Commit Graph

98 Commits

Author SHA1 Message Date
Qiaojin.Bao cf65271e46 [llvm-shlib] Fix windows build failed while llvm non-standalone building.
While build llvm-project as a sub-project on windows, met a build error: 
libllvm-c.exports /llvm/bin\llvm-nm.exe: error: ...builds/rel64ninja/./lib/LLVMDemangle.lib: no such file or directory
The libllvm-c.exports, libllvm-c.args, and lib/*.lib should under LLVM_BINARY_DIR, using CMAKE_BINARY_DIR will cause 'no such file' error while llvm-project built as a sub-project.
2021-10-19 09:10:11 +01:00
Martin Storsjö 314b5a0efd [llvm-shlib] Fix the i686 MSVC triple check for listing symbols to export in LLVM-C.dll
https://reviews.llvm.org/D47381 / eb46c95c3e
changed the triples set up by GetHostTriple.cmake for i686 MSVC
from i686-pc-win32 to i686-pc-windows-msvc without changing
the corresponding condition in llvm-shlib.

Since then, the 32 bit x86 build of LLVM-C.dll has contained no
exported symbols at all.

Differential Revision: https://reviews.llvm.org/D109493
2021-09-11 19:50:03 +03:00
Martin Storsjö bf6770f9bd [CMake] Don't use -Bsymbolic-functions for MinGW targets
This is an ELF specific option which isn't supported for Windows/MinGW
targets, even if the MinGW linker otherwise uses an ld.bfd like linker
interface.

Differential Revision: https://reviews.llvm.org/D105148
2021-06-30 22:54:26 +03:00
Fangrui Song 4f05f4c8e6 [CMake][ELF] Link libLLVM.so and libclang-cpp.so with -Bsymbolic-functions
llvm-dev message: https://lists.llvm.org/pipermail/llvm-dev/2021-May/150465.html

In an ELF shared object, a default visibility defined symbol is preemptible by
default. This creates some missed optimization opportunities.
-Bsymbolic-functions is more aggressive than our current -fvisibility-inlines-hidden
(present since 2012) as it applies to all function definitions.  It can

* avoid PLT for cross-TU function calls && reduce dynamic symbol lookup
* reduce dynamic symbol lookup for taking function addresses and optimize out GOT/TOC on x86-64/ppc64

In a -DLLVM_TARGETS_TO_BUILD=X86 build, the number of JUMP_SLOT decreases from 12716 to 1628, and the number of GLOB_DAT decreases from 1918 to 1313
The built clang with `-DLLVM_LINK_LLVM_DYLIB=on -DCLANG_LINK_CLANG_DYLIB=on` is significantly faster.
See the Linux kernel build result https://bugs.archlinux.org/task/70697

Note: the performance of -fno-semantic-interposition -Bsymbolic-functions
libLLVM.so and libclang-cpp.so is close to a PIE binary linking against
`libLLVM*.a` and `libclang*.a`. When the host compiler is Clang,
-Bsymbolic-functions is the major contributor.  On x86-64 (with GOTPCRELX) and
ppc64 ELFv2, the GOT/TOC relocations can be optimized.

Some implication:

Interposing a subset of functions is no longer supported.
(This is fragile on ELF and unsupported on Mach-O at all. For Mach-O we don't
use `ld -interpose` or `-flat_namespace`)

Compiling a program which takes the address of any LLVM function with
`{gcc,clang} -fno-pic` and expects the address to equal to the address taken
from libLLVM.so or libclang-cpp.so is unsupported. I am fairly confident that
llvm-project shouldn't have different behaviors depending on such pointer
equality (as we've been using -fvisibility-inlines-hidden which applies to
inline functions for a long time), but if we accidentally do, users should be
aware that they should not make assumption on pointer equality in `-fno-pic`
mode.

See more on https://maskray.me/blog/2021-05-09-fno-semantic-interposition

Reviewed By: phosek

Differential Revision: https://reviews.llvm.org/D102090
2021-05-13 13:44:57 -07:00
Oliver Stannard 92260d7a18 Revert "[CMake][ELF] Add -fno-semantic-interposition and -Bsymbolic-functions"
This reverts commit 3bf1acab5b.

This is causing the test `gcov-shared-flush.c' to fail on the 2-stage
aarch64 buildbots (https://lab.llvm.org/buildbot/#/builders/7/builds/2720).
2021-05-13 14:31:17 +01:00
Fangrui Song 3bf1acab5b [CMake][ELF] Add -fno-semantic-interposition and -Bsymbolic-functions
llvm-dev message: https://lists.llvm.org/pipermail/llvm-dev/2021-May/150465.html

In an ELF shared object, a default visibility defined symbol is preemptible by default.
This creates some missed optimization opportunities. -fno-semantic-interposition can optimize -fPIC:

* in Clang: avoid GOT/PLT cost for variable access/function calls to external linkage definition in the same TU
* in GCC: enable interprocedural optimizations (including inlining) and avoid PLT

See https://gist.github.com/MaskRay/2d4dfcfc897341163f734afb59f689c6 for more information.

-Bsymbolic-functions is more aggressive than -fvisibility-inlines-hidden (present since 2012) as it applies
to all function definitions.  It can

* avoid PLT for cross-TU function calls && reduce dynamic symbol lookup
* reduce dynamic symbol lookup for taking function addresses and optimize out GOT/TOC on x86-64/ppc64

With both options, the libLLVM.so and libclang-cpp.so performance should
be closer to PIE binary linking against `libLLVM*.a` and `libclang*.a`

(In a -DLLVM_TARGETS_TO_BUILD=X86 build, the number of JUMP_SLOT decreases from 12716 to 1628, and the number of GLOB_DAT decreases from 1918 to 1313
The built clang with `-DLLVM_LINK_LLVM_DYLIB=on -DCLANG_LINK_CLANG_DYLIB=on` is significantly faster.
See the Linux kernel build result https://bugs.archlinux.org/task/70697
)

Some implication:

Interposing a subset of functions is no longer supported.
(This is fragile anyway and cannot really be supported. For Mach-O we don't use
`ld -interpose`, so interposition is not supported on Mach-O at all.)

Compiling a program which takes the address of any LLVM function with
`{gcc,clang} -fno-pic` and expects the address to equal to the address taken
from libLLVM.so or libclang-cpp.so is unsupported. I am fairly confident that
llvm-project shouldn't have different behaviors depending on such pointer
equality (as we've been using -fvisibility-inlines-hidden which applies to
inline functions for a long time), but if we accidentally do, users should be
aware that they should not make assumption on pointer equality in `-fno-pic`
mode.

Reviewed By: phosek

Differential Revision: https://reviews.llvm.org/D102090
2021-05-12 10:34:31 -07:00
Tom Stellard e07e08f366 Revert "llvm-shlib: Create object libraries for each component and link against them"
This reverts commit 43ceb74eb1.

This caused some build failures: https://bugs.llvm.org/show_bug.cgi?id=49818
2021-04-05 10:46:19 -07:00
Tom Stellard 43ceb74eb1 llvm-shlib: Create object libraries for each component and link against them
This makes it possible to build libLLVM.so without first creating a
static library for each component.  In the case where only libLLVM.so is
built (i.e. ninja LLVM) this eliminates 150 linker jobs.

Reviewed By: stellaraccident

Differential Revision: https://reviews.llvm.org/D95727
2021-04-01 14:58:44 -07:00
Alexandre Ganea a6a37a2fcd [Support] On Windows, add optional support for {rpmalloc|snmalloc|mimalloc}
This patch optionally replaces the CRT allocator (i.e., malloc and free) with rpmalloc (mixed public domain licence/MIT licence) or snmalloc (MIT licence) or mimalloc (MIT licence). Please note that the source code for these allocators must be available outside of LLVM's tree.

To enable, use `cmake ... -DLLVM_INTEGRATED_CRT_ALLOC=D:/git/rpmalloc -DLLVM_USE_CRT_RELEASE=MT` where `D:/git/rpmalloc` has already been git clone'd from `https://github.com/mjansson/rpmalloc`. The same applies to snmalloc and mimalloc.

When enabled, the allocator will be embeded (statically linked) into the LLVM tools & libraries. This currently only works with the static CRT (/MT), although using the dynamic CRT (/MD) could potentially work as well in the future.

When enabled, this changes the memory stack from:
  new/delete -> MS VC++ CRT malloc/free -> HeapAlloc -> VirtualAlloc
to:
  new/delete -> {rpmalloc|snmalloc|mimalloc} -> VirtualAlloc

The goal of this patch is to bypass the application's global heap - which is thread-safe thus inducing locking - and instead take advantage of a modern lock-free, thread cache, allocator. On a 6-core Xeon Skylake we observe a 2.5x decrease in execution time when linking a large scale application with LLD and ThinLTO (12 min 20 sec -> 5 min 34 sec), when all hardware threads are being used (using LLD's flag /opt:lldltojobs=all). On a dual 36-core Xeon Skylake with all hardware threads used, we observe a 24x decrease in execution time (1 h 2 min -> 2 min 38 sec) when linking a large application with LLD and ThinLTO. Clang build times also see a decrease in the range 5-10% depending on the configuration.

Differential Revision: https://reviews.llvm.org/D71786
2020-08-27 11:09:46 -04:00
Arlo Siemsen 1d8cb09923 Add option LLVM_NM to allow specifying the location of the llvm-nm tool
The new option works like the existing LLVM_TABLEGEN, and
LLVM_CONFIG_PATH options.  Instead of building llvm-nm, the build uses
the executable defined by LLVM_NM.

This is useful for cross-compilation scenarios where the host cannot run
the cross-compiled tool, and recursing into another cmake build is not
an option (due to required DEFINE's, for example).

Reviewed By: smeenai

Differential Revision: https://reviews.llvm.org/D83022
2020-07-06 13:27:56 -07:00
Marek Kurdej eddcce0814 [CMake] Fix typos. NFC 2020-05-22 14:40:43 +02:00
Saleem Abdulrasool 216833b32b Revert "Temporarily revert "build: use `find_package(Python3)` if available""
This reverts commit 35edd704e0.

Revert the revert and extend the patch further to account for the use of
the `PYTHONINTERP_FOUND`.
2020-04-29 01:38:08 +00:00
Eric Christopher 35edd704e0 Temporarily revert "build: use `find_package(Python3)` if available"
as it seems to be causing multiple people problems with running tests
and building.

This reverts commit c4c3883b00.
2020-04-28 16:41:22 -07:00
Saleem Abdulrasool c4c3883b00 build: use `find_package(Python3)` if available
This is primarily motivated by the desire to move from Python2 to
Python3.  `PYTHON_EXECUTABLE` is ambiguous.  This explicitly identifies
the python interpreter in use.  Since the LLVM build seems to be able to
completed successfully with python3, use that across the build.  The old
path aliases `PYTHON_EXECUTABLE` to be treated as Python3.
2020-04-28 09:24:27 -07:00
Saleem Abdulrasool be884b7935 Revert "build: use `find_package(Python3)` if available"
This reverts commit cd84bfb814.  Although
this passed the CI in phabricator, some of the bots are missing python3
packages, revert it temporarily.
2020-04-27 20:03:32 -07:00
Saleem Abdulrasool cd84bfb814 build: use `find_package(Python3)` if available
This is primarily motivated by the desire to move from Python2 to
Python3.  `PYTHON_EXECUTABLE` is ambiguous.  This explicitly identifies
the python interpreter in use.  Since the LLVM build seems to be able to
completed successfully with python3, use that across the build.  The old
path aliases `PYTHON_EXECUTABLE` to be treated as Python3.
2020-04-28 01:33:10 +00:00
Aaron Ballman 95eb50c447 Check LLVM_BUILD_LLVM_C_DYLIB before building the C DLL with MSVC. 2020-04-07 13:13:58 -04:00
Tom Stellard ab411801b8 [cmake] Explicitly mark libraries defined in lib/ as "Component Libraries"
Summary:
Most libraries are defined in the lib/ directory but there are also a
few libraries defined in tools/ e.g. libLLVM, libLTO.  I'm defining
"Component Libraries" as libraries defined in lib/ that may be included in
libLLVM.so.  Explicitly marking the libraries in lib/ as component
libraries allows us to remove some fragile checks that attempt to
differentiate between lib/ libraries and tools/ libraires:

1. In tools/llvm-shlib, because
llvm_map_components_to_libnames(LIB_NAMES "all") returned a list of
all libraries defined in the whole project, there was custom code
needed to filter out libraries defined in tools/, none of which should
be included in libLLVM.so.  This code assumed that any library
defined as static was from lib/ and everything else should be
excluded.

With this change, llvm_map_components_to_libnames(LIB_NAMES, "all")
only returns libraries that have been added to the LLVM_COMPONENT_LIBS
global cmake property, so this custom filtering logic can be removed.
Doing this also fixes the build with BUILD_SHARED_LIBS=ON
and LLVM_BUILD_LLVM_DYLIB=ON.

2. There was some code in llvm_add_library that assumed that
libraries defined in lib/ would not have LLVM_LINK_COMPONENTS or
ARG_LINK_COMPONENTS set.  This is only true because libraries
defined lib lib/ use LLVMBuild.txt and don't set these values.
This code has been fixed now to check if the library has been
explicitly marked as a component library, which should now make it
easier to remove LLVMBuild at some point in the future.

I have tested this patch on Windows, MacOS and Linux with release builds
and the following combinations of CMake options:

- "" (No options)
- -DLLVM_BUILD_LLVM_DYLIB=ON
- -DLLVM_LINK_LLVM_DYLIB=ON
- -DBUILD_SHARED_LIBS=ON
- -DBUILD_SHARED_LIBS=ON -DLLVM_BUILD_LLVM_DYLIB=ON
- -DBUILD_SHARED_LIBS=ON -DLLVM_LINK_LLVM_DYLIB=ON

Reviewers: beanz, smeenai, compnerd, phosek

Reviewed By: beanz

Subscribers: wuzish, jholewinski, arsenm, dschuff, jyknight, dylanmckay, sdardis, nemanjai, jvesely, nhaehnle, mgorny, mehdi_amini, sbc100, jgravelle-google, hiraditya, aheejin, fedor.sergeev, asb, rbar, johnrusso, simoncook, apazos, sabuasal, niosHD, jrtc27, MaskRay, zzheng, edward-jones, atanasyan, steven_wu, rogfer01, MartinMosbeck, brucehoult, the_o, dexonsmith, PkmX, jocewei, jsji, dang, Jim, lenary, s.egerton, pzheng, sameer.abuasal, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D70179
2019-11-21 10:48:08 -08:00
Tom Stellard 5be949e3d0 [LLVM-C] Fix omission of INSTALL_WITH_TOOLCHAIN to llvm_add_library()
Due to a misstake with r365902 that tried to simplify the install with
toolchain logic LLVM-C.dll was no longer being installed.

Patch By: Jakob Bornecrantz

llvm-svn: 370271
2019-08-28 22:59:04 +00:00
Tom Stellard a196469e67 cmake: Add INSTALL_WITH_TOOLCHAIN option to add_*_library macros
Summary:
This will simplify the macros by allowing us to remove the hard-coded
list of libraries that should be installed when
LLVM_INSTALL_TOOLCHAIN_ONLY is enabled.

Reviewers: beanz, smeenai

Reviewed By: beanz

Subscribers: aheejin, mehdi_amini, mgorny, steven_wu, dexonsmith, cfe-commits, llvm-commits

Tags: #clang, #llvm

Differential Revision: https://reviews.llvm.org/D64580

llvm-svn: 365902
2019-07-12 14:40:18 +00:00
Pirama Arumuga Nainar 7803eac24f [llvm-shlib] Do not use version script when building with MinGW
Summary:
The MinGW driver for lld does not support the --version-script option.
For GNU ld, it's a no-op since LLVM.dll exports all symbols.

Reviewers: srhines, mstorsjo

Subscribers: mgorny, fedor.sergeev, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D63743

llvm-svn: 364343
2019-06-25 19:34:52 +00:00
Shoaib Meenai 7c16c5b6ae [llvm-shlib] Fix cross-compilation for LLVM-C
When we're cross-compiling, build and use a native llvm-nm instead of
attempting to use the one from the target's build tree.

A nice follow-up would be to add a cache variable to allow specifying a
path to an external native llvm-nm instead of building one ourselves,
similar to LLVM_TABLEGEN and LLVM_CONFIG_PATH.

Differential Revision: https://reviews.llvm.org/D60025

llvm-svn: 357487
2019-04-02 15:58:05 +00:00
Serge Guelton d2f2f33ef2 Use response file when generating LLVM-C.dll
As discovered in D56774 the command line gets to long, so use a response file
to give the script the libs. This change has been tested and is confirmed
working for me.

Commited on behalf of Jakob Bornecrantz.
Differential Revision: https://reviews.llvm.org/D56781

llvm-svn: 356443
2019-03-19 09:14:09 +00:00
Hans Wennborg 81675c8f3b Revert r351833 and r352250.
They were breaking the Windows build when using MSBuild, see the
discussion on D56781.

r351833: "Use response file when generating LLVM-C.dll"

> Use response file when generating LLVM-C.dll
>
> As discovered in D56774 the command line gets to long, so use a response file to give the script the libs. This change has been tested and is confirmed working for me.
>
> Commited on behalf of Jakob Bornecrantz
>
> Differential Revision: https://reviews.llvm.org/D56781

r352250: "Build LLVM-C.dll by default on windows and enable in release package"

>  Build LLVM-C.dll by default on windows and enable in release package
>
>  With the fixes to the building of LLVM-C.dll in D56781 this should now
>  be safe to land. This will greatly simplify dealing with LLVM for people
>  that just want to use the C API on windows. This is a follow up from
>  D35077.
>
>  Patch by Jakob Bornecrantz!
>
>  Differential revision: https://reviews.llvm.org/D56774

llvm-svn: 352492
2019-01-29 13:43:22 +00:00
Serge Guelton d62eb16331 Use response file when generating LLVM-C.dll
As discovered in D56774 the command line gets to long, so use a response file to give the script the libs. This change has been tested and is confirmed working for me.

Commited on behalf of Jakob Bornecrantz

Differential Revision: https://reviews.llvm.org/D56781

llvm-svn: 351833
2019-01-22 16:25:17 +00:00
Chandler Carruth 2946cd7010 Update the file headers across all of the LLVM projects in the monorepo
to reflect the new license.

We understand that people may be surprised that we're moving the header
entirely to discuss the new license. We checked this carefully with the
Foundation's lawyer and we believe this is the correct approach.

Essentially, all code in the project is now made available by the LLVM
project under our new license, so you will see that the license headers
include that license only. Some of our contributors have contributed
code under our old license, and accordingly, we have retained a copy of
our old license notice in the top-level files in each project and
repository.

llvm-svn: 351636
2019-01-19 08:50:56 +00:00
Sylvestre Ledru a9b271b320 Support of hurd in llvm-shlib
Svante Signell

llvm-svn: 344756
2018-10-18 20:07:44 +00:00
David Bolvansky ab2cbad6fe [RFC] Build LLVM-C.dll on MSVC that exports only the C API
Summary:
Hello!

This commit adds a LLVM-C target that is always built on MSVC. A big fat warning, this is my first cmake code ever so there is a fair bit of I-have-no-idea-what-I'm-doing going on here. Which is also why I placed it outside of llvm-shlib as I was afraid of breaking things of other people. Secondly llvm-shlib builds a LLVM.so which exports all symbols and then does a thin library that points to it, but on Windows we do not build a LLVM.dll so that would have complicated the code more.

The patch includes a python script that calls dumpbin.exe to get all of the symbols from the built libraries. It then grabs all the symbols starting with LLVM and generates the export file from those. The export file is then used to create the library just like the LLVM-C that is built on darwin.

Improvements that I need help with, to follow up this review.
  - Get cmake to make sure that dumpbin.exe is on the path and wire the full path to the script.
  - Use LLVM-C.dll when building llvm-c-test so we can verify that the symbols are exported.
  - Bundle the LLVM-C.dll with the windows installer.

Why do this?  I'm building a language frontend which is self-hosting, and on windows because of various tooling issues we have a problem of consuming the LLVM*.lib directly on windows. Me and the users of my projects using LLVM would be greatly helped by having LLVM-C.dll built and shipped by the Windows installer. Not only does LLVM takes forever to build, you have to run a extra python script in order to get the final DLL.

Any comments, thoughts or help is greatly appreciated.

Cheers, Jakob.

Patch by: Wallbraker (Jakob Bornecrantz)

Reviewers: compnerd, beanz, hans, smeenai

Reviewed By: beanz

Subscribers: xbolva00, bhelyer, Memnarch, rnk, fedor.sergeev, chapuni, smeenai, john.brawn, deadalnix, llvm-commits, mgorny

Differential Revision: https://reviews.llvm.org/D35077

llvm-svn: 339151
2018-08-07 15:54:50 +00:00
Tom Stellard 910f70238c CMake: Remove LLVM_DYLIB_SYMBOL_VERSIONING
Summary:
This option is no longer needed since r300496 added symbol
versioning by default

Reviewers: sylvestre.ledru, beanz, mgorny

Reviewed By: mgorny

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D49835

llvm-svn: 338751
2018-08-02 18:16:10 +00:00
Brad Smith ee0e66026b [CMake] Support building shared library for OpenBSD
llvm-svn: 335424
2018-06-23 21:26:44 +00:00
Petr Hosek dfbb941669 [CMake] Support building shared library for Fuchsia
Fuchsia uses ELF as a file format and LLD as the linker so we can
use the same implementation as other ELF based platforms.

Differential Revision: https://reviews.llvm.org/D46991

llvm-svn: 332570
2018-05-17 03:39:03 +00:00
Sylvestre Ledru f22ebb7599 Rename llvm library from libLLVM-X.Y to libLLVM-X
Summary:
As we are only doing X.0.Z releases (not using the minor version), there is no need to keep -X.Y in the version.

Like patch https://reviews.llvm.org/D41808, I propose that we rename libLLVM-7.0svn.so to libLLVM-7svn.so 
This patch will also rename downstream libraries like liblldb-7.0 to liblldb-7

Reviewers: axw, beanz, dim, hans

Reviewed By: dim, hans

Subscribers: mgorny, llvm-commits

Differential Revision: https://reviews.llvm.org/D41869

llvm-svn: 328768
2018-03-29 09:44:09 +00:00
Sylvestre Ledru 2b536542e4 [Solaris] enable --whole-archive for shared-library build, disable --version-script for Solaris-ld
Shared-library build on Solaris requires --whole-archive to be specified (option accepted by all available linkers).

At the same time, --version-script can not be handled by Solaris-ld, so it should be skipped.
-M is of no use here, since there is no syntax in Solaris-ld mapfiles that allows to version all global symbols,
not just the named ones (at least this is my impression from digging deep into the docs).

Patch by Fedor Sergeev <fedor.sergeev@oracle.com>

llvm-svn: 308490
2017-07-19 16:07:51 +00:00
Andrew Wilkins 098b147347 [cmake] Check for Haiku when setting LIB_NAMES for GNU ld
Haiku uses GNU ld for linking, but is not captured in the
conditional when setting LIB_NAMES. This causes a shared
library with no symbols on Haiku. This patch simply adds
a check for whether the CMake system name is Haiku in
addition to the existing checks.

Patch by Jérôme Duval.

Differential Revision: https://reviews.llvm.org/D34998

llvm-svn: 307607
2017-07-11 01:17:44 +00:00
Tom Stellard d6f39ddc26 CMake: Add LLVM_DYLIB_SYMBOL_VERSIONING option
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
2017-05-03 14:43:44 +00:00
Sylvestre Ledru b0cec31db2 Add a linker script to version LLVM symbols
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
2017-04-17 20:51:50 +00:00
Andrew Wilkins ebfe3a9df8 Add check for BSD when setting LIB_NAMES for GNU ld
Patch by Koop Mast and Alex Arslan!

Differential Revision: https://reviews.llvm.org/D28215

llvm-svn: 298798
2017-03-26 05:58:48 +00:00
Chris Bieneman 3603e61238 Fix llvm-shlib cmake build
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
2016-11-01 20:19:33 +00:00
Steven Wu ec6f56eb39 Revert "[CMake] LINK_LIBS need to be public for Darwin dylib targets"
This reverts r270723. This commit breaks greendragon.

llvm-svn: 270820
2016-05-26 04:35:35 +00:00
Chris Bieneman b136a25c5c [CMake] LINK_LIBS need to be public for Darwin dylib targets
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
2016-05-25 17:08:43 +00:00
Chris Bieneman ed737d7881 [CMake] If set we should pass LLVM_VERSION_INFO into config.h
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
2016-04-25 23:02:47 +00:00
Justin Bogner 2414c5d46b llvm-shlib: Remove the option to override __cxa_atexit
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
2016-03-14 21:54:45 +00:00
Chris Bieneman e49730d4ba Remove autoconf support
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
2016-01-26 21:29:08 +00:00
Chris Bieneman 5e96fe905b [CMake] Bug 25059 - CMake libllvm.so.$MAJOR.$MINOR shared object name not compatible with ldconfig
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
2015-11-04 23:11:12 +00:00
Chris Bieneman 9c5e41f329 [CMake] Get rid of LLVM_DYLIB_EXPORT_ALL, and make it the default, add libLLVM-C on darwin to cover the C API needs.
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
2015-10-27 16:02:04 +00:00
Chris Bieneman cfa310946f [CMake] Add LLVM_VERSION_PATCH to the -current_version flag for libLTO and libLLVM.
This is to match autoconf where LLVM_SUBMIT_SUBVERSION is usually set to ${LLVM_VERSION_MINOR}.${LLVM_VERSION_PATCH}.

llvm-svn: 250277
2015-10-14 07:50:21 +00:00
Chris Bieneman 20b641be2b [CMake] libLLVM's compatibility version should be 1.
This is in matching with the autoconf build system.

llvm-svn: 250244
2015-10-13 22:54:27 +00:00
Chris Bieneman 0ac9109d22 [CMake] If LLVM_DYLIB_EXPORT_ALL is On don't generate an export list at all, just export the world.
This should resolve Bug 24157 - CMake built shared library does not export all public symbols

llvm-svn: 249862
2015-10-09 17:55:21 +00:00
Andrew Wilkins bb6d95fc3a [cmake] rework LLVM_LINK_LLVM_DYLIB option handling
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
2015-09-05 08:27:33 +00:00
Andrew Wilkins 9211396d82 Enable linking tools, shared libraries against libLLVM
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
2015-09-01 03:14:31 +00:00