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

Provided by: mlton-compiler_20210117+dfsg-3_amd64

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