gdb: Fix building with latest libc++

Latest libc++[1] causes transitive include to <locale> when
<mutex> or <thread> header is included. This causes
gdb to not build[2] since <locale> defines isupper/islower etc.
functions that are explicitly macroed-out in safe-ctype.h to
prevent their use.
Use the suggestion from libc++ to include <locale> internally when
building in C++ mode to avoid build errors.
Use safe-gdb-ctype.h as the include instead of "safe-ctype.h"
to keep this isolated to gdb since rest of binutils
does not seem to use much C++.

[1]: https://reviews.llvm.org/D144331
[2]: https://issuetracker.google.com/issues/277967395

gdb/cp-name-parser.y

@@ -40,7 +40,7 @@
 #include "defs.h"
 
 #include <unistd.h>
-#include "safe-ctype.h"
+#include "gdbsupport/gdb-safe-ctype.h"
 #include "demangle.h"
 #include "cp-support.h"
 #include "c-support.h"

gdb/cp-support.c

@@ -36,7 +36,7 @@
 #include "namespace.h"
 #include <signal.h>
 #include "gdbsupport/gdb_setjmp.h"
-#include "safe-ctype.h"
+#include "gdbsupport/gdb-safe-ctype.h"
 #include "gdbsupport/selftest.h"
 #include "gdbsupport/gdb-sigmask.h"
 #include <atomic>

gdb/dictionary.c

@@ -26,7 +26,7 @@
 #include "symtab.h"
 #include "buildsym.h"
 #include "dictionary.h"
-#include "safe-ctype.h"
+#include "gdbsupport/gdb-safe-ctype.h"
 #include <unordered_map>
 #include "language.h"
 

gdb/disasm.c

@@ -27,7 +27,7 @@
 #include "gdbcmd.h"
 #include "dis-asm.h"
 #include "source.h"
-#include "safe-ctype.h"
+#include "gdbsupport/gdb-safe-ctype.h"
 #include <algorithm>
 #include "gdbsupport/gdb_optional.h"
 #include "valprint.h"

gdb/dwarf2/cooked-index.c

@@ -29,7 +29,7 @@
 #include "observable.h"
 #include "run-on-main-thread.h"
 #include <algorithm>
-#include "safe-ctype.h"
+#include "gdbsupport/gdb-safe-ctype.h"
 #include "gdbsupport/selftest.h"
 #include <chrono>
 #include <unordered_set>

gdb/mi/mi-cmd-stack.c

@@ -35,7 +35,7 @@
 #include <ctype.h>
 #include "mi-parse.h"
 #include "gdbsupport/gdb_optional.h"
-#include "safe-ctype.h"
+#include "gdbsupport/gdb-safe-ctype.h"
 #include "inferior.h"
 #include "observable.h"
 

gdb/minsyms.c

@@ -52,7 +52,7 @@
 #include "cli/cli-utils.h"
 #include "gdbsupport/symbol.h"
 #include <algorithm>
-#include "safe-ctype.h"
+#include "gdbsupport/gdb-safe-ctype.h"
 #include "gdbsupport/parallel-for.h"
 #include "inferior.h"
 

gdb/or1k-tdep.c

@@ -29,7 +29,7 @@
 #include "gdbtypes.h"
 #include "target.h"
 #include "regcache.h"
-#include "safe-ctype.h"
+#include "gdbsupport/gdb-safe-ctype.h"
 #include "reggroups.h"
 #include "arch-utils.h"
 #include "frame-unwind.h"

gdb/printcmd.c

@@ -53,7 +53,7 @@
 #include "source.h"
 #include "gdbsupport/byte-vector.h"
 #include "gdbsupport/gdb_optional.h"
-#include "safe-ctype.h"
+#include "gdbsupport/gdb-safe-ctype.h"
 #include "gdbsupport/rsp-low.h"
 
 /* Chain containing all defined memory-tag subcommands.  */

gdb/riscv-tdep.c

@@ -56,7 +56,7 @@
 #include "prologue-value.h"
 #include "arch/riscv.h"
 #include "riscv-ravenscar-thread.h"
-#include "safe-ctype.h"
+#include "gdbsupport/gdb-safe-ctype.h"
 
 /* The stack must be 16-byte aligned.  */
 #define SP_ALIGNMENT 16

gdb/tui/tui-layout.c

@@ -43,7 +43,7 @@
 #include "tui/tui-layout.h"
 #include "tui/tui-source.h"
 #include "gdb_curses.h"
-#include "safe-ctype.h"
+#include "gdbsupport/gdb-safe-ctype.h"
 
 static void extract_display_start_addr (struct gdbarch **, CORE_ADDR *);
 

gdb/tui/tui-winsource.c

@@ -28,7 +28,7 @@
 #include "source.h"
 #include "objfiles.h"
 #include "filenames.h"
-#include "safe-ctype.h"
+#include "gdbsupport/gdb-safe-ctype.h"
 
 #include "tui/tui.h"
 #include "tui/tui-data.h"

gdb/xml-support.c

@@ -22,7 +22,7 @@
 #include "xml-builtin.h"
 #include "xml-support.h"
 #include "gdbsupport/filestuff.h"
-#include "safe-ctype.h"
+#include "gdbsupport/gdb-safe-ctype.h"
 #include <vector>
 #include <string>
 

gdbsupport/common-utils.cc

@@ -20,7 +20,7 @@
 #include "common-defs.h"
 #include "common-utils.h"
 #include "host-defs.h"
-#include "safe-ctype.h"
+#include "gdbsupport/gdb-safe-ctype.h"
 #include "gdbsupport/gdb-xfree.h"
 
 void *

gdbsupport/gdb-safe-ctype.h

@@ -23,7 +23,9 @@
 /* After safe-ctype.h is included, we can no longer use the host's
    ctype routines.  Trying to do so results in compile errors.  Code
    that uses safe-ctype.h that wants to refer to the locale-dependent
-   ctype functions must call these wrapper versions instead.  */
+   ctype functions must call these wrapper versions instead.
+   When compiling in C++ mode, also include <locale> before "safe-ctype.h"
+   which also defines is* functions.  */
 
 static inline int
 gdb_isprint (int ch)
@@ -41,6 +43,7 @@ gdb_isprint (int ch)
 #undef ISUPPER
 #undef ISXDIGIT
 
+#include <locale>
 #include "safe-ctype.h"
 
 #endif