Re: Building Emacs-cvs on Cygwin

[Eli Zaretskii]

> Date: Sat, 23 Sep 2006 23:19:27 +0200 (MET DST)
> From: Angelo Graziosi <address@hidden>
> cc: address@hidden
> > 
> > Can you please add -v to the compilation command line, like this:
> > 
> >   gcc -v -gdwarf-2 -g3 hello.c -o hello
> > 
> > and post here everything that is displayed by the compiler?
> > 
> 
> 
> This is the output:
> ----------------------------------------------------------------
> $ gcc -v -gdwarf-2 -g3 hello.c -o hello
> Reading specs from /usr/lib/gcc/i686-pc-cygwin/3.4.4/specs
> Configured with: /usr/build/package/orig/test.new4/gcc-3.4.4-2/configure
> --verbose --prefix=/usr --exec-prefix=/usr --sysconfdir=/etc --libdir=/usr/lib
> --libexecdir=/usr/lib --mandir=/usr/share/man --infodir=/usr/share/info
> --enable-languages=c,ada,c++,d,f77,pascal,java,objc --enable-nls
> --without-included-gettext --enable-version-specific-runtime-libs --without-x 
> --enable-libgcj
> --disable-java-awt --with-system-zlib --enable-interpreter 
> --disable-libgcj-debug
> --enable-threads=posix --enable-java-gc=boehm --disable-win32-registry
> --enable-sjlj-exceptions
>  --enable-hash-synchronization --enable-libstdcxx-debug
> Thread model: posix
> gcc version 3.4.4 (cygming special, gdc 0.12, using dmd 0.125)
>  /usr/lib/gcc/i686-pc-cygwin/3.4.4/cc1.exe -quiet -v -dD -D__CYGWIN32__
> -D__CYGW
> IN__ -Dunix -D__unix__ -D__unix -idirafter
> /usr/lib/gcc/i686-pc-cygwin/3.4.4/../
> ../../../include/w32api -idirafter
> /usr/lib/gcc/i686-pc-cygwin/3.4.4/../../../..
> /i686-pc-cygwin/lib/../../include/w32api hello.c -quiet -dumpbase hello.c
> -mtune=pentiumpro -auxbase hello-gdwarf-2 -g3 -version -o
> /c/DOCUME~1/Angelo/IMPOST~1/Temp/ccqUrPqN.s
> ignoring nonexistent directory
> "/usr/lib/gcc/i686-pc-cygwin/3.4.4/../../../../i686-pc-cygwin/include"
> ignoring duplicate directory
> "/usr/lib/gcc/i686-pc-cygwin/3.4.4/../../../../i686-pc-cygwin/lib/../../include/w32api"
> #include "..." search starts here:
> #include <...> search starts here:
>  /usr/local/include
>  /usr/lib/gcc/i686-pc-cygwin/3.4.4/include
>  /usr/include
>  /usr/lib/gcc/i686-pc-cygwin/3.4.4/../../../../include/w32api
> End of search list.
> GNU C version 3.4.4 (cygming special, gdc 0.12, using dmd
> 0.125) (i686-pc-cygwin
> )
>         compiled by GNU C version 3.4.4 (cygming special, gdc 0.12, using
> dmd 0.125).
> GGC heuristics: --param ggc-min-expand=100 --param ggc-min-heapsize=131072
>  /usr/lib/gcc/i686-pc-cygwin/3.4.4/../../../../i686-pc-cygwin/bin/as.exe
> -o /c/D
> OCUME~1/Angelo/IMPOST~1/Temp/ccLc4MTM.o
> /c/DOCUME~1/Angelo/IMPOST~1/Temp/ccqUrPq
> N.s
>  /usr/lib/gcc/i686-pc-cygwin/3.4.4/collect2.exe -Bdynamic
> --dll-search-prefix=cy
> g -o hello.exe /usr/lib/gcc/i686-pc-cygwin/3.4.4/../../../crt0.o
> -L/usr/lib/gcc/
> i686-pc-cygwin/3.4.4 -L/usr/lib/gcc/i686-pc-cygwin/3.4.4
> -L/usr/lib/gcc/i686-pc-cygwin/3.4.4/../../.. 
> /c/DOCUME~1/Angelo/IMPOST~1/Temp/ccLc4MTM.o -lgcc
> -lcygwin
>  -luser32 -lkernel32 -ladvapi32 -lshell32 -lgcc

Thanks.

And after all this, "gdb ./hello.exe" _still_ says that hello.c was
compiled with stabs debugging info?

If so, please post this information to the Cygwin mailing list and ask
for the experts there to comment on these two problems: (1) that "gcc -g"
produces a program for which GDB says that it find no debugging
symbols, and (2) that "gcc -gdwarf-2" produces a program for which GDB
says that it was compiled with stabs debugging format, not DWARF 2
debugging format.  There are hints in what GCC displays which suggest
that perhaps DWARF 2 is not supported at all by the Cygwin port of
GCC.

(This sounds like a side issue for the original problem, but I think
we need to solve this first, before we continue debugging the crash.
DWARF 2 debug info is much more powerful than stabs, especially when
looking at function call stack backtraces, so I'd like to find a way
to build Emacs with DWARF 2 debug info.  And, on top of that, the
strange behavior of GCC/GDB wrt debugging symbols is something that
might mean we misunderstand some important aspect of what is going
on.)