[clang-tidy] Warn about arrays in bugprone-undefined-memory-manipulation

Adds basic support for arrays to non-trivial types.

Fixes #55579

Differential Revision: https://reviews.llvm.org/D127036

Author: FabianWolff

clang-tools-extra/clang-tidy/bugprone/UndefinedMemoryManipulationCheck.cpp

@@ -22,9 +22,14 @@ AST_MATCHER(CXXRecordDecl, isNotTriviallyCopyable) {
 } // namespace
 
 void UndefinedMemoryManipulationCheck::registerMatchers(MatchFinder *Finder) {
-  const auto NotTriviallyCopyableObject =
-      hasType(ast_matchers::hasCanonicalType(
-          pointsTo(cxxRecordDecl(isNotTriviallyCopyable()))));
+  const auto HasNotTriviallyCopyableDecl =
+      hasDeclaration(cxxRecordDecl(isNotTriviallyCopyable()));
+  const auto ArrayOfNotTriviallyCopyable =
+      arrayType(hasElementType(HasNotTriviallyCopyableDecl));
+  const auto NotTriviallyCopyableObject = hasType(hasCanonicalType(
+      anyOf(pointsTo(qualType(anyOf(HasNotTriviallyCopyableDecl,
+                                    ArrayOfNotTriviallyCopyable))),
+            ArrayOfNotTriviallyCopyable)));
 
   // Check whether destination object is not TriviallyCopyable.
   // Applicable to all three memory manipulation functions.

clang-tools-extra/test/clang-tidy/checkers/bugprone/undefined-memory-manipulation.cpp

@@ -126,6 +126,12 @@ void notTriviallyCopyable() {
   ::memmove(&p, &vb, sizeof(int));
   // CHECK-MESSAGES: :[[@LINE-1]]:3: warning: undefined behavior, source object type 'types::VirtualBase'
 
+  types::Copy ca[10];
+  memset(ca, 0, sizeof(ca));
+  // CHECK-MESSAGES: :[[@LINE-1]]:3: warning: undefined behavior, destination object type 'types::Copy[10]'
+  memset(&ca, 0, sizeof(ca));
+  // CHECK-MESSAGES: :[[@LINE-1]]:3: warning: undefined behavior, destination object type 'types::Copy[10]'
+
 #define MEMSET memset(&vf, 0, sizeof(int));
   MEMSET
   // CHECK-MESSAGES: :[[@LINE-1]]:3: warning: undefined behavior, destination object type 'types::VirtualFunc'
@@ -159,6 +165,17 @@ void notTriviallyCopyable() {
   // CHECK-MESSAGES: :[[@LINE-1]]:3: warning: undefined behavior, destination object type 'aliases::Copy2'
   memset(pc3, 0, sizeof(int));
   // CHECK-MESSAGES: :[[@LINE-1]]:3: warning: undefined behavior, destination object type 'Copy3'
+  using Copy3Arr = Copy3[5];
+  Copy3Arr c3a;
+  memset(c3a, 0, sizeof(c3a));
+  // CHECK-MESSAGES: :[[@LINE-1]]:3: warning: undefined behavior, destination object type 'Copy3Arr'
+  memset(&c3a, 0, sizeof(c3a));
+  // CHECK-MESSAGES: :[[@LINE-1]]:3: warning: undefined behavior, destination object type 'Copy3Arr'
+
+  typedef Copy3 Copy3Arr2[5];
+  Copy3Arr2 c3a2;
+  memset(c3a2, 0, sizeof(c3a2));
+  // CHECK-MESSAGES: :[[@LINE-1]]:3: warning: undefined behavior, destination object type 'Copy3Arr2'
 }
 
 void triviallyCopyable() {