[10/49] Add -fdiagnostics-nn-line-numbers

Message ID 1573867416-55618-11-git-send-email-dmalcolm@redhat.com
State Superseded
Headers show
Series
  • RFC: Add a static analysis framework to GCC
Related show

Commit Message

David Malcolm Nov. 16, 2019, 1:22 a.m.
This patch implements -fdiagnostics-nn-line-numbers, a new option
which makes diagnostic_show_locus print "NN" rather than specific
line numbers when printing the left margin.

This is intended purely to make it easier to write certain kinds of
DejaGnu test; various integration tests for diagnostic paths later
in the patch kit make use of it.

gcc/ChangeLog:
	* common.opt (fdiagnostics-nn-line-numbers): New option.
	* diagnostic-show-locus.c (layout::m_use_nn_for_line_numbers_p):
	New field.
	(layout::layout): Initialize it and use it when computing
	m_linenum_width.
	(layout::print_source_line): Implement printing "NN" rather than
	the line number.
	(selftest::test_line_numbers_multiline_range): Add a test of "NN"
	printing.
	* diagnostic.c (diagnostic_initialize): Initialize
	use_nn_for_line_numbers_p.
	(num_digits): Add "use_nn_p" param.
	(selftest::test_num_digits): Add a test for use_nn_p==true.
	* diagnostic.h (diagnostic_context::use_nn_for_line_numbers_p):
	New field.
	(num_digits): Add optional "use_nn_p" param.
	* doc/invoke.texi (-fdiagnostics-nn-line-numbers): New option.
	* dwarf2out.c (gen_producer_string): Ignore
	OPT_fdiagnostics_nn_line_numbers.
	* lto-wrapper.c (merge_and_complain): Handle
	OPT_fdiagnostics_nn_line_numbers.
	(append_compiler_options): Likewise.
	(append_diag_options): Likewise.
	* opts.c (common_handle_option): Likewise.
	* toplev.c (general_init): Initialize
	global_dc->use_nn_for_line_numbers_p.
---
 gcc/common.opt              |  4 ++++
 gcc/diagnostic-show-locus.c | 51 ++++++++++++++++++++++++++++++++-------------
 gcc/diagnostic.c            | 13 ++++++++++--
 gcc/diagnostic.h            |  6 +++++-
 gcc/doc/invoke.texi         |  7 +++++++
 gcc/dwarf2out.c             |  1 +
 gcc/lto-wrapper.c           |  3 +++
 gcc/opts.c                  |  4 ++++
 gcc/toplev.c                |  2 ++
 9 files changed, 73 insertions(+), 18 deletions(-)

-- 
1.8.5.3

Comments

Martin Sebor Dec. 4, 2019, 5:18 p.m. | #1
On 11/15/19 6:22 PM, David Malcolm wrote:
> This patch implements -fdiagnostics-nn-line-numbers, a new option

> which makes diagnostic_show_locus print "NN" rather than specific

> line numbers when printing the left margin.

> 

> This is intended purely to make it easier to write certain kinds of

> DejaGnu test; various integration tests for diagnostic paths later

> in the patch kit make use of it.

> 

> gcc/ChangeLog:

> 	* common.opt (fdiagnostics-nn-line-numbers): New option.

> 	* diagnostic-show-locus.c (layout::m_use_nn_for_line_numbers_p):

> 	New field.

> 	(layout::layout): Initialize it and use it when computing

> 	m_linenum_width.

> 	(layout::print_source_line): Implement printing "NN" rather than

> 	the line number.

> 	(selftest::test_line_numbers_multiline_range): Add a test of "NN"

> 	printing.

> 	* diagnostic.c (diagnostic_initialize): Initialize

> 	use_nn_for_line_numbers_p.

> 	(num_digits): Add "use_nn_p" param.

> 	(selftest::test_num_digits): Add a test for use_nn_p==true.

> 	* diagnostic.h (diagnostic_context::use_nn_for_line_numbers_p):

> 	New field.

> 	(num_digits): Add optional "use_nn_p" param.

> 	* doc/invoke.texi (-fdiagnostics-nn-line-numbers): New option.

> 	* dwarf2out.c (gen_producer_string): Ignore

> 	OPT_fdiagnostics_nn_line_numbers.

> 	* lto-wrapper.c (merge_and_complain): Handle

> 	OPT_fdiagnostics_nn_line_numbers.

> 	(append_compiler_options): Likewise.

> 	(append_diag_options): Likewise.

> 	* opts.c (common_handle_option): Likewise.

> 	* toplev.c (general_init): Initialize

> 	global_dc->use_nn_for_line_numbers_p.

> ---

>   gcc/common.opt              |  4 ++++

>   gcc/diagnostic-show-locus.c | 51 ++++++++++++++++++++++++++++++++-------------

>   gcc/diagnostic.c            | 13 ++++++++++--

>   gcc/diagnostic.h            |  6 +++++-

>   gcc/doc/invoke.texi         |  7 +++++++

>   gcc/dwarf2out.c             |  1 +

>   gcc/lto-wrapper.c           |  3 +++

>   gcc/opts.c                  |  4 ++++

>   gcc/toplev.c                |  2 ++

>   9 files changed, 73 insertions(+), 18 deletions(-)

> 

> diff --git a/gcc/common.opt b/gcc/common.opt

> index 124e8cf..3c024b3 100644

> --- a/gcc/common.opt

> +++ b/gcc/common.opt

> @@ -1257,6 +1257,10 @@ fdiagnostics-show-line-numbers

>   Common Var(flag_diagnostics_show_line_numbers) Init(1)

>   Show line numbers in the left margin when showing source.

>   

> +fdiagnostics-nn-line-numbers

> +Common Var(flag_diagnostics_nn_line_numbers) Init(0)

> +Replace line numbers with 'NN' when showing source.

> +

>   fdiagnostics-color

>   Common Alias(fdiagnostics-color=,always,never)

>   ;

> diff --git a/gcc/diagnostic-show-locus.c b/gcc/diagnostic-show-locus.c

> index 412b0d4..ec5fdc0 100644

> --- a/gcc/diagnostic-show-locus.c

> +++ b/gcc/diagnostic-show-locus.c

> @@ -303,6 +303,7 @@ class layout

>     bool m_colorize_source_p;

>     bool m_show_labels_p;

>     bool m_show_line_numbers_p;

> +  bool m_use_nn_for_line_numbers_p;

>     auto_vec <layout_range> m_layout_ranges;

>     auto_vec <const fixit_hint *> m_fixit_hints;

>     auto_vec <line_span> m_line_spans;

> @@ -849,6 +850,7 @@ layout::layout (diagnostic_context * context,

>     m_colorize_source_p (context->colorize_source_p),

>     m_show_labels_p (context->show_labels_p),

>     m_show_line_numbers_p (context->show_line_numbers_p),

> +  m_use_nn_for_line_numbers_p (context->use_nn_for_line_numbers_p),

>     m_layout_ranges (richloc->get_num_locations ()),

>     m_fixit_hints (richloc->get_num_fixit_hints ()),

>     m_line_spans (1 + richloc->get_num_locations ()),

> @@ -884,7 +886,7 @@ layout::layout (diagnostic_context * context,

>     int highest_line = last_span->m_last_line;

>     if (highest_line < 0)

>       highest_line = 0;

> -  m_linenum_width = num_digits (highest_line);

> +  m_linenum_width = num_digits (highest_line, m_use_nn_for_line_numbers_p);

>     /* If we're showing jumps in the line-numbering, allow at least 3 chars.  */

>     if (m_line_spans.length () > 1)

>       m_linenum_width = MAX (m_linenum_width, 3);

> @@ -1272,10 +1274,13 @@ layout::print_source_line (linenum_type row, const char *line, int line_width,

>   

>     if (m_show_line_numbers_p)

>       {

> -      int width = num_digits (row);

> +      int width = num_digits (row, m_use_nn_for_line_numbers_p);

>         for (int i = 0; i < m_linenum_width - width; i++)

>   	pp_space (m_pp);

> -      pp_printf (m_pp, "%i | ", row);

> +      if (m_use_nn_for_line_numbers_p)

> +	pp_printf (m_pp, "%s | ", "NN");

> +      else

> +	pp_printf (m_pp, "%i | ", row);

>       }

>     else

>       pp_space (m_pp);

> @@ -3778,18 +3783,34 @@ test_line_numbers_multiline_range ()

>       = linemap_position_for_line_and_column (line_table, ord_map, 11, 4);

>     location_t loc = make_location (caret, start, finish);

>   

> -  test_diagnostic_context dc;

> -  dc.show_line_numbers_p = true;

> -  dc.min_margin_width = 0;

> -  gcc_rich_location richloc (loc);

> -  diagnostic_show_locus (&dc, &richloc, DK_ERROR);

> -  ASSERT_STREQ (" 9 | this is line 9\n"

> -		"   |         ~~~~~~\n"

> -		"10 | this is line 10\n"

> -		"   | ~~~~~^~~~~~~~~~\n"

> -		"11 | this is line 11\n"

> -		"   | ~~~~  \n",

> -		pp_formatted_text (dc.printer));

> +  {

> +    test_diagnostic_context dc;

> +    dc.show_line_numbers_p = true;

> +    dc.min_margin_width = 0;

> +    gcc_rich_location richloc (loc);

> +    diagnostic_show_locus (&dc, &richloc, DK_ERROR);

> +    ASSERT_STREQ (" 9 | this is line 9\n"

> +		  "   |         ~~~~~~\n"

> +		  "10 | this is line 10\n"

> +		  "   | ~~~~~^~~~~~~~~~\n"

> +		  "11 | this is line 11\n"

> +		  "   | ~~~~  \n",

> +		  pp_formatted_text (dc.printer));

> +  }

> +

> +  /* Verify that obscuring line numbers via "NN" works (and always uses

> +     at least two columns).  */

> +  {

> +    test_diagnostic_context dc;

> +    dc.show_line_numbers_p = true;

> +    dc.use_nn_for_line_numbers_p = true;

> +    dc.min_margin_width = 0;

> +    gcc_rich_location richloc (start);

> +    diagnostic_show_locus (&dc, &richloc, DK_ERROR);

> +    ASSERT_STREQ ("NN | this is line 9\n"

> +		  "   |         ^\n",

> +		  pp_formatted_text (dc.printer));

> +  }

>   }

>   

>   /* Run all of the selftests within this file.  */

> diff --git a/gcc/diagnostic.c b/gcc/diagnostic.c

> index d6604e6..81e0a10 100644

> --- a/gcc/diagnostic.c

> +++ b/gcc/diagnostic.c

> @@ -209,6 +209,7 @@ diagnostic_initialize (diagnostic_context *context, int n_opts)

>     context->colorize_source_p = false;

>     context->show_labels_p = false;

>     context->show_line_numbers_p = false;

> +  context->use_nn_for_line_numbers_p = false;

>     context->min_margin_width = 0;

>     context->show_ruler_p = false;

>     context->parseable_fixits_p = false;

> @@ -1078,15 +1079,21 @@ diagnostic_report_diagnostic (diagnostic_context *context,

>     return true;

>   }

>   

> -/* Get the number of digits in the decimal representation of VALUE.  */

> +/* Get the number of digits in the decimal representation of VALUE.

> +

> +   If USE_NN_P is true, return 2 (for the case where all numbers are to

> +   be printed as just "NN").  */

>   

>   int

> -num_digits (int value)

> +num_digits (int value, bool use_nn_p)

>   {

>     /* Perhaps simpler to use log10 for this, but doing it this way avoids

>        using floating point.  */

>     gcc_assert (value >= 0);

>   

> +  if (use_nn_p)

> +    return 2;

> +


I assume you added the argument to the function to avoid having
to test m_use_nn_for_line_numbers_p at each call site, but, FWIW,
I don't really think it belongs in such a general purpose utility
function.  I don't see it called too many times so it's not a big
deal either way, but it is something that jumped out at me as odd.

Martin

>     if (value == 0)

>       return 1;

>   

> @@ -1885,6 +1892,8 @@ test_num_digits ()

>     ASSERT_EQ (7, num_digits (9999999));

>     ASSERT_EQ (8, num_digits (10000000));

>     ASSERT_EQ (8, num_digits (99999999));

> +

> +  ASSERT_EQ (2, num_digits (1000, true));

>   }

>   

>   /* Run all of the selftests within this file.  */

> diff --git a/gcc/diagnostic.h b/gcc/diagnostic.h

> index 91e4c50..2fb75e6 100644

> --- a/gcc/diagnostic.h

> +++ b/gcc/diagnostic.h

> @@ -233,6 +233,10 @@ struct diagnostic_context

>        showing line numbers?  */

>     bool show_line_numbers_p;

>   

> +  /* When printing line numbers, should the actual numbers be replaced with

> +     "NN"? (for ease of DejaGnu testing)  */

> +  bool use_nn_for_line_numbers_p;

> +

>     /* If printing source code, what should the minimum width of the margin

>        be?  Line numbers will be right-aligned, and padded to this width.  */

>     int min_margin_width;

> @@ -432,6 +436,6 @@ extern void diagnostic_output_format_init (diagnostic_context *,

>   					   enum diagnostics_output_format);

>   

>   /* Compute the number of digits in the decimal representation of an integer.  */

> -extern int num_digits (int);

> +extern int num_digits (int, bool use_nn_p = false);

>   

>   #endif /* ! GCC_DIAGNOSTIC_H */

> diff --git a/gcc/doc/invoke.texi b/gcc/doc/invoke.texi

> index 384848a..fc92913 100644

> --- a/gcc/doc/invoke.texi

> +++ b/gcc/doc/invoke.texi

> @@ -278,6 +278,7 @@ Objective-C and Objective-C++ Dialects}.

>   -fdiagnostics-format=@r{[}text@r{|}json@r{]}  @gol

>   -fno-diagnostics-show-option  -fno-diagnostics-show-caret @gol

>   -fno-diagnostics-show-labels  -fno-diagnostics-show-line-numbers @gol

> +-fdiagnostics-nn-line-numbers @gol

>   -fdiagnostics-minimum-margin-width=@var{width} @gol

>   -fdiagnostics-parseable-fixits  -fdiagnostics-generate-patch @gol

>   -fdiagnostics-show-template-tree  -fno-elide-type @gol

> @@ -4018,6 +4019,12 @@ By default, when printing source code (via @option{-fdiagnostics-show-caret}),

>   a left margin is printed, showing line numbers.  This option suppresses this

>   left margin.

>   

> +@item -fdiagnostics-nn-line-numbers

> +@opindex fdiagnostics-nn-line-numbers

> +When printing source code in diagnostics, replace line numbers ``NN''.

> +This option is intended for GCC developers, to make it easier to write

> +certain kinds of automated test.

> +

>   @item -fdiagnostics-minimum-margin-width=@var{width}

>   @opindex fdiagnostics-minimum-margin-width

>   This option controls the minimum width of the left margin printed by

> diff --git a/gcc/dwarf2out.c b/gcc/dwarf2out.c

> index bf69ce4..3207040 100644

> --- a/gcc/dwarf2out.c

> +++ b/gcc/dwarf2out.c

> @@ -24490,6 +24490,7 @@ gen_producer_string (void)

>         case OPT_fdiagnostics_show_caret:

>         case OPT_fdiagnostics_show_labels:

>         case OPT_fdiagnostics_show_line_numbers:

> +      case OPT_fdiagnostics_nn_line_numbers:

>         case OPT_fdiagnostics_color_:

>         case OPT_fdiagnostics_format_:

>         case OPT_fverbose_asm:

> diff --git a/gcc/lto-wrapper.c b/gcc/lto-wrapper.c

> index 9a7bbd0..aabfe6d 100644

> --- a/gcc/lto-wrapper.c

> +++ b/gcc/lto-wrapper.c

> @@ -260,6 +260,7 @@ merge_and_complain (struct cl_decoded_option **decoded_options,

>   	case OPT_fdiagnostics_show_caret:

>   	case OPT_fdiagnostics_show_labels:

>   	case OPT_fdiagnostics_show_line_numbers:

> +	case OPT_fdiagnostics_nn_line_numbers:

>   	case OPT_fdiagnostics_show_option:

>   	case OPT_fdiagnostics_show_location_:

>   	case OPT_fshow_column:

> @@ -605,6 +606,7 @@ append_compiler_options (obstack *argv_obstack, struct cl_decoded_option *opts,

>   	case OPT_fdiagnostics_show_caret:

>   	case OPT_fdiagnostics_show_labels:

>   	case OPT_fdiagnostics_show_line_numbers:

> +	case OPT_fdiagnostics_nn_line_numbers:

>   	case OPT_fdiagnostics_show_option:

>   	case OPT_fdiagnostics_show_location_:

>   	case OPT_fshow_column:

> @@ -653,6 +655,7 @@ append_diag_options (obstack *argv_obstack, struct cl_decoded_option *opts,

>   	case OPT_fdiagnostics_format_:

>   	case OPT_fdiagnostics_show_caret:

>   	case OPT_fdiagnostics_show_labels:

> +	case OPT_fdiagnostics_nn_line_numbers:

>   	case OPT_fdiagnostics_show_line_numbers:

>   	case OPT_fdiagnostics_show_option:

>   	case OPT_fdiagnostics_show_location_:

> diff --git a/gcc/opts.c b/gcc/opts.c

> index 32869ca..9928d01 100644

> --- a/gcc/opts.c

> +++ b/gcc/opts.c

> @@ -2470,6 +2470,10 @@ common_handle_option (struct gcc_options *opts,

>         dc->show_line_numbers_p = value;

>         break;

>   

> +    case OPT_fdiagnostics_nn_line_numbers:

> +      dc->use_nn_for_line_numbers_p = value;

> +      break;

> +

>       case OPT_fdiagnostics_color_:

>         diagnostic_color_init (dc, value);

>         break;

> diff --git a/gcc/toplev.c b/gcc/toplev.c

> index 1c7002f..2d0a390 100644

> --- a/gcc/toplev.c

> +++ b/gcc/toplev.c

> @@ -1100,6 +1100,8 @@ general_init (const char *argv0, bool init_signals)

>       = global_options_init.x_flag_diagnostics_show_labels;

>     global_dc->show_line_numbers_p

>       = global_options_init.x_flag_diagnostics_show_line_numbers;

> +  global_dc->use_nn_for_line_numbers_p

> +    = global_options_init.x_flag_diagnostics_nn_line_numbers;

>     global_dc->show_option_requested

>       = global_options_init.x_flag_diagnostics_show_option;

>     global_dc->min_margin_width

>
Martin Sebor Dec. 4, 2019, 5:24 p.m. | #2
On 11/15/19 6:22 PM, David Malcolm wrote:
> This patch implements -fdiagnostics-nn-line-numbers, a new option

> which makes diagnostic_show_locus print "NN" rather than specific

> line numbers when printing the left margin.

> 

> This is intended purely to make it easier to write certain kinds of

> DejaGnu test; various integration tests for diagnostic paths later

> in the patch kit make use of it.


Is there no other way to expose this internal feature than under
a user-visible option?  Or get the tests to work without it?

Martin

> gcc/ChangeLog:

> 	* common.opt (fdiagnostics-nn-line-numbers): New option.

> 	* diagnostic-show-locus.c (layout::m_use_nn_for_line_numbers_p):

> 	New field.

> 	(layout::layout): Initialize it and use it when computing

> 	m_linenum_width.

> 	(layout::print_source_line): Implement printing "NN" rather than

> 	the line number.

> 	(selftest::test_line_numbers_multiline_range): Add a test of "NN"

> 	printing.

> 	* diagnostic.c (diagnostic_initialize): Initialize

> 	use_nn_for_line_numbers_p.

> 	(num_digits): Add "use_nn_p" param.

> 	(selftest::test_num_digits): Add a test for use_nn_p==true.

> 	* diagnostic.h (diagnostic_context::use_nn_for_line_numbers_p):

> 	New field.

> 	(num_digits): Add optional "use_nn_p" param.

> 	* doc/invoke.texi (-fdiagnostics-nn-line-numbers): New option.

> 	* dwarf2out.c (gen_producer_string): Ignore

> 	OPT_fdiagnostics_nn_line_numbers.

> 	* lto-wrapper.c (merge_and_complain): Handle

> 	OPT_fdiagnostics_nn_line_numbers.

> 	(append_compiler_options): Likewise.

> 	(append_diag_options): Likewise.

> 	* opts.c (common_handle_option): Likewise.

> 	* toplev.c (general_init): Initialize

> 	global_dc->use_nn_for_line_numbers_p.

> ---

>   gcc/common.opt              |  4 ++++

>   gcc/diagnostic-show-locus.c | 51 ++++++++++++++++++++++++++++++++-------------

>   gcc/diagnostic.c            | 13 ++++++++++--

>   gcc/diagnostic.h            |  6 +++++-

>   gcc/doc/invoke.texi         |  7 +++++++

>   gcc/dwarf2out.c             |  1 +

>   gcc/lto-wrapper.c           |  3 +++

>   gcc/opts.c                  |  4 ++++

>   gcc/toplev.c                |  2 ++

>   9 files changed, 73 insertions(+), 18 deletions(-)

> 

> diff --git a/gcc/common.opt b/gcc/common.opt

> index 124e8cf..3c024b3 100644

> --- a/gcc/common.opt

> +++ b/gcc/common.opt

> @@ -1257,6 +1257,10 @@ fdiagnostics-show-line-numbers

>   Common Var(flag_diagnostics_show_line_numbers) Init(1)

>   Show line numbers in the left margin when showing source.

>   

> +fdiagnostics-nn-line-numbers

> +Common Var(flag_diagnostics_nn_line_numbers) Init(0)

> +Replace line numbers with 'NN' when showing source.

> +

>   fdiagnostics-color

>   Common Alias(fdiagnostics-color=,always,never)

>   ;

> diff --git a/gcc/diagnostic-show-locus.c b/gcc/diagnostic-show-locus.c

> index 412b0d4..ec5fdc0 100644

> --- a/gcc/diagnostic-show-locus.c

> +++ b/gcc/diagnostic-show-locus.c

> @@ -303,6 +303,7 @@ class layout

>     bool m_colorize_source_p;

>     bool m_show_labels_p;

>     bool m_show_line_numbers_p;

> +  bool m_use_nn_for_line_numbers_p;

>     auto_vec <layout_range> m_layout_ranges;

>     auto_vec <const fixit_hint *> m_fixit_hints;

>     auto_vec <line_span> m_line_spans;

> @@ -849,6 +850,7 @@ layout::layout (diagnostic_context * context,

>     m_colorize_source_p (context->colorize_source_p),

>     m_show_labels_p (context->show_labels_p),

>     m_show_line_numbers_p (context->show_line_numbers_p),

> +  m_use_nn_for_line_numbers_p (context->use_nn_for_line_numbers_p),

>     m_layout_ranges (richloc->get_num_locations ()),

>     m_fixit_hints (richloc->get_num_fixit_hints ()),

>     m_line_spans (1 + richloc->get_num_locations ()),

> @@ -884,7 +886,7 @@ layout::layout (diagnostic_context * context,

>     int highest_line = last_span->m_last_line;

>     if (highest_line < 0)

>       highest_line = 0;

> -  m_linenum_width = num_digits (highest_line);

> +  m_linenum_width = num_digits (highest_line, m_use_nn_for_line_numbers_p);

>     /* If we're showing jumps in the line-numbering, allow at least 3 chars.  */

>     if (m_line_spans.length () > 1)

>       m_linenum_width = MAX (m_linenum_width, 3);

> @@ -1272,10 +1274,13 @@ layout::print_source_line (linenum_type row, const char *line, int line_width,

>   

>     if (m_show_line_numbers_p)

>       {

> -      int width = num_digits (row);

> +      int width = num_digits (row, m_use_nn_for_line_numbers_p);

>         for (int i = 0; i < m_linenum_width - width; i++)

>   	pp_space (m_pp);

> -      pp_printf (m_pp, "%i | ", row);

> +      if (m_use_nn_for_line_numbers_p)

> +	pp_printf (m_pp, "%s | ", "NN");

> +      else

> +	pp_printf (m_pp, "%i | ", row);

>       }

>     else

>       pp_space (m_pp);

> @@ -3778,18 +3783,34 @@ test_line_numbers_multiline_range ()

>       = linemap_position_for_line_and_column (line_table, ord_map, 11, 4);

>     location_t loc = make_location (caret, start, finish);

>   

> -  test_diagnostic_context dc;

> -  dc.show_line_numbers_p = true;

> -  dc.min_margin_width = 0;

> -  gcc_rich_location richloc (loc);

> -  diagnostic_show_locus (&dc, &richloc, DK_ERROR);

> -  ASSERT_STREQ (" 9 | this is line 9\n"

> -		"   |         ~~~~~~\n"

> -		"10 | this is line 10\n"

> -		"   | ~~~~~^~~~~~~~~~\n"

> -		"11 | this is line 11\n"

> -		"   | ~~~~  \n",

> -		pp_formatted_text (dc.printer));

> +  {

> +    test_diagnostic_context dc;

> +    dc.show_line_numbers_p = true;

> +    dc.min_margin_width = 0;

> +    gcc_rich_location richloc (loc);

> +    diagnostic_show_locus (&dc, &richloc, DK_ERROR);

> +    ASSERT_STREQ (" 9 | this is line 9\n"

> +		  "   |         ~~~~~~\n"

> +		  "10 | this is line 10\n"

> +		  "   | ~~~~~^~~~~~~~~~\n"

> +		  "11 | this is line 11\n"

> +		  "   | ~~~~  \n",

> +		  pp_formatted_text (dc.printer));

> +  }

> +

> +  /* Verify that obscuring line numbers via "NN" works (and always uses

> +     at least two columns).  */

> +  {

> +    test_diagnostic_context dc;

> +    dc.show_line_numbers_p = true;

> +    dc.use_nn_for_line_numbers_p = true;

> +    dc.min_margin_width = 0;

> +    gcc_rich_location richloc (start);

> +    diagnostic_show_locus (&dc, &richloc, DK_ERROR);

> +    ASSERT_STREQ ("NN | this is line 9\n"

> +		  "   |         ^\n",

> +		  pp_formatted_text (dc.printer));

> +  }

>   }

>   

>   /* Run all of the selftests within this file.  */

> diff --git a/gcc/diagnostic.c b/gcc/diagnostic.c

> index d6604e6..81e0a10 100644

> --- a/gcc/diagnostic.c

> +++ b/gcc/diagnostic.c

> @@ -209,6 +209,7 @@ diagnostic_initialize (diagnostic_context *context, int n_opts)

>     context->colorize_source_p = false;

>     context->show_labels_p = false;

>     context->show_line_numbers_p = false;

> +  context->use_nn_for_line_numbers_p = false;

>     context->min_margin_width = 0;

>     context->show_ruler_p = false;

>     context->parseable_fixits_p = false;

> @@ -1078,15 +1079,21 @@ diagnostic_report_diagnostic (diagnostic_context *context,

>     return true;

>   }

>   

> -/* Get the number of digits in the decimal representation of VALUE.  */

> +/* Get the number of digits in the decimal representation of VALUE.

> +

> +   If USE_NN_P is true, return 2 (for the case where all numbers are to

> +   be printed as just "NN").  */

>   

>   int

> -num_digits (int value)

> +num_digits (int value, bool use_nn_p)

>   {

>     /* Perhaps simpler to use log10 for this, but doing it this way avoids

>        using floating point.  */

>     gcc_assert (value >= 0);

>   

> +  if (use_nn_p)

> +    return 2;

> +

>     if (value == 0)

>       return 1;

>   

> @@ -1885,6 +1892,8 @@ test_num_digits ()

>     ASSERT_EQ (7, num_digits (9999999));

>     ASSERT_EQ (8, num_digits (10000000));

>     ASSERT_EQ (8, num_digits (99999999));

> +

> +  ASSERT_EQ (2, num_digits (1000, true));

>   }

>   

>   /* Run all of the selftests within this file.  */

> diff --git a/gcc/diagnostic.h b/gcc/diagnostic.h

> index 91e4c50..2fb75e6 100644

> --- a/gcc/diagnostic.h

> +++ b/gcc/diagnostic.h

> @@ -233,6 +233,10 @@ struct diagnostic_context

>        showing line numbers?  */

>     bool show_line_numbers_p;

>   

> +  /* When printing line numbers, should the actual numbers be replaced with

> +     "NN"? (for ease of DejaGnu testing)  */

> +  bool use_nn_for_line_numbers_p;

> +

>     /* If printing source code, what should the minimum width of the margin

>        be?  Line numbers will be right-aligned, and padded to this width.  */

>     int min_margin_width;

> @@ -432,6 +436,6 @@ extern void diagnostic_output_format_init (diagnostic_context *,

>   					   enum diagnostics_output_format);

>   

>   /* Compute the number of digits in the decimal representation of an integer.  */

> -extern int num_digits (int);

> +extern int num_digits (int, bool use_nn_p = false);

>   

>   #endif /* ! GCC_DIAGNOSTIC_H */

> diff --git a/gcc/doc/invoke.texi b/gcc/doc/invoke.texi

> index 384848a..fc92913 100644

> --- a/gcc/doc/invoke.texi

> +++ b/gcc/doc/invoke.texi

> @@ -278,6 +278,7 @@ Objective-C and Objective-C++ Dialects}.

>   -fdiagnostics-format=@r{[}text@r{|}json@r{]}  @gol

>   -fno-diagnostics-show-option  -fno-diagnostics-show-caret @gol

>   -fno-diagnostics-show-labels  -fno-diagnostics-show-line-numbers @gol

> +-fdiagnostics-nn-line-numbers @gol

>   -fdiagnostics-minimum-margin-width=@var{width} @gol

>   -fdiagnostics-parseable-fixits  -fdiagnostics-generate-patch @gol

>   -fdiagnostics-show-template-tree  -fno-elide-type @gol

> @@ -4018,6 +4019,12 @@ By default, when printing source code (via @option{-fdiagnostics-show-caret}),

>   a left margin is printed, showing line numbers.  This option suppresses this

>   left margin.

>   

> +@item -fdiagnostics-nn-line-numbers

> +@opindex fdiagnostics-nn-line-numbers

> +When printing source code in diagnostics, replace line numbers ``NN''.

> +This option is intended for GCC developers, to make it easier to write

> +certain kinds of automated test.

> +

>   @item -fdiagnostics-minimum-margin-width=@var{width}

>   @opindex fdiagnostics-minimum-margin-width

>   This option controls the minimum width of the left margin printed by

> diff --git a/gcc/dwarf2out.c b/gcc/dwarf2out.c

> index bf69ce4..3207040 100644

> --- a/gcc/dwarf2out.c

> +++ b/gcc/dwarf2out.c

> @@ -24490,6 +24490,7 @@ gen_producer_string (void)

>         case OPT_fdiagnostics_show_caret:

>         case OPT_fdiagnostics_show_labels:

>         case OPT_fdiagnostics_show_line_numbers:

> +      case OPT_fdiagnostics_nn_line_numbers:

>         case OPT_fdiagnostics_color_:

>         case OPT_fdiagnostics_format_:

>         case OPT_fverbose_asm:

> diff --git a/gcc/lto-wrapper.c b/gcc/lto-wrapper.c

> index 9a7bbd0..aabfe6d 100644

> --- a/gcc/lto-wrapper.c

> +++ b/gcc/lto-wrapper.c

> @@ -260,6 +260,7 @@ merge_and_complain (struct cl_decoded_option **decoded_options,

>   	case OPT_fdiagnostics_show_caret:

>   	case OPT_fdiagnostics_show_labels:

>   	case OPT_fdiagnostics_show_line_numbers:

> +	case OPT_fdiagnostics_nn_line_numbers:

>   	case OPT_fdiagnostics_show_option:

>   	case OPT_fdiagnostics_show_location_:

>   	case OPT_fshow_column:

> @@ -605,6 +606,7 @@ append_compiler_options (obstack *argv_obstack, struct cl_decoded_option *opts,

>   	case OPT_fdiagnostics_show_caret:

>   	case OPT_fdiagnostics_show_labels:

>   	case OPT_fdiagnostics_show_line_numbers:

> +	case OPT_fdiagnostics_nn_line_numbers:

>   	case OPT_fdiagnostics_show_option:

>   	case OPT_fdiagnostics_show_location_:

>   	case OPT_fshow_column:

> @@ -653,6 +655,7 @@ append_diag_options (obstack *argv_obstack, struct cl_decoded_option *opts,

>   	case OPT_fdiagnostics_format_:

>   	case OPT_fdiagnostics_show_caret:

>   	case OPT_fdiagnostics_show_labels:

> +	case OPT_fdiagnostics_nn_line_numbers:

>   	case OPT_fdiagnostics_show_line_numbers:

>   	case OPT_fdiagnostics_show_option:

>   	case OPT_fdiagnostics_show_location_:

> diff --git a/gcc/opts.c b/gcc/opts.c

> index 32869ca..9928d01 100644

> --- a/gcc/opts.c

> +++ b/gcc/opts.c

> @@ -2470,6 +2470,10 @@ common_handle_option (struct gcc_options *opts,

>         dc->show_line_numbers_p = value;

>         break;

>   

> +    case OPT_fdiagnostics_nn_line_numbers:

> +      dc->use_nn_for_line_numbers_p = value;

> +      break;

> +

>       case OPT_fdiagnostics_color_:

>         diagnostic_color_init (dc, value);

>         break;

> diff --git a/gcc/toplev.c b/gcc/toplev.c

> index 1c7002f..2d0a390 100644

> --- a/gcc/toplev.c

> +++ b/gcc/toplev.c

> @@ -1100,6 +1100,8 @@ general_init (const char *argv0, bool init_signals)

>       = global_options_init.x_flag_diagnostics_show_labels;

>     global_dc->show_line_numbers_p

>       = global_options_init.x_flag_diagnostics_show_line_numbers;

> +  global_dc->use_nn_for_line_numbers_p

> +    = global_options_init.x_flag_diagnostics_nn_line_numbers;

>     global_dc->show_option_requested

>       = global_options_init.x_flag_diagnostics_show_option;

>     global_dc->min_margin_width

>

Patch

diff --git a/gcc/common.opt b/gcc/common.opt
index 124e8cf..3c024b3 100644
--- a/gcc/common.opt
+++ b/gcc/common.opt
@@ -1257,6 +1257,10 @@  fdiagnostics-show-line-numbers
 Common Var(flag_diagnostics_show_line_numbers) Init(1)
 Show line numbers in the left margin when showing source.
 
+fdiagnostics-nn-line-numbers
+Common Var(flag_diagnostics_nn_line_numbers) Init(0)
+Replace line numbers with 'NN' when showing source.
+
 fdiagnostics-color
 Common Alias(fdiagnostics-color=,always,never)
 ;
diff --git a/gcc/diagnostic-show-locus.c b/gcc/diagnostic-show-locus.c
index 412b0d4..ec5fdc0 100644
--- a/gcc/diagnostic-show-locus.c
+++ b/gcc/diagnostic-show-locus.c
@@ -303,6 +303,7 @@  class layout
   bool m_colorize_source_p;
   bool m_show_labels_p;
   bool m_show_line_numbers_p;
+  bool m_use_nn_for_line_numbers_p;
   auto_vec <layout_range> m_layout_ranges;
   auto_vec <const fixit_hint *> m_fixit_hints;
   auto_vec <line_span> m_line_spans;
@@ -849,6 +850,7 @@  layout::layout (diagnostic_context * context,
   m_colorize_source_p (context->colorize_source_p),
   m_show_labels_p (context->show_labels_p),
   m_show_line_numbers_p (context->show_line_numbers_p),
+  m_use_nn_for_line_numbers_p (context->use_nn_for_line_numbers_p),
   m_layout_ranges (richloc->get_num_locations ()),
   m_fixit_hints (richloc->get_num_fixit_hints ()),
   m_line_spans (1 + richloc->get_num_locations ()),
@@ -884,7 +886,7 @@  layout::layout (diagnostic_context * context,
   int highest_line = last_span->m_last_line;
   if (highest_line < 0)
     highest_line = 0;
-  m_linenum_width = num_digits (highest_line);
+  m_linenum_width = num_digits (highest_line, m_use_nn_for_line_numbers_p);
   /* If we're showing jumps in the line-numbering, allow at least 3 chars.  */
   if (m_line_spans.length () > 1)
     m_linenum_width = MAX (m_linenum_width, 3);
@@ -1272,10 +1274,13 @@  layout::print_source_line (linenum_type row, const char *line, int line_width,
 
   if (m_show_line_numbers_p)
     {
-      int width = num_digits (row);
+      int width = num_digits (row, m_use_nn_for_line_numbers_p);
       for (int i = 0; i < m_linenum_width - width; i++)
 	pp_space (m_pp);
-      pp_printf (m_pp, "%i | ", row);
+      if (m_use_nn_for_line_numbers_p)
+	pp_printf (m_pp, "%s | ", "NN");
+      else
+	pp_printf (m_pp, "%i | ", row);
     }
   else
     pp_space (m_pp);
@@ -3778,18 +3783,34 @@  test_line_numbers_multiline_range ()
     = linemap_position_for_line_and_column (line_table, ord_map, 11, 4);
   location_t loc = make_location (caret, start, finish);
 
-  test_diagnostic_context dc;
-  dc.show_line_numbers_p = true;
-  dc.min_margin_width = 0;
-  gcc_rich_location richloc (loc);
-  diagnostic_show_locus (&dc, &richloc, DK_ERROR);
-  ASSERT_STREQ (" 9 | this is line 9\n"
-		"   |         ~~~~~~\n"
-		"10 | this is line 10\n"
-		"   | ~~~~~^~~~~~~~~~\n"
-		"11 | this is line 11\n"
-		"   | ~~~~  \n",
-		pp_formatted_text (dc.printer));
+  {
+    test_diagnostic_context dc;
+    dc.show_line_numbers_p = true;
+    dc.min_margin_width = 0;
+    gcc_rich_location richloc (loc);
+    diagnostic_show_locus (&dc, &richloc, DK_ERROR);
+    ASSERT_STREQ (" 9 | this is line 9\n"
+		  "   |         ~~~~~~\n"
+		  "10 | this is line 10\n"
+		  "   | ~~~~~^~~~~~~~~~\n"
+		  "11 | this is line 11\n"
+		  "   | ~~~~  \n",
+		  pp_formatted_text (dc.printer));
+  }
+
+  /* Verify that obscuring line numbers via "NN" works (and always uses
+     at least two columns).  */
+  {
+    test_diagnostic_context dc;
+    dc.show_line_numbers_p = true;
+    dc.use_nn_for_line_numbers_p = true;
+    dc.min_margin_width = 0;
+    gcc_rich_location richloc (start);
+    diagnostic_show_locus (&dc, &richloc, DK_ERROR);
+    ASSERT_STREQ ("NN | this is line 9\n"
+		  "   |         ^\n",
+		  pp_formatted_text (dc.printer));
+  }
 }
 
 /* Run all of the selftests within this file.  */
diff --git a/gcc/diagnostic.c b/gcc/diagnostic.c
index d6604e6..81e0a10 100644
--- a/gcc/diagnostic.c
+++ b/gcc/diagnostic.c
@@ -209,6 +209,7 @@  diagnostic_initialize (diagnostic_context *context, int n_opts)
   context->colorize_source_p = false;
   context->show_labels_p = false;
   context->show_line_numbers_p = false;
+  context->use_nn_for_line_numbers_p = false;
   context->min_margin_width = 0;
   context->show_ruler_p = false;
   context->parseable_fixits_p = false;
@@ -1078,15 +1079,21 @@  diagnostic_report_diagnostic (diagnostic_context *context,
   return true;
 }
 
-/* Get the number of digits in the decimal representation of VALUE.  */
+/* Get the number of digits in the decimal representation of VALUE.
+
+   If USE_NN_P is true, return 2 (for the case where all numbers are to
+   be printed as just "NN").  */
 
 int
-num_digits (int value)
+num_digits (int value, bool use_nn_p)
 {
   /* Perhaps simpler to use log10 for this, but doing it this way avoids
      using floating point.  */
   gcc_assert (value >= 0);
 
+  if (use_nn_p)
+    return 2;
+
   if (value == 0)
     return 1;
 
@@ -1885,6 +1892,8 @@  test_num_digits ()
   ASSERT_EQ (7, num_digits (9999999));
   ASSERT_EQ (8, num_digits (10000000));
   ASSERT_EQ (8, num_digits (99999999));
+
+  ASSERT_EQ (2, num_digits (1000, true));
 }
 
 /* Run all of the selftests within this file.  */
diff --git a/gcc/diagnostic.h b/gcc/diagnostic.h
index 91e4c50..2fb75e6 100644
--- a/gcc/diagnostic.h
+++ b/gcc/diagnostic.h
@@ -233,6 +233,10 @@  struct diagnostic_context
      showing line numbers?  */
   bool show_line_numbers_p;
 
+  /* When printing line numbers, should the actual numbers be replaced with
+     "NN"? (for ease of DejaGnu testing)  */
+  bool use_nn_for_line_numbers_p;
+
   /* If printing source code, what should the minimum width of the margin
      be?  Line numbers will be right-aligned, and padded to this width.  */
   int min_margin_width;
@@ -432,6 +436,6 @@  extern void diagnostic_output_format_init (diagnostic_context *,
 					   enum diagnostics_output_format);
 
 /* Compute the number of digits in the decimal representation of an integer.  */
-extern int num_digits (int);
+extern int num_digits (int, bool use_nn_p = false);
 
 #endif /* ! GCC_DIAGNOSTIC_H */
diff --git a/gcc/doc/invoke.texi b/gcc/doc/invoke.texi
index 384848a..fc92913 100644
--- a/gcc/doc/invoke.texi
+++ b/gcc/doc/invoke.texi
@@ -278,6 +278,7 @@  Objective-C and Objective-C++ Dialects}.
 -fdiagnostics-format=@r{[}text@r{|}json@r{]}  @gol
 -fno-diagnostics-show-option  -fno-diagnostics-show-caret @gol
 -fno-diagnostics-show-labels  -fno-diagnostics-show-line-numbers @gol
+-fdiagnostics-nn-line-numbers @gol
 -fdiagnostics-minimum-margin-width=@var{width} @gol
 -fdiagnostics-parseable-fixits  -fdiagnostics-generate-patch @gol
 -fdiagnostics-show-template-tree  -fno-elide-type @gol
@@ -4018,6 +4019,12 @@  By default, when printing source code (via @option{-fdiagnostics-show-caret}),
 a left margin is printed, showing line numbers.  This option suppresses this
 left margin.
 
+@item -fdiagnostics-nn-line-numbers
+@opindex fdiagnostics-nn-line-numbers
+When printing source code in diagnostics, replace line numbers ``NN''.
+This option is intended for GCC developers, to make it easier to write
+certain kinds of automated test.
+
 @item -fdiagnostics-minimum-margin-width=@var{width}
 @opindex fdiagnostics-minimum-margin-width
 This option controls the minimum width of the left margin printed by
diff --git a/gcc/dwarf2out.c b/gcc/dwarf2out.c
index bf69ce4..3207040 100644
--- a/gcc/dwarf2out.c
+++ b/gcc/dwarf2out.c
@@ -24490,6 +24490,7 @@  gen_producer_string (void)
       case OPT_fdiagnostics_show_caret:
       case OPT_fdiagnostics_show_labels:
       case OPT_fdiagnostics_show_line_numbers:
+      case OPT_fdiagnostics_nn_line_numbers:
       case OPT_fdiagnostics_color_:
       case OPT_fdiagnostics_format_:
       case OPT_fverbose_asm:
diff --git a/gcc/lto-wrapper.c b/gcc/lto-wrapper.c
index 9a7bbd0..aabfe6d 100644
--- a/gcc/lto-wrapper.c
+++ b/gcc/lto-wrapper.c
@@ -260,6 +260,7 @@  merge_and_complain (struct cl_decoded_option **decoded_options,
 	case OPT_fdiagnostics_show_caret:
 	case OPT_fdiagnostics_show_labels:
 	case OPT_fdiagnostics_show_line_numbers:
+	case OPT_fdiagnostics_nn_line_numbers:
 	case OPT_fdiagnostics_show_option:
 	case OPT_fdiagnostics_show_location_:
 	case OPT_fshow_column:
@@ -605,6 +606,7 @@  append_compiler_options (obstack *argv_obstack, struct cl_decoded_option *opts,
 	case OPT_fdiagnostics_show_caret:
 	case OPT_fdiagnostics_show_labels:
 	case OPT_fdiagnostics_show_line_numbers:
+	case OPT_fdiagnostics_nn_line_numbers:
 	case OPT_fdiagnostics_show_option:
 	case OPT_fdiagnostics_show_location_:
 	case OPT_fshow_column:
@@ -653,6 +655,7 @@  append_diag_options (obstack *argv_obstack, struct cl_decoded_option *opts,
 	case OPT_fdiagnostics_format_:
 	case OPT_fdiagnostics_show_caret:
 	case OPT_fdiagnostics_show_labels:
+	case OPT_fdiagnostics_nn_line_numbers:
 	case OPT_fdiagnostics_show_line_numbers:
 	case OPT_fdiagnostics_show_option:
 	case OPT_fdiagnostics_show_location_:
diff --git a/gcc/opts.c b/gcc/opts.c
index 32869ca..9928d01 100644
--- a/gcc/opts.c
+++ b/gcc/opts.c
@@ -2470,6 +2470,10 @@  common_handle_option (struct gcc_options *opts,
       dc->show_line_numbers_p = value;
       break;
 
+    case OPT_fdiagnostics_nn_line_numbers:
+      dc->use_nn_for_line_numbers_p = value;
+      break;
+
     case OPT_fdiagnostics_color_:
       diagnostic_color_init (dc, value);
       break;
diff --git a/gcc/toplev.c b/gcc/toplev.c
index 1c7002f..2d0a390 100644
--- a/gcc/toplev.c
+++ b/gcc/toplev.c
@@ -1100,6 +1100,8 @@  general_init (const char *argv0, bool init_signals)
     = global_options_init.x_flag_diagnostics_show_labels;
   global_dc->show_line_numbers_p
     = global_options_init.x_flag_diagnostics_show_line_numbers;
+  global_dc->use_nn_for_line_numbers_p
+    = global_options_init.x_flag_diagnostics_nn_line_numbers;
   global_dc->show_option_requested
     = global_options_init.x_flag_diagnostics_show_option;
   global_dc->min_margin_width