This addition first creates the macro DEPS, which is the set of. $(CC) $(CFLAGS) -o hellomake hellomake.o hellofunc.o
$(CC) $< $(CFLAGS) -c -o hellomake.o hellofunc.o Writing a simple rule and adding it to the makefile. In order to fix this, we need to tell make If you were to make a change to hellomake.h, forĮxample, make would not recompile the. However, there is one thing missing: dependency on the Using this form of makefile is sufficient for most small scale Individually, and then build the executable hellomake. Rule, make knows it must first compile the. By putting the objectįiles- hellomake.o and hellofunc.o-in the dependency list and in the What C compiler to use, and CFLAGS is the list of flags to It turns out these are special constants thatĬommunicate to make how we want to compile the files So now we've defined some constants CC andĬFLAGS. $(CC) -o hellomake hellomake.o hellofunc.o In order to be a bit more efficient, let's try the following: Makefile 2 There must be a tab at the beginning of anyĬommand, and make will not be happy if it's not there.
One very important thing to note is that there is a tab before the gccĬommand in the makefile. However, the system is still not being efficient in terms of Using the up arrow repeatedly, looking for your last compileĬommand. Immediately, you have solved problem #1 and can avoid That the rule hellomake needs to be executed if any of thoseįiles change. The command depends on the first line after the :, make knows Furthermore, by putting the list of files on which Note that make with no arguments executes the first Will execute the compile command as you have written it in the Makefile and then type make on the command line it If you put this rule into a file called Makefile or The simplest makefile you could create would look something like: Makefile 1 c file, recompiling all of them every time isĪlso time-consuming and inefficient. It from scratch, which is inefficient at best. If you lose the compile command or switch computers you have to retype Unfortunately, this approach to compilation has two downfalls. The typical approach to the test/modify/debug cycle is to use the upĪrrow in a terminal to go back to your last compile command so youĭon't have to type it each time, especially once you've added a few (we will look at using the debugger during the next lab). The -g flag tells the compiler to produce information needed by the debugger c files and names the executable hellomake. Gcc -g -o hellomake hellomake.c hellofunc.c
#SIMPLE C MAKEFILE EXAMPLE CODE#
Normally, you would compile this collection of code by executing the following command:
Program, some functional code in a separate file, and an include file, Hellofunc.c, and hellomake.h, which would represent a typical main
Let's start off with the following three files, hellomake.c, Quickly and easily create your own makefiles for small to medium-sized Make, but is intended as a starter's guide so that you can This tutorialĭoes not even scratch the surface of what is possible using Makefiles are a simple way to organize code compilation. Donald House for use at Clemson in CPSC 1070 from a tutorial developed at Colby College by Dr. In order to generate an executable from this object file we would usually call esql again using the generated object file and any dependent object files as input.A Simple Makefile Tutorial A Simple Makefile Tutorial Modified by Dr. The linker isn’t invoked by esql when the –c flag is set which means no executable is created. The cc -c or gcc -c option will create an object *.o file from any input source *.c file. Note that -c is not a valid ESQL-C compiler option but a C compiler option. This essentially acts as a generic rule for any input ESQL-C source file that is presented as an argument to the make utility or not included as a dependency in an explicit rule. Most of the more obvious pattern rules are predefined and this type of rule isn’t particularly relevant for a very small project like this, but a version of it was included in the original so we’ve kept it in there.