diff --git a/SOURCES/gcc8-add-Wbidirectional.patch b/SOURCES/gcc8-add-Wbidirectional.patch
new file mode 100644
index 0000000..b907335
--- /dev/null
+++ b/SOURCES/gcc8-add-Wbidirectional.patch
@@ -0,0 +1,1263 @@
+diff --git a/gcc/c-family/c.opt b/gcc/c-family/c.opt
+index f591b39be5a..3e9a97f4ae2 100644
+--- a/gcc/c-family/c.opt
++++ b/gcc/c-family/c.opt
+@@ -334,6 +334,30 @@ Wbad-function-cast
+ C ObjC Var(warn_bad_function_cast) Warning
+ Warn about casting functions to incompatible types.
+
++Wbidirectional
++C ObjC C++ ObjC++ Warning Alias(Wbidirectional=,any,none)
++;
++
++Wbidirectional=
++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)
++-Wbidirectional=[none|unpaired|any] Warn about UTF-8 bidirectional characters.
++
++; Required for these enum values.
++SourceInclude
++cpplib.h
++
++Enum
++Name(cpp_bidirectional_level) Type(int) UnknownError(argument %qs to %<-Wbidirectional%> 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 78ca7738df2..7342dd2e142 100644
+--- a/gcc/doc/invoke.texi
++++ b/gcc/doc/invoke.texi
+@@ -264,7 +264,9 @@ Objective-C and Objective-C++ Dialects}.
+ -Walloc-zero -Walloc-size-larger-than=@var{n}
+ -Walloca -Walloca-larger-than=@var{n} @gol
+ -Wno-aggressive-loop-optimizations -Warray-bounds -Warray-bounds=@var{n} @gol
+--Wno-attributes -Wbool-compare -Wbool-operation @gol
++-Wno-attributes @gol
++-Wbidirectional=@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
+ -Wc++-compat -Wc++11-compat -Wc++14-compat @gol
+@@ -5606,6 +5608,21 @@ Warn about declarations using the @code{alias} and similar attributes whose
+ target is incompatible with the type of the alias. @xref{Function Attributes,
+ ,Declaring Attributes of Functions}.
+
++@item -Wbidirectional=@r{[}none@r{|}unpaired@r{|}any@r{]}
++@opindex Wbidirectional=
++@opindex Wbidirectional
++@opindex Wno-bidirectional
++Warn about UTF-8 bidirectional characters. 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{-Wbidirectional=unpaired}, which warns about improperly terminated
++bidi contexts. @option{-Wbidirectional=none} turns the warning off.
++@option{-Wbidirectional=any} warns about any use of bidirectional characters.
++
+ @item -Wbool-compare
+ @opindex Wno-bool-compare
+ @opindex Wbool-compare
+diff --git a/gcc/testsuite/c-c++-common/Wbidirectional-1.c b/gcc/testsuite/c-c++-common/Wbidirectional-1.c
+new file mode 100644
+index 00000000000..750de81fdd8
+--- /dev/null
++++ b/gcc/testsuite/c-c++-common/Wbidirectional-1.c
+@@ -0,0 +1,11 @@
++/* { dg-do compile } */
++
++int main() {
++ int isAdmin = 0;
++ /* } if (isAdmin) begin admins only */
++/* { dg-warning "bidirectional" "" { target *-*-* } .-1 } */
++ __builtin_printf("You are an admin.\n");
++ /* end admins only { */
++/* { dg-warning "bidirectional" "" { target *-*-* } .-1 } */
++ return 0;
++}
+diff --git a/gcc/testsuite/c-c++-common/Wbidirectional-10.c b/gcc/testsuite/c-c++-common/Wbidirectional-10.c
+new file mode 100644
+index 00000000000..cd4abeeefbd
+--- /dev/null
++++ b/gcc/testsuite/c-c++-common/Wbidirectional-10.c
+@@ -0,0 +1,27 @@
++/* { dg-do compile } */
++/* { dg-options "-Wbidirectional=unpaired" } */
++/* More nesting testing. */
++
++/* RLE LRI PDF PDI*/
++/* { 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;
++/* { dg-warning "unpaired" "" { target *-*-* } .-1 } */
++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/Wbidirectional-11.c b/gcc/testsuite/c-c++-common/Wbidirectional-11.c
+new file mode 100644
+index 00000000000..89ed6e8affc
+--- /dev/null
++++ b/gcc/testsuite/c-c++-common/Wbidirectional-11.c
+@@ -0,0 +1,8 @@
++/* { dg-do compile } */
++/* { dg-options "-Wbidirectional=unpaired" } */
++/* Test that we warn when mixing UCN and UTF-8. */
++
++const char *s1 = "LRE__PDF_\u202c";
++/* { dg-warning "mismatch" "" { target *-*-* } .-1 } */
++const char *s2 = "LRE_\u202a_PDF_";
++/* { dg-warning "mismatch" "" { target *-*-* } .-1 } */
+diff --git a/gcc/testsuite/c-c++-common/Wbidirectional-12.c b/gcc/testsuite/c-c++-common/Wbidirectional-12.c
+new file mode 100644
+index 00000000000..20d1566401a
+--- /dev/null
++++ b/gcc/testsuite/c-c++-common/Wbidirectional-12.c
+@@ -0,0 +1,18 @@
++/* { dg-do compile { target { c || c++11 } } } */
++/* { dg-options "-Wbidirectional=any" } */
++/* Test raw strings. */
++
++const char *s1 = R"(a b c LRE 1 2 3 PDF x y z)";
++/* { dg-warning "U\\+202A" "" { target *-*-* } .-1 } */
++const char *s2 = R"(a b c RLE 1 2 3 PDF x y z)";
++/* { dg-warning "U\\+202B" "" { target *-*-* } .-1 } */
++const char *s3 = R"(a b c LRO 1 2 3 PDF x y z)";
++/* { dg-warning "U\\+202D" "" { target *-*-* } .-1 } */
++const char *s4 = R"(a b c RLO 1 2 3 PDF x y z)";
++/* { dg-warning "U\\+202E" "" { target *-*-* } .-1 } */
++const char *s7 = R"(a b c FSI 1 2 3 PDI x y) z";
++/* { dg-warning "U\\+2068" "" { target *-*-* } .-1 } */
++const char *s8 = R"(a b c PDI x y )z";
++/* { dg-warning "U\\+2069" "" { target *-*-* } .-1 } */
++const char *s9 = R"(a b c PDF x y z)";
++/* { dg-warning "U\\+202C" "" { target *-*-* } .-1 } */
+diff --git a/gcc/testsuite/c-c++-common/Wbidirectional-13.c b/gcc/testsuite/c-c++-common/Wbidirectional-13.c
+new file mode 100644
+index 00000000000..08010e3b37b
+--- /dev/null
++++ b/gcc/testsuite/c-c++-common/Wbidirectional-13.c
+@@ -0,0 +1,16 @@
++/* { dg-do compile { target { c || c++11 } } } */
++/* { dg-options "-Wbidirectional=unpaired" } */
++/* Test raw strings. */
++
++const char *s1 = R"(a b c LRE 1 2 3)";
++/* { dg-warning "unpaired" "" { target *-*-* } .-1 } */
++const char *s2 = R"(a b c RLE 1 2 3)";
++/* { dg-warning "unpaired" "" { target *-*-* } .-1 } */
++const char *s3 = R"(a b c LRO 1 2 3)";
++/* { dg-warning "unpaired" "" { target *-*-* } .-1 } */
++const char *s4 = R"(a b c FSI 1 2 3)";
++/* { dg-warning "unpaired" "" { target *-*-* } .-1 } */
++const char *s5 = R"(a b c LRI 1 2 3)";
++/* { dg-warning "unpaired" "" { target *-*-* } .-1 } */
++const char *s6 = R"(a b c RLI 1 2 3)";
++/* { dg-warning "unpaired" "" { target *-*-* } .-1 } */
+diff --git a/gcc/testsuite/c-c++-common/Wbidirectional-2.c b/gcc/testsuite/c-c++-common/Wbidirectional-2.c
+new file mode 100644
+index 00000000000..4e04202e058
+--- /dev/null
++++ b/gcc/testsuite/c-c++-common/Wbidirectional-2.c
+@@ -0,0 +1,8 @@
++/* { dg-do compile } */
++
++int main() {
++ /* Say hello; newline/*/ return 0 ;
++/* { dg-warning "bidirectional" "" { target *-*-* } .-1 } */
++ __builtin_printf("Hello world.\n");
++ return 0;
++}
+diff --git a/gcc/testsuite/c-c++-common/Wbidirectional-3.c b/gcc/testsuite/c-c++-common/Wbidirectional-3.c
+new file mode 100644
+index 00000000000..921300e94e0
+--- /dev/null
++++ b/gcc/testsuite/c-c++-common/Wbidirectional-3.c
+@@ -0,0 +1,10 @@
++/* { dg-do compile } */
++
++int main() {
++ const char* access_level = "user";
++ if (__builtin_strcmp(access_level, "user // Check if admin ")) {
++/* { dg-warning "bidirectional" "" { target *-*-* } .-1 } */
++ __builtin_printf("You are an admin.\n");
++ }
++ return 0;
++}
+diff --git a/gcc/testsuite/c-c++-common/Wbidirectional-4.c b/gcc/testsuite/c-c++-common/Wbidirectional-4.c
+new file mode 100644
+index 00000000000..bdf334d9986
+--- /dev/null
++++ b/gcc/testsuite/c-c++-common/Wbidirectional-4.c
+@@ -0,0 +1,149 @@
++/* { dg-do compile } */
++/* { dg-options "-Wbidirectional=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 LRE 1 2 3 PDF x y z */
++/* { dg-warning "U\\+202A" "" { target *-*-* } .-1 } */
++/* a b c RLE 1 2 3 PDF x y z */
++/* { dg-warning "U\\+202B" "" { target *-*-* } .-1 } */
++/* a b c LRO 1 2 3 PDF x y z */
++/* { dg-warning "U\\+202D" "" { target *-*-* } .-1 } */
++/* a b c RLO 1 2 3 PDF x y z */
++/* { dg-warning "U\\+202E" "" { target *-*-* } .-1 } */
++/* a b c LRI 1 2 3 PDI x y z */
++/* { dg-warning "U\\+2066" "" { target *-*-* } .-1 } */
++/* a b c RLI 1 2 3 PDI x y */
++/* { dg-warning "U\\+2067" "" { target *-*-* } .-1 } */
++/* a b c FSI 1 2 3 PDI x y z */
++/* { dg-warning "U\\+2068" "" { target *-*-* } .-1 } */
++
++/* Same but C++ comments instead. */
++// a b c LRE 1 2 3 PDF x y z
++/* { dg-warning "U\\+202A" "" { target *-*-* } .-1 } */
++// a b c RLE 1 2 3 PDF x y z
++/* { dg-warning "U\\+202B" "" { target *-*-* } .-1 } */
++// a b c LRO 1 2 3 PDF x y z
++/* { dg-warning "U\\+202D" "" { target *-*-* } .-1 } */
++// a b c RLO 1 2 3 PDF x y z
++/* { dg-warning "U\\+202E" "" { target *-*-* } .-1 } */
++// a b c LRI 1 2 3 PDI x y z
++/* { dg-warning "U\\+2066" "" { target *-*-* } .-1 } */
++// a b c RLI 1 2 3 PDI x y
++/* { dg-warning "U\\+2067" "" { target *-*-* } .-1 } */
++// a b c FSI 1 2 3 PDI x y z
++/* { dg-warning "U\\+2068" "" { target *-*-* } .-1 } */
++
++/* Here we're closing an unopened context, warn when =any. */
++/* a b c PDI x y z */
++/* { dg-warning "U\\+2069" "" { target *-*-* } .-1 } */
++/* a b c PDF x y z */
++/* { dg-warning "U\\+202C" "" { target *-*-* } .-1 } */
++// a b c PDI x y z
++/* { dg-warning "U\\+2069" "" { target *-*-* } .-1 } */
++// a b c PDF x y z
++/* { dg-warning "U\\+202C" "" { target *-*-* } .-1 } */
++
++void
++g1 ()
++{
++ const char *s1 = "a b c LRE 1 2 3 PDF x y z";
++/* { dg-warning "U\\+202A" "" { target *-*-* } .-1 } */
++ const char *s2 = "a b c RLE 1 2 3 PDF x y z";
++/* { dg-warning "U\\+202B" "" { target *-*-* } .-1 } */
++ const char *s3 = "a b c LRO 1 2 3 PDF x y z";
++/* { dg-warning "U\\+202D" "" { target *-*-* } .-1 } */
++ const char *s4 = "a b c RLO 1 2 3 PDF x y z";
++/* { dg-warning "U\\+202E" "" { target *-*-* } .-1 } */
++ const char *s5 = "a b c LRI 1 2 3 PDI x y z";
++/* { dg-warning "U\\+2066" "" { target *-*-* } .-1 } */
++ const char *s6 = "a b c RLI 1 2 3 PDI x y z";
++/* { dg-warning "U\\+2067" "" { target *-*-* } .-1 } */
++ const char *s7 = "a b c FSI 1 2 3 PDI x y z";
++/* { dg-warning "U\\+2068" "" { target *-*-* } .-1 } */
++ const char *s8 = "a b c PDI x y z";
++/* { dg-warning "U\\+2069" "" { target *-*-* } .-1 } */
++ const char *s9 = "a b c PDF 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 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/Wbidirectional-5.c b/gcc/testsuite/c-c++-common/Wbidirectional-5.c
+new file mode 100644
+index 00000000000..08b373a1bda
+--- /dev/null
++++ b/gcc/testsuite/c-c++-common/Wbidirectional-5.c
+@@ -0,0 +1,149 @@
++/* { dg-do compile } */
++/* { dg-options "-Wbidirectional=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 LRE 1 2 3 PDF x y z */
++/* { dg-bogus "unpaired" "" { target *-*-* } .-1 } */
++/* a b c RLE 1 2 3 PDF x y z */
++/* { dg-bogus "unpaired" "" { target *-*-* } .-1 } */
++/* a b c LRO 1 2 3 PDF x y z */
++/* { dg-bogus "unpaired" "" { target *-*-* } .-1 } */
++/* a b c RLO 1 2 3 PDF x y z */
++/* { dg-bogus "unpaired" "" { target *-*-* } .-1 } */
++/* a b c LRI 1 2 3 PDI x y z */
++/* { dg-bogus "unpaired" "" { target *-*-* } .-1 } */
++/* a b c RLI 1 2 3 PDI x y */
++/* { dg-bogus "unpaired" "" { target *-*-* } .-1 } */
++/* a b c FSI 1 2 3 PDI x y z */
++/* { dg-bogus "unpaired" "" { target *-*-* } .-1 } */
++
++/* Same but C++ comments instead. */
++// a b c LRE 1 2 3 PDF x y z
++/* { dg-bogus "unpaired" "" { target *-*-* } .-1 } */
++// a b c RLE 1 2 3 PDF x y z
++/* { dg-bogus "unpaired" "" { target *-*-* } .-1 } */
++// a b c LRO 1 2 3 PDF x y z
++/* { dg-bogus "unpaired" "" { target *-*-* } .-1 } */
++// a b c RLO 1 2 3 PDF x y z
++/* { dg-bogus "unpaired" "" { target *-*-* } .-1 } */
++// a b c LRI 1 2 3 PDI x y z
++/* { dg-bogus "unpaired" "" { target *-*-* } .-1 } */
++// a b c RLI 1 2 3 PDI x y
++/* { dg-bogus "unpaired" "" { target *-*-* } .-1 } */
++// a b c FSI 1 2 3 PDI x y z
++/* { dg-bogus "unpaired" "" { target *-*-* } .-1 } */
++
++/* Here we're closing an unopened context, warn when =any. */
++/* a b c PDI x y z */
++/* { dg-bogus "unpaired" "" { target *-*-* } .-1 } */
++/* a b c PDF x y z */
++/* { dg-bogus "unpaired" "" { target *-*-* } .-1 } */
++// a b c PDI x y z
++/* { dg-bogus "unpaired" "" { target *-*-* } .-1 } */
++// a b c PDF x y z
++/* { dg-bogus "unpaired" "" { target *-*-* } .-1 } */
++
++void
++g1 ()
++{
++ const char *s1 = "a b c LRE 1 2 3 PDF x y z";
++/* { dg-bogus "unpaired" "" { target *-*-* } .-1 } */
++ const char *s2 = "a b c RLE 1 2 3 PDF x y z";
++/* { dg-bogus "unpaired" "" { target *-*-* } .-1 } */
++ const char *s3 = "a b c LRO 1 2 3 PDF x y z";
++/* { dg-bogus "unpaired" "" { target *-*-* } .-1 } */
++ const char *s4 = "a b c RLO 1 2 3 PDF x y z";
++/* { dg-bogus "unpaired" "" { target *-*-* } .-1 } */
++ const char *s5 = "a b c LRI 1 2 3 PDI x y z";
++/* { dg-bogus "unpaired" "" { target *-*-* } .-1 } */
++ const char *s6 = "a b c RLI 1 2 3 PDI x y z";
++/* { dg-bogus "unpaired" "" { target *-*-* } .-1 } */
++ const char *s7 = "a b c FSI 1 2 3 PDI x y z";
++/* { dg-bogus "unpaired" "" { target *-*-* } .-1 } */
++ const char *s8 = "a b c PDI x y z";
++/* { dg-bogus "unpaired" "" { target *-*-* } .-1 } */
++ const char *s9 = "a b c PDF 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 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/Wbidirectional-6.c b/gcc/testsuite/c-c++-common/Wbidirectional-6.c
+new file mode 100644
+index 00000000000..c0b37c3a130
+--- /dev/null
++++ b/gcc/testsuite/c-c++-common/Wbidirectional-6.c
+@@ -0,0 +1,129 @@
++/* { dg-do compile } */
++/* { dg-options "-Wbidirectional=unpaired" } */
++/* Test nesting of bidi chars in various contexts. */
++
++/* Terminated by the wrong char: */
++/* a b c LRE 1 2 3 PDI x y z */
++/* { dg-warning "unpaired" "" { target *-*-* } .-1 } */
++/* a b c RLE 1 2 3 PDI x y z*/
++/* { dg-warning "unpaired" "" { target *-*-* } .-1 } */
++/* a b c LRO 1 2 3 PDI x y z */
++/* { dg-warning "unpaired" "" { target *-*-* } .-1 } */
++/* a b c RLO 1 2 3 PDI x y z */
++/* { dg-warning "unpaired" "" { target *-*-* } .-1 } */
++/* a b c LRI 1 2 3 PDF x y z */
++/* { dg-warning "unpaired" "" { target *-*-* } .-1 } */
++/* a b c RLI 1 2 3 PDF x y z */
++/* { dg-warning "unpaired" "" { target *-*-* } .-1 } */
++/* a b c FSI 1 2 3 PDF x y z*/
++/* { dg-warning "unpaired" "" { target *-*-* } .-1 } */
++
++/* LRE PDF */
++/* LRE LRE PDF PDF */
++/* PDF LRE PDF */
++/* LRE PDF LRE PDF */
++/* LRE LRE PDF */
++/* { dg-warning "unpaired" "" { target *-*-* } .-1 } */
++/* PDF LRE */
++/* { dg-warning "unpaired" "" { target *-*-* } .-1 } */
++
++// a b c LRE 1 2 3 PDI x y z
++/* { dg-warning "unpaired" "" { target *-*-* } .-1 } */
++// a b c RLE 1 2 3 PDI x y z*/
++/* { dg-warning "unpaired" "" { target *-*-* } .-1 } */
++// a b c LRO 1 2 3 PDI x y z
++/* { dg-warning "unpaired" "" { target *-*-* } .-1 } */
++// a b c RLO 1 2 3 PDI x y z
++/* { dg-warning "unpaired" "" { target *-*-* } .-1 } */
++// a b c LRI 1 2 3 PDF x y z
++/* { dg-warning "unpaired" "" { target *-*-* } .-1 } */
++// a b c RLI 1 2 3 PDF x y z
++/* { dg-warning "unpaired" "" { target *-*-* } .-1 } */
++// a b c FSI 1 2 3 PDF x y z
++/* { dg-warning "unpaired" "" { target *-*-* } .-1 } */
++
++// LRE PDF
++// LRE LRE PDF PDF
++// PDF LRE PDF
++// LRE PDF LRE PDF
++// LRE LRE PDF
++/* { dg-warning "unpaired" "" { target *-*-* } .-1 } */
++// PDF LRE
++/* { dg-warning "unpaired" "" { target *-*-* } .-1 } */
++
++void
++g1 ()
++{
++ const char *s1 = "a b c LRE 1 2 3 PDI 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 RLE 1 2 3 PDI 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 LRO 1 2 3 PDI 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 RLO 1 2 3 PDI 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 LRI 1 2 3 PDF 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 RLI 1 2 3 PDF 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 FSI 1 2 3 PDF 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 = "PDF LRE";
++/* { dg-warning "unpaired" "" { target *-*-* } .-1 } */
++ const char *s16 = "PDF\u202c LRE\u202a";
++/* { dg-warning "unpaired" "" { target *-*-* } .-1 } */
++ const char *s17 = "LRE PDF";
++ const char *s18 = "LRE\u202a PDF\u202c";
++ const char *s19 = "LRE LRE PDF PDF";
++ const char *s20 = "LRE\u202a LRE\u202a PDF\u202c PDF\u202c";
++ const char *s21 = "PDF LRE PDF";
++ const char *s22 = "PDF\u202c LRE\u202a PDF\u202c";
++ const char *s23 = "LRE LRE PDF";
++/* { dg-warning "unpaired" "" { target *-*-* } .-1 } */
++ const char *s24 = "LRE\u202a LRE\u202a PDF\u202c";
++/* { dg-warning "unpaired" "" { target *-*-* } .-1 } */
++ const char *s25 = "PDF LRE";
++/* { dg-warning "unpaired" "" { target *-*-* } .-1 } */
++ const char *s26 = "PDF\u202c LRE\u202a";
++/* { dg-warning "unpaired" "" { target *-*-* } .-1 } */
++ const char *s27 = "PDF LRE\u202a";
++/* { dg-warning "unpaired" "" { target *-*-* } .-1 } */
++ const char *s28 = "PDF\u202c LRE";
++/* { dg-warning "unpaired" "" { target *-*-* } .-1 } */
++}
++
++int A\u202aB\u2069C;
++/* { dg-warning "unpaired" "" { target *-*-* } .-1 } */
++int a\u202bB\u2069c;
++/* { dg-warning "unpaired" "" { target *-*-* } .-1 } */
++int a\u202db\u2069c2;
++/* { dg-warning "unpaired" "" { target *-*-* } .-1 } */
++int a\u202eb\u2069;
++/* { dg-warning "unpaired" "" { target *-*-* } .-1 } */
++int a\u2066b\u202c;
++/* { dg-warning "unpaired" "" { target *-*-* } .-1 } */
++int a\u2067b\u202c;
++/* { dg-warning "unpaired" "" { target *-*-* } .-1 } */
++int a\u2068b\u202c;
++/* { dg-warning "unpaired" "" { target *-*-* } .-1 } */
++int A\u202aB\u202c;
++int A\u202aA\u202aB\u202cB\u202c;
++int a_\u202C_\u202a_\u202c;
++int a_\u202a_\u202c_\u202a_\u202c_;
++int a_\u202a_\u202c_\u202a_;
++/* { dg-warning "unpaired" "" { target *-*-* } .-1 } */
+diff --git a/gcc/testsuite/c-c++-common/Wbidirectional-7.c b/gcc/testsuite/c-c++-common/Wbidirectional-7.c
+new file mode 100644
+index 00000000000..f0f7b3ca14a
+--- /dev/null
++++ b/gcc/testsuite/c-c++-common/Wbidirectional-7.c
+@@ -0,0 +1,8 @@
++/* { dg-do compile } */
++/* { dg-options "-Wbidirectional=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/Wbidirectional-8.c b/gcc/testsuite/c-c++-common/Wbidirectional-8.c
+new file mode 100644
+index 00000000000..c7d02193131
+--- /dev/null
++++ b/gcc/testsuite/c-c++-common/Wbidirectional-8.c
+@@ -0,0 +1,12 @@
++/* { dg-do compile } */
++/* { dg-options "-Wbidirectional=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/Wbidirectional-9.c b/gcc/testsuite/c-c++-common/Wbidirectional-9.c
+new file mode 100644
+index 00000000000..d029209babb
+--- /dev/null
++++ b/gcc/testsuite/c-c++-common/Wbidirectional-9.c
+@@ -0,0 +1,28 @@
++/* { dg-do compile } */
++/* { dg-options "-Wbidirectional=unpaired" } */
++/* Test that we properly separate bidi contexts (comment/identifier/character
++ constant/string literal). */
++
++/* LRE -><- */ int pdf_\u202c_1;
++/* { dg-warning "unpaired" "" { target *-*-* } .-1 } */
++/* RLE -><- */ int pdf_\u202c_2;
++/* { dg-warning "unpaired" "" { target *-*-* } .-1 } */
++/* LRO -><- */ int pdf_\u202c_3;
++/* { dg-warning "unpaired" "" { target *-*-* } .-1 } */
++/* RLO -><- */ int pdf_\u202c_4;
++/* { dg-warning "unpaired" "" { target *-*-* } .-1 } */
++/* LRI -><-*/ int pdi_\u2069_1;
++/* { dg-warning "unpaired" "" { target *-*-* } .-1 } */
++/* RLI -><- */ int pdi_\u2069_12;
++/* { dg-warning "unpaired" "" { target *-*-* } .-1 } */
++/* FSI -><- */ int pdi_\u2069_3;
++/* { dg-warning "unpaired" "" { target *-*-* } .-1 } */
++
++const char *s1 = "LRE\u202a"; /* PDF -><- */
++/* { dg-warning "unpaired" "" { target *-*-* } .-1 } */
++/* LRE -><- */ 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 3ad52d5e01e..cecbefd59d4 100644
+--- a/libcpp/include/cpplib.h
++++ b/libcpp/include/cpplib.h
+@@ -305,6 +305,17 @@ enum cpp_normalize_level {
+ normalized_none
+ };
+
++/* The possible bidirectional characters checking levels, from least
++ restrictive to most. */
++enum cpp_bidirectional_level {
++ /* No checking. */
++ bidirectional_none,
++ /* Only detect unpaired uses of bidirectional characters. */
++ bidirectional_unpaired,
++ /* Detect any use of bidirectional characters. */
++ bidirectional_any
++};
++
+ /* This structure is nested inside struct cpp_reader, and
+ carries all the options visible to the command line. */
+ struct cpp_options
+@@ -506,6 +517,10 @@ struct cpp_options
+ /* True if warn about differences between C++98 and C++11. */
+ bool cpp_warn_cxx11_compat;
+
++ /* Nonzero of bidirectional characters checking is on. See enum
++ cpp_bidirectional_level. */
++ unsigned char cpp_warn_bidirectional;
++
+ /* Dependency generation. */
+ struct
+ {
+@@ -1063,7 +1078,8 @@ enum {
+ CPP_W_PEDANTIC,
+ CPP_W_C90_C99_COMPAT,
+ CPP_W_CXX11_COMPAT,
+- CPP_W_EXPANSION_TO_DEFINED
++ CPP_W_EXPANSION_TO_DEFINED,
++ CPP_W_BIDIRECTIONAL
+ };
+
+ /* Output a diagnostic of some kind. */
+diff --git a/libcpp/init.c b/libcpp/init.c
+index ca3fbaa5c05..5c15da82ff8 100644
+--- a/libcpp/init.c
++++ b/libcpp/init.c
+@@ -208,6 +208,7 @@ cpp_create_reader (enum c_lang lang, cpp_hash_table *table,
+ = 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/lex.c b/libcpp/lex.c
+index a408f912c5c..3ba0a7ba818 100644
+--- a/libcpp/lex.c
++++ b/libcpp/lex.c
+@@ -1164,6 +1164,284 @@ _cpp_process_line_notes (cpp_reader *pfile, int in_comment)
+ }
+ }
+
++namespace bidi {
++ enum kind {
++ NONE, LRE, RLE, LRO, RLO, LRI, RLI, FSI, PDF, PDI
++ };
++
++ /* All the UTF-8 encodings of bidi characters start with E2. */
++ const 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 which context is currently opened. */
++ kind current_ctx ()
++ {
++ unsigned int len = vec.count ();
++ if (len == 0)
++ return NONE;
++ return (vec[len - 1] & 1) ? PDF : PDI;
++ }
++
++ /* 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 LRE:
++ case RLE:
++ case LRO:
++ case RLO:
++ vec.push (ucn_p ? 3u : 1u);
++ break;
++ case LRI:
++ case RLI:
++ case FSI:
++ vec.push (ucn_p ? 2u : 0u);
++ break;
++ case PDF:
++ if (current_ctx () == PDF)
++ pop ();
++ break;
++ case PDI:
++ if (current_ctx () == PDI)
++ pop ();
++ break;
++ [[likely]] case NONE:
++ break;
++ default:
++ abort ();
++ }
++ }
++
++ /* Return a descriptive string for K. */
++ const char *to_str (kind k)
++ {
++ switch (k)
++ {
++ case LRE:
++ return "U+202A (LEFT-TO-RIGHT EMBEDDING)";
++ case RLE:
++ return "U+202B (RIGHT-TO-LEFT EMBEDDING)";
++ case LRO:
++ return "U+202D (LEFT-TO-RIGHT OVERRIDE)";
++ case RLO:
++ return "U+202E (RIGHT-TO-LEFT OVERRIDE)";
++ case LRI:
++ return "U+2066 (LEFT-TO-RIGHT ISOLATE)";
++ case RLI:
++ return "U+2067 (RIGHT-TO-LEFT ISOLATE)";
++ case FSI:
++ return "U+2068 (FIRST STRONG ISOLATE)";
++ case PDF:
++ return "U+202C (POP DIRECTIONAL FORMATTING)";
++ case PDI:
++ return "U+2069 (POP DIRECTIONAL ISOLATE)";
++ 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::LRE;
++ case 0xab:
++ return bidi::RLE;
++ case 0xac:
++ return bidi::PDF;
++ case 0xad:
++ return bidi::LRO;
++ case 0xae:
++ return bidi::RLO;
++ default:
++ break;
++ }
++ else if (p[1] == 0x81)
++ switch (p[2])
++ {
++ case 0xa6:
++ return bidi::LRI;
++ case 0xa7:
++ return bidi::RLI;
++ case 0xa8:
++ return bidi::FSI;
++ case 0xa9:
++ return bidi::PDI;
++ default:
++ break;
++ }
++
++ return bidi::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::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::NONE;
++ else if (p[2] == '2')
++ switch (p[3])
++ {
++ case 'a':
++ case 'A':
++ return bidi::LRE;
++ case 'b':
++ case 'B':
++ return bidi::RLE;
++ case 'c':
++ case 'C':
++ return bidi::PDF;
++ case 'd':
++ case 'D':
++ return bidi::LRO;
++ case 'e':
++ case 'E':
++ return bidi::RLO;
++ default:
++ break;
++ }
++ else if (p[2] == '6')
++ switch (p[3])
++ {
++ case '6':
++ return bidi::LRI;
++ case '7':
++ return bidi::RLI;
++ case '8':
++ return bidi::FSI;
++ case '9':
++ return bidi::PDI;
++ default:
++ break;
++ }
++
++ return bidi::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 source_location 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 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::NONE, 1))
++ return;
++
++ const unsigned char warn_bidi = CPP_OPTION (pfile, cpp_warn_bidirectional);
++
++ if (warn_bidi != bidirectional_none)
++ {
++ const source_location 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::PDF || kind == bidi::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.
+@@ -1175,7 +1453,8 @@ _cpp_skip_block_comment (cpp_reader *pfile)
+ cpp_buffer *buffer = pfile->buffer;
+ const uchar *cur = buffer->cur;
+ uchar c;
+-
++ const bool warn_bidi_p = (CPP_OPTION (pfile, cpp_warn_bidirectional)
++ != bidirectional_none);
+ cur++;
+ if (*cur == '/')
+ cur++;
+@@ -1189,7 +1468,11 @@ _cpp_skip_block_comment (cpp_reader *pfile)
+ 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 +1491,8 @@ _cpp_skip_block_comment (cpp_reader *pfile)
+ {
+ 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 +1503,13 @@ _cpp_skip_block_comment (cpp_reader *pfile)
+
+ cur = buffer->cur;
+ }
++ /* If this is a beginning of a UTF-8 encoding, it might be
++ a bidirectional 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 +1525,32 @@ skip_line_comment (cpp_reader *pfile)
+ {
+ cpp_buffer *buffer = pfile->buffer;
+ source_location orig_line = pfile->line_table->highest_line;
++ const bool warn_bidi_p = (CPP_OPTION (pfile, cpp_warn_bidirectional)
++ != bidirectional_none);
+
+- 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;
+@@ -1315,11 +1630,14 @@ warn_about_normalization (cpp_reader *pfile,
+
+ /* Returns TRUE if the sequence starting at buffer->cur is invalid 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 = (CPP_OPTION (pfile, cpp_warn_bidirectional)
++ != bidirectional_none);
+
+ if (*buffer->cur == '$')
+ {
+@@ -1343,6 +1661,12 @@ forms_identifier_p (cpp_reader *pfile, int first,
+ {
+ cppchar_t s;
+ 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;
+@@ -1450,6 +1774,8 @@ lex_identifier (cpp_reader *pfile, const uchar *base, bool starts_ucn,
+ const uchar *cur;
+ unsigned int len;
+ unsigned int hash = HT_HASHSTEP (0, *base);
++ const bool warn_bidi_p = (CPP_OPTION (pfile, cpp_warn_bidirectional)
++ != bidirectional_none);
+
+ cur = pfile->buffer->cur;
+ if (! starts_ucn)
+@@ -1472,6 +1798,8 @@ lex_identifier (cpp_reader *pfile, const uchar *base, bool starts_ucn,
+ 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);
+@@ -1673,6 +2001,8 @@ lex_raw_string (cpp_reader *pfile, cpp_token *token, const uchar *base,
+ _cpp_buff *first_buff = NULL, *last_buff = NULL;
+ size_t raw_prefix_start;
+ _cpp_line_note *note = &pfile->buffer->notes[pfile->buffer->cur_note];
++ const bool warn_bidi_p = (CPP_OPTION (pfile, cpp_warn_bidirectional)
++ != bidirectional_none);
+
+ type = (*base == 'L' ? CPP_WSTRING :
+ *base == 'U' ? CPP_STRING32 :
+@@ -1909,8 +2239,16 @@ lex_raw_string (cpp_reader *pfile, cpp_token *token, const uchar *base,
+ cur = 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, cur - 1,
++ get_bidi_utf8 (cur - 1),
++ /*ucn_p=*/false);
+ }
+
++ if (warn_bidi_p)
++ maybe_warn_bidi_on_close (pfile, cur);
++
+ if (CPP_OPTION (pfile, user_literals))
+ {
+ /* If a string format macro, say from inttypes.h, is placed touching
+@@ -2005,15 +2343,28 @@ lex_string (cpp_reader *pfile, cpp_token *token, const uchar *base)
+ else
+ terminator = '>', type = CPP_HEADER_NAME;
+
++ const bool warn_bidi_p = (CPP_OPTION (pfile, cpp_warn_bidirectional)
++ != bidirectional_none);
+ 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--;
+@@ -2030,6 +2381,11 @@ lex_string (cpp_reader *pfile, cpp_token *token, const uchar *base)
+ }
+ 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)
diff --git a/SOURCES/gcc8-rh1981822.patch b/SOURCES/gcc8-rh1981822.patch
index af47325..08787bd 100644
--- a/SOURCES/gcc8-rh1981822.patch
+++ b/SOURCES/gcc8-rh1981822.patch
@@ -25,8 +25,6 @@ gcc/testsuite/ChangeLog:
2 files changed, 13 insertions(+), 9 deletions(-)
create mode 100644 gcc/testsuite/g++.dg/abi/lambda-defarg1.C
-diff --git a/gcc/cp/mangle.c b/gcc/cp/mangle.c
-index 6c111342b97..4399165ee23 100644
--- gcc/cp/mangle.c
+++ gcc/cp/mangle.c
@@ -1628,6 +1628,7 @@ write_literal_operator_name (tree identifier)
@@ -54,9 +52,6 @@ index 6c111342b97..4399165ee23 100644
write_char ('d');
write_compact_number (i - 1);
}
-diff --git a/gcc/testsuite/g++.dg/abi/lambda-defarg1.C b/gcc/testsuite/g++.dg/abi/lambda-defarg1.C
-new file mode 100644
-index 00000000000..8c538581240
--- /dev/null
+++ gcc/testsuite/g++.dg/abi/lambda-defarg1.C
@@ -0,0 +1,11 @@
diff --git a/SPECS/gcc.spec b/SPECS/gcc.spec
index d2627b3..ea4f09c 100644
--- a/SPECS/gcc.spec
+++ b/SPECS/gcc.spec
@@ -4,7 +4,7 @@
%global gcc_major 8
# Note, gcc_release must be integer, if you want to add suffixes to
# %%{release}, append them after %%{gcc_release} on Release: line.
-%global gcc_release 3
+%global gcc_release 4
%global nvptx_tools_gitrev c28050f60193b3b95a18866a96f03334e874e78f
%global nvptx_newlib_gitrev aadc8eb0ec43b7cd0dd2dfb484bae63c8b05ef24
%global _unpackaged_files_terminate_build 0
@@ -279,6 +279,7 @@ Patch18: gcc8-remove-old-demangle.patch
Patch19: gcc8-rh1960701.patch
Patch20: gcc8-pr100797.patch
Patch21: gcc8-rh1981822.patch
+Patch22: gcc8-add-Wbidirectional.patch
Patch30: gcc8-rh1668903-1.patch
Patch31: gcc8-rh1668903-2.patch
@@ -859,6 +860,7 @@ to NVidia PTX capable devices if available.
%patch19 -p0 -b .rh1960701~
%patch20 -p0 -b .pr100797~
%patch21 -p0 -b .rh1981822~
+%patch22 -p1 -b .bidi~
%patch30 -p0 -b .rh1668903-1~
%patch31 -p0 -b .rh1668903-2~
@@ -3175,6 +3177,9 @@ fi
%endif
%changelog
+* Fri Oct 29 2021 Marek Polacek <polacek@redhat.com> 8.5.0-4
+- add -Wbidirectional patch (#2008391)
+
* Tue Jul 13 2021 Marek Polacek <polacek@redhat.com> 8.5.0-3
- fix mangling of lambdas in default args (PR c++/91241, #1981822)
- add a few Provides: bundled