diff --git a/poky/meta/recipes-devtools/gcc/gcc/0002-CVE-2021-42574.patch b/poky/meta/recipes-devtools/gcc/gcc/0002-CVE-2021-42574.patch
new file mode 100644
index 0000000..9bad81d
--- /dev/null
+++ b/poky/meta/recipes-devtools/gcc/gcc/0002-CVE-2021-42574.patch
@@ -0,0 +1,1765 @@
+From 51c500269bf53749b107807d84271385fad35628 Mon Sep 17 00:00:00 2001
+From: Marek Polacek <polacek@redhat.com>
+Date: Wed, 6 Oct 2021 14:33:59 -0400
+Subject: [PATCH] libcpp: Implement -Wbidi-chars for CVE-2021-42574 [PR103026]
+
+From a link below:
+"An issue was discovered in the Bidirectional Algorithm in the Unicode
+Specification through 14.0. It permits the visual reordering of
+characters via control sequences, which can be used to craft source code
+that renders different logic than the logical ordering of tokens
+ingested by compilers and interpreters. Adversaries can leverage this to
+encode source code for compilers accepting Unicode such that targeted
+vulnerabilities are introduced invisibly to human reviewers."
+
+More info:
+https://nvd.nist.gov/vuln/detail/CVE-2021-42574
+https://trojansource.codes/
+
+This is not a compiler bug.  However, to mitigate the problem, this patch
+implements -Wbidi-chars=[none|unpaired|any] to warn about possibly
+misleading Unicode bidirectional control characters the preprocessor may
+encounter.
+
+The default is =unpaired, which warns about improperly terminated
+bidirectional control characters; e.g. a LRE without its corresponding PDF.
+The level =any warns about any use of bidirectional control characters.
+
+This patch handles both UCNs and UTF-8 characters.  UCNs designating
+bidi characters in identifiers are accepted since r204886.  Then r217144
+enabled -fextended-identifiers by default.  Extended characters in C/C++
+identifiers have been accepted since r275979.  However, this patch still
+warns about mixing UTF-8 and UCN bidi characters; there seems to be no
+good reason to allow mixing them.
+
+We warn in different contexts: comments (both C and C++-style), string
+literals, character constants, and identifiers.  Expectedly, UCNs are ignored
+in comments and raw string literals.  The bidirectional control characters
+can nest so this patch handles that as well.
+
+I have not included nor tested this at all with Fortran (which also has
+string literals and line comments).
+
+Dave M. posted patches improving diagnostic involving Unicode characters.
+This patch does not make use of this new infrastructure yet.
+
+	PR preprocessor/103026
+
+gcc/c-family/ChangeLog:
+
+	* c.opt (Wbidi-chars, Wbidi-chars=): New option.
+
+gcc/ChangeLog:
+
+	* doc/invoke.texi: Document -Wbidi-chars.
+
+libcpp/ChangeLog:
+
+	* include/cpplib.h (enum cpp_bidirectional_level): New.
+	(struct cpp_options): Add cpp_warn_bidirectional.
+	(enum cpp_warning_reason): Add CPP_W_BIDIRECTIONAL.
+	* internal.h (struct cpp_reader): Add warn_bidi_p member
+	function.
+	* init.c (cpp_create_reader): Set cpp_warn_bidirectional.
+	* lex.c (bidi): New namespace.
+	(get_bidi_utf8): New function.
+	(get_bidi_ucn): Likewise.
+	(maybe_warn_bidi_on_close): Likewise.
+	(maybe_warn_bidi_on_char): Likewise.
+	(_cpp_skip_block_comment): Implement warning about bidirectional
+	control characters.
+	(skip_line_comment): Likewise.
+	(forms_identifier_p): Likewise.
+	(lex_identifier): Likewise.
+	(lex_string): Likewise.
+	(lex_raw_string): Likewise.
+
+gcc/testsuite/ChangeLog:
+
+	* c-c++-common/Wbidi-chars-1.c: New test.
+	* c-c++-common/Wbidi-chars-2.c: New test.
+	* c-c++-common/Wbidi-chars-3.c: New test.
+	* c-c++-common/Wbidi-chars-4.c: New test.
+	* c-c++-common/Wbidi-chars-5.c: New test.
+	* c-c++-common/Wbidi-chars-6.c: New test.
+	* c-c++-common/Wbidi-chars-7.c: New test.
+	* c-c++-common/Wbidi-chars-8.c: New test.
+	* c-c++-common/Wbidi-chars-9.c: New test.
+	* c-c++-common/Wbidi-chars-10.c: New test.
+	* c-c++-common/Wbidi-chars-11.c: New test.
+	* c-c++-common/Wbidi-chars-12.c: New test.
+	* c-c++-common/Wbidi-chars-13.c: New test.
+	* c-c++-common/Wbidi-chars-14.c: New test.
+	* c-c++-common/Wbidi-chars-15.c: New test.
+	* c-c++-common/Wbidi-chars-16.c: New test.
+	* c-c++-common/Wbidi-chars-17.c: New test.
+
+CVE: CVE-2021-42574
+Upstream-Status: Backport [https://gcc.gnu.org/git/gitweb.cgi?p=gcc.git;h=51c500269bf53749b107807d84271385fad35628]
+Signed-off-by: Pgowda <pgowda.cve@gmail.com>
+
+---
+ gcc/c-family/c.opt                          |  24 ++
+ gcc/doc/invoke.texi                         |  21 +-
+ gcc/testsuite/c-c++-common/Wbidi-chars-1.c  |  12 +
+ gcc/testsuite/c-c++-common/Wbidi-chars-10.c |  27 ++
+ gcc/testsuite/c-c++-common/Wbidi-chars-11.c |  13 +
+ gcc/testsuite/c-c++-common/Wbidi-chars-12.c |  19 +
+ gcc/testsuite/c-c++-common/Wbidi-chars-13.c |  17 +
+ gcc/testsuite/c-c++-common/Wbidi-chars-14.c |  38 ++
+ gcc/testsuite/c-c++-common/Wbidi-chars-15.c |  59 +++
+ gcc/testsuite/c-c++-common/Wbidi-chars-16.c |  26 ++
+ gcc/testsuite/c-c++-common/Wbidi-chars-17.c |  30 ++
+ gcc/testsuite/c-c++-common/Wbidi-chars-2.c  |   9 +
+ gcc/testsuite/c-c++-common/Wbidi-chars-3.c  |  11 +
+ gcc/testsuite/c-c++-common/Wbidi-chars-4.c  | 188 +++++++++
+ gcc/testsuite/c-c++-common/Wbidi-chars-5.c  | 188 +++++++++
+ gcc/testsuite/c-c++-common/Wbidi-chars-6.c  | 155 ++++++++
+ gcc/testsuite/c-c++-common/Wbidi-chars-7.c  |   9 +
+ gcc/testsuite/c-c++-common/Wbidi-chars-8.c  |  13 +
+ gcc/testsuite/c-c++-common/Wbidi-chars-9.c  |  29 ++
+ libcpp/include/cpplib.h                     |  18 +-
+ libcpp/init.c                               |   1 +
+ libcpp/internal.h                           |   7 +
+ libcpp/lex.c                                | 408 +++++++++++++++++++-
+ 23 files changed, 1315 insertions(+), 7 deletions(-)
+ create mode 100644 gcc/testsuite/c-c++-common/Wbidi-chars-1.c
+ create mode 100644 gcc/testsuite/c-c++-common/Wbidi-chars-10.c
+ create mode 100644 gcc/testsuite/c-c++-common/Wbidi-chars-11.c
+ create mode 100644 gcc/testsuite/c-c++-common/Wbidi-chars-12.c
+ create mode 100644 gcc/testsuite/c-c++-common/Wbidi-chars-13.c
+ create mode 100644 gcc/testsuite/c-c++-common/Wbidi-chars-14.c
+ create mode 100644 gcc/testsuite/c-c++-common/Wbidi-chars-15.c
+ create mode 100644 gcc/testsuite/c-c++-common/Wbidi-chars-16.c
+ create mode 100644 gcc/testsuite/c-c++-common/Wbidi-chars-17.c
+ create mode 100644 gcc/testsuite/c-c++-common/Wbidi-chars-2.c
+ create mode 100644 gcc/testsuite/c-c++-common/Wbidi-chars-3.c
+ create mode 100644 gcc/testsuite/c-c++-common/Wbidi-chars-4.c
+ create mode 100644 gcc/testsuite/c-c++-common/Wbidi-chars-5.c
+ create mode 100644 gcc/testsuite/c-c++-common/Wbidi-chars-6.c
+ create mode 100644 gcc/testsuite/c-c++-common/Wbidi-chars-7.c
+ create mode 100644 gcc/testsuite/c-c++-common/Wbidi-chars-8.c
+ create mode 100644 gcc/testsuite/c-c++-common/Wbidi-chars-9.c
+
+diff --git a/gcc/c-family/c.opt b/gcc/c-family/c.opt
+index 8a4cd634f77..3976fc368db 100644
+--- a/gcc/c-family/c.opt
++++ b/gcc/c-family/c.opt
+@@ -370,6 +370,30 @@ Wbad-function-cast
+ C ObjC Var(warn_bad_function_cast) Warning
+ Warn about casting functions to incompatible types.
+ 
++Wbidi-chars
++C ObjC C++ ObjC++ Warning Alias(Wbidi-chars=,any,none)
++;
++
++Wbidi-chars=
++C ObjC C++ ObjC++ RejectNegative Joined Warning CPP(cpp_warn_bidirectional) CppReason(CPP_W_BIDIRECTIONAL) Var(warn_bidirectional) Init(bidirectional_unpaired) Enum(cpp_bidirectional_level)
++-Wbidi-chars=[none|unpaired|any] Warn about UTF-8 bidirectional control characters.
++
++; Required for these enum values.
++SourceInclude
++cpplib.h
++
++Enum
++Name(cpp_bidirectional_level) Type(int) UnknownError(argument %qs to %<-Wbidi-chars%> not recognized)
++
++EnumValue
++Enum(cpp_bidirectional_level) String(none) Value(bidirectional_none)
++
++EnumValue
++Enum(cpp_bidirectional_level) String(unpaired) Value(bidirectional_unpaired)
++
++EnumValue
++Enum(cpp_bidirectional_level) String(any) Value(bidirectional_any)
++
+ Wbool-compare
+ C ObjC C++ ObjC++ Var(warn_bool_compare) Warning LangEnabledBy(C ObjC C++ ObjC++,Wall)
+ Warn about boolean expression compared with an integer value different from true/false.
+diff --git a/gcc/doc/invoke.texi b/gcc/doc/invoke.texi
+index 6070288856c..a22758d18ee 100644
+--- a/gcc/doc/invoke.texi
++++ b/gcc/doc/invoke.texi
+@@ -326,7 +326,9 @@ Objective-C and Objective-C++ Dialects}.
+ -Warith-conversion @gol
+ -Warray-bounds  -Warray-bounds=@var{n} @gol
+ -Wno-attributes  -Wattribute-alias=@var{n} -Wno-attribute-alias @gol
+--Wno-attribute-warning  -Wbool-compare  -Wbool-operation @gol
++-Wno-attribute-warning  @gol
++-Wbidi-chars=@r{[}none@r{|}unpaired@r{|}any@r{]} @gol
++-Wbool-compare  -Wbool-operation @gol
+ -Wno-builtin-declaration-mismatch @gol
+ -Wno-builtin-macro-redefined  -Wc90-c99-compat  -Wc99-c11-compat @gol
+ -Wc11-c2x-compat @gol
+@@ -7559,6 +7561,23 @@ Attributes considered include @code{allo
+ This is the default.  You can disable these warnings with either
+ @option{-Wno-attribute-alias} or @option{-Wattribute-alias=0}.
+ 
++@item -Wbidi-chars=@r{[}none@r{|}unpaired@r{|}any@r{]}
++@opindex Wbidi-chars=
++@opindex Wbidi-chars
++@opindex Wno-bidi-chars
++Warn about possibly misleading UTF-8 bidirectional control characters in
++comments, string literals, character constants, and identifiers.  Such
++characters can change left-to-right writing direction into right-to-left
++(and vice versa), which can cause confusion between the logical order and
++visual order.  This may be dangerous; for instance, it may seem that a piece
++of code is not commented out, whereas it in fact is.
++
++There are three levels of warning supported by GCC@.  The default is
++@option{-Wbidi-chars=unpaired}, which warns about improperly terminated
++bidi contexts.  @option{-Wbidi-chars=none} turns the warning off.
++@option{-Wbidi-chars=any} warns about any use of bidirectional control
++characters.
++
+ @item -Wbool-compare
+ @opindex Wno-bool-compare
+ @opindex Wbool-compare
+diff --git a/gcc/testsuite/c-c++-common/Wbidi-chars-10.c b/gcc/testsuite/c-c++-common/Wbidi-chars-10.c
+new file mode 100644
+index 00000000000..34f5ac19271
+--- /dev/null
++++ b/gcc/testsuite/c-c++-common/Wbidi-chars-10.c
+@@ -0,0 +1,27 @@
++/* PR preprocessor/103026 */
++/* { dg-do compile } */
++/* { dg-options "-Wbidi-chars=unpaired" } */
++/* More nesting testing.  */
++
++/* RLEâ« LRIâ¦ PDFâ¬ PDIâ©*/
++/* { dg-warning "unpaired" "" { target *-*-* } .-1 } */
++int LRE_\u202a_PDF_\u202c;
++int LRE_\u202a_PDF_\u202c_LRE_\u202a_PDF_\u202c;
++int LRE_\u202a_LRI_\u2066_PDF_\u202c_PDI_\u2069;
++/* { dg-warning "unpaired" "" { target *-*-* } .-1 } */
++int RLE_\u202b_RLI_\u2067_PDF_\u202c_PDI_\u2069;
++/* { dg-warning "unpaired" "" { target *-*-* } .-1 } */
++int RLE_\u202b_RLI_\u2067_PDI_\u2069_PDF_\u202c;
++int FSI_\u2068_LRO_\u202d_PDI_\u2069_PDF_\u202c;
++int FSI_\u2068;
++/* { dg-warning "unpaired" "" { target *-*-* } .-1 } */
++int FSI_\u2068_PDI_\u2069;
++int FSI_\u2068_FSI_\u2068_PDI_\u2069;
++/* { dg-warning "unpaired" "" { target *-*-* } .-1 } */
++int RLI_\u2067_RLI_\u2067_RLI_\u2067_RLI_\u2067_RLI_\u2067_RLI_\u2067_RLI_\u2067_PDI_\u2069_PDI_\u2069_PDI_\u2069_PDI_\u2069_PDI_\u2069_PDI_\u2069_PDI_\u2069;
++int RLI_\u2067_RLI_\u2067_RLI_\u2067_RLI_\u2067_RLI_\u2067_RLI_\u2067_RLI_\u2067_PDI_\u2069_PDI_\u2069_PDI_\u2069_PDI_\u2069_PDI_\u2069_PDI_\u2069;
++/* { dg-warning "unpaired" "" { target *-*-* } .-1 } */
++int RLI_\u2067_RLI_\u2067_RLI_\u2067_RLI_\u2067_RLI_\u2067_RLI_\u2067_RLI_\u2067_PDI_\u2069_PDI_\u2069_PDI_\u2069_PDI_\u2069_PDI_\u2069_PDI_\u2069_PDF_\u202c;
++/* { dg-warning "unpaired" "" { target *-*-* } .-1 } */
++int RLI_\u2067_RLI_\u2067_RLI_\u2067_RLI_\u2067_FSI_\u2068_PDI_\u2069_PDI_\u2069_PDI_\u2069_PDI_\u2069;
++/* { dg-warning "unpaired" "" { target *-*-* } .-1 } */
+diff --git a/gcc/testsuite/c-c++-common/Wbidi-chars-11.c b/gcc/testsuite/c-c++-common/Wbidi-chars-11.c
+new file mode 100644
+index 00000000000..270ce2368a9
+--- /dev/null
++++ b/gcc/testsuite/c-c++-common/Wbidi-chars-11.c
+@@ -0,0 +1,13 @@
++/* PR preprocessor/103026 */
++/* { dg-do compile } */
++/* { dg-options "-Wbidi-chars=unpaired" } */
++/* Test that we warn when mixing UCN and UTF-8.  */
++
++int LRE_âª_PDF_\u202c;
++/* { dg-warning "mismatch" "" { target *-*-* } .-1 } */
++int LRE_\u202a_PDF_â¬_;
++/* { dg-warning "mismatch" "" { target *-*-* } .-1 } */
++const char *s1 = "LRE_âª_PDF_\u202c";
++/* { dg-warning "mismatch" "" { target *-*-* } .-1 } */
++const char *s2 = "LRE_\u202a_PDF_â¬";
++/* { dg-warning "mismatch" "" { target *-*-* } .-1 } */
+diff --git a/gcc/testsuite/c-c++-common/Wbidi-chars-12.c b/gcc/testsuite/c-c++-common/Wbidi-chars-12.c
+new file mode 100644
+index 00000000000..b07eec1da91
+--- /dev/null
++++ b/gcc/testsuite/c-c++-common/Wbidi-chars-12.c
+@@ -0,0 +1,19 @@
++/* PR preprocessor/103026 */
++/* { dg-do compile { target { c || c++11 } } } */
++/* { dg-options "-Wbidi-chars=any" } */
++/* Test raw strings.  */
++
++const char *s1 = R"(a b c LREâª 1 2 3 PDFâ¬ x y z)";
++/* { dg-warning "U\\+202A" "" { target *-*-* } .-1 } */
++const char *s2 = R"(a b c RLEâ« 1 2 3 PDFâ¬ x y z)";
++/* { dg-warning "U\\+202B" "" { target *-*-* } .-1 } */
++const char *s3 = R"(a b c LROâ­ 1 2 3 PDFâ¬ x y z)";
++/* { dg-warning "U\\+202D" "" { target *-*-* } .-1 } */
++const char *s4 = R"(a b c RLOâ® 1 2 3 PDFâ¬ x y z)";
++/* { dg-warning "U\\+202E" "" { target *-*-* } .-1 } */
++const char *s7 = R"(a b c FSIâ¨ 1 2 3 PDIâ© x y) z";
++/* { dg-warning "U\\+2068" "" { target *-*-* } .-1 } */
++const char *s8 = R"(a b c PDIâ© x y )z";
++/* { dg-warning "U\\+2069" "" { target *-*-* } .-1 } */
++const char *s9 = R"(a b c PDFâ¬ x y z)";
++/* { dg-warning "U\\+202C" "" { target *-*-* } .-1 } */
+diff -uprN '-x*.orig' '-x*.rej' del/gcc-11.2.0/gcc/testsuite/c-c++-common/Wbidi-chars-13.c gcc-11.2.0/gcc/testsuite/c-c++-common/Wbidi-chars-13.c
+--- del/gcc-11.2.0/gcc/testsuite/c-c++-common/Wbidi-chars-13.c	1969-12-31 16:00:00.000000000 -0800
++++ gcc-11.2.0/gcc/testsuite/c-c++-common/Wbidi-chars-13.c	2021-12-13 23:11:22.328439287 -0800
+@@ -0,0 +1,17 @@
++/* PR preprocessor/103026 */
++/* { dg-do compile { target { c || c++11 } } } */
++/* { dg-options "-Wbidi-chars=unpaired" } */
++/* Test raw strings.  */
++
++const char *s1 = R"(a b c LREâª 1 2 3)";
++/* { dg-warning "unpaired" "" { target *-*-* } .-1 } */
++const char *s2 = R"(a b c RLEâ« 1 2 3)";
++/* { dg-warning "unpaired" "" { target *-*-* } .-1 } */
++const char *s3 = R"(a b c LROâ­ 1 2 3)";
++/* { dg-warning "unpaired" "" { target *-*-* } .-1 } */
++const char *s4 = R"(a b c FSIâ¨ 1 2 3)";
++/* { dg-warning "unpaired" "" { target *-*-* } .-1 } */
++const char *s5 = R"(a b c LRIâ¦ 1 2 3)";
++/* { dg-warning "unpaired" "" { target *-*-* } .-1 } */
++const char *s6 = R"(a b c RLIâ§ 1 2 3)";
++/* { dg-warning "unpaired" "" { target *-*-* } .-1 } */
+diff --git a/gcc/testsuite/c-c++-common/Wbidi-chars-14.c b/gcc/testsuite/c-c++-common/Wbidi-chars-14.c
+new file mode 100644
+index 00000000000..ba5f75d9553
+--- /dev/null
++++ b/gcc/testsuite/c-c++-common/Wbidi-chars-14.c
+@@ -0,0 +1,38 @@
++/* PR preprocessor/103026 */
++/* { dg-do compile } */
++/* { dg-options "-Wbidi-chars=unpaired" } */
++/* Test PDI handling, which also pops any subsequent LREs, RLEs, LROs,
++   or RLOs.  */
++
++/* LRI_â¦_LRI_â¦_RLE_â«_RLE_â«_RLE_â«_PDI_â©*/
++/* { dg-warning "unpaired" "" { target *-*-* } .-1 } */
++// LRI_â¦_RLE_â«_RLE_â«_RLE_â«_PDI_â©
++// LRI_â¦_RLO_â®_RLE_â«_RLE_â«_PDI_â©
++// LRI_â¦_RLO_â®_RLE_â«_PDI_â©
++// FSI_â¨_RLO_â®_PDI_â©
++// FSI_â¨_FSI_â¨_RLO_â®_PDI_â©
++/* { dg-warning "unpaired" "" { target *-*-* } .-1 } */
++
++int LRI_\u2066_LRI_\u2066_LRE_\u202a_LRE_\u202a_LRE_\u202a_PDI_\u2069;
++/* { dg-warning "unpaired" "" { target *-*-* } .-1 } */
++int LRI_\u2066_LRI_\u2066_LRE_\u202a_LRE_\u202a_LRE_\u202a_PDI_\u2069_PDI_\u2069;
++int LRI_\u2066_LRI_\u2066_LRI_\u2066_LRE_\u202a_LRE_\u202a_LRE_\u202a_PDI_\u2069_PDI_\u2069;
++/* { dg-warning "unpaired" "" { target *-*-* } .-1 } */
++int PDI_\u2069;
++int LRI_\u2066_PDI_\u2069;
++int RLI_\u2067_PDI_\u2069;
++int LRE_\u202a_LRI_\u2066_PDI_\u2069;
++/* { dg-warning "unpaired" "" { target *-*-* } .-1 } */
++int LRI_\u2066_LRE_\u202a_PDF_\u202c_PDI_\u2069;
++int LRI_\u2066_LRE_\u202a_LRE_\u202a_PDF_\u202c_PDI_\u2069;
++int RLI_\u2067_LRI_\u2066_LRE_\u202a_LRE_\u202a_PDF_\u202c_PDI_\u2069;
++/* { dg-warning "unpaired" "" { target *-*-* } .-1 } */
++int FSI_\u2068_LRI_\u2066_LRE_\u202a_LRE_\u202a_PDF_\u202c_PDI_\u2069;
++/* { dg-warning "unpaired" "" { target *-*-* } .-1 } */
++int RLO_\u202e_PDI_\u2069;
++/* { dg-warning "unpaired" "" { target *-*-* } .-1 } */
++int RLI_\u2067_PDI_\u2069_RLI_\u2067;
++/* { dg-warning "unpaired" "" { target *-*-* } .-1 } */
++int FSI_\u2068_PDF_\u202c_PDI_\u2069;
++int FSI_\u2068_FSI_\u2068_PDF_\u202c_PDI_\u2069;
++/* { dg-warning "unpaired" "" { target *-*-* } .-1 } */
+diff --git a/gcc/testsuite/c-c++-common/Wbidi-chars-15.c b/gcc/testsuite/c-c++-common/Wbidi-chars-15.c
+new file mode 100644
+index 00000000000..a0ce8ff5e2c
+--- /dev/null
++++ b/gcc/testsuite/c-c++-common/Wbidi-chars-15.c
+@@ -0,0 +1,59 @@
++/* PR preprocessor/103026 */
++/* { dg-do compile } */
++/* { dg-options "-Wbidi-chars=unpaired" } */
++/* Test unpaired bidi control chars in multiline comments.  */
++
++/*
++ * LREâª end
++ */
++/* { dg-warning "unpaired" "" { target *-*-* } .-2 } */
++/*
++ * RLEâ« end
++ */
++/* { dg-warning "unpaired" "" { target *-*-* } .-2 } */
++/*
++ * LROâ­ end
++ */
++/* { dg-warning "unpaired" "" { target *-*-* } .-2 } */
++/*
++ * RLOâ® end
++ */
++/* { dg-warning "unpaired" "" { target *-*-* } .-2 } */
++/*
++ * LRIâ¦ end
++ */
++/* { dg-warning "unpaired" "" { target *-*-* } .-2 } */
++/*
++ * RLIâ§ end
++ */
++/* { dg-warning "unpaired" "" { target *-*-* } .-2 } */
++/*
++ * FSIâ¨ end
++ */
++/* { dg-warning "unpaired" "" { target *-*-* } .-2 } */
++/* LREâª
++   PDFâ¬ */
++/* { dg-warning "unpaired" "" { target *-*-* } .-2 } */
++/* FSIâ¨
++   PDIâ© */
++/* { dg-warning "unpaired" "" { target *-*-* } .-2 } */
++
++/* LRE<âª>
++ *
++ */
++/* { dg-warning "unpaired" "" { target *-*-* } .-3 } */
++
++/*
++ * LRE<âª>
++ */
++/* { dg-warning "unpaired" "" { target *-*-* } .-2 } */
++
++/*
++ *
++ * LRE<âª> */
++/* { dg-warning "unpaired" "" { target *-*-* } .-1 } */
++
++/* RLI<â§> */ /* PDI<â©> */
++/* { dg-warning "unpaired" "" { target *-*-* } .-1 } */
++/* LRE<âª> */ /* PDF<â¬> */
++/* { dg-warning "unpaired" "" { target *-*-* } .-1 } */
+diff --git a/gcc/testsuite/c-c++-common/Wbidi-chars-16.c b/gcc/testsuite/c-c++-common/Wbidi-chars-16.c
+new file mode 100644
+index 00000000000..baa0159861c
+--- /dev/null
++++ b/gcc/testsuite/c-c++-common/Wbidi-chars-16.c
+@@ -0,0 +1,26 @@
++/* PR preprocessor/103026 */
++/* { dg-do compile } */
++/* { dg-options "-Wbidi-chars=any" } */
++/* Test LTR/RTL chars.  */
++
++/* LTR<â> */
++/* { dg-warning "U\\+200E" "" { target *-*-* } .-1 } */
++// LTR<â>
++/* { dg-warning "U\\+200E" "" { target *-*-* } .-1 } */
++/* RTL<â> */
++/* { dg-warning "U\\+200F" "" { target *-*-* } .-1 } */
++// RTL<â>
++/* { dg-warning "U\\+200F" "" { target *-*-* } .-1 } */
++
++const char *s1 = "LTR<â>";
++/* { dg-warning "U\\+200E" "" { target *-*-* } .-1 } */
++const char *s2 = "LTR\u200e";
++/* { dg-warning "U\\+200E" "" { target *-*-* } .-1 } */
++const char *s3 = "LTR\u200E";
++/* { dg-warning "U\\+200E" "" { target *-*-* } .-1 } */
++const char *s4 = "RTL<â>";
++/* { dg-warning "U\\+200F" "" { target *-*-* } .-1 } */
++const char *s5 = "RTL\u200f";
++/* { dg-warning "U\\+200F" "" { target *-*-* } .-1 } */
++const char *s6 = "RTL\u200F";
++/* { dg-warning "U\\+200F" "" { target *-*-* } .-1 } */
+diff --git a/gcc/testsuite/c-c++-common/Wbidi-chars-17.c b/gcc/testsuite/c-c++-common/Wbidi-chars-17.c
+new file mode 100644
+index 00000000000..07cb4321f96
+--- /dev/null
++++ b/gcc/testsuite/c-c++-common/Wbidi-chars-17.c
+@@ -0,0 +1,30 @@
++/* PR preprocessor/103026 */
++/* { dg-do compile } */
++/* { dg-options "-Wbidi-chars=unpaired" } */
++/* Test LTR/RTL chars.  */
++
++/* LTR<â> */
++/* { dg-bogus "unpaired" "" { target *-*-* } .-1 } */
++// LTR<â>
++/* { dg-bogus "unpaired" "" { target *-*-* } .-1 } */
++/* RTL<â> */
++/* { dg-bogus "unpaired" "" { target *-*-* } .-1 } */
++// RTL<â>
++/* { dg-bogus "unpaired" "" { target *-*-* } .-1 } */
++int ltr_\u200e;
++/* { dg-error "universal character " "" { target *-*-* } .-1 } */
++int rtl_\u200f;
++/* { dg-error "universal character " "" { target *-*-* } .-1 } */
++
++const char *s1 = "LTR<â>";
++/* { dg-bogus "unpaired" "" { target *-*-* } .-1 } */
++const char *s2 = "LTR\u200e";
++/* { dg-bogus "unpaired" "" { target *-*-* } .-1 } */
++const char *s3 = "LTR\u200E";
++/* { dg-bogus "unpaired" "" { target *-*-* } .-1 } */
++const char *s4 = "RTL<â>";
++/* { dg-bogus "unpaired" "" { target *-*-* } .-1 } */
++const char *s5 = "RTL\u200f";
++/* { dg-bogus "unpaired" "" { target *-*-* } .-1 } */
++const char *s6 = "RTL\u200F";
++/* { dg-bogus "unpaired" "" { target *-*-* } .-1 } */
+diff --git a/gcc/testsuite/c-c++-common/Wbidi-chars-1.c b/gcc/testsuite/c-c++-common/Wbidi-chars-1.c
+new file mode 100644
+index 00000000000..2340374f276
+--- /dev/null
++++ b/gcc/testsuite/c-c++-common/Wbidi-chars-1.c
+@@ -0,0 +1,12 @@
++/* PR preprocessor/103026 */
++/* { dg-do compile } */
++
++int main() {
++    int isAdmin = 0;
++    /*â® } â¦if (isAdmin)â© â¦ begin admins only */
++/* { dg-warning "bidirectional" "" { target *-*-* } .-1 } */
++        __builtin_printf("You are an admin.\n");
++    /* end admins only â® { â¦*/
++/* { dg-warning "bidirectional" "" { target *-*-* } .-1 } */
++    return 0;
++}
+diff --git a/gcc/testsuite/c-c++-common/Wbidi-chars-2.c b/gcc/testsuite/c-c++-common/Wbidi-chars-2.c
+new file mode 100644
+index 00000000000..2340374f276
+--- /dev/null
++++ b/gcc/testsuite/c-c++-common/Wbidi-chars-2.c
+@@ -0,0 +1,9 @@
++/* PR preprocessor/103026 */
++/* { dg-do compile } */
++
++int main() {
++    /* Say hello; newlineâ§/*/ return 0 ;
++/* { dg-warning "bidirectional" "" { target *-*-* } .-1 } */
++    __builtin_printf("Hello world.\n");
++    return 0;
++}
+diff --git a/gcc/testsuite/c-c++-common/Wbidi-chars-3.c b/gcc/testsuite/c-c++-common/Wbidi-chars-3.c
+new file mode 100644
+index 00000000000..9dc7edb6e64
+--- /dev/null
++++ b/gcc/testsuite/c-c++-common/Wbidi-chars-3.c
+@@ -0,0 +1,11 @@
++/* PR preprocessor/103026 */
++/* { dg-do compile } */
++
++int main() {
++    const char* access_level = "user";
++    if (__builtin_strcmp(access_level, "userâ® â¦// Check if adminâ© â¦")) {
++/* { dg-warning "bidirectional" "" { target *-*-* } .-1 } */
++        __builtin_printf("You are an admin.\n");
++    }
++    return 0;
++}
+diff --git a/gcc/testsuite/c-c++-common/Wbidi-chars-4.c b/gcc/testsuite/c-c++-common/Wbidi-chars-4.c
+new file mode 100644
+index 00000000000..639e5c62e88
+--- /dev/null
++++ b/gcc/testsuite/c-c++-common/Wbidi-chars-4.c
+@@ -0,0 +1,188 @@
++/* PR preprocessor/103026 */
++/* { dg-do compile } */
++/* { dg-options "-Wbidi-chars=any -Wno-multichar -Wno-overflow" } */
++/* Test all bidi chars in various contexts (identifiers, comments,
++   string literals, character constants), both UCN and UTF-8.  The bidi
++   chars here are properly terminated, except for the character constants.  */
++
++/* a b c LREâª 1 2 3 PDFâ¬ x y z */
++/* { dg-warning "U\\+202A" "" { target *-*-* } .-1 } */
++/* a b c RLEâ« 1 2 3 PDFâ¬ x y z */
++/* { dg-warning "U\\+202B" "" { target *-*-* } .-1 } */
++/* a b c LROâ­ 1 2 3 PDFâ¬ x y z */
++/* { dg-warning "U\\+202D" "" { target *-*-* } .-1 } */
++/* a b c RLOâ® 1 2 3 PDFâ¬ x y z */
++/* { dg-warning "U\\+202E" "" { target *-*-* } .-1 } */
++/* a b c LRIâ¦ 1 2 3 PDIâ© x y z */
++/* { dg-warning "U\\+2066" "" { target *-*-* } .-1 } */
++/* a b c RLIâ§ 1 2 3 PDIâ© x y */
++/* { dg-warning "U\\+2067" "" { target *-*-* } .-1 } */
++/* a b c FSIâ¨ 1 2 3 PDIâ© x y z */
++/* { dg-warning "U\\+2068" "" { target *-*-* } .-1 } */
++
++/* Same but C++ comments instead.  */
++// a b c LREâª 1 2 3 PDFâ¬ x y z
++/* { dg-warning "U\\+202A" "" { target *-*-* } .-1 } */
++// a b c RLEâ« 1 2 3 PDFâ¬ x y z
++/* { dg-warning "U\\+202B" "" { target *-*-* } .-1 } */
++// a b c LROâ­ 1 2 3 PDFâ¬ x y z
++/* { dg-warning "U\\+202D" "" { target *-*-* } .-1 } */
++// a b c RLOâ® 1 2 3 PDFâ¬ x y z
++/* { dg-warning "U\\+202E" "" { target *-*-* } .-1 } */
++// a b c LRIâ¦ 1 2 3 PDIâ© x y z
++/* { dg-warning "U\\+2066" "" { target *-*-* } .-1 } */
++// a b c RLIâ§ 1 2 3 PDIâ© x y
++/* { dg-warning "U\\+2067" "" { target *-*-* } .-1 } */
++// a b c FSIâ¨ 1 2 3 PDIâ© x y z
++/* { dg-warning "U\\+2068" "" { target *-*-* } .-1 } */
++
++/* Here we're closing an unopened context, warn when =any.  */
++/* a b c PDIâ© x y z */
++/* { dg-warning "U\\+2069" "" { target *-*-* } .-1 } */
++/* a b c PDFâ¬ x y z */
++/* { dg-warning "U\\+202C" "" { target *-*-* } .-1 } */
++// a b c PDIâ© x y z
++/* { dg-warning "U\\+2069" "" { target *-*-* } .-1 } */
++// a b c PDFâ¬ x y z
++/* { dg-warning "U\\+202C" "" { target *-*-* } .-1 } */
++
++/* Multiline comments.  */
++/* a b c PDIâ© x y z
++   */
++/* { dg-warning "U\\+2069" "" { target *-*-* } .-2 } */
++/* a b c PDFâ¬ x y z
++   */
++/* { dg-warning "U\\+202C" "" { target *-*-* } .-2 } */
++/* first
++   a b c PDIâ© x y z
++   */
++/* { dg-warning "U\\+2069" "" { target *-*-* } .-2 } */
++/* first
++   a b c PDFâ¬ x y z
++   */
++/* { dg-warning "U\\+202C" "" { target *-*-* } .-2 } */
++/* first
++   a b c PDIâ© x y z */
++/* { dg-warning "U\\+2069" "" { target *-*-* } .-1 } */
++/* first
++   a b c PDFâ¬ x y z */
++/* { dg-warning "U\\+202C" "" { target *-*-* } .-1 } */
++
++void
++g1 ()
++{
++  const char *s1 = "a b c LREâª 1 2 3 PDFâ¬ x y z";
++/* { dg-warning "U\\+202A" "" { target *-*-* } .-1 } */
++  const char *s2 = "a b c RLEâ« 1 2 3 PDFâ¬ x y z";
++/* { dg-warning "U\\+202B" "" { target *-*-* } .-1 } */
++  const char *s3 = "a b c LROâ­ 1 2 3 PDFâ¬ x y z";
++/* { dg-warning "U\\+202D" "" { target *-*-* } .-1 } */
++  const char *s4 = "a b c RLOâ® 1 2 3 PDFâ¬ x y z";
++/* { dg-warning "U\\+202E" "" { target *-*-* } .-1 } */
++  const char *s5 = "a b c LRIâ¦ 1 2 3 PDIâ© x y z";
++/* { dg-warning "U\\+2066" "" { target *-*-* } .-1 } */
++  const char *s6 = "a b c RLIâ§ 1 2 3 PDIâ© x y z";
++/* { dg-warning "U\\+2067" "" { target *-*-* } .-1 } */
++  const char *s7 = "a b c FSIâ¨ 1 2 3 PDIâ© x y z";
++/* { dg-warning "U\\+2068" "" { target *-*-* } .-1 } */
++  const char *s8 = "a b c PDIâ© x y z";
++/* { dg-warning "U\\+2069" "" { target *-*-* } .-1 } */
++  const char *s9 = "a b c PDFâ¬ x y z";
++/* { dg-warning "U\\+202C" "" { target *-*-* } .-1 } */
++
++  const char *s10 = "a b c LRE\u202a 1 2 3 PDF\u202c x y z";
++/* { dg-warning "U\\+202A" "" { target *-*-* } .-1 } */
++  const char *s11 = "a b c LRE\u202A 1 2 3 PDF\u202c x y z";
++/* { dg-warning "U\\+202A" "" { target *-*-* } .-1 } */
++  const char *s12 = "a b c RLE\u202b 1 2 3 PDF\u202c x y z";
++/* { dg-warning "U\\+202B" "" { target *-*-* } .-1 } */
++  const char *s13 = "a b c RLE\u202B 1 2 3 PDF\u202c x y z";
++/* { dg-warning "U\\+202B" "" { target *-*-* } .-1 } */
++  const char *s14 = "a b c LRO\u202d 1 2 3 PDF\u202c x y z";
++/* { dg-warning "U\\+202D" "" { target *-*-* } .-1 } */
++  const char *s15 = "a b c LRO\u202D 1 2 3 PDF\u202c x y z";
++/* { dg-warning "U\\+202D" "" { target *-*-* } .-1 } */
++  const char *s16 = "a b c RLO\u202e 1 2 3 PDF\u202c x y z";
++/* { dg-warning "U\\+202E" "" { target *-*-* } .-1 } */
++  const char *s17 = "a b c RLO\u202E 1 2 3 PDF\u202c x y z";
++/* { dg-warning "U\\+202E" "" { target *-*-* } .-1 } */
++  const char *s18 = "a b c LRI\u2066 1 2 3 PDI\u2069 x y z";
++/* { dg-warning "U\\+2066" "" { target *-*-* } .-1 } */
++  const char *s19 = "a b c RLI\u2067 1 2 3 PDI\u2069 x y z";
++/* { dg-warning "U\\+2067" "" { target *-*-* } .-1 } */
++  const char *s20 = "a b c FSI\u2068 1 2 3 PDI\u2069 x y z";
++/* { dg-warning "U\\+2068" "" { target *-*-* } .-1 } */
++}
++
++void
++g2 ()
++{
++  const char c1 = '\u202a';
++/* { dg-warning "U\\+202A" "" { target *-*-* } .-1 } */
++  const char c2 = '\u202A';
++/* { dg-warning "U\\+202A" "" { target *-*-* } .-1 } */
++  const char c3 = '\u202b';
++/* { dg-warning "U\\+202B" "" { target *-*-* } .-1 } */
++  const char c4 = '\u202B';
++/* { dg-warning "U\\+202B" "" { target *-*-* } .-1 } */
++  const char c5 = '\u202d';
++/* { dg-warning "U\\+202D" "" { target *-*-* } .-1 } */
++  const char c6 = '\u202D';
++/* { dg-warning "U\\+202D" "" { target *-*-* } .-1 } */
++  const char c7 = '\u202e';
++/* { dg-warning "U\\+202E" "" { target *-*-* } .-1 } */
++  const char c8 = '\u202E';
++/* { dg-warning "U\\+202E" "" { target *-*-* } .-1 } */
++  const char c9 = '\u2066';
++/* { dg-warning "U\\+2066" "" { target *-*-* } .-1 } */
++  const char c10 = '\u2067';
++/* { dg-warning "U\\+2067" "" { target *-*-* } .-1 } */
++  const char c11 = '\u2068';
++/* { dg-warning "U\\+2068" "" { target *-*-* } .-1 } */
++}
++
++int aâªbâ¬c;
++/* { dg-warning "U\\+202A" "" { target *-*-* } .-1 } */
++int aâ«bâ¬c;
++/* { dg-warning "U\\+202B" "" { target *-*-* } .-1 } */
++int aâ­bâ¬c;
++/* { dg-warning "U\\+202D" "" { target *-*-* } .-1 } */
++int aâ®bâ¬c;
++/* { dg-warning "U\\+202E" "" { target *-*-* } .-1 } */
++int aâ¦bâ©c;
++/* { dg-warning "U\\+2066" "" { target *-*-* } .-1 } */
++int aâ§bâ©c;
++/* { dg-warning "U\\+2067" "" { target *-*-* } .-1 } */
++int aâ¨bâ©c;
++/* { dg-warning "U\\+2068" "" { target *-*-* } .-1 } */
++int Aâ¬X;
++/* { dg-warning "U\\+202C" "" { target *-*-* } .-1 } */
++int A\u202cY;
++/* { dg-warning "U\\+202C" "" { target *-*-* } .-1 } */
++int A\u202CY2;
++/* { dg-warning "U\\+202C" "" { target *-*-* } .-1 } */
++
++int d\u202ae\u202cf;
++/* { dg-warning "U\\+202A" "" { target *-*-* } .-1 } */
++int d\u202Ae\u202cf2;
++/* { dg-warning "U\\+202A" "" { target *-*-* } .-1 } */
++int d\u202be\u202cf;
++/* { dg-warning "U\\+202B" "" { target *-*-* } .-1 } */
++int d\u202Be\u202cf2;
++/* { dg-warning "U\\+202B" "" { target *-*-* } .-1 } */
++int d\u202de\u202cf;
++/* { dg-warning "U\\+202D" "" { target *-*-* } .-1 } */
++int d\u202De\u202cf2;
++/* { dg-warning "U\\+202D" "" { target *-*-* } .-1 } */
++int d\u202ee\u202cf;
++/* { dg-warning "U\\+202E" "" { target *-*-* } .-1 } */
++int d\u202Ee\u202cf2;
++/* { dg-warning "U\\+202E" "" { target *-*-* } .-1 } */
++int d\u2066e\u2069f;
++/* { dg-warning "U\\+2066" "" { target *-*-* } .-1 } */
++int d\u2067e\u2069f;
++/* { dg-warning "U\\+2067" "" { target *-*-* } .-1 } */
++int d\u2068e\u2069f;
++/* { dg-warning "U\\+2068" "" { target *-*-* } .-1 } */
++int X\u2069;
++/* { dg-warning "U\\+2069" "" { target *-*-* } .-1 } */
+diff --git a/gcc/testsuite/c-c++-common/Wbidi-chars-5.c b/gcc/testsuite/c-c++-common/Wbidi-chars-5.c
+new file mode 100644
+index 00000000000..68cb053144b
+--- /dev/null
++++ b/gcc/testsuite/c-c++-common/Wbidi-chars-5.c
+@@ -0,0 +1,188 @@
++/* PR preprocessor/103026 */
++/* { dg-do compile } */
++/* { dg-options "-Wbidi-chars=unpaired -Wno-multichar -Wno-overflow" } */
++/* Test all bidi chars in various contexts (identifiers, comments,
++   string literals, character constants), both UCN and UTF-8.  The bidi
++   chars here are properly terminated, except for the character constants.  */
++
++/* a b c LREâª 1 2 3 PDFâ¬ x y z */
++/* { dg-bogus "unpaired" "" { target *-*-* } .-1 } */
++/* a b c RLEâ« 1 2 3 PDFâ¬ x y z */
++/* { dg-bogus "unpaired" "" { target *-*-* } .-1 } */
++/* a b c LROâ­ 1 2 3 PDFâ¬ x y z */
++/* { dg-bogus "unpaired" "" { target *-*-* } .-1 } */
++/* a b c RLOâ® 1 2 3 PDFâ¬ x y z */
++/* { dg-bogus "unpaired" "" { target *-*-* } .-1 } */
++/* a b c LRIâ¦ 1 2 3 PDIâ© x y z */
++/* { dg-bogus "unpaired" "" { target *-*-* } .-1 } */
++/* a b c RLIâ§ 1 2 3 PDIâ© x y */
++/* { dg-bogus "unpaired" "" { target *-*-* } .-1 } */
++/* a b c FSIâ¨ 1 2 3 PDIâ© x y z */
++/* { dg-bogus "unpaired" "" { target *-*-* } .-1 } */
++
++/* Same but C++ comments instead.  */
++// a b c LREâª 1 2 3 PDFâ¬ x y z
++/* { dg-bogus "unpaired" "" { target *-*-* } .-1 } */
++// a b c RLEâ« 1 2 3 PDFâ¬ x y z
++/* { dg-bogus "unpaired" "" { target *-*-* } .-1 } */
++// a b c LROâ­ 1 2 3 PDFâ¬ x y z
++/* { dg-bogus "unpaired" "" { target *-*-* } .-1 } */
++// a b c RLOâ® 1 2 3 PDFâ¬ x y z
++/* { dg-bogus "unpaired" "" { target *-*-* } .-1 } */
++// a b c LRIâ¦ 1 2 3 PDIâ© x y z
++/* { dg-bogus "unpaired" "" { target *-*-* } .-1 } */
++// a b c RLIâ§ 1 2 3 PDIâ© x y
++/* { dg-bogus "unpaired" "" { target *-*-* } .-1 } */
++// a b c FSIâ¨ 1 2 3 PDIâ© x y z
++/* { dg-bogus "unpaired" "" { target *-*-* } .-1 } */
++
++/* Here we're closing an unopened context, warn when =any.  */
++/* a b c PDIâ© x y z */
++/* { dg-bogus "unpaired" "" { target *-*-* } .-1 } */
++/* a b c PDFâ¬ x y z */
++/* { dg-bogus "unpaired" "" { target *-*-* } .-1 } */
++// a b c PDIâ© x y z
++/* { dg-bogus "unpaired" "" { target *-*-* } .-1 } */
++// a b c PDFâ¬ x y z
++/* { dg-bogus "unpaired" "" { target *-*-* } .-1 } */
++
++/* Multiline comments.  */
++/* a b c PDIâ© x y z
++   */
++/* { dg-bogus "unpaired" "" { target *-*-* } .-2 } */
++/* a b c PDFâ¬ x y z
++   */
++/* { dg-bogus "unpaired" "" { target *-*-* } .-2 } */
++/* first
++   a b c PDIâ© x y z
++   */
++/* { dg-bogus "unpaired" "" { target *-*-* } .-2 } */
++/* first
++   a b c PDFâ¬ x y z
++   */
++/* { dg-bogus "unpaired" "" { target *-*-* } .-2 } */
++/* first
++   a b c PDIâ© x y z */
++/* { dg-bogus "unpaired" "" { target *-*-* } .-1 } */
++/* first
++   a b c PDFâ¬ x y z */
++/* { dg-bogus "unpaired" "" { target *-*-* } .-1 } */
++
++void
++g1 ()
++{
++  const char *s1 = "a b c LREâª 1 2 3 PDFâ¬ x y z";
++/* { dg-bogus "unpaired" "" { target *-*-* } .-1 } */
++  const char *s2 = "a b c RLEâ« 1 2 3 PDFâ¬ x y z";
++/* { dg-bogus "unpaired" "" { target *-*-* } .-1 } */
++  const char *s3 = "a b c LROâ­ 1 2 3 PDFâ¬ x y z";
++/* { dg-bogus "unpaired" "" { target *-*-* } .-1 } */
++  const char *s4 = "a b c RLOâ® 1 2 3 PDFâ¬ x y z";
++/* { dg-bogus "unpaired" "" { target *-*-* } .-1 } */
++  const char *s5 = "a b c LRIâ¦ 1 2 3 PDIâ© x y z";
++/* { dg-bogus "unpaired" "" { target *-*-* } .-1 } */
++  const char *s6 = "a b c RLIâ§ 1 2 3 PDIâ© x y z";
++/* { dg-bogus "unpaired" "" { target *-*-* } .-1 } */
++  const char *s7 = "a b c FSIâ¨ 1 2 3 PDIâ© x y z";
++/* { dg-bogus "unpaired" "" { target *-*-* } .-1 } */
++  const char *s8 = "a b c PDIâ© x y z";
++/* { dg-bogus "unpaired" "" { target *-*-* } .-1 } */
++  const char *s9 = "a b c PDFâ¬ x y z";
++/* { dg-bogus "unpaired" "" { target *-*-* } .-1 } */
++
++  const char *s10 = "a b c LRE\u202a 1 2 3 PDF\u202c x y z";
++/* { dg-bogus "unpaired" "" { target *-*-* } .-1 } */
++  const char *s11 = "a b c LRE\u202A 1 2 3 PDF\u202c x y z";
++/* { dg-bogus "unpaired" "" { target *-*-* } .-1 } */
++  const char *s12 = "a b c RLE\u202b 1 2 3 PDF\u202c x y z";
++/* { dg-bogus "unpaired" "" { target *-*-* } .-1 } */
++  const char *s13 = "a b c RLE\u202B 1 2 3 PDF\u202c x y z";
++/* { dg-bogus "unpaired" "" { target *-*-* } .-1 } */
++  const char *s14 = "a b c LRO\u202d 1 2 3 PDF\u202c x y z";
++/* { dg-bogus "unpaired" "" { target *-*-* } .-1 } */
++  const char *s15 = "a b c LRO\u202D 1 2 3 PDF\u202c x y z";
++/* { dg-bogus "unpaired" "" { target *-*-* } .-1 } */
++  const char *s16 = "a b c RLO\u202e 1 2 3 PDF\u202c x y z";
++/* { dg-bogus "unpaired" "" { target *-*-* } .-1 } */
++  const char *s17 = "a b c RLO\u202E 1 2 3 PDF\u202c x y z";
++/* { dg-bogus "unpaired" "" { target *-*-* } .-1 } */
++  const char *s18 = "a b c LRI\u2066 1 2 3 PDI\u2069 x y z";
++/* { dg-bogus "unpaired" "" { target *-*-* } .-1 } */
++  const char *s19 = "a b c RLI\u2067 1 2 3 PDI\u2069 x y z";
++/* { dg-bogus "unpaired" "" { target *-*-* } .-1 } */
++  const char *s20 = "a b c FSI\u2068 1 2 3 PDI\u2069 x y z";
++/* { dg-bogus "unpaired" "" { target *-*-* } .-1 } */
++}
++
++void
++g2 ()
++{
++  const char c1 = '\u202a';
++/* { dg-warning "unpaired" "" { target *-*-* } .-1 } */
++  const char c2 = '\u202A';
++/* { dg-warning "unpaired" "" { target *-*-* } .-1 } */
++  const char c3 = '\u202b';
++/* { dg-warning "unpaired" "" { target *-*-* } .-1 } */
++  const char c4 = '\u202B';
++/* { dg-warning "unpaired" "" { target *-*-* } .-1 } */
++  const char c5 = '\u202d';
++/* { dg-warning "unpaired" "" { target *-*-* } .-1 } */
++  const char c6 = '\u202D';
++/* { dg-warning "unpaired" "" { target *-*-* } .-1 } */
++  const char c7 = '\u202e';
++/* { dg-warning "unpaired" "" { target *-*-* } .-1 } */
++  const char c8 = '\u202E';
++/* { dg-warning "unpaired" "" { target *-*-* } .-1 } */
++  const char c9 = '\u2066';
++/* { dg-warning "unpaired" "" { target *-*-* } .-1 } */
++  const char c10 = '\u2067';
++/* { dg-warning "unpaired" "" { target *-*-* } .-1 } */
++  const char c11 = '\u2068';
++/* { dg-warning "unpaired" "" { target *-*-* } .-1 } */
++}
++
++int aâªbâ¬c;
++/* { dg-bogus "unpaired" "" { target *-*-* } .-1 } */
++int aâ«bâ¬c;
++/* { dg-bogus "unpaired" "" { target *-*-* } .-1 } */
++int aâ­bâ¬c;
++/* { dg-bogus "unpaired" "" { target *-*-* } .-1 } */
++int aâ®bâ¬c;
++/* { dg-bogus "unpaired" "" { target *-*-* } .-1 } */
++int aâ¦bâ©c;
++/* { dg-bogus "unpaired" "" { target *-*-* } .-1 } */
++int aâ§bâ©c;
++/* { dg-bogus "unpaired" "" { target *-*-* } .-1 } */
++int aâ¨bâ©c;
++/* { dg-bogus "unpaired" "" { target *-*-* } .-1 } */
++int Aâ¬X;
++/* { dg-bogus "unpaired" "" { target *-*-* } .-1 } */
++int A\u202cY;
++/* { dg-bogus "unpaired" "" { target *-*-* } .-1 } */
++int A\u202CY2;
++/* { dg-bogus "unpaired" "" { target *-*-* } .-1 } */
++
++int d\u202ae\u202cf;
++/* { dg-bogus "unpaired" "" { target *-*-* } .-1 } */
++int d\u202Ae\u202cf2;
++/* { dg-bogus "unpaired" "" { target *-*-* } .-1 } */
++int d\u202be\u202cf;
++/* { dg-bogus "unpaired" "" { target *-*-* } .-1 } */
++int d\u202Be\u202cf2;
++/* { dg-bogus "unpaired" "" { target *-*-* } .-1 } */
++int d\u202de\u202cf;
++/* { dg-bogus "unpaired" "" { target *-*-* } .-1 } */
++int d\u202De\u202cf2;
++/* { dg-bogus "unpaired" "" { target *-*-* } .-1 } */
++int d\u202ee\u202cf;
++/* { dg-bogus "unpaired" "" { target *-*-* } .-1 } */
++int d\u202Ee\u202cf2;
++/* { dg-bogus "unpaired" "" { target *-*-* } .-1 } */
++int d\u2066e\u2069f;
++/* { dg-bogus "unpaired" "" { target *-*-* } .-1 } */
++int d\u2067e\u2069f;
++/* { dg-bogus "unpaired" "" { target *-*-* } .-1 } */
++int d\u2068e\u2069f;
++/* { dg-bogus "unpaired" "" { target *-*-* } .-1 } */
++int X\u2069;
++/* { dg-bogus "unpaired" "" { target *-*-* } .-1 } */
+diff --git a/gcc/testsuite/c-c++-common/Wbidi-chars-6.c b/gcc/testsuite/c-c++-common/Wbidi-chars-6.c
+new file mode 100644
+index 00000000000..0ce6fff2dee
+--- /dev/null
++++ b/gcc/testsuite/c-c++-common/Wbidi-chars-6.c
+@@ -0,0 +1,155 @@
++/* PR preprocessor/103026 */
++/* { dg-do compile } */
++/* { dg-options "-Wbidi-chars=unpaired" } */
++/* Test nesting of bidi chars in various contexts.  */
++
++/* Terminated by the wrong char:  */
++/* a b c LREâª 1 2 3 PDIâ© x y z */
++/* { dg-warning "unpaired" "" { target *-*-* } .-1 } */
++/* a b c RLEâ« 1 2 3 PDIâ© x y  z*/
++/* { dg-warning "unpaired" "" { target *-*-* } .-1 } */
++/* a b c LROâ­ 1 2 3 PDIâ© x y z */
++/* { dg-warning "unpaired" "" { target *-*-* } .-1 } */
++/* a b c RLOâ® 1 2 3 PDIâ© x y z */
++/* { dg-warning "unpaired" "" { target *-*-* } .-1 } */
++/* a b c LRIâ¦ 1 2 3 PDFâ¬ x y z */
++/* { dg-warning "unpaired" "" { target *-*-* } .-1 } */
++/* a b c RLIâ§ 1 2 3 PDFâ¬ x y z */
++/* { dg-warning "unpaired" "" { target *-*-* } .-1 } */
++/* a b c FSIâ¨ 1 2 3 PDFâ¬ x y  z*/
++/* { dg-warning "unpaired" "" { target *-*-* } .-1 } */
++
++/* LREâª PDFâ¬ */
++/* LREâª LREâª PDFâ¬ PDFâ¬ */
++/* PDFâ¬ LREâª PDFâ¬ */
++/* LREâª PDFâ¬ LREâª PDFâ¬ */
++/* LREâª LREâª PDFâ¬ */
++/* { dg-warning "unpaired" "" { target *-*-* } .-1 } */
++/* PDFâ¬ LREâª */
++/* { dg-warning "unpaired" "" { target *-*-* } .-1 } */
++
++// a b c LREâª 1 2 3 PDIâ© x y z
++/* { dg-warning "unpaired" "" { target *-*-* } .-1 } */
++// a b c RLEâ« 1 2 3 PDIâ© x y  z*/
++/* { dg-warning "unpaired" "" { target *-*-* } .-1 } */
++// a b c LROâ­ 1 2 3 PDIâ© x y z 
++/* { dg-warning "unpaired" "" { target *-*-* } .-1 } */
++// a b c RLOâ® 1 2 3 PDIâ© x y z 
++/* { dg-warning "unpaired" "" { target *-*-* } .-1 } */
++// a b c LRIâ¦ 1 2 3 PDFâ¬ x y z 
++/* { dg-warning "unpaired" "" { target *-*-* } .-1 } */
++// a b c RLIâ§ 1 2 3 PDFâ¬ x y z 
++/* { dg-warning "unpaired" "" { target *-*-* } .-1 } */
++// a b c FSIâ¨ 1 2 3 PDFâ¬ x y  z
++/* { dg-warning "unpaired" "" { target *-*-* } .-1 } */
++
++// LREâª PDFâ¬ 
++// LREâª LREâª PDFâ¬ PDFâ¬
++// PDFâ¬ LREâª PDFâ¬
++// LREâª PDFâ¬ LREâª PDFâ¬
++// LREâª LREâª PDFâ¬
++/* { dg-warning "unpaired" "" { target *-*-* } .-1 } */
++// PDFâ¬ LREâª
++/* { dg-warning "unpaired" "" { target *-*-* } .-1 } */
++
++void
++g1 ()
++{
++  const char *s1 = "a b c LREâª 1 2 3 PDIâ© x y z";
++/* { dg-warning "unpaired" "" { target *-*-* } .-1 } */
++  const char *s2 = "a b c LRE\u202a 1 2 3 PDI\u2069 x y z";
++/* { dg-warning "unpaired" "" { target *-*-* } .-1 } */
++  const char *s3 = "a b c RLEâ« 1 2 3 PDIâ© x y ";
++/* { dg-warning "unpaired" "" { target *-*-* } .-1 } */
++  const char *s4 = "a b c RLE\u202b 1 2 3 PDI\u2069 x y z";
++/* { dg-warning "unpaired" "" { target *-*-* } .-1 } */
++  const char *s5 = "a b c LROâ­ 1 2 3 PDIâ© x y z";
++/* { dg-warning "unpaired" "" { target *-*-* } .-1 } */
++  const char *s6 = "a b c LRO\u202d 1 2 3 PDI\u2069 x y z";
++/* { dg-warning "unpaired" "" { target *-*-* } .-1 } */
++  const char *s7 = "a b c RLOâ® 1 2 3 PDIâ© x y z";
++/* { dg-warning "unpaired" "" { target *-*-* } .-1 } */
++  const char *s8 = "a b c RLO\u202e 1 2 3 PDI\u2069 x y z";
++/* { dg-warning "unpaired" "" { target *-*-* } .-1 } */
++  const char *s9 = "a b c LRIâ¦ 1 2 3 PDFâ¬ x y z";
++/* { dg-warning "unpaired" "" { target *-*-* } .-1 } */
++  const char *s10 = "a b c LRI\u2066 1 2 3 PDF\u202c x y z";
++/* { dg-warning "unpaired" "" { target *-*-* } .-1 } */
++  const char *s11 = "a b c RLIâ§ 1 2 3 PDFâ¬ x y z\
++    ";
++/* { dg-warning "unpaired" "" { target *-*-* } .-2 } */
++  const char *s12 = "a b c RLI\u2067 1 2 3 PDF\u202c x y z";
++/* { dg-warning "unpaired" "" { target *-*-* } .-1 } */
++  const char *s13 = "a b c FSIâ¨ 1 2 3 PDFâ¬ x y z";
++/* { dg-warning "unpaired" "" { target *-*-* } .-1 } */
++  const char *s14 = "a b c FSI\u2068 1 2 3 PDF\u202c x y z";
++/* { dg-warning "unpaired" "" { target *-*-* } .-1 } */
++  const char *s15 = "PDFâ¬ LREâª";
++/* { dg-warning "unpaired" "" { target *-*-* } .-1 } */
++  const char *s16 = "PDF\u202c LRE\u202a";
++/* { dg-warning "unpaired" "" { target *-*-* } .-1 } */
++  const char *s17 = "LREâª PDFâ¬";
++  const char *s18 = "LRE\u202a PDF\u202c";
++  const char *s19 = "LREâª LREâª PDFâ¬ PDFâ¬";
++  const char *s20 = "LRE\u202a LRE\u202a PDF\u202c PDF\u202c";
++  const char *s21 = "PDFâ¬ LREâª PDFâ¬";
++  const char *s22 = "PDF\u202c LRE\u202a PDF\u202c";
++  const char *s23 = "LREâª LREâª PDFâ¬";
++/* { dg-warning "unpaired" "" { target *-*-* } .-1 } */
++  const char *s24 = "LRE\u202a LRE\u202a PDF\u202c";
++/* { dg-warning "unpaired" "" { target *-*-* } .-1 } */
++  const char *s25 = "PDFâ¬ LREâª";
++/* { dg-warning "unpaired" "" { target *-*-* } .-1 } */
++  const char *s26 = "PDF\u202c LRE\u202a";
++/* { dg-warning "unpaired" "" { target *-*-* } .-1 } */
++  const char *s27 = "PDFâ¬ LRE\u202a";
++/* { dg-warning "unpaired" "" { target *-*-* } .-1 } */
++  const char *s28 = "PDF\u202c LREâª";
++/* { dg-warning "unpaired" "" { target *-*-* } .-1 } */
++}
++
++int aLREâªbPDIâ©;
++/* { dg-warning "unpaired" "" { target *-*-* } .-1 } */
++int A\u202aB\u2069C;
++/* { dg-warning "unpaired" "" { target *-*-* } .-1 } */
++int aRLEâ«bPDIâ©;
++/* { dg-warning "unpaired" "" { target *-*-* } .-1 } */
++int a\u202bB\u2069c;
++/* { dg-warning "unpaired" "" { target *-*-* } .-1 } */
++int aLROâ­bPDIâ©;
++/* { dg-warning "unpaired" "" { target *-*-* } .-1 } */
++int a\u202db\u2069c2;
++/* { dg-warning "unpaired" "" { target *-*-* } .-1 } */
++int aRLOâ®bPDIâ©;
++/* { dg-warning "unpaired" "" { target *-*-* } .-1 } */
++int a\u202eb\u2069;
++/* { dg-warning "unpaired" "" { target *-*-* } .-1 } */
++int aLRIâ¦bPDFâ¬;
++/* { dg-warning "unpaired" "" { target *-*-* } .-1 } */
++int a\u2066b\u202c;
++/* { dg-warning "unpaired" "" { target *-*-* } .-1 } */
++int aRLIâ§bPDFâ¬c
++;
++/* { dg-warning "unpaired" "" { target *-*-* } .-2 } */
++int a\u2067b\u202c;
++/* { dg-warning "unpaired" "" { target *-*-* } .-1 } */
++int aFSIâ¨bPDFâ¬;
++/* { dg-warning "unpaired" "" { target *-*-* } .-1 } */
++int a\u2068b\u202c;
++/* { dg-warning "unpaired" "" { target *-*-* } .-1 } */
++int aFSIâ¨bPD\u202C;
++/* { dg-warning "unpaired" "" { target *-*-* } .-1 } */
++int aFSI\u2068bPDFâ¬_;
++/* { dg-warning "unpaired" "" { target *-*-* } .-1 } */
++int aLREâªbPDFâ¬b; 
++int A\u202aB\u202c;
++int a_LREâª_LREâª_b_PDFâ¬_PDFâ¬;
++int A\u202aA\u202aB\u202cB\u202c;
++int aPDFâ¬bLREadPDFâ¬;
++int a_\u202C_\u202a_\u202c;
++int a_LREâª_b_PDFâ¬_c_LREâª_PDFâ¬;
++int a_\u202a_\u202c_\u202a_\u202c_;
++int a_LREâª_b_PDFâ¬_c_LREâª;
++/* { dg-warning "unpaired" "" { target *-*-* } .-1 } */
++int a_\u202a_\u202c_\u202a_;
++/* { dg-warning "unpaired" "" { target *-*-* } .-1 } */
+diff --git a/gcc/testsuite/c-c++-common/Wbidi-chars-7.c b/gcc/testsuite/c-c++-common/Wbidi-chars-7.c
+new file mode 100644
+index 00000000000..d012d420ec0
+--- /dev/null
++++ b/gcc/testsuite/c-c++-common/Wbidi-chars-7.c
+@@ -0,0 +1,9 @@
++/* PR preprocessor/103026 */
++/* { dg-do compile } */
++/* { dg-options "-Wbidi-chars=any" } */
++/* Test we ignore UCNs in comments.  */
++
++// a b c \u202a 1 2 3
++// a b c \u202A 1 2 3
++/* a b c \u202a 1 2 3 */
++/* a b c \u202A 1 2 3 */
+diff --git a/gcc/testsuite/c-c++-common/Wbidi-chars-8.c b/gcc/testsuite/c-c++-common/Wbidi-chars-8.c
+new file mode 100644
+index 00000000000..4f54c5092ec
+--- /dev/null
++++ b/gcc/testsuite/c-c++-common/Wbidi-chars-8.c
+@@ -0,0 +1,13 @@
++/* PR preprocessor/103026 */
++/* { dg-do compile } */
++/* { dg-options "-Wbidi-chars=any" } */
++/* Test \u vs \U.  */
++
++int a_\u202A;
++/* { dg-warning "U\\+202A" "" { target *-*-* } .-1 } */
++int a_\u202a_2;
++/* { dg-warning "U\\+202A" "" { target *-*-* } .-1 } */
++int a_\U0000202A_3;
++/* { dg-warning "U\\+202A" "" { target *-*-* } .-1 } */
++int a_\U0000202a_4;
++/* { dg-warning "U\\+202A" "" { target *-*-* } .-1 } */
+diff --git a/gcc/testsuite/c-c++-common/Wbidi-chars-9.c b/gcc/testsuite/c-c++-common/Wbidi-chars-9.c
+new file mode 100644
+index 00000000000..e2af1b1ca97
+--- /dev/null
++++ b/gcc/testsuite/c-c++-common/Wbidi-chars-9.c
+@@ -0,0 +1,29 @@
++/* PR preprocessor/103026 */
++/* { dg-do compile } */
++/* { dg-options "-Wbidi-chars=unpaired" } */
++/* Test that we properly separate bidi contexts (comment/identifier/character
++   constant/string literal).  */
++
++/* LRE ->âª<- */ int pdf_\u202c_1;
++/* { dg-warning "unpaired" "" { target *-*-* } .-1 } */
++/* RLE ->â«<- */ int pdf_\u202c_2;
++/* { dg-warning "unpaired" "" { target *-*-* } .-1 } */
++/* LRO ->â­<- */ int pdf_\u202c_3;
++/* { dg-warning "unpaired" "" { target *-*-* } .-1 } */
++/* RLO ->â®<- */ int pdf_\u202c_4;
++/* { dg-warning "unpaired" "" { target *-*-* } .-1 } */
++/* LRI ->â¦<-*/ int pdi_\u2069_1;
++/* { dg-warning "unpaired" "" { target *-*-* } .-1 } */
++/* RLI ->â§<- */ int pdi_\u2069_12;
++/* { dg-warning "unpaired" "" { target *-*-* } .-1 } */
++/* FSI ->â¨<- */ int pdi_\u2069_3;
++/* { dg-warning "unpaired" "" { target *-*-* } .-1 } */
++
++const char *s1 = "LRE\u202a"; /* PDF ->â¬<- */
++/* { dg-warning "unpaired" "" { target *-*-* } .-1 } */
++/* LRE ->âª<- */ const char *s2 = "PDF\u202c";
++/* { dg-warning "unpaired" "" { target *-*-* } .-1 } */
++const char *s3 = "LRE\u202a"; int pdf_\u202c_5;
++/* { dg-warning "unpaired" "" { target *-*-* } .-1 } */
++int lre_\u202a; const char *s4 = "PDF\u202c";
++/* { dg-warning "unpaired" "" { target *-*-* } .-1 } */
+diff --git a/libcpp/include/cpplib.h b/libcpp/include/cpplib.h
+index 176f8c5bbce..112b9c24751 100644
+--- a/libcpp/include/cpplib.h
++++ b/libcpp/include/cpplib.h
+@@ -318,6 +318,17 @@ enum cpp_main_search
+   CMS_system,  /* Search the system INCLUDE path.  */
+ };
+ 
++/* The possible bidirectional control characters checking levels, from least
++   restrictive to most.  */
++enum cpp_bidirectional_level {
++  /* No checking.  */
++  bidirectional_none,
++  /* Only detect unpaired uses of bidirectional control characters.  */
++  bidirectional_unpaired,
++  /* Detect any use of bidirectional control characters.  */
++  bidirectional_any
++};
++
+ /* This structure is nested inside struct cpp_reader, and
+    carries all the options visible to the command line.  */
+ struct cpp_options
+@@ -531,6 +542,10 @@ struct cpp_options
+   /* True if warn about differences between C++98 and C++11.  */
+   bool cpp_warn_cxx11_compat;
+ 
++  /* Nonzero if bidirectional control characters checking is on.  See enum
++     cpp_bidirectional_level.  */
++  unsigned char cpp_warn_bidirectional;
++
+   /* Dependency generation.  */
+   struct
+   {
+@@ -635,7 +650,8 @@ enum cpp_warning_reason {
+   CPP_W_C90_C99_COMPAT,
+   CPP_W_C11_C2X_COMPAT,
+   CPP_W_CXX11_COMPAT,
+-  CPP_W_EXPANSION_TO_DEFINED
++  CPP_W_EXPANSION_TO_DEFINED,
++  CPP_W_BIDIRECTIONAL
+ };
+ 
+ /* Callback for header lookup for HEADER, which is the name of a
+diff --git a/libcpp/init.c b/libcpp/init.c
+index 5a424e23553..f9a8f5f088f 100644
+--- a/libcpp/init.c
++++ b/libcpp/init.c
+@@ -219,6 +219,7 @@ cpp_create_reader (enum c_lang lang, cpp
+       = ENABLE_CANONICAL_SYSTEM_HEADERS;
+   CPP_OPTION (pfile, ext_numeric_literals) = 1;
+   CPP_OPTION (pfile, warn_date_time) = 0;
++  CPP_OPTION (pfile, cpp_warn_bidirectional) = bidirectional_unpaired;
+ 
+   /* Default CPP arithmetic to something sensible for the host for the
+      benefit of dumb users like fix-header.  */
+diff --git a/libcpp/internal.h b/libcpp/internal.h
+index 8577cab6c83..0ce0246c5a2 100644
+--- a/libcpp/internal.h
++++ b/libcpp/internal.h
+@@ -597,6 +597,13 @@ struct cpp_reader
+   /* Location identifying the main source file -- intended to be line
+      zero of said file.  */
+   location_t main_loc;
++
++  /* Returns true iff we should warn about UTF-8 bidirectional control
++     characters.  */
++  bool warn_bidi_p () const
++  {
++    return CPP_OPTION (this, cpp_warn_bidirectional) != bidirectional_none;
++  }
+ };
+ 
+ /* Character classes.  Based on the more primitive macros in safe-ctype.h.
+diff --git a/libcpp/lex.c b/libcpp/lex.c
+index fa2253d41c3..6a4fbce6030 100644
+--- a/libcpp/lex.c
++++ b/libcpp/lex.c
+@@ -1164,6 +1164,324 @@ _cpp_process_line_notes (cpp_reader *pfi
+     }
+ }
+ 
++namespace bidi {
++  enum class kind {
++    NONE, LRE, RLE, LRO, RLO, LRI, RLI, FSI, PDF, PDI, LTR, RTL
++  };
++
++  /* All the UTF-8 encodings of bidi characters start with E2.  */
++  constexpr uchar utf8_start = 0xe2;
++
++  /* A vector holding currently open bidi contexts.  We use a char for
++     each context, its LSB is 1 if it represents a PDF context, 0 if it
++     represents a PDI context.  The next bit is 1 if this context was open
++     by a bidi character written as a UCN, and 0 when it was UTF-8.  */
++  semi_embedded_vec <unsigned char, 16> vec;
++
++  /* Close the whole comment/identifier/string literal/character constant
++     context.  */
++  void on_close ()
++  {
++    vec.truncate (0);
++  }
++
++  /* Pop the last element in the vector.  */
++  void pop ()
++  {
++    unsigned int len = vec.count ();
++    gcc_checking_assert (len > 0);
++    vec.truncate (len - 1);
++  }
++
++  /* Return the context of the Ith element.  */
++  kind ctx_at (unsigned int i)
++  {
++    return (vec[i] & 1) ? kind::PDF : kind::PDI;
++  }
++
++  /* Return which context is currently opened.  */
++  kind current_ctx ()
++  {
++    unsigned int len = vec.count ();
++    if (len == 0)
++      return kind::NONE;
++    return ctx_at (len - 1);
++  }
++
++  /* Return true if the current context comes from a UCN origin, that is,
++     the bidi char which started this bidi context was written as a UCN.  */
++  bool current_ctx_ucn_p ()
++  {
++    unsigned int len = vec.count ();
++    gcc_checking_assert (len > 0);
++    return (vec[len - 1] >> 1) & 1;
++  }
++
++  /* We've read a bidi char, update the current vector as necessary.  */
++  void on_char (kind k, bool ucn_p)
++  {
++    switch (k)
++      {
++      case kind::LRE:
++      case kind::RLE:
++      case kind::LRO:
++      case kind::RLO:
++	vec.push (ucn_p ? 3u : 1u);
++	break;
++      case kind::LRI:
++      case kind::RLI:
++      case kind::FSI:
++	vec.push (ucn_p ? 2u : 0u);
++	break;
++      /* PDF terminates the scope of the last LRE, RLE, LRO, or RLO
++	 whose scope has not yet been terminated.  */
++      case kind::PDF:
++	if (current_ctx () == kind::PDF)
++	  pop ();
++	break;
++      /* PDI terminates the scope of the last LRI, RLI, or FSI whose
++	 scope has not yet been terminated, as well as the scopes of
++	 any subsequent LREs, RLEs, LROs, or RLOs whose scopes have not
++	 yet been terminated.  */
++      case kind::PDI:
++	for (int i = vec.count () - 1; i >= 0; --i)
++	  if (ctx_at (i) == kind::PDI)
++	    {
++	      vec.truncate (i);
++	      break;
++	    }
++	break;
++      case kind::LTR:
++      case kind::RTL:
++	/* These aren't popped by a PDF/PDI.  */
++	break;
++      [[likely]] case kind::NONE:
++	break;
++      default:
++	abort ();
++      }
++  }
++
++  /* Return a descriptive string for K.  */
++  const char *to_str (kind k)
++  {
++    switch (k)
++      {
++      case kind::LRE:
++	return "U+202A (LEFT-TO-RIGHT EMBEDDING)";
++      case kind::RLE:
++	return "U+202B (RIGHT-TO-LEFT EMBEDDING)";
++      case kind::LRO:
++	return "U+202D (LEFT-TO-RIGHT OVERRIDE)";
++      case kind::RLO:
++	return "U+202E (RIGHT-TO-LEFT OVERRIDE)";
++      case kind::LRI:
++	return "U+2066 (LEFT-TO-RIGHT ISOLATE)";
++      case kind::RLI:
++	return "U+2067 (RIGHT-TO-LEFT ISOLATE)";
++      case kind::FSI:
++	return "U+2068 (FIRST STRONG ISOLATE)";
++      case kind::PDF:
++	return "U+202C (POP DIRECTIONAL FORMATTING)";
++      case kind::PDI:
++	return "U+2069 (POP DIRECTIONAL ISOLATE)";
++      case kind::LTR:
++	return "U+200E (LEFT-TO-RIGHT MARK)";
++      case kind::RTL:
++	return "U+200F (RIGHT-TO-LEFT MARK)";
++      default:
++	abort ();
++      }
++  }
++}
++
++/* Parse a sequence of 3 bytes starting with P and return its bidi code.  */
++
++static bidi::kind
++get_bidi_utf8 (const unsigned char *const p)
++{
++  gcc_checking_assert (p[0] == bidi::utf8_start);
++
++  if (p[1] == 0x80)
++    switch (p[2])
++      {
++      case 0xaa:
++	return bidi::kind::LRE;
++      case 0xab:
++	return bidi::kind::RLE;
++      case 0xac:
++	return bidi::kind::PDF;
++      case 0xad:
++	return bidi::kind::LRO;
++      case 0xae:
++	return bidi::kind::RLO;
++      case 0x8e:
++	return bidi::kind::LTR;
++      case 0x8f:
++	return bidi::kind::RTL;
++      default:
++	break;
++      }
++  else if (p[1] == 0x81)
++    switch (p[2])
++      {
++      case 0xa6:
++	return bidi::kind::LRI;
++      case 0xa7:
++	return bidi::kind::RLI;
++      case 0xa8:
++	return bidi::kind::FSI;
++      case 0xa9:
++	return bidi::kind::PDI;
++      default:
++	break;
++      }
++
++  return bidi::kind::NONE;
++}
++
++/* Parse a UCN where P points just past \u or \U and return its bidi code.  */
++
++static bidi::kind
++get_bidi_ucn (const unsigned char *p, bool is_U)
++{
++  /* 6.4.3 Universal Character Names
++      \u hex-quad
++      \U hex-quad hex-quad
++     where \unnnn means \U0000nnnn.  */
++
++  if (is_U)
++    {
++      if (p[0] != '0' || p[1] != '0' || p[2] != '0' || p[3] != '0')
++	return bidi::kind::NONE;
++      /* Skip 4B so we can treat \u and \U the same below.  */
++      p += 4;
++    }
++
++  /* All code points we are looking for start with 20xx.  */
++  if (p[0] != '2' || p[1] != '0')
++    return bidi::kind::NONE;
++  else if (p[2] == '2')
++    switch (p[3])
++      {
++      case 'a':
++      case 'A':
++	return bidi::kind::LRE;
++      case 'b':
++      case 'B':
++	return bidi::kind::RLE;
++      case 'c':
++      case 'C':
++	return bidi::kind::PDF;
++      case 'd':
++      case 'D':
++	return bidi::kind::LRO;
++      case 'e':
++      case 'E':
++	return bidi::kind::RLO;
++      default:
++	break;
++      }
++  else if (p[2] == '6')
++    switch (p[3])
++      {
++      case '6':
++	return bidi::kind::LRI;
++      case '7':
++	return bidi::kind::RLI;
++      case '8':
++	return bidi::kind::FSI;
++      case '9':
++	return bidi::kind::PDI;
++      default:
++	break;
++      }
++  else if (p[2] == '0')
++    switch (p[3])
++      {
++      case 'e':
++      case 'E':
++	return bidi::kind::LTR;
++      case 'f':
++      case 'F':
++	return bidi::kind::RTL;
++      default:
++	break;
++      }
++
++  return bidi::kind::NONE;
++}
++
++/* We're closing a bidi context, that is, we've encountered a newline,
++   are closing a C-style comment, or are at the end of a string literal,
++   character constant, or identifier.  Warn if this context was not
++   properly terminated by a PDI or PDF.  P points to the last character
++   in this context.  */
++
++static void
++maybe_warn_bidi_on_close (cpp_reader *pfile, const uchar *p)
++{
++  if (CPP_OPTION (pfile, cpp_warn_bidirectional) == bidirectional_unpaired
++      && bidi::vec.count () > 0)
++    {
++      const location_t loc
++	= linemap_position_for_column (pfile->line_table,
++				       CPP_BUF_COLUMN (pfile->buffer, p));
++      cpp_warning_with_line (pfile, CPP_W_BIDIRECTIONAL, loc, 0,
++			     "unpaired UTF-8 bidirectional control character "
++			     "detected");
++    }
++  /* We're done with this context.  */
++  bidi::on_close ();
++}
++
++/* We're at the beginning or in the middle of an identifier/comment/string
++   literal/character constant.  Warn if we've encountered a bidi character.
++   KIND says which bidi character it was; P points to it in the character
++   stream.  UCN_P is true iff this bidi character was written as a UCN.  */
++
++static void
++maybe_warn_bidi_on_char (cpp_reader *pfile, const uchar *p, bidi::kind kind,
++			 bool ucn_p)
++{
++  if (__builtin_expect (kind == bidi::kind::NONE, 1))
++    return;
++
++  const auto warn_bidi = CPP_OPTION (pfile, cpp_warn_bidirectional);
++
++  if (warn_bidi != bidirectional_none)
++    {
++      const location_t loc
++	= linemap_position_for_column (pfile->line_table,
++				       CPP_BUF_COLUMN (pfile->buffer, p));
++      /* It seems excessive to warn about a PDI/PDF that is closing
++	 an opened context because we've already warned about the
++	 opening character.  Except warn when we have a UCN x UTF-8
++	 mismatch.  */
++      if (kind == bidi::current_ctx ())
++	{
++	  if (warn_bidi == bidirectional_unpaired
++	      && bidi::current_ctx_ucn_p () != ucn_p)
++	    cpp_warning_with_line (pfile, CPP_W_BIDIRECTIONAL, loc, 0,
++				   "UTF-8 vs UCN mismatch when closing "
++				   "a context by \"%s\"", bidi::to_str (kind));
++	}
++      else if (warn_bidi == bidirectional_any)
++	{
++	  if (kind == bidi::kind::PDF || kind == bidi::kind::PDI)
++	    cpp_warning_with_line (pfile, CPP_W_BIDIRECTIONAL, loc, 0,
++				   "\"%s\" is closing an unopened context",
++				   bidi::to_str (kind));
++	  else
++	    cpp_warning_with_line (pfile, CPP_W_BIDIRECTIONAL, loc, 0,
++				   "found problematic Unicode character \"%s\"",
++				   bidi::to_str (kind));
++	}
++    }
++  /* We're done with this context.  */
++  bidi::on_char (kind, ucn_p);
++}
++
+ /* Skip a C-style block comment.  We find the end of the comment by
+    seeing if an asterisk is before every '/' we encounter.  Returns
+    nonzero if comment terminated by EOF, zero otherwise.
+@@ -1175,6 +1493,7 @@ _cpp_skip_block_comment (cpp_reader *pfi
+   cpp_buffer *buffer = pfile->buffer;
+   const uchar *cur = buffer->cur;
+   uchar c;
++  const bool warn_bidi_p = pfile->warn_bidi_p ();
+ 
+   cur++;
+   if (*cur == '/')
+@@ -1189,7 +1508,11 @@ _cpp_skip_block_comment (cpp_reader *pfi
+       if (c == '/')
+ 	{
+ 	  if (cur[-2] == '*')
+-	    break;
++	    {
++	      if (warn_bidi_p)
++		maybe_warn_bidi_on_close (pfile, cur);
++	      break;
++	    }
+ 
+ 	  /* Warn about potential nested comments, but not if the '/'
+ 	     comes immediately before the true comment delimiter.
+@@ -1208,6 +1531,8 @@ _cpp_skip_block_comment (cpp_reader *pfi
+ 	{
+ 	  unsigned int cols;
+ 	  buffer->cur = cur - 1;
++	  if (warn_bidi_p)
++	    maybe_warn_bidi_on_close (pfile, cur);
+ 	  _cpp_process_line_notes (pfile, true);
+ 	  if (buffer->next_line >= buffer->rlimit)
+ 	    return true;
+@@ -1218,6 +1543,13 @@ _cpp_skip_block_comment (cpp_reader *pfi
+ 
+ 	  cur = buffer->cur;
+ 	}
++      /* If this is a beginning of a UTF-8 encoding, it might be
++	 a bidirectional control character.  */
++      else if (__builtin_expect (c == bidi::utf8_start, 0) && warn_bidi_p)
++	{
++	  bidi::kind kind = get_bidi_utf8 (cur - 1);
++	  maybe_warn_bidi_on_char (pfile, cur, kind, /*ucn_p=*/false);
++	}
+     }
+ 
+   buffer->cur = cur;
+@@ -1233,9 +1565,31 @@ skip_line_comment (cpp_reader *pfile)
+ {
+   cpp_buffer *buffer = pfile->buffer;
+   location_t orig_line = pfile->line_table->highest_line;
++  const bool warn_bidi_p = pfile->warn_bidi_p ();
+ 
+-  while (*buffer->cur != '\n')
+-    buffer->cur++;
++  if (!warn_bidi_p)
++    while (*buffer->cur != '\n')
++      buffer->cur++;
++  else
++    {
++      while (*buffer->cur != '\n'
++	     && *buffer->cur != bidi::utf8_start)
++	buffer->cur++;
++      if (__builtin_expect (*buffer->cur == bidi::utf8_start, 0))
++	{
++	  while (*buffer->cur != '\n')
++	    {
++	      if (__builtin_expect (*buffer->cur == bidi::utf8_start, 0))
++		{
++		  bidi::kind kind = get_bidi_utf8 (buffer->cur);
++		  maybe_warn_bidi_on_char (pfile, buffer->cur, kind,
++					   /*ucn_p=*/false);
++		}
++	      buffer->cur++;
++	    }
++	  maybe_warn_bidi_on_close (pfile, buffer->cur);
++	}
++    }
+ 
+   _cpp_process_line_notes (pfile, true);
+   return orig_line != pfile->line_table->highest_line;
+@@ -1317,11 +1671,13 @@ static const cppchar_t utf8_signifier =
+ 
+ /* Returns TRUE if the sequence starting at buffer->cur is valid in
+    an identifier.  FIRST is TRUE if this starts an identifier.  */
++
+ static bool
+ forms_identifier_p (cpp_reader *pfile, int first,
+ 		    struct normalize_state *state)
+ {
+   cpp_buffer *buffer = pfile->buffer;
++  const bool warn_bidi_p = pfile->warn_bidi_p ();
+ 
+   if (*buffer->cur == '$')
+     {
+@@ -1344,6 +1700,13 @@ forms_identifier_p (cpp_reader *pfile, i
+       cppchar_t s;
+       if (*buffer->cur >= utf8_signifier)
+ 	{
++	  if (__builtin_expect (*buffer->cur == bidi::utf8_start, 0)
++	      && warn_bidi_p)
++	    {
++	      bidi::kind kind = get_bidi_utf8 (buffer->cur);
++	      maybe_warn_bidi_on_char (pfile, buffer->cur, kind,
++				       /*ucn_p=*/false);
++	    }
+ 	  if (_cpp_valid_utf8 (pfile, &buffer->cur, buffer->rlimit, 1 + !first,
+ 			       state, &s))
+ 	    return true;
+@@ -1352,6 +1715,13 @@ forms_identifier_p (cpp_reader *pfile, i
+ 	       && (buffer->cur[1] == 'u' || buffer->cur[1] == 'U'))
+ 	{
+ 	  buffer->cur += 2;
++	  if (warn_bidi_p)
++	    {
++	      bidi::kind kind = get_bidi_ucn (buffer->cur,
++					      buffer->cur[-1] == 'U');
++	      maybe_warn_bidi_on_char (pfile, buffer->cur, kind,
++				       /*ucn_p=*/true);
++	    }
+ 	  if (_cpp_valid_ucn (pfile, &buffer->cur, buffer->rlimit, 1 + !first,
+ 			      state, &s, NULL, NULL))
+ 	    return true;
+@@ -1460,6 +1830,7 @@ lex_identifier (cpp_reader *pfile, const
+   const uchar *cur;
+   unsigned int len;
+   unsigned int hash = HT_HASHSTEP (0, *base);
++  const bool warn_bidi_p = pfile->warn_bidi_p ();
+ 
+   cur = pfile->buffer->cur;
+   if (! starts_ucn)
+@@ -1483,6 +1854,8 @@ lex_identifier (cpp_reader *pfile, const
+ 	    pfile->buffer->cur++;
+ 	  }
+       } while (forms_identifier_p (pfile, false, nst));
++      if (warn_bidi_p)
++	maybe_warn_bidi_on_close (pfile, pfile->buffer->cur);
+       result = _cpp_interpret_identifier (pfile, base,
+ 					  pfile->buffer->cur - base);
+       *spelling = cpp_lookup (pfile, base, pfile->buffer->cur - base);
+@@ -1719,6 +2092,7 @@ static void
+ lex_raw_string (cpp_reader *pfile, cpp_token *token, const uchar *base)
+ {
+   const uchar *pos = base;
++  const bool warn_bidi_p = pfile->warn_bidi_p ();
+ 
+   /* 'tis a pity this information isn't passed down from the lexer's
+      initial categorization of the token.  */
+@@ -1955,8 +2329,15 @@ lex_raw_string (cpp_reader *pfile, cpp_t
+ 	  pos = base = pfile->buffer->cur;
+ 	  note = &pfile->buffer->notes[pfile->buffer->cur_note];
+ 	}
++      else if (__builtin_expect ((unsigned char) c == bidi::utf8_start, 0)
++	       && warn_bidi_p)
++	maybe_warn_bidi_on_char (pfile, pos - 1, get_bidi_utf8 (pos - 1),
++				 /*ucn_p=*/false);
+     }
+ 
++  if (warn_bidi_p)
++    maybe_warn_bidi_on_close (pfile, pos);
++
+   if (CPP_OPTION (pfile, user_literals))
+     {
+       /* If a string format macro, say from inttypes.h, is placed touching
+@@ -2051,15 +2432,27 @@ lex_string (cpp_reader *pfile, cpp_token
+   else
+     terminator = '>', type = CPP_HEADER_NAME;
+ 
++  const bool warn_bidi_p = pfile->warn_bidi_p ();
+   for (;;)
+     {
+       cppchar_t c = *cur++;
+ 
+       /* In #include-style directives, terminators are not escapable.  */
+       if (c == '\\' && !pfile->state.angled_headers && *cur != '\n')
+-	cur++;
++	{
++	  if ((cur[0] == 'u' || cur[0] == 'U') && warn_bidi_p)
++	    {
++	      bidi::kind kind = get_bidi_ucn (cur + 1, cur[0] == 'U');
++	      maybe_warn_bidi_on_char (pfile, cur, kind, /*ucn_p=*/true);
++	    }
++	  cur++;
++	}
+       else if (c == terminator)
+-	break;
++	{
++	  if (warn_bidi_p)
++	    maybe_warn_bidi_on_close (pfile, cur - 1);
++	  break;
++	}
+       else if (c == '\n')
+ 	{
+ 	  cur--;
+@@ -2076,6 +2469,11 @@ lex_string (cpp_reader *pfile, cpp_token
+ 	}
+       else if (c == '\0')
+ 	saw_NUL = true;
++      else if (__builtin_expect (c == bidi::utf8_start, 0) && warn_bidi_p)
++	{
++	  bidi::kind kind = get_bidi_utf8 (cur - 1);
++	  maybe_warn_bidi_on_char (pfile, cur - 1, kind, /*ucn_p=*/false);
++	}
+     }
+ 
+   if (saw_NUL && !pfile->state.skipping)