NAME¶
jocamlopt - The JoCaml native-code compiler
SYNOPSIS¶
jocamlopt [
-acivS ] [
-cclib libname ] [
-ccopt option ] [
-compact ] [
-unsafe ] [
-o exec-file ] [
-I lib-dir ]
filename ...
jocamlopt.opt (same options)
DESCRIPTION¶
The JoCaml high-performance native-code compiler
jocamlopt(1) compiles
Caml source files to native code object files and link these object files to
produce standalone executables.
The
jocamlopt(1) command has a command-line interface very close to that
of
jocamlc(1). It accepts the same types of arguments and processes
them sequentially:
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
jocamlopt(1) compiler produces a compiled interface in the file
x.cmi. The interface produced is identical to that produced by the
bytecode compiler
jocamlc(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
jocamlopt(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,
jocamlopt(1) assumes that it
contains code compiled from C, not from Caml).
The implementation is checked against the interface file
x.mli (if it
exists) as described in the manual for
jocamlc(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 Caml Light 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
jocamlopt -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
jocamlrun(1) to run.
jocamlopt.opt is the same compiler as
jocamlopt, but compiled with
itself instead of with the bytecode compiler
jocamlc(1). Thus, it
behaves exactly like
jocamlopt, but compiles faster.
jocamlopt.opt is not available in all installations of JoCaml.
OPTIONS¶
The following command-line options are recognized by
jocamlopt(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 can be set with the -o
option. The default name is library.cmxa.
- -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.
- -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 -L dir causes the C linker to search for C
libraries in directory dir.
- -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.
- -i
- Cause the compiler to print all defined names (with their
inferred types or their definitions) when compiling an implementation (.ml
file). 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) and compiled object code files (.cmo).
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.
- -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.
- -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.
- -v
- Print the version number of the compiler.
- -unsafe
- Turn bound checking off on array and string accesses (the
v.(i) and s.[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.
SEE ALSO¶
jocamlc(1).
The Objective Caml user's manual, chapter "Native-code
compilation".