[PATCH 1/3 v2] Refactor get_init_files to use std::string

["Christian Biesinger via gdb-patches" <gdb-patches at sourceware dot org>]

To avoid manual memory management.

Tested on buildbot.

gdb/ChangeLog:

2019-08-20  Christian Biesinger  <cbiesinger@google.com>

	* main.c (get_init_files): Change to use std::string.
	(captured_main_1): Update.
	(print_gdb_help): Update.
---
 gdb/main.c | 102 ++++++++++++++++++++++++++---------------------------
 1 file changed, 50 insertions(+), 52 deletions(-)

diff --git a/gdb/main.c b/gdb/main.c
index 678c413021..724b2928a7 100644
--- a/gdb/main.c
+++ b/gdb/main.c
@@ -195,27 +195,26 @@ relocate_gdb_directory (const char *initial, int flag)
    return them in SYSTEM_GDBINIT, HOME_GDBINIT, LOCAL_GDBINIT.  If
    there is no system gdbinit (resp. home gdbinit and local gdbinit)
    to be loaded, then SYSTEM_GDBINIT (resp. HOME_GDBINIT and
-   LOCAL_GDBINIT) is set to NULL.  */
+   LOCAL_GDBINIT) is set to the empty string.  */
 static void
-get_init_files (const char **system_gdbinit,
-		const char **home_gdbinit,
-		const char **local_gdbinit)
+get_init_files (std::string *system_gdbinit,
+		std::string *home_gdbinit,
+		std::string *local_gdbinit)
 {
-  static const char *sysgdbinit = NULL;
-  static char *homeinit = NULL;
-  static const char *localinit = NULL;
+  static std::string sysgdbinit;
+  static std::string homeinit;
+  static std::string localinit;
   static int initialized = 0;
 
   if (!initialized)
     {
       struct stat homebuf, cwdbuf, s;
-      const char *homedir;
 
       if (SYSTEM_GDBINIT[0])
 	{
-	  int datadir_len = strlen (GDB_DATADIR);
-	  int sys_gdbinit_len = strlen (SYSTEM_GDBINIT);
-	  char *relocated_sysgdbinit;
+	  size_t datadir_len = strlen (GDB_DATADIR);
+	  size_t sys_gdbinit_len = strlen (SYSTEM_GDBINIT);
+	  std::string relocated_sysgdbinit;
 
 	  /* If SYSTEM_GDBINIT lives in data-directory, and data-directory
 	     has been provided, search for SYSTEM_GDBINIT there.  */
@@ -226,28 +225,30 @@ get_init_files (const char **system_gdbinit,
 	    {
 	      /* Append the part of SYSTEM_GDBINIT that follows GDB_DATADIR
 		 to gdb_datadir.  */
-	      char *tmp_sys_gdbinit = xstrdup (&SYSTEM_GDBINIT[datadir_len]);
-	      char *p;
 
-	      for (p = tmp_sys_gdbinit; IS_DIR_SEPARATOR (*p); ++p)
+	      size_t start = datadir_len;
+	      for (; IS_DIR_SEPARATOR (SYSTEM_GDBINIT[start]); ++start)
 		continue;
-	      relocated_sysgdbinit = concat (gdb_datadir, SLASH_STRING, p,
-					     (char *) NULL);
-	      xfree (tmp_sys_gdbinit);
+	      relocated_sysgdbinit = std::string (gdb_datadir) + SLASH_STRING +
+		&SYSTEM_GDBINIT[start];
 	    }
 	  else
 	    {
-	      relocated_sysgdbinit = relocate_path (gdb_program_name,
-						    SYSTEM_GDBINIT,
-						    SYSTEM_GDBINIT_RELOCATABLE);
+	      char *relocated = relocate_path (gdb_program_name,
+					       SYSTEM_GDBINIT,
+					       SYSTEM_GDBINIT_RELOCATABLE);
+	      if (relocated != nullptr)
+	        {
+		  relocated_sysgdbinit = relocated;
+		  xfree (relocated);
+		}
 	    }
-	  if (relocated_sysgdbinit && stat (relocated_sysgdbinit, &s) == 0)
+	  if (!relocated_sysgdbinit.empty () &&
+	      stat (relocated_sysgdbinit.c_str (), &s) == 0)
 	    sysgdbinit = relocated_sysgdbinit;
-	  else
-	    xfree (relocated_sysgdbinit);
 	}
 
-      homedir = getenv ("HOME");
+      const char *homedir = getenv ("HOME");
 
       /* If the .gdbinit file in the current directory is the same as
 	 the $HOME/.gdbinit file, it should not be sourced.  homebuf
@@ -260,17 +261,16 @@ get_init_files (const char **system_gdbinit,
 
       if (homedir)
 	{
-	  homeinit = xstrprintf ("%s/%s", homedir, GDBINIT);
-	  if (stat (homeinit, &homebuf) != 0)
+	  homeinit = std::string (homedir) + SLASH_STRING + GDBINIT;
+	  if (stat (homeinit.c_str (), &homebuf) != 0)
 	    {
-	      xfree (homeinit);
-	      homeinit = NULL;
+	      homeinit = "";
 	    }
 	}
 
       if (stat (GDBINIT, &cwdbuf) == 0)
 	{
-	  if (!homeinit
+	  if (homeinit.empty ()
 	      || memcmp ((char *) &homebuf, (char *) &cwdbuf,
 			 sizeof (struct stat)))
 	    localinit = GDBINIT;
@@ -470,11 +470,6 @@ captured_main_1 (struct captured_main_args *context)
   /* All arguments of --directory option.  */
   std::vector<char *> dirarg;
 
-  /* gdb init files.  */
-  const char *system_gdbinit;
-  const char *home_gdbinit;
-  const char *local_gdbinit;
-
   int i;
   int save_auto_load;
   int ret = 1;
@@ -908,6 +903,9 @@ captured_main_1 (struct captured_main_args *context)
   /* Lookup gdbinit files.  Note that the gdbinit file name may be
      overriden during file initialization, so get_init_files should be
      called after gdb_init.  */
+  std::string system_gdbinit;
+  std::string home_gdbinit;
+  std::string local_gdbinit;
   get_init_files (&system_gdbinit, &home_gdbinit, &local_gdbinit);
 
   /* Do these (and anything which might call wrap_here or *_filtered)
@@ -984,16 +982,16 @@ captured_main_1 (struct captured_main_args *context)
      This is done *before* all the command line arguments are
      processed; it sets global parameters, which are independent of
      what file you are debugging or what directory you are in.  */
-  if (system_gdbinit && !inhibit_gdbinit)
-    ret = catch_command_errors (source_script, system_gdbinit, 0);
+  if (!system_gdbinit.empty () && !inhibit_gdbinit)
+    ret = catch_command_errors (source_script, system_gdbinit.c_str (), 0);
 
   /* Read and execute $HOME/.gdbinit file, if it exists.  This is done
      *before* all the command line arguments are processed; it sets
      global parameters, which are independent of what file you are
      debugging or what directory you are in.  */
 
-  if (home_gdbinit && !inhibit_gdbinit && !inhibit_home_gdbinit)
-    ret = catch_command_errors (source_script, home_gdbinit, 0);
+  if (!home_gdbinit.empty () && !inhibit_gdbinit && !inhibit_home_gdbinit)
+    ret = catch_command_errors (source_script, home_gdbinit.c_str (), 0);
 
   /* Process '-ix' and '-iex' options early.  */
   for (i = 0; i < cmdarg_vec.size (); i++)
@@ -1096,20 +1094,20 @@ captured_main_1 (struct captured_main_args *context)
 
   /* Read the .gdbinit file in the current directory, *if* it isn't
      the same as the $HOME/.gdbinit file (it should exist, also).  */
-  if (local_gdbinit)
+  if (!local_gdbinit.empty ())
     {
       auto_load_local_gdbinit_pathname
-	= gdb_realpath (local_gdbinit).release ();
+	= gdb_realpath (local_gdbinit.c_str ()).release ();
 
       if (!inhibit_gdbinit && auto_load_local_gdbinit
-	  && file_is_auto_load_safe (local_gdbinit,
+	  && file_is_auto_load_safe (local_gdbinit.c_str (),
 				     _("auto-load: Loading .gdbinit "
 				       "file \"%s\".\n"),
-				     local_gdbinit))
+				     local_gdbinit.c_str ()))
 	{
 	  auto_load_local_gdbinit_loaded = 1;
 
-	  ret = catch_command_errors (source_script, local_gdbinit, 0);
+	  ret = catch_command_errors (source_script, local_gdbinit.c_str (), 0);
 	}
     }
 
@@ -1203,9 +1201,9 @@ gdb_main (struct captured_main_args *args)
 static void
 print_gdb_help (struct ui_file *stream)
 {
-  const char *system_gdbinit;
-  const char *home_gdbinit;
-  const char *local_gdbinit;
+  std::string system_gdbinit;
+  std::string home_gdbinit;
+  std::string local_gdbinit;
 
   get_init_files (&system_gdbinit, &home_gdbinit, &local_gdbinit);
 
@@ -1283,18 +1281,18 @@ Other options:\n\n\
   fputs_unfiltered (_("\n\
 At startup, GDB reads the following init files and executes their commands:\n\
 "), stream);
-  if (system_gdbinit)
+  if (!system_gdbinit.empty ())
     fprintf_unfiltered (stream, _("\
    * system-wide init file: %s\n\
-"), system_gdbinit);
-  if (home_gdbinit)
+"), system_gdbinit.c_str ());
+  if (!home_gdbinit.empty ())
     fprintf_unfiltered (stream, _("\
    * user-specific init file: %s\n\
-"), home_gdbinit);
-  if (local_gdbinit)
+"), home_gdbinit.c_str ());
+  if (!local_gdbinit.empty ())
     fprintf_unfiltered (stream, _("\
    * local init file (see also 'set auto-load local-gdbinit'): ./%s\n\
-"), local_gdbinit);
+"), local_gdbinit.c_str ());
   fputs_unfiltered (_("\n\
 For more information, type \"help\" from within GDB, or consult the\n\
 GDB manual (available as on-line info or a printed manual).\n\
-- 
2.23.0.rc1.153.gdeed80330f-goog