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.

Option Action
/AT Enables 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 filename Selects an alternate linker.
/c Assembles only. Does not link.
/coff Generates common object file format (COFF) type of object module. Generally required for Win32 assembly language development.

Not available in ml64.exe.
/Cp Preserves case of all user identifiers.
/Cu Maps all identifiers to upper case (default).

Not available in ml64.exe.
/Cx Preserves 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.
/EP Generates 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 hexnum Sets 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 filename Names the executable file.
/Flfilename Generates an assembled code listing. See /Sf.
/Fmfilename Creates a linker map file.
/Fo filename Names an object file. See Remarks section for more information.
/FPi Generates emulator fix-ups for floating-point arithmetic (mixed language only).

Not available in ml64.exe.
/Frfilename Generates a source browser .sbr file.
/FRfilename Generates an extended form of a source browser .sbr file.
/Gc Specifies use of FORTRAN- or Pascal-style function calling and naming conventions. Same as OPTION LANGUAGE:PASCAL.

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

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

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

Not available in ml64.exe.
/help Calls QuickHelp for help on ML.
/I pathname Sets path for include file. A maximum of 10 /I options is allowed.
/nologo Suppresses messages for successful assembly.
/omf Generates 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.
/Sa Turns on listing of all available information.
/safeseh Marks the object as either containing no exception handlers or containing exception handlers that are all declared with .SAFESEH.

Not available in ml64.exe.
/Sf Adds first-pass listing to listing file.
/Sl width Sets the line width of source listing in characters per line. Range is 60 to 255 or 0. Default is 0. Same as PAGE width.
/Sn Turns off symbol table when producing a listing.
/Sp length Sets 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 text Specifies text for source listing. Same as SUBTITLE text.
/St text Specifies title for source listing. Same as TITLE text.
/Sx Turns on false conditionals in listing.
/Ta filename Assembles source file whose name does not end with the .asm extension.
/w Same as /W0/WX.
/W level Sets the warning level, where level = 0, 1, 2, or 3.
/WX Returns an error code if warnings are generated.
/X Ignore INCLUDE environment path.
/Zd Generates line-number information in object file.
/Zf Makes all symbols public.
/Zi Generates CodeView information in object file.
/Zm EnablesM510 option for maximum compatibility with MASM 5.1.

Not available in ml64.exe.
/Zpalignment Packs structures on the specified byte boundary. The alignment can be 1, 2, or 4.
/Zs Performs 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

Environment Variables

Variable Description
INCLUDE Specifies search path for include files.
ML Specifies default command-line options.
TMP Specifies path for temporary files.

See also

ML Error Messages
Microsoft Macro Assembler Reference