From c93ba18c603b01ae0fff8915af9c1a36ec35511b Mon Sep 17 00:00:00 2001 From: Roger Ferrer Ibanez Date: Mon, 13 Mar 2017 13:18:21 +0000 Subject: [PATCH] When diagnosing taking address of packed members skip __unaligned-qualified expressions Given that we have already explicitly stated in the qualifier that the expression is __unaligned, it makes little sense to diagnose that the address of the packed member may not be aligned. Differential Revision: https://reviews.llvm.org/D30884 git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@297620 91177308-0d34-0410-b5e6-96231b3b80d8 --- lib/Sema/SemaChecking.cpp | 4 ++++ test/Sema/address-unaligned.c | 16 ++++++++++++++++ 2 files changed, 20 insertions(+) create mode 100644 test/Sema/address-unaligned.c diff --git a/lib/Sema/SemaChecking.cpp b/lib/Sema/SemaChecking.cpp index c15f4b9060..b34a1c146f 100644 --- a/lib/Sema/SemaChecking.cpp +++ b/lib/Sema/SemaChecking.cpp @@ -11851,6 +11851,10 @@ void Sema::RefersToMemberWithReducedAlignment( if (!ME) return; + // No need to check expressions with an __unaligned-qualified type. + if (E->getType().getQualifiers().hasUnaligned()) + return; + // For a chain of MemberExpr like "a.b.c.d" this list // will keep FieldDecl's like [d, c, b]. SmallVector ReverseMemberChain; diff --git a/test/Sema/address-unaligned.c b/test/Sema/address-unaligned.c new file mode 100644 index 0000000000..6719509051 --- /dev/null +++ b/test/Sema/address-unaligned.c @@ -0,0 +1,16 @@ +// RUN: %clang_cc1 -fsyntax-only -fms-extensions -verify %s +// expected-no-diagnostics + +typedef +struct __attribute__((packed)) S1 { + char c0; + int x; + char c1; +} S1; + +void bar(__unaligned int *); + +void foo(__unaligned S1* s1) +{ + bar(&s1->x); +} -- 2.40.0