NAME¶
jocamlc - The JoCaml bytecode compiler
SYNOPSIS¶
jocamlc [
-aciv ] [
-cclib libname ] [
-ccopt option ] [
-custom ] [
-unsafe ] [
-o exec-file ] [
-I lib-dir ]
filename ...
jocamlc.opt (same options)
DESCRIPTION¶
The JoCaml bytecode compiler
jocamlc(1) compiles Caml source files to
bytecode object files and link these object files to produce standalone
bytecode executable files. These executable files are then run by the bytecode
interpreter
jocamlrun(1).
The
jocamlc(1) command has a command-line interface similar to the one of
most C compilers. It accepts several 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
jocamlc(1) compiler produces a compiled interface in the file
x.cmi.
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
jocamlc(1) compiler produces compiled
object bytecode in the file
x.cmo.
If the interface file
x.mli exists, the implementation
x.ml is
checked against the corresponding compiled interface
x.cmi, which is
assumed to exist. If no interface
x.mli is provided, the compilation of
x.ml produces a compiled interface file
x.cmi in addition to the
compiled object code file
x.cmo. The file
x.cmi produced
corresponds to an interface that exports everything that is defined in the
implementation
x.ml.
Arguments ending in .cmo are taken to be compiled object bytecode. 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
standalone executable program. The order in which .cmo 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.cmo file must come
before all .cmo files that refer to the unit
x.
Arguments ending in .cma are taken to be libraries of object bytecode. A library
of object bytecode packs in a single file a set of object bytecode files (.cmo
files). Libraries are built with
ocamlc -a (see the description of the
-a option below). The object files contained in the library are linked
as regular .cmo files (see above), in the order specified when the .cma file
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 if the
-custom flag
is set (see the description of
-custom below).
Arguments ending in .o or .a are assumed to be C object files and libraries.
They are passed to the C linker when linking in
-custom mode (see the
description of
-custom below).
jocamlc.opt is the same compiler as
jocamlc, but compiled with the
native-code compiler
jocamlopt(1). Thus, it behaves exactly like
jocamlc, but compiles faster.
jocamlc.opt is not available in
all installations of JoCaml.
OPTIONS¶
The following command-line options are recognized by
jocamlc(1).
- -a
- Build a library (.cma file) with the object files (.cmo
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.cma.
- -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 C linker
when linking in ``custom runtime'' mode (see the -custom option).
This causes the given C library to be linked with the program.
- -ccopt
- Pass the given option to the C compiler and linker, when
linking in ``custom runtime'' mode (see the -custom option). For
instance, -ccopt -L dir causes the C linker to search for C
libraries in directory dir.
- -custom
- Link in ``custom runtime'' mode. In the default linking
mode, the linker produces bytecode that is intended to be executed with
the shared runtime system, jocamlrun(1). In the custom runtime
mode, the linker produces an output file that contains both the runtime
system and the bytecode for the program. The resulting file is larger, but
it can be executed directly, even if the jocamlrun(1) command is
not installed. Moreover, the ``custom runtime'' mode enables linking Caml
code with user-defined C functions.
- -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.
- -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 slightly faster, but unsafe: anything can
happen if the program accesses an array or string outside of its bounds.
SEE ALSO¶
jocaml(1),
jocamlrun(1).
The Objective Caml user's manual, chapter "Batch
compilation".