Re: [Boost-build] specifying libraries on the link line, was "incorrect library names embedded on hp-ux ia64"

Subject: Re: [Boost-build] specifying libraries on the link line, was "incorrect library names embedded on hp-ux ia64"
From: Jim Gallagher (jim_at_[hidden])
Date: 2009-06-11 14:15:41

>> OK, I have learned more over at the HP IT Resource Center. On hp-ux, a
>> dependent shared lib supplied to the linker by a path will have the
>> supplied path embedded as the dependent library name
>> (<http://docs.hp.com/en/9482/linkertasks.htm#notrecordinglinktime>).
>> This would appear to be a good thing only if you are linking against
>> libraries that are in their final installed location and you supply
>> the full path. Do other unix variants work the same?
>
>Usual unix variants have a special option to make a shared library
>contain 'soname'. If a executable is linking to a shared library,
>it will reference it via 'soname', not the name specified on the link
>line. Can you figure of HPUX has something like that>

Yes, I did run across that. On hp-ux it is +h<internal name>. However,
it doesn't seem to work when multiple libs are involved. For example,
if I have three libs, foo, bar and baz, bar depends on foo and baz depends
on bar, and I add appropriate build requirements using +h:
   <toolset>acc:<linkflags>-Wl,+h,libfoo.so

Libbar links fine, but libbaz does not:

$ for DIR in foo bar baz; do^Jcd $DIR^Jbjam clean^Jbjam -d+2^Jcd ..^Jdone
...found 1 target...
...updating 1 target...
common.Clean clean
...updated 1 target...
acc.compile.c bin/acc/debug/foo.o

    aCC -Ae -c    +d +Z -g   -o "bin/acc/debug/foo.o" "foo.c"

acc.link.dll bin/acc/debug/libfoo.so

    aCC -AA -b -g -Wl,+h,libfoo.so -o "bin/acc/debug/libfoo.so"
"bin/acc/debug/foo.o"

...found 1 target...
...updating 1 target...
common.Clean clean
...updated 1 target...
acc.compile.c bin/acc/debug/bar.o

    aCC -Ae -c    +d +Z -g -I"../foo"  -o "bin/acc/debug/bar.o" "bar.c"

acc.link.dll bin/acc/debug/libbar.so

    aCC -AA -b -g -Wl,+h,libbar.so -o "bin/acc/debug/libbar.so"
"bin/acc/debug/bar.o" "../foo/bin/acc/debug/libfoo.so"

...found 1 target...
...updating 1 target...
common.Clean clean
...updated 1 target...
acc.compile.c bin/acc/debug/baz.o

    aCC -Ae -c    +d +Z -g -I"../bar" -I"../foo"  -o
"bin/acc/debug/baz.o" "baz.c"

acc.link.dll bin/acc/debug/libbaz.so

    aCC -AA -b -g -Wl,+h,libbaz.so -o "bin/acc/debug/libbaz.so"
"bin/acc/debug/baz.o" "../bar/bin/acc/debug/libbar.so"
"../foo/bin/acc/debug/libfoo.so"

ld: Can't find dependent library "libfoo.so"
Fatal error.
...failed updating 1 target...

Yet, both libfoo.so and libbar.so appear to have the correct
dependencies and embedded names:
$ elfdump -L foo/bin/acc/debug/libfoo.so

foo/bin/acc/debug/libfoo.so:

                *** DYNAMIC Section ***

.dynamic:

Index   Tag      Value

0       Soname   libfoo.so
1       Runpath  /usr/lib/hpux32:/opt/langtools/lib/hpux32
2       Flags    0x0
3       HP Flags 0x0
4       Link tab 0x40010010
5       Hash     0x40002e8
6       Dynstr   0x4000278
7       Dynsym   0x4000218
8       PltRsrv  0x40010000
9       GSTHshVl 0x4000368
10      GSTVersn 0x1
11      HPTime   Thu Jun 11 11:06:53 2009
12      HPChksum 0xf6566078
13      HPSyCksm 0x509b87c5
14      Strsz    0x6f
15      Syment   0x10

$ elfdump -L bar/bin/acc/debug/libbar.so

bar/bin/acc/debug/libbar.so:

                *** DYNAMIC Section ***

.dynamic:

Index   Tag      Value

0       Needed   libfoo.so
1       Soname   libbar.so
2       Runpath  /usr/lib/hpux32:/opt/langtools/lib/hpux32
3       Flags    0x0
4       HP Flags 0x0
5       Link tab 0x40010018
6       Hash     0x4000340
7       Dynstr   0x40002c0
8       Dynsym   0x4000250
9       PltRsrv  0x40010010
10      GSTHshVl 0x40003d8
11      GSTVersn 0x1
12      HPTime   Thu Jun 11 11:06:55 2009
13      HPChksum 0xcea03a5d
14      HPSyCksm 0xa65c4ebe
15      Rela     0x4000368
16      Relasz   0xc
17      Pltrel   0x7
18      Jmprel   0x4000368
19      Pltrelsz 0xc
20      Relaent  0xc
21      Strsz    0x7d
22      Syment   0x10

I think it should work, but it doesn't.

>
>>
>> So, how can I make boost-build tell the linker about dependent libs
>> the normal unix way, using -L<search dir> -l<lib name>?
>
>It's not possible now. I can change to do it this way, but please check
>if some soname equivalent is available.
>
>- Volodya

Thanks,
Jim