Author: Akira Hatanaka Date: 2020-07-07T17:45:04-07:00 New Revision: 04027052a72f982c9e09472427ec7339415fb777
URL: https://github.com/llvm/llvm-project/commit/04027052a72f982c9e09472427ec7339415fb777 DIFF: https://github.com/llvm/llvm-project/commit/04027052a72f982c9e09472427ec7339415fb777.diff LOG: [Sema] Teach -Wcast-align to compute alignment of CXXThisExpr This fixes https://bugs.llvm.org/show_bug.cgi?id=46605. rdar://problem/65158878 Differential Revision: https://reviews.llvm.org/D83317 Added: Modified: clang/lib/Sema/SemaChecking.cpp clang/test/SemaCXX/warn-cast-align.cpp Removed: ################################################################################ diff --git a/clang/lib/Sema/SemaChecking.cpp b/clang/lib/Sema/SemaChecking.cpp index 77858b17d62c..efaf36a69306 100644 --- a/clang/lib/Sema/SemaChecking.cpp +++ b/clang/lib/Sema/SemaChecking.cpp @@ -13560,12 +13560,14 @@ static getBaseAlignmentAndOffsetFromLValue(const Expr *E, ASTContext &Ctx) { } case Stmt::MemberExprClass: { auto *ME = cast<MemberExpr>(E); - if (ME->isArrow()) - break; auto *FD = dyn_cast<FieldDecl>(ME->getMemberDecl()); if (!FD || FD->getType()->isReferenceType()) break; - auto P = getBaseAlignmentAndOffsetFromLValue(ME->getBase(), Ctx); + Optional<std::pair<CharUnits, CharUnits>> P; + if (ME->isArrow()) + P = getBaseAlignmentAndOffsetFromPtr(ME->getBase(), Ctx); + else + P = getBaseAlignmentAndOffsetFromLValue(ME->getBase(), Ctx); if (!P) break; const ASTRecordLayout &Layout = Ctx.getASTRecordLayout(FD->getParent()); @@ -13629,6 +13631,11 @@ static getBaseAlignmentAndOffsetFromPtr(const Expr *E, ASTContext &Ctx) { } break; } + case Stmt::CXXThisExprClass: { + auto *RD = E->getType()->getPointeeType()->getAsCXXRecordDecl(); + CharUnits Alignment = Ctx.getASTRecordLayout(RD).getNonVirtualAlignment(); + return std::make_pair(Alignment, CharUnits::Zero()); + } case Stmt::UnaryOperatorClass: { auto *UO = cast<UnaryOperator>(E); if (UO->getOpcode() == UO_AddrOf) diff --git a/clang/test/SemaCXX/warn-cast-align.cpp b/clang/test/SemaCXX/warn-cast-align.cpp index 53cd75fb1405..1e84ba9cd67a 100644 --- a/clang/test/SemaCXX/warn-cast-align.cpp +++ b/clang/test/SemaCXX/warn-cast-align.cpp @@ -44,9 +44,16 @@ void test1(void *P) { c = IntPtr(P); } +struct __attribute__((aligned(16))) AlignedS { + char m[16]; +}; + struct __attribute__((aligned(16))) A { char m0[16]; char m1[16]; + AlignedS *getAlignedS() { + return (AlignedS *)m1; + } }; struct B0 { @@ -92,6 +99,9 @@ struct __attribute__((aligned(16))) D4 : virtual D2 { struct D5 : virtual D0 { char m0[16]; + AlignedS *get() { + return (AlignedS *)m0; // expected-warning {{cast from 'char *' to 'AlignedS *'}} + } }; struct D6 : virtual D5 { _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits