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GAS: Consistently fix labels at the `.end' pseudo-op 

Fix a functional regression with the `.end' pseudo-op, introduced with
commit ecb4347ade ("Last take: approval for MIPS_STABS_ELF killing"),
<https://sourceware.org/ml/binutils/2002-06/msg00443.html>, and commit
dcd410fe15 ("GNU as 2.14 on IRIX 6: crashes with shared libs"),
<https://sourceware.org/ml/binutils/2003-07/msg00415.html>, which caused
symbol values for labels placed between the end of a function's contents
and its terminating `.end' followed by one of the alignment pseudo-ops
to be different depending on whether either `-mdebug', or `-mno-pdr', or
neither of the command-line options is in effect, be it implied or
specified.

Given debug-label-end.s as follows and the `mips-linux' target we have:

$ cat debug-label-end.s
	.text

	.globl	foo
	.globl	bar
	.align	4, 0
	.ent	foo
foo:
	nop
	.aent	bar
bar:
	.insn
	.end	foo
	.align	4, 0
	.space	16

	.globl	baz
	.ent	baz
baz:
	nop
	.end	baz
	.align	4, 0
	.space	16
$ as -o debug-label-end.o debug-label-end.s
$ readelf -s debug-label-end.o | grep bar
     9: 00000004     0 FUNC    GLOBAL DEFAULT    1 bar
$ as -mdebug -o debug-label-end.o debug-label-end.s
$ readelf -s debug-label-end.o | grep bar
     9: 00000010     0 FUNC    GLOBAL DEFAULT    1 bar
$ as -mno-pdr -o debug-label-end.o debug-label-end.s
$ readelf -s debug-label-end.o | grep bar
     8: 00000010     0 FUNC    GLOBAL DEFAULT    1 bar
$

The reason is the call to `md_flush_pending_output', which in the case
of `mips*-*-*' targets expands to `mips_emit_delays', which in turn
calls `mips_no_prev_insn', which calls `mips_clear_insn_labels', which
clears the list of outstanding labels.  That list is in turn consulted
in `mips_align', called in the interpretation of alignment directives,
and the labels adjusted to the current location.

A call to `md_flush_pending_output' is only made from `s_mips_end' and
then only if `-mpdr' is in effect, which is the default for `*-*-linux*'
and some other `mips*-*-*' targets.  A call to `md_flush_pending_output'
is never made from `ecoff_directive_end', which is used in place of
`s_mips_end' when `-mdebug' is in effect.  Consequently if `-mno-pdr' or
`-mdebug' is in effect the list of outstanding labels makes it through
to any alignment directive that follows and the labels are differently
interpreted depending on the command-lines options used.  And we want
code produced to be always the same.

Call `md_flush_pending_output' unconditionally then in `s_mips_end' and
add such a call from `ecoff_directive_end' as well, as long as the macro
is defined.  While `ecoff_directive_end' is shared among targets, the
only one other than `mips*-*-*' actually using it is `alpha*-*-*' and it
does not define `md_flush_pending_output'.  So the semantics isn't going
to change for it and neither it has to have its `s_alpha_end' updated
or have code in `ecoff_directive_end' conditionalized.

	gas/
	* ecoff.c (ecoff_directive_end) [md_flush_pending_output]: Call
	`md_flush_pending_output'.
	* config/tc-mips.c (s_mips_end) [md_flush_pending_output]: Call
	`md_flush_pending_output' unconditionally.
	* testsuite/gas/mips/debug-label-end-1.d: New test.
	* testsuite/gas/mips/debug-label-end-2.d: New test.
	* testsuite/gas/mips/debug-label-end-3.d: New test.
	* testsuite/gas/mips/debug-label-end.s: New test source.
	* testsuite/gas/mips/mips.exp: Run the new tests.
This commit is contained in:
Maciej W. Rozycki 2017-02-17 20:30:55 +00:00
parent 758d96d834
commit 5ff6a06c21
8 changed files with 101 additions and 4 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

12
gas/ChangeLog
View File

@ -1,3 +1,15 @@
2017-02-22 Maciej W. Rozycki <macro@imgtec.com>
* ecoff.c (ecoff_directive_end) [md_flush_pending_output]: Call
`md_flush_pending_output'.
* config/tc-mips.c (s_mips_end) [md_flush_pending_output]: Call
`md_flush_pending_output' unconditionally.
* testsuite/gas/mips/debug-label-end-1.d: New test.
* testsuite/gas/mips/debug-label-end-2.d: New test.
* testsuite/gas/mips/debug-label-end-3.d: New test.
* testsuite/gas/mips/debug-label-end.s: New test source.
* testsuite/gas/mips/mips.exp: Run the new tests.
2017-02-22 Hans-Peter Nilsson <hp@axis.com>
* testsuite/gas/all/err-sizeof.s: Include cris*-*-* in the list of

8
gas/config/tc-mips.c
View File

@ -19080,6 +19080,10 @@ s_mips_end (int x ATTRIBUTE_UNUSED)
cur_proc_ptr->func_end_sym = exp->X_add_symbol;
}
#ifdef md_flush_pending_output
md_flush_pending_output ();
#endif
/* Generate a .pdr section. */
if (!ECOFF_DEBUGGING && mips_flag_pdr)
{
@ -19088,10 +19092,6 @@ s_mips_end (int x ATTRIBUTE_UNUSED)
expressionS exp;
char *fragp;
#ifdef md_flush_pending_output
md_flush_pending_output ();
#endif
gas_assert (pdr_seg);
subseg_set (pdr_seg, 0);

4
gas/ecoff.c
View File

@ -3025,6 +3025,10 @@ ecoff_directive_end (int ignore ATTRIBUTE_UNUSED)
frag_now),
(bfd_vma) 0, (symint_t) 0, (symint_t) 0);
#ifdef md_flush_pending_output
md_flush_pending_output ();
#endif
cur_proc_ptr = (proc_t *) NULL;
(void) restore_line_pointer (name_end);

21
gas/testsuite/gas/mips/debug-label-end-1.d Normal file
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@ -0,0 +1,21 @@
#readelf: -s
#name: MIPS ECOFF/PDR debug interaction with labels at .end 1
#as: -32 -no-mdebug -mpdr
#source: debug-label-end.s
# Verify that .end finalizes any labels outstanding
# where PDR debug generation is enabled, e.g.:
# Num: Value Size Type Bind Vis Ndx Name
# 7: 00000000 4 FUNC GLOBAL DEFAULT 1 foo
# 8: 00000004 0 FUNC GLOBAL DEFAULT 1 bar
# 9: 00000020 4 FUNC GLOBAL DEFAULT 1 baz
# vs:
# Num: Value Size Type Bind Vis Ndx Name
# 7: 00000000 4 FUNC GLOBAL DEFAULT 1 foo
# 8: 00000010 0 FUNC GLOBAL DEFAULT 1 bar
# 9: 00000020 4 FUNC GLOBAL DEFAULT 1 baz
#...
*[0-9]+: +0+000000 +4 +FUNC +GLOBAL +DEFAULT +[0-9]+ foo
*[0-9]+: +0+000004 +0 +FUNC +GLOBAL +DEFAULT +[0-9]+ bar
*[0-9]+: +0+000020 +4 +FUNC +GLOBAL +DEFAULT +[0-9]+ baz
#pass

17
gas/testsuite/gas/mips/debug-label-end-2.d Normal file
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@ -0,0 +1,17 @@
#readelf: -s
#name: MIPS ECOFF/PDR debug interaction with labels at .end 2
#as: -32 -mdebug -mno-pdr
#source: debug-label-end.s
#dump: debug-label-end-1.d
# Verify that .end finalizes any labels outstanding
# where ECOFF debug generation is enabled, e.g.:
# Num: Value Size Type Bind Vis Ndx Name
# 7: 00000000 4 FUNC GLOBAL DEFAULT 1 foo
# 8: 00000004 0 FUNC GLOBAL DEFAULT 1 bar
# 9: 00000020 4 FUNC GLOBAL DEFAULT 1 baz
# vs:
# Num: Value Size Type Bind Vis Ndx Name
# 7: 00000000 4 FUNC GLOBAL DEFAULT 1 foo
# 8: 00000010 0 FUNC GLOBAL DEFAULT 1 bar
# 9: 00000020 4 FUNC GLOBAL DEFAULT 1 baz

17
gas/testsuite/gas/mips/debug-label-end-3.d Normal file
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@ -0,0 +1,17 @@
#readelf: -s
#name: MIPS ECOFF/PDR debug interaction with labels at .end 3
#as: -32 -no-mdebug -mno-pdr
#source: debug-label-end.s
#dump: debug-label-end-1.d
# Verify that .end finalizes any labels outstanding
# where both ECOFF and PDR generation is disabled, e.g.:
# Num: Value Size Type Bind Vis Ndx Name
# 7: 00000000 4 FUNC GLOBAL DEFAULT 1 foo
# 8: 00000004 0 FUNC GLOBAL DEFAULT 1 bar
# 9: 00000020 4 FUNC GLOBAL DEFAULT 1 baz
# vs:
# Num: Value Size Type Bind Vis Ndx Name
# 7: 00000000 4 FUNC GLOBAL DEFAULT 1 foo
# 8: 00000010 0 FUNC GLOBAL DEFAULT 1 bar
# 9: 00000020 4 FUNC GLOBAL DEFAULT 1 baz

22
gas/testsuite/gas/mips/debug-label-end.s Normal file
View File

@ -0,0 +1,22 @@
.text
.globl foo
.globl bar
.align 4, 0
.ent foo
foo:
nop
.aent bar
bar:
.insn
.end foo
.align 4, 0
.space 16
.globl baz
.ent baz
baz:
nop
.end baz
.align 4, 0
.space 16

4
gas/testsuite/gas/mips/mips.exp
View File

@ -1794,6 +1794,10 @@ if { [istarget mips*-*-vxworks*] } {
run_dump_test_arches "isa-override-1" "" [mips_arch_list_matching mips1]
run_list_test_arches "isa-override-2" "-32" [mips_arch_list_matching mips1]
run_dump_test "debug-label-end-1"
run_dump_test "debug-label-end-2"
run_dump_test "debug-label-end-3"
run_dump_test_arches "r6" [mips_arch_list_matching mips32r6]
if $has_newabi {
run_dump_test_arches "r6-n32" [mips_arch_list_matching mips64r6]