Re: [ECOS] Pure trick for _inpure_ptr and modern toolchains

[Sergei Gavrikov <w3sg at SoftHome dot net>]

On Fri, Oct 19, 2007 at 12:34:08AM +0300, Sergei Gavrikov wrote:
> Hi,
> 
> Last days I built a few a bit modern toolchains for eCos and played with
> them. The stuff was binutils-1.16, newlib-1.14, gcc-*-3.4.4. And I found
                      ^^^^^^^^^^^^^
                                    It's 2.16 certainly :-)

> that for such test builds you can easy resolve the '_impure_ptr issue'
> in a bloodless manner just using the <target>-ar. Well, I had disliked to
> mess up the toolchain or eCos sources to keep the peace.
> 
> SYNOPSIS
> 
> Build eCos "as is" using modern toolchain
> 
> ecosconfig new pid
> ecosconfig tree
> make -s
> headers finished
> build finished
> make -s tests TESTS=tests/cxxsup -C infra/current
> /gnutools/arm-elf/lib/gcc/arm-elf/3.4.4/../../../../arm-elf/lib/libsupc++.a(vterminate.o): In function `__gnu_cxx::__verbose_terminate_handler()':
> /test/src/gcc-3.4.4/libstdc++-v3/libsupc++/vterminate.cc:94: undefined reference to `_impure_ptr'
> collect2: ld returned 1 exit status
> make: *** [/tmp/build/install/tests/infra/current/tests/cxxsupp] Error 1
> 
> 
> "Tricked" eCos build (use extra commands <target>-gcc, <target>-ar)
> 
> ecosconfig new pid
> ecosconfig tree
> make -s
> headers finished
> build finished
> cat <<_EOF >impure.c
> void *_impure_ptr;
> _EOF
> arm-elf-gcc -c impure.c
> arm-elf-ar q install/lib/libtarget.a impure.o
> make -s tests TESTS=tests/cxxsup -C infra/current
> 
> Silent GCC... Yep, I like it!
> 
> For pedants, that "impure.c" can be like the below.
> 
> --------------------------------------------------------------->8
> #include <sys/reent.h>
> #include <stdio.h>
> 
> static struct _reent __impure_data = _REENT_INIT (__impure_data);
> struct _reent  *_impure_ptr = &__impure_data;
> 
> --------------------------------------------------------------->8
> 
> Note: <target>-gcc knows where to find newlib headers.
> 
> Playing a bit with GCC-3.4.4 (arm-elf, i386-elf, powerpc-eabi) I found
> what it doesn't know more about -mno-short-load-words flag. It seems,
> you can quite replace that by -mno-alignment-traps flag.
> 
> And when I tried to make all eCos tests with new GCC-3.4.4 I got the
> warnings "inlining failed" at <include/cyg/libc/signals/signal.inl>. I
> have got no warnings using stable eCos compiler (GCC-3.2.1). But, the
> medicine was just to specify '--param inline-unit-growth=150'. It was
> strange, because man page arm-elf-gcc.1 from GCC-3.4.4 suite said: The
> default value is 150.
> 
> If this is interesting for community, I can attach new patches and
> simple bash script to get the same toolchains.
> 
> One note: I won't be able to manage your experiences and success.  Host
> system to build the toolchains was just a "home" Linux distro -- Ubuntu
> Feisty Fawn.
> 
> Between you and me, it would seem what eCos official guide how to build
> own toolchain (http://ecos.sourceware.org/build-toolchain.html) is an
> obsolete document. No, it isn't. I was guided this HOWTO only.
> 
> 
> --
> Sergei
> 
> 
> -- 
> Before posting, please read the FAQ: http://ecos.sourceware.org/fom/ecos
> and search the list archive: http://ecos.sourceware.org/ml/ecos-discuss

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