[llvm] r233310 - [ADT][CMake][AutoConf] Fail-fast iterators for DenseMap
Eric Fiselier
eric at efcs.ca
Tue Mar 31 12:53:44 PDT 2015
I'm having a similar problem when building libc++abi out of tree.
libc++abi includes the HandleLLVMOptions.cmake file without including
LLVM's top level CMakeLists.txt so LLVM_ABI_BREAKING_CHECKS is not
defined. Your new patch fixes this for me as well.
/Eric
On Tue, Mar 31, 2015 at 6:35 AM, Daniel Sanders
<Daniel.Sanders at imgtec.com> wrote:
> That patch works for me, thanks. I can add that to LLVMLinux's clang patches to get the buildbot working again for now. I'm not sure it's the correct change to commit though (see below).
>
>> Ideally, clang should not need to worry about this option at all -- it
>> is handled entirely within LLVM and is used to generate a "#define
>> LLVM_ENABLE_ABI_BREAKING_CHECKS" (or not) in
>> llvm/Config/llvm-config.h, and that header is included by all headers
>> from LLVM that need it. Does building clang with an existing llvm
>> re-generate llvm/Config/llvm-config.h?
>
> I don't think it's re-generating llvm-config.h. From what I can tell, HandleLLVMOptions.cmake is installed at $prefix/share/llvm/cmake/HandleLLVMOptions.cmake. This file is included by clang's CMakeLists.txt without LLVM_ABI_BREAKING_CHECKS being set beforehand. I think that we need to add 'set(LLVM_ABI_BREAKING_CHECKS @LLVM_ABI_BREAKING_CHECKS@)' to cmake/modules/LLVMConfig.cmake.in so that the value is available in $prefix/share/llvm/cmake/LLVMConfig.cmake as well as llvm-config.h. Do you agree? I've already tested this and it works for me.
>
>> -----Original Message-----
>> From: Sanjoy Das [mailto:sanjoy at playingwithpointers.com]
>> Sent: 30 March 2015 17:32
>> To: Daniel Sanders
>> Cc: llvm-commits at cs.uiuc.edu
>> Subject: Re: [llvm] r233310 - [ADT][CMake][AutoConf] Fail-fast iterators for
>> DenseMap
>>
>> Ideally, clang should not need to worry about this option at all -- it
>> is handled entirely within LLVM and is used to generate a "#define
>> LLVM_ENABLE_ABI_BREAKING_CHECKS" (or not) in
>> llvm/Config/llvm-config.h, and that header is included by all headers
>> from LLVM that need it. Does building clang with an existing llvm
>> re-generate llvm/Config/llvm-config.h?
>>
>> In any case, I think the safest bet is to pretend
>> LLVM_ABI_BREAKING_CHECKS="" is
>> LLVM_ABI_BREAKING_CHECKS="FORCE_OFF".
>> If you have an easy way to test this, can you please try this patch:
>>
>> diff --git a/cmake/modules/HandleLLVMOptions.cmake
>> b/cmake/modules/HandleLLVMOptions.cmake
>> index 67f86a6..898af87 100644
>> --- a/cmake/modules/HandleLLVMOptions.cmake
>> +++ b/cmake/modules/HandleLLVMOptions.cmake
>> @@ -88,6 +88,10 @@ elseif( uppercase_LLVM_ABI_BREAKING_CHECKS
>> STREQUAL
>> "FORCE_ON" )
>> set( LLVM_ENABLE_ABI_BREAKING_CHECKS 1 )
>> elseif( uppercase_LLVM_ABI_BREAKING_CHECKS STREQUAL "FORCE_OFF" )
>> # We don't need to do anything special to turn off ABI breaking checks.
>> +elseif ( uppercase_LLVM_ABI_BREAKING_CHECKS STREQUAL "" )
>> + # We're being run with a cached value of LLVM_ABI_BREAKING_CHECKS
>> that is an
>> + # empty string. This means we're building against an LLVM that did not
>> have
>> + # this enabled when configured, so treat this like "FORCE_OFF"
>> else()
>> message(FATAL_ERROR "Unknown value for
>> LLVM_ABI_BREAKING_CHECKS:
>> "${LLVM_ABI_BREAKING_CHECKS}"!")
>> endif()
>>
>>
>> If not, please let me know, I'll try reproducing this myself.
>>
>> -- Sanjoy
>>
>> On Mon, Mar 30, 2015 at 2:24 AM, Daniel Sanders
>> <Daniel.Sanders at imgtec.com> wrote:
>> > Hi,
>> >
>> > It seems that this change has broken clang builds where clang is built for an
>> already-compiled llvm. See
>> http://buildbot.llvm.linuxfoundation.org/builders/malta/builds/87/steps/sh
>> ell_3/logs/stdio for the full log but the relevant part is:
>> > -- Found LLVM_CONFIG as /home/das/llvm-
>> linux/llvmlinux/toolchain/clang/head/install/bin/llvm-config
>> > CMake Error at /home/das/llvm-
>> linux/llvmlinux/toolchain/clang/head/install/share/llvm/cmake/HandleLLVM
>> Options.cmake:92 (message):
>> > Unknown value for LLVM_ABI_BREAKING_CHECKS: ""!
>> > Call Stack (most recent call first):
>> > CMakeLists.txt:102 (include)
>> >
>> > Should clang be setting this cmake variable from llvm-config or should it be
>> setting it itself?
>> >
>> >> -----Original Message-----
>> >> From: llvm-commits-bounces at cs.uiuc.edu [mailto:llvm-commits-
>> >> bounces at cs.uiuc.edu] On Behalf Of Sanjoy Das
>> >> Sent: 26 March 2015 19:25
>> >> To: llvm-commits at cs.uiuc.edu
>> >> Subject: [llvm] r233310 - [ADT][CMake][AutoConf] Fail-fast iterators for
>> >> DenseMap
>> >>
>> >> Author: sanjoy
>> >> Date: Thu Mar 26 14:25:01 2015
>> >> New Revision: 233310
>> >>
>> >> URL: http://llvm.org/viewvc/llvm-project?rev=233310&view=rev
>> >> Log:
>> >> [ADT][CMake][AutoConf] Fail-fast iterators for DenseMap
>> >>
>> >> Summary:
>> >> This patch is an attempt at making `DenseMapIterator`s "fail-fast".
>> >> Fail-fast iterators that have been invalidated due to insertion into
>> >> the host `DenseMap` deterministically trip an assert (in debug mode)
>> >> on access, instead of non-deterministically hitting memory corruption
>> >> issues.
>> >>
>> >> Enabling fail-fast iterators breaks the LLVM C++ ABI, so they are
>> >> predicated on `LLVM_ENABLE_ABI_BREAKING_CHECKS`.
>> >> `LLVM_ENABLE_ABI_BREAKING_CHECKS` by default flips with
>> >> `LLVM_ENABLE_ASSERTS`, but can be clamped to ON or OFF using the
>> CMake
>> >> /
>> >> autoconf build system.
>> >>
>> >> Reviewers: chandlerc, dexonsmith, rnk, zturner
>> >>
>> >> Subscribers: llvm-commits
>> >>
>> >> Differential Revision: http://reviews.llvm.org/D8351
>> >>
>> >> Added:
>> >> llvm/trunk/include/llvm/ADT/EpochTracker.h
>> >> Modified:
>> >> llvm/trunk/CMakeLists.txt
>> >> llvm/trunk/autoconf/configure.ac
>> >> llvm/trunk/cmake/modules/HandleLLVMOptions.cmake
>> >> llvm/trunk/configure
>> >> llvm/trunk/docs/CMake.rst
>> >> llvm/trunk/docs/ProgrammersManual.rst
>> >> llvm/trunk/include/llvm/ADT/DenseMap.h
>> >> llvm/trunk/include/llvm/Config/config.h.in
>> >> llvm/trunk/include/llvm/Config/llvm-config.h.cmake
>> >> llvm/trunk/include/llvm/Config/llvm-config.h.in
>> >>
>> >> Modified: llvm/trunk/CMakeLists.txt
>> >> URL: http://llvm.org/viewvc/llvm-
>> >>
>> project/llvm/trunk/CMakeLists.txt?rev=233310&r1=233309&r2=233310&view
>> >> =diff
>> >>
>> ==========================================================
>> >> ====================
>> >> --- llvm/trunk/CMakeLists.txt (original)
>> >> +++ llvm/trunk/CMakeLists.txt Thu Mar 26 14:25:01 2015
>> >> @@ -252,6 +252,9 @@ else()
>> >> option(LLVM_ENABLE_ASSERTIONS "Enable assertions" ON)
>> >> endif()
>> >>
>> >> +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_HOST_TOOLCHAIN
>> >> "Set to ON to force using an old, unsupported host toolchain." OFF)
>> >>
>> >>
>> >> Modified: llvm/trunk/autoconf/configure.ac
>> >> URL: http://llvm.org/viewvc/llvm-
>> >>
>> project/llvm/trunk/autoconf/configure.ac?rev=233310&r1=233309&r2=23331
>> >> 0&view=diff
>> >>
>> ==========================================================
>> >> ====================
>> >> --- llvm/trunk/autoconf/configure.ac (original)
>> >> +++ llvm/trunk/autoconf/configure.ac Thu Mar 26 14:25:01 2015
>> >> @@ -701,8 +701,10 @@ AC_ARG_ENABLE(assertions,AS_HELP_STRING(
>> >> --enable-assertions,[Compile with assertion checks enabled (default is
>> >> YES)]),, enableval="yes")
>> >> if test ${enableval} = "yes" ; then
>> >> AC_SUBST(DISABLE_ASSERTIONS,[[]])
>> >> + assertions_enabled="yes"
>> >> else
>> >> AC_SUBST(DISABLE_ASSERTIONS,[[DISABLE_ASSERTIONS=1]])
>> >> + assertions_enabled="no"
>> >> fi
>> >>
>> >> dnl --enable-werror : check whether we want Werror on by default
>> >> @@ -726,6 +728,20 @@ else
>> >> AC_SUBST(EXPENSIVE_CHECKS,[[no]])
>> >> fi
>> >>
>> >> +dnl --enable-abi-breaking-checks : decide whether we should compile in
>> >> asserts and
>> >> +dnl checks that make the build ABI incompatible with an llvm built
>> without
>> >> these
>> >> +dnl checks enabled.
>> >> +AC_ARG_ENABLE(abi-breaking-checks,AS_HELP_STRING(
>> >> + --enable-abi-breaking-checks,[Compile with abi-breaking asserts
>> support
>> >> (default is with-asserts)]),, enableval="with-asserts")
>> >> +case "$enableval" in
>> >> + with-asserts) if test ${assertions_enabled} = "yes" ; then
>> >> +
>> AC_DEFINE([LLVM_ENABLE_ABI_BREAKING_CHECKS],[1],[Define
>> >> to enable checks that alter the LLVM C++ ABI])
>> >> + fi ;;
>> >> + yes) AC_DEFINE([LLVM_ENABLE_ABI_BREAKING_CHECKS],[1],[Define
>> to
>> >> enable checks that alter the LLVM C++ ABI]) ;;
>> >> + no) ;;
>> >> + *) AC_MSG_ERROR([Invalid setting for --enable-abi-breaking-checks.
>> Use
>> >> "with-asserts", "yes" or "no"])
>> >> +esac
>> >> +
>> >> dnl --enable-debug-runtime : should runtime libraries have debug
>> symbols?
>> >> AC_ARG_ENABLE(debug-runtime,
>> >> AS_HELP_STRING(--enable-debug-runtime,[Build runtime libs with
>> debug
>> >> symbols (default is NO)]),,enableval=no)
>> >>
>> >> Modified: llvm/trunk/cmake/modules/HandleLLVMOptions.cmake
>> >> URL: http://llvm.org/viewvc/llvm-
>> >>
>> project/llvm/trunk/cmake/modules/HandleLLVMOptions.cmake?rev=23331
>> >> 0&r1=233309&r2=233310&view=diff
>> >>
>> ==========================================================
>> >> ====================
>> >> --- llvm/trunk/cmake/modules/HandleLLVMOptions.cmake (original)
>> >> +++ llvm/trunk/cmake/modules/HandleLLVMOptions.cmake Thu Mar 26
>> >> 14:25:01 2015
>> >> @@ -78,6 +78,20 @@ if( LLVM_ENABLE_ASSERTIONS )
>> >> endif()
>> >> endif()
>> >>
>> >> +string(TOUPPER "${LLVM_ABI_BREAKING_CHECKS}"
>> >> uppercase_LLVM_ABI_BREAKING_CHECKS)
>> >> +
>> >> +if( uppercase_LLVM_ABI_BREAKING_CHECKS STREQUAL
>> "WITH_ASSERTS" )
>> >> + if( LLVM_ENABLE_ASSERTIONS )
>> >> + set( LLVM_ENABLE_ABI_BREAKING_CHECKS 1 )
>> >> + endif()
>> >> +elseif( uppercase_LLVM_ABI_BREAKING_CHECKS STREQUAL
>> "FORCE_ON" )
>> >> + set( LLVM_ENABLE_ABI_BREAKING_CHECKS 1 )
>> >> +elseif( uppercase_LLVM_ABI_BREAKING_CHECKS STREQUAL
>> "FORCE_OFF"
>> >> )
>> >> + # We don't need to do anything special to turn off ABI breaking checks.
>> >> +else()
>> >> + message(FATAL_ERROR "Unknown value for
>> >> LLVM_ABI_BREAKING_CHECKS: \"${LLVM_ABI_BREAKING_CHECKS}\"!")
>> >> +endif()
>> >> +
>> >> if(WIN32)
>> >> set(LLVM_HAVE_LINK_VERSION_SCRIPT 0)
>> >> if(CYGWIN)
>> >>
>> >> Modified: llvm/trunk/configure
>> >> URL: http://llvm.org/viewvc/llvm-
>> >>
>> project/llvm/trunk/configure?rev=233310&r1=233309&r2=233310&view=diff
>> >>
>> ==========================================================
>> >> ====================
>> >> --- llvm/trunk/configure (original)
>> >> +++ llvm/trunk/configure Thu Mar 26 14:25:01 2015
>> >> @@ -1426,6 +1426,9 @@ Optional Features:
>> >> --enable-expensive-checks
>> >> Compile with expensive debug checks enabled (default
>> >> is NO)
>> >> + --enable-abi-breaking-checks
>> >> + Compile with abi-breaking asserts support (default
>> >> + is with-asserts)
>> >> --enable-debug-runtime Build runtime libs with debug symbols (default
>> is
>> >> NO)
>> >> --enable-debug-symbols Build compiler with debug symbols (default is
>> NO
>> >> if
>> >> @@ -4980,9 +4983,11 @@ fi
>> >> if test ${enableval} = "yes" ; then
>> >> DISABLE_ASSERTIONS=
>> >>
>> >> + assertions_enabled="yes"
>> >> else
>> >> DISABLE_ASSERTIONS=DISABLE_ASSERTIONS=1
>> >>
>> >> + assertions_enabled="no"
>> >> fi
>> >>
>> >> # Check whether --enable-werror was given.
>> >> @@ -5023,6 +5028,32 @@ else
>> >>
>> >> fi
>> >>
>> >> +# Check whether --enable-abi-breaking-checks was given.
>> >> +if test "${enable_abi_breaking_checks+set}" = set; then
>> >> + enableval=$enable_abi_breaking_checks;
>> >> +else
>> >> + enableval="with-asserts"
>> >> +fi
>> >> +
>> >> +case "$enableval" in
>> >> + with-asserts) if test ${assertions_enabled} = "yes" ; then
>> >> +
>> >> +cat >>confdefs.h <<\_ACEOF
>> >> +#define LLVM_ENABLE_ABI_BREAKING_CHECKS 1
>> >> +_ACEOF
>> >> +
>> >> + fi ;;
>> >> + yes)
>> >> +cat >>confdefs.h <<\_ACEOF
>> >> +#define LLVM_ENABLE_ABI_BREAKING_CHECKS 1
>> >> +_ACEOF
>> >> + ;;
>> >> + no) ;;
>> >> + *) { { echo "$as_me:$LINENO: error: Invalid setting for --enable-abi-
>> >> breaking-checks. Use \"with-asserts\", \"yes\" or \"no\"" >&5
>> >> +echo "$as_me: error: Invalid setting for --enable-abi-breaking-checks.
>> Use
>> >> \"with-asserts\", \"yes\" or \"no\"" >&2;}
>> >> + { (exit 1); exit 1; }; }
>> >> +esac
>> >> +
>> >> # Check whether --enable-debug-runtime was given.
>> >> if test "${enable_debug_runtime+set}" = set; then
>> >> enableval=$enable_debug_runtime;
>> >>
>> >> Modified: llvm/trunk/docs/CMake.rst
>> >> URL: http://llvm.org/viewvc/llvm-
>> >>
>> project/llvm/trunk/docs/CMake.rst?rev=233310&r1=233309&r2=233310&vie
>> >> w=diff
>> >>
>> ==========================================================
>> >> ====================
>> >> --- llvm/trunk/docs/CMake.rst (original)
>> >> +++ llvm/trunk/docs/CMake.rst Thu Mar 26 14:25:01 2015
>> >> @@ -270,6 +270,15 @@ LLVM-specific variables
>> >> **LLVM_ENABLE_WERROR**:BOOL
>> >> Stop and fail build, if a compiler warning is triggered. Defaults to OFF.
>> >>
>> >> +**LLVM_ABI_BREAKING_CHECKS**:STRING
>> >> + Used to decide if LLVM should be built with ABI breaking checks or
>> >> + not. Allowed values are `WITH_ASSERTS` (default), `FORCE_ON` and
>> >> + `FORCE_OFF`. `WITH_ASSERTS` turns on ABI breaking checks in an
>> >> + assertion enabled build. `FORCE_ON` (`FORCE_OFF`) turns them on
>> >> + (off) irrespective of whether normal (`NDEBUG` based) assertions are
>> >> + enabled or not. A version of LLVM built with ABI breaking checks
>> >> + is not ABI compatible with a version built without it.
>> >> +
>> >> **LLVM_BUILD_32_BITS**:BOOL
>> >> Build 32-bits executables and libraries on 64-bits systems. This option is
>> >> available only on some 64-bits unix systems. Defaults to OFF.
>> >>
>> >> Modified: llvm/trunk/docs/ProgrammersManual.rst
>> >> URL: http://llvm.org/viewvc/llvm-
>> >>
>> project/llvm/trunk/docs/ProgrammersManual.rst?rev=233310&r1=233309&r
>> >> 2=233310&view=diff
>> >>
>> ==========================================================
>> >> ====================
>> >> --- llvm/trunk/docs/ProgrammersManual.rst (original)
>> >> +++ llvm/trunk/docs/ProgrammersManual.rst Thu Mar 26 14:25:01 2015
>> >> @@ -2553,6 +2553,22 @@ section on :ref:`isa and dyn_cast <isa>`
>> >> <HowToSetUpLLVMStyleRTTI>` which describes how you can implement
>> this
>> >> pattern for use with the LLVM helpers.
>> >>
>> >> +.. _abi_breaking_checks:
>> >> +
>> >> +ABI Breaking Checks
>> >> +-------------------
>> >> +
>> >> +Checks and asserts that alter the LLVM C++ ABI are predicated on the
>> >> +preprocessor symbol `LLVM_ENABLE_ABI_BREAKING_CHECKS` -- LLVM
>> >> +libraries built with `LLVM_ENABLE_ABI_BREAKING_CHECKS` are not ABI
>> >> +compatible LLVM libraries built without it defined. By default,
>> >> +turning on assertions also turns on
>> >> `LLVM_ENABLE_ABI_BREAKING_CHECKS`
>> >> +so a default +Asserts build is not ABI compatible with a
>> >> +default -Asserts build. Clients that want ABI compatibility
>> >> +between +Asserts and -Asserts builds should use the CMake or autoconf
>> >> +build systems to set `LLVM_ENABLE_ABI_BREAKING_CHECKS`
>> >> independently
>> >> +of `LLVM_ENABLE_ASSERTIONS`.
>> >> +
>> >> .. _coreclasses:
>> >>
>> >> The Core LLVM Class Hierarchy Reference
>> >>
>> >> Modified: llvm/trunk/include/llvm/ADT/DenseMap.h
>> >> URL: http://llvm.org/viewvc/llvm-
>> >>
>> project/llvm/trunk/include/llvm/ADT/DenseMap.h?rev=233310&r1=233309&
>> >> r2=233310&view=diff
>> >>
>> ==========================================================
>> >> ====================
>> >> --- llvm/trunk/include/llvm/ADT/DenseMap.h (original)
>> >> +++ llvm/trunk/include/llvm/ADT/DenseMap.h Thu Mar 26 14:25:01 2015
>> >> @@ -15,6 +15,7 @@
>> >> #define LLVM_ADT_DENSEMAP_H
>> >>
>> >> #include "llvm/ADT/DenseMapInfo.h"
>> >> +#include "llvm/ADT/EpochTracker.h"
>> >> #include "llvm/Support/AlignOf.h"
>> >> #include "llvm/Support/Compiler.h"
>> >> #include "llvm/Support/MathExtras.h"
>> >> @@ -50,7 +51,7 @@ class DenseMapIterator;
>> >>
>> >> template <typename DerivedT, typename KeyT, typename ValueT,
>> >> typename KeyInfoT,
>> >> typename BucketT>
>> >> -class DenseMapBase {
>> >> +class DenseMapBase : public DebugEpochBase {
>> >> public:
>> >> typedef unsigned size_type;
>> >> typedef KeyT key_type;
>> >> @@ -62,16 +63,17 @@ public:
>> >> const_iterator;
>> >> inline iterator begin() {
>> >> // When the map is empty, avoid the overhead of
>> >> AdvancePastEmptyBuckets().
>> >> - return empty() ? end() : iterator(getBuckets(), getBucketsEnd());
>> >> + return empty() ? end() : iterator(getBuckets(), getBucketsEnd(),
>> *this);
>> >> }
>> >> inline iterator end() {
>> >> - return iterator(getBucketsEnd(), getBucketsEnd(), true);
>> >> + return iterator(getBucketsEnd(), getBucketsEnd(), *this, true);
>> >> }
>> >> inline const_iterator begin() const {
>> >> - return empty() ? end() : const_iterator(getBuckets(),
>> getBucketsEnd());
>> >> + return empty() ? end()
>> >> + : const_iterator(getBuckets(), getBucketsEnd(), *this);
>> >> }
>> >> inline const_iterator end() const {
>> >> - return const_iterator(getBucketsEnd(), getBucketsEnd(), true);
>> >> + return const_iterator(getBucketsEnd(), getBucketsEnd(), *this, true);
>> >> }
>> >>
>> >> bool LLVM_ATTRIBUTE_UNUSED_RESULT empty() const {
>> >> @@ -81,11 +83,13 @@ public:
>> >>
>> >> /// Grow the densemap so that it has at least Size buckets. Does not
>> shrink
>> >> void resize(size_type Size) {
>> >> + incrementEpoch();
>> >> if (Size > getNumBuckets())
>> >> grow(Size);
>> >> }
>> >>
>> >> void clear() {
>> >> + incrementEpoch();
>> >> if (getNumEntries() == 0 && getNumTombstones() == 0) return;
>> >>
>> >> // If the capacity of the array is huge, and the # elements used is small,
>> >> @@ -118,13 +122,13 @@ public:
>> >> iterator find(const KeyT &Val) {
>> >> BucketT *TheBucket;
>> >> if (LookupBucketFor(Val, TheBucket))
>> >> - return iterator(TheBucket, getBucketsEnd(), true);
>> >> + return iterator(TheBucket, getBucketsEnd(), *this, true);
>> >> return end();
>> >> }
>> >> const_iterator find(const KeyT &Val) const {
>> >> const BucketT *TheBucket;
>> >> if (LookupBucketFor(Val, TheBucket))
>> >> - return const_iterator(TheBucket, getBucketsEnd(), true);
>> >> + return const_iterator(TheBucket, getBucketsEnd(), *this, true);
>> >> return end();
>> >> }
>> >>
>> >> @@ -137,14 +141,14 @@ public:
>> >> iterator find_as(const LookupKeyT &Val) {
>> >> BucketT *TheBucket;
>> >> if (LookupBucketFor(Val, TheBucket))
>> >> - return iterator(TheBucket, getBucketsEnd(), true);
>> >> + return iterator(TheBucket, getBucketsEnd(), *this, true);
>> >> return end();
>> >> }
>> >> template<class LookupKeyT>
>> >> const_iterator find_as(const LookupKeyT &Val) const {
>> >> const BucketT *TheBucket;
>> >> if (LookupBucketFor(Val, TheBucket))
>> >> - return const_iterator(TheBucket, getBucketsEnd(), true);
>> >> + return const_iterator(TheBucket, getBucketsEnd(), *this, true);
>> >> return end();
>> >> }
>> >>
>> >> @@ -163,12 +167,13 @@ public:
>> >> std::pair<iterator, bool> insert(const std::pair<KeyT, ValueT> &KV) {
>> >> BucketT *TheBucket;
>> >> if (LookupBucketFor(KV.first, TheBucket))
>> >> - return std::make_pair(iterator(TheBucket, getBucketsEnd(), true),
>> >> + return std::make_pair(iterator(TheBucket, getBucketsEnd(), *this,
>> true),
>> >> false); // Already in map.
>> >>
>> >> // Otherwise, insert the new element.
>> >> TheBucket = InsertIntoBucket(KV.first, KV.second, TheBucket);
>> >> - return std::make_pair(iterator(TheBucket, getBucketsEnd(), true),
>> true);
>> >> + return std::make_pair(iterator(TheBucket, getBucketsEnd(), *this,
>> true),
>> >> + true);
>> >> }
>> >>
>> >> // Inserts key,value pair into the map if the key isn't already in the map.
>> >> @@ -177,14 +182,15 @@ public:
>> >> std::pair<iterator, bool> insert(std::pair<KeyT, ValueT> &&KV) {
>> >> BucketT *TheBucket;
>> >> if (LookupBucketFor(KV.first, TheBucket))
>> >> - return std::make_pair(iterator(TheBucket, getBucketsEnd(), true),
>> >> + return std::make_pair(iterator(TheBucket, getBucketsEnd(), *this,
>> true),
>> >> false); // Already in map.
>> >> -
>> >> +
>> >> // Otherwise, insert the new element.
>> >> TheBucket = InsertIntoBucket(std::move(KV.first),
>> >> std::move(KV.second),
>> >> TheBucket);
>> >> - return std::make_pair(iterator(TheBucket, getBucketsEnd(), true),
>> true);
>> >> + return std::make_pair(iterator(TheBucket, getBucketsEnd(), *this,
>> true),
>> >> + true);
>> >> }
>> >>
>> >> /// insert - Range insertion of pairs.
>> >> @@ -431,6 +437,8 @@ private:
>> >> }
>> >>
>> >> BucketT *InsertIntoBucketImpl(const KeyT &Key, BucketT *TheBucket) {
>> >> + incrementEpoch();
>> >> +
>> >> // If the load of the hash table is more than 3/4, or if fewer than 1/8 of
>> >> // the buckets are empty (meaning that many are filled with
>> tombstones),
>> >> // grow the table.
>> >> @@ -987,9 +995,10 @@ private:
>> >>
>> >> template <typename KeyT, typename ValueT, typename KeyInfoT,
>> >> typename Bucket,
>> >> bool IsConst>
>> >> -class DenseMapIterator {
>> >> +class DenseMapIterator : DebugEpochBase::HandleBase {
>> >> typedef DenseMapIterator<KeyT, ValueT, KeyInfoT, Bucket, true>
>> >> ConstIterator;
>> >> friend class DenseMapIterator<KeyT, ValueT, KeyInfoT, Bucket, true>;
>> >> + friend class DenseMapIterator<KeyT, ValueT, KeyInfoT, Bucket, false>;
>> >>
>> >> public:
>> >> typedef ptrdiff_t difference_type;
>> >> @@ -1003,8 +1012,10 @@ private:
>> >> public:
>> >> DenseMapIterator() : Ptr(nullptr), End(nullptr) {}
>> >>
>> >> - DenseMapIterator(pointer Pos, pointer E, bool NoAdvance = false)
>> >> - : Ptr(Pos), End(E) {
>> >> + DenseMapIterator(pointer Pos, pointer E, const DebugEpochBase
>> &Epoch,
>> >> + bool NoAdvance = false)
>> >> + : DebugEpochBase::HandleBase(&Epoch), Ptr(Pos), End(E) {
>> >> + assert(isHandleInSync() && "invalid construction!");
>> >> if (!NoAdvance) AdvancePastEmptyBuckets();
>> >> }
>> >>
>> >> @@ -1015,28 +1026,40 @@ public:
>> >> typename = typename std::enable_if<!IsConstSrc &&
>> IsConst>::type>
>> >> DenseMapIterator(
>> >> const DenseMapIterator<KeyT, ValueT, KeyInfoT, Bucket, IsConstSrc>
>> &I)
>> >> - : Ptr(I.Ptr), End(I.End) {}
>> >> + : DebugEpochBase::HandleBase(I), Ptr(I.Ptr), End(I.End) {}
>> >>
>> >> reference operator*() const {
>> >> + assert(isHandleInSync() && "invalid iterator access!");
>> >> return *Ptr;
>> >> }
>> >> pointer operator->() const {
>> >> + assert(isHandleInSync() && "invalid iterator access!");
>> >> return Ptr;
>> >> }
>> >>
>> >> bool operator==(const ConstIterator &RHS) const {
>> >> - return Ptr == RHS.operator->();
>> >> + assert((!Ptr || isHandleInSync()) && "handle not in sync!");
>> >> + assert((!RHS.Ptr || RHS.isHandleInSync()) && "handle not in sync!");
>> >> + assert(getEpochAddress() == RHS.getEpochAddress() &&
>> >> + "comparing incomparable iterators!");
>> >> + return Ptr == RHS.Ptr;
>> >> }
>> >> bool operator!=(const ConstIterator &RHS) const {
>> >> - return Ptr != RHS.operator->();
>> >> + assert((!Ptr || isHandleInSync()) && "handle not in sync!");
>> >> + assert((!RHS.Ptr || RHS.isHandleInSync()) && "handle not in sync!");
>> >> + assert(getEpochAddress() == RHS.getEpochAddress() &&
>> >> + "comparing incomparable iterators!");
>> >> + return Ptr != RHS.Ptr;
>> >> }
>> >>
>> >> inline DenseMapIterator& operator++() { // Preincrement
>> >> + assert(isHandleInSync() && "invalid iterator access!");
>> >> ++Ptr;
>> >> AdvancePastEmptyBuckets();
>> >> return *this;
>> >> }
>> >> DenseMapIterator operator++(int) { // Postincrement
>> >> + assert(isHandleInSync() && "invalid iterator access!");
>> >> DenseMapIterator tmp = *this; ++*this; return tmp;
>> >> }
>> >>
>> >>
>> >> Added: llvm/trunk/include/llvm/ADT/EpochTracker.h
>> >> URL: http://llvm.org/viewvc/llvm-
>> >>
>> project/llvm/trunk/include/llvm/ADT/EpochTracker.h?rev=233310&view=aut
>> >> o
>> >>
>> ==========================================================
>> >> ====================
>> >> --- llvm/trunk/include/llvm/ADT/EpochTracker.h (added)
>> >> +++ llvm/trunk/include/llvm/ADT/EpochTracker.h Thu Mar 26 14:25:01
>> 2015
>> >> @@ -0,0 +1,99 @@
>> >> +//===- llvm/ADT/EpochTracker.h - ADT epoch tracking --------------*- C++
>> -*-
>> >> ==//
>> >> +//
>> >> +// The LLVM Compiler Infrastructure
>> >> +//
>> >> +// This file is distributed under the University of Illinois Open Source
>> >> +// License. See LICENSE.TXT for details.
>> >> +//
>> >> +//===----------------------------------------------------------------------===//
>> >> +//
>> >> +// This file defines the DebugEpochBase and
>> DebugEpochBase::HandleBase
>> >> classes.
>> >> +// These can be used to write iterators that are fail-fast when LLVM is
>> built
>> >> +// with asserts enabled.
>> >> +//
>> >> +//===----------------------------------------------------------------------===//
>> >> +
>> >> +#ifndef LLVM_ADT_EPOCH_TRACKER_H
>> >> +#define LLVM_ADT_EPOCH_TRACKER_H
>> >> +
>> >> +#include "llvm/Config/llvm-config.h"
>> >> +
>> >> +#include <cstdint>
>> >> +
>> >> +namespace llvm {
>> >> +
>> >> +#ifndef LLVM_ENABLE_ABI_BREAKING_CHECKS
>> >> +
>> >> +class DebugEpochBase {
>> >> +public:
>> >> + void incrementEpoch() {}
>> >> +
>> >> + class HandleBase {
>> >> + public:
>> >> + HandleBase() {}
>> >> + explicit HandleBase(const DebugEpochBase *) {}
>> >> + bool isHandleInSync() const { return true; }
>> >> + const void *getEpochAddress() const { return nullptr; }
>> >> + };
>> >> +};
>> >> +
>> >> +#else
>> >> +
>> >> +/// \brief A base class for data structure classes wishing to make iterators
>> >> +/// ("handles") pointing into themselves fail-fast. When building without
>> >> +/// asserts, this class is empty and does nothing.
>> >> +///
>> >> +/// DebugEpochBase does not by itself track handles pointing into itself.
>> >> The
>> >> +/// expectation is that routines touching the handles will poll on
>> >> +/// isHandleInSync at appropriate points to assert that the handle
>> they're
>> >> using
>> >> +/// is still valid.
>> >> +///
>> >> +class DebugEpochBase {
>> >> + uint64_t Epoch;
>> >> +
>> >> +public:
>> >> + DebugEpochBase() : Epoch(0) {}
>> >> +
>> >> + /// \brief Calling incrementEpoch invalidates all handles pointing into
>> the
>> >> + /// calling instance.
>> >> + void incrementEpoch() { ++Epoch; }
>> >> +
>> >> + /// \brief The destructor calls incrementEpoch to make use-after-free
>> bugs
>> >> + /// more likely to crash deterministically.
>> >> + ~DebugEpochBase() { incrementEpoch(); }
>> >> +
>> >> + /// \brief A base class for iterator classes ("handles") that wish to poll
>> for
>> >> + /// iterator invalidating modifications in the underlying data structure.
>> >> + /// When LLVM is built without asserts, this class is empty and does
>> >> nothing.
>> >> + ///
>> >> + /// HandleBase does not track the parent data structure by itself. It
>> >> expects
>> >> + /// the routines modifying the data structure to call incrementEpoch
>> when
>> >> they
>> >> + /// make an iterator-invalidating modification.
>> >> + ///
>> >> + class HandleBase {
>> >> + const uint64_t *EpochAddress;
>> >> + uint64_t EpochAtCreation;
>> >> +
>> >> + public:
>> >> + HandleBase() : EpochAddress(nullptr),
>> EpochAtCreation(UINT64_MAX) {}
>> >> +
>> >> + explicit HandleBase(const DebugEpochBase *Parent)
>> >> + : EpochAddress(&Parent->Epoch), EpochAtCreation(Parent->Epoch)
>> {}
>> >> +
>> >> + /// \brief Returns true if the DebugEpochBase this Handle is linked to
>> has
>> >> + /// not called incrementEpoch on itself since the creation of this
>> >> + /// HandleBase instance.
>> >> + bool isHandleInSync() const { return *EpochAddress ==
>> EpochAtCreation;
>> >> }
>> >> +
>> >> + /// \brief Returns a pointer to the epoch word stored in the data
>> >> structure
>> >> + /// this handle points into. Can be used to check if two iterators point
>> >> + /// into the same data structure.
>> >> + const void *getEpochAddress() const { return EpochAddress; }
>> >> + };
>> >> +};
>> >> +
>> >> +#endif // LLVM_ENABLE_ABI_BREAKING_CHECKS
>> >> +
>> >> +} // namespace llvm
>> >> +
>> >> +#endif
>> >>
>> >> Modified: llvm/trunk/include/llvm/Config/config.h.in
>> >> URL: http://llvm.org/viewvc/llvm-
>> >>
>> project/llvm/trunk/include/llvm/Config/config.h.in?rev=233310&r1=233309&
>> >> r2=233310&view=diff
>> >>
>> ==========================================================
>> >> ====================
>> >> --- llvm/trunk/include/llvm/Config/config.h.in (original)
>> >> +++ llvm/trunk/include/llvm/Config/config.h.in Thu Mar 26 14:25:01 2015
>> >> @@ -417,6 +417,9 @@
>> >> /* Installation directory for documentation */
>> >> #undef LLVM_DOCSDIR
>> >>
>> >> +/* Define to enable checks that alter the LLVM C++ ABI */
>> >> +#undef LLVM_ENABLE_ABI_BREAKING_CHECKS
>> >> +
>> >> /* Define if threads enabled */
>> >> #undef LLVM_ENABLE_THREADS
>> >>
>> >>
>> >> Modified: llvm/trunk/include/llvm/Config/llvm-config.h.cmake
>> >> URL: http://llvm.org/viewvc/llvm-
>> >> project/llvm/trunk/include/llvm/Config/llvm-
>> >> config.h.cmake?rev=233310&r1=233309&r2=233310&view=diff
>> >>
>> ==========================================================
>> >> ====================
>> >> --- llvm/trunk/include/llvm/Config/llvm-config.h.cmake (original)
>> >> +++ llvm/trunk/include/llvm/Config/llvm-config.h.cmake Thu Mar 26
>> 14:25:01
>> >> 2015
>> >> @@ -101,4 +101,8 @@
>> >> /* Define if we link Polly to the tools */
>> >> #cmakedefine LINK_POLLY_INTO_TOOLS
>> >>
>> >> +/* Define if LLVM is built with asserts and checks that change the layout
>> of
>> >> + client-visible data structures. */
>> >> +#cmakedefine LLVM_ENABLE_ABI_BREAKING_CHECKS
>> >> +
>> >> #endif
>> >>
>> >> Modified: llvm/trunk/include/llvm/Config/llvm-config.h.in
>> >> URL: http://llvm.org/viewvc/llvm-
>> >> project/llvm/trunk/include/llvm/Config/llvm-
>> >> config.h.in?rev=233310&r1=233309&r2=233310&view=diff
>> >>
>> ==========================================================
>> >> ====================
>> >> --- llvm/trunk/include/llvm/Config/llvm-config.h.in (original)
>> >> +++ llvm/trunk/include/llvm/Config/llvm-config.h.in Thu Mar 26 14:25:01
>> >> 2015
>> >> @@ -98,4 +98,7 @@
>> >> /* LLVM version string */
>> >> #undef LLVM_VERSION_STRING
>> >>
>> >> +/* Define to enable checks that alter the LLVM C++ ABI */
>> >> +#undef LLVM_ENABLE_ABI_BREAKING_CHECKS
>> >> +
>> >> #endif
>> >>
>> >>
>> >> _______________________________________________
>> >> llvm-commits mailing list
>> >> llvm-commits at cs.uiuc.edu
>> >> http://lists.cs.uiuc.edu/mailman/listinfo/llvm-commits
>
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