[llvm] r233310 - [ADT][CMake][AutoConf] Fail-fast iterators for DenseMap
Sanjoy Das
sanjoy at playingwithpointers.com
Tue Mar 31 20:20:48 PDT 2015
I fixed this in r233784 (using Daniel's approach). Please let me know
if the fix does not work.
Thanks!
-- Sanjoy
On Tue, Mar 31, 2015 at 12:53 PM, Eric Fiselier <eric at efcs.ca> wrote:
> 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
>>
>> _______________________________________________
>> llvm-commits mailing list
>> llvm-commits at cs.uiuc.edu
>> http://lists.cs.uiuc.edu/mailman/listinfo/llvm-commits
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