1OCAMLOPT(1) General Commands Manual OCAMLOPT(1)
2
6 ocamlopt - The OCaml native-code compiler
7
10 ocamlopt [ options ] filename ...
11 ocamlopt.opt (same options)
13
16 The OCaml high-performance native-code compiler ocamlopt(1) compiles
17 OCaml source files to native code object files and link these object
18 files to produce standalone executables.
19 The ocamlopt(1) command has a command-line interface very close to that
21 of ocamlc(1). It accepts the same types of arguments and processes
22 them sequentially, after all options have been processed:
23 Arguments ending in .mli are taken to be source files for compilation
25 unit interfaces. Interfaces specify the names exported by compilation
26 units: they declare value names with their types, define public data
27 types, declare abstract data types, and so on. From the file x.mli, the
28 ocamlopt(1) compiler produces a compiled interface in the file x.cmi.
29 The interface produced is identical to that produced by the bytecode
30 compiler ocamlc(1).
31 Arguments ending in .ml are taken to be source files for compilation
33 unit implementations. Implementations provide definitions for the names
34 exported by the unit, and also contain expressions to be evaluated for
35 their side-effects. From the file x.ml, the ocamlopt(1) compiler pro‐
36 duces two files: x.o, containing native object code, and x.cmx, con‐
37 taining extra information for linking and optimization of the clients
38 of the unit. The compiled implementation should always be referred to
39 under the name x.cmx (when given a .o file, ocamlopt(1) assumes that it
40 contains code compiled from C, not from OCaml).
41 The implementation is checked against the interface file x.mli (if it
43 exists) as described in the manual for ocamlc(1).
44 Arguments ending in .cmx are taken to be compiled object code. These
46 files are linked together, along with the object files obtained by com‐
47 piling .ml arguments (if any), and the OCaml standard library, to pro‐
48 duce a native-code executable program. The order in which .cmx and .ml
49 arguments are presented on the command line is relevant: compilation
50 units are initialized in that order at run-time, and it is a link-time
51 error to use a component of a unit before having initialized it. Hence,
52 a given x.cmx file must come before all .cmx files that refer to the
53 unit x.
54 Arguments ending in .cmxa are taken to be libraries of object code.
56 Such a library packs in two files lib.cmxa and lib.a a set of object
57 files (.cmx/.o files). Libraries are build with ocamlopt -a (see the
58 description of the -a option below). The object files contained in the
59 library are linked as regular .cmx files (see above), in the order
60 specified when the library was built. The only difference is that if an
61 object file contained in a library is not referenced anywhere in the
62 program, then it is not linked in.
63 Arguments ending in .c are passed to the C compiler, which generates a
65 .o object file. This object file is linked with the program.
66 Arguments ending in .o or .a are assumed to be C object files and
68 libraries. They are linked with the program.
69 The output of the linking phase is a regular Unix executable file. It
71 does not need ocamlrun(1) to run.
72 ocamlopt.opt is the same compiler as ocamlopt, but compiled with itself
74 instead of with the bytecode compiler ocamlc(1). Thus, it behaves
75 exactly like ocamlopt, but compiles faster. ocamlopt.opt is not avail‐
76 able in all installations of OCaml.
77
80 The following command-line options are recognized by ocamlopt(1).
81 -a Build a library (.cmxa/.a file) with the object files (.cmx/.o
83 files) given on the command line, instead of linking them into
84 an executable file. The name of the library must be set with the
85 -o option.
86 If -cclib or -ccopt options are passed on the command line,
88 these options are stored in the resulting .cmxa library. Then,
89 linking with this library automatically adds back the
90 -cclib and -ccopt options as if they had been provided on the
91 command line, unless the -noautolink option is given. Addition‐
92 ally, a substring $CAMLORIGIN inside a -ccopt options will be
93 replaced by the full path to the .cma library, excluding the
94 filename.
95 -absname
97 Show absolute filenames in error messages.
98 -annot Dump detailed information about the compilation (types, bind‐
100 ings, tail-calls, etc). The information for file src.ml is put
101 into file src.annot. In case of a type error, dump all the
102 information inferred by the type-checker before the error. The
103 src.annot file can be used with the emacs commands given in
104 emacs/caml-types.el to display types and other annotations
105 interactively.
106 -bin-annot
108 Dump detailed information about the compilation (types, bind‐
109 ings, tail-calls, etc) in binary format. The information for
110 file src.ml is put into file src.cmt. In case of a type error,
111 dump all the information inferred by the type-checker before the
112 error. The annotation files produced by -bin-annot contain more
113 information and are much more compact than the files produced by
114 -annot.
115 -c Compile only. Suppress the linking phase of the compilation.
117 Source code files are turned into compiled files, but no exe‐
118 cutable file is produced. This option is useful to compile mod‐
119 ules separately.
120 -cc ccomp
122 Use ccomp as the C linker called to build the final executable
123 and as the C compiler for compiling .c source files.
124 -cclib -llibname
126 Pass the -llibname option to the linker. This causes the given C
127 library to be linked with the program.
128 -ccopt option
130 Pass the given option to the C compiler and linker. For
131 instance, -ccopt -Ldir causes the C linker to search for C
132 libraries in directory dir.
133 -color mode
135 Enable or disable colors in compiler messages (especially warn‐
136 ings and errors). The following modes are supported:
137 auto use heuristics to enable colors only if the output supports
139 them (an ANSI-compatible tty terminal);
140 always enable colors unconditionally;
142 never disable color output.
144 The default setting is auto, and the current heuristic checks
146 that the "TERM" environment variable exists and is not empty or
147 "dumb", and that isatty(stderr) holds.
148 The environment variable "OCAML_COLOR" is considered if -color
150 is not provided. Its values are auto/always/never as above.
151 -compact
154 Optimize the produced code for space rather than for time. This
155 results in smaller but slightly slower programs. The default is
156 to optimize for speed.
157 -config
159 Print the version number of ocamlopt(1) and a detailed summary
160 of its configuration, then exit.
161 -for-pack module-path
163 Generate an object file (.cmx and .o files) that can later be
164 included as a sub-module (with the given access path) of a com‐
165 pilation unit constructed with -pack. For instance, ocam‐
166 lopt -for-pack P -c A.ml will generate a.cmx and a.o files that
167 can later be used with ocamlopt -pack -o P.cmx a.cmx.
168 -g Add debugging information while compiling and linking. This
170 option is required in order to produce stack backtraces when the
171 program terminates on an uncaught exception (see ocamlrun(1)).
172 -i Cause the compiler to print all defined names (with their
174 inferred types or their definitions) when compiling an implemen‐
175 tation (.ml file). No compiled files (.cmo and .cmi files) are
176 produced. This can be useful to check the types inferred by the
177 compiler. Also, since the output follows the syntax of inter‐
178 faces, it can help in writing an explicit interface (.mli file)
179 for a file: just redirect the standard output of the compiler to
180 a .mli file, and edit that file to remove all declarations of
181 unexported names.
182 -I directory
184 Add the given directory to the list of directories searched for
185 compiled interface files (.cmi), compiled object code files
186 (.cmx), and libraries (.cmxa). By default, the current directory
187 is searched first, then the standard library directory. Directo‐
188 ries added with -I are searched after the current directory, in
189 the order in which they were given on the command line, but
190 before the standard library directory. See also option -nost‐
191 dlib.
192 If the given directory starts with +, it is taken relative to
194 the standard library directory. For instance, -I +compiler-libs
195 adds the subdirectory compiler-libs of the standard library to
196 the search path.
197 -impl filename
199 Compile the file filename as an implementation file, even if its
200 extension is not .ml.
201 -inline n
203 Set aggressiveness of inlining to n, where n is a positive inte‐
204 ger. Specifying -inline 0 prevents all functions from being
205 inlined, except those whose body is smaller than the call site.
206 Thus, inlining causes no expansion in code size. The default
207 aggressiveness, -inline 1, allows slightly larger functions to
208 be inlined, resulting in a slight expansion in code size. Higher
209 values for the -inline option cause larger and larger functions
210 to become candidate for inlining, but can result in a serious
211 increase in code size.
212 -intf filename
214 Compile the file filename as an interface file, even if its
215 extension is not .mli.
216 -intf-suffix string
218 Recognize file names ending with string as interface files
219 (instead of the default .mli).
220 -keep-locs
222 Keep documentation strings in generated .cmi files.
223 -keep-locs
225 Keep locations in generated .cmi files.
226 -labels
228 Labels are not ignored in types, labels may be used in applica‐
229 tions, and labelled parameters can be given in any order. This
230 is the default.
231 -linkall
233 Force all modules contained in libraries to be linked in. If
234 this flag is not given, unreferenced modules are not linked in.
235 When building a library (-a flag), setting the -linkall flag
236 forces all subsequent links of programs involving that library
237 to link all the modules contained in the library. When compil‐
238 ing a module (option -c), setting the -linkall option ensures
239 that this module will always be linked if it is put in a library
240 and this library is linked.
241 -no-alias-deps
243 Do not record dependencies for module aliases.
244 -no-app-funct
246 Deactivates the applicative behaviour of functors. With this
247 option, each functor application generates new types in its
248 result and applying the same functor twice to the same argument
249 yields two incompatible structures.
250 -noassert
252 Do not compile assertion checks. Note that the special form
253 assert false is always compiled because it is typed specially.
254 This flag has no effect when linking already-compiled files.
255 -noautolink
257 When linking .cmxa libraries, ignore -cclib and -ccopt options
258 potentially contained in the libraries (if these options were
259 given when building the libraries). This can be useful if a
260 library contains incorrect specifications of C libraries or C
261 options; in this case, during linking, set -noautolink and pass
262 the correct C libraries and options on the command line.
263 -nodynlink
265 Allow the compiler to use some optimizations that are valid only
266 for code that is never dynlinked.
267 -nostdlib
269 Do not automatically add the standard library directory the list
270 of directories searched for compiled interface files (.cmi),
271 compiled object code files (.cmx), and libraries (.cmxa). See
272 also option -I.
273 -nolabels
275 Ignore non-optional labels in types. Labels cannot be used in
276 applications, and parameter order becomes strict.
277 -o exec-file
279 Specify the name of the output file produced by the linker. The
280 default output name is a.out, in keeping with the Unix tradi‐
281 tion. If the -a option is given, specify the name of the library
282 produced. If the -pack option is given, specify the name of the
283 packed object file produced. If the -output-obj option is
284 given, specify the name of the output file produced. If the
285 -shared option is given, specify the name of plugin file pro‐
286 duced. This can also be used when compiling an interface or
287 implementation file, without linking, in which case it sets the
288 name of the cmi or cmo file, and also sets the module name to
289 the file name up to the first dot.
290 -opaque
292 When compiling a .mli interface file, this has the same effect
293 as the -opaque option of the bytecode compiler. When compiling a
294 .ml implementation file, this produces a .cmx file without
295 cross-module optimization information, which reduces recompila‐
296 tion on module change.
297 -open module
299 Opens the given module before processing the interface or imple‐
300 mentation files. If several -open options are given, they are
301 processed in order, just as if the statements open! module1;;
302 ... open! moduleN;; were added at the top of each file.
303 -output-obj
305 Cause the linker to produce a C object file instead of an exe‐
306 cutable file. This is useful to wrap OCaml code as a C library,
307 callable from any C program. The name of the output object file
308 must be set with the -o option. This option can also be used to
309 produce a compiled shared/dynamic library (.so extension).
310 -p Generate extra code to write profile information when the pro‐
312 gram is executed. The profile information can then be examined
313 with the analysis program gprof(1). The -p option must be given
314 both at compile-time and at link-time. Linking object files not
315 compiled with -p is possible, but results in less precise pro‐
316 filing.
317 See the gprof(1) man page for more information about the pro‐
319 files.
320 Full support for gprof(1) is only available for certain plat‐
322 forms (currently: Intel x86/Linux and Alpha/Digital Unix). On
323 other platforms, the -p option will result in a less precise
324 profile (no call graph information, only a time profile).
325 -pack Build an object file (.cmx and .o files) and its associated com‐
327 piled interface (.cmi) that combines the .cmx object files given
328 on the command line, making them appear as sub-modules of the
329 output .cmx file. The name of the output .cmx file must be
330 given with the -o option. For instance, ocam‐
331 lopt -pack -o P.cmx A.cmx B.cmx C.cmx generates compiled files
332 P.cmx, P.o and P.cmi describing a compilation unit having three
333 sub-modules A, B and C, corresponding to the contents of the
334 object files A.cmx, B.cmx and C.cmx. These contents can be ref‐
335 erenced as P.A, P.B and P.C in the remainder of the program.
336 The .cmx object files being combined must have been compiled
338 with the appropriate -for-pack option. In the example above,
339 A.cmx, B.cmx and C.cmx must have been compiled with ocam‐
340 lopt -for-pack P.
341 Multiple levels of packing can be achieved by combining -pack
343 with -for-pack. See The OCaml user's manual, chapter "Native-
344 code compilation" for more details.
345 -plugin plugin
347 Dynamically load the code of the given plugin (a .cmo, .cma or
348 .cmxs file) in the compiler. The plugin must exist in the same
349 kind of code as the compiler (ocamlopt.byte must load bytecode
350 plugins, while ocamlopt.opt must load native code plugins), and
351 extension adaptation is done automatically for .cma files (to
352 .cmxs files if the compiler is compiled in native code).
353 -pp command
355 Cause the compiler to call the given command as a preprocessor
356 for each source file. The output of command is redirected to an
357 intermediate file, which is compiled. If there are no compila‐
358 tion errors, the intermediate file is deleted afterwards.
359 -ppx command
361 After parsing, pipe the abstract syntax tree through the pre‐
362 processor command. The module Ast_mapper(3) implements the
363 external interface of a preprocessor.
364 -principal
366 Check information path during type-checking, to make sure that
367 all types are derived in a principal way. All programs accepted
368 in -principal mode are also accepted in default mode with equiv‐
369 alent types, but different binary signatures.
370 -rectypes
372 Allow arbitrary recursive types during type-checking. By
373 default, only recursive types where the recursion goes through
374 an object type are supported. Note that once you have created an
375 interface using this flag, you must use it again for all depen‐
376 dencies.
377 -runtime-variant suffix
379 Add suffix to the name of the runtime library that will be used
380 by the program. If OCaml was configured with option
381 -with-debug-runtime, then the d suffix is supported and gives a
382 debug version of the runtime.
383 -S Keep the assembly code produced during the compilation. The
385 assembly code for the source file x.ml is saved in the file x.s.
386 -safe-string
388 Enforce the separation between types string and bytes, thereby
389 making strings read-only. This will become the default in a
390 future version of OCaml.
391 -shared
393 Build a plugin (usually .cmxs) that can be dynamically loaded
394 with the Dynlink module. The name of the plugin must be set with
395 the -o option. A plugin can include a number of OCaml modules
396 and libraries, and extra native objects (.o, .a files). Build‐
397 ing native plugins is only supported for some operating system.
398 Under some systems (currently, only Linux AMD 64), all the OCaml
399 code linked in a plugin must have been compiled without the
400 -nodynlink flag. Some constraints might also apply to the way
401 the extra native objects have been compiled (under Linux AMD 64,
402 they must contain only position-independent code).
403 -short-paths
405 When a type is visible under several module-paths, use the
406 shortest one when printing the type's name in inferred inter‐
407 faces and error and warning messages.
408 -strict-sequence
410 The left-hand part of a sequence must have type unit.
411 -thread
413 Compile or link multithreaded programs, in combination with the
414 system threads library described in The OCaml user's manual.
415 -unboxed-types
417 When a type is unboxable (i.e. a record with a single argument
418 or a concrete datatype with a single constructor of one argu‐
419 ment) it will be unboxed unless annotated with [@@ocaml.boxed].
420 -no-unboxed-types
422 When a type is unboxable it will be boxed unless annotated with
423 [@@ocaml.unboxed]. This is the default.
424 -unsafe
426 Turn bound checking off for array and string accesses (the
427 v.(i)ands.[i] constructs). Programs compiled with -unsafe are
428 therefore faster, but unsafe: anything can happen if the program
429 accesses an array or string outside of its bounds. Additionally,
430 turn off the check for zero divisor in integer division and mod‐
431 ulus operations. With -unsafe, an integer division (or modulus)
432 by zero can halt the program or continue with an unspecified
433 result instead of raising a Division_by_zero exception.
434 -unsafe-string
436 Identify the types string and bytes, thereby making strings
437 writable. For reasons of backward compatibility, this is the
438 default setting for the moment, but this will change in a future
439 version of OCaml.
440 -v Print the version number of the compiler and the location of the
442 standard library directory, then exit.
443 -verbose
445 Print all external commands before they are executed, in partic‐
446 ular invocations of the assembler, C compiler, and linker.
447 -version or -vnum
449 Print the version number of the compiler in short form (e.g.
450 "3.11.0"), then exit.
451 -w warning-list
453 Enable, disable, or mark as fatal the warnings specified by the
454 argument warning-list. See ocamlc(1) for the syntax of warning-
455 list.
456 -warn-error warning-list
458 Mark as fatal the warnings specified in the argument warn‐
459 ing-list. The compiler will stop with an error when one of
460 these warnings is emitted. The warning-list has the same mean‐
461 ing as for the -w option: a + sign (or an uppercase letter)
462 marks the corresponding warnings as fatal, a - sign (or a lower‐
463 case letter) turns them back into non-fatal warnings, and a @
464 sign both enables and marks as fatal the corresponding warnings.
465 Note: it is not recommended to use the -warn-error option in
467 production code, because it will almost certainly prevent com‐
468 piling your program with later versions of OCaml when they add
469 new warnings or modify existing warnings.
470 The default setting is -warn-error -a+31 (only warning 31 is
472 fatal).
473 -warn-help
475 Show the description of all available warning numbers.
476 -where Print the location of the standard library, then exit.
478 - file Process file as a file name, even if it starts with a dash (-)
480 character.
481 -help or --help
483 Display a short usage summary and exit.
484
487 The IA32 code generator (Intel Pentium, AMD Athlon) supports the fol‐
488 lowing additional option:
489 -ffast-math
491 Use the IA32 instructions to compute trigonometric and exponen‐
492 tial functions, instead of calling the corresponding library
493 routines. The functions affected are: atan, atan2, cos, log,
494 log10, sin, sqrt and tan. The resulting code runs faster, but
495 the range of supported arguments and the precision of the result
496 can be reduced. In particular, trigonometric operations cos,
497 sin, tan have their range reduced to [-2^64, 2^64].
498
501 The AMD64 code generator (64-bit versions of Intel Pentium and AMD
502 Athlon) supports the following additional options:
503 -fPIC Generate position-independent machine code. This is the
505 default.
506 -fno-PIC
508 Generate position-dependent machine code.
509
512 The Sparc code generator supports the following additional options:
513 -march=v8
515 Generate SPARC version 8 code.
516 -march=v9
518 Generate SPARC version 9 code.
519 The default is to generate code for SPARC version 7, which runs on all
521 SPARC processors.
522
525 The ARM code generator supports the following additional options:
526 -farch=armv4|armv5|armv5te|armv6|armv6t2|armv7
528 Select the ARM target architecture
529 -ffpu=soft|vfpv2|vfpv3-d16|vfpv3
531 Select the floating-point hardware
532 -fPIC Generate position-independent machine code.
534 -fno-PIC
536 Generate position-dependent machine code. This is the default.
537 -fthumb
539 Enable Thumb/Thumb-2 code generation
540 -fno-thumb
542 Disable Thumb/Thumb-2 code generation
543 The default values for target architecture, floating-point hardware and
545 thumb usage were selected at configure-time when building ocamlopt
546 itself. This configuration can be inspected using ocamlopt -config.
547 Target architecture depends on the "model" setting, while floating-
548 point hardware and thumb support are determined from the ABI setting in
549 "system" ( linux_eabiorlinux_eabihf).
550
553 ocamlc(1).
554 The OCaml user's manual, chapter "Native-code compilation".
555 OCAMLOPT(1)