Re: [Plplot-devel] Comprehensive testing on Cygwin with Tcl/Tk/Itcl/Itk and Ada

[Alan W. I. <ir...@be...>]

On 2015-06-17 10:39-0000 Arjen Markus wrote:

> Hi Alan,
>
>
>
> Hm, something is failing in the non_dynamic tests:
>
> CMakeFiles/pltcl.dir/pltcl.c.o:pltcl.c:(.text+0x20e): undefined reference to `__imp_Pltcl_Init'
>
> CMakeFiles/pltcl.dir/pltcl.c.o:pltcl.c:(.text+0x20e): relocation truncated to fit: R_X86_64_PC32 against undefined symbol `__imp_Pltcl_Init'
>
> So your latest changes regarding the reduction of the llibraries for the non-dynamic drivers seem to have introduced a bug. I have attached the complete tarball.

Hi Arjen:

Thanks for this test.

I. Comments on your setup of this test.

For some reason there was a regression in your X setup so that
you are now encountering that DISPLAY issue again.  The message (in
cmake.out) was

Application initialization failed: no display name and no $DISPLAY
environment variable

I encourage you to automate your X setup to avoid this regression in
behaviour in future.

Also please drop the -DENABLE_itk=OFF workaround which should not be
necessary if you have all Tcl/Tk/Itcl/Itk/Iwidgets packages properly
installed on Cygwin.  And if those are not properly installed, please
fix that.

Also, in retrospect it was a good idea for you to be cautious and test
first with --do_test_interactive no.  But once the current issue is
fixed, I will encourage you to drop that restriction so that all
the Tcl, etc., interactive results can also be run-time tested.

II. Comments on the bug you found.

The link command that is failing above is (after line wrapping at each
white space to help clarify the command and redacting the many irrelevant
parts)

/usr/bin/cc
-Wl,--enable-auto-import
CMakeFiles/pltcl.dir/pltcl.c.o
-o
pltcl.exe
-Wl,--out-implib,libpltcl.dll.a
-Wl,--major-image-version,0,--minor-image-version,0
../../dll/libplplottcltk_Main.dll.a
/usr/lib/itcl3.4/libitcl3.4.dll.a
-ltcl
../../dll/libplplot.dll.a
[...]
/usr/local/lib/libLASi.dll.a
[...]
/usr/local/lib/libshp.a
[...]

II A.  The /usr/local issue.

Sorry I did not notice this issue before.  My assumption is that anything in /usr/local cannot be due to an
official Cygwin install so should be avoided (at least for now). So to follow up on this
I looked for "local" in cmake.out and found the following:

-- TCL_INCLUDE_PATH = /usr/local/include

-- FindShapelib: Found shapelib header directory, /usr/local/include,
and library, /usr/local/lib/libshp.a.

libplplot_LINK_FLAGS =
/usr/lib/libltdl.dll.a;/usr/lib/libdl.a;/usr/local/lib/libshp.a;/usr/lib/libfreetype.dll.a;-lcsirocsa;-lcsironn;-lqhull;-lqsastime

So please do the appropriate /usr/local renaming (perhaps of all of
/usr/local) to force CMake to find the official Cygwin versions of
Tcl, shapelib, and libLASi which I presume you have long-since already
installed.  The result should be no mention of /usr/local in cmake.out
the CMake cache files or any of your build commands.

I suspect all those /usr/local results are leftovers from an epa_build
attempt you did long ago.  At some point you might want to try
epa_build again (but with an install prefix other that /usr/local so
the results don't necessarily take CMake precedence over all others),
but only after you make sure all the official Cygwin packages work.

II B. The linking issue with pltcl that you discovered above.

The above link command for pltcl shows that libplplot
is properly linked.  So one
possibility to explain this is either Pltcl_Init is not defined in the
plplot library or it is defined in that library but not visible.  To
check that, please use the nm command (which likely is already
installed, but if not you should be able to find it in
binutils-2.25-2) as follows:

# Change to _nondynamic_ build directory
cd ../comprehensive_test_disposeable/nondynamic/build_tree/
# Build plplot library (which was cleaned by the script) in the
# nondynamic case
make plplot
# Test for definition of Pltcl_Init in that library
nm --defined-only <library_name> |grep Pltcl_Init

where <library_name> is the appropriate name of the plplot library you
just built.  Here that is src/libplplot.so, but I am aware there are
two locations (in src and in dll) of the plplot library for Cygwin,
and I don't know which one you should be using with the nm command so
you will have to experiment to find which to use with nm.

The result of the above command here is

000000000008f120 T Pltcl_Init

which indicates that symbol is defined in the plplot library
and you should be getting something similar there.

Once you have proved that symbol is defined in the plplot library
the next issue is whether that symbol is externally
visible.  "nm" tests symbol visibility with the --extern-only
option, e.g.,

nm --extern-only --defined-only <library_name> |grep Pltcl_Init

and if Pltcl_Init is externally visible you should get the
same result whether --extern-only is used or not.  And that proved
to be the case here when I compiled with

CXXFLAGS=-O3 -fvisibility=hidden -Wuninitialized
CFLAGS=-O3 -fvisibility=hidden -Wuninitialized

which should make gcc act very similarly on Linux to the way it handles
visibility issues for C or C++ library on Windows.

So from my good visibility results here, I am pretty sure visibility
should not be an issue for you there, but please get back to me with
the Pltcl_Init definition and visibility results via the "nm" command
for the plplot library for the nondynamic case to confirm that (or
not), and we can take it from there.

Alan
__________________________
Alan W. Irwin

Astronomical research affiliation with Department of Physics and Astronomy,
University of Victoria (astrowww.phys.uvic.ca).

Programming affiliations with the FreeEOS equation-of-state
implementation for stellar interiors (freeeos.sf.net); the Time
Ephemerides project (timeephem.sf.net); PLplot scientific plotting
software package (plplot.sf.net); the libLASi project
(unifont.org/lasi); the Loads of Linux Links project (loll.sf.net);
and the Linux Brochure Project (lbproject.sf.net).
__________________________

Linux-powered Science
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