r192143 - Suppress useless -Wshadow warning when using _mm* macros from emmintrin.h

[Ted Kremenek]

Author: kremenek
Date: Mon Oct  7 18:51:11 2013
New Revision: 192143

URL: http://llvm.org/viewvc/llvm-project?rev=192143&view=rev
Log:
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.

Modified:
    cfe/trunk/lib/Headers/emmintrin.h
    cfe/trunk/test/Sema/warn-shadow.c

Modified: cfe/trunk/lib/Headers/emmintrin.h
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Headers/emmintrin.h?rev=192143&r1=192142&r2=192143&view=diff
==============================================================================
--- cfe/trunk/lib/Headers/emmintrin.h (original)
+++ cfe/trunk/lib/Headers/emmintrin.h Mon Oct  7 18:51:11 2013
@@ -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 __cou
 
 
 #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__))

Modified: cfe/trunk/test/Sema/warn-shadow.c
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/Sema/warn-shadow.c?rev=192143&r1=192142&r2=192143&view=diff
==============================================================================
--- cfe/trunk/test/Sema/warn-shadow.c (original)
+++ cfe/trunk/test/Sema/warn-shadow.c Mon Oct  7 18:51:11 2013
@@ -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;
+}