Provided by: ocaml_4.13.1-6ubuntu1_amd64 bug

NAME

       ocamlopt - The OCaml native-code compiler

SYNOPSIS

       ocamlopt [ options ] filename ...

       ocamlopt.opt (same options)

DESCRIPTION

       The OCaml high-performance native-code compiler ocamlopt(1) compiles OCaml source files to
       native code object files and link these object files to produce standalone executables.

       The ocamlopt(1) command has a command-line interface very close to that of ocamlc(1).   It
       accepts  the  same  types  of arguments and processes them sequentially, after all options
       have been processed:

       Arguments ending in .mli are taken to be source files  for  compilation  unit  interfaces.
       Interfaces  specify the names exported by compilation units: they declare value names with
       their types, define public data types, declare abstract data types, and so  on.  From  the
       file x.mli, the ocamlopt(1) compiler produces a compiled interface in the file x.cmi.  The
       interface produced is identical to that produced by the bytecode compiler ocamlc(1).

       Arguments ending in .ml are taken to be source files for compilation unit implementations.
       Implementations  provide  definitions for the names exported by the unit, and also contain
       expressions to be evaluated for their side-effects.  From the file x.ml,  the  ocamlopt(1)
       compiler  produces  two  files:  x.o, containing native object code, and x.cmx, containing
       extra information for linking and optimization of the clients of the  unit.  The  compiled
       implementation  should  always  be referred to under the name x.cmx (when given a .o file,
       ocamlopt(1) assumes that it contains code compiled from C, not from OCaml).

       The implementation is checked against the interface file x.mli (if it exists) as described
       in the manual for ocamlc(1).

       Arguments  ending  in  .cmx  are taken to be compiled object code.  These files are linked
       together, along with the object files obtained by compiling .ml arguments  (if  any),  and
       the  OCaml  standard  library,  to  produce a native-code executable program. The order in
       which .cmx and .ml arguments are presented on the command line  is  relevant:  compilation
       units  are  initialized  in  that  order at run-time, and it is a link-time error to use a
       component of a unit before having initialized it. Hence, a  given  x.cmx  file  must  come
       before all .cmx files that refer to the unit x.

       Arguments  ending in .cmxa are taken to be libraries of object code.  Such a library packs
       in two files lib.cmxa and lib.a a set of object files (.cmx/.o files). Libraries are build
       with  ocamlopt -a (see the description of the -a option below). The object files contained
       in the library are linked as regular .cmx files (see above), in the order  specified  when
       the  library  was  built.  The  only  difference  is that if an object file contained in a
       library is not referenced anywhere in the program, then it is not linked in.

       Arguments ending in .c are passed to the C compiler, which generates  a  .o  object  file.
       This object file is linked with the program.

       Arguments  ending  in  .o  or  .a are assumed to be C object files and libraries. They are
       linked with the program.

       The output of the linking phase is a regular  Unix  executable  file.  It  does  not  need
       ocamlrun(1) to run.

       ocamlopt.opt  is  the  same compiler as ocamlopt, but compiled with itself instead of with
       the bytecode compiler ocamlc(1).  Thus, it behaves exactly  like  ocamlopt,  but  compiles
       faster.  ocamlopt.opt is not available in all installations of OCaml.

OPTIONS

       The following command-line options are recognized by ocamlopt(1).

       -a     Build  a library (.cmxa/.a file) with the object files (.cmx/.o files) given on the
              command line, instead of linking them into an executable  file.  The  name  of  the
              library must be set with the -o option.

              If  -cclib or -ccopt  options  are  passed  on  the command line, these options are
              stored  in  the  resulting  .cmxa  library.   Then,  linking  with   this   library
              automatically  adds back the -cclib and -ccopt options as if they had been provided
              on the command line, unless  the  -noautolink  option  is  given.  Additionally,  a
              substring $CAMLORIGIN inside a  -ccopt options will be replaced by the full path to
              the .cma library, excluding the filename.

       -absname
              Show absolute filenames in error messages.

       -annot Deprecated since OCaml 4.11. Please use -bin-annot instead.

       -bin-annot
              Dump detailed information about the compilation (types, bindings, tail-calls,  etc)
              in  binary  format.  The  information for file src.ml is put into file src.cmt.  In
              case of a type error, dump all the information inferred by the type-checker  before
              the  error.   The  annotation files produced by -bin-annot contain more information
              and are much more compact than the files produced by -annot.

       -c     Compile only. Suppress the linking phase of the compilation. Source code files  are
              turned  into  compiled  files,  but  no executable file is produced. This option is
              useful to compile modules separately.

       -cc ccomp
              Use ccomp as the C linker called to  build  the  final  executable  and  as  the  C
              compiler for compiling .c source files.

       -cclib -llibname
              Pass  the  -llibname  option  to  the linker. This causes the given C library to be
              linked with the program.

       -ccopt option
              Pass the given option to the C compiler  and  linker.  For  instance,  -ccopt -Ldir
              causes the C linker to search for C libraries in directory dir.

       -color mode
              Enable  or  disable  colors  in compiler messages (especially warnings and errors).
              The following modes are supported:

              auto use heuristics to enable colors only if the output  supports  them  (an  ANSI-
              compatible tty terminal);

              always enable colors unconditionally;

              never disable color output.

              The  default  setting  is  auto,  and  the current heuristic checks that the "TERM"
              environment variable exists and is not empty or  "dumb",  and  that  isatty(stderr)
              holds.

              The environment variable "OCAML_COLOR" is considered if -color is not provided. Its
              values are auto/always/never as above.

       -error-style mode
              Control the way error messages and warnings are printed.  The following  modes  are
              supported:

              short only print the error and its location;

              contextual  like "short", but also display the source code snippet corresponding to
              the location of the error.

              The default setting is contextual.

              The environment variable "OCAML_ERROR_STYLE" is considered if -error-style  is  not
              provided. Its values are short/contextual as above.

       -compact
              Optimize  the produced code for space rather than for time. This results in smaller
              but slightly slower programs. The default is to optimize for speed.

       -config
              Print  the  version  number  of  ocamlopt(1)  and  a  detailed   summary   of   its
              configuration, then exit.

       -config-var
              Print  the value of a specific configuration variable from the -config output, then
              exit. If the variable does not exist, the exit code is non-zero.

       -depend ocamldep-args
              Compute dependencies, as ocamldep would do.

       -for-pack module-path
              Generate an object file (.cmx and .o files) that can later be included  as  a  sub-
              module  (with  the given access path) of a compilation unit constructed with -pack.
              For instance, ocamlopt -for-pack P -c A.ml will generate a.cmx and a.o  files  that
              can later be used with ocamlopt -pack -o P.cmx a.cmx.

       -g     Add  debugging  information while compiling and linking. This option is required in
              order to produce stack backtraces  when  the  program  terminates  on  an  uncaught
              exception (see ocamlrun(1)).

       -i     Cause  the  compiler to print all defined names (with their inferred types or their
              definitions) when compiling an implementation (.ml file). No compiled  files  (.cmo
              and  .cmi  files)  are produced.  This can be useful to check the types inferred by
              the compiler. Also, since the output follows the syntax of interfaces, it can  help
              in writing an explicit interface (.mli file) for a file: just redirect the standard
              output of the  compiler  to  a  .mli  file,  and  edit  that  file  to  remove  all
              declarations of unexported names.

       -I directory
              Add  the given directory to the list of directories searched for compiled interface
              files (.cmi), compiled object code files (.cmx), and libraries (.cmxa). By default,
              the  current  directory  is  searched  first,  then the standard library directory.
              Directories added with -I are searched after the current directory, in the order in
              which  they  were  given  on  the  command  line,  but  before the standard library
              directory. See also option -nostdlib.

              If the given directory starts with +, it is taken relative to the standard  library
              directory.  For  instance, -I +compiler-libs adds the subdirectory compiler-libs of
              the standard library to the search path.

       -impl filename
              Compile the file filename as an implementation file, even if its extension  is  not
              .ml.

       -inline n
              Set  aggressiveness  of  inlining  to  n, where n is a positive integer. Specifying
              -inline 0 prevents all functions from being inlined, except  those  whose  body  is
              smaller  than  the  call site. Thus, inlining causes no expansion in code size. The
              default aggressiveness, -inline 1, allows slightly larger functions to be  inlined,
              resulting  in a slight expansion in code size. Higher values for the -inline option
              cause larger and larger functions to become candidate for inlining, but can  result
              in a serious increase in code size.

       -insn-sched
              Enables the instruction scheduling pass in the compiler backend.

       -intf filename
              Compile the file filename as an interface file, even if its extension is not .mli.

       -intf-suffix string
              Recognize  file names ending with string as interface files (instead of the default
              .mli).

       -keep-docs
              Keep documentation strings in generated .cmi files.

       -keep-locs
              Keep locations in generated .cmi files.

       -labels
              Labels are not ignored in types, labels may be used in applications,  and  labelled
              parameters can be given in any order.  This is the default.

       -linkall
              Force  all  modules  contained  in  libraries  to be linked in. If this flag is not
              given, unreferenced modules are not linked in. When building a library  (-a  flag),
              setting  the  -linkall  flag forces all subsequent links of programs involving that
              library to link all the modules contained in the library.  When compiling a  module
              (option  -c),  setting  the -linkall option ensures that this module will always be
              linked if it is put in a library and this library is linked.

       -linscan
              Use linear scan register allocation.  Compiling with this allocator is faster  than
              with  the  usual  graph coloring allocator, sometimes quite drastically so for long
              functions and modules. On the other hand, the generated code can be a bit slower.

       -match-context-rows
              Set number of rows of context  used  during  pattern  matching  compilation.  Lower
              values cause faster compilation, but less optimized code. The default value is 32.

       -no-alias-deps
              Do not record dependencies for module aliases.

       -no-app-funct
              Deactivates  the  applicative behaviour of functors. With this option, each functor
              application generates new types in its result and applying the same  functor  twice
              to the same argument yields two incompatible structures.

       -noassert
              Do not compile assertion checks.  Note that the special form assert false is always
              compiled because it is typed specially.  This  flag  has  no  effect  when  linking
              already-compiled files.

       -noautolink
              When   linking   .cmxa  libraries,  ignore  -cclib and -ccopt  options  potentially
              contained in  the  libraries  (if  these  options  were  given  when  building  the
              libraries).  This can be useful if a library contains incorrect specifications of C
              libraries or C options; in this case, during linking, set -noautolink and pass  the
              correct C libraries and options on the command line.

       -nodynlink
              Allow  the  compiler to use some optimizations that are valid only for code that is
              never dynlinked.

       -no-insn-sched
              Disables the instruction scheduling pass in the compiler backend.

       -nostdlib
              Do not automatically add the standard library directory to the list of  directories
              searched  for  compiled  interface files (.cmi), compiled object code files (.cmx),
              and libraries (.cmxa). See also option -I.

       -nolabels
              Ignore non-optional labels in types. Labels cannot be  used  in  applications,  and
              parameter order becomes strict.

       -o exec-file
              Specify the name of the output file produced by the linker. The default output name
              is a.out, in keeping with the Unix tradition. If the -a option  is  given,  specify
              the name of the library produced. If the -pack option is given, specify the name of
              the packed object file produced.  If the -output-obj option is given,  specify  the
              name  of the output file produced. If the -shared option is given, specify the name
              of plugin file produced.  This can also be used  when  compiling  an  interface  or
              implementation  file, without linking, in which case it sets the name of the cmi or
              cmo file, and also sets the module name to the file name up to the first dot.

       -opaque
              When compiling a .mli interface file, this has  the  same  effect  as  the  -opaque
              option  of  the  bytecode  compiler. When compiling a .ml implementation file, this
              produces a .cmx file without cross-module optimization information,  which  reduces
              recompilation on module change.

       -open module
              Opens  the given module before processing the interface or implementation files. If
              several -open options are given, they are  processed  in  order,  just  as  if  the
              statements open! module1;; ... open! moduleN;; were added at the top of each file.

       -output-obj
              Cause  the linker to produce a C object file instead of an executable file. This is
              useful to wrap OCaml code as a C library, callable from any C program. The name  of
              the  output  object  file  must be set with the -o option.  This option can also be
              used   to   produce   a   compiled   shared/dynamic   library   (.so    extension).
              -output-complete-obj  Same  as -output-obj except the object file produced includes
              the runtime and autolink libraries.

       -pack  Build an object file (.cmx and .o files)  and  its  associated  compiled  interface
              (.cmi)  that  combines the .cmx object files given on the command line, making them
              appear as sub-modules of the output .cmx file.  The name of the  output  .cmx  file
              must      be      given      with     the     -o     option.      For     instance,
              ocamlopt -pack -o P.cmx A.cmx B.cmx C.cmx generates compiled files P.cmx,  P.o  and
              P.cmi  describing  a  compilation  unit  having  three  sub-modules  A,  B  and  C,
              corresponding to the contents of the object files A.cmx, B.cmx  and  C.cmx.   These
              contents can be referenced as P.A, P.B and P.C in the remainder of the program.

              The  .cmx  object files being combined must have been compiled with the appropriate
              -for-pack option.  In the example above, A.cmx, B.cmx  and  C.cmx  must  have  been
              compiled with ocamlopt -for-pack P.

              Multiple  levels of packing can be achieved by combining -pack with -for-pack.  See
              The OCaml user's manual, chapter "Native-code compilation" for more details.

       -pp command
              Cause the compiler to call the given command as  a  preprocessor  for  each  source
              file.  The  output  of  command  is  redirected  to  an intermediate file, which is
              compiled. If there are no compilation errors,  the  intermediate  file  is  deleted
              afterwards.

       -ppx command
              After parsing, pipe the abstract syntax tree through the preprocessor command.  The
              module Ast_mapper(3) implements the external interface of a preprocessor.

       -principal
              Check information path during type-checking,  to  make  sure  that  all  types  are
              derived  in  a  principal  way.  All  programs accepted in -principal mode are also
              accepted in default mode with equivalent types, but different binary signatures.

       -rectypes
              Allow arbitrary recursive types during type-checking.  By default,  only  recursive
              types where the recursion goes through an object type are supported. Note that once
              you have created an interface using this flag,  you  must  use  it  again  for  all
              dependencies.

       -runtime-variant suffix
              Add suffix to the name of the runtime library that will be used by the program.  If
              OCaml was  configured  with  option  -with-debug-runtime,  then  the  d  suffix  is
              supported and gives a debug version of the runtime.

       -S     Keep  the  assembly code produced during the compilation. The assembly code for the
              source file x.ml is saved in the file x.s.

       -stop-after pass
              Stop compilation after the given compilation pass. The currently  supported  passes
              are: parsing, typing, scheduling, emit.

       -save-ir-after pass
              Save  intermediate  representation  after the given compilation pass. The currently
              supported passes are: scheduling.

       -safe-string
              Enforce the separation between types string and bytes, thereby making strings read-
              only. This is the default.

       -shared
              Build  a  plugin  (usually  .cmxs)  that can be dynamically loaded with the Dynlink
              module. The name of the plugin must be set with the -o option. A plugin can include
              a  number  of OCaml modules and libraries, and extra native objects (.o, .a files).
              Building native plugins is only supported for some  operating  system.  Under  some
              systems  (currently, only Linux AMD 64), all the OCaml code linked in a plugin must
              have been compiled without the -nodynlink flag. Some constraints might  also  apply
              to  the  way  the extra native objects have been compiled (under Linux AMD 64, they
              must contain only position-independent code).

       -short-paths
              When a type is visible under  several  module-paths,  use  the  shortest  one  when
              printing the type's name in inferred interfaces and error and warning messages.

       -strict-sequence
              The left-hand part of a sequence must have type unit.

       -unboxed-types
              When  a  type  is  unboxable  (i.e.  a  record with a single argument or a concrete
              datatype with a single constructor of one  argument)  it  will  be  unboxed  unless
              annotated with [@@ocaml.boxed].

       -no-unboxed-types
              When a type is unboxable  it will be boxed unless annotated with [@@ocaml.unboxed].
              This is the default.

       -unsafe
              Turn  bound  checking  off  for  array  and  string  accesses  (the   v.(i)ands.[i]
              constructs).  Programs  compiled  with  -unsafe  are  therefore faster, but unsafe:
              anything can happen if the program accesses an  array  or  string  outside  of  its
              bounds.  Additionally,  turn off the check for zero divisor in integer division and
              modulus operations.  With -unsafe, an integer division (or  modulus)  by  zero  can
              halt  the  program  or  continue  with  an  unspecified result instead of raising a
              Division_by_zero exception.

       -unsafe-string
              Identify the types string and bytes, thereby  making  strings  writable.   This  is
              intended  for  compatibility  with  old source code and should not be used with new
              software.

       -v     Print the version number of the compiler and the location of the  standard  library
              directory, then exit.

       -verbose
              Print  all external commands before they are executed, in particular invocations of
              the assembler, C compiler, and linker.

       -version or -vnum
              Print the version number of the compiler in short form (e.g. "3.11.0"), then exit.

       -w warning-list
              Enable,  disable,  or  mark  as  fatal  the  warnings  specified  by  the  argument
              warning-list.  See ocamlc(1) for the syntax of warning-list.

       -warn-error warning-list
              Mark  as  fatal  the warnings specified in the argument warning-list.  The compiler
              will stop with an error when one of these warnings is  emitted.   The  warning-list
              has  the same meaning as for the -w option: a + sign (or an uppercase letter) marks
              the corresponding warnings as fatal, a - sign (or a lowercase  letter)  turns  them
              back  into  non-fatal  warnings,  and  a @ sign both enables and marks as fatal the
              corresponding warnings.

              Note: it is not recommended to use  the  -warn-error  option  in  production  code,
              because it will almost certainly prevent compiling your program with later versions
              of OCaml when they add new warnings or modify existing warnings.

              The default setting is -warn-error -a+31 (only warning 31 is fatal).

       -warn-help
              Show the description of all available warning numbers.

       -where Print the location of the standard library, then exit.

       -with-runtime
              Include the runtime system in the generated program. This is the default.

       -without-runtime
              The compiler does not include the runtime system (nor a reference  to  it)  in  the
              generated program; it must be supplied separately.

       - file Process file as a file name, even if it starts with a dash (-) character.

       -help or --help
              Display a short usage summary and exit.

OPTIONS FOR THE IA32 ARCHITECTURE

       The  IA32  code  generator  (Intel  Pentium, AMD Athlon) supports the following additional
       option:

       -ffast-math
              Use the IA32 instructions  to  compute  trigonometric  and  exponential  functions,
              instead of calling the corresponding library routines.  The functions affected are:
              atan, atan2, cos, log, log10, sin, sqrt and tan.  The resulting code  runs  faster,
              but  the  range  of  supported  arguments  and  the  precision of the result can be
              reduced.  In particular, trigonometric operations cos, sin, tan  have  their  range
              reduced to [-2^64, 2^64].

OPTIONS FOR THE AMD64 ARCHITECTURE

       The  AMD64  code  generator (64-bit versions of Intel Pentium and AMD Athlon) supports the
       following additional options:

       -fPIC  Generate position-independent machine code.  This is the default.

       -fno-PIC
              Generate position-dependent machine code.

OPTIONS FOR THE POWER ARCHITECTURE

       The PowerPC code generator supports the following additional options:

       -flarge-toc
              Enables the PowerPC large  model  allowing  the  TOC  (table  of  contents)  to  be
              arbitrarily large.  This is the default since 4.11.

       -fsmall-toc
              Enables  the  PowerPC  small  model  allowing  the  TOC  to  be up to 64 kbytes per
              compilation unit.  Prior to 4.11 this was the default behaviour.  \nd{options}

OPTIONS FOR THE ARM ARCHITECTURE

       The ARM code generator supports the following additional options:

       -farch=armv4|armv5|armv5te|armv6|armv6t2|armv7
              Select the ARM target architecture

       -ffpu=soft|vfpv2|vfpv3-d16|vfpv3
              Select the floating-point hardware

       -fPIC  Generate position-independent machine code.

       -fno-PIC
              Generate position-dependent machine code.  This is the default.

       -fthumb
              Enable Thumb/Thumb-2 code generation

       -fno-thumb
              Disable Thumb/Thumb-2 code generation

       The default values for target architecture, floating-point hardware and thumb  usage  were
       selected  at  configure-time  when  building  ocamlopt  itself.  This configuration can be
       inspected using ocamlopt -config.  Target architecture depends  on  the  "model"  setting,
       while  floating-point  hardware  and  thumb support are determined from the ABI setting in
       "system" ( linux_eabiorlinux_eabihf).

SEE ALSO

       ocamlc(1).
       The OCaml user's manual, chapter "Native-code compilation".

                                                                                      OCAMLOPT(1)