Re: [flashrom] [PATCH] More robust libpci detection

[Idwer Vollering]

2010/3/22 Carl-Daniel Hailfinger
> On 01.03.2010 16:34, Carl-Daniel Hailfinger wrote:
> > On 28.02.2010 16:30, Idwer Vollering wrote:
> > > 2010/2/26 Carl-Daniel Hailfinger
> > > > Idwer reported problems with the current libpci check on
> > > >
> > > > FreeBSD 8.0-RELEASE i386
> > > >
> > > > This is caused by a strict linker. Parsing linker error messages is an
> > > > exercise in futility, so I implemented fallback library detection with
> > > > $CC --print-file-name.
> > > > This fallback will fail on llvm-clang (llvm bug 5137), but such
>
> machines
> > > > hopefully have a more permissive linker and will never hit that code
>
> path.
> > > > The fallback will also fail on NetBSD where we should look for
> > > > libpciutils instead, but that hopefully doesn't have a strict linker
> > > > either.
> > > >
> > > > Side note: The configure checks in the Makefile are now so unwieldy
>
> that
> > > > a separate configure script will definitely improve readability.
> > > >
> > > > Signed-off-by: Carl-Daniel Hailfinger <
>
> [e-mail]>
> > > >
> > >
> > > $ gmake
> > > Checking for a C compiler... found.
> > > Checking for libpci headers... found.
> > > Checking for libpci (method 1)... not found.
> > > Checking for dynamic libpci (method 2)... not found.
> > > not found.
> > >
> > > Please install libpci (package pciutils).
> > > See README for more information.
> > >
> > > unavailable.
> > >
> > > Please install libpci (package pciutils).
> > > See README for more information.
> >
> > Ouch. Turns out the patch had one error message too many, a missing
> > semicolon and missing LDFLAGS in some CC calls.
> > New version
> > .
> > Idwer reported problems with the current libpci check on
> > FreeBSD 8.0-RELEASE i386
> > This is caused by a strict linker. Parsing linker error messages is an
> > exercise in futility, so I implemented fallback library detection with
> > $CC --print-file-name.
> > This fallback may cause false positives/negatives on llvm-clang (llvm
> > bug 5137), but such machines hopefully have a more permissive linker and
> > will never hit that code path.
> > The fallback will be unreliable on NetBSD where we should look for
> > libpciutils instead, but that hopefully doesn't have a strict linker
> > either. A fix is easy (replace libpci with PCI_LIB_NAME), but outside
> > the scope of this patch.
> > Tested with error injection at various levels.
>
> Turns out that --print-file-name is totally useless for libraries
> outside the standard hardcoded builtin gcc search path. Oh well. Back to
> some really simple code which should even work. Nice benefit is that we
> use the correct libpci on NetBSD for the check.
>
> Signed-off-by: Carl-Daniel Hailfinger

Acked-by: Idwer Vollering
> Index: flashrom-libpci_robust_detection/Makefile
>
> --- flashrom-libpci_robust_detection/Makefile   (Revision 964)
> +++ flashrom-libpci_robust_detection/Makefile   (Arbeitskopie)
> @@ -279,26 +279,17 @@
>                 echo "Please install libpci headers (package
> pciutils-devel)."; \
>                echo "See README for more information."; echo;
>    \
>                rm -f .test.c .test.o; exit 1)
>   @printf "Checking for libpci... "
>   @$(shell ( echo "#include <pci/pci.h>";            \
>              echo "int main(int argc, char **argv)"; \
>              echo "{ return 0; }"; ) > .test1.c )
>   @$(CC) $(CPPFLAGS) $(CFLAGS) $(LDFLAGS) .test1.c -o .test1 -lpci
>
> $(LIBS) >/dev/null 2>&1 &&     \
>           echo "found." || ( echo "not found."; echo;
>       \
>           echo "Please install libpci (package pciutils).";
>       \
>           echo "See README for more information."; echo;
>        \
>           rm -f .test1.c .test1; exit 1)
>   @printf "Checking if libpci is sufficient... "
>   @printf "Checking if libpci is present and sufficient... "
>   @printf "" > .libdeps
>   @$(CC) $(LDFLAGS) .test.o -o .test -lpci $(LIBS) >/dev/null 2>&1 &&
>                       \
>   @$(CC) $(LDFLAGS) .test.o -o .test $(LIBS) >/dev/null 2>&1 &&
>               \
>          echo "yes." || ( echo "no.";
>              \
>           printf "Checking if libz is present and supplies all needed
>
> symbols...";        \
>           $(CC) $(LDFLAGS) .test.o -o .test -lpci -lz $(LIBS)
> > /dev/null 2>&1 &&          \
>           printf "Checking if libz+libpci are present and
>
> sufficient..."; \
>           $(CC) $(LDFLAGS) .test.o -o .test $(LIBS) -lz >/dev/null
>
> 2>&1 &&                \
>                ( echo "yes."; echo "NEEDLIBZ := yes" > .libdeps ) || ( echo
> "no."; echo;       \
>           echo "Please install libz.";                    \
>           echo "Please install libpci (package pciutils) and/or
>
> libz.";                   \
>                 echo "See README for more information."; echo;
>              \
>                 rm -f .test.c .test.o .test; exit 1) )
>   @rm -f .test.c .test.o .test .test1.c .test1
>   @rm -f .test.c .test.o .test
>
> else
>  pciutils: compiler
>        @printf "" > .libdeps