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If someone is reviewing the pull request, then could they also check -https://opensource.org/licenses/NCSA This license likely contains placeholder values from the original license which should be replaced with real values - like Copyright changing from University of Illinois at Urbana-Champaign. to Apple Inc. |
Thank you, but we are not diverging from upstream clang unless we have to. Please submit this change to the llvm.org project. |
gottesmm
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Feb 7, 2016
member function exists on a class. The previous trick depended on inheriting from the class it was checking, which will fail when I start marking things 'final'. Attempt #2: now with a special #ifdef branch for MSVC. Hopefully *this* actually builds with all supported compilers... git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@256564 91177308-0d34-0410-b5e6-96231b3b80d8
fredriss
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May 13, 2016
…lookup Reapply r269100 and r269270, reverted due to https://llvm.org/bugs/show_bug.cgi?id=27725. Isolate the testcase that corresponds to the new feature side of this commit and skip it on windows hosts until we find why it does not work on these platforms. Original commit message: The way we currently build the internal VFS overlay representation leads to inefficient path search and might yield wrong answers when asked for recursive or regular directory iteration. Currently, when reading an YAML file, each YAML root entry is placed inside a new root in the filesystem overlay. In the crash reproducer, a simple "@import Foundation" currently maps to 43 roots, and when looking up paths, we traverse a directory tree for each of these different roots, until we find a match (or don't). This has two consequences: - It's slow. - Directory iteration gives incomplete results since it only return results within one root - since contents of the same directory can be declared inside different roots, the result isn't accurate. This is in part fault of the way we currently write out the YAML file when emitting the crash reproducer - we could generate only one root and that would make it fast and correct again. However, we should not rely on how the client writes the YAML, but provide a good internal representation regardless. Build a proper virtual directory tree out of the YAML representation, allowing faster search and proper iteration. Besides the crash reproducer, this potentially benefits other VFS clients. git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@269327 91177308-0d34-0410-b5e6-96231b3b80d8
bcardosolopes
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May 18, 2016
…lookup Reapply r269100 and r269270, reverted due to https://llvm.org/bugs/show_bug.cgi?id=27725. Isolate the testcase that corresponds to the new feature side of this commit and skip it on windows hosts until we find why it does not work on these platforms. Original commit message: The way we currently build the internal VFS overlay representation leads to inefficient path search and might yield wrong answers when asked for recursive or regular directory iteration. Currently, when reading an YAML file, each YAML root entry is placed inside a new root in the filesystem overlay. In the crash reproducer, a simple "@import Foundation" currently maps to 43 roots, and when looking up paths, we traverse a directory tree for each of these different roots, until we find a match (or don't). This has two consequences: - It's slow. - Directory iteration gives incomplete results since it only return results within one root - since contents of the same directory can be declared inside different roots, the result isn't accurate. This is in part fault of the way we currently write out the YAML file when emitting the crash reproducer - we could generate only one root and that would make it fast and correct again. However, we should not rely on how the client writes the YAML, but provide a good internal representation regardless. Build a proper virtual directory tree out of the YAML representation, allowing faster search and proper iteration. Besides the crash reproducer, this potentially benefits other VFS clients. rdar://problem/25880368 git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@269327 91177308-0d34-0410-b5e6-96231b3b80d8 (cherry picked from commit dfa97d2)
fredriss
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Jun 21, 2016
…known to appease *-win32 targets. <stdin>:9:25: note: possible intended match here %call = tail call i8 @"\01?convert_char_rte@@$$J0YADD@Z"(i8 %x) #2 ^ git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@273230 91177308-0d34-0410-b5e6-96231b3b80d8
fredriss
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Sep 12, 2016
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@281195 91177308-0d34-0410-b5e6-96231b3b80d8
bcardosolopes
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Oct 22, 2016
…rules. This has two significant effects: 1) Direct relational comparisons between null pointer constants (0 and nullopt) and pointers are now ill-formed. This was always the case for C, and it appears that C++ only ever permitted by accident. For instance, cases like nullptr < &a are now rejected. 2) Comparisons and conditional operators between differently-cv-qualified pointer types now work, and produce a composite type that both source pointer types can convert to (when possible). For instance, comparison between 'int **' and 'const int **' is now valid, and uses an intermediate type of 'const int *const *'. Clang previously supported #2 as an extension. We do not accept the cases in #1 as an extension. I've tested a fair amount of code to check that this doesn't break it, but if it turns out that someone is relying on this, we can easily add it back as an extension. git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@284800 91177308-0d34-0410-b5e6-96231b3b80d8
bcardosolopes
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Oct 22, 2016
…rules. This has two significant effects: 1) Direct relational comparisons between null pointer constants (0 and nullopt) and pointers are now ill-formed. This was always the case for C, and it appears that C++ only ever permitted by accident. For instance, cases like nullptr < &a are now rejected. 2) Comparisons and conditional operators between differently-cv-qualified pointer types now work, and produce a composite type that both source pointer types can convert to (when possible). For instance, comparison between 'int **' and 'const int **' is now valid, and uses an intermediate type of 'const int *const *'. Clang previously supported #2 as an extension. We do not accept the cases in #1 as an extension. I've tested a fair amount of code to check that this doesn't break it, but if it turns out that someone is relying on this, we can easily add it back as an extension. This is a re-commit of r284800. git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@284890 91177308-0d34-0410-b5e6-96231b3b80d8
fredriss
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Feb 14, 2017
…and. Rank such guides below explicit ones, and ensure that references to the class's template parameters are not treated as forwarding references. We make a few tweaks to the wording in the current standard: 1) The constructor parameter list is copied faithfully to the deduction guide, without losing default arguments or a varargs ellipsis (which the standard wording loses by omission). 2) If the class template declares no constructors, we add a T() -> T<...> guide (which will only ever work if T has default arguments for all non-pack template parameters). 3) If the class template declares nothing that looks like a copy or move constructor, we add a T(T<...>) -> T<...> guide. #2 and #3 follow from the "pretend we had a class type with these constructors" philosophy for deduction guides. git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@295007 91177308-0d34-0410-b5e6-96231b3b80d8
fredriss
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May 18, 2017
Summary: The test being added in this patch used to cause an assertion failure: /build/./bin/clang -cc1 -internal-isystem /build/lib/clang/5.0.0/include -nostdsysteminc -verify -fsyntax-only -std=c++11 -Wshadow-all /src/tools/clang/test/SemaCXX/warn-shadow.cpp -- Exit Code: 134 Command Output (stderr): -- clang: /src/tools/clang/lib/AST/ASTDiagnostic.cpp:424: void clang::FormatASTNodeDiagnosticArgument(DiagnosticsEngine::ArgumentKind, intptr_t, llvm::StringRef, llvm::StringRef, ArrayRef<DiagnosticsEngine::ArgumentValue>, SmallVectorImpl<char> &, void *, ArrayRef<intptr_t>): Assertion `isa<NamedDecl>(DC) && "Expected a NamedDecl"' failed. #0 0x0000000001c7a1b4 PrintStackTraceSignalHandler(void*) (/build/./bin/clang+0x1c7a1b4) #1 0x0000000001c7a4e6 SignalHandler(int) (/build/./bin/clang+0x1c7a4e6) #2 0x00007f30880078d0 __restore_rt (/lib/x86_64-linux-gnu/libpthread.so.0+0xf8d0) #3 0x00007f3087054067 gsignal (/lib/x86_64-linux-gnu/libc.so.6+0x35067) #4 0x00007f3087055448 abort (/lib/x86_64-linux-gnu/libc.so.6+0x36448) #5 0x00007f308704d266 (/lib/x86_64-linux-gnu/libc.so.6+0x2e266) #6 0x00007f308704d312 (/lib/x86_64-linux-gnu/libc.so.6+0x2e312) #7 0x00000000035b7f22 clang::FormatASTNodeDiagnosticArgument(clang::DiagnosticsEngine::ArgumentKind, long, llvm::StringRef, llvm::StringRef, llvm::ArrayRef<std::pair<clang::DiagnosticsEngine::ArgumentKind, long> >, llvm::SmallVectorImpl<char>&, void*, llvm::ArrayRef<long>) (/build/ ./bin/clang+0x35b7f22) #8 0x0000000001ddbae4 clang::Diagnostic::FormatDiagnostic(char const*, char const*, llvm::SmallVectorImpl<char>&) const (/build/./bin/clang+0x1ddbae4) #9 0x0000000001ddb323 clang::Diagnostic::FormatDiagnostic(char const*, char const*, llvm::SmallVectorImpl<char>&) const (/build/./bin/clang+0x1ddb323) #10 0x00000000022878a4 clang::TextDiagnosticBuffer::HandleDiagnostic(clang::DiagnosticsEngine::Level, clang::Diagnostic const&) (/build/./bin/clang+0x22878a4) #11 0x0000000001ddf387 clang::DiagnosticIDs::ProcessDiag(clang::DiagnosticsEngine&) const (/build/./bin/clang+0x1ddf387) #12 0x0000000001dd9dea clang::DiagnosticsEngine::EmitCurrentDiagnostic(bool) (/build/./bin/clang+0x1dd9dea) #13 0x0000000002cad00c clang::Sema::EmitCurrentDiagnostic(unsigned int) (/build/./bin/clang+0x2cad00c) #14 0x0000000002d91cd2 clang::Sema::CheckShadow(clang::NamedDecl*, clang::NamedDecl*, clang::LookupResult const&) (/build/./bin/clang+0x2d91cd2) Stack dump: 0. Program arguments: /build/./bin/clang -cc1 -internal-isystem /build/lib/clang/5.0.0/include -nostdsysteminc -verify -fsyntax-only -std=c++11 -Wshadow-all /src/tools/clang/test/SemaCXX/warn-shadow.cpp 1. /src/tools/clang/test/SemaCXX/warn-shadow.cpp:214:23: current parser token ';' 2. /src/tools/clang/test/SemaCXX/warn-shadow.cpp:213:26: parsing function body 'handleLinkageSpec' 3. /src/tools/clang/test/SemaCXX/warn-shadow.cpp:213:26: in compound statement ('{}') /build/tools/clang/test/SemaCXX/Output/warn-shadow.cpp.script: line 1: 15595 Aborted (core dumped) /build/./bin/clang -cc1 -internal-isystem /build/lib/clang/5.0.0/include -nostdsysteminc -verify -fsyntax-only -std=c++11 -Wshadow-all /src/tools/clang/test/SemaCXX/warn-shadow.cpp Reviewers: rsmith Reviewed By: rsmith Subscribers: krytarowski, cfe-commits Differential Revision: https://reviews.llvm.org/D33207 git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@303325 91177308-0d34-0410-b5e6-96231b3b80d8
fredriss
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Jul 26, 2017
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@309061 91177308-0d34-0410-b5e6-96231b3b80d8
fredriss
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Aug 9, 2017
"error: unable to create target: 'No available targets are compatible with this triple.'" git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@310445 91177308-0d34-0410-b5e6-96231b3b80d8
haoNoQ
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Oct 3, 2017
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@309061 91177308-0d34-0410-b5e6-96231b3b80d8 (cherry picked from commit e49d515)
cheshire
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Nov 10, 2017
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@309061 91177308-0d34-0410-b5e6-96231b3b80d8
fredriss
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Jan 23, 2018
…the speculative execution vulnerabilities disclosed today, specifically identified by CVE-2017-5715, "Branch Target Injection", and is one of the two halves to Spectre.. Summary: First, we need to explain the core of the vulnerability. Note that this is a very incomplete description, please see the Project Zero blog post for details: https://googleprojectzero.blogspot.com/2018/01/reading-privileged-memory-with-side.html The basis for branch target injection is to direct speculative execution of the processor to some "gadget" of executable code by poisoning the prediction of indirect branches with the address of that gadget. The gadget in turn contains an operation that provides a side channel for reading data. Most commonly, this will look like a load of secret data followed by a branch on the loaded value and then a load of some predictable cache line. The attacker then uses timing of the processors cache to determine which direction the branch took *in the speculative execution*, and in turn what one bit of the loaded value was. Due to the nature of these timing side channels and the branch predictor on Intel processors, this allows an attacker to leak data only accessible to a privileged domain (like the kernel) back into an unprivileged domain. The goal is simple: avoid generating code which contains an indirect branch that could have its prediction poisoned by an attacker. In many cases, the compiler can simply use directed conditional branches and a small search tree. LLVM already has support for lowering switches in this way and the first step of this patch is to disable jump-table lowering of switches and introduce a pass to rewrite explicit indirectbr sequences into a switch over integers. However, there is no fully general alternative to indirect calls. We introduce a new construct we call a "retpoline" to implement indirect calls in a non-speculatable way. It can be thought of loosely as a trampoline for indirect calls which uses the RET instruction on x86. Further, we arrange for a specific call->ret sequence which ensures the processor predicts the return to go to a controlled, known location. The retpoline then "smashes" the return address pushed onto the stack by the call with the desired target of the original indirect call. The result is a predicted return to the next instruction after a call (which can be used to trap speculative execution within an infinite loop) and an actual indirect branch to an arbitrary address. On 64-bit x86 ABIs, this is especially easily done in the compiler by using a guaranteed scratch register to pass the target into this device. For 32-bit ABIs there isn't a guaranteed scratch register and so several different retpoline variants are introduced to use a scratch register if one is available in the calling convention and to otherwise use direct stack push/pop sequences to pass the target address. This "retpoline" mitigation is fully described in the following blog post: https://support.google.com/faqs/answer/7625886 We also support a target feature that disables emission of the retpoline thunk by the compiler to allow for custom thunks if users want them. These are particularly useful in environments like kernels that routinely do hot-patching on boot and want to hot-patch their thunk to different code sequences. They can write this custom thunk and use `-mretpoline-external-thunk` *in addition* to `-mretpoline`. In this case, on x86-64 thu thunk names must be: ``` __llvm_external_retpoline_r11 ``` or on 32-bit: ``` __llvm_external_retpoline_eax __llvm_external_retpoline_ecx __llvm_external_retpoline_edx __llvm_external_retpoline_push ``` And the target of the retpoline is passed in the named register, or in the case of the `push` suffix on the top of the stack via a `pushl` instruction. There is one other important source of indirect branches in x86 ELF binaries: the PLT. These patches also include support for LLD to generate PLT entries that perform a retpoline-style indirection. The only other indirect branches remaining that we are aware of are from precompiled runtimes (such as crt0.o and similar). The ones we have found are not really attackable, and so we have not focused on them here, but eventually these runtimes should also be replicated for retpoline-ed configurations for completeness. For kernels or other freestanding or fully static executables, the compiler switch `-mretpoline` is sufficient to fully mitigate this particular attack. For dynamic executables, you must compile *all* libraries with `-mretpoline` and additionally link the dynamic executable and all shared libraries with LLD and pass `-z retpolineplt` (or use similar functionality from some other linker). We strongly recommend also using `-z now` as non-lazy binding allows the retpoline-mitigated PLT to be substantially smaller. When manually apply similar transformations to `-mretpoline` to the Linux kernel we observed very small performance hits to applications running typical workloads, and relatively minor hits (approximately 2%) even for extremely syscall-heavy applications. This is largely due to the small number of indirect branches that occur in performance sensitive paths of the kernel. When using these patches on statically linked applications, especially C++ applications, you should expect to see a much more dramatic performance hit. For microbenchmarks that are switch, indirect-, or virtual-call heavy we have seen overheads ranging from 10% to 50%. However, real-world workloads exhibit substantially lower performance impact. Notably, techniques such as PGO and ThinLTO dramatically reduce the impact of hot indirect calls (by speculatively promoting them to direct calls) and allow optimized search trees to be used to lower switches. If you need to deploy these techniques in C++ applications, we *strongly* recommend that you ensure all hot call targets are statically linked (avoiding PLT indirection) and use both PGO and ThinLTO. Well tuned servers using all of these techniques saw 5% - 10% overhead from the use of retpoline. We will add detailed documentation covering these components in subsequent patches, but wanted to make the core functionality available as soon as possible. Happy for more code review, but we'd really like to get these patches landed and backported ASAP for obvious reasons. We're planning to backport this to both 6.0 and 5.0 release streams and get a 5.0 release with just this cherry picked ASAP for distros and vendors. This patch is the work of a number of people over the past month: Eric, Reid, Rui, and myself. I'm mailing it out as a single commit due to the time sensitive nature of landing this and the need to backport it. Huge thanks to everyone who helped out here, and everyone at Intel who helped out in discussions about how to craft this. Also, credit goes to Paul Turner (at Google, but not an LLVM contributor) for much of the underlying retpoline design. Reviewers: echristo, rnk, ruiu, craig.topper, DavidKreitzer Subscribers: sanjoy, emaste, mcrosier, mgorny, mehdi_amini, hiraditya, llvm-commits Differential Revision: https://reviews.llvm.org/D41723 git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@323155 91177308-0d34-0410-b5e6-96231b3b80d8
fredriss
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Feb 2, 2018
------------------------------------------------------------------------ r323155 | chandlerc | 2018-01-22 14:05:25 -0800 (Mon, 22 Jan 2018) | 133 lines Introduce the "retpoline" x86 mitigation technique for variant #2 of the speculative execution vulnerabilities disclosed today, specifically identified by CVE-2017-5715, "Branch Target Injection", and is one of the two halves to Spectre.. Summary: First, we need to explain the core of the vulnerability. Note that this is a very incomplete description, please see the Project Zero blog post for details: https://googleprojectzero.blogspot.com/2018/01/reading-privileged-memory-with-side.html The basis for branch target injection is to direct speculative execution of the processor to some "gadget" of executable code by poisoning the prediction of indirect branches with the address of that gadget. The gadget in turn contains an operation that provides a side channel for reading data. Most commonly, this will look like a load of secret data followed by a branch on the loaded value and then a load of some predictable cache line. The attacker then uses timing of the processors cache to determine which direction the branch took *in the speculative execution*, and in turn what one bit of the loaded value was. Due to the nature of these timing side channels and the branch predictor on Intel processors, this allows an attacker to leak data only accessible to a privileged domain (like the kernel) back into an unprivileged domain. The goal is simple: avoid generating code which contains an indirect branch that could have its prediction poisoned by an attacker. In many cases, the compiler can simply use directed conditional branches and a small search tree. LLVM already has support for lowering switches in this way and the first step of this patch is to disable jump-table lowering of switches and introduce a pass to rewrite explicit indirectbr sequences into a switch over integers. However, there is no fully general alternative to indirect calls. We introduce a new construct we call a "retpoline" to implement indirect calls in a non-speculatable way. It can be thought of loosely as a trampoline for indirect calls which uses the RET instruction on x86. Further, we arrange for a specific call->ret sequence which ensures the processor predicts the return to go to a controlled, known location. The retpoline then "smashes" the return address pushed onto the stack by the call with the desired target of the original indirect call. The result is a predicted return to the next instruction after a call (which can be used to trap speculative execution within an infinite loop) and an actual indirect branch to an arbitrary address. On 64-bit x86 ABIs, this is especially easily done in the compiler by using a guaranteed scratch register to pass the target into this device. For 32-bit ABIs there isn't a guaranteed scratch register and so several different retpoline variants are introduced to use a scratch register if one is available in the calling convention and to otherwise use direct stack push/pop sequences to pass the target address. This "retpoline" mitigation is fully described in the following blog post: https://support.google.com/faqs/answer/7625886 We also support a target feature that disables emission of the retpoline thunk by the compiler to allow for custom thunks if users want them. These are particularly useful in environments like kernels that routinely do hot-patching on boot and want to hot-patch their thunk to different code sequences. They can write this custom thunk and use `-mretpoline-external-thunk` *in addition* to `-mretpoline`. In this case, on x86-64 thu thunk names must be: ``` __llvm_external_retpoline_r11 ``` or on 32-bit: ``` __llvm_external_retpoline_eax __llvm_external_retpoline_ecx __llvm_external_retpoline_edx __llvm_external_retpoline_push ``` And the target of the retpoline is passed in the named register, or in the case of the `push` suffix on the top of the stack via a `pushl` instruction. There is one other important source of indirect branches in x86 ELF binaries: the PLT. These patches also include support for LLD to generate PLT entries that perform a retpoline-style indirection. The only other indirect branches remaining that we are aware of are from precompiled runtimes (such as crt0.o and similar). The ones we have found are not really attackable, and so we have not focused on them here, but eventually these runtimes should also be replicated for retpoline-ed configurations for completeness. For kernels or other freestanding or fully static executables, the compiler switch `-mretpoline` is sufficient to fully mitigate this particular attack. For dynamic executables, you must compile *all* libraries with `-mretpoline` and additionally link the dynamic executable and all shared libraries with LLD and pass `-z retpolineplt` (or use similar functionality from some other linker). We strongly recommend also using `-z now` as non-lazy binding allows the retpoline-mitigated PLT to be substantially smaller. When manually apply similar transformations to `-mretpoline` to the Linux kernel we observed very small performance hits to applications running typical workloads, and relatively minor hits (approximately 2%) even for extremely syscall-heavy applications. This is largely due to the small number of indirect branches that occur in performance sensitive paths of the kernel. When using these patches on statically linked applications, especially C++ applications, you should expect to see a much more dramatic performance hit. For microbenchmarks that are switch, indirect-, or virtual-call heavy we have seen overheads ranging from 10% to 50%. However, real-world workloads exhibit substantially lower performance impact. Notably, techniques such as PGO and ThinLTO dramatically reduce the impact of hot indirect calls (by speculatively promoting them to direct calls) and allow optimized search trees to be used to lower switches. If you need to deploy these techniques in C++ applications, we *strongly* recommend that you ensure all hot call targets are statically linked (avoiding PLT indirection) and use both PGO and ThinLTO. Well tuned servers using all of these techniques saw 5% - 10% overhead from the use of retpoline. We will add detailed documentation covering these components in subsequent patches, but wanted to make the core functionality available as soon as possible. Happy for more code review, but we'd really like to get these patches landed and backported ASAP for obvious reasons. We're planning to backport this to both 6.0 and 5.0 release streams and get a 5.0 release with just this cherry picked ASAP for distros and vendors. This patch is the work of a number of people over the past month: Eric, Reid, Rui, and myself. I'm mailing it out as a single commit due to the time sensitive nature of landing this and the need to backport it. Huge thanks to everyone who helped out here, and everyone at Intel who helped out in discussions about how to craft this. Also, credit goes to Paul Turner (at Google, but not an LLVM contributor) for much of the underlying retpoline design. Reviewers: echristo, rnk, ruiu, craig.topper, DavidKreitzer Subscribers: sanjoy, emaste, mcrosier, mgorny, mehdi_amini, hiraditya, llvm-commits Differential Revision: https://reviews.llvm.org/D41723 ------------------------------------------------------------------------ git-svn-id: https://llvm.org/svn/llvm-project/cfe/branches/release_50@324012 91177308-0d34-0410-b5e6-96231b3b80d8
fredriss
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Feb 3, 2018
------------------------------------------------------------------------ r323155 | chandlerc | 2018-01-22 23:05:25 +0100 (Mon, 22 Jan 2018) | 133 lines Introduce the "retpoline" x86 mitigation technique for variant #2 of the speculative execution vulnerabilities disclosed today, specifically identified by CVE-2017-5715, "Branch Target Injection", and is one of the two halves to Spectre.. Summary: First, we need to explain the core of the vulnerability. Note that this is a very incomplete description, please see the Project Zero blog post for details: https://googleprojectzero.blogspot.com/2018/01/reading-privileged-memory-with-side.html The basis for branch target injection is to direct speculative execution of the processor to some "gadget" of executable code by poisoning the prediction of indirect branches with the address of that gadget. The gadget in turn contains an operation that provides a side channel for reading data. Most commonly, this will look like a load of secret data followed by a branch on the loaded value and then a load of some predictable cache line. The attacker then uses timing of the processors cache to determine which direction the branch took *in the speculative execution*, and in turn what one bit of the loaded value was. Due to the nature of these timing side channels and the branch predictor on Intel processors, this allows an attacker to leak data only accessible to a privileged domain (like the kernel) back into an unprivileged domain. The goal is simple: avoid generating code which contains an indirect branch that could have its prediction poisoned by an attacker. In many cases, the compiler can simply use directed conditional branches and a small search tree. LLVM already has support for lowering switches in this way and the first step of this patch is to disable jump-table lowering of switches and introduce a pass to rewrite explicit indirectbr sequences into a switch over integers. However, there is no fully general alternative to indirect calls. We introduce a new construct we call a "retpoline" to implement indirect calls in a non-speculatable way. It can be thought of loosely as a trampoline for indirect calls which uses the RET instruction on x86. Further, we arrange for a specific call->ret sequence which ensures the processor predicts the return to go to a controlled, known location. The retpoline then "smashes" the return address pushed onto the stack by the call with the desired target of the original indirect call. The result is a predicted return to the next instruction after a call (which can be used to trap speculative execution within an infinite loop) and an actual indirect branch to an arbitrary address. On 64-bit x86 ABIs, this is especially easily done in the compiler by using a guaranteed scratch register to pass the target into this device. For 32-bit ABIs there isn't a guaranteed scratch register and so several different retpoline variants are introduced to use a scratch register if one is available in the calling convention and to otherwise use direct stack push/pop sequences to pass the target address. This "retpoline" mitigation is fully described in the following blog post: https://support.google.com/faqs/answer/7625886 We also support a target feature that disables emission of the retpoline thunk by the compiler to allow for custom thunks if users want them. These are particularly useful in environments like kernels that routinely do hot-patching on boot and want to hot-patch their thunk to different code sequences. They can write this custom thunk and use `-mretpoline-external-thunk` *in addition* to `-mretpoline`. In this case, on x86-64 thu thunk names must be: ``` __llvm_external_retpoline_r11 ``` or on 32-bit: ``` __llvm_external_retpoline_eax __llvm_external_retpoline_ecx __llvm_external_retpoline_edx __llvm_external_retpoline_push ``` And the target of the retpoline is passed in the named register, or in the case of the `push` suffix on the top of the stack via a `pushl` instruction. There is one other important source of indirect branches in x86 ELF binaries: the PLT. These patches also include support for LLD to generate PLT entries that perform a retpoline-style indirection. The only other indirect branches remaining that we are aware of are from precompiled runtimes (such as crt0.o and similar). The ones we have found are not really attackable, and so we have not focused on them here, but eventually these runtimes should also be replicated for retpoline-ed configurations for completeness. For kernels or other freestanding or fully static executables, the compiler switch `-mretpoline` is sufficient to fully mitigate this particular attack. For dynamic executables, you must compile *all* libraries with `-mretpoline` and additionally link the dynamic executable and all shared libraries with LLD and pass `-z retpolineplt` (or use similar functionality from some other linker). We strongly recommend also using `-z now` as non-lazy binding allows the retpoline-mitigated PLT to be substantially smaller. When manually apply similar transformations to `-mretpoline` to the Linux kernel we observed very small performance hits to applications running typical workloads, and relatively minor hits (approximately 2%) even for extremely syscall-heavy applications. This is largely due to the small number of indirect branches that occur in performance sensitive paths of the kernel. When using these patches on statically linked applications, especially C++ applications, you should expect to see a much more dramatic performance hit. For microbenchmarks that are switch, indirect-, or virtual-call heavy we have seen overheads ranging from 10% to 50%. However, real-world workloads exhibit substantially lower performance impact. Notably, techniques such as PGO and ThinLTO dramatically reduce the impact of hot indirect calls (by speculatively promoting them to direct calls) and allow optimized search trees to be used to lower switches. If you need to deploy these techniques in C++ applications, we *strongly* recommend that you ensure all hot call targets are statically linked (avoiding PLT indirection) and use both PGO and ThinLTO. Well tuned servers using all of these techniques saw 5% - 10% overhead from the use of retpoline. We will add detailed documentation covering these components in subsequent patches, but wanted to make the core functionality available as soon as possible. Happy for more code review, but we'd really like to get these patches landed and backported ASAP for obvious reasons. We're planning to backport this to both 6.0 and 5.0 release streams and get a 5.0 release with just this cherry picked ASAP for distros and vendors. This patch is the work of a number of people over the past month: Eric, Reid, Rui, and myself. I'm mailing it out as a single commit due to the time sensitive nature of landing this and the need to backport it. Huge thanks to everyone who helped out here, and everyone at Intel who helped out in discussions about how to craft this. Also, credit goes to Paul Turner (at Google, but not an LLVM contributor) for much of the underlying retpoline design. Reviewers: echristo, rnk, ruiu, craig.topper, DavidKreitzer Subscribers: sanjoy, emaste, mcrosier, mgorny, mehdi_amini, hiraditya, llvm-commits Differential Revision: https://reviews.llvm.org/D41723 ------------------------------------------------------------------------ git-svn-id: https://llvm.org/svn/llvm-project/cfe/branches/release_60@324068 91177308-0d34-0410-b5e6-96231b3b80d8
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It turns out that the AVX bots have different alignment for their vectors, and my test mistakenly assumed a particular vector alignent on the stack. Instead, capture the alignment and test for it in subsequent operations. git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@339093 91177308-0d34-0410-b5e6-96231b3b80d8
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It turns out that the AVX bots have different alignment for their vectors, and my test mistakenly assumed a particular vector alignent on the stack. Instead, capture the alignment and test for it in subsequent operations. git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@339093 91177308-0d34-0410-b5e6-96231b3b80d8
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…r - try #2 Turns out it can't be removed from the analyzer since it relies on CallEvent. Moving to staticAnalyzer/core Differential Revision: https://reviews.llvm.org/D51023 git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@340247 91177308-0d34-0410-b5e6-96231b3b80d8
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It turns out that the AVX bots have different alignment for their vectors, and my test mistakenly assumed a particular vector alignent on the stack. Instead, capture the alignment and test for it in subsequent operations. git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@339093 91177308-0d34-0410-b5e6-96231b3b80d8
cheshire
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…r - try #2 Turns out it can't be removed from the analyzer since it relies on CallEvent. Moving to staticAnalyzer/core Differential Revision: https://reviews.llvm.org/D51023 git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@340247 91177308-0d34-0410-b5e6-96231b3b80d8
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… CompoundAssign operators Summary: As reported by @regehr (thanks!) on twitter (https://twitter.com/johnregehr/status/1057681496255815686), we (me) has completely forgot about the binary assignment operator. In AST, it isn't represented as separate `ImplicitCastExpr`'s, but as a single `CompoundAssignOperator`, that does all the casts internally. Which means, out of these two, only the first one is diagnosed: ``` auto foo() { unsigned char c = 255; c = c + 1; return c; } auto bar() { unsigned char c = 255; c += 1; return c; } ``` https://godbolt.org/z/JNyVc4 This patch does handle the `CompoundAssignOperator`: ``` int main() { unsigned char c = 255; c += 1; return c; } ``` ``` $ ./bin/clang -g -fsanitize=integer /tmp/test.c && ./a.out /tmp/test.c:3:5: runtime error: implicit conversion from type 'int' of value 256 (32-bit, signed) to type 'unsigned char' changed the value to 0 (8-bit, unsigned) #0 0x2392b8 in main /tmp/test.c:3:5 #1 0x7fec4a612b16 in __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x22b16) #2 0x214029 in _start (/build/llvm-build-GCC-release/a.out+0x214029) ``` However, the pre/post increment/decrement is still not handled. Reviewers: rsmith, regehr, vsk, rjmccall, #sanitizers Reviewed By: rjmccall Subscribers: mclow.lists, cfe-commits, regehr Tags: #clang, #sanitizers Differential Revision: https://reviews.llvm.org/D53949 git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@347258 91177308-0d34-0410-b5e6-96231b3b80d8
fredriss
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Introduces memory leak in FunctionTest.GetPointerAlignment that breaks sanitizer buildbots: ``` ================================================================= ==2453==ERROR: LeakSanitizer: detected memory leaks Direct leak of 128 byte(s) in 1 object(s) allocated from: #0 0x610428 in operator new(unsigned long) /b/sanitizer-x86_64-linux-bootstrap/build/llvm/projects/compiler-rt/lib/asan/asan_new_delete.cc:105 #1 0x16936bc in llvm::User::operator new(unsigned long) /b/sanitizer-x86_64-linux-bootstrap/build/llvm/lib/IR/User.cpp:151:19 #2 0x7c3fe9 in Create /b/sanitizer-x86_64-linux-bootstrap/build/llvm/include/llvm/IR/Function.h:144:12 #3 0x7c3fe9 in (anonymous namespace)::FunctionTest_GetPointerAlignment_Test::TestBody() /b/sanitizer-x86_64-linux-bootstrap/build/llvm/unittests/IR/FunctionTest.cpp:136 #4 0x1a836a0 in HandleExceptionsInMethodIfSupported<testing::Test, void> /b/sanitizer-x86_64-linux-bootstrap/build/llvm/utils/unittest/googletest/src/gtest.cc #5 0x1a836a0 in testing::Test::Run() /b/sanitizer-x86_64-linux-bootstrap/build/llvm/utils/unittest/googletest/src/gtest.cc:2474 #6 0x1a85c55 in testing::TestInfo::Run() /b/sanitizer-x86_64-linux-bootstrap/build/llvm/utils/unittest/googletest/src/gtest.cc:2656:11 #7 0x1a870d0 in testing::TestCase::Run() /b/sanitizer-x86_64-linux-bootstrap/build/llvm/utils/unittest/googletest/src/gtest.cc:2774:28 #8 0x1aa5b84 in testing::internal::UnitTestImpl::RunAllTests() /b/sanitizer-x86_64-linux-bootstrap/build/llvm/utils/unittest/googletest/src/gtest.cc:4649:43 #9 0x1aa4d30 in HandleExceptionsInMethodIfSupported<testing::internal::UnitTestImpl, bool> /b/sanitizer-x86_64-linux-bootstrap/build/llvm/utils/unittest/googletest/src/gtest.cc #10 0x1aa4d30 in testing::UnitTest::Run() /b/sanitizer-x86_64-linux-bootstrap/build/llvm/utils/unittest/googletest/src/gtest.cc:4257 #11 0x1a6b656 in RUN_ALL_TESTS /b/sanitizer-x86_64-linux-bootstrap/build/llvm/utils/unittest/googletest/include/gtest/gtest.h:2233:46 #12 0x1a6b656 in main /b/sanitizer-x86_64-linux-bootstrap/build/llvm/utils/unittest/UnitTestMain/TestMain.cpp:50 #13 0x7f5af37a22e0 in __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x202e0) Indirect leak of 40 byte(s) in 1 object(s) allocated from: #0 0x610428 in operator new(unsigned long) /b/sanitizer-x86_64-linux-bootstrap/build/llvm/projects/compiler-rt/lib/asan/asan_new_delete.cc:105 #1 0x151be6b in make_unique<llvm::ValueSymbolTable> /b/sanitizer-x86_64-linux-bootstrap/build/llvm/include/llvm/ADT/STLExtras.h:1349:29 #2 0x151be6b in llvm::Function::Function(llvm::FunctionType*, llvm::GlobalValue::LinkageTypes, unsigned int, llvm::Twine const&, llvm::Module*) /b/sanitizer-x86_64-linux-bootstrap/build/llvm/lib/IR/Function.cpp:241 #3 0x7c4006 in Create /b/sanitizer-x86_64-linux-bootstrap/build/llvm/include/llvm/IR/Function.h:144:16 #4 0x7c4006 in (anonymous namespace)::FunctionTest_GetPointerAlignment_Test::TestBody() /b/sanitizer-x86_64-linux-bootstrap/build/llvm/unittests/IR/FunctionTest.cpp:136 #5 0x1a836a0 in HandleExceptionsInMethodIfSupported<testing::Test, void> /b/sanitizer-x86_64-linux-bootstrap/build/llvm/utils/unittest/googletest/src/gtest.cc #6 0x1a836a0 in testing::Test::Run() /b/sanitizer-x86_64-linux-bootstrap/build/llvm/utils/unittest/googletest/src/gtest.cc:2474 #7 0x1a85c55 in testing::TestInfo::Run() /b/sanitizer-x86_64-linux-bootstrap/build/llvm/utils/unittest/googletest/src/gtest.cc:2656:11 #8 0x1a870d0 in testing::TestCase::Run() /b/sanitizer-x86_64-linux-bootstrap/build/llvm/utils/unittest/googletest/src/gtest.cc:2774:28 #9 0x1aa5b84 in testing::internal::UnitTestImpl::RunAllTests() /b/sanitizer-x86_64-linux-bootstrap/build/llvm/utils/unittest/googletest/src/gtest.cc:4649:43 #10 0x1aa4d30 in HandleExceptionsInMethodIfSupported<testing::internal::UnitTestImpl, bool> /b/sanitizer-x86_64-linux-bootstrap/build/llvm/utils/unittest/googletest/src/gtest.cc #11 0x1aa4d30 in testing::UnitTest::Run() /b/sanitizer-x86_64-linux-bootstrap/build/llvm/utils/unittest/googletest/src/gtest.cc:4257 #12 0x1a6b656 in RUN_ALL_TESTS /b/sanitizer-x86_64-linux-bootstrap/build/llvm/utils/unittest/googletest/include/gtest/gtest.h:2233:46 #13 0x1a6b656 in main /b/sanitizer-x86_64-linux-bootstrap/build/llvm/utils/unittest/UnitTestMain/TestMain.cpp:50 #14 0x7f5af37a22e0 in __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x202e0) SUMMARY: AddressSanitizer: 168 byte(s) leaked in 2 allocation(s). ``` See http://lab.llvm.org:8011/builders/sanitizer-x86_64-linux-bootstrap/builds/11358/steps/check-llvm%20asan/logs/stdio for more information. Also introduces use-of-uninitialized-value in ConstantsTest.FoldGlobalVariablePtr: ``` ==7070==WARNING: MemorySanitizer: use-of-uninitialized-value #0 0x14e703c in User /b/sanitizer-x86_64-linux-fast/build/llvm/include/llvm/IR/User.h:79:5 #1 0x14e703c in Constant /b/sanitizer-x86_64-linux-fast/build/llvm/include/llvm/IR/Constant.h:44 #2 0x14e703c in llvm::GlobalValue::GlobalValue(llvm::Type*, llvm::Value::ValueTy, llvm::Use*, unsigned int, llvm::GlobalValue::LinkageTypes, llvm::Twine const&, unsigned int) /b/sanitizer-x86_64-linux-fast/build/llvm/include/llvm/IR/GlobalValue.h:78 #3 0x14e5467 in GlobalObject /b/sanitizer-x86_64-linux-fast/build/llvm/include/llvm/IR/GlobalObject.h:34:9 #4 0x14e5467 in llvm::GlobalVariable::GlobalVariable(llvm::Type*, bool, llvm::GlobalValue::LinkageTypes, llvm::Constant*, llvm::Twine const&, llvm::GlobalValue::ThreadLocalMode, unsigned int, bool) /b/sanitizer-x86_64-linux-fast/build/llvm/lib/IR/Globals.cpp:314 #5 0x6938f1 in llvm::(anonymous namespace)::ConstantsTest_FoldGlobalVariablePtr_Test::TestBody() /b/sanitizer-x86_64-linux-fast/build/llvm/unittests/IR/ConstantsTest.cpp:565:18 #6 0x1a240a1 in HandleExceptionsInMethodIfSupported<testing::Test, void> /b/sanitizer-x86_64-linux-fast/build/llvm/utils/unittest/googletest/src/gtest.cc #7 0x1a240a1 in testing::Test::Run() /b/sanitizer-x86_64-linux-fast/build/llvm/utils/unittest/googletest/src/gtest.cc:2474 #8 0x1a26d26 in testing::TestInfo::Run() /b/sanitizer-x86_64-linux-fast/build/llvm/utils/unittest/googletest/src/gtest.cc:2656:11 #9 0x1a2815f in testing::TestCase::Run() /b/sanitizer-x86_64-linux-fast/build/llvm/utils/unittest/googletest/src/gtest.cc:2774:28 #10 0x1a43de8 in testing::internal::UnitTestImpl::RunAllTests() /b/sanitizer-x86_64-linux-fast/build/llvm/utils/unittest/googletest/src/gtest.cc:4649:43 #11 0x1a42c47 in HandleExceptionsInMethodIfSupported<testing::internal::UnitTestImpl, bool> /b/sanitizer-x86_64-linux-fast/build/llvm/utils/unittest/googletest/src/gtest.cc #12 0x1a42c47 in testing::UnitTest::Run() /b/sanitizer-x86_64-linux-fast/build/llvm/utils/unittest/googletest/src/gtest.cc:4257 #13 0x1a0dfba in RUN_ALL_TESTS /b/sanitizer-x86_64-linux-fast/build/llvm/utils/unittest/googletest/include/gtest/gtest.h:2233:46 #14 0x1a0dfba in main /b/sanitizer-x86_64-linux-fast/build/llvm/utils/unittest/UnitTestMain/TestMain.cpp:50 #15 0x7f2081c412e0 in __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x202e0) #16 0x4dff49 in _start (/b/sanitizer-x86_64-linux-fast/build/llvm_build_msan/unittests/IR/IRTests+0x4dff49) SUMMARY: MemorySanitizer: use-of-uninitialized-value /b/sanitizer-x86_64-linux-fast/build/llvm/include/llvm/IR/User.h:79:5 in User ``` See http://lab.llvm.org:8011/builders/sanitizer-x86_64-linux-fast/builds/30222/steps/check-llvm%20msan/logs/stdio for more information. git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@355616 91177308-0d34-0410-b5e6-96231b3b80d8
fredriss
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The assertion prevents it from applying fixes when used along with compilation databases with relative paths. Added a test that demonstrates the assertion failure. An example of the assertion: input.cpp:11:14: error: expected ';' after top level declarator typedef int T ^ ; input.cpp:11:14: note: FIX-IT applied suggested code changes clang-check: clang/tools/clang-check/ClangCheck.cpp:94: virtual std::string (anonymous namespace)::FixItOptions::RewriteFilename(const std::string &, int &): Assertion `llvm::sys::path::is_absolute(filename) && "clang-fixit expects absolute paths only."' failed. #0 llvm::sys::PrintStackTrace(llvm::raw_ostream&) llvm/lib/Support/Unix/Signals.inc:494:13 #1 llvm::sys::RunSignalHandlers() llvm/lib/Support/Signals.cpp:69:18 #2 SignalHandler(int) llvm/lib/Support/Unix/Signals.inc:357:1 #3 __restore_rt (/lib/x86_64-linux-gnu/libpthread.so.0+0x110c0) #4 raise (/lib/x86_64-linux-gnu/libc.so.6+0x32fcf) #5 abort (/lib/x86_64-linux-gnu/libc.so.6+0x343fa) #6 (/lib/x86_64-linux-gnu/libc.so.6+0x2be37) #7 (/lib/x86_64-linux-gnu/libc.so.6+0x2bee2) #8 void std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >::_M_construct<char*>(char*, char*, std::forward_iterator_tag) #9 void std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >::_M_construct_aux<char*>(char*, char*, std::__false_type) #10 void std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >::_M_construct<char*>(char*, char*) #11 std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >::basic_string(std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&) #12 (anonymous namespace)::FixItOptions::RewriteFilename(std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&, int&) clang/tools/clang-check/ClangCheck.cpp:101:0 #13 std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >::_M_data() const #14 std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >::_M_is_local() const #15 std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >::_M_dispose() #16 std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >::~basic_string() #17 clang::FixItRewriter::WriteFixedFiles(std::vector<std::pair<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > >, std::allocator<std::pair<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > > > >*) clang/lib/Frontend/Rewrite/FixItRewriter.cpp:98:0 #18 std::__shared_ptr<clang::CompilerInvocation, (__gnu_cxx::_Lock_policy)2>::get() const #19 std::__shared_ptr_access<clang::CompilerInvocation, (__gnu_cxx::_Lock_policy)2, false, false>::_M_get() const #20 std::__shared_ptr_access<clang::CompilerInvocation, (__gnu_cxx::_Lock_policy)2, false, false>::operator->() const #21 clang::CompilerInstance::getFrontendOpts() clang/include/clang/Frontend/CompilerInstance.h:290:0 #22 clang::FrontendAction::EndSourceFile() clang/lib/Frontend/FrontendAction.cpp:966:0 #23 __gnu_cxx::__normal_iterator<clang::FrontendInputFile*, std::vector<clang::FrontendInputFile, std::allocator<clang::FrontendInputFile> > >::operator++() #24 clang::CompilerInstance::ExecuteAction(clang::FrontendAction&) clang/lib/Frontend/CompilerInstance.cpp:943:0 #25 clang::tooling::FrontendActionFactory::runInvocation(std::shared_ptr<clang::CompilerInvocation>, clang::FileManager*, std::shared_ptr<clang::PCHContainerOperations>, clang::DiagnosticConsumer*) clang/lib/Tooling/Tooling.cpp:369:33 #26 clang::tooling::ToolInvocation::runInvocation(char const*, clang::driver::Compilation*, std::shared_ptr<clang::CompilerInvocation>, std::shared_ptr<clang::PCHContainerOperations>) clang/lib/Tooling/Tooling.cpp:344:18 #27 clang::tooling::ToolInvocation::run() clang/lib/Tooling/Tooling.cpp:329:10 #28 clang::tooling::ClangTool::run(clang::tooling::ToolAction*) clang/lib/Tooling/Tooling.cpp:518:11 #29 main clang/tools/clang-check/ClangCheck.cpp:187:15 git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@357915 91177308-0d34-0410-b5e6-96231b3b80d8
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Apr 9, 2019
…heck. The assertion prevents it from applying fixes when used along with compilation databases with relative paths. Added a test that demonstrates the assertion failure. An example of the assertion: input.cpp:11:14: error: expected ';' after top level declarator typedef int T ^ ; input.cpp:11:14: note: FIX-IT applied suggested code changes clang-check: clang/tools/clang-check/ClangCheck.cpp:94: virtual std::string (anonymous namespace)::FixItOptions::RewriteFilename(const std::string &, int &): Assertion `llvm::sys::path::is_absolute(filename) && "clang-fixit expects absolute paths only."' failed. #0 llvm::sys::PrintStackTrace(llvm::raw_ostream&) llvm/lib/Support/Unix/Signals.inc:494:13 #1 llvm::sys::RunSignalHandlers() llvm/lib/Support/Signals.cpp:69:18 #2 SignalHandler(int) llvm/lib/Support/Unix/Signals.inc:357:1 #3 __restore_rt (/lib/x86_64-linux-gnu/libpthread.so.0+0x110c0) #4 raise (/lib/x86_64-linux-gnu/libc.so.6+0x32fcf) #5 abort (/lib/x86_64-linux-gnu/libc.so.6+0x343fa) #6 (/lib/x86_64-linux-gnu/libc.so.6+0x2be37) #7 (/lib/x86_64-linux-gnu/libc.so.6+0x2bee2) #8 void std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >::_M_construct<char*>(char*, char*, std::forward_iterator_tag) #9 void std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >::_M_construct_aux<char*>(char*, char*, std::__false_type) #10 void std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >::_M_construct<char*>(char*, char*) #11 std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >::basic_string(std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&) #12 (anonymous namespace)::FixItOptions::RewriteFilename(std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&, int&) clang/tools/clang-check/ClangCheck.cpp:101:0 #13 std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >::_M_data() const #14 std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >::_M_is_local() const #15 std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >::_M_dispose() #16 std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >::~basic_string() #17 clang::FixItRewriter::WriteFixedFiles(std::vector<std::pair<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > >, std::allocator<std::pair<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > > > >*) clang/lib/Frontend/Rewrite/FixItRewriter.cpp:98:0 #18 std::__shared_ptr<clang::CompilerInvocation, (__gnu_cxx::_Lock_policy)2>::get() const #19 std::__shared_ptr_access<clang::CompilerInvocation, (__gnu_cxx::_Lock_policy)2, false, false>::_M_get() const #20 std::__shared_ptr_access<clang::CompilerInvocation, (__gnu_cxx::_Lock_policy)2, false, false>::operator->() const #21 clang::CompilerInstance::getFrontendOpts() clang/include/clang/Frontend/CompilerInstance.h:290:0 #22 clang::FrontendAction::EndSourceFile() clang/lib/Frontend/FrontendAction.cpp:966:0 #23 __gnu_cxx::__normal_iterator<clang::FrontendInputFile*, std::vector<clang::FrontendInputFile, std::allocator<clang::FrontendInputFile> > >::operator++() #24 clang::CompilerInstance::ExecuteAction(clang::FrontendAction&) clang/lib/Frontend/CompilerInstance.cpp:943:0 #25 clang::tooling::FrontendActionFactory::runInvocation(std::shared_ptr<clang::CompilerInvocation>, clang::FileManager*, std::shared_ptr<clang::PCHContainerOperations>, clang::DiagnosticConsumer*) clang/lib/Tooling/Tooling.cpp:369:33 #26 clang::tooling::ToolInvocation::runInvocation(char const*, clang::driver::Compilation*, std::shared_ptr<clang::CompilerInvocation>, std::shared_ptr<clang::PCHContainerOperations>) clang/lib/Tooling/Tooling.cpp:344:18 #27 clang::tooling::ToolInvocation::run() clang/lib/Tooling/Tooling.cpp:329:10 #28 clang::tooling::ClangTool::run(clang::tooling::ToolAction*) clang/lib/Tooling/Tooling.cpp:518:11 #29 main clang/tools/clang-check/ClangCheck.cpp:187:15 ........ Breaks windows buildbots git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@357918 91177308-0d34-0410-b5e6-96231b3b80d8
fredriss
pushed a commit
that referenced
this pull request
Apr 9, 2019
Re-commit r357915 with a fix for windows. The assertion prevents it from applying fixes when used along with compilation databases with relative paths. Added a test that demonstrates the assertion failure. An example of the assertion: input.cpp:11:14: error: expected ';' after top level declarator typedef int T ^ ; input.cpp:11:14: note: FIX-IT applied suggested code changes clang-check: clang/tools/clang-check/ClangCheck.cpp:94: virtual std::string (anonymous namespace)::FixItOptions::RewriteFilename(const std::string &, int &): Assertion `llvm::sys::path::is_absolute(filename) && "clang-fixit expects absolute paths only."' failed. #0 llvm::sys::PrintStackTrace(llvm::raw_ostream&) llvm/lib/Support/Unix/Signals.inc:494:13 #1 llvm::sys::RunSignalHandlers() llvm/lib/Support/Signals.cpp:69:18 #2 SignalHandler(int) llvm/lib/Support/Unix/Signals.inc:357:1 #3 __restore_rt (/lib/x86_64-linux-gnu/libpthread.so.0+0x110c0) #4 raise (/lib/x86_64-linux-gnu/libc.so.6+0x32fcf) #5 abort (/lib/x86_64-linux-gnu/libc.so.6+0x343fa) #6 (/lib/x86_64-linux-gnu/libc.so.6+0x2be37) #7 (/lib/x86_64-linux-gnu/libc.so.6+0x2bee2) #8 void std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >::_M_construct<char*>(char*, char*, std::forward_iterator_tag) #9 void std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >::_M_construct_aux<char*>(char*, char*, std::__false_type) #10 void std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >::_M_construct<char*>(char*, char*) #11 std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >::basic_string(std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&) #12 (anonymous namespace)::FixItOptions::RewriteFilename(std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&, int&) clang/tools/clang-check/ClangCheck.cpp:101:0 #13 std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >::_M_data() const #14 std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >::_M_is_local() const #15 std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >::_M_dispose() #16 std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >::~basic_string() #17 clang::FixItRewriter::WriteFixedFiles(std::vector<std::pair<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > >, std::allocator<std::pair<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > > > >*) clang/lib/Frontend/Rewrite/FixItRewriter.cpp:98:0 #18 std::__shared_ptr<clang::CompilerInvocation, (__gnu_cxx::_Lock_policy)2>::get() const #19 std::__shared_ptr_access<clang::CompilerInvocation, (__gnu_cxx::_Lock_policy)2, false, false>::_M_get() const #20 std::__shared_ptr_access<clang::CompilerInvocation, (__gnu_cxx::_Lock_policy)2, false, false>::operator->() const #21 clang::CompilerInstance::getFrontendOpts() clang/include/clang/Frontend/CompilerInstance.h:290:0 #22 clang::FrontendAction::EndSourceFile() clang/lib/Frontend/FrontendAction.cpp:966:0 #23 __gnu_cxx::__normal_iterator<clang::FrontendInputFile*, std::vector<clang::FrontendInputFile, std::allocator<clang::FrontendInputFile> > >::operator++() #24 clang::CompilerInstance::ExecuteAction(clang::FrontendAction&) clang/lib/Frontend/CompilerInstance.cpp:943:0 #25 clang::tooling::FrontendActionFactory::runInvocation(std::shared_ptr<clang::CompilerInvocation>, clang::FileManager*, std::shared_ptr<clang::PCHContainerOperations>, clang::DiagnosticConsumer*) clang/lib/Tooling/Tooling.cpp:369:33 #26 clang::tooling::ToolInvocation::runInvocation(char const*, clang::driver::Compilation*, std::shared_ptr<clang::CompilerInvocation>, std::shared_ptr<clang::PCHContainerOperations>) clang/lib/Tooling/Tooling.cpp:344:18 #27 clang::tooling::ToolInvocation::run() clang/lib/Tooling/Tooling.cpp:329:10 #28 clang::tooling::ClangTool::run(clang::tooling::ToolAction*) clang/lib/Tooling/Tooling.cpp:518:11 #29 main clang/tools/clang-check/ClangCheck.cpp:187:15 git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@357921 91177308-0d34-0410-b5e6-96231b3b80d8
fredriss
pushed a commit
that referenced
this pull request
May 1, 2019
Summary: This is a follow up to r355253 and a better fix than the first attempt which was r359257. We can't install anything from ${CMAKE_CFG_INTDIR}, because this value is only defined at build time, but we still must make sure to copy the headers into ${CMAKE_CFG_INTDIR}/lib/clang/$VERSION/include, because the lit tests look for headers there. So for this fix we revert to the old behavior of copying the headers to ${CMAKE_CFG_INTDIR}/lib/clang/$VERSION/include during the build and then installing them from the source tree. Reviewers: smeenai, vzakhari, phosek Reviewed By: smeenai, vzakhari Subscribers: mgorny, cfe-commits Tags: #clang Differential Revision: https://reviews.llvm.org/D61220 git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@359654 91177308-0d34-0410-b5e6-96231b3b80d8
fredriss
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Jun 15, 2019
Summary: Since the addition of __builtin_is_constant_evaluated the result of an expression can change based on whether it is evaluated in constant context. a lot of semantic checking performs evaluations with out specifying context. which can lead to wrong diagnostics. for example: ``` constexpr int i0 = (long long)__builtin_is_constant_evaluated() * (1ll << 33); //#1 constexpr int i1 = (long long)!__builtin_is_constant_evaluated() * (1ll << 33); //#2 ``` before the patch, #2 was diagnosed incorrectly and #1 wasn't diagnosed. after the patch #1 is diagnosed as it should and #2 isn't. Changes: - add a flag to Sema to passe in constant context mode. - in SemaChecking.cpp calls to Expr::Evaluate* are now done in constant context when they should. - in SemaChecking.cpp diagnostics for UB are not checked for in constant context because an error will be emitted by the constant evaluator. - in SemaChecking.cpp diagnostics for construct that cannot appear in constant context are not checked for in constant context. - in SemaChecking.cpp diagnostics on constant expression are always emitted because constant expression are always evaluated. - semantic checking for initialization of constexpr variables is now done in constant context. - adapt test that were depending on warning changes. - add test. Reviewers: rsmith Reviewed By: rsmith Subscribers: cfe-commits Tags: #clang Differential Revision: https://reviews.llvm.org/D62009 git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@363488 91177308-0d34-0410-b5e6-96231b3b80d8
fredriss
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Aug 16, 2019
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@369020 91177308-0d34-0410-b5e6-96231b3b80d8
fredriss
pushed a commit
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Sep 26, 2019
Fixes a leak introduced in r372903, detected on the ASan bot. http://lab.llvm.org:8011/builders/sanitizer-x86_64-linux-fast/builds/35430/steps/check-clang%20asan/logs/stdio Direct leak of 192 byte(s) in 1 object(s) allocated from: #0 0x561d88 in operator new(unsigned long) /b/sanitizer-x86_64-linux-fast/build/llvm-project/compiler-rt/lib/asan/asan_new_delete.cc:105 #1 0x1a48779 in clang::ItaniumMangleContext::create(clang::ASTContext&, clang::DiagnosticsEngine&) /b/sanitizer-x86_64-linux-fast/build/llvm-project/clang/lib/AST/ItaniumMangle.cpp:5134:10 #2 0xdff000 in Decl_AsmLabelAttr_Test::TestBody() /b/sanitizer-x86_64-linux-fast/build/llvm-project/clang/unittests/AST/DeclTest.cpp:97:23 git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@372925 91177308-0d34-0410-b5e6-96231b3b80d8
fredriss
pushed a commit
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Oct 11, 2019
…the branch where it's used The existing code is not defined, you are not allowed to produce non-null pointer from null pointer (F->FileSortedDecls here). That being said, i'm not really confident this is fix-enough, but we'll see. FAIL: Clang :: Modules/no-module-map.cpp (6879 of 16079) ******************** TEST 'Clang :: Modules/no-module-map.cpp' FAILED ******************** Script: -- : 'RUN: at line 1'; /b/sanitizer-x86_64-linux-bootstrap-ubsan/build/llvm_build_ubsan/bin/clang -cc1 -internal-isystem /b/sanitizer-x86_64-linux-bootstrap-ubsan/build/llvm_build_ubsan/lib/clang/10.0.0/include -nostdsysteminc -fmodules-ts -fmodule-name=ab -x c++-header /b/sanitizer-x86_64-linux-bootstrap-ubsan/build/llvm-project/clang/test/Modules/Inputs/no-module-map/a.h /b/sanitizer-x86_64-linux-bootstrap-ubsan/build/llvm-project/clang/test/Modules/Inputs/no-module-map/b.h -emit-header-module -o /b/sanitizer-x86_64-linux-bootstrap-ubsan/build/llvm_build_ubsan/tools/clang/test/Modules/Output/no-module-map.cpp.tmp.pcm : 'RUN: at line 2'; /b/sanitizer-x86_64-linux-bootstrap-ubsan/build/llvm_build_ubsan/bin/clang -cc1 -internal-isystem /b/sanitizer-x86_64-linux-bootstrap-ubsan/build/llvm_build_ubsan/lib/clang/10.0.0/include -nostdsysteminc -fmodules-ts -fmodule-file=/b/sanitizer-x86_64-linux-bootstrap-ubsan/build/llvm_build_ubsan/tools/clang/test/Modules/Output/no-module-map.cpp.tmp.pcm /b/sanitizer-x86_64-linux-bootstrap-ubsan/build/llvm-project/clang/test/Modules/no-module-map.cpp -I/b/sanitizer-x86_64-linux-bootstrap-ubsan/build/llvm-project/clang/test/Modules/Inputs/no-module-map -verify : 'RUN: at line 3'; /b/sanitizer-x86_64-linux-bootstrap-ubsan/build/llvm_build_ubsan/bin/clang -cc1 -internal-isystem /b/sanitizer-x86_64-linux-bootstrap-ubsan/build/llvm_build_ubsan/lib/clang/10.0.0/include -nostdsysteminc -fmodules-ts -fmodule-file=/b/sanitizer-x86_64-linux-bootstrap-ubsan/build/llvm_build_ubsan/tools/clang/test/Modules/Output/no-module-map.cpp.tmp.pcm /b/sanitizer-x86_64-linux-bootstrap-ubsan/build/llvm-project/clang/test/Modules/no-module-map.cpp -I/b/sanitizer-x86_64-linux-bootstrap-ubsan/build/llvm-project/clang/test/Modules/Inputs/no-module-map -verify -DA : 'RUN: at line 4'; /b/sanitizer-x86_64-linux-bootstrap-ubsan/build/llvm_build_ubsan/bin/clang -cc1 -internal-isystem /b/sanitizer-x86_64-linux-bootstrap-ubsan/build/llvm_build_ubsan/lib/clang/10.0.0/include -nostdsysteminc -fmodules-ts -fmodule-file=/b/sanitizer-x86_64-linux-bootstrap-ubsan/build/llvm_build_ubsan/tools/clang/test/Modules/Output/no-module-map.cpp.tmp.pcm /b/sanitizer-x86_64-linux-bootstrap-ubsan/build/llvm-project/clang/test/Modules/no-module-map.cpp -I/b/sanitizer-x86_64-linux-bootstrap-ubsan/build/llvm-project/clang/test/Modules/Inputs/no-module-map -verify -DB : 'RUN: at line 5'; /b/sanitizer-x86_64-linux-bootstrap-ubsan/build/llvm_build_ubsan/bin/clang -cc1 -internal-isystem /b/sanitizer-x86_64-linux-bootstrap-ubsan/build/llvm_build_ubsan/lib/clang/10.0.0/include -nostdsysteminc -fmodules-ts -fmodule-file=/b/sanitizer-x86_64-linux-bootstrap-ubsan/build/llvm_build_ubsan/tools/clang/test/Modules/Output/no-module-map.cpp.tmp.pcm /b/sanitizer-x86_64-linux-bootstrap-ubsan/build/llvm-project/clang/test/Modules/no-module-map.cpp -I/b/sanitizer-x86_64-linux-bootstrap-ubsan/build/llvm-project/clang/test/Modules/Inputs/no-module-map -verify -DA -DB : 'RUN: at line 7'; /b/sanitizer-x86_64-linux-bootstrap-ubsan/build/llvm_build_ubsan/bin/clang -cc1 -internal-isystem /b/sanitizer-x86_64-linux-bootstrap-ubsan/build/llvm_build_ubsan/lib/clang/10.0.0/include -nostdsysteminc -E /b/sanitizer-x86_64-linux-bootstrap-ubsan/build/llvm_build_ubsan/tools/clang/test/Modules/Output/no-module-map.cpp.tmp.pcm -o - | /b/sanitizer-x86_64-linux-bootstrap-ubsan/build/llvm_build_ubsan/bin/FileCheck /b/sanitizer-x86_64-linux-bootstrap-ubsan/build/llvm-project/clang/test/Modules/no-module-map.cpp : 'RUN: at line 8'; /b/sanitizer-x86_64-linux-bootstrap-ubsan/build/llvm_build_ubsan/bin/clang -cc1 -internal-isystem /b/sanitizer-x86_64-linux-bootstrap-ubsan/build/llvm_build_ubsan/lib/clang/10.0.0/include -nostdsysteminc -frewrite-imports -E /b/sanitizer-x86_64-linux-bootstrap-ubsan/build/llvm_build_ubsan/tools/clang/test/Modules/Output/no-module-map.cpp.tmp.pcm -o - | /b/sanitizer-x86_64-linux-bootstrap-ubsan/build/llvm_build_ubsan/bin/FileCheck /b/sanitizer-x86_64-linux-bootstrap-ubsan/build/llvm-project/clang/test/Modules/no-module-map.cpp -- Exit Code: 2 Command Output (stderr): -- /b/sanitizer-x86_64-linux-bootstrap-ubsan/build/llvm-project/clang/lib/Serialization/ASTReader.cpp:1526:50: runtime error: applying non-zero offset 8 to null pointer #0 0x3a9bd0c in clang::ASTReader::ReadSLocEntry(int) /b/sanitizer-x86_64-linux-bootstrap-ubsan/build/llvm-project/clang/lib/Serialization/ASTReader.cpp:1526:50 #1 0x328b6f8 in clang::SourceManager::loadSLocEntry(unsigned int, bool*) const /b/sanitizer-x86_64-linux-bootstrap-ubsan/build/llvm-project/clang/lib/Basic/SourceManager.cpp:461:28 #2 0x328b351 in clang::SourceManager::initializeForReplay(clang::SourceManager const&) /b/sanitizer-x86_64-linux-bootstrap-ubsan/build/llvm-project/clang/lib/Basic/SourceManager.cpp:399:11 #3 0x3996c71 in clang::FrontendAction::BeginSourceFile(clang::CompilerInstance&, clang::FrontendInputFile const&) /b/sanitizer-x86_64-linux-bootstrap-ubsan/build/llvm-project/clang/lib/Frontend/FrontendAction.cpp:581:27 #4 0x394f341 in clang::CompilerInstance::ExecuteAction(clang::FrontendAction&) /b/sanitizer-x86_64-linux-bootstrap-ubsan/build/llvm-project/clang/lib/Frontend/CompilerInstance.cpp:956:13 #5 0x3a8a92b in clang::ExecuteCompilerInvocation(clang::CompilerInstance*) /b/sanitizer-x86_64-linux-bootstrap-ubsan/build/llvm-project/clang/lib/FrontendTool/ExecuteCompilerInvocation.cpp:290:25 #6 0xaf8d62 in cc1_main(llvm::ArrayRef<char const*>, char const*, void*) /b/sanitizer-x86_64-linux-bootstrap-ubsan/build/llvm-project/clang/tools/driver/cc1_main.cpp:250:15 #7 0xaf1602 in ExecuteCC1Tool /b/sanitizer-x86_64-linux-bootstrap-ubsan/build/llvm-project/clang/tools/driver/driver.cpp:309:12 #8 0xaf1602 in main /b/sanitizer-x86_64-linux-bootstrap-ubsan/build/llvm-project/clang/tools/driver/driver.cpp:382:12 #9 0x7f2c1eecc2e0 in __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x202e0) #10 0xad57f9 in _start (/b/sanitizer-x86_64-linux-bootstrap-ubsan/build/llvm_build_ubsan/bin/clang-10+0xad57f9) SUMMARY: UndefinedBehaviorSanitizer: undefined-behavior /b/sanitizer-x86_64-linux-bootstrap-ubsan/build/llvm-project/clang/lib/Serialization/ASTReader.cpp:1526:50 in git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@374328 91177308-0d34-0410-b5e6-96231b3b80d8
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