[llvm] r352954 - Revert "Bump minimum toolchain version"

JF Bastien via llvm-commits llvm-commits at lists.llvm.org
Fri Feb 1 22:01:13 PST 2019


Author: jfb
Date: Fri Feb  1 22:01:12 2019
New Revision: 352954

URL: http://llvm.org/viewvc/llvm-project?rev=352954&view=rev
Log:
Revert "Bump minimum toolchain version"

Reverting D57264 again, it looks like we're down to two bots that need fixing:

polly-amd64-linux
polly-arm-linux

They both have old versions of libstdc++ and recent clang.

Modified:
    llvm/trunk/CMakeLists.txt
    llvm/trunk/cmake/modules/CheckCompilerVersion.cmake
    llvm/trunk/docs/CMake.rst
    llvm/trunk/docs/GettingStarted.rst

Modified: llvm/trunk/CMakeLists.txt
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/CMakeLists.txt?rev=352954&r1=352953&r2=352954&view=diff
==============================================================================
--- llvm/trunk/CMakeLists.txt (original)
+++ llvm/trunk/CMakeLists.txt Fri Feb  1 22:01:12 2019
@@ -383,12 +383,9 @@ option(LLVM_ENABLE_EXPENSIVE_CHECKS "Ena
 set(LLVM_ABI_BREAKING_CHECKS "WITH_ASSERTS" CACHE STRING
   "Enable abi-breaking checks.  Can be WITH_ASSERTS, FORCE_ON or FORCE_OFF.")
 
-option(LLVM_FORCE_USE_OLD_TOOLCHAIN
+option(LLVM_FORCE_USE_OLD_HOST_TOOLCHAIN
        "Set to ON to force using an old, unsupported host toolchain." OFF)
 
-option(LLVM_TEMPORARILY_ALLOW_OLD_TOOLCHAIN
-       "Set to ON to only warn when using a toolchain which is about to be deprecated, instead of emitting an error." OFF)
-
 option(LLVM_USE_INTEL_JITEVENTS
   "Use Intel JIT API to inform Intel(R) VTune(TM) Amplifier XE 2011 about JIT code"
   OFF)

Modified: llvm/trunk/cmake/modules/CheckCompilerVersion.cmake
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/cmake/modules/CheckCompilerVersion.cmake?rev=352954&r1=352953&r2=352954&view=diff
==============================================================================
--- llvm/trunk/cmake/modules/CheckCompilerVersion.cmake (original)
+++ llvm/trunk/cmake/modules/CheckCompilerVersion.cmake Fri Feb  1 22:01:12 2019
@@ -5,18 +5,13 @@
 include(CheckCXXSourceCompiles)
 
 set(GCC_MIN 4.8)
-set(GCC_SOFT_ERROR 5.1)
+set(GCC_WARN 4.8)
 set(CLANG_MIN 3.1)
-set(CLANG_SOFT_ERROR 3.5)
+set(CLANG_WARN 3.1)
 set(APPLECLANG_MIN 3.1)
-set(APPLECLANG_SOFT_ERROR 6.0)
-set(MSVC_MIN 19.00.24213.1)
-set(MSVC_SOFT_ERROR 19.1)
-
-# Map the above GCC versions to dates: https://gcc.gnu.org/develop.html#timeline
-set(GCC_MIN_DATE 20130322)
-set(GCC_SOFT_ERROR_DATE 20150422)
-
+set(APPLECLANG_WARN 3.1)
+set(MSVC_MIN 19.0)
+set(MSVC_WARN 19.00.24213.1)
 
 if(DEFINED LLVM_COMPILER_CHECKED)
   return()
@@ -27,25 +22,21 @@ if(LLVM_FORCE_USE_OLD_TOOLCHAIN)
   return()
 endif()
 
-function(check_compiler_version NAME NICE_NAME MINIMUM_VERSION SOFT_ERROR_VERSION)
+function(check_compiler_version NAME NICE_NAME MINIMUM_VERSION WARN_VERSION)
   if(NOT CMAKE_CXX_COMPILER_ID STREQUAL NAME)
     return()
   endif()
   if(CMAKE_CXX_COMPILER_VERSION VERSION_LESS MINIMUM_VERSION)
     message(FATAL_ERROR "Host ${NICE_NAME} version must be at least ${MINIMUM_VERSION}, your version is ${CMAKE_CXX_COMPILER_VERSION}.")
-  elseif(CMAKE_CXX_COMPILER_VERSION VERSION_LESS SOFT_ERROR_VERSION)
-    if(LLVM_TEMPORARILY_ALLOW_OLD_TOOLCHAIN)
-      message(WARNING "Host ${NICE_NAME} version should be at least ${SOFT_ERROR_VERSION} because LLVM will soon use new C++ features which your toolchain version doesn't support. Your version is ${CMAKE_CXX_COMPILER_VERSION}. Ignoring because you've set LLVM_TEMPORARILY_ALLOW_OLD_TOOLCHAIN, but very soon your toolchain won't be supported.")
-    else()
-      message(FATAL_ERROR "Host ${NICE_NAME} version should be at least ${SOFT_ERROR_VERSION} because LLVM will soon use new C++ features which your toolchain version doesn't support. Your version is ${CMAKE_CXX_COMPILER_VERSION}. You can temporarily opt out using LLVM_TEMPORARILY_ALLOW_OLD_TOOLCHAIN, but very soon your toolchain won't be supported.")
-    endif()
+  elseif(CMAKE_CXX_COMPILER_VERSION VERSION_LESS WARN_VERSION)
+    message(WARNING "Host ${NICE_NAME} version must be at least ${WARN_VERSION} due to miscompiles from earlier versions, your version is ${CMAKE_CXX_COMPILER_VERSION}.")
   endif()
 endfunction(check_compiler_version)
 
-check_compiler_version("GNU" "GCC" ${GCC_MIN} ${GCC_SOFT_ERROR})
-check_compiler_version("Clang" "Clang" ${CLANG_MIN} ${CLANG_SOFT_ERROR})
-check_compiler_version("AppleClang" "Apple Clang" ${APPLECLANG_MIN} ${APPLECLANG_SOFT_ERROR})
-check_compiler_version("MSVC" "Visual Studio" ${MSVC_MIN} ${MSVC_SOFT_ERROR})
+check_compiler_version("GNU" "GCC" ${GCC_MIN} ${GCC_WARN})
+check_compiler_version("Clang" "Clang" ${CLANG_MIN} ${CLANG_WARN})
+check_compiler_version("AppleClang" "Apple Clang" ${APPLECLANG_MIN} ${APPLECLANG_WARN})
+check_compiler_version("MSVC" "Visual Studio" ${MSVC_MIN} ${MSVC_WARN})
 
 if(CMAKE_CXX_COMPILER_ID STREQUAL "Clang")
   if (CMAKE_CXX_SIMULATE_ID MATCHES "MSVC")
@@ -54,39 +45,20 @@ if(CMAKE_CXX_COMPILER_ID STREQUAL "Clang
     endif()
     set(CLANG_CL 1)
   elseif(NOT LLVM_ENABLE_LIBCXX)
-    # Test that we aren't using too old of a version of libstdc++.
+    # Test that we aren't using too old of a version of libstdc++
+    # with the Clang compiler. This is tricky as there is no real way to
+    # check the version of libstdc++ directly. Instead we test for a known
+    # bug in libstdc++4.6 that is fixed in libstdc++4.7.
     set(OLD_CMAKE_REQUIRED_FLAGS ${CMAKE_REQUIRED_FLAGS})
     set(OLD_CMAKE_REQUIRED_LIBRARIES ${CMAKE_REQUIRED_LIBRARIES})
     set(CMAKE_REQUIRED_FLAGS "${CMAKE_REQUIRED_FLAGS} -std=c++0x")
     check_cxx_source_compiles("
-#include <iosfwd>
-#if defined(__GLIBCXX__)
-#if __GLIBCXX__ < ${GCC_MIN_DATE}
-#error Unsupported libstdc++ version
-#endif
-#endif
-int main() { return 0; }
-"
-      LLVM_LIBSTDCXX_MIN)
-    if(NOT LLVM_LIBSTDCXX_MIN)
-      message(FATAL_ERROR "libstdc++ version must be at least ${GCC_MIN}.")
-    endif()
-    check_cxx_source_compiles("
-#include <iosfwd>
-#if defined(__GLIBCXX__)
-#if __GLIBCXX__ < ${GCC_SOFT_ERROR_DATE}
-#error Unsupported libstdc++ version
-#endif
-#endif
-int main() { return 0; }
-"
-      LLVM_LIBSTDCXX_SOFT_ERROR)
-    if(NOT LLVM_LIBSTDCXX_SOFT_ERROR)
-      if(LLVM_TEMPORARILY_ALLOW_OLD_TOOLCHAIN)
-        message(WARNING "libstdc++ version should be at least ${GCC_SOFT_ERROR} because LLVM will soon use new C++ features which your toolchain version doesn't support. Ignoring because you've set LLVM_TEMPORARILY_ALLOW_OLD_TOOLCHAIN, but very soon your toolchain won't be supported.")
-      else()
-        message(FATAL_ERROR "libstdc++ version should be at least ${GCC_SOFT_ERROR} because LLVM will soon use new C++ features which your toolchain version doesn't support. You can temporarily opt out using LLVM_TEMPORARILY_ALLOW_OLD_TOOLCHAIN, but very soon your toolchain won't be supported.")
-      endif()
+#include <atomic>
+std::atomic<float> x(0.0f);
+int main() { return (float)x; }"
+      LLVM_NO_OLD_LIBSTDCXX)
+    if(NOT LLVM_NO_OLD_LIBSTDCXX)
+      message(FATAL_ERROR "Host Clang must be able to find libstdc++4.8 or newer!")
     endif()
     set(CMAKE_REQUIRED_FLAGS ${OLD_CMAKE_REQUIRED_FLAGS})
     set(CMAKE_REQUIRED_LIBRARIES ${OLD_CMAKE_REQUIRED_LIBRARIES})

Modified: llvm/trunk/docs/CMake.rst
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/docs/CMake.rst?rev=352954&r1=352953&r2=352954&view=diff
==============================================================================
--- llvm/trunk/docs/CMake.rst (original)
+++ llvm/trunk/docs/CMake.rst Fri Feb  1 22:01:12 2019
@@ -578,10 +578,6 @@ LLVM-specific variables
   may not compile at all, or might fail at runtime due to known bugs in these
   toolchains.
 
-**LLVM_TEMPORARILY_ALLOW_OLD_TOOLCHAIN**:BOOL
-  If enabled, the compiler version check will only warn when using a toolchain
-  which is about to be deprecated, instead of emitting an error.
-
 CMake Caches
 ============
 

Modified: llvm/trunk/docs/GettingStarted.rst
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/docs/GettingStarted.rst?rev=352954&r1=352953&r2=352954&view=diff
==============================================================================
--- llvm/trunk/docs/GettingStarted.rst (original)
+++ llvm/trunk/docs/GettingStarted.rst Fri Feb  1 22:01:12 2019
@@ -170,7 +170,7 @@ uses the package and provides other deta
 Package                                                     Version      Notes
 =========================================================== ============ ==========================================
 `GNU Make <http://savannah.gnu.org/projects/make>`_         3.79, 3.79.1 Makefile/build processor
-`GCC <http://gcc.gnu.org/>`_                                >=5.1.0      C/C++ compiler\ :sup:`1`
+`GCC <http://gcc.gnu.org/>`_                                >=4.8.0      C/C++ compiler\ :sup:`1`
 `python <http://www.python.org/>`_                          >=2.7        Automated test suite\ :sup:`2`
 `zlib <http://zlib.net>`_                                   >=1.2.3.4    Compression library\ :sup:`3`
 =========================================================== ============ ==========================================
@@ -228,15 +228,6 @@ LLVM is written using the subset of C++
 standards<CodingStandards>`. To enforce this language version, we check the most
 popular host toolchains for specific minimum versions in our build systems:
 
-* Clang 3.5
-* Apple Clang 6.0
-* GCC 5.1
-* Visual Studio 2017
-
-The below versions currently soft-error as we transition to the new compiler
-versions listed above. The LLVM codebase is currently known to compile correctly
-with the following compilers, though this will change in the near future:
-
 * Clang 3.1
 * Apple Clang 3.1
 * GCC 4.8
@@ -292,36 +283,33 @@ The first step is to get a recent GCC to
 distribution on which users have struggled with the version requirements is
 Ubuntu Precise, 12.04 LTS. For this distribution, one easy option is to install
 the `toolchain testing PPA`_ and use it to install a modern GCC. There is
-a really nice discussions of this on the `ask ubuntu stack exchange`_ and a
-`github gist`_ with updated commands. However, not all users can use PPAs and
-there are many other distributions, so it may be necessary (or just useful, if
-you're here you *are* doing compiler development after all) to build and install
-GCC from source. It is also quite easy to do these days.
+a really nice discussions of this on the `ask ubuntu stack exchange`_. However,
+not all users can use PPAs and there are many other distributions, so it may be
+necessary (or just useful, if you're here you *are* doing compiler development
+after all) to build and install GCC from source. It is also quite easy to do
+these days.
 
 .. _toolchain testing PPA:
   https://launchpad.net/~ubuntu-toolchain-r/+archive/test
 .. _ask ubuntu stack exchange:
-  https://askubuntu.com/questions/466651/how-do-i-use-the-latest-gcc-on-ubuntu/581497#58149
-.. _github gist:
-  https://gist.github.com/application2000/73fd6f4bf1be6600a2cf9f56315a2d91
+  http://askubuntu.com/questions/271388/how-to-install-gcc-4-8-in-ubuntu-12-04-from-the-terminal
 
-Easy steps for installing GCC 5.1.0:
+Easy steps for installing GCC 4.8.2:
 
 .. code-block:: console
 
-  % gcc_version=5.1.0
-  % wget https://ftp.gnu.org/gnu/gcc/gcc-${gcc_version}/gcc-${gcc_version}.tar.bz2
-  % wget https://ftp.gnu.org/gnu/gcc/gcc-${gcc_version}/gcc-${gcc_version}.tar.bz2.sig
+  % wget https://ftp.gnu.org/gnu/gcc/gcc-4.8.2/gcc-4.8.2.tar.bz2
+  % wget https://ftp.gnu.org/gnu/gcc/gcc-4.8.2/gcc-4.8.2.tar.bz2.sig
   % wget https://ftp.gnu.org/gnu/gnu-keyring.gpg
-  % signature_invalid=`gpg --verify --no-default-keyring --keyring ./gnu-keyring.gpg gcc-${gcc_version}.tar.bz2.sig`
+  % signature_invalid=`gpg --verify --no-default-keyring --keyring ./gnu-keyring.gpg gcc-4.8.2.tar.bz2.sig`
   % if [ $signature_invalid ]; then echo "Invalid signature" ; exit 1 ; fi
-  % tar -xvjf gcc-${gcc_version}.tar.bz2
-  % cd gcc-${gcc_version}
+  % tar -xvjf gcc-4.8.2.tar.bz2
+  % cd gcc-4.8.2
   % ./contrib/download_prerequisites
   % cd ..
-  % mkdir gcc-${gcc_version}-build
-  % cd gcc-${gcc_version}-build
-  % $PWD/../gcc-${gcc_version}/configure --prefix=$HOME/toolchains --enable-languages=c,c++
+  % mkdir gcc-4.8.2-build
+  % cd gcc-4.8.2-build
+  % $PWD/../gcc-4.8.2/configure --prefix=$HOME/toolchains --enable-languages=c,c++
   % make -j$(nproc)
   % make install
 
@@ -329,7 +317,7 @@ For more details, check out the excellen
 of this information from.
 
 .. _GCC wiki entry:
-  https://gcc.gnu.org/wiki/InstallingGCC
+  http://gcc.gnu.org/wiki/InstallingGCC
 
 Once you have a GCC toolchain, configure your build of LLVM to use the new
 toolchain for your host compiler and C++ standard library. Because the new




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