[-Wunsafe-buffer-usage] Enable fixits for const ptr array declarations

Author: jkorous-apple

clang/lib/Analysis/UnsafeBufferUsage.cpp

@@ -2478,22 +2478,6 @@ static FixItList fixVarDeclWithArray(const VarDecl *D, const ASTContext &Ctx,
     const QualType &ArrayEltT = CAT->getElementType();
     assert(!ArrayEltT.isNull() && "Trying to fix a non-array type variable!");
 
-    // For most types the transformation is simple:
-    //   T foo[10]; => std::array<T, 10> foo;
-    // Cv-specifiers are straigtforward:
-    //   const T foo[10]; => std::array<const T, 10> foo;
-    // Pointers are straightforward:
-    //   T * foo[10]; => std::array<T *, 10> foo;
-    //
-    // However, for const pointers the transformation is different:
-    //   T * const foo[10]; => const std::array<T *, 10> foo;
-    if (ArrayEltT->isPointerType() && ArrayEltT.isConstQualified()) {
-      DEBUG_NOTE_DECL_FAIL(D, " : const size array of const pointers");
-      // FIXME: implement the support
-      // FIXME: bail if the const pointer is a typedef
-      return {};
-    }
-
     const SourceLocation IdentifierLoc = getVarDeclIdentifierLoc(D);
 
     // Get the spelling of the element type as written in the source file

clang/test/SemaCXX/warn-unsafe-buffer-usage-debug.cpp

@@ -32,13 +32,6 @@ void foo() {
                         // debug-note{{safe buffers debug: gadget 'ULCArraySubscript' refused to produce a fix}}
 }
 
-void failed_decl(const int* out, unsigned idx) {
-  const int* const a[10] = {nullptr};  // expected-warning{{'a' is an unsafe buffer that does not perform bounds checks}} \
-              // debug-note{{safe buffers debug: failed to produce fixit for declaration 'a' : const size array of const pointers}}
-
-  out = a[idx];  // expected-note{{used in buffer access here}}
-}
-
 void failed_multiple_decl() {
   int *a = new int[4], b;  // expected-warning{{'a' is an unsafe pointer used for buffer access}} \
                           // debug-note{{safe buffers debug: failed to produce fixit for declaration 'a' : multiple VarDecls}}

clang/test/SemaCXX/warn-unsafe-buffer-usage-fixits-local-var-array.cpp

@@ -73,25 +73,22 @@ void local_array_ptr_to_const(unsigned idx, const int*& a) {
 
 void local_array_const_ptr(unsigned idx, int*& a) {
   int * const buffer[10] = {a};
-// CHECK-NOT: fix-it:"{{.*}}":{[[@LINE-1]]:.*-[[@LINE-1]]:.*}
-// FIXME: implement support
+// CHECK: fix-it:"{{.*}}":{[[@LINE-1]]:3-[[@LINE-1]]:25}:"std::array<int * const, 10> buffer"
 
   a = buffer[idx];
 }
 
 void local_array_const_ptr_via_typedef(unsigned idx, int*& a) {
   typedef int * const my_const_ptr;
   my_const_ptr buffer[10] = {a};
-// CHECK-NOT: fix-it:"{{.*}}":{[[@LINE-1]]:.*-[[@LINE-1]]:.*}
-// FIXME: implement support
+// CHECK: fix-it:"{{.*}}":{[[@LINE-1]]:3-[[@LINE-1]]:26}:"std::array<my_const_ptr, 10> buffer"
 
   a = buffer[idx];
 }
 
 void local_array_const_ptr_to_const(unsigned idx, const int*& a) {
   const int * const buffer[10] = {a};
-// CHECK-NOT: fix-it:"{{.*}}":{[[@LINE-1]]:.*-[[@LINE-1]]:.*}
-// FIXME: implement support
+// CHECK: fix-it:"{{.*}}":{[[@LINE-1]]:3-[[@LINE-1]]:31}:"std::array<const int * const, 10> buffer"
 
   a = buffer[idx];