Maybe we should teach Clang not to warn on shadowing if the declaration and all its uses come from the same macro expansion?
On Mon, Oct 7, 2013 at 4:51 PM, Ted Kremenek <[email protected]> wrote: > 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; > +} > > > _______________________________________________ > cfe-commits mailing list > [email protected] > http://lists.cs.uiuc.edu/mailman/listinfo/cfe-commits >
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