How to use the command gnatmake (with examples)

The gnatmake command is a low-level build tool for Ada programs. It is part of the GNAT toolchain and is used to compile Ada source code and generate executable files. In this article, we will explore three different use cases for the gnatmake command.

Use case 1: Compile an executable

Code:

gnatmake source_file1.adb source_file2.adb ...

Motivation: The gnatmake command is used to compile Ada source code and generate executable files. By providing one or more source files to gnatmake, it will compile the source code and generate an executable file for each source file specified.

Explanation: In this use case, we provide one or more source files (source_file1.adb, source_file2.adb, etc.) to the gnatmake command. The command will compile each source file and generate an executable file with the same name as the source file, but without the .adb extension. It will also compile any necessary dependencies.

Example output:

gnatmake source_file.adb
gcc -c source_file.adb
gnatbind -x source_file.ali
gnatlink source_file.ali

Use case 2: Set a custom executable name

Code:

gnatmake -o executable_name source_file.adb

Motivation: Sometimes, we may want to set a custom name for the executable file generated by gnatmake. This can be useful when we want to have more control over the naming conventions or when we want to distinguish between different executable files generated from the same source file.

Explanation: In this use case, we use the -o option followed by an executable_name and provide a source_file.adb to the gnatmake command. The command will compile the source file and generate an executable file with the specified executable_name. It will also compile any necessary dependencies.

Example output:

gnatmake -o my_executable source_file.adb
gcc -c source_file.adb
gnatbind -x source_file.ali
gnatlink -o my_executable source_file.ali

Use case 3: [f]orce recompilation

Code:

gnatmake -f source_file.adb

Motivation: Sometimes, we may want to force the recompilation of a source file even if it has not changed. This can be useful when we suspect that there may be issues with the existing compiled version and want to ensure that the latest version of the source file is compiled.

Explanation: In this use case, we use the -f option and provide a source_file.adb to the gnatmake command. The command will compile the source file and generate an executable file. If the source file has not changed since the last compilation, the command will still force the recompilation.

Example output:

gnatmake -f source_file.adb
gcc -c source_file.adb
gnatbind -x source_file.ali
gnatlink source_file.ali

Conclusion:

The gnatmake command is a versatile low-level build tool for Ada programs. It allows us to compile Ada source code and generate executable files with ease. By exploring these use cases, we have learned how to compile an executable, set a custom executable name, and force recompilation using the gnatmake command. These examples should provide a good starting point for using the gnatmake command effectively in Ada development projects.