r371222 - [Diagnostics] Refactor code for -Wsizeof-pointer-div, catch more cases; also add -Wsizeof-array-div

David Bolvansky via cfe-commits cfe-commits at lists.llvm.org
Fri Sep 6 09:12:48 PDT 2019


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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