Import 80d60e7 from yoctoproject.org meta-arm
To support ARMv8 SoCs.
meta-arm has several patch files. Since they are maintained by the
upstream meta-arm community, add meta-arm to the ignore list in
run-repotest.
Change-Id: Ia87a2e947bbabd347d256eccc47a343e1c885479
Signed-off-by: Brad Bishop <bradleyb@fuzziesquirrel.com>
diff --git a/meta-arm/meta-arm-toolchain/recipes-devtools/gcc/gcc-arm-11.2/0001-CVE-2021-42574.patch b/meta-arm/meta-arm-toolchain/recipes-devtools/gcc/gcc-arm-11.2/0001-CVE-2021-42574.patch
new file mode 100644
index 0000000..4d680cc
--- /dev/null
+++ b/meta-arm/meta-arm-toolchain/recipes-devtools/gcc/gcc-arm-11.2/0001-CVE-2021-42574.patch
@@ -0,0 +1,2282 @@
+From bd5e882cf6e0def3dd1bc106075d59a303fe0d1e Mon Sep 17 00:00:00 2001
+From: David Malcolm <dmalcolm@redhat.com>
+Date: Mon, 18 Oct 2021 18:55:31 -0400
+Subject: [PATCH] diagnostics: escape non-ASCII source bytes for certain
+ diagnostics
+MIME-Version: 1.0
+Content-Type: text/plain; charset=utf8
+Content-Transfer-Encoding: 8bit
+
+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:
+
+ beforeÏXafter
+ ^
+
+(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>
+
+CVE: CVE-2021-42574
+Upstream-Status: Backport [https://gcc.gnu.org/git/gitweb.cgi?p=gcc.git;h=bd5e882cf6e0def3dd1bc106075d59a303fe0d1e]
+Signed-off-by: Pgowda <pgowda.cve@gmail.com>
+
+---
+ gcc/c-family/c-lex.c | 6 +-
+ gcc/common.opt | 13 +
+ gcc/diagnostic-format-json.cc | 3 +
+ gcc/diagnostic-show-locus.c | 580 +++++++++++++++---
+ gcc/diagnostic.c | 10 +-
+ gcc/diagnostic.h | 18 +
+ gcc/doc/invoke.texi | 43 +-
+ gcc/input.c | 62 +-
+ gcc/input.h | 7 +-
+ gcc/opts.c | 4 +
+ gcc/selftest.c | 15 +
+ gcc/selftest.h | 2 +
+ .../c-c++-common/diagnostic-format-json-1.c | 1 +
+ .../c-c++-common/diagnostic-format-json-2.c | 1 +
+ .../c-c++-common/diagnostic-format-json-3.c | 1 +
+ .../c-c++-common/diagnostic-format-json-4.c | 2 +
+ .../c-c++-common/diagnostic-format-json-5.c | 1 +
+ .../gcc.dg/cpp/warn-normalized-4-bytes.c | 21 +
+ .../gcc.dg/cpp/warn-normalized-4-unicode.c | 19 +
+ gcc/testsuite/gcc.dg/encoding-issues-bytes.c | Bin 0 -> 595 bytes
+ .../gcc.dg/encoding-issues-unicode.c | Bin 0 -> 613 bytes
+ .../gfortran.dg/diagnostic-format-json-1.F90 | 1 +
+ .../gfortran.dg/diagnostic-format-json-2.F90 | 1 +
+ .../gfortran.dg/diagnostic-format-json-3.F90 | 1 +
+ libcpp/charset.c | 63 +-
+ libcpp/errors.c | 82 ++-
+ libcpp/include/cpplib.h | 76 ++-
+ libcpp/include/line-map.h | 13 +
+ libcpp/internal.h | 23 +
+ libcpp/lex.c | 38 +-
+ libcpp/line-map.c | 3 +-
+ 31 files changed, 942 insertions(+), 168 deletions(-)
+ create mode 100644 gcc/testsuite/gcc.dg/cpp/warn-normalized-4-bytes.c
+ create mode 100644 gcc/testsuite/gcc.dg/cpp/warn-normalized-4-unicode.c
+ create mode 100644 gcc/testsuite/gcc.dg/encoding-issues-bytes.c
+ create mode 100644 gcc/testsuite/gcc.dg/encoding-issues-unicode.c
+
+diff --git a/gcc/c-family/c-lex.c b/gcc/c-family/c-lex.c
+--- a/gcc/c-family/c-lex.c 2021-07-27 23:55:06.980283060 -0700
++++ b/gcc/c-family/c-lex.c 2021-12-14 01:16:01.541943272 -0800
+@@ -603,7 +603,11 @@ c_lex_with_flags (tree *value, location_
+ else if (ISGRAPH (c))
+ error_at (*loc, "stray %qc in program", (int) c);
+ else
+- error_at (*loc, "stray %<\\%o%> in program", (int) c);
++ {
++ rich_location rich_loc (line_table, *loc);
++ rich_loc.set_escape_on_output (true);
++ error_at (&rich_loc, "stray %<\\%o%> in program", (int) c);
++ }
+ }
+ goto retry;
+
+diff --git a/gcc/common.opt b/gcc/common.opt
+--- a/gcc/common.opt 2021-12-13 22:08:44.939137107 -0800
++++ b/gcc/common.opt 2021-12-14 01:16:01.541943272 -0800
+@@ -1348,6 +1348,10 @@ fdiagnostics-format=
+ Common Joined RejectNegative Enum(diagnostics_output_format)
+ -fdiagnostics-format=[text|json] Select output format.
+
++fdiagnostics-escape-format=
++Common Joined RejectNegative Enum(diagnostics_escape_format)
++-fdiagnostics-escape-format=[unicode|bytes] Select how to escape non-printable-ASCII bytes in the source for diagnostics that suggest it.
++
+ ; Required for these enum values.
+ SourceInclude
+ diagnostic.h
+@@ -1362,6 +1366,15 @@ EnumValue
+ Enum(diagnostics_column_unit) String(byte) Value(DIAGNOSTICS_COLUMN_UNIT_BYTE)
+
+ Enum
++Name(diagnostics_escape_format) Type(int)
++
++EnumValue
++Enum(diagnostics_escape_format) String(unicode) Value(DIAGNOSTICS_ESCAPE_FORMAT_UNICODE)
++
++EnumValue
++Enum(diagnostics_escape_format) String(bytes) Value(DIAGNOSTICS_ESCAPE_FORMAT_BYTES)
++
++Enum
+ Name(diagnostics_output_format) Type(int)
+
+ EnumValue
+diff --git a/gcc/diagnostic.c b/gcc/diagnostic.c
+--- a/gcc/diagnostic.c 2021-07-27 23:55:07.232286576 -0700
++++ b/gcc/diagnostic.c 2021-12-14 01:16:01.545943202 -0800
+@@ -230,6 +230,7 @@ diagnostic_initialize (diagnostic_contex
+ context->column_unit = DIAGNOSTICS_COLUMN_UNIT_DISPLAY;
+ context->column_origin = 1;
+ context->tabstop = 8;
++ context->escape_format = DIAGNOSTICS_ESCAPE_FORMAT_UNICODE;
+ context->edit_context_ptr = NULL;
+ context->diagnostic_group_nesting_depth = 0;
+ context->diagnostic_group_emission_count = 0;
+@@ -382,7 +383,10 @@ convert_column_unit (enum diagnostics_co
+ gcc_unreachable ();
+
+ case DIAGNOSTICS_COLUMN_UNIT_DISPLAY:
+- return location_compute_display_column (s, tabstop);
++ {
++ cpp_char_column_policy policy (tabstop, cpp_wcwidth);
++ return location_compute_display_column (s, policy);
++ }
+
+ case DIAGNOSTICS_COLUMN_UNIT_BYTE:
+ return s.column;
+@@ -2275,8 +2279,8 @@ test_diagnostic_get_location_text ()
+ const char *const content = "smile \xf0\x9f\x98\x82\n";
+ const int line_bytes = strlen (content) - 1;
+ const int def_tabstop = 8;
+- const int display_width = cpp_display_width (content, line_bytes,
+- def_tabstop);
++ const cpp_char_column_policy policy (def_tabstop, cpp_wcwidth);
++ const int display_width = cpp_display_width (content, line_bytes, policy);
+ ASSERT_EQ (line_bytes - 2, display_width);
+ temp_source_file tmp (SELFTEST_LOCATION, ".c", content);
+ const char *const fname = tmp.get_filename ();
+diff --git a/gcc/diagnostic-format-json.cc b/gcc/diagnostic-format-json.cc
+--- a/gcc/diagnostic-format-json.cc 2021-07-27 23:55:07.232286576 -0700
++++ b/gcc/diagnostic-format-json.cc 2021-12-14 01:16:01.541943272 -0800
+@@ -264,6 +264,9 @@ json_end_diagnostic (diagnostic_context
+ json::value *path_value = context->make_json_for_path (context, path);
+ diag_obj->set ("path", path_value);
+ }
++
++ diag_obj->set ("escape-source",
++ new json::literal (richloc->escape_on_output_p ()));
+ }
+
+ /* No-op implementation of "begin_group_cb" for JSON output. */
+diff --git a/gcc/diagnostic.h b/gcc/diagnostic.h
+--- a/gcc/diagnostic.h 2021-07-27 23:55:07.236286632 -0700
++++ b/gcc/diagnostic.h 2021-12-14 01:16:01.545943202 -0800
+@@ -38,6 +38,20 @@ enum diagnostics_column_unit
+ DIAGNOSTICS_COLUMN_UNIT_BYTE
+ };
+
++/* An enum for controlling how to print non-ASCII characters/bytes when
++ a diagnostic suggests escaping the source code on output. */
++
++enum diagnostics_escape_format
++{
++ /* Escape non-ASCII Unicode characters in the form <U+XXXX> and
++ non-UTF-8 bytes in the form <XX>. */
++ DIAGNOSTICS_ESCAPE_FORMAT_UNICODE,
++
++ /* Escape non-ASCII bytes in the form <XX> (thus showing the underlying
++ encoding of non-ASCII Unicode characters). */
++ DIAGNOSTICS_ESCAPE_FORMAT_BYTES
++};
++
+ /* Enum for overriding the standard output format. */
+
+ enum diagnostics_output_format
+@@ -320,6 +334,10 @@ struct diagnostic_context
+ /* The size of the tabstop for tab expansion. */
+ int tabstop;
+
++ /* How should non-ASCII/non-printable bytes be escaped when
++ a diagnostic suggests escaping the source code on output. */
++ enum diagnostics_escape_format escape_format;
++
+ /* If non-NULL, an edit_context to which fix-it hints should be
+ applied, for generating patches. */
+ edit_context *edit_context_ptr;
+diff --git a/gcc/diagnostic-show-locus.c b/gcc/diagnostic-show-locus.c
+--- a/gcc/diagnostic-show-locus.c 2021-07-27 23:55:07.232286576 -0700
++++ b/gcc/diagnostic-show-locus.c 2021-12-14 01:16:01.545943202 -0800
+@@ -175,10 +175,26 @@ enum column_unit {
+ class exploc_with_display_col : public expanded_location
+ {
+ public:
+- exploc_with_display_col (const expanded_location &exploc, int tabstop)
+- : expanded_location (exploc),
+- m_display_col (location_compute_display_column (exploc, tabstop))
+- {}
++ exploc_with_display_col (const expanded_location &exploc,
++ const cpp_char_column_policy &policy,
++ enum location_aspect aspect)
++ : expanded_location (exploc),
++ m_display_col (location_compute_display_column (exploc, policy))
++ {
++ if (exploc.column > 0)
++ {
++ /* m_display_col is now the final column of the byte.
++ If escaping has happened, we may want the first column instead. */
++ if (aspect != LOCATION_ASPECT_FINISH)
++ {
++ expanded_location prev_exploc (exploc);
++ prev_exploc.column--;
++ int prev_display_col
++ = (location_compute_display_column (prev_exploc, policy));
++ m_display_col = prev_display_col + 1;
++ }
++ }
++ }
+
+ int m_display_col;
+ };
+@@ -313,6 +329,31 @@ test_line_span ()
+
+ #endif /* #if CHECKING_P */
+
++/* A bundle of information containing how to print unicode
++ characters and bytes when quoting source code.
++
++ Provides a unified place to support escaping some subset
++ of characters to some format.
++
++ Extends char_column_policy; printing is split out to avoid
++ libcpp having to know about pretty_printer. */
++
++struct char_display_policy : public cpp_char_column_policy
++{
++ public:
++ char_display_policy (int tabstop,
++ int (*width_cb) (cppchar_t c),
++ void (*print_cb) (pretty_printer *pp,
++ const cpp_decoded_char &cp))
++ : cpp_char_column_policy (tabstop, width_cb),
++ m_print_cb (print_cb)
++ {
++ }
++
++ void (*m_print_cb) (pretty_printer *pp,
++ const cpp_decoded_char &cp);
++};
++
+ /* A class to control the overall layout when printing a diagnostic.
+
+ The layout is determined within the constructor.
+@@ -345,6 +386,8 @@ class layout
+
+ void print_line (linenum_type row);
+
++ void on_bad_codepoint (const char *ptr, cppchar_t ch, size_t ch_sz);
++
+ private:
+ bool will_show_line_p (linenum_type row) const;
+ void print_leading_fixits (linenum_type row);
+@@ -386,6 +429,7 @@ class layout
+ private:
+ diagnostic_context *m_context;
+ pretty_printer *m_pp;
++ char_display_policy m_policy;
+ location_t m_primary_loc;
+ exploc_with_display_col m_exploc;
+ colorizer m_colorizer;
+@@ -398,6 +442,7 @@ class layout
+ auto_vec <line_span> m_line_spans;
+ int m_linenum_width;
+ int m_x_offset_display;
++ bool m_escape_on_output;
+ };
+
+ /* Implementation of "class colorizer". */
+@@ -646,6 +691,11 @@ layout_range::intersects_line_p (linenum
+ /* Default for when we don't care what the tab expansion is set to. */
+ static const int def_tabstop = 8;
+
++static cpp_char_column_policy def_policy ()
++{
++ return cpp_char_column_policy (8, cpp_wcwidth);
++}
++
+ /* Create some expanded locations for testing layout_range. The filename
+ member of the explocs is set to the empty string. This member will only be
+ inspected by the calls to location_compute_display_column() made from the
+@@ -662,10 +712,13 @@ make_range (int start_line, int start_co
+ = {"", start_line, start_col, NULL, false};
+ const expanded_location finish_exploc
+ = {"", end_line, end_col, NULL, false};
+- return layout_range (exploc_with_display_col (start_exploc, def_tabstop),
+- exploc_with_display_col (finish_exploc, def_tabstop),
++ return layout_range (exploc_with_display_col (start_exploc, def_policy (),
++ LOCATION_ASPECT_START),
++ exploc_with_display_col (finish_exploc, def_policy (),
++ LOCATION_ASPECT_FINISH),
+ SHOW_RANGE_WITHOUT_CARET,
+- exploc_with_display_col (start_exploc, def_tabstop),
++ exploc_with_display_col (start_exploc, def_policy (),
++ LOCATION_ASPECT_CARET),
+ 0, NULL);
+ }
+
+@@ -959,6 +1012,164 @@ fixit_cmp (const void *p_a, const void *
+ return hint_a->get_start_loc () - hint_b->get_start_loc ();
+ }
+
++/* Callbacks for use when not escaping the source. */
++
++/* The default callback for char_column_policy::m_width_cb is cpp_wcwidth. */
++
++/* Callback for char_display_policy::m_print_cb for printing source chars
++ when not escaping the source. */
++
++static void
++default_print_decoded_ch (pretty_printer *pp,
++ const cpp_decoded_char &decoded_ch)
++{
++ for (const char *ptr = decoded_ch.m_start_byte;
++ ptr != decoded_ch.m_next_byte; ptr++)
++ {
++ if (*ptr == '\0' || *ptr == '\r')
++ {
++ pp_space (pp);
++ continue;
++ }
++
++ pp_character (pp, *ptr);
++ }
++}
++
++/* Callbacks for use with DIAGNOSTICS_ESCAPE_FORMAT_BYTES. */
++
++static const int width_per_escaped_byte = 4;
++
++/* Callback for char_column_policy::m_width_cb for determining the
++ display width when escaping with DIAGNOSTICS_ESCAPE_FORMAT_BYTES. */
++
++static int
++escape_as_bytes_width (cppchar_t ch)
++{
++ if (ch < 0x80 && ISPRINT (ch))
++ return cpp_wcwidth (ch);
++ else
++ {
++ if (ch <= 0x7F) return 1 * width_per_escaped_byte;
++ if (ch <= 0x7FF) return 2 * width_per_escaped_byte;
++ if (ch <= 0xFFFF) return 3 * width_per_escaped_byte;
++ return 4 * width_per_escaped_byte;
++ }
++}
++
++/* Callback for char_display_policy::m_print_cb for printing source chars
++ when escaping with DIAGNOSTICS_ESCAPE_FORMAT_BYTES. */
++
++static void
++escape_as_bytes_print (pretty_printer *pp,
++ const cpp_decoded_char &decoded_ch)
++{
++ if (!decoded_ch.m_valid_ch)
++ {
++ for (const char *iter = decoded_ch.m_start_byte;
++ iter != decoded_ch.m_next_byte; ++iter)
++ {
++ char buf[16];
++ sprintf (buf, "<%02x>", (unsigned char)*iter);
++ pp_string (pp, buf);
++ }
++ return;
++ }
++
++ cppchar_t ch = decoded_ch.m_ch;
++ if (ch < 0x80 && ISPRINT (ch))
++ pp_character (pp, ch);
++ else
++ {
++ for (const char *iter = decoded_ch.m_start_byte;
++ iter < decoded_ch.m_next_byte; ++iter)
++ {
++ char buf[16];
++ sprintf (buf, "<%02x>", (unsigned char)*iter);
++ pp_string (pp, buf);
++ }
++ }
++}
++
++/* Callbacks for use with DIAGNOSTICS_ESCAPE_FORMAT_UNICODE. */
++
++/* Callback for char_column_policy::m_width_cb for determining the
++ display width when escaping with DIAGNOSTICS_ESCAPE_FORMAT_UNICODE. */
++
++static int
++escape_as_unicode_width (cppchar_t ch)
++{
++ if (ch < 0x80 && ISPRINT (ch))
++ return cpp_wcwidth (ch);
++ else
++ {
++ // Width of "<U+%04x>"
++ if (ch > 0xfffff)
++ return 10;
++ else if (ch > 0xffff)
++ return 9;
++ else
++ return 8;
++ }
++}
++
++/* Callback for char_display_policy::m_print_cb for printing source chars
++ when escaping with DIAGNOSTICS_ESCAPE_FORMAT_UNICODE. */
++
++static void
++escape_as_unicode_print (pretty_printer *pp,
++ const cpp_decoded_char &decoded_ch)
++{
++ if (!decoded_ch.m_valid_ch)
++ {
++ escape_as_bytes_print (pp, decoded_ch);
++ return;
++ }
++
++ cppchar_t ch = decoded_ch.m_ch;
++ if (ch < 0x80 && ISPRINT (ch))
++ pp_character (pp, ch);
++ else
++ {
++ char buf[16];
++ sprintf (buf, "<U+%04X>", ch);
++ pp_string (pp, buf);
++ }
++}
++
++/* Populate a char_display_policy based on DC and RICHLOC. */
++
++static char_display_policy
++make_policy (const diagnostic_context &dc,
++ const rich_location &richloc)
++{
++ /* The default is to not escape non-ASCII bytes. */
++ char_display_policy result
++ (dc.tabstop, cpp_wcwidth, default_print_decoded_ch);
++
++ /* If the diagnostic suggests escaping non-ASCII bytes, then
++ use policy from user-supplied options. */
++ if (richloc.escape_on_output_p ())
++ {
++ result.m_undecoded_byte_width = width_per_escaped_byte;
++ switch (dc.escape_format)
++ {
++ default:
++ gcc_unreachable ();
++ case DIAGNOSTICS_ESCAPE_FORMAT_UNICODE:
++ result.m_width_cb = escape_as_unicode_width;
++ result.m_print_cb = escape_as_unicode_print;
++ break;
++ case DIAGNOSTICS_ESCAPE_FORMAT_BYTES:
++ result.m_width_cb = escape_as_bytes_width;
++ result.m_print_cb = escape_as_bytes_print;
++ break;
++ }
++ }
++
++ return result;
++}
++
+ /* Implementation of class layout. */
+
+ /* Constructor for class layout.
+@@ -975,8 +1186,10 @@ layout::layout (diagnostic_context * con
+ diagnostic_t diagnostic_kind)
+ : m_context (context),
+ m_pp (context->printer),
++ m_policy (make_policy (*context, *richloc)),
+ m_primary_loc (richloc->get_range (0)->m_loc),
+- m_exploc (richloc->get_expanded_location (0), context->tabstop),
++ m_exploc (richloc->get_expanded_location (0), m_policy,
++ LOCATION_ASPECT_CARET),
+ m_colorizer (context, diagnostic_kind),
+ m_colorize_source_p (context->colorize_source_p),
+ m_show_labels_p (context->show_labels_p),
+@@ -986,7 +1199,8 @@ layout::layout (diagnostic_context * con
+ m_fixit_hints (richloc->get_num_fixit_hints ()),
+ m_line_spans (1 + richloc->get_num_locations ()),
+ m_linenum_width (0),
+- m_x_offset_display (0)
++ m_x_offset_display (0),
++ m_escape_on_output (richloc->escape_on_output_p ())
+ {
+ for (unsigned int idx = 0; idx < richloc->get_num_locations (); idx++)
+ {
+@@ -1072,10 +1286,13 @@ layout::maybe_add_location_range (const
+
+ /* Everything is now known to be in the correct source file,
+ but it may require further sanitization. */
+- layout_range ri (exploc_with_display_col (start, m_context->tabstop),
+- exploc_with_display_col (finish, m_context->tabstop),
++ layout_range ri (exploc_with_display_col (start, m_policy,
++ LOCATION_ASPECT_START),
++ exploc_with_display_col (finish, m_policy,
++ LOCATION_ASPECT_FINISH),
+ loc_range->m_range_display_kind,
+- exploc_with_display_col (caret, m_context->tabstop),
++ exploc_with_display_col (caret, m_policy,
++ LOCATION_ASPECT_CARET),
+ original_idx, loc_range->m_label);
+
+ /* If we have a range that finishes before it starts (perhaps
+@@ -1409,7 +1626,7 @@ layout::calculate_x_offset_display ()
+ = get_line_bytes_without_trailing_whitespace (line.get_buffer (),
+ line.length ());
+ int eol_display_column
+- = cpp_display_width (line.get_buffer (), line_bytes, m_context->tabstop);
++ = cpp_display_width (line.get_buffer (), line_bytes, m_policy);
+ if (caret_display_column > eol_display_column
+ || !caret_display_column)
+ {
+@@ -1488,7 +1705,7 @@ layout::print_source_line (linenum_type
+ /* This object helps to keep track of which display column we are at, which is
+ necessary for computing the line bounds in display units, for doing
+ tab expansion, and for implementing m_x_offset_display. */
+- cpp_display_width_computation dw (line, line_bytes, m_context->tabstop);
++ cpp_display_width_computation dw (line, line_bytes, m_policy);
+
+ /* Skip the first m_x_offset_display display columns. In case the leading
+ portion that will be skipped ends with a character with wcwidth > 1, then
+@@ -1536,7 +1753,8 @@ layout::print_source_line (linenum_type
+ tabs and replacing some control bytes with spaces as necessary. */
+ const char *c = dw.next_byte ();
+ const int start_disp_col = dw.display_cols_processed () + 1;
+- const int this_display_width = dw.process_next_codepoint ();
++ cpp_decoded_char cp;
++ const int this_display_width = dw.process_next_codepoint (&cp);
+ if (*c == '\t')
+ {
+ /* The returned display width is the number of spaces into which the
+@@ -1545,15 +1763,6 @@ layout::print_source_line (linenum_type
+ pp_space (m_pp);
+ continue;
+ }
+- if (*c == '\0' || *c == '\r')
+- {
+- /* cpp_wcwidth() promises to return 1 for all control bytes, and we
+- want to output these as a single space too, so this case is
+- actually the same as the '\t' case. */
+- gcc_assert (this_display_width == 1);
+- pp_space (m_pp);
+- continue;
+- }
+
+ /* We have a (possibly multibyte) character to output; update the line
+ bounds if it is not whitespace. */
+@@ -1565,7 +1774,8 @@ layout::print_source_line (linenum_type
+ }
+
+ /* Output the character. */
+- while (c != dw.next_byte ()) pp_character (m_pp, *c++);
++ m_policy.m_print_cb (m_pp, cp);
++ c = dw.next_byte ();
+ }
+ print_newline ();
+ return lbounds;
+@@ -1664,14 +1874,14 @@ layout::print_annotation_line (linenum_t
+ class line_label
+ {
+ public:
+- line_label (diagnostic_context *context, int state_idx, int column,
++ line_label (const cpp_char_column_policy &policy,
++ int state_idx, int column,
+ label_text text)
+ : m_state_idx (state_idx), m_column (column),
+ m_text (text), m_label_line (0), m_has_vbar (true)
+ {
+ const int bytes = strlen (text.m_buffer);
+- m_display_width
+- = cpp_display_width (text.m_buffer, bytes, context->tabstop);
++ m_display_width = cpp_display_width (text.m_buffer, bytes, policy);
+ }
+
+ /* Sorting is primarily by column, then by state index. */
+@@ -1731,7 +1941,7 @@ layout::print_any_labels (linenum_type r
+ if (text.m_buffer == NULL)
+ continue;
+
+- labels.safe_push (line_label (m_context, i, disp_col, text));
++ labels.safe_push (line_label (m_policy, i, disp_col, text));
+ }
+ }
+
+@@ -2011,7 +2221,7 @@ public:
+
+ /* Get the range of bytes or display columns that HINT would affect. */
+ static column_range
+-get_affected_range (diagnostic_context *context,
++get_affected_range (const cpp_char_column_policy &policy,
+ const fixit_hint *hint, enum column_unit col_unit)
+ {
+ expanded_location exploc_start = expand_location (hint->get_start_loc ());
+@@ -2022,13 +2232,11 @@ get_affected_range (diagnostic_context *
+ int finish_column;
+ if (col_unit == CU_DISPLAY_COLS)
+ {
+- start_column
+- = location_compute_display_column (exploc_start, context->tabstop);
++ start_column = location_compute_display_column (exploc_start, policy);
+ if (hint->insertion_p ())
+ finish_column = start_column - 1;
+ else
+- finish_column
+- = location_compute_display_column (exploc_finish, context->tabstop);
++ finish_column = location_compute_display_column (exploc_finish, policy);
+ }
+ else
+ {
+@@ -2041,12 +2249,13 @@ get_affected_range (diagnostic_context *
+ /* Get the range of display columns that would be printed for HINT. */
+
+ static column_range
+-get_printed_columns (diagnostic_context *context, const fixit_hint *hint)
++get_printed_columns (const cpp_char_column_policy &policy,
++ const fixit_hint *hint)
+ {
+ expanded_location exploc = expand_location (hint->get_start_loc ());
+- int start_column = location_compute_display_column (exploc, context->tabstop);
++ int start_column = location_compute_display_column (exploc, policy);
+ int hint_width = cpp_display_width (hint->get_string (), hint->get_length (),
+- context->tabstop);
++ policy);
+ int final_hint_column = start_column + hint_width - 1;
+ if (hint->insertion_p ())
+ {
+@@ -2056,8 +2265,7 @@ get_printed_columns (diagnostic_context
+ {
+ exploc = expand_location (hint->get_next_loc ());
+ --exploc.column;
+- int finish_column
+- = location_compute_display_column (exploc, context->tabstop);
++ int finish_column = location_compute_display_column (exploc, policy);
+ return column_range (start_column,
+ MAX (finish_column, final_hint_column));
+ }
+@@ -2075,13 +2283,13 @@ public:
+ column_range affected_columns,
+ column_range printed_columns,
+ const char *new_text, size_t new_text_len,
+- int tabstop)
++ const cpp_char_column_policy &policy)
+ : m_affected_bytes (affected_bytes),
+ m_affected_columns (affected_columns),
+ m_printed_columns (printed_columns),
+ m_text (xstrdup (new_text)),
+ m_byte_length (new_text_len),
+- m_tabstop (tabstop),
++ m_policy (policy),
+ m_alloc_sz (new_text_len + 1)
+ {
+ compute_display_cols ();
+@@ -2099,7 +2307,7 @@ public:
+
+ void compute_display_cols ()
+ {
+- m_display_cols = cpp_display_width (m_text, m_byte_length, m_tabstop);
++ m_display_cols = cpp_display_width (m_text, m_byte_length, m_policy);
+ }
+
+ void overwrite (int dst_offset, const char_span &src_span)
+@@ -2127,7 +2335,7 @@ public:
+ char *m_text;
+ size_t m_byte_length; /* Not including null-terminator. */
+ int m_display_cols;
+- int m_tabstop;
++ const cpp_char_column_policy &m_policy;
+ size_t m_alloc_sz;
+ };
+
+@@ -2163,15 +2371,16 @@ correction::ensure_terminated ()
+ class line_corrections
+ {
+ public:
+- line_corrections (diagnostic_context *context, const char *filename,
++ line_corrections (const char_display_policy &policy,
++ const char *filename,
+ linenum_type row)
+- : m_context (context), m_filename (filename), m_row (row)
++ : m_policy (policy), m_filename (filename), m_row (row)
+ {}
+ ~line_corrections ();
+
+ void add_hint (const fixit_hint *hint);
+
+- diagnostic_context *m_context;
++ const char_display_policy &m_policy;
+ const char *m_filename;
+ linenum_type m_row;
+ auto_vec <correction *> m_corrections;
+@@ -2217,10 +2426,10 @@ source_line::source_line (const char *fi
+ void
+ line_corrections::add_hint (const fixit_hint *hint)
+ {
+- column_range affected_bytes = get_affected_range (m_context, hint, CU_BYTES);
+- column_range affected_columns = get_affected_range (m_context, hint,
++ column_range affected_bytes = get_affected_range (m_policy, hint, CU_BYTES);
++ column_range affected_columns = get_affected_range (m_policy, hint,
+ CU_DISPLAY_COLS);
+- column_range printed_columns = get_printed_columns (m_context, hint);
++ column_range printed_columns = get_printed_columns (m_policy, hint);
+
+ /* Potentially consolidate. */
+ if (!m_corrections.is_empty ())
+@@ -2289,7 +2498,7 @@ line_corrections::add_hint (const fixit_
+ printed_columns,
+ hint->get_string (),
+ hint->get_length (),
+- m_context->tabstop));
++ m_policy));
+ }
+
+ /* If there are any fixit hints on source line ROW, print them.
+@@ -2303,7 +2512,7 @@ layout::print_trailing_fixits (linenum_t
+ {
+ /* Build a list of correction instances for the line,
+ potentially consolidating hints (for the sake of readability). */
+- line_corrections corrections (m_context, m_exploc.file, row);
++ line_corrections corrections (m_policy, m_exploc.file, row);
+ for (unsigned int i = 0; i < m_fixit_hints.length (); i++)
+ {
+ const fixit_hint *hint = m_fixit_hints[i];
+@@ -2646,6 +2855,59 @@ namespace selftest {
+
+ /* Selftests for diagnostic_show_locus. */
+
++/* Verify that cpp_display_width correctly handles escaping. */
++
++static void
++test_display_widths ()
++{
++ gcc_rich_location richloc (UNKNOWN_LOCATION);
++
++ /* U+03C0 "GREEK SMALL LETTER PI". */
++ const char *pi = "\xCF\x80";
++ /* U+1F642 "SLIGHTLY SMILING FACE". */
++ const char *emoji = "\xF0\x9F\x99\x82";
++ /* Stray trailing byte of a UTF-8 character. */
++ const char *stray = "\xBF";
++ /* U+10FFFF. */
++ const char *max_codepoint = "\xF4\x8F\xBF\xBF";
++
++ /* No escaping. */
++ {
++ test_diagnostic_context dc;
++ char_display_policy policy (make_policy (dc, richloc));
++ ASSERT_EQ (cpp_display_width (pi, strlen (pi), policy), 1);
++ ASSERT_EQ (cpp_display_width (emoji, strlen (emoji), policy), 2);
++ ASSERT_EQ (cpp_display_width (stray, strlen (stray), policy), 1);
++ /* Don't check width of U+10FFFF; it's in a private use plane. */
++ }
++
++ richloc.set_escape_on_output (true);
++
++ {
++ test_diagnostic_context dc;
++ dc.escape_format = DIAGNOSTICS_ESCAPE_FORMAT_UNICODE;
++ char_display_policy policy (make_policy (dc, richloc));
++ ASSERT_EQ (cpp_display_width (pi, strlen (pi), policy), 8);
++ ASSERT_EQ (cpp_display_width (emoji, strlen (emoji), policy), 9);
++ ASSERT_EQ (cpp_display_width (stray, strlen (stray), policy), 4);
++ ASSERT_EQ (cpp_display_width (max_codepoint, strlen (max_codepoint),
++ policy),
++ strlen ("<U+10FFFF>"));
++ }
++
++ {
++ test_diagnostic_context dc;
++ dc.escape_format = DIAGNOSTICS_ESCAPE_FORMAT_BYTES;
++ char_display_policy policy (make_policy (dc, richloc));
++ ASSERT_EQ (cpp_display_width (pi, strlen (pi), policy), 8);
++ ASSERT_EQ (cpp_display_width (emoji, strlen (emoji), policy), 16);
++ ASSERT_EQ (cpp_display_width (stray, strlen (stray), policy), 4);
++ ASSERT_EQ (cpp_display_width (max_codepoint, strlen (max_codepoint),
++ policy),
++ 16);
++ }
++}
++
+ /* For precise tests of the layout, make clear where the source line will
+ start. test_left_margin sets the total byte count from the left side of the
+ screen to the start of source lines, after the line number and the separator,
+@@ -2715,10 +2977,10 @@ test_layout_x_offset_display_utf8 (const
+ char_span lspan = location_get_source_line (tmp.get_filename (), 1);
+ ASSERT_EQ (line_display_cols,
+ cpp_display_width (lspan.get_buffer (), lspan.length (),
+- def_tabstop));
++ def_policy ()));
+ ASSERT_EQ (line_display_cols,
+ location_compute_display_column (expand_location (line_end),
+- def_tabstop));
++ def_policy ()));
+ ASSERT_EQ (0, memcmp (lspan.get_buffer () + (emoji_col - 1),
+ "\xf0\x9f\x98\x82\xf0\x9f\x98\x82", 8));
+
+@@ -2866,12 +3128,13 @@ test_layout_x_offset_display_tab (const
+ ASSERT_EQ ('\t', *(lspan.get_buffer () + (tab_col - 1)));
+ for (int tabstop = 1; tabstop != num_tabstops; ++tabstop)
+ {
++ cpp_char_column_policy policy (tabstop, cpp_wcwidth);
+ ASSERT_EQ (line_bytes + extra_width[tabstop],
+ cpp_display_width (lspan.get_buffer (), lspan.length (),
+- tabstop));
++ policy));
+ ASSERT_EQ (line_bytes + extra_width[tabstop],
+ location_compute_display_column (expand_location (line_end),
+- tabstop));
++ policy));
+ }
+
+ /* Check that the tab is expanded to the expected number of spaces. */
+@@ -4003,6 +4266,43 @@ test_one_liner_labels_utf8 ()
+ " bb\xf0\x9f\x98\x82\xf0\x9f\x98\x82\n",
+ pp_formatted_text (dc.printer));
+ }
++
++ /* Example of escaping the source lines. */
++ {
++ text_range_label label0 ("label 0\xf0\x9f\x98\x82");
++ text_range_label label1 ("label 1\xcf\x80");
++ text_range_label label2 ("label 2\xcf\x80");
++ gcc_rich_location richloc (foo, &label0);
++ richloc.add_range (bar, SHOW_RANGE_WITHOUT_CARET, &label1);
++ richloc.add_range (field, SHOW_RANGE_WITHOUT_CARET, &label2);
++ richloc.set_escape_on_output (true);
++
++ {
++ test_diagnostic_context dc;
++ dc.escape_format = DIAGNOSTICS_ESCAPE_FORMAT_UNICODE;
++ diagnostic_show_locus (&dc, &richloc, DK_ERROR);
++ ASSERT_STREQ (" <U+1F602>_foo = <U+03C0>_bar.<U+1F602>_field<U+03C0>;\n"
++ " ^~~~~~~~~~~~~ ~~~~~~~~~~~~ ~~~~~~~~~~~~~~~~~~~~~~~\n"
++ " | | |\n"
++ " | | label 2\xcf\x80\n"
++ " | label 1\xcf\x80\n"
++ " label 0\xf0\x9f\x98\x82\n",
++ pp_formatted_text (dc.printer));
++ }
++ {
++ test_diagnostic_context dc;
++ dc.escape_format = DIAGNOSTICS_ESCAPE_FORMAT_BYTES;
++ diagnostic_show_locus (&dc, &richloc, DK_ERROR);
++ ASSERT_STREQ
++ (" <f0><9f><98><82>_foo = <cf><80>_bar.<f0><9f><98><82>_field<cf><80>;\n"
++ " ^~~~~~~~~~~~~~~~~~~~ ~~~~~~~~~~~~ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~\n"
++ " | | |\n"
++ " | | label 2\xcf\x80\n"
++ " | label 1\xcf\x80\n"
++ " label 0\xf0\x9f\x98\x82\n",
++ pp_formatted_text (dc.printer));
++ }
++ }
+ }
+
+ /* Make sure that colorization codes don't interrupt a multibyte
+@@ -4057,9 +4357,9 @@ test_diagnostic_show_locus_one_liner_utf
+
+ char_span lspan = location_get_source_line (tmp.get_filename (), 1);
+ ASSERT_EQ (25, cpp_display_width (lspan.get_buffer (), lspan.length (),
+- def_tabstop));
++ def_policy ()));
+ ASSERT_EQ (25, location_compute_display_column (expand_location (line_end),
+- def_tabstop));
++ def_policy ()));
+
+ test_one_liner_simple_caret_utf8 ();
+ test_one_liner_caret_and_range_utf8 ();
+@@ -4445,30 +4745,31 @@ test_overlapped_fixit_printing (const li
+ pp_formatted_text (dc.printer));
+
+ /* Unit-test the line_corrections machinery. */
++ char_display_policy policy (make_policy (dc, richloc));
+ ASSERT_EQ (3, richloc.get_num_fixit_hints ());
+ const fixit_hint *hint_0 = richloc.get_fixit_hint (0);
+ ASSERT_EQ (column_range (12, 12),
+- get_affected_range (&dc, hint_0, CU_BYTES));
++ get_affected_range (policy, hint_0, CU_BYTES));
+ ASSERT_EQ (column_range (12, 12),
+- get_affected_range (&dc, hint_0, CU_DISPLAY_COLS));
+- ASSERT_EQ (column_range (12, 22), get_printed_columns (&dc, hint_0));
++ get_affected_range (policy, hint_0, CU_DISPLAY_COLS));
++ ASSERT_EQ (column_range (12, 22), get_printed_columns (policy, hint_0));
+ const fixit_hint *hint_1 = richloc.get_fixit_hint (1);
+ ASSERT_EQ (column_range (18, 18),
+- get_affected_range (&dc, hint_1, CU_BYTES));
++ get_affected_range (policy, hint_1, CU_BYTES));
+ ASSERT_EQ (column_range (18, 18),
+- get_affected_range (&dc, hint_1, CU_DISPLAY_COLS));
+- ASSERT_EQ (column_range (18, 20), get_printed_columns (&dc, hint_1));
++ get_affected_range (policy, hint_1, CU_DISPLAY_COLS));
++ ASSERT_EQ (column_range (18, 20), get_printed_columns (policy, hint_1));
+ const fixit_hint *hint_2 = richloc.get_fixit_hint (2);
+ ASSERT_EQ (column_range (29, 28),
+- get_affected_range (&dc, hint_2, CU_BYTES));
++ get_affected_range (policy, hint_2, CU_BYTES));
+ ASSERT_EQ (column_range (29, 28),
+- get_affected_range (&dc, hint_2, CU_DISPLAY_COLS));
+- ASSERT_EQ (column_range (29, 29), get_printed_columns (&dc, hint_2));
++ get_affected_range (policy, hint_2, CU_DISPLAY_COLS));
++ ASSERT_EQ (column_range (29, 29), get_printed_columns (policy, hint_2));
+
+ /* Add each hint in turn to a line_corrections instance,
+ and verify that they are consolidated into one correction instance
+ as expected. */
+- line_corrections lc (&dc, tmp.get_filename (), 1);
++ line_corrections lc (policy, tmp.get_filename (), 1);
+
+ /* The first replace hint by itself. */
+ lc.add_hint (hint_0);
+@@ -4660,30 +4961,31 @@ test_overlapped_fixit_printing_utf8 (con
+ pp_formatted_text (dc.printer));
+
+ /* Unit-test the line_corrections machinery. */
++ char_display_policy policy (make_policy (dc, richloc));
+ ASSERT_EQ (3, richloc.get_num_fixit_hints ());
+ const fixit_hint *hint_0 = richloc.get_fixit_hint (0);
+ ASSERT_EQ (column_range (14, 14),
+- get_affected_range (&dc, hint_0, CU_BYTES));
++ get_affected_range (policy, hint_0, CU_BYTES));
+ ASSERT_EQ (column_range (12, 12),
+- get_affected_range (&dc, hint_0, CU_DISPLAY_COLS));
+- ASSERT_EQ (column_range (12, 22), get_printed_columns (&dc, hint_0));
++ get_affected_range (policy, hint_0, CU_DISPLAY_COLS));
++ ASSERT_EQ (column_range (12, 22), get_printed_columns (policy, hint_0));
+ const fixit_hint *hint_1 = richloc.get_fixit_hint (1);
+ ASSERT_EQ (column_range (22, 22),
+- get_affected_range (&dc, hint_1, CU_BYTES));
++ get_affected_range (policy, hint_1, CU_BYTES));
+ ASSERT_EQ (column_range (18, 18),
+- get_affected_range (&dc, hint_1, CU_DISPLAY_COLS));
+- ASSERT_EQ (column_range (18, 20), get_printed_columns (&dc, hint_1));
++ get_affected_range (policy, hint_1, CU_DISPLAY_COLS));
++ ASSERT_EQ (column_range (18, 20), get_printed_columns (policy, hint_1));
+ const fixit_hint *hint_2 = richloc.get_fixit_hint (2);
+ ASSERT_EQ (column_range (35, 34),
+- get_affected_range (&dc, hint_2, CU_BYTES));
++ get_affected_range (policy, hint_2, CU_BYTES));
+ ASSERT_EQ (column_range (30, 29),
+- get_affected_range (&dc, hint_2, CU_DISPLAY_COLS));
+- ASSERT_EQ (column_range (30, 30), get_printed_columns (&dc, hint_2));
++ get_affected_range (policy, hint_2, CU_DISPLAY_COLS));
++ ASSERT_EQ (column_range (30, 30), get_printed_columns (policy, hint_2));
+
+ /* Add each hint in turn to a line_corrections instance,
+ and verify that they are consolidated into one correction instance
+ as expected. */
+- line_corrections lc (&dc, tmp.get_filename (), 1);
++ line_corrections lc (policy, tmp.get_filename (), 1);
+
+ /* The first replace hint by itself. */
+ lc.add_hint (hint_0);
+@@ -4877,15 +5179,16 @@ test_overlapped_fixit_printing_2 (const
+ richloc.add_fixit_insert_before (col_21, "}");
+
+ /* These fixits should be accepted; they can't be consolidated. */
++ char_display_policy policy (make_policy (dc, richloc));
+ ASSERT_EQ (2, richloc.get_num_fixit_hints ());
+ const fixit_hint *hint_0 = richloc.get_fixit_hint (0);
+ ASSERT_EQ (column_range (23, 22),
+- get_affected_range (&dc, hint_0, CU_BYTES));
+- ASSERT_EQ (column_range (23, 23), get_printed_columns (&dc, hint_0));
++ get_affected_range (policy, hint_0, CU_BYTES));
++ ASSERT_EQ (column_range (23, 23), get_printed_columns (policy, hint_0));
+ const fixit_hint *hint_1 = richloc.get_fixit_hint (1);
+ ASSERT_EQ (column_range (21, 20),
+- get_affected_range (&dc, hint_1, CU_BYTES));
+- ASSERT_EQ (column_range (21, 21), get_printed_columns (&dc, hint_1));
++ get_affected_range (policy, hint_1, CU_BYTES));
++ ASSERT_EQ (column_range (21, 21), get_printed_columns (policy, hint_1));
+
+ /* Verify that they're printed correctly. */
+ diagnostic_show_locus (&dc, &richloc, DK_ERROR);
+@@ -5152,10 +5455,11 @@ test_tab_expansion (const line_table_cas
+ ....................123 45678901234 56789012345 columns */
+
+ const int tabstop = 8;
++ cpp_char_column_policy policy (tabstop, cpp_wcwidth);
+ const int first_non_ws_byte_col = 7;
+ const int right_quote_byte_col = 15;
+ const int last_byte_col = 25;
+- ASSERT_EQ (35, cpp_display_width (content, last_byte_col, tabstop));
++ ASSERT_EQ (35, cpp_display_width (content, last_byte_col, policy));
+
+ temp_source_file tmp (SELFTEST_LOCATION, ".c", content);
+ line_table_test ltt (case_);
+@@ -5198,6 +5502,114 @@ test_tab_expansion (const line_table_cas
+ }
+ }
+
++/* Verify that the escaping machinery can cope with a variety of different
++ invalid bytes. */
++
++static void
++test_escaping_bytes_1 (const line_table_case &case_)
++{
++ const char content[] = "before\0\1\2\3\r\x80\xff""after\n";
++ const size_t sz = sizeof (content);
++ temp_source_file tmp (SELFTEST_LOCATION, ".c", content, sz);
++ line_table_test ltt (case_);
++ const line_map_ordinary *ord_map = linemap_check_ordinary
++ (linemap_add (line_table, LC_ENTER, false, tmp.get_filename (), 0));
++ linemap_line_start (line_table, 1, 100);
++
++ location_t finish
++ = linemap_position_for_line_and_column (line_table, ord_map, 1,
++ strlen (content));
++
++ if (finish > LINE_MAP_MAX_LOCATION_WITH_COLS)
++ return;
++
++ /* Locations of the NUL and \r bytes. */
++ location_t nul_loc
++ = linemap_position_for_line_and_column (line_table, ord_map, 1, 7);
++ location_t r_loc
++ = linemap_position_for_line_and_column (line_table, ord_map, 1, 11);
++ gcc_rich_location richloc (nul_loc);
++ richloc.add_range (r_loc);
++
++ {
++ test_diagnostic_context dc;
++ diagnostic_show_locus (&dc, &richloc, DK_ERROR);
++ ASSERT_STREQ (" before \1\2\3 \x80\xff""after\n"
++ " ^ ~\n",
++ pp_formatted_text (dc.printer));
++ }
++ richloc.set_escape_on_output (true);
++ {
++ test_diagnostic_context dc;
++ dc.escape_format = DIAGNOSTICS_ESCAPE_FORMAT_UNICODE;
++ diagnostic_show_locus (&dc, &richloc, DK_ERROR);
++ ASSERT_STREQ
++ (" before<U+0000><U+0001><U+0002><U+0003><U+000D><80><ff>after\n"
++ " ^~~~~~~~ ~~~~~~~~\n",
++ pp_formatted_text (dc.printer));
++ }
++ {
++ test_diagnostic_context dc;
++ dc.escape_format = DIAGNOSTICS_ESCAPE_FORMAT_BYTES;
++ diagnostic_show_locus (&dc, &richloc, DK_ERROR);
++ ASSERT_STREQ (" before<00><01><02><03><0d><80><ff>after\n"
++ " ^~~~ ~~~~\n",
++ pp_formatted_text (dc.printer));
++ }
++}
++
++/* As above, but verify that we handle the initial byte of a line
++ correctly. */
++
++static void
++test_escaping_bytes_2 (const line_table_case &case_)
++{
++ const char content[] = "\0after\n";
++ const size_t sz = sizeof (content);
++ temp_source_file tmp (SELFTEST_LOCATION, ".c", content, sz);
++ line_table_test ltt (case_);
++ const line_map_ordinary *ord_map = linemap_check_ordinary
++ (linemap_add (line_table, LC_ENTER, false, tmp.get_filename (), 0));
++ linemap_line_start (line_table, 1, 100);
++
++ location_t finish
++ = linemap_position_for_line_and_column (line_table, ord_map, 1,
++ strlen (content));
++
++ if (finish > LINE_MAP_MAX_LOCATION_WITH_COLS)
++ return;
++
++ /* Location of the NUL byte. */
++ location_t nul_loc
++ = linemap_position_for_line_and_column (line_table, ord_map, 1, 1);
++ gcc_rich_location richloc (nul_loc);
++
++ {
++ test_diagnostic_context dc;
++ diagnostic_show_locus (&dc, &richloc, DK_ERROR);
++ ASSERT_STREQ (" after\n"
++ " ^\n",
++ pp_formatted_text (dc.printer));
++ }
++ richloc.set_escape_on_output (true);
++ {
++ test_diagnostic_context dc;
++ dc.escape_format = DIAGNOSTICS_ESCAPE_FORMAT_UNICODE;
++ diagnostic_show_locus (&dc, &richloc, DK_ERROR);
++ ASSERT_STREQ (" <U+0000>after\n"
++ " ^~~~~~~~\n",
++ pp_formatted_text (dc.printer));
++ }
++ {
++ test_diagnostic_context dc;
++ dc.escape_format = DIAGNOSTICS_ESCAPE_FORMAT_BYTES;
++ diagnostic_show_locus (&dc, &richloc, DK_ERROR);
++ ASSERT_STREQ (" <00>after\n"
++ " ^~~~\n",
++ pp_formatted_text (dc.printer));
++ }
++}
++
+ /* Verify that line numbers are correctly printed for the case of
+ a multiline range in which the width of the line numbers changes
+ (e.g. from "9" to "10"). */
+@@ -5254,6 +5666,8 @@ diagnostic_show_locus_c_tests ()
+ test_layout_range_for_single_line ();
+ test_layout_range_for_multiple_lines ();
+
++ test_display_widths ();
++
+ for_each_line_table_case (test_layout_x_offset_display_utf8);
+ for_each_line_table_case (test_layout_x_offset_display_tab);
+
+@@ -5274,6 +5688,8 @@ diagnostic_show_locus_c_tests ()
+ for_each_line_table_case (test_fixit_replace_containing_newline);
+ for_each_line_table_case (test_fixit_deletion_affecting_newline);
+ for_each_line_table_case (test_tab_expansion);
++ for_each_line_table_case (test_escaping_bytes_1);
++ for_each_line_table_case (test_escaping_bytes_2);
+
+ test_line_numbers_multiline_range ();
+ }
+diff --git a/gcc/doc/invoke.texi b/gcc/doc/invoke.texi
+--- a/gcc/doc/invoke.texi 2021-12-13 23:23:05.764437151 -0800
++++ b/gcc/doc/invoke.texi 2021-12-14 01:16:01.553943061 -0800
+@@ -312,7 +312,8 @@ Objective-C and Objective-C++ Dialects}.
+ -fdiagnostics-show-path-depths @gol
+ -fno-show-column @gol
+ -fdiagnostics-column-unit=@r{[}display@r{|}byte@r{]} @gol
+--fdiagnostics-column-origin=@var{origin}}
++-fdiagnostics-column-origin=@var{origin} @gol
++-fdiagnostics-escape-format=@r{[}unicode@r{|}bytes@r{]}}
+
+ @item Warning Options
+ @xref{Warning Options,,Options to Request or Suppress Warnings}.
+@@ -5083,6 +5084,38 @@ first column. The default value of 1 co
+ behavior and to the GNU style guide. Some utilities may perform better with an
+ origin of 0; any non-negative value may be specified.
+
++@item -fdiagnostics-escape-format=@var{FORMAT}
++@opindex fdiagnostics-escape-format
++When GCC prints pertinent source lines for a diagnostic it normally attempts
++to print the source bytes directly. However, some diagnostics relate to encoding
++issues in the source file, such as malformed UTF-8, or issues with Unicode
++normalization. These diagnostics are flagged so that GCC will escape bytes
++that are not printable ASCII when printing their pertinent source lines.
++
++This option controls how such bytes should be escaped.
++
++The default @var{FORMAT}, @samp{unicode} displays Unicode characters that
++are not printable ASCII in the form @samp{<U+XXXX>}, and bytes that do not
++correspond to a Unicode character validly-encoded in UTF-8-encoded will be
++displayed as hexadecimal in the form @samp{<XX>}.
++
++For example, a source line containing the string @samp{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 @samp{after} will be printed for such a diagnostic as:
++
++@smallexample
++ before<U+03C0><BF>after
++@end smallexample
++
++Setting @var{FORMAT} to @samp{bytes} will display all non-printable-ASCII bytes
++in the form @samp{<XX>}, thus showing the underlying encoding of non-ASCII
++Unicode characters. For the example above, the following will be printed:
++
++@smallexample
++ before<CF><80><BF>after
++@end smallexample
++
+ @item -fdiagnostics-format=@var{FORMAT}
+ @opindex fdiagnostics-format
+ Select a different format for printing diagnostics.
+@@ -5150,9 +5183,11 @@ might be printed in JSON form (after for
+ @}
+ @}
+ ],
++ "escape-source": false,
+ "message": "...this statement, but the latter is @dots{}"
+ @}
+ ]
++ "escape-source": false,
+ "column-origin": 1,
+ @},
+ @dots{}
+@@ -5239,6 +5274,7 @@ of the expression, which have labels. I
+ "label": "T @{aka struct t@}"
+ @}
+ ],
++ "escape-source": false,
+ "message": "invalid operands to binary + @dots{}"
+ @}
+ @end smallexample
+@@ -5292,6 +5328,7 @@ might be printed in JSON form as:
+ @}
+ @}
+ ],
++ "escape-source": false,
+ "message": "\u2018struct s\u2019 has no member named @dots{}"
+ @}
+ @end smallexample
+@@ -5349,6 +5386,10 @@ For example, the intraprocedural example
+ ]
+ @end smallexample
+
++Diagnostics have a boolean attribute @code{escape-source}, hinting whether
++non-ASCII bytes should be escaped when printing the pertinent lines of
++source code (@code{true} for diagnostics involving source encoding issues).
++
+ @end table
+
+ @node Warning Options
+diff --git a/gcc/input.c b/gcc/input.c
+--- a/gcc/input.c 2021-07-27 23:55:07.328287915 -0700
++++ b/gcc/input.c 2021-12-14 01:16:01.553943061 -0800
+@@ -913,7 +913,8 @@ make_location (location_t caret, source_
+ source line in order to calculate the display width. If that cannot be done
+ for any reason, then returns the byte column as a fallback. */
+ int
+-location_compute_display_column (expanded_location exploc, int tabstop)
++location_compute_display_column (expanded_location exploc,
++ const cpp_char_column_policy &policy)
+ {
+ if (!(exploc.file && *exploc.file && exploc.line && exploc.column))
+ return exploc.column;
+@@ -921,7 +922,7 @@ location_compute_display_column (expande
+ /* If line is NULL, this function returns exploc.column which is the
+ desired fallback. */
+ return cpp_byte_column_to_display_column (line.get_buffer (), line.length (),
+- exploc.column, tabstop);
++ exploc.column, policy);
+ }
+
+ /* Dump statistics to stderr about the memory usage of the line_table
+@@ -3611,43 +3612,50 @@ test_line_offset_overflow ()
+ void test_cpp_utf8 ()
+ {
+ const int def_tabstop = 8;
++ cpp_char_column_policy policy (def_tabstop, cpp_wcwidth);
++
+ /* Verify that wcwidth of invalid UTF-8 or control bytes is 1. */
+ {
+- int w_bad = cpp_display_width ("\xf0!\x9f!\x98!\x82!", 8, def_tabstop);
++ int w_bad = cpp_display_width ("\xf0!\x9f!\x98!\x82!", 8, policy);
+ ASSERT_EQ (8, w_bad);
+- int w_ctrl = cpp_display_width ("\r\n\v\0\1", 5, def_tabstop);
++ int w_ctrl = cpp_display_width ("\r\n\v\0\1", 5, policy);
+ ASSERT_EQ (5, w_ctrl);
+ }
+
+ /* Verify that wcwidth of valid UTF-8 is as expected. */
+ {
+- const int w_pi = cpp_display_width ("\xcf\x80", 2, def_tabstop);
++ const int w_pi = cpp_display_width ("\xcf\x80", 2, policy);
+ ASSERT_EQ (1, w_pi);
+- const int w_emoji = cpp_display_width ("\xf0\x9f\x98\x82", 4, def_tabstop);
++ const int w_emoji = cpp_display_width ("\xf0\x9f\x98\x82", 4, policy);
+ ASSERT_EQ (2, w_emoji);
+ const int w_umlaut_precomposed = cpp_display_width ("\xc3\xbf", 2,
+- def_tabstop);
++ policy);
+ ASSERT_EQ (1, w_umlaut_precomposed);
+ const int w_umlaut_combining = cpp_display_width ("y\xcc\x88", 3,
+- def_tabstop);
++ policy);
+ ASSERT_EQ (1, w_umlaut_combining);
+- const int w_han = cpp_display_width ("\xe4\xb8\xba", 3, def_tabstop);
++ const int w_han = cpp_display_width ("\xe4\xb8\xba", 3, policy);
+ ASSERT_EQ (2, w_han);
+- const int w_ascii = cpp_display_width ("GCC", 3, def_tabstop);
++ const int w_ascii = cpp_display_width ("GCC", 3, policy);
+ ASSERT_EQ (3, w_ascii);
+ const int w_mixed = cpp_display_width ("\xcf\x80 = 3.14 \xf0\x9f\x98\x82"
+ "\x9f! \xe4\xb8\xba y\xcc\x88",
+- 24, def_tabstop);
++ 24, policy);
+ ASSERT_EQ (18, w_mixed);
+ }
+
+ /* Verify that display width properly expands tabs. */
+ {
+ const char *tstr = "\tabc\td";
+- ASSERT_EQ (6, cpp_display_width (tstr, 6, 1));
+- ASSERT_EQ (10, cpp_display_width (tstr, 6, 3));
+- ASSERT_EQ (17, cpp_display_width (tstr, 6, 8));
+- ASSERT_EQ (1, cpp_display_column_to_byte_column (tstr, 6, 7, 8));
++ ASSERT_EQ (6, cpp_display_width (tstr, 6,
++ cpp_char_column_policy (1, cpp_wcwidth)));
++ ASSERT_EQ (10, cpp_display_width (tstr, 6,
++ cpp_char_column_policy (3, cpp_wcwidth)));
++ ASSERT_EQ (17, cpp_display_width (tstr, 6,
++ cpp_char_column_policy (8, cpp_wcwidth)));
++ ASSERT_EQ (1,
++ cpp_display_column_to_byte_column
++ (tstr, 6, 7, cpp_char_column_policy (8, cpp_wcwidth)));
+ }
+
+ /* Verify that cpp_byte_column_to_display_column can go past the end,
+@@ -3660,13 +3668,13 @@ void test_cpp_utf8 ()
+ /* 111122223456
+ Byte columns. */
+
+- ASSERT_EQ (5, cpp_display_width (str, 6, def_tabstop));
++ ASSERT_EQ (5, cpp_display_width (str, 6, policy));
+ ASSERT_EQ (105,
+- cpp_byte_column_to_display_column (str, 6, 106, def_tabstop));
++ cpp_byte_column_to_display_column (str, 6, 106, policy));
+ ASSERT_EQ (10000,
+- cpp_byte_column_to_display_column (NULL, 0, 10000, def_tabstop));
++ cpp_byte_column_to_display_column (NULL, 0, 10000, policy));
+ ASSERT_EQ (0,
+- cpp_byte_column_to_display_column (NULL, 10000, 0, def_tabstop));
++ cpp_byte_column_to_display_column (NULL, 10000, 0, policy));
+ }
+
+ /* Verify that cpp_display_column_to_byte_column can go past the end,
+@@ -3680,25 +3688,25 @@ void test_cpp_utf8 ()
+ /* 000000000000000000000000000000000111111
+ 111122223333444456666777788889999012345
+ Byte columns. */
+- ASSERT_EQ (4, cpp_display_column_to_byte_column (str, 15, 2, def_tabstop));
++ ASSERT_EQ (4, cpp_display_column_to_byte_column (str, 15, 2, policy));
+ ASSERT_EQ (15,
+- cpp_display_column_to_byte_column (str, 15, 11, def_tabstop));
++ cpp_display_column_to_byte_column (str, 15, 11, policy));
+ ASSERT_EQ (115,
+- cpp_display_column_to_byte_column (str, 15, 111, def_tabstop));
++ cpp_display_column_to_byte_column (str, 15, 111, policy));
+ ASSERT_EQ (10000,
+- cpp_display_column_to_byte_column (NULL, 0, 10000, def_tabstop));
++ cpp_display_column_to_byte_column (NULL, 0, 10000, policy));
+ ASSERT_EQ (0,
+- cpp_display_column_to_byte_column (NULL, 10000, 0, def_tabstop));
++ cpp_display_column_to_byte_column (NULL, 10000, 0, policy));
+
+ /* Verify that we do not interrupt a UTF-8 sequence. */
+- ASSERT_EQ (4, cpp_display_column_to_byte_column (str, 15, 1, def_tabstop));
++ ASSERT_EQ (4, cpp_display_column_to_byte_column (str, 15, 1, policy));
+
+ for (int byte_col = 1; byte_col <= 15; ++byte_col)
+ {
+ const int disp_col
+- = cpp_byte_column_to_display_column (str, 15, byte_col, def_tabstop);
++ = cpp_byte_column_to_display_column (str, 15, byte_col, policy);
+ const int byte_col2
+- = cpp_display_column_to_byte_column (str, 15, disp_col, def_tabstop);
++ = cpp_display_column_to_byte_column (str, 15, disp_col, policy);
+
+ /* If we ask for the display column in the middle of a UTF-8
+ sequence, it will return the length of the partial sequence,
+diff --git a/gcc/input.h b/gcc/input.h
+--- a/gcc/input.h 2021-07-27 23:55:07.328287915 -0700
++++ b/gcc/input.h 2021-12-14 01:16:01.553943061 -0800
+@@ -39,8 +39,11 @@ STATIC_ASSERT (BUILTINS_LOCATION < RESER
+ extern bool is_location_from_builtin_token (location_t);
+ extern expanded_location expand_location (location_t);
+
+-extern int location_compute_display_column (expanded_location exploc,
+- int tabstop);
++class cpp_char_column_policy;
++
++extern int
++location_compute_display_column (expanded_location exploc,
++ const cpp_char_column_policy &policy);
+
+ /* A class capturing the bounds of a buffer, to allow for run-time
+ bounds-checking in a checked build. */
+diff --git a/gcc/opts.c b/gcc/opts.c
+--- a/gcc/opts.c 2021-07-27 23:55:07.364288417 -0700
++++ b/gcc/opts.c 2021-12-14 01:16:01.553943061 -0800
+@@ -2573,6 +2573,10 @@ common_handle_option (struct gcc_options
+ dc->column_origin = value;
+ break;
+
++ case OPT_fdiagnostics_escape_format_:
++ dc->escape_format = (enum diagnostics_escape_format)value;
++ break;
++
+ case OPT_fdiagnostics_show_cwe:
+ dc->show_cwe = value;
+ break;
+diff --git a/gcc/selftest.c b/gcc/selftest.c
+--- a/gcc/selftest.c 2021-07-27 23:55:07.500290315 -0700
++++ b/gcc/selftest.c 2021-12-14 01:16:01.557942991 -0800
+@@ -193,6 +193,21 @@ temp_source_file::temp_source_file (cons
+ fclose (out);
+ }
+
++/* As above, but with a size, to allow for NUL bytes in CONTENT. */
++
++temp_source_file::temp_source_file (const location &loc,
++ const char *suffix,
++ const char *content,
++ size_t sz)
++: named_temp_file (suffix)
++{
++ FILE *out = fopen (get_filename (), "w");
++ if (!out)
++ fail_formatted (loc, "unable to open tempfile: %s", get_filename ());
++ fwrite (content, sz, 1, out);
++ fclose (out);
++}
++
+ /* Avoid introducing locale-specific differences in the results
+ by hardcoding open_quote and close_quote. */
+
+diff --git a/gcc/selftest.h b/gcc/selftest.h
+--- a/gcc/selftest.h 2021-07-27 23:55:07.500290315 -0700
++++ b/gcc/selftest.h 2021-12-14 01:16:01.557942991 -0800
+@@ -112,6 +112,8 @@ class temp_source_file : public named_te
+ public:
+ temp_source_file (const location &loc, const char *suffix,
+ const char *content);
++ temp_source_file (const location &loc, const char *suffix,
++ const char *content, size_t sz);
+ };
+
+ /* RAII-style class for avoiding introducing locale-specific differences
+diff --git a/gcc/testsuite/c-c++-common/diagnostic-format-json-1.c b/gcc/testsuite/c-c++-common/diagnostic-format-json-1.c
+--- a/gcc/testsuite/c-c++-common/diagnostic-format-json-1.c 2021-07-27 23:55:07.596291654 -0700
++++ b/gcc/testsuite/c-c++-common/diagnostic-format-json-1.c 2021-12-14 01:16:01.557942991 -0800
+@@ -9,6 +9,7 @@
+
+ /* { dg-regexp "\"kind\": \"error\"" } */
+ /* { dg-regexp "\"column-origin\": 1" } */
++/* { dg-regexp "\"escape-source\": false" } */
+ /* { dg-regexp "\"message\": \"#error message\"" } */
+
+ /* { dg-regexp "\"caret\": \{" } */
+diff --git a/gcc/testsuite/c-c++-common/diagnostic-format-json-2.c b/gcc/testsuite/c-c++-common/diagnostic-format-json-2.c
+--- a/gcc/testsuite/c-c++-common/diagnostic-format-json-2.c 2021-07-27 23:55:07.596291654 -0700
++++ b/gcc/testsuite/c-c++-common/diagnostic-format-json-2.c 2021-12-14 01:16:01.557942991 -0800
+@@ -9,6 +9,7 @@
+
+ /* { dg-regexp "\"kind\": \"warning\"" } */
+ /* { dg-regexp "\"column-origin\": 1" } */
++/* { dg-regexp "\"escape-source\": false" } */
+ /* { dg-regexp "\"message\": \"#warning message\"" } */
+ /* { dg-regexp "\"option\": \"-Wcpp\"" } */
+ /* { dg-regexp "\"option_url\": \"https:\[^\n\r\"\]*#index-Wcpp\"" } */
+diff --git a/gcc/testsuite/c-c++-common/diagnostic-format-json-3.c b/gcc/testsuite/c-c++-common/diagnostic-format-json-3.c
+--- a/gcc/testsuite/c-c++-common/diagnostic-format-json-3.c 2021-07-27 23:55:07.596291654 -0700
++++ b/gcc/testsuite/c-c++-common/diagnostic-format-json-3.c 2021-12-14 01:16:01.557942991 -0800
+@@ -9,6 +9,7 @@
+
+ /* { dg-regexp "\"kind\": \"error\"" } */
+ /* { dg-regexp "\"column-origin\": 1" } */
++/* { dg-regexp "\"escape-source\": false" } */
+ /* { dg-regexp "\"message\": \"#warning message\"" } */
+ /* { dg-regexp "\"option\": \"-Werror=cpp\"" } */
+ /* { dg-regexp "\"option_url\": \"https:\[^\n\r\"\]*#index-Wcpp\"" } */
+diff --git a/gcc/testsuite/c-c++-common/diagnostic-format-json-4.c b/gcc/testsuite/c-c++-common/diagnostic-format-json-4.c
+--- a/gcc/testsuite/c-c++-common/diagnostic-format-json-4.c 2021-07-27 23:55:07.596291654 -0700
++++ b/gcc/testsuite/c-c++-common/diagnostic-format-json-4.c 2021-12-14 01:16:01.557942991 -0800
+@@ -19,6 +19,7 @@ int test (void)
+
+ /* { dg-regexp "\"kind\": \"note\"" } */
+ /* { dg-regexp "\"message\": \"...this statement, but the latter is misleadingly indented as if it were guarded by the 'if'\"" } */
++/* { dg-regexp "\"escape-source\": false" } */
+
+ /* { dg-regexp "\"caret\": \{" } */
+ /* { dg-regexp "\"file\": \"\[^\n\r\"\]*diagnostic-format-json-4.c\"" } */
+@@ -39,6 +40,7 @@ int test (void)
+ /* { dg-regexp "\"kind\": \"warning\"" } */
+ /* { dg-regexp "\"column-origin\": 1" } */
+ /* { dg-regexp "\"message\": \"this 'if' clause does not guard...\"" } */
++/* { dg-regexp "\"escape-source\": false" } */
+ /* { dg-regexp "\"option\": \"-Wmisleading-indentation\"" } */
+ /* { dg-regexp "\"option_url\": \"https:\[^\n\r\"\]*#index-Wmisleading-indentation\"" } */
+
+diff --git a/gcc/testsuite/c-c++-common/diagnostic-format-json-5.c b/gcc/testsuite/c-c++-common/diagnostic-format-json-5.c
+--- a/gcc/testsuite/c-c++-common/diagnostic-format-json-5.c 2021-07-27 23:55:07.596291654 -0700
++++ b/gcc/testsuite/c-c++-common/diagnostic-format-json-5.c 2021-12-14 01:16:01.557942991 -0800
+@@ -14,6 +14,7 @@ int test (struct s *ptr)
+
+ /* { dg-regexp "\"kind\": \"error\"" } */
+ /* { dg-regexp "\"column-origin\": 1" } */
++/* { dg-regexp "\"escape-source\": false" } */
+ /* { dg-regexp "\"message\": \".*\"" } */
+
+ /* Verify fix-it hints. */
+diff --git a/gcc/testsuite/gcc.dg/cpp/warn-normalized-4-bytes.c b/gcc/testsuite/gcc.dg/cpp/warn-normalized-4-bytes.c
+--- a/gcc/testsuite/gcc.dg/cpp/warn-normalized-4-bytes.c 1969-12-31 16:00:00.000000000 -0800
++++ b/gcc/testsuite/gcc.dg/cpp/warn-normalized-4-bytes.c 2021-12-14 01:16:01.557942991 -0800
+@@ -0,0 +1,21 @@
++// { dg-do preprocess }
++// { dg-options "-std=gnu99 -Werror=normalized=nfc -fdiagnostics-show-caret -fdiagnostics-escape-format=bytes" }
++/* { dg-message "some warnings being treated as errors" "" {target "*-*-*"} 0 } */
++
++/* འ= U+0F43 TIBETAN LETTER GHA, which has decomposition "0F42 0FB7" i.e.
++ U+0F42 TIBETAN LETTER GA: à½
++ U+0FB7 TIBETAN SUBJOINED LETTER HA: ྷ
++
++ The UTF-8 encoding of U+0F43 TIBETAN LETTER GHA is: E0 BD 83. */
++
++foo before_\u0F43_after bar // { dg-error "`before_.U00000f43_after' is not in NFC .-Werror=normalized=." }
++/* { dg-begin-multiline-output "" }
++ foo before_\u0F43_after bar
++ ^~~~~~~~~~~~~~~~~~~
++ { dg-end-multiline-output "" } */
++
++foo before_à½_after bar // { dg-error "`before_.U00000f43_after' is not in NFC .-Werror=normalized=." }
++/* { dg-begin-multiline-output "" }
++ foo before_<e0><bd><83>_after bar
++ ^~~~~~~~~~~~~~~~~~~~~~~~~
++ { dg-end-multiline-output "" } */
+diff --git a/gcc/testsuite/gcc.dg/cpp/warn-normalized-4-unicode.c b/gcc/testsuite/gcc.dg/cpp/warn-normalized-4-unicode.c
+--- a/gcc/testsuite/gcc.dg/cpp/warn-normalized-4-unicode.c 1969-12-31 16:00:00.000000000 -0800
++++ b/gcc/testsuite/gcc.dg/cpp/warn-normalized-4-unicode.c 2021-12-14 01:16:01.557942991 -0800
+@@ -0,0 +1,19 @@
++// { dg-do preprocess }
++// { dg-options "-std=gnu99 -Werror=normalized=nfc -fdiagnostics-show-caret -fdiagnostics-escape-format=unicode" }
++/* { dg-message "some warnings being treated as errors" "" {target "*-*-*"} 0 } */
++
++/* འ= U+0F43 TIBETAN LETTER GHA, which has decomposition "0F42 0FB7" i.e.
++ U+0F42 TIBETAN LETTER GA: à½
++ U+0FB7 TIBETAN SUBJOINED LETTER HA: ྷ */
++
++foo before_\u0F43_after bar // { dg-error "`before_.U00000f43_after' is not in NFC .-Werror=normalized=." }
++/* { dg-begin-multiline-output "" }
++ foo before_\u0F43_after bar
++ ^~~~~~~~~~~~~~~~~~~
++ { dg-end-multiline-output "" } */
++
++foo before_à½_after bar // { dg-error "`before_.U00000f43_after' is not in NFC .-Werror=normalized=." }
++/* { dg-begin-multiline-output "" }
++ foo before_<U+0F43>_after bar
++ ^~~~~~~~~~~~~~~~~~~~~
++ { dg-end-multiline-output "" } */
+diff --git a/gcc/testsuite/gfortran.dg/diagnostic-format-json-1.F90 b/gcc/testsuite/gfortran.dg/diagnostic-format-json-1.F90
+--- a/gcc/testsuite/gfortran.dg/diagnostic-format-json-1.F90 2021-07-27 23:55:08.472303878 -0700
++++ b/gcc/testsuite/gfortran.dg/diagnostic-format-json-1.F90 2021-12-14 01:16:01.557942991 -0800
+@@ -9,6 +9,7 @@
+
+ ! { dg-regexp "\"kind\": \"error\"" }
+ ! { dg-regexp "\"column-origin\": 1" }
++! { dg-regexp "\"escape-source\": false" }
+ ! { dg-regexp "\"message\": \"#error message\"" }
+
+ ! { dg-regexp "\"caret\": \{" }
+diff --git a/gcc/testsuite/gfortran.dg/diagnostic-format-json-2.F90 b/gcc/testsuite/gfortran.dg/diagnostic-format-json-2.F90
+--- a/gcc/testsuite/gfortran.dg/diagnostic-format-json-2.F90 2021-07-27 23:55:08.472303878 -0700
++++ b/gcc/testsuite/gfortran.dg/diagnostic-format-json-2.F90 2021-12-14 01:16:01.557942991 -0800
+@@ -9,6 +9,7 @@
+
+ ! { dg-regexp "\"kind\": \"warning\"" }
+ ! { dg-regexp "\"column-origin\": 1" }
++! { dg-regexp "\"escape-source\": false" }
+ ! { dg-regexp "\"message\": \"#warning message\"" }
+ ! { dg-regexp "\"option\": \"-Wcpp\"" }
+ ! { dg-regexp "\"option_url\": \"\[^\n\r\"\]*#index-Wcpp\"" }
+diff --git a/gcc/testsuite/gfortran.dg/diagnostic-format-json-3.F90 b/gcc/testsuite/gfortran.dg/diagnostic-format-json-3.F90
+--- a/gcc/testsuite/gfortran.dg/diagnostic-format-json-3.F90 2021-07-27 23:55:08.472303878 -0700
++++ b/gcc/testsuite/gfortran.dg/diagnostic-format-json-3.F90 2021-12-14 01:16:01.557942991 -0800
+@@ -9,6 +9,7 @@
+
+ ! { dg-regexp "\"kind\": \"error\"" }
+ ! { dg-regexp "\"column-origin\": 1" }
++! { dg-regexp "\"escape-source\": false" }
+ ! { dg-regexp "\"message\": \"#warning message\"" }
+ ! { dg-regexp "\"option\": \"-Werror=cpp\"" }
+ ! { dg-regexp "\"option_url\": \"\[^\n\r\"\]*#index-Wcpp\"" }
+diff --git a/libcpp/charset.c b/libcpp/charset.c
+--- a/libcpp/charset.c 2021-07-27 23:55:08.712307227 -0700
++++ b/libcpp/charset.c 2021-12-14 01:16:01.557942991 -0800
+@@ -1552,12 +1552,14 @@ convert_escape (cpp_reader *pfile, const
+ "unknown escape sequence: '\\%c'", (int) c);
+ else
+ {
++ encoding_rich_location rich_loc (pfile);
++
+ /* diagnostic.c does not support "%03o". When it does, this
+ code can use %03o directly in the diagnostic again. */
+ char buf[32];
+ sprintf(buf, "%03o", (int) c);
+- cpp_error (pfile, CPP_DL_PEDWARN,
+- "unknown escape sequence: '\\%s'", buf);
++ cpp_error_at (pfile, CPP_DL_PEDWARN, &rich_loc,
++ "unknown escape sequence: '\\%s'", buf);
+ }
+ }
+
+@@ -2280,14 +2282,16 @@ cpp_string_location_reader::get_next ()
+ }
+
+ cpp_display_width_computation::
+-cpp_display_width_computation (const char *data, int data_length, int tabstop) :
++cpp_display_width_computation (const char *data, int data_length,
++ const cpp_char_column_policy &policy) :
+ m_begin (data),
+ m_next (m_begin),
+ m_bytes_left (data_length),
+- m_tabstop (tabstop),
++ m_policy (policy),
+ m_display_cols (0)
+ {
+- gcc_assert (m_tabstop > 0);
++ gcc_assert (policy.m_tabstop > 0);
++ gcc_assert (policy.m_width_cb);
+ }
+
+
+@@ -2299,19 +2303,28 @@ cpp_display_width_computation (const cha
+ point to a valid UTF-8-encoded sequence, then it will be treated as a single
+ byte with display width 1. m_cur_display_col is the current display column,
+ relative to which tab stops should be expanded. Returns the display width of
+- the codepoint just processed. */
++ the codepoint just processed.
++ If OUT is non-NULL, it is populated. */
+
+ int
+-cpp_display_width_computation::process_next_codepoint ()
++cpp_display_width_computation::process_next_codepoint (cpp_decoded_char *out)
+ {
+ cppchar_t c;
+ int next_width;
+
++ if (out)
++ out->m_start_byte = m_next;
++
+ if (*m_next == '\t')
+ {
+ ++m_next;
+ --m_bytes_left;
+- next_width = m_tabstop - (m_display_cols % m_tabstop);
++ next_width = m_policy.m_tabstop - (m_display_cols % m_policy.m_tabstop);
++ if (out)
++ {
++ out->m_ch = '\t';
++ out->m_valid_ch = true;
++ }
+ }
+ else if (one_utf8_to_cppchar ((const uchar **) &m_next, &m_bytes_left, &c)
+ != 0)
+@@ -2321,14 +2334,24 @@ cpp_display_width_computation::process_n
+ of one. */
+ ++m_next;
+ --m_bytes_left;
+- next_width = 1;
++ next_width = m_policy.m_undecoded_byte_width;
++ if (out)
++ out->m_valid_ch = false;
+ }
+ else
+ {
+ /* one_utf8_to_cppchar() has updated m_next and m_bytes_left for us. */
+- next_width = cpp_wcwidth (c);
++ next_width = m_policy.m_width_cb (c);
++ if (out)
++ {
++ out->m_ch = c;
++ out->m_valid_ch = true;
++ }
+ }
+
++ if (out)
++ out->m_next_byte = m_next;
++
+ m_display_cols += next_width;
+ return next_width;
+ }
+@@ -2344,7 +2367,7 @@ cpp_display_width_computation::advance_d
+ const int start = m_display_cols;
+ const int target = start + n;
+ while (m_display_cols < target && !done ())
+- process_next_codepoint ();
++ process_next_codepoint (NULL);
+ return m_display_cols - start;
+ }
+
+@@ -2352,29 +2375,33 @@ cpp_display_width_computation::advance_d
+ how many display columns are occupied by the first COLUMN bytes. COLUMN
+ may exceed DATA_LENGTH, in which case the phantom bytes at the end are
+ treated as if they have display width 1. Tabs are expanded to the next tab
+- stop, relative to the start of DATA. */
++ stop, relative to the start of DATA, and non-printable-ASCII characters
++ will be escaped as per POLICY. */
+
+ int
+ cpp_byte_column_to_display_column (const char *data, int data_length,
+- int column, int tabstop)
++ int column,
++ const cpp_char_column_policy &policy)
+ {
+ const int offset = MAX (0, column - data_length);
+- cpp_display_width_computation dw (data, column - offset, tabstop);
++ cpp_display_width_computation dw (data, column - offset, policy);
+ while (!dw.done ())
+- dw.process_next_codepoint ();
++ dw.process_next_codepoint (NULL);
+ return dw.display_cols_processed () + offset;
+ }
+
+ /* For the string of length DATA_LENGTH bytes that begins at DATA, compute
+ the least number of bytes that will result in at least DISPLAY_COL display
+ columns. The return value may exceed DATA_LENGTH if the entire string does
+- not occupy enough display columns. */
++ not occupy enough display columns. Non-printable-ASCII characters
++ will be escaped as per POLICY. */
+
+ int
+ cpp_display_column_to_byte_column (const char *data, int data_length,
+- int display_col, int tabstop)
++ int display_col,
++ const cpp_char_column_policy &policy)
+ {
+- cpp_display_width_computation dw (data, data_length, tabstop);
++ cpp_display_width_computation dw (data, data_length, policy);
+ const int avail_display = dw.advance_display_cols (display_col);
+ return dw.bytes_processed () + MAX (0, display_col - avail_display);
+ }
+diff --git a/libcpp/errors.c b/libcpp/errors.c
+--- a/libcpp/errors.c 2021-07-27 23:55:08.712307227 -0700
++++ b/libcpp/errors.c 2021-12-14 01:16:01.557942991 -0800
+@@ -27,6 +27,31 @@ along with this program; see the file CO
+ #include "cpplib.h"
+ #include "internal.h"
+
++/* Get a location_t for the current location in PFILE,
++ generally that of the previously lexed token. */
++
++location_t
++cpp_diagnostic_get_current_location (cpp_reader *pfile)
++{
++ if (CPP_OPTION (pfile, traditional))
++ {
++ if (pfile->state.in_directive)
++ return pfile->directive_line;
++ else
++ return pfile->line_table->highest_line;
++ }
++ /* We don't want to refer to a token before the beginning of the
++ current run -- that is invalid. */
++ else if (pfile->cur_token == pfile->cur_run->base)
++ {
++ return 0;
++ }
++ else
++ {
++ return pfile->cur_token[-1].src_loc;
++ }
++}
++
+ /* Print a diagnostic at the given location. */
+
+ ATTRIBUTE_FPTR_PRINTF(5,0)
+@@ -52,25 +77,7 @@ cpp_diagnostic (cpp_reader * pfile, enum
+ enum cpp_warning_reason reason,
+ const char *msgid, va_list *ap)
+ {
+- location_t src_loc;
+-
+- if (CPP_OPTION (pfile, traditional))
+- {
+- if (pfile->state.in_directive)
+- src_loc = pfile->directive_line;
+- else
+- src_loc = pfile->line_table->highest_line;
+- }
+- /* We don't want to refer to a token before the beginning of the
+- current run -- that is invalid. */
+- else if (pfile->cur_token == pfile->cur_run->base)
+- {
+- src_loc = 0;
+- }
+- else
+- {
+- src_loc = pfile->cur_token[-1].src_loc;
+- }
++ location_t src_loc = cpp_diagnostic_get_current_location (pfile);
+ rich_location richloc (pfile->line_table, src_loc);
+ return cpp_diagnostic_at (pfile, level, reason, &richloc, msgid, ap);
+ }
+@@ -142,6 +149,43 @@ cpp_warning_syshdr (cpp_reader * pfile,
+
+ va_end (ap);
+ return ret;
++}
++
++/* As cpp_warning above, but use RICHLOC as the location of the diagnostic. */
++
++bool cpp_warning_at (cpp_reader *pfile, enum cpp_warning_reason reason,
++ rich_location *richloc, const char *msgid, ...)
++{
++ va_list ap;
++ bool ret;
++
++ va_start (ap, msgid);
++
++ ret = cpp_diagnostic_at (pfile, CPP_DL_WARNING, reason, richloc,
++ msgid, &ap);
++
++ va_end (ap);
++ return ret;
++
++}
++
++/* As cpp_pedwarning above, but use RICHLOC as the location of the
++ diagnostic. */
++
++bool
++cpp_pedwarning_at (cpp_reader * pfile, enum cpp_warning_reason reason,
++ rich_location *richloc, const char *msgid, ...)
++{
++ va_list ap;
++ bool ret;
++
++ va_start (ap, msgid);
++
++ ret = cpp_diagnostic_at (pfile, CPP_DL_PEDWARN, reason, richloc,
++ msgid, &ap);
++
++ va_end (ap);
++ return ret;
+ }
+
+ /* Print a diagnostic at a specific location. */
+diff --git a/libcpp/include/cpplib.h b/libcpp/include/cpplib.h
+--- a/libcpp/include/cpplib.h 2021-12-13 23:23:05.768437079 -0800
++++ b/libcpp/include/cpplib.h 2021-12-14 01:20:16.189507386 -0800
+@@ -1275,6 +1275,14 @@ extern bool cpp_warning_syshdr (cpp_read
+ const char *msgid, ...)
+ ATTRIBUTE_PRINTF_3;
+
++/* As their counterparts above, but use RICHLOC. */
++extern bool cpp_warning_at (cpp_reader *, enum cpp_warning_reason,
++ rich_location *richloc, const char *msgid, ...)
++ ATTRIBUTE_PRINTF_4;
++extern bool cpp_pedwarning_at (cpp_reader *, enum cpp_warning_reason,
++ rich_location *richloc, const char *msgid, ...)
++ ATTRIBUTE_PRINTF_4;
++
+ /* Output a diagnostic with "MSGID: " preceding the
+ error string of errno. No location is printed. */
+ extern bool cpp_errno (cpp_reader *, enum cpp_diagnostic_level,
+@@ -1435,42 +1443,95 @@ extern const char * cpp_get_userdef_suff
+
+ /* In charset.c */
+
++/* The result of attempting to decode a run of UTF-8 bytes. */
++
++struct cpp_decoded_char
++{
++ const char *m_start_byte;
++ const char *m_next_byte;
++
++ bool m_valid_ch;
++ cppchar_t m_ch;
++};
++
++/* Information for mapping between code points and display columns.
++
++ This is a tabstop value, along with a callback for getting the
++ widths of characters. Normally this callback is cpp_wcwidth, but we
++ support other schemes for escaping non-ASCII unicode as a series of
++ ASCII chars when printing the user's source code in diagnostic-show-locus.c
++
++ For example, consider:
++ - the Unicode character U+03C0 "GREEK SMALL LETTER PI" (UTF-8: 0xCF 0x80)
++ - the Unicode character U+1F642 "SLIGHTLY SMILING FACE"
++ (UTF-8: 0xF0 0x9F 0x99 0x82)
++ - the byte 0xBF (a stray trailing byte of a UTF-8 character)
++ Normally U+03C0 would occupy one display column, U+1F642
++ would occupy two display columns, and the stray byte would be
++ printed verbatim as one display column.
++
++ However when escaping them as unicode code points as "<U+03C0>"
++ and "<U+1F642>" they occupy 8 and 9 display columns respectively,
++ and when escaping them as bytes as "<CF><80>" and "<F0><9F><99><82>"
++ they occupy 8 and 16 display columns respectively. In both cases
++ the stray byte is escaped to <BF> as 4 display columns. */
++
++struct cpp_char_column_policy
++{
++ cpp_char_column_policy (int tabstop,
++ int (*width_cb) (cppchar_t c))
++ : m_tabstop (tabstop),
++ m_undecoded_byte_width (1),
++ m_width_cb (width_cb)
++ {}
++
++ int m_tabstop;
++ /* Width in display columns of a stray byte that isn't decodable
++ as UTF-8. */
++ int m_undecoded_byte_width;
++ int (*m_width_cb) (cppchar_t c);
++};
++
+ /* A class to manage the state while converting a UTF-8 sequence to cppchar_t
+ and computing the display width one character at a time. */
+ class cpp_display_width_computation {
+ public:
+ cpp_display_width_computation (const char *data, int data_length,
+- int tabstop);
++ const cpp_char_column_policy &policy);
+ const char *next_byte () const { return m_next; }
+ int bytes_processed () const { return m_next - m_begin; }
+ int bytes_left () const { return m_bytes_left; }
+ bool done () const { return !bytes_left (); }
+ int display_cols_processed () const { return m_display_cols; }
+
+- int process_next_codepoint ();
++ int process_next_codepoint (cpp_decoded_char *out);
+ int advance_display_cols (int n);
+
+ private:
+ const char *const m_begin;
+ const char *m_next;
+ size_t m_bytes_left;
+- const int m_tabstop;
++ const cpp_char_column_policy &m_policy;
+ int m_display_cols;
+ };
+
+ /* Convenience functions that are simple use cases for class
+ cpp_display_width_computation. Tab characters will be expanded to spaces
+- as determined by TABSTOP. */
++ as determined by POLICY.m_tabstop, and non-printable-ASCII characters
++ will be escaped as per POLICY. */
++
+ int cpp_byte_column_to_display_column (const char *data, int data_length,
+- int column, int tabstop);
++ int column,
++ const cpp_char_column_policy &policy);
+ inline int cpp_display_width (const char *data, int data_length,
+- int tabstop)
++ const cpp_char_column_policy &policy)
+ {
+ return cpp_byte_column_to_display_column (data, data_length, data_length,
+- tabstop);
++ policy);
+ }
+ int cpp_display_column_to_byte_column (const char *data, int data_length,
+- int display_col, int tabstop);
++ int display_col,
++ const cpp_char_column_policy &policy);
+ int cpp_wcwidth (cppchar_t c);
+
+ #endif /* ! LIBCPP_CPPLIB_H */
+diff --git a/libcpp/include/line-map.h b/libcpp/include/line-map.h
+--- a/libcpp/include/line-map.h 2021-07-27 23:55:08.716307283 -0700
++++ b/libcpp/include/line-map.h 2021-12-14 01:16:01.557942991 -0800
+@@ -1781,6 +1781,18 @@ class rich_location
+ const diagnostic_path *get_path () const { return m_path; }
+ void set_path (const diagnostic_path *path) { m_path = path; }
+
++ /* A flag for hinting that the diagnostic involves character encoding
++ issues, and thus that it will be helpful to the user if we show some
++ representation of how the characters in the pertinent source lines
++ are encoded.
++ The default is false (i.e. do not escape).
++ When set to true, non-ASCII bytes in the pertinent source lines will
++ be escaped in a manner controlled by the user-supplied option
++ -fdiagnostics-escape-format=, so that the user can better understand
++ what's going on with the encoding in their source file. */
++ bool escape_on_output_p () const { return m_escape_on_output; }
++ void set_escape_on_output (bool flag) { m_escape_on_output = flag; }
++
+ private:
+ bool reject_impossible_fixit (location_t where);
+ void stop_supporting_fixits ();
+@@ -1807,6 +1819,7 @@ protected:
+ bool m_fixits_cannot_be_auto_applied;
+
+ const diagnostic_path *m_path;
++ bool m_escape_on_output;
+ };
+
+ /* A struct for the result of range_label::get_text: a NUL-terminated buffer
+diff --git a/libcpp/internal.h b/libcpp/internal.h
+--- a/libcpp/internal.h 2021-12-13 23:23:05.768437079 -0800
++++ b/libcpp/internal.h 2021-12-14 01:16:01.557942991 -0800
+@@ -776,6 +776,9 @@ extern void _cpp_do_file_change (cpp_rea
+ extern void _cpp_pop_buffer (cpp_reader *);
+ extern char *_cpp_bracket_include (cpp_reader *);
+
++/* In errors.c */
++extern location_t cpp_diagnostic_get_current_location (cpp_reader *);
++
+ /* In traditional.c. */
+ extern bool _cpp_scan_out_logical_line (cpp_reader *, cpp_macro *, bool);
+ extern bool _cpp_read_logical_line_trad (cpp_reader *);
+@@ -942,6 +945,26 @@ int linemap_get_expansion_line (class li
+ const char* linemap_get_expansion_filename (class line_maps *,
+ location_t);
+
++/* A subclass of rich_location for emitting a diagnostic
++ at the current location of the reader, but flagging
++ it with set_escape_on_output (true). */
++class encoding_rich_location : public rich_location
++{
++ public:
++ encoding_rich_location (cpp_reader *pfile)
++ : rich_location (pfile->line_table,
++ cpp_diagnostic_get_current_location (pfile))
++ {
++ set_escape_on_output (true);
++ }
++
++ encoding_rich_location (cpp_reader *pfile, location_t loc)
++ : rich_location (pfile->line_table, loc)
++ {
++ set_escape_on_output (true);
++ }
++};
++
+ #ifdef __cplusplus
+ }
+ #endif
+diff --git a/libcpp/lex.c b/libcpp/lex.c
+--- a/libcpp/lex.c 2021-12-14 01:14:48.435225968 -0800
++++ b/libcpp/lex.c 2021-12-14 01:24:37.220995816 -0800
+@@ -1774,7 +1774,11 @@ skip_whitespace (cpp_reader *pfile, cppc
+ while (is_nvspace (c));
+
+ if (saw_NUL)
+- cpp_error (pfile, CPP_DL_WARNING, "null character(s) ignored");
++ {
++ encoding_rich_location rich_loc (pfile);
++ cpp_error_at (pfile, CPP_DL_WARNING, &rich_loc,
++ "null character(s) ignored");
++ }
+
+ buffer->cur--;
+ }
+@@ -1803,6 +1807,28 @@ warn_about_normalization (cpp_reader *pf
+ if (CPP_OPTION (pfile, warn_normalize) < NORMALIZE_STATE_RESULT (s)
+ && !pfile->state.skipping)
+ {
++ location_t loc = token->src_loc;
++
++ /* If possible, create a location range for the token. */
++ if (loc >= RESERVED_LOCATION_COUNT
++ && token->type != CPP_EOF
++ /* There must be no line notes to process. */
++ && (!(pfile->buffer->cur
++ >= pfile->buffer->notes[pfile->buffer->cur_note].pos
++ && !pfile->overlaid_buffer)))
++ {
++ source_range tok_range;
++ tok_range.m_start = loc;
++ tok_range.m_finish
++ = linemap_position_for_column (pfile->line_table,
++ CPP_BUF_COLUMN (pfile->buffer,
++ pfile->buffer->cur));
++ loc = COMBINE_LOCATION_DATA (pfile->line_table,
++ loc, tok_range, NULL);
++ }
++
++ encoding_rich_location rich_loc (pfile, loc);
++
+ /* Make sure that the token is printed using UCNs, even
+ if we'd otherwise happily print UTF-8. */
+ unsigned char *buf = XNEWVEC (unsigned char, cpp_token_len (token));
+@@ -1810,11 +1836,11 @@ warn_about_normalization (cpp_reader *pf
+
+ sz = cpp_spell_token (pfile, token, buf, false) - buf;
+ if (NORMALIZE_STATE_RESULT (s) == normalized_C)
+- cpp_warning_with_line (pfile, CPP_W_NORMALIZE, token->src_loc, 0,
+- "`%.*s' is not in NFKC", (int) sz, buf);
++ cpp_warning_at (pfile, CPP_W_NORMALIZE, &rich_loc,
++ "`%.*s' is not in NFKC", (int) sz, buf);
+ else
+- cpp_warning_with_line (pfile, CPP_W_NORMALIZE, token->src_loc, 0,
+- "`%.*s' is not in NFC", (int) sz, buf);
++ cpp_warning_at (pfile, CPP_W_NORMALIZE, &rich_loc,
++ "`%.*s' is not in NFC", (int) sz, buf);
+ free (buf);
+ }
+ }
+diff --git a/libcpp/line-map.c b/libcpp/line-map.c
+--- a/libcpp/line-map.c 2021-07-27 23:55:08.716307283 -0700
++++ b/libcpp/line-map.c 2021-12-14 01:16:01.561942921 -0800
+@@ -2086,7 +2086,8 @@ rich_location::rich_location (line_maps
+ m_fixit_hints (),
+ m_seen_impossible_fixit (false),
+ m_fixits_cannot_be_auto_applied (false),
+- m_path (NULL)
++ m_path (NULL),
++ m_escape_on_output (false)
+ {
+ add_range (loc, SHOW_RANGE_WITH_CARET, label);
+ }