Re: #include in a C file

[ali hagigat]

the section 4.13 makes reader confused a bit!!
-------------------------------------------
For example, the command:
cc -M main.c
Note that such a prerequisite constitutes mentioning ‘main.o’ in a
makefile, so it can
never be considered an intermediate file by implicit rule search.
-------------------------------------------
What file will be considered as an intermediate file? and how?


> On 12/1/10, Paul Smith <address@hidden> wrote:
>> On Tue, 2010-11-30 at 11:54 +0330, ali hagigat wrote:
>>> If compiler generates the necessary prerequisites automatically by -M
>>> option why we need to have one makefile for each source file?
>>
>> I don't understand the relationship between the first part of the
>> sentence and the second part.
>>
>> The reason we recommend having one makefile per source file is that it's
>> very difficult to update the makefile with a new set of prerequisites
>> for a single file that's changed, if you concatenate them all together
>> into one big makefile.
>>
>> If you have foo.c, bar.c, and baz.c and you write all the dependencies
>> into one makefile, say deps.mk:
>>
>>      foo.o: foo.c foo.h bar.h
>>      bar.o: bar.c bar.h baz.h \
>>              stdio.h stdlib.h
>>      baz.o: baz.c bar.h foo.h baz.h
>>
>> Now say you edit "bar.c" and so the build system wants to regenerate its
>> prerequisite list... it's a lot harder to write a rule to update just
>> those lines for "bar.o" in that combined makefile than it would be to
>> overwrite the entire contents of a single file "bar.deps" or whatever.
>>
>> --
>> -------------------------------------------------------------------------------
>>  Paul D. Smith <address@hidden>          Find some GNU make tips at:
>>  http://www.gnu.org                      http://make.mad-scientist.net
>>  "Please remain calm...I may be mad, but I am a professional." --Mad
>> Scientist
>>
>>
>