From c93ba18c603b01ae0fff8915af9c1a36ec35511b Mon Sep 17 00:00:00 2001
From: Roger Ferrer Ibanez <roger.ferreribanez@arm.com>
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 c15f4b9060b..b34a1c146fc 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<FieldDecl *, 4> ReverseMemberChain;
diff --git a/test/Sema/address-unaligned.c b/test/Sema/address-unaligned.c
new file mode 100644
index 00000000000..6719509051b
--- /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);
+}
--
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