Disassembler

A disassembler is a <a href="/facts/Computer_program/e38jH9N9">computer program</a> that <a href="/facts/Translator_(computing)/D3TIzmrI">translates</a> <a href="/facts/Machine_language/bgdQ1Fxf">machine language</a> into <a href="/facts/Assembly_language/7XuV0cla">assembly language</a>—the inverse operation to that of an <a href="/facts/Assembly_language/7XuV0cla">assembler</a>. The output of disassembly is typically formatted for human-readability rather than for input to an assembler, making disassemblers primarily a <a href="/facts/Reverse_engineering/pmJCV7J7">reverse-engineering</a> tool. Common uses include analyzing the output of <a href="/facts/High-level_language/smjECUhx">high-level programming language</a> <a href="/facts/Compiler/WNfCDFJe">compilers</a> and their optimizations, recovering <a href="/facts/Source_code/o9J6Jv23">source code</a> when the original is lost, performing <a href="/facts/Malware_analysis/Y0sz0SeK">malware analysis</a>, modifying software (such as binary patching), and <a href="/facts/Software_cracking/GFHWRHCG">software cracking</a>.
A disassembler differs from a <a href="/facts/Decompiler/Lz46oVoa">decompiler</a>, which targets a <a href="/facts/High-level_language/smjECUhx">high-level language</a> rather than an assembly language.
Assembly language <a href="/facts/Source_code/o9J6Jv23">source code</a> generally permits the use of <a href="/facts/Constant_(programming)/pVQqffen">constants</a> and programmer <a href="/facts/Comment_(computer_programming)/Q8hHFq8h">comments</a>. These are usually removed from the assembled <a href="/facts/Machine_code/bgdQ1Fxf">machine code</a> by the assembler. If so, a disassembler operating on the machine code would produce disassembly lacking these constants and comments; the disassembled output becomes more difficult for a human to interpret than the original annotated source code. Some disassemblers provide a built-in code commenting feature where the generated output is enriched with comments regarding called API functions or parameters of called functions. Some disassemblers make use of the <a href="/facts/Symbolic_debugging/ITvjepr0">symbolic debugging</a> information present in object files such as <a href="/facts/Executable_and_Linking_Format/ro2CYqso">ELF</a>. For example, <a href="/facts/Interactive_Disassembler/rpodNyJ2">IDA</a> allows the human user to make up mnemonic symbols for values or regions of code in an interactive session: human insight applied to the disassembly process often parallels human creativity in the code writing process.

Disassembler open-in-new

Disassembler