[llvm] r233310 - [ADT][CMake][AutoConf] Fail-fast iterators for DenseMap
Daniel Sanders
Daniel.Sanders at imgtec.com
Tue Mar 31 03:35:18 PDT 2015
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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