Author: Roman Lebedev Date: 2020-01-24T17:49:17+03:00 New Revision: 1d0972ff5eab544579c400ee674d5c9c60391ee1
URL: https://github.com/llvm/llvm-project/commit/1d0972ff5eab544579c400ee674d5c9c60391ee1 DIFF: https://github.com/llvm/llvm-project/commit/1d0972ff5eab544579c400ee674d5c9c60391ee1.diff LOG: [Sema] Introduce MaximumAlignment value, to be used instead of magical constants There is llvm::Value::MaximumAlignment, which is numerically equivalent to these constants, but we can't use it directly because we can't include llvm IR headers in clang Sema. So instead, copy-paste the constant, and fixup the places to use it. This was initially reviewed in https://reviews.llvm.org/D72998 Added: Modified: clang/include/clang/Sema/Sema.h clang/lib/Sema/SemaChecking.cpp clang/lib/Sema/SemaDeclAttr.cpp clang/test/CXX/drs/dr6xx.cpp clang/test/Sema/attr-aligned.c Removed: ################################################################################ diff --git a/clang/include/clang/Sema/Sema.h b/clang/include/clang/Sema/Sema.h index fae1ade80ca9..92d964d6603d 100644 --- a/clang/include/clang/Sema/Sema.h +++ b/clang/include/clang/Sema/Sema.h @@ -372,6 +372,15 @@ class Sema final { QualType ResultTy, ArrayRef<QualType> Args); + /// The maximum alignment, same as in llvm::Value. We duplicate them here + /// because that allows us not to duplicate the constants in clang code, + /// which we must to since we can't directly use the llvm constants. + /// + /// This is the greatest alignment value supported by load, store, and alloca + /// instructions, and global values. + static const unsigned MaxAlignmentExponent = 29; + static const unsigned MaximumAlignment = 1u << MaxAlignmentExponent; + public: typedef OpaquePtr<DeclGroupRef> DeclGroupPtrTy; typedef OpaquePtr<TemplateName> TemplateTy; diff --git a/clang/lib/Sema/SemaChecking.cpp b/clang/lib/Sema/SemaChecking.cpp index 4485539f3f1c..186f2b5b990c 100644 --- a/clang/lib/Sema/SemaChecking.cpp +++ b/clang/lib/Sema/SemaChecking.cpp @@ -3665,11 +3665,9 @@ void Sema::checkCall(NamedDecl *FDecl, const FunctionProtoType *Proto, return; } - // Alignment calculations can wrap around if it's greater than 2**29. - unsigned MaximumAlignment = 536870912; - if (I > MaximumAlignment) + if (I > Sema::MaximumAlignment) Diag(Arg->getExprLoc(), diag::warn_assume_aligned_too_great) - << Arg->getSourceRange() << MaximumAlignment; + << Arg->getSourceRange() << Sema::MaximumAlignment; } } } @@ -5394,11 +5392,9 @@ bool Sema::SemaBuiltinAssumeAligned(CallExpr *TheCall) { return Diag(TheCall->getBeginLoc(), diag::err_alignment_not_power_of_two) << Arg->getSourceRange(); - // Alignment calculations can wrap around if it's greater than 2**29. - unsigned MaximumAlignment = 536870912; - if (Result > MaximumAlignment) + if (Result > Sema::MaximumAlignment) Diag(TheCall->getBeginLoc(), diag::warn_assume_aligned_too_great) - << Arg->getSourceRange() << MaximumAlignment; + << Arg->getSourceRange() << Sema::MaximumAlignment; } if (NumArgs > 2) { diff --git a/clang/lib/Sema/SemaDeclAttr.cpp b/clang/lib/Sema/SemaDeclAttr.cpp index 8ad981f89b6e..e097ec0f1c59 100644 --- a/clang/lib/Sema/SemaDeclAttr.cpp +++ b/clang/lib/Sema/SemaDeclAttr.cpp @@ -1626,11 +1626,9 @@ void Sema::AddAssumeAlignedAttr(Decl *D, const AttributeCommonInfo &CI, Expr *E, return; } - // Alignment calculations can wrap around if it's greater than 2**29. - unsigned MaximumAlignment = 536870912; - if (I > MaximumAlignment) + if (I > Sema::MaximumAlignment) Diag(CI.getLoc(), diag::warn_assume_aligned_too_great) - << CI.getRange() << MaximumAlignment; + << CI.getRange() << Sema::MaximumAlignment; } if (OE) { @@ -3816,13 +3814,12 @@ void Sema::AddAlignedAttr(Decl *D, const AttributeCommonInfo &CI, Expr *E, } } - // Alignment calculations can wrap around if it's greater than 2**28. - unsigned MaxValidAlignment = - Context.getTargetInfo().getTriple().isOSBinFormatCOFF() ? 8192 - : 268435456; - if (AlignVal > MaxValidAlignment) { + unsigned MaximumAlignment = Sema::MaximumAlignment; + if (Context.getTargetInfo().getTriple().isOSBinFormatCOFF()) + MaximumAlignment = std::min(MaximumAlignment, 8192u); + if (AlignVal > MaximumAlignment) { Diag(AttrLoc, diag::err_attribute_aligned_too_great) - << MaxValidAlignment << E->getSourceRange(); + << MaximumAlignment << E->getSourceRange(); return; } diff --git a/clang/test/CXX/drs/dr6xx.cpp b/clang/test/CXX/drs/dr6xx.cpp index 6ff162545826..7a0adb5fe406 100644 --- a/clang/test/CXX/drs/dr6xx.cpp +++ b/clang/test/CXX/drs/dr6xx.cpp @@ -551,9 +551,9 @@ namespace dr648 { // dr648: yes #if __cplusplus >= 201103L namespace dr649 { // dr649: yes - alignas(0x20000000) int n; // expected-error {{requested alignment}} - struct alignas(0x20000000) X {}; // expected-error {{requested alignment}} - struct Y { int n alignas(0x20000000); }; // expected-error {{requested alignment}} + alignas(0x40000000) int n; // expected-error {{requested alignment}}1 + struct alignas(0x40000000) X {}; // expected-error {{requested alignment}} + struct Y { int n alignas(0x40000000); }; // expected-error {{requested alignment}} struct alignas(256) Z {}; // This part is superseded by dr2130 and eventually by aligned allocation support. auto *p = new Z; diff --git a/clang/test/Sema/attr-aligned.c b/clang/test/Sema/attr-aligned.c index b8d2fc6863d2..1d65ef41b810 100644 --- a/clang/test/Sema/attr-aligned.c +++ b/clang/test/Sema/attr-aligned.c @@ -1,14 +1,15 @@ // RUN: %clang_cc1 -triple i386-apple-darwin9 -fsyntax-only -verify %s int x __attribute__((aligned(3))); // expected-error {{requested alignment is not a power of 2}} -int y __attribute__((aligned(1 << 29))); // expected-error {{requested alignment must be 268435456 bytes or smaller}} +int y __attribute__((aligned(1 << 30))); // expected-error {{requested alignment must be 536870912 bytes or smaller}} // PR26444 +int y __attribute__((aligned(1 << 29))); int y __attribute__((aligned(1 << 28))); // PR3254 short g0[3] __attribute__((aligned)); -short g0_chk[__alignof__(g0) == 16 ? 1 : -1]; +short g0_chk[__alignof__(g0) == 16 ? 1 : -1]; // <rdar://problem/6840045> typedef char ueber_aligned_char __attribute__((aligned(8))); _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
