r371222 - [Diagnostics] Refactor code for -Wsizeof-pointer-div, catch more cases; also add -Wsizeof-array-div
Nico Weber via cfe-commits
cfe-commits at lists.llvm.org
Fri Sep 6 12:38:16 PDT 2019
This reports things like
error: expresion will return the incorrect number of elements in the array;
the array element type is 'const char *', not 'char *'
which doesn't look quite right...
On Fri, Sep 6, 2019 at 12:11 PM David Bolvansky via cfe-commits <
cfe-commits at lists.llvm.org> wrote:
> Author: xbolva00
> Date: Fri Sep 6 09:12:48 2019
> New Revision: 371222
>
> URL: http://llvm.org/viewvc/llvm-project?rev=371222&view=rev
> Log:
> [Diagnostics] Refactor code for -Wsizeof-pointer-div, catch more cases;
> also add -Wsizeof-array-div
>
> Previously, -Wsizeof-pointer-div failed to catch:
> const int *r;
> sizeof(r) / sizeof(int);
>
> Now fixed.
> Also introduced -Wsizeof-array-div which catches bugs like:
> sizeof(r) / sizeof(short);
>
> (Array element type does not match type of sizeof operand).
>
>
> Modified:
> cfe/trunk/include/clang/Basic/DiagnosticSemaKinds.td
> cfe/trunk/lib/Sema/SemaChecking.cpp
> cfe/trunk/lib/Sema/SemaExpr.cpp
> cfe/trunk/test/Sema/div-sizeof-ptr.cpp
>
> Modified: cfe/trunk/include/clang/Basic/DiagnosticSemaKinds.td
> URL:
> http://llvm.org/viewvc/llvm-project/cfe/trunk/include/clang/Basic/DiagnosticSemaKinds.td?rev=371222&r1=371221&r2=371222&view=diff
>
> ==============================================================================
> --- cfe/trunk/include/clang/Basic/DiagnosticSemaKinds.td (original)
> +++ cfe/trunk/include/clang/Basic/DiagnosticSemaKinds.td Fri Sep 6
> 09:12:48 2019
> @@ -3391,6 +3391,10 @@ def note_pointer_declared_here : Note<
> def warn_division_sizeof_ptr : Warning<
> "'%0' will return the size of the pointer, not the array itself">,
> InGroup<DiagGroup<"sizeof-pointer-div">>;
> +def warn_division_sizeof_array : Warning<
> + "expresion will return the incorrect number of elements in the array;
> the array "
> + "element type is %0, not %1">,
> + InGroup<DiagGroup<"sizeof-array-div">>;
>
> def note_function_warning_silence : Note<
> "prefix with the address-of operator to silence this warning">;
> @@ -8003,7 +8007,7 @@ def warn_array_index_precedes_bounds : W
> def warn_array_index_exceeds_bounds : Warning<
> "array index %0 is past the end of the array (which contains %1 "
> "element%s2)">, InGroup<ArrayBounds>;
> -def note_array_index_out_of_bounds : Note<
> +def note_array_declared_here : Note<
> "array %0 declared here">;
>
> def warn_printf_insufficient_data_args : Warning<
>
> Modified: cfe/trunk/lib/Sema/SemaChecking.cpp
> URL:
> http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Sema/SemaChecking.cpp?rev=371222&r1=371221&r2=371222&view=diff
>
> ==============================================================================
> --- cfe/trunk/lib/Sema/SemaChecking.cpp (original)
> +++ cfe/trunk/lib/Sema/SemaChecking.cpp Fri Sep 6 09:12:48 2019
> @@ -13008,7 +13008,7 @@ void Sema::CheckArrayAccess(const Expr *
>
> if (ND)
> DiagRuntimeBehavior(ND->getBeginLoc(), BaseExpr,
> - PDiag(diag::note_array_index_out_of_bounds)
> + PDiag(diag::note_array_declared_here)
> << ND->getDeclName());
> }
>
>
> Modified: cfe/trunk/lib/Sema/SemaExpr.cpp
> URL:
> http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Sema/SemaExpr.cpp?rev=371222&r1=371221&r2=371222&view=diff
>
> ==============================================================================
> --- cfe/trunk/lib/Sema/SemaExpr.cpp (original)
> +++ cfe/trunk/lib/Sema/SemaExpr.cpp Fri Sep 6 09:12:48 2019
> @@ -9135,7 +9135,7 @@ static void checkArithmeticNull(Sema &S,
> << LHS.get()->getSourceRange() << RHS.get()->getSourceRange();
> }
>
> -static void DiagnoseDivisionSizeofPointer(Sema &S, Expr *LHS, Expr *RHS,
> +static void DiagnoseDivisionSizeofPointerOrArray(Sema &S, Expr *LHS, Expr
> *RHS,
> SourceLocation Loc) {
> const auto *LUE = dyn_cast<UnaryExprOrTypeTraitExpr>(LHS);
> const auto *RUE = dyn_cast<UnaryExprOrTypeTraitExpr>(RHS);
> @@ -9154,16 +9154,29 @@ static void DiagnoseDivisionSizeofPointe
> else
> RHSTy = RUE->getArgumentExpr()->IgnoreParens()->getType();
>
> - if (!LHSTy->isPointerType() || RHSTy->isPointerType())
> - return;
> - if (LHSTy->getPointeeType().getCanonicalType() !=
> RHSTy.getCanonicalType())
> - return;
> -
> - S.Diag(Loc, diag::warn_division_sizeof_ptr) << LHS <<
> LHS->getSourceRange();
> - if (const auto *DRE = dyn_cast<DeclRefExpr>(LHSArg)) {
> - if (const ValueDecl *LHSArgDecl = DRE->getDecl())
> - S.Diag(LHSArgDecl->getLocation(), diag::note_pointer_declared_here)
> - << LHSArgDecl;
> + if (LHSTy->isPointerType() && !RHSTy->isPointerType()) {
> + if (LHSTy->getPointeeType().getCanonicalType().getUnqualifiedType() !=
> + RHSTy.getCanonicalType().getUnqualifiedType())
> + return;
> +
> + S.Diag(Loc, diag::warn_division_sizeof_ptr) << LHS <<
> LHS->getSourceRange();
> + if (const auto *DRE = dyn_cast<DeclRefExpr>(LHSArg)) {
> + if (const ValueDecl *LHSArgDecl = DRE->getDecl())
> + S.Diag(LHSArgDecl->getLocation(),
> diag::note_pointer_declared_here)
> + << LHSArgDecl;
> + }
> + } else if (isa<ArrayType>(LHSTy) && !RHSTy->isArrayType()) {
> + QualType ArrayElemTy = cast<ArrayType>(LHSTy)->getElementType();
> + if (isa<ArrayType>(ArrayElemTy) ||
> + ArrayElemTy.getCanonicalType().getUnqualifiedType() ==
> + RHSTy.getCanonicalType().getUnqualifiedType())
> + return;
> + S.Diag(Loc, diag::warn_division_sizeof_array) << ArrayElemTy << RHSTy;
> + if (const auto *DRE = dyn_cast<DeclRefExpr>(LHSArg)) {
> + if (const ValueDecl *LHSArgDecl = DRE->getDecl())
> + S.Diag(LHSArgDecl->getLocation(), diag::note_array_declared_here)
> + << LHSArgDecl;
> + }
> }
> }
>
> @@ -9200,7 +9213,7 @@ QualType Sema::CheckMultiplyDivideOperan
> return InvalidOperands(Loc, LHS, RHS);
> if (IsDiv) {
> DiagnoseBadDivideOrRemainderValues(*this, LHS, RHS, Loc, IsDiv);
> - DiagnoseDivisionSizeofPointer(*this, LHS.get(), RHS.get(), Loc);
> + DiagnoseDivisionSizeofPointerOrArray(*this, LHS.get(), RHS.get(),
> Loc);
> }
> return compType;
> }
>
> Modified: cfe/trunk/test/Sema/div-sizeof-ptr.cpp
> URL:
> http://llvm.org/viewvc/llvm-project/cfe/trunk/test/Sema/div-sizeof-ptr.cpp?rev=371222&r1=371221&r2=371222&view=diff
>
> ==============================================================================
> --- cfe/trunk/test/Sema/div-sizeof-ptr.cpp (original)
> +++ cfe/trunk/test/Sema/div-sizeof-ptr.cpp Fri Sep 6 09:12:48 2019
> @@ -7,18 +7,20 @@ int f(Ty (&Array)[N]) {
>
> typedef int int32;
>
> -void test(int *p, int **q) { // expected-note 5 {{pointer 'p'
> declared here}}
> - int a1 = sizeof(p) / sizeof(*p); // expected-warning {{'sizeof (p)'
> will return the size of the pointer, not the array itself}}
> - int a2 = sizeof p / sizeof *p; // expected-warning {{'sizeof p'
> will return the size of the pointer, not the array itself}}
> - int a3 = sizeof(p) / sizeof(int); // expected-warning {{'sizeof (p)'
> will return the size of the pointer, not the array itself}}
> - int a4 = sizeof(p) / sizeof(p[0]); // expected-warning {{'sizeof (p)'
> will return the size of the pointer, not the array itself}}
> +void test(int *p, int **q) { // expected-note 5 {{pointer 'p'
> declared here}}
> + const int *r; // expected-note {{pointer 'r'
> declared here}}
> + int a1 = sizeof(p) / sizeof(*p); // expected-warning {{'sizeof (p)'
> will return the size of the pointer, not the array itself}}
> + int a2 = sizeof p / sizeof *p; // expected-warning {{'sizeof p'
> will return the size of the pointer, not the array itself}}
> + int a3 = sizeof(p) / sizeof(int); // expected-warning {{'sizeof (p)'
> will return the size of the pointer, not the array itself}}
> + int a4 = sizeof(p) / sizeof(p[0]); // expected-warning {{'sizeof (p)'
> will return the size of the pointer, not the array itself}}
> int a5 = sizeof(p) / sizeof(int32); // expected-warning {{'sizeof (p)'
> will return the size of the pointer, not the array itself}}
> + int a6 = sizeof(r) / sizeof(int); // expected-warning {{'sizeof (r)'
> will return the size of the pointer, not the array itself}}
>
> int32 *d; // expected-note 2 {{pointer 'd'
> declared here}}
> - int a6 = sizeof(d) / sizeof(int32); // expected-warning {{'sizeof (d)'
> will return the size of the pointer, not the array itself}}
> - int a7 = sizeof(d) / sizeof(int); // expected-warning {{'sizeof (d)'
> will return the size of the pointer, not the array itself}}
> + int a7 = sizeof(d) / sizeof(int32); // expected-warning {{'sizeof (d)'
> will return the size of the pointer, not the array itself}}
> + int a8 = sizeof(d) / sizeof(int); // expected-warning {{'sizeof (d)'
> will return the size of the pointer, not the array itself}}
>
> - int a8 = sizeof(*q) / sizeof(**q); // expected-warning {{'sizeof (*q)'
> will return the size of the pointer, not the array itself}}
> + int a9 = sizeof(*q) / sizeof(**q); // expected-warning {{'sizeof (*q)'
> will return the size of the pointer, not the array itself}}
>
> // Should not warn
> int b1 = sizeof(int *) / sizeof(int);
>
>
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