[lit] Extend --xfail/LIT_XFAIL to take full test name

The new documentation entry gives an example use case from
libomptarget.

Reviewed By: yln, jhenderson, davezarzycki

Differential Revision: https://reviews.llvm.org/D105208

llvm/docs/CommandGuide/lit.rst

@@ -239,6 +239,31 @@ The timing data is stored in the `test_exec_root` in a file named
   this option, which is especially useful in environments where the call to
   ``lit`` is issued indirectly.
 
+  A test name can specified as a file name relative to the test suite directory.
+  For example:
+
+  .. code-block:: none
+
+    LIT_XFAIL="affinity/kmp-hw-subset.c;offloading/memory_manager.cpp"
+
+  In this case, all of the following tests are treated as ``XFAIL``:
+
+  .. code-block:: none
+
+    libomp :: affinity/kmp-hw-subset.c
+    libomptarget :: nvptx64-nvidia-cuda :: offloading/memory_manager.cpp
+    libomptarget :: x86_64-pc-linux-gnu :: offloading/memory_manager.cpp
+
+  Alternatively, a test name can be specified as the full test name
+  reported in LIT output.  For example, we can adjust the previous
+  example not to treat the ``nvptx64-nvidia-cuda`` version of
+  ``offloading/memory_manager.cpp`` as XFAIL:
+
+  .. code-block:: none
+
+    LIT_XFAIL="affinity/kmp-hw-subset.c;libomptarget :: x86_64-pc-linux-gnu :: offloading/memory_manager.cpp"
+
+
 ADDITIONAL OPTIONS
 ------------------
 

llvm/utils/lit/lit/main.py

@@ -193,7 +193,9 @@ def filter_by_shard(tests, run, shards, lit_config):
 
 def mark_xfail(selected_tests, opts):
     for t in selected_tests:
-        if os.sep.join(t.path_in_suite) in opts.xfail:
+        test_file = os.sep.join(t.path_in_suite)
+        test_full_name = t.getFullName()
+        if test_file in opts.xfail or test_full_name in opts.xfail:
             t.xfails += '*'
 
 def mark_excluded(discovered_tests, selected_tests):

llvm/utils/lit/tests/Inputs/xfail-cl/a/false.txt

@@ -0,0 +1 @@
+# RUN: false

llvm/utils/lit/tests/Inputs/xfail-cl/a/lit.cfg

@@ -0,0 +1,4 @@
+import lit.formats
+config.name = 'top-level-suite :: a'
+config.suffixes = ['.txt']
+config.test_format = lit.formats.ShTest()

llvm/utils/lit/tests/Inputs/xfail-cl/a/test.txt

@@ -0,0 +1 @@
+# RUN: true

llvm/utils/lit/tests/Inputs/xfail-cl/b/false.txt

@@ -0,0 +1 @@
+# RUN: false

llvm/utils/lit/tests/Inputs/xfail-cl/b/lit.cfg

@@ -0,0 +1,4 @@
+import lit.formats
+config.name = 'top-level-suite :: b'
+config.suffixes = ['.txt']
+config.test_format = lit.formats.ShTest()

llvm/utils/lit/tests/Inputs/xfail-cl/b/test.txt

@@ -0,0 +1 @@
+# RUN: false

llvm/utils/lit/tests/xfail-cl.py

@@ -1,9 +1,20 @@
-# Check that regex-XFAILing works and can be configured via env var.
-#
-# RUN: %{lit} --xfail 'false.txt;false2.txt' %{inputs}/xfail-cl | FileCheck --check-prefix=CHECK-FILTER %s
-# RUN: env LIT_XFAIL='false.txt;false2.txt' %{lit} %{inputs}/xfail-cl | FileCheck --check-prefix=CHECK-FILTER %s
+# Check that XFAILing works via command line or env var.
+
+# RUN: %{lit} --xfail 'false.txt;false2.txt;top-level-suite :: b :: test.txt' \
+# RUN:        %{inputs}/xfail-cl \
+# RUN: | FileCheck --check-prefix=CHECK-FILTER %s
+
+# RUN: env LIT_XFAIL='false.txt;false2.txt;top-level-suite :: b :: test.txt' \
+# RUN: %{lit} %{inputs}/xfail-cl \
+# RUN: | FileCheck --check-prefix=CHECK-FILTER %s
+
 # END.
-# CHECK-FILTER: Testing: 3 tests, {{[1-3]}} workers
-# CHECK-FILTER-DAG: XFAIL: top-level-suite :: false.txt
-# CHECK-FILTER-DAG: XFAIL: top-level-suite :: false2.txt
-# CHECK-FILTER-DAG: PASS: top-level-suite :: true.txt
+
+# CHECK-FILTER: Testing: 7 tests, {{[1-7]}} workers
+# CHECK-FILTER-DAG: {{^}}PASS: top-level-suite :: a :: test.txt
+# CHECK-FILTER-DAG: {{^}}XFAIL: top-level-suite :: b :: test.txt
+# CHECK-FILTER-DAG: {{^}}XFAIL: top-level-suite :: a :: false.txt
+# CHECK-FILTER-DAG: {{^}}XFAIL: top-level-suite :: b :: false.txt
+# CHECK-FILTER-DAG: {{^}}XFAIL: top-level-suite :: false.txt
+# CHECK-FILTER-DAG: {{^}}XFAIL: top-level-suite :: false2.txt
+# CHECK-FILTER-DAG: {{^}}PASS: top-level-suite :: true.txt