11.8.2 Syntax of aggregate library projects

An aggregate library project follows the general syntax of project files. The recommended extension is still .gpr. However, a special aggregate library qualifier must be put before the keyword project.

An aggregate library project cannot with any other project (standard or aggregate), except an abstract project which can be used to share attribute values.

An aggregate library project does not have any source files directly (only through other standard projects). Therefore a number of the standard attributes and packages are forbidden in an aggregate library project. Here is the (non exhaustive) list:

• Languages
• Source_Files, Source_List_File and other attributes dealing with list of sources.
• Source_Dirs, Exec_Dir and Object_Dir
• Main
• Roots
• Externally_Built
• Inherit_Source_Path
• Excluded_Source_Dirs
• Locally_Removed_Files
• Excluded_Source_Files
• Excluded_Source_List_File
• Interfaces

The only package that is authorized (albeit optional) is Builder.

The Project_Files attribute (See see Aggregate Projects) is used to described the aggregated projects whose object files have to be included into the aggregate library. The environment variables ADA_PROJECT_PATH, GPR_PROJECT_PATH and GPR_PROJECT_PATH_FILE are not used to find the project files.