diff --git a/gdb/aarch64-linux-tdep.c b/gdb/aarch64-linux-tdep.c
index 76bde85188b..048be4f3532 100644
--- a/gdb/aarch64-linux-tdep.c
+++ b/gdb/aarch64-linux-tdep.c
@@ -47,7 +47,6 @@
 #include "parser-defs.h"
 #include "user-regs.h"
 #include "xml-syscall.h"
-#include <ctype.h>
 
 #include "record-full.h"
 #include "linux-record.h"
@@ -1749,9 +1748,9 @@ aarch64_linux_core_read_description (struct gdbarch *gdbarch,
 static int
 aarch64_stap_is_single_operand (struct gdbarch *gdbarch, const char *s)
 {
-  return (*s == '#' || isdigit (*s) /* Literal number.  */
+  return (*s == '#' || c_isdigit (*s) /* Literal number.  */
 	  || *s == '[' /* Register indirection.  */
-	  || isalpha (*s)); /* Register value.  */
+	  || c_isalpha (*s)); /* Register value.  */
 }
 
 /* This routine is used to parse a special token in AArch64's assembly.
@@ -1782,7 +1781,7 @@ aarch64_stap_parse_special_token (struct gdbarch *gdbarch,
       start = tmp;
 
       /* Register name.  */
-      while (isalnum (*tmp))
+      while (c_isalnum (*tmp))
 	++tmp;
 
       if (*tmp != ',')
@@ -1810,7 +1809,7 @@ aarch64_stap_parse_special_token (struct gdbarch *gdbarch,
       else if (*tmp == '+')
 	++tmp;
 
-      if (!isdigit (*tmp))
+      if (!c_isdigit (*tmp))
 	return {};
 
       displacement = strtol (tmp, &endp, 10);
diff --git a/gdb/ada-exp.y b/gdb/ada-exp.y
index 7ac103de61c..ed5694e2f1f 100644
--- a/gdb/ada-exp.y
+++ b/gdb/ada-exp.y
@@ -35,7 +35,6 @@
 
 %{
 
-#include <ctype.h>
 #include "gdbsupport/unordered_map.h"
 #include "expression.h"
 #include "value.h"
@@ -1380,7 +1379,7 @@ write_object_renaming (struct parser_state *par_state,
 	[[fallthrough]];
       case 'S':
 	renaming_expr += 1;
-	if (isdigit (*renaming_expr))
+	if (c_isdigit (*renaming_expr))
 	  {
 	    char *next;
 	    long val = strtol (renaming_expr, &next, 10);
@@ -1888,7 +1887,7 @@ ada_parse_state::find_completion_bounds ()
   const char *end = pstate->lexptr;
   /* First the end of the prefix.  Here we stop at the token start or
      at '.' or space.  */
-  for (; end > m_original_expr && end[-1] != '.' && !isspace (end[-1]); --end)
+  for (; end > m_original_expr && end[-1] != '.' && !c_isspace (end[-1]); --end)
     {
       /* Nothing.  */
     }
diff --git a/gdb/ada-lang.c b/gdb/ada-lang.c
index b7039fdddfe..b403c5a366e 100644
--- a/gdb/ada-lang.c
+++ b/gdb/ada-lang.c
@@ -18,7 +18,6 @@
    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
 
 
-#include <ctype.h>
 #include "event-top.h"
 #include "exceptions.h"
 #include "extract-store-integer.h"
@@ -875,7 +874,7 @@ is_compiler_suffix (const char *str)
 {
   gdb_assert (*str == '[');
   ++str;
-  while (*str != '\0' && isalpha (*str))
+  while (*str != '\0' && c_isalpha (*str))
     ++str;
   /* We accept a missing "]" in order to support completion.  */
   return *str == '\0' || (str[0] == ']' && str[1] == '\0');
@@ -1167,7 +1166,7 @@ ada_encode (const char *decoded, bool fold)
 static int
 is_lower_alphanum (const char c)
 {
-  return (isdigit (c) || (isalpha (c) && islower (c)));
+  return (c_isdigit (c) || (c_isalpha (c) && c_islower (c)));
 }
 
 /* ENCODED is the linkage name of a symbol and LEN contains its length.
@@ -1185,11 +1184,11 @@ is_lower_alphanum (const char c)
 static void
 ada_remove_trailing_digits (const char *encoded, int *len)
 {
-  if (*len > 1 && isdigit (encoded[*len - 1]))
+  if (*len > 1 && c_isdigit (encoded[*len - 1]))
     {
       int i = *len - 2;
 
-      while (i > 0 && isdigit (encoded[i]))
+      while (i > 0 && c_isdigit (encoded[i]))
 	i--;
       if (i >= 0 && encoded[i] == '.')
 	*len = i;
@@ -1220,7 +1219,7 @@ ada_remove_po_subprogram_suffix (const char *encoded, int *len)
 
   if (*len > 1
       && encoded[*len - 1] == 'N'
-      && (isdigit (encoded[*len - 2]) || islower (encoded[*len - 2])))
+      && (c_isdigit (encoded[*len - 2]) || c_islower (encoded[*len - 2])))
     *len = *len - 1;
 }
 
@@ -1232,7 +1231,7 @@ static int
 remove_compiler_suffix (const char *encoded, int *len)
 {
   int offset = *len - 1;
-  while (offset > 0 && isalpha (encoded[offset]))
+  while (offset > 0 && c_isalpha (encoded[offset]))
     --offset;
   if (offset > 0 && encoded[offset] == '.')
     {
@@ -1252,7 +1251,7 @@ convert_hex (const char *str, int n, uint32_t *out)
 
   for (int i = 0; i < n; ++i)
     {
-      if (!isxdigit (str[i]))
+      if (!c_isxdigit (str[i]))
 	return false;
       result <<= 4;
       result |= fromhex (str[i]);
@@ -1384,11 +1383,11 @@ ada_decode (const char *encoded, bool wrap, bool operators, bool wide)
 
   /* Remove trailing __{digit}+ or trailing ${digit}+.  */
 
-  if (len0 > 1 && isdigit (encoded[len0 - 1]))
+  if (len0 > 1 && c_isdigit (encoded[len0 - 1]))
     {
       i = len0 - 2;
-      while ((i >= 0 && isdigit (encoded[i]))
-	     || (i >= 1 && encoded[i] == '_' && isdigit (encoded[i - 1])))
+      while ((i >= 0 && c_isdigit (encoded[i]))
+	     || (i >= 1 && encoded[i] == '_' && c_isdigit (encoded[i - 1])))
 	i -= 1;
       if (i > 1 && encoded[i] == '_' && encoded[i - 1] == '_')
 	len0 = i - 1;
@@ -1399,7 +1398,7 @@ ada_decode (const char *encoded, bool wrap, bool operators, bool wide)
   /* The first few characters that are not alphabetic are not part
      of any encoding we use, so we can copy them over verbatim.  */
 
-  for (i = 0; i < len0 && !isalpha (encoded[i]); i += 1)
+  for (i = 0; i < len0 && !c_isalpha (encoded[i]); i += 1)
     decoded.push_back (encoded[i]);
 
   at_start_name = 1;
@@ -1415,7 +1414,7 @@ ada_decode (const char *encoded, bool wrap, bool operators, bool wide)
 	      int op_len = strlen (ada_opname_table[k].encoded);
 	      if ((strncmp (ada_opname_table[k].encoded + 1, encoded + i + 1,
 			    op_len - 1) == 0)
-		  && !isalnum (encoded[i + op_len]))
+		  && !c_isalnum (encoded[i + op_len]))
 		{
 		  decoded.append (ada_opname_table[k].decoded);
 		  at_start_name = 0;
@@ -1440,11 +1439,11 @@ ada_decode (const char *encoded, bool wrap, bool operators, bool wide)
 
       if (len0 - i > 5 && encoded [i] == '_' && encoded [i+1] == '_'
 	  && encoded [i+2] == 'B' && encoded [i+3] == '_'
-	  && isdigit (encoded [i+4]))
+	  && c_isdigit (encoded [i+4]))
 	{
 	  int k = i + 5;
 	  
-	  while (k < len0 && isdigit (encoded[k]))
+	  while (k < len0 && c_isdigit (encoded[k]))
 	    k++;  /* Skip any extra digit.  */
 
 	  /* Double-check that the "__B_{DIGITS}+" sequence we found
@@ -1467,11 +1466,11 @@ ada_decode (const char *encoded, bool wrap, bool operators, bool wide)
 	 internally generated.  */
 
       if (len0 - i > 3 && encoded [i] == '_' && encoded[i+1] == 'E'
-	  && isdigit (encoded[i+2]))
+	  && c_isdigit (encoded[i+2]))
 	{
 	  int k = i + 3;
 
-	  while (k < len0 && isdigit (encoded[k]))
+	  while (k < len0 && c_isdigit (encoded[k]))
 	    k++;
 
 	  if (k < len0
@@ -1505,7 +1504,7 @@ ada_decode (const char *encoded, bool wrap, bool operators, bool wide)
 	    i++;
 	}
 
-      if (wide && i < len0 + 3 && encoded[i] == 'U' && isxdigit (encoded[i + 1]))
+      if (wide && i < len0 + 3 && encoded[i] == 'U' && c_isxdigit (encoded[i + 1]))
 	{
 	  if (convert_from_hex_encoded (decoded, &encoded[i + 1], 2))
 	    {
@@ -1513,7 +1512,7 @@ ada_decode (const char *encoded, bool wrap, bool operators, bool wide)
 	      continue;
 	    }
 	}
-      else if (wide && i < len0 + 5 && encoded[i] == 'W' && isxdigit (encoded[i + 1]))
+      else if (wide && i < len0 + 5 && encoded[i] == 'W' && c_isxdigit (encoded[i + 1]))
 	{
 	  if (convert_from_hex_encoded (decoded, &encoded[i + 1], 4))
 	    {
@@ -1522,7 +1521,7 @@ ada_decode (const char *encoded, bool wrap, bool operators, bool wide)
 	    }
 	}
       else if (wide && i < len0 + 10 && encoded[i] == 'W' && encoded[i + 1] == 'W'
-	       && isxdigit (encoded[i + 2]))
+	       && c_isxdigit (encoded[i + 2]))
 	{
 	  if (convert_from_hex_encoded (decoded, &encoded[i + 2], 8))
 	    {
@@ -1531,7 +1530,7 @@ ada_decode (const char *encoded, bool wrap, bool operators, bool wide)
 	    }
 	}
 
-      if (encoded[i] == 'X' && i != 0 && isalnum (encoded[i - 1]))
+      if (encoded[i] == 'X' && i != 0 && c_isalnum (encoded[i - 1]))
 	{
 	  /* This is a X[bn]* sequence not separated from the previous
 	     part of the name with a non-alpha-numeric character (in other
@@ -1568,7 +1567,7 @@ ada_decode (const char *encoded, bool wrap, bool operators, bool wide)
   if (operators)
     {
       for (i = 0; i < decoded.length(); ++i)
-	if (isupper (decoded[i]) || decoded[i] == ' ')
+	if (c_isupper (decoded[i]) || decoded[i] == ' ')
 	  goto Suppress;
     }
 
@@ -5729,10 +5728,10 @@ is_name_suffix (const char *str)
 
   /* Skip optional leading __[0-9]+.  */
 
-  if (len > 3 && str[0] == '_' && str[1] == '_' && isdigit (str[2]))
+  if (len > 3 && str[0] == '_' && str[1] == '_' && c_isdigit (str[2]))
     {
       str += 3;
-      while (isdigit (str[0]))
+      while (c_isdigit (str[0]))
 	str += 1;
     }
   
@@ -5741,7 +5740,7 @@ is_name_suffix (const char *str)
   if (str[0] == '.' || str[0] == '$')
     {
       matching = str + 1;
-      while (isdigit (matching[0]))
+      while (c_isdigit (matching[0]))
 	matching += 1;
       if (matching[0] == '\0')
 	return 1;
@@ -5752,7 +5751,7 @@ is_name_suffix (const char *str)
   if (len > 3 && str[0] == '_' && str[1] == '_' && str[2] == '_')
     {
       matching = str + 3;
-      while (isdigit (matching[0]))
+      while (c_isdigit (matching[0]))
 	matching += 1;
       if (matching[0] == '\0')
 	return 1;
@@ -5781,10 +5780,10 @@ is_name_suffix (const char *str)
 #endif
 
   /* _E[0-9]+[bs]$ */
-  if (len > 3 && str[0] == '_' && str [1] == 'E' && isdigit (str[2]))
+  if (len > 3 && str[0] == '_' && str [1] == 'E' && c_isdigit (str[2]))
     {
       matching = str + 3;
-      while (isdigit (matching[0]))
+      while (c_isdigit (matching[0]))
 	matching += 1;
       if ((matching[0] == 'b' || matching[0] == 's')
 	  && matching [1] == '\0')
@@ -5834,17 +5833,17 @@ is_name_suffix (const char *str)
 	    return 1;
 	  return 0;
 	}
-      if (!isdigit (str[2]))
+      if (!c_isdigit (str[2]))
 	return 0;
       for (k = 3; str[k] != '\0'; k += 1)
-	if (!isdigit (str[k]) && str[k] != '_')
+	if (!c_isdigit (str[k]) && str[k] != '_')
 	  return 0;
       return 1;
     }
-  if (str[0] == '$' && isdigit (str[1]))
+  if (str[0] == '$' && c_isdigit (str[1]))
     {
       for (k = 2; str[k] != '\0'; k += 1)
-	if (!isdigit (str[k]) && str[k] != '_')
+	if (!c_isdigit (str[k]) && str[k] != '_')
 	  return 0;
       return 1;
     }
@@ -5867,7 +5866,7 @@ is_valid_name_for_wild_match (const char *name0)
     return 0;
 
   for (i=0; decoded_name[i] != '\0'; i++)
-    if (isalpha (decoded_name[i]) && !islower (decoded_name[i]))
+    if (c_isalpha (decoded_name[i]) && !c_islower (decoded_name[i]))
       return 0;
 
   return 1;
@@ -6091,7 +6090,7 @@ ada_lookup_name_info::matches
 	 angle bracket notation.  */
       const char *tmp;
 
-      for (tmp = sym_name; *tmp != '\0' && !isupper (*tmp); tmp++);
+      for (tmp = sym_name; *tmp != '\0' && !c_isupper (*tmp); tmp++);
       if (*tmp != '\0')
 	match = false;
     }
@@ -6206,7 +6205,7 @@ ada_is_ignored_field (struct type *type, int field_num)
       {
 	/* Wrapper field.  */
       }
-    else if (isupper (name[0]))
+    else if (c_isupper (name[0]))
       return 1;
   }
 
@@ -6717,14 +6716,14 @@ ada_scan_number (const char str[], int k, LONGEST * R, int *new_k)
 {
   ULONGEST RU;
 
-  if (!isdigit (str[k]))
+  if (!c_isdigit (str[k]))
     return 0;
 
   /* Do it the hard way so as not to make any assumption about
      the relationship of unsigned long (%lu scan format code) and
      LONGEST.  */
   RU = 0;
-  while (isdigit (str[k]))
+  while (c_isdigit (str[k]))
     {
       RU = RU * 10 + (str[k] - '0');
       k += 1;
@@ -7380,10 +7379,10 @@ field_alignment (struct type *type, int f)
 
   len = strlen (name);
 
-  if (!isdigit (name[len - 1]))
+  if (!c_isdigit (name[len - 1]))
     return 1;
 
-  if (isdigit (name[len - 2]))
+  if (c_isdigit (name[len - 2]))
     align_offset = len - 2;
   else
     align_offset = len - 1;
@@ -8964,7 +8963,7 @@ ada_unqualify_enum_name (const char *name)
     {
       while ((tmp = strstr (name, "__")) != NULL)
 	{
-	  if (isdigit (tmp[2]))
+	  if (c_isdigit (tmp[2]))
 	    break;
 	  else
 	    name = tmp + 2;
@@ -9007,7 +9006,7 @@ ada_enum_name (const char *name)
       else
 	return name;
 
-      if (isascii (v) && isprint (v))
+      if (c_isascii (v) && c_isprint (v))
 	storage = string_printf ("'%c'", v);
       else if (name[1] == 'U')
 	storage = string_printf ("'[\"%02x\"]'", v);
@@ -12556,7 +12555,7 @@ catch_ada_exception_command_split (const char *args,
 
   args = skip_spaces (args);
   if (startswith (args, "if")
-      && (isspace (args[2]) || args[2] == '\0'))
+      && (c_isspace (args[2]) || args[2] == '\0'))
     {
       args += 2;
       args = skip_spaces (args);
@@ -12833,7 +12832,7 @@ catch_ada_assert_command_split (const char *args, std::string &cond_string)
 
   /* Check whether a condition was provided.  */
   if (startswith (args, "if")
-      && (isspace (args[2]) || args[2] == '\0'))
+      && (c_isspace (args[2]) || args[2] == '\0'))
     {
       args += 2;
       args = skip_spaces (args);
@@ -13237,7 +13236,7 @@ do_full_match (const char *symbol_search_name,
 	      && symbol_search_name[1] == '_')
 	    {
 	      symbol_search_name += 2;
-	      while (isdigit (*symbol_search_name))
+	      while (c_isdigit (*symbol_search_name))
 		++symbol_search_name;
 	      if (symbol_search_name[0] == '_'
 		  && symbol_search_name[1] == '_')
diff --git a/gdb/ada-lex.l b/gdb/ada-lex.l
index 0cfa0c8c551..eec80cfb207 100644
--- a/gdb/ada-lex.l
+++ b/gdb/ada-lex.l
@@ -335,7 +335,6 @@ false		{ return FALSEKEYWORD; }
 .		{ error (_("Invalid character '%s' in expression."), yytext); }
 %%
 
-#include <ctype.h>
 /* Initialize the lexer for processing new expression. */
 
 static void
@@ -355,7 +354,7 @@ canonicalizeNumeral (char *s1, const char *s2)
     {
       if (*s2 != '_')
 	{
-	  *s1 = tolower(*s2);
+	  *s1 = c_tolower(*s2);
 	  s1 += 1;
 	}
     }
@@ -411,7 +410,7 @@ processInt (struct parser_state *par_state, const char *base0,
     exp = strtol(exp0, (char **) NULL, 10);
 
   gdb_mpz result;
-  while (isxdigit (*num0))
+  while (c_isxdigit (*num0))
     {
       int dig = fromhex (*num0);
       if (dig >= base)
@@ -527,7 +526,7 @@ processId (const char *name0, int len)
   struct stoken result;
 
   result.ptr = name;
-  while (len > 0 && isspace (name0[len-1]))
+  while (len > 0 && c_isspace (name0[len-1]))
     len -= 1;
 
   if (name0[0] == '<' || strstr (name0, "___") != NULL)
@@ -549,12 +548,12 @@ processId (const char *name0, int len)
 	}
       else if (in_quotes)
 	name[i++] = name0[i0++];
-      else if (isalnum (name0[i0]))
+      else if (c_isalnum (name0[i0]))
 	{
-	  name[i] = tolower (name0[i0]);
+	  name[i] = c_tolower (name0[i0]);
 	  i += 1; i0 += 1;
 	}
-      else if (isspace (name0[i0]))
+      else if (c_isspace (name0[i0]))
 	i0 += 1;
       else if (name0[i0] == '\'')
 	{
@@ -634,10 +633,10 @@ find_dot_all (const char *str)
 
 	do
 	  i += 1;
-	while (isspace (str[i]));
+	while (c_isspace (str[i]));
 
 	if (strncasecmp (str + i, "all", 3) == 0
-	    && !isalnum (str[i + 3]) && str[i + 3] != '_')
+	    && !c_isalnum (str[i + 3]) && str[i + 3] != '_')
 	  return i0;
       }
   return -1;
@@ -653,7 +652,7 @@ subseqMatch (const char *subseq, const char *str)
     return 1;
   else if (str[0] == '\0')
     return 0;
-  else if (tolower (subseq[0]) == tolower (str[0]))
+  else if (c_tolower (subseq[0]) == c_tolower (str[0]))
     return subseqMatch (subseq+1, str+1) || subseqMatch (subseq, str+1);
   else
     return subseqMatch (subseq, str+1);
@@ -690,7 +689,7 @@ processAttribute (const char *str)
 {
   gdb_assert (*str == '\'');
   ++str;
-  while (isspace (*str))
+  while (c_isspace (*str))
     ++str;
 
   int len = strlen (str);
@@ -749,7 +748,7 @@ static void
 rewind_to_char (int ch)
 {
   pstate->lexptr -= yyleng;
-  while (toupper (*pstate->lexptr) != toupper (ch))
+  while (c_toupper (*pstate->lexptr) != c_toupper (ch))
     pstate->lexptr -= 1;
   yyrestart (NULL);
 }
diff --git a/gdb/ada-typeprint.c b/gdb/ada-typeprint.c
index defd828934e..5829a9b4ef3 100644
--- a/gdb/ada-typeprint.c
+++ b/gdb/ada-typeprint.c
@@ -23,7 +23,6 @@
 #include "cli/cli-style.h"
 #include "typeprint.h"
 #include "ada-lang.h"
-#include <ctype.h>
 
 static int print_selected_record_field_types (struct type *, struct type *,
 					      int, int,
@@ -70,7 +69,7 @@ decoded_type_name (struct type *type)
       if (s == name_buffer)
 	return name_buffer;
 
-      if (!islower (s[1]))
+      if (!c_islower (s[1]))
 	return NULL;
 
       for (s = q = name_buffer; *s != '\0'; q += 1)
diff --git a/gdb/ada-valprint.c b/gdb/ada-valprint.c
index 7c6826e49e2..c198fa519f8 100644
--- a/gdb/ada-valprint.c
+++ b/gdb/ada-valprint.c
@@ -17,7 +17,6 @@
    You should have received a copy of the GNU General Public License
    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
 
-#include <ctype.h>
 #include "event-top.h"
 #include "extract-store-integer.h"
 #include "gdbtypes.h"
@@ -265,10 +264,10 @@ ada_emit_char (int c, struct type *type, struct ui_file *stream,
   /* If this character fits in the normal ASCII range, and is
      a printable character, then print the character as if it was
      an ASCII character, even if this is a wide character.
-     The UCHAR_MAX check is necessary because the isascii function
+     The UCHAR_MAX check is necessary because the c_isascii function
      requires that its argument have a value of an unsigned char,
      or EOF (EOF is obviously not printable).  */
-  if (c <= UCHAR_MAX && isascii (c) && isprint (c))
+  if (c <= UCHAR_MAX && c_isascii (c) && c_isprint (c))
     {
       if (c == quoter && c == '"')
 	gdb_printf (stream, "\"\"");
diff --git a/gdb/arm-linux-tdep.c b/gdb/arm-linux-tdep.c
index cc10679a51c..ff20ed88d46 100644
--- a/gdb/arm-linux-tdep.c
+++ b/gdb/arm-linux-tdep.c
@@ -56,7 +56,6 @@
 #include "stap-probe.h"
 #include "parser-defs.h"
 #include "user-regs.h"
-#include <ctype.h>
 #include "elf/common.h"
 
 /* Under ARM GNU/Linux the traditional way of performing a breakpoint
@@ -1167,10 +1166,10 @@ arm_linux_displaced_step_copy_insn (struct gdbarch *gdbarch,
 static int
 arm_stap_is_single_operand (struct gdbarch *gdbarch, const char *s)
 {
-  return (*s == '#' || *s == '$' || isdigit (*s) /* Literal number.  */
+  return (*s == '#' || *s == '$' || c_isdigit (*s) /* Literal number.  */
 	  || *s == '[' /* Register indirection or
 			  displacement.  */
-	  || isalpha (*s)); /* Register value.  */
+	  || c_isalpha (*s)); /* Register value.  */
 }
 
 /* This routine is used to parse a special token in ARM's assembly.
@@ -1202,7 +1201,7 @@ arm_stap_parse_special_token (struct gdbarch *gdbarch,
       start = tmp;
 
       /* Register name.  */
-      while (isalnum (*tmp))
+      while (c_isalnum (*tmp))
 	++tmp;
 
       if (*tmp != ',')
@@ -1212,7 +1211,7 @@ arm_stap_parse_special_token (struct gdbarch *gdbarch,
       regname = (char *) alloca (len + 2);
 
       offset = 0;
-      if (isdigit (*start))
+      if (c_isdigit (*start))
 	{
 	  /* If we are dealing with a register whose name begins with a
 	     digit, it means we should prefix the name with the letter
diff --git a/gdb/arm-tdep.c b/gdb/arm-tdep.c
index a4bc0bd3e3d..940d05f75e6 100644
--- a/gdb/arm-tdep.c
+++ b/gdb/arm-tdep.c
@@ -18,7 +18,6 @@
    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
 
 
-#include <ctype.h>
 
 #include "extract-store-integer.h"
 #include "frame.h"
diff --git a/gdb/auto-load.c b/gdb/auto-load.c
index 114a7d56448..8817bd12cb0 100644
--- a/gdb/auto-load.c
+++ b/gdb/auto-load.c
@@ -17,7 +17,6 @@
    You should have received a copy of the GNU General Public License
    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
 
-#include <ctype.h>
 #include "auto-load.h"
 #include "gdbsupport/gdb_vecs.h"
 #include "progspace.h"
@@ -1045,7 +1044,7 @@ execute_script_contents (struct auto_load_pspace_info *pspace_info,
       buf = name_holder.c_str ();
       for (p = buf; *p != '\0'; ++p)
 	{
-	  if (isspace (*p))
+	  if (c_isspace (*p))
 	    break;
 	}
       /* We don't allow nameless scripts, they're not helpful to the user.  */
diff --git a/gdb/break-catch-exec.c b/gdb/break-catch-exec.c
index 570018c53e3..9bfdb442f44 100644
--- a/gdb/break-catch-exec.c
+++ b/gdb/break-catch-exec.c
@@ -164,7 +164,7 @@ ep_parse_optional_if_clause (const char **arg)
 {
   const char *cond_string;
 
-  if (((*arg)[0] != 'i') || ((*arg)[1] != 'f') || !isspace ((*arg)[2]))
+  if (((*arg)[0] != 'i') || ((*arg)[1] != 'f') || !c_isspace ((*arg)[2]))
     return NULL;
 
   /* Skip the "if" keyword.  */
@@ -204,7 +204,7 @@ catch_exec_command_1 (const char *arg, int from_tty,
      First, check if there's an if clause.  */
   cond_string = ep_parse_optional_if_clause (&arg);
 
-  if ((*arg != '\0') && !isspace (*arg))
+  if ((*arg != '\0') && !c_isspace (*arg))
     error (_("Junk at end of arguments."));
 
   std::unique_ptr<exec_catchpoint> c
diff --git a/gdb/break-catch-fork.c b/gdb/break-catch-fork.c
index c8a63301f2b..535040c90f7 100644
--- a/gdb/break-catch-fork.c
+++ b/gdb/break-catch-fork.c
@@ -221,7 +221,7 @@ catch_fork_command_1 (const char *arg, int from_tty,
      First, check if there's an if clause.  */
   cond_string = ep_parse_optional_if_clause (&arg);
 
-  if ((*arg != '\0') && !isspace (*arg))
+  if ((*arg != '\0') && !c_isspace (*arg))
     error (_("Junk at end of arguments."));
 
   /* If this target supports it, create a fork or vfork catchpoint
diff --git a/gdb/break-catch-syscall.c b/gdb/break-catch-syscall.c
index 96f22a173fc..fad76e718d0 100644
--- a/gdb/break-catch-syscall.c
+++ b/gdb/break-catch-syscall.c
@@ -17,7 +17,6 @@
    You should have received a copy of the GNU General Public License
    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
 
-#include <ctype.h>
 #include "breakpoint.h"
 #include "inferior.h"
 #include "cli/cli-utils.h"
@@ -369,7 +368,7 @@ catch_syscall_split_args (const char *arg)
       /* Skip whitespace.  */
       arg = skip_spaces (arg);
 
-      for (i = 0; i < 127 && arg[i] && !isspace (arg[i]); ++i)
+      for (i = 0; i < 127 && arg[i] && !c_isspace (arg[i]); ++i)
 	cur_name[i] = arg[i];
       cur_name[i] = '\0';
       arg += i;
diff --git a/gdb/break-catch-throw.c b/gdb/break-catch-throw.c
index 6da38ebfd70..1a45d7c7498 100644
--- a/gdb/break-catch-throw.c
+++ b/gdb/break-catch-throw.c
@@ -18,7 +18,6 @@
    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
 
 #include "arch-utils.h"
-#include <ctype.h>
 #include "breakpoint.h"
 #include "exceptions.h"
 #include "inferior.h"
@@ -420,7 +419,7 @@ catch_exception_event (enum exception_event_kind ex_event,
 
   cond_string = ep_parse_optional_if_clause (&arg);
 
-  if ((*arg != '\0') && !isspace (*arg))
+  if ((*arg != '\0') && !c_isspace (*arg))
     error (_("Junk at end of arguments."));
 
   if (ex_event != EX_EVENT_THROW
diff --git a/gdb/break-cond-parse.c b/gdb/break-cond-parse.c
index 31b534371f1..b7713446e56 100644
--- a/gdb/break-cond-parse.c
+++ b/gdb/break-cond-parse.c
@@ -66,12 +66,12 @@ find_next_token (const char **curr, parse_direction direction)
     {
       gdb_assert (direction == parse_direction::backward);
 
-      while (isspace (**curr))
+      while (c_isspace (**curr))
 	--(*curr);
 
       tok_end = *curr;
 
-      while (!isspace (**curr))
+      while (!c_isspace (**curr))
 	--(*curr);
 
       tok_start = (*curr) + 1;
diff --git a/gdb/breakpoint.c b/gdb/breakpoint.c
index 460934299a8..5d87fb94aea 100644
--- a/gdb/breakpoint.c
+++ b/gdb/breakpoint.c
@@ -18,7 +18,6 @@
    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
 
 #include "arch-utils.h"
-#include <ctype.h>
 #include "event-top.h"
 #include "exceptions.h"
 #include "gdbsupport/gdb_vecs.h"
@@ -1288,7 +1287,7 @@ condition_completer (struct cmd_list_element *cmd,
 	{
 	  tracker.advance_custom_word_point_by (1);
 	  /* We don't support completion of history indices.  */
-	  if (!isdigit (text[1]))
+	  if (!c_isdigit (text[1]))
 	    complete_internalvar (tracker, &text[1]);
 	  return;
 	}
@@ -10465,7 +10464,7 @@ watch_command_1 (const char *arg, int accessflag, int from_tty,
       int len;
 
       len = exp_end - exp_start;
-      while (len > 0 && isspace (exp_start[len - 1]))
+      while (len > 0 && c_isspace (exp_start[len - 1]))
 	len--;
       error (_("Cannot watch constant value `%.*s'."), len, exp_start);
     }
@@ -14111,7 +14110,7 @@ strace_command (const char *arg, int from_tty)
 
   /* Decide if we are dealing with a static tracepoint marker (`-m'),
      or with a normal static tracepoint.  */
-  if (arg && startswith (arg, "-m") && isspace (arg[2]))
+  if (arg && startswith (arg, "-m") && c_isspace (arg[2]))
     {
       ops = &strace_marker_breakpoint_ops;
       locspec = new_linespec_location_spec (&arg,
diff --git a/gdb/btrace.c b/gdb/btrace.c
index b23de887abe..3d43261280f 100644
--- a/gdb/btrace.c
+++ b/gdb/btrace.c
@@ -39,7 +39,6 @@
 #include "record-btrace.h"
 
 #include <inttypes.h>
-#include <ctype.h>
 #include <algorithm>
 #include <string>
 
@@ -3258,7 +3257,7 @@ get_uint (const char **arg)
   begin = *arg;
   pos = skip_spaces (begin);
 
-  if (!isdigit (*pos))
+  if (!c_isdigit (*pos))
     error (_("Expected positive number, got: %s."), pos);
 
   number = strtoul (pos, &end, 10);
@@ -3277,7 +3276,7 @@ get_context_size (const char **arg)
 {
   const char *pos = skip_spaces (*arg);
 
-  if (!isdigit (*pos))
+  if (!c_isdigit (*pos))
     error (_("Expected positive number, got: %s."), pos);
 
   char *end;
diff --git a/gdb/c-exp.y b/gdb/c-exp.y
index cd5dc268a4c..98be2da7234 100644
--- a/gdb/c-exp.y
+++ b/gdb/c-exp.y
@@ -35,7 +35,6 @@
 
 %{
 
-#include <ctype.h>
 #include "expression.h"
 #include "value.h"
 #include "parser-defs.h"
diff --git a/gdb/c-lang.c b/gdb/c-lang.c
index 7fff11a76f7..e8e66a6e19f 100644
--- a/gdb/c-lang.c
+++ b/gdb/c-lang.c
@@ -33,7 +33,6 @@
 #include "cp-abi.h"
 #include "cp-support.h"
 #include "gdbsupport/gdb_obstack.h"
-#include <ctype.h>
 #include "gdbcore.h"
 #include "gdbarch.h"
 #include "c-exp.h"
diff --git a/gdb/charset.c b/gdb/charset.c
index 259362563b2..fe725efcfd1 100644
--- a/gdb/charset.c
+++ b/gdb/charset.c
@@ -24,7 +24,6 @@
 #include "charset-list.h"
 #include "gdbsupport/environ.h"
 #include "arch-utils.h"
-#include <ctype.h>
 
 #ifdef USE_WIN32API
 #include <windows.h>
diff --git a/gdb/cli/cli-cmds.c b/gdb/cli/cli-cmds.c
index a15a04a27fd..d3536547c33 100644
--- a/gdb/cli/cli-cmds.c
+++ b/gdb/cli/cli-cmds.c
@@ -301,8 +301,8 @@ with_command_completer_1 (const char *set_cmd_prefix,
      command as if it was a "set" command.  */
   if (delim == text
       || delim == nullptr
-      || !isspace (delim[-1])
-      || !(isspace (delim[2]) || delim[2] == '\0'))
+      || !c_isspace (delim[-1])
+      || !(c_isspace (delim[2]) || delim[2] == '\0'))
     {
       std::string new_text = std::string (set_cmd_prefix) + text;
       tracker.advance_custom_word_point_by (-(int) strlen (set_cmd_prefix));
@@ -785,14 +785,14 @@ source_command (const char *args, int from_tty)
 	  if (args[0] != '-')
 	    break;
 
-	  if (args[1] == 'v' && isspace (args[2]))
+	  if (args[1] == 'v' && c_isspace (args[2]))
 	    {
 	      source_verbose = 1;
 
 	      /* Skip passed -v.  */
 	      args = &args[3];
 	    }
-	  else if (args[1] == 's' && isspace (args[2]))
+	  else if (args[1] == 's' && c_isspace (args[2]))
 	    {
 	      search_path = 1;
 
@@ -1184,7 +1184,7 @@ pipe_command_completer (struct cmd_list_element *ignore,
     delimiter = opts.delimiter.c_str ();
 
   /* Check if we're past option values already.  */
-  if (text > org_text && !isspace (text[-1]))
+  if (text > org_text && !c_isspace (text[-1]))
     return;
 
   const char *delim = strstr (text, delimiter);
@@ -1669,7 +1669,7 @@ disassemble_command (const char *arg, int from_tty)
       if (*p == '\0')
 	error (_("Missing modifier."));
 
-      while (*p && ! isspace (*p))
+      while (*p && ! c_isspace (*p))
 	{
 	  switch (*p++)
 	    {
@@ -1938,8 +1938,8 @@ alias_command_completer (struct cmd_list_element *ignore,
      typing COMMAND DEFAULT-ARGS...  */
   if (delim != text
       && delim != nullptr
-      && isspace (delim[-1])
-      && (isspace (delim[1]) || delim[1] == '\0'))
+      && c_isspace (delim[-1])
+      && (c_isspace (delim[1]) || delim[1] == '\0'))
     {
       std::string new_text = std::string (delim + 1);
 
diff --git a/gdb/cli/cli-decode.c b/gdb/cli/cli-decode.c
index 48a34667c37..2b30a6e04fb 100644
--- a/gdb/cli/cli-decode.c
+++ b/gdb/cli/cli-decode.c
@@ -16,7 +16,6 @@
    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
 
 #include "symtab.h"
-#include <ctype.h>
 #include "gdbsupport/gdb_regex.h"
 #include "completer.h"
 #include "ui-out.h"
@@ -2053,8 +2052,8 @@ print_doc_line (struct ui_file *stream, const char *str,
   if (for_value_prefix)
     {
       char &c = (*line_buffer)[0];
-      if (islower (c))
-	c = toupper (c);
+      if (c_islower (c))
+	c = c_toupper (c);
       if (line_buffer->back () == '.')
 	line_buffer->pop_back ();
     }
@@ -2227,7 +2226,7 @@ valid_cmd_char_p (int c)
   /* Alas "42" is a legitimate user-defined command.
      In the interests of not breaking anything we preserve that.  */
 
-  return isalnum (c) || c == '-' || c == '_' || c == '.';
+  return c_isalnum (c) || c == '-' || c == '_' || c == '.';
 }
 
 /* See command.h.  */
@@ -2491,7 +2490,7 @@ lookup_cmd (const char **line, struct cmd_list_element *list,
     }
   else
     {
-      if (c->type == set_cmd && **line != '\0' && !isspace (**line))
+      if (c->type == set_cmd && **line != '\0' && !c_isspace (**line))
 	error (_("Argument must be preceded by space."));
 
       /* We've got something.  It may still not be what the caller
diff --git a/gdb/cli/cli-dump.c b/gdb/cli/cli-dump.c
index afbbea6cd58..3cdd9a334d3 100644
--- a/gdb/cli/cli-dump.c
+++ b/gdb/cli/cli-dump.c
@@ -23,7 +23,6 @@
 #include "cli/cli-cmds.h"
 #include "value.h"
 #include "completer.h"
-#include <ctype.h>
 #include "target.h"
 #include "readline/tilde.h"
 #include "gdbcore.h"
diff --git a/gdb/cli/cli-option.c b/gdb/cli/cli-option.c
index a30261e5c0f..5da8c737c43 100644
--- a/gdb/cli/cli-option.c
+++ b/gdb/cli/cli-option.c
@@ -227,7 +227,7 @@ parse_option (gdb::array_view<const option_def_group> options_group,
 	      match = &o;
 	      match_ctx = grp.ctx;
 
-	      if ((isspace (arg[len]) || arg[len] == '\0')
+	      if ((c_isspace (arg[len]) || arg[len] == '\0')
 		  && strlen (o.name) == len)
 		break; /* Exact match.  */
 	    }
@@ -635,7 +635,7 @@ complete_options (completion_tracker &tracker,
 	      if (ov
 		  && !tracker.have_completions ()
 		  && **args == '\0'
-		  && *args > text && !isspace ((*args)[-1]))
+		  && *args > text && !c_isspace ((*args)[-1]))
 		{
 		  tracker.advance_custom_word_point_by
 		    (*args - text);
diff --git a/gdb/cli/cli-script.c b/gdb/cli/cli-script.c
index 3ea80a50f38..048d3914ffd 100644
--- a/gdb/cli/cli-script.c
+++ b/gdb/cli/cli-script.c
@@ -19,7 +19,6 @@
 
 #include "event-top.h"
 #include "value.h"
-#include <ctype.h>
 
 #include "ui-out.h"
 #include "top.h"
@@ -829,7 +828,7 @@ locate_arg (const char *p)
   while ((p = strchr (p, '$')))
     {
       if (startswith (p, "$arg")
-	  && (isdigit (p[4]) || p[4] == 'c'))
+	  && (c_isdigit (p[4]) || p[4] == 'c'))
 	return p;
       p++;
     }
@@ -1324,9 +1323,9 @@ validate_comname (const char **comname)
 
   /* Find the last word of the argument.  */
   p = *comname + strlen (*comname);
-  while (p > *comname && isspace (p[-1]))
+  while (p > *comname && c_isspace (p[-1]))
     p--;
-  while (p > *comname && !isspace (p[-1]))
+  while (p > *comname && !c_isspace (p[-1]))
     p--;
   last_word = p;
 
diff --git a/gdb/cli/cli-setshow.c b/gdb/cli/cli-setshow.c
index 4d4695f9456..8528ac52148 100644
--- a/gdb/cli/cli-setshow.c
+++ b/gdb/cli/cli-setshow.c
@@ -17,7 +17,6 @@
 
 #include "readline/tilde.h"
 #include "value.h"
-#include <ctype.h>
 #include "arch-utils.h"
 #include "observable.h"
 #include "interps.h"
@@ -49,7 +48,7 @@ parse_auto_binary_operation (const char *arg)
     {
       int length = strlen (arg);
 
-      while (isspace (arg[length - 1]) && length > 0)
+      while (c_isspace (arg[length - 1]) && length > 0)
 	length--;
 
       /* Note that "o" is ambiguous.  */
diff --git a/gdb/cli/cli-utils.c b/gdb/cli/cli-utils.c
index 23706e00d3a..d0ca594671d 100644
--- a/gdb/cli/cli-utils.c
+++ b/gdb/cli/cli-utils.c
@@ -20,7 +20,6 @@
 #include "cli/cli-utils.h"
 #include "value.h"
 
-#include <ctype.h>
 
 /* See documentation in cli-utils.h.  */
 
@@ -46,7 +45,7 @@ get_ulongest (const char **pp, int trailer)
 	  /* Internal variable.  Make a copy of the name, so we can
 	     null-terminate it to pass to lookup_internalvar().  */
 	  const char *start = ++p;
-	  while (isalnum (*p) || *p == '_')
+	  while (c_isalnum (*p) || *p == '_')
 	    p++;
 	  std::string varname (start, p - start);
 	  if (!get_internalvar_integer (lookup_internalvar (varname.c_str ()),
@@ -67,7 +66,7 @@ get_ulongest (const char **pp, int trailer)
       p = end;
     }
 
-  if (!(isspace (*p) || *p == '\0' || *p == trailer))
+  if (!(c_isspace (*p) || *p == '\0' || *p == trailer))
     error (_("Trailing junk at: %s"), p);
   p = skip_spaces (p);
   *pp = p;
@@ -111,7 +110,7 @@ get_number_trailer (const char **pp, int trailer)
 	  const char *start = ++p;
 	  LONGEST longest_val;
 
-	  while (isalnum (*p) || *p == '_')
+	  while (c_isalnum (*p) || *p == '_')
 	    p++;
 	  varname = (char *) alloca (p - start + 1);
 	  strncpy (varname, start, p - start);
@@ -136,7 +135,7 @@ get_number_trailer (const char **pp, int trailer)
 	/* There is no number here.  (e.g. "cond a == b").  */
 	{
 	  /* Skip non-numeric token.  */
-	  while (*p && !isspace((int) *p))
+	  while (*p && !c_isspace((int) *p))
 	    ++p;
 	  /* Return zero, which caller must interpret as error.  */
 	  retval = 0;
@@ -144,10 +143,10 @@ get_number_trailer (const char **pp, int trailer)
       else
 	retval = atoi (p1);
     }
-  if (!(isspace (*p) || *p == '\0' || *p == trailer))
+  if (!(c_isspace (*p) || *p == '\0' || *p == trailer))
     {
       /* Trailing junk: return 0 and let caller print error msg.  */
-      while (!(isspace (*p) || *p == '\0' || *p == trailer))
+      while (!(c_isspace (*p) || *p == '\0' || *p == trailer))
 	++p;
       retval = 0;
     }
@@ -262,8 +261,8 @@ number_or_range_parser::get_number ()
 	 option rather than an incomplete range, so check for end of
 	 string as well.  */
       if (m_cur_tok[0] == '-'
-	  && !(isspace (m_cur_tok[-1])
-	       && (isalpha (m_cur_tok[1])
+	  && !(c_isspace (m_cur_tok[-1])
+	       && (c_isalpha (m_cur_tok[1])
 		   || m_cur_tok[1] == '-'
 		   || m_cur_tok[1] == '\0')))
 	{
@@ -293,7 +292,7 @@ number_or_range_parser::get_number ()
     }
   else
     {
-      if (isdigit (*(m_cur_tok + 1)))
+      if (c_isdigit (*(m_cur_tok + 1)))
 	error (_("negative value"));
       if (*(m_cur_tok + 1) == '$')
 	{
@@ -330,9 +329,9 @@ number_or_range_parser::finished () const
      integer, convenience var or negative convenience var.  */
   return (m_cur_tok == NULL || *m_cur_tok == '\0'
 	  || (!m_in_range
-	      && !(isdigit (*m_cur_tok) || *m_cur_tok == '$')
+	      && !(c_isdigit (*m_cur_tok) || *m_cur_tok == '$')
 	      && !(*m_cur_tok == '-'
-		   && (isdigit (m_cur_tok[1]) || m_cur_tok[1] == '$'))));
+		   && (c_isdigit (m_cur_tok[1]) || m_cur_tok[1] == '$'))));
 }
 
 /* Accept a number and a string-form list of numbers such as is 
@@ -370,7 +369,7 @@ number_is_in_list (const char *list, int number)
 const char *
 remove_trailing_whitespace (const char *start, const char *s)
 {
-  while (s > start && isspace (*(s - 1)))
+  while (s > start && c_isspace (*(s - 1)))
     --s;
 
   return s;
@@ -420,7 +419,7 @@ int
 check_for_argument (const char **str, const char *arg, int arg_len)
 {
   if (strncmp (*str, arg, arg_len) == 0
-      && ((*str)[arg_len] == '\0' || isspace ((*str)[arg_len])))
+      && ((*str)[arg_len] == '\0' || c_isspace ((*str)[arg_len])))
     {
       *str += arg_len;
       *str = skip_spaces (*str);
diff --git a/gdb/coff-pe-read.c b/gdb/coff-pe-read.c
index 0061007b6fd..9255555231f 100644
--- a/gdb/coff-pe-read.c
+++ b/gdb/coff-pe-read.c
@@ -35,7 +35,6 @@
 #include "gdbsupport/common-utils.h"
 #include "coff/internal.h"
 
-#include <ctype.h>
 
 /* Internal section information */
 
@@ -189,7 +188,7 @@ add_pe_forwarded_sym (minimal_symbol_reader &reader,
       int i;
 
       for (i = 0; i < forward_dll_name_len; i++)
-	forward_qualified_name[i] = tolower (forward_qualified_name[i]);
+	forward_qualified_name[i] = c_tolower (forward_qualified_name[i]);
       msymbol = lookup_minimal_symbol (current_program_space,
 				       forward_qualified_name.c_str ());
     }
diff --git a/gdb/coffread.c b/gdb/coffread.c
index b69c06f381d..44e761abe89 100644
--- a/gdb/coffread.c
+++ b/gdb/coffread.c
@@ -25,7 +25,6 @@
 
 #include "bfd.h"
 #include "gdbsupport/gdb_obstack.h"
-#include <ctype.h>
 
 #include "coff/internal.h"
 #include "libcoff.h"
@@ -336,7 +335,7 @@ coff_locate_sections (bfd *abfd, asection *sectp, void *csip)
       /* We can have multiple .stab sections if linked with
 	 --split-by-reloc.  */
       for (s = name + sizeof ".stab" - 1; *s != '\0'; s++)
-	if (!isdigit (*s))
+	if (!c_isdigit (*s))
 	  break;
       if (*s == '\0')
 	csi->stabsects->push_back (sectp);
@@ -525,9 +524,9 @@ is_import_fixup_symbol (struct coff_symbol *cs,
   /* The name must start with "__fu<digits>__".  */
   if (!startswith (cs->c_name, "__fu"))
     return 0;
-  if (! isdigit (cs->c_name[4]))
+  if (! c_isdigit (cs->c_name[4]))
     return 0;
-  for (i = 5; cs->c_name[i] != '\0' && isdigit (cs->c_name[i]); i++)
+  for (i = 5; cs->c_name[i] != '\0' && c_isdigit (cs->c_name[i]); i++)
     /* Nothing, just incrementing index past all digits.  */;
   if (cs->c_name[i] != '_' || cs->c_name[i + 1] != '_')
     return 0;
diff --git a/gdb/d-exp.y b/gdb/d-exp.y
index f77b15e46f2..6b4fd048e6f 100644
--- a/gdb/d-exp.y
+++ b/gdb/d-exp.y
@@ -38,7 +38,6 @@
 
 %{
 
-#include <ctype.h>
 #include "expression.h"
 #include "value.h"
 #include "parser-defs.h"
@@ -684,15 +683,15 @@ parse_number (struct parser_state *ps, const char *p,
       len = strlen (s);
 
       /* Check suffix for `i' , `fi' or `li' (idouble, ifloat or ireal).  */
-      if (len >= 1 && tolower (s[len - 1]) == 'i')
+      if (len >= 1 && c_tolower (s[len - 1]) == 'i')
 	{
-	  if (len >= 2 && tolower (s[len - 2]) == 'f')
+	  if (len >= 2 && c_tolower (s[len - 2]) == 'f')
 	    {
 	      putithere->typed_val_float.type
 		= parse_d_type (ps)->builtin_ifloat;
 	      len -= 2;
 	    }
-	  else if (len >= 2 && tolower (s[len - 2]) == 'l')
+	  else if (len >= 2 && c_tolower (s[len - 2]) == 'l')
 	    {
 	      putithere->typed_val_float.type
 		= parse_d_type (ps)->builtin_ireal;
@@ -706,13 +705,13 @@ parse_number (struct parser_state *ps, const char *p,
 	    }
 	}
       /* Check suffix for `f' or `l'' (float or real).  */
-      else if (len >= 1 && tolower (s[len - 1]) == 'f')
+      else if (len >= 1 && c_tolower (s[len - 1]) == 'f')
 	{
 	  putithere->typed_val_float.type
 	    = parse_d_type (ps)->builtin_float;
 	  len -= 1;
 	}
-      else if (len >= 1 && tolower (s[len - 1]) == 'l')
+      else if (len >= 1 && c_tolower (s[len - 1]) == 'l')
 	{
 	  putithere->typed_val_float.type
 	    = parse_d_type (ps)->builtin_real;
@@ -1133,8 +1132,8 @@ lex_one_token (struct parser_state *par_state)
 	    /* Hex exponents start with 'p', because 'e' is a valid hex
 	       digit and thus does not indicate a floating point number
 	       when the radix is hex.  */
-	    if ((!hex && !got_e && tolower (p[0]) == 'e')
-		|| (hex && !got_e && tolower (p[0] == 'p')))
+	    if ((!hex && !got_e && c_tolower (p[0]) == 'e')
+		|| (hex && !got_e && c_tolower (p[0] == 'p')))
 	      got_dot = got_e = 1;
 	    /* A '.' always indicates a decimal floating point number
 	       regardless of the radix.  If we have a '..' then its the
@@ -1142,7 +1141,8 @@ lex_one_token (struct parser_state *par_state)
 	    else if (!got_dot && (p[0] == '.' && p[1] != '.'))
 		got_dot = 1;
 	    /* This is the sign of the exponent, not the end of the number.  */
-	    else if (got_e && (tolower (p[-1]) == 'e' || tolower (p[-1]) == 'p')
+	    else if (got_e && (c_tolower (p[-1]) == 'e'
+			       || c_tolower (p[-1]) == 'p')
 		     && (*p == '-' || *p == '+'))
 	      continue;
 	    /* We will take any letters or digits, ignoring any embedded '_'.
@@ -1167,9 +1167,9 @@ lex_one_token (struct parser_state *par_state)
 	const char *p = &tokstart[1];
 	size_t len = strlen ("entry");
 
-	while (isspace (*p))
+	while (c_isspace (*p))
 	  p++;
-	if (strncmp (p, "entry", len) == 0 && !isalnum (p[len])
+	if (strncmp (p, "entry", len) == 0 && !c_isalnum (p[len])
 	    && p[len] != '_')
 	  {
 	    pstate->lexptr = &p[len];
diff --git a/gdb/darwin-nat.c b/gdb/darwin-nat.c
index 7acf6394859..e73b5a1395b 100644
--- a/gdb/darwin-nat.c
+++ b/gdb/darwin-nat.c
@@ -47,7 +47,6 @@
 #include <sys/types.h>
 #include <unistd.h>
 #include <signal.h>
-#include <ctype.h>
 #include <sys/sysctl.h>
 #include <sys/proc.h>
 #include <libproc.h>
diff --git a/gdb/dictionary.c b/gdb/dictionary.c
index 17c9b448f59..e53331bed45 100644
--- a/gdb/dictionary.c
+++ b/gdb/dictionary.c
@@ -20,7 +20,6 @@
    You should have received a copy of the GNU General Public License
    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
 
-#include <ctype.h>
 #include "gdbsupport/gdb_obstack.h"
 #include "symtab.h"
 #include "buildsym.h"
diff --git a/gdb/dwarf2/index-common.c b/gdb/dwarf2/index-common.c
index c24c8fc6c27..a314ce7b0e2 100644
--- a/gdb/dwarf2/index-common.c
+++ b/gdb/dwarf2/index-common.c
@@ -31,7 +31,7 @@ mapped_index_string_hash (int index_version, const void *p)
   while ((c = *str++) != 0)
     {
       if (index_version >= 5)
-	c = tolower (c);
+	c = c_tolower (c);
       r = r * 67 + c - 113;
     }
 
@@ -45,12 +45,12 @@ dwarf5_djb_hash (const char *str_)
 {
   const unsigned char *str = (const unsigned char *) str_;
 
-  /* Note: tolower here ignores UTF-8, which isn't fully compliant.
+  /* Note: c_tolower here ignores UTF-8, which isn't fully compliant.
      See http://dwarfstd.org/ShowIssue.php?issue=161027.1.  */
 
   uint32_t hash = 5381;
   while (int c = *str++)
-    hash = hash * 33 + tolower (c);
+    hash = hash * 33 + c_tolower (c);
   return hash;
 }
 
@@ -59,11 +59,11 @@ dwarf5_djb_hash (const char *str_)
 uint32_t
 dwarf5_djb_hash (std::string_view str)
 {
-  /* Note: tolower here ignores UTF-8, which isn't fully compliant.
+  /* Note: c_tolower here ignores UTF-8, which isn't fully compliant.
      See http://dwarfstd.org/ShowIssue.php?issue=161027.1.  */
 
   uint32_t hash = 5381;
   for (char c : str)
-    hash = hash * 33 + tolower (c & 0xff);
+    hash = hash * 33 + c_tolower (c & 0xff);
   return hash;
 }
diff --git a/gdb/dwarf2/read.c b/gdb/dwarf2/read.c
index 30a0141b65d..c76086fbc04 100644
--- a/gdb/dwarf2/read.c
+++ b/gdb/dwarf2/read.c
@@ -13440,7 +13440,7 @@ ada_get_gnat_encoded_number (const char *encoding, int &k, gdb_mpz *result)
 {
   /* The next character should be an underscore ('_') followed
      by a digit.  */
-  if (encoding[k] != '_' || !isdigit (encoding[k + 1]))
+  if (encoding[k] != '_' || !c_isdigit (encoding[k + 1]))
     return false;
 
   /* Skip the underscore.  */
@@ -13448,7 +13448,7 @@ ada_get_gnat_encoded_number (const char *encoding, int &k, gdb_mpz *result)
   int start = k;
 
   /* Determine the number of digits for our number.  */
-  while (isdigit (encoding[k]))
+  while (c_isdigit (encoding[k]))
     k++;
   if (k == start)
     return false;
diff --git a/gdb/eval.c b/gdb/eval.c
index 491125c7409..498c0bffd1e 100644
--- a/gdb/eval.c
+++ b/gdb/eval.c
@@ -38,7 +38,6 @@
 #include "gdbsupport/gdb_obstack.h"
 #include "objfiles.h"
 #include "typeprint.h"
-#include <ctype.h>
 #include "expop.h"
 #include "c-exp.h"
 #include "inferior.h"
diff --git a/gdb/exec.c b/gdb/exec.c
index 0db5d9030bd..a904f5c53ad 100644
--- a/gdb/exec.c
+++ b/gdb/exec.c
@@ -42,7 +42,6 @@
 #include "readline/tilde.h"
 #include "gdbcore.h"
 
-#include <ctype.h>
 #include <sys/stat.h>
 #include "solib.h"
 #include <algorithm>
@@ -1015,7 +1014,7 @@ set_section_command (const char *args, int from_tty)
     error (_("Must specify section name and its virtual address"));
 
   /* Parse out section name.  */
-  for (secname = args; !isspace (*args); args++);
+  for (secname = args; !c_isspace (*args); args++);
   unsigned seclen = args - secname;
 
   /* Parse out new virtual address.  */
diff --git a/gdb/expprint.c b/gdb/expprint.c
index c87be741a12..a32b7acc4b3 100644
--- a/gdb/expprint.c
+++ b/gdb/expprint.c
@@ -33,7 +33,6 @@
 #include "expop.h"
 #include "ada-exp.h"
 
-#include <ctype.h>
 
 /* Meant to be used in debug sessions, so don't export it in a header file.  */
 extern void ATTRIBUTE_USED debug_exp (struct expression *exp);
diff --git a/gdb/f-exp.y b/gdb/f-exp.y
index afcdc4141cc..07fc54ca9a1 100644
--- a/gdb/f-exp.y
+++ b/gdb/f-exp.y
@@ -48,7 +48,6 @@
 #include "language.h"
 #include "f-lang.h"
 #include "block.h"
-#include <ctype.h>
 #include <algorithm>
 #include "type-stack.h"
 #include "f-exp.h"
@@ -1061,8 +1060,8 @@ parse_number (struct parser_state *par_state,
   while (len-- > 0)
     {
       c = *p++;
-      if (isupper (c))
-	c = tolower (c);
+      if (c_isupper (c))
+	c = c_tolower (c);
       if (len == 0 && c == 'l')
 	long_p = 1;
       else if (len == 0 && c == 'u')
diff --git a/gdb/fbsd-nat.c b/gdb/fbsd-nat.c
index 935b9479e68..81bd6d98469 100644
--- a/gdb/fbsd-nat.c
+++ b/gdb/fbsd-nat.c
@@ -304,7 +304,7 @@ fbsd_nat_target::info_proc (const char *args, enum info_proc_what what)
       if (pid == 0)
 	error (_("No current process: you must name one."));
     }
-  else if (built_argv.count () == 1 && isdigit (built_argv[0][0]))
+  else if (built_argv.count () == 1 && c_isdigit (built_argv[0][0]))
     pid = strtol (built_argv[0], NULL, 10);
   else
     error (_("Invalid arguments."));
diff --git a/gdb/findcmd.c b/gdb/findcmd.c
index 4e478779b67..03c3fccad86 100644
--- a/gdb/findcmd.c
+++ b/gdb/findcmd.c
@@ -18,7 +18,6 @@
    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
 
 #include "arch-utils.h"
-#include <ctype.h>
 #include "cli/cli-cmds.h"
 #include "value.h"
 #include "target.h"
@@ -76,12 +75,12 @@ parse_find_args (const char *args, ULONGEST *max_countp,
     {
       ++s;
 
-      while (*s != '\0' && *s != '/' && !isspace (*s))
+      while (*s != '\0' && *s != '/' && !c_isspace (*s))
 	{
-	  if (isdigit (*s))
+	  if (c_isdigit (*s))
 	    {
 	      max_count = atoi (s);
-	      while (isdigit (*s))
+	      while (c_isdigit (*s))
 		++s;
 	      continue;
 	    }
diff --git a/gdb/gdb_wchar.h b/gdb/gdb_wchar.h
index 417d5bab739..9db0d5e043a 100644
--- a/gdb/gdb_wchar.h
+++ b/gdb/gdb_wchar.h
@@ -113,8 +113,8 @@ typedef char gdb_wchar_t;
 typedef int gdb_wint_t;
 
 #define gdb_wcslen strlen
-#define gdb_iswprint isprint
-#define gdb_iswxdigit isxdigit
+#define gdb_iswprint c_isprint
+#define gdb_iswxdigit c_isxdigit
 #define gdb_btowc /* empty */
 #define gdb_WEOF EOF
 
diff --git a/gdb/gnu-nat.c b/gdb/gnu-nat.c
index dd639fec8a9..33391ba35f2 100644
--- a/gdb/gnu-nat.c
+++ b/gdb/gnu-nat.c
@@ -50,7 +50,6 @@ extern "C"
 }
 
 
-#include <ctype.h>
 #include <setjmp.h>
 #include <signal.h>
 #include <sys/ptrace.h>
@@ -2926,7 +2925,7 @@ set_sig_thread_cmd (const char *args, int from_tty)
 {
   struct inf *inf = cur_inf ();
 
-  if (!args || (!isdigit (*args) && strcmp (args, "none") != 0))
+  if (!args || (!c_isdigit (*args) && strcmp (args, "none") != 0))
     error (_("Illegal argument to \"set signal-thread\" command.\n"
 	     "Should be a thread ID, or \"none\"."));
 
diff --git a/gdb/gnu-v2-abi.c b/gdb/gnu-v2-abi.c
index 924678819a7..1fbc41d2c39 100644
--- a/gdb/gnu-v2-abi.c
+++ b/gdb/gnu-v2-abi.c
@@ -26,7 +26,6 @@
 #include "gdb-demangle.h"
 #include "cp-abi.h"
 #include "cp-support.h"
-#include <ctype.h>
 
 static cp_abi_ops gnu_v2_abi_ops;
 
@@ -46,7 +45,7 @@ static enum ctor_kinds
 gnuv2_is_constructor_name (const char *name)
 {
   if ((name[0] == '_' && name[1] == '_'
-       && (isdigit (name[2]) || strchr ("Qt", name[2])))
+       && (c_isdigit (name[2]) || strchr ("Qt", name[2])))
       || startswith (name, "__ct__"))
     return complete_object_ctor;
   else
diff --git a/gdb/go-exp.y b/gdb/go-exp.y
index a61724285c4..5da8cefd64b 100644
--- a/gdb/go-exp.y
+++ b/gdb/go-exp.y
@@ -51,7 +51,6 @@
 
 %{
 
-#include <ctype.h>
 #include "expression.h"
 #include "value.h"
 #include "parser-defs.h"
@@ -663,13 +662,13 @@ parse_number (struct parser_state *par_state,
 
       /* Handle suffixes: 'f' for float32, 'l' for long double.
 	 FIXME: This appears to be an extension -- do we want this?  */
-      if (len >= 1 && tolower (p[len - 1]) == 'f')
+      if (len >= 1 && c_tolower (p[len - 1]) == 'f')
 	{
 	  putithere->typed_val_float.type
 	    = builtin_go_types->builtin_float32;
 	  len--;
 	}
-      else if (len >= 1 && tolower (p[len - 1]) == 'l')
+      else if (len >= 1 && c_tolower (p[len - 1]) == 'l')
 	{
 	  putithere->typed_val_float.type
 	    = parse_type (par_state)->builtin_long_double;
@@ -1113,9 +1112,9 @@ lex_one_token (struct parser_state *par_state)
 	const char *p = &tokstart[1];
 	size_t len = strlen ("entry");
 
-	while (isspace (*p))
+	while (c_isspace (*p))
 	  p++;
-	if (strncmp (p, "entry", len) == 0 && !isalnum (p[len])
+	if (strncmp (p, "entry", len) == 0 && !c_isalnum (p[len])
 	    && p[len] != '_')
 	  {
 	    par_state->lexptr = &p[len];
diff --git a/gdb/go-lang.c b/gdb/go-lang.c
index bad2ccfc35a..23ffedb042a 100644
--- a/gdb/go-lang.c
+++ b/gdb/go-lang.c
@@ -41,7 +41,6 @@
 #include "parser-defs.h"
 #include "gdbarch.h"
 
-#include <ctype.h>
 
 /* The main function in the main package.  */
 static const char GO_MAIN_MAIN[] = "main.main";
@@ -292,7 +291,7 @@ unpack_mangled_go_symbol (const char *mangled_name,
   while (p > buf)
     {
       int current = *(const unsigned char *) --p;
-      int current_is_digit = isdigit (current);
+      int current_is_digit = c_isdigit (current);
 
       if (saw_digit)
 	{
diff --git a/gdb/go32-nat.c b/gdb/go32-nat.c
index 4d8e6c9fee0..ab13b574114 100644
--- a/gdb/go32-nat.c
+++ b/gdb/go32-nat.c
@@ -103,7 +103,6 @@
 #include "cli/cli-utils.h"
 #include "inf-child.h"
 
-#include <ctype.h>
 #include <unistd.h>
 #include <sys/utsname.h>
 #include <io.h>
diff --git a/gdb/guile/scm-cmd.c b/gdb/guile/scm-cmd.c
index 19fb742f7f1..ef4c9d6b011 100644
--- a/gdb/guile/scm-cmd.c
+++ b/gdb/guile/scm-cmd.c
@@ -20,7 +20,6 @@
 /* See README file in this directory for implementation notes, coding
    conventions, et.al.  */
 
-#include <ctype.h>
 #include "charset.h"
 #include "cli/cli-cmds.h"
 #include "cli/cli-decode.h"
diff --git a/gdb/i386-tdep.c b/gdb/i386-tdep.c
index f75745a3ecf..d3ad402addc 100644
--- a/gdb/i386-tdep.c
+++ b/gdb/i386-tdep.c
@@ -61,7 +61,6 @@
 #include "stap-probe.h"
 #include "user-regs.h"
 #include "expression.h"
-#include <ctype.h>
 #include <algorithm>
 #include <unordered_set>
 #include "producer.h"
@@ -3895,9 +3894,9 @@ int
 i386_stap_is_single_operand (struct gdbarch *gdbarch, const char *s)
 {
   return (*s == '$' /* Literal number.  */
-	  || (isdigit (*s) && s[1] == '(' && s[2] == '%') /* Displacement.  */
+	  || (c_isdigit (*s) && s[1] == '(' && s[2] == '%') /* Displacement.  */
 	  || (*s == '(' && s[1] == '%') /* Register indirection.  */
-	  || (*s == '%' && isalpha (s[1]))); /* Register access.  */
+	  || (*s == '%' && c_isalpha (s[1]))); /* Register access.  */
 }
 
 /* Helper function for i386_stap_parse_special_token.
@@ -3914,7 +3913,7 @@ i386_stap_parse_special_token_triplet (struct gdbarch *gdbarch,
 {
   const char *s = p->arg;
 
-  if (isdigit (*s) || *s == '-' || *s == '+')
+  if (c_isdigit (*s) || *s == '-' || *s == '+')
     {
       bool got_minus[3];
       int i;
@@ -3932,7 +3931,7 @@ i386_stap_parse_special_token_triplet (struct gdbarch *gdbarch,
 	  got_minus[0] = true;
 	}
 
-      if (!isdigit ((unsigned char) *s))
+      if (!c_isdigit (*s))
 	return {};
 
       displacements[0] = strtol (s, &endp, 10);
@@ -3953,7 +3952,7 @@ i386_stap_parse_special_token_triplet (struct gdbarch *gdbarch,
 	  got_minus[1] = true;
 	}
 
-      if (!isdigit ((unsigned char) *s))
+      if (!c_isdigit (*s))
 	return {};
 
       displacements[1] = strtol (s, &endp, 10);
@@ -3974,7 +3973,7 @@ i386_stap_parse_special_token_triplet (struct gdbarch *gdbarch,
 	  got_minus[2] = true;
 	}
 
-      if (!isdigit ((unsigned char) *s))
+      if (!c_isdigit (*s))
 	return {};
 
       displacements[2] = strtol (s, &endp, 10);
@@ -3986,7 +3985,7 @@ i386_stap_parse_special_token_triplet (struct gdbarch *gdbarch,
       s += 2;
       start = s;
 
-      while (isalnum (*s))
+      while (c_isalnum (*s))
 	++s;
 
       if (*s++ != ')')
@@ -4047,7 +4046,7 @@ i386_stap_parse_special_token_three_arg_disp (struct gdbarch *gdbarch,
 {
   const char *s = p->arg;
 
-  if (isdigit (*s) || *s == '(' || *s == '-' || *s == '+')
+  if (c_isdigit (*s) || *s == '(' || *s == '-' || *s == '+')
     {
       bool offset_minus = false;
       long offset = 0;
@@ -4065,10 +4064,10 @@ i386_stap_parse_special_token_three_arg_disp (struct gdbarch *gdbarch,
 	  offset_minus = true;
 	}
 
-      if (offset_minus && !isdigit (*s))
+      if (offset_minus && !c_isdigit (*s))
 	return {};
 
-      if (isdigit (*s))
+      if (c_isdigit (*s))
 	{
 	  char *endp;
 
@@ -4082,7 +4081,7 @@ i386_stap_parse_special_token_three_arg_disp (struct gdbarch *gdbarch,
       s += 2;
       start = s;
 
-      while (isalnum (*s))
+      while (c_isalnum (*s))
 	++s;
 
       if (*s != ',' || s[1] != '%')
@@ -4098,7 +4097,7 @@ i386_stap_parse_special_token_three_arg_disp (struct gdbarch *gdbarch,
       s += 2;
       start = s;
 
-      while (isalnum (*s))
+      while (c_isalnum (*s))
 	++s;
 
       len_index = s - start;
diff --git a/gdb/ia64-linux-tdep.c b/gdb/ia64-linux-tdep.c
index 6afffeea4e3..8b4e1f95291 100644
--- a/gdb/ia64-linux-tdep.c
+++ b/gdb/ia64-linux-tdep.c
@@ -29,7 +29,6 @@
 #include "solib-svr4-linux.h"
 #include "regset.h"
 
-#include <ctype.h>
 
 /* The sigtramp code is in a non-readable (executable-only) region
    of memory called the ``gate page''.  The addresses in question
@@ -128,9 +127,9 @@ ia64_linux_write_pc (struct regcache *regcache, CORE_ADDR pc)
 static int
 ia64_linux_stap_is_single_operand (struct gdbarch *gdbarch, const char *s)
 {
-  return ((isdigit (*s) && s[1] == '[' && s[2] == 'r') /* Displacement.  */
+  return ((c_isdigit (*s) && s[1] == '[' && s[2] == 'r') /* Displacement.  */
 	  || *s == 'r' /* Register value.  */
-	  || isdigit (*s));  /* Literal number.  */
+	  || c_isdigit (*s));  /* Literal number.  */
 }
 
 /* Core file support. */
diff --git a/gdb/infcmd.c b/gdb/infcmd.c
index a785ae37758..d20b6464eeb 100644
--- a/gdb/infcmd.c
+++ b/gdb/infcmd.c
@@ -40,7 +40,6 @@
 #include "reggroups.h"
 #include "block.h"
 #include "solib.h"
-#include <ctype.h>
 #include "observable.h"
 #include "target-descriptions.h"
 #include "user-regs.h"
@@ -210,7 +209,7 @@ strip_bg_char (const char *args, int *bg_char_p)
   if (p[-1] == '&')
     {
       p--;
-      while (p > args && isspace (p[-1]))
+      while (p > args && c_isspace (p[-1]))
 	p--;
 
       *bg_char_p = 1;
@@ -2309,12 +2308,12 @@ registers_info (const char *addr_exp, int fpregs)
 	 resembling a register following it.  */
       if (addr_exp[0] == '$')
 	addr_exp++;
-      if (isspace ((*addr_exp)) || (*addr_exp) == '\0')
+      if (c_isspace ((*addr_exp)) || (*addr_exp) == '\0')
 	error (_("Missing register name"));
 
       /* Find the start/end of this register name/num/group.  */
       start = addr_exp;
-      while ((*addr_exp) != '\0' && !isspace ((*addr_exp)))
+      while ((*addr_exp) != '\0' && !c_isspace ((*addr_exp)))
 	addr_exp++;
       end = addr_exp;
 
diff --git a/gdb/infrun.c b/gdb/infrun.c
index 3b5cff71cc2..289c503963c 100644
--- a/gdb/infrun.c
+++ b/gdb/infrun.c
@@ -22,7 +22,6 @@
 #include "cli/cli-style.h"
 #include "displaced-stepping.h"
 #include "infrun.h"
-#include <ctype.h>
 #include "exceptions.h"
 #include "symtab.h"
 #include "frame.h"
@@ -9843,7 +9842,7 @@ handle_command (const char *args, int from_tty)
   for (char *arg : built_argv)
     {
       wordlen = strlen (arg);
-      for (digits = 0; isdigit (arg[digits]); digits++)
+      for (digits = 0; c_isdigit (arg[digits]); digits++)
 	{;
 	}
       allsigs = 0;
diff --git a/gdb/language.c b/gdb/language.c
index 212a236e247..c070169e7b2 100644
--- a/gdb/language.c
+++ b/gdb/language.c
@@ -28,7 +28,6 @@
    return data out of a "language-specific" struct pointer that is set
    whenever the working language changes.  That would be a lot faster.  */
 
-#include <ctype.h>
 #include "symtab.h"
 #include "gdbtypes.h"
 #include "value.h"
diff --git a/gdb/linespec.c b/gdb/linespec.c
index e634bf22f3c..70e2af94419 100644
--- a/gdb/linespec.c
+++ b/gdb/linespec.c
@@ -35,7 +35,6 @@
 #include "interps.h"
 #include "target.h"
 #include "arch-utils.h"
-#include <ctype.h>
 #include "cli/cli-utils.h"
 #include "filenames.h"
 #include "ada-lang.h"
@@ -459,7 +458,7 @@ linespec_lexer_lex_number (linespec_parser *parser, linespec_token *tokenp)
       ++(parser->lexer.stream);
     }
 
-  while (isdigit (*parser->lexer.stream))
+  while (c_isdigit (*parser->lexer.stream))
     {
       ++tokenp->data.string.length;
       ++(parser->lexer.stream);
@@ -468,7 +467,7 @@ linespec_lexer_lex_number (linespec_parser *parser, linespec_token *tokenp)
   /* If the next character in the input buffer is not a space, comma,
      quote, or colon, this input does not represent a number.  */
   if (*parser->lexer.stream != '\0'
-      && !isspace (*parser->lexer.stream) && *parser->lexer.stream != ','
+      && !c_isspace (*parser->lexer.stream) && *parser->lexer.stream != ','
       && *parser->lexer.stream != ':'
       && !strchr (linespec_quote_characters, *parser->lexer.stream))
     {
@@ -512,7 +511,7 @@ linespec_lexer_lex_keyword (const char *p)
 	      if (i == FORCE_KEYWORD_INDEX && p[len] == '\0')
 		return linespec_keywords[i];
 
-	      if (!isspace (p[len]))
+	      if (!c_isspace (p[len]))
 		continue;
 
 	      if (i == FORCE_KEYWORD_INDEX)
@@ -524,7 +523,7 @@ linespec_lexer_lex_keyword (const char *p)
 		      int nextlen = strlen (linespec_keywords[j]);
 
 		      if (strncmp (p, linespec_keywords[j], nextlen) == 0
-			  && isspace (p[nextlen]))
+			  && c_isspace (p[nextlen]))
 			return linespec_keywords[i];
 		    }
 		}
@@ -538,7 +537,7 @@ linespec_lexer_lex_keyword (const char *p)
 		      int nextlen = strlen (linespec_keywords[j]);
 
 		      if (strncmp (p, linespec_keywords[j], nextlen) == 0
-			  && isspace (p[nextlen]))
+			  && c_isspace (p[nextlen]))
 			return NULL;
 		    }
 		}
@@ -763,7 +762,7 @@ linespec_lexer_lex_string (linespec_parser *parser)
 
       while (1)
 	{
-	  if (isspace (*parser->lexer.stream))
+	  if (c_isspace (*parser->lexer.stream))
 	    {
 	      p = skip_spaces (parser->lexer.stream);
 	      /* When we get here we know we've found something followed by
@@ -841,14 +840,14 @@ linespec_lexer_lex_string (linespec_parser *parser)
 		{
 		  const char *op = parser->lexer.stream;
 
-		  while (op > start && isspace (op[-1]))
+		  while (op > start && c_isspace (op[-1]))
 		    op--;
 		  if (op - start >= CP_OPERATOR_LEN)
 		    {
 		      op -= CP_OPERATOR_LEN;
 		      if (strncmp (op, CP_OPERATOR_STR, CP_OPERATOR_LEN) == 0
 			  && (op == start
-			      || !(isalnum (op[-1]) || op[-1] == '_')))
+			      || !(c_isalnum (op[-1]) || op[-1] == '_')))
 			{
 			  /* This is an operator name.  Keep going.  */
 			  ++(parser->lexer.stream);
@@ -1642,7 +1641,7 @@ linespec_parse_line_offset (const char *string)
   else
     line_offset.sign = LINE_OFFSET_NONE;
 
-  if (*string != '\0' && !isdigit (*string))
+  if (*string != '\0' && !c_isdigit (*string))
     error (_("malformed line offset: \"%s\""), start);
 
   /* Right now, we only allow base 10 for offsets.  */
diff --git a/gdb/linux-fork.c b/gdb/linux-fork.c
index 9e986d8d7ca..0171259bea5 100644
--- a/gdb/linux-fork.c
+++ b/gdb/linux-fork.c
@@ -37,7 +37,6 @@
 #include "gdbsupport/eintr.h"
 #include "target/waitstatus.h"
 #include <dirent.h>
-#include <ctype.h>
 
 #include <list>
 
@@ -421,7 +420,7 @@ fork_save_infrun_state (struct fork_info *fp)
       /* Now find actual file positions.  */
       rewinddir (d);
       while ((de = readdir (d)) != NULL)
-	if (isdigit (de->d_name[0]))
+	if (c_isdigit (de->d_name[0]))
 	  {
 	    tmp = strtol (&de->d_name[0], NULL, 10);
 	    fp->filepos[tmp] = call_lseek (tmp, 0, SEEK_CUR);
diff --git a/gdb/linux-nat.c b/gdb/linux-nat.c
index c3c5ddf4e40..87fb800e544 100644
--- a/gdb/linux-nat.c
+++ b/gdb/linux-nat.c
@@ -42,7 +42,6 @@
 #include "elf-bfd.h"
 #include "gregset.h"
 #include "gdbcore.h"
-#include <ctype.h>
 #include <sys/stat.h>
 #include <fcntl.h>
 #include "inf-loop.h"
diff --git a/gdb/linux-tdep.c b/gdb/linux-tdep.c
index f07f9879614..4b679c8759e 100644
--- a/gdb/linux-tdep.c
+++ b/gdb/linux-tdep.c
@@ -46,7 +46,6 @@
 #include "cli/cli-style.h"
 #include "gdbsupport/unordered_map.h"
 
-#include <ctype.h>
 #include <algorithm>
 
 /* This enum represents the values that the user can choose when
@@ -488,7 +487,7 @@ read_mapping (const char *line)
 
   p = skip_spaces (p);
   const char *permissions_start = p;
-  while (*p && !isspace (*p))
+  while (*p && !c_isspace (*p))
     p++;
   mapping.permissions = std::string (permissions_start,
 				     (size_t) (p - permissions_start));
@@ -497,7 +496,7 @@ read_mapping (const char *line)
 
   p = skip_spaces (p);
   const char *device_start = p;
-  while (*p && !isspace (*p))
+  while (*p && !c_isspace (*p))
     p++;
   mapping.device = {device_start, (size_t) (p - device_start)};
 
@@ -843,7 +842,7 @@ linux_info_proc (struct gdbarch *gdbarch, const char *args,
   char filename[100];
   fileio_error target_errno;
 
-  if (args && isdigit (args[0]))
+  if (args && c_isdigit (args[0]))
     {
       char *tem;
 
@@ -2227,7 +2226,7 @@ linux_fill_prpsinfo (struct elf_internal_linux_prpsinfo *p)
      specifically under the entry of `/proc/[pid]/stat'.  */
 
   /* Getting rid of the PID, since we already have it.  */
-  while (isdigit (*proc_stat))
+  while (c_isdigit (*proc_stat))
     ++proc_stat;
 
   proc_stat = skip_spaces (proc_stat);
@@ -2299,10 +2298,10 @@ linux_fill_prpsinfo (struct elf_internal_linux_prpsinfo *p)
     {
       /* Advancing the pointer to the beginning of the UID.  */
       tmpstr += sizeof ("Uid:");
-      while (*tmpstr != '\0' && !isdigit (*tmpstr))
+      while (*tmpstr != '\0' && !c_isdigit (*tmpstr))
 	++tmpstr;
 
-      if (isdigit (*tmpstr))
+      if (c_isdigit (*tmpstr))
 	p->pr_uid = strtol (tmpstr, &tmpstr, 10);
     }
 
@@ -2312,10 +2311,10 @@ linux_fill_prpsinfo (struct elf_internal_linux_prpsinfo *p)
     {
       /* Advancing the pointer to the beginning of the GID.  */
       tmpstr += sizeof ("Gid:");
-      while (*tmpstr != '\0' && !isdigit (*tmpstr))
+      while (*tmpstr != '\0' && !c_isdigit (*tmpstr))
 	++tmpstr;
 
-      if (isdigit (*tmpstr))
+      if (c_isdigit (*tmpstr))
 	p->pr_gid = strtol (tmpstr, &tmpstr, 10);
     }
 
diff --git a/gdb/linux-thread-db.c b/gdb/linux-thread-db.c
index 8d49508d1ab..82bfe080223 100644
--- a/gdb/linux-thread-db.c
+++ b/gdb/linux-thread-db.c
@@ -43,7 +43,6 @@
 #include "auto-load.h"
 #include "cli/cli-utils.h"
 #include <signal.h>
-#include <ctype.h>
 #include "nat/linux-namespaces.h"
 #include <algorithm>
 #include "gdbsupport/pathstuff.h"
diff --git a/gdb/location.c b/gdb/location.c
index 378fafc60f7..197c47bbe47 100644
--- a/gdb/location.c
+++ b/gdb/location.c
@@ -26,7 +26,6 @@
 #include "probe.h"
 #include "cp-support.h"
 
-#include <ctype.h>
 #include <string.h>
 
 static std::string
@@ -408,15 +407,15 @@ explicit_location_spec_lex_one (const char **inp,
      whitespace or comma.  */
   if (*start == '-' || *start == '+')
     {
-      while (*inp[0] != '\0' && *inp[0] != ',' && !isspace (*inp[0]))
+      while (*inp[0] != '\0' && *inp[0] != ',' && !c_isspace (*inp[0]))
 	++(*inp);
     }
   else
     {
       /* Handle numbers first, stopping at the next whitespace or ','.  */
-      while (isdigit (*inp[0]))
+      while (c_isdigit (*inp[0]))
 	++(*inp);
-      if (*inp[0] == '\0' || isspace (*inp[0]) || *inp[0] == ',')
+      if (*inp[0] == '\0' || c_isspace (*inp[0]) || *inp[0] == ',')
 	return gdb::unique_xmalloc_ptr<char> (savestring (start,
 							  *inp - start));
 
@@ -425,7 +424,7 @@ explicit_location_spec_lex_one (const char **inp,
       *inp = start;
       while ((*inp)[0]
 	     && (*inp)[0] != ','
-	     && !(isspace ((*inp)[0])
+	     && !(c_isspace ((*inp)[0])
 		  || linespec_lexer_lex_keyword (&(*inp)[1])))
 	{
 	  /* Special case: C++ operator,.  */
@@ -454,14 +453,14 @@ is_cp_operator (const char *start, const char *comma)
     {
       const char *p = comma;
 
-      while (p > start && isspace (p[-1]))
+      while (p > start && c_isspace (p[-1]))
 	p--;
       if (p - start >= CP_OPERATOR_LEN)
 	{
 	  p -= CP_OPERATOR_LEN;
 	  if (strncmp (p, CP_OPERATOR_STR, CP_OPERATOR_LEN) == 0
 	      && (p == start
-		  || !(isalnum (p[-1]) || p[-1] == '_')))
+		  || !(c_isalnum (p[-1]) || p[-1] == '_')))
 	    {
 	      return true;
 	    }
@@ -624,7 +623,7 @@ string_to_explicit_location_spec (const char **argp,
   if (argp == NULL
       || *argp == NULL
       || *argp[0] != '-'
-      || !isalpha ((*argp)[1])
+      || !c_isalpha ((*argp)[1])
       || ((*argp)[0] == '-' && (*argp)[1] == 'p'))
     return NULL;
 
@@ -728,7 +727,7 @@ string_to_explicit_location_spec (const char **argp,
 	}
       /* Only emit an "invalid argument" error for options
 	 that look like option strings.  */
-      else if (opt.get ()[0] == '-' && !isdigit (opt.get ()[1]))
+      else if (opt.get ()[0] == '-' && !c_isdigit (opt.get ()[1]))
 	{
 	  if (completion_info == NULL)
 	    error (_("invalid explicit location argument, \"%s\""), opt.get ());
diff --git a/gdb/main.c b/gdb/main.c
index eac70895580..e1ef537c357 100644
--- a/gdb/main.c
+++ b/gdb/main.c
@@ -30,7 +30,6 @@
 
 #include <sys/types.h>
 #include <sys/stat.h>
-#include <ctype.h>
 #include "gdbsupport/event-loop.h"
 #include "ui-out.h"
 
@@ -1254,7 +1253,7 @@ captured_main_1 (struct captured_main_args *context)
 	 If pid_or_core_arg's first character is a digit, try attach
 	 first and then corefile.  Otherwise try just corefile.  */
 
-      if (isdigit (pid_or_core_arg[0]))
+      if (c_isdigit (pid_or_core_arg[0]))
 	{
 	  ret = catch_command_errors (attach_command, pid_or_core_arg,
 				      !batch_flag);
diff --git a/gdb/maint.c b/gdb/maint.c
index d76d957b6e6..8bc28562d10 100644
--- a/gdb/maint.c
+++ b/gdb/maint.c
@@ -21,7 +21,6 @@
 
 
 #include "arch-utils.h"
-#include <ctype.h>
 #include <cmath>
 #include <signal.h>
 #include "command.h"
@@ -571,9 +570,9 @@ maintenance_translate_address (const char *arg, int from_tty)
   sect = NULL;
   p = arg;
 
-  if (!isdigit (*p))
+  if (!c_isdigit (*p))
     {				/* See if we have a valid section name.  */
-      while (*p && !isspace (*p))	/* Find end of section name.  */
+      while (*p && !c_isspace (*p))	/* Find end of section name.  */
 	p++;
       if (*p == '\000')		/* End of command?  */
 	error (_("Need to specify section name and address"));
diff --git a/gdb/mi/mi-cmd-break.c b/gdb/mi/mi-cmd-break.c
index e4cb2e7d335..1cb84354513 100644
--- a/gdb/mi/mi-cmd-break.c
+++ b/gdb/mi/mi-cmd-break.c
@@ -28,7 +28,6 @@
 #include "language.h"
 #include "location.h"
 #include "linespec.h"
-#include <ctype.h>
 #include "tracepoint.h"
 
 enum
@@ -133,7 +132,7 @@ mi_argv_to_format (const char *const *argv, int argc)
 	  result += "\\\"";
 	  break;
 	default:
-	  if (isprint (argv[0][i]))
+	  if (c_isprint (argv[0][i]))
 	    result += argv[0][i];
 	  else
 	    {
diff --git a/gdb/mi/mi-cmd-stack.c b/gdb/mi/mi-cmd-stack.c
index fad058efb28..52ae11b39af 100644
--- a/gdb/mi/mi-cmd-stack.c
+++ b/gdb/mi/mi-cmd-stack.c
@@ -29,7 +29,6 @@
 #include "valprint.h"
 #include "mi-getopt.h"
 #include "extension.h"
-#include <ctype.h>
 #include "mi-parse.h"
 #include <optional>
 #include "inferior.h"
diff --git a/gdb/mi/mi-cmd-var.c b/gdb/mi/mi-cmd-var.c
index 9cbb85722b3..09d6107c11b 100644
--- a/gdb/mi/mi-cmd-var.c
+++ b/gdb/mi/mi-cmd-var.c
@@ -25,7 +25,6 @@
 #include "varobj.h"
 #include "language.h"
 #include "value.h"
-#include <ctype.h>
 #include "mi-getopt.h"
 #include "gdbthread.h"
 #include "mi-parse.h"
@@ -109,7 +108,7 @@ mi_cmd_var_create (const char *command, const char *const *argv, int argc)
       gen_name = varobj_gen_name ();
       name = gen_name.c_str ();
     }
-  else if (!isalpha (name[0]))
+  else if (!c_isalpha (name[0]))
     error (_("-var-create: name of object must begin with a letter"));
 
   if (strcmp (frame, "*") == 0)
diff --git a/gdb/mi/mi-main.c b/gdb/mi/mi-main.c
index 789e6fa4ad5..bcc32f9bfea 100644
--- a/gdb/mi/mi-main.c
+++ b/gdb/mi/mi-main.c
@@ -52,7 +52,6 @@
 #include <optional>
 #include "gdbsupport/byte-vector.h"
 
-#include <ctype.h>
 #include "gdbsupport/run-time-clock.h"
 #include <chrono>
 #include "progspace-and-thread.h"
diff --git a/gdb/mi/mi-parse.c b/gdb/mi/mi-parse.c
index 0af90cb711b..58bdf4a4066 100644
--- a/gdb/mi/mi-parse.c
+++ b/gdb/mi/mi-parse.c
@@ -22,7 +22,6 @@
 #include "mi-cmds.h"
 #include "mi-parse.h"
 
-#include <ctype.h>
 #include "cli/cli-utils.h"
 #include "language.h"
 
@@ -61,7 +60,7 @@ mi_parse_escape (const char **string_ptr)
 	  while (++count < 3)
 	    {
 	      c = (**string_ptr);
-	      if (isdigit (c) && c != '8' && c != '9')
+	      if (c_isdigit (c) && c != '8' && c != '9')
 		{
 		  (*string_ptr)++;
 		  i *= 8;
@@ -162,7 +161,7 @@ mi_parse::parse_argv ()
 		return;
 	      }
 	    /* Insist on trailing white space.  */
-	    if (chp[1] != '\0' && !isspace (chp[1]))
+	    if (chp[1] != '\0' && !c_isspace (chp[1]))
 	      {
 		freeargv (argv);
 		return;
@@ -193,7 +192,7 @@ mi_parse::parse_argv ()
 	    int len;
 	    const char *start = chp;
 
-	    while (*chp != '\0' && !isspace (*chp))
+	    while (*chp != '\0' && !c_isspace (*chp))
 	      {
 		chp++;
 	      }
@@ -313,7 +312,7 @@ mi_parse::mi_parse (const char *cmd, std::string *token)
   {
     const char *tmp = chp + 1;	/* discard ``-'' */
 
-    for (; *chp && !isspace (*chp); chp++)
+    for (; *chp && !c_isspace (*chp); chp++)
       ;
     this->command = make_unique_xstrndup (tmp, chp - tmp);
   }
@@ -391,7 +390,7 @@ mi_parse::mi_parse (const char *cmd, std::string *token)
       else
 	break;
 
-      if (*chp != '\0' && !isspace (*chp))
+      if (*chp != '\0' && !c_isspace (*chp))
 	error (_("Invalid value for the '%s' option"), option);
       chp = skip_spaces (chp);
     }
diff --git a/gdb/minsyms.c b/gdb/minsyms.c
index 765535cc32e..c4a0fa87376 100644
--- a/gdb/minsyms.c
+++ b/gdb/minsyms.c
@@ -36,7 +36,6 @@
    to figure out what full symbol table entries need to be read in.  */
 
 
-#include <ctype.h>
 #include "maint.h"
 #include "symtab.h"
 #include "bfd.h"
diff --git a/gdb/nat/linux-osdata.c b/gdb/nat/linux-osdata.c
index b52a8ed5f36..0a309b863d3 100644
--- a/gdb/nat/linux-osdata.c
+++ b/gdb/nat/linux-osdata.c
@@ -21,7 +21,6 @@
 
 #include <sys/types.h>
 #include <sys/sysinfo.h>
-#include <ctype.h>
 #include <utmp.h>
 #include <time.h>
 #include <unistd.h>
@@ -205,7 +204,7 @@ get_cores_used_by_process (PID_T pid, int *cores, const int num_cores)
 	  PID_T tid;
 	  int core;
 
-	  if (!isdigit (dp->d_name[0])
+	  if (!c_isdigit (dp->d_name[0])
 	      || NAMELEN (dp) > MAX_PID_T_STRLEN)
 	    continue;
 
@@ -310,7 +309,7 @@ linux_xfer_osdata_processes ()
 	  std::string cores_str;
 	  int i;
 
-	  if (!isdigit (dp->d_name[0])
+	  if (!c_isdigit (dp->d_name[0])
 	      || NAMELEN (dp) > MAX_PID_T_STRLEN)
 	    continue;
 
@@ -419,7 +418,7 @@ linux_xfer_osdata_processgroups ()
 	{
 	  PID_T pid, pgid;
 
-	  if (!isdigit (dp->d_name[0])
+	  if (!c_isdigit (dp->d_name[0])
 	      || NAMELEN (dp) > MAX_PID_T_STRLEN)
 	    continue;
 
@@ -483,7 +482,7 @@ linux_xfer_osdata_threads ()
 	  struct stat statbuf;
 	  char procentry[sizeof ("/proc/4294967295")];
 
-	  if (!isdigit (dp->d_name[0])
+	  if (!c_isdigit (dp->d_name[0])
 	      || NAMELEN (dp) > sizeof ("4294967295") - 1)
 	    continue;
 
@@ -513,7 +512,7 @@ linux_xfer_osdata_threads ()
 		      PID_T tid;
 		      int core;
 
-		      if (!isdigit (dp2->d_name[0])
+		      if (!c_isdigit (dp2->d_name[0])
 			  || NAMELEN (dp2) > sizeof ("4294967295") - 1)
 			continue;
 
@@ -633,7 +632,7 @@ linux_xfer_osdata_fds ()
 	  struct stat statbuf;
 	  char procentry[sizeof ("/proc/4294967295")];
 
-	  if (!isdigit (dp->d_name[0])
+	  if (!c_isdigit (dp->d_name[0])
 	      || NAMELEN (dp) > sizeof ("4294967295") - 1)
 	    continue;
 
@@ -662,7 +661,7 @@ linux_xfer_osdata_fds ()
 		      char buf[1000];
 		      ssize_t rslt;
 
-		      if (!isdigit (dp2->d_name[0]))
+		      if (!c_isdigit (dp2->d_name[0]))
 			continue;
 
 		      std::string fdname
diff --git a/gdb/netbsd-nat.c b/gdb/netbsd-nat.c
index 060134f7b20..207e69cfdc5 100644
--- a/gdb/netbsd-nat.c
+++ b/gdb/netbsd-nat.c
@@ -318,7 +318,7 @@ nbsd_nat_target::info_proc (const char *args, enum info_proc_what what)
       if (pid == 0)
 	error (_("No current process: you must name one."));
     }
-  else if (built_argv.count () == 1 && isdigit (built_argv[0][0]))
+  else if (built_argv.count () == 1 && c_isdigit (built_argv[0][0]))
     pid = strtol (built_argv[0], NULL, 10);
   else
     error (_("Invalid arguments."));
diff --git a/gdb/objc-lang.c b/gdb/objc-lang.c
index 6bba8d33af9..492020df8dc 100644
--- a/gdb/objc-lang.c
+++ b/gdb/objc-lang.c
@@ -46,7 +46,6 @@
 #include "cli/cli-utils.h"
 #include "c-exp.h"
 
-#include <ctype.h>
 #include <algorithm>
 
 struct objc_object {
@@ -850,9 +849,9 @@ parse_selector (char *method, char **selector)
 
   for (;;)
     {
-      if (isalnum (*s2) || (*s2 == '_') || (*s2 == ':'))
+      if (c_isalnum (*s2) || (*s2 == '_') || (*s2 == ':'))
 	*s1++ = *s2;
-      else if (isspace (*s2))
+      else if (c_isspace (*s2))
 	;
       else if ((*s2 == '\0') || (*s2 == '\''))
 	break;
@@ -914,7 +913,7 @@ parse_method (char *method, char *type, char **theclass,
   s1++;
 
   nclass = s1;
-  while (isalnum (*s1) || (*s1 == '_'))
+  while (c_isalnum (*s1) || (*s1 == '_'))
     s1++;
   
   s2 = s1;
@@ -925,7 +924,7 @@ parse_method (char *method, char *type, char **theclass,
       s2++;
       s2 = skip_spaces (s2);
       ncategory = s2;
-      while (isalnum (*s2) || (*s2 == '_'))
+      while (c_isalnum (*s2) || (*s2 == '_'))
 	s2++;
       *s2++ = '\0';
     }
@@ -938,9 +937,9 @@ parse_method (char *method, char *type, char **theclass,
 
   for (;;)
     {
-      if (isalnum (*s2) || (*s2 == '_') || (*s2 == ':'))
+      if (c_isalnum (*s2) || (*s2 == '_') || (*s2 == ':'))
 	*s1++ = *s2;
-      else if (isspace (*s2))
+      else if (c_isspace (*s2))
 	;
       else if (*s2 == ']')
 	break;
diff --git a/gdb/p-exp.y b/gdb/p-exp.y
index 2b923ab44df..a68443a5b7f 100644
--- a/gdb/p-exp.y
+++ b/gdb/p-exp.y
@@ -43,7 +43,6 @@
    Probably also lots of other problems, less well defined PM.  */
 %{
 
-#include <ctype.h>
 #include "expression.h"
 #include "value.h"
 #include "parser-defs.h"
@@ -817,13 +816,13 @@ parse_number (struct parser_state *par_state,
     {
       /* Handle suffixes: 'f' for float, 'l' for long double.
 	 FIXME: This appears to be an extension -- do we want this?  */
-      if (len >= 1 && tolower (p[len - 1]) == 'f')
+      if (len >= 1 && c_tolower (p[len - 1]) == 'f')
 	{
 	  putithere->typed_val_float.type
 	    = parse_type (par_state)->builtin_float;
 	  len--;
 	}
-      else if (len >= 1 && tolower (p[len - 1]) == 'l')
+      else if (len >= 1 && c_tolower (p[len - 1]) == 'l')
 	{
 	  putithere->typed_val_float.type
 	    = parse_type (par_state)->builtin_long_double;
@@ -1089,9 +1088,9 @@ yylex (void)
   if (explen > 2)
     for (const auto &token : tokentab3)
       if (strncasecmp (tokstart, token.oper, 3) == 0
-	  && (!isalpha (token.oper[0]) || explen == 3
-	      || (!isalpha (tokstart[3])
-		  && !isdigit (tokstart[3]) && tokstart[3] != '_')))
+	  && (!c_isalpha (token.oper[0]) || explen == 3
+	      || (!c_isalpha (tokstart[3])
+		  && !c_isdigit (tokstart[3]) && tokstart[3] != '_')))
 	{
 	  pstate->lexptr += 3;
 	  yylval.opcode = token.opcode;
@@ -1102,9 +1101,9 @@ yylex (void)
   if (explen > 1)
     for (const auto &token : tokentab2)
       if (strncasecmp (tokstart, token.oper, 2) == 0
-	  && (!isalpha (token.oper[0]) || explen == 2
-	      || (!isalpha (tokstart[2])
-		  && !isdigit (tokstart[2]) && tokstart[2] != '_')))
+	  && (!c_isalpha (token.oper[0]) || explen == 2
+	      || (!c_isalpha (tokstart[2])
+		  && !c_isdigit (tokstart[2]) && tokstart[2] != '_')))
 	{
 	  pstate->lexptr += 2;
 	  yylval.opcode = token.opcode;
diff --git a/gdb/p-lang.c b/gdb/p-lang.c
index 3ded1524bde..1dc1a34663c 100644
--- a/gdb/p-lang.c
+++ b/gdb/p-lang.c
@@ -30,7 +30,6 @@
 #include "p-lang.h"
 #include "valprint.h"
 #include "value.h"
-#include <ctype.h>
 #include "c-lang.h"
 #include "gdbarch.h"
 #include "cli/cli-style.h"
diff --git a/gdb/p-typeprint.c b/gdb/p-typeprint.c
index 7994ccfc77d..8b5f2b548a5 100644
--- a/gdb/p-typeprint.c
+++ b/gdb/p-typeprint.c
@@ -30,7 +30,6 @@
 #include "p-lang.h"
 #include "typeprint.h"
 #include "gdb-demangle.h"
-#include <ctype.h>
 #include "cli/cli-style.h"
 
 /* See language.h.  */
@@ -138,13 +137,13 @@ pascal_language::type_print_method_args (const char *physname,
     {
       gdb_puts (" (", stream);
       /* We must demangle this.  */
-      while (isdigit (physname[0]))
+      while (c_isdigit (physname[0]))
 	{
 	  int len = 0;
 	  int i, j;
 	  char *argname;
 
-	  while (isdigit (physname[len]))
+	  while (c_isdigit (physname[len]))
 	    {
 	      len++;
 	    }
diff --git a/gdb/parse.c b/gdb/parse.c
index 6ad4e712a77..e24a0d01d54 100644
--- a/gdb/parse.c
+++ b/gdb/parse.c
@@ -29,7 +29,6 @@
    during the process of parsing; the lower levels of the tree always
    come first in the result.  */
 
-#include <ctype.h>
 #include "arch-utils.h"
 #include "symtab.h"
 #include "gdbtypes.h"
diff --git a/gdb/ppc-linux-tdep.c b/gdb/ppc-linux-tdep.c
index 39566a48d29..b5f8bbfd59e 100644
--- a/gdb/ppc-linux-tdep.c
+++ b/gdb/ppc-linux-tdep.c
@@ -61,7 +61,6 @@
 #include "cli/cli-utils.h"
 #include "parser-defs.h"
 #include "user-regs.h"
-#include <ctype.h>
 #include "elf-bfd.h"
 #include "producer.h"
 #include "target-float.h"
@@ -1712,10 +1711,10 @@ static int
 ppc_stap_is_single_operand (struct gdbarch *gdbarch, const char *s)
 {
   return (*s == 'i' /* Literal number.  */
-	  || (isdigit (*s) && s[1] == '('
-	      && isdigit (s[2])) /* Displacement.  */
-	  || (*s == '(' && isdigit (s[1])) /* Register indirection.  */
-	  || isdigit (*s)); /* Register value.  */
+	  || (c_isdigit (*s) && s[1] == '('
+	      && c_isdigit (s[2])) /* Displacement.  */
+	  || (*s == '(' && c_isdigit (s[1])) /* Register indirection.  */
+	  || c_isdigit (*s)); /* Register value.  */
 }
 
 /* Implementation of `gdbarch_stap_parse_special_token', as defined in
@@ -1725,7 +1724,7 @@ static expr::operation_up
 ppc_stap_parse_special_token (struct gdbarch *gdbarch,
 			      struct stap_parse_info *p)
 {
-  if (isdigit (*p->arg))
+  if (c_isdigit (*p->arg))
     {
       /* This temporary pointer is needed because we have to do a lookahead.
 	  We could be dealing with a register displacement, and in such case
@@ -1734,7 +1733,7 @@ ppc_stap_parse_special_token (struct gdbarch *gdbarch,
       char *regname;
       int len;
 
-      while (isdigit (*s))
+      while (c_isdigit (*s))
 	++s;
 
       if (*s == '(')
diff --git a/gdb/probe.c b/gdb/probe.c
index 6679f39cc67..c2b8270a476 100644
--- a/gdb/probe.c
+++ b/gdb/probe.c
@@ -33,7 +33,6 @@
 #include "ax.h"
 #include "ax-gdb.h"
 #include "location.h"
-#include <ctype.h>
 #include <algorithm>
 #include <optional>
 
@@ -826,7 +825,7 @@ probe_is_linespec_by_keyword (const char **linespecp, const char *const *keyword
       const char *keyword = *csp;
       size_t len = strlen (keyword);
 
-      if (strncmp (s, keyword, len) == 0 && isspace (s[len]))
+      if (strncmp (s, keyword, len) == 0 && c_isspace (s[len]))
 	{
 	  *linespecp += len + 1;
 	  return 1;
diff --git a/gdb/procfs.c b/gdb/procfs.c
index a10574af629..ca7ecbbe190 100644
--- a/gdb/procfs.c
+++ b/gdb/procfs.c
@@ -38,7 +38,6 @@
 #include <sys/syscall.h>
 #include "gdbsupport/gdb_wait.h"
 #include <signal.h>
-#include <ctype.h>
 #include "gdb_bfd.h"
 #include "auxv.h"
 #include "procfs.h"
@@ -3304,7 +3303,7 @@ procfs_target::info_proc (const char *args, enum info_proc_what what)
   gdb_argv built_argv (args);
   for (char *arg : built_argv)
     {
-      if (isdigit (arg[0]))
+      if (c_isdigit (arg[0]))
 	{
 	  pid = strtoul (arg, &tmp, 10);
 	  if (*tmp == '/')
@@ -3415,7 +3414,7 @@ proc_trace_syscalls (const char *args, int from_tty, int entry_or_exit, int mode
     error_no_arg (_("system call to trace"));
 
   pi = find_procinfo_or_die (inferior_ptid.pid (), 0);
-  if (isdigit (args[0]))
+  if (c_isdigit (args[0]))
     {
       const int syscallnum = atoi (args);
 
diff --git a/gdb/producer.c b/gdb/producer.c
index 5d754faedb8..71e1b92e95e 100644
--- a/gdb/producer.c
+++ b/gdb/producer.c
@@ -66,9 +66,9 @@ producer_is_gcc (const char *producer, int *major, int *minor)
 	 "GNU Fortran 4.8.2 20140120 (Red Hat 4.8.2-16) -mtune=generic ..."
 	 "GNU C++14 5.0.0 20150123 (experimental)"
       */
-      while (*cs && !isspace (*cs))
+      while (*cs && !c_isspace (*cs))
 	cs++;
-      if (*cs && isspace (*cs))
+      if (*cs && c_isspace (*cs))
 	cs++;
       if (sscanf (cs, "%d.%d", major, minor) == 2)
 	return 1;
diff --git a/gdb/python/py-mi.c b/gdb/python/py-mi.c
index 9b871d42c92..b2ab4e20e41 100644
--- a/gdb/python/py-mi.c
+++ b/gdb/python/py-mi.c
@@ -218,11 +218,11 @@ py_object_to_mi_key (PyObject *key_obj)
   {
     gdb_assert (name != nullptr);
 
-    if (*name == '\0' || !isalpha (*name))
+    if (*name == '\0' || !c_isalpha (*name))
       return false;
 
     for (; *name != '\0'; ++name)
-      if (!isalnum (*name) && *name != '_' && *name != '-')
+      if (!c_isalnum (*name) && *name != '_' && *name != '-')
 	return false;
 
     return true;
@@ -363,7 +363,7 @@ gdbpy_notify_mi (PyObject *self, PyObject *args, PyObject *kwargs)
     }
   for (int i = 0; i < name_len; i++)
     {
-      if (!isalnum (name[i]) && name[i] != '-')
+      if (!c_isalnum (name[i]) && name[i] != '-')
 	{
 	  PyErr_Format
 	    (PyExc_ValueError,
diff --git a/gdb/python/py-micmd.c b/gdb/python/py-micmd.c
index 72f427f24b2..07db0cca50d 100644
--- a/gdb/python/py-micmd.c
+++ b/gdb/python/py-micmd.c
@@ -350,7 +350,7 @@ micmdpy_init (PyObject *self, PyObject *args, PyObject *kwargs)
       PyErr_SetString (PyExc_ValueError, _("MI command name is empty."));
       return -1;
     }
-  else if ((name_len < 2) || (name[0] != '-') || !isalnum (name[1]))
+  else if ((name_len < 2) || (name[0] != '-') || !c_isalnum (name[1]))
     {
       PyErr_SetString (PyExc_ValueError,
 		       _("MI command name does not start with '-'"
@@ -361,7 +361,7 @@ micmdpy_init (PyObject *self, PyObject *args, PyObject *kwargs)
     {
       for (int i = 2; i < name_len; i++)
 	{
-	  if (!isalnum (name[i]) && name[i] != '-')
+	  if (!c_isalnum (name[i]) && name[i] != '-')
 	    {
 	      PyErr_Format
 		(PyExc_ValueError,
diff --git a/gdb/python/py-objfile.c b/gdb/python/py-objfile.c
index 8f92642d488..a9f5754cfa5 100644
--- a/gdb/python/py-objfile.c
+++ b/gdb/python/py-objfile.c
@@ -556,7 +556,7 @@ objfpy_build_id_ok (const char *string)
     return 0;
   for (i = 0; i < n; ++i)
     {
-      if (!isxdigit (string[i]))
+      if (!c_isxdigit (string[i]))
 	return 0;
     }
   return 1;
diff --git a/gdb/python/python.c b/gdb/python/python.c
index 3b5d06944b2..740b1968742 100644
--- a/gdb/python/python.c
+++ b/gdb/python/python.c
@@ -31,7 +31,6 @@
 #include "python.h"
 #include "extension-priv.h"
 #include "cli/cli-utils.h"
-#include <ctype.h>
 #include "location.h"
 #include "run-on-main-thread.h"
 #include "observable.h"
diff --git a/gdb/record.c b/gdb/record.c
index 248cfaa481a..de1a7a87a8e 100644
--- a/gdb/record.c
+++ b/gdb/record.c
@@ -28,7 +28,6 @@
 #include "interps.h"
 #include "top.h"
 
-#include <ctype.h>
 
 /* This is the debug switch for process record.  */
 unsigned int record_debug = 0;
@@ -423,7 +422,7 @@ get_insn_number (const char **arg)
   begin = *arg;
   pos = skip_spaces (begin);
 
-  if (!isdigit (*pos))
+  if (!c_isdigit (*pos))
     error (_("Expected positive number, got: %s."), pos);
 
   number = strtoulst (pos, &end, 10);
@@ -443,7 +442,7 @@ get_context_size (const char **arg)
 
   pos = skip_spaces (*arg);
 
-  if (!isdigit (*pos))
+  if (!c_isdigit (*pos))
     error (_("Expected positive number, got: %s."), pos);
 
   long result = strtol (pos, &end, 10);
@@ -483,7 +482,7 @@ get_insn_history_modifiers (const char **arg)
 
       for (; *args; ++args)
 	{
-	  if (isspace (*args))
+	  if (c_isspace (*args))
 	    break;
 
 	  if (*args == '/')
@@ -627,7 +626,7 @@ get_call_history_modifiers (const char **arg)
 
       for (; *args; ++args)
 	{
-	  if (isspace (*args))
+	  if (c_isspace (*args))
 	    break;
 
 	  if (*args == '/')
diff --git a/gdb/remote-sim.c b/gdb/remote-sim.c
index 425e50ddfc0..a325ffa5898 100644
--- a/gdb/remote-sim.c
+++ b/gdb/remote-sim.c
@@ -25,7 +25,6 @@
 #include "inferior.h"
 #include "infrun.h"
 #include "value.h"
-#include <ctype.h>
 #include <fcntl.h>
 #include <signal.h>
 #include <setjmp.h>
diff --git a/gdb/remote.c b/gdb/remote.c
index 1d8d9b10339..1eb4f7279cf 100644
--- a/gdb/remote.c
+++ b/gdb/remote.c
@@ -19,7 +19,6 @@
 
 /* See the GDB User Guide for details of the GDB remote protocol.  */
 
-#include <ctype.h>
 #include <fcntl.h>
 #include "exceptions.h"
 #include "gdbsupport/common-inferior.h"
@@ -2559,7 +2558,7 @@ packet_check_result (const char *buf)
       /* The stub recognized the packet request.  Check that the
 	 operation succeeded.  */
       if (buf[0] == 'E'
-	  && isxdigit (buf[1]) && isxdigit (buf[2])
+	  && c_isxdigit (buf[1]) && c_isxdigit (buf[2])
 	  && buf[3] == '\0')
 	/* "Enn"  - definitely an error.  */
 	return packet_result::make_numeric_error (buf + 1);
@@ -11950,7 +11949,7 @@ remote_target::xfer_partial (enum target_object object,
   while (annex[i] && (i < (get_remote_packet_size () - 8)))
     {
       /* Bad caller may have sent forbidden characters.  */
-      gdb_assert (isprint (annex[i]) && annex[i] != '$' && annex[i] != '#');
+      gdb_assert (c_isprint (annex[i]) && annex[i] != '$' && annex[i] != '#');
       *p2++ = annex[i];
       i++;
     }
@@ -12200,7 +12199,7 @@ private:
     for (int i = 0; i < buf.size (); ++i)
       {
 	gdb_byte c = buf[i];
-	if (isprint (c))
+	if (c_isprint (c))
 	  gdb_putc (c, &stb);
 	else
 	  gdb_printf (&stb, "\\x%02x", (unsigned char) c);
diff --git a/gdb/rust-lang.c b/gdb/rust-lang.c
index 360555280c3..4626685e616 100644
--- a/gdb/rust-lang.c
+++ b/gdb/rust-lang.c
@@ -18,7 +18,6 @@
    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
 
 
-#include <ctype.h>
 
 #include "block.h"
 #include "c-lang.h"
@@ -1788,7 +1787,7 @@ rust_language::emitchar (int ch, struct type *chtype,
     gdb_puts ("\\t", stream);
   else if (ch == '\0')
     gdb_puts ("\\0", stream);
-  else if (ch >= 32 && ch <= 127 && isprint (ch))
+  else if (ch >= 32 && ch <= 127 && c_isprint (ch))
     gdb_putc (ch, stream);
   else if (ch <= 255)
     gdb_printf (stream, "\\x%02x", ch);
diff --git a/gdb/s12z-tdep.c b/gdb/s12z-tdep.c
index 28d56356661..0d49f9888c9 100644
--- a/gdb/s12z-tdep.c
+++ b/gdb/s12z-tdep.c
@@ -516,7 +516,7 @@ s12z_print_ccw_info (struct gdbarch *gdbarch,
 	    gdb_putc (ccw_bits[b], file);
 	}
       else
-	gdb_putc (tolower (ccw_bits[b]), file);
+	gdb_putc (c_tolower (ccw_bits[b]), file);
     }
   gdb_putc ('\n', file);
 }
diff --git a/gdb/s390-tdep.c b/gdb/s390-tdep.c
index c5fa24eb231..0cef5f4645d 100644
--- a/gdb/s390-tdep.c
+++ b/gdb/s390-tdep.c
@@ -7057,10 +7057,10 @@ s390_gnu_triplet_regexp (struct gdbarch *gdbarch)
 static int
 s390_stap_is_single_operand (struct gdbarch *gdbarch, const char *s)
 {
-  return ((isdigit (*s) && s[1] == '(' && s[2] == '%') /* Displacement
+  return ((c_isdigit (*s) && s[1] == '(' && s[2] == '%') /* Displacement
 							  or indirection.  */
 	  || *s == '%' /* Register access.  */
-	  || isdigit (*s)); /* Literal number.  */
+	  || c_isdigit (*s)); /* Literal number.  */
 }
 
 /* gdbarch init.  */
diff --git a/gdb/serial.c b/gdb/serial.c
index d66c6379f3b..d047fdf5c75 100644
--- a/gdb/serial.c
+++ b/gdb/serial.c
@@ -17,7 +17,6 @@
    You should have received a copy of the GNU General Public License
    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
 
-#include <ctype.h>
 #include "serial.h"
 #include "cli/cli-cmds.h"
 #include "cli/cli-utils.h"
@@ -116,7 +115,7 @@ serial_logchar (struct ui_file *stream, int ch_type, int ch, int timeout)
 	    break;
 	  default:
 	    gdb_printf (stream,
-			isprint (ch) ? "%c" : "\\x%02x", ch & 0xFF);
+			c_isprint (ch) ? "%c" : "\\x%02x", ch & 0xFF);
 	    break;
 	  }
     }
diff --git a/gdb/solib-rocm.c b/gdb/solib-rocm.c
index c39d9d712a4..c3c2e44505e 100644
--- a/gdb/solib-rocm.c
+++ b/gdb/solib-rocm.c
@@ -511,7 +511,7 @@ rocm_bfd_iovec_open (bfd *abfd, inferior *inferior)
   protocol_end += protocol_delim.length ();
 
   std::transform (protocol.begin (), protocol.end (), protocol.begin (),
-		  [] (unsigned char c) { return std::tolower (c); });
+		  [] (unsigned char c) { return c_tolower (c); });
 
   std::string_view path;
   size_t path_end = uri.find_first_of ("#?", protocol_end);
@@ -526,8 +526,8 @@ rocm_bfd_iovec_open (bfd *abfd, inferior *inferior)
   for (size_t i = 0; i < path.length (); ++i)
     if (path[i] == '%'
 	&& i < path.length () - 2
-	&& std::isxdigit (path[i + 1])
-	&& std::isxdigit (path[i + 2]))
+	&& c_isxdigit (path[i + 1])
+	&& c_isxdigit (path[i + 2]))
       {
 	std::string_view hex_digits = path.substr (i + 1, 2);
 	decoded_path += std::stoi (std::string (hex_digits), 0, 16);
diff --git a/gdb/stabsread.c b/gdb/stabsread.c
index 2d1411e9146..733fc9e6ddc 100644
--- a/gdb/stabsread.c
+++ b/gdb/stabsread.c
@@ -46,7 +46,6 @@
 #include "c-lang.h"
 #include "cp-abi.h"
 #include "cp-support.h"
-#include <ctype.h>
 #include "block.h"
 #include "filenames.h"
 
@@ -3067,7 +3066,7 @@ process_reference (const char **string)
   p = *string + 1;
 
   /* Read number as reference id.  */
-  while (*p && isdigit (*p))
+  while (*p && c_isdigit (*p))
     {
       refnum = refnum * 10 + *p - '0';
       p++;
@@ -3251,7 +3250,7 @@ define_symbol (CORE_ADDR valu, const char *string, int desc, int type,
      deftypes we know how to handle is a local.  */
   if (!strchr ("cfFGpPrStTvVXCR", *p))
 #else
-  if (isdigit (*p) || *p == '(' || *p == '-')
+  if (c_isdigit (*p) || *p == '(' || *p == '-')
 #endif
     deftype = 'l';
   else
@@ -4340,7 +4339,7 @@ again:
       break;
 
     case '@':
-      if (isdigit (**pp) || **pp == '(' || **pp == '-')
+      if (c_isdigit (**pp) || **pp == '(' || **pp == '-')
 	{			/* Member (class & variable) type */
 	  /* FIXME -- we should be doing smash_to_XXX types here.  */
 
diff --git a/gdb/stack.c b/gdb/stack.c
index c0af030bd74..add1c547b55 100644
--- a/gdb/stack.c
+++ b/gdb/stack.c
@@ -3064,7 +3064,7 @@ frame_apply_level_cmd_completer (struct cmd_list_element *ignore,
 
   /* Check if we're past a valid LEVEL already.  */
   if (levels.finished ()
-      && cmd > text && !isspace (cmd[-1]))
+      && cmd > text && !c_isspace (cmd[-1]))
     return;
 
   /* We're past LEVELs, advance word point.  */
@@ -3098,7 +3098,7 @@ frame_apply_cmd_completer (struct cmd_list_element *ignore,
     return;
 
   /* Check if we're past a valid COUNT already.  */
-  if (cmd > text && !isspace (cmd[-1]))
+  if (cmd > text && !c_isspace (cmd[-1]))
     return;
 
   /* We're past COUNT, advance word point.  */
diff --git a/gdb/stap-probe.c b/gdb/stap-probe.c
index 3b692e29238..6c15bce704c 100644
--- a/gdb/stap-probe.c
+++ b/gdb/stap-probe.c
@@ -39,7 +39,6 @@
 #include "expop.h"
 #include "gdbsupport/unordered_map.h"
 
-#include <ctype.h>
 
 /* The name of the SystemTap section where we will find information about
    the probes.  */
@@ -575,14 +574,14 @@ stap_is_integer_prefix (struct gdbarch *gdbarch, const char *s,
       if (r != NULL)
 	*r = "";
 
-      return isdigit (*s) > 0;
+      return c_isdigit (*s) > 0;
     }
 
   for (p = t; *p != NULL; ++p)
     {
       size_t len = strlen (*p);
 
-      if ((len == 0 && isdigit (*s))
+      if ((len == 0 && c_isdigit (*s))
 	  || (len > 0 && strncasecmp (s, *p, len) == 0))
 	{
 	  /* Integers may or may not have a prefix.  The "len == 0"
@@ -732,7 +731,7 @@ stap_parse_register_operand (struct stap_parse_info *p)
 
   struct type *long_type = builtin_type (gdbarch)->builtin_long;
   operation_up disp_op;
-  if (isdigit (*p->arg))
+  if (c_isdigit (*p->arg))
     {
       /* The value of the displacement.  */
       long displacement;
@@ -767,14 +766,14 @@ stap_parse_register_operand (struct stap_parse_info *p)
   start = p->arg;
 
   /* We assume the register name is composed by letters and numbers.  */
-  while (isalnum (*p->arg))
+  while (c_isalnum (*p->arg))
     ++p->arg;
 
   std::string regname (start, p->arg - start);
 
   /* We only add the GDB's register prefix/suffix if we are dealing with
      a numeric register.  */
-  if (isdigit (*start))
+  if (c_isdigit (*start))
     {
       if (gdb_reg_prefix != NULL)
 	regname = gdb_reg_prefix + regname;
@@ -921,7 +920,7 @@ stap_parse_single_operand (struct stap_parse_info *p)
       if (p->inside_paren_p)
 	tmp = skip_spaces (tmp);
 
-      while (isdigit (*tmp))
+      while (c_isdigit (*tmp))
 	{
 	  /* We skip the digit here because we are only interested in
 	     knowing what kind of unary operation this is.  The digit
@@ -959,7 +958,7 @@ stap_parse_single_operand (struct stap_parse_info *p)
 		      (std::move (result)));
 	}
     }
-  else if (isdigit (*p->arg))
+  else if (c_isdigit (*p->arg))
     {
       /* A temporary variable, needed for lookahead.  */
       const char *tmp = p->arg;
@@ -1042,7 +1041,7 @@ stap_parse_argument_conditionally (struct stap_parse_info *p)
 
   expr::operation_up result;
   if (*p->arg == '-' || *p->arg == '~' || *p->arg == '+' || *p->arg == '!'
-      || isdigit (*p->arg)
+      || c_isdigit (*p->arg)
       || gdbarch_stap_is_single_operand (p->gdbarch, p->arg))
     result = stap_parse_single_operand (p);
   else if (*p->arg == '(')
@@ -1111,7 +1110,7 @@ stap_parse_argument_1 (struct stap_parse_info *p,
      This loop shall continue until we run out of characters in the input,
      or until we find a close-parenthesis, which means that we've reached
      the end of a sub-expression.  */
-  while (*p->arg != '\0' && *p->arg != ')' && !isspace (*p->arg))
+  while (*p->arg != '\0' && *p->arg != ')' && !c_isspace (*p->arg))
     {
       const char *tmp_exp_buf;
       enum exp_opcode opcode;
@@ -1270,8 +1269,8 @@ stap_probe::parse_arguments (struct gdbarch *gdbarch)
 	 Where `N' can be [+,-][1,2,4,8].  This is not mandatory, so
 	 we check it here.  If we don't find it, go to the next
 	 state.  */
-      if ((cur[0] == '-' && isdigit (cur[1]) && cur[2] == '@')
-	  || (isdigit (cur[0]) && cur[1] == '@'))
+      if ((cur[0] == '-' && c_isdigit (cur[1]) && cur[2] == '@')
+	  || (c_isdigit (cur[0]) && cur[1] == '@'))
 	{
 	  if (*cur == '-')
 	    {
diff --git a/gdb/symfile.c b/gdb/symfile.c
index 8e4888fe008..15e9ed3bb6b 100644
--- a/gdb/symfile.c
+++ b/gdb/symfile.c
@@ -58,7 +58,6 @@
 #include <sys/types.h>
 #include <fcntl.h>
 #include <sys/stat.h>
-#include <ctype.h>
 #include <chrono>
 #include <algorithm>
 
@@ -2748,7 +2747,7 @@ set_ext_lang_command (const char *args,
     error (_("'%s': Filename extension must begin with '.'"), ext_args.c_str ());
 
   /* Find end of first arg.  */
-  while (*end != '\0' && !isspace (*end))
+  while (*end != '\0' && !c_isspace (*end))
     end++;
 
   if (*end == '\0')
diff --git a/gdb/symtab.c b/gdb/symtab.c
index 245eab20cfe..13416075200 100644
--- a/gdb/symtab.c
+++ b/gdb/symtab.c
@@ -56,7 +56,6 @@
 #include <sys/types.h>
 #include <fcntl.h>
 #include <sys/stat.h>
-#include <ctype.h>
 #include "cp-abi.h"
 #include "cp-support.h"
 #include "observable.h"
@@ -4332,7 +4331,7 @@ operator_chars (const char *p, const char **end)
 
   /* Don't get faked out by `operator' being part of a longer
      identifier.  */
-  if (isalpha (*p) || *p == '_' || *p == '$' || *p == '\0')
+  if (c_isalpha (*p) || *p == '_' || *p == '$' || *p == '\0')
     return *end;
 
   /* Allow some whitespace between `operator' and the operator symbol.  */
@@ -4341,11 +4340,11 @@ operator_chars (const char *p, const char **end)
 
   /* Recognize 'operator TYPENAME'.  */
 
-  if (isalpha (*p) || *p == '_' || *p == '$')
+  if (c_isalpha (*p) || *p == '_' || *p == '$')
     {
       const char *q = p + 1;
 
-      while (isalnum (*q) || *q == '_' || *q == '$')
+      while (c_isalnum (*q) || *q == '_' || *q == '$')
 	q++;
       *end = q;
       return p;
@@ -5119,7 +5118,7 @@ global_symbol_searcher::search () const
 	  int fix = -1;		/* -1 means ok; otherwise number of
 				    spaces needed.  */
 
-	  if (isalpha (*opname) || *opname == '_' || *opname == '$')
+	  if (c_isalpha (*opname) || *opname == '_' || *opname == '$')
 	    {
 	      /* There should 1 space between 'operator' and 'TYPENAME'.  */
 	      if (opname[-1] != ' ' || opname[-2] == ' ')
@@ -5601,7 +5600,7 @@ rbreak_command (const char *regexp, int from_tty)
       if (colon && *(colon + 1) != ':')
 	{
 	  int colon_index = colon - regexp;
-	  while (colon_index > 0 && isspace (regexp[colon_index - 1]))
+	  while (colon_index > 0 && c_isspace (regexp[colon_index - 1]))
 	    --colon_index;
 
 	  file_name = make_unique_xstrndup (regexp, colon_index);
@@ -5853,7 +5852,7 @@ language_search_unquoted_string (const char *text, const char *p)
 {
   for (; p > text; --p)
     {
-      if (isalnum (p[-1]) || p[-1] == '_' || p[-1] == '\0')
+      if (c_isalnum (p[-1]) || p[-1] == '_' || p[-1] == '\0')
 	continue;
       else
 	{
@@ -5873,7 +5872,7 @@ language_search_unquoted_string (const char *text, const char *p)
 		     Unfortunately we have to find it now to decide.  */
 
 		  while (t > text)
-		    if (isalnum (t[-1]) || t[-1] == '_' ||
+		    if (c_isalnum (t[-1]) || t[-1] == '_' ||
 			t[-1] == ' '    || t[-1] == ':' ||
 			t[-1] == '('    || t[-1] == ')')
 		      --t;
@@ -6081,7 +6080,7 @@ default_collect_symbol_completion_matches_break_on
 	     which are in symbols.  */
 	  while (p > text)
 	    {
-	      if (isalnum (p[-1]) || p[-1] == '_' || p[-1] == '\0'
+	      if (c_isalnum (p[-1]) || p[-1] == '_' || p[-1] == '\0'
 		  || p[-1] == ':' || strchr (break_on, p[-1]) != NULL)
 		--p;
 	      else
diff --git a/gdb/thread.c b/gdb/thread.c
index 920d8dc07a8..b6c19f9bfc1 100644
--- a/gdb/thread.c
+++ b/gdb/thread.c
@@ -33,7 +33,6 @@
 #include "regcache.h"
 #include "btrace.h"
 
-#include <ctype.h>
 #include <sys/types.h>
 #include <signal.h>
 #include "ui-out.h"
@@ -1808,7 +1807,7 @@ thread_apply_command_completer (cmd_list_element *ignore,
 
   /* Check if we're past a valid thread ID list already.  */
   if (parser.finished ()
-      && cmd > text && !isspace (cmd[-1]))
+      && cmd > text && !c_isspace (cmd[-1]))
     return;
 
   /* We're past the thread ID list, advance word point.  */
@@ -1871,7 +1870,7 @@ thread_apply_command (const char *tidlist, int from_tty)
   if (*cmd == '\0')
     error (_("Please specify a command following the thread ID list"));
 
-  if (tidlist == cmd || isdigit (cmd[0]))
+  if (tidlist == cmd || c_isdigit (cmd[0]))
     invalid_thread_id_error (cmd);
 
   scoped_restore_current_thread restore_thread;
diff --git a/gdb/tid-parse.c b/gdb/tid-parse.c
index 4e45798b27b..9f79fba6077 100644
--- a/gdb/tid-parse.c
+++ b/gdb/tid-parse.c
@@ -20,7 +20,6 @@
 #include "tid-parse.h"
 #include "inferior.h"
 #include "gdbthread.h"
-#include <ctype.h>
 
 /* See tid-parse.h.  */
 
@@ -184,7 +183,7 @@ tid_range_parser::finished () const
 	 or we are not in a range and not in front of an integer, negative
 	 integer, convenience var or negative convenience var.  */
       return (*m_cur_tok == '\0'
-	      || !(isdigit (*m_cur_tok)
+	      || !(c_isdigit (*m_cur_tok)
 		   || *m_cur_tok == '$'
 		   || *m_cur_tok == '*'));
     case STATE_THREAD_RANGE:
@@ -261,7 +260,7 @@ tid_range_parser::get_tid_or_range (int *inf_num,
 	  m_qualified = true;
 	  p = dot + 1;
 
-	  if (isspace (*p))
+	  if (c_isspace (*p))
 	    return false;
 	}
       else
@@ -272,7 +271,7 @@ tid_range_parser::get_tid_or_range (int *inf_num,
 	}
 
       m_range_parser.init (p);
-      if (p[0] == '*' && (p[1] == '\0' || isspace (p[1])))
+      if (p[0] == '*' && (p[1] == '\0' || c_isspace (p[1])))
 	{
 	  /* Setup the number range parser to return numbers in the
 	     whole [1,INT_MAX] range.  */
diff --git a/gdb/top.c b/gdb/top.c
index b34f291f0e6..f5b9fdc3034 100644
--- a/gdb/top.c
+++ b/gdb/top.c
@@ -69,7 +69,6 @@
 
 #include "event-top.h"
 #include <sys/stat.h>
-#include <ctype.h>
 #include "ui-out.h"
 #include "cli-out.h"
 #include "tracepoint.h"
diff --git a/gdb/tracectf.c b/gdb/tracectf.c
index 0f80d08e6d6..c2231ff32d2 100644
--- a/gdb/tracectf.c
+++ b/gdb/tracectf.c
@@ -28,7 +28,6 @@
 #include "inferior.h"
 #include "gdbthread.h"
 #include "tracefile.h"
-#include <ctype.h>
 #include <algorithm>
 #include "gdbsupport/filestuff.h"
 #include "gdbarch.h"
diff --git a/gdb/tracepoint.c b/gdb/tracepoint.c
index 58aad4430c7..879e4a6b33e 100644
--- a/gdb/tracepoint.c
+++ b/gdb/tracepoint.c
@@ -308,12 +308,12 @@ validate_trace_state_variable_name (const char *name)
 
   /* All digits in the name is reserved for value history
      references.  */
-  for (p = name; isdigit (*p); p++)
+  for (p = name; c_isdigit (*p); p++)
     ;
   if (*p == '\0')
     error (_("$%s is not a valid trace state variable name"), name);
 
-  for (p = name; isalnum (*p) || *p == '_'; p++)
+  for (p = name; c_isalnum (*p) || *p == '_'; p++)
     ;
   if (*p != '\0')
     error (_("$%s is not a valid trace state variable name"), name);
@@ -339,7 +339,7 @@ trace_variable_command (const char *args, int from_tty)
     error (_("Name of trace variable should start with '$'"));
 
   name_start = p;
-  while (isalnum (*p) || *p == '_')
+  while (c_isalnum (*p) || *p == '_')
     p++;
   std::string name (name_start, p - name_start);
 
diff --git a/gdb/tui/tui-win.c b/gdb/tui/tui-win.c
index d4fbbf157f1..b411d074ffe 100644
--- a/gdb/tui/tui-win.c
+++ b/gdb/tui/tui-win.c
@@ -45,7 +45,6 @@
 #include "tui/tui-win.h"
 
 #include "gdb_curses.h"
-#include <ctype.h>
 #include "readline/readline.h"
 #include <signal.h>
 #include <string_view>
@@ -1041,7 +1040,7 @@ parse_scrolling_args (const char *arg,
       /* Process the number of lines to scroll.  */
       std::string copy = arg;
       buf_ptr = &copy[0];
-      if (isdigit (*buf_ptr))
+      if (c_isdigit (*buf_ptr))
 	{
 	  char *num_str;
 
diff --git a/gdb/typeprint.c b/gdb/typeprint.c
index 8f2836a610d..42fbf381c0b 100644
--- a/gdb/typeprint.c
+++ b/gdb/typeprint.c
@@ -31,7 +31,6 @@
 #include "cp-abi.h"
 #include "typeprint.h"
 #include "valprint.h"
-#include <ctype.h>
 #include "cli/cli-utils.h"
 #include "extension.h"
 #include "completer.h"
@@ -367,7 +366,7 @@ whatis_exp (const char *exp, int show)
 	{
 	  int seen_one = 0;
 
-	  for (++exp; *exp && !isspace (*exp); ++exp)
+	  for (++exp; *exp && !c_isspace (*exp); ++exp)
 	    {
 	      switch (*exp)
 		{
@@ -413,7 +412,7 @@ whatis_exp (const char *exp, int show)
 
 	  if (!*exp && !seen_one)
 	    error (_("flag expected"));
-	  if (!isspace (*exp))
+	  if (!c_isspace (*exp))
 	    error (_("expected space after format"));
 	  exp = skip_spaces (exp);
 	}
diff --git a/gdb/unittests/command-def-selftests.c b/gdb/unittests/command-def-selftests.c
index 0a54d31fbc6..095b57f6e95 100644
--- a/gdb/unittests/command-def-selftests.c
+++ b/gdb/unittests/command-def-selftests.c
@@ -72,7 +72,7 @@ check_doc (struct cmd_list_element *commandlist, const char *prefix)
 	   "first line is not terminated with a '.' character");
 
       /* Checks the doc is not terminated with a new line.  */
-      if (isspace (c->doc[strlen (c->doc) - 1]))
+      if (c_isspace (c->doc[strlen (c->doc) - 1]))
 	broken_doc_invariant
 	  (prefix, c->name,
 	   "has superfluous trailing whitespace");
@@ -87,7 +87,7 @@ check_doc (struct cmd_list_element *commandlist, const char *prefix)
 	  else
 	    {
 	      /* \n\n is ok, so we check that explicitly here.  */
-	      if (isspace (nl[-1]) && nl[-1] != '\n')
+	      if (c_isspace (nl[-1]) && nl[-1] != '\n')
 		broken_doc_invariant (prefix, c->name,
 				      "has whitespace before a newline");
 	    }
diff --git a/gdb/utils.c b/gdb/utils.c
index 5994ef9fb55..57c739ee530 100644
--- a/gdb/utils.c
+++ b/gdb/utils.c
@@ -17,7 +17,6 @@
    You should have received a copy of the GNU General Public License
    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
 
-#include <ctype.h>
 #include "gdbsupport/gdb_wait.h"
 #include "gdbsupport/scoped_signal_handler.h"
 #include "event-top.h"
diff --git a/gdb/valprint.c b/gdb/valprint.c
index 305faf73a56..b8c1c06ec87 100644
--- a/gdb/valprint.c
+++ b/gdb/valprint.c
@@ -34,7 +34,6 @@
 #include "gdbsupport/gdb_obstack.h"
 #include "charset.h"
 #include "typeprint.h"
-#include <ctype.h>
 #include <algorithm>
 #include "gdbsupport/byte-vector.h"
 #include "cli/cli-option.h"
diff --git a/gdb/value.c b/gdb/value.c
index 82d9a86e372..c78bb98cb7e 100644
--- a/gdb/value.c
+++ b/gdb/value.c
@@ -35,7 +35,6 @@
 #include "valprint.h"
 #include "cli/cli-decode.h"
 #include "extension.h"
-#include <ctype.h>
 #include "tracepoint.h"
 #include "cp-abi.h"
 #include "user-regs.h"
@@ -3723,11 +3722,11 @@ value_from_history_ref (const char *h, const char **endp)
     len = 2;
 
   /* Find length of numeral string.  */
-  for (; isdigit (h[len]); len++)
+  for (; c_isdigit (h[len]); len++)
     ;
 
   /* Make sure numeral string is not part of an identifier.  */
-  if (h[len] == '_' || isalpha (h[len]))
+  if (h[len] == '_' || c_isalpha (h[len]))
     return NULL;
 
   /* Now collect the index value.  */
diff --git a/gdb/windows-nat.c b/gdb/windows-nat.c
index c001d38fc51..f74ea0cc11b 100644
--- a/gdb/windows-nat.c
+++ b/gdb/windows-nat.c
@@ -2426,7 +2426,7 @@ redir_set_redirection (const char *s, int *inp, int *out, int *err)
   /* cmd.exe recognizes "&N" only immediately after the redirection symbol.  */
   if (*s != '&')
     {
-      while (isspace (*s))  /* skip whitespace before file name */
+      while (c_isspace (*s))  /* skip whitespace before file name */
 	s++;
       *d++ = ' ';	    /* separate file name with a single space */
     }
@@ -2453,7 +2453,7 @@ redir_set_redirection (const char *s, int *inp, int *out, int *err)
 	    s++;
 	  *d++ = *s++;
 	}
-      else if (isspace (*s) && !quote)
+      else if (c_isspace (*s) && !quote)
 	break;
       else
 	*d++ = *s++;
@@ -2489,7 +2489,7 @@ redirect_inferior_handles (const char *cmd_orig, char *cmd,
   int quote = 0;
   bool retval = false;
 
-  while (isspace (*s))
+  while (c_isspace (*s))
     *d++ = *s++;
 
   while (*s)
diff --git a/gdb/xcoffread.c b/gdb/xcoffread.c
index 6528cab633a..d8b99a05911 100644
--- a/gdb/xcoffread.c
+++ b/gdb/xcoffread.c
@@ -23,7 +23,6 @@
 
 #include <sys/types.h>
 #include <fcntl.h>
-#include <ctype.h>
 #ifdef HAVE_SYS_FILE_H
 #include <sys/file.h>
 #endif
diff --git a/gdbserver/gdbreplay.cc b/gdbserver/gdbreplay.cc
index a5170317156..1c6c41c3459 100644
--- a/gdbserver/gdbreplay.cc
+++ b/gdbserver/gdbreplay.cc
@@ -32,7 +32,6 @@
 #if HAVE_SIGNAL_H
 #include <signal.h>
 #endif
-#include <ctype.h>
 #if HAVE_FCNTL_H
 #include <fcntl.h>
 #endif
diff --git a/gdbserver/remote-utils.cc b/gdbserver/remote-utils.cc
index 15f073dd6be..760655994c5 100644
--- a/gdbserver/remote-utils.cc
+++ b/gdbserver/remote-utils.cc
@@ -30,7 +30,6 @@
 #include "gdbsupport/netstuff.h"
 #include "gdbsupport/filestuff.h"
 #include "gdbsupport/gdb-sigmask.h"
-#include <ctype.h>
 #if HAVE_SYS_IOCTL_H
 #include <sys/ioctl.h>
 #endif
@@ -759,7 +758,7 @@ input_interrupt (int unused)
       else if (cc != 1 || c != '\003')
 	{
 	  fprintf (stderr, "input_interrupt, count = %d c = %d ", cc, c);
-	  if (isprint (c))
+	  if (c_isprint (c))
 	    fprintf (stderr, "('%c')\n", c);
 	  else
 	    fprintf (stderr, "('\\x%02x')\n", c & 0xff);
@@ -1165,8 +1164,8 @@ prepare_resume_reply (char *buf, ptid_t ptid, const target_waitstatus &status)
 	       here is convert the buffer from a T packet to an S packet
 	       and the avoid adding any extra content by breaking out.  */
 	    gdb_assert (buf_start[0] == 'T');
-	    gdb_assert (isxdigit (buf_start[1]));
-	    gdb_assert (isxdigit (buf_start[2]));
+	    gdb_assert (c_isxdigit (buf_start[1]));
+	    gdb_assert (c_isxdigit (buf_start[2]));
 	    buf_start[0] = 'S';
 	    buf_start[3] = '\0';
 	    break;
diff --git a/gdbserver/server.cc b/gdbserver/server.cc
index 669c76159ac..6dc805abd4d 100644
--- a/gdbserver/server.cc
+++ b/gdbserver/server.cc
@@ -22,7 +22,6 @@
 #include "tdesc.h"
 #include "gdbsupport/rsp-low.h"
 #include "gdbsupport/signals-state-save-restore.h"
-#include <ctype.h>
 #include <unistd.h>
 #if HAVE_SIGNAL_H
 #include <signal.h>
@@ -1427,7 +1426,7 @@ parse_debug_format_options (const char *arg, int is_monitor)
   debug_timestamp = 0;
 
   /* First remove leading spaces, for "monitor set debug-format".  */
-  while (isspace (*arg))
+  while (c_isspace (*arg))
     ++arg;
 
   std::vector<gdb::unique_xmalloc_ptr<char>> options
@@ -1473,8 +1472,8 @@ parse_debug_format_options (const char *arg, int is_monitor)
 struct debug_opt
 {
   /* NAME is the name of this debug option, this should be a simple string
-     containing no whitespace, starting with a letter from isalpha(), and
-     contain only isalnum() characters and '_' underscore and '-' hyphen.
+     containing no whitespace, starting with a letter from c_isalpha(), and
+     contain only c_isalnum() characters and '_' underscore and '-' hyphen.
 
      SETTER is a callback function used to set the debug variable.  This
      callback will be passed true to enable the debug setting, or false to
@@ -1483,7 +1482,7 @@ struct debug_opt
     : m_name (name),
       m_setter (setter)
   {
-    gdb_assert (isalpha (*name));
+    gdb_assert (c_isalpha (*name));
   }
 
   /* Called to enable or disable the debug setting.  */
diff --git a/gdbserver/thread-db.cc b/gdbserver/thread-db.cc
index 20e1dccab18..b964389e959 100644
--- a/gdbserver/thread-db.cc
+++ b/gdbserver/thread-db.cc
@@ -32,7 +32,6 @@
 #include <dlfcn.h>
 #endif
 #include <limits.h>
-#include <ctype.h>
 
 struct thread_db
 {
@@ -849,7 +848,7 @@ thread_db_handle_monitor_command (char *mon)
 	free (libthread_db_search_path);
 
       /* Skip leading space (if any).  */
-      while (isspace (*cp))
+      while (c_isspace (*cp))
 	++cp;
 
       if (*cp == '\0')
diff --git a/gdbserver/tracepoint.cc b/gdbserver/tracepoint.cc
index b308c821e8f..e1044dca558 100644
--- a/gdbserver/tracepoint.cc
+++ b/gdbserver/tracepoint.cc
@@ -20,7 +20,6 @@
 #include "gdbthread.h"
 #include "gdbsupport/rsp-low.h"
 
-#include <ctype.h>
 #include <fcntl.h>
 #include <unistd.h>
 #include <chrono>
@@ -1867,7 +1866,7 @@ add_tracepoint_action (struct tracepoint *tpoint, const char *packet)
 	    trace_debug ("Want to collect registers");
 	    ++act;
 	    /* skip past hex digits of mask for now */
-	    while (isxdigit(*act))
+	    while (c_isxdigit(*act))
 	      ++act;
 	    break;
 	  }
diff --git a/gdbsupport/pathstuff.cc b/gdbsupport/pathstuff.cc
index ce01c953048..1866949d62d 100644
--- a/gdbsupport/pathstuff.cc
+++ b/gdbsupport/pathstuff.cc
@@ -106,7 +106,7 @@ gdb_realpath_keepfile (const char *filename)
 #ifdef HAVE_DOS_BASED_FILE_SYSTEM
   /* We need to be careful when filename is of the form 'd:foo', which
      is equivalent of d:./foo, which is totally different from d:/foo.  */
-  if (strlen (dir_name) == 2 && isalpha (dir_name[0]) && dir_name[1] == ':')
+  if (strlen (dir_name) == 2 && c_isalpha (dir_name[0]) && dir_name[1] == ':')
     {
       dir_name[2] = '.';
       dir_name[3] = '\000';