[libc++] tests with picolibc: XFAIL uses of atomics

Author: domin144

libcxx/test/libcxx/atomics/lit.local.cfg

@@ -0,0 +1,3 @@
+# Disable all of the atomics tests if the correct feature is not available.
+if "has-no-atomics" in config.available_features:
+    config.unsupported = True

libcxx/test/libcxx/experimental/memory/lit.local.cfg

@@ -0,0 +1,3 @@
+# Disable all of the atomics tests if the correct feature is not available.
+if "has-no-atomics" in config.available_features:
+    config.unsupported = True

libcxx/test/libcxx/thread/thread.stoptoken/intrusive_shared_ptr.pass.cpp

@@ -7,6 +7,8 @@
 //===----------------------------------------------------------------------===//
 //
 
+// XFAIL: has-no-atomics
+
 // UNSUPPORTED: c++03, c++11, c++14, c++17
 // ADDITIONAL_COMPILE_FLAGS: -Wno-private-header
 

libcxx/test/std/atomics/lit.local.cfg

@@ -0,0 +1,3 @@
+# Disable all of the atomics tests if the correct feature is not available.
+if "has-no-atomics" in config.available_features:
+    config.unsupported = True

libcxx/test/std/experimental/memory/memory.polymorphic.allocator.class/lit.local.cfg

@@ -0,0 +1,3 @@
+# Disable all of the atomics tests if the correct feature is not available.
+if "has-no-atomics" in config.available_features:
+    config.unsupported = True

libcxx/test/std/experimental/memory/memory.resource.aliases/lit.local.cfg

@@ -0,0 +1,3 @@
+# Disable all of the atomics tests if the correct feature is not available.
+if "has-no-atomics" in config.available_features:
+    config.unsupported = True

libcxx/test/std/experimental/memory/memory.resource.global/lit.local.cfg

@@ -0,0 +1,3 @@
+# Disable all of the atomics tests if the correct feature is not available.
+if "has-no-atomics" in config.available_features:
+    config.unsupported = True

libcxx/utils/libcxx/test/features.py

@@ -211,6 +211,21 @@ def _mingwSupportsModules(cfg):
           """,
         ),
     ),
+    Feature(
+        name="has-no-atomics",
+        when=lambda cfg: not sourceBuilds(
+            cfg,
+            """
+            #include <atomic>
+            std::atomic_uint x;
+            int main(int, char**) { (void)x.load(); return 0; }
+          """,
+        ),
+        actions=[
+            AddFeature("availability-pmr-missing"),
+            AddFeature("libcpp-has-no-incomplete-pstl"),
+        ],
+    ),
     # Tests that require 64-bit architecture
     Feature(
         name="32-bit-pointer",