Changes in alloc-align-attr.c

e765e0bc - Use functions with prototypes when appropriate; NFC

Thu, 03 Feb 2022 21:39:21 +0000

Use functions with prototypes when appropriate; NFCA significant number of our tests in C accidentally use functionswithout prototypes. This patch converts the function signatures to havea prototype for the situations where the test is not specific to K&R Cdeclarations. e.g., void func();becomes void func(void);This is the first batch of tests being updated (there are a significantnumber of other tests left to be updated). List of files: /llvm-project-15.0.7/clang/test/Sema/alloc-align-attr.c

a6891d21 - [clang] Set max allowed alignment to 2^32

Wed, 06 Oct 2021 18:20:44 +0000

[clang] Set max allowed alignment to 2^32Followup to D110451 which set LLVM's max allowed alignment to 2^32.Reviewed By: hansDifferential Revision: https://reviews.llvm.org/D111250 List of files: /llvm-project-15.0.7/clang/test/Sema/alloc-align-attr.c

564d85e0 - The maximal representable alignment in LLVM IR is 1GiB, not 512MiB

Thu, 26 Aug 2021 08:51:28 +0000

The maximal representable alignment in LLVM IR is 1GiB, not 512MiBIn LLVM IR, `AlignmentBitfieldElementT` is 5-bit wideBut that means that the maximal alignment exponent is `(1<<5)-2`,which is `30`, not `29`. And indeed, alignment of `1073741824`roundtrips IR serialization-deserialization.While this doesn't seem all that important, this doublesthe maximal supported alignment from 512MiB to 1GiB,and there's actually one noticeable use-case for that;On X86, the huge pages can have sizes of 2MiB and 1GiB (!).So while this doesn't add support for truly huge alignments,which i think we can easily-ish do if wanted, i think this addszero-cost support for a not-trivially-dismissable case.I don't believe we need any upgrade infrastructure,and since we don't explicitly record the IR version,we don't need to bump one either.As @craig.topper speculates in D108661#2963519,this might be an artificial limit imposed by the original implementationof the `getAlignment()` functions.Differential Revision: https://reviews.llvm.org/D108661 List of files: /llvm-project-15.0.7/clang/test/Sema/alloc-align-attr.c

9ea5d17c - [Sema] Demote call-site-based 'alignment is a power of two' check for AllocAlignAttr into a warning

Thu, 20 Feb 2020 13:39:26 +0000

[Sema] Demote call-site-based 'alignment is a power of two' check for AllocAlignAttr into a warningSummary:As @rsmith notes in https://reviews.llvm.org/D73020#inline-672219while that is certainly UB land, it may not be actually reachable at runtime, e.g.:```template void *make() { if ((N & (N-1)) == 0) return operator new(N, std::align_val_t(N)); else return operator new(N);}void *p = make<7>();```and we shouldn't really error-out there.That being said, i'm not really following the logic here.Which ones of these cases should remain being an error?Reviewers: rsmith, erichkeaneReviewed By: erichkeaneSubscribers: cfe-commits, rsmithTags: #clangDifferential Revision: https://reviews.llvm.org/D73996 List of files: /llvm-project-15.0.7/clang/test/Sema/alloc-align-attr.c

ba545c81 - [Sema] Try 2: Attempt to perform call-size-specific `attribute((alloc_align(param_idx)))` validation

Thu, 23 Jan 2020 19:49:50 +0000

[Sema] Try 2: Attempt to perform call-size-specific `__attribute__((alloc_align(param_idx)))` validationSummary:`alloc_align` attribute takes parameter number, not the alignment itself,so given **just** the attribute/function declaration we can't do anysanity checking for said alignment.However, at call site, given the actual `Expr` that is passedinto that parameter, we //might// be able to evaluate said `Expr`as Integer Constant Expression, and perform the sanity checks.But since there is no requirement for that argument to be an immediate,we may fail, and that's okay.However if we did evaluate, we should enforce the same constraintsas with `__builtin_assume_aligned()`/`__attribute__((assume_aligned(imm)))`:said alignment is a power of two, and is not greater than our magic thresholdThis was initially committed in c2a9061ac5166e48fe85ea2b6dbce9457c964958but reverted in 00756b182398b92abe16559287467079087aa631 because ofsuspicious bot failures.Reviewers: erichkeane, aaron.ballman, hfinkel, rsmith, jdoerfertReviewed By: erichkeaneSubscribers: cfe-commitsTags: #clangDifferential Revision: https://reviews.llvm.org/D72996 List of files: /llvm-project-15.0.7/clang/test/Sema/alloc-align-attr.c

00756b18 - Revert "[Sema] Attempt to perform call-size-specific `attribute((alloc_align(param_idx)))` validation"

Thu, 23 Jan 2020 20:07:58 +0000

Revert "[Sema] Attempt to perform call-size-specific `__attribute__((alloc_align(param_idx)))` validation"Likely makes bots angry.This reverts commit c2a9061ac5166e48fe85ea2b6dbce9457c964958. List of files: /llvm-project-15.0.7/clang/test/Sema/alloc-align-attr.c

c2a9061a - [Sema] Attempt to perform call-size-specific `attribute((alloc_align(param_idx)))` validation

Thu, 23 Jan 2020 19:49:50 +0000

[Sema] Attempt to perform call-size-specific `__attribute__((alloc_align(param_idx)))` validationSummary:`alloc_align` attribute takes parameter number, not the alignment itself,so given **just** the attribute/function declaration we can't do anysanity checking for said alignment.However, at call site, given the actual `Expr` that is passedinto that parameter, we //might// be able to evaluate said `Expr`as Integer Constant Expression, and perform the sanity checks.But since there is no requirement for that argument to be an immediate,we may fail, and that's okay.However if we did evaluate, we should enforce the same constraintsas with `__builtin_assume_aligned()`/`__attribute__((assume_aligned(imm)))`:said alignment is a power of two, and is not greater than our magic thresholdReviewers: erichkeane, aaron.ballman, hfinkel, rsmith, jdoerfertReviewed By: erichkeaneSubscribers: cfe-commitsTags: #clangDifferential Revision: https://reviews.llvm.org/D72996 List of files: /llvm-project-15.0.7/clang/test/Sema/alloc-align-attr.c

24952fbc - Add #pragma clang attribute support to the external_source_symbol attribute

Wed, 19 Apr 2017 15:52:11 +0000

Add #pragma clang attribute support to the external_source_symbol attributePrior to this commit the external_source_symbol attribute wasn't supported by#pragma clang attribute for the following two reasons:- The Named attribute subject hasn't been supported by TableGen.- There was no way to specify a subject match rule for #pragma clang attribute that could operate on a set of attribute subjects (e.g. the ones that derive from NamedDecl).This commit fixes the two issues and thus adds external_source_symbol support to#pragma clang attribute.rdar://31169028Differential Revision: https://reviews.llvm.org/D32176llvm-svn: 300712 List of files: /llvm-project-15.0.7/clang/test/Sema/alloc-align-attr.c

623efd8a - Clang changes for alloc_align attribute

Thu, 30 Mar 2017 21:48:55 +0000

Clang changes for alloc_align attribute GCC has the alloc_align attribute, which is similar to assume_aligned, except the attribute's parameter is the index of the integer parameter that needs aligning to.Differential Revision: https://reviews.llvm.org/D29599llvm-svn: 299117 List of files: /llvm-project-15.0.7/clang/test/Sema/alloc-align-attr.c