JUST REPOSITORY CONFIG(5) | File Formats Manual()

NAME
just-repository-config - The format of the repository config used by justbuild(1)

DESCRIPTION
justbuild’s repository configuration is read as JSON. Any other serialization describing the same JSON object is equivalent. We assume, that in JSON objects, each key occurs at most once; it is implementation defined how repetitions of the same key are treated.

  File root description
Each repository can have multiple file roots. Each file root is defined as a non-empty JSON list with its first element being a string, which determines the type and semantic of the subsequent elements:

•   "file" refers to a file root that is located in the file system. The list has to be of length 2 and the second argument contains the path to the file root.

•   "git tree" refers to a file root that is available as part of a Git repository. The list has to be of length 2 or 3 with the remaining two elements being:

    1.  The git tree hash, which is sufficient to describe the content of an entire tree including its sub-trees and blobs. The tree hash has to be specified in hex encoding.

    2.  The path to a Git repository on the file system with the promise that it contains the aforementioned git tree hash; if this entry is missing, the root is considered absent and any target requiring this root has to come from a specified serve end point.

•   "computed" refers to a file root that is the result of evaluating an export target of a content-fixed repository. The list has to have length 5 or 6, with the remaining arguments being the global repository name, the module name, the target name, and the configuration, in that order, optionally followed by a pragma object. If the pragma object contains the entry true for the key "absent", that root is considered absent, otherwise not.

•   "tree structure" refers to the directory structure of a file root. The list has to have length 2 or 3. The second argument contains the global name of the repository which workspace root gets taken for computation. The third argument is an optional pragma object. If the pragma object contains the key "absent", the entry must be a boolean. If the entry is true, that root is considered absent, otherwise not.

  Repository description
A single repository description is defined as a JSON object, which contains file roots, file names, and bindings to other repositories. Specifically the following fields are supported:

•   "workspace_root" contains the file root where source files are located. If this entry is missing for the main repository, justbuild will perform the normal workspace root resolution starting from the current working directory.

•   "target_root" contains the file root where the target files are located. If this entry is missing, the workspace root is taken.

•   "target_file_name" contains the file name of target files to use. If this entry is missing, the default target file name TARGETS is used.

•   "rule_root" contains the file root where the rule files are located. If this entry is missing, the target root is taken.

•   "rule_file_name" contains the file name of rule files to use. If this entry is missing, the default rule file name RULES is used.

•   "expression_root" contains the file root where the expression files are located. If this entry is missing, the rule root is taken.

•   "expression_file_name" contains the file name of expression files to use. If this entry is missing, the default expression file name EXPRESSIONS is used.

•   "bindings" contains a JSON object that defines bindings to other repositories by mapping local repository names to global ones. The object’s key is local name, while the value is a string representing the global name.

Note that any other unsupported field is accepted but ignored. There are no guarantees that any yet unsupported field may not become meaningful in future versions.

  Repository configuration format
The repository configuration format is a JSON object with the following keys:

•   "main" contains a string, which defines the repository name to consider by default if not explicitly specified on the command line (i.e., via --main). This entry is optional and if omitted justbuild will use the lexicographically first repository, as usual.

•   "repositories" contains a JSON object that defines all repositories by mapping global repository names to repository descriptions documented above. This entry is optional and if omitted an empty JSON object is used.

NOTES
Although the repository configuration is human-readable and can be written by hand, in many cases it will be generated by an independent tool. just-mr(1) is one such tool that can be used for configuration generation, but not necessarily the only one.

See also
justbuild(1), just-mr(1), just-mr-repository-config(5)