OCaml Rules Last updated June 2, 2022

required

data

Runtime dependencies: list of labels of data files needed by this executable at runtime.

optional

[]

cc_deps

Dictionary specifying C/C++ library dependencies. Key: a target label; value: a linkmode string, which determines which file to link. Valid linkmodes: 'default', 'static', 'dynamic', 'shared' (synonym for 'dynamic'). For more information see [CC Dependencies: Linkmode](../ug/cc_deps.md#linkmode).

optional

{}

cc_linkall

True: use -whole-archive (GCC toolchain) or -force_load (Clang toolchain). Deps in this attribute must also be listed in cc_deps.

optional

[]

cc_linkopts

List of C/C link options. E.g. ["-lstd"].

List of strings

optional

[]

data_prefix_map

Map for replacing path prefixes of data files

optional

{}

env

Env variables

optional

{}

epilogue

List of OCaml dependencies.

optional

[]

exe

By default, executable name is derived from 'name' attribute; use this to override.

String

optional

""

main

Label of module containing entry point of executable. In the list of dependencies, this will be placed after 'prologue' deps and before 'epilogue' deps.

required

opts

List of compile options; overrides configurable default options. Supports -no- prefix for each option; for example, -no-linkall.

List of strings

optional

[]

prologue

List of OCaml dependencies.

optional

[]

vm_runtime

@rules_ocaml//cfg/runtime:dynamic (default), @rules_ocaml//cfg/runtime:static, or a custom ocaml_vm_runtime target label

optional

"@rules_ocaml//cfg/runtime:dynamic"

ocaml_exec_module

ocaml_exec_module(name, deps, data, cc_deps, cc_linkage, deps_runtime, env, module_name, ns_resolver, open, opts, pack, ppx, ppx_args, ppx_data, ppx_print, ppx_verbose, sig, struct)

See documentation for ocaml_module.

ATTRIBUTES for rule ocaml_exec_module:

Name Description Type Mandatory Default

Name	Description	Type	Mandatory	Default
name	A unique name for this target.	Name	required
deps	List of dependencies.	List of labels	optional	[]
data	Runtime data dependencies: list of labels of data files needed by this module at runtime. This is a standard Bazel attribute; see Typical attributes.	List of labels	optional	[]
cc_deps	Static (.a) or dynamic (.so, .dylib) libraries. Must by built or imported using Bazel’s rules_cc ruleset (thus providing CcInfo output).	List of labels	optional	[]
cc_linkage	Dictionary specifying C/C++ library dependencies. Allows finer control over linking than the 'cc_deps' attribute. Key: a target label providing CcInfo; value: a linkmode string, which determines which file to link. Valid linkmodes: 'default', 'static', 'dynamic', 'shared' (synonym for 'dynamic'). For more information see CC Dependencies: Linkmode.	Dictionary: Label -> String	optional	{}
deps_runtime	Runtime module dependencies, e.g. .cmxs plugins. Use the `data` attribute for runtime data dependencies.	List of labels	optional	[]
env	Env variables	Dictionary: String -> String	optional	{}
module_name	Use this string as module name, instead of deriving it from sig or struct	String	optional	""
ns_resolver	NS resolver module for bottom-up namespacing. Modules may use this attribute to elect membership in a bottom-up namespace.	Label	optional	None
open	List of OCaml dependencies to be passed with `-open`.	List of labels	optional	[]
opts	List of compile options; overrides configurable default options. Supports `-no-` prefix for each option; for example, `-no-linkall`.	List of strings	optional	[]
pack	Experimental. List of pack submodules. They will be compiled with -for-pack, and this module will be compile with -pack.	List of labels	optional	[]
ppx	Label of `ppx_executable` target to be used to transform source before compilation.	Label	optional	None
ppx_args	Options to pass to PPX executable passed by the `ppx` attribute.	List of strings	optional	[]
ppx_data	PPX runtime data dependencies. List of labels of files needed by the PPX executable passed via the `ppx` attribute when it is executed to transform the source file. For example, a source file using ppx_optcomp may import a file using extension `[%%import ]`; this file should be listed in this attribute.	List of labels	optional	[]
ppx_print	Format of output of PPX transform: binary (default) or text. Value must be one of `@rules_ocaml//ppx/print:binary!` or `@rules_ocaml//ppx/print:text!`.	Label	optional	"@rules_ocaml//ppx/print"
ppx_verbose	-	Boolean	optional	False
sig	Single label of a target producing `OcamlSignatureProvider` (i.e. rule `ocaml_signature`) OR a sig source file. Optional.	Label	optional	None
struct	A single module (struct) source file label.	Label	required

name

A unique name for this target.

required

deps

List of dependencies.

optional

[]

data

Runtime data dependencies: list of labels of data files needed by this module at runtime. This is a standard Bazel attribute; see Typical attributes.

optional

[]

cc_deps

Static (.a) or dynamic (.so, .dylib) libraries. Must by built or imported using Bazel’s rules_cc ruleset (thus providing CcInfo output).

optional

[]

cc_linkage

Dictionary specifying C/C++ library dependencies. Allows finer control over linking than the 'cc_deps' attribute. Key: a target label providing CcInfo; value: a linkmode string, which determines which file to link. Valid linkmodes: 'default', 'static', 'dynamic', 'shared' (synonym for 'dynamic'). For more information see CC Dependencies: Linkmode.

optional

{}

deps_runtime

Runtime module dependencies, e.g. .cmxs plugins. Use the data attribute for runtime data dependencies.

optional

[]

env

Env variables

optional

{}

module_name

Use this string as module name, instead of deriving it from sig or struct

String

optional

""

ns_resolver

NS resolver module for bottom-up namespacing. Modules may use this attribute to elect membership in a bottom-up namespace.

optional

None

open

List of OCaml dependencies to be passed with -open.

optional

[]

opts

List of compile options; overrides configurable default options. Supports -no- prefix for each option; for example, -no-linkall.

List of strings

optional

[]

pack

Experimental. List of pack submodules. They will be compiled with -for-pack, and this module will be compile with -pack.

optional

[]

ppx

Label of ppx_executable target to be used to transform source before compilation.

optional

None

ppx_args

Options to pass to PPX executable passed by the ppx attribute.

List of strings

optional

[]

ppx_data

PPX runtime data dependencies. List of labels of files needed by the PPX executable passed via the ppx attribute when it is executed to transform the source file. For example, a source file using ppx_optcomp may import a file using extension [%%import ]; this file should be listed in this attribute.

optional

[]

ppx_print

Format of output of PPX transform: binary (default) or text. Value must be one of @rules_ocaml//ppx/print:binary! or @rules_ocaml//ppx/print:text!.

optional

"@rules_ocaml//ppx/print"

ppx_verbose

-

Boolean

optional

False

sig

Single label of a target producing OcamlSignatureProvider (i.e. rule ocaml_signature) OR a sig source file. Optional.

optional

None

struct

A single module (struct) source file label.

required

ocaml_import

ocaml_import(name, deps, srcs, afiles, all, archive, astructs, cc_deps, cmtis, cmts, cmxs, doc, jsoo_runtime, ocaml_version, ofiles, plugin, ppx_codeps, sigs, version, vmlibs)

Imports pre-compiled OCaml files. [User Guide](../ug/ocaml_import.md).

ATTRIBUTES for rule ocaml_import:

Name	Description	Type	Mandatory	Default
name	A unique name for this target.	Name	required
deps	-	List of labels	optional	[]
srcs	-	List of labels	optional	[]
afiles	list of .a files that go with .cmxa files	List of labels	optional	[]
all	Glob all cm* files except for 'archive' or 'plugin' so theey can be added to action ldeps (rather than cmd line). I.e. the (transitive) deps of an archive, which must be accessible to the compiler (via search path, not command line), and so must be added to the action ldeps.	List of labels	optional	[]
archive	-	Label	optional	None
astructs	-	List of labels	optional	[]
cc_deps	C archive files (.a) for integrating OCaml and C libs	List of labels	optional	[]
cmtis	-	List of labels	optional	[]
cmts	-	List of labels	optional	[]
cmxs	-	Label	optional	None
doc	-	String	optional	""
jsoo_runtime	-	Label	optional	None
ocaml_version	-	String	optional	""
ofiles	list of .o files that go with .cmx files	List of labels	optional	[]
plugin	-	Label	optional	None
ppx_codeps	-	List of labels	optional	[]
sigs	-	List of labels	optional	[]
version	-	String	optional	""
vmlibs	Dynamically-loadable, for ocamlrun. Standard naming is 'dll<name>_stubs.so' or 'dll<name>.so'.	List of labels	optional	[]

Name

Description

Type

Mandatory

Default

name

A unique name for this target.

required

deps

-

optional

[]

srcs

-

optional

[]

afiles

list of .a files that go with .cmxa files

optional

[]

all

Glob all cm* files except for 'archive' or 'plugin' so theey can be added to action ldeps (rather than cmd line). I.e. the (transitive) deps of an archive, which must be accessible to the compiler (via search path, not command line), and so must be added to the action ldeps.

optional

[]

ocaml_library

ocaml_library(name, archive_name, archived, cc_deps, cc_linkage, env, manifest, ns_name, opts, shared, standalone, vm_runtime)

Aggregates a collection of OCaml modules. [User Guide](../ug/ocaml_library.md). Provides: [OcamlLibraryMarker](providers_ocaml.md#ocamllibraryprovider).

An ocaml_library is a collection of modules packaged into an OBazl target; it is not a single binary file. It is a OBazl convenience rule that allows a target to depend on a collection of deps under a single label, rather than having to list each individually.

Be careful not to confuse ocaml_library with ocaml_archive. The latter generates OCaml binaries (.cma, .cmxa, '.a' archive files); the former does not generate anything, it just passes on its dependencies under a single label, packaged in a [OcamlLibraryMarker](providers_ocaml.md#ocamllibraryprovider). For more information see [Collections: Libraries, Archives and Packages](../ug/collections.md).

ATTRIBUTES for rule ocaml_library:

Name Description Type Mandatory Default

Name	Description	Type	Mandatory	Default
name	A unique name for this target.	Name	required
archive_name	Name of generated archive file, without extension. If not provided, name will be derived from target 'name' attribute. Ignored if archived == False.	String	optional	""
archived	-	Boolean	optional	False
cc_deps	Static (.a) or dynamic (.so, .dylib) libraries. Must deliver a CcInfo provider. Since ocaml rules may deliver CcInfo providers, we cannnot assume these deps are produced directly by rules_cc.	List of labels	optional	[]
cc_linkage	Dictionary specifying C/C++ library dependencies. Allows finer control over linking than the 'cc_deps' attribute. Key: a target label providing CcInfo; value: a linkmode string, which determines which file to link. Valid linkmodes: 'default', 'static', 'dynamic', 'shared' (synonym for 'dynamic'). For more information see CC Dependencies: Linkmode.	Dictionary: Label -> String	optional	{}
env	Env variables	Dictionary: String -> String	optional	{}
manifest	List of component modules, for libraries and archives.	List of labels	optional	[]
ns_name	-	String	optional	""
opts	List of compile options; overrides configurable default options. Supports `-no-` prefix for each option; for example, `-no-linkall`.	List of strings	optional	[]
shared	True: build a shared lib (.cmxs)	Boolean	optional	False
standalone	True: link total depgraph. False: link only direct deps.	Boolean	optional	False
vm_runtime	@rules_ocaml//cfg/runtime:dynamic (default), @rules_ocaml//cfg/runtime:static, or a custom ocaml_vm_runtime target label	Label	optional	"@rules_ocaml//cfg/runtime:dynamic"

name

A unique name for this target.

required

archive_name

Name of generated archive file, without extension. If not provided, name will be derived from target 'name' attribute. Ignored if archived == False.

String

optional

""

archived

-

Boolean

optional

False

cc_deps

Static (.a) or dynamic (.so, .dylib) libraries. Must deliver a CcInfo provider. Since ocaml rules may deliver CcInfo providers, we cannnot assume these deps are produced directly by rules_cc.

optional

[]

cc_linkage

Dictionary specifying C/C++ library dependencies. Allows finer control over linking than the 'cc_deps' attribute. Key: a target label providing CcInfo; value: a linkmode string, which determines which file to link. Valid linkmodes: 'default', 'static', 'dynamic', 'shared' (synonym for 'dynamic'). For more information see CC Dependencies: Linkmode.

optional

{}

env

Env variables

optional

{}

manifest

List of component modules, for libraries and archives.

optional

[]

ns_name

-

String

optional

""

opts

List of compile options; overrides configurable default options. Supports -no- prefix for each option; for example, -no-linkall.

List of strings

optional

[]

shared

True: build a shared lib (.cmxs)

Boolean

optional

False

standalone

True: link total depgraph. False: link only direct deps.

Boolean

optional

False

vm_runtime

@rules_ocaml//cfg/runtime:dynamic (default), @rules_ocaml//cfg/runtime:static, or a custom ocaml_vm_runtime target label

optional

"@rules_ocaml//cfg/runtime:dynamic"

ocaml_module

ocaml_module(name, deps, data, cc_deps, cc_linkage, deps_runtime, env, module_name, ns_resolver, open, opts, pack, ppx, ppx_args, ppx_data, ppx_print, ppx_verbose, sig, struct)

Compiles an OCaml module. The module name is determined by rule, based on the struct, sig, name, and module attributes:

If the sig attribute is the label of an ocaml_signature target, then the module name is derived from the name of the compiled sigfile, since compiled interface files cannot be renamed. The structfile will be renamed if it does not match the sigfile name.
If the sig attribute is a filename, then:
- if its principal name is equal to the principal name of the file named in the struct attribute, then the module name is derived from it.
- if the principal names of the sigfile and structfile do not match, then the module name is derived from from the name attribute. Both the sigfile and the structfile will be renamed accordingly.
- The module attribute may be used to force the module name. Both the sigfile and the structfile will be renamed accordingly.
If the sig attribute is not specified (i.e. the structfile is "orphaned"), then the module name will be derived from the structfile name, unless the module attribute is specified, in which case it overrides.

CONFIGURABLE DEFAULTS for rule ocaml_module:

In addition to the Configurable defaults that apply to all ocaml_* rules, the following apply to this rule:

Options

Label Default Comments

Label	Default	Comments
@rules_ocaml//cfg/module:deps	`@rules_ocaml//cfg:null`	list of OCaml deps to add to all `ocaml_module` instances
@rules_ocaml//cfg/module:cc_deps¹	`@rules_ocaml//cfg:null`	list of cc_deps to add to all `ocaml_module` instances
@rules_ocaml//cfg/module:cc_linkstatic¹	`@rules_ocaml//cfg:null`	list of cc_deps to link statically (DEPRECATED)
@rules_ocaml//cfg/module:warnings	`@1..3@5..28@30..39@43@46..47@49..57@61..62-40`	sets `-w` option for all `ocaml_module` instances

@rules_ocaml//cfg/module:deps

@rules_ocaml//cfg:null

list of OCaml deps to add to all ocaml_module instances

@rules_ocaml//cfg/module:cc_deps¹

@rules_ocaml//cfg:null

list of cc_deps to add to all ocaml_module instances

@rules_ocaml//cfg/module:cc_linkstatic¹

@rules_ocaml//cfg:null

list of cc_deps to link statically (DEPRECATED)

@rules_ocaml//cfg/module:warnings

@1..3@5..28@30..39@43@46..47@49..57@61..62-40

sets -w option for all ocaml_module instances

¹ See CC Dependencies for more information on CC deps.

Boolean Flags

These do not support :enable, :disable syntax.

Label Default opts attrib equivalent

Label	Default	`opts` attrib equivalent
@rules_ocaml//cfg/module/linkall	False	`-linkall`, `-no-linkall`
@rules_ocaml//cfg/module:verbose	False	`-verbose`, `-no-verbose`

@rules_ocaml//cfg/module/linkall

False

-linkall, -no-linkall

@rules_ocaml//cfg/module:verbose

False

-verbose, -no-verbose

ATTRIBUTES for rule ocaml_module:

Name Description Type Mandatory Default

Name	Description	Type	Mandatory	Default
name	A unique name for this target.	Name	required
deps	List of dependencies.	List of labels	optional	[]
data	Runtime data dependencies: list of labels of data files needed by this module at runtime. This is a standard Bazel attribute; see Typical attributes.	List of labels	optional	[]
cc_deps	Static (.a) or dynamic (.so, .dylib) libraries. Must by built or imported using Bazel’s rules_cc ruleset (thus providing CcInfo output).	List of labels	optional	[]
cc_linkage	Dictionary specifying C/C++ library dependencies. Allows finer control over linking than the 'cc_deps' attribute. Key: a target label providing CcInfo; value: a linkmode string, which determines which file to link. Valid linkmodes: 'default', 'static', 'dynamic', 'shared' (synonym for 'dynamic'). For more information see CC Dependencies: Linkmode.	Dictionary: Label -> String	optional	{}
deps_runtime	Runtime module dependencies, e.g. .cmxs plugins. Use the `data` attribute for runtime data dependencies.	List of labels	optional	[]
env	Env variables	Dictionary: String -> String	optional	{}
module_name	Use this string as module name, instead of deriving it from sig or struct	String	optional	""
ns_resolver	NS resolver module for bottom-up namespacing. Modules may use this attribute to elect membership in a bottom-up namespace.	Label	optional	None
open	List of OCaml dependencies to be passed with `-open`.	List of labels	optional	[]
opts	List of compile options; overrides configurable default options. Supports `-no-` prefix for each option; for example, `-no-linkall`.	List of strings	optional	[]
pack	Experimental. List of pack submodules. They will be compiled with -for-pack, and this module will be compile with -pack.	List of labels	optional	[]
ppx	Label of `ppx_executable` target to be used to transform source before compilation.	Label	optional	None
ppx_args	Options to pass to PPX executable passed by the `ppx` attribute.	List of strings	optional	[]
ppx_data	PPX runtime data dependencies. List of labels of files needed by the PPX executable passed via the `ppx` attribute when it is executed to transform the source file. For example, a source file using ppx_optcomp may import a file using extension `[%%import ]`; this file should be listed in this attribute.	List of labels	optional	[]
ppx_print	Format of output of PPX transform: binary (default) or text. Value must be one of `@rules_ocaml//ppx/print:binary!` or `@rules_ocaml//ppx/print:text!`.	Label	optional	"@rules_ocaml//ppx/print"
ppx_verbose	-	Boolean	optional	False
sig	Single label of a target producing `OcamlSignatureProvider` (i.e. rule `ocaml_signature`) OR a sig source file. Optional.	Label	optional	None
struct	A single module (struct) source file label.	Label	required

name

A unique name for this target.

required

deps

List of dependencies.

optional

[]

data

Runtime data dependencies: list of labels of data files needed by this module at runtime. This is a standard Bazel attribute; see Typical attributes.

optional

[]

cc_deps

Static (.a) or dynamic (.so, .dylib) libraries. Must by built or imported using Bazel’s rules_cc ruleset (thus providing CcInfo output).

optional

[]

cc_linkage

Dictionary specifying C/C++ library dependencies. Allows finer control over linking than the 'cc_deps' attribute. Key: a target label providing CcInfo; value: a linkmode string, which determines which file to link. Valid linkmodes: 'default', 'static', 'dynamic', 'shared' (synonym for 'dynamic'). For more information see CC Dependencies: Linkmode.

optional

{}

deps_runtime

Runtime module dependencies, e.g. .cmxs plugins. Use the data attribute for runtime data dependencies.

optional

[]

env

Env variables

optional

{}

module_name

Use this string as module name, instead of deriving it from sig or struct

String

optional

""

ns_resolver

NS resolver module for bottom-up namespacing. Modules may use this attribute to elect membership in a bottom-up namespace.

optional

None

open

List of OCaml dependencies to be passed with -open.

optional

[]

opts

List of compile options; overrides configurable default options. Supports -no- prefix for each option; for example, -no-linkall.

List of strings

optional

[]

pack

Experimental. List of pack submodules. They will be compiled with -for-pack, and this module will be compile with -pack.

optional

[]

ppx

Label of ppx_executable target to be used to transform source before compilation.

optional

None

ppx_args

Options to pass to PPX executable passed by the ppx attribute.

List of strings

optional

[]

ppx_data

PPX runtime data dependencies. List of labels of files needed by the PPX executable passed via the ppx attribute when it is executed to transform the source file. For example, a source file using ppx_optcomp may import a file using extension [%%import ]; this file should be listed in this attribute.

optional

[]

ppx_print

Format of output of PPX transform: binary (default) or text. Value must be one of @rules_ocaml//ppx/print:binary! or @rules_ocaml//ppx/print:text!.

optional

"@rules_ocaml//ppx/print"

ppx_verbose

-

Boolean

optional

False

sig

Single label of a target producing OcamlSignatureProvider (i.e. rule ocaml_signature) OR a sig source file. Optional.

optional

None

struct

A single module (struct) source file label.

required

ocaml_ns_archive

ocaml_ns_archive(name, archive_name, cc_deps, cc_linkage, env, manifest, ns_name, opts, shared)

Generate a 'namespace' module. [User Guide](../ug/ocaml_ns.md). Provides: [OcamlNsMarker](providers_ocaml.md#ocamlnsmoduleprovider).

Deprecated.  Use ocaml_ns_library with 'archived = True' instead.

NOTE 'name' must be a legal OCaml module name string. Leading underscore is illegal.

See [Namespacing](../ug/namespacing.md) for more information on namespaces.

ATTRIBUTES for rule ocaml_ns_archive:

Name Description Type Mandatory Default

Name	Description	Type	Mandatory	Default
name	A unique name for this target.	Name	required
archive_name	Name of generated archive file, without extension. If not provided, name will be derived from target 'name' attribute. Ignored if archived == False.	String	optional	""
cc_deps	Static (.a) or dynamic (.so, .dylib) libraries. Must by built or imported using Bazel’s rules_cc ruleset (thus providing CcInfo output).	List of labels	optional	[]
cc_linkage	Dictionary specifying C/C++ library dependencies. Allows finer control over linking than the 'cc_deps' attribute. Key: a target label providing CcInfo; value: a linkmode string, which determines which file to link. Valid linkmodes: 'default', 'static', 'dynamic', 'shared' (synonym for 'dynamic'). For more information see CC Dependencies: Linkmode.	Dictionary: Label -> String	optional	{}
env	Env variables	Dictionary: String -> String	optional	{}
manifest	List of namespaced submodules; will be renamed by prefixing the namespace,	List of labels	optional	[]
ns_name	Namespace name is derived from 'name' attribute by default; use this to override.	String	optional	""
opts	List of compile options; overrides configurable default options. Supports `-no-` prefix for each option; for example, `-no-linkall`.	List of strings	optional	[]
shared	True: build a shared lib (.cmxs)	Boolean	optional	False

name

A unique name for this target.

required

archive_name

Name of generated archive file, without extension. If not provided, name will be derived from target 'name' attribute. Ignored if archived == False.

String

optional

""

cc_deps

Static (.a) or dynamic (.so, .dylib) libraries. Must by built or imported using Bazel’s rules_cc ruleset (thus providing CcInfo output).

optional

[]

cc_linkage

Dictionary specifying C/C++ library dependencies. Allows finer control over linking than the 'cc_deps' attribute. Key: a target label providing CcInfo; value: a linkmode string, which determines which file to link. Valid linkmodes: 'default', 'static', 'dynamic', 'shared' (synonym for 'dynamic'). For more information see CC Dependencies: Linkmode.

optional

{}

env

Env variables

optional

{}

manifest

List of namespaced submodules; will be renamed by prefixing the namespace,

optional

[]

ns_name

Namespace name is derived from 'name' attribute by default; use this to override.

String

optional

""

opts

List of compile options; overrides configurable default options. Supports -no- prefix for each option; for example, -no-linkall.

List of strings

optional

[]

shared

True: build a shared lib (.cmxs)

Boolean

optional

False

ocaml_ns_library

ocaml_ns_library(name, archive_name, archived, cc_deps, cc_linkage, env, manifest, ns_name, opts, shared)

Generate a 'namespace' module. [User Guide](../ug/ocaml_ns.md). Provides: [OcamlNsMarker](providers_ocaml.md#ocamlnsmoduleprovider).

NOTE 'name' must be a legal OCaml module name string. Leading underscore is illegal.

See [Namespacing](../ug/namespacing.md) for more information on namespaces.

ATTRIBUTES for rule ocaml_ns_library:

Name Description Type Mandatory Default

Name	Description	Type	Mandatory	Default
name	A unique name for this target.	Name	required
archive_name	Name of generated archive file, without extension. If not provided, name will be derived from target 'name' attribute. Ignored if archived == False.	String	optional	""
archived	-	Boolean	optional	False
cc_deps	Static (.a) or dynamic (.so, .dylib) libraries. Must by built or imported using Bazel’s rules_cc ruleset (thus providing CcInfo output).	List of labels	optional	[]
cc_linkage	Dictionary specifying C/C++ library dependencies. Allows finer control over linking than the 'cc_deps' attribute. Key: a target label providing CcInfo; value: a linkmode string, which determines which file to link. Valid linkmodes: 'default', 'static', 'dynamic', 'shared' (synonym for 'dynamic'). For more information see CC Dependencies: Linkmode.	Dictionary: Label -> String	optional	{}
env	Env variables	Dictionary: String -> String	optional	{}
manifest	List of namespaced submodules; will be renamed by prefixing the namespace,	List of labels	optional	[]
ns_name	Namespace name is derived from 'name' attribute by default; use this to override.	String	optional	""
opts	List of compile options; overrides configurable default options. Supports `-no-` prefix for each option; for example, `-no-linkall`.	List of strings	optional	[]
shared	True: build a shared lib (.cmxs)	Boolean	optional	False

name

A unique name for this target.

required

archive_name

Name of generated archive file, without extension. If not provided, name will be derived from target 'name' attribute. Ignored if archived == False.

String

optional

""

archived

-

Boolean

optional

False

cc_deps

Static (.a) or dynamic (.so, .dylib) libraries. Must by built or imported using Bazel’s rules_cc ruleset (thus providing CcInfo output).

optional

[]

cc_linkage

Dictionary specifying C/C++ library dependencies. Allows finer control over linking than the 'cc_deps' attribute. Key: a target label providing CcInfo; value: a linkmode string, which determines which file to link. Valid linkmodes: 'default', 'static', 'dynamic', 'shared' (synonym for 'dynamic'). For more information see CC Dependencies: Linkmode.

optional

{}

env

Env variables

optional

{}

manifest

List of namespaced submodules; will be renamed by prefixing the namespace,

optional

[]

ns_name

Namespace name is derived from 'name' attribute by default; use this to override.

String

optional

""

opts

List of compile options; overrides configurable default options. Supports -no- prefix for each option; for example, -no-linkall.

List of strings

optional

[]

shared

True: build a shared lib (.cmxs)

Boolean

optional

False

ocaml_ns_resolver

ocaml_ns_resolver(name, deps, data, cc_deps, cc_linkage, deps_runtime, embed, env, include, manifest, merge, module_name, ns, open, opts, pack, ppx, ppx_args, ppx_data, ppx_print, ppx_verbose, sig, struct)

OBSOLETE DOCSTRING! under revision…

This rule initializes a 'namespace evaluation environment' consisting of a pseudo-namespace prefix string and optionally an ns resolver module. A pseudo-namespace prefix string is a string that is used to form (by prefixation) a (presumably) globally unique name for a module. An ns resolver module is a module that contains nothing but alias equations mapping module names to pseudo-namespaced module names.

This rule is designed to work in conjujnction with rules [ocaml_module](rules_ocaml.md#ocaml_module) and [ocaml_ns_module](rules_ocaml.md#ocaml_ns_module). An ocaml_module instance can use the prefix string of an ppx_ns to rename its source file by using attribute ns to reference the label of an ppx_ns target. Instances of ocaml_ns_module can list such modules as submodule dependencies. They can also use an ppx_ns prefix string to name themselves, by using their ns attribute similarly. This allows ns modules to be (pseudo-)namespaced in the same way submodules are namespaced.

The prefix string defaults to the (Bazel) package name string, with each segment capitalized and the path separator ('/') replaced by the sep string (default: _). If you pass a prefix string it must be a legal OCaml module path; each segment will be capitalized and the segment separator ('.') will be replaced by the sep string. The resulting prefix may be used by ocaml_module rules (via the ns attribute) to rename their source files, and, if module = True, by this rule to generate alias equations.

For example, if package //alpha/beta/gamma contains`foo.ml`:

ns_resolver() => Alpha_Beta_Gamma__foo.ml
ns_resolver(sep="") => AlphaBetaGamma__foo.ml
ns_resolver(sep="__") => Alpha__Beta__Gamma__foo.ml
ns_resolver(prefix="foo.bar") => Foo_Bar__foo.ml (pkg path ignored)
ns_resolver(prefix="foo.bar", sep="") => FooBar__foo.ml

The optional ns resolver module will be named <prefix>__00.ml; since 0 is not a legal initial character for an OCaml module name, this ensures it will never clash with a user-defined module.

The ns resolver module will contain alias equations mapping module names derived from the srcs list to pseudo-namespaced module names (and thus indirectly filenames). For example, if srcs contains foo.ml, and the prefix is a.b, then the resolver module will contain module Foo = A_b_foo.

Submodule file names will be formed by prefixing the pseudo-ns prefix to the (original, un-namespaced) module name, separated by 'sep' (default: ''). For example, if the prefix is 'Foo_bar' and the module is 'baz.ml', the submodule file name will be 'Foo_barbaz.ml'.

The main namespace module will contain aliasing equations that map module names to these prefixed module names.

By default, the ns prefix string is formed from the package name, with '/' replaced by '_'. You can use the 'ns' attribute to change this:

ns(ns = "foobar", srcs = glob(["*.ml"]))

ATTRIBUTES for rule ocaml_ns_resolver:

Name Description Type Mandatory Default

Name	Description	Type	Mandatory	Default
name	A unique name for this target.	Name	required
deps	List of dependencies.	List of labels	optional	[]
data	Runtime data dependencies: list of labels of data files needed by this module at runtime. This is a standard Bazel attribute; see Typical attributes.	List of labels	optional	[]
cc_deps	Static (.a) or dynamic (.so, .dylib) libraries. Must by built or imported using Bazel’s rules_cc ruleset (thus providing CcInfo output).	List of labels	optional	[]
cc_linkage	Dictionary specifying C/C++ library dependencies. Allows finer control over linking than the 'cc_deps' attribute. Key: a target label providing CcInfo; value: a linkmode string, which determines which file to link. Valid linkmodes: 'default', 'static', 'dynamic', 'shared' (synonym for 'dynamic'). For more information see CC Dependencies: Linkmode.	Dictionary: Label -> String	optional	{}
deps_runtime	Runtime module dependencies, e.g. .cmxs plugins. Use the `data` attribute for runtime data dependencies.	List of labels	optional	[]
embed	Exogenous namespaces (resolver modules).	Dictionary: Label -> String	optional	{}
env	Env variables	Dictionary: String -> String	optional	{}
include	Exogenous (sub)modules, namespaced or non-namespaced. Aliased names will not be prefixed with ns name of this ns_resolver. Keys: labels of modules; Values: alias name to be used in this resolver. e.g. '//mwe/rgb:R': 'Red' will generate module R = Red	Dictionary: Label -> String	optional	{}
manifest	List of strings from which submodule names are to be derived for aliasing. Bazel labels may be used; the submodule name will be derived from the target part. For example, '//a/b:c' normalizes to C. But they are just strings, and will not be checked against any files. The normalized submodule names must match the names of the modules electing membership via the 'ns_resolver' attribute. Module source code generated by ocamllex and ocamlyacc can be accomodated by using the module name for the source file and generating a .ml source file of the same name, e.g. lexer.mll → lexer.ml.	List of strings	optional	[]
merge	Includes all submodules of an exogenous namespace.	List of labels	optional	[]
module_name	Use this string as module name, instead of deriving it from sig or struct	String	optional	""
ns	-	String	required
open	List of OCaml dependencies to be passed with `-open`.	List of labels	optional	[]
opts	List of compile options; overrides configurable default options. Supports `-no-` prefix for each option; for example, `-no-linkall`.	List of strings	optional	[]
pack	Experimental. List of pack submodules. They will be compiled with -for-pack, and this module will be compile with -pack.	List of labels	optional	[]
ppx	Label of `ppx_executable` target to be used to transform source before compilation.	Label	optional	None
ppx_args	Options to pass to PPX executable passed by the `ppx` attribute.	List of strings	optional	[]
ppx_data	PPX runtime data dependencies. List of labels of files needed by the PPX executable passed via the `ppx` attribute when it is executed to transform the source file. For example, a source file using ppx_optcomp may import a file using extension `[%%import ]`; this file should be listed in this attribute.	List of labels	optional	[]
ppx_print	Format of output of PPX transform: binary (default) or text. Value must be one of `@rules_ocaml//ppx/print:binary!` or `@rules_ocaml//ppx/print:text!`.	Label	optional	"@rules_ocaml//ppx/print"
ppx_verbose	-	Boolean	optional	False
sig	Single label of a target producing `OcamlSignatureProvider` (i.e. rule `ocaml_signature`) OR a sig source file. Optional.	Label	optional	None
struct	A single module (struct) source file label.	Label	optional	None

name

A unique name for this target.

required

deps

List of dependencies.

optional

[]

data

Runtime data dependencies: list of labels of data files needed by this module at runtime. This is a standard Bazel attribute; see Typical attributes.

optional

[]

cc_deps

Static (.a) or dynamic (.so, .dylib) libraries. Must by built or imported using Bazel’s rules_cc ruleset (thus providing CcInfo output).

optional

[]

cc_linkage

Dictionary specifying C/C++ library dependencies. Allows finer control over linking than the 'cc_deps' attribute. Key: a target label providing CcInfo; value: a linkmode string, which determines which file to link. Valid linkmodes: 'default', 'static', 'dynamic', 'shared' (synonym for 'dynamic'). For more information see CC Dependencies: Linkmode.

optional

{}

deps_runtime

Runtime module dependencies, e.g. .cmxs plugins. Use the data attribute for runtime data dependencies.

optional

[]

embed

Exogenous namespaces (resolver modules).

optional

{}

env

Env variables

optional

{}

include

Exogenous (sub)modules, namespaced or non-namespaced. Aliased names will not be prefixed with ns name of this ns_resolver.

Keys: labels of modules; Values: alias name to be used in this resolver.

e.g. '//mwe/rgb:R': 'Red' will generate

module R = Red

optional

{}

manifest

List of strings from which submodule names are to be derived for aliasing. Bazel labels may be used; the submodule name will be derived from the target part. For example, '//a/b:c' normalizes to C. But they are just strings, and will not be checked against any files.

The normalized submodule names must match the names of the modules electing membership via the 'ns_resolver' attribute.

Module source code generated by ocamllex and ocamlyacc can be accomodated by using the module name for the source file and generating a .ml source file of the same name, e.g. lexer.mll → lexer.ml.

List of strings

optional

[]

merge

Includes all submodules of an exogenous namespace.

optional

[]

module_name

Use this string as module name, instead of deriving it from sig or struct

String

optional

""

ns

-

String

required

open

List of OCaml dependencies to be passed with -open.

optional

[]

opts

List of compile options; overrides configurable default options. Supports -no- prefix for each option; for example, -no-linkall.

List of strings

optional

[]

pack

Experimental. List of pack submodules. They will be compiled with -for-pack, and this module will be compile with -pack.

optional

[]

ppx

Label of ppx_executable target to be used to transform source before compilation.

optional

None

ppx_args

Options to pass to PPX executable passed by the ppx attribute.

List of strings

optional

[]

ppx_data

PPX runtime data dependencies. List of labels of files needed by the PPX executable passed via the ppx attribute when it is executed to transform the source file. For example, a source file using ppx_optcomp may import a file using extension [%%import ]; this file should be listed in this attribute.

optional

[]

ppx_print

Format of output of PPX transform: binary (default) or text. Value must be one of @rules_ocaml//ppx/print:binary! or @rules_ocaml//ppx/print:text!.

optional

"@rules_ocaml//ppx/print"

ppx_verbose

-

Boolean

optional

False

sig

Single label of a target producing OcamlSignatureProvider (i.e. rule ocaml_signature) OR a sig source file. Optional.

optional

None

struct

A single module (struct) source file label.

optional

None

ocaml_signature

ocaml_signature(name, deps, src, data, env, module, ns_resolver, open, opts, pack, ppx, ppx_args, ppx_data, ppx_print, ppx_verbose, xmo)

Generates OCaml .cmi (inteface) file. [User Guide](../ug/ocaml_signature.md). Provides OcamlSignatureProvider.

CONFIGURABLE DEFAULTS for rule ocaml_signature

In addition to the Configurable defaults that apply to all ocaml_* rules, the following apply to this rule. (Note the difference between '/' and ':' in such labels):

Label Default opts attrib

Label	Default	`opts` attrib
@rules_ocaml//cfg/signature/linkall	True	`-linkall`, `-no-linkall`
@rules_ocaml//cfg/signature:warnings	`@1..3@5..28@30..39@43@46..47@49..57@61..62-40`	`-w` plus option value

@rules_ocaml//cfg/signature/linkall

True

-linkall, -no-linkall

@rules_ocaml//cfg/signature:warnings

@1..3@5..28@30..39@43@46..47@49..57@61..62-40

-w plus option value

ATTRIBUTES for rule ocaml_signature:

Name Description Type Mandatory Default

Name	Description	Type	Mandatory	Default
name	A unique name for this target.	Name	required
deps	List of OCaml dependencies. Use this for compiling a .mli source file with deps. See [Dependencies](#deps) for details.	List of labels	optional	[]
src	A single .mli source file label	Label	optional	None
data	-	List of labels	optional	[]
env	Env variables	Dictionary: String -> String	optional	{}
module	Set module (sig) name to this string	String	optional	""
ns_resolver	Bottom-up namespacing	Label	optional	None
open	List of OCaml dependencies to be passed with -open.	List of labels	optional	[]
opts	List of compile options; overrides configurable default options. Supports `-no-` prefix for each option; for example, `-no-linkall`.	List of strings	optional	[]
pack	Experimental	String	optional	""
ppx	Label of `ppx_executable` target to be used to transform source before compilation.	Label	optional	None
ppx_args	Options to pass to PPX executable passed by the `ppx` attribute.	List of strings	optional	[]
ppx_data	PPX runtime data dependencies. List of labels of files needed by the PPX executable passed via the `ppx` attribute when it is executed to transform the source file. For example, a source file using ppx_optcomp may import a file using extension `[%%import ]`; this file should be listed in this attribute.	List of labels	optional	[]
ppx_print	Format of output of PPX transform: binary (default) or text. Value must be one of `@rules_ocaml//ppx/print:binary!` or `@rules_ocaml//ppx/print:text!`.	Label	optional	"@rules_ocaml//ppx/print"
ppx_verbose	-	Boolean	optional	False
xmo	Cross-module optimization. If false, compile with -opaque	Boolean	optional	True

name

A unique name for this target.

required

deps

List of OCaml dependencies. Use this for compiling a .mli source file with deps. See [Dependencies](#deps) for details.

optional

[]

src

A single .mli source file label

optional

None

data

-

optional

[]

env

Env variables

optional

{}

module

Set module (sig) name to this string

String

optional

""

ns_resolver

Bottom-up namespacing

optional

None

open

List of OCaml dependencies to be passed with -open.

optional

[]

opts

List of compile options; overrides configurable default options. Supports -no- prefix for each option; for example, -no-linkall.

List of strings

optional

[]

pack

Experimental

String

optional

""

ppx

Label of ppx_executable target to be used to transform source before compilation.

optional

None

ppx_args

Options to pass to PPX executable passed by the ppx attribute.

List of strings

optional

[]

ppx_data

PPX runtime data dependencies. List of labels of files needed by the PPX executable passed via the ppx attribute when it is executed to transform the source file. For example, a source file using ppx_optcomp may import a file using extension [%%import ]; this file should be listed in this attribute.

optional

[]

ppx_print

Format of output of PPX transform: binary (default) or text. Value must be one of @rules_ocaml//ppx/print:binary! or @rules_ocaml//ppx/print:text!.

optional

"@rules_ocaml//ppx/print"

ppx_verbose

-

Boolean

optional

False

xmo

Cross-module optimization. If false, compile with -opaque

Boolean

optional

True

ocaml_test

ocaml_test(name, data, cc_deps, cc_libs, cc_linkall, cc_linkopts, data_prefix_map, diff_cmd, env, epilogue, exe, main, opts, prologue, vm_runtime)

OCaml test rule.

CONFIGURABLE DEFAULTS for rule ocaml_test

In addition to the [OCaml configurable defaults](#configdefs) that apply to all ocaml_* rules, the following apply to this rule:

| Label | Default | opts attrib | | ----- | ------- | ------- | | @rules_ocaml//cfg/executable:linkall | True | -linkall, -no-linkall| | @rules_ocaml//cfg/executable:threads | False | true: -I +thread| | @rules_ocaml//cfg/executable:warnings | @1..3@5..28@30..39@43@46..47@49..57@61..62-40| -w plus option value |

NOTE These do not support :enable, :disable syntax.

See [Configurable Defaults](../ug/configdefs_doc.md) for more information.

ATTRIBUTES for rule ocaml_test:

Name Description Type Mandatory Default

Name	Description	Type	Mandatory	Default
name	A unique name for this target.	Name	required
data	Runtime dependencies: list of labels of data files needed by this executable at runtime.	List of labels	optional	[]
cc_deps	Dictionary specifying C/C++ library dependencies. Key: a target label; value: a linkmode string, which determines which file to link. Valid linkmodes: 'default', 'static', 'dynamic', 'shared' (synonym for 'dynamic'). For more information see [CC Dependencies: Linkmode](../ug/cc_deps.md#linkmode).	Dictionary: Label -> String	optional	{}
cc_libs	-	List of labels	optional	[]
cc_linkall	True: use `-whole-archive` (GCC toolchain) or `-force_load` (Clang toolchain). Deps in this attribute must also be listed in cc_deps.	List of labels	optional	[]
cc_linkopts	List of C/C link options. E.g. ["-lstd"].	List of strings	optional	[]
data_prefix_map	Map for replacing path prefixes of data files	Dictionary: String -> String	optional	{}
diff_cmd	-	Label	optional	None
env	Env variables	Dictionary: String -> String	optional	{}
epilogue	List of OCaml dependencies.	List of labels	optional	[]
exe	By default, executable name is derived from 'name' attribute; use this to override.	String	optional	""
main	Label of module containing entry point of executable. In the list of dependencies, this will be placed after 'prologue' deps and before 'epilogue' deps.	Label	required
opts	List of compile options; overrides configurable default options. Supports `-no-` prefix for each option; for example, `-no-linkall`.	List of strings	optional	[]
prologue	List of OCaml dependencies.	List of labels	optional	[]
vm_runtime	@rules_ocaml//cfg/runtime:dynamic (default), @rules_ocaml//cfg/runtime:static, or a custom ocaml_vm_runtime target label	Label	optional	"@rules_ocaml//cfg/runtime:dynamic"

name

A unique name for this target.

required

data

Runtime dependencies: list of labels of data files needed by this executable at runtime.

optional

[]

cc_deps

Dictionary specifying C/C++ library dependencies. Key: a target label; value: a linkmode string, which determines which file to link. Valid linkmodes: 'default', 'static', 'dynamic', 'shared' (synonym for 'dynamic'). For more information see [CC Dependencies: Linkmode](../ug/cc_deps.md#linkmode).

optional

{}

cc_libs

-

optional

[]

cc_linkall

True: use -whole-archive (GCC toolchain) or -force_load (Clang toolchain). Deps in this attribute must also be listed in cc_deps.

optional

[]

cc_linkopts

List of C/C link options. E.g. ["-lstd"].

List of strings

optional

[]

data_prefix_map

Map for replacing path prefixes of data files

optional

{}

diff_cmd

-

optional

None

env

Env variables

optional

{}

epilogue

List of OCaml dependencies.

optional

[]

exe

By default, executable name is derived from 'name' attribute; use this to override.

String

optional

""

main

Label of module containing entry point of executable. In the list of dependencies, this will be placed after 'prologue' deps and before 'epilogue' deps.

required

opts

List of compile options; overrides configurable default options. Supports -no- prefix for each option; for example, -no-linkall.

List of strings

optional

[]

prologue

List of OCaml dependencies.

optional

[]

vm_runtime

@rules_ocaml//cfg/runtime:dynamic (default), @rules_ocaml//cfg/runtime:static, or a custom ocaml_vm_runtime target label

optional

"@rules_ocaml//cfg/runtime:dynamic"

ocaml_vm_runtime

ocaml_vm_runtime(name, deps)

User-defined runtime, using ocamlc -make-runtime

ATTRIBUTES for rule ocaml_vm_runtime:

Name	Description	Type	Mandatory	Default
name	A unique name for this target.	Name	required
deps	Libraries whose cc deps should be included in the runtime	List of labels	optional	[]

Name

Description

Type

Mandatory

Default

name

A unique name for this target.

required

deps

Libraries whose cc deps should be included in the runtime

optional

[]

ocamllex

ocamllex(name, src, out, opts)

Generates an OCaml source file from an ocamllex source file.

ATTRIBUTES for rule ocamllex:

Name	Description	Type	Mandatory	Default
name	A unique name for this target.	Name	required
src	A single .mll source file label	Label	optional	None
out	Output filename.	Label	required
opts	Options	List of strings	optional	[]

Name

Description

Type

Mandatory

Default

name

A unique name for this target.

required

src

A single .mll source file label

optional

None

out

Output filename.

required

opts

Options

List of strings

optional

[]

ocamlyacc

ocamlyacc(name, src, outs, opts)

Generates OCaml source files from an ocamlyacc source file.

ATTRIBUTES for rule ocamlyacc:

Name	Description	Type	Mandatory	Default
name	A unique name for this target.	Name	required
src	A single .mly ocamlyacc source file label	Label	optional	None
outs	Output filenames.	List of labels	required
opts	Options	List of strings	optional	[]

Name

Description

Type

Mandatory

Default

name

A unique name for this target.

required

src

A single .mly ocamlyacc source file label

optional

None

outs

Output filenames.

List of labels

required

opts

Options

List of strings

optional

[]

ppx_executable

ppx_executable(name, data, bin, cc_deps, cc_linkall, cc_linkopts, data_prefix_map, env, epilogue, exe, main, opts, ppx_codeps, prologue, vm_runtime)

Generates a PPX executable. Provides: [PpxExecutableMarker](providers_ppx.md#ppxexecutableprovider).

ATTRIBUTES for rule ppx_executable:

Name Description Type Mandatory Default

Name	Description	Type	Mandatory	Default
name	A unique name for this target.	Name	required
data	Runtime data dependencies. E.g. a file used by %%import from ppx_optcomp.	List of labels	optional	[]
bin	Precompiled ppx executable	Label	optional	None
cc_deps	C/C++ library dependencies	Dictionary: Label -> String	optional	{}
cc_linkall	True: use `-whole-archive` (GCC toolchain) or `-force_load` (Clang toolchain). Deps in this attribute must also be listed in cc_deps.	List of labels	optional	[]
cc_linkopts	List of C/C link options. E.g. `["-lstd"]`.	List of strings	optional	[]
data_prefix_map	Map for replacing path prefixes of data files. May be used to strip a path prefix (set value to empty string "").	Dictionary: String -> String	optional	{}
env	Env variables	Dictionary: String -> String	optional	{}
epilogue	List of OCaml dependencies.	List of labels	optional	[]
exe	Name for output executable file. Overrides 'name' attribute.	String	optional	""
main	A module to be listed after those in 'prologue' and before those in 'epilogue'. For more information see [Main Module](../ug/ppx.md#main_module).	Label	required
opts	List of compile options; overrides configurable default options. Supports `-no-` prefix for each option; for example, `-no-linkall`.	List of strings	optional	[]
ppx_codeps	List of non-opam adjunct dependencies (labels).	List of labels	optional	[]
prologue	List of OCaml dependencies.	List of labels	optional	[]
vm_runtime	@ocaml_rules//cfg/runtime:dynamic (default), @ocaml_rules//cfg/runtime:static, or a custom ocaml_vm_runtime target label	Label	optional	"@rules_ocaml//cfg/runtime:dynamic"

name

A unique name for this target.

required

data

Runtime data dependencies. E.g. a file used by %%import from ppx_optcomp.

optional

[]

bin

Precompiled ppx executable

optional

None

cc_deps

C/C++ library dependencies

optional

{}

cc_linkall

True: use -whole-archive (GCC toolchain) or -force_load (Clang toolchain). Deps in this attribute must also be listed in cc_deps.

optional

[]

cc_linkopts

List of C/C link options. E.g. `["-lstd"]`.

List of strings

optional

[]

data_prefix_map

Map for replacing path prefixes of data files. May be used to strip a path prefix (set value to empty string "").

optional

{}

env

Env variables

optional

{}

epilogue

List of OCaml dependencies.

optional

[]

exe

Name for output executable file. Overrides 'name' attribute.

String

optional

""

main

A module to be listed after those in 'prologue' and before those in 'epilogue'. For more information see [Main Module](../ug/ppx.md#main_module).

required

opts

List of compile options; overrides configurable default options. Supports -no- prefix for each option; for example, -no-linkall.

List of strings

optional

[]

ppx_codeps

List of non-opam adjunct dependencies (labels).

optional

[]

prologue

List of OCaml dependencies.

optional

[]

vm_runtime

@ocaml_rules//cfg/runtime:dynamic (default), @ocaml_rules//cfg/runtime:static, or a custom ocaml_vm_runtime target label

optional

"@rules_ocaml//cfg/runtime:dynamic"

ppx_module

ppx_module(name, deps, data, cc_deps, cc_linkage, deps_runtime, env, module_name, ns_resolver, open, opts, pack, ppx, ppx_args, ppx_codeps, ppx_compile_codeps, ppx_data, ppx_link_codeps, ppx_print, ppx_verbose, sig, struct)

Compiles a PPX module. Same as ocaml_module but with added ppx_codeps attribute. A ppx_module may depend on a standard ocaml_module, but not the other way around.

The module name is determined by rule, based on the struct, sig, name, and module attributes:

If the sig attribute is the label of an ocaml_signature target, then the module name is derived from the name of the compiled sigfile, since compiled interface files cannot be renamed. The structfile will be renamed if it does not match the sigfile name.
If the sig attribute is a filename, then:
- if its principal name is equal to the principal name of the file named in the struct attribute, then the module name is derived from it.
- if the principal names of the sigfile and structfile do not match, then the module name is derived from from the name attribute. Both the sigfile and the structfile will be renamed accordingly.
- The module attribute may be used to force the module name. Both the sigfile and the structfile will be renamed accordingly.
If the sig attribute is not specified (i.e. the structfile is "orphaned"), then the module name will be derived from the structfile name, unless the module attribute is specified, in which case it overrides.

CONFIGURABLE DEFAULTS for rule ppx_module:

In addition to the Configurable defaults that apply to all ocaml_* rules, the following apply to this rule:

Options

Label Default Comments

Label	Default	Comments
@rules_ocaml//cfg/module:deps	`@rules_ocaml//cfg:null`	list of OCaml deps to add to all `ocaml_module` instances
@rules_ocaml//cfg/module:cc_deps¹	`@rules_ocaml//cfg:null`	list of cc_deps to add to all `ocaml_module` instances
@rules_ocaml//cfg/module:cc_linkstatic¹	`@rules_ocaml//cfg:null`	list of cc_deps to link statically (DEPRECATED)
@rules_ocaml//cfg/module:warnings	`@1..3@5..28@30..39@43@46..47@49..57@61..62-40`	sets `-w` option for all `ocaml_module` instances

@rules_ocaml//cfg/module:deps

@rules_ocaml//cfg:null

list of OCaml deps to add to all ocaml_module instances

@rules_ocaml//cfg/module:cc_deps¹

@rules_ocaml//cfg:null

list of cc_deps to add to all ocaml_module instances

@rules_ocaml//cfg/module:cc_linkstatic¹

@rules_ocaml//cfg:null

list of cc_deps to link statically (DEPRECATED)

@rules_ocaml//cfg/module:warnings

@1..3@5..28@30..39@43@46..47@49..57@61..62-40

sets -w option for all ocaml_module instances

¹ See CC Dependencies for more information on CC deps.

Boolean Flags

These do not support :enable, :disable syntax.

Label Default opts attrib equivalent

Label	Default	`opts` attrib equivalent
@rules_ocaml//cfg/module/linkall	False	`-linkall`, `-no-linkall`
@rules_ocaml//cfg/module:verbose	False	`-verbose`, `-no-verbose`

@rules_ocaml//cfg/module/linkall

False

-linkall, -no-linkall

@rules_ocaml//cfg/module:verbose

False

-verbose, -no-verbose

ATTRIBUTES for rule ppx_module:

Name Description Type Mandatory Default

Name	Description	Type	Mandatory	Default
name	A unique name for this target.	Name	required
deps	List of dependencies.	List of labels	optional	[]
data	Runtime data dependencies: list of labels of data files needed by this module at runtime. This is a standard Bazel attribute; see Typical attributes.	List of labels	optional	[]
cc_deps	Static (.a) or dynamic (.so, .dylib) libraries. Must by built or imported using Bazel’s rules_cc ruleset (thus providing CcInfo output).	List of labels	optional	[]
cc_linkage	Dictionary specifying C/C++ library dependencies. Allows finer control over linking than the 'cc_deps' attribute. Key: a target label providing CcInfo; value: a linkmode string, which determines which file to link. Valid linkmodes: 'default', 'static', 'dynamic', 'shared' (synonym for 'dynamic'). For more information see CC Dependencies: Linkmode.	Dictionary: Label -> String	optional	{}
deps_runtime	Runtime module dependencies, e.g. .cmxs plugins. Use the `data` attribute for runtime data dependencies.	List of labels	optional	[]
env	Env variables	Dictionary: String -> String	optional	{}
module_name	Use this string as module name, instead of deriving it from sig or struct	String	optional	""
ns_resolver	NS resolver module for bottom-up namespacing. Modules may use this attribute to elect membership in a bottom-up namespace.	Label	optional	None
open	List of OCaml dependencies to be passed with `-open`.	List of labels	optional	[]
opts	List of compile options; overrides configurable default options. Supports `-no-` prefix for each option; for example, `-no-linkall`.	List of strings	optional	[]
pack	Experimental. List of pack submodules. They will be compiled with -for-pack, and this module will be compile with -pack.	List of labels	optional	[]
ppx	Label of `ppx_executable` target to be used to transform source before compilation.	Label	optional	None
ppx_args	Options to pass to PPX executable passed by the `ppx` attribute.	List of strings	optional	[]
ppx_codeps	List of non-opam adjunct dependencies (labels).	List of labels	optional	[]
ppx_compile_codeps	List labels of compile-time dependencies. These are required to compile any file transformed by this ppx.	List of labels	optional	[]
ppx_data	PPX runtime data dependencies. List of labels of files needed by the PPX executable passed via the `ppx` attribute when it is executed to transform the source file. For example, a source file using ppx_optcomp may import a file using extension `[%%import ]`; this file should be listed in this attribute.	List of labels	optional	[]
ppx_link_codeps	List labels of link-time dependencies. These are required to link any file transformed by this ppx.	List of labels	optional	[]
ppx_print	Format of output of PPX transform: binary (default) or text. Value must be one of `@rules_ocaml//ppx/print:binary!` or `@rules_ocaml//ppx/print:text!`.	Label	optional	"@rules_ocaml//ppx/print"
ppx_verbose	-	Boolean	optional	False
sig	Single label of a target producing `OcamlSignatureProvider` (i.e. rule `ocaml_signature`) OR a sig source file. Optional.	Label	optional	None
struct	A single module (struct) source file label.	Label	required

name

A unique name for this target.

required

deps

List of dependencies.

optional

[]

data

Runtime data dependencies: list of labels of data files needed by this module at runtime. This is a standard Bazel attribute; see Typical attributes.

optional

[]

cc_deps

Static (.a) or dynamic (.so, .dylib) libraries. Must by built or imported using Bazel’s rules_cc ruleset (thus providing CcInfo output).

optional

[]

cc_linkage

Dictionary specifying C/C++ library dependencies. Allows finer control over linking than the 'cc_deps' attribute. Key: a target label providing CcInfo; value: a linkmode string, which determines which file to link. Valid linkmodes: 'default', 'static', 'dynamic', 'shared' (synonym for 'dynamic'). For more information see CC Dependencies: Linkmode.

optional

{}

deps_runtime

Runtime module dependencies, e.g. .cmxs plugins. Use the data attribute for runtime data dependencies.

optional

[]

env

Env variables

optional

{}

module_name

Use this string as module name, instead of deriving it from sig or struct

String

optional

""

ns_resolver

NS resolver module for bottom-up namespacing. Modules may use this attribute to elect membership in a bottom-up namespace.

optional

None

open

List of OCaml dependencies to be passed with -open.

optional

[]

opts

List of compile options; overrides configurable default options. Supports -no- prefix for each option; for example, -no-linkall.

List of strings

optional

[]

pack

Experimental. List of pack submodules. They will be compiled with -for-pack, and this module will be compile with -pack.

optional

[]

ppx

Label of ppx_executable target to be used to transform source before compilation.

optional

None

ppx_args

Options to pass to PPX executable passed by the ppx attribute.

List of strings

optional

[]

ppx_codeps

List of non-opam adjunct dependencies (labels).

optional

[]

ppx_compile_codeps

List labels of compile-time dependencies. These are required to compile any file transformed by this ppx.

optional

[]

ppx_data

PPX runtime data dependencies. List of labels of files needed by the PPX executable passed via the ppx attribute when it is executed to transform the source file. For example, a source file using ppx_optcomp may import a file using extension [%%import ]; this file should be listed in this attribute.

optional

[]

ppx_link_codeps

List labels of link-time dependencies. These are required to link any file transformed by this ppx.

optional

[]

ppx_print

Format of output of PPX transform: binary (default) or text. Value must be one of @rules_ocaml//ppx/print:binary! or @rules_ocaml//ppx/print:text!.

optional

"@rules_ocaml//ppx/print"

ppx_verbose

-

Boolean

optional

False

sig

Single label of a target producing OcamlSignatureProvider (i.e. rule ocaml_signature) OR a sig source file. Optional.

optional

None

struct

A single module (struct) source file label.

required

ppx_transform

ppx_transform(name, src, data, args, env, opts, ppx, print)

Runs a ppx executable to transform a source file. Also propagates ppx_codeps from the provider of the ppx dependency.

ATTRIBUTES for rule ppx_transform:

Name Description Type Mandatory Default

Name	Description	Type	Mandatory	Default
name	A unique name for this target.	Name	required
src	A single source file (struct or sig) label.	Label	required
data	Runtime data dependencies: list of labels of data files needed by ppx executable at runtime.	List of labels	optional	[]
args	List of args to pass to ppx executable at runtime.	List of strings	optional	[]
env	Env variables	Dictionary: String -> String	optional	{}
opts	List of compile options; overrides configurable default options. Supports `-no-` prefix for each option; for example, `-no-linkall`.	List of strings	optional	[]
ppx	Label of `ppx_executable` target to be used to transform source before compilation.	Label	optional	None
print	Format of output of PPX transform. Value must be one of `@rules_ocaml//ppx/print:binary`, `@rules_ocaml//ppx/print:text`. See PPX Support for more information	Label	optional	"@rules_ocaml//ppx/print"

name

A unique name for this target.

required

src

A single source file (struct or sig) label.

required

data

Runtime data dependencies: list of labels of data files needed by ppx executable at runtime.

optional

[]

args

List of args to pass to ppx executable at runtime.

List of strings

optional

[]

env

Env variables

optional

{}

opts

List of compile options; overrides configurable default options. Supports -no- prefix for each option; for example, -no-linkall.

List of strings

optional

[]

ppx

Label of ppx_executable target to be used to transform source before compilation.

optional

None

print

Format of output of PPX transform. Value must be one of @rules_ocaml//ppx/print:binary, @rules_ocaml//ppx/print:text. See PPX Support for more information