Author: Richard Smith Date: 2020-03-18T15:47:24-07:00 New Revision: f18233dad4669eaf59ca996dca79beae8d364247
URL: https://github.com/llvm/llvm-project/commit/f18233dad4669eaf59ca996dca79beae8d364247 DIFF: https://github.com/llvm/llvm-project/commit/f18233dad4669eaf59ca996dca79beae8d364247.diff LOG: Fix -fsanitize=array-bound to treat T[0] union members as flexible array members regardless of whether they're the last member of the union. Added: Modified: clang/lib/CodeGen/CGExpr.cpp clang/test/CodeGen/bounds-checking.c Removed: ################################################################################ diff --git a/clang/lib/CodeGen/CGExpr.cpp b/clang/lib/CodeGen/CGExpr.cpp index 6457852f1b6d..671ada019cec 100644 --- a/clang/lib/CodeGen/CGExpr.cpp +++ b/clang/lib/CodeGen/CGExpr.cpp @@ -866,8 +866,12 @@ void CodeGenFunction::EmitTypeCheck(TypeCheckKind TCK, SourceLocation Loc, static bool isFlexibleArrayMemberExpr(const Expr *E) { // For compatibility with existing code, we treat arrays of length 0 or // 1 as flexible array members. + // FIXME: This is inconsistent with the warning code in SemaChecking. Unify + // the two mechanisms. const ArrayType *AT = E->getType()->castAsArrayTypeUnsafe(); if (const auto *CAT = dyn_cast<ConstantArrayType>(AT)) { + // FIXME: Sema doesn't treat [1] as a flexible array member if the bound + // was produced by macro expansion. if (CAT->getSize().ugt(1)) return false; } else if (!isa<IncompleteArrayType>(AT)) @@ -880,6 +884,10 @@ static bool isFlexibleArrayMemberExpr(const Expr *E) { // FIXME: If the base type of the member expr is not FD->getParent(), // this should not be treated as a flexible array member access. if (const auto *FD = dyn_cast<FieldDecl>(ME->getMemberDecl())) { + // FIXME: Sema doesn't treat a T[1] union member as a flexible array + // member, only a T[0] or T[] member gets that treatment. + if (FD->getParent()->isUnion()) + return true; RecordDecl::field_iterator FI( DeclContext::decl_iterator(const_cast<FieldDecl *>(FD))); return ++FI == FD->getParent()->field_end(); diff --git a/clang/test/CodeGen/bounds-checking.c b/clang/test/CodeGen/bounds-checking.c index 2e6a08650dd9..15cef8c007a5 100644 --- a/clang/test/CodeGen/bounds-checking.c +++ b/clang/test/CodeGen/bounds-checking.c @@ -1,7 +1,7 @@ // RUN: %clang_cc1 -fsanitize=local-bounds -emit-llvm -triple x86_64-apple-darwin10 %s -o - | FileCheck %s // RUN: %clang_cc1 -fsanitize=local-bounds -fexperimental-new-pass-manager -emit-llvm -triple x86_64-apple-darwin10 %s -o - | FileCheck %s -// RUN: %clang_cc1 -fsanitize=array-bounds -O -fsanitize-trap=array-bounds -emit-llvm -triple x86_64-apple-darwin10 -DNO_DYNAMIC %s -o - | FileCheck %s -// RUN: %clang_cc1 -fsanitize=array-bounds -O -fsanitize-trap=array-bounds -fexperimental-new-pass-manager -emit-llvm -triple x86_64-apple-darwin10 -DNO_DYNAMIC %s -o - | FileCheck %s +// RUN: %clang_cc1 -fsanitize=array-bounds -O -fsanitize-trap=array-bounds -emit-llvm -triple x86_64-apple-darwin10 -DNO_DYNAMIC %s -o - | FileCheck %s --check-prefixes=CHECK,NONLOCAL +// RUN: %clang_cc1 -fsanitize=array-bounds -O -fsanitize-trap=array-bounds -fexperimental-new-pass-manager -emit-llvm -triple x86_64-apple-darwin10 -DNO_DYNAMIC %s -o - | FileCheck %s --check-prefixes=CHECK,NONLOCAL // // REQUIRES: x86-registered-target @@ -31,3 +31,21 @@ void f3() { // CHECK: call {{.*}} @llvm.trap a[2] = 1; } + +union U { int a[0]; int b[1]; int c[2]; }; + +// CHECK-LABEL: define {{.*}} @f4 +int f4(union U *u, int i) { + // a and b are treated as flexible array members. + // CHECK-NOT: @llvm.trap + return u->a[i] + u->b[i]; + // CHECK: } +} + +// CHECK-LABEL: define {{.*}} @f5 +int f5(union U *u, int i) { + // c is not a flexible array member. + // NONLOCAL: call {{.*}} @llvm.trap + return u->c[i]; + // CHECK: } +} _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
