[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).



git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@371222 91177308-0d34-0410-b5e6-96231b3b80d8

2 files changed, 25 insertions, 12 deletions

diff --git a/lib/Sema/SemaChecking.cpp b/lib/Sema/SemaChecking.cpp
index b060ec73da..7d17b0ecd4 100644
--- a/lib/Sema/SemaChecking.cpp
+++ b/lib/Sema/SemaChecking.cpp
@@ -13008,7 +13008,7 @@ void Sema::CheckArrayAccess(const Expr *BaseExpr, const Expr *IndexExpr,
 
   if (ND)
     DiagRuntimeBehavior(ND->getBeginLoc(), BaseExpr,
-                        PDiag(diag::note_array_index_out_of_bounds)
+                        PDiag(diag::note_array_declared_here)
                             << ND->getDeclName());
 }
 
diff --git a/lib/Sema/SemaExpr.cpp b/lib/Sema/SemaExpr.cpp
index b5ad208e99..ca7cf94f9c 100644
--- a/lib/Sema/SemaExpr.cpp
+++ b/lib/Sema/SemaExpr.cpp
@@ -9135,7 +9135,7 @@ static void checkArithmeticNull(Sema &S, ExprResult &LHS, ExprResult &RHS,
       << 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 DiagnoseDivisionSizeofPointer(Sema &S, Expr *LHS, Expr *RHS,
   else
     RHSTy = RUE->getArgumentExpr()->IgnoreParens()->getType();
 
-  if (!LHSTy->isPointerType() || RHSTy->isPointerType())
-    return;
-  if (LHSTy->getPointeeType().getCanonicalType() != RHSTy.getCanonicalType())
-    return;
+  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;
+    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::CheckMultiplyDivideOperands(ExprResult &LHS, ExprResult &RHS,
     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;
 }