Author: Yonghong Song Date: 2019-11-14T14:14:59-08:00 New Revision: dd16b3fe2559789adcdd7d4d0bfe2796897877a3
URL: https://github.com/llvm/llvm-project/commit/dd16b3fe2559789adcdd7d4d0bfe2796897877a3 DIFF: https://github.com/llvm/llvm-project/commit/dd16b3fe2559789adcdd7d4d0bfe2796897877a3.diff LOG: [BPF] Restrict preserve_access_index attribute to C only This patch is a follow-up for commit 4e2ce228ae79 [BPF] Add preserve_access_index attribute for record definition to restrict attribute for C only. A new test case is added to check for this restriction. Additional code polishing is done based on Aaron Ballman's suggestion in https://reviews.llvm.org/D69759/new/. Differential Revision: https://reviews.llvm.org/D70257 Added: clang/test/Sema/bpf-attr-preserve-access-index.cpp Modified: clang/include/clang/Basic/Attr.td clang/lib/CodeGen/CGExpr.cpp Removed: ################################################################################ diff --git a/clang/include/clang/Basic/Attr.td b/clang/include/clang/Basic/Attr.td index 91140c0ddf17..ce7ad2ceaac2 100644 --- a/clang/include/clang/Basic/Attr.td +++ b/clang/include/clang/Basic/Attr.td @@ -1584,6 +1584,7 @@ def BPFPreserveAccessIndex : InheritableAttr, let Spellings = [Clang<"preserve_access_index">]; let Subjects = SubjectList<[Record], ErrorDiag>; let Documentation = [BPFPreserveAccessIndexDocs]; + let LangOpts = [COnly]; } def WebAssemblyImportModule : InheritableAttr, diff --git a/clang/lib/CodeGen/CGExpr.cpp b/clang/lib/CodeGen/CGExpr.cpp index e32db8c56df9..384e8f72a619 100644 --- a/clang/lib/CodeGen/CGExpr.cpp +++ b/clang/lib/CodeGen/CGExpr.cpp @@ -3408,10 +3408,6 @@ static bool IsPreserveAIArrayBase(CodeGenFunction &CGF, const Expr *ArrayBase) { if (!ArrayBase || !CGF.getDebugInfo()) return false; - const auto *ImplicitCast = dyn_cast<ImplicitCastExpr>(ArrayBase); - if (!ImplicitCast) - return false; - // Only support base as either a MemberExpr or DeclRefExpr. // DeclRefExpr to cover cases like: // struct s { int a; int b[10]; }; @@ -3419,39 +3415,24 @@ static bool IsPreserveAIArrayBase(CodeGenFunction &CGF, const Expr *ArrayBase) { // p[1].a // p[1] will generate a DeclRefExpr and p[1].a is a MemberExpr. // p->b[5] is a MemberExpr example. - const Expr *E = ImplicitCast->getSubExpr(); - const auto *MemberCast = dyn_cast<MemberExpr>(E); - if (MemberCast) - return MemberCast->getMemberDecl()->hasAttr<BPFPreserveAccessIndexAttr>(); - - const auto *DeclRefCast = dyn_cast<DeclRefExpr>(E); - if (DeclRefCast) { - const VarDecl *VarDef = dyn_cast<VarDecl>(DeclRefCast->getDecl()); + const Expr *E = ArrayBase->IgnoreImpCasts(); + if (const auto *ME = dyn_cast<MemberExpr>(E)) + return ME->getMemberDecl()->hasAttr<BPFPreserveAccessIndexAttr>(); + + if (const auto *DRE = dyn_cast<DeclRefExpr>(E)) { + const auto *VarDef = dyn_cast<VarDecl>(DRE->getDecl()); if (!VarDef) return false; - const auto *PtrT = dyn_cast<PointerType>(VarDef->getType().getTypePtr()); + const auto *PtrT = VarDef->getType()->getAs<PointerType>(); if (!PtrT) return false; - const auto *PointeeT = PtrT->getPointeeType().getTypePtr(); - - // Peel off typedef's - const auto *TypedefT = dyn_cast<TypedefType>(PointeeT); - while (TypedefT) { - PointeeT = TypedefT->desugar().getTypePtr(); - TypedefT = dyn_cast<TypedefType>(PointeeT); - } - - // Not a typedef any more, it should be an elaborated type. - const auto ElaborateT = dyn_cast<ElaboratedType>(PointeeT); - if (!ElaborateT) - return false; - const auto *RecT = dyn_cast<RecordType>(ElaborateT->desugar().getTypePtr()); - if (!RecT) - return false; - - return RecT->getDecl()->hasAttr<BPFPreserveAccessIndexAttr>(); + const auto *PointeeT = PtrT->getPointeeType() + ->getUnqualifiedDesugaredType(); + if (const auto *RecT = dyn_cast<RecordType>(PointeeT)) + return RecT->getDecl()->hasAttr<BPFPreserveAccessIndexAttr>(); + return false; } return false; diff --git a/clang/test/Sema/bpf-attr-preserve-access-index.cpp b/clang/test/Sema/bpf-attr-preserve-access-index.cpp new file mode 100644 index 000000000000..4a88ec2eda3c --- /dev/null +++ b/clang/test/Sema/bpf-attr-preserve-access-index.cpp @@ -0,0 +1,9 @@ +// RUN: %clang_cc1 -x c++ -triple bpf-pc-linux-gnu -dwarf-version=4 -fsyntax-only -verify %s + +#define __reloc__ __attribute__((preserve_access_index)) + +struct t1 { + int a; + int b[4]; + int c:1; +} __reloc__; // expected-warning {{'preserve_access_index' attribute ignored}} _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
