ML and ML64 Command-Line Reference


The new home for Visual Studio documentation is Visual Studio 2017 Documentation on

The latest version of this topic can be found at ML and ML64 Command-Line Reference.

Assembles and links one or more assembly-language source files. The command-line options are case sensitive.

For more information on ml64.exe, see MASM for x64 (ml64.exe).

ML [[options]] filename [[ [[options]]  filename]]  
ML64 [[options]] filename [[ [[options]]  filename]]  
[[/link linkoptions]]  


The options listed in the following table.

/ATEnables tiny-memory-model support. Enables error messages for code constructs that violate the requirements for .com format files. Note that this is not equivalent to the .MODEL TINY directive.

Not available in ml64.exe.
/Bl filenameSelects an alternate linker.
/cAssembles only. Does not link.
/coffGenerates common object file format (COFF) type of object module. Generally required for Win32 assembly language development.

Not available in ml64.exe.
/CpPreserves case of all user identifiers.
/CuMaps all identifiers to upper case (default).

Not available in ml64.exe.
/CxPreserves case in public and extern symbols.
/D symbol[[=value]]Defines a text macro with the given name. If value is missing, it is blank. Multiple tokens separated by spaces must be enclosed in quotation marks.
/EPGenerates a preprocessed source listing (sent to STDOUT). See /Sf.
/ERRORREPORT [ NONE | PROMPT | QUEUE | SEND ]If ml.exe or ml64.exe fails at runtime, you can use /ERRORREPORT to send information to Microsoft about these internal errors.

For more information about /ERRORREPORT, see /errorReport (Report Internal Compiler Errors).
/F hexnumSets stack size to hexnum bytes (this is the same as /link/STACK:number). The value must be expressed in hexadecimal notation. There must be a space between /F and hexnum.
/Fe filenameNames the executable file.
/Fl[[filename]]Generates an assembled code listing. See /Sf.
/Fm[[filename]]Creates a linker map file.
/Fo filenameNames an object file. See Remarks section for more information.
/FPiGenerates emulator fix-ups for floating-point arithmetic (mixed language only).

Not available in ml64.exe.
/Fr[[filename]]Generates a source browser .sbr file.
/FR[[filename]]Generates an extended form of a source browser .sbr file.
/GcSpecifies use of FORTRAN- or Pascal-style function calling and naming conventions. Same as OPTION LANGUAGE:PASCAL.

Not available in ml64.exe.
/GdSpecifies use of C-style function calling and naming conventions. Same as OPTION LANGUAGE:C.

Not available in ml64.exe.
/GZSpecifies use of __stdcall function calling and naming conventions. Same as OPTION LANGUAGE:STCALL.

Not available in ml64.exe.
/H numberRestricts external names to number significant characters. The default is 31 characters.

Not available in ml64.exe.
/helpCalls QuickHelp for help on ML.
/I pathnameSets path for include file. A maximum of 10 /I options is allowed.
/nologoSuppresses messages for successful assembly.
/omfGenerates object module file format (OMF) type of object module. /omf implies /c; ML.exe does not support linking OMF objects.

Not available in ml64.exe.
/SaTurns on listing of all available information.
/safesehMarks the object as either containing no exception handlers or containing exception handlers that are all declared with .SAFESEH.

Not available in ml64.exe.
/SfAdds first-pass listing to listing file.
/Sl widthSets the line width of source listing in characters per line. Range is 60 to 255 or 0. Default is 0. Same as PAGE width.
/SnTurns off symbol table when producing a listing.
/Sp lengthSets the page length of source listing in lines per page. Range is 10 to 255 or 0. Default is 0. Same as PAGE length.
/Ss textSpecifies text for source listing. Same as SUBTITLE text.
/St textSpecifies title for source listing. Same as TITLE text.
/SxTurns on false conditionals in listing.
/Ta filenameAssembles source file whose name does not end with the .asm extension.
/wSame as /W0/WX.
/W levelSets the warning level, where level = 0, 1, 2, or 3.
/WXReturns an error code if warnings are generated.
/XIgnore INCLUDE environment path.
/ZdGenerates line-number information in object file.
/ZfMakes all symbols public.
/ZiGenerates CodeView information in object file.
/ZmEnablesM510 option for maximum compatibility with MASM 5.1.

Not available in ml64.exe.
/Zp[[alignment]]Packs structures on the specified byte boundary. The alignment can be 1, 2, or 4.
/ZsPerforms a syntax check only.
/?Displays a summary of ML command-line syntax.

The name of the file.

The link options. See Linker Options for more information.

Some command-line options to ML and ML64 are placement-sensitive. For example, because ML and ML64 can accept several /c options, any corresponding /Fo options must be specified before /c. The following command-line example illustrates an object file specification for each assembly file specification:

ml.exe /Fo a1.obj /c a.asm /Fo b1.obj /c b.asm

INCLUDESpecifies search path for include files.
MLSpecifies default command-line options.
TMPSpecifies path for temporary files.

ML Error Messages
Microsoft Macro Assembler Reference