This patch adds support to GCC's diagnostic subsystem for escaping certain
bytes and Unicode characters when quoting source code.
Specifically, this patch adds a new flag rich_location::m_escape_on_output
which is a hint from a diagnostic that non-ASCII bytes in the pertinent
lines of the user's source code should be escaped when printed.
The patch sets this for the following diagnostics:
- when complaining about stray bytes in the program (when these
are non-printable)
- when complaining about "null character(s) ignored");
- for -Wnormalized= (and generate source ranges for such warnings)
The escaping is controlled by a new option:
-fdiagnostics-escape-format=[unicode|bytes]
For example, consider a diagnostic involing a source line containing the
string "before" followed by the Unicode character U+03C0 ("GREEK SMALL
LETTER PI", with UTF-8 encoding 0xCF 0x80) followed by the byte 0xBF
(a stray UTF-8 trailing byte), followed by the string "after", where the
diagnostic highlights the U+03C0 character.
By default, this line will be printed verbatim to the user when
reporting a diagnostic at it, as:
beforeπXafter
^
(using X for the stray byte to avoid putting invalid UTF-8 in this
commit message)
If the diagnostic sets the "escape" flag, it will be printed as:
before<U+03C0><BF>after
^~~~~~~~
with -fdiagnostics-escape-format=unicode (the default), or as:
before<CF><80><BF>after
^~~~~~~~
if the user supplies -fdiagnostics-escape-format=bytes.
This only affects how the source is printed; it does not affect
how column numbers that are printed (as per -fdiagnostics-column-unit=
and -fdiagnostics-column-origin=).
gcc/c-family/ChangeLog:
* c-lex.c (c_lex_with_flags): When complaining about non-printable
CPP_OTHER tokens, set the "escape on output" flag.
gcc/ChangeLog:
* common.opt (fdiagnostics-escape-format=): New.
(diagnostics_escape_format): New enum.
(DIAGNOSTICS_ESCAPE_FORMAT_UNICODE): New enum value.
(DIAGNOSTICS_ESCAPE_FORMAT_BYTES): Likewise.
* diagnostic-format-json.cc (json_end_diagnostic): Add
"escape-source" attribute.
* diagnostic-show-locus.c
(exploc_with_display_col::exploc_with_display_col): Replace
"tabstop" param with a cpp_char_column_policy and add an "aspect"
param. Use these to compute m_display_col accordingly.
(struct char_display_policy): New struct.
(layout::m_policy): New field.
(layout::m_escape_on_output): New field.
(def_policy): New function.
(make_range): Update for changes to exploc_with_display_col ctor.
(default_print_decoded_ch): New.
(width_per_escaped_byte): New.
(escape_as_bytes_width): New.
(escape_as_bytes_print): New.
(escape_as_unicode_width): New.
(escape_as_unicode_print): New.
(make_policy): New.
(layout::layout): Initialize new fields. Update m_exploc ctor
call for above change to ctor.
(layout::maybe_add_location_range): Update for changes to
exploc_with_display_col ctor.
(layout::calculate_x_offset_display): Update for change to
cpp_display_width.
(layout::print_source_line): Pass policy
to cpp_display_width_computation. Capture cpp_decoded_char when
calling process_next_codepoint. Move printing of source code to
m_policy.m_print_cb.
(line_label::line_label): Pass in policy rather than context.
(layout::print_any_labels): Update for change to line_label ctor.
(get_affected_range): Pass in policy rather than context, updating
calls to location_compute_display_column accordingly.
(get_printed_columns): Likewise, also for cpp_display_width.
(correction::correction): Pass in policy rather than tabstop.
(correction::compute_display_cols): Pass m_policy rather than
m_tabstop to cpp_display_width.
(correction::m_tabstop): Replace with...
(correction::m_policy): ...this.
(line_corrections::line_corrections): Pass in policy rather than
context.
(line_corrections::m_context): Replace with...
(line_corrections::m_policy): ...this.
(line_corrections::add_hint): Update to use m_policy rather than
m_context.
(line_corrections::add_hint): Likewise.
(layout::print_trailing_fixits): Likewise.
(selftest::test_display_widths): New.
(selftest::test_layout_x_offset_display_utf8): Update to use
policy rather than tabstop.
(selftest::test_one_liner_labels_utf8): Add test of escaping
source lines.
(selftest::test_diagnostic_show_locus_one_liner_utf8): Update to
use policy rather than tabstop.
(selftest::test_overlapped_fixit_printing): Likewise.
(selftest::test_overlapped_fixit_printing_utf8): Likewise.
(selftest::test_overlapped_fixit_printing_2): Likewise.
(selftest::test_tab_expansion): Likewise.
(selftest::test_escaping_bytes_1): New.
(selftest::test_escaping_bytes_2): New.
(selftest::diagnostic_show_locus_c_tests): Call the new tests.
* diagnostic.c (diagnostic_initialize): Initialize
context->escape_format.
(convert_column_unit): Update to use default character width policy.
(selftest::test_diagnostic_get_location_text): Likewise.
* diagnostic.h (enum diagnostics_escape_format): New enum.
(diagnostic_context::escape_format): New field.
* doc/invoke.texi (-fdiagnostics-escape-format=): New option.
(-fdiagnostics-format=): Add "escape-source" attribute to examples
of JSON output, and document it.
* input.c (location_compute_display_column): Pass in "policy"
rather than "tabstop", passing to
cpp_byte_column_to_display_column.
(selftest::test_cpp_utf8): Update to use cpp_char_column_policy.
* input.h (class cpp_char_column_policy): New forward decl.
(location_compute_display_column): Pass in "policy" rather than
"tabstop".
* opts.c (common_handle_option): Handle
OPT_fdiagnostics_escape_format_.
* selftest.c (temp_source_file::temp_source_file): New ctor
overload taking a size_t.
* selftest.h (temp_source_file::temp_source_file): Likewise.
gcc/testsuite/ChangeLog:
* c-c++-common/diagnostic-format-json-1.c: Add regexp to consume
"escape-source" attribute.
* c-c++-common/diagnostic-format-json-2.c: Likewise.
* c-c++-common/diagnostic-format-json-3.c: Likewise.
* c-c++-common/diagnostic-format-json-4.c: Likewise, twice.
* c-c++-common/diagnostic-format-json-5.c: Likewise.
* gcc.dg/cpp/warn-normalized-4-bytes.c: New test.
* gcc.dg/cpp/warn-normalized-4-unicode.c: New test.
* gcc.dg/encoding-issues-bytes.c: New test.
* gcc.dg/encoding-issues-unicode.c: New test.
* gfortran.dg/diagnostic-format-json-1.F90: Add regexp to consume
"escape-source" attribute.
* gfortran.dg/diagnostic-format-json-2.F90: Likewise.
* gfortran.dg/diagnostic-format-json-3.F90: Likewise.
libcpp/ChangeLog:
* charset.c (convert_escape): Use encoding_rich_location when
complaining about nonprintable unknown escape sequences.
(cpp_display_width_computation::::cpp_display_width_computation):
Pass in policy rather than tabstop.
(cpp_display_width_computation::process_next_codepoint): Add "out"
param and populate *out if non-NULL.
(cpp_display_width_computation::advance_display_cols): Pass NULL
to process_next_codepoint.
(cpp_byte_column_to_display_column): Pass in policy rather than
tabstop. Pass NULL to process_next_codepoint.
(cpp_display_column_to_byte_column): Pass in policy rather than
tabstop.
* errors.c (cpp_diagnostic_get_current_location): New function,
splitting out the logic from...
(cpp_diagnostic): ...here.
(cpp_warning_at): New function.
(cpp_pedwarning_at): New function.
* include/cpplib.h (cpp_warning_at): New decl for rich_location.
(cpp_pedwarning_at): Likewise.
(struct cpp_decoded_char): New.
(struct cpp_char_column_policy): New.
(cpp_display_width_computation::cpp_display_width_computation):
Replace "tabstop" param with "policy".
(cpp_display_width_computation::process_next_codepoint): Add "out"
param.
(cpp_display_width_computation::m_tabstop): Replace with...
(cpp_display_width_computation::m_policy): ...this.
(cpp_byte_column_to_display_column): Replace "tabstop" param with
"policy".
(cpp_display_width): Likewise.
(cpp_display_column_to_byte_column): Likewise.
* include/line-map.h (rich_location::escape_on_output_p): New.
(rich_location::set_escape_on_output): New.
(rich_location::m_escape_on_output): New.
* internal.h (cpp_diagnostic_get_current_location): New decl.
(class encoding_rich_location): New.
* lex.c (skip_whitespace): Use encoding_rich_location when
complaining about null characters.
(warn_about_normalization): Generate a source range when
complaining about improperly normalized tokens, rather than just a
point, and use encoding_rich_location so that the source code
is escaped on printing.
* line-map.c (rich_location::rich_location): Initialize
m_escape_on_output.
Signed-off-by: David Malcolm <dmalcolm@redhat.com>
bd5e882cf6