C++ify gdb/common/environ.c

As part of the preparation necessary for my upcoming task, I'd like to
propose that we turn gdb_environ into a class.  The approach taken
here is simple: the class gdb_environ contains everything that is
needed to manipulate the environment variables.  These variables are
stored in an std::vector<char *>, which can be converted to a 'char
**' and passed as argument to functions that need it.

The usage has not changed much.  As per Pedro's suggestion, this class
uses a static factory method initialization.  This means that when an
instance is created, it is initially empty.  When needed, it has to be
initialized using the static method 'from_host_environ'.

As mentioned before, this is a preparation for an upcoming work that I
will be posting in the next few weeks or so.  For that work, I'll
probably create another data structure that will contain all the
environment variables that were set by the user using the 'set
environment' command, because I'll need access to them.  This will be
much easier with the class-ification of gdb_environ.

As noted, this has been regression-tested with the new version of
environ.exp and no regressions were found.

gdb/ChangeLog:
2017-06-20  Sergio Durigan Junior  <sergiodj@redhat.com>

	* Makefile.in (SUBDIR_UNITTESTS_SRCS): Add
	'unittests/environ-selftests.c'.
	(SUBDIR_UNITTESTS_OBS): Add 'environ-selftests.o'.
	* charset.c (find_charset_names): Declare object 'iconv_env'.
	Update code to use 'iconv_env' object.  Remove call to
	'free_environ'.
	* common/environ.c: Include <utility>.
	(make_environ): Delete function.
	(free_environ): Delete function.
	(gdb_environ::clear): New function.
	(gdb_environ::operator=): New function.
	(gdb_environ::get): Likewise.
	(environ_vector): Delete function.
	(set_in_environ): Delete function.
	(gdb_environ::set): New function.
	(unset_in_environ): Delete function.
	(gdb_environ::unset): New function.
	(gdb_environ::envp): Likewise.
	* common/environ.h: Include <vector>.
	(struct gdb_environ): Delete; transform into...
	(class gdb_environ): ... this class.
	(free_environ): Delete prototype.
	(init_environ, get_in_environ, set_in_environ, unset_in_environ,
	environ_vector): Likewise.
	* infcmd.c (run_command_1): Update code to call
	'envp' from 'gdb_environ' class.
	(environment_info): Update code to call methods from 'gdb_environ'
	class.
	(unset_environment_command): Likewise.
	(path_info): Likewise.
	(path_command): Likewise.
	* inferior.c (inferior::~inferior): Delete call to 'free_environ'.
	(inferior::inferior): Initialize 'environment' using the host's
	information.
	* inferior.h: Remove forward declaration of 'struct gdb_environ'.
	Include "environ.h".
	(class inferior) <environment>: Change type from 'struct
	gdb_environ' to 'gdb_environ'.
	* mi/mi-cmd-env.c (mi_cmd_env_path): Update code to call
	methods from 'gdb_environ' class.
	* solib.c (solib_find_1): Likewise
	* unittests/environ-selftests.c: New file.

gdb/gdbserver/ChangeLog:
2017-06-20  Sergio Durigan Junior  <sergiodj@redhat.com>

	* linux-low.c (linux_create_inferior): Adjust code to access the
	environment information via 'gdb_environ' class.
	* lynx-low.c (lynx_create_inferior): Likewise.
	* server.c (our_environ): Make it an instance of 'gdb_environ'.
	(get_environ): Return a pointer to 'our_environ'.
	(captured_main): Initialize 'our_environ'.
	* server.h (get_environ): Adjust prototype.
	* spu-low.c (spu_create_inferior): Adjust code to access the
	environment information via 'gdb_environ' class.

1 files changed, 12 insertions, 16 deletions

diff --git a/gdb/infcmd.c b/gdb/infcmd.c
index d55163960f..defa7b0c48 100644
--- a/gdb/infcmd.c
+++ b/gdb/infcmd.c
@@ -610,7 +610,7 @@ run_command_1 (char *args, int from_tty, int tbreak_at_main)
      the value now.  */
   run_target->to_create_inferior (run_target, exec_file,
 				  std::string (get_inferior_args ()),
-				  environ_vector (current_inferior ()->environment),
+				  current_inferior ()->environment.envp (),
 				  from_tty);
   /* to_create_inferior should push the target, so after this point we
      shouldn't refer to run_target again.  */
@@ -2131,7 +2131,7 @@ environment_info (char *var, int from_tty)
 {
   if (var)
     {
-      char *val = get_in_environ (current_inferior ()->environment, var);
+      const char *val = current_inferior ()->environment.get (var);
 
       if (val)
 	{
@@ -2149,11 +2149,11 @@ environment_info (char *var, int from_tty)
     }
   else
     {
-      char **vector = environ_vector (current_inferior ()->environment);
+      char **envp = current_inferior ()->environment.envp ();
 
-      while (*vector)
+      for (int idx = 0; envp[idx] != NULL; ++idx)
 	{
-	  puts_filtered (*vector++);
+	  puts_filtered (envp[idx]);
 	  puts_filtered ("\n");
 	}
     }
@@ -2215,10 +2215,10 @@ set_environment_command (char *arg, int from_tty)
       printf_filtered (_("Setting environment variable "
 			 "\"%s\" to null value.\n"),
 		       var);
-      set_in_environ (current_inferior ()->environment, var, "");
+      current_inferior ()->environment.set (var, "");
     }
   else
-    set_in_environ (current_inferior ()->environment, var, val);
+    current_inferior ()->environment.set (var, val);
   xfree (var);
 }
 
@@ -2230,13 +2230,10 @@ unset_environment_command (char *var, int from_tty)
       /* If there is no argument, delete all environment variables.
          Ask for confirmation if reading from the terminal.  */
       if (!from_tty || query (_("Delete all environment variables? ")))
-	{
-	  free_environ (current_inferior ()->environment);
-	  current_inferior ()->environment = make_environ ();
-	}
+	current_inferior ()->environment = gdb_environ::from_host_environ ();
     }
   else
-    unset_in_environ (current_inferior ()->environment, var);
+    current_inferior ()->environment.unset (var);
 }
 
 /* Handle the execution path (PATH variable).  */
@@ -2247,8 +2244,7 @@ static void
 path_info (char *args, int from_tty)
 {
   puts_filtered ("Executable and object file path: ");
-  puts_filtered (get_in_environ (current_inferior ()->environment,
-				 path_var_name));
+  puts_filtered (current_inferior ()->environment.get (path_var_name));
   puts_filtered ("\n");
 }
 
@@ -2261,13 +2257,13 @@ path_command (char *dirname, int from_tty)
   const char *env;
 
   dont_repeat ();
-  env = get_in_environ (current_inferior ()->environment, path_var_name);
+  env = current_inferior ()->environment.get (path_var_name);
   /* Can be null if path is not set.  */
   if (!env)
     env = "";
   exec_path = xstrdup (env);
   mod_path (dirname, &exec_path);
-  set_in_environ (current_inferior ()->environment, path_var_name, exec_path);
+  current_inferior ()->environment.set (path_var_name, exec_path);
   xfree (exec_path);
   if (from_tty)
     path_info ((char *) NULL, from_tty);