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6. The GNAT Make Program gnatmake

6.1 Running gnatmake
6.2 Switches for gnatmake
6.3 Mode Switches for gnatmake
6.4 Notes on the Command Line
6.5 How gnatmake Works
6.6 Examples of gnatmake Usage

1. Edit some sources to fix bugs.

2. Add enhancements.

3. Compile all sources affected.

4. Rebind and relink.

5. Test.

The third step can be tricky, because not only do the modified files have to be compiled, but any files depending on these files must also be recompiled. The dependency rules in Ada can be quite complex, especially in the presence of overloading, use clauses, generics and inlined subprograms.

gnatmake automatically takes care of the third and fourth steps of this process. It determines which sources need to be compiled, compiles them, and binds and links the resulting object files.

Unlike some other Ada make programs, the dependencies are always accurately recomputed from the new sources. The source based approach of the GNAT compilation model makes this possible. This means that if changes to the source program cause corresponding changes in dependencies, they will always be tracked exactly correctly by gnatmake.