C++: fix-it hints suggesting accessors for private fields
authorDavid Malcolm <dmalcolm@redhat.com>
Tue, 16 May 2017 19:52:26 +0000 (19:52 +0000)
committerDavid Malcolm <dmalcolm@gcc.gnu.org>
Tue, 16 May 2017 19:52:26 +0000 (19:52 +0000)
gcc/cp/ChangeLog:
* call.c (enforce_access): Add access_failure_info * param and use
it to record access failures.
* cp-tree.h (class access_failure_info): New class.
(enforce_access): Add access_failure_info * param, defaulting to
NULL.
(lookup_member): Likewise.
(locate_field_accessor): New function decl.
(perform_or_defer_access_check): Add access_failure_info * param,
defaulting to NULL.
* search.c (lookup_member): Add access_failure_info * param and
pass it on to call to perform_or_defer_access_check.
(matches_code_and_type_p): New function.
(field_access_p): New function.
(direct_accessor_p): New function.
(reference_accessor_p): New function.
(field_accessor_p): New function.
(struct locate_field_data): New struct.
(dfs_locate_field_accessor_pre): New function.
(locate_field_accessor): New function.
* semantics.c (perform_or_defer_access_check): Add
access_failure_info * param, and pass it on to call to
enforce_access.
* typeck.c (access_failure_info::record_access_failure): New method.
(access_failure_info::maybe_suggest_accessor): New method.
(finish_class_member_access_expr): Pass an access_failure_info
instance to the lookup_member call, and call its
maybe_suggest_accessor method afterwards.

gcc/testsuite/ChangeLog:
* g++.dg/other/accessor-fixits-1.C: New test case.
* g++.dg/other/accessor-fixits-2.C: New test case.
* g++.dg/other/accessor-fixits-3.C: New test case.
* g++.dg/other/accessor-fixits-4.C: New test case.

From-SVN: r248128

gcc/cp/ChangeLog
gcc/cp/call.c
gcc/cp/cp-tree.h
gcc/cp/search.c
gcc/cp/semantics.c
gcc/cp/typeck.c
gcc/testsuite/ChangeLog
gcc/testsuite/g++.dg/other/accessor-fixits-1.C [new file with mode: 0644]
gcc/testsuite/g++.dg/other/accessor-fixits-2.C [new file with mode: 0644]
gcc/testsuite/g++.dg/other/accessor-fixits-3.C [new file with mode: 0644]
gcc/testsuite/g++.dg/other/accessor-fixits-4.C [new file with mode: 0644]

index 228f0adb5aa05f8a5478230ef7e6b3c9db9a33c0..d659fb9b8f141a6968f46388e31c336de4e6166f 100644 (file)
@@ -1,3 +1,33 @@
+2017-05-16  David Malcolm  <dmalcolm@redhat.com>
+
+       * call.c (enforce_access): Add access_failure_info * param and use
+       it to record access failures.
+       * cp-tree.h (class access_failure_info): New class.
+       (enforce_access): Add access_failure_info * param, defaulting to
+       NULL.
+       (lookup_member): Likewise.
+       (locate_field_accessor): New function decl.
+       (perform_or_defer_access_check): Add access_failure_info * param,
+       defaulting to NULL.
+       * search.c (lookup_member): Add access_failure_info * param and
+       pass it on to call to perform_or_defer_access_check.
+       (matches_code_and_type_p): New function.
+       (field_access_p): New function.
+       (direct_accessor_p): New function.
+       (reference_accessor_p): New function.
+       (field_accessor_p): New function.
+       (struct locate_field_data): New struct.
+       (dfs_locate_field_accessor_pre): New function.
+       (locate_field_accessor): New function.
+       * semantics.c (perform_or_defer_access_check): Add
+       access_failure_info * param, and pass it on to call to
+       enforce_access.
+       * typeck.c (access_failure_info::record_access_failure): New method.
+       (access_failure_info::maybe_suggest_accessor): New method.
+       (finish_class_member_access_expr): Pass an access_failure_info
+       instance to the lookup_member call, and call its
+       maybe_suggest_accessor method afterwards.
+
 2017-05-16  Marek Polacek  <polacek@redhat.com>
 
        PR sanitizer/80536
index 1367344308fb3d2d3314cb943d18a3f0f71190d1..cc642025a7e1ca0f8e6ae61aeccd4d6907b5c33b 100644 (file)
@@ -6396,7 +6396,7 @@ build_op_delete_call (enum tree_code code, tree addr, tree size,
 
 bool
 enforce_access (tree basetype_path, tree decl, tree diag_decl,
-               tsubst_flags_t complain)
+               tsubst_flags_t complain, access_failure_info *afi)
 {
   gcc_assert (TREE_CODE (basetype_path) == TREE_BINFO);
 
@@ -6422,17 +6422,23 @@ enforce_access (tree basetype_path, tree decl, tree diag_decl,
              error ("%q#D is private within this context", diag_decl);
              inform (DECL_SOURCE_LOCATION (diag_decl),
                      "declared private here");
+             if (afi)
+               afi->record_access_failure (basetype_path, diag_decl);
            }
          else if (TREE_PROTECTED (decl))
            {
              error ("%q#D is protected within this context", diag_decl);
              inform (DECL_SOURCE_LOCATION (diag_decl),
                      "declared protected here");
+             if (afi)
+               afi->record_access_failure (basetype_path, diag_decl);
            }
          else
            {
              error ("%q#D is inaccessible within this context", diag_decl);
              inform (DECL_SOURCE_LOCATION (diag_decl), "declared here");
+             if (afi)
+               afi->record_access_failure (basetype_path, diag_decl);
            }
        }
       return false;
index 739ff184abb3e98b64f8b2a24cc85f691d071e3b..0efc5dbbe9b4f65b4023ffa0e7dafbc15224e154 100644 (file)
@@ -5758,8 +5758,30 @@ extern bool can_convert_arg                      (tree, tree, tree, int,
                                                 tsubst_flags_t);
 extern bool can_convert_arg_bad                        (tree, tree, tree, int,
                                                 tsubst_flags_t);
+
+/* A class for recording information about access failures (e.g. private
+   fields), so that we can potentially supply a fix-it hint about
+   an accessor (from a context in which the constness of the object
+   is known).  */
+
+class access_failure_info
+{
+ public:
+  access_failure_info () : m_was_inaccessible (false), m_basetype_path (NULL_TREE),
+    m_field_decl (NULL_TREE) {}
+
+  void record_access_failure (tree basetype_path, tree field_decl);
+  void maybe_suggest_accessor (bool const_p) const;
+
+ private:
+  bool m_was_inaccessible;
+  tree m_basetype_path;
+  tree m_field_decl;
+};
+
 extern bool enforce_access                     (tree, tree, tree,
-                                                tsubst_flags_t);
+                                                tsubst_flags_t,
+                                                access_failure_info *afi = NULL);
 extern void push_defarg_context                        (tree);
 extern void pop_defarg_context                 (void);
 extern tree convert_default_arg                        (tree, tree, tree, int,
@@ -6412,8 +6434,10 @@ extern tree lookup_fnfields_slot_nolazy          (tree, tree);
 extern int class_method_index_for_fn           (tree, tree);
 extern tree lookup_fnfields                    (tree, tree, int);
 extern tree lookup_member                      (tree, tree, int, bool,
-                                                tsubst_flags_t);
+                                                tsubst_flags_t,
+                                                access_failure_info *afi = NULL);
 extern tree lookup_member_fuzzy                (tree, tree, bool);
+extern tree locate_field_accessor              (tree, tree, bool);
 extern int look_for_overrides                  (tree, tree);
 extern void get_pure_virtuals                  (tree);
 extern void maybe_suppress_debug_info          (tree);
@@ -6468,7 +6492,8 @@ extern bool perform_access_checks (vec<deferred_access_check, va_gc> *,
                                   tsubst_flags_t);
 extern bool perform_deferred_access_checks     (tsubst_flags_t);
 extern bool perform_or_defer_access_check      (tree, tree, tree,
-                                                tsubst_flags_t);
+                                                tsubst_flags_t,
+                                                access_failure_info *afi = NULL);
 
 /* RAII sentinel to ensures that deferred access checks are popped before
   a function returns.  */
index fa72c47d4f7faafea8787dac53fb22bcb1e70dfc..61bdb93bd511ac9b57cbca85f7199f0d8b381809 100644 (file)
@@ -1232,11 +1232,13 @@ build_baselink (tree binfo, tree access_binfo, tree functions, tree optype)
 
    WANT_TYPE is 1 when we should only return TYPE_DECLs.
 
-   If nothing can be found return NULL_TREE and do not issue an error.  */
+   If nothing can be found return NULL_TREE and do not issue an error.
+
+   If non-NULL, failure information is written back to AFI.  */
 
 tree
 lookup_member (tree xbasetype, tree name, int protect, bool want_type,
-              tsubst_flags_t complain)
+              tsubst_flags_t complain, access_failure_info *afi)
 {
   tree rval, rval_binfo = NULL_TREE;
   tree type = NULL_TREE, basetype_path = NULL_TREE;
@@ -1337,7 +1339,7 @@ lookup_member (tree xbasetype, tree name, int protect, bool want_type,
       tree decl = is_overloaded_fn (rval) ? get_first_fn (rval) : rval;
       if (!DECL_NONSTATIC_MEMBER_FUNCTION_P (decl)
          && !perform_or_defer_access_check (basetype_path, decl, decl,
-                                            complain))
+                                            complain, afi))
        rval = error_mark_node;
     }
 
@@ -1993,6 +1995,238 @@ dfs_walk_once_accessible (tree binfo, bool friends_p,
   return rval;
 }
 
+/* Return true iff the code of T is CODE, and it has compatible
+   type with TYPE.  */
+
+static bool
+matches_code_and_type_p (tree t, enum tree_code code, tree type)
+{
+  if (TREE_CODE (t) != code)
+    return false;
+  if (!cxx_types_compatible_p (TREE_TYPE (t), type))
+    return false;
+  return true;
+}
+
+/* Subroutine of direct_accessor_p and reference_accessor_p.
+   Determine if COMPONENT_REF is a simple field lookup of this->FIELD_DECL.
+   We expect a tree of the form:
+            <component_ref:
+              <indirect_ref:S>
+                <nop_expr:P*
+                  <parm_decl (this)>
+                <field_decl (FIELD_DECL)>>>.  */
+
+static bool
+field_access_p (tree component_ref, tree field_decl, tree field_type)
+{
+  if (!matches_code_and_type_p (component_ref, COMPONENT_REF, field_type))
+    return false;
+
+  tree indirect_ref = TREE_OPERAND (component_ref, 0);
+  if (TREE_CODE (indirect_ref) != INDIRECT_REF)
+    return false;
+
+  tree ptr = STRIP_NOPS (TREE_OPERAND (indirect_ref, 0));
+  if (!is_this_parameter (ptr))
+    return false;
+
+  /* Must access the correct field.  */
+  if (TREE_OPERAND (component_ref, 1) != field_decl)
+    return false;
+  return true;
+}
+
+/* Subroutine of field_accessor_p.
+
+   Assuming that INIT_EXPR has already had its code and type checked,
+   determine if it is a simple accessor for FIELD_DECL
+   (of type FIELD_TYPE).
+
+   Specifically, a simple accessor within struct S of the form:
+       T get_field () { return m_field; }
+   should have a DECL_SAVED_TREE of the form:
+       <return_expr
+        <init_expr:T
+          <result_decl:T
+          <nop_expr:T
+            <component_ref:
+              <indirect_ref:S>
+                <nop_expr:P*
+                  <parm_decl (this)>
+                <field_decl (FIELD_DECL)>>>.  */
+
+static bool
+direct_accessor_p (tree init_expr, tree field_decl, tree field_type)
+{
+  tree result_decl = TREE_OPERAND (init_expr, 0);
+  if (!matches_code_and_type_p (result_decl, RESULT_DECL, field_type))
+    return false;
+
+  tree component_ref = STRIP_NOPS (TREE_OPERAND (init_expr, 1));
+  if (!field_access_p (component_ref, field_decl, field_type))
+    return false;
+
+  return true;
+}
+
+/* Subroutine of field_accessor_p.
+
+   Assuming that INIT_EXPR has already had its code and type checked,
+   determine if it is a "reference" accessor for FIELD_DECL
+   (of type FIELD_REFERENCE_TYPE).
+
+   Specifically, a simple accessor within struct S of the form:
+       T& get_field () { return m_field; }
+   should have a DECL_SAVED_TREE of the form:
+       <return_expr
+        <init_expr:T&
+          <result_decl:T&
+          <nop_expr: T&
+            <addr_expr: T*
+              <component_ref:T
+                <indirect_ref:S
+                  <nop_expr
+                    <parm_decl (this)>>
+                  <field (FIELD_DECL)>>>>>>.  */
+static bool
+reference_accessor_p (tree init_expr, tree field_decl, tree field_type,
+                     tree field_reference_type)
+{
+  tree result_decl = TREE_OPERAND (init_expr, 0);
+  if (!matches_code_and_type_p (result_decl, RESULT_DECL, field_reference_type))
+    return false;
+
+  tree field_pointer_type = build_pointer_type (field_type);
+  tree addr_expr = STRIP_NOPS (TREE_OPERAND (init_expr, 1));
+  if (!matches_code_and_type_p (addr_expr, ADDR_EXPR, field_pointer_type))
+    return false;
+
+  tree component_ref = STRIP_NOPS (TREE_OPERAND (addr_expr, 0));
+
+  if (!field_access_p (component_ref, field_decl, field_type))
+    return false;
+
+  return true;
+}
+
+/* Return true if FN is an accessor method for FIELD_DECL.
+   i.e. a method of the form { return FIELD; }, with no
+   conversions.
+
+   If CONST_P, then additionally require that FN be a const
+   method.  */
+
+static bool
+field_accessor_p (tree fn, tree field_decl, bool const_p)
+{
+  if (TREE_CODE (fn) != FUNCTION_DECL)
+    return false;
+
+  /* We don't yet support looking up static data, just fields.  */
+  if (TREE_CODE (field_decl) != FIELD_DECL)
+    return false;
+
+  tree fntype = TREE_TYPE (fn);
+  if (TREE_CODE (fntype) != METHOD_TYPE)
+    return false;
+
+  /* If the field is accessed via a const "this" argument, verify
+     that the "this" parameter is const.  */
+  if (const_p)
+    {
+      tree this_type = type_of_this_parm (fntype);
+      if (!TYPE_READONLY (this_type))
+       return false;
+    }
+
+  tree saved_tree = DECL_SAVED_TREE (fn);
+
+  if (saved_tree == NULL_TREE)
+    return false;
+
+  if (TREE_CODE (saved_tree) != RETURN_EXPR)
+    return false;
+
+  tree init_expr = TREE_OPERAND (saved_tree, 0);
+  if (TREE_CODE (init_expr) != INIT_EXPR)
+    return false;
+
+  /* Determine if this is a simple accessor within struct S of the form:
+       T get_field () { return m_field; }.  */
+   tree field_type = TREE_TYPE (field_decl);
+  if (cxx_types_compatible_p (TREE_TYPE (init_expr), field_type))
+    return direct_accessor_p (init_expr, field_decl, field_type);
+
+  /* Failing that, determine if it is an accessor of the form:
+       T& get_field () { return m_field; }.  */
+  tree field_reference_type = cp_build_reference_type (field_type, false);
+  if (cxx_types_compatible_p (TREE_TYPE (init_expr), field_reference_type))
+    return reference_accessor_p (init_expr, field_decl, field_type,
+                                field_reference_type);
+
+  return false;
+}
+
+/* Callback data for dfs_locate_field_accessor_pre.  */
+
+struct locate_field_data
+{
+  locate_field_data (tree field_decl_, bool const_p_)
+  : field_decl (field_decl_), const_p (const_p_) {}
+
+  tree field_decl;
+  bool const_p;
+};
+
+/* Return a FUNCTION_DECL that is an "accessor" method for DATA, a FIELD_DECL,
+   callable via binfo, if one exists, otherwise return NULL_TREE.
+
+   Callback for dfs_walk_once_accessible for use within
+   locate_field_accessor.  */
+
+static tree
+dfs_locate_field_accessor_pre (tree binfo, void *data)
+{
+  locate_field_data *lfd = (locate_field_data *)data;
+  tree type = BINFO_TYPE (binfo);
+
+  vec<tree, va_gc> *method_vec;
+  tree fn;
+  size_t i;
+
+  if (!CLASS_TYPE_P (type))
+    return NULL_TREE;
+
+  method_vec = CLASSTYPE_METHOD_VEC (type);
+  if (!method_vec)
+    return NULL_TREE;
+
+  for (i = 0; vec_safe_iterate (method_vec, i, &fn); ++i)
+    if (fn)
+      if (field_accessor_p (fn, lfd->field_decl, lfd->const_p))
+       return fn;
+
+  return NULL_TREE;
+}
+
+/* Return a FUNCTION_DECL that is an "accessor" method for FIELD_DECL,
+   callable via BASETYPE_PATH, if one exists, otherwise return NULL_TREE.  */
+
+tree
+locate_field_accessor (tree basetype_path, tree field_decl, bool const_p)
+{
+  if (TREE_CODE (basetype_path) != TREE_BINFO)
+    return NULL_TREE;
+
+  /* Walk the hierarchy, looking for a method of some base class that allows
+     access to the field.  */
+  locate_field_data lfd (field_decl, const_p);
+  return dfs_walk_once_accessible (basetype_path, /*friends=*/true,
+                                  dfs_locate_field_accessor_pre,
+                                  NULL, &lfd);
+}
+
 /* Check that virtual overrider OVERRIDER is acceptable for base function
    BASEFN. Issue diagnostic, and return zero, if unacceptable.  */
 
index ce2899b7aef29b3652c4a22f9bcabf613788425e..d3249fedd8d89131329a2f69ff020cc59c4b102b 100644 (file)
@@ -305,11 +305,13 @@ perform_deferred_access_checks (tsubst_flags_t complain)
 
 /* Defer checking the accessibility of DECL, when looked up in
    BINFO. DIAG_DECL is the declaration to use to print diagnostics.
-   Return value like perform_access_checks above.  */
+   Return value like perform_access_checks above.
+   If non-NULL, report failures to AFI.  */
 
 bool
 perform_or_defer_access_check (tree binfo, tree decl, tree diag_decl,
-                              tsubst_flags_t complain)
+                              tsubst_flags_t complain,
+                              access_failure_info *afi)
 {
   int i;
   deferred_access *ptr;
@@ -328,7 +330,7 @@ perform_or_defer_access_check (tree binfo, tree decl, tree diag_decl,
   /* If we are not supposed to defer access checks, just check now.  */
   if (ptr->deferring_access_checks_kind == dk_no_deferred)
     {
-      bool ok = enforce_access (binfo, decl, diag_decl, complain);
+      bool ok = enforce_access (binfo, decl, diag_decl, complain, afi);
       return (complain & tf_error) ? true : ok;
     }
 
index 46a6bf8df35291098534b8e9265934a309ef5142..8c94d20388773f0bd7724f153c87caf9e1f142c6 100644 (file)
@@ -2647,6 +2647,46 @@ check_template_keyword (tree decl)
     }
 }
 
+/* Record that an access failure occurred on BASETYPE_PATH attempting
+   to access FIELD_DECL.  */
+
+void
+access_failure_info::record_access_failure (tree basetype_path,
+                                           tree field_decl)
+{
+  m_was_inaccessible = true;
+  m_basetype_path = basetype_path;
+  m_field_decl = field_decl;
+}
+
+/* If an access failure was recorded, then attempt to locate an
+   accessor function for the pertinent field, and if one is
+   available, add a note and fix-it hint suggesting using it.  */
+
+void
+access_failure_info::maybe_suggest_accessor (bool const_p) const
+{
+  if (!m_was_inaccessible)
+    return;
+
+  tree accessor
+    = locate_field_accessor (m_basetype_path, m_field_decl, const_p);
+  if (!accessor)
+    return;
+
+  /* The accessor must itself be accessible for it to be a reasonable
+     suggestion.  */
+  if (!accessible_p (m_basetype_path, accessor, true))
+    return;
+
+  rich_location richloc (line_table, input_location);
+  pretty_printer pp;
+  pp_printf (&pp, "%s()", IDENTIFIER_POINTER (DECL_NAME (accessor)));
+  richloc.add_fixit_replace (pp_formatted_text (&pp));
+  inform_at_rich_loc (&richloc, "field %q#D can be accessed via %q#D",
+                     m_field_decl, accessor);
+}
+
 /* This function is called by the parser to process a class member
    access expression of the form OBJECT.NAME.  NAME is a node used by
    the parser to represent a name; it is not yet a DECL.  It may,
@@ -2829,8 +2869,11 @@ finish_class_member_access_expr (cp_expr object, tree name, bool template_p,
       else
        {
          /* Look up the member.  */
+         access_failure_info afi;
          member = lookup_member (access_path, name, /*protect=*/1,
-                                 /*want_type=*/false, complain);
+                                 /*want_type=*/false, complain,
+                                 &afi);
+         afi.maybe_suggest_accessor (TYPE_READONLY (object_type));
          if (member == NULL_TREE)
            {
              if (dependent_type_p (object_type))
index 29208f36b62945f5195aa24fd12da34b5f133b90..b3dd772e7da1089d8ffd981d221f3be2f8393a02 100644 (file)
@@ -1,3 +1,10 @@
+2017-05-16  David Malcolm  <dmalcolm@redhat.com>
+
+       * g++.dg/other/accessor-fixits-1.C: New test case.
+       * g++.dg/other/accessor-fixits-2.C: New test case.
+       * g++.dg/other/accessor-fixits-3.C: New test case.
+       * g++.dg/other/accessor-fixits-4.C: New test case.
+
 2017-05-16  Carl Love  <cel@us.ibm.com>
 
        * gcc.target/powerpc/builtins-3.c: New vec_mule, vec_mulo test cases.
diff --git a/gcc/testsuite/g++.dg/other/accessor-fixits-1.C b/gcc/testsuite/g++.dg/other/accessor-fixits-1.C
new file mode 100644 (file)
index 0000000..cc96b87
--- /dev/null
@@ -0,0 +1,178 @@
+// { dg-options "-fdiagnostics-show-caret" }
+
+class t1
+{
+public:
+  int get_color () const { return m_color; }
+  int get_shape () const { return m_shape; }
+
+private:
+  int m_color;
+
+protected:
+  int m_shape;
+};
+
+int test_access_t1_color (t1 &ref)
+{
+  return ref.m_color; // { dg-error ".int t1::m_color. is private within this context" }
+  /* { dg-begin-multiline-output "" }
+   return ref.m_color;
+              ^~~~~~~
+     { dg-end-multiline-output "" } */
+
+  // { dg-message "declared private here" "" { target *-*-* } 10 }
+  /* { dg-begin-multiline-output "" }
+   int m_color;
+       ^~~~~~~
+     { dg-end-multiline-output "" } */
+
+  // { dg-message "field .int t1::m_color. can be accessed via .int t1::get_color\\(\\) const." "" { target *-*-* } .-12 }
+  /* { dg-begin-multiline-output "" }
+   return ref.m_color;
+              ^~~~~~~
+              get_color()
+     { dg-end-multiline-output "" } */
+}
+
+int test_access_t1_shape (t1 &ref)
+{
+  return ref.m_shape; // { dg-error ".int t1::m_shape. is protected within this context" }
+  /* { dg-begin-multiline-output "" }
+   return ref.m_shape;
+              ^~~~~~~
+     { dg-end-multiline-output "" } */
+
+  // { dg-message "declared protected here" "" { target *-*-* } 13 }
+  /* { dg-begin-multiline-output "" }
+   int m_shape;
+       ^~~~~~~
+     { dg-end-multiline-output "" } */
+
+  // { dg-message "field .int t1::m_shape. can be accessed via .int t1::get_shape\\(\\) const." "" { target *-*-* } .-12 }
+  /* { dg-begin-multiline-output "" }
+   return ref.m_shape;
+              ^~~~~~~
+              get_shape()
+     { dg-end-multiline-output "" } */
+}
+
+int test_deref_t1_color (t1 *ptr)
+{
+  return ptr->m_color; // { dg-error ".int t1::m_color. is private within this context" }
+  /* { dg-begin-multiline-output "" }
+   return ptr->m_color;
+               ^~~~~~~
+     { dg-end-multiline-output "" } */
+
+
+  /* { dg-begin-multiline-output "" }
+   int m_color;
+       ^~~~~~~
+     { dg-end-multiline-output "" } */
+
+  // { dg-message "field .int t1::m_color. can be accessed via .int t1::get_color\\(\\) const." "" { target *-*-* } .-12 }
+  /* { dg-begin-multiline-output "" }
+   return ptr->m_color;
+               ^~~~~~~
+               get_color()
+     { dg-end-multiline-output "" } */
+}
+
+int test_deref_t1_shape (t1 *ptr)
+{
+  return ptr->m_shape; // { dg-error ".int t1::m_shape. is protected within this context" }
+  /* { dg-begin-multiline-output "" }
+   return ptr->m_shape;
+               ^~~~~~~
+     { dg-end-multiline-output "" } */
+
+
+  /* { dg-begin-multiline-output "" }
+   int m_shape;
+       ^~~~~~~
+     { dg-end-multiline-output "" } */
+
+  // { dg-message "field .int t1::m_shape. can be accessed via .int t1::get_shape\\(\\) const." "" { target *-*-* } .-12 }
+  /* { dg-begin-multiline-output "" }
+   return ptr->m_shape;
+               ^~~~~~~
+               get_shape()
+     { dg-end-multiline-output "" } */
+}
+
+/* Example of public inheritance.  */
+
+class t2 : public t1
+{
+};
+
+int test_deref_t2_color (t2 *ptr)
+{
+  return ptr->m_color; // { dg-error ".int t1::m_color. is private within this context" }
+  /* { dg-begin-multiline-output "" }
+   return ptr->m_color;
+               ^~~~~~~
+     { dg-end-multiline-output "" } */
+
+
+  /* { dg-begin-multiline-output "" }
+   int m_color;
+       ^~~~~~~
+     { dg-end-multiline-output "" } */
+
+  // { dg-message "field .int t1::m_color. can be accessed via .int t1::get_color\\(\\) const." "" { target *-*-* } .-12 }
+  /* { dg-begin-multiline-output "" }
+   return ptr->m_color;
+               ^~~~~~~
+               get_color()
+     { dg-end-multiline-output "" } */
+}
+
+/* Example of private inheritance.  */
+
+class t3 : private t1
+{
+};
+
+int test_deref_t3_color (t3 *ptr)
+{
+  return ptr->m_color; // { dg-error ".int t1::m_color. is private within this context" }
+  /* { dg-begin-multiline-output "" }
+   return ptr->m_color;
+               ^~~~~~~
+     { dg-end-multiline-output "" } */
+
+  /* { dg-begin-multiline-output "" }
+   int m_color;
+       ^~~~~~~
+     { dg-end-multiline-output "" } */
+
+  /* We shouldn't provide a fix-it hint for this case due to the
+     private inheritance.  */
+}
+
+/* Example of non-public "accessor".  */
+
+class t4
+{
+  int m_field;
+  int get_field () { return m_field; }
+};
+
+int test_deref_t4_field (t4 *ptr)
+{
+  return ptr->m_field; // { dg-error ".int t4::m_field. is private within this context" }
+  /* { dg-begin-multiline-output "" }
+   return ptr->m_field;
+               ^~~~~~~
+     { dg-end-multiline-output "" } */
+
+  /* { dg-begin-multiline-output "" }
+   int m_field;
+       ^~~~~~~
+     { dg-end-multiline-output "" } */
+
+  /* We shouldn't provide a fix-it hint for this case, as the accessor is
+     itself private.  */
+}
diff --git a/gcc/testsuite/g++.dg/other/accessor-fixits-2.C b/gcc/testsuite/g++.dg/other/accessor-fixits-2.C
new file mode 100644 (file)
index 0000000..e1a2b78
--- /dev/null
@@ -0,0 +1,104 @@
+// { dg-options "-fdiagnostics-show-caret" }
+
+/* Test of accessors that return references.  */
+
+class t1
+{
+public:
+  int& get_color () { return m_color; }
+  int& get_shape () { return m_shape; }
+
+private:
+  int m_color;
+
+protected:
+  int m_shape;
+};
+
+int test_access_t1_color (t1 &ref)
+{
+  return ref.m_color; // { dg-error ".int t1::m_color. is private within this context" }
+  /* { dg-begin-multiline-output "" }
+   return ref.m_color;
+              ^~~~~~~
+     { dg-end-multiline-output "" } */
+
+  // { dg-message "declared private here" "" { target *-*-* } 12 }
+  /* { dg-begin-multiline-output "" }
+   int m_color;
+       ^~~~~~~
+     { dg-end-multiline-output "" } */
+
+  // { dg-message "field .int t1::m_color. can be accessed via .int& t1::get_color\\(\\)." "" { target *-*-* } .-12 }
+  /* { dg-begin-multiline-output "" }
+   return ref.m_color;
+              ^~~~~~~
+              get_color()
+     { dg-end-multiline-output "" } */
+}
+
+int test_access_t1_shape (t1 &ref)
+{
+  return ref.m_shape; // { dg-error ".int t1::m_shape. is protected within this context" }
+  /* { dg-begin-multiline-output "" }
+   return ref.m_shape;
+              ^~~~~~~
+     { dg-end-multiline-output "" } */
+
+  // { dg-message "declared protected here" "" { target *-*-* } 15 }
+  /* { dg-begin-multiline-output "" }
+   int m_shape;
+       ^~~~~~~
+     { dg-end-multiline-output "" } */
+
+  // { dg-message "field .int t1::m_shape. can be accessed via .int& t1::get_shape\\(\\)." "" { target *-*-* } .-12 }
+  /* { dg-begin-multiline-output "" }
+   return ref.m_shape;
+              ^~~~~~~
+              get_shape()
+     { dg-end-multiline-output "" } */
+}
+
+int test_deref_t1_color (t1 *ptr)
+{
+  return ptr->m_color; // { dg-error ".int t1::m_color. is private within this context" }
+  /* { dg-begin-multiline-output "" }
+   return ptr->m_color;
+               ^~~~~~~
+     { dg-end-multiline-output "" } */
+
+
+  /* { dg-begin-multiline-output "" }
+   int m_color;
+       ^~~~~~~
+     { dg-end-multiline-output "" } */
+
+  // { dg-message "field .int t1::m_color. can be accessed via .int& t1::get_color\\(\\)." "" { target *-*-* } .-12 }
+  /* { dg-begin-multiline-output "" }
+   return ptr->m_color;
+               ^~~~~~~
+               get_color()
+     { dg-end-multiline-output "" } */
+}
+
+int test_deref_t1_shape (t1 *ptr)
+{
+  return ptr->m_shape; // { dg-error ".int t1::m_shape. is protected within this context" }
+  /* { dg-begin-multiline-output "" }
+   return ptr->m_shape;
+               ^~~~~~~
+     { dg-end-multiline-output "" } */
+
+
+  /* { dg-begin-multiline-output "" }
+   int m_shape;
+       ^~~~~~~
+     { dg-end-multiline-output "" } */
+
+  // { dg-message "field .int t1::m_shape. can be accessed via .int& t1::get_shape\\(\\)." "" { target *-*-* } .-12 }
+  /* { dg-begin-multiline-output "" }
+   return ptr->m_shape;
+               ^~~~~~~
+               get_shape()
+     { dg-end-multiline-output "" } */
+}
diff --git a/gcc/testsuite/g++.dg/other/accessor-fixits-3.C b/gcc/testsuite/g++.dg/other/accessor-fixits-3.C
new file mode 100644 (file)
index 0000000..27d2eb4
--- /dev/null
@@ -0,0 +1,15 @@
+class foo
+{
+public:
+  static foo& get_singleton () { return s_singleton; }
+
+private:
+  static foo s_singleton;
+};
+
+foo & test_access_singleton ()
+{
+  return foo::s_singleton; // { dg-error ".foo foo::s_singleton. is private within this context" }
+  // { dg-message "declared private here" "" { target *-*-* } 7 }
+  // We don't yet support generating a fix-it hint for this case.
+}
diff --git a/gcc/testsuite/g++.dg/other/accessor-fixits-4.C b/gcc/testsuite/g++.dg/other/accessor-fixits-4.C
new file mode 100644 (file)
index 0000000..c03dd4e
--- /dev/null
@@ -0,0 +1,48 @@
+// { dg-options "-fdiagnostics-show-caret" }
+
+class t1
+{
+public:
+  int& get_color () { return m_color; }
+  int& get_shape () { return m_shape; }
+
+private:
+  int m_color; // { dg-line color_decl }
+  int m_shape; // { dg-line shape_decl }
+};
+
+int test_const_ptr (const t1 *ptr)
+{
+  return ptr->m_color; // { dg-error ".int t1::m_color. is private within this context" }
+  /* { dg-begin-multiline-output "" }
+   return ptr->m_color;
+               ^~~~~~~
+     { dg-end-multiline-output "" } */
+
+  // { dg-message "declared private here" "" { target *-*-* } color_decl }
+  /* { dg-begin-multiline-output "" }
+   int m_color;
+       ^~~~~~~
+     { dg-end-multiline-output "" } */
+
+  /* We shouldn't issue a suggestion: the accessor is non-const, and we
+     only have a const ptr.  */
+}
+
+int test_const_reference (const t1 &ref)
+{
+  return ref.m_shape; // { dg-error ".int t1::m_shape. is private within this context" }
+  /* { dg-begin-multiline-output "" }
+   return ref.m_shape;
+              ^~~~~~~
+     { dg-end-multiline-output "" } */
+
+  // { dg-message "declared private here" "" { target *-*-* } shape_decl }
+  /* { dg-begin-multiline-output "" }
+   int m_shape;
+       ^~~~~~~
+     { dg-end-multiline-output "" } */
+
+  /* We shouldn't issue a suggestion: the accessor is non-const, and we
+     only have a const ptr.  */
+}