Add Unit Tests for shared_utils.py (#309)

* Added test cases for shared_utils

Signed-off-by: Aditya Mohan <[email protected]>

* Added definition for logging an error shared_utils.py

Signed-off-by: Jay Dev Jha <[email protected]>

* Pre-commit fixes for shared_utils.py

Signed-off-by: Jay Dev Jha <[email protected]>

* pyright fixes for test.py

Signed-off-by: Jay Dev Jha <[email protected]>

* Minor changes to shared_utils.py

Signed-off-by: Jay Dev Jha <[email protected]>

* Updated test.py

Signed-off-by: Jay Dev Jha <[email protected]>

---------

Signed-off-by: Aditya Mohan <[email protected]>
Signed-off-by: Jay Dev Jha <[email protected]>
Co-authored-by: Jay Dev Jha <[email protected]>

shared_utils.py

@@ -17,10 +17,9 @@
 logging.basicConfig(level=LOG_LEVEL, format=LOG_FORMAT)
 
 
+# Log an error message
 def log_and_exit(message: str):
-    """
-    Log an error message and then exit with EXIT_FAILURE.
-    """
+    """Log an error message and exit the program."""
     logging.error(message)
     raise SystemExit(1)
 

test.py

@@ -2,41 +2,238 @@
 
 import logging
 import unittest
+from unittest.mock import Mock, patch
 
-from parse import *
 from shared_utils import *
 
 
-class EncodingLineTest(unittest.TestCase):
+class EncodingUtilsTest(unittest.TestCase):
+    """Tests for basic encoding utilities"""
+
     def setUp(self):
-        logger = logging.getLogger()
-        logger.disabled = True
+        self.logger = logging.getLogger()
+        self.logger.disabled = True
+
+    def test_initialize_encoding(self):
+        """Test encoding initialization with different bit lengths"""
+        self.assertEqual(initialize_encoding(32), ["-"] * 32)
+        self.assertEqual(initialize_encoding(16), ["-"] * 16)
+        self.assertEqual(initialize_encoding(), ["-"] * 32)  # default case
+
+    def test_validate_bit_range(self):
+        """Test bit range validation"""
+        # Valid cases
+        validate_bit_range(7, 3, 15, "test_instr")  # 15 fits in 5 bits
+        validate_bit_range(31, 0, 0xFFFFFFFF, "test_instr")  # max 32-bit value
 
-    def assertError(self, string: str):
-        self.assertRaises(SystemExit, process_enc_line, string, "rv_i")
+        # Invalid cases
+        with self.assertRaises(SystemExit):
+            validate_bit_range(3, 7, 1, "test_instr")  # msb < lsb
+        with self.assertRaises(SystemExit):
+            validate_bit_range(3, 0, 16, "test_instr")  # value too large for range
+
+    def test_parse_instruction_line(self):
+        """Test instruction line parsing"""
+        name, remaining = parse_instruction_line("add.w r1, r2, r3")
+        self.assertEqual(name, "add_w")
+        self.assertEqual(remaining, "r1, r2, r3")
+
+        name, remaining = parse_instruction_line("lui rd imm20 6..2=0x0D")
+        self.assertEqual(name, "lui")
+        self.assertEqual(remaining, "rd imm20 6..2=0x0D")
+
+
+class BitManipulationTest(unittest.TestCase):
+    """Tests for bit manipulation and checking functions"""
+
+    def setUp(self):
+        self.logger = logging.getLogger()
+        self.logger.disabled = True
+        self.test_encoding = initialize_encoding()
+
+    def test_check_overlapping_bits(self):
+        """Test overlapping bits detection"""
+        # Valid case - no overlap
+        self.test_encoding[31 - 5] = "-"
+        check_overlapping_bits(self.test_encoding, 5, "test_instr")
+
+        # Invalid case - overlap
+        self.test_encoding[31 - 5] = "1"
+        with self.assertRaises(SystemExit):
+            check_overlapping_bits(self.test_encoding, 5, "test_instr")
+
+    def test_update_encoding_for_fixed_range(self):
+        """Test encoding updates for fixed ranges"""
+        encoding = initialize_encoding()
+        update_encoding_for_fixed_range(encoding, 6, 2, 0x0D, "test_instr")
+
+        # Check specific bits are set correctly
+        self.assertEqual(encoding[31 - 6 : 31 - 1], ["0", "1", "1", "0", "1"])
+
+    def test_process_fixed_ranges(self):
+        """Test processing of fixed bit ranges"""
+        encoding = initialize_encoding()
+        remaining = "rd imm20 6..2=0x0D 1..0=3"
+
+        result = process_fixed_ranges(remaining, encoding, "test_instr")
+        self.assertNotIn("6..2=0x0D", result)
+        self.assertNotIn("1..0=3", result)
+
+
+class EncodingArgsTest(unittest.TestCase):
+    """Tests for encoding arguments handling"""
+
+    def setUp(self):
+        self.logger = logging.getLogger()
+        self.logger.disabled = True
+
+    @patch.dict("shared_utils.arg_lut", {"rd": (11, 7), "rs1": (19, 15)})
+    def test_check_arg_lut(self):
+        """Test argument lookup table checking"""
+        encoding_args = initialize_encoding()
+        args = ["rd", "rs1"]
+        check_arg_lut(args, encoding_args, "test_instr")
+
+        # Verify encoding_args has been updated correctly
+        self.assertEqual(encoding_args[31 - 11 : 31 - 6], ["rd"] * 5)
+        self.assertEqual(encoding_args[31 - 19 : 31 - 14], ["rs1"] * 5)
+
+    @patch.dict("shared_utils.arg_lut", {"rs1": (19, 15)})
+    def test_handle_arg_lut_mapping(self):
+        """Test handling of argument mappings"""
+        # Valid mapping
+        result = handle_arg_lut_mapping("rs1=new_arg", "test_instr")
+        self.assertEqual(result, "rs1=new_arg")
+
+        # Invalid mapping
+        with self.assertRaises(SystemExit):
+            handle_arg_lut_mapping("invalid_arg=new_arg", "test_instr")
+
+
+class ISAHandlingTest(unittest.TestCase):
+    """Tests for ISA type handling and validation"""
+
+    def test_extract_isa_type(self):
+        """Test ISA type extraction"""
+        self.assertEqual(extract_isa_type("rv32_i"), "rv32")
+        self.assertEqual(extract_isa_type("rv64_m"), "rv64")
+        self.assertEqual(extract_isa_type("rv_c"), "rv")
+
+    def test_is_rv_variant(self):
+        """Test RV variant checking"""
+        self.assertTrue(is_rv_variant("rv32", "rv"))
+        self.assertTrue(is_rv_variant("rv", "rv64"))
+        self.assertFalse(is_rv_variant("rv32", "rv64"))
+
+    def test_same_base_isa(self):
+        """Test base ISA comparison"""
+        self.assertTrue(same_base_isa("rv32_i", ["rv32_m", "rv32_a"]))
+        self.assertTrue(same_base_isa("rv_i", ["rv32_i", "rv64_i"]))
+        self.assertFalse(same_base_isa("rv32_i", ["rv64_m"]))
+
+
+class StringManipulationTest(unittest.TestCase):
+    """Tests for string manipulation utilities"""
+
+    def test_pad_to_equal_length(self):
+        """Test string padding"""
+        str1, str2 = pad_to_equal_length("101", "1101")
+        self.assertEqual(len(str1), len(str2))
+        self.assertEqual(str1, "-101")
+        self.assertEqual(str2, "1101")
+
+    def test_overlaps(self):
+        """Test string overlap checking"""
+        self.assertTrue(overlaps("1-1", "101"))
+        self.assertTrue(overlaps("---", "101"))
+        self.assertFalse(overlaps("111", "101"))
+
+
+class InstructionProcessingTest(unittest.TestCase):
+    """Tests for instruction processing and validation"""
+
+    def setUp(self):
+        self.logger = logging.getLogger()
+        self.logger.disabled = True
+        # Create a patch for arg_lut
+        self.arg_lut_patcher = patch.dict(
+            "shared_utils.arg_lut", {"rd": (11, 7), "imm20": (31, 12)}
+        )
+        self.arg_lut_patcher.start()
+
+    def tearDown(self):
+        self.arg_lut_patcher.stop()
+
+    @patch("shared_utils.fixed_ranges")
+    @patch("shared_utils.single_fixed")
+    def test_process_enc_line(self, mock_single_fixed: Mock, mock_fixed_ranges: Mock):
+        """Test processing of encoding lines"""
+        # Setup mock return values
+        mock_fixed_ranges.findall.return_value = [(6, 2, "0x0D")]
+        mock_fixed_ranges.sub.return_value = "rd imm20"
+        mock_single_fixed.findall.return_value = []
+        mock_single_fixed.sub.return_value = "rd imm20"
+
+        # Create a mock for split() that returns the expected list
+        mock_split = Mock(return_value=["rd", "imm20"])
+        mock_single_fixed.sub.return_value = Mock(split=mock_split)
+
+        name, data = process_enc_line("lui rd imm20 6..2=0x0D", "rv_i")
 
-    def test_lui(self):
-        name, data = process_enc_line("lui     rd imm20 6..2=0x0D 1=1 0=1", "rv_i")
         self.assertEqual(name, "lui")
         self.assertEqual(data["extension"], ["rv_i"])
-        self.assertEqual(data["match"], "0x37")
-        self.assertEqual(data["mask"], "0x7f")
+        self.assertIn("rd", data["variable_fields"])
+        self.assertIn("imm20", data["variable_fields"])
+
+    @patch("os.path.exists")
+    @patch("shared_utils.logging.error")
+    def test_find_extension_file(self, mock_logging: Mock, mock_exists: Mock):
+        """Test extension file finding"""
+        # Test successful case - file exists in main directory
+        mock_exists.side_effect = [True, False]
+        result = find_extension_file("rv32i", "/path/to/opcodes")
+        self.assertEqual(result, "/path/to/opcodes/rv32i")
+
+        # Test successful case - file exists in unratified directory
+        mock_exists.side_effect = [False, True]
+        result = find_extension_file("rv32i", "/path/to/opcodes")
+        self.assertEqual(result, "/path/to/opcodes/unratified/rv32i")
+
+        # Test failure case - file doesn't exist anywhere
+        mock_exists.side_effect = [False, False]
+        with self.assertRaises(SystemExit):
+            find_extension_file("rv32i", "/path/to/opcodes")
+        mock_logging.assert_called_with("Extension rv32i not found.")
+
+    def test_process_standard_instructions(self):
+        """Test processing of standard instructions"""
+        lines = [
+            "add rd rs1 rs2 31..25=0 14..12=0 6..2=0x0C 1..0=3",
+            "sub rd rs1 rs2 31..25=0x20 14..12=0 6..2=0x0C 1..0=3",
+            "$pseudo add_pseudo rd rs1 rs2",  # Should be skipped
+            "$import rv32i::mul",  # Should be skipped
+        ]
+
+        instr_dict: InstrDict = {}
+        file_name = "rv32i"
+
+        with patch("shared_utils.process_enc_line") as mock_process_enc:
+            # Setup mock return values
+            mock_process_enc.side_effect = [
+                ("add", {"extension": ["rv32i"], "encoding": "encoding1"}),
+                ("sub", {"extension": ["rv32i"], "encoding": "encoding2"}),
+            ]
 
-    def test_overlapping(self):
-        self.assertError("jol rd jimm20 6..2=0x00 3..0=7")
-        self.assertError("jol rd jimm20 6..2=0x00 3=1")
-        self.assertError("jol rd jimm20 6..2=0x00 10=1")
-        self.assertError("jol rd jimm20 6..2=0x00 31..10=1")
+            process_standard_instructions(lines, instr_dict, file_name)
 
-    def test_invalid_order(self):
-        self.assertError("jol 2..6=0x1b")
+            # Verify process_enc_line was called twice (skipping pseudo and import)
+            self.assertEqual(mock_process_enc.call_count, 2)
 
-    def test_illegal_value(self):
-        self.assertError("jol rd jimm20 2..0=10")
-        self.assertError("jol rd jimm20 2..0=0xB")
+            # Verify the instruction dictionary was updated correctly
+            self.assertEqual(len(instr_dict), 2)
+            self.assertIn("add", instr_dict)
+            self.assertIn("sub", instr_dict)
 
-    def test_overlapping_field(self):
-        self.assertError("jol rd rs1 jimm20 6..2=0x1b 1..0=3")
 
-    def test_illegal_field(self):
-        self.assertError("jol rd jimm128 2..0=3")
+if __name__ == "__main__":
+    unittest.main()