PR 62314: add ability to add fixit-hints to a diagnostic

This is the combination of two patches:
  [PATCH 01/02] PR/62314: add ability to add fixit-hints
  [PATCH 02/02] C FE: add fix-it hint for . vs ->

gcc/ChangeLog:
	PR 62314
	* diagnostic-show-locus.c (colorizer::set_fixit_hint): New.
	(class layout): Update comment
	(layout::print_any_fixits): New method.
	(layout::move_to_column): New method.
	(diagnostic_show_locus): Add call to layout.print_any_fixits.

gcc/c/ChangeLog:
	PR 62314
	* c-typeck.c (should_suggest_deref_p): New function.
	(build_component_ref): Special-case POINTER_TYPE when
	generating a "not a structure of union"  error message, and
	suggest a "->" rather than a ".", providing a fix-it hint.

gcc/testsuite/ChangeLog:
	PR 62314
	* gcc.dg/fixits.c: New file.
	* gcc.dg/plugin/diagnostic-test-show-locus-ascii-bw.c
	(test_fixit_insert): New.
	(test_fixit_remove): New.
	(test_fixit_replace): New.
	* gcc.dg/plugin/diagnostic-test-show-locus-ascii-color.c
	(test_fixit_insert): New.
	(test_fixit_remove): New.
	(test_fixit_replace): New.
	* gcc.dg/plugin/diagnostic_plugin_test_show_locus.c
	(test_show_locus): Add tests of rendering fixit hints.

libcpp/ChangeLog:
	PR 62314
	* include/line-map.h (source_range::intersects_line_p): New
	method.
	(rich_location::~rich_location): New.
	(rich_location::add_fixit_insert): New method.
	(rich_location::add_fixit_remove): New method.
	(rich_location::add_fixit_replace): New method.
	(rich_location::get_num_fixit_hints): New accessor.
	(rich_location::get_fixit_hint): New accessor.
	(rich_location::MAX_FIXIT_HINTS): New constant.
	(rich_location::m_num_fixit_hints): New field.
	(rich_location::m_fixit_hints): New field.
	(class fixit_hint): New class.
	(class fixit_insert): New class.
	(class fixit_remove): New class.
	(class fixit_replace): New class.
	* line-map.c (source_range::intersects_line_p): New method.
	(rich_location::rich_location): Add initialization of
	m_num_fixit_hints to both ctors.
	(rich_location::~rich_location): New.
	(rich_location::add_fixit_insert): New method.
	(rich_location::add_fixit_remove): New method.
	(rich_location::add_fixit_replace): New method.
	(fixit_insert::fixit_insert): New.
	(fixit_insert::~fixit_insert): New.
	(fixit_insert::affects_line_p): New.
	(fixit_remove::fixit_remove): New.
	(fixit_remove::affects_line_p): New.
	(fixit_replace::fixit_replace): New.
	(fixit_replace::~fixit_replace): New.
	(fixit_replace::affects_line_p): New.

From-SVN: r230674

3 files changed, 264 insertions, 2 deletions

diff --git a/libcpp/ChangeLog b/libcpp/ChangeLog
index ce294ae88..78a0d7c 100644
--- a/libcpp/ChangeLog
+++ b/libcpp/ChangeLog
@@ -1,3 +1,37 @@
+2015-11-20  David Malcolm  <dmalcolm@redhat.com>
+
+	PR 62314
+	* include/line-map.h (source_range::intersects_line_p): New
+	method.
+	(rich_location::~rich_location): New.
+	(rich_location::add_fixit_insert): New method.
+	(rich_location::add_fixit_remove): New method.
+	(rich_location::add_fixit_replace): New method.
+	(rich_location::get_num_fixit_hints): New accessor.
+	(rich_location::get_fixit_hint): New accessor.
+	(rich_location::MAX_FIXIT_HINTS): New constant.
+	(rich_location::m_num_fixit_hints): New field.
+	(rich_location::m_fixit_hints): New field.
+	(class fixit_hint): New class.
+	(class fixit_insert): New class.
+	(class fixit_remove): New class.
+	(class fixit_replace): New class.
+	* line-map.c (source_range::intersects_line_p): New method.
+	(rich_location::rich_location): Add initialization of
+	m_num_fixit_hints to both ctors.
+	(rich_location::~rich_location): New.
+	(rich_location::add_fixit_insert): New method.
+	(rich_location::add_fixit_remove): New method.
+	(rich_location::add_fixit_replace): New method.
+	(fixit_insert::fixit_insert): New.
+	(fixit_insert::~fixit_insert): New.
+	(fixit_insert::affects_line_p): New.
+	(fixit_remove::fixit_remove): New.
+	(fixit_remove::affects_line_p): New.
+	(fixit_replace::fixit_replace): New.
+	(fixit_replace::~fixit_replace): New.
+	(fixit_replace::affects_line_p): New.
+
 2015-11-19  Jakub Jelinek  <jakub@redhat.com>
 
 	PR preprocessor/60736
diff --git a/libcpp/include/line-map.h b/libcpp/include/line-map.h
index e7608f1..4f440fa 100644
--- a/libcpp/include/line-map.h
+++ b/libcpp/include/line-map.h
@@ -299,6 +299,9 @@ struct GTY(()) source_range
     result.m_finish = loc;
     return result;
   }
+
+  /* Is there any part of this range on the given line?  */
+  bool intersects_line_p (const char *file, int line) const;
 };
 
 /* Memory allocation function typedef.  Works like xrealloc.  */
@@ -1267,6 +1270,11 @@ struct location_range
   expanded_location m_caret;
 };
 
+class fixit_hint;
+  class fixit_insert;
+  class fixit_remove;
+  class fixit_replace;
+
 /* A "rich" source code location, for use when printing diagnostics.
    A rich_location has one or more ranges, each optionally with
    a caret.   Typically the zeroth range has a caret; other ranges
@@ -1349,6 +1357,9 @@ class rich_location
   /* Constructing from a source_range.  */
   rich_location (source_range src_range);
 
+  /* Destructor.  */
+  ~rich_location ();
+
   /* Accessors.  */
   source_location get_loc () const { return m_loc; }
 
@@ -1381,8 +1392,24 @@ class rich_location
   void
   override_column (int column);
 
+  /* Fix-it hints.  */
+  void
+  add_fixit_insert (source_location where,
+		    const char *new_content);
+
+  void
+  add_fixit_remove (source_range src_range);
+
+  void
+  add_fixit_replace (source_range src_range,
+		     const char *new_content);
+
+  unsigned int get_num_fixit_hints () const { return m_num_fixit_hints; }
+  fixit_hint *get_fixit_hint (int idx) const { return m_fixit_hints[idx]; }
+
 public:
   static const int MAX_RANGES = 3;
+  static const int MAX_FIXIT_HINTS = 2;
 
 protected:
   source_location m_loc;
@@ -1392,8 +1419,77 @@ protected:
 
   bool m_have_expanded_location;
   expanded_location m_expanded_location;
+
+  unsigned int m_num_fixit_hints;
+  fixit_hint *m_fixit_hints[MAX_FIXIT_HINTS];
+};
+
+class fixit_hint
+{
+public:
+  enum kind {INSERT, REMOVE, REPLACE};
+
+  virtual ~fixit_hint () {}
+
+  virtual enum kind get_kind () const = 0;
+  virtual bool affects_line_p (const char *file, int line) = 0;
+};
+
+class fixit_insert : public fixit_hint
+{
+ public:
+  fixit_insert (source_location where,
+		const char *new_content);
+  ~fixit_insert ();
+  enum kind get_kind () const { return INSERT; }
+  bool affects_line_p (const char *file, int line);
+
+  source_location get_location () const { return m_where; }
+  const char *get_string () const { return m_bytes; }
+  size_t get_length () const { return m_len; }
+
+ private:
+  source_location m_where;
+  char *m_bytes;
+  size_t m_len;
+};
+
+class fixit_remove : public fixit_hint
+{
+ public:
+  fixit_remove (source_range src_range);
+  ~fixit_remove () {}
+
+  enum kind get_kind () const { return REMOVE; }
+  bool affects_line_p (const char *file, int line);
+
+  source_range get_range () const { return m_src_range; }
+
+ private:
+  source_range m_src_range;
 };
 
+class fixit_replace : public fixit_hint
+{
+ public:
+  fixit_replace (source_range src_range,
+                 const char *new_content);
+  ~fixit_replace ();
+
+  enum kind get_kind () const { return REPLACE; }
+  bool affects_line_p (const char *file, int line);
+
+  source_range get_range () const { return m_src_range; }
+  const char *get_string () const { return m_bytes; }
+  size_t get_length () const { return m_len; }
+
+ private:
+  source_range m_src_range;
+  char *m_bytes;
+  size_t m_len;
+};
+
+
 /* This is enum is used by the function linemap_resolve_location
    below.  The meaning of the values is explained in the comment of
    that function.  */
diff --git a/libcpp/line-map.c b/libcpp/line-map.c
index c5aa422..4284303 100644
--- a/libcpp/line-map.c
+++ b/libcpp/line-map.c
@@ -1947,6 +1947,28 @@ line_table_dump (FILE *stream, struct line_maps *set, unsigned int num_ordinary,
     }
 }
 
+/* struct source_range.  */
+
+/* Is there any part of this range on the given line?  */
+
+bool
+source_range::intersects_line_p (const char *file, int line) const
+{
+  expanded_location exploc_start
+    = linemap_client_expand_location_to_spelling_point (m_start);
+  if (file != exploc_start.file)
+    return false;
+  if (line < exploc_start.line)
+      return false;
+  expanded_location exploc_finish
+    = linemap_client_expand_location_to_spelling_point (m_finish);
+  if (file != exploc_finish.file)
+    return false;
+  if (line > exploc_finish.line)
+      return false;
+  return true;
+}
+
 /* class rich_location.  */
 
 /* Construct a rich_location with location LOC as its initial range.  */
@@ -1954,7 +1976,8 @@ line_table_dump (FILE *stream, struct line_maps *set, unsigned int num_ordinary,
 rich_location::rich_location (line_maps *set, source_location loc) :
   m_loc (loc),
   m_num_ranges (0),
-  m_have_expanded_location (false)
+  m_have_expanded_location (false),
+  m_num_fixit_hints (0)
 {
   /* Set up the 0th range, extracting any range from LOC.  */
   source_range src_range = get_range_from_loc (set, loc);
@@ -1968,12 +1991,21 @@ rich_location::rich_location (line_maps *set, source_location loc) :
 rich_location::rich_location (source_range src_range)
 : m_loc (src_range.m_start),
   m_num_ranges (0),
-  m_have_expanded_location (false)
+  m_have_expanded_location (false),
+  m_num_fixit_hints (0)
 {
   /* Set up the 0th range: */
   add_range (src_range, true);
 }
 
+/* The destructor for class rich_location.  */
+
+rich_location::~rich_location ()
+{
+  for (unsigned int i = 0; i < m_num_fixit_hints; i++)
+    delete m_fixit_hints[i];
+}
+
 /* Get an expanded_location for this rich_location's primary
    location.  */
 
@@ -2077,3 +2109,103 @@ rich_location::set_range (unsigned int idx, source_range src_range,
       m_have_expanded_location = false;
     }
 }
+
+/* Add a fixit-hint, suggesting insertion of NEW_CONTENT
+   at WHERE.  */
+
+void
+rich_location::add_fixit_insert (source_location where,
+				 const char *new_content)
+{
+  linemap_assert (m_num_fixit_hints < MAX_FIXIT_HINTS);
+  m_fixit_hints[m_num_fixit_hints++]
+    = new fixit_insert (where, new_content);
+}
+
+/* Add a fixit-hint, suggesting removal of the content at
+   SRC_RANGE.  */
+
+void
+rich_location::add_fixit_remove (source_range src_range)
+{
+  linemap_assert (m_num_fixit_hints < MAX_FIXIT_HINTS);
+  m_fixit_hints[m_num_fixit_hints++] = new fixit_remove (src_range);
+}
+
+/* Add a fixit-hint, suggesting replacement of the content at
+   SRC_RANGE with NEW_CONTENT.  */
+
+void
+rich_location::add_fixit_replace (source_range src_range,
+				  const char *new_content)
+{
+  linemap_assert (m_num_fixit_hints < MAX_FIXIT_HINTS);
+  m_fixit_hints[m_num_fixit_hints++]
+    = new fixit_replace (src_range, new_content);
+}
+
+/* class fixit_insert.  */
+
+fixit_insert::fixit_insert (source_location where,
+			    const char *new_content)
+: m_where (where),
+  m_bytes (xstrdup (new_content)),
+  m_len (strlen (new_content))
+{
+}
+
+fixit_insert::~fixit_insert ()
+{
+  free (m_bytes);
+}
+
+/* Implementation of fixit_hint::affects_line_p for fixit_insert.  */
+
+bool
+fixit_insert::affects_line_p (const char *file, int line)
+{
+  expanded_location exploc
+    = linemap_client_expand_location_to_spelling_point (m_where);
+  if (file == exploc.file)
+    if (line == exploc.line)
+      return true;
+  return false;
+}
+
+/* class fixit_remove.  */
+
+fixit_remove::fixit_remove (source_range src_range)
+: m_src_range (src_range)
+{
+}
+
+/* Implementation of fixit_hint::affects_line_p for fixit_remove.  */
+
+bool
+fixit_remove::affects_line_p (const char *file, int line)
+{
+  return m_src_range.intersects_line_p (file, line);
+}
+
+/* class fixit_replace.  */
+
+fixit_replace::fixit_replace (source_range src_range,
+			      const char *new_content)
+: m_src_range (src_range),
+  m_bytes (xstrdup (new_content)),
+  m_len (strlen (new_content))
+{
+}
+
+fixit_replace::~fixit_replace ()
+{
+  free (m_bytes);
+}
+
+/* Implementation of fixit_hint::affects_line_p for fixit_replace.  */
+
+bool
+fixit_replace::affects_line_p (const char *file, int line)
+{
+  return m_src_range.intersects_line_p (file, line);
+}