Use ui_file_as_string throughout more

This replaces most of the remaining ui_file_xstrdup calls with
ui_file_as_string calls.  Whenever a call was replaced, that led to a
cascade of other necessary adjustments throughout, to make the code
use std::string instead of raw pointers.  And then whenever I added a
std::string as member of a struct, I needed to adjust
allocation/destruction of said struct to use new/delete instead of
xmalloc/xfree.

The stopping point was once gdb built again.  These doesn't seem to be
a way to reasonably split this out further.

Maybe-not-obvious changes:

 - demangle_for_lookup returns a cleanup today.  To get rid of that,
   and avoid unnecessary string dupping/copying, this introduces a
   demangle_result_storage type that the caller instantiates and
   passes to demangle_for_lookup.

 - Many methods returned a "char *" to indicate that the caller owns
   the memory and must free it.  Those are switched to return a
   std::string instead.  Methods that return a "view" into some
   internal string return a "const char *" instead.  I.e., we only
   copy/allocate when necessary.

gdb/ChangeLog:
2016-11-08  Pedro Alves  <palves@redhat.com>

	* ada-lang.c (ada_name_for_lookup, type_as_string): Use and return
	std::string.
	(type_as_string_and_cleanup): Delete.
	(ada_lookup_struct_elt_type): Use type_as_string.
	* ada-lang.h (ada_name_for_lookup): Now returns std::string.
	* ada-varobj.c (ada_varobj_scalar_image): Return a std::string.
	(ada_varobj_describe_child): Make 'child_name' and
	'child_path_expr' parameters std::string pointers.
	(ada_varobj_describe_struct_child, ada_varobj_describe_ptr_child):
	Likewise, and use string_printf.
	(ada_varobj_describe_simple_array_child)
	(ada_varobj_describe_child): Likewise.
	(ada_varobj_get_name_of_child, ada_varobj_get_path_expr_of_child)
	(ada_varobj_get_value_image)
	(ada_varobj_get_value_of_array_variable)
	(ada_varobj_get_value_of_variable, ada_name_of_variable)
	(ada_name_of_child, ada_path_expr_of_child)
	(ada_value_of_variable): Now returns std::string.  Use
	string_printf.
	(ada_value_of_child): Adjust.
	* break-catch-throw.c (check_status_exception_catchpoint): Adjust
	to use std::string.
	* breakpoint.c (watch_command_1): Adjust to use std::string.
	* c-lang.c (c_get_string): Adjust to use std::string.
	* c-typeprint.c (print_name_maybe_canonical): Use std::string.
	* c-varobj.c (varobj_is_anonymous_child): Use ==/!= std::string
	operators.
	(c_name_of_variable): Now returns a std::string.
	(c_describe_child): The 'cname' and 'cfull_expression' output
	parameters are now std::string pointers.  Adjust.
	(c_name_of_child, c_path_expr_of_child, c_value_of_variable)
	(cplus_number_of_children): Adjust to use std::string and
	string_printf.
	(cplus_name_of_variable): Now returns a std::string.
	(cplus_describe_child): The 'cname' and 'cfull_expression' output
	parameters are now std::string pointers.  Adjust.
	(cplus_name_of_child, cplus_path_expr_of_child)
	(cplus_value_of_variable): Now returns a std::string.
	* cp-abi.c (cplus_typename_from_type_info): Return std::string.
	* cp-abi.h (cplus_typename_from_type_info): Return std::string.
	(struct cp_abi_ops) <get_typename_from_type_info>: Return
	std::string.
	* cp-support.c (inspect_type): Use std::string.
	(cp_canonicalize_string_full, cp_canonicalize_string_no_typedefs)
	(cp_canonicalize_string): Return std::string and adjust.
	* cp-support.h (cp_canonicalize_string)
	(cp_canonicalize_string_no_typedefs, cp_canonicalize_string_full):
	Return std::string.
	* dbxread.c (read_dbx_symtab): Use std::string.
	* dwarf2read.c (dwarf2_canonicalize_name): Adjust to use std::string.
	* gdbcmd.h (lookup_struct_elt_type): Adjust to use std::string.
	* gnu-v3-abi.c (gnuv3_get_typeid): Use std::string.
	(gnuv3_get_typename_from_type_info): Return a std::string and
	adjust.
	(gnuv3_get_type_from_type_info): Adjust to use std::string.
	* guile/guile.c (gdbscm_execute_gdb_command): Adjust to use
	std::string.
	* infcmd.c (print_return_value_1): Adjust to use std::string.
	* linespec.c (find_linespec_symbols): Adjust to
	demangle_for_lookup API change.  Use std::string.
	* mi/mi-cmd-var.c (print_varobj, mi_cmd_var_set_format)
	(mi_cmd_var_info_type, mi_cmd_var_info_path_expression)
	(mi_cmd_var_info_expression, mi_cmd_var_evaluate_expression)
	(mi_cmd_var_assign, varobj_update_one): Adjust to use std::string.
	* minsyms.c (lookup_minimal_symbol): Use std::string.
	* python/py-varobj.c (py_varobj_iter_next): Use new instead of
	XNEW.  vitem->name is a std::string now, adjust.
	* rust-exp.y (convert_ast_to_type, convert_name): Adjust to use
	std::string.
	* stabsread.c (define_symbol): Adjust to use std::string.
	* symtab.c (demangle_for_lookup): Now returns 'const char *'.  Add
	a demangle_result_storage parameter.  Use it for storage.
	(lookup_symbol_in_language)
	(lookup_symbol_in_objfile_from_linkage_name): Adjust to new
	demangle_for_lookup API.
	* symtab.h (struct demangle_result_storage): New type.
	(demangle_for_lookup): Now returns 'const char *'.  Add a
	demangle_result_storage parameter.
	* typeprint.c (type_to_string): Return std::string and use
	ui_file_as_string.
	* value.h (type_to_string): Change return type to std::string.
	* varobj-iter.h (struct varobj_item) <name>: Now a std::string.
	(varobj_iter_delete): Use delete instead of xfree.
	* varobj.c (create_child): Return std::string instead of char * in
	output parameter.
	(name_of_variable, name_of_child, my_value_of_variable): Return
	std::string instead of char *.
	(varobj_create, varobj_get_handle): Constify 'objname' parameter.
	Adjust to std::string fields.
	(varobj_get_objname): Return a const char * instead of a char *.
	(varobj_get_expression): Return a std::string.
	(varobj_list_children): Adjust to use std::string.
	(varobj_get_type): Return a std::string.
	(varobj_get_path_expr): Return a const char * instead of a char *.
	Adjust to std::string fields.
	(varobj_get_formatted_value, varobj_get_value): Return a
	std::string.
	(varobj_set_value): Change type of 'expression' parameter to
	std::string.  Use std::string.
	(install_new_value): Use std::string.
	(delete_variable_1): Adjust to use std::string.
	(create_child): Change the 'name' parameter to a std::string
	reference.  Swap it into the new item's name.
	(create_child_with_value): Swap item's name into the new child's
	name.  Use string_printf.
	(new_variable): Use new instead of XNEW.
	(free_variable): Don't xfree fields that are now std::string.
	(name_of_variable, name_of_child): Now returns std::string.
	(value_of_root): Adjust to use std::string.
	(my_value_of_variable, varobj_value_get_print_value): Return
	and use std::string.
	(varobj_value_get_print_value): Adjust to use ui_file_as_string
	and std::string.
	* varobj.h (struct varobj) <name, path_expr, obj_name,
	print_value>: Now std::string's.
	<name_of_variable, name_of_child, path_expr_of_child,
	value_of_variable>: Return std::string.
	(varobj_create, varobj_get_handle): Constify 'objname' parameter.
	(varobj_get_objname): Return a const char * instead of a char *.
	(varobj_get_expression, varobj_get_type): Return a std::string.
	(varobj_get_path_expr): Return a const char * instead of a char *.
	(varobj_get_formatted_value, varobj_get_value): Return a
	std::string.
	(varobj_set_value): Constify 'expression' parameter.
	(varobj_value_get_print_value): Return a std::string.

1 files changed, 4 insertions, 11 deletions

diff --git a/gdb/ada-lang.c b/gdb/ada-lang.c
index 3c04554..d9b46c6 100644
--- a/gdb/ada-lang.c
+++ b/gdb/ada-lang.c
@@ -5871,28 +5871,21 @@ ada_iterate_over_symbols (const struct block *block,
 }
 
 /* If NAME is the name of an entity, return a string that should
-   be used to look that entity up in Ada units.  This string should
-   be deallocated after use using xfree.
+   be used to look that entity up in Ada units.
 
    NAME can have any form that the "break" or "print" commands might
    recognize.  In other words, it does not have to be the "natural"
    name, or the "encoded" name.  */
 
-char *
+std::string
 ada_name_for_lookup (const char *name)
 {
-  char *canon;
   int nlen = strlen (name);
 
   if (name[0] == '<' && name[nlen - 1] == '>')
-    {
-      canon = (char *) xmalloc (nlen - 1);
-      memcpy (canon, name + 1, nlen - 2);
-      canon[nlen - 2] = '\0';
-    }
+    return std::string (name + 1, nlen - 2);
   else
-    canon = xstrdup (ada_encode (ada_fold_name (name)));
-  return canon;
+    return ada_encode (ada_fold_name (name));
 }
 
 /* The result is as for ada_lookup_symbol_list with FULL_SEARCH set