This patch combines:
  [PATCH 05/10] Add ranges to libcpp tokens (via ad-hoc data, unoptimized)
  [PATCH 06/10] Track expression ranges in C frontend
  [PATCH 07/10] Add plugin to recursively dump the source-ranges in a tree (v2)
  [PATCH 08/10] Wire things up so that libcpp users get token underlines
  [PATCH 09/10] Delay some resolution of ad-hoc locations, preserving ranges
  [PATCH 10/10] Compress short ranges into source_location
  [PATCH] libcpp: add examples to source_location description
along with fixes for the nits identified during review.

gcc/ChangeLog:
	* Makefile.in (OBJS): Add gcc-rich-location.o.
	* diagnostic.c (diagnostic_append_note): Pass line_table to
	rich_location ctor.
	(emit_diagnostic): Likewise.
	(inform): Likewise.
	(inform_n): Likewise.
	(warning): Likewise.
	(warning_at): Likewise.
	(warning_n): Likewise.
	(pedwarn): Likewise.
	(permerror): Likewise.
	(error): Likewise.
	(error_n): Likewise.
	(error_at): Likewise.
	(sorry): Likewise.
	(fatal_error): Likewise.
	(internal_error): Likewise.
	(internal_error_no_backtrace): Likewise.
	(source_range::debug): Likewise.
	* gcc-rich-location.c: New file.
	* gcc-rich-location.h: New file.
	* genmatch.c (fatal_at): Pass line_table to rich_location ctor.
	(warning_at): Likewise.
	* gimple.h (gimple_set_block): Use set_block function.
	* input.c (dump_line_table_statistics): Dump stats on how many
	ranges were optimized vs how many needed ad-hoc table.
	(write_digit_row): Add "map" param; use its range_bits
	to calculate the per-character offset.
	(dump_location_info): Print the range and column bits for each
	ordinary map.  Use the range bits to calculate the per-character
	offset.  Pass the map as a new param to the various calls to
	write_digit_row.  Eliminate uses of
	ORDINARY_MAP_NUMBER_OF_COLUMN_BITS.
	* print-tree.c (print_node): Print any source range information.
	* rtl-error.c (diagnostic_for_asm): Likewise.
	* toplev.c (general_init): Initialize line_table's
	default_range_bits.
	* tree-cfg.c (move_block_to_fn): Likewise.
	(move_block_to_fn): Likewise.
	* tree-inline.c (copy_phis_for_bb): Likewise.
	* tree.c (tree_set_block): Likewise.
	(get_pure_location): New function.
	(set_source_range): New functions.
	(set_block): New function.
	(set_source_range): New functions.
	* tree.h (CAN_HAVE_RANGE_P): New.
	(EXPR_LOCATION_RANGE): New.
	(EXPR_HAS_RANGE): New.
	(get_expr_source_range): New inline function.
	(DECL_LOCATION_RANGE): New.
	(set_source_range): New decls.
	(get_decl_source_range): New inline function.

gcc/ada/ChangeLog:
	* gcc-interface/trans.c (Sloc_to_locus): Add line_table param when
	calling linemap_position_for_line_and_column.

gcc/c-family/ChangeLog:
	* c-common.c (c_fully_fold_internal): Capture existing souce_range,
	and store it on the result.
	* c-opts.c (c_common_init_options): Set
	global_dc->colorize_source_p.

gcc/c/ChangeLog:
	* c-decl.c (warn_defaults_to): Pass line_table to
	rich_location ctor.
	* c-errors.c (pedwarn_c99): Likewise.
	(pedwarn_c90): Likewise.
	* c-parser.c (set_c_expr_source_range): New functions.
	(c_token::get_range): New method.
	(c_token::get_finish): New method.
	(c_parser_expr_no_commas): Call set_c_expr_source_range on the ret
	based on the range from the start of the LHS to the end of the
	RHS.
	(c_parser_conditional_expression): Likewise, based on the range
	from the start of the cond.value to the end of exp2.value.
	(c_parser_binary_expression): Call set_c_expr_source_range on
	the stack values for TRUTH_ANDIF_EXPR and TRUTH_ORIF_EXPR.
	(c_parser_cast_expression): Call set_c_expr_source_range on ret
	based on the cast_loc through to the end of the expr.
	(c_parser_unary_expression): Likewise, based on the
	op_loc through to the end of op.
	(c_parser_sizeof_expression) Likewise, based on the start of the
	sizeof token through to either the closing paren or the end of
	expr.
	(c_parser_postfix_expression): Likewise, using the token range,
	or from the open paren through to the close paren for
	parenthesized expressions.
	(c_parser_postfix_expression_after_primary): Likewise, for
	various kinds of expression.
	* c-tree.h (struct c_expr): Add field "src_range".
	(c_expr::get_start): New method.
	(c_expr::get_finish): New method.
	(set_c_expr_source_range): New decls.
	* c-typeck.c (parser_build_unary_op): Call set_c_expr_source_range
	on ret for prefix unary ops.
	(parser_build_binary_op): Likewise, running from the start of
	arg1.value through to the end of arg2.value.

gcc/cp/ChangeLog:
	* error.c (pedwarn_cxx98): Pass line_table to rich_location ctor.

gcc/fortran/ChangeLog:
	* error.c (gfc_warning): Pass line_table to rich_location ctor.
	(gfc_warning_now_at): Likewise.
	(gfc_warning_now): Likewise.
	(gfc_error_now): Likewise.
	(gfc_fatal_error): Likewise.
	(gfc_error): Likewise.
	(gfc_internal_error): Likewise.

gcc/testsuite/ChangeLog:
	* gcc.dg/diagnostic-token-ranges.c: New file.
	* gcc.dg/diagnostic-tree-expr-ranges-2.c: New file.
	* gcc.dg/plugin/diagnostic-test-expressions-1.c: New file.
	* gcc.dg/plugin/diagnostic-test-show-trees-1.c: New file.
	* gcc.dg/plugin/diagnostic_plugin_show_trees.c: New file.
	* gcc.dg/plugin/diagnostic_plugin_test_show_locus.c (get_loc): Add
	line_table param when calling
	linemap_position_for_line_and_column.
	(test_show_locus): Pass line_table to rich_location ctors.
	(plugin_init): Remove setting of global_dc->colorize_source_p.
	* gcc.dg/plugin/diagnostic_plugin_test_tree_expression_range.c:
	New file.
	* gcc.dg/plugin/plugin.exp (plugin_test_list): Add
	diagnostic_plugin_test_tree_expression_range.c,
	diagnostic-test-expressions-1.c, diagnostic_plugin_show_trees.c,
	and diagnostic-test-show-trees-1.c.

libcpp/ChangeLog:
	* errors.c (cpp_diagnostic): Pass pfile->line_table to
	rich_location ctor.
	(cpp_diagnostic_with_line): Likewise.
	* include/cpplib.h (struct cpp_token): Update comment for src_loc
	to indicate that the range of the token is "baked into" the
	source_location.
	* include/line-map.h (source_location): Update the descriptive
	comment to reflect the packing scheme for short ranges, adding
	worked examples of location encoding.
	(struct line_map_ordinary): Drop field "column_bits" in favor
	of field "m_column_and_range_bits"; add field "m_range_bits".
	(ORDINARY_MAP_NUMBER_OF_COLUMN_BITS): Delete.
	(location_adhoc_data): Add source_range field.
	(struct line_maps): Add fields "default_range_bits",
	"num_optimized_ranges" and "num_unoptimized_ranges".
	(get_combined_adhoc_loc): Add source_range param.
	(get_range_from_loc): New declaration.
	(pure_location_p): New prototype.
	(COMBINE_LOCATION_DATA):  Add source_range param.
	(SOURCE_LINE): Update for renaming of column_bits.
	(SOURCE_COLUMN): Likewise.  Shift the column right by the map's
	range_bits.
	(LAST_SOURCE_LINE_LOCATION): Update for renaming of column_bits.
	(linemap_position_for_line_and_column): Add line_maps * params.
	(rich_location::rich_location): Likewise.
	* lex.c (_cpp_lex_direct): Capture the range of the token, baking
	it into token->src_loc via a call to COMBINE_LOCATION_DATA.
	* line-map.c (LINE_MAP_MAX_COLUMN_NUMBER): Reduce from 1U << 17 to
	1U << 12.
	(location_adhoc_data_hash): Add the src_range into
	the hash value.
	(location_adhoc_data_eq): Require equality of the src_range
	values.
	(can_be_stored_compactly_p): New function.
	(get_combined_adhoc_loc): Add src_range param, and store it,
	via a bit-packing scheme for short ranges, otherwise within the
	lookaside table.  Remove the requirement that data is non-NULL.
	(get_range_from_adhoc_loc): New function.
	(get_range_from_loc): New function.
	(pure_location_p): New function.
	(linemap_add): Ensure that start_location has zero for the
	range_bits, unless we're past LINE_MAP_MAX_LOCATION_WITH_COLS.
	Initialize range_bits to zero.  Assert that the start_location
	is "pure".
	(linemap_line_start): Assert that the
	column_and_range_bits >= range_bits.
	Update determinination of whether we need to start a new map
	using the effective column bits, without the range bits.
	Use the set's default_range_bits in new maps, apart from
	those with column_bits == 0, which should also have 0 range_bits.
	Increase the column bits for new maps by the range bits.
	When adding lines to an existing map, use set->highest_line
	directly rather than offsetting highest by SOURCE_COLUMN.
	Add assertions to sanity-check the return value.
	(linemap_position_for_column): Offset to_column by range_bits.
	Update set->highest_location if necessary.
	(linemap_position_for_line_and_column): Add line_maps * param.
	Update the calculation to offset the column by range_bits, and
	conditionalize it on being <= LINE_MAP_MAX_LOCATION_WITH_COLS.
	Bound it by LINEMAPS_MACRO_LOWEST_LOCATION.  Update
	set->highest_location if necessary.
	(linemap_position_for_loc_and_offset): Handle ad-hoc locations;
	pass "set" to linemap_position_for_line_and_column.
	(linemap_macro_map_loc_unwind_toward_spelling): Add line_maps
	param.  Handle ad-hoc locations.
	(linemap_location_in_system_header_p): Pass on "set" to call to
	linemap_macro_map_loc_unwind_toward_spelling.
	(linemap_macro_loc_to_spelling_point): Retain ad-hoc locations.
	Pass on "set" to call to
	linemap_macro_map_loc_unwind_toward_spelling.
	(linemap_resolve_location): Retain ad-hoc locations.  Pass on
	"set" to call to linemap_macro_map_loc_unwind_toward_spelling.
	(linemap_unwind_toward_expansion):  Pass on "set" to call to
	linemap_macro_map_loc_unwind_toward_spelling.
	(linemap_expand_location): Extract the data pointer before
	extracting the location.
	(rich_location::rich_location): Add line_maps param; use it to
	extract the range from the source_location.
	* location-example.txt: Regenerate, showing new representation.

From-SVN: r230331