[clang-tidy] Extend bugprone-sizeof-expression to check sizeof(pointers to structures)

Accidentally taking the size of a struct-pointer type or a value of this type
is more common than explicitly using the & operator for the value. This patch
extends the check to include these cases.

Differential Revision: https://reviews.llvm.org/D61260

llvm-svn: 360114

diff --git a/clang-tools-extra/clang-tidy/bugprone/SizeofExpressionCheck.cpp b/clang-tools-extra/clang-tidy/bugprone/SizeofExpressionCheck.cpp
index fb16195..bb23202 100644 (file)
--- a/clang-tools-extra/clang-tidy/bugprone/SizeofExpressionCheck.cpp
+++ b/clang-tools-extra/clang-tidy/bugprone/SizeofExpressionCheck.cpp
@@ -145,10 +145,17 @@ void SizeofExpressionCheck::registerMatchers(MatchFinder *Finder) {
       unaryOperator(hasOperatorName("&"),
                     hasUnaryOperand(ignoringParenImpCasts(expr(
                         hasType(qualType(hasCanonicalType(recordType())))))));
+  const auto PointerToStructType = type(hasUnqualifiedDesugaredType(
+      pointerType(pointee(recordType()))));
+  const auto PointerToStructExpr = expr(ignoringParenImpCasts(expr(
+      hasType(qualType(hasCanonicalType(PointerToStructType))),
+      unless(cxxThisExpr()))));
 
   Finder->addMatcher(
-      expr(sizeOfExpr(has(expr(ignoringParenImpCasts(
-               anyOf(ArrayCastExpr, PointerToArrayExpr, StructAddrOfExpr))))))
+      expr(anyOf(sizeOfExpr(has(expr(ignoringParenImpCasts(
+               anyOf(ArrayCastExpr, PointerToArrayExpr, StructAddrOfExpr,
+                     PointerToStructExpr))))),
+                            sizeOfExpr(has(PointerToStructType))))
           .bind("sizeof-pointer-to-aggregate"),
       this);
 

diff --git a/clang-tools-extra/test/clang-tidy/bugprone-sizeof-expression.cpp b/clang-tools-extra/test/clang-tidy/bugprone-sizeof-expression.cpp
index 57b73ea..b82becc 100644 (file)
--- a/clang-tools-extra/test/clang-tidy/bugprone-sizeof-expression.cpp
+++ b/clang-tools-extra/test/clang-tidy/bugprone-sizeof-expression.cpp
@@ -193,11 +193,15 @@ int Test5() {
     Array10* ptr;
   };
   typedef const MyStruct TMyStruct;
+  typedef const MyStruct *PMyStruct;
+  typedef TMyStruct *PMyStruct2;
 
   static TMyStruct kGlocalMyStruct = {};
   static TMyStruct volatile * kGlocalMyStructPtr = &kGlocalMyStruct;
 
   MyStruct S;
+  PMyStruct PS;
+  PMyStruct2 PS2;
   Array10 A10;
 
   int sum = 0;
@@ -225,6 +229,14 @@ int Test5() {
   // CHECK-MESSAGES: :[[@LINE-1]]:10: warning: suspicious usage of 'sizeof(A*)'; pointer to aggregate
   sum += sizeof(&S);
   // CHECK-MESSAGES: :[[@LINE-1]]:10: warning: suspicious usage of 'sizeof(A*)'; pointer to aggregate
+  sum += sizeof(MyStruct*);
+  // CHECK-MESSAGES: :[[@LINE-1]]:10: warning: suspicious usage of 'sizeof(A*)'; pointer to aggregate
+  sum += sizeof(PMyStruct);
+  // CHECK-MESSAGES: :[[@LINE-1]]:10: warning: suspicious usage of 'sizeof(A*)'; pointer to aggregate
+  sum += sizeof(PS);
+  // CHECK-MESSAGES: :[[@LINE-1]]:10: warning: suspicious usage of 'sizeof(A*)'; pointer to aggregate
+  sum += sizeof(PS2);
+  // CHECK-MESSAGES: :[[@LINE-1]]:10: warning: suspicious usage of 'sizeof(A*)'; pointer to aggregate
   sum += sizeof(&A10);
   // CHECK-MESSAGES: :[[@LINE-1]]:10: warning: suspicious usage of 'sizeof(A*)'; pointer to aggregate