[PATCH 10/10] Compress short ranges into source_location

[Jeff Law]

On 10/23/2015 02:41 PM, David Malcolm wrote:
>
> gcc/ada/ChangeLog:
> 	* gcc-interface/trans.c (Sloc_to_locus): Add line_table param when
> 	calling linemap_position_for_line_and_column.
>
> gcc/ChangeLog:
> 	* 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.
> 	* toplev.c (general_init): Initialize line_table's
> 	default_range_bits.
> 	* tree.c (get_pure_location): New function.
> 	(set_block): Use the pure form of the location for the
> 	caret in the combined location.
> 	(set_source_range): Likewise.
>
> gcc/testsuite/ChangeLog:
> 	* gcc.dg/plugin/diagnostic_plugin_test_show_locus.c (get_loc): Add
> 	line_table param when calling
> 	linemap_position_for_line_and_column.
> 	* gcc.dg/plugin/diagnostic_plugin_test_tree_expression_range.c
> 	(emit_warning): Remove restriction that "loc" must be ad-hoc.
>
> libcpp/ChangeLog:
> 	* include/line-map.h (source_location): Update the descriptive
> 	comment to reflect the packing scheme for short ranges.
> 	(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.
> 	(struct line_maps): Add fields "default_range_bits",
> 	"num_optimized_ranges" and "num_unoptimized_ranges".
> 	(get_range_from_adhoc_loc): Delete prototype.
> 	(get_range_from_loc): Convert from an inline function to a
> 	prototype.
> 	(pure_location_p): New prototype.
> 	(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.
> 	* lex.c (_cpp_lex_direct): Don't attempt to record token ranges
> 	for UNKNOWN_LOCATION and BUILTINS_LOCATION.
> 	* line-map.c (LINE_MAP_MAX_COLUMN_NUMBER): Reduce from 1U << 17 to
> 	1U << 9.
> 	(can_be_stored_compactly_p): New function.
> 	(get_combined_adhoc_loc): Implement bit-packing scheme for short
> 	ranges.
> 	(get_range_from_adhoc_loc): Make static.
> 	(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->hightest_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): Pass "set" to
> 	linemap_position_for_line_and_column.
> 	* location-example.txt: Regenerate, showing new representation.
"determinination"? :-)

> ---
>   gcc/ada/gcc-interface/trans.c                      |   3 +-
>   gcc/input.c                                        |  28 ++-
>   .../plugin/diagnostic_plugin_test_show_locus.c     |   3 +-
>   .../diagnostic_plugin_test_tree_expression_range.c |   8 +-
>   gcc/toplev.c                                       |   1 +
>   gcc/tree.c                                         |  25 ++-
>   libcpp/include/line-map.h                          | 121 +++++++----
>   libcpp/lex.c                                       |   9 +-
>   libcpp/line-map.c                                  | 229 +++++++++++++++++++--
>   libcpp/location-example.txt                        | 188 +++++++++--------
>   10 files changed, 450 insertions(+), 165 deletions(-)
>

> diff --git a/gcc/tree.c b/gcc/tree.c
> index a676352..4ec4a38 100644
> --- a/gcc/tree.c
> +++ b/gcc/tree.c
> @@ -13653,11 +13653,31 @@ nonnull_arg_p (const_tree arg)
>     return false;
>   }
>
> +static location_t
> +get_pure_location (location_t loc)
Function comment.



> diff --git a/libcpp/include/line-map.h b/libcpp/include/line-map.h
> index 0ef29d9..1a2dab8 100644
> --- a/libcpp/include/line-map.h
> +++ b/libcpp/include/line-map.h
  > @@ -821,8 +871,10 @@ extern source_location get_combined_adhoc_loc 
(struct line_maps *,
>   extern void *get_data_from_adhoc_loc (struct line_maps *, source_location);
>   extern source_location get_location_from_adhoc_loc (struct line_maps *,
>   						    source_location);
> -extern source_range get_range_from_adhoc_loc (struct line_maps *,
> -					      source_location);
> +
> +extern source_range
> +get_range_from_loc (line_maps *set,
> +		    source_location loc);
Nit.  Should probably all be on one line.

  diff --git a/libcpp/line-map.c b/libcpp/line-map.c
> index 6385fdf..fe8d784 100644
> --- a/libcpp/line-map.c
> +++ b/libcpp/line-map.c
> @@ -29,7 +29,7 @@ along with this program; see the file COPYING3.  If not see
>   /* Do not track column numbers higher than this one.  As a result, the
>      range of column_bits is [7, 18] (or 0 if column numbers are
>      disabled).  */
> -const unsigned int LINE_MAP_MAX_COLUMN_NUMBER = (1U << 17);
> +const unsigned int LINE_MAP_MAX_COLUMN_NUMBER = (1U << 9);
Comment needs updating, right?


> +/* Helper function for get_combined_adhoc_loc.
> +   Can the given LOCUS + SRC_RANGE and DATA pointer be stored compactly
> +   within a source_location, without needing to use an ad-hoc location.  */
> +
> +static bool
> +can_be_stored_compactly_p (struct line_maps *set,
> +			   source_location locus,
> +			   source_range src_range,
> +			   void *data)
> +{
> +  /* If there's an ad-hoc pointer, we can't store it directly in the
> +     source_location, we need the lookaside.  */
> +  if (data)
> +    return false;
> +
> +  /* We only store ranges that begin at the locus and that are sufficientl
sufficiently


> +
> +#define DEBUG_PACKING 0
> +
> +#if DEBUG_PACKING
> +  fprintf (stderr, "get_combined_adhoc_loc: %x %x %x\n",
> +	   locus, src_range.m_start, src_range.m_finish);
> +#endif
Shouldn't this stuff (DEBUG_PACKING) just go away?


With the nits above fixed, this is OK.  Obviously there's prereqs that 
need to be approved and committed together.

jeff