sys-devel/llvm: Backport unloading prevention fix

Bug: https://bugs.gentoo.org/617154

5 files changed, 139 insertions, 0 deletions

diff --git a/sys-devel/llvm/files/4.0.1/0001-cmake-Pass-Wl-z-nodelete-on-Linux-to-prevent-unloadi.patch b/sys-devel/llvm/files/4.0.1/0001-cmake-Pass-Wl-z-nodelete-on-Linux-to-prevent-unloadi.patch
new file mode 100644
index 000000000000..b857136498b0
--- /dev/null
+++ b/sys-devel/llvm/files/4.0.1/0001-cmake-Pass-Wl-z-nodelete-on-Linux-to-prevent-unloadi.patch
@@ -0,0 +1,56 @@
+From 937b23b5fffa59deb1dc342cc5602d387d84a762 Mon Sep 17 00:00:00 2001
+From: Michal Gorny <mgorny@gentoo.org>
+Date: Mon, 27 Nov 2017 22:23:09 +0000
+Subject: [PATCH] [cmake] Pass -Wl,-z,nodelete on Linux to prevent unloading
+
+Prevent unloading shared libraries on Linux when dlclose() is called.
+This is necessary since command-line option parsing API relies on
+registering the global option instances in the option parser instance
+which can be loaded in a different shared library.
+
+Given that we can't reliably remove those options when a library is
+unloaded, the parser ends up containing dangling references. Since glibc
+has relatively complex library unloading rules, some of the LLVM
+libraries can be unloaded while others (including the Support library)
+stay loaded causing quite a mayhem. To reliably prevent that, just
+forbid unloading all libraries -- it's a very bad idea anyway.
+
+While the issue arguably happens only with BUILD_SHARED_LIBS, it may
+affect any library reusing llvm::cl interface.
+
+Based on patch provided Ross Hayward on https://bugs.gentoo.org/617154.
+Previously hit by Fedora back in Feb 2016:
+https://lists.freedesktop.org/archives/mesa-dev/2016-February/107242.html
+
+Differential Revision: https://reviews.llvm.org/D40459
+
+git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@319105 91177308-0d34-0410-b5e6-96231b3b80d8
+---
+ cmake/modules/HandleLLVMOptions.cmake           | 8 ++++++++
+ unittests/Support/DynamicLibrary/CMakeLists.txt | 7 +++++++
+ 2 files changed, 15 insertions(+)
+
+ 4.0.1 backport: removed the unittest part
+
+diff --git a/cmake/modules/HandleLLVMOptions.cmake b/cmake/modules/HandleLLVMOptions.cmake
+index c5390371845..b5059a8a60e 100644
+--- a/cmake/modules/HandleLLVMOptions.cmake
++++ b/cmake/modules/HandleLLVMOptions.cmake
+@@ -151,6 +151,14 @@ if(NOT (${CMAKE_SYSTEM_NAME} MATCHES "Darwin" OR WIN32 OR CYGWIN OR
+   set(CMAKE_SHARED_LINKER_FLAGS "${CMAKE_SHARED_LINKER_FLAGS} -Wl,-z,defs")
+ endif()
+ 
++# Pass -Wl,-z,nodelete. This makes sure our shared libraries are not unloaded
++# by dlclose(). We need that since the CLI API relies on cross-references
++# between global objects which became horribly broken when one of the libraries
++# is unloaded.
++if(${CMAKE_SYSTEM_NAME} MATCHES "Linux")
++  set(CMAKE_SHARED_LINKER_FLAGS "${CMAKE_SHARED_LINKER_FLAGS} -Wl,-z,nodelete")
++endif()
++
+ 
+ function(append value)
+   foreach(variable ${ARGN})
+-- 
+2.15.1
+
diff --git a/sys-devel/llvm/files/5.0.1/0001-cmake-Pass-Wl-z-nodelete-on-Linux-to-prevent-unloadi.patch b/sys-devel/llvm/files/5.0.1/0001-cmake-Pass-Wl-z-nodelete-on-Linux-to-prevent-unloadi.patch
new file mode 100644
index 000000000000..21702748893c
--- /dev/null
+++ b/sys-devel/llvm/files/5.0.1/0001-cmake-Pass-Wl-z-nodelete-on-Linux-to-prevent-unloadi.patch
@@ -0,0 +1,71 @@
+From 937b23b5fffa59deb1dc342cc5602d387d84a762 Mon Sep 17 00:00:00 2001
+From: Michal Gorny <mgorny@gentoo.org>
+Date: Mon, 27 Nov 2017 22:23:09 +0000
+Subject: [PATCH] [cmake] Pass -Wl,-z,nodelete on Linux to prevent unloading
+
+Prevent unloading shared libraries on Linux when dlclose() is called.
+This is necessary since command-line option parsing API relies on
+registering the global option instances in the option parser instance
+which can be loaded in a different shared library.
+
+Given that we can't reliably remove those options when a library is
+unloaded, the parser ends up containing dangling references. Since glibc
+has relatively complex library unloading rules, some of the LLVM
+libraries can be unloaded while others (including the Support library)
+stay loaded causing quite a mayhem. To reliably prevent that, just
+forbid unloading all libraries -- it's a very bad idea anyway.
+
+While the issue arguably happens only with BUILD_SHARED_LIBS, it may
+affect any library reusing llvm::cl interface.
+
+Based on patch provided Ross Hayward on https://bugs.gentoo.org/617154.
+Previously hit by Fedora back in Feb 2016:
+https://lists.freedesktop.org/archives/mesa-dev/2016-February/107242.html
+
+Differential Revision: https://reviews.llvm.org/D40459
+
+git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@319105 91177308-0d34-0410-b5e6-96231b3b80d8
+---
+ cmake/modules/HandleLLVMOptions.cmake           | 8 ++++++++
+ unittests/Support/DynamicLibrary/CMakeLists.txt | 7 +++++++
+ 2 files changed, 15 insertions(+)
+
+diff --git a/cmake/modules/HandleLLVMOptions.cmake b/cmake/modules/HandleLLVMOptions.cmake
+index c5390371845..b5059a8a60e 100644
+--- a/cmake/modules/HandleLLVMOptions.cmake
++++ b/cmake/modules/HandleLLVMOptions.cmake
+@@ -151,6 +151,14 @@ if(NOT (${CMAKE_SYSTEM_NAME} MATCHES "Darwin" OR WIN32 OR CYGWIN OR
+   set(CMAKE_SHARED_LINKER_FLAGS "${CMAKE_SHARED_LINKER_FLAGS} -Wl,-z,defs")
+ endif()
+ 
++# Pass -Wl,-z,nodelete. This makes sure our shared libraries are not unloaded
++# by dlclose(). We need that since the CLI API relies on cross-references
++# between global objects which became horribly broken when one of the libraries
++# is unloaded.
++if(${CMAKE_SYSTEM_NAME} MATCHES "Linux")
++  set(CMAKE_SHARED_LINKER_FLAGS "${CMAKE_SHARED_LINKER_FLAGS} -Wl,-z,nodelete")
++endif()
++
+ 
+ function(append value)
+   foreach(variable ${ARGN})
+diff --git a/unittests/Support/DynamicLibrary/CMakeLists.txt b/unittests/Support/DynamicLibrary/CMakeLists.txt
+index 9355979221a..c6201b1ad31 100644
+--- a/unittests/Support/DynamicLibrary/CMakeLists.txt
++++ b/unittests/Support/DynamicLibrary/CMakeLists.txt
+@@ -24,5 +24,12 @@ function(dynlib_add_module NAME)
+   add_dependencies(DynamicLibraryTests ${NAME})
+ endfunction(dynlib_add_module)
+ 
++# Revert -Wl,-z,nodelete on this test since it relies on the file
++# being unloaded.
++if(${CMAKE_SYSTEM_NAME} MATCHES "Linux")
++  string(REPLACE "-Wl,-z,nodelete" "" CMAKE_SHARED_LINKER_FLAGS
++    ${CMAKE_SHARED_LINKER_FLAGS})
++endif()
++
+ dynlib_add_module(PipSqueak)
+ dynlib_add_module(SecondLib)
+-- 
+2.15.1
+
diff --git a/sys-devel/llvm/llvm-4.0.1.ebuild b/sys-devel/llvm/llvm-4.0.1-r1.ebuild
index 6ee123541ac5..1931365e8a7e 100644
--- a/sys-devel/llvm/llvm-4.0.1.ebuild
+++ b/sys-devel/llvm/llvm-4.0.1-r1.ebuild
@@ -75,6 +75,10 @@ src_prepare() {
 	# https://bugs.gentoo.org/show_bug.cgi?id=565358
 	eapply "${FILESDIR}"/9999/0007-llvm-config-Clean-up-exported-values-update-for-shar.patch
 
+	# Backport the fix for dlclose() causing option parser mess
+	# e.g. https://bugs.gentoo.org/617154
+	eapply "${FILESDIR}"/4.0.1/0001-cmake-Pass-Wl-z-nodelete-on-Linux-to-prevent-unloadi.patch
+
 	# support building llvm against musl-libc
 	use elibc_musl && eapply "${FILESDIR}"/9999/musl-fixes.patch
 
diff --git a/sys-devel/llvm/llvm-5.0.1_rc2.ebuild b/sys-devel/llvm/llvm-5.0.1_rc2.ebuild
index 374656b01b23..42978ec5cce1 100644
--- a/sys-devel/llvm/llvm-5.0.1_rc2.ebuild
+++ b/sys-devel/llvm/llvm-5.0.1_rc2.ebuild
@@ -75,6 +75,10 @@ src_prepare() {
 	# https://bugs.gentoo.org/show_bug.cgi?id=565358
 	eapply "${FILESDIR}"/9999/0007-llvm-config-Clean-up-exported-values-update-for-shar.patch
 
+	# Backport the fix for dlclose() causing option parser mess
+	# e.g. https://bugs.gentoo.org/617154
+	eapply "${FILESDIR}"/5.0.1/0001-cmake-Pass-Wl-z-nodelete-on-Linux-to-prevent-unloadi.patch
+
 	# disable use of SDK on OSX, bug #568758
 	sed -i -e 's/xcrun/false/' utils/lit/lit/util.py || die
 
diff --git a/sys-devel/llvm/llvm-5.0.9999.ebuild b/sys-devel/llvm/llvm-5.0.9999.ebuild
index 3bf676e43609..2c8a9d8ecf07 100644
--- a/sys-devel/llvm/llvm-5.0.9999.ebuild
+++ b/sys-devel/llvm/llvm-5.0.9999.ebuild
@@ -75,6 +75,10 @@ src_prepare() {
 	# https://bugs.gentoo.org/show_bug.cgi?id=565358
 	eapply "${FILESDIR}"/9999/0007-llvm-config-Clean-up-exported-values-update-for-shar.patch
 
+	# Backport the fix for dlclose() causing option parser mess
+	# e.g. https://bugs.gentoo.org/617154
+	eapply "${FILESDIR}"/5.0.1/0001-cmake-Pass-Wl-z-nodelete-on-Linux-to-prevent-unloadi.patch
+
 	# disable use of SDK on OSX, bug #568758
 	sed -i -e 's/xcrun/false/' utils/lit/lit/util.py || die