Remove offsets before instructions in objdump

diffoscope/comparators/elf.py

@@ -202,6 +202,9 @@ class ReadelfStringSection(ReadElfSection):
 
 
 class ObjdumpSection(Command):
+    # Remove offsets before instructions (see issue #17)
+    RE_INSTRUCTION_OFFSET = re.compile(rb"^\s*[0-9a-f]+:")
+
     def __init__(self, path, section_name, *args, **kwargs):
         self._path = path
         self._path_bin = path.encode("utf-8")
@@ -226,7 +229,7 @@ class ObjdumpSection(Command):
         if line.startswith(b"In archive"):
             return b""
 
-        return line
+        return ObjdumpSection.RE_INSTRUCTION_OFFSET.sub(b"", line)
 
 
 class ObjdumpDisassembleSection(ObjdumpSection):
@@ -248,8 +251,9 @@ class ObjdumpDisassembleSection(ObjdumpSection):
         ]
 
     def filter(self, line):
-        line = super().filter(line)
-        return ObjdumpDisassembleSection.RE_SYMBOL_COMMENT.sub(r"\1", line)
+        # Apply this filter first as super() removes offsets
+        line = ObjdumpDisassembleSection.RE_SYMBOL_COMMENT.sub(r"\1", line)
+        return super().filter(line)
 
 
 class ObjdumpDisassembleSectionNoLineNumbers(ObjdumpDisassembleSection):

tests/data/elf_lib_objdump_expected_diff

@@ -4,9 +4,9 @@
  
  0000000000000000 <f>:
  f():
-    0:	push   %rbp
-    1:	mov    %rsp,%rbp
--   4:	mov    $0x2a,%eax
-+   4:	mov    $0xffffffff,%eax
-    9:	pop    %rbp
-    a:	retq   
+ 	push   %rbp
+ 	mov    %rsp,%rbp
+-	mov    $0x2a,%eax
++	mov    $0xffffffff,%eax
+ 	pop    %rbp
+ 	retq   

tests/data/elf_obj_expected_diff

@@ -4,9 +4,9 @@
  
  0000000000000000 <f>:
  f():
-    0:	push   %rbp
-    1:	mov    %rsp,%rbp
--   4:	mov    $0x2a,%eax
-+   4:	mov    $0xffffffff,%eax
-    9:	pop    %rbp
-    a:	retq   
+ 	push   %rbp
+ 	mov    %rsp,%rbp
+-	mov    $0x2a,%eax
++	mov    $0xffffffff,%eax
+ 	pop    %rbp
+ 	retq   

tests/data/elfmix_disassembly_expected_diff

@@ -4,9 +4,9 @@
  
  0000000000000000 <return42_or_3>:
  return42_or_3():
-    0:	push   %rbp
-    1:	mov    %rsp,%rbp
--   4:	mov    $0x2a,%eax
-+   4:	mov    $0x2b,%eax
-    9:	pop    %rbp
-    a:	retq   
+ 	push   %rbp
+ 	mov    %rsp,%rbp
+-	mov    $0x2a,%eax
++	mov    $0x2b,%eax
+ 	pop    %rbp
+ 	retq   

tests/data/rlib_elf_expected_diff

 @@ -6,15 +6,15 @@
  0000000000000000 <__rust_reallocate>:
  __rust_reallocate():
-    0:	push   %r15
-    2:	push   %r14
-    4:	push   %r12
-    6:	push   %rbx
-    7:	push   %rax
--   8:	mov    %rdx,%rbx
-+   8:	mov    %rdx,%rcx
-    b:	mov    %rsi,%r15
-    e:	mov    %rdi,%r14
-   11:	cmp    $0x10,%rcx
-   15:	ja     2d <__rust_reallocate+0x2d>
-   17:	mov    %r14,%rdi
-   1a:	mov    %rbx,%rsi
-   1d:	add    $0x8,%rsp
+ 	push   %r15
+ 	push   %r14
+ 	push   %r12
+ 	push   %rbx
+ 	push   %rax
+-	mov    %rdx,%rbx
++	mov    %rdx,%rcx
+ 	mov    %rsi,%r15
+ 	mov    %rdi,%r14
+ 	cmp    $0x10,%rcx
+ 	ja     2d <__rust_reallocate+0x2d>
+ 	mov    %r14,%rdi
+ 	mov    %rbx,%rsi
+ 	add    $0x8,%rsp