From: Jim Blandy <jimb@codesourcery.com>
Date: Fri, 12 Sep 2003 23:34:55 +0000 (+0000)
Subject: * dbxread.c (read_dbx_symtab): Add FIXME about finding section
X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=4f49b26b87af3624ba0170fcb54d450a7812402a;p=binutils-gdb.git

* dbxread.c (read_dbx_symtab): Add FIXME about finding section
offsets for global and static variables.
---

diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index 0060e87e798..17f2be97218 100644
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,5 +1,8 @@
 2003-09-12  Jim Blandy  <jimb@redhat.com>
 
+	* dbxread.c (read_dbx_symtab): Add FIXME about finding section
+	offsets for global and static variables.
+
 	* dbxread.c (read_dbx_symtab): The N_DATA and N_DATA | N_EXT
 	symbol types are, by definition, in the .data section, so it is
 	correct to use SECT_OFF_DATA (objfile) here, not data_sect_index.
diff --git a/gdb/dbxread.c b/gdb/dbxread.c
index d0b3710c5d8..57201307066 100644
--- a/gdb/dbxread.c
+++ b/gdb/dbxread.c
@@ -1357,7 +1357,26 @@ read_dbx_symtab (struct objfile *objfile)
   textlow_not_set = 1;
   has_line_numbers = 0;
 
-  /* If the objfile has no .data section, try using the .bss section.  */
+  /* FIXME: jimb/2003-09-12: We don't apply the right section's offset
+     to global and static variables.  The stab for a global or static
+     variable doesn't give us any indication of which section it's in,
+     so we can't tell immediately which offset in
+     objfile->section_offsets we should apply to the variable's
+     address.
+
+     We could certainly find out which section contains the variable
+     by looking up the variable's unrelocated address with
+     find_pc_section, but that would be expensive; this is the
+     function that constructs the partial symbol tables by examining
+     every symbol in the entire executable, and it's
+     performance-critical.  So that expense would not be welcome.  I'm
+     not sure what to do about this at the moment.
+
+     What we have done for years is to simply assume that the .data
+     section's offset is appropriate for all global and static
+     variables.  Recently, this was expanded to fall back to the .bss
+     section's offset if there is no .data section, and then to the
+     .rodata section's offset.  */
   data_sect_index = objfile->sect_index_data;
   if (data_sect_index == -1)
     data_sect_index = SECT_OFF_BSS (objfile);