[En-Nut-Discussion] Compiling toolchain and programs on Windows

[Philipp Burch]

Hi everyone,

the project I've been working on for quite a while now has reached a 
state in which I should get the development environment on our company 
computers. Unlike my notebook, those all boot Windows, so I'm facing the 
(usual) Linux-to-Windows-hassles.

Using Cygwin, I've now managed to compile the Ethernut tools itself 
(nutconfigure.exe at least) and generate the build and application 
trees. So far, everything OK. When I try to build the libraries for the 
first time (i.e. there are no object and especially no dep files), the 
"all" target builds fine. But when make wants to take care of the 
"install" target, it fails:

------------ 8< ---------------

make -C arch install
make[1]: Entering directory '/cygdrive/c/Dokumente und 
Einstellungen/p.burch/Eigene Dateien/devnut_lm3s/nutbld/arch'
cm3/dev/lm3/lm3s_uart0.d:1: *** Mehrfache Target-Muster.  Schluss.
make[1]: Leaving directory '/cygdrive/c/Dokumente und 
Einstellungen/p.burch/Eigene Dateien/devnut_lm3s/nutbld/arch'
Makefile:18: recipe for target 'install' failed
make: *** [install] Error 2

------------ 8< ---------------

I know that those damn whitespaced Windows paths eventually will cause 
trouble, but right now, this seems not to be the root cause. When I open 
the offending dep file, the problem is revealed:

------------ 8< ---------------

cm3/dev/lm3/lm3s_uart0.o: ../.././nut/arch/cm3/dev/lm3/lm3s_uart0.c \
  ../.././nut/include/sys/atom.h ../.././nutbld/include/cfg/os.h \
  ../.././nut/include/sys/types.h ../.././nut/include/compiler.h \
  ../.././nut/include/toolchain.h ../.././nut/include/toolchain/gcc.h \
  ../.././nut/include/arch/cm3.h \
  c:\programme\gnu\ tools\ arm\ embedded\4.7\ 
2013q3\bin\../lib/gcc/arm-none-eabi/4.7.4/include/stddef.h \
  ../.././nutbld/include/cfg/arch.h \
  ../.././nut/include/arch/cm3/cortexM3.h \
  c:\programme\gnu\ tools\ arm\ embedded\4.7\ 
2013q3\bin\../lib/gcc/arm-none-eabi/4.7.4/include/stdint.h \
  c:\programme\gnu\ tools\ arm\ embedded\4.7\ 
2013q3\bin\../lib/gcc/arm-none-eabi/4.7.4/../../../../arm-none-eabi/include/stdint.h 
\
  c:\programme\gnu\ tools\ arm\ embedded\4.7\ 
2013q3\bin\../lib/gcc/arm-none-eabi/4.7.4/../../../../arm-none-eabi/include/_ansi.h 
\

[...]

------------ 8< ---------------

Obviously, the ARM toolchain in use (it's the official GNU ARM 
toolchain, setup with the windows installer), places absolute paths into 
the Makefile - in the Windows format with colons and backslashes. At 
least the make supplied with Cygwin can't handle this, which does not 
really surprise me. How to tell if a colon belongs to the drive letter 
or marks the end of a target? Not to speak of the backslashes, anyway.

So my question is now, how to fix this? I don't mind installing another 
more Windows-targeted make, but I doubt that this will get everything 
running smoothly. Path styles switch between UNIX/Windows even inside a 
single location, so how could this really be handled? In my opinion, 
there should be a way to tell GCC that it should emit UNIX-style paths 
with the /cygdrive notion and backslashes replaced by forward ones.

How do you do that in your setups?

Thanks,

Philipp