diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index cd71dc3192..8d40fc95ea 100644
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,3 +1,25 @@
+2019-05-16  Sergio Durigan Junior  <sergiodj@redhat.com>
+
+	* i386-tdep.c (i386_stap_parse_special_token_triplet): Change
+	return type to 'bool'.  Adjust comment.  Use 'bool' when
+	appropriate.
+	(i386_stap_parse_special_token_three_arg_disp): Likewise.
+	* stap-probe.c (stap_parse_argument_1): Likewise.
+	(stap_is_operator): Likewise.
+	(stap_is_generic_prefix): Likewise.
+	(stap_is_register_prefix): Likewise.
+	(stap_is_register_indirection_prefix): Likewise.
+	(stap_is_integer_prefix): Likewise.
+	(stap_generic_check_suffix): Likewise.
+	(stap_check_integer_suffix): Likewise.
+	(stap_check_register_suffix): Likewise.
+	(stap_check_register_indirection_suffix): Likewise.
+	(stap_parse_register_operand): Likewise.
+	(stap_parse_single_operand): Likewise.
+	(stap_parse_argument_1): Likewise.
+	(stap_probe::get_argument_count): Likewise.
+	(stap_is_operator): Likewise.
+
 2019-05-16  Tom Tromey  <tromey@adacore.com>
 
 	* darwin-nat.c (thread_info_from_private_thread_info): Add struct
diff --git a/gdb/i386-tdep.c b/gdb/i386-tdep.c
index 54d9dd873b..8990583d87 100644
--- a/gdb/i386-tdep.c
+++ b/gdb/i386-tdep.c
@@ -4033,10 +4033,10 @@ i386_stap_is_single_operand (struct gdbarch *gdbarch, const char *s)
    This function parses operands of the form `-8+3+1(%rbp)', which
    must be interpreted as `*(-8 + 3 - 1 + (void *) $eax)'.
 
-   Return 1 if the operand was parsed successfully, zero
+   Return true if the operand was parsed successfully, false
    otherwise.  */
 
-static int
+static bool
 i386_stap_parse_special_token_triplet (struct gdbarch *gdbarch,
 				       struct stap_parse_info *p)
 {
@@ -4044,7 +4044,7 @@ i386_stap_parse_special_token_triplet (struct gdbarch *gdbarch,
 
   if (isdigit (*s) || *s == '-' || *s == '+')
     {
-      int got_minus[3];
+      bool got_minus[3];
       int i;
       long displacements[3];
       const char *start;
@@ -4053,17 +4053,17 @@ i386_stap_parse_special_token_triplet (struct gdbarch *gdbarch,
       struct stoken str;
       char *endp;
 
-      got_minus[0] = 0;
+      got_minus[0] = false;
       if (*s == '+')
 	++s;
       else if (*s == '-')
 	{
 	  ++s;
-	  got_minus[0] = 1;
+	  got_minus[0] = true;
 	}
 
       if (!isdigit ((unsigned char) *s))
-	return 0;
+	return false;
 
       displacements[0] = strtol (s, &endp, 10);
       s = endp;
@@ -4071,20 +4071,20 @@ i386_stap_parse_special_token_triplet (struct gdbarch *gdbarch,
       if (*s != '+' && *s != '-')
 	{
 	  /* We are not dealing with a triplet.  */
-	  return 0;
+	  return false;
 	}
 
-      got_minus[1] = 0;
+      got_minus[1] = false;
       if (*s == '+')
 	++s;
       else
 	{
 	  ++s;
-	  got_minus[1] = 1;
+	  got_minus[1] = true;
 	}
 
       if (!isdigit ((unsigned char) *s))
-	return 0;
+	return false;
 
       displacements[1] = strtol (s, &endp, 10);
       s = endp;
@@ -4092,26 +4092,26 @@ i386_stap_parse_special_token_triplet (struct gdbarch *gdbarch,
       if (*s != '+' && *s != '-')
 	{
 	  /* We are not dealing with a triplet.  */
-	  return 0;
+	  return false;
 	}
 
-      got_minus[2] = 0;
+      got_minus[2] = false;
       if (*s == '+')
 	++s;
       else
 	{
 	  ++s;
-	  got_minus[2] = 1;
+	  got_minus[2] = true;
 	}
 
       if (!isdigit ((unsigned char) *s))
-	return 0;
+	return false;
 
       displacements[2] = strtol (s, &endp, 10);
       s = endp;
 
       if (*s != '(' || s[1] != '%')
-	return 0;
+	return false;
 
       s += 2;
       start = s;
@@ -4120,7 +4120,7 @@ i386_stap_parse_special_token_triplet (struct gdbarch *gdbarch,
 	++s;
 
       if (*s++ != ')')
-	return 0;
+	return false;
 
       len = s - start - 1;
       regname = (char *) alloca (len + 1);
@@ -4167,10 +4167,10 @@ i386_stap_parse_special_token_triplet (struct gdbarch *gdbarch,
 
       p->arg = s;
 
-      return 1;
+      return true;
     }
 
-  return 0;
+  return false;
 }
 
 /* Helper function for i386_stap_parse_special_token.
@@ -4179,10 +4179,10 @@ i386_stap_parse_special_token_triplet (struct gdbarch *gdbarch,
    (register index * size) + offset', as represented in
    `(%rcx,%rax,8)', or `[OFFSET](BASE_REG,INDEX_REG[,SIZE])'.
 
-   Return 1 if the operand was parsed successfully, zero
+   Return true if the operand was parsed successfully, false
    otherwise.  */
 
-static int
+static bool
 i386_stap_parse_special_token_three_arg_disp (struct gdbarch *gdbarch,
 					      struct stap_parse_info *p)
 {
@@ -4190,9 +4190,9 @@ i386_stap_parse_special_token_three_arg_disp (struct gdbarch *gdbarch,
 
   if (isdigit (*s) || *s == '(' || *s == '-' || *s == '+')
     {
-      int offset_minus = 0;
+      bool offset_minus = false;
       long offset = 0;
-      int size_minus = 0;
+      bool size_minus = false;
       long size = 0;
       const char *start;
       char *base;
@@ -4206,11 +4206,11 @@ i386_stap_parse_special_token_three_arg_disp (struct gdbarch *gdbarch,
       else if (*s == '-')
 	{
 	  ++s;
-	  offset_minus = 1;
+	  offset_minus = true;
 	}
 
       if (offset_minus && !isdigit (*s))
-	return 0;
+	return false;
 
       if (isdigit (*s))
 	{
@@ -4221,7 +4221,7 @@ i386_stap_parse_special_token_three_arg_disp (struct gdbarch *gdbarch,
 	}
 
       if (*s != '(' || s[1] != '%')
-	return 0;
+	return false;
 
       s += 2;
       start = s;
@@ -4230,7 +4230,7 @@ i386_stap_parse_special_token_three_arg_disp (struct gdbarch *gdbarch,
 	++s;
 
       if (*s != ',' || s[1] != '%')
-	return 0;
+	return false;
 
       len_base = s - start;
       base = (char *) alloca (len_base + 1);
@@ -4257,7 +4257,7 @@ i386_stap_parse_special_token_three_arg_disp (struct gdbarch *gdbarch,
 	       index, p->saved_arg);
 
       if (*s != ',' && *s != ')')
-	return 0;
+	return false;
 
       if (*s == ',')
 	{
@@ -4269,14 +4269,14 @@ i386_stap_parse_special_token_three_arg_disp (struct gdbarch *gdbarch,
 	  else if (*s == '-')
 	    {
 	      ++s;
-	      size_minus = 1;
+	      size_minus = true;
 	    }
 
 	  size = strtol (s, &endp, 10);
 	  s = endp;
 
 	  if (*s != ')')
-	    return 0;
+	    return false;
 	}
 
       ++s;
@@ -4330,10 +4330,10 @@ i386_stap_parse_special_token_three_arg_disp (struct gdbarch *gdbarch,
 
       p->arg = s;
 
-      return 1;
+      return true;
     }
 
-  return 0;
+  return false;
 }
 
 /* Implementation of `gdbarch_stap_parse_special_token', as defined in
diff --git a/gdb/stap-probe.c b/gdb/stap-probe.c
index e70940c487..89cd780747 100644
--- a/gdb/stap-probe.c
+++ b/gdb/stap-probe.c
@@ -257,14 +257,14 @@ enum stap_operand_prec
   STAP_OPERAND_PREC_MUL
 };
 
-static void stap_parse_argument_1 (struct stap_parse_info *p, int has_lhs,
+static void stap_parse_argument_1 (struct stap_parse_info *p, bool has_lhs,
 				   enum stap_operand_prec prec);
 
 static void stap_parse_argument_conditionally (struct stap_parse_info *p);
 
-/* Returns 1 if *S is an operator, zero otherwise.  */
+/* Returns true if *S is an operator, false otherwise.  */
 
-static int stap_is_operator (const char *op);
+static bool stap_is_operator (const char *op);
 
 static void
 show_stapexpressiondebug (struct ui_file *file, int from_tty,
@@ -474,9 +474,9 @@ stap_get_expected_argument_type (struct gdbarch *gdbarch,
 
    This function does a case-insensitive match.
 
-   Return 1 if any prefix has been found, zero otherwise.  */
+   Return true if any prefix has been found, false otherwise.  */
 
-static int
+static bool
 stap_is_generic_prefix (struct gdbarch *gdbarch, const char *s,
 			const char **r, const char *const *prefixes)
 {
@@ -487,7 +487,7 @@ stap_is_generic_prefix (struct gdbarch *gdbarch, const char *s,
       if (r != NULL)
 	*r = "";
 
-      return 1;
+      return true;
     }
 
   for (p = prefixes; *p != NULL; ++p)
@@ -496,16 +496,16 @@ stap_is_generic_prefix (struct gdbarch *gdbarch, const char *s,
 	if (r != NULL)
 	  *r = *p;
 
-	return 1;
+	return true;
       }
 
-  return 0;
+  return false;
 }
 
-/* Return 1 if S points to a register prefix, zero otherwise.  For a
-   description of the arguments, look at stap_is_generic_prefix.  */
+/* Return true if S points to a register prefix, false otherwise.  For
+   a description of the arguments, look at stap_is_generic_prefix.  */
 
-static int
+static bool
 stap_is_register_prefix (struct gdbarch *gdbarch, const char *s,
 			 const char **r)
 {
@@ -514,11 +514,11 @@ stap_is_register_prefix (struct gdbarch *gdbarch, const char *s,
   return stap_is_generic_prefix (gdbarch, s, r, t);
 }
 
-/* Return 1 if S points to a register indirection prefix, zero
+/* Return true if S points to a register indirection prefix, false
    otherwise.  For a description of the arguments, look at
    stap_is_generic_prefix.  */
 
-static int
+static bool
 stap_is_register_indirection_prefix (struct gdbarch *gdbarch, const char *s,
 				     const char **r)
 {
@@ -527,15 +527,15 @@ stap_is_register_indirection_prefix (struct gdbarch *gdbarch, const char *s,
   return stap_is_generic_prefix (gdbarch, s, r, t);
 }
 
-/* Return 1 if S points to an integer prefix, zero otherwise.  For a
-   description of the arguments, look at stap_is_generic_prefix.
+/* Return true if S points to an integer prefix, false otherwise.  For
+   a description of the arguments, look at stap_is_generic_prefix.
 
    This function takes care of analyzing whether we are dealing with
    an expected integer prefix, or, if there is no integer prefix to be
    expected, whether we are dealing with a digit.  It does a
    case-insensitive match.  */
 
-static int
+static bool
 stap_is_integer_prefix (struct gdbarch *gdbarch, const char *s,
 			const char **r)
 {
@@ -549,7 +549,7 @@ stap_is_integer_prefix (struct gdbarch *gdbarch, const char *s,
       if (r != NULL)
 	*r = "";
 
-      return isdigit (*s);
+      return isdigit (*s) > 0;
     }
 
   for (p = t; *p != NULL; ++p)
@@ -567,35 +567,35 @@ stap_is_integer_prefix (struct gdbarch *gdbarch, const char *s,
 	  if (r != NULL)
 	    *r = *p;
 
-	  return 1;
+	  return true;
 	}
     }
 
-  return 0;
+  return false;
 }
 
 /* Helper function to check for a generic list of suffixes.  If we are
    not expecting any suffixes, then it just returns 1.  If we are
-   expecting at least one suffix, then it returns 1 if a suffix has
-   been found, zero otherwise.  GDBARCH is the current gdbarch being
+   expecting at least one suffix, then it returns true if a suffix has
+   been found, false otherwise.  GDBARCH is the current gdbarch being
    used.  S is the expression being analyzed.  If R is not NULL, it
    will be used to return the found suffix.  SUFFIXES is the list of
    expected suffixes.  This function does a case-insensitive
    match.  */
 
-static int
+static bool
 stap_generic_check_suffix (struct gdbarch *gdbarch, const char *s,
 			   const char **r, const char *const *suffixes)
 {
   const char *const *p;
-  int found = 0;
+  bool found = false;
 
   if (suffixes == NULL)
     {
       if (r != NULL)
 	*r = "";
 
-      return 1;
+      return true;
     }
 
   for (p = suffixes; *p != NULL; ++p)
@@ -604,18 +604,18 @@ stap_generic_check_suffix (struct gdbarch *gdbarch, const char *s,
 	if (r != NULL)
 	  *r = *p;
 
-	found = 1;
+	found = true;
 	break;
       }
 
   return found;
 }
 
-/* Return 1 if S points to an integer suffix, zero otherwise.  For a
-   description of the arguments, look at
+/* Return true if S points to an integer suffix, false otherwise.  For
+   a description of the arguments, look at
    stap_generic_check_suffix.  */
 
-static int
+static bool
 stap_check_integer_suffix (struct gdbarch *gdbarch, const char *s,
 			   const char **r)
 {
@@ -624,11 +624,11 @@ stap_check_integer_suffix (struct gdbarch *gdbarch, const char *s,
   return stap_generic_check_suffix (gdbarch, s, r, p);
 }
 
-/* Return 1 if S points to a register suffix, zero otherwise.  For a
-   description of the arguments, look at
+/* Return true if S points to a register suffix, false otherwise.  For
+   a description of the arguments, look at
    stap_generic_check_suffix.  */
 
-static int
+static bool
 stap_check_register_suffix (struct gdbarch *gdbarch, const char *s,
 			    const char **r)
 {
@@ -637,11 +637,11 @@ stap_check_register_suffix (struct gdbarch *gdbarch, const char *s,
   return stap_generic_check_suffix (gdbarch, s, r, p);
 }
 
-/* Return 1 if S points to a register indirection suffix, zero
+/* Return true if S points to a register indirection suffix, false
    otherwise.  For a description of the arguments, look at
    stap_generic_check_suffix.  */
 
-static int
+static bool
 stap_check_register_indirection_suffix (struct gdbarch *gdbarch, const char *s,
 					const char **r)
 {
@@ -674,10 +674,11 @@ stap_parse_register_operand (struct stap_parse_info *p)
 {
   /* Simple flag to indicate whether we have seen a minus signal before
      certain number.  */
-  int got_minus = 0;
+  bool got_minus = false;
   /* Flags to indicate whether this register access is being displaced and/or
      indirected.  */
-  int disp_p = 0, indirect_p = 0;
+  bool disp_p = false;
+  bool indirect_p = false;
   struct gdbarch *gdbarch = p->gdbarch;
   /* Needed to generate the register name as a part of an expression.  */
   struct stoken str;
@@ -705,7 +706,7 @@ stap_parse_register_operand (struct stap_parse_info *p)
 
   if (*p->arg == '-')
     {
-      got_minus = 1;
+      got_minus = true;
       ++p->arg;
     }
 
@@ -715,7 +716,7 @@ stap_parse_register_operand (struct stap_parse_info *p)
       long displacement;
       char *endp;
 
-      disp_p = 1;
+      disp_p = true;
       displacement = strtol (p->arg, &endp, 10);
       p->arg = endp;
 
@@ -731,7 +732,7 @@ stap_parse_register_operand (struct stap_parse_info *p)
   /* Getting rid of register indirection prefix.  */
   if (stap_is_register_indirection_prefix (gdbarch, p->arg, &reg_ind_prefix))
     {
-      indirect_p = 1;
+      indirect_p = true;
       p->arg += strlen (reg_ind_prefix);
     }
 
@@ -854,7 +855,7 @@ stap_parse_single_operand (struct stap_parse_info *p)
       char c = *p->arg;
       /* We use this variable to do a lookahead.  */
       const char *tmp = p->arg;
-      int has_digit = 0;
+      bool has_digit = false;
 
       /* Skipping signal.  */
       ++tmp;
@@ -879,7 +880,7 @@ stap_parse_single_operand (struct stap_parse_info *p)
 	     called below ('stap_parse_argument_conditionally' or
 	     'stap_parse_register_operand').  */
 	  ++tmp;
-	  has_digit = 1;
+	  has_digit = true;
 	}
 
       if (has_digit && stap_is_register_indirection_prefix (gdbarch, tmp,
@@ -1023,7 +1024,7 @@ stap_parse_argument_conditionally (struct stap_parse_info *p)
    better understand what this function does.  */
 
 static void
-stap_parse_argument_1 (struct stap_parse_info *p, int has_lhs,
+stap_parse_argument_1 (struct stap_parse_info *p, bool has_lhs,
 		       enum stap_operand_prec prec)
 {
   /* This is an operator-precedence parser.
@@ -1295,7 +1296,7 @@ stap_probe::get_argument_count (struct frame_info *frame)
 	this->parse_arguments (gdbarch);
       else
 	{
-	  static int have_warned_stap_incomplete = 0;
+	  static bool have_warned_stap_incomplete = false;
 
 	  if (!have_warned_stap_incomplete)
 	    {
@@ -1303,7 +1304,7 @@ stap_probe::get_argument_count (struct frame_info *frame)
 "The SystemTap SDT probe support is not fully implemented on this target;\n"
 "you will not be able to inspect the arguments of the probes.\n"
 "Please report a bug against GDB requesting a port to this target."));
-	      have_warned_stap_incomplete = 1;
+	      have_warned_stap_incomplete = true;
 	    }
 
 	  /* Marking the arguments as "already parsed".  */
@@ -1315,13 +1316,13 @@ stap_probe::get_argument_count (struct frame_info *frame)
   return m_parsed_args.size ();
 }
 
-/* Return 1 if OP is a valid operator inside a probe argument, or zero
-   otherwise.  */
+/* Return true if OP is a valid operator inside a probe argument, or
+   false otherwise.  */
 
-static int
+static bool
 stap_is_operator (const char *op)
 {
-  int ret = 1;
+  bool ret = true;
 
   switch (*op)
     {
@@ -1340,12 +1341,12 @@ stap_is_operator (const char *op)
 
     case '=':
       if (op[1] != '=')
-	ret = 0;
+	ret = false;
       break;
 
     default:
       /* We didn't find any operator.  */
-      ret = 0;
+      ret = false;
     }
 
   return ret;
