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Add ALIGNOF
- From: Nathan Sidwell <nathan at codesourcery dot com>
- To: binutils at sources dot redhat dot com
- Date: Mon, 11 Jun 2007 09:32:10 +0100
- Subject: Add ALIGNOF
This patch adds an ALIGNOF linker script operator. It returns the alignment of
an output section.
This is needed for upcoming vxworks __thread support, which is implemented in a
target independent fashion that avoids any existing TLS support such a target
might have.
ok?
nathan
--
Nathan Sidwell :: http://www.codesourcery.com :: CodeSourcery
nathan@codesourcery.com :: http://www.planetfall.pwp.blueyonder.co.uk
2007-06-11 Nathan Sidwell <nathan@codesourcery.com>
ld/
* ldlex.l, ldgram.y: Add ALIGNOF.
* ldexp.c (exp_print_token, foldname): Likewise.
* ld.texinfo: Likewise.
ld/testsuite/
* ld-scripts/alignof.s: New.
* ld-scripts/alignof.t: New
* ld-scripts/alignof.exp: New.
Index: ld/ldlex.l
===================================================================
--- ld/ldlex.l (revision 173558)
+++ ld/ldlex.l (working copy)
@@ -254,6 +254,7 @@ V_IDENTIFIER [*?.$_a-zA-Z\[\]\-\!\^\\]([
<EXPRESSION,BOTH,SCRIPT>"DATA_SEGMENT_END" { RTOKEN(DATA_SEGMENT_END);}
<EXPRESSION,BOTH,SCRIPT>"ADDR" { RTOKEN(ADDR);}
<EXPRESSION,BOTH,SCRIPT>"LOADADDR" { RTOKEN(LOADADDR);}
+<EXPRESSION,BOTH>"ALIGNOF" { RTOKEN(ALIGNOF); }
<EXPRESSION,BOTH>"MAX" { RTOKEN(MAX_K); }
<EXPRESSION,BOTH>"MIN" { RTOKEN(MIN_K); }
<EXPRESSION,BOTH>"ASSERT" { RTOKEN(ASSERT_K); }
Index: ld/ldgram.y
===================================================================
--- ld/ldgram.y (revision 173558)
+++ ld/ldgram.y (working copy)
@@ -137,7 +137,7 @@ static int error_index;
%token NOLOAD DSECT COPY INFO OVERLAY
%token DEFINED TARGET_K SEARCH_DIR MAP ENTRY
%token <integer> NEXT
-%token SIZEOF ADDR LOADADDR MAX_K MIN_K
+%token SIZEOF ALIGNOF ADDR LOADADDR MAX_K MIN_K
%token STARTUP HLL SYSLIB FLOAT NOFLOAT NOCROSSREFS
%token ORIGIN FILL
%token LENGTH CREATE_OBJECT_SYMBOLS INPUT GROUP OUTPUT CONSTRUCTORS
@@ -837,6 +837,8 @@ exp :
| SIZEOF_HEADERS
{ $$ = exp_nameop (SIZEOF_HEADERS,0); }
+ | ALIGNOF '(' NAME ')'
+ { $$ = exp_nameop (ALIGNOF,$3); }
| SIZEOF '(' NAME ')'
{ $$ = exp_nameop (SIZEOF,$3); }
| ADDR '(' NAME ')'
Index: ld/ldexp.c
===================================================================
--- ld/ldexp.c (revision 173558)
+++ ld/ldexp.c (working copy)
@@ -97,6 +97,7 @@ exp_print_token (token_code_type code, i
{ MAP, "MAP" },
{ ENTRY, "ENTRY" },
{ NEXT, "NEXT" },
+ { ALIGNOF, "ALIGNOF" },
{ SIZEOF, "SIZEOF" },
{ ADDR, "ADDR" },
{ LOADADDR, "LOADADDR" },
@@ -606,6 +607,7 @@ fold_name (etree_type *tree)
break;
case SIZEOF:
+ case ALIGNOF:
if (expld.phase != lang_first_phase_enum)
{
int opb = bfd_octets_per_byte (output_bfd);
@@ -620,7 +622,15 @@ fold_name (etree_type *tree)
new_abs (0);
}
else if (os->processed_vma)
- new_abs (os->bfd_section->size / opb);
+ {
+ bfd_vma val;
+
+ val = tree->type.node_code == SIZEOF
+ ? os->bfd_section->size
+ : (bfd_vma)1 << os->bfd_section->alignment_power;
+
+ new_abs (val / opb);
+ }
}
break;
Index: ld/ld.texinfo
===================================================================
--- ld/ld.texinfo (revision 173558)
+++ ld/ld.texinfo (working copy)
@@ -5004,6 +5004,25 @@ of @code{ALIGN} is used to defines the v
The builtin function @code{NEXT} is closely related to @code{ALIGN}.
+@item ALIGNOF(@var{section})
+@kindex ALIGNOF(@var{section})
+@cindex section alignment
+Return the alignment in bytes of the named @var{section}, if that section has
+been allocated. If the section has not been allocated when this is
+evaluated, the linker will report an error. In the following example,
+the alignment of the @code{.output} section is stored as the first
+value in that section.
+@smallexample
+@group
+SECTIONS@{ @dots{}
+ .output @{
+ LONG (ALIGNOF (.output))
+ @dots{}
+ @}
+@dots{} @}
+@end group
+@end smallexample
+
@item BLOCK(@var{exp})
@kindex BLOCK(@var{exp})
This is a synonym for @code{ALIGN}, for compatibility with older linker
Index: ld/testsuite/ld-scripts/alignof.s
===================================================================
--- ld/testsuite/ld-scripts/alignof.s (revision 0)
+++ ld/testsuite/ld-scripts/alignof.s (revision 0)
@@ -0,0 +1,9 @@
+
+ .text
+ .p2align 6
+ .long 0
+
+ .data
+ .p2align 4
+ .long 0
+
Index: ld/testsuite/ld-scripts/alignof.t
===================================================================
--- ld/testsuite/ld-scripts/alignof.t (revision 0)
+++ ld/testsuite/ld-scripts/alignof.t (revision 0)
@@ -0,0 +1,15 @@
+SECTIONS {
+ .text :
+ {
+ tmpdir/alignof.o (.text)
+ }
+ .data :
+ {
+ tmpdir/alignof.o (.data)
+ LONG (ALIGNOF(.text))
+ LONG (ALIGNOF(.data))
+ }
+}
+
+alignof_text = ALIGNOF(.text);
+alignof_data = ALIGNOF(.data);
Index: ld/testsuite/ld-scripts/alignof.exp
===================================================================
--- ld/testsuite/ld-scripts/alignof.exp (revision 0)
+++ ld/testsuite/ld-scripts/alignof.exp (revision 0)
@@ -0,0 +1,57 @@
+# Test ALIGNOF in a linker script.
+# By Nathan Sidwell <nathan@codesourcery.com>
+#
+# This file is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 2 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program; if not, write to the Free Software
+# Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston, MA 02110-1301, USA.
+
+set testname "ALIGNOF"
+
+if ![ld_assemble $as $srcdir/$subdir/alignof.s tmpdir/alignof.o] {
+ unresolved $testname
+ return
+}
+
+if ![ld_simple_link $ld tmpdir/alignof "-T $srcdir/$subdir/alignof.t tmpdir/alignof.o"] {
+ fail $testname
+ return
+}
+
+if ![ld_nm $nm "" tmpdir/alignof] {
+ unresolved $testname
+ return
+}
+
+if {![info exists nm_output(alignof_text)] \
+ || ![info exists nm_output(alignof_data)]} {
+ send_log "bad output from nm\n"
+ verbose "bad output from nm"
+ fail $testname
+ return
+}
+
+if {$nm_output(alignof_text) != 64} {
+ send_log "alignof_text != 64\n"
+ verbose "alignof_text != 64"
+ fail $testname
+ return
+}
+
+if {$nm_output(alignof_data) != 16} {
+ send_log "alignof_data != 16\n"
+ verbose "alignof_data != 16"
+ fail $testname
+ return
+}
+
+pass $testname