frontend: add module to expose core operations (#1891)

* frontend: add module to expose core operations

Signed-off-by: David Korczynski <[email protected]>

* nit

Signed-off-by: David Korczynski <[email protected]>

* show more extensions

Signed-off-by: David Korczynski <[email protected]>

---------

Signed-off-by: David Korczynski <[email protected]>

Author: DavidKorczynski

src/fuzz_introspector/frontends/core.py

@@ -0,0 +1,41 @@
+# Copyright 2024 Fuzz Introspector Authors
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License 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.
+"""APIs that make it easy to access frontend analysis."""
+
+import logging
+
+from fuzz_introspector.frontends import frontend_c
+from fuzz_introspector.frontends import frontend_cpp
+
+logger = logging.getLogger(name=__name__)
+
+
+def analyse_source_file(code: bytes, language: str):
+    """Runs frontend analysis on a code snippet.
+
+    The code snippet should correspond to what you'd normally find in
+    a source file, e.g. a number of functions, include statements and so
+    on.
+
+    Returns a frontend Source code module if successful and None otherwise."""
+
+    if language == 'c':
+        return frontend_c.analyse_source_code(code)
+    elif language == 'cpp':
+        return frontend_cpp.analyse_source_code(code)
+    elif language == 'go':
+        logger.info('Go is not implement yet.')
+    else:
+        logger.info('Language %s not supported', language)
+    return None

src/fuzz_introspector/frontends/frontend_c.py

@@ -184,6 +184,15 @@ def find_source_with_func_def(self, target_function_name):
 
         return None
 
+    def get_function(self, target_function_name):
+        """Gets the first instance of a given function."""
+
+        for source_code in self.source_code_files:
+            func = source_code.get_function_node(target_function_name)
+            if func is not None:
+                return func
+        return None
+
 
 class FunctionDefinition():
     """Wrapper for a function definition"""

src/fuzz_introspector/frontends/frontend_cpp.py

@@ -377,3 +377,12 @@ def load_treesitter_trees(source_files, log_harnesses=True):
                         logger.info('harness: %s', code_file)
                 results.append(source_cls)
     return results
+
+
+def analyse_source_code(source_content: str) -> Project:
+    """Returns a Project based on a single source string."""
+    source_code = SourceCodeFile(source_file='in-memory string',
+                                 language='cpp',
+                                 source_content=source_content.encode())
+    project = Project([source_code])
+    return project