cmake.default: fix exhausted iterable bug and clarify check-only scope

beman_tidy/lib/checks/beman_standard/cmake.py

@@ -5,7 +5,7 @@
 from collections.abc import Iterable
 
 import cmake_parser
-from cmake_parser.ast import AstNode, Command
+from cmake_parser.ast import AstNode, Command, If, Option
 
 from beman_tidy.lib.utils.cmake import (
     cmake_build_skip_subdir_option_pattern,
@@ -127,7 +127,90 @@ def get_cmake_target_names(self):
         return cmake_target_names
 
 
-# TODO cmake.default
+@register_beman_standard_check("cmake.default")
+class CMakeDefaultCheck(CMakeBaseCheck):
+    def __init__(self, repo_info, beman_standard_check_config):
+        super().__init__(repo_info, beman_standard_check_config)
+
+    def _is_library_add_library_command(self, command):
+        if command.identifier != "add_library":
+            return False
+        if not command.args:
+            return False
+        if command.args[0].value != self.library_name:
+            return False
+        if len(command.args) >= 2 and command.args[1].value == "ALIAS":
+            return False
+        return True
+
+    def _has_unconditional_library_target(self, ast_tree):
+        for item in ast_tree:
+            if isinstance(item, Command) and self._is_library_add_library_command(item):
+                return True
+        return False
+
+    def _get_option_defaults(self, ast_tree):
+        options = {}
+        for item in ast_tree:
+            if isinstance(item, Option) and item.args:
+                args = [arg.value for arg in item.args]
+                if args:
+                    options[args[0]] = args[2] if len(args) >= 3 else None
+        return options
+
+    def _library_if_conditions(self, ast_tree):
+        conditions = []
+        for item in ast_tree:
+            if isinstance(item, If) and item.args:
+                condition = item.args[0].value
+                for sub in item.if_true or []:
+                    if isinstance(sub, Command) and self._is_library_add_library_command(sub):
+                        conditions.append(condition)
+        return conditions
+
+    def check(self):
+        ast_raw = self.get_cmake_parse_raw()
+        ast_tree = list(self.get_cmake_parse_tree())
+
+        has_library_in_raw = any(
+            self._is_library_add_library_command(item)
+            for item in ast_raw
+            if isinstance(item, Command)
+        )
+
+        if not has_library_in_raw:
+            self.log("CMake library target is not built by default. "
+                     f"Expected unconditional add_library('{self.library_name}') in the root CMakeLists.txt. "
+                     "Please update the CMakeLists.txt file according to the Beman Standard. "
+                     "See https://github.com/bemanproject/beman/blob/main/docs/beman_standard.md#cmakedefault for more information.")
+            return False
+
+        if self._has_unconditional_library_target(ast_tree):
+            return True
+
+        option_defaults = self._get_option_defaults(ast_tree)
+        if_conditions = self._library_if_conditions(ast_tree)
+
+        for condition in if_conditions:
+            if condition in option_defaults and option_defaults[condition] == "OFF":
+                self.log("CMake library target is guarded by an option defaulting to OFF. "
+                         f"The library target '{self.library_name}' must be built unconditionally. "
+                         "Please update the CMakeLists.txt file according to the Beman Standard. "
+                         "See https://github.com/bemanproject/beman/blob/main/docs/beman_standard.md#cmakedefault for more information.")
+                return False
+
+        self.log("CMake library target is only built conditionally. "
+                 f"Expected unconditional add_library('{self.library_name}') in the root CMakeLists.txt. "
+                 "Please update the CMakeLists.txt file according to the Beman Standard. "
+                 "See https://github.com/bemanproject/beman/blob/main/docs/beman_standard.md#cmakedefault for more information.")
+        return False
+
+    def fix(self):
+        self.log(
+            "Please update the root CMakeLists.txt so that the main library target is built unconditionally by default. "
+            "See https://github.com/bemanproject/beman/blob/main/docs/beman_standard.md#cmakedefault for more information."
+        )
+        return False
 
 
 # TODO cmake.use_find_package

tests/lib/checks/beman_standard/cmake/data/invalid/invalid-default-v1.txt

@@ -0,0 +1,21 @@
+# SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+
+cmake_minimum_required(VERSION 3.30...4.3)
+
+project(
+    beman.exemplar
+    DESCRIPTION "A Beman Library Exemplar"
+    LANGUAGES CXX
+    VERSION 0.1.0
+)
+
+option(
+    BEMAN_EXEMPLAR_BUILD_LIBRARY
+    "Enable building the library. Default: OFF. Values: { ON, OFF }."
+    OFF
+)
+
+if(BEMAN_EXEMPLAR_BUILD_LIBRARY)
+    add_library(beman.exemplar INTERFACE)
+    add_library(beman::exemplar ALIAS beman.exemplar)
+endif()

tests/lib/checks/beman_standard/cmake/data/invalid/invalid-default-v2.txt

@@ -0,0 +1,15 @@
+# SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+
+cmake_minimum_required(VERSION 3.30...4.3)
+
+project(
+    beman.exemplar
+    DESCRIPTION "A Beman Library Exemplar"
+    LANGUAGES CXX
+    VERSION 0.1.0
+)
+
+if(PROJECT_IS_TOP_LEVEL)
+    add_library(beman.exemplar INTERFACE)
+    add_library(beman::exemplar ALIAS beman.exemplar)
+endif()

tests/lib/checks/beman_standard/cmake/data/valid/valid-default-v1.txt

@@ -0,0 +1,56 @@
+# SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+
+cmake_minimum_required(VERSION 3.30...4.3)
+
+project(
+    beman.exemplar # CMake Project Name, which is also the name of the top-level
+    # targets (e.g., library, executable, etc.).
+    DESCRIPTION "A Beman Library Exemplar"
+    LANGUAGES CXX
+    VERSION 0.1.0
+)
+
+# [CMAKE.SKIP_TESTS]
+option(
+    BEMAN_EXEMPLAR_BUILD_TESTS
+    "Enable building tests and test infrastructure. Default: ${PROJECT_IS_TOP_LEVEL}. Values: { ON, OFF }."
+    ${PROJECT_IS_TOP_LEVEL}
+)
+
+# [CMAKE.SKIP_EXAMPLES]
+option(
+    BEMAN_EXEMPLAR_BUILD_EXAMPLES
+    "Enable building examples. Default: ${PROJECT_IS_TOP_LEVEL}. Values: { ON, OFF }."
+    ${PROJECT_IS_TOP_LEVEL}
+)
+
+# for find of beman_install_library and configure_build_telemetry
+include(infra/cmake/beman-install-library.cmake)
+include(infra/cmake/BuildTelemetryConfig.cmake)
+
+add_library(beman.exemplar INTERFACE)
+add_library(beman::exemplar ALIAS beman.exemplar)
+
+target_sources(
+    beman.exemplar
+    PUBLIC FILE_SET HEADERS BASE_DIRS "${CMAKE_CURRENT_SOURCE_DIR}/include"
+)
+
+set_target_properties(
+    beman.exemplar
+    PROPERTIES VERIFY_INTERFACE_HEADER_SETS ${PROJECT_IS_TOP_LEVEL}
+)
+
+add_subdirectory(include/beman/exemplar)
+
+beman_install_library(beman.exemplar TARGETS beman.exemplar)
+configure_build_telemetry()
+
+if(BEMAN_EXEMPLAR_BUILD_TESTS)
+    enable_testing()
+    add_subdirectory(tests/beman/exemplar)
+endif()
+
+if(BEMAN_EXEMPLAR_BUILD_EXAMPLES)
+    add_subdirectory(examples)
+endif()

tests/lib/checks/beman_standard/cmake/test_cmake.py

@@ -10,6 +10,7 @@
 
 # Actual tested checks.
 from beman_tidy.lib.checks.beman_standard.cmake import (
+    CMakeDefaultCheck,
     CMakeProjectNameCheck,
     CMakeLibraryNameCheck,
     CMakeLibraryAliasCheck,
@@ -23,6 +24,54 @@
 invalid_prefix = f"{test_data_prefix}/invalid"
 
 
+def test__cmake_default__valid(repo_info, beman_standard_check_config):
+    """
+    Test that a valid CMakeLists.txt file passes the cmake.default check.
+    """
+    valid_cmake_paths = [
+        # CMakeLists.txt from beman.exemplar
+        Path(f"{valid_prefix}/valid-default-v1.txt"),
+    ]
+
+    run_check_for_each_path(
+        True,
+        valid_cmake_paths,
+        CMakeDefaultCheck,
+        repo_info,
+        beman_standard_check_config,
+    )
+
+
+def test__cmake_default__invalid(repo_info, beman_standard_check_config):
+    """
+    Test that an invalid CMakeLists.txt file fails the cmake.default check.
+    """
+    invalid_cmake_paths = [
+        # CMakeLists.txt with library behind OFF option
+        Path(f"{invalid_prefix}/invalid-default-v1.txt"),
+        # CMakeLists.txt with library only inside if()
+        Path(f"{invalid_prefix}/invalid-default-v2.txt"),
+    ]
+
+    run_check_for_each_path(
+        False,
+        invalid_cmake_paths,
+        CMakeDefaultCheck,
+        repo_info,
+        beman_standard_check_config,
+    )
+
+
+@pytest.mark.skip(reason="fix-inplace not yet implemented: cmake.default is check-only")
+def test__cmake_default__fix_inplace(repo_info, beman_standard_check_config):
+    """
+    Test that the fix method corrects an invalid CMakeLists.txt file.
+    Note: Skipping this test as fix-inplace is not implemented for cmake.default.
+    The check is currently check-only; fix() logs guidance and returns False.
+    """
+    pass
+
+
 def test__cmake_project_name__valid(repo_info, beman_standard_check_config):
     """
     Test that a valid CMakeLists.txt file passes the cmake.project_name check.