CODEWITHSUNDEEP
makefilegnu-make
yashC
yashC

Reputation: 995

What does the following expression in make file mean?

I am going through a SDK's Makefile and the <project>.elf rule depends on the C_OBJS, and the C_OBJS is defined as the following.

C_OBJS = $(C_FILES:%.c=$(BUILD_DIR)/%.o)

C_FILES is a collection of all the C files.

What I am unable to figure out is that how does the Makefile know how to convert these C files to respective OBJS before linking them to form elf(as the elf rule only links them)

Upvotes: 0

Views: 69

Answers (1)

HardcoreHenry
HardcoreHenry

Reputation: 6387

The $(C_FILES:%.c=$(BUILD_DIR)/%.o) is shorthand for a patsubst function. See here.

As far as knowing how to build the .o files, unless you explicitly disable them, make will use a set of predefined implicit rules, one of which builds .o files from .c files.

Upvotes: 1

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