Hi, Richard,
> On Apr 23, 2020, at 1:27 PM, Richard Sandiford <richard.sandif...@arm.com>
> wrote:
>
> Qing Zhao <qing.z...@oracle.com> writes:
>> ---
>> gcc/c-family/c-indentation.c | 3 +++
>> gcc/common.opt | 5 +++++
>> gcc/doc/invoke.texi | 15 ++++++++++++++-
>> gcc/testsuite/gcc.dg/plugin/location-overflow-test-1.c | 2 +-
>> gcc/toplev.c | 3 +++
>> 5 files changed, 26 insertions(+), 2 deletions(-)
>>
>> diff --git a/gcc/c-family/c-indentation.c b/gcc/c-family/c-indentation.c
>> index f737555..7074b10 100644
>> --- a/gcc/c-family/c-indentation.c
>> +++ b/gcc/c-family/c-indentation.c
>> @@ -67,6 +67,9 @@ get_visual_column (expanded_location exploc, location_t
>> loc,
>> "%<-Wmisleading-indentation%> is disabled from this point"
>> " onwards, since column-tracking was disabled due to"
>> " the size of the code/headers");
>> + inform (loc,
>> + "please add %<-flarge-source-files%> to invoke more"
>> + " column-tracking for large source files");
>> }
>> return false;
>> }
>
> This should be conditional on !flag_large_source_files.
Yes, indeed, will add it.
>
>> diff --git a/gcc/common.opt b/gcc/common.opt
>> index 4368910..10a3d5b 100644
>> --- a/gcc/common.opt
>> +++ b/gcc/common.opt
>> @@ -1597,6 +1597,11 @@ fkeep-gc-roots-live
>> Common Undocumented Report Var(flag_keep_gc_roots_live) Optimization
>> ; Always keep a pointer to a live memory block
>>
>> +flarge-source-files
>> +Common Report Var(flag_large_source_files) Init(0)
>> +Adjust GCC to cope with large source files to provide more accurate
>> +column information.
>> +
>
> I'm having difficulty suggesting wording here, but I think would be good
> to mention the downside. How about:
>
> ----------------------
> Improve GCC's ability to track column numbers in large source files,
> at the expense of slower compilation.
> ———————————
Sounds better than my previous wording. Thanks.
>
>> floop-parallelize-all
>> Common Report Var(flag_loop_parallelize_all) Optimization
>> Mark all loops as parallel.
>> diff --git a/gcc/doc/invoke.texi b/gcc/doc/invoke.texi
>> index 96a9516..c6ea9ef 100644
>> --- a/gcc/doc/invoke.texi
>> +++ b/gcc/doc/invoke.texi
>> @@ -574,7 +574,7 @@ Objective-C and Objective-C++ Dialects}.
>> -fdebug-cpp -fdirectives-only -fdollars-in-identifiers @gol
>> -fexec-charset=@var{charset} -fextended-identifiers @gol
>> -finput-charset=@var{charset} -fmacro-prefix-map=@var{old}=@var{new} @gol
>> --fmax-include-depth=@var{depth} @gol
>> +-fmax-include-depth=@var{depth} -flarge-source-files @gol
>> -fno-canonical-system-headers -fpch-deps -fpch-preprocess @gol
>> -fpreprocessed -ftabstop=@var{width} -ftrack-macro-expansion @gol
>> -fwide-exec-charset=@var{charset} -fworking-directory @gol
>
> This should be kept in alphabetical order, so after -finput-charset.
Okay.
>
>> @@ -14151,6 +14151,19 @@ This option may be useful in conjunction with the
>> @option{-B} or
>> perform additional processing of the program source between
>> normal preprocessing and compilation.
>>
>> +@item -flarge-source-files
>> +@opindex flarge-source-files
>> +Adjust GCC to cope with large source files to provide more accurate
>> +column information.
>> +By default, GCC will lose accurate column information if the source
>> +file is very large.
>> +If this option is provided, GCC will adapt accordingly to provide more
>> +accurate column information.
>> +This option may be useful when any user hits the
>> @option{-Wmisleading-indent}
>> +note, "is disabled from this point onwards, since column-tracking was
>> disabled
>> +due to the size of the code/headers", or hits the limit at which columns get
>> +dropped from diagnostics.
>> +
>
> On a similar vein, how about:
>
> ----------------------
> Adjust GCC to expect large source files, at the expense of slower
> compilation and higher memory usage.
>
> Specifically, GCC normally tracks both column numbers and line numbers
> within source files and it normally prints both of these numbers in
> diagnostics. However, once it has processed a certain number of source
> lines, it stops tracking column numbers and only tracks line numbers.
> This means that diagnostics for later lines do not include column numbers.
> It also means that options like @option{-Wmisleading-indent} cease to work
> at that point, although the compiler prints a note if this happens.
> Passing @option{-flarge-source-files} significantly increases the number
> of source lines that GCC can process before it stops tracking column
> numbers.
> ———————————
Thanks a lot for this paragraph. I will use it.
Qing
>
> Thanks,
> Richard
