CLHEP%20Infrastructure%20Improvements

1
CLHEP Infrastructure Improvements

• CHEP 2004
• Lynn Garren, FNAL
• and
• Andreas Pfeiffer, CERN

2
What is CLHEP?

• HEP-specific foundation and utility classes that
  provide
• Random number generators
• Physics vectors
• Particle data table
• Etc.
• Used by Geant4, ThePeg,

3
The problem

• CLHEP has traditionally been distributed as one
  large package which builds one large library
• Some packages are updated more frequently than
  CLHEP releases
• Users may want only some of the packages
• Users may want to get single package updates

4
The solution

• Enable separate builds of each CLHEP package
• Each package needs its own configure
• Have to worry about dependencies
• Still build entire CLHEP
• Default option
• Use infrastructure in each package

5
Other changes

• Use namespace everywhere
• Namespace CLHEP if no other namespace
• Add exception handling packages
• Exceptions, Cast, Refcount
• Disabled by default
• Geometry package substantially rewritten
• Updates to several packages

6
Code Structure

• Old source code
• CLHEP/ltpackagegt (.cc, .hh, .h, .icc)
• CLHEP/ltpackagegt/doc
• CLHEP/test (tests for all packages)
• New source code
• CLHEP/ltpackagegt/ltpackagegt (.h, .hh, .icc)
• CLHEP/ltpackagegt/src (.cc)
• CLHEP/ltpackagegt/doc
• CLHEP/ltpackagegt/test (tests for this package)

7
Concerns

• Backwards compatibility
• Headers invoked as CLHEP/ltpackagegt/myheader.h
• Notice that this does not match the source code
  structure
• Create a temporary header directory when building

8
Supported Compilers

• gcc 3.3 (all operating systems)
• gcc 2.95.2 (only for backwards compatibility)
• gcc 3.4 tested, but not yet officially supported
• Solaris CC 5.4
• Windows VisualC 7.1
• Must compile under cygwin
• Do not need to be in cygwin to use libraries

9
Releases

• Two concurrent releases
• CLHEP 1.9.x.x is backwards compatible
• using namespace CLHEP in headers
• CLHEP.h and package defs.h headers
• Supports gcc 2.95.2
• CLHEP 2.0.x.x is NOT backwards compatible
• Otherwise identical to 1.9
• No using namespace statements in headers
• CLHEP.h replaced by package defs.h headers
• Does not support gcc 2.95.2
• Major source code changes in CLHEP 2.1.x.x

10
Using Autotools

• Take advantage of the power of autotools
• Recent versions required
• support operating system and compiler
  configurations
• autoconf 2.59 or later
• Configure
• automake 1.9.1 or later
• Makefiles
• libtool 1.9b or later
• Build shared and static libraries
• Lots of knowledge about compilers

11
Infrastructure Files

• These files are used by developers, not
  installers
• CLHEP/bootstrap
• Run autotools commands for this and all package
  directories
• CLHEP/ltpackagegt/bootstrap
• CLHEP/configure.in
• CLHEP/ltpackagegt/configure.in
• Makefile.am
• In top directory and all subdirectories
• CLHEP/setup.cygwin-VC71
• For Windows VisualC 7.1

12
configure.in

• Identify the package and initialize autotools
• AC_INIT(CLHEP Vector, 1.9.1.1, CLHEP_at_cern.ch,
  Vector)
• AC_CONFIG_SRCDIR(src/AxisAngle.cc)
• tell autoconf the name of the configuration
  header
• AM_CONFIG_HEADER(Vector/defs.h)
• various files to be generated from xxx.in
• AC_CONFIG_FILES(Vector/Makefile)

13
configure.in boilerplate for defs.h

• AH_TOP(ifndef VECTOR_DEFS_H
• define VECTOR_DEFS_H)
• .
• backwards compatibility
• AH_VERBATIM(ENABLE_BACKWARDS_COMPATIBILITY,/
  backwards compatibility will be enabled ONLY in
  CLHEP 1.9 /
• ifndef ENABLE_BACKWARDS_COMPATIBILITY
• define ENABLE_BACKWARDS_COMPATIBILITY
• endif)
• AH_BOTTOM(endif // VECTOR_DEFS_H)

14
configure.in compiler section

• Locate a C compiler
• AC_PROG_CXX(cl g c aCC CC cxx cc FCC KCC
  RCC xlC_r xlC gpp)
• Use it hereinafter
• AC_LANG(C)

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configure.in compiler flags

• case "CXX" in
• g)
• case "target" in
• --linux) AM_CXXFLAGS"-O -ansi -pedantic
  -Wall -D_GNU_SOURCE"
• ) AM_CXXFLAGS"-O -ansi -pedantic -Wall"
• esac
• cl) AM_CXXFLAGS"-EHsc"
• ) echo UNEXPECTED CHOICE OF C COMPILER CXX
• esac
• tell configure to use AM_CXXFLAGS when building
  the Makefile
• must be called after defining AM_CXXFLAGS
• AC_SUBST(AM_CXXFLAGS)

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configure.in - finalizing

• Checks already exist for most C deficiencies
• Check for needed header files
• AC_CHECK_HEADERS(sstream)
• Check for needed typedefs, structures, and
  compiler characteristics
• AC_CHECK_TYPES(ptrdiff_t)
• Finish up
• AC_OUTPUT

17
CLHEP/ltpackagegt/Makefile.am

• Process this file with automake to produce
  Makefile.in
• includedir (prefix)/include/CLHEP
• SUBDIRS order is very important this is the
  processing order
• SUBDIRS Vector . src test
• list all subdirectories - for distribution and
  cleaning
• DIST_SUBDIRS Vector . src test doc
• create temporary CLHEP header tree
• all-local (top_builddir)/CLHEP
• add rules to build documentation
• docs
• cd doc (MAKE) (AM_MAKEFLAGS)

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CLHEP/ltpackagegt/ltpackagegt/Makefile.am

• makefile for the header subdirectory
• includedir (prefix)/include/CLHEP
• tempincludedir (TEMPDIR)/CLHEP/_at_PACKAGE_at_
• list each header explicitly
• be sure to also list defs.h
• pkginclude_HEADERS \
• AxisAngle.h AxisAngle.icc TwoVector.h
  defs.h
• copy headers into (tempincludedir)
• this instruction is called by various
  CLHEP/ltpackagegt/Makefiles
• install-tmpHEADERS

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CLHEP/ltpackagegt/src/Makefile.am

• INCLUDES -I(top_builddir)
• lib_LTLIBRARIES libCLHEP-Vector-_at_VERSION_at_.la
• libCLHEP_Vector__at_VERSION_at__la_SOURCES \
• AxisAngle.cc Boost.cc \
• ..
• ThreeVector.cc ThreeVectorR.cc
  TwoVector.cc
• List each file explicitly
• Not much here
• configure generates final Makefile with
  compilation rules

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Building CLHEP

• Get a source code tarball
• bootstrap has already been run
• Create a separate build directory
• Identify your install directory
• cd build-directory
• /CLHEP/configure prefix/fullpath/installdir
  options
• make
• make check
• make install
• make docs
• make install-docs

21
Updating a single package

• Get the source from a source code tarball
• cd build-directory
• Define CLHEP_DIR
• Allows you to get headers from standard
  installation
• Choice of CLHEP_DIR was arbitrary
• /CLHEP/ltpackagegt/configure options
• make
• make check
• make install

22
configure options

• CXXxyz (set the C compiler)
• CXXFLAGSsome stuff
• Appends to compiler flags defined in configure.in
• --disable-shared (build only static libraries)
• --enable-exceptions (enable Exceptions package)
• --help
• Using environmental variables is not recommended

23
clheplib utility

• Lists individual package libraries needed for
  linking
• clheplib
• -L/fullpath/lib lCLHEP-1.9.1.1
• clheplib HepMC
• -L/fullpath/lib lCLHEP-HepMC-1.9.1.1
• lCLHEP-Geometry-1.9.1.1
• lCLHEP-HepPDT-1.9.1.1 lCLHEP-Vector-1.9.1.1
• Also, clhep-config --lib --include

24
Source code distribution

• Source code tarball
• bootstrap has already been run
• Do not need autotools
• Recommended for installers
• Source code also available from cvs
• Must have autotools and run bootstrap
• Only recommended for code developers

25
Comments about Autotools

• Pro
• Very smart
• Allow lots of configuration
• Build libraries cleanly and properly
• Checks times and will reconfigure if necessary
• Con
• Sometimes too smart for its own good
• Libtool knows everything about building for
  various operating system and compiler
  combinations
• Will sometimes reconfigure when unnecessary
• Has been very useful for CLHEP