On Thu, Sep 10, 2020 at 11:27 AM Nico Weber <tha...@chromium.org> wrote: > > Looks like this broke the sphinx bot: > http://lab.llvm.org:8011/builders/clang-tools-sphinx-docs/builds/65757/steps/docs-clang-tools-html/logs/stdio > > Can you take a look?
Hopefully 66ac212ea97a529e171a7b8aea10638d7b9b9907 will resolve the issue while I get sphinx up and running on this box in case it doesn't. ~Aaron > > On Tue, Sep 8, 2020 at 9:36 AM Aaron Ballman via cfe-commits > <cfe-commits@lists.llvm.org> wrote: >> >> >> Author: Frank Derry Wanye >> Date: 2020-09-08T09:35:14-04:00 >> New Revision: 156b127945a8c923d141e608b7380427da024376 >> >> URL: >> https://github.com/llvm/llvm-project/commit/156b127945a8c923d141e608b7380427da024376 >> DIFF: >> https://github.com/llvm/llvm-project/commit/156b127945a8c923d141e608b7380427da024376.diff >> >> LOG: Add a new altera check for structure packing and alignment. >> >> The altera struct pack align lint check finds structs that are inefficiently >> packed or aligned and recommends packing/aligning of the structs using the >> packed and aligned attributes as needed in a warning. >> >> Added: >> clang-tools-extra/clang-tidy/altera/AlteraTidyModule.cpp >> clang-tools-extra/clang-tidy/altera/CMakeLists.txt >> clang-tools-extra/clang-tidy/altera/StructPackAlignCheck.cpp >> clang-tools-extra/clang-tidy/altera/StructPackAlignCheck.h >> clang-tools-extra/docs/clang-tidy/checks/altera-struct-pack-align.rst >> clang-tools-extra/test/clang-tidy/checkers/altera-struct-pack-align.cpp >> >> Modified: >> clang-tools-extra/clang-tidy/CMakeLists.txt >> clang-tools-extra/clang-tidy/ClangTidyForceLinker.h >> clang-tools-extra/docs/ReleaseNotes.rst >> clang-tools-extra/docs/clang-tidy/checks/list.rst >> clang-tools-extra/docs/clang-tidy/index.rst >> >> Removed: >> >> >> >> ################################################################################ >> diff --git a/clang-tools-extra/clang-tidy/CMakeLists.txt >> b/clang-tools-extra/clang-tidy/CMakeLists.txt >> index 02573534ccae..923976197ebe 100644 >> --- a/clang-tools-extra/clang-tidy/CMakeLists.txt >> +++ b/clang-tools-extra/clang-tidy/CMakeLists.txt >> @@ -46,6 +46,7 @@ endif() >> # If you add a check, also add it to ClangTidyForceLinker.h in this >> directory. >> add_subdirectory(android) >> add_subdirectory(abseil) >> +add_subdirectory(altera) >> add_subdirectory(boost) >> add_subdirectory(bugprone) >> add_subdirectory(cert) >> @@ -71,6 +72,7 @@ add_subdirectory(zircon) >> set(ALL_CLANG_TIDY_CHECKS >> clangTidyAndroidModule >> clangTidyAbseilModule >> + clangTidyAlteraModule >> clangTidyBoostModule >> clangTidyBugproneModule >> clangTidyCERTModule >> >> diff --git a/clang-tools-extra/clang-tidy/ClangTidyForceLinker.h >> b/clang-tools-extra/clang-tidy/ClangTidyForceLinker.h >> index 1d6bd2a4fd62..63e681f878db 100644 >> --- a/clang-tools-extra/clang-tidy/ClangTidyForceLinker.h >> +++ b/clang-tools-extra/clang-tidy/ClangTidyForceLinker.h >> @@ -20,6 +20,11 @@ extern volatile int AbseilModuleAnchorSource; >> static int LLVM_ATTRIBUTE_UNUSED AbseilModuleAnchorDestination = >> AbseilModuleAnchorSource; >> >> +// This anchor is used to force the linker to link the AlteraModule. >> +extern volatile int AlteraModuleAnchorSource; >> +static int LLVM_ATTRIBUTE_UNUSED AlteraModuleAnchorDestination = >> + AlteraModuleAnchorSource; >> + >> // This anchor is used to force the linker to link the AndroidModule. >> extern volatile int AndroidModuleAnchorSource; >> static int LLVM_ATTRIBUTE_UNUSED AndroidModuleAnchorDestination = >> >> diff --git a/clang-tools-extra/clang-tidy/altera/AlteraTidyModule.cpp >> b/clang-tools-extra/clang-tidy/altera/AlteraTidyModule.cpp >> new file mode 100644 >> index 000000000000..d91f67ac1485 >> --- /dev/null >> +++ b/clang-tools-extra/clang-tidy/altera/AlteraTidyModule.cpp >> @@ -0,0 +1,39 @@ >> +//===--- AlteraTidyModule.cpp - clang-tidy >> --------------------------------===// >> +// >> +// Part of the LLVM Project, under the Apache License v2.0 with LLVM >> Exceptions. >> +// See https://llvm.org/LICENSE.txt for license information. >> +// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception >> +// >> +//===----------------------------------------------------------------------===// >> + >> +#include "../ClangTidy.h" >> +#include "../ClangTidyModule.h" >> +#include "../ClangTidyModuleRegistry.h" >> +#include "StructPackAlignCheck.h" >> + >> +using namespace clang::ast_matchers; >> + >> +namespace clang { >> +namespace tidy { >> +namespace altera { >> + >> +class AlteraModule : public ClangTidyModule { >> +public: >> + void addCheckFactories(ClangTidyCheckFactories &CheckFactories) override { >> + CheckFactories.registerCheck<StructPackAlignCheck>( >> + "altera-struct-pack-align"); >> + } >> +}; >> + >> +} // namespace altera >> + >> +// Register the AlteraTidyModule using this statically initialized variable. >> +static ClangTidyModuleRegistry::Add<altera::AlteraModule> >> + X("altera-module", "Adds Altera FPGA OpenCL lint checks."); >> + >> +// This anchor is used to force the linker to link in the generated object >> file >> +// and thus register the AlteraModule. >> +volatile int AlteraModuleAnchorSource = 0; >> + >> +} // namespace tidy >> +} // namespace clang >> >> diff --git a/clang-tools-extra/clang-tidy/altera/CMakeLists.txt >> b/clang-tools-extra/clang-tidy/altera/CMakeLists.txt >> new file mode 100644 >> index 000000000000..45131c1809a2 >> --- /dev/null >> +++ b/clang-tools-extra/clang-tidy/altera/CMakeLists.txt >> @@ -0,0 +1,15 @@ >> +set(LLVM_LINK_COMPONENTS support) >> + >> +add_clang_library(clangTidyAlteraModule >> + AlteraTidyModule.cpp >> + StructPackAlignCheck.cpp >> + >> + LINK_LIBS >> + clangAnalysis >> + clangAST >> + clangASTMatchers >> + clangBasic >> + clangLex >> + clangTidy >> + clangTidyUtils >> + ) >> >> diff --git a/clang-tools-extra/clang-tidy/altera/StructPackAlignCheck.cpp >> b/clang-tools-extra/clang-tidy/altera/StructPackAlignCheck.cpp >> new file mode 100644 >> index 000000000000..9f28a22a9d03 >> --- /dev/null >> +++ b/clang-tools-extra/clang-tidy/altera/StructPackAlignCheck.cpp >> @@ -0,0 +1,144 @@ >> +//===--- StructPackAlignCheck.cpp - clang-tidy >> ----------------------------===// >> +// >> +// Part of the LLVM Project, under the Apache License v2.0 with LLVM >> Exceptions. >> +// See https://llvm.org/LICENSE.txt for license information. >> +// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception >> +// >> +//===----------------------------------------------------------------------===// >> + >> +#include "StructPackAlignCheck.h" >> +#include "clang/AST/ASTContext.h" >> +#include "clang/AST/RecordLayout.h" >> +#include "clang/ASTMatchers/ASTMatchFinder.h" >> +#include <math.h> >> +#include <sstream> >> + >> +using namespace clang::ast_matchers; >> + >> +namespace clang { >> +namespace tidy { >> +namespace altera { >> + >> +void StructPackAlignCheck::registerMatchers(MatchFinder *Finder) { >> + Finder->addMatcher(recordDecl(isStruct(), isDefinition(), >> + unless(isExpansionInSystemHeader())) >> + .bind("struct"), >> + this); >> +} >> + >> +CharUnits >> +StructPackAlignCheck::computeRecommendedAlignment(CharUnits MinByteSize) { >> + CharUnits NewAlign = CharUnits::fromQuantity(1); >> + if (!MinByteSize.isPowerOfTwo()) { >> + int MSB = (int)MinByteSize.getQuantity(); >> + for (; MSB > 0; MSB /= 2) { >> + NewAlign = NewAlign.alignTo( >> + CharUnits::fromQuantity(((int)NewAlign.getQuantity()) * 2)); >> + // Abort if the computed alignment meets the maximum configured >> alignment. >> + if (NewAlign.getQuantity() >= MaxConfiguredAlignment) >> + break; >> + } >> + } else { >> + NewAlign = MinByteSize; >> + } >> + return NewAlign; >> +} >> + >> +void StructPackAlignCheck::check(const MatchFinder::MatchResult &Result) { >> + const auto *Struct = Result.Nodes.getNodeAs<RecordDecl>("struct"); >> + >> + // Do not trigger on templated struct declarations because the packing and >> + // alignment requirements are unknown. >> + if (Struct->isTemplated()) >> + return; >> + >> + // Get sizing info for the struct. >> + llvm::SmallVector<std::pair<unsigned int, unsigned int>, 10> FieldSizes; >> + unsigned int TotalBitSize = 0; >> + for (const FieldDecl *StructField : Struct->fields()) { >> + // For each StructField, record how big it is (in bits). >> + // Would be good to use a pair of <offset, size> to advise a better >> + // packing order. >> + unsigned int StructFieldWidth = >> + (unsigned int)Result.Context >> + ->getTypeInfo(StructField->getType().getTypePtr()) >> + .Width; >> + FieldSizes.emplace_back(StructFieldWidth, StructField->getFieldIndex()); >> + // FIXME: Recommend a reorganization of the struct (sort by StructField >> + // size, largest to smallest). >> + TotalBitSize += StructFieldWidth; >> + } >> + >> + uint64_t CharSize = Result.Context->getCharWidth(); >> + CharUnits CurrSize = Result.Context->getASTRecordLayout(Struct).getSize(); >> + CharUnits MinByteSize = >> + CharUnits::fromQuantity(ceil((float)TotalBitSize / CharSize)); >> + CharUnits MaxAlign = CharUnits::fromQuantity( >> + ceil((float)Struct->getMaxAlignment() / CharSize)); >> + CharUnits CurrAlign = >> + Result.Context->getASTRecordLayout(Struct).getAlignment(); >> + CharUnits NewAlign = computeRecommendedAlignment(MinByteSize); >> + >> + bool IsPacked = Struct->hasAttr<PackedAttr>(); >> + bool NeedsPacking = (MinByteSize < CurrSize) && (MaxAlign != NewAlign) && >> + (CurrSize != NewAlign); >> + bool NeedsAlignment = CurrAlign.getQuantity() != NewAlign.getQuantity(); >> + >> + if (!NeedsAlignment && !NeedsPacking) >> + return; >> + >> + // If it's using much more space than it needs, suggest packing. >> + // (Do not suggest packing if it is currently explicitly aligned to what >> the >> + // minimum byte size would suggest as the new alignment.) >> + if (NeedsPacking && !IsPacked) { >> + diag(Struct->getLocation(), >> + "accessing fields in struct %0 is inefficient due to padding; only >> " >> + "needs %1 bytes but is using %2 bytes") >> + << Struct << (int)MinByteSize.getQuantity() >> + << (int)CurrSize.getQuantity() >> + << >> FixItHint::CreateInsertion(Struct->getEndLoc().getLocWithOffset(1), >> + " __attribute__((packed))"); >> + diag(Struct->getLocation(), >> + "use \"__attribute__((packed))\" to reduce the amount of padding " >> + "applied to struct %0", >> + DiagnosticIDs::Note) >> + << Struct; >> + } >> + >> + FixItHint FixIt; >> + AlignedAttr *Attribute = Struct->getAttr<AlignedAttr>(); >> + std::string NewAlignQuantity = >> std::to_string((int)NewAlign.getQuantity()); >> + if (Attribute) { >> + std::ostringstream FixItString; >> + FixItString << "aligned(" << NewAlignQuantity << ")"; >> + FixIt = >> + FixItHint::CreateReplacement(Attribute->getRange(), >> FixItString.str()); >> + } else { >> + std::ostringstream FixItString; >> + FixItString << " __attribute__((aligned(" << NewAlignQuantity << ")))"; >> + FixIt = >> FixItHint::CreateInsertion(Struct->getEndLoc().getLocWithOffset(1), >> + FixItString.str()); >> + } >> + >> + // And suggest the minimum power-of-two alignment for the struct as a >> whole >> + // (with and without packing). >> + if (NeedsAlignment) { >> + diag(Struct->getLocation(), >> + "accessing fields in struct %0 is inefficient due to poor >> alignment; " >> + "currently aligned to %1 bytes, but recommended alignment is %2 >> bytes") >> + << Struct << (int)CurrAlign.getQuantity() << NewAlignQuantity << >> FixIt; >> + >> + diag(Struct->getLocation(), >> + "use \"__attribute__((aligned(%0)))\" to align struct %1 to %0 >> bytes", >> + DiagnosticIDs::Note) >> + << NewAlignQuantity << Struct; >> + } >> +} >> + >> +void StructPackAlignCheck::storeOptions(ClangTidyOptions::OptionMap &Opts) { >> + Options.store(Opts, "MaxConfiguredAlignment", MaxConfiguredAlignment); >> +} >> + >> +} // namespace altera >> +} // namespace tidy >> +} // namespace clang >> >> diff --git a/clang-tools-extra/clang-tidy/altera/StructPackAlignCheck.h >> b/clang-tools-extra/clang-tidy/altera/StructPackAlignCheck.h >> new file mode 100644 >> index 000000000000..b903641247e3 >> --- /dev/null >> +++ b/clang-tools-extra/clang-tidy/altera/StructPackAlignCheck.h >> @@ -0,0 +1,41 @@ >> +//===--- StructPackAlignCheck.h - clang-tidy --------------------*- C++ >> -*-===// >> +// >> +// Part of the LLVM Project, under the Apache License v2.0 with LLVM >> Exceptions. >> +// See https://llvm.org/LICENSE.txt for license information. >> +// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception >> +// >> +//===----------------------------------------------------------------------===// >> + >> +#ifndef LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_ALTERA_STRUCTPACKALIGNCHECK_H >> +#define LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_ALTERA_STRUCTPACKALIGNCHECK_H >> + >> +#include "../ClangTidyCheck.h" >> + >> +namespace clang { >> +namespace tidy { >> +namespace altera { >> + >> +/// Finds structs that are inefficiently packed or aligned, and recommends >> +/// packing and/or aligning of said structs as needed. >> +/// >> +/// For the user-facing documentation see: >> +/// >> http://clang.llvm.org/extra/clang-tidy/checks/altera-struct-pack-align.html >> +class StructPackAlignCheck : public ClangTidyCheck { >> +public: >> + StructPackAlignCheck(StringRef Name, ClangTidyContext *Context) >> + : ClangTidyCheck(Name, Context), >> + MaxConfiguredAlignment(Options.get("MaxConfiguredAlignment", 128)) {} >> + void registerMatchers(ast_matchers::MatchFinder *Finder) override; >> + void check(const ast_matchers::MatchFinder::MatchResult &Result) override; >> + void storeOptions(ClangTidyOptions::OptionMap &Opts); >> + >> +private: >> + const unsigned MaxConfiguredAlignment; >> + CharUnits computeRecommendedAlignment(CharUnits MinByteSize); >> +}; >> + >> +} // namespace altera >> +} // namespace tidy >> +} // namespace clang >> + >> +#endif // LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_ALTERA_STRUCTPACKALIGNCHECK_H >> >> diff --git a/clang-tools-extra/docs/ReleaseNotes.rst >> b/clang-tools-extra/docs/ReleaseNotes.rst >> index 781fef27c476..53c3894914e5 100644 >> --- a/clang-tools-extra/docs/ReleaseNotes.rst >> +++ b/clang-tools-extra/docs/ReleaseNotes.rst >> @@ -67,6 +67,27 @@ The improvements are... >> Improvements to clang-tidy >> -------------------------- >> >> +New modules >> +^^^^^^^^^^^ >> + >> +- New :doc:`altera <clang-tidy/modules/altera>` module. >> + >> + Includes checks related to OpenCL for FPGA coding guidelines, based on the >> + `Altera SDK for OpenCL: Best Practices Guide >> + >> <https://www.altera.com/en_US/pdfs/literature/hb/opencl-sdk/aocl_optimization_guide.pdf>`_. >> + >> +New checks >> +^^^^^^^^^^ >> + >> +- New :doc:`altera-struct-pack-align >> + <clang-tidy/checks/altera-struct-pack-align>` check. >> + >> + Finds structs that are inefficiently packed or aligned, and recommends >> + packing and/or aligning of said structs as needed. >> + >> +- New :doc:`bugprone-misplaced-pointer-arithmetic-in-alloc >> + <clang-tidy/checks/bugprone-misplaced-pointer-arithmetic-in-alloc>` check. >> + >> - New :doc:`bugprone-redundant-branch-condition >> <clang-tidy/checks/bugprone-redundant-branch-condition>` check. >> >> >> diff --git >> a/clang-tools-extra/docs/clang-tidy/checks/altera-struct-pack-align.rst >> b/clang-tools-extra/docs/clang-tidy/checks/altera-struct-pack-align.rst >> new file mode 100644 >> index 000000000000..b03a4fcf7fcf >> --- /dev/null >> +++ b/clang-tools-extra/docs/clang-tidy/checks/altera-struct-pack-align.rst >> @@ -0,0 +1,54 @@ >> +.. title:: clang-tidy - altera-struct-pack-align >> + >> +altera-struct-pack-align >> +======================== >> + >> +Finds structs that are inefficiently packed or aligned, and recommends >> +packing and/or aligning of said structs as needed. >> + >> +Structs that are not packed take up more space than they should, and >> accessing >> +structs that are not well aligned is inefficient. >> + >> +Fix-its are provided to fix both of these issues by inserting and/or >> amending >> +relevant struct attributes. >> + >> +Based on the `Altera SDK for OpenCL: Best Practices Guide >> +<https://www.altera.com/en_US/pdfs/literature/hb/opencl-sdk/aocl_optimization_guide.pdf>`_. >> + >> +.. code-block:: c++ >> + >> + // The following struct is originally aligned to 4 bytes, and thus takes >> up >> + // 12 bytes of memory instead of 10. Packing the struct will make it use >> + // only 10 bytes of memory, and aligning it to 16 bytes will make it >> + // efficient to access. >> + struct example { >> + char a; // 1 byte >> + double b; // 8 bytes >> + char c; // 1 byte >> + }; >> + >> + // The following struct is arranged in such a way that packing is not >> needed. >> + // However, it is aligned to 4 bytes instead of 8, and thus needs to be >> + // explicitly aligned. >> + struct implicitly_packed_example { >> + char a; // 1 byte >> + char b; // 1 byte >> + char c; // 1 byte >> + char d; // 1 byte >> + int e; // 4 bytes >> + }; >> + >> + // The following struct is explicitly aligned and packed. >> + struct good_example { >> + char a; // 1 byte >> + double b; // 8 bytes >> + char c; // 1 byte >> + } __attribute__((packed)) __attribute__((aligned(16)); >> + >> + // Explicitly aligning a struct to the wrong value will result in a >> warning. >> + // The following example should be aligned to 16 bytes, not 32. >> + struct badly_aligned_example { >> + char a; // 1 byte >> + double b; // 8 bytes >> + char c; // 1 byte >> + } __attribute__((packed)) __attribute__((aligned(32))); >> >> diff --git a/clang-tools-extra/docs/clang-tidy/checks/list.rst >> b/clang-tools-extra/docs/clang-tidy/checks/list.rst >> index 91414ee8c90f..c569ce704d97 100644 >> --- a/clang-tools-extra/docs/clang-tidy/checks/list.rst >> +++ b/clang-tools-extra/docs/clang-tidy/checks/list.rst >> @@ -30,6 +30,7 @@ Clang-Tidy Checks >> `abseil-time-comparison <abseil-time-comparison.html>`_, "Yes" >> `abseil-time-subtraction <abseil-time-subtraction.html>`_, "Yes" >> `abseil-upgrade-duration-conversions >> <abseil-upgrade-duration-conversions.html>`_, "Yes" >> + `altera-struct-pack-align <altera-struct-pack-align.html>`_, >> `android-cloexec-accept <android-cloexec-accept.html>`_, "Yes" >> `android-cloexec-accept4 <android-cloexec-accept4.html>`_, >> `android-cloexec-creat <android-cloexec-creat.html>`_, "Yes" >> >> diff --git a/clang-tools-extra/docs/clang-tidy/index.rst >> b/clang-tools-extra/docs/clang-tidy/index.rst >> index b9a4a7d694b4..a85c72154178 100644 >> --- a/clang-tools-extra/docs/clang-tidy/index.rst >> +++ b/clang-tools-extra/docs/clang-tidy/index.rst >> @@ -58,6 +58,7 @@ There are currently the following groups of checks: >> Name prefix Description >> ====================== >> ========================================================= >> ``abseil-`` Checks related to Abseil library. >> +``altera-`` Checks related to OpenCL programming for FPGAs. >> ``android-`` Checks related to Android. >> ``boost-`` Checks related to Boost library. >> ``bugprone-`` Checks that target bugprone code constructs. >> >> diff --git >> a/clang-tools-extra/test/clang-tidy/checkers/altera-struct-pack-align.cpp >> b/clang-tools-extra/test/clang-tidy/checkers/altera-struct-pack-align.cpp >> new file mode 100644 >> index 000000000000..615b6cafe87a >> --- /dev/null >> +++ b/clang-tools-extra/test/clang-tidy/checkers/altera-struct-pack-align.cpp >> @@ -0,0 +1,101 @@ >> +// RUN: %check_clang_tidy %s altera-struct-pack-align %t -- >> -header-filter=.* >> + >> +// Struct needs both alignment and packing >> +struct error { >> + char a; >> + double b; >> + char c; >> +}; >> +// CHECK-MESSAGES: :[[@LINE-5]]:8: warning: accessing fields in struct >> 'error' is inefficient due to padding; only needs 10 bytes but is using 24 >> bytes [altera-struct-pack-align] >> +// CHECK-MESSAGES: :[[@LINE-6]]:8: note: use "__attribute__((packed))" to >> reduce the amount of padding applied to struct 'error' >> +// CHECK-MESSAGES: :[[@LINE-7]]:8: warning: accessing fields in struct >> 'error' is inefficient due to poor alignment; currently aligned to 8 bytes, >> but recommended alignment is 16 bytes [altera-struct-pack-align] >> +// CHECK-MESSAGES: :[[@LINE-8]]:8: note: use "__attribute__((aligned(16)))" >> to align struct 'error' to 16 bytes >> +// CHECK-FIXES: __attribute__((packed)) >> +// CHECK-FIXES: __attribute__((aligned(16))); >> + >> +// Struct is explicitly packed, but needs alignment >> +struct error_packed { >> + char a; >> + double b; >> + char c; >> +} __attribute__((packed)); >> +// CHECK-MESSAGES: :[[@LINE-5]]:8: warning: accessing fields in struct >> 'error_packed' is inefficient due to poor alignment; currently aligned to 1 >> bytes, but recommended alignment is 16 bytes [altera-struct-pack-align] >> +// CHECK-MESSAGES: :[[@LINE-6]]:8: note: use "__attribute__((aligned(16)))" >> to align struct 'error_packed' to 16 bytes >> +// CHECK-FIXES: __attribute__((aligned(16))) >> + >> +// Struct is properly packed, but needs alignment >> +struct align_only { >> + char a; >> + char b; >> + char c; >> + char d; >> + int e; >> + double f; >> +}; >> +// CHECK-MESSAGES: :[[@LINE-8]]:8: warning: accessing fields in struct >> 'align_only' is inefficient due to poor alignment; currently aligned to 8 >> bytes, but recommended alignment is 16 bytes [altera-struct-pack-align] >> +// CHECK-MESSAGES: :[[@LINE-9]]:8: note: use "__attribute__((aligned(16)))" >> to align struct 'align_only' to 16 bytes >> +// CHECK-FIXES: __attribute__((aligned(16))); >> + >> +// Struct is perfectly packed but wrongly aligned >> +struct bad_align { >> + char a; >> + double b; >> + char c; >> +} __attribute__((packed)) __attribute__((aligned(8))); >> +// CHECK-MESSAGES: :[[@LINE-5]]:8: warning: accessing fields in struct >> 'bad_align' is inefficient due to poor alignment; currently aligned to 8 >> bytes, but recommended alignment is 16 bytes [altera-struct-pack-align] >> +// CHECK-MESSAGES: :[[@LINE-6]]:8: note: use "__attribute__((aligned(16)))" >> to align struct 'bad_align' to 16 bytes >> +// CHECK-FIXES: __attribute__((aligned(16))); >> + >> +struct bad_align2 { >> + char a; >> + double b; >> + char c; >> +} __attribute__((packed)) __attribute__((aligned(32))); >> +// CHECK-MESSAGES: :[[@LINE-5]]:8: warning: accessing fields in struct >> 'bad_align2' is inefficient due to poor alignment; currently aligned to 32 >> bytes, but recommended alignment is 16 bytes [altera-struct-pack-align] >> +// CHECK-MESSAGES: :[[@LINE-6]]:8: note: use "__attribute__((aligned(16)))" >> to align struct 'bad_align2' to 16 bytes >> +// CHECK-FIXES: __attribute__((aligned(16))); >> + >> +struct bad_align3 { >> + char a; >> + double b; >> + char c; >> +} __attribute__((packed)) __attribute__((aligned(4))); >> +// CHECK-MESSAGES: :[[@LINE-5]]:8: warning: accessing fields in struct >> 'bad_align3' is inefficient due to poor alignment; currently aligned to 4 >> bytes, but recommended alignment is 16 bytes [altera-struct-pack-align] >> +// CHECK-MESSAGES: :[[@LINE-6]]:8: note: use "__attribute__((aligned(16)))" >> to align struct 'bad_align3' to 16 bytes >> +// CHECK-FIXES: __attribute__((aligned(16))); >> + >> +// Struct is both perfectly packed and aligned >> +struct success { >> + char a; >> + double b; >> + char c; >> +} __attribute__((packed)) __attribute__((aligned(16))); >> +//Should take 10 bytes and be aligned to 16 bytes >> + >> +// Struct is properly packed, and explicitly aligned >> +struct success2 { >> + int a; >> + int b; >> + int c; >> +} __attribute__((aligned(16))); >> + >> +// If struct is properly aligned, packing not needed >> +struct success3 { >> + char a; >> + double b; >> + char c; >> +} __attribute__((aligned(16))); >> + >> +// If struct is templated, warnings should not be triggered >> +template <typename A, typename B> >> +struct success4 { >> + A a; >> + B b; >> + int c; >> +}; >> + >> +// Warnings should not trigger on struct instantiations >> +void no_trigger_on_instantiation() { >> + struct bad_align3 instantiated { 'a', 0.001, 'b' }; >> +} >> + >> >> >> >> _______________________________________________ >> cfe-commits mailing list >> cfe-commits@lists.llvm.org >> https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
