[CI][Github] Enable CIR CI build and test (#147430)

This change modifies CI scripts to add a pseudo-project for CIR and
detect when CIR-specific files are modified. It also enables building
clang with CIR enabled whenever both the clang and mlir projects are
being built.

Building and testing CIR is only enabled on Linux at this time, as CIR
doesn't properly support Windows or MacOS yet.

.ci/compute_projects.py

@@ -19,6 +19,7 @@ import sys
 PROJECT_DEPENDENCIES = {
     "llvm": set(),
     "clang": {"llvm"},
+    "CIR": {"clang", "mlir"},
     "bolt": {"clang", "lld", "llvm"},
     "clang-tools-extra": {"clang", "llvm"},
     "compiler-rt": {"clang", "lld"},
@@ -55,6 +56,7 @@ DEPENDENTS_TO_TEST = {
     ".ci": {
         "llvm",
         "clang",
+        "CIR",
         "lld",
         "lldb",
         "bolt",
@@ -128,6 +130,7 @@ PROJECT_CHECK_TARGETS = {
     "lldb": "check-lldb",
     "llvm": "check-llvm",
     "clang": "check-clang",
+    "CIR": "check-clang-cir",
     "bolt": "check-bolt",
     "lld": "check-lld",
     "flang": "check-flang",
@@ -247,6 +250,14 @@ def _get_modified_projects(modified_files: list[str]) -> Set[str]:
         # capacity.
         if len(path_parts) > 3 and path_parts[:3] == ("llvm", "utils", "gn"):
             continue
+        # If the file is in the clang/lib/CIR directory, add the CIR project.
+        if len(path_parts) > 3 and (
+            path_parts[:3] == ("clang", "lib", "CIR")
+            or path_parts[:3] == ("clang", "test", "CIR")
+            or path_parts[:4] == ("clang", "include", "clang", "CIR")
+        ):
+            modified_projects.add("CIR")
+            # Fall through to add clang.
         modified_projects.add(pathlib.Path(modified_file).parts[0])
     return modified_projects
 
@@ -267,6 +278,13 @@ def get_env_variables(modified_files: list[str], platform: str) -> Set[str]:
     runtimes_check_targets_needs_reconfig = _compute_project_check_targets(
         runtimes_to_test_needs_reconfig
     )
+
+    # CIR is used as a pseudo-project in this script. It is built as part of the
+    # clang build, but it requires an explicit option to enable. We set that
+    # option here, and remove it from the projects_to_build list.
+    enable_cir = "ON" if "CIR" in projects_to_build else "OFF"
+    projects_to_build.discard("CIR")
+
     # We use a semicolon to separate the projects/runtimes as they get passed
     # to the CMake invocation and thus we need to use the CMake list separator
     # (;). We use spaces to separate the check targets as they end up getting
@@ -279,6 +297,7 @@ def get_env_variables(modified_files: list[str], platform: str) -> Set[str]:
         "runtimes_check_targets_needs_reconfig": " ".join(
             sorted(runtimes_check_targets_needs_reconfig)
         ),
+        "enable_cir": enable_cir,
     }
 
 

.ci/compute_projects_test.py

@@ -104,6 +104,10 @@ class TestComputeProjects(unittest.TestCase):
             env_variables["runtimes_check_targets_needs_reconfig"],
             "check-cxx check-cxxabi check-unwind",
         )
+        self.assertEqual(
+            env_variables["enable_cir"],
+            "OFF",
+        )
 
     def test_clang_windows(self):
         env_variables = compute_projects.get_env_variables(
@@ -126,6 +130,32 @@ class TestComputeProjects(unittest.TestCase):
             env_variables["runtimes_check_targets_needs_reconfig"],
             "check-cxx check-cxxabi check-unwind",
         )
+        self.assertEqual(env_variables["enable_cir"], "OFF")
+
+    def test_cir(self):
+        env_variables = compute_projects.get_env_variables(
+            ["clang/lib/CIR/CMakeLists.txt"], "Linux"
+        )
+        self.assertEqual(
+            env_variables["projects_to_build"],
+            "clang;clang-tools-extra;lld;llvm;mlir",
+        )
+        self.assertEqual(
+            env_variables["project_check_targets"],
+            "check-clang check-clang-cir check-clang-tools",
+        )
+        self.assertEqual(
+            env_variables["runtimes_to_build"], "compiler-rt;libcxx;libcxxabi;libunwind"
+        )
+        self.assertEqual(
+            env_variables["runtimes_check_targets"],
+            "check-compiler-rt",
+        )
+        self.assertEqual(
+            env_variables["runtimes_check_targets_needs_reconfig"],
+            "check-cxx check-cxxabi check-unwind",
+        )
+        self.assertEqual(env_variables["enable_cir"], "ON")
 
     def test_bolt(self):
         env_variables = compute_projects.get_env_variables(
@@ -158,6 +188,7 @@ class TestComputeProjects(unittest.TestCase):
         self.assertEqual(env_variables["runtimes_to_build"], "")
         self.assertEqual(env_variables["runtimes_check_targets"], "")
         self.assertEqual(env_variables["runtimes_check_targets_needs_reconfig"], "")
+        self.assertEqual(env_variables["enable_cir"], "OFF")
 
     def test_flang(self):
         env_variables = compute_projects.get_env_variables(
@@ -168,6 +199,7 @@ class TestComputeProjects(unittest.TestCase):
         self.assertEqual(env_variables["runtimes_to_build"], "")
         self.assertEqual(env_variables["runtimes_check_targets"], "")
         self.assertEqual(env_variables["runtimes_check_targets_needs_reconfig"], "")
+        self.assertEqual(env_variables["enable_cir"], "OFF")
 
     def test_invalid_subproject(self):
         env_variables = compute_projects.get_env_variables(
@@ -237,7 +269,7 @@ class TestComputeProjects(unittest.TestCase):
         )
         self.assertEqual(
             env_variables["project_check_targets"],
-            "check-bolt check-clang check-clang-tools check-flang check-lld check-lldb check-llvm check-mlir check-polly",
+            "check-bolt check-clang check-clang-cir check-clang-tools check-flang check-lld check-lldb check-llvm check-mlir check-polly",
         )
         self.assertEqual(
             env_variables["runtimes_to_build"],

.ci/monolithic-linux.sh

@@ -48,6 +48,7 @@ targets="${2}"
 runtimes="${3}"
 runtime_targets="${4}"
 runtime_targets_needs_reconfig="${5}"
+enable_cir="${6}"
 
 lit_args="-v --xunit-xml-output ${BUILD_DIR}/test-results.xml --use-unique-output-file-name --timeout=1200 --time-tests"
 
@@ -67,6 +68,7 @@ cmake -S "${MONOREPO_ROOT}"/llvm -B "${BUILD_DIR}" \
       -G Ninja \
       -D CMAKE_PREFIX_PATH="${HOME}/.local" \
       -D CMAKE_BUILD_TYPE=Release \
+      -D CLANG_ENABLE_CIR=${enable_cir} \
       -D LLVM_ENABLE_ASSERTIONS=ON \
       -D LLVM_BUILD_EXAMPLES=ON \
       -D COMPILER_RT_BUILD_LIBFUZZER=OFF \

.github/workflows/premerge.yaml

@@ -62,7 +62,7 @@ jobs:
           export CC=/opt/llvm/bin/clang
           export CXX=/opt/llvm/bin/clang++
 
-          ./.ci/monolithic-linux.sh "${projects_to_build}" "${project_check_targets}" "${runtimes_to_build}" "${runtimes_check_targets}" "${runtimes_check_targets_needs_reconfig}"
+          ./.ci/monolithic-linux.sh "${projects_to_build}" "${project_check_targets}" "${runtimes_to_build}" "${runtimes_check_targets}" "${runtimes_check_targets_needs_reconfig}" "${enable_cir}"
       - name: Upload Artifacts
         if: '!cancelled()'
         uses: actions/upload-artifact@65c4c4a1ddee5b72f698fdd19549f0f0fb45cf08 # v4.6.0