Re: [PATCH 3/5] dwarf2read.c: Make dir_index and file_name_index strong typedefs

[Pedro Alves <palves@redhat.com>]

On 03/29/2017 04:35 PM, Simon Marchi wrote:
> On 2017-03-28 22:24, Pedro Alves wrote:
>> @@ -1169,7 +1179,7 @@ file_entry::include_dir (const line_header *lh)
>> const
>>  {
>>    /* lh->include_dirs is 0-based, but the directory index numbers in
>>       the statement program are 1-based.  */
>> -  return lh->include_dir_at (dir_index - 1);
>> +  return lh->include_dir_at (to_underlying (d_index) - 1);
> 
> Should include_dir_at's parameter be a dir_index?  At this point,
> exposing a zero based index in the line_header interface is exposing its
> internal implementation.  Same for file_name_at.

You're right.  I don't know what I was thinking...

Thanks, here's what I'm squashing before pushing.

From 2ee1360f37c05080f2d1084a458b7218cdaffc2b Mon Sep 17 00:00:00 2001
From: Pedro Alves <palves@redhat.com>
Date: Tue, 4 Apr 2017 19:31:12 +0100
Subject: [PATCH] index

---
 gdb/dwarf2read.c | 36 +++++++++++++++++++++---------------
 1 file changed, 21 insertions(+), 15 deletions(-)

diff --git a/gdb/dwarf2read.c b/gdb/dwarf2read.c
index cd137c9..f18c072 100644
--- a/gdb/dwarf2read.c
+++ b/gdb/dwarf2read.c
@@ -1112,22 +1112,30 @@ struct line_header
   void add_file_name (const char *name, dir_index d_index,
 		      unsigned int mod_time, unsigned int length);
 
-  /* Return the include dir at INDEX (0-based).  Returns NULL if INDEX
+  /* Return the include dir at INDEX (1-based).  Returns NULL if INDEX
      is out of bounds.  */
-  const char *include_dir_at (unsigned int index) const
+  const char *include_dir_at (dir_index index) const
   {
-    if (index >= include_dirs.size ())
+    /* Convert directory index number (1-based) to vector index
+       (0-based).  */
+    size_t vec_index = to_underlying (index) - 1;
+
+    if (vec_index >= include_dirs.size ())
       return NULL;
-    return include_dirs[index];
+    return include_dirs[vec_index];
   }
 
-  /* Return the file name at INDEX (0-based).  Returns NULL if INDEX
+  /* Return the file name at INDEX (1-based).  Returns NULL if INDEX
      is out of bounds.  */
-  file_entry *file_name_at (unsigned int index)
+  file_entry *file_name_at (file_name_index index)
   {
-    if (index >= file_names.size ())
+    /* Convert file name index number (1-based) to vector index
+       (0-based).  */
+    size_t vec_index = to_underlying (index) - 1;
+
+    if (vec_index >= file_names.size ())
       return NULL;
-    return &file_names[index];
+    return &file_names[vec_index];
   }
 
   /* Const version of the above.  */
@@ -1177,9 +1185,7 @@ typedef std::unique_ptr<line_header> line_header_up;
 const char *
 file_entry::include_dir (const line_header *lh) const
 {
-  /* lh->include_dirs is 0-based, but the directory index numbers in
-     the statement program are 1-based.  */
-  return lh->include_dir_at (to_underlying (d_index) - 1);
+  return lh->include_dir_at (d_index);
 }
 
 /* When we construct a partial symbol table entry we only
@@ -18053,7 +18059,7 @@ struct lnp_state_machine
   {
     /* lh->file_names is 0-based, but the file name numbers in the
        statement program are 1-based.  */
-    return the_line_header->file_name_at (to_underlying (file) - 1);
+    return the_line_header->file_name_at (file);
   }
 
   /* The line number header.  */
@@ -18885,11 +18891,11 @@ new_symbol_full (struct die_info *die, struct type *type, struct dwarf2_cu *cu,
 			  cu);
       if (attr)
 	{
-	  unsigned int file_index = DW_UNSND (attr);
+	  file_name_index file_index = (file_name_index) DW_UNSND (attr);
 	  struct file_entry *fe;
 
-	  if (cu->line_header != NULL && file_index > 0)
-	    fe = cu->line_header->file_name_at (file_index - 1);
+	  if (cu->line_header != NULL)
+	    fe = cu->line_header->file_name_at (file_index);
 	  else
 	    fe = NULL;
 
-- 
2.5.5