What is a makefile directive?
What is a makefile directive?
A directive is a command for make to do something special while reading the makefile. These include: Reading another makefile (see section Including Other Makefiles). Deciding (based on the values of variables) whether to use or ignore a part of the makefile (see section Conditional Parts of Makefiles).
How do I check if a variable is set in makefile?
Check if variable is defined in a Makefile check_defined = \ $(strip $(foreach 1,$1, \ $(call __check_defined,$1,$(strip $(value 2))))) __check_defined = \ $(if $(value $1),, \ $(error Undefined $1$(if $2, ($2)))) install: $(call check_defined, var1) $(call check_defined, var2) # do stuff here..
How do you set a variable in makefile?
How to Use Variables
- A variable is a name defined in a makefile to represent a string of text, called the variable’s value.
- To substitute a variable’s value, write a dollar sign followed by the name of the variable in parentheses or braces: either `$(foo)’ or `${foo}’ is a valid reference to the variable foo .
What is wildcard in makefile?
4.4. 3 The Function wildcard $(wildcard pattern …) This string, used anywhere in a makefile, is replaced by a space-separated list of names of existing files that match one of the given file name patterns. If no existing file name matches a pattern, then that pattern is omitted from the output of the wildcard function.
Why do I need a makefile?
Compiling the source code files can be tiring, especially when you have to include several source files and type the compiling command every time you need to compile. Makefiles are the solution to simplify this task. Makefiles are special format files that help build and manage the projects automatically.
How do I edit makefile in Linux?
How to Modify the Makefile
- Log in as a superuser.
- Modify the line that starts with the word all by adding the name(s) of the database you want to add:
- Add the following lines at the end of the Makefile :
- Add an entry for auto_direct.
- Run make .
What is Vpath in makefile?
The value of the make variable VPATH specifies a list of directories that make should search. Most often, the directories are expected to contain prerequisite files that are not in the current directory; however, make uses VPATH as a search list for both prerequisites and targets of rules.