[PATCH 1/3] (v3) Non-C++ parts of template type diff printing

[David Malcolm <dmalcolm at redhat dot com>]

This patch is broken out from the C++ patch, for ease of review.

I believe I can self-approve this one, assuming the other patches
in the kit are OK.

The patch:
- adds the bool and const char ** params to the
pp_format_decoder callback
- adds the format_postprocessor class
- adds the "type-diff" colorization code.

All are unused until patch 2 in the kit.

gcc/c/ChangeLog:
	* c-objc-common.c (c_tree_printer): Gain bool and const char **
	parameters.

gcc/cp/ChangeLog:
	* error.c (cp_printer): Gain bool and const char ** parameters.

gcc/ChangeLog:
	* diagnostic-color.c (color_dict): Add "type-diff".
	(parse_gcc_colors): Update comment.
	* doc/invoke.texi (Diagnostic Message Formatting Options): Add
	-fdiagnostics-show-template-tree and -fno-elide-type.
	(GCC_COLORS): Add type-diff to example.
	(type-diff=): New.

gcc/fortran/ChangeLog:
	* error.c (gfc_format_decoder): Update for new bool and
	const char ** params.

gcc/ChangeLog:
	* pretty-print.c (pp_format): Pass quote and formatters[argno] to
	the pp_format_decoder callback.  Call any m_format_postprocessor's
	"handle" method.
	(pretty_printer::pretty_printer): Initialize
	m_format_postprocessor.
	(pretty_printer::~pretty_printer): Delete any
	m_format_postprocessor.
	* pretty-print.h (printer_fn): Add bool and const char **
	parameters.
	(class format_postprocessor): New class.
	(struct pretty_printer::format_decoder): Document the new
	parameters.
	(struct pretty_printer::m_format_postprocessor): New field.
	* tree-diagnostic.c (default_tree_printer): Update for new
	bool and const char ** params.
	* tree-diagnostic.h (default_tree_printer): Likewise.
---
 gcc/c/c-objc-common.c  |  5 +++--
 gcc/cp/error.c         |  5 +++--
 gcc/diagnostic-color.c |  6 ++++--
 gcc/doc/invoke.texi    |  8 +++++++-
 gcc/fortran/error.c    |  5 +++--
 gcc/pretty-print.c     | 11 ++++++++++-
 gcc/pretty-print.h     | 20 ++++++++++++++++++--
 gcc/tree-diagnostic.c  |  3 ++-
 gcc/tree-diagnostic.h  |  2 +-
 9 files changed, 51 insertions(+), 14 deletions(-)

diff --git a/gcc/c/c-objc-common.c b/gcc/c/c-objc-common.c
index 5e69488..05212b2 100644
--- a/gcc/c/c-objc-common.c
+++ b/gcc/c/c-objc-common.c
@@ -28,7 +28,7 @@ along with GCC; see the file COPYING3.  If not see
 #include "c-objc-common.h"
 
 static bool c_tree_printer (pretty_printer *, text_info *, const char *,
-			    int, bool, bool, bool);
+			    int, bool, bool, bool, bool, const char **);
 
 bool
 c_missing_noreturn_ok_p (tree decl)
@@ -75,7 +75,8 @@ c_objc_common_init (void)
    diagnostic machinery.  */
 static bool
 c_tree_printer (pretty_printer *pp, text_info *text, const char *spec,
-		int precision, bool wide, bool set_locus, bool hash)
+		int precision, bool wide, bool set_locus, bool hash,
+		bool, const char **)
 {
   tree t = NULL_TREE;
   tree name;
diff --git a/gcc/cp/error.c b/gcc/cp/error.c
index a83ecb2..4934c51 100644
--- a/gcc/cp/error.c
+++ b/gcc/cp/error.c
@@ -99,7 +99,7 @@ static void cp_diagnostic_starter (diagnostic_context *, diagnostic_info *);
 static void cp_print_error_function (diagnostic_context *, diagnostic_info *);
 
 static bool cp_printer (pretty_printer *, text_info *, const char *,
-			int, bool, bool, bool);
+			int, bool, bool, bool, bool, const char **);
 
 /* CONTEXT->printer is a basic pretty printer that was constructed
    presumably by diagnostic_initialize(), called early in the
@@ -3582,7 +3582,8 @@ maybe_print_constexpr_context (diagnostic_context *context)
    %X   exception-specification.  */
 static bool
 cp_printer (pretty_printer *pp, text_info *text, const char *spec,
-	    int precision, bool wide, bool set_locus, bool verbose)
+	    int precision, bool wide, bool set_locus, bool verbose,
+	    bool, const char **)
 {
   const char *result;
   tree t = NULL;
diff --git a/gcc/diagnostic-color.c b/gcc/diagnostic-color.c
index 8353fe0..6adb872 100644
--- a/gcc/diagnostic-color.c
+++ b/gcc/diagnostic-color.c
@@ -174,6 +174,7 @@ static struct color_cap color_dict[] =
   { "diff-hunk", SGR_SEQ (COLOR_FG_CYAN), 9, false },
   { "diff-delete", SGR_SEQ (COLOR_FG_RED), 11, false },
   { "diff-insert", SGR_SEQ (COLOR_FG_GREEN), 11, false },
+  { "type-diff", SGR_SEQ (COLOR_BOLD COLOR_SEPARATOR COLOR_FG_GREEN), 9, false },
   { NULL, NULL, 0, false }
 };
 
@@ -204,8 +205,9 @@ colorize_stop (bool show_color)
 /* Parse GCC_COLORS.  The default would look like:
    GCC_COLORS='error=01;31:warning=01;35:note=01;36:\
    range1=32:range2=34:locus=01:quote=01:\
-   fixit-insert=32:fixit-delete=31'\
-   diff-filename=01:diff-hunk=32:diff-delete=31:diff-insert=32'
+   fixit-insert=32:fixit-delete=31:'\
+   diff-filename=01:diff-hunk=32:diff-delete=31:diff-insert=32:\
+   type-diff=01;32'
    No character escaping is needed or supported.  */
 static bool
 parse_gcc_colors (void)
diff --git a/gcc/doc/invoke.texi b/gcc/doc/invoke.texi
index 65308c9..1ba45cf 100644
--- a/gcc/doc/invoke.texi
+++ b/gcc/doc/invoke.texi
@@ -3442,7 +3442,8 @@ The default @env{GCC_COLORS} is
 @smallexample
 error=01;31:warning=01;35:note=01;36:range1=32:range2=34:locus=01:\
 quote=01:fixit-insert=32:fixit-delete=31:\
-diff-filename=01:diff-hunk=32:diff-delete=31:diff-insert=32
+diff-filename=01:diff-hunk=32:diff-delete=31:diff-insert=32:\
+type-diff=01;32
 @end smallexample
 @noindent
 where @samp{01;31} is bold red, @samp{01;35} is bold magenta,
@@ -3506,6 +3507,11 @@ SGR substring for deleted lines within generated patches.
 @item diff-insert=
 @vindex diff-insert GCC_COLORS @r{capability}
 SGR substring for inserted lines within generated patches.
+
+@item type-diff=
+@vindex type-diff GCC_COLORS @r{capability}
+SGR substring for highlighting mismatching types within template
+arguments in the C++ frontend.
 @end table
 
 @item -fno-diagnostics-show-option
diff --git a/gcc/fortran/error.c b/gcc/fortran/error.c
index 0312499..af72581 100644
--- a/gcc/fortran/error.c
+++ b/gcc/fortran/error.c
@@ -917,7 +917,8 @@ gfc_notify_std (int std, const char *gmsgid, ...)
 */
 static bool
 gfc_format_decoder (pretty_printer *pp, text_info *text, const char *spec,
-		    int precision, bool wide, bool set_locus, bool hash)
+		    int precision, bool wide, bool set_locus, bool hash,
+		    bool quoted, const char **buffer_ptr)
 {
   switch (*spec)
     {
@@ -948,7 +949,7 @@ gfc_format_decoder (pretty_printer *pp, text_info *text, const char *spec,
 	 etc. diagnostics can use the FE printer while the FE is still
 	 active.  */
       return default_tree_printer (pp, text, spec, precision, wide,
-				   set_locus, hash);
+				   set_locus, hash, quoted, buffer_ptr);
     }
 }
 
diff --git a/gcc/pretty-print.c b/gcc/pretty-print.c
index bcb1a70..570dec7 100644
--- a/gcc/pretty-print.c
+++ b/gcc/pretty-print.c
@@ -677,7 +677,8 @@ pp_format (pretty_printer *pp, text_info *text)
 
 	    gcc_assert (pp_format_decoder (pp));
 	    ok = pp_format_decoder (pp) (pp, text, p,
-					 precision, wide, plus, hash);
+					 precision, wide, plus, hash, quote,
+					 formatters[argno]);
 	    gcc_assert (ok);
 	  }
 	}
@@ -696,6 +697,11 @@ pp_format (pretty_printer *pp, text_info *text)
     for (; argno < PP_NL_ARGMAX; argno++)
       gcc_assert (!formatters[argno]);
 
+  /* If the client supplied a postprocessing object, call its "handle"
+     hook here.  */
+  if (pp->m_format_postprocessor)
+    pp->m_format_postprocessor->handle (pp);
+
   /* Revert to normal obstack and wrapping mode.  */
   buffer->obstack = &buffer->formatted_obstack;
   buffer->line_length = 0;
@@ -847,6 +853,7 @@ pretty_printer::pretty_printer (const char *p, int l)
     indent_skip (),
     wrapping (),
     format_decoder (),
+    m_format_postprocessor (NULL),
     emitted_prefix (),
     need_newline (),
     translate_identifiers (true),
@@ -860,6 +867,8 @@ pretty_printer::pretty_printer (const char *p, int l)
 
 pretty_printer::~pretty_printer ()
 {
+  if (m_format_postprocessor)
+    delete m_format_postprocessor;
   buffer->~output_buffer ();
   XDELETE (buffer);
 }
diff --git a/gcc/pretty-print.h b/gcc/pretty-print.h
index 2596678..40e56a3 100644
--- a/gcc/pretty-print.h
+++ b/gcc/pretty-print.h
@@ -180,11 +180,20 @@ struct pp_wrapping_mode_t
    A client-supplied formatter returns true if everything goes well,
    otherwise it returns false.  */
 typedef bool (*printer_fn) (pretty_printer *, text_info *, const char *,
-			    int, bool, bool, bool);
+			    int, bool, bool, bool, bool, const char **);
 
 /* Client supplied function used to decode formats.  */
 #define pp_format_decoder(PP) (PP)->format_decoder
 
+/* Base class for an optional client-supplied object for doing additional
+   processing between stages 2 and 3 of formatted printing.  */
+class format_postprocessor
+{
+ public:
+  virtual ~format_postprocessor () {}
+  virtual void handle (pretty_printer *) = 0;
+};
+
 /* TRUE if a newline character needs to be added before further
    formatting.  */
 #define pp_needs_newline(PP)  (PP)->need_newline
@@ -239,9 +248,16 @@ struct pretty_printer
      If the BUFFER needs additional characters from the format string, it
      should advance the TEXT->format_spec as it goes.  When FORMAT_DECODER
      returns, TEXT->format_spec should point to the last character processed.
-  */
+     The QUOTE and BUFFER_PTR are passed in, to allow for deferring-handling
+     of format codes (e.g. %H and %I in the C++ frontend).  */
   printer_fn format_decoder;
 
+  /* If non-NULL, this is called by pp_format once after all format codes
+     have been processed, to allow for client-specific postprocessing.
+     This is used by the C++ frontend for handling the %H and %I
+     format codes (which interract with each other).  */
+  format_postprocessor *m_format_postprocessor;
+
   /* Nonzero if current PREFIX was emitted at least once.  */
   bool emitted_prefix;
 
diff --git a/gcc/tree-diagnostic.c b/gcc/tree-diagnostic.c
index 4f211ed..ebce1a4 100644
--- a/gcc/tree-diagnostic.c
+++ b/gcc/tree-diagnostic.c
@@ -245,7 +245,8 @@ virt_loc_aware_diagnostic_finalizer (diagnostic_context *context,
 /* Default tree printer.   Handles declarations only.  */
 bool
 default_tree_printer (pretty_printer *pp, text_info *text, const char *spec,
-		      int precision, bool wide, bool set_locus, bool hash)
+		      int precision, bool wide, bool set_locus, bool hash,
+		      bool, const char **)
 {
   tree t;
 
diff --git a/gcc/tree-diagnostic.h b/gcc/tree-diagnostic.h
index e95183f..85aa980 100644
--- a/gcc/tree-diagnostic.h
+++ b/gcc/tree-diagnostic.h
@@ -55,6 +55,6 @@ void virt_loc_aware_diagnostic_finalizer (diagnostic_context *,
 
 void tree_diagnostics_defaults (diagnostic_context *context);
 bool default_tree_printer (pretty_printer *, text_info *, const char *,
-			   int, bool, bool, bool);
+			   int, bool, bool, bool, bool, const char **);
 
 #endif /* ! GCC_TREE_DIAGNOSTIC_H */
-- 
1.8.5.3