[SYCL][E2E] Add option to build tests on run-only mode if marked as REQUIRES: build-and-run-mode (#16306)

Prior if a test was marked as `REQUIRES: build-and-run-mode` it would be
reported as unsupported in `run-only` mode, because there would be no
test binaries created from `build-only` mode to be able to run the test.

When calling lit with `--param test-mode=run-only --param
fallback-to-build-if-requires-build-and-run=True`, tests that are marked
with `REQUIRES: build-and-run-mode` will override the `RUN:` line
filtering, and run all lines, including those that compile the test
binaries. This makes it so we still have coverage of tests marked as
exceptions for splitting on the `run-only` system.

Author: ayylol

sycl/test-e2e/format.py

@@ -234,14 +234,19 @@ def get_extra_env(sycl_devices):
                 new_script.append(directive)
                 continue
 
-            # Filter commands based on split-mode
+            # Filter commands based on testing mode
             is_run_line = any(
                 i in directive.command
                 for i in ["%{run}", "%{run-unfiltered-devices}", "%if run-mode"]
             )
 
-            if (is_run_line and test.config.test_mode == "build-only") or (
-                not is_run_line and test.config.test_mode == "run-only"
+            ignore_line_filtering = (
+                "build-and-run-mode" in test.requires
+                and test.config.fallback_build_run_only
+            )
+            if not ignore_line_filtering and (
+                (is_run_line and test.config.test_mode == "build-only")
+                or (not is_run_line and test.config.test_mode == "run-only")
             ):
                 directive.command = ""
 

sycl/test-e2e/lit.cfg.py

@@ -39,12 +39,16 @@
 
 # test-mode: Set if tests should run normally or only build/run
 config.test_mode = lit_config.params.get("test-mode", "full")
+config.fallback_build_run_only = False
 if config.test_mode == "full":
     config.available_features.add("run-mode")
     config.available_features.add("build-and-run-mode")
 elif config.test_mode == "run-only":
     lit_config.note("run-only test mode enabled, only executing tests")
     config.available_features.add("run-mode")
+    if lit_config.params.get("fallback-to-build-if-requires-build-and-run", False):
+        config.available_features.add("build-and-run-mode")
+        config.fallback_build_run_only = True
 elif config.test_mode == "build-only":
     lit_config.note("build-only test mode enabled, only compiling tests")
     config.sycl_devices = []