

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@@ -30,15 +36,14 @@ function(_get_common_test_compile_options output_var c_test flags)
   libc_add_definition(compile_options
     "LIBC_TEST_SUBPROCESS_TESTS=${LIBC_TEST_SUBPROCESS_TESTS}")
 
-  if(LIBC_TEST_SUBPROCESS_TESTS)
-    # EXPECT_DEATH and ASSERT_DEATH might be quite slow.  LIBC_TEST_SKIP_DEATH_TESTS
-    # will make those tests no-op to reduce the overall test time.
-    if(LIBC_TEST_SKIP_DEATH_TESTS)
-      if(LIBC_CMAKE_VERBOSE_LOGGING)
-        message(STATUS "LIBC_TEST_SKIP_DEATH_TESTS is set.  EXPECT_DEATH/ASSERT_DEATH are no-op.")
-      endif()
-      list(APPEND compile_options "-DLIBC_TEST_SKIP_DEATH_TESTS")
+  # Set LIBC_TEST_SKIP_DEATH_TESTS to skip running tests that use EXPECT_DEATH
+  # and ASSERT_DEATH. On platforms where they work, they can be slow; on
+  # bare-metal platforms it might not be possible to implement them at all.
+  if(LIBC_TEST_SKIP_DEATH_TESTS)
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statham-arm wrote:

You mean, leave the existing ifdefs as they originally were, but whenever LIBC_TEST_SUBPROCESS_TESTS isn't defined, we have a second `#else` branch where we define EXPECT_DEATH to be empty? OK.

We aren't seeing any test-program build failures relating to EXPECT_EXIT (in that with this patch and Mark's linked one we see no failures at all). I think that's just because the EXPECT_EXIT tests are all specific to functions that deal with complicated exiting behaviour, like `atexit`, and the bare-metal libc configuration doesn't include those functions, hence the tests aren't built or run either.

Whereas EXPECT_DEATH is more widespread, because it appears in tests of functions that have nothing _per se_ to do with exiting, such as testing that if you pass a null pointer to `localtime` then something appropriately horrible happens.

https://github.com/llvm/llvm-project/pull/215830