This is the mail archive of the
binutils@sourceware.org
mailing list for the binutils project.
Overlay load address symbols
- From: Alan Modra <amodra at bigpond dot net dot au>
- To: binutils at sourceware dot org
- Date: Fri, 23 Mar 2007 21:23:22 +1030
- Subject: Overlay load address symbols
__load_start_* and __load_stop_* symbols marking overlay load
addresses are currently defined whether or not the symbols are used.
I reckon we should reduce useless symbol table clutter and make them
PROVIDE()'d. Does anyone object to the following?
ld/
* ldlang.c (lang_insert_orphan): Provide start/stop loadaddr syms
rather than defining unconditionally.
(lang_leave_overlay_section): Likewise.
* ld.texinfo (Overlay Description): Update description and examples
for start/stop syms.
ld/testsuite/
* ld-elf/overlay.d: -u symbols we want to see in the output.
Index: ld/ld.texinfo
===================================================================
RCS file: /cvs/src/src/ld/ld.texinfo,v
retrieving revision 1.189
diff -u -p -r1.189 ld.texinfo
--- ld/ld.texinfo 22 Mar 2007 21:18:34 -0000 1.189
+++ ld/ld.texinfo 23 Mar 2007 06:24:48 -0000
@@ -4030,7 +4030,7 @@ section to refer directly to another. @
NOCROSSREFS}.
For each section within the @code{OVERLAY}, the linker automatically
-defines two symbols. The symbol @code{__load_start_@var{secname}} is
+provides two symbols. The symbol @code{__load_start_@var{secname}} is
defined as the starting load address of the section. The symbol
@code{__load_stop_@var{secname}} is defined as the final load address of
the section. Any characters within @var{secname} which are not legal
@@ -4055,7 +4055,7 @@ Here is an example. Remember that this
This will define both @samp{.text0} and @samp{.text1} to start at
address 0x1000. @samp{.text0} will be loaded at address 0x4000, and
@samp{.text1} will be loaded immediately after @samp{.text0}. The
-following symbols will be defined: @code{__load_start_text0},
+following symbols will be defined if referenced: @code{__load_start_text0},
@code{__load_stop_text0}, @code{__load_start_text1},
@code{__load_stop_text1}.
@@ -4077,11 +4077,11 @@ example could have been written identica
@smallexample
@group
.text0 0x1000 : AT (0x4000) @{ o1/*.o(.text) @}
- __load_start_text0 = LOADADDR (.text0);
- __load_stop_text0 = LOADADDR (.text0) + SIZEOF (.text0);
+ PROVIDE (__load_start_text0 = LOADADDR (.text0));
+ PROVIDE (__load_stop_text0 = LOADADDR (.text0) + SIZEOF (.text0));
.text1 0x1000 : AT (0x4000 + SIZEOF (.text0)) @{ o2/*.o(.text) @}
- __load_start_text1 = LOADADDR (.text1);
- __load_stop_text1 = LOADADDR (.text1) + SIZEOF (.text1);
+ PROVIDE (__load_start_text1 = LOADADDR (.text1));
+ PROVIDE (__load_stop_text1 = LOADADDR (.text1) + SIZEOF (.text1));
. = 0x1000 + MAX (SIZEOF (.text0), SIZEOF (.text1));
@end group
@end smallexample
Index: ld/ldlang.c
===================================================================
RCS file: /cvs/src/src/ld/ldlang.c,v
retrieving revision 1.253
diff -u -p -r1.253 ldlang.c
--- ld/ldlang.c 16 Mar 2007 15:13:21 -0000 1.253
+++ ld/ldlang.c 22 Mar 2007 22:04:17 -0000
@@ -1490,8 +1490,9 @@ lang_insert_orphan (asection *s,
e_align = exp_unop (ALIGN_K,
exp_intop ((bfd_vma) 1 << s->alignment_power));
lang_add_assignment (exp_assop ('=', ".", e_align));
- lang_add_assignment (exp_assop ('=', symname,
- exp_nameop (NAME, ".")));
+ lang_add_assignment (exp_provide (symname,
+ exp_nameop (NAME, "."),
+ FALSE));
}
}
@@ -1521,8 +1522,9 @@ lang_insert_orphan (asection *s,
symname = (char *) xmalloc (ps - secname + sizeof "__stop_" + 1);
symname[0] = bfd_get_symbol_leading_char (output_bfd);
sprintf (symname + (symname[0] != 0), "__stop_%s", secname);
- lang_add_assignment (exp_assop ('=', symname,
- exp_nameop (NAME, ".")));
+ lang_add_assignment (exp_provide (symname,
+ exp_nameop (NAME, "."),
+ FALSE));
}
/* Restore the global list pointer. */
@@ -6436,15 +6438,17 @@ lang_leave_overlay_section (fill_type *f
buf = xmalloc (strlen (clean) + sizeof "__load_start_");
sprintf (buf, "__load_start_%s", clean);
- lang_add_assignment (exp_assop ('=', buf,
- exp_nameop (LOADADDR, name)));
+ lang_add_assignment (exp_provide (buf,
+ exp_nameop (LOADADDR, name),
+ FALSE));
buf = xmalloc (strlen (clean) + sizeof "__load_stop_");
sprintf (buf, "__load_stop_%s", clean);
- lang_add_assignment (exp_assop ('=', buf,
- exp_binop ('+',
- exp_nameop (LOADADDR, name),
- exp_nameop (SIZEOF, name))));
+ lang_add_assignment (exp_provide (buf,
+ exp_binop ('+',
+ exp_nameop (LOADADDR, name),
+ exp_nameop (SIZEOF, name)),
+ FALSE));
free (clean);
}
Index: ld/testsuite/ld-elf/overlay.d
===================================================================
RCS file: /cvs/src/src/ld/testsuite/ld-elf/overlay.d,v
retrieving revision 1.1
diff -u -p -r1.1 overlay.d
--- ld/testsuite/ld-elf/overlay.d 23 Aug 2006 14:43:56 -0000 1.1
+++ ld/testsuite/ld-elf/overlay.d 22 Mar 2007 22:04:18 -0000
@@ -1,4 +1,4 @@
-# ld: -T overlay.t
+# ld: -T overlay.t -u __load_start_text1 -u __load_start_text2 -u __load_stop_text1 -u __load_stop_text2
#readelf: -s
#...
--
Alan Modra
IBM OzLabs - Linux Technology Centre