r277787 - [Sema] Add sizeof diagnostics for bzero
David Majnemer via cfe-commits
cfe-commits at lists.llvm.org
Fri Aug 5 10:09:41 PDT 2016
On Thu, Aug 4, 2016 at 4:55 PM, Bruno Cardoso Lopes via cfe-commits <
cfe-commits at lists.llvm.org> wrote:
> Author: bruno
> Date: Thu Aug 4 18:55:22 2016
> New Revision: 277787
>
> URL: http://llvm.org/viewvc/llvm-project?rev=277787&view=rev
> Log:
> [Sema] Add sizeof diagnostics for bzero
>
> For memset (and others) we can get diagnostics like:
>
> struct stat { int x; };
> void foo(struct stat *stamps) {
> bzero(stamps, sizeof(stamps));
> memset(stamps, 0, sizeof(stamps));
> }
>
> t.c:7:28: warning: 'memset' call operates on objects of type 'struct
> stat' while the size is based on a different type 'struct stat *'
> [-Wsizeof-pointer-memaccess]
> memset(stamps, 0, sizeof(stamps));
> ~~~~~~ ^~~~~~
> t.c:7:28: note: did you mean to dereference the argument to 'sizeof'
> (and multiply it by the number of elements)?
> memset(stamps, 0, sizeof(stamps));
> ^~~~~~
>
> This patch implements the same class of warnings for bzero.
>
> Differential Revision: https://reviews.llvm.org/D22525
>
> rdar://problem/18963514
>
> Modified:
> cfe/trunk/lib/AST/Decl.cpp
> cfe/trunk/lib/Sema/SemaChecking.cpp
> cfe/trunk/test/SemaCXX/warn-memset-bad-sizeof.cpp
>
> Modified: cfe/trunk/lib/AST/Decl.cpp
> URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/AST/
> Decl.cpp?rev=277787&r1=277786&r2=277787&view=diff
> ============================================================
> ==================
> --- cfe/trunk/lib/AST/Decl.cpp (original)
> +++ cfe/trunk/lib/AST/Decl.cpp Thu Aug 4 18:55:22 2016
> @@ -3408,6 +3408,10 @@ unsigned FunctionDecl::getMemoryFunction
> case Builtin::BIstrlen:
> return Builtin::BIstrlen;
>
> + case Builtin::BI__builtin_bzero:
> + case Builtin::BIbzero:
> + return Builtin::BIbzero;
> +
> default:
> if (isExternC()) {
> if (FnInfo->isStr("memset"))
> @@ -3430,6 +3434,8 @@ unsigned FunctionDecl::getMemoryFunction
> return Builtin::BIstrndup;
> else if (FnInfo->isStr("strlen"))
> return Builtin::BIstrlen;
> + else if (FnInfo->isStr("bzero"))
> + return Builtin::BIbzero;
> }
> break;
> }
>
> Modified: cfe/trunk/lib/Sema/SemaChecking.cpp
> URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Sema/
> SemaChecking.cpp?rev=277787&r1=277786&r2=277787&view=diff
> ============================================================
> ==================
> --- cfe/trunk/lib/Sema/SemaChecking.cpp (original)
> +++ cfe/trunk/lib/Sema/SemaChecking.cpp Thu Aug 4 18:55:22 2016
> @@ -6179,13 +6179,15 @@ void Sema::CheckMemaccessArguments(const
>
> // It is possible to have a non-standard definition of memset. Validate
> // we have enough arguments, and if not, abort further checking.
> - unsigned ExpectedNumArgs = (BId == Builtin::BIstrndup ? 2 : 3);
> + unsigned ExpectedNumArgs =
> + (BId == Builtin::BIstrndup || Builtin::BIbzero ? 2 : 3);
>
This looks suspicious. Should it be (BId == Builtin::BIstrndup || Bld ==
Builtin::BIbzero ? 2 : 3);
> if (Call->getNumArgs() < ExpectedNumArgs)
> return;
>
> - unsigned LastArg = (BId == Builtin::BImemset ||
> + unsigned LastArg = (BId == Builtin::BImemset || BId == Builtin::BIbzero
> ||
> BId == Builtin::BIstrndup ? 1 : 2);
> - unsigned LenArg = (BId == Builtin::BIstrndup ? 1 : 2);
> + unsigned LenArg =
> + (BId == Builtin::BIbzero || BId == Builtin::BIstrndup ? 1 : 2);
> const Expr *LenExpr = Call->getArg(LenArg)->IgnoreParenImpCasts();
>
> if (CheckMemorySizeofForComparison(*this, LenExpr, FnName,
>
> Modified: cfe/trunk/test/SemaCXX/warn-memset-bad-sizeof.cpp
> URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/
> SemaCXX/warn-memset-bad-sizeof.cpp?rev=277787&r1=
> 277786&r2=277787&view=diff
> ============================================================
> ==================
> --- cfe/trunk/test/SemaCXX/warn-memset-bad-sizeof.cpp (original)
> +++ cfe/trunk/test/SemaCXX/warn-memset-bad-sizeof.cpp Thu Aug 4 18:55:22
> 2016
> @@ -1,5 +1,6 @@
> // RUN: %clang_cc1 -fsyntax-only -verify -Wno-sizeof-array-argument %s
> //
> +extern "C" void *bzero(void *, unsigned);
> extern "C" void *memset(void *, int, unsigned);
> extern "C" void *memmove(void *s1, const void *s2, unsigned n);
> extern "C" void *memcpy(void *s1, const void *s2, unsigned n);
> @@ -47,6 +48,19 @@ void f(Mat m, const Foo& const_foo, char
> memset(heap_buffer, 0, sizeof(heap_buffer)); // \
> // expected-warning {{'memset' call operates on objects of type
> 'char' while the size is based on a different type 'char *'}}
> expected-note{{did you mean to provide an explicit length?}}
>
> + bzero(&s, sizeof(&s)); // \
> + // expected-warning {{'bzero' call operates on objects of type 'S'
> while the size is based on a different type 'S *'}} expected-note{{did you
> mean to remove the addressof in the argument to 'sizeof' (and multiply it
> by the number of elements)?}}
> + bzero(ps, sizeof(ps)); // \
> + // expected-warning {{'bzero' call operates on objects of type 'S'
> while the size is based on a different type 'S *'}} expected-note{{did you
> mean to dereference the argument to 'sizeof' (and multiply it by the number
> of elements)?}}
> + bzero(ps2, sizeof(ps2)); // \
> + // expected-warning {{'bzero' call operates on objects of type 'S'
> while the size is based on a different type 'PS' (aka 'S *')}}
> expected-note{{did you mean to dereference the argument to 'sizeof' (and
> multiply it by the number of elements)?}}
> + bzero(ps2, sizeof(typeof(ps2))); // \
> + // expected-warning {{argument to 'sizeof' in 'bzero' call is the
> same pointer type}}
> + bzero(ps2, sizeof(PS)); // \
> + // expected-warning {{argument to 'sizeof' in 'bzero' call is the
> same pointer type}}
> + bzero(heap_buffer, sizeof(heap_buffer)); // \
> + // expected-warning {{'bzero' call operates on objects of type
> 'char' while the size is based on a different type 'char *'}}
> expected-note{{did you mean to provide an explicit length?}}
> +
> memcpy(&s, 0, sizeof(&s)); // \
> // expected-warning {{'memcpy' call operates on objects of type 'S'
> while the size is based on a different type 'S *'}} expected-note{{did you
> mean to remove the addressof in the argument to 'sizeof' (and multiply it
> by the number of elements)?}}
> memcpy(0, &s, sizeof(&s)); // \
> @@ -73,6 +87,21 @@ void f(Mat m, const Foo& const_foo, char
> memset(arr, 0, sizeof(arr));
> memset(parr, 0, sizeof(parr));
>
> + bzero((void*)&s, sizeof(&s));
> + bzero(&s, sizeof(s));
> + bzero(&s, sizeof(S));
> + bzero(&s, sizeof(const S));
> + bzero(&s, sizeof(volatile S));
> + bzero(&s, sizeof(volatile const S));
> + bzero(&foo, sizeof(CFoo));
> + bzero(&foo, sizeof(VFoo));
> + bzero(&foo, sizeof(CVFoo));
> + bzero(ps, sizeof(*ps));
> + bzero(ps2, sizeof(*ps2));
> + bzero(ps2, sizeof(typeof(*ps2)));
> + bzero(arr, sizeof(arr));
> + bzero(parr, sizeof(parr));
> +
> memcpy(&foo, &const_foo, sizeof(Foo));
> memcpy((void*)&s, 0, sizeof(&s));
> memcpy(0, (void*)&s, sizeof(&s));
> @@ -96,12 +125,17 @@ void f(Mat m, const Foo& const_foo, char
> int iarr[14];
> memset(&iarr[0], 0, sizeof iarr);
> memset(iarr, 0, sizeof iarr);
> + bzero(&iarr[0], sizeof iarr);
> + bzero(iarr, sizeof iarr);
>
> int* iparr[14];
> memset(&iparr[0], 0, sizeof iparr);
> memset(iparr, 0, sizeof iparr);
> + bzero(&iparr[0], sizeof iparr);
> + bzero(iparr, sizeof iparr);
>
> memset(m, 0, sizeof(Mat));
> + bzero(m, sizeof(Mat));
>
> // Copy to raw buffer shouldn't warn either
> memcpy(&foo, &arr, sizeof(Foo));
> @@ -114,12 +148,21 @@ void f(Mat m, const Foo& const_foo, char
> for (;;) {}
> &s;
> }), 0, sizeof(s));
> +
> + bzero(({
> + if (0) {}
> + while (0) {}
> + for (;;) {}
> + &s;
> + }), sizeof(s));
> }
>
> namespace ns {
> void memset(void* s, char c, int n);
> +void bzero(void* s, int n);
> void f(int* i) {
> memset(i, 0, sizeof(i));
> + bzero(i, sizeof(i));
> }
> }
>
>
>
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> cfe-commits at lists.llvm.org
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