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11.2.1 Source Files and Directories

When you create a new project, the first thing to describe is how to find the corresponding source files. This is the only settings that are needed by all the tools that will use this project (builder, compiler, binder and linker for the compilation, IDEs to edit the source files,...).

First step is to declare the source directories, which are the directories to be searched to find source files. In the case of the example, the common directory is the only source directory.

There are several ways of defining source directories:

When applied to the simple example, and because we generally prefer to have the project file at the toplevel directory rather than mixed with the sources, we will create the following file

        project Build is
           for Source_Dirs use ("common");  --  <<<<
        end Build;

Once source directories have been specified, one may need to indicate source files of interest. By default, all source files present in the source directories are considered by the project manager. When this is not desired, it is possible to specify the list of sources to consider explicitly. In such a case, only source file base names are indicated and not their absolute or relative path names. The project manager is in charge of locating the specified source files in the specified source directories.

In most simple cases, such as the above example, the default source file search behavior provides the expected result, and we do not need to add anything after setting Source_Dirs. The project manager automatically finds, pack.adb and proc.adb as source files of the project.

Note that it is considered an error for a project file to have no sources attached to it unless explicitly declared as mentioned above.

If the order of the source directories is known statically, that is if "/**" is not used in the string list Source_Dirs, then there may be several files with the same source file name sitting in different directories of the project. In this case, only the file in the first directory is considered as a source of the project and the others are hidden. If "/**" is not used in the string list Source_Dirs, it is an error to have several files with the same source file name in the same directory "/**" subtree, since there would be an ambiguity as to which one should be used. However, two files with the same source file name may in two single directories or directory subtrees. In this case, the one in the first directory or directory subtree is a source of the project.