GNU make

Date: 2022-02-25
| If some other rule is not depended on by the goal (or anything it
| depends on, etc.), that rule is not processed, unless you tell make
| to do so (with a command such as make clean).
Chapter: Content


Date: 2022-02-25
| First, any directories you have specified with the ‘-I’ or
| ‘--include-dir’ option are searched
Chapter: Content


Date: 2022-02-26
| If the makefiles specify a double-colon rule to remake a file with
| a recipe but no prerequisites, that file will always be remade
Chapter: Content


Date: 2022-02-26
| Conditional directives are parsed immediately. This means, for
| example, that automatic variables cannot be used in conditional
| directives, as automatic variables are not set until the recipe
| for that rule is invoked
Chapter: Content


Date: 2022-02-26
| A rule tells make two things: when the targets are out of date,
| and how to update them when necessary
Chapter: Content


Date: 2022-02-26
| Consider an example where your targets are to be placed in a
| separate directory, and that directory might not exist before make
| is run. In this situation, you want the directory to be created
| before any targets are placed into it but, because the timestamps on
| directories change whenever a file is added, removed, or renamed,
| we certainly don’t want to rebuild all the targets whenever
| the directory’s timestamp changes. One way to manage this is
| with order-only prerequisites: make the directory an order-only
| prerequisite on all the targets
Chapter: Content