gdb: remove symtab::dirname

I think the symtab::dirname method is bogus, or at least very
misleading.  It makes you think that it returns the directory that was
used to find that symtab's file during compilation (i.e. the directory
the file refers to in the DWARF line header file table), or the
directory part of the symtab's filename maybe.  In fact, it returns the
compilation unit's directory, which is the CWD of the compiler, at
compilation time.  At least for DWARF, if the symtab's filename is
relative, it will be relative to that directory.  But if the symtab's
filename is absolute, then the directory returned by symtab::dirname has
nothing to do with the symtab's filename.

Remove symtab::dirname to avoid this confusion, change all users to
fetch the same information through the compunit.  At least, it will be
clear that this is a compunit property, not a symtab property.

Change-Id: I2894c3bf3789d7359a676db3c58be2c10763f5f0

4 files changed, 12 insertions, 19 deletions

diff --git a/gdb/cli/cli-cmds.c b/gdb/cli/cli-cmds.c
index 945fd35..31b493e 100644
--- a/gdb/cli/cli-cmds.c
+++ b/gdb/cli/cli-cmds.c
@@ -2050,8 +2050,8 @@ ambiguous_line_spec (gdb::array_view<const symtab_and_line> sals,
 static int
 cmp_symtabs (const symtab_and_line &sala, const symtab_and_line &salb)
 {
-  const char *dira = sala.symtab->dirname ();
-  const char *dirb = salb.symtab->dirname ();
+  const char *dira = sala.symtab->compunit ()->dirname ();
+  const char *dirb = salb.symtab->compunit ()->dirname ();
   int r;
 
   if (dira == NULL)
diff --git a/gdb/source.c b/gdb/source.c
index 020e94d..2025c93 100644
--- a/gdb/source.c
+++ b/gdb/source.c
@@ -713,8 +713,8 @@ info_source_command (const char *ignore, int from_tty)
 
   cust = s->compunit ();
   gdb_printf (_("Current source file is %s\n"), s->filename);
-  if (s->dirname () != NULL)
-    gdb_printf (_("Compilation directory is %s\n"), s->dirname ());
+  if (s->compunit ()->dirname () != NULL)
+    gdb_printf (_("Compilation directory is %s\n"), s->compunit ()->dirname ());
   if (s->fullname)
     gdb_printf (_("Located in %s\n"), s->fullname);
   const std::vector<off_t> *offsets;
@@ -1180,7 +1180,7 @@ open_source_file (struct symtab *s)
 
   gdb::unique_xmalloc_ptr<char> fullname (s->fullname);
   s->fullname = NULL;
-  scoped_fd fd = find_and_open_source (s->filename, s->dirname (),
+  scoped_fd fd = find_and_open_source (s->filename, s->compunit ()->dirname (),
 				       &fullname);
 
   if (fd.get () < 0)
@@ -1192,9 +1192,9 @@ open_source_file (struct symtab *s)
 	  std::string srcpath;
 	  if (IS_ABSOLUTE_PATH (s->filename))
 	    srcpath = s->filename;
-	  else if (s->dirname () != nullptr)
+	  else if (s->compunit ()->dirname () != nullptr)
 	    {
-	      srcpath = s->dirname ();
+	      srcpath = s->compunit ()->dirname ();
 	      srcpath += SLASH_STRING;
 	      srcpath += s->filename;
 	    }
@@ -1268,10 +1268,11 @@ symtab_to_fullname (struct symtab *s)
 	  /* rewrite_source_path would be applied by find_and_open_source, we
 	     should report the pathname where GDB tried to find the file.  */
 
-	  if (s->dirname () == NULL || IS_ABSOLUTE_PATH (s->filename))
+	  if (s->compunit ()->dirname () == nullptr
+	      || IS_ABSOLUTE_PATH (s->filename))
 	    fullname.reset (xstrdup (s->filename));
 	  else
-	    fullname.reset (concat (s->dirname (), SLASH_STRING,
+	    fullname.reset (concat (s->compunit ()->dirname (), SLASH_STRING,
 				    s->filename, (char *) NULL));
 
 	  s->fullname = rewrite_source_path (fullname.get ()).release ();
diff --git a/gdb/symmisc.c b/gdb/symmisc.c
index e8092e8..5d8d641 100644
--- a/gdb/symmisc.c
+++ b/gdb/symmisc.c
@@ -249,9 +249,9 @@ dump_symtab_1 (struct symtab *symtab, struct ui_file *outfile)
 	      symtab_to_filename_for_display (symtab),
 	      host_address_to_string (symtab));
 
-  if (symtab->dirname () != NULL)
+  if (symtab->compunit ()->dirname () != NULL)
     gdb_printf (outfile, "Compilation directory is %s\n",
-		symtab->dirname ());
+		symtab->compunit ()->dirname ());
   gdb_printf (outfile, "Read from object file %s (%s)\n",
 	      objfile_name (objfile),
 	      host_address_to_string (objfile));
diff --git a/gdb/symtab.h b/gdb/symtab.h
index 25b4f7d..567c0fc 100644
--- a/gdb/symtab.h
+++ b/gdb/symtab.h
@@ -1482,8 +1482,6 @@ struct symtab
 
   program_space *pspace () const;
 
-  const char *dirname () const;
-
   /* Unordered chain of all filetabs in the compunit,  with the exception
      that the "main" source file is the first entry in the list.  */
 
@@ -1769,12 +1767,6 @@ symtab::objfile () const
   return this->compunit ()->objfile ();
 }
 
-inline const char *
-symtab::dirname () const
-{
-  return this->compunit ()->dirname ();
-}
-
 /* Return the language of CUST.  */
 
 extern enum language compunit_language (const struct compunit_symtab *cust);