Manifest reference

The fpm.toml file for each project is called its manifest. It is written using the TOML format. Every manifest file consists of the following sections:

Project name

The project name identifies the package and is used to refer to it. It is used when listing the project as dependency for another package and the default name of the library and executable target. Therefore, the project name must always be present.

Example:

name = "hello_world"

Project version

The version number of the project is specified as string. A standardized way to manage and specify versions is the Semantic Versioning scheme.

Example:

version = "1.0.0"

The version entry can also contain a filename relative to the project root, which contains the version number of the project

Example:

version = "VERSION"

Project license

The project license field contains the license identifier. A standardized way to specify licensing information are SPDX identifiers.

Examples:

Projects licensed under the GNU Lesser General Public License, either version 3 or any later version, is specified as

license = "LGPL-3.0-or-later"

Dual licensed project under the Apache license, version 2.0 or the MIT license are specified as

license = "Apache-2.0 OR MIT"

Project maintainer

Information on the project maintainer and means to reach out to them.

Example:

maintainer = "jane.doe@example.com"

Project author

Information on the project author.

Example:

author = "Jane Doe"

Project description

The description provides a short summary on the project. It should be plain text and not using any markup formatting.

Example:

description = "A short summary on this project"

Project categories

The project can be associated with different categories.

Example:

categories = ["io"]

Project keywords

The keywords field is an array of strings describing the project.

Example:

keywords = ["hdf5", "mpi"]

Project homepage

URL to the webpage of the project.

Example:

homepage = "https://stdlib.fortran-lang.org"

Project targets

Every fpm project can define library, executable and test targets. Library targets are exported and useable for other projects.

Library configuration

Defines the exported library target of the project. A library is generated if the source directory or include directory is found in a project. The default source and include directories are src and include; these can be modified in the library section using the source-dir and include-dir entries. Paths for the source and include directories are given relative to the project root and use / as path separator on all platforms.

Example:

[library]
source-dir = "lib"
include-dir = "inc"

Include directory

Note

Supported in Fortran fpm only

Projects which use the Fortran include statement or C preprocessor #include statement, can use the include-dir key to specify search directories for the included files. include-dir can contain one or more directories, where multiple directories are specified using a list of strings. Include directories from all project dependencies are passed to the compiler using the appropriate compiler flag.

Example:

[library]
include-dir = ["include", "third_party/include"]

Note

include-dir does not currently allow using pre-built module .mod files

Executable targets

Executable targets are Fortran programs defined as executable sections. If no executable section is specified the app directory is searched for program definitions. For explicitly specified executables the name entry must always be specified. The source directory for each executable can be adjusted in the source-dir entry. Paths for the source directory are given relative to the project root and use / as path separator on all platforms. The source file containing the program body can be specified in the main entry.

Executables can have their own dependencies. See specifying dependencies for more details.

Executables can also specify their own external library dependencies. See external libraries for more details.

Note

Linking against libraries is supported in Fortran fpm only

Example:

[[executable]]
name = "app-name"
source-dir = "prog"
main = "program.f90"

[[executable]]
name = "app-tool"
link = "z"
[executable.dependencies]
helloff = { git = "https://gitlab.com/everythingfunctional/helloff.git" }

Specifying many separate executables can be done by using inline tables for brevity instead

executable = [
  { name = "a-prog" },
  { name = "app-tool", source-dir = "tool" },
]

Example targets

Example applications for a project are defined as example sections. If no example section is specified the example directory is searched for program definitions. For explicitly specified examples the name entry must always be specified. The source directory for each example can be adjusted in the source-dir entry. Paths for the source directory are given relative to the project root and use / as path separator on all platforms. The source file containing the program body can be specified in the main entry.

Examples can have their own dependencies. See specifying dependencies for more details.

Examples can also specify their own external library dependencies. See external libraries for more details.

Note

Linking against libraries is supported in Fortran fpm only

Example:

[[example]]
name = "demo-app"
source-dir = "demo"
main = "program.f90"

[[example]]
name = "example-tool"
link = "z"
[example.dependencies]
helloff = { git = "https://gitlab.com/everythingfunctional/helloff.git" }

Test targets

Test targets are Fortran programs defined as test sections. They follow similar rules as the executable targets. If no test section is specified the test directory is searched for program definitions. For explicitly specified tests the name entry must always be specified. The source directory for each test can be adjusted in the source-dir entry. Paths for the source directory are given relative to the project root and use / as path separator on all platforms. The source file containing the program body can be specified in the main entry.

Tests can have their own dependencies. See specifying dependencies for more details.

Tests can also specify their own external library dependencies. See external libraries for more details.

Note

Linking against libraries is supported in Fortran fpm only

Example:

[[test]]
name = "test-name"
source-dir = "testing"
main = "tester.F90"

[[test]]
name = "tester"
link = ["blas", "lapack"]
[test.dependencies]
helloff = { git = "https://gitlab.com/everythingfunctional/helloff.git" }

Use system-installed modules

To use modules that are not defined within your fpm package or its dependencies, specify the module name using the external-modules key in the build table.

Important

fpm cannot automatically locate external module files; it is the responsibility of the user to specify the necessary include directories using compiler flags such that the compiler can locate external module files during compilation.

Example:

[build]
external-modules = "netcdf"

Multiple external modules can be specified as a list.

Example:

[build]
external-modules = ["netcdf", "h5lt"]

Automatic target discovery

Note

Supported in Fortran fpm only

Executables and test can be discovered automatically in their default directories. The automatic discovery recursively searches the app, example, and test directories for program definitions and declares them as executable, example, and test targets, respectively. The automatic discovery is enabled by default.

To disable the automatic discovery of targets set the auto-executables, auto-examples, and auto-tests entry to false.

[build]
auto-executables = false
auto-examples = false
auto-tests = false

Fortran features

Allows to enable and disable specific language features

Implicit typing

Allows to toggle whether the default implicit typing should be used. The default option is false.

[fortran]
implicit-typing = true  # default: false

Implicit external

Allows to toggle whether external interfaces can be declared implicitly. The default option is false.

[fortran]
implicit-external = true  # default: false

Source form

Allows to specifiy the source form to be used for all files in the project. Possible choices are "free" to assume all files are free form source, "fixed" to assume all files are fixed form source, and "default" to let the compiler decide based on its own heuristics. The default option is "free".

[fortran]
source-form = "fixed"  # default: "free"

Specifying dependencies

Dependencies can be declared in the dependencies table in the manifest root or the executable or test sections. When declared in the manifest root the dependencies are exported with the project.

Dependencies from version control systems

Dependencies can be specified by the projects git repository.

[dependencies]
toml-f = { git = "https://github.com/toml-f/toml-f" }

To use a specific upstream branch declare the branch name with

[dependencies]
toml-f = { git = "https://github.com/toml-f/toml-f", branch = "main" }

Alternatively, reference tags by using the tag entry

[dependencies]
toml-f = { git = "https://github.com/toml-f/toml-f", tag = "v0.2.1" }

To pin a specific revision specify the commit hash in the rev entry

[dependencies]
toml-f = { git = "https://github.com/toml-f/toml-f", rev = "2f5eaba" }

For more verbose layout use normal tables rather than inline tables to specify dependencies

[dependencies]
[dependencies.toml-f]
git = "https://github.com/toml-f/toml-f"
rev = "2f5eaba864ff630ba0c3791126a3f811b6e437f3"

Dependencies from a registry

Note

To enable the usage of a registry in fpm make sure you read the instructions in the registry section first.

Namespace

Packages obtained from a registry (both remote and local) are required to specify a namespace, which provides a way to uniquely identify and differentiate packages with identical names. The namespace is declared in the manifest (fpm.toml).

[dependencies]
my-package.namespace = "my-namespace"

This will prompt fpm to download the newest version of “my-package”, which belongs to “my-namespace”, from the registry.

Version

If you want to download a specific version of a package instead of the newest one available, you can specify the version (v) in the manifest.

[dependencies]
example-package.namespace = "example-namespace"
example-package.v = "1.0.0"

Local dependencies

To declare local dependencies use the path entry.

[dependencies]
my-utils = { path = "utils" }

The local dependency path is given relative to the fpm.toml it is written to, and uses / as the path separator on all platforms.

Dependency-specific macro setting

As of fpm>=0.9.1, an array of dependency-specific macros can be passed to a single dependency from the manifest, in the same fashion as in the manifest’s preprocessor configuration table. Its preprocess table needs to be entered as part of the dependency entry. fpm will not check if the passed macros collide with the dependencie’s own manifest, so, it is the user’s responsibility to ensure that no collisions or unexpected behavior occur. For example, one can control the REAL precision that one library is to be used with:

[dependencies]
fftpack = { git="https://github.com/fortran-lang/fftpack.git", preprocess.cpp.macros = ["REAL32"] }

Development dependencies

Development dependencies allow to declare dev-dependencies in the manifest root, which are available to all tests but not exported with the project.

Installation configuration

In the install section components for the installation can be selected. By default only executables are installed, library projects can set the library boolean to also installatation the module files and the archive.

Example

[install]
library = true

Preprocessor configuration

Under the preprocess section, you can specify one or more preprocessor to use in an fpm project.

Specifying the preprocessor

The preprocess section allows one or more preprocessors to be specified. For example, cpp can be specified like this :

Example

[preprocess]
[preprocess.cpp]

To use multiple preprocessors, for example cpp and fypp, specify them like this:

Example

[preprocess]
[preprocess.cpp]
[preprocess.fypp]

You can also specify source file suffixes that the preprocessor should run on:

Example

[preprocess]
[preprocess.cpp]
suffixes = ["F90", "f90"]

Further, you can instruct the preprocessor to run on source files in specific directories:

Example

[preprocess]
[preprocess.cpp]
directories = ["src/feature1", "src/models"]

Preprocessor macros can be defined like this:

Example

[preprocess]
[preprocess.cpp]
macros = ["FOO", "BAR"]

We can also use dotted keys to define our preprocessor settings.

Example

[preprocess]
cpp.suffixes = ["F90", "f90"]
cpp.directories = ["src/feature1", "src/models"]
cpp.macros = ["FOO", "BAR"]

We can also define valued macros in preprocess table.

Example

[preprocess]
[preprocess.cpp]
macros=["FOO=2", "BAR=4"]

We can also reuse values like version number from manifest as a value for a macro.

Example

version = "1"

[preprocess]
[preprocess.cpp]
macros=["VERSION={version}"]

Additional free data field

Third-party tools can store their configuration inside the extra section. This section will never be evaluated by fpm itself, the only constraint imposed is that it has to be valid TOML.

Since the format of this section is free, only recommendations are provided here for adding data to the extra section.

  1. Only use subtables, never add configuration data to the top level of the extra section. Reasoning: different tools can avoid collisions of key names by placing their data in separate subtables.

  2. Use the concrete name of the tool rather than a generic name for the subtable. Reasoning: different formatter or linter tools might use conflicting keywords in a format or lint subtable. Also, users can tell from the table name which tool is preferred to use with the project.

  3. Fpm plugins should use a subtable with their plugin name in the extra.fpm section to store their data. Reasoning: following this convention provides the user of fpm plugins with one section to configure their used plugins.

  4. Use the fpm preferred style for keywords which is lowercase with dashes. Reasoning: while there is no style check in this section, a consistent style in the whole manifest will make it easier for the user to understand the whole package manifest.

Feedback for the recommendations above is very much welcome. If you have a tool that uses the extra section in the package manifest, feel free to post it in at the fpm discussion board.