features/insn.py: revert added strace-based API feature

capa/features/insn.py

@@ -6,7 +6,7 @@
 #  is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 # See the License for the specific language governing permissions and limitations under the License.
 import abc
-from typing import Dict, Tuple, Union, Optional
+from typing import Union, Optional
 
 import capa.helpers
 from capa.features.common import VALID_FEATURE_ACCESS, Feature
@@ -21,56 +21,8 @@ def hex(n: int) -> str:
 
 
 class API(Feature):
-    def __init__(self, signature: str, description=None):
-        if signature.isidentifier():
-            # api call is in the legacy format
-            super().__init__(signature, description=description)
-            self.args: Dict[str, str] = {}
-            self.ret = ""
-        else:
-            # api call is in the strace format and therefore has to be parsed
-            name, self.args, self.ret = self.parse_signature(signature)
-            super().__init__(name, description=description)
-
-        # store the original signature for hashing purposes
-        self.signature = signature
-
-    def __hash__(self):
-        return hash(self.signature)
-
-    def __eq__(self, other):
-        if not isinstance(other, API):
-            return False
-
-        assert isinstance(other, API)
-        if {} in (self.args, other.args) or "" in (self.ret, other.ret):
-            # Legacy API feature
-            return super().__eq__(other)
-
-        # API call with arguments
-        return super().__eq__(other) and self.args == other.args and self.ret == other.ret
-
-    def parse_signature(self, signature: str) -> Tuple[str, Dict[str, str], str]:
-        # todo: optimize this method and improve the code quality
-        import re
-
-        args: Dict[str, str] = {}
-        ret = ""
-
-        match = re.findall(r"(.+\(.*\)) ?=? ?([^=]*)", signature)
-        if not match:
-            return "", {}, ""
-        if len(match[0]) == 2:
-            ret = match[0][1]
-
-        match = re.findall(r"(.*)\((.*)\)", match[0][0])
-        if len(match[0]) == 2:
-            args_: Dict[str, str] = (match[0][1] + ", ").split(", ")
-            map(lambda x: {f"arg{x[0]}": x[1]}, enumerate(args))
-            for num, arg in enumerate(args_):
-                args.update({f"arg {0}": arg})
-
-        return match[0][0], args, ret
+    def __init__(self, name: str, description=None):
+        super().__init__(name, description=description)
 
 
 class _AccessFeature(Feature, abc.ABC):