Support conan in packagedcode (#3650)

- Parse and collect version and download_url for conan package
- Override the assembly to enhance the package data from conanfile.py
- Test conan data file handlers

Signed-off-by: Keshav Priyadarshi <git@keshav.space>

CHANGELOG.rst

@@ -103,6 +103,13 @@ Changes in Output Data Structure:
 - Upgraded spdx-tools dependency to v0.8.
   See https://github.com/nexB/scancode-toolkit/issues/3455
 
+Support for Conan package parser:
+
+- We now support the parsing of Conan manifest files, such as
+  `conanfile.py`, as described here https://docs.conan.io/2.0/reference/conanfile.html.
+  We also support source extraction from `conandata.yml`, as described here
+  https://docs.conan.io/2/tutorial/creating_packages/handle_sources_in_packages.html#using-the-conandata-yml-file.
+
 
 v32.0.8 - 2023-10-11
 ------------------------

docs/source/reference/available_package_parsers.rst

@@ -177,6 +177,18 @@ parsers in scancode-toolkit during documentation builds.
      - ``php_composer_lock``
      - PHP
      - https://getcomposer.org/doc/01-basic-usage.md#commit-your-composer-lock-file-to-version-control
+   * - conan external source
+     - ``*/conandata.yml``
+     - ``conan``
+     - ``conan_conandata_yml``
+     - C++
+     - https://docs.conan.io/2/tutorial/creating_packages/handle_sources_in_packages.html#using-the-conandata-yml-file
+   * - conan recipe
+     - ``*/conanfile.py``
+     - ``conan``
+     - ``conan_conanfile_py``
+     - C++
+     - https://docs.conan.io/2.0/reference/conanfile.html
    * - Conda meta.yml manifest
      - ``*/meta.yaml``
      - ``conda``

src/packagedcode/__init__.py

@@ -21,6 +21,7 @@
 from packagedcode import debian_copyright
 from packagedcode import distro
 from packagedcode import conda
+from packagedcode import conan
 from packagedcode import cocoapods
 from packagedcode import cran
 from packagedcode import freebsd
@@ -77,6 +78,9 @@
     conda.CondaYamlHandler,
     conda.CondaMetaYamlHandler,
 
+    conan.ConanFileHandler,
+    conan.ConanDataHandler,
+
     cran.CranDescriptionFileHandler,
 
     debian_copyright.DebianCopyrightFileInPackageHandler,

src/packagedcode/conan.py

@@ -0,0 +1,297 @@
+# Copyright (c) nexB Inc. and others. All rights reserved.
+# ScanCode is a trademark of nexB Inc.
+# SPDX-License-Identifier: Apache-2.0
+# See http://www.apache.org/licenses/LICENSE-2.0 for the license text.
+# See https://github.com/nexB/scancode-toolkit for support or download.
+# See https://aboutcode.org for more information about nexB OSS projects.
+#
+
+import ast
+import io
+import logging
+import os
+
+import saneyaml
+from packageurl import PackageURL
+
+from packagedcode import models
+
+"""
+Handle conanfile recipes for conan packages
+https://docs.conan.io/2/reference/conanfile.html
+"""
+
+
+SCANCODE_DEBUG_PACKAGE = os.environ.get("SCANCODE_DEBUG_PACKAGE", False)
+
+TRACE = SCANCODE_DEBUG_PACKAGE
+
+
+def logger_debug(*args):
+    pass
+
+
+logger = logging.getLogger(__name__)
+
+if TRACE:
+    import sys
+
+    logging.basicConfig(stream=sys.stdout)
+    logger.setLevel(logging.DEBUG)
+
+    def logger_debug(*args):
+        return logger.debug(" ".join(isinstance(a, str) and a or repr(a) for a in args))
+
+
+class ConanFileParser(ast.NodeVisitor):
+    def __init__(self):
+        self.name = None
+        self.version = None
+        self.description = None
+        self.author = None
+        self.homepage_url = None
+        self.vcs_url = None
+        self.license = []
+        self.keywords = []
+        self.requires = []
+
+    def to_dict(self):
+        return {
+            "name": self.name,
+            "version": self.version,
+            "description": self.description,
+            "author": self.author,
+            "homepage_url": self.homepage_url,
+            "vcs_url": self.vcs_url,
+            "license": self.license,
+            "keywords": self.keywords,
+            "requires": self.requires,
+        }
+
+    def visit_Assign(self, node):
+        if not node.targets or not isinstance(node.targets[0], ast.Name):
+            return
+        if not node.value or not (
+            isinstance(node.value, ast.Constant) or isinstance(node.value, ast.Tuple)
+        ):
+            return
+
+        attribute_mapping = {
+            "name": "name",
+            "version": "version",
+            "description": "description",
+            "author": "author",
+            "homepage": "homepage_url",
+            "url": "vcs_url",
+            "license": "license",
+            "topics": "keywords",
+            "requires": "requires",
+        }
+        variable_name = node.targets[0].id
+        values = node.value
+
+        if variable_name in attribute_mapping:
+            attribute_name = attribute_mapping[variable_name]
+            if variable_name in ("topics", "requires", "license"):
+                current_list = getattr(self, attribute_name)
+                if isinstance(values, ast.Tuple):
+                    current_list.extend(
+                        [el.value for el in values.elts if isinstance(el, ast.Constant)]
+                    )
+                elif isinstance(values, ast.Constant):
+                    current_list.append(values.value)
+                setattr(self, attribute_name, current_list)
+            else:
+                setattr(self, attribute_name, values.value)
+
+    def visit_Call(self, node):
+        if not isinstance(node.func, ast.Attribute) or not isinstance(
+            node.func.value, ast.Name
+        ):
+            return
+        if node.func.value.id == "self" and node.func.attr == "requires":
+            if node.args and isinstance(node.args[0], ast.Constant):
+                self.requires.append(node.args[0].value)
+
+
+class ConanFileHandler(models.DatafileHandler):
+    datasource_id = "conan_conanfile_py"
+    path_patterns = ("*/conanfile.py",)
+    default_package_type = "conan"
+    default_primary_language = "C++"
+    description = "conan recipe"
+    documentation_url = "https://docs.conan.io/2.0/reference/conanfile.html"
+
+    @classmethod
+    def _parse(cls, conan_recipe):
+        try:
+            tree = ast.parse(conan_recipe)
+            recipe_class_def = next(
+                (
+                    node
+                    for node in tree.body
+                    if isinstance(node, ast.ClassDef)
+                    and node.bases
+                    and isinstance(node.bases[0], ast.Name)
+                    and node.bases[0].id == "ConanFile"
+                ),
+                None,
+            )
+
+            parser = ConanFileParser()
+            parser.visit(recipe_class_def)
+        except SyntaxError as e:
+            if TRACE:
+                logger_debug(f"Syntax error in conan recipe: {e}")
+            return
+
+        if TRACE:
+            logger_debug(f"ConanFileHandler: parse: package: {parser.to_dict()}")
+
+        dependencies = get_dependencies(parser.requires)
+
+        return models.PackageData(
+            datasource_id=cls.datasource_id,
+            type=cls.default_package_type,
+            primary_language=cls.default_primary_language,
+            namespace=None,
+            name=parser.name,
+            version=parser.version,
+            description=parser.description,
+            homepage_url=parser.homepage_url,
+            keywords=parser.keywords,
+            extracted_license_statement=parser.license,
+            dependencies=dependencies,
+        )
+
+    @classmethod
+    def parse(cls, location):
+        with io.open(location, encoding="utf-8") as loc:
+            conan_recipe = loc.read()
+
+        yield cls._parse(conan_recipe)
+
+
+class ConanDataHandler(models.DatafileHandler):
+    datasource_id = "conan_conandata_yml"
+    path_patterns = ("*/conandata.yml",)
+    default_package_type = "conan"
+    default_primary_language = "C++"
+    description = "conan external source"
+    documentation_url = (
+        "https://docs.conan.io/2/tutorial/creating_packages/"
+        "handle_sources_in_packages.html#using-the-conandata-yml-file"
+    )
+
+    @classmethod
+    def parse(cls, location):
+        with io.open(location, encoding="utf-8") as loc:
+            conan_data = loc.read()
+
+        conan_data = saneyaml.load(conan_data)
+        sources = conan_data.get("sources", {})
+
+        for version, source in sources.items():
+            sha256 = source.get("sha256", None)
+            source_urls = source.get("url")
+            if not source_urls:
+                continue
+
+            url = None
+            if isinstance(source_urls, str):
+                url = source_urls
+            elif isinstance(source_urls, list):
+                url = source_urls[0]
+
+            yield models.PackageData(
+                datasource_id=cls.datasource_id,
+                type=cls.default_package_type,
+                primary_language=cls.default_primary_language,
+                namespace=None,
+                version=version,
+                download_url=url,
+                sha256=sha256,
+            )
+
+    @classmethod
+    def assemble(
+        cls, package_data, resource, codebase, package_adder=models.add_to_package
+    ):
+        """
+        `conandata.yml` only contains the `version` and `download_url` use the conanfile.py
+        to enhance the package metadata.
+        """
+        siblings = resource.siblings(codebase)
+        conanfile_package_resource = [r for r in siblings if r.name == "conanfile.py"]
+        package_data_dict = package_data.to_dict()
+
+        if conanfile_package_resource:
+            conanfile_package_resource = conanfile_package_resource[0]
+
+            conanfile_package_data = conanfile_package_resource.package_data
+            if conanfile_package_data:
+                conanfile_package_data = conanfile_package_data[0]
+
+                package_data_dict["name"] = conanfile_package_data.get("name")
+                package_data_dict["description"] = conanfile_package_data.get(
+                    "description"
+                )
+                package_data_dict["homepage_url"] = conanfile_package_data.get(
+                    "homepage_url"
+                )
+                package_data_dict["keywords"] = conanfile_package_data.get("keywords")
+                package_data_dict[
+                    "extracted_license_statement"
+                ] = conanfile_package_data.get("extracted_license_statement")
+
+        datafile_path = resource.path
+        pkg_data = models.PackageData.from_dict(package_data_dict)
+
+        if pkg_data.purl:
+            package = models.Package.from_package_data(
+                package_data=pkg_data,
+                datafile_path=datafile_path,
+            )
+            package.datafile_paths.append(conanfile_package_resource.path)
+            package.datasource_ids.append(ConanFileHandler.datasource_id)
+
+            package.populate_license_fields()
+            yield package
+
+            cls.assign_package_to_resources(
+                package=package,
+                resource=resource,
+                codebase=codebase,
+                package_adder=package_adder,
+            )
+        yield resource
+
+
+def is_constraint_resolved(constraint):
+    """
+    Checks if a constraint is resolved and it specifies an exact version.
+    """
+    range_characters = {">", "<", "[", "]", ">=", "<="}
+    return not any(char in range_characters for char in constraint)
+
+
+def get_dependencies(requires):
+    dependent_packages = []
+    for req in requires:
+        name, constraint = req.split("/", 1)
+        is_resolved = is_constraint_resolved(constraint)
+        version = None
+        if is_resolved:
+            version = constraint
+        purl = PackageURL(type="conan", name=name, version=version)
+        dependent_packages.append(
+            models.DependentPackage(
+                purl=purl.to_string(),
+                scope="install",
+                is_runtime=True,
+                is_optional=False,
+                is_resolved=is_resolved,
+                extracted_requirement=constraint,
+            )
+        )
+    return dependent_packages