Thread: Confused with a make file

Hi,
I got a following Make file. Could anyone give me a hint of what
COMPILEDIRS = $(SUBDIRS:=.compile)

means ? Does it replace all subdirs with .compile ???


Many thanks.
Anh

Code:

# Source, Executable, Includes, Library Defines
INCL   = trees.h
SRCDIR= src
LIBDIR = lib
INCDIR = include

# Compiler, Linker Defines
CC      = gcc
CFLAGS  = -Wall 

# make sure all variables are exported to sub-makes
export

# subdirectories to be built
SUBDIRS = $(SRCDIR) $(LIBDIR)

# path definitions 

prefix = /usr/local
exec_prefix = $(prefix)
bindir = $(exec_prefix)/bin
libdir = $(exec_prefix)/lib

# installation programs
INSTALL = /usr/bin/install
INSTALL_PROGRAM = $(INSTALL)
INSTALL_DATA = $(INSTALL) -m 644


# build everything recursively 

all: srcdirs

COMPILEDIRS = $(SUBDIRS:=.compile)

.PHONY: srcdirs $(COMPILEDIRS)

# must build library first
src.compile: lib.compile

srcdirs: $(COMPILEDIRS)

$(COMPILEDIRS):
	$(MAKE) -C $(@:.compile=) all  

# install everything in the right place - again done recursively
install: installdirs

INSTALLDIRS = $(SUBDIRS:=.install)

.PHONY: installdirs $(INSTALLDIRS)

installdirs: $(INSTALLDIRS)

$(INSTALLDIRS): all
	$(MAKE) -C $(@:.install=) install 

# clear up after build
.PHONY:	clean

clean:
	(cd $(SRCDIR) ; $(MAKE) clean )
	(cd $(LIBDIR) ; $(MAKE) clean )

</code>

Use code tags!!

Could anyone give me a hint of what
COMPILEDIRS = $(SUBDIRS:=.compile)

means ? Does it replace all subdirs with .compile ???

Yes. Substitution References with GNU make, as the name implies, substitutes each instance of the left of := with what's on the right.