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* [Sema] Mark target of __attribute__((alias("target"))) used for CNick Desaulniers2019-01-091-1/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Summary: Prevents -Wunneeded-internal-delcaration warnings when the target has no other references. This occurs frequently in device drivers in the Linux kernel. Sema would need to invoke the demangler on the target, since in C++ the target name is mangled: int f() { return 42; } int g() __attribute__((alias("_Z1fv"))); Sema does not have the ability to demangle names at this time. https://bugs.llvm.org/show_bug.cgi?id=39088 https://github.com/ClangBuiltLinux/linux/issues/232 Reviewers: rsmith, rjmccall Reviewed By: rsmith Subscribers: erik.pilkington, cfe-commits, pirama, srhines Differential Revision: https://reviews.llvm.org/D54188 llvm-svn: 350776
* [ObjC] Allow the use of implemented unavailable methods from withinAlex Lorenz2019-01-091-6/+22
| | | | | | | | | | | | | | | | | | the @implementation context In Objective-C, it's common for some frameworks to mark some methods like init as unavailable in the @interface to prohibit their usage. However, these frameworks then often implemented said method and refer to it in another method that acts as a factory for that object. The recent change to how messages to self are type checked in clang (r349841) introduced a regression which started to prohibit this pattern with an X is unavailable error. This commit addresses the aforementioned regression. rdar://47134898 Differential Revision: https://reviews.llvm.org/D56469 llvm-svn: 350768
* [ObjCARC] Add an new attribute, objc_externally_retainedErik Pilkington2019-01-041-6/+90
| | | | | | | | | | | | | | | | | | | | This attribute, called "objc_externally_retained", exposes clang's notion of pseudo-__strong variables in ARC. Pseudo-strong variables "borrow" their initializer, meaning that they don't retain/release it, instead assuming that someone else is keeping their value alive. If a function is annotated with this attribute, implicitly strong parameters of that function aren't implicitly retained/released in the function body, and are implicitly const. This is useful to expose for performance reasons, most functions don't need the extra safety of the retain/release, so programmers can opt out as needed. This attribute can also apply to declarations of local variables, with similar effect. Differential revision: https://reviews.llvm.org/D55865 llvm-svn: 350422
* Automatic variable initializationJF Bastien2018-12-181-0/+12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Summary: Add an option to initialize automatic variables with either a pattern or with zeroes. The default is still that automatic variables are uninitialized. Also add attributes to request uninitialized on a per-variable basis, mainly to disable initialization of large stack arrays when deemed too expensive. This isn't meant to change the semantics of C and C++. Rather, it's meant to be a last-resort when programmers inadvertently have some undefined behavior in their code. This patch aims to make undefined behavior hurt less, which security-minded people will be very happy about. Notably, this means that there's no inadvertent information leak when: - The compiler re-uses stack slots, and a value is used uninitialized. - The compiler re-uses a register, and a value is used uninitialized. - Stack structs / arrays / unions with padding are copied. This patch only addresses stack and register information leaks. There's many more infoleaks that we could address, and much more undefined behavior that could be tamed. Let's keep this patch focused, and I'm happy to address related issues elsewhere. To keep the patch simple, only some `undef` is removed for now, see `replaceUndef`. The padding-related infoleaks are therefore not all gone yet. This will be addressed in a follow-up, mainly because addressing padding-related leaks should be a stand-alone option which is implied by variable initialization. There are three options when it comes to automatic variable initialization: 0. Uninitialized This is C and C++'s default. It's not changing. Depending on code generation, a programmer who runs into undefined behavior by using an uninialized automatic variable may observe any previous value (including program secrets), or any value which the compiler saw fit to materialize on the stack or in a register (this could be to synthesize an immediate, to refer to code or data locations, to generate cookies, etc). 1. Pattern initialization This is the recommended initialization approach. Pattern initialization's goal is to initialize automatic variables with values which will likely transform logic bugs into crashes down the line, are easily recognizable in a crash dump, without being values which programmers can rely on for useful program semantics. At the same time, pattern initialization tries to generate code which will optimize well. You'll find the following details in `patternFor`: - Integers are initialized with repeated 0xAA bytes (infinite scream). - Vectors of integers are also initialized with infinite scream. - Pointers are initialized with infinite scream on 64-bit platforms because it's an unmappable pointer value on architectures I'm aware of. Pointers are initialize to 0x000000AA (small scream) on 32-bit platforms because 32-bit platforms don't consistently offer unmappable pages. When they do it's usually the zero page. As people try this out, I expect that we'll want to allow different platforms to customize this, let's do so later. - Vectors of pointers are initialized the same way pointers are. - Floating point values and vectors are initialized with a negative quiet NaN with repeated 0xFF payload (e.g. 0xffffffff and 0xffffffffffffffff). NaNs are nice (here, anways) because they propagate on arithmetic, making it more likely that entire computations become NaN when a single uninitialized value sneaks in. - Arrays are initialized to their homogeneous elements' initialization value, repeated. Stack-based Variable-Length Arrays (VLAs) are runtime-initialized to the allocated size (no effort is made for negative size, but zero-sized VLAs are untouched even if technically undefined). - Structs are initialized to their heterogeneous element's initialization values. Zero-size structs are initialized as 0xAA since they're allocated a single byte. - Unions are initialized using the initialization for the largest member of the union. Expect the values used for pattern initialization to change over time, as we refine heuristics (both for performance and security). The goal is truly to avoid injecting semantics into undefined behavior, and we should be comfortable changing these values when there's a worthwhile point in doing so. Why so much infinite scream? Repeated byte patterns tend to be easy to synthesize on most architectures, and otherwise memset is usually very efficient. For values which aren't entirely repeated byte patterns, LLVM will often generate code which does memset + a few stores. 2. Zero initialization Zero initialize all values. This has the unfortunate side-effect of providing semantics to otherwise undefined behavior, programs therefore might start to rely on this behavior, and that's sad. However, some programmers believe that pattern initialization is too expensive for them, and data might show that they're right. The only way to make these programmers wrong is to offer zero-initialization as an option, figure out where they are right, and optimize the compiler into submission. Until the compiler provides acceptable performance for all security-minded code, zero initialization is a useful (if blunt) tool. I've been asked for a fourth initialization option: user-provided byte value. This might be useful, and can easily be added later. Why is an out-of band initialization mecanism desired? We could instead use -Wuninitialized! Indeed we could, but then we're forcing the programmer to provide semantics for something which doesn't actually have any (it's uninitialized!). It's then unclear whether `int derp = 0;` lends meaning to `0`, or whether it's just there to shut that warning up. It's also way easier to use a compiler flag than it is to manually and intelligently initialize all values in a program. Why not just rely on static analysis? Because it cannot reason about all dynamic code paths effectively, and it has false positives. It's a great tool, could get even better, but it's simply incapable of catching all uses of uninitialized values. Why not just rely on memory sanitizer? Because it's not universally available, has a 3x performance cost, and shouldn't be deployed in production. Again, it's a great tool, it'll find the dynamic uses of uninitialized variables that your test coverage hits, but it won't find the ones that you encounter in production. What's the performance like? Not too bad! Previous publications [0] have cited 2.7 to 4.5% averages. We've commmitted a few patches over the last few months to address specific regressions, both in code size and performance. In all cases, the optimizations are generally useful, but variable initialization benefits from them a lot more than regular code does. We've got a handful of other optimizations in mind, but the code is in good enough shape and has found enough latent issues that it's a good time to get the change reviewed, checked in, and have others kick the tires. We'll continue reducing overheads as we try this out on diverse codebases. Is it a good idea? Security-minded folks think so, and apparently so does the Microsoft Visual Studio team [1] who say "Between 2017 and mid 2018, this feature would have killed 49 MSRC cases that involved uninitialized struct data leaking across a trust boundary. It would have also mitigated a number of bugs involving uninitialized struct data being used directly.". They seem to use pure zero initialization, and claim to have taken the overheads down to within noise. Don't just trust Microsoft though, here's another relevant person asking for this [2]. It's been proposed for GCC [3] and LLVM [4] before. What are the caveats? A few! - Variables declared in unreachable code, and used later, aren't initialized. This goto, Duff's device, other objectionable uses of switch. This should instead be a hard-error in any serious codebase. - Volatile stack variables are still weird. That's pre-existing, it's really the language's fault and this patch keeps it weird. We should deprecate volatile [5]. - As noted above, padding isn't fully handled yet. I don't think these caveats make the patch untenable because they can be addressed separately. Should this be on by default? Maybe, in some circumstances. It's a conversation we can have when we've tried it out sufficiently, and we're confident that we've eliminated enough of the overheads that most codebases would want to opt-in. Let's keep our precious undefined behavior until that point in time. How do I use it: 1. On the command-line: -ftrivial-auto-var-init=uninitialized (the default) -ftrivial-auto-var-init=pattern -ftrivial-auto-var-init=zero -enable-trivial-auto-var-init-zero-knowing-it-will-be-removed-from-clang 2. Using an attribute: int dont_initialize_me __attribute((uninitialized)); [0]: https://users.elis.ugent.be/~jsartor/researchDocs/OOPSLA2011Zero-submit.pdf [1]: https://twitter.com/JosephBialek/status/1062774315098112001 [2]: https://outflux.net/slides/2018/lss/danger.pdf [3]: https://gcc.gnu.org/ml/gcc-patches/2014-06/msg00615.html [4]: https://github.com/AndroidHardeningArchive/platform_external_clang/commit/776a0955ef6686d23a82d2e6a3cbd4a6a882c31c [5]: http://wg21.link/p1152 I've also posted an RFC to cfe-dev: http://lists.llvm.org/pipermail/cfe-dev/2018-November/060172.html <rdar://problem/39131435> Reviewers: pcc, kcc, rsmith Subscribers: JDevlieghere, jkorous, dexonsmith, cfe-commits Differential Revision: https://reviews.llvm.org/D54604 llvm-svn: 349442
* Fix ms-layout_version declspec test and add missing new testReid Kleckner2018-12-171-6/+6
| | | | | | | | | | Now that MSVC compatibility versions are stored as a four digit number (1912) instead of a two digit number (19), we need to adjust how we handle this attribute. Also add a new test that was intended to be part of r349414. llvm-svn: 349415
* Update Microsoft name mangling scheme for exception specifiers in the type ↵Reid Kleckner2018-12-171-0/+5
| | | | | | | | | | | | | | | | | | | | | system Summary: The msvc exception specifier for noexcept function types has changed from the prior default of "Z" to "_E" if the function cannot throw when compiling with /std:C++17. Patch by Zachary Henkel! Reviewers: zturner, rnk Reviewed By: rnk Subscribers: cfe-commits Differential Revision: https://reviews.llvm.org/D55685 llvm-svn: 349414
* Fix "enumeral mismatch in conditional expression" gcc7 warnings. NFCI.Simon Pilgrim2018-12-171-3/+4
| | | | llvm-svn: 349342
* [attributes] Add an attribute os_consumes_this, with similar semantics to ↵George Karpenkov2018-12-061-0/+3
| | | | | | | | | | | ns_consumes_self The attribute specifies that the call of the C++ method consumes a reference to "this". Differential Revision: https://reviews.llvm.org/D55155 llvm-svn: 348532
* [attributes] Add a family of OS_CONSUMED, OS_RETURNS and OS_RETURNS_RETAINED ↵George Karpenkov2018-11-301-61/+129
| | | | | | | | | | | | | | | | | | | | | attributes The addition adds three attributes for communicating ownership, analogous to existing NS_ and CF_ attributes. The attributes are meant to be used for communicating ownership of all objects in XNU (Darwin kernel) and all of the kernel modules. The ownership model there is very similar, but still different from the Foundation model, so we think that introducing a new family of attributes is appropriate. The addition required a sizeable refactoring of the existing code for CF_ and NS_ ownership attributes, due to tight coupling and the fact that differentiating between the types was previously done using a boolean. Differential Revision: https://reviews.llvm.org/D54912 llvm-svn: 347947
* [clang][slh] add attribute for speculative load hardeningZola Bridges2018-11-271-0/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | Summary: Resubmit this with no changes because I think the build was broken by a different diff. ----- The prior diff had to be reverted because there were two tests that failed. I updated the two tests in this diff clang/test/Misc/pragma-attribute-supported-attributes-list.test clang/test/SemaCXX/attr-speculative-load-hardening.cpp ----- Summary from Previous Diff (Still Accurate) ----- LLVM IR already has an attribute for speculative_load_hardening. Before this commit, when a user passed the -mspeculative-load-hardening flag to Clang, every function would have this attribute added to it. This Clang attribute will allow users to opt into SLH on a function by function basis. This can be applied to functions and Objective C methods. Reviewers: chandlerc, echristo, kristof.beyls, aaron.ballman Subscribers: llvm-commits Differential Revision: https://reviews.llvm.org/D54915 llvm-svn: 347701
* Revert "[clang][slh] add attribute for speculative load hardening"Zola Bridges2018-11-271-3/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | until I figure out why the build is failing or timing out *************************** Summary: The prior diff had to be reverted because there were two tests that failed. I updated the two tests in this diff clang/test/Misc/pragma-attribute-supported-attributes-list.test clang/test/SemaCXX/attr-speculative-load-hardening.cpp LLVM IR already has an attribute for speculative_load_hardening. Before this commit, when a user passed the -mspeculative-load-hardening flag to Clang, every function would have this attribute added to it. This Clang attribute will allow users to opt into SLH on a function by function basis. This can be applied to functions and Objective C methods. Reviewers: chandlerc, echristo, kristof.beyls, aaron.ballman Subscribers: llvm-commits Differential Revision: https://reviews.llvm.org/D54915 This reverts commit a5b3c232d1e3613f23efbc3960f8e23ea70f2a79. (r347617) llvm-svn: 347628
* [clang][slh] add attribute for speculative load hardeningZola Bridges2018-11-271-0/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | Summary: The prior diff had to be reverted because there were two tests that failed. I updated the two tests in this diff clang/test/Misc/pragma-attribute-supported-attributes-list.test clang/test/SemaCXX/attr-speculative-load-hardening.cpp ----- Summary from Previous Diff (Still Accurate) ----- LLVM IR already has an attribute for speculative_load_hardening. Before this commit, when a user passed the -mspeculative-load-hardening flag to Clang, every function would have this attribute added to it. This Clang attribute will allow users to opt into SLH on a function by function basis. This can be applied to functions and Objective C methods. Reviewers: chandlerc, echristo, kristof.beyls, aaron.ballman Subscribers: llvm-commits Differential Revision: https://reviews.llvm.org/D54915 llvm-svn: 347617
* Revert "[clang][slh] add attribute for speculative load hardening"Zola Bridges2018-11-261-3/+0
| | | | | | This reverts commit 801eaf91221ba6dd6996b29ff82659ad6359e885. llvm-svn: 347588
* [clang][slh] add attribute for speculative load hardeningZola Bridges2018-11-261-0/+3
| | | | | | | | | | | | | | | | | | Summary: LLVM IR already has an attribute for speculative_load_hardening. Before this commit, when a user passed the -mspeculative-load-hardening flag to Clang, every function would have this attribute added to it. This Clang attribute will allow users to opt into SLH on a function by function basis. This can be applied to functions and Objective C methods. Reviewers: chandlerc, echristo Subscribers: llvm-commits Differential Revision: https://reviews.llvm.org/D54555 llvm-svn: 347586
* [AArch64] Add aarch64_vector_pcs function attribute to ClangSander de Smalen2018-11-261-8/+17
| | | | | | | | | | | | | | | | | | | | This is the Clang patch to complement the following LLVM patches: https://reviews.llvm.org/D51477 https://reviews.llvm.org/D51479 More information describing the vector ABI and procedure call standard can be found here: https://developer.arm.com/products/software-development-tools/\ hpc/arm-compiler-for-hpc/vector-function-abi Patch by Kerry McLaughlin. Reviewed By: rjmccall Differential Revision: https://reviews.llvm.org/D54425 llvm-svn: 347571
* Support Swift in platform availability attributeMichael Wu2018-11-121-0/+9
| | | | | | | | | | | | | | Summary: This adds support for Swift platform availability attributes. It's largely a port of the changes made to https://github.com/apple/swift-clang/ for Swift availability attributes. Specifically, https://github.com/apple/swift-clang/commit/84b5a21c31cb5b0d7d958a478bc01964939b6952 and https://github.com/apple/swift-clang/commit/e5b87f265aede41c8381094bbf54e2715c8293b0 . The implementation of attribute_availability_swift is a little different and additional tests in test/Index/availability.c were added. Reviewers: manmanren, friss, doug.gregor, arphaman, jfb, erik.pilkington, aaron.ballman Reviewed By: aaron.ballman Subscribers: aaron.ballman, ColinKinloch, jrmuizel, cfe-commits Differential Revision: https://reviews.llvm.org/D50318 llvm-svn: 346633
* NFC: Remove the ObjC1/ObjC2 distinction from clang (and related projects)Erik Pilkington2018-10-301-5/+5
| | | | | | | | | | We haven't supported compiling ObjC1 for a long time (and never will again), so there isn't any reason to keep these separate. This patch replaces LangOpts::ObjC1 and LangOpts::ObjC2 with LangOpts::ObjC. Differential revision: https://reviews.llvm.org/D53547 llvm-svn: 345637
* Support accepting __gnu__ as a scoped attribute namespace that aliases to gnu.Aaron Ballman2018-10-241-10/+8
| | | | | | This is useful in libstdc++ to avoid clashes with identifiers in the user's namespace. llvm-svn: 345132
* [clang] Add the exclude_from_explicit_instantiation attributeLouis Dionne2018-10-041-0/+3
| | | | | | | | | | | | | | | | | | | | | | Summary: This attribute allows excluding a member of a class template from being part of an explicit template instantiation of that class template. This also makes sure that code using such a member will not take for granted that an external instantiation exists in another translation unit. The attribute was discussed on cfe-dev at [1] and is primarily motivated by the removal of always_inline in libc++ to control what's part of the ABI (see links in [1]). [1]: http://lists.llvm.org/pipermail/cfe-dev/2018-August/059024.html rdar://problem/43428125 Reviewers: rsmith Subscribers: dexonsmith, cfe-commits Differential Revision: https://reviews.llvm.org/D51789 llvm-svn: 343790
* [HIP] Support early finalization of device code for -fno-gpu-rdcYaxun Liu2018-10-021-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | This patch renames -f{no-}cuda-rdc to -f{no-}gpu-rdc and keeps the original options as aliases. When -fgpu-rdc is off, clang will assume the device code in each translation unit does not call external functions except those in the device library, therefore it is possible to compile the device code in each translation unit to self-contained kernels and embed them in the host object, so that the host object behaves like usual host object which can be linked by lld. The benefits of this feature is: 1. allow users to create static libraries which can be linked by host linker; 2. amortized device code linking time. This patch modifies HIP action builder to insert actions for linking device code and generating HIP fatbin, and pass HIP fatbin to host backend action. It extracts code for constructing command for generating HIP fatbin as a function so that it can be reused by early finalization. It also modifies codegen of HIP host constructor functions to embed the device fatbin when it is available. Differential Revision: https://reviews.llvm.org/D52377 llvm-svn: 343611
* llvm::sort(C.begin(), C.end(), ...) -> llvm::sort(C, ...)Fangrui Song2018-09-261-1/+1
| | | | | | | | | | | | | | Summary: The convenience wrapper in STLExtras is available since rL342102. Reviewers: rsmith, #clang, dblaikie Reviewed By: rsmith, #clang Subscribers: mgrang, arphaman, kadircet, cfe-commits Differential Revision: https://reviews.llvm.org/D52576 llvm-svn: 343147
* P0969R0: allow structured binding of accessible members, not only public ↵Richard Smith2018-09-251-0/+8
| | | | | | members. llvm-svn: 343036
* Update smart pointer detection for thread safety analysis.Richard Trieu2018-09-221-8/+27
| | | | | | | | | Objects are determined to be smart pointers if they have both a star and arrow operator. Some implementations of smart pointers have these overloaded operators in a base class, while the check only searched the derived class. This fix will also look for the operators in the base class. llvm-svn: 342794
* Thread Safety Analysis: warnings for attributes without argumentsAaron Puchert2018-09-201-16/+44
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Summary: When thread safety annotations are used without capability arguments, they are assumed to apply to `this` instead. So we warn when either `this` doesn't exist, or the class is not a capability type. This is based on earlier work by Josh Gao that was committed in r310403, but reverted in r310698 because it didn't properly work in template classes. See also D36237. The solution is not to go via the QualType of `this`, which is then a template type, hence the attributes are not known because it could be specialized. Instead we look directly at the class in which we are contained. Additionally I grouped two of the warnings together. There are two issues here: the existence of `this`, which requires us to be a non-static member function, and the appropriate annotation on the class we are contained in. So we don't distinguish between not being in a class and being static, because in both cases we don't have `this`. Fixes PR38399. Reviewers: aaron.ballman, delesley, jmgao, rtrieu Reviewed By: delesley Subscribers: cfe-commits Differential Revision: https://reviews.llvm.org/D51901 llvm-svn: 342605
* Merge two attribute diagnostics into oneAndrew Savonichev2018-09-171-1/+2
| | | | | | | | | | | | | | | | | | Summary: Merged the recently added `err_attribute_argument_negative` diagnostic with existing `err_attribute_requires_positive_integer` diagnostic: the former allows only strictly positive integer, while the latter also allows zero. Reviewers: aaron.ballman Reviewed By: aaron.ballman Subscribers: cfe-commits Differential Revision: https://reviews.llvm.org/D51853 llvm-svn: 342367
* [Sema][ObjC] Infer availability of +new from availability of -init.Erik Pilkington2018-09-101-8/+35
| | | | | | | | | | | When defined in NSObject, +new will call -init. If -init has been marked unavailable, diagnose uses of +new. rdar://18335828 Differential revision: https://reviews.llvm.org/D51189 llvm-svn: 341874
* Prevent cpu-specific/cpu-dispatch from giong on a lambda.Erich Keane2018-09-101-0/+8
| | | | | | | It is non-sensical to use cpu-specific/cpu-dispatch multiversioning on a lambda, so prevent it when trying to add the attribute. llvm-svn: 341833
* [OpenCL] Relax diagnostics on OpenCL access qualifiersAndrew Savonichev2018-09-061-4/+10
| | | | | | | | | | | | | | | | | Summary: Emit warning for multiple access qualifiers if they do not conflict. Patch by Alexey Bader Reviewers: Anastasia, yaxunl Reviewed By: Anastasia Subscribers: asavonic, bader, cfe-commits Differential Revision: https://reviews.llvm.org/D51302 llvm-svn: 341553
* [OpenCL] Disallow negative attribute argumentsAndrew Savonichev2018-09-061-2/+12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Summary: Negative arguments in kernel attributes are silently bitcast'ed to unsigned, for example: __attribute__((reqd_work_group_size(1, -1, 1))) __kernel void k() {} is a complete equivalent of: __attribute__((reqd_work_group_size(1, 4294967294, 1))) __kernel void k() {} This is likely an error, so the patch forbids negative arguments in several OpenCL attributes. Users who really want 4294967294 can still use it as an unsigned representation. Reviewers: Anastasia, yaxunl, bader Reviewed By: Anastasia, yaxunl, bader Subscribers: bader, cfe-commits Differential Revision: https://reviews.llvm.org/D50259 llvm-svn: 341539
* Address Aaron Ballman's post-commit review comments from r340306, NFCErik Pilkington2018-08-211-4/+3
| | | | llvm-svn: 340311
* Add a new flag and attributes to control static destructor registrationErik Pilkington2018-08-211-0/+19
| | | | | | | | | | | | | | | | | | | | This commit adds the flag -fno-c++-static-destructors and the attributes [[clang::no_destroy]] and [[clang::always_destroy]]. no_destroy specifies that a specific static or thread duration variable shouldn't have it's destructor registered, and is the default in -fno-c++-static-destructors mode. always_destroy is the opposite, and is the default in -fc++-static-destructors mode. A variable whose destructor is disabled (either because of -fno-c++-static-destructors or [[clang::no_destroy]]) doesn't count as a use of the destructor, so we don't do any access checking or mark it referenced. We also don't emit -Wexit-time-destructors for these variables. rdar://21734598 Differential revision: https://reviews.llvm.org/D50994 llvm-svn: 340306
* Summary:Add clang::reinitializes attributeMartin Bohme2018-08-131-0/+5
| | | | | | | | | | | | | | | | Summary: This is for use by clang-tidy's bugprone-use-after-move check -- see corresponding clang-tidy patch at https://reviews.llvm.org/D49910. Reviewers: aaron.ballman, rsmith Reviewed By: aaron.ballman Subscribers: cfe-commits Differential Revision: https://reviews.llvm.org/D49911 llvm-svn: 339569
* Port getLocEnd -> getEndLocStephen Kelly2018-08-091-5/+5
| | | | | | | | | | Reviewers: teemperor! Subscribers: cfe-commits Differential Revision: https://reviews.llvm.org/D50351 llvm-svn: 339386
* Port getLocStart -> getBeginLocStephen Kelly2018-08-091-29/+29
| | | | | | | | | | Reviewers: teemperor! Subscribers: jholewinski, whisperity, jfb, cfe-commits Differential Revision: https://reviews.llvm.org/D50350 llvm-svn: 339385
* Implement diagnostic stream operator for ParsedAttr.Erich Keane2018-08-091-251/+229
| | | | | | | | | | | | | As a part of attempting to clean up the way attributes are printed, this patch adds an operator << to the diagnostics/ partialdiagnostics so that ParsedAttr can be sent directly. This patch also rewrites a large amount* of the times when ParsedAttr was printed using its IdentifierInfo object instead of being printed itself. *"a large amount" == "All I could find". llvm-svn: 339344
* [P0936R0] add [[clang::lifetimebound]] attributeRichard Smith2018-08-011-0/+3
| | | | | | | | | | | | | | | | | | | This patch adds support for a new attribute, [[clang::lifetimebound]], that indicates that the lifetime of a function result is related to one of the function arguments. When walking an initializer to make sure that the lifetime of the initial value is at least as long as the lifetime of the initialized object, we step through parameters (including the implicit object parameter of a non-static member function) that are marked with this attribute. There's nowhere to write an attribute on the implicit object parameter, so in lieu of that, it may be applied to a function type (where it appears immediately after the cv-qualifiers and ref-qualifier, which is as close to a declaration of the implicit object parameter as we have). I'm currently modeling this in the AST as the attribute appertaining to the function type. Differential Revision: https://reviews.llvm.org/D49922 llvm-svn: 338464
* Remove trailing spaceFangrui Song2018-07-301-37/+37
| | | | | | sed -Ei 's/[[:space:]]+$//' include/**/*.{def,h,td} lib/**/*.{cpp,h} llvm-svn: 338291
* [RISCV] Add support for interrupt attributeAna Pazos2018-07-261-0/+62
| | | | | | | | | | | | | | | | | | | Summary: Clang supports the GNU style ``__attribute__((interrupt))`` attribute on RISCV targets. Permissible values for this parameter are user, supervisor, and machine. If there is no parameter, then it defaults to machine. Reference: https://gcc.gnu.org/onlinedocs/gcc/RISC-V-Function-Attributes.html Based on initial patch by Zhaoshi Zheng. Reviewers: asb, aaron.ballman Reviewed By: asb, aaron.ballman Subscribers: rkruppe, the_o, aaron.ballman, MartinMosbeck, brucehoult, rbar, johnrusso, simoncook, sabuasal, niosHD, kito-cheng, shiva0217, zzheng, edward-jones, mgrang, rogfer01, cfe-commits Differential Revision: https://reviews.llvm.org/D48412 llvm-svn: 338045
* Implement cpu_dispatch/cpu_specific MultiversioningErich Keane2018-07-201-0/+48
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | As documented here: https://software.intel.com/en-us/node/682969 and https://software.intel.com/en-us/node/523346. cpu_dispatch multiversioning is an ICC feature that provides for function multiversioning. This feature is implemented with two attributes: First, cpu_specific, which specifies the individual function versions. Second, cpu_dispatch, which specifies the location of the resolver function and the list of resolvable functions. This is valuable since it provides a mechanism where the resolver's TU can be specified in one location, and the individual implementions each in their own translation units. The goal of this patch is to be source-compatible with ICC, so this implementation diverges from the ICC implementation in a few ways: 1- Linux x86/64 only: This implementation uses ifuncs in order to properly dispatch functions. This is is a valuable performance benefit over the ICC implementation. A future patch will be provided to enable this feature on Windows, but it will obviously more closely fit ICC's implementation. 2- CPU Identification functions: ICC uses a set of custom functions to identify the feature list of the host processor. This patch uses the cpu_supports functionality in order to better align with 'target' multiversioning. 1- cpu_dispatch function def/decl: ICC's cpu_dispatch requires that the function marked cpu_dispatch be an empty definition. This patch supports that as well, however declarations are also permitted, since the linker will solve the issue of multiple emissions. Differential Revision: https://reviews.llvm.org/D47474 llvm-svn: 337552
* Change \t to spacesFangrui Song2018-07-201-1/+1
| | | | llvm-svn: 337530
* Add support for __declspec(code_seg("segname"))Erich Keane2018-07-181-2/+67
| | | | | | | | | | | | | | | | | | | This patch uses CodeSegAttr to represent __declspec(code_seg) rather than building on the existing support for #pragma code_seg. The code_seg declspec is applied on functions and classes. This attribute enables the placement of code into separate named segments, including compiler- generated codes and template instantiations. For more information, please see the following: https://msdn.microsoft.com/en-us/library/dn636922.aspx This patch fixes the regression for the support for attribute ((section). https://github.com/llvm-mirror/clang/commit/746b78de7812bc785fbb5207b788348040b23fa7 Patch by Soumi Manna (Manna) Differential Revision: https://reviews.llvm.org/D48841 llvm-svn: 337420
* [NFC] Rename clang::AttributeList to clang::ParsedAttrErich Keane2018-07-131-507/+482
| | | | | | | Since The type no longer contains the 'next' item anymore, it isn't a list, so rename it to ParsedAttr to be more accurate. llvm-svn: 337005
* AttributeList de-listifying:Erich Keane2018-07-121-42/+45
| | | | | | | | | | | Basically, "AttributeList" loses all list-like mechanisms, ParsedAttributes is switched to use a TinyPtrVector (and a ParsedAttributesView is created to have a non-allocating attributes list). DeclaratorChunk gets the later kind, Declarator/DeclSpec keep ParsedAttributes. Iterators are added to the ParsedAttribute types so that for-loops work. llvm-svn: 336945
* [Builtins][Attributes][X86] Tag all X86 builtins with their required vector ↵Craig Topper2018-07-091-0/+22
| | | | | | | | | | | | | | | | | | | | | | | | width. Add a min_vector_width function attribute and tag all x86 instrinsics with it This is part of an ongoing attempt at making 512 bit vectors illegal in the X86 backend type legalizer due to CPU frequency penalties associated with wide vectors on Skylake Server CPUs. We want the loop vectorizer to be able to emit IR containing wide vectors as intermediate operations in vectorized code and allow these wide vectors to be legalized to 256 bits by the X86 backend even though we are targetting a CPU that supports 512 bit vectors. This is similar to what happens with an AVX2 CPU, the vectorizer can emit wide vectors and the backend will split them. We want this splitting behavior, but still be able to use new Skylake instructions that work on 256-bit vectors and support things like masking and gather/scatter. Of course if the user uses explicit vector code in their source code we need to not split those operations. Especially if they have used any of the 512-bit vector intrinsics from immintrin.h. And we need to make it so that merely using the intrinsics produces the expected code in order to be backwards compatible. To support this goal, this patch adds a new IR function attribute "min-legal-vector-width" that can indicate the need for a minimum vector width to be legal in the backend. We need to ensure this attribute is set to the largest vector width needed by any intrinsics from immintrin.h that the function uses. The inliner will be reponsible for merging this attribute when a function is inlined. We may also need a way to limit inlining in the future as well, but we can discuss that in the future. To make things more complicated, there are two different ways intrinsics are implemented in immintrin.h. Either as an always_inline function containing calls to builtins(can be target specific or target independent) or vector extension code. Or as a macro wrapper around a taget specific builtin. I believe I've removed all cases where the macro was around a target independent builtin. To support the always_inline function case this patch adds attribute((min_vector_width(128))) that can be used to tag these functions with their vector width. All x86 intrinsic functions that operate on vectors have been tagged with this attribute. To support the macro case, all x86 specific builtins have also been tagged with the vector width that they require. Use of any builtin with this property will implicitly increase the min_vector_width of the function that calls it. I've done this as a new property in the attribute string for the builtin rather than basing it on the type string so that we can opt into it on a per builtin basis and avoid any impact to target independent builtins. There will be future work to support vectors passed as function arguments and supporting inline assembly. And whatever else we can find that isn't covered by this patch. Special thanks to Chandler who suggested this direction and reviewed a preview version of this patch. And thanks to Eric Christopher who has had many conversations with me about this issue. Differential Revision: https://reviews.llvm.org/D48617 llvm-svn: 336583
* When a dependent alignas is applied to a non-dependent typedef,Richard Smith2018-06-201-11/+12
| | | | | | | prioritize the error for the bad subject over the error for the dependent / non-dependent mismatch. llvm-svn: 335191
* [CUDA][HIP] Allow CUDA __global__ functions to have amdgpu kernel attributesYaxun Liu2018-06-121-16/+18
| | | | | | | | | | | | There are HIP applications e.g. Tensorflow 1.3 using amdgpu kernel attributes, however currently they are only allowed on OpenCL kernel functions. This patch will allow amdgpu kernel attributes to be applied to CUDA/HIP __global__ functions. Differential Revision: https://reviews.llvm.org/D47958 llvm-svn: 334561
* Revert r332470 (and corresponding tests in r332492).Richard Smith2018-05-181-31/+0
| | | | | | | This regressed our support for __attribute__((section)). See added test file for example of code broken by this. llvm-svn: 332760
* Add support for __declspec(code_seg("segname"))Erich Keane2018-05-161-0/+31
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add support for __declspec(code_seg("segname")) This patch is built on the existing support for #pragma code_seg. The code_seg declspec is allowed on functions and classes. The attribute enables the placement of code into separate named segments, including compiler-generated members and template instantiations. For more information, please see the following: https://msdn.microsoft.com/en-us/library/dn636922.aspx A new CodeSeg attribute is used instead of adding a new spelling to the existing Section attribute since they don’t apply to the same Subjects. Section attributes are also added for the code_seg declspec since they are used for #pragma code_seg. No CodeSeg attributes are added to the AST. The patch is written to match with the Microsoft compiler’s behavior even where that behavior is a little complicated (see https://reviews.llvm.org/D22931, the Microsoft feedback page is no longer available since MS has removed the page). That code is in getImplicitSectionAttrFromClass routine. Diagnostics messages are added to match with the Microsoft compiler for code-seg attribute mismatches on base and derived classes and virtual overrides. Differential Revision: https://reviews.llvm.org/D43352 llvm-svn: 332470
* [Clang] Implement function attribute no_stack_protector.Manoj Gupta2018-05-091-0/+4
| | | | | | | | | | | | | | | | | | | | | | Summary: This attribute tells clang to skip this function from stack protector when -stack-protector option is passed. GCC option for this is: __attribute__((__optimize__("no-stack-protector"))) and the equivalent clang syntax would be: __attribute__((no_stack_protector)) This is used in Linux kernel to selectively disable stack protector in certain functions. Reviewers: aaron.ballman, rsmith, rnk, probinson Reviewed By: aaron.ballman Subscribers: probinson, srhines, cfe-commits Differential Revision: https://reviews.llvm.org/D46300 llvm-svn: 331925
* Remove \brief commands from doxygen comments.Adrian Prantl2018-05-091-21/+21
| | | | | | | | | | | | | | | | | | | This is similar to the LLVM change https://reviews.llvm.org/D46290. We've been running doxygen with the autobrief option for a couple of years now. This makes the \brief markers into our comments redundant. Since they are a visual distraction and we don't want to encourage more \brief markers in new code either, this patch removes them all. Patch produced by for i in $(git grep -l '\@brief'); do perl -pi -e 's/\@brief //g' $i & done for i in $(git grep -l '\\brief'); do perl -pi -e 's/\\brief //g' $i & done Differential Revision: https://reviews.llvm.org/D46320 llvm-svn: 331834
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