Re: Problem generating dependency files

[arvind raju]

Hi Philip,

Adding makefile and %.d rules did not help.

What i am wondering here is, if make finds the target "tld2lec_msg.o (see debug log below) and if it doesn't exist, it should search for the prerequisite i.e tld2lec_msg.c and search the same in the path given in VPATH. Why does it use implicit rule for ld2lec_msg.c then pattern rule 
ld2lec_msg? If make does this for each and every file, then to build around 500 files will be very slow.

Is there a way to avoid make to look for implicit rule ?
Considering target file `tld2lec_msg.o'.
       File `tld2lec_msg.o' does not exist.
        Considering target file `tld2lec_msg.c'.
         Looking for an implicit rule for `tld2lec_msg.c'.
         Trying pattern rule with stem `tld2lec_msg'.
         Trying implicit prerequisite `tld2lec_msg.y'.
         Trying pattern rule with stem `tld2lec_msg'.
         Trying implicit prerequisite `tld2lec_msg.l'.
         Trying pattern rule with stem `tld2lec_msg'.
         Trying implicit prerequisite `tld2lec_msg.w'.
         Trying pattern rule with stem `tld2lec_msg'.
         Trying implicit prerequisite `tld2lec_msg.w'.
         Trying pattern rule with stem `tld2lec_msg.c'.
         Trying implicit prerequisite `tld2lec_msg.c,v'.
         Trying pattern rule with stem `tld2lec_msg.c'.
         Trying implicit prerequisite `RCS/tld2lec_msg.c,v'.
         Trying pattern rule with stem `tld2lec_msg.c'.
         Trying implicit prerequisite `RCS/tld2lec_msg.c'.
         Trying pattern rule with stem `tld2lec_msg.c'.
         Trying implicit prerequisite `s.tld2lec_msg.c'.
         Trying pattern rule with stem `tld2lec_msg.c'.
         Trying implicit prerequisite `SCCS/s.tld2lec_msg.c'.
         Trying pattern rule with stem `tld2lec_msg'.
         Trying implicit prerequisite `tld2lec_msg.y'.
         Looking for a rule with intermediate file `tld2lec_msg.y'.
          Avoiding implicit rule recursion.
          Trying pattern rule with stem `tld2lec_msg.y'.
          Trying implicit prerequisite `tld2lec_msg.y,v'.
          Trying pattern rule with stem `tld2lec_msg.y'.
          Trying implicit prerequisite `RCS/tld2lec_msg.y,v'.
          Trying pattern rule with stem `tld2lec_msg.y'.
          Trying implicit prerequisite `RCS/tld2lec_msg.y'.
          Trying pattern rule with stem `tld2lec_msg.y'.
          Trying implicit prerequisite `s.tld2lec_msg.y'.
          Trying pattern rule with stem `tld2lec_msg.y'.
          Trying implicit prerequisite `SCCS/s.tld2lec_msg.y'.
         Trying pattern rule with stem `tld2lec_msg'.
         Trying implicit prerequisite `tld2lec_msg.l'.
         Looking for a rule with intermediate file `tld2lec_msg.l'.
          Avoiding implicit rule recursion.
          Trying pattern rule with stem `tld2lec_msg.l'.
          Trying implicit prerequisite `tld2lec_msg.l,v'.
          Trying pattern rule with stem `tld2lec_msg.l'.
          Trying implicit prerequisite `RCS/tld2lec_msg.l,v'.
          Trying pattern rule with stem `tld2lec_msg.l'.
          Trying implicit prerequisite `RCS/tld2lec_msg.l'.
          Trying pattern rule with stem `tld2lec_msg.l'.
          Trying implicit prerequisite `s.tld2lec_msg.l'.
          Trying pattern rule with stem `tld2lec_msg.l'.
          Trying implicit prerequisite `SCCS/s.tld2lec_msg.l'.
         Trying pattern rule with stem `tld2lec_msg'.
         Trying implicit prerequisite `tld2lec_msg.w'.
         Looking for a rule with intermediate file `tld2lec_msg.w'.
          Avoiding implicit rule recursion.
          Trying pattern rule with stem `tld2lec_msg.w'.
          Trying implicit prerequisite `tld2lec_msg.w,v'.
          Trying pattern rule with stem `tld2lec_msg.w'.
          Trying implicit prerequisite `RCS/tld2lec_msg.w,v'.
          Trying pattern rule with stem `tld2lec_msg.w'.
          Trying implicit prerequisite `RCS/tld2lec_msg.w'.
          Trying pattern rule with stem `tld2lec_msg.w'.
          Trying implicit prerequisite `s.tld2lec_msg.w'.
          Trying pattern rule with stem `tld2lec_msg.w'.
          Trying implicit prerequisite `SCCS/s.tld2lec_msg.w'.
         Trying pattern rule with stem `tld2lec_msg'.
         Rejecting impossible implicit prerequisite `tld2lec_msg.w'.
         No implicit rule found for `tld2lec_msg.c'.
         Finished prerequisites of target file `tld2lec_msg.c'.
        No need to remake target `tld2lec_msg.c'; using VPATH name `..\..\..\.\platform\bt\lec\src/tld2lec_msg.c'.
       Finished prerequisites of target file `tld2lec_msg.o'.
      Must remake target `tld2lec_msg.o'.
Creating temporary batch file c:\tmp\make29283.sh
CreateProcess(C:\cygwin\bin\sh.exe,C:/cygwin/bin/sh.exe c:\tmp\make29283.sh,...)
Putting child 0x009643e0 (tld2lec_msg.o) PID 9857296 on the chain.
Live child 0x009643e0 (tld2lec_msg.o) PID 9857296 
Compling ..\..\..\.\platform\bt\lec\src/tld2lec_msg.c
Reaping winning child 0x009643e0 PID 9857296 
Cleaning up temp batch file c:\tmp\make29283.sh
armcc -MD -c ..\..\..\.\platform\bt\lec\src/tld2lec_msg.c -via b.txt
CreateProcess(c:\Program Files\ARM\ADSv1_2\12_EL\bin\armcc.exe,armcc -MD -c ..\..\..\.\platform\bt\lec\src/tld2lec_msg.c -via b.txt,...)
Live child 0x009643e0 (tld2lec_msg.o) PID 9857296 
Reaping winning child 0x009643e0 PID 9857296 
Removing child 0x009643e0 PID 9857296  from chain.
      Successfully remade target file `tld2lec_msg.o'.

Thanks in Advance!

On Thu, May 6, 2010 at 9:43 PM, Philip Guenther <address@hidden> wrote:

On Thu, May 6, 2010 at 2:02 AM, nature <address@hidden> wrote:
> I got away with the problem by making use of the compiler switch "-MD" to
> get the dependency files during compilation itself .
> When i included this .d files, make takes lot of time to build (its almost
> hung).
> Even before this change ,build was slow, but after this change its worst.
> I run make in the debug mode to find out where the problem is and was
> surprised to see the log message.

> Inspite of using VPATH to find for the source files, make searches it
> elsewhere and at the end it looks into the path specified in the VPATH .
>

> What is going wrong here? any suggestions please??

Try adding rules for the Makefile and dependency files that do nothing, ala:

Makefile:
%.d:

Those will short-circuit make's "how do I build this make file?" search.

(If you actually build your Makefile, perhaps from RCS or similar,
then you should obviously not use an empty rule for it.)


Philip Guenther