Provided by: mlton-compiler_20210117+dfsg-3_amd64 bug

NAME

       mlton - whole-program compiler for the Standard ML (SML) programming language

SYNOPSIS

       mlton [option ...] file.{c|mlb|o|sml} [file.{c|o|s|S} ...]

DESCRIPTION

       MLton  is  run  from the command line with a collection of options followed by a file name
       and a list of files with which to compile, assemble, and link with.  The simplest case  is
       to  run  mlton  foo.sml,  where  foo.sml contains a valid SML program, in which case MLton
       compiles the program to produce an executable foo.  Since MLton does not support  separate
       compilation,  the  program  must  be the entire program you wish to compile.  However, the
       program may refer to signatures and structures defined in the Basis Library.

       Larger programs, spanning many files, may be compiled with the ML Basis system.   In  this
       case,  mlton foo.mlb will compile the complete SML program described by the basis foo.mlb,
       which may specify both SML files and additional bases.  See the MLton Guide for details.

       MLton's compile-time options control the  name  of  the  output  file,  the  verbosity  of
       compile-time  messages, and whether or not certain optimizations are performed.  They also
       can specify which intermediate files are saved and can stop the compilation process early,
       at  some  intermediate  pass,  in  which  case  compilation  can be resumed by passing the
       generated files to MLton.  MLton uses the input file suffix to determine the type of input
       program.  The possibilities are .c, .mlb, .o, .s, and .sml.

       With  no  arguments,  MLton prints the version number and exits.  For a usage message, run
       MLton with an invalid switch, e.g.  mlton -z.  In the explanation below and in  the  usage
       message,  for  flags  that  take  a number of choices (e.g. {true|false}), the first value
       listed is the default.

Compile-time options

       -align n
              Aligns objects in memory by the specified alignment (4 or 8).  The  default  varies
              depending on architecture.

       -as-opt option
              Pass option to gcc when compiling assembler code.  If you wish to pass an option to
              the assembler, you must use gcc's -Wa, syntax.

       -cc-opt option
              Pass option to gcc when compiling C code.

       -codegen {native|x86|amd64|c|llvm}
              Generate native object code via amd64 assembly, C code, LLVM code, or x86 assembly.
              With  -codegen  native  (-codegen  amd64 or -codegen x86), MLton typically compiles
              more quickly and generates better code.

       -const 'name value'
              Set the value of a compile-time constant.  Here is a list of  available  constants,
              their default values, and what they control.

              Exn.keepHistory {false|true}
                   Enable  MLton.Exn.history.   There  is  a  performance cost to setting this to
                   true, both in  memory  usage  of  exceptions  and  in  run  time,  because  of
                   additional  work that must be performed at each exception construction, raise,
                   and handle.

       -default-ann ann
              Specify default ML Basis annotations.  For example, -default-ann 'warnUnused  true'
              causes  unused  variable  warnings  to  be  enabled  by  default.   Defaults may be
              overridden by an annotation in an ML Basis file.

       -default-type type
              Specify the default binding for  a  primitive  type.   For  example,  -default-type
              word64 causes the top-level type word and the top-level structure Word in the Basis
              Library to be equal  to  Word64.word  and  Word64:WORD,  respectively.   Similarly,
              -default-type  intinf causes the top-level type int and the top-level structure Int
              in the Basis Library to be equal to IntInf.int and IntInf:INTEGER, respectively.

       -disable-ann ann
              Ignore the specified ML Basis annotation in every ML Basis File.  For  example,  to
              see  all  match  and  unused warnings, compile with -default-ann 'warnUnused true',
              -disable-ann    forceUsed,    -disable-ann     nonexhaustiveMatch,     -disable-ann
              redundantMatch, and -disable-ann warnUnused.

       -export-header file
              Write  C  prototypes  to file for all of the functions in the program exported from
              SML to C.

       -ieee-fp {false|true}
              Cause the x86 native code  generator  to  be  pedantic  about  following  the  IEEE
              floating  point  standard.  By default, it is not, because of the performance cost.
              This only has an effect with -codegen x86.

       -inline n
              Set the inlining threshold used in the optimizer.  The threshold is an  approximate
              measure of code size of a procedure.  The default is 320.

       -keep {g|o}
              Save  intermediate files.  If no -keep argument is given, then only the output file
              is saved.
                   g    generated .c and .s files passed to gcc and generated .ll files passed to
                   llvm-as
                   o    object (.o) files

       -link-opt option
              Pass option to gcc when linking.  You can use this to specify library search paths,
              e.g. -link-opt -Lpath, and libraries to link with, e.g. -link-opt  -lfoo,  or  even
              both  at  the  same  time,  e.g.  -link-opt '-Lpath -lfoo'.  If you wish to pass an
              option  to  the  linker,  you  must  use  gcc's  -Wl,   syntax,   e.g.,   -link-opt
              '-Wl,--export-dynamic'.

       -llvm-as-opt option
              Pass option to llvm-as when assembling (.ll to .bc) LLVM code.

       -llvm-llc-opt option
              Pass option to llc when compiling (.bc to .o) LLVM code.

       -llvm-opt-opt option
              Pass option to opt when optimizing (.bc to .bc) LLVM code.

       -mlb-path-map file
              Use file as an ML Basis path map to define additional MLB path variables.  Multiple
              uses of -mlb-path-map and -mlb-path-var are allowed, with variable  definitions  in
              later path maps taking precedence over earlier ones.

       -mlb-path-var 'name value'
              Define  an  additional  MLB  path  variable.   Multiple  uses  of -mlb-path-map and
              -mlb-path-var are allowed, with variable definitions  in  later  path  maps  taking
              precedence over earlier ones.

       -output file
              Specify the name of the final output file.  The default name is the input file name
              with its suffix removed and an appropriate, possibly empty, suffix added.

       -profile {no|alloc|count|time}
              Produce an executable that gathers profiling data.  When such an executable is run,
              it will produce an mlmon.out file.  The man page on mlprof describes how to extract
              information from this file.

       -profile-branch {false|true}
              If true, the profiler will separately gather profiling data for each  branch  of  a
              function definition, case expression, and if expression.

       -profile-stack {false|true}
              If  true,  the  profiler will gather profiling data for all functions on the stack,
              not just the currently executing function.

       -profile-val {false|true}
              If true, the profiler will separately gather profiling data  for  each  (expansive)
              val declaration.

       -runtime arg
              Pass  argument  to  the  runtime system via @MLton.  The argument will be processed
              before other @MLton command line switches.  Multiple uses of -runtime are  allowed,
              and  will  pass all the arguments in order.  If the same runtime switch occurs more
              than once, then the last setting will take effect.  There is no need to supply  the
              leading @MLton or the trailing --; these will be supplied automatically.

              An  argument  to  -runtime  may contain spaces, which will cause the argument to be
              treated as a sequence of words by the runtime.  For example, the command line:
                   mlton -runtime 'ram-slop 0.4' foo.sml
              will cause foo to run as if it had been called like
                   foo @MLton ram-slop 0.4 --

              An executable created with -runtime stop  doesn't  process  any  @MLton  arguments.
              This  is useful to create an executable, e.g. echo, that must treat @MLton like any
              other command-line argument.
                   % mlton -runtime stop echo.sml
                   % echo @MLton --
                   @MLton --

       -show-basis file
              Pretty print to file the basis defined by the input program.

       -show-def-use file
              Output def-use information to file.  Each identifier that is defined appears  on  a
              line, followed on subsequent lines by the position of each use.

       -stop {f|g|o|tc}
              Specify when to stop.
                   f    list of files on stdout (only makes sense when input is foo.mlb)
                   g    generated .c and .s files
                   o    object (.o) files
                   tc   after type checking
              If  you  compile -stop g or -stop o, you can resume compilation by running MLton on
              the generated .c and .s or .o files.

       -target {self|...}
              Generate an executable that runs on the specified platform.  The default  is  self,
              which  means to compile for the machine that MLton is running on.  To use any other
              target, you must first install a cross compiler.  See the MLton Guide for details.

       -target-as-opt target option
              Like -as-opt, this passes option to gcc when  assembling,  except  it  only  passes
              option when the target architecture or operating system is target.

       -target-cc-opt target option
              Like  -cc-opt,  this  passes  option  to  gcc when compiling C code, except it only
              passes option when the target architecture or operating system is target.

       -target-link-opt target option
              Like -link-opt, this passes option to gcc  when  linking,  except  it  only  passes
              option when the target architecture or operating system is target.

       -verbose {0|1|2|3}
              How verbose to be about what passes are running.  The default is 0.
                   0  silent
                   1  calls to compiler, assembler, and linker
                   2  1, plus intermediate compiler passes
                   3  2, plus some data structure sizes

Runtime system options

       Executables produced by MLton take command line arguments that control the runtime system.
       These arguments are optional, and occur before the executable's usual arguments.   To  use
       these  options,  the  first  argument  to  the  executable  must  be @MLton.  The optional
       arguments then follow, must be terminated by --, and are followed by any arguments to  the
       program.   The  optional  arguments  are  not  made  available  to  the  SML  program  via
       CommandLine.arguments.  For example, a valid call to hello-world is:
            hello-world @MLton gc-summary fixed-heap 10k -- a b c
       In the above example, CommandLine.arguments () = ["a", "b", "c"].

       It is allowed to have a sequence of @MLton arguments, as in:
            hello-world @MLton gc-summary -- @MLton fixed-heap 10k -- a b c

       Run-time options can also control MLton, as in
            mlton @MLton fixed-heap 0.5g -- foo.sml

       fixed-heap x{k|K|m|M|g|G}
              Use a fixed size heap of size x, where x is a real number and the  trailing  letter
              indicates its units.
                   k or K    1024
                   m or M   1,048,576
                   g or G    1,073,741,824
              A value of 0 means to use almost all the RAM present on the machine.

              The  heap  size  used  by  fixed-heap  includes  all  memory allocated by SML code,
              including memory for the stack (or stacks, if there are multiple threads).  It does
              not,  however, include any memory used for code itself or memory used by C globals,
              the C stack, or malloc.

       gc-messages
              Print a message at the start and end of every garbage collection.

       gc-summary
              Print a summary of garbage collection statistics upon program termination.

       gc-summary-file file
              Print a summary of garbage collection statistics upon program  termination  to  the
              file specified by file.

       load-world world
              Restart  the  computation  with  the  file specified by world, which must have been
              created by a call to MLton.World.save by the same executable.  See the MLton  Guide
              for details.

       max-heap x{k|K|m|M|g|G}
              Run the computation with an automatically resized heap that is never larger than x,
              where x is a real number and the  trailing  letter  indicates  the  units  as  with
              fixed-heap.  The heap size for max-heap is accounted for as with fixed-heap.

       may-page-heap {false|true}
              Enable paging the heap to disk when unable to grow the heap to a desired size.

       no-load-world
              Disable  load-world.   This can be used as an argument to the compiler via -runtime
              no-load-world to create executables that will not load a world.  This may be useful
              to ensure that set-uid executables do not load some strange world.

       ram-slop x
              Multiply  x by the amount of RAM on the machine to obtain what the runtime views as
              the amount of RAM it can use.  Typically x is less than 1, and is used  to  account
              for space used by other programs running on the same machine.

       stop   Causes the runtime to stop processing @MLton arguments once the next -- is reached.
              This can be used as an argument  to  the  compiler  via  -runtime  stop  to  create
              executables that don't process any @MLton arguments.

DIAGNOSTICS

       MLton's  type  error  messages  are  not  in a form suitable for processing by Emacs.  For
       details on how to fix this, see http://mlton.org/Emacs.

SEE ALSO

       mlprof(1) and the MLton Guide.

                                         January 17, 2021                                mlton(1)