Split class rtx_reader into md_reader vs rtx_reader

This moves read_rtx and friends into rtx_reader, and splits
rtx_reader into two classes:

class md_reader: has responsibility for reading chars, managing
include files, top-level directives etc.  It is the read-md.o part.

class rtx_reader, a subclass, has the code for reading hierarchical
rtx expressions using the format codes.   It is the read-rtl.o part.

This split is needed by a followup patch, which converts
read_rtx_operand to a virtual function of rtx_reader.  To do this,
instances of rtx_reader (or its subclasses) need a vtable, which
needs to include a ptr to the code in read-rtl.o.  Splitting it up
allows the gen* tools that currently purely use read-md.o to continue
to do so.

gcc/ChangeLog:
	* genpreds.c (write_tm_constrs_h): Update for renaming of
	rtx_reader_ptr to md_reader_ptr.
	(write_tm_preds_h): Likewise.
	(write_insn_preds_c): Likewise.
	* read-md.c (rtx_reader_ptr): Rename to...
	(md_reader_ptr): ...this, and convert from an
	rtx_reader * to a md_reader *.
	(rtx_reader::set_md_ptr_loc): Rename to...
	(md_reader::set_md_ptr_loc): ...this.
	(rtx_reader::get_md_ptr_loc): Rename to...
	(md_reader::get_md_ptr_loc): ...this.
	(rtx_reader::copy_md_ptr_loc): Rename to...
	(md_reader::copy_md_ptr_loc): ...this.
	(rtx_reader::fprint_md_ptr_loc): Rename to...
	(md_reader::fprint_md_ptr_loc): ...this.
	(rtx_reader::print_md_ptr_loc): Rename to...
	(md_reader::print_md_ptr_loc): ...this.
	(rtx_reader::join_c_conditions): Rename to...
	(md_reader::join_c_conditions): ...this.
	(rtx_reader::fprint_c_condition): ...this.
	(rtx_reader::print_c_condition): Rename to...
	(md_reader::print_c_condition): ...this.
	(fatal_with_file_and_line):  Update for renaming of
	rtx_reader_ptr to md_reader_ptr.
	(rtx_reader::require_char): Rename to...
	(md_reader::require_char): ...this.
	(rtx_reader::require_char_ws): Rename to...
	(md_reader::require_char_ws): ...this.
	(rtx_reader::require_word_ws): Rename to...
	(md_reader::require_word_ws): ...this.
	(rtx_reader::read_char): Rename to...
	(md_reader::read_char): ...this.
	(rtx_reader::unread_char): Rename to...
	(md_reader::unread_char): ...this.
	(rtx_reader::peek_char): Rename to...
	(md_reader::peek_char): ...this.
	(rtx_reader::read_name): Rename to...
	(md_reader::read_name): ...this.
	(rtx_reader::read_escape): Rename to...
	(md_reader::read_escape): ...this.
	(rtx_reader::read_quoted_string): Rename to...
	(md_reader::read_quoted_string): ...this.
	(rtx_reader::read_braced_string): Rename to...
	(md_reader::read_braced_string): ...this.
	(rtx_reader::read_string): Rename to...
	(md_reader::read_string): ...this.
	(rtx_reader::read_skip_construct): Rename to...
	(md_reader::read_skip_construct): ...this.
	(rtx_reader::handle_constants): Rename to...
	(md_reader::handle_constants): ...this.
	(rtx_reader::traverse_md_constants): Rename to...
	(md_reader::traverse_md_constants): ...this.
	(rtx_reader::handle_enum): Rename to...
	(md_reader::handle_enum): ...this.
	(rtx_reader::lookup_enum_type): Rename to...
	(md_reader::lookup_enum_type): ...this.
	(rtx_reader::traverse_enum_types): Rename to...
	(md_reader::traverse_enum_types): ...this.
	(rtx_reader::rtx_reader): Rename to...
	(md_reader::md_reader): ...this, and update for renaming of
	rtx_reader_ptr to md_reader_ptr.
	(rtx_reader::~rtx_reader): Rename to...
	(md_reader::~md_reader): ...this, and update for renaming of
	rtx_reader_ptr to md_reader_ptr.
	(rtx_reader::handle_include): Rename to...
	(md_reader::handle_include): ...this.
	(rtx_reader::handle_file): Rename to...
	(md_reader::handle_file): ...this.
	(rtx_reader::handle_toplevel_file): Rename to...
	(md_reader::handle_toplevel_file): ...this.
	(rtx_reader::get_current_location): Rename to...
	(md_reader::get_current_location): ...this.
	(rtx_reader::add_include_path): Rename to...
	(md_reader::add_include_path): ...this.
	(rtx_reader::read_md_files): Rename to...
	(md_reader::read_md_files): ...this.
	* read-md.h (class rtx_reader): Split into...
	(class md_reader): ...new class.
	(rtx_reader_ptr): Rename to...
	(md_reader_ptr): ...this, and convert to a md_reader *.
	(class noop_reader): Update base class to be md_reader.
	(class rtx_reader): Reintroduce as a subclass of md_reader.
	(rtx_reader_ptr): Reintroduce as a rtx_reader *.
	(read_char): Update for renaming of rtx_reader_ptr to
	md_reader_ptr.
	(unread_char): Likewise.
	* read-rtl.c (rtx_reader_ptr): New global.
	(rtx_reader::apply_iterator_to_string): Rename to...
	(md_reader::apply_iterator_to_string): ...this.
	(rtx_reader::copy_rtx_for_iterators): Rename to...
	(md_reader::copy_rtx_for_iterators): ...this.
	(rtx_reader::read_conditions): Rename to...
	(md_reader::read_conditions): ...this.
	(rtx_reader::record_potential_iterator_use): Rename to...
	(md_reader::record_potential_iterator_use): ...this.
	(rtx_reader::read_mapping): Rename to...
	(md_reader::read_mapping): ...this.
	(rtx_reader::read_rtx): Use rtx_reader_ptr when calling
	read_rtx_code.
	(rtx_reader::read_rtx_operand): Use get_string_obstack rather
	than directly accessing m_string_obstack.
	(rtx_reader::rtx_reader): New ctor.
	(rtx_reader::~rtx_reader): New dtor.

From-SVN: r243426

gcc/ChangeLog

+2016-12-07  David Malcolm  <dmalcolm@redhat.com>
+
+	* genpreds.c (write_tm_constrs_h): Update for renaming of
+	rtx_reader_ptr to md_reader_ptr.
+	(write_tm_preds_h): Likewise.
+	(write_insn_preds_c): Likewise.
+	* read-md.c (rtx_reader_ptr): Rename to...
+	(md_reader_ptr): ...this, and convert from an
+	rtx_reader * to a md_reader *.
+	(rtx_reader::set_md_ptr_loc): Rename to...
+	(md_reader::set_md_ptr_loc): ...this.
+	(rtx_reader::get_md_ptr_loc): Rename to...
+	(md_reader::get_md_ptr_loc): ...this.
+	(rtx_reader::copy_md_ptr_loc): Rename to...
+	(md_reader::copy_md_ptr_loc): ...this.
+	(rtx_reader::fprint_md_ptr_loc): Rename to...
+	(md_reader::fprint_md_ptr_loc): ...this.
+	(rtx_reader::print_md_ptr_loc): Rename to...
+	(md_reader::print_md_ptr_loc): ...this.
+	(rtx_reader::join_c_conditions): Rename to...
+	(md_reader::join_c_conditions): ...this.
+	(rtx_reader::fprint_c_condition): ...this.
+	(rtx_reader::print_c_condition): Rename to...
+	(md_reader::print_c_condition): ...this.
+	(fatal_with_file_and_line):  Update for renaming of
+	rtx_reader_ptr to md_reader_ptr.
+	(rtx_reader::require_char): Rename to...
+	(md_reader::require_char): ...this.
+	(rtx_reader::require_char_ws): Rename to...
+	(md_reader::require_char_ws): ...this.
+	(rtx_reader::require_word_ws): Rename to...
+	(md_reader::require_word_ws): ...this.
+	(rtx_reader::read_char): Rename to...
+	(md_reader::read_char): ...this.
+	(rtx_reader::unread_char): Rename to...
+	(md_reader::unread_char): ...this.
+	(rtx_reader::peek_char): Rename to...
+	(md_reader::peek_char): ...this.
+	(rtx_reader::read_name): Rename to...
+	(md_reader::read_name): ...this.
+	(rtx_reader::read_escape): Rename to...
+	(md_reader::read_escape): ...this.
+	(rtx_reader::read_quoted_string): Rename to...
+	(md_reader::read_quoted_string): ...this.
+	(rtx_reader::read_braced_string): Rename to...
+	(md_reader::read_braced_string): ...this.
+	(rtx_reader::read_string): Rename to...
+	(md_reader::read_string): ...this.
+	(rtx_reader::read_skip_construct): Rename to...
+	(md_reader::read_skip_construct): ...this.
+	(rtx_reader::handle_constants): Rename to...
+	(md_reader::handle_constants): ...this.
+	(rtx_reader::traverse_md_constants): Rename to...
+	(md_reader::traverse_md_constants): ...this.
+	(rtx_reader::handle_enum): Rename to...
+	(md_reader::handle_enum): ...this.
+	(rtx_reader::lookup_enum_type): Rename to...
+	(md_reader::lookup_enum_type): ...this.
+	(rtx_reader::traverse_enum_types): Rename to...
+	(md_reader::traverse_enum_types): ...this.
+	(rtx_reader::rtx_reader): Rename to...
+	(md_reader::md_reader): ...this, and update for renaming of
+	rtx_reader_ptr to md_reader_ptr.
+	(rtx_reader::~rtx_reader): Rename to...
+	(md_reader::~md_reader): ...this, and update for renaming of
+	rtx_reader_ptr to md_reader_ptr.
+	(rtx_reader::handle_include): Rename to...
+	(md_reader::handle_include): ...this.
+	(rtx_reader::handle_file): Rename to...
+	(md_reader::handle_file): ...this.
+	(rtx_reader::handle_toplevel_file): Rename to...
+	(md_reader::handle_toplevel_file): ...this.
+	(rtx_reader::get_current_location): Rename to...
+	(md_reader::get_current_location): ...this.
+	(rtx_reader::add_include_path): Rename to...
+	(md_reader::add_include_path): ...this.
+	(rtx_reader::read_md_files): Rename to...
+	(md_reader::read_md_files): ...this.
+	* read-md.h (class rtx_reader): Split into...
+	(class md_reader): ...new class.
+	(rtx_reader_ptr): Rename to...
+	(md_reader_ptr): ...this, and convert to a md_reader *.
+	(class noop_reader): Update base class to be md_reader.
+	(class rtx_reader): Reintroduce as a subclass of md_reader.
+	(rtx_reader_ptr): Reintroduce as a rtx_reader *.
+	(read_char): Update for renaming of rtx_reader_ptr to
+	md_reader_ptr.
+	(unread_char): Likewise.
+	* read-rtl.c (rtx_reader_ptr): New global.
+	(rtx_reader::apply_iterator_to_string): Rename to...
+	(md_reader::apply_iterator_to_string): ...this.
+	(rtx_reader::copy_rtx_for_iterators): Rename to...
+	(md_reader::copy_rtx_for_iterators): ...this.
+	(rtx_reader::read_conditions): Rename to...
+	(md_reader::read_conditions): ...this.
+	(rtx_reader::record_potential_iterator_use): Rename to...
+	(md_reader::record_potential_iterator_use): ...this.
+	(rtx_reader::read_mapping): Rename to...
+	(md_reader::read_mapping): ...this.
+	(rtx_reader::read_rtx): Use rtx_reader_ptr when calling
+	read_rtx_code.
+	(rtx_reader::read_rtx_operand): Use get_string_obstack rather
+	than directly accessing m_string_obstack.
+	(rtx_reader::rtx_reader): New ctor.
+	(rtx_reader::~rtx_reader): New dtor.
+
 2016-12-07  Martin Sebor  <msebor@redhat.com>
 
 	PR middle-end/77784

gcc/genpreds.c

@@ -1205,7 +1205,7 @@ write_tm_constrs_h (void)
   printf ("\
 /* Generated automatically by the program '%s'\n\
    from the machine description file '%s'.  */\n\n", progname,
-	  rtx_reader_ptr->get_top_level_filename ());
+	  md_reader_ptr->get_top_level_filename ());
 
   puts ("\
 #ifndef GCC_TM_CONSTRS_H\n\
@@ -1405,7 +1405,7 @@ write_tm_preds_h (void)
   printf ("\
 /* Generated automatically by the program '%s'\n\
    from the machine description file '%s'.  */\n\n", progname,
-	  rtx_reader_ptr->get_top_level_filename ());
+	  md_reader_ptr->get_top_level_filename ());
 
   puts ("\
 #ifndef GCC_TM_PREDS_H\n\
@@ -1555,7 +1555,7 @@ write_insn_preds_c (void)
   printf ("\
 /* Generated automatically by the program '%s'\n\
    from the machine description file '%s'.  */\n\n", progname,
-	  rtx_reader_ptr->get_top_level_filename ());
+	  md_reader_ptr->get_top_level_filename ());
 
   puts ("\
 #include \"config.h\"\n\

gcc/read-md.h

@@ -91,11 +91,23 @@ struct enum_type {
   unsigned int num_values;
 };
 
-class rtx_reader
+/* A class for reading .md files and RTL dump files.
+
+   Implemented in read-md.c.
+
+   This class has responsibility for reading chars from input files, and
+   for certain common top-level directives including the "include"
+   directive.
+
+   It does not handle parsing the hierarchically-nested expressions of
+   rtl.def; for that see the rtx_reader subclass below (implemented in
+   read-rtl.c).  */
+
+class md_reader
 {
  public:
-  rtx_reader ();
-  virtual ~rtx_reader ();
+  md_reader ();
+  virtual ~md_reader ();
 
   bool read_md_files (int, const char **, bool (*) (const char *));
 
@@ -145,11 +157,6 @@ class rtx_reader
   void record_potential_iterator_use (struct iterator_group *group,
 				      void *ptr, const char *name);
   struct mapping *read_mapping (struct iterator_group *group, htab_t table);
-  bool read_rtx (const char *rtx_name, vec<rtx> *rtxen);
-  rtx read_rtx_code (const char *code_name);
-  void read_rtx_operand (rtx return_rtx, int idx);
-  rtx read_nested_rtx ();
-  rtx read_rtx_variadic (rtx form);
 
   const char *get_top_level_filename () const { return m_toplevel_fname; }
   const char *get_filename () const { return m_read_md_filename; }
@@ -231,20 +238,42 @@ class rtx_reader
   htab_t m_enum_types;
 };
 
-/* Global singleton.  */
-extern rtx_reader *rtx_reader_ptr;
+/* Global singleton; constrast with rtx_reader_ptr below.  */
+extern md_reader *md_reader_ptr;
 
-/* An rtx_reader subclass which skips unknown directives.  */
+/* An md_reader subclass which skips unknown directives, for
+   the gen* tools that purely use read-md.o.  */
 
-class noop_reader : public rtx_reader
+class noop_reader : public md_reader
 {
  public:
-  noop_reader () : rtx_reader () {}
+  noop_reader () : md_reader () {}
 
   /* A dummy implementation which skips unknown directives.  */
   void handle_unknown_directive (file_location, const char *);
 };
 
+/* An md_reader subclass that actually handles full hierarchical
+   rtx expressions.
+
+   Implemented in read-rtl.c.  */
+
+class rtx_reader : public md_reader
+{
+ public:
+  rtx_reader ();
+  ~rtx_reader ();
+
+  bool read_rtx (const char *rtx_name, vec<rtx> *rtxen);
+  rtx read_rtx_code (const char *code_name);
+  void read_rtx_operand (rtx return_rtx, int idx);
+  rtx read_nested_rtx ();
+  rtx read_rtx_variadic (rtx form);
+};
+
+/* Global singleton; constrast with md_reader_ptr above.  */
+extern rtx_reader *rtx_reader_ptr;
+
 extern void (*include_callback) (const char *);
 
 /* Read the next character from the MD file.  */
@@ -252,7 +281,7 @@ extern void (*include_callback) (const char *);
 static inline int
 read_char (void)
 {
-  return rtx_reader_ptr->read_char ();
+  return md_reader_ptr->read_char ();
 }
 
 /* Put back CH, which was the last character read from the MD file.  */
@@ -260,7 +289,7 @@ read_char (void)
 static inline void
 unread_char (int ch)
 {
-  rtx_reader_ptr->unread_char (ch);
+  md_reader_ptr->unread_char (ch);
 }
 
 extern hashval_t leading_string_hash (const void *);

gcc/read-rtl.c

@@ -107,6 +107,9 @@ const char *current_iterator_name;
 
 static void validate_const_int (const char *);
 
+/* Global singleton.  */
+rtx_reader *rtx_reader_ptr = NULL;
+
 /* The mode and code iterator structures.  */
 static struct iterator_group modes, codes, ints, substs;
 
@@ -326,7 +329,7 @@ map_attr_string (const char *p)
    if any changes were needed, otherwise return STRING itself.  */
 
 const char *
-rtx_reader::apply_iterator_to_string (const char *string)
+md_reader::apply_iterator_to_string (const char *string)
 {
   char *base, *copy, *p, *start, *end;
   struct map_value *v;
@@ -365,7 +368,7 @@ rtx_reader::apply_iterator_to_string (const char *string)
    values into any strings.  */
 
 rtx
-rtx_reader::copy_rtx_for_iterators (rtx original)
+md_reader::copy_rtx_for_iterators (rtx original)
 {
   const char *format_ptr, *p;
   int i, j;
@@ -735,7 +738,7 @@ atoll (const char *p)
    slipped in at the beginning of the sequence of MD files read by
    most of the other generators.  */
 void
-rtx_reader::read_conditions ()
+md_reader::read_conditions ()
 {
   int c;
 
@@ -834,8 +837,8 @@ record_attribute_use (struct iterator_group *group, void *ptr,
    callback.  */
 
 void
-rtx_reader::record_potential_iterator_use (struct iterator_group *group,
-					   void *ptr, const char *name)
+md_reader::record_potential_iterator_use (struct iterator_group *group,
+					  void *ptr, const char *name)
 {
   struct mapping *m;
   size_t len;
@@ -869,7 +872,7 @@ rtx_reader::record_potential_iterator_use (struct iterator_group *group,
    (which belongs to GROUP) and return it.  */
 
 struct mapping *
-rtx_reader::read_mapping (struct iterator_group *group, htab_t table)
+md_reader::read_mapping (struct iterator_group *group, htab_t table)
 {
   struct md_name name;
   struct mapping *m;
@@ -1072,7 +1075,7 @@ rtx_reader::read_rtx (const char *rtx_name, vec<rtx> *rtxen)
       return true;
     }
 
-  apply_iterators (read_rtx_code (rtx_name), rtxen);
+  apply_iterators (rtx_reader_ptr->read_rtx_code (rtx_name), rtxen);
   iterator_uses.truncate (0);
   attribute_uses.truncate (0);
 
@@ -1270,6 +1273,7 @@ rtx_reader::read_rtx_operand (rtx return_rtx, int idx)
       {
 	char *stringbuf;
 	int star_if_braced;
+	struct obstack *string_obstack = get_string_obstack ();
 
 	c = read_skip_spaces ();
 	unread_char (c);
@@ -1306,11 +1310,11 @@ rtx_reader::read_rtx_operand (rtx return_rtx, int idx)
 	    for (slash = fn; *slash; slash ++)
 	      if (*slash == '/' || *slash == '\\' || *slash == ':')
 		fn = slash + 1;
-	    obstack_1grow (&m_string_obstack, '*');
-	    obstack_grow (&m_string_obstack, fn, strlen (fn));
+	    obstack_1grow (string_obstack, '*');
+	    obstack_grow (string_obstack, fn, strlen (fn));
 	    sprintf (line_name, ":%d", get_lineno ());
-	    obstack_grow (&m_string_obstack, line_name, strlen (line_name)+1);
-	    stringbuf = XOBFINISH (&m_string_obstack, char *);
+	    obstack_grow (string_obstack, line_name, strlen (line_name)+1);
+	    stringbuf = XOBFINISH (string_obstack, char *);
 	  }
 
 	/* Find attr-names in the string.  */
@@ -1447,3 +1451,20 @@ rtx_reader::read_rtx_variadic (rtx form)
   unread_char (c);
   return form;
 }
+
+/* Constructor for class rtx_reader.  */
+
+rtx_reader::rtx_reader ()
+: md_reader ()
+{
+  /* Set the global singleton pointer.  */
+  rtx_reader_ptr = this;
+}
+
+/* Destructor for class rtx_reader.  */
+
+rtx_reader::~rtx_reader ()
+{
+  /* Clear the global singleton pointer.  */
+  rtx_reader_ptr = NULL;
+}