Remove arbitrary limits from rich_location

This patch eliminates the hard-coded limits within rich_location
(up to 3 ranges, up to 2 fixits).  The common case is still
handled by embedding the values inside rich_location - it only
uses dynamic allocation if these limits are exceeded, so
creation of rich_location instances on the stack should still
be fast.  This is implemented via a new container class,
semi_embedded_vec <T, N>.

gcc/ChangeLog:
	* diagnostic-show-locus.c (colorizer::begin_state): Support more
	than 3 ranges per diagnostic by alternating between color 1 and
	color 2.
	(layout::layout): Replace use of rich_location::MAX_RANGES
	with richloc->get_num_locations ().
	(layout::calculate_line_spans): Replace use of
	rich_location::MAX_RANGES with m_layout_ranges.length ().
	(layout::print_annotation_line): Handle arbitrary numbers of
	ranges in caret-printing by defaulting to '^'.
	(selftest::test_one_liner_many_fixits): New function.
	(test_diagnostic_show_locus_one_liner): Call it.
	* diagnostic.c (diagnostic_initialize): Update for renaming
	of rich_location::MAX_RANGES to
	rich_location::STATICALLY_ALLOCATED_RANGES.
	* diagnostic.h (struct diagnostic_context): Likewise.

gcc/testsuite/ChangeLog:
	* gcc.dg/plugin/diagnostic-test-show-locus-bw.c
	(test_many_nested_locations): New function.
	* gcc.dg/plugin/diagnostic_plugin_test_show_locus.c
	(test_show_locus): Handle "test_many_nested_locations".

libcpp/ChangeLog:
	* include/line-map.h (class semi_embedded_vec): New class.
	(semi_embedded_vec<T, NUM_EMBEDDED>::semi_embedded_vec): New ctor.
	(semi_embedded_vec<T, NUM_EMBEDDED>::~semi_embedded_vec): New
	dtor.
	(semi_embedded_vec<T, NUM_EMBEDDED>::operator[]): New methods.
	(semi_embedded_vec<T, NUM_EMBEDDED>::push): New method.
	(semi_embedded_vec<T, NUM_EMBEDDED>::truncate): New method.
	(rich_location::get_num_locations): Reimplement in terms of
	m_ranges.
	(rich_location::get_range): Make non-inline.
	(rich_location::get_num_fixit_hints): Reimplement in terms of
	m_fixit_hints.
	(rich_location::add_fixit): New function.
	(rich_location::MAX_RANGES): Rename to...
	(rich_location::STATICALLY_ALLOCATED_RANGES): ...this.
	(rich_location::MAX_FIXIT_HINTS): Rename to...
	(rich_location::STATICALLY_ALLOCATED_RANGES): ...this, and make
	private.
	(rich_location::m_num_ranges): Eliminate in favor of...
	(rich_location::m_ranges): ...this, converting from a fixed-size
	array to a semi_embedded_vec.
	(rich_location::m_num_fixit_hints): Eliminate in favor of...
	(rich_location::m_fixit_hints): ...this, converting from a
	fixed-size array to a semi_embedded_vec.
	* line-map.c (rich_location::rich_location): Update for above
	changes.
	(rich_location::~rich_location): Likewise.
	(rich_location::get_loc): Likewise.
	(rich_location::get_range): New methods.
	(rich_location::add_range): Update for above changes.
	(rich_location::set_range): Likewise.
	(rich_location::add_fixit_insert): Likewise.
	(rich_location::add_fixit_replace): Likewise.
	(rich_location::get_last_fixit_hint): Likewise.
	(rich_location::reject_impossible_fixit): Likewise.
	(rich_location::add_fixit): New method.



git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@239879 138bc75d-0d04-0410-961f-82ee72b054a4

3 files changed, 224 insertions, 52 deletions

diff --git a/libcpp/ChangeLog b/libcpp/ChangeLog
index a753033b8261..595d6ca4cca8 100644
--- a/libcpp/ChangeLog
+++ b/libcpp/ChangeLog
@@ -1,5 +1,44 @@
 2016-08-30  David Malcolm  <dmalcolm@redhat.com>
 
+	* include/line-map.h (class semi_embedded_vec): New class.
+	(semi_embedded_vec<T, NUM_EMBEDDED>::semi_embedded_vec): New ctor.
+	(semi_embedded_vec<T, NUM_EMBEDDED>::~semi_embedded_vec): New
+	dtor.
+	(semi_embedded_vec<T, NUM_EMBEDDED>::operator[]): New methods.
+	(semi_embedded_vec<T, NUM_EMBEDDED>::push): New method.
+	(semi_embedded_vec<T, NUM_EMBEDDED>::truncate): New method.
+	(rich_location::get_num_locations): Reimplement in terms of
+	m_ranges.
+	(rich_location::get_range): Make non-inline.
+	(rich_location::get_num_fixit_hints): Reimplement in terms of
+	m_fixit_hints.
+	(rich_location::add_fixit): New function.
+	(rich_location::MAX_RANGES): Rename to...
+	(rich_location::STATICALLY_ALLOCATED_RANGES): ...this.
+	(rich_location::MAX_FIXIT_HINTS): Rename to...
+	(rich_location::STATICALLY_ALLOCATED_RANGES): ...this, and make
+	private.
+	(rich_location::m_num_ranges): Eliminate in favor of...
+	(rich_location::m_ranges): ...this, converting from a fixed-size
+	array to a semi_embedded_vec.
+	(rich_location::m_num_fixit_hints): Eliminate in favor of...
+	(rich_location::m_fixit_hints): ...this, converting from a
+	fixed-size array to a semi_embedded_vec.
+	* line-map.c (rich_location::rich_location): Update for above
+	changes.
+	(rich_location::~rich_location): Likewise.
+	(rich_location::get_loc): Likewise.
+	(rich_location::get_range): New methods.
+	(rich_location::add_range): Update for above changes.
+	(rich_location::set_range): Likewise.
+	(rich_location::add_fixit_insert): Likewise.
+	(rich_location::add_fixit_replace): Likewise.
+	(rich_location::get_last_fixit_hint): Likewise.
+	(rich_location::reject_impossible_fixit): Likewise.
+	(rich_location::add_fixit): New method.
+
+2016-08-30  David Malcolm  <dmalcolm@redhat.com>
+
 	* include/line-map.h (rich_location::add_fixit_insert): Add
 	comments.  Add overload omitting the source_location param.
 	(rich_location::add_fixit_remove): Add comments.  Add overloads
diff --git a/libcpp/include/line-map.h b/libcpp/include/line-map.h
index 122e4742ed3d..0c95b292599b 100644
--- a/libcpp/include/line-map.h
+++ b/libcpp/include/line-map.h
@@ -1288,6 +1288,128 @@ struct location_range
   bool m_show_caret_p;
 };
 
+/* A partially-embedded vec for use within rich_location for storing
+   ranges and fix-it hints.
+
+   Elements [0..NUM_EMBEDDED) are allocated within m_embed, after
+   that they are within the dynamically-allocated m_extra.
+
+   This allows for static allocation in the common case, whilst
+   supporting the rarer case of an arbitrary number of elements.
+
+   Dynamic allocation is not performed unless it's needed.  */
+
+template <typename T, int NUM_EMBEDDED>
+class semi_embedded_vec
+{
+ public:
+  semi_embedded_vec ();
+  ~semi_embedded_vec ();
+
+  unsigned int count () const { return m_num; }
+  T& operator[] (int idx);
+  const T& operator[] (int idx) const;
+
+  void push (const T&);
+  void truncate (int len);
+
+ private:
+  int m_num;
+  T m_embedded[NUM_EMBEDDED];
+  int m_alloc;
+  T *m_extra;
+};
+
+/* Constructor for semi_embedded_vec.  In particular, no dynamic allocation
+   is done.  */
+
+template <typename T, int NUM_EMBEDDED>
+semi_embedded_vec<T, NUM_EMBEDDED>::semi_embedded_vec ()
+: m_num (0), m_alloc (0), m_extra (NULL)
+{
+}
+
+/* semi_embedded_vec's dtor.  Release any dynamically-allocated memory.  */
+
+template <typename T, int NUM_EMBEDDED>
+semi_embedded_vec<T, NUM_EMBEDDED>::~semi_embedded_vec ()
+{
+  XDELETEVEC (m_extra);
+}
+
+/* Look up element IDX, mutably.  */
+
+template <typename T, int NUM_EMBEDDED>
+T&
+semi_embedded_vec<T, NUM_EMBEDDED>::operator[] (int idx)
+{
+  linemap_assert (idx < m_num);
+  if (idx < NUM_EMBEDDED)
+    return m_embedded[idx];
+  else
+    {
+      linemap_assert (m_extra != NULL);
+      return m_extra[idx - NUM_EMBEDDED];
+    }
+}
+
+/* Look up element IDX (const).  */
+
+template <typename T, int NUM_EMBEDDED>
+const T&
+semi_embedded_vec<T, NUM_EMBEDDED>::operator[] (int idx) const
+{
+  linemap_assert (idx < m_num);
+  if (idx < NUM_EMBEDDED)
+    return m_embedded[idx];
+  else
+    {
+      linemap_assert (m_extra != NULL);
+      return m_extra[idx - NUM_EMBEDDED];
+    }
+}
+
+/* Append VALUE to the end of the semi_embedded_vec.  */
+
+template <typename T, int NUM_EMBEDDED>
+void
+semi_embedded_vec<T, NUM_EMBEDDED>::push (const T& value)
+{
+  int idx = m_num++;
+  if (idx < NUM_EMBEDDED)
+    m_embedded[idx] = value;
+  else
+    {
+      /* Offset "idx" to be an index within m_extra.  */
+      idx -= NUM_EMBEDDED;
+      if (NULL == m_extra)
+	{
+	  linemap_assert (m_alloc == 0);
+	  m_alloc = 16;
+	  m_extra = XNEWVEC (T, m_alloc);
+	}
+      else if (idx >= m_alloc)
+	{
+	  linemap_assert (m_alloc > 0);
+	  m_alloc *= 2;
+	  m_extra = XRESIZEVEC (T, m_extra, m_alloc);
+	}
+      linemap_assert (m_extra);
+      linemap_assert (idx < m_alloc);
+      m_extra[idx] = value;
+    }
+}
+
+/* Truncate to length LEN.  No deallocation is performed.  */
+
+template <typename T, int NUM_EMBEDDED>
+void
+semi_embedded_vec<T, NUM_EMBEDDED>::truncate (int len)
+{
+  linemap_assert (len <= m_num);
+  m_num = len;
+}
+
 class fixit_hint;
   class fixit_insert;
   class fixit_remove;
@@ -1387,13 +1509,10 @@ class rich_location
   set_range (line_maps *set, unsigned int idx, source_location loc,
 	     bool show_caret_p);
 
-  unsigned int get_num_locations () const { return m_num_ranges; }
+  unsigned int get_num_locations () const { return m_ranges.count (); }
 
-  location_range *get_range (unsigned int idx)
-  {
-    linemap_assert (idx < m_num_ranges);
-    return &m_ranges[idx];
-  }
+  const location_range *get_range (unsigned int idx) const;
+  location_range *get_range (unsigned int idx);
 
   expanded_location get_expanded_location (unsigned int idx);
 
@@ -1446,29 +1565,29 @@ class rich_location
   add_fixit_replace (source_range src_range,
 		     const char *new_content);
 
-  unsigned int get_num_fixit_hints () const { return m_num_fixit_hints; }
+  unsigned int get_num_fixit_hints () const { return m_fixit_hints.count (); }
   fixit_hint *get_fixit_hint (int idx) const { return m_fixit_hints[idx]; }
   fixit_hint *get_last_fixit_hint () const;
 
 private:
   bool reject_impossible_fixit (source_location where);
+  void add_fixit (fixit_hint *hint);
 
 public:
-  static const int MAX_RANGES = 3;
-  static const int MAX_FIXIT_HINTS = 2;
+  static const int STATICALLY_ALLOCATED_RANGES = 3;
 
 protected:
   line_maps *m_line_table;
-  unsigned int m_num_ranges;
-  location_range m_ranges[MAX_RANGES];
+  semi_embedded_vec <location_range, STATICALLY_ALLOCATED_RANGES> m_ranges;
 
   int m_column_override;
 
   bool m_have_expanded_location;
   expanded_location m_expanded_location;
 
-  unsigned int m_num_fixit_hints;
-  fixit_hint *m_fixit_hints[MAX_FIXIT_HINTS];
+  static const int MAX_STATIC_FIXIT_HINTS = 2;
+  semi_embedded_vec <fixit_hint *, MAX_STATIC_FIXIT_HINTS> m_fixit_hints;
+
   bool m_seen_impossible_fixit;
 };
 
diff --git a/libcpp/line-map.c b/libcpp/line-map.c
index 318932646a9b..72549ba0732d 100644
--- a/libcpp/line-map.c
+++ b/libcpp/line-map.c
@@ -1983,10 +1983,10 @@ source_range::intersects_line_p (const char *file, int line) const
 
 rich_location::rich_location (line_maps *set, source_location loc) :
   m_line_table (set),
-  m_num_ranges (0),
+  m_ranges (),
   m_column_override (0),
   m_have_expanded_location (false),
-  m_num_fixit_hints (0),
+  m_fixit_hints (),
   m_seen_impossible_fixit (false)
 {
   add_range (loc, true);
@@ -1996,8 +1996,8 @@ rich_location::rich_location (line_maps *set, source_location loc) :
 
 rich_location::~rich_location ()
 {
-  for (unsigned int i = 0; i < m_num_fixit_hints; i++)
-    delete m_fixit_hints[i];
+  for (unsigned int i = 0; i < m_fixit_hints.count (); i++)
+    delete get_fixit_hint (i);
 }
 
 /* Get location IDX within this rich_location.  */
@@ -2005,8 +2005,24 @@ rich_location::~rich_location ()
 source_location
 rich_location::get_loc (unsigned int idx) const
 {
-  linemap_assert (idx < m_num_ranges);
-  return m_ranges[idx].m_loc;
+  const location_range *locrange = get_range (idx);
+  return locrange->m_loc;
+}
+
+/* Get range IDX within this rich_location.  */
+
+const location_range *
+rich_location::get_range (unsigned int idx) const
+{
+  return &m_ranges[idx];
+}
+
+/* Mutable access to range IDX within this rich_location.  */
+
+location_range *
+rich_location::get_range (unsigned int idx)
+{
+  return &m_ranges[idx];
 }
 
 /* Expand location IDX within this rich_location.  */
@@ -2049,11 +2065,10 @@ rich_location::override_column (int column)
 void
 rich_location::add_range (source_location loc, bool show_caret_p)
 {
-  linemap_assert (m_num_ranges < MAX_RANGES);
-
-  location_range *range = &m_ranges[m_num_ranges++];
-  range->m_loc = loc;
-  range->m_show_caret_p = show_caret_p;
+  location_range range;
+  range.m_loc = loc;
+  range.m_show_caret_p = show_caret_p;
+  m_ranges.push (range);
 }
 
 /* Add or overwrite the location given by IDX, setting its location to LOC,
@@ -2073,19 +2088,18 @@ void
 rich_location::set_range (line_maps * /*set*/, unsigned int idx,
 			  source_location loc, bool show_caret_p)
 {
-  linemap_assert (idx < MAX_RANGES);
-
   /* We can either overwrite an existing range, or add one exactly
      on the end of the array.  */
-  linemap_assert (idx <= m_num_ranges);
-
-  location_range *locrange = &m_ranges[idx];
-  locrange->m_loc = loc;
-  locrange->m_show_caret_p = show_caret_p;
+  linemap_assert (idx <= m_ranges.count ());
 
-  /* Are we adding a range onto the end?  */
-  if (idx == m_num_ranges)
-    m_num_ranges = idx + 1;
+  if (idx == m_ranges.count ())
+    add_range (loc,  show_caret_p);
+  else
+    {
+      location_range *locrange = get_range (idx);
+      locrange->m_loc = loc;
+      locrange->m_show_caret_p = show_caret_p;
+    }
 
   if (idx == 0)
     /* Mark any cached value here as dirty.  */
@@ -2114,10 +2128,7 @@ rich_location::add_fixit_insert (source_location where,
 
   if (reject_impossible_fixit (where))
     return;
-
-  linemap_assert (m_num_fixit_hints < MAX_FIXIT_HINTS);
-  m_fixit_hints[m_num_fixit_hints++]
-    = new fixit_insert (where, new_content);
+  add_fixit (new fixit_insert (where, new_content));
 }
 
 /* Methods for adding removal fix-it hints.  */
@@ -2217,8 +2228,6 @@ void
 rich_location::add_fixit_replace (source_range src_range,
 				  const char *new_content)
 {
-  linemap_assert (m_num_fixit_hints < MAX_FIXIT_HINTS);
-
   src_range.m_start = get_pure_location (m_line_table, src_range.m_start);
   src_range.m_finish = get_pure_location (m_line_table, src_range.m_finish);
 
@@ -2229,14 +2238,11 @@ rich_location::add_fixit_replace (source_range src_range,
 
   /* Consolidate neighboring fixits.  */
   fixit_hint *prev = get_last_fixit_hint ();
-  if (m_num_fixit_hints > 0)
-    {
-      if (prev->maybe_append_replace (m_line_table, src_range, new_content))
-	return;
-    }
+  if (prev)
+    if (prev->maybe_append_replace (m_line_table, src_range, new_content))
+      return;
 
-  m_fixit_hints[m_num_fixit_hints++]
-    = new fixit_replace (src_range, new_content);
+  add_fixit (new fixit_replace (src_range, new_content));
 }
 
 /* Get the last fix-it hint within this rich_location, or NULL if none.  */
@@ -2244,8 +2250,8 @@ rich_location::add_fixit_replace (source_range src_range,
 fixit_hint *
 rich_location::get_last_fixit_hint () const
 {
-  if (m_num_fixit_hints > 0)
-    return m_fixit_hints[m_num_fixit_hints - 1];
+  if (m_fixit_hints.count () > 0)
+    return get_fixit_hint (m_fixit_hints.count () - 1);
   else
     return NULL;
 }
@@ -2275,13 +2281,21 @@ rich_location::reject_impossible_fixit (source_location where)
   m_seen_impossible_fixit = true;
 
   /* Purge the rich_location of any fix-its that were already added. */
-  for (unsigned int i = 0; i < m_num_fixit_hints; i++)
-    delete m_fixit_hints[i];
-  m_num_fixit_hints = 0;
+  for (unsigned int i = 0; i < m_fixit_hints.count (); i++)
+    delete get_fixit_hint (i);
+  m_fixit_hints.truncate (0);
 
   return true;
 }
 
+/* Add HINT to the fix-it hints in this rich_location.  */
+
+void
+rich_location::add_fixit (fixit_hint *hint)
+{
+  m_fixit_hints.push (hint);
+}
+
 /* class fixit_insert.  */
 
 fixit_insert::fixit_insert (source_location where,