\[\begin{split}\newcommand{\as}{\kw{as}} \newcommand{\case}{\kw{case}} \newcommand{\cons}{\textsf{cons}} \newcommand{\consf}{\textsf{consf}} \newcommand{\emptyf}{\textsf{emptyf}} \newcommand{\End}{\kw{End}} \newcommand{\kwend}{\kw{end}} \newcommand{\even}{\textsf{even}} \newcommand{\evenO}{\textsf{even}_\textsf{O}} \newcommand{\evenS}{\textsf{even}_\textsf{S}} \newcommand{\Fix}{\kw{Fix}} \newcommand{\fix}{\kw{fix}} \newcommand{\for}{\textsf{for}} \newcommand{\forest}{\textsf{forest}} \newcommand{\Functor}{\kw{Functor}} \newcommand{\In}{\kw{in}} \newcommand{\ind}[3]{\kw{Ind}~[#1]\left(#2\mathrm{~:=~}#3\right)} \newcommand{\Indp}[4]{\kw{Ind}_{#4}[#1](#2:=#3)} \newcommand{\Indpstr}[5]{\kw{Ind}_{#4}[#1](#2:=#3)/{#5}} \newcommand{\injective}{\kw{injective}} \newcommand{\kw}[1]{\textsf{#1}} \newcommand{\length}{\textsf{length}} \newcommand{\letin}[3]{\kw{let}~#1:=#2~\kw{in}~#3} \newcommand{\List}{\textsf{list}} \newcommand{\lra}{\longrightarrow} \newcommand{\Match}{\kw{match}} \newcommand{\Mod}[3]{{\kw{Mod}}({#1}:{#2}\,\zeroone{:={#3}})} \newcommand{\ModImp}[3]{{\kw{Mod}}({#1}:{#2}:={#3})} \newcommand{\ModA}[2]{{\kw{ModA}}({#1}=={#2})} \newcommand{\ModS}[2]{{\kw{Mod}}({#1}:{#2})} \newcommand{\ModType}[2]{{\kw{ModType}}({#1}:={#2})} \newcommand{\mto}{.\;} \newcommand{\nat}{\textsf{nat}} \newcommand{\Nil}{\textsf{nil}} \newcommand{\nilhl}{\textsf{nil\_hl}} \newcommand{\nO}{\textsf{O}} \newcommand{\node}{\textsf{node}} \newcommand{\nS}{\textsf{S}} \newcommand{\odd}{\textsf{odd}} \newcommand{\oddS}{\textsf{odd}_\textsf{S}} \newcommand{\ovl}[1]{\overline{#1}} \newcommand{\Pair}{\textsf{pair}} \newcommand{\plus}{\mathsf{plus}} \newcommand{\SProp}{\textsf{SProp}} \newcommand{\Prop}{\textsf{Prop}} \newcommand{\return}{\kw{return}} \newcommand{\Set}{\textsf{Set}} \newcommand{\Sort}{\mathcal{S}} \newcommand{\Str}{\textsf{Stream}} \newcommand{\Struct}{\kw{Struct}} \newcommand{\subst}[3]{#1\{#2/#3\}} \newcommand{\tl}{\textsf{tl}} \newcommand{\tree}{\textsf{tree}} \newcommand{\trii}{\triangleright_\iota} \newcommand{\Type}{\textsf{Type}} \newcommand{\WEV}[3]{\mbox{$#1[] \vdash #2 \lra #3$}} \newcommand{\WEVT}[3]{\mbox{$#1[] \vdash #2 \lra$}\\ \mbox{$ #3$}} \newcommand{\WF}[2]{{\mathcal{W\!F}}(#1)[#2]} \newcommand{\WFE}[1]{\WF{E}{#1}} \newcommand{\WFT}[2]{#1[] \vdash {\mathcal{W\!F}}(#2)} \newcommand{\WFTWOLINES}[2]{{\mathcal{W\!F}}\begin{array}{l}(#1)\\\mbox{}[{#2}]\end{array}} \newcommand{\with}{\kw{with}} \newcommand{\WS}[3]{#1[] \vdash #2 <: #3} \newcommand{\WSE}[2]{\WS{E}{#1}{#2}} \newcommand{\WT}[4]{#1[#2] \vdash #3 : #4} \newcommand{\WTE}[3]{\WT{E}{#1}{#2}{#3}} \newcommand{\WTEG}[2]{\WTE{\Gamma}{#1}{#2}} \newcommand{\WTM}[3]{\WT{#1}{}{#2}{#3}} \newcommand{\zeroone}[1]{[{#1}]} \end{split}\]

Utilities

The distribution provides utilities to simplify some tedious works beside proof development, tactics writing or documentation.

Using Coq as a library

In previous versions, coqmktop was used to build custom toplevels - for example for better debugging or custom static linking. Nowadays, the preferred method is to use ocamlfind.

The most basic custom toplevel is built using:

% ocamlfind ocamlopt -thread -rectypes -linkall -linkpkg \
              -package coq.toplevel \
              topbin/coqtop_bin.ml -o my_toplevel.native

For example, to statically link Ltac, you can just do:

% ocamlfind ocamlopt -thread -rectypes -linkall -linkpkg \
              -package coq.toplevel,coq.plugins.ltac \
              topbin/coqtop_bin.ml -o my_toplevel.native

and similarly for other plugins.

Building a Coq project

As of today it is possible to build Coq projects using two tools:

  • coq_makefile, which is distributed by Coq and is based on generating a makefile,

  • Dune, the standard OCaml build tool, which, since version 1.9, supports building Coq libraries.

Building a Coq project with coq_makefile

The majority of Coq projects are very similar: a collection of .v files and eventually some .ml ones (a Coq plugin). The main piece of metadata needed in order to build the project are the command line options to coqc (e.g. -R, -Q, -I, see command line options). Collecting the list of files and options is the job of the _CoqProject file.

A _CoqProject file may contain the following kinds of entries in any order, separated by whitespace:

  • Selected options of coqc, which are forwarded directly to it. Currently these are -Q, -I, -R and -native-compiler.

  • -arg options for other options of coqc that don’t fall in the above set.

  • Options specific to coq_makefile. Currently there are two options: -generate-meta-for-package (see below for details), and -docroot.

  • Directory names, which include all appropriate files in the directory and its subdirectories.

  • Comments, started with an unquoted # and continuing to the end of the line.

A simple example of a _CoqProject file follows:

-R theories/ MyCode
-arg "-w all"
theories/foo.v
theories/bar.v
-I src/
src/baz.mlg
src/bazaux.ml
src/qux_plugin.mlpack
-generate-meta-for-package my-package

Lines in the form -arg foo pass the argument foo to coqc: in the example, this allows to pass the two-word option -w all (see command line options).

Note that it is mandatory to specify a -R/-Q flag for your project, so its modules are properly qualified. Omitting it will generate object files that are not usable except for expert cases.

Also note that when a project includes a plugin it also needs to include a META file, as per findlib. If the project has only a single plugin, the META file can be generated automatically when the option -generate-meta-for-package my-package is given. The generated file makes the plugin available to the Declare ML Module as my-package.plugin. If the generated file doesn't suit your needs (for instance because it depends on some OCaml packages) or your project has multiple plugins, then create a file named META.my-package and list it in the _CoqProject file. You can use ocamlfind lint META.my-package to lint the hand written file. Typically my-package is the name of the OPAM package for your project (which conventionally starts with coq-). If the project includes a .mlg file (to be pre-processed by coqpp) that declares a plugin, then the given name must match the findlib plugin name, e.g. DECLARE PLUGIN "my-package.plugin".

The -native-compiler option given in the _CoqProject file will override the global one passed at configure time.

CoqIDE, Proof General, VsCoq and Coqtail all understand _CoqProject files and can be used to invoke Coq with the desired options.

The coq_makefile utility can be used to set up a build infrastructure for the Coq project based on makefiles. The recommended way of invoking coq_makefile is the following one:

coq_makefile -f _CoqProject -o CoqMakefile

Such command generates the following files:

CoqMakefile

is a makefile for GNU Make with targets to build the project (e.g. generate .vo or .html files from .v or compile .ml* files) and install it in the user-contrib directory where the Coq library is installed.

CoqMakefile.conf

contains make variables assignments that reflect the contents of the _CoqProject file as well as the path relevant to Coq.

Run coq_makefile --help for a description of command line options.

The recommended approach is to invoke CoqMakefile from a standard Makefile of the following form:

Example

# KNOWNTARGETS will not be passed along to CoqMakefile
KNOWNTARGETS := CoqMakefile extra-stuff extra-stuff2
# KNOWNFILES will not get implicit targets from the final rule, and so
# depending on them won't invoke the submake
# Warning: These files get declared as PHONY, so any targets depending
# on them always get rebuilt
KNOWNFILES   := Makefile _CoqProject

.DEFAULT_GOAL := invoke-coqmakefile

CoqMakefile: Makefile _CoqProject
        $(COQBIN)coq_makefile -f _CoqProject -o CoqMakefile

invoke-coqmakefile: CoqMakefile
        $(MAKE) --no-print-directory -f CoqMakefile $(filter-out $(KNOWNTARGETS),$(MAKECMDGOALS))

.PHONY: invoke-coqmakefile $(KNOWNFILES)

####################################################################
##                      Your targets here                         ##
####################################################################

# This should be the last rule, to handle any targets not declared above
%: invoke-coqmakefile
        @true

The advantage of a wrapper, compared to directly calling the generated Makefile, is that it provides a target independent of the version of Coq to regenerate a Makefile specific to the current version of Coq. Additionally, the master Makefile can be extended with targets not specific to Coq. Including the generated makefile with an include directive is discouraged, since the contents of this file, including variable names and status of rules, may change in the future.

Use the optional file CoqMakefile.local to extend CoqMakefile. In particular, you can declare custom actions to run before or after the build process. Similarly you can customize the install target or even provide new targets. See CoqMakefile.local for extension-point documentation. Although you can use all variables defined in CoqMakefile in the recipes of rules that you write and in the definitions of any variables that you assign with =, many variables are not available for use if you assign variable values with := nor to define the targets of rules nor in top-level conditionals such as ifeq. Additionally, you must use secondary expansion to make use of such variables in the prerequisites of rules. To access variables defined in CoqMakefile in rule target computation, top-level conditionals, and := variable assignment, for example to add new dependencies to compiled outputs, use the optional file CoqMakefile.local-late. See CoqMakefile.local-late for a non-exhaustive list of variables.

The extensions of files listed in _CoqProject determine how they are built. In particular:

  • Coq files must use the .v extension

  • OCaml files must use the .ml or .mli extension

  • OCaml files that require pre processing for syntax extensions (like VERNAC EXTEND) must use the .mlg extension

  • In order to generate a plugin one has to list all OCaml modules (i.e. Baz for baz.ml) in a .mlpack file (or .mllib file).

The use of .mlpack files has to be preferred over .mllib files, since it results in a “packed” plugin: All auxiliary modules (as Baz and Bazaux) are hidden inside the plugin’s "namespace" (Qux_plugin). This reduces the chances of begin unable to load two distinct plugins because of a clash in their auxiliary module names.

Comments

# outside of double quotes starts a comment that continues to the end of the line. Comments are ignored.

Quoting arguments to coqc

Any string in a _CoqProject file may be enclosed in double quotes to include whitespace characters or #. For example, use -arg "-w all" to pass the argument -w all to coqc. If the argument to coqc needs some quotes as well, use single-quotes inside the double-quotes. For example -arg "-set 'Default Goal Selector=!'" gets passed to coqc as -set 'Default Goal Selector=!'.

But note, that single-quotes in a _CoqProject file are only special characters if they appear in the string following -arg. And on their own they don't quote spaces. For example -arg 'foo bar' in _CoqProject is equivalent to -arg foo "bar'" (in _CoqProject notation). -arg "'foo bar'" behaves differently and passes 'foo bar' to coqc.

Forbidden filenames

The paths of files given in a _CoqProject file may not contain any of the following characters: \n, \t, space, \, ', ", #, $, %. These characters have special meaning in Makefiles and coq_makefile doesn't support encoding them correctly.

Warning: No common logical root

When a _CoqProject file contains something like -R theories Foo theories/Bar.v, the install-doc target installs the documentation generated by coqdoc into user-contrib/Foo/, in the folder where Coq was installed.

But if the _CoqProject file contains something like:

-R theories/Foo Foo
-R theories/Bar Bar
theories/Foo/Foo.v
theories/Bar/Bar.v

the Coq files of the project don’t have a logical path in common and coq_makefile doesn’t know where to install the documentation. It will give a warning: "No common logical root" and generate a Makefile that installs the documentation in some folder beginning with "orphan", in the above example, it'd be user-contrib/orphan_Foo_Bar.

In this case, specify the -docroot option in _CoqProject to override the automatically selected logical root.

CoqMakefile.local

The optional file CoqMakefile.local is included by the generated file CoqMakefile. It can contain two kinds of directives.

Variable assignment

The variable must belong to the variables listed in the Parameters section of the generated makefile. These include:

CAMLPKGS

can be used to specify third party findlib packages, and is passed to the OCaml compiler on building or linking of modules. Eg: -package yojson.

CAMLFLAGS

can be used to specify additional flags to the OCaml compiler, like -bin-annot or -w....

OCAMLWARN

it contains a default of -warn-error +a-3, useful to modify this setting; beware this is not recommended for projects in Coq's CI.

COQC, COQDEP, COQDOC

can be set in order to use alternative binaries (e.g. wrappers)

COQ_SRC_SUBDIRS

can be extended by including other paths in which *.cm* files are searched. For example COQ_SRC_SUBDIRS+=user-contrib/Unicoq lets you build a plugin containing OCaml code that depends on the OCaml code of Unicoq

COQFLAGS

override the flags passed to coqc. By default -q.

COQEXTRAFLAGS

extend the flags passed to coqc

COQCHKFLAGS

override the flags passed to coqchk. By default -silent -o.

COQCHKEXTRAFLAGS

extend the flags passed to coqchk

COQDOCFLAGS

override the flags passed to coqdoc. By default -interpolate -utf8.

COQDOCEXTRAFLAGS

extend the flags passed to coqdoc

COQLIBINSTALL, COQPLUGININSTALL, COQDOCINSTALL

specify where the Coq libraries, plugins and documentation will be installed. By default a combination of $(DESTDIR) (if defined) with $(COQLIB)/user-contrib, $(COQCORELIB)/.. and $(DOCDIR)/coq/user-contrib.

Use CoqMakefile.local-late instead to access more variables.

Rule extension

The following makefile rules can be extended.

Example

pre-all::
        echo "This line is print before making the all target"
install-extra::
        cp ThisExtraFile /there/it/goes
pre-all::

run before the all target. One can use this to configure the project, or initialize sub modules or check dependencies are met.

post-all::

run after the all target. One can use this to run a test suite, or compile extracted code.

install-extra::

run after install. One can use this to install extra files.

install-doc::

One can use this to install extra doc.

uninstall::

uninstall-doc::

clean::

cleanall::

archclean::

merlin-hook::

One can append lines to the generated .merlin file extending this target.

CoqMakefile.local-late

The optional file CoqMakefile.local-late is included at the end of the generated file CoqMakefile. The following is a partial list of accessible variables:

COQ_VERSION

the version of coqc being used, which can be used to provide different behavior depending on the Coq version

COQMAKEFILE_VERSION

the version of Coq used to generate the Makefile, which can be used to detect version mismatches

ALLDFILES

the list of generated dependency files, which can be used, for example, to cause make to recompute dependencies when files change by writing $(ALLDFILES): myfiles or to indicate that files must be generated before dependencies can be computed by writing $(ALLDFILES): | mygeneratedfiles

VOFILES, GLOBFILES, CMOFILES, CMXFILES, OFILES, CMAFILES, CMXAFILES, CMIFILES, CMXSFILES

lists of files that are generated by various invocations of the compilers

In addition, the following variables may be useful for deciding what targets to present via $(shell ...); these variables are already accessible in recipes for rules added in CoqMakefile.local, but are only accessible from top-level $(shell ...) invocations in CoqMakefile.local-late:

COQC, COQDEP, COQDOC, CAMLC, CAMLOPTC

compiler binaries

COQFLAGS, CAMLFLAGS, COQLIBS, COQDEBUG, OCAMLLIBS

flags passed to the Coq or OCaml compilers

Timing targets and performance testing

The generated Makefile supports the generation of two kinds of timing data: per-file build-times, and per-line times for an individual file.

The following targets and Makefile variables allow collection of per- file timing data:

  • TIMED=1

    passing this variable will cause make to emit a line describing the user-space build-time and peak memory usage for each file built.

    Note

    On Mac OS, this works best if you’ve installed gnu-time.

    Example

    For example, the output of make TIMED=1 may look like this:

    COQDEP Fast.v
COQDEP Slow.v
COQC Slow.v
Slow.vo (user: 0.34 mem: 395448 ko)
COQC Fast.v
Fast.vo (user: 0.01 mem: 45184 ko)
  • pretty-timed

    this target stores the output of make TIMED=1 into time-of-build.log, and displays a table of the times and peak memory usages, sorted from slowest to fastest, which is also stored in time-of-build-pretty.log. If you want to construct the log for targets other than the default one, you can pass them via the variable TGTS, e.g., make pretty-timed TGTS="a.vo b.vo".

    Note

    This target requires python to build the table.

    Note

    This target will append to the timing log; if you want a fresh start, you must remove the file time-of-build.log or run make cleanall.

    Note

    By default the table displays user times. If the build log contains real times (which it does by default), passing TIMING_REAL=1 to make pretty-timed will use real times rather than user times in the table.

    Note

    Passing TIMING_INCLUDE_MEM=0 to make will result in the tables not including peak memory usage information. Passing TIMING_SORT_BY_MEM=1 to make will result in the tables be sorted by peak memory usage rather than by the time taken.

    Example

    For example, the output of make pretty-timed may look like this:

    COQDEP VFILES
COQC Slow.v
Slow.vo (real: 0.52, user: 0.39, sys: 0.12, mem: 394648 ko)
COQC Fast.v
Fast.vo (real: 0.06, user: 0.02, sys: 0.03, mem: 56980 ko)
    Time |  Peak Mem | File Name
--------------------------------------------
0m00.41s | 394648 ko | Total Time / Peak Mem
--------------------------------------------
0m00.39s | 394648 ko | Slow.vo
0m00.02s |  56980 ko | Fast.vo
  • print-pretty-timed-diff

    this target builds a table of timing changes between two compilations; run make make-pretty-timed-before to build the log of the “before” times, and run make make-pretty-timed-after to build the log of the “after” times. The table is printed on the command line, and stored in time-of-build-both.log. This target is most useful for profiling the difference between two commits in a repository.

    Note

    This target requires python to build the table.

    Note

    The make-pretty-timed-before and make-pretty-timed-after targets will append to the timing log; if you want a fresh start, you must remove the files time-of-build-before.log and time-of-build-after.log or run make cleanall before building either the “before” or “after” targets.

    Note

    The table will be sorted first by absolute time differences rounded towards zero to a whole-number of seconds, then by times in the “after” column, and finally lexicographically by file name. This will put the biggest changes in either direction first, and will prefer sorting by build-time over subsecond changes in build time (which are frequently noise); lexicographic sorting forces an order on files which take effectively no time to compile.

    If you prefer a different sorting order, you can pass TIMING_SORT_BY=absolute to sort by the total time taken, or TIMING_SORT_BY=diff to sort by the signed difference in time.

    Note

    Just like pretty-timed, this table defaults to using user times. Pass TIMING_REAL=1 to make on the command line to show real times instead.

    Note

    Just like pretty-timed, passing TIMING_INCLUDE_MEM=0 to make will result in the tables not including peak memory usage information. Passing TIMING_SORT_BY_MEM=1 to make will result in the tables be sorted by peak memory usage rather than by the time taken.

    Example

    For example, the output table from make print-pretty-timed-diff may look like this:

       After |  Peak Mem | File Name             |   Before |  Peak Mem ||    Change || Change (mem) |  % Change | % Change (mem)
-----------------------------------------------------------------------------------------------------------------------------
0m00.43s | 394700 ko | Total Time / Peak Mem | 0m00.41s | 394648 ko || +0m00.01s ||        52 ko |    +4.87% |         +0.01%
-----------------------------------------------------------------------------------------------------------------------------
0m00.39s | 394700 ko | Fast.vo               | 0m00.02s |  56980 ko || +0m00.37s ||    337720 ko | +1850.00% |       +592.69%
0m00.04s |  56772 ko | Slow.vo               | 0m00.39s | 394648 ko || -0m00.35s ||   -337876 ko |   -89.74% |        -85.61%

The following targets and Makefile variables allow collection of per- line timing data:

  • TIMING=1

    passing this variable will cause make to use coqc -time to write to a .v.timing file for each .v file compiled, which contains line-by-line timing information.

    Example

    For example, running make all TIMING=1 may result in a file like this:

    Chars 0 - 26 [Require~Coq.ZArith.BinInt.] 0.157 secs (0.128u,0.028s)
Chars 27 - 68 [Declare~Reduction~comp~:=~vm_c...] 0. secs (0.u,0.s)
Chars 69 - 162 [Definition~foo0~:=~Eval~comp~i...] 0.153 secs (0.136u,0.019s)
Chars 163 - 208 [Definition~foo1~:=~Eval~comp~i...] 0.239 secs (0.236u,0.s)
  • print-pretty-single-time-diff
    print-pretty-single-time-diff AFTER=path/to/file.v.after-timing BEFORE=path/to/file.v.before-timing

    this target will make a sorted table of the per-line timing differences between the timing logs in the BEFORE and AFTER files, display it, and save it to the file specified by the TIME_OF_PRETTY_BUILD_FILE variable, which defaults to time-of-build-pretty.log. To generate the .v.before-timing or .v.after-timing files, you should pass TIMING=before or TIMING=after rather than TIMING=1.

    Note

    The sorting used here is the same as in the print-pretty-timed-diff target.

    Note

    This target requires python to build the table.

    Note

    This target follows the same sorting order as the print-pretty-timed-diff target, and supports the same options for the TIMING_SORT_BY variable.

    Note

    By default, two lines are only considered the same if the character offsets and initial code strings are identical. Passing TIMING_FUZZ=N relaxes this constraint by allowing the character locations to differ by up to N, as long as the total number of characters and initial code strings continue to match. This is useful when there are small changes to a file, and you want to match later lines that have not changed even though the character offsets have changed.

    Note

    By default the table picks up real times, under the assumption that when comparing line-by-line, the real time is a more accurate representation as it includes disk time and time spent in the native compiler. Passing TIMING_REAL=0 to make will use user times rather than real times in the table.

    Example

    For example, running print-pretty-single-time-diff might give a table like this:

    After     | Code                                                | Before    || Change    | % Change
---------------------------------------------------------------------------------------------------
0m00.50s  | Total                                               | 0m04.17s  || -0m03.66s | -87.96%
---------------------------------------------------------------------------------------------------
0m00.145s | Chars 069 - 162 [Definition~foo0~:=~Eval~comp~i...] | 0m00.192s || -0m00.04s | -24.47%
0m00.126s | Chars 000 - 026 [Require~Coq.ZArith.BinInt.]        | 0m00.143s || -0m00.01s | -11.88%
   N/A    | Chars 027 - 068 [Declare~Reduction~comp~:=~nati...] | 0m00.s    || +0m00.00s | N/A
0m00.s    | Chars 027 - 068 [Declare~Reduction~comp~:=~vm_c...] |    N/A    || +0m00.00s | N/A
0m00.231s | Chars 163 - 208 [Definition~foo1~:=~Eval~comp~i...] | 0m03.836s || -0m03.60s | -93.97%
  • all.timing.diff, path/to/file.v.timing.diff

    The path/to/file.v.timing.diff target will make a .v.timing.diff file for the corresponding .v file, with a table as would be generated by the print-pretty-single-time-diff target; it depends on having already made the corresponding .v.before-timing and .v.after-timing files, which can be made by passing TIMING=before and TIMING=after. The all.timing.diff target will make such timing difference files for all of the .v files that the Makefile knows about. It will fail if some .v.before-timing or .v.after-timing files don’t exist.

    Note

    This target requires python to build the table.

Building a subset of the targets with -j

To build, say, two targets foo.vo and bar.vo in parallel one can use make only TGTS="foo.vo bar.vo" -j.

Note

make foo.vo bar.vo -j has a different meaning for the make utility, in particular it may build a shared prerequisite twice.

Precompiling for native_compute

To compile files for native_compute, one can use the -native-compiler yes option of Coq, by putting it in the _CoqProject file.

The generated installation target of CoqMakefile will then take care of installing the extra .coq-native directories.

Note

As an alternative to modifying _CoqProject, one can set an environment variable when calling make:

COQEXTRAFLAGS="-native-compiler yes" make

This can be useful when files cannot be modified, for instance when installing via OPAM a package built with coq_makefile:

COQEXTRAFLAGS="-native-compiler yes" opam install coq-package

Note

This requires all dependencies to be themselves compiled with -native-compiler yes.

The grammar of _CoqProject

A _CoqProject file encodes a list of strings using the following syntax:

CoqProject::=blank​comment​quoted_string​unquoted_string*blank::=space​horizontal_tab​newlinecomment::=# comment_char* newlinequoted_string::=" quoted_char* "unquoted_string::=string_start_char unquoted_char*

where the following definitions apply:

  • space, horizontal_tab and newline stand for the corresponding ASCII characters.

  • comment_char is the set of all characters except newline.

  • quoted_char is the set of all characters except ".

  • string_start_char is the set of all characters except those that match blank, or are " or #.

  • unquoted_char is the set of all characters except those that match blank or are #.

The parser produces a list of strings in the same order as they were encountered in _CoqProject. Blanks and comments are removed and the double quotes of quoted_string tokens are removed as well. The list is then treated as a list of command-line arguments of coq_makefile.

The semantics of -arg are as follows: the string given as argument is split on whitespace, but single quotes prevent splitting. The resulting list of strings is then passed to coqc.

The current approach has a few limitations: Double quotes in a _CoqProject file are only special characters at the start of a string. For lack of an escaping mechanism, it is currently impossible to pass the following kinds of strings to coq_makefile using a _CoqProject file:

  • strings starting with "

  • strings starting with # and containing "

  • strings containing both whitespace and "

In addition, it is impossible to pass strings containing ' to coqc via -arg.

Building a Coq project with Dune

Note

Dune's Coq support is still experimental; we strongly recommend using Dune 3.2 or later.

Note

The canonical documentation for the Coq Dune extension is maintained upstream; please refer to the Dune manual for up-to-date information. The documentation below is up to date for Dune 3.2

Building a Coq project with Dune requires setting up a Dune project for your files. This involves adding a dune-project and pkg.opam file to the root (pkg.opam can be empty or generated by Dune itself), and then providing dune files in the directories your .v files are placed. For the experimental version "0.3" of the Coq Dune language, Coq library stanzas look like:

(coq.theory
 (name <module_prefix>)
 (package <opam_package>)
 (synopsis <text>)
 (modules <ordered_set_lang>)
 (libraries <ocaml_libraries>)
 (flags <coq_flags>))

This stanza will build all .v files in the given directory, wrapping the library under <module_prefix>. If you declare an <opam_package>, an .install file for the library will be generated; the optional (modules <ordered_set_lang>) field allows you to filter the list of modules, and (libraries <ocaml_libraries>) allows the Coq theory depend on ML plugins. For the moment, Dune relies on Coq's standard mechanisms (such as COQPATH) to locate installed Coq libraries.

By default Dune will skip .v files present in subdirectories. In order to enable the usual recursive organization of Coq projects add

(include_subdirs qualified)

to you dune file.

Once your project is set up, dune build will generate the pkg.install files and all the files necessary for the installation of your project.

Note that projects using Dune to build need to use the compatibility syntax for Declare ML Module, see example below:

Example

A typical stanza for a Coq plugin is split into two parts. An OCaml build directive, which is standard Dune:

(library
 (name equations_plugin)
 (public_name equations.plugin)
 (flags :standard -warn-error -3-9-27-32-33-50)
 (libraries coq.plugins.cc coq.plugins.extraction))

(coq.pp (modules g_equations))

And a Coq-specific part that depends on it via the libraries field:

(coq.theory
 (name Equations) ; -R flag
 (package equations)
 (synopsis "Equations Plugin")
 (libraries coq.plugins.extraction equations.plugin)
 (modules :standard \ IdDec NoCycle)) ; exclude some modules that don't build

(include_subdirs qualified)

For now, each .v file that loads the plugin must use the following special syntax on its Declare ML Module command for compatibility with current Dune versions (as of Coq 8.16):

Declare ML Module "equations_plugin:equations.plugin".

Computing Module dependencies

In order to compute module dependencies (to be used by make or dune), Coq provides the coqdep tool.

coqdep computes inter-module dependencies for Coq programs, and prints the dependencies on the standard output in a format readable by make. When a directory is given as argument, it is recursively looked at.

Dependencies of Coq modules are computed by looking at Require and Declare ML Module commands.

See the man page of coqdep for more details and options.

Both Dune and coq_makefile use coqdep to compute the dependencies among the files part of a Coq project.

Split compilation of native computation files

Coq features a native_compute tactic to provide fast computation in the kernel. This process performs compilation of Coq terms to OCaml programs using the OCaml compiler, which may cause an important overhead. Hence native compilation is an opt-in configure flag.

When native compilation is activated, Coq generates the compiled files upfront, i.e. during the coqc invocation on the corresponding .v file. This is impractical because it means one must chose in advance whether they will use a native-capable Coq installation. In particular, activating native compilation forces the recompilation of the whole Coq installation. See command line options for more details.

Starting from Coq 8.14, a new binary coqnative is available. It allows performing split native compilation by generating the native compute files out of the compiled .vo file rather than out of the source .v file.

The coqnative command takes a name file.vo as argument and tries to perform native compilation on it. It assumes that the Coq libraries on which file.vo depends have been first compiled to their native files, and will fail otherwise. It accepts the -R, -Q, -I and -nI arguments with the same semantics as if the native compilation process had been performed through coqc. In particular, it means that:

  • -R and -Q are equivalent

  • -I is a no-op that is accepted only for scripting convenience

Embedded Coq phrases inside LaTeX documents

When writing documentation about a proof development, one may want to insert Coq phrases inside a LaTeX document, possibly together with the corresponding answers of the system. We provide a mechanical way to process such Coq phrases embedded in LaTeX files: the coq-tex filter. This filter extracts Coq phrases embedded in LaTeX files, evaluates them, and insert the outcome of the evaluation after each phrase.

Starting with a file file.tex containing Coq phrases, the coq-tex filter produces a file named file.v.tex with the Coq outcome.

There are options to produce the Coq parts in smaller font, italic, between horizontal rules, etc. See the man page of coq-tex for more details.

Man pages

There are man pages for the commands coqdep and coq-tex. Man pages are installed at installation time (see installation instructions in file INSTALL, step 6).