Merge pull request #31 from quentinlampin/bugfix-buffer-add-2

[bugfix] buffer concatenation fix
quentinlampin · Jan 14, 2025 · 8bddf0f · 8bddf0f
2 parents 685f7e7 + 1bf74c9
commit 8bddf0f
Show file tree

Hide file tree

Showing 2 changed files with 25 additions and 30 deletions.
diff --git a/microschc/binary/buffer.py b/microschc/binary/buffer.py
@@ -318,7 +318,17 @@ def __add__(self, other: 'Buffer') -> 'Buffer':
                         new_content = left.content[0:-1] + (left.content[-1] + right.content[0]).to_bytes(1, 'big') + right.content[1:]
                     else:
                         # right padding is not aligned with left padding
-                        if right.padding_length > left.padding_length:
+                        if 8 - left.padding_length < right.padding_length:
+                            bit_shift: int = abs(right.padding_length - left.padding_length)
+                            # shift right to the left, careful with the carry that will spill over right's left boundary
+                            new_content: bytes = b''
+                            carry: int = 0
+                            for b in right.content[::-1]:
+                                sb:int = ((b << bit_shift) & 0xff) + carry
+                                new_content = sb.to_bytes(1, 'big') + new_content
+                                carry = b >> (8-bit_shift)
+                            new_content = left.content[0:-1] + (left.content[-1] + carry).to_bytes(1, 'big') + new_content
+                        else:
                             bit_shift: int = 8 - left.padding_length - right.padding_length
                             new_content: bytes = b''
                             # shift right to the right
@@ -329,16 +339,7 @@ def __add__(self, other: 'Buffer') -> 'Buffer':
                                 carry = (b & carry_mask) << (8 - bit_shift)
                                 new_content += sb.to_bytes(1, 'big')
                             new_content = left.content[0:-1] + (left.content[-1] + new_content[0]).to_bytes(1, 'big') + new_content[1:] + carry.to_bytes(1, 'big')
-                        else:
-                            bit_shift: int = abs(right.padding_length - left.padding_length)
-                            # shift right to the left, careful with the carry that will spill over right's left boundary
-                            new_content: bytes = b''
-                            carry: int = 0
-                            for b in right.content[::-1]:
-                                sb:int = ((b << bit_shift) & 0xff) + carry
-                                new_content = sb.to_bytes(1, 'big') + new_content
-                                carry = b >> (8-bit_shift)
-                            new_content = left.content[0:-1] + (left.content[-1] + carry).to_bytes(1, 'big') + new_content
+
                 else:
                     # right is right padded
                     # shift right to the right

diff --git a/tests/binary/test_buffer.py b/tests/binary/test_buffer.py
@@ -314,6 +314,17 @@ def test_add():
     expected: Buffer = Buffer(content=b'\xff\xff\xff\xf8', length=29, padding=Padding.RIGHT)
     assert left_right == expected
 
+    left: Buffer = Buffer(content=b'\x40', length=5, padding=Padding.RIGHT)
+    right: Buffer = Buffer(content=b'\x00', length=1, padding=Padding.LEFT)
+    left_right: Buffer = left + right
+    expected: Buffer = Buffer(content=b'\x40', length=6, padding=Padding.RIGHT)
+    assert left_right == expected
+
+    left: Buffer = Buffer(content=b'\x00\x8a\xf8', length=23, padding=Padding.RIGHT)
+    right: Buffer = Buffer(content=b'\x22', length=6, padding=Padding.LEFT)
+    left_right: Buffer = left + right
+    expected: Buffer = Buffer(content=b'\x00\x8a\xf9\x10', length=29, padding=Padding.RIGHT)
+    assert left_right == expected
 
 def test_or():
     #              0x08          0x68        
@@ -371,25 +382,8 @@ def test_and():
     buffer_1_and_1_left: Buffer = buffer_1 & buffer_1_pad_left
     expected_1_and_1_left: Buffer = Buffer(content=b'\x08\x68', length=13, padding=Padding.RIGHT)
     assert buffer_1_and_1_left == expected_1_and_1_left
-
-def test_complement():
-    buffer: Buffer = Buffer(content=b'\x01\xff\xf0', length=24)
-    complement = ~buffer
-    expected_buffer = Buffer(content=b'\xfe\x00\x0f', length=24)
-    assert complement == expected_buffer
-
-def test_complement_padding_left():
-    buffer: Buffer = Buffer(content=b'\x0f\xff\xf0', length=20)
-    complement = ~buffer
-    expected_buffer = Buffer(content=b'\x00\x00\x0f', length=20)
-    assert complement == expected_buffer
-
-def test_complement_padding_right():
-    buffer: Buffer = Buffer(content=b'\x0f\xff\x80', length=20, padding=Padding.RIGHT)
-    complement = ~buffer
-    expected_buffer = Buffer(content=b'\xf0\x00\x70', length=20, padding=Padding.RIGHT)
-    assert complement == expected_buffer
-
+
+
 def test_value():
 
     buffer: Buffer = Buffer(content=b'\x00\x01', length=16)