1OCAMLC(1) General Commands Manual OCAMLC(1)
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6 ocamlc - The Objective Caml bytecode compiler
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11 ocamlc [ -aciv ] [ -cclib libname ] [ -ccopt option ] [ -custom ] [
12 -unsafe ] [ -o exec-file ] [ -I lib-dir ] filename ...
13 ocamlc.opt (same options)
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18 The Objective Caml bytecode compiler ocamlc(1) compiles Caml source
19 files to bytecode object files and link these object files to produce
20 standalone bytecode executable files. These executable files are then
21 run by the bytecode interpreter ocamlrun(1).
22 The ocamlc(1) command has a command-line interface similar to the one
24 of most C compilers. It accepts several types of arguments and pro‐
25 cesses them sequentially:
26 Arguments ending in .mli are taken to be source files for compilation
28 unit interfaces. Interfaces specify the names exported by compilation
29 units: they declare value names with their types, define public data
30 types, declare abstract data types, and so on. From the file x.mli, the
31 ocamlc(1) compiler produces a compiled interface in the file x.cmi.
32 Arguments ending in .ml are taken to be source files for compilation
34 unit implementations. Implementations provide definitions for the names
35 exported by the unit, and also contain expressions to be evaluated for
36 their side-effects. From the file x.ml, the ocamlc(1) compiler pro‐
37 duces compiled object bytecode in the file x.cmo.
38 If the interface file x.mli exists, the implementation x.ml is checked
40 against the corresponding compiled interface x.cmi, which is assumed to
41 exist. If no interface x.mli is provided, the compilation of x.ml pro‐
42 duces a compiled interface file x.cmi in addition to the compiled
43 object code file x.cmo. The file x.cmi produced corresponds to an
44 interface that exports everything that is defined in the implementation
45 x.ml.
46 Arguments ending in .cmo are taken to be compiled object bytecode.
48 These files are linked together, along with the object files obtained
49 by compiling .ml arguments (if any), and the Caml Light standard
50 library, to produce a standalone executable program. The order in which
51 .cmo and.ml arguments are presented on the command line is relevant:
52 compilation units are initialized in that order at run-time, and it is
53 a link-time error to use a component of a unit before having initial‐
54 ized it. Hence, a given x.cmo file must come before all .cmo files that
55 refer to the unit x.
56 Arguments ending in .cma are taken to be libraries of object bytecode.
58 A library of object bytecode packs in a single file a set of object
59 bytecode files (.cmo files). Libraries are built with ocamlc -a (see
60 the description of the -a option below). The object files contained in
61 the library are linked as regular .cmo files (see above), in the order
62 specified when the .cma file was built. The only difference is that if
63 an object file contained in a library is not referenced anywhere in the
64 program, then it is not linked in.
65 Arguments ending in .c are passed to the C compiler, which generates a
67 .o object file. This object file is linked with the program if the
68 -custom flag is set (see the description of -custom below).
69 Arguments ending in .o or .a are assumed to be C object files and
71 libraries. They are passed to the C linker when linking in -custom mode
72 (see the description of -custom below).
73 ocamlc.opt is the same compiler as ocamlc, but compiled with the
75 native-code compiler ocamlopt(1). Thus, it behaves exactly like
76 ocamlc, but compiles faster. ocamlc.opt is not available in all
77 installations of Objective Caml.
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81 The following command-line options are recognized by ocamlc(1).
82 -a Build a library (.cma file) with the object files (.cmo files)
85 given on the command line, instead of linking them into an exe‐
86 cutable file. The name of the library can be set with the -o
87 option. The default name is library.cma.
88 -c Compile only. Suppress the linking phase of the compilation.
91 Source code files are turned into compiled files, but no exe‐
92 cutable file is produced. This option is useful to compile mod‐
93 ules separately.
94 -cclib -llibname
97 Pass the -llibname option to the C linker when linking in ``cus‐
98 tom runtime'' mode (see the -custom option). This causes the
99 given C library to be linked with the program.
100 -ccopt Pass the given option to the C compiler and linker, when linking
103 in ``custom runtime'' mode (see the -custom option). For
104 instance, -ccopt -L dir causes the C linker to search for C
105 libraries in directory dir.
106 -custom
109 Link in ``custom runtime'' mode. In the default linking mode,
110 the linker produces bytecode that is intended to be executed
111 with the shared runtime system, ocamlrun(1). In the custom run‐
112 time mode, the linker produces an output file that contains both
113 the runtime system and the bytecode for the program. The result‐
114 ing file is larger, but it can be executed directly, even if the
115 ocamlrun(1) command is not installed. Moreover, the ``custom
116 runtime'' mode enables linking Caml code with user-defined C
117 functions.
118 -i Cause the compiler to print all defined names (with their
121 inferred types or their definitions) when compiling an implemen‐
122 tation (.ml file). This can be useful to check the types
123 inferred by the compiler. Also, since the output follows the
124 syntax of interfaces, it can help in writing an explicit inter‐
125 face (.mli file) for a file: just redirect the standard output
126 of the compiler to a .mli file, and edit that file to remove all
127 declarations of unexported names.
128 -Idirectory
131 Add the given directory to the list of directories searched for
132 compiled interface files (.cmi) and compiled object code files
133 (.cmo). By default, the current directory is searched first,
134 then the standard library directory. Directories added with -I
135 are searched after the current directory, in the order in which
136 they were given on the command line, but before the standard
137 library directory.
138 -o exec-file
141 Specify the name of the output file produced by the linker. The
142 default output name is a.out, in keeping with the Unix tradi‐
143 tion. If the -a option is given, specify the name of the library
144 produced.
145 -v Print the version number of the compiler.
148 -unsafe
151 Turn bound checking off on array and string accesses (the v.(i)
152 and s.[i] constructs). Programs compiled with -unsafe are there‐
153 fore slightly faster, but unsafe: anything can happen if the
154 program accesses an array or string outside of its bounds.
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158 ocaml(1), ocamlrun(1).
159 The Objective Caml user's manual, chapter "Batch compilation".
160 OCAMLC(1)