[PATCH] PR other/69554: avoid excessive source printing for widely-separated locations

[Jeff Law]

On 02/12/2016 12:06 PM, David Malcolm wrote:
> On Fri, 2016-02-12 at 11:25 -0700, Jeff Law wrote:
>> On 02/09/2016 01:54 PM, David Malcolm wrote:
>>
>>> gcc/ChangeLog:
>>> 	PR other/69554
>>> 	* diagnostic-show-locus.c (struct line_span): New struct.
>>> 	(layout::get_first_line): Delete.
>>> 	(layout::get_last_line): Delete.
>>> 	(layout::get_num_line_spans): New member function.
>>> 	(layout::get_line_span): Likewise.
>>> 	(layout::print_heading_for_line_span_index_p): Likewise.
>>> 	(layout::get_expanded_location): Likewise.
>>> 	(layout::calculate_line_spans): Likewise.
>>> 	(layout::m_first_line): Delete.
>>> 	(layout::m_last_line): Delete.
>>> 	(layout::m_line_spans): New field.
>>> 	(layout::layout): Update comment.  Replace m_first_line and
>>> 	m_last_line with m_line_spans, replacing their initialization
>>> 	with a call to calculate_line_spans.
>>> 	(diagnostic_show_locus): When printing source lines and
>>> 	annotations, rather than looping over a single span
>>> 	of lines, instead loop over each line_span within
>>> 	the layout, with an inner loop over the lines within them.
>>> 	Call the context's start_span callback when changing line
>>> spans.
>>> 	* diagnostic.c (diagnostic_initialize): Initialize start_span.
>>> 	(diagnostic_build_prefix): Break out the building of the
>>> location
>>> 	part of the string into...
>>> 	(diagnostic_get_location_text): ...this new function, rewriting
>>> 	it from nested ternary expressions to a sequence of "if"
>>> 	statements.
>>> 	(default_diagnostic_start_span_fn): New function.
>>> 	* diagnostic.h (diagnostic_start_span_fn): New typedef.
>>> 	(diagnostic_context::start_span): New field.
>>> 	(default_diagnostic_start_span_fn): New prototype.
>>>
>>> gcc/fortran/ChangeLog:
>>> 	PR other/69554
>>> 	* error.c (gfc_diagnostic_start_span): New function.
>>> 	(gfc_diagnostics_init): Initialize global_dc's start_span.
>>>
>>> gcc/testsuite/ChangeLog:
>>> 	PR other/69554
>>> 	* gcc.dg/pr69554-1.c: New test.
>>> 	* gfortran.dg/pr69554-1.F90: New test.
>>> 	* gfortran.dg/pr69554-2.F90: New test.
>>> 	* lib/gcc-dg.exp (proc dg-locus): New function.
>>> 	* lib/gfortran-dg.exp (proc gfortran-dg-test): Update comment
>>> to
>>> 	distinguish between the caret-printing and non-caret-printing
>>> 	cases.  If caret-printing has been explicitly enabled, bail out
>>> 	without attempting to fix up the output.
>>> ---
>>>    gcc/diagnostic-show-locus.c             | 226
>>> ++++++++++++++++++++++++++++----
>>>    gcc/diagnostic.c                        |  62 ++++++---
>>>    gcc/diagnostic.h                        |  11 ++
>>>    gcc/fortran/error.c                     |  15 +++
>>>    gcc/testsuite/gcc.dg/pr69554-1.c        | 152
>>> +++++++++++++++++++++
>>>    gcc/testsuite/gfortran.dg/pr69554-1.F90 |  28 ++++
>>>    gcc/testsuite/gfortran.dg/pr69554-2.F90 |  21 +++
>>>    gcc/testsuite/lib/gcc-dg.exp            |  27 ++++
>>>    gcc/testsuite/lib/gfortran-dg.exp       |  19 ++-
>>>    9 files changed, 520 insertions(+), 41 deletions(-)
>>>    create mode 100644 gcc/testsuite/gcc.dg/pr69554-1.c
>>>    create mode 100644 gcc/testsuite/gfortran.dg/pr69554-1.F90
>>>    create mode 100644 gcc/testsuite/gfortran.dg/pr69554-2.F90
>>>
>>> diff --git a/gcc/diagnostic-show-locus.c b/gcc/diagnostic-show
>>> -locus.c
>>> index d9b6750..698f42e 100644
>>> --- a/gcc/diagnostic-show-locus.c
>>> +++ b/gcc/diagnostic-show-locus.c
>>
>>> @@ -437,8 +477,7 @@ layout::layout (diagnostic_context * context,
>>>      m_colorizer (context, diagnostic),
>>>      m_colorize_source_p (context->colorize_source_p),
>>>      m_layout_ranges (rich_location::MAX_RANGES),
>>> -  m_first_line (m_exploc.line),
>>> -  m_last_line  (m_exploc.line),
>>> +  m_line_spans (1 + rich_location::MAX_RANGES),
>>>      m_x_offset (0)
>> Umm, does that allocate 1 + rich_location::MAX_RANGES linespans?
>>
>>
>>
>>> +  auto_vec<line_span> tmp_spans (1 + rich_location::MAX_RANGES);
>>
>> Similarly.
>
> Yes, it's preallocating space in the vecs.  rich_location::MAX_RANGES
> is 3, so there can be at most 4 line spans to consider.
Ah, nevermind then.  If it's just 4, then I'm not worried.

OK for the trunk.
jeff