Summary:
When apps or other libraries link against a library with symbol
versions, the version string is recorded in the import table, and used
at runtime to resolve the symbol back to a library that provides that
version (vaguely like how two-level namespaces work in Mach-O). ld's
--default-symver flag tags every exported symbol with a symbol version
string equal to the library's soname. Using --default-symver means
multiple versions of libLLVM can coexist within the same process, at
least to the extent that they don't try to pass data between each
other's llvms.
As an example, imagine a language like Rust using llvm for CPU codegen,
binding to OpenGL, with Mesa as the OpenGL implementation using llvm for
R600 codegen. With --default-symver Rust and Mesa will resolve their
llvm usage to the version each was linked against, which need not match.
(Other ELF platforms like BSD and Solaris might have similar semantics,
I've not checked.)
This is based on an autoconf version of this patch by Adam Jackson.
This new option can be used to add --default-symver to the linker flags
for libLLVM.so.
Reviewers: beanz
Reviewed By: beanz
Subscribers: mgorny, llvm-commits
Differential Revision: https://reviews.llvm.org/D30997
llvm-svn: 302026
Summary:
This patch adds a very simple linker script to version the lib's symbols
and thus trying to avoid crashes if an application loads two different
LLVM versions (as long as they do not share data between them).
Note that we deliberately *don't* make LLVM_5.0 depend on LLVM_4.0:
they're incompatible and the whole point of this patch is
to tell the linker that.
Avoid unexpected crashes when two LLVM versions are used in the same process.
Author: Rebecca N. Palmer <rebecca_palmer@zoho.com>
Author: Lisandro Damían Nicanor Pérez Meyer <lisandro@debian.org>
Author: Sylvestre Ledru <sylvestre@debian.org>
Bug-Debian: https://bugs.debian.org/848368
Reviewers: beanz, rnk
Reviewed By: rnk
Subscribers: mgorny, llvm-commits
Differential Revision: https://reviews.llvm.org/D31524
llvm-svn: 300496
Summary:
This fixes a few things that used to work with a Makefile build, but were broken in cmake.
1. Treat MINGW like a Linux system.
2. The shlib should never contain other shared libraries.
Patch By: Valentin Churavy
Reviewers: axw, beanz
Subscribers: modocache, beanz, mgorny
Differential Revision: https://reviews.llvm.org/D25865
llvm-svn: 285737
This should actually address PR27855. This results in adding references to the system libs inside generated dylibs so that they get correctly pulled in when linking against the dylib.
llvm-svn: 270723
Autoconf used to support setting LLVM_VERSION_INFO and there is some code filtered around llvm in Support/CommandLine.cpp and LTO/LTOCodeGenerator.cpp that uses it if it is set.
We also shouldn't be explicitly setting it as a define on llvm-shlib. It is pointless there because there is no code using it in llvm-shlib, and it is better to have it as part of the generated config.h so that it is available everywhere.
llvm-svn: 267490
If anybody is actually using this, it probably doesn't do what they
think it does. This actually causes the dylib to *export* a
__cxa_atexit symbol, so anything that links it probably loses their
exit time destructors as well as disabling LLVM's.
This just removes the option entirely. If somebody does need this
behaviour we should figure out a more principled way to do it.
This is effectively a revert of r223805.
llvm-svn: 263498
Summary:
This patch is provided in preparation for removing autoconf on 1/26. The proposal to remove autoconf on 1/26 was discussed on the llvm-dev thread here: http://lists.llvm.org/pipermail/llvm-dev/2016-January/093875.html
"I felt a great disturbance in the [build system], as if millions of [makefiles] suddenly cried out in terror and were suddenly silenced. I fear something [amazing] has happened."
- Obi Wan Kenobi
Reviewers: chandlerc, grosbach, bob.wilson, tstellarAMD, echristo, whitequark
Subscribers: chfast, simoncook, emaste, jholewinski, tberghammer, jfb, danalbert, srhines, arsenm, dschuff, jyknight, dsanders, joker.eph, llvm-commits
Differential Revision: http://reviews.llvm.org/D16471
llvm-svn: 258861
Summary:
This change makes the CMake build system generate libraries for Linux and Darwin matching the makefile build system.
Linux libraries follow the pattern lib${name}.${MAJOR}.${MINOR}.so so that ldconfig won't pick it up incorrectly.
Darwin libraries are not versioned.
Note: On linux the non-versioned symlink is generated at install-time not build time. I plan to fix that eventually, but I expect that is good enough for the purposes of fixing this bug.
Reviewers: loladiro, tstellarAMD
Subscribers: axw, llvm-commits
Differential Revision: http://reviews.llvm.org/D13841
llvm-svn: 252093
Summary:
We've had a lot of discussion in the past about the meaningful and useful default behaviors for the llvm-shlib tool. The original implementation was heavily geared toward Apple's use, and I think that was wrong. This patch seeks to correct that.
I've removed the LLVM_DYLIB_EXPORT_ALL variable and made libLLVM export everything by default.
I've also added a new target that is only built on Darwin for libLLVM-C as a library that re-exports the LLVM-C API. This library is not built on Linux because ELF doesn't support re-export libraries in the same way MachO does.
Reviewers: chapuni, resistor, bogner, axw
Subscribers: llvm-commits
Differential Revision: http://reviews.llvm.org/D13842
llvm-svn: 251411
Summary:
This diff attempts to address the concerns raised in
http://reviews.llvm.org/D12488.
We introduce a new USE_SHARED option to llvm_config,
which, if set, causes the target to be linked against
libLLVM.
add_llvm_utility now uniformly disables linking against
libLLVM. These utilities are not intended for distribution,
and this keeps the option handling more centralised.
llvm-shlib is now processes before any other "tools"
subdirectories, ensuring the libLLVM target is defined
before its dependents.
One main difference from what was requested: llvm_config
does not prune LLVM_DYLIB_COMPONENTS from the components
passed into explicit_llvm_config. This is because the "all"
component does something special, adding additional
libraries (namely libLTO). Adding the component libraries
after libLLVM should not be a problem, as symbols will be
resolved in libLLVM first.
Finally, I'm not really happy with the
DISABLE_LLVM_LINK_LLVM option, but I'm not sure of a
better way to get the following:
- link all tools and shared libraries to libLLVM if
LLVM_LINK_LLVM_DYLIB is set
- some way of explicitly *not* doing so for utilities
and libLLVM itself
Suggestions for improvement here are particularly welcome.
Reviewers: beanz
Subscribers: llvm-commits
Differential Revision: http://reviews.llvm.org/D12590
llvm-svn: 246918
Summary:
Three closely related changes, to have a mode in which we link all
executables and shared libraries against libLLVM.
1. Add a new LLVM_LINK_LLVM_DYLIB cmake option, which, when ON, will link
executables and shared libraries against libLLVM. For this to work, it
is necessary to also set LLVM_BUILD_LLVM_DYLIB and LLVM_DYLIB_EXPORT_ALL.
It is not strictly necessary to set LLVM_DISABLE_LLVM_DYLIB_ATEXIT, but
we also default to OFF in this mode, or tools tend to misbehave (e.g.
stdout may not flush on exit when output is buffered.)
llvm-config and Tablegen do not use libLLVM, as they are dependencies of
libLLVM.
2. Modify llvm-go to take a new flag, "linkmode=component-libs|dylib".
Depending on which one is passed (default is component-libs), we link
with the individual libraries or libLLVM respectively. We pass in dylib
when LLVM_LINK_LLVM_DYLIB is ON.
3. Fix LLVM_DYLIB_EXPORT_ALL on Linux, and expand the symbols exported to
actually export all. Don't strip leading underscore from symbols on Linux,
and make sure we get all exported symbols and weak-with-default symbols
("W" in nm output). Without these changes, passes won't load because
the "Annotate..." symbols defined in lib/Support/Valigrind.cpp are not
found.
Testing:
- Ran default build ("ninja") with LLVM, clang, compiler-rt, llgo, lldb.
- Ran "check", "check-clang", "check-tsan", "check-libgo" targets. I've
never had much success with LLDB tests, and llgoi is currently broken
so check-llgo fails for an unrelated reason.
- Ran "lldb" to ensure it loads.
Reviewers: chandlerc, beanz, pcc, rnk
Subscribers: rnk, chapuni, sylvestre.ledru, llvm-commits
Differential Revision: http://reviews.llvm.org/D12488
llvm-svn: 246527
folding the code into the main Analysis library.
There already wasn't much of a distinction between Analysis and IPA.
A number of the passes in Analysis are actually IPA passes, and there
doesn't seem to be any advantage to separating them.
Moreover, it makes it hard to have interactions between analyses that
are both local and interprocedural. In trying to make the Alias Analysis
infrastructure work with the new pass manager, it becomes particularly
awkward to navigate this split.
I've tried to find all the places where we referenced this, but I may
have missed some. I have also adjusted the C API to continue to be
equivalently functional after this change.
Differential Revision: http://reviews.llvm.org/D12075
llvm-svn: 245318
This reverts commit r230062.
Debian stable (wheezy) ships still with cmake 2.8.9.
The commit broke my LLVM/Polly buildbot, to my knowledge our only Linux+cmake
buildbot.
llvm-svn: 230343
*numerous* places where it was missing in the CMake build. The primary
change here is that the suffix is now actually used for all of the lib
directories in the LLVM project's CMake. The various subprojects still
need similar treatment.
This is the first of a series of commits to try to make LLVM's cmake
effective in a multilib Linux installation. I don't think many people
are seriously using this variable so I'm hoping the fallout will be
minimal. A somewhat unfortunate consequence of the nature of these
commits is that until I land all of them, they will in part make the
brokenness of our multilib support more apparant. At the end, things
should actually work.
llvm-svn: 224919
Summary:
This is desirable for WebKit and other clients of the llvm-shlib because C++ exit time destructors have a tendency to crash when invoked from multi-threaded applications.
Ideally this option will be temporary, because the ideal fix is to just not have exit time destructors.
Reviewers: chapuni, ributzka
Reviewed By: ributzka
Subscribers: llvm-commits
Differential Revision: http://reviews.llvm.org/D6572
llvm-svn: 223805
FIXME: It should work on not only Linux but elf-targeting gnu ld.
For example if LLVM_DYLIB_COMPONENTS is "BitWriter Support", CMake emits the command line like;
-Wl,--whole-archive
lib/libLLVMBitWriter.a
lib/libLLVMSupport.a *1
-Wl,--no-whole-archive
lib/libLLVMCore.a
lib/libLLVMSupport.a *2
-lrt -ldl -ltinfo -lpthread -lm
It works since symbols in LLVMCore is resolved with not *2 but *1.
Unfortunately, --gc-sections is not powerful in this case to prune unused "visibility(default)" entries.
I am still experimenting other way not to rely on --whole-archive.
llvm-svn: 221591
Summary:
This patch adds a new CMake build setting LLVM_BUILD_LLVM_DYLIB, which defaults to OFF. When set to ON, this will generate a shared library containing most of LLVM. The contents of the shared library can be overriden by specifying LLVM_DYLIB_COMPONENTS. LLVM_DYLIB_COMPONENTS can be set to a semi-colon delimited list of any LLVM components that you llvm-config can resolve.
On Windows, unless you are using Cygwin, you must specify an explicit symbol export file using LLVM_EXPORTED_SYMBOL_FILE. On Cygwin and all unix-like platforms if you do not specify LLVM_EXPORTED_SYMBOL_FILE, an export file containing only the LLVM C API will be auto-generated from the list of LLVM components specified in LLVM_DYLIB_COMPONENTS.
Reviewers: rnk
Reviewed By: rnk
Subscribers: rnk, llvm-commits
Differential Revision: http://reviews.llvm.org/D5890
llvm-svn: 220490
"Create a default symver on Linux like ELF OSes."
Fails the build under Debian with ld.gold:
/usr/bin/ld.gold: --default-symver: unknown option
llvm-svn: 214482
We were using libLLVM-Major.Minor.Patch.so for the soname, but we
need the soname to stay consistent for all Major.Minor.* releases
otherwise operating system distributors will need to rebuild all
packages that link with LLVM every time there is a new point release.
This patch also reverses the compatibility symlink, so
libLLVM-Major.Minor.Patch.so is now a symlink that points
to libLLVM-Major-Minor.so.
llvm-svn: 208721
We were using libLLVM-Major.Minor.Patch.so for the soname, but we
need the soname to stay consistent for all Major.Minor.* releases
otherwise operating system distributors will need to rebuild all
packages that link with LLVM every time there is a new point release.
This patch also reverses the compatibility symlink, so
libLLVM-Major.Minor.Patch.so is now a symlink that points
to libLLVM-Major-Minor.so.
llvm-svn: 208708
The shared library generated by autoconf will now be called
libLLVM-$(VERSION_MAJOR).$(VERSION_MINOR).$(VERSION_PATCH)$(VERSION_SUFFIX).so
and a symlink named
libLLVM-$(VERSION_MAJOR).$(VERSION_MINOR)$(VERSION_SUFFIX).so will
also be created in the install directory.
llvm-svn: 202720
This centralizes the Makefile handling of -install_name and -rpath. It also
moves the cmake build to using @rpath. The reason being that libclang needs it,
and it works for everything else.
A followup patch will move clang to using this and then there will be a single
point to edit to support other systems.
llvm-svn: 202499
This reduces the size of clang-format from 22 MB to 1.8 MB, diagtool goes from
21 MB to 2.8 MB, libclang.so goes from 29 MB to 20 MB, etc. The size of the
bin/ folder shrinks from 270 MB to 200 MB.
Targets that support plugins and don't already use EXPORTED_SYMBOL_FILE
(which libclang and libLTO already do) can set NO_DEAD_STRIP to opt out.
llvm-svn: 198087
This kind of simplification is sometimes useful, but in general it's not correct.
As GNU/kFreeBSD is an hybrid system, for kernel-related issues we want to match the
build definitions used for FreeBSD, whereas for userland-related issues we want to
match the definitions used for other systems with Glibc.
The current modification adjusts the build system so that they can be distinguished,
and explicitly adds GNU/kFreeBSD to the build checks in which it belongs.
Fixes bug #16444.
Patch by Robert Millan in the context of Debian.
llvm-svn: 185311
Specifying the load address for Darwin i386 dylibs was a performance
optimization for dyld that is not relevant for x86_64 or arm. We can just
remove this now.
llvm-svn: 183230
Tom Stellard