[llvm] [CI] Add Python Script for Computing Projects/Runtimes to Test (PR #132634)

[Aiden Grossman via llvm-commits]

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+# Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+# See https://llvm.org/LICENSE.txt for license information.
+# SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+"""Computes the list of projects that need to be tested from a diff.
+
+Does some things, spits out a list of projects.
+"""
+
+from collections.abc import Set
+import pathlib
+import platform
+import sys
+
+PROJECT_DEPENDENCIES = {
+    "llvm": set(),
+    "clang": {"llvm"},
+    "bolt": {"clang", "lld", "llvm"},
+    "clang-tools-extra": {"clang", "llvm"},
+    "compiler-rt": {"clang", "lld"},
+    "libc": {"clang", "lld"},
+    "openmp": {"clang", "lld"},
+    "flang": {"llvm", "clang"},
+    "lldb": {"llvm", "clang"},
+    "libclc": {"llvm", "clang"},
+    "lld": {"llvm"},
+    "mlir": {"llvm"},
+    "polly": {"llvm"},
+}
+
+DEPENDENTS_TO_TEST = {
+    "llvm": {"bolt", "clang", "clang-tools-extra", "lld", "lldb", "mlir", "polly"},
+    "lld": {"bolt", "cross-project-tests"},
+    "clang": {"clang-tools-extra", "compiler-rt", "cross-project-tests"},
+    "clang-tools-extra": {"libc"},
+    "mlir": {"flang"},
+}
+
+DEPENDENT_RUNTIMES_TO_TEST = {"clang": {"libcxx", "libcxxabi", "libunwind"}}
+
+EXCLUDE_LINUX = {
+    "cross-project-tests",  # Tests are failing.
+    "openmp",  # https://github.com/google/llvm-premerge-checks/issues/410
+}
+
+EXCLUDE_WINDOWS = {
+    "cross-project-tests",  # Tests are failing.
+    "compiler-rt",  # Tests are taking too long.
+    "openmp",  # Does not detect perl installation.
+    "libc",  # No Windows Support.
+    "lldb",  # Custom environment requirements.
+    "bolt",  # No Windows Support.
+}
+
+EXCLUDE_MAC = {
+    "bolt",
+    "compiler-rt",
+    "cross-project-tests",
+    "flang",
+    "libc",
+    "libcxx",
+    "libcxxabi",
+    "libunwind",
+    "lldb",
+    "openmp",
+    "polly",
+}
+
+PROJECT_CHECK_TARGETS = {
+    "clang-tools-extra": "check-clang-tools",
+    "compiler-rt": "check-compiler-rt",
+    "cross-project-tests": "check-cross-project",
+    "libcxx": "check-cxx",
+    "libcxxabi": "check-cxxabi",
+    "libunwind": "check-unwind",
+    "lldb": "check-lldb",
+    "llvm": "check-llvm",
+    "clang": "check-clang",
+    "bolt": "check-bolt",
+    "lld": "check-lld",
+    "flang": "check-flang",
+    "libc": "check-libc",
+    "lld": "check-lld",
+    "lldb": "check-lldb",
+    "mlir": "check-mlir",
+    "openmp": "check-openmp",
+    "polly": "check-polly",
+}
+
+
+def _add_dependencies(projects: Set[str]) -> Set[str]:
+    projects_with_dependents = set(projects)
+    current_projects_count = 0
+    while current_projects_count != len(projects_with_dependents):
+        current_projects_count = len(projects_with_dependents)
+        for project in list(projects_with_dependents):
+            if project not in PROJECT_DEPENDENCIES:
+                continue
+            projects_with_dependents.update(PROJECT_DEPENDENCIES[project])
+    return projects_with_dependents
+
+
+def _compute_projects_to_test(modified_projects: Set[str], platform: str) -> Set[str]:
+    projects_to_test = set()
+    for modified_project in modified_projects:
+        # Skip all projects where we cannot run tests.
+        if modified_project not in PROJECT_CHECK_TARGETS:
+            continue
+        projects_to_test.add(modified_project)
+        if modified_project not in DEPENDENTS_TO_TEST:
+            continue
+        projects_to_test.update(DEPENDENTS_TO_TEST[modified_project])
+    if platform == "Linux":
+        for to_exclude in EXCLUDE_LINUX:
+            if to_exclude in projects_to_test:
+                projects_to_test.remove(to_exclude)
+    elif platform == "Windows":
+        for to_exclude in EXCLUDE_WINDOWS:
+            if to_exclude in projects_to_test:
+                projects_to_test.remove(to_exclude)
+    elif platform == "Darwin":
+        for to_exclude in EXCLUDE_MAC:
+            if to_exclude in projects_to_test:
+                projects_to_test.remove(to_exclude)
+    else:
+        raise ValueError("Unexpected platform.")
+    return projects_to_test
+
+
+def _compute_projects_to_build(projects_to_test: Set[str]) -> Set[str]:
+    return _add_dependencies(projects_to_test)
+
+
+def _compute_project_check_targets(projects_to_test: Set[str]) -> Set[str]:
+    check_targets = set()
+    for project_to_test in projects_to_test:
+        if project_to_test not in PROJECT_CHECK_TARGETS:
+            continue
+        check_targets.add(PROJECT_CHECK_TARGETS[project_to_test])
+    return check_targets
+
+
+def _compute_runtimes_to_test(projects_to_test: Set[str]) -> Set[str]:
+    runtimes_to_test = set()
+    for project_to_test in projects_to_test:
+        if project_to_test not in DEPENDENT_RUNTIMES_TO_TEST:
+            continue
+        runtimes_to_test.update(DEPENDENT_RUNTIMES_TO_TEST[project_to_test])
+    return runtimes_to_test
+
+
+def _compute_runtime_check_targets(runtimes_to_test: Set[str]) -> Set[str]:
+    check_targets = set()
+    for runtime_to_test in runtimes_to_test:
+        check_targets.add(PROJECT_CHECK_TARGETS[runtime_to_test])
+    return check_targets
+
+
+def _get_modified_projects(modified_files: list[str]) -> Set[str]:
+    modified_projects = set()
+    for modified_file in modified_files:
+        modified_projects.add(pathlib.Path(modified_file).parts[0])
+    return modified_projects
+
+
+def get_env_variables(modified_files: list[str], platform: str) -> Set[str]:
+    modified_projects = _get_modified_projects(modified_files)
+    projects_to_test = _compute_projects_to_test(modified_projects, platform)
+    projects_to_build = _compute_projects_to_build(projects_to_test)
+    projects_check_targets = _compute_project_check_targets(projects_to_test)
+    runtimes_to_test = _compute_runtimes_to_test(projects_to_test)
+    runtimes_check_targets = _compute_runtime_check_targets(runtimes_to_test)
+    return {
+        "projects_to_build": ";".join(sorted(projects_to_build)),
+        "project_check_targets": " ".join(sorted(projects_check_targets)),
+        "runtimes_to_build": ";".join(sorted(runtimes_to_test)),
+        "runtimes_check_targets": " ".join(sorted(runtimes_check_targets)),
----------------
boomanaiden154 wrote:

What is the benefit of doing the replace closer to the location? To me, it seems like it just adds (slight) unnecessary complexity on the workflow side without any actual benefit. I think it's reasonably clear that `projects_to_build` and `runtimes_to_build` are going to be passed as CMake arguments to `LLVM_ENABLE_PROJECTS` and `LLVM_ENABLE_RUNTIMES` and the `*_check_targets` variables are going to be passed to a ninja invocation.

I added a comment though which will hopefully make things a bit more clear.

https://github.com/llvm/llvm-project/pull/132634