From: Ted Kremenek <kremenek@apple.com>
Date: Mon, 7 Oct 2013 23:51:11 +0000 (+0000)
Subject: Suppress useless -Wshadow warning when using _mm* macros from emmintrin.h
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=185f156e41b38c2452dba7bb0ee44067f8d92538;p=clang

Suppress useless -Wshadow warning when using _mm* macros from emmintrin.h

Fixes <rdar://problem/10679282>.

I'm not completely satisfied with this patch.  Sprinkling "diagnostic ignored"
_Pragmas throughout this file is gross, but I couldn't suppress
it for the entire file.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@192143 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/lib/Headers/emmintrin.h b/lib/Headers/emmintrin.h
index 505773e388..9ab0a73aad 100644
--- a/lib/Headers/emmintrin.h
+++ b/lib/Headers/emmintrin.h
@@ -826,7 +826,9 @@ _mm_xor_si128(__m128i __a, __m128i __b)
 }
 
 #define _mm_slli_si128(a, count) __extension__ ({ \
+  _Pragma("clang diagnostic push") _Pragma("clang diagnostic ignored \"-Wshadow\""); \
   __m128i __a = (a); \
+   _Pragma("clang diagnostic pop"); \
   (__m128i)__builtin_ia32_pslldqi128(__a, (count)*8); })
 
 static __inline__ __m128i __attribute__((__always_inline__, __nodebug__))
@@ -891,7 +893,9 @@ _mm_sra_epi32(__m128i __a, __m128i __count)
 
 
 #define _mm_srli_si128(a, count) __extension__ ({ \
+  _Pragma("clang diagnostic push") _Pragma("clang diagnostic ignored \"-Wshadow\""); \
   __m128i __a = (a); \
+  _Pragma("clang diagnostic pop"); \
   (__m128i)__builtin_ia32_psrldqi128(__a, (count)*8); })
 
 static __inline__ __m128i __attribute__((__always_inline__, __nodebug__))
@@ -1280,20 +1284,26 @@ _mm_movemask_epi8(__m128i __a)
 }
 
 #define _mm_shuffle_epi32(a, imm) __extension__ ({ \
+  _Pragma("clang diagnostic push") _Pragma("clang diagnostic ignored \"-Wshadow\""); \
   __m128i __a = (a); \
+  _Pragma("clang diagnostic pop"); \
   (__m128i)__builtin_shufflevector((__v4si)__a, (__v4si) _mm_set1_epi32(0), \
                                    (imm) & 0x3, ((imm) & 0xc) >> 2, \
                                    ((imm) & 0x30) >> 4, ((imm) & 0xc0) >> 6); })
 
 #define _mm_shufflelo_epi16(a, imm) __extension__ ({ \
+  _Pragma("clang diagnostic push") _Pragma("clang diagnostic ignored \"-Wshadow\""); \
   __m128i __a = (a); \
+  _Pragma("clang diagnostic pop"); \
   (__m128i)__builtin_shufflevector((__v8hi)__a, (__v8hi) _mm_set1_epi16(0), \
                                    (imm) & 0x3, ((imm) & 0xc) >> 2, \
                                    ((imm) & 0x30) >> 4, ((imm) & 0xc0) >> 6, \
                                    4, 5, 6, 7); })
 
 #define _mm_shufflehi_epi16(a, imm) __extension__ ({ \
+  _Pragma("clang diagnostic push") _Pragma("clang diagnostic ignored \"-Wshadow\""); \
   __m128i __a = (a); \
+  _Pragma("clang diagnostic pop"); \
   (__m128i)__builtin_shufflevector((__v8hi)__a, (__v8hi) _mm_set1_epi16(0), \
                                    0, 1, 2, 3, \
                                    4 + (((imm) & 0x03) >> 0), \
@@ -1386,8 +1396,10 @@ _mm_movemask_pd(__m128d __a)
 }
 
 #define _mm_shuffle_pd(a, b, i) __extension__ ({ \
+  _Pragma("clang diagnostic push") _Pragma("clang diagnostic ignored \"-Wshadow\""); \
   __m128d __a = (a); \
   __m128d __b = (b); \
+  _Pragma("clang diagnostic pop"); \
   __builtin_shufflevector(__a, __b, (i) & 1, (((i) & 2) >> 1) + 2); })
 
 static __inline__ __m128 __attribute__((__always_inline__, __nodebug__))
diff --git a/test/Sema/warn-shadow.c b/test/Sema/warn-shadow.c
index 32aca8d612..a9979ff9d7 100644
--- a/test/Sema/warn-shadow.c
+++ b/test/Sema/warn-shadow.c
@@ -1,5 +1,7 @@
 // RUN: %clang_cc1 -verify -fsyntax-only -fblocks -Wshadow %s
 
+#include <emmintrin.h>
+
 int i;          // expected-note 3 {{previous declaration is here}}
 
 void foo() {
@@ -59,3 +61,11 @@ void rdar8883302() {
 void test8() {
   int bob; // expected-warning {{declaration shadows a variable in the global scope}}
 }
+
+// Test that using two macros from emmintrin do not cause a
+// useless -Wshadow warning.
+void rdar10679282() {
+  __m128i qf = _mm_setzero_si128();
+  qf = _mm_slli_si128(_mm_add_epi64(qf, _mm_srli_si128(qf, 8)), 8); // no-warning
+  (void) qf;
+}