llvm 12.0.0

2021-06-05 00:05:01 +03:00
parent 7f33ace299
commit cf574378fa
5 changed files with 156 additions and 19 deletions
@@ -0,0 +1,22 @@
+diff --git a/llvm/cmake/modules/HandleLLVMOptions.cmake b/llvm/cmake/modules/HandleLLVMOptions.cmake
+--- a/llvm/cmake/modules/HandleLLVMOptions.cmake
+++ b/llvm/cmake/modules/HandleLLVMOptions.cmake
+@@ -305,6 +305,17 @@
+     # On Windows all code is PIC. MinGW warns if -fPIC is used.
+   else()
+     add_flag_or_print_warning("-fPIC" FPIC)
+    # Enable interprocedural optimizations for non-inline functions which would
+    # otherwise be disabled due to GCC -fPIC's default.
+    #
+    # Note: Clang allows IPO for -fPIC so this optimization is less effective.
+    # Older Clang may support -fno-semantic-interposition but it used local
+    # aliases to optimize global variables, which is incompatible with copy
+    # relocations due to -fno-pic.
+    if (CMAKE_COMPILER_IS_GNUCXX OR (CMAKE_CXX_COMPILER_ID MATCHES "Clang" AND
+        CMAKE_CXX_COMPILER_VERSION GREATER_EQUAL 13))
+      add_flag_if_supported("-fno-semantic-interposition" FNO_SEMANTIC_INTERPOSITION)
+    endif()
+   endif()
+   # GCC for MIPS can miscompile LLVM due to PR37701.
+   if(CMAKE_COMPILER_IS_GNUCXX AND LLVM_NATIVE_ARCH STREQUAL "Mips" AND
+
@@ -0,0 +1,42 @@
+From 3d3abc22b3ef189813a3b9061c2a90ba86a32f44 Mon Sep 17 00:00:00 2001
+From: serge-sans-paille <sguelton@redhat.com>
+Date: Tue, 11 May 2021 20:46:58 +0200
+Subject: [PATCH] Force visibility of llvm::Any to external
+
+llvm::Any::TypeId::Id relies on the uniqueness of the address of a static
+variable defined in a template function. hidden visibility implies vague linkage
+for that variable, which does not guarantee the uniqueness of the address across
+a binary and a shared library. This totally breaks the implementation of
+llvm::Any.
+
+Ideally, setting visibility to llvm::Any::TypeId::Id should be enough,
+unfortunately this doesn't work as expected and we lack time (before 12.0.1
+release) to understand why setting the visibility to llvm::Any does work.
+
+See https://gcc.gnu.org/wiki/Visibility and
+https://gcc.gnu.org/onlinedocs/gcc/Vague-Linkage.html
+for more information on that topic.
+
+Differential Revision: https://reviews.llvm.org/D101972
+---
+ llvm/include/llvm/ADT/Any.h | 7 ++++++-
+ 1 file changed, 6 insertions(+), 1 deletion(-)
+
+diff --git a/llvm/include/llvm/ADT/Any.h b/llvm/include/llvm/ADT/Any.h
+index 15b114f7932d..e513586845a1 100644
+--- a/llvm/include/llvm/ADT/Any.h
+++ b/llvm/include/llvm/ADT/Any.h
+@@ -23,7 +23,12 @@
+ 
+ namespace llvm {
+ 
+-class Any {
+class LLVM_EXTERNAL_VISIBILITY Any {
+
+  // The `Typeid<T>::Id` static data member below is a globally unique
+  // identifier for the type `T`. It is explicitly marked with default
+  // visibility so that when `-fvisibility=hidden` is used, the loader still
+  // merges duplicate definitions across DSO boundaries.
+   template <typename T> struct TypeId { static const char Id; };
+ 
+   struct StorageBase {
@@ -0,0 +1,66 @@
+From 4f05f4c8e66bc76b1d94f5283494404382e3bacd Mon Sep 17 00:00:00 2001
+From: Fangrui Song <i@maskray.me>
+Date: Thu, 13 May 2021 13:44:57 -0700
+Subject: [PATCH] [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
+---
+ llvm/tools/llvm-shlib/CMakeLists.txt | 5 +++++
+ 1 file changed, 5 insertions(+)
+
+diff --git a/llvm/tools/llvm-shlib/CMakeLists.txt b/llvm/tools/llvm-shlib/CMakeLists.txt
+index b0ee19049e6f..03e1383ec8b4 100644
+--- a/llvm/tools/llvm-shlib/CMakeLists.txt
+++ b/llvm/tools/llvm-shlib/CMakeLists.txt
+@@ -50,6 +50,11 @@ if(LLVM_BUILD_LLVM_DYLIB)
+       # Solaris ld does not accept global: *; so there is no way to version *all* global symbols
+       set(LIB_NAMES -Wl,--version-script,${LLVM_LIBRARY_DIR}/tools/llvm-shlib/simple_version_script.map ${LIB_NAMES})
+     endif()
+    # Optimize function calls for default visibility definitions to avoid PLT and
+    # reduce dynamic relocations.
+    # Note: for -fno-pic default, the address of a function may be different from
+    # inside and outside libLLVM.so.
+    target_link_options(LLVM PRIVATE LINKER:-Bsymbolic-functions)
+   elseif("${CMAKE_SYSTEM_NAME}" STREQUAL "Darwin")
+     set(LIB_NAMES -Wl,-all_load ${LIB_NAMES})
+   endif()