[PATCH] xtensa: fix .init/.fini literals moving

[Max Filippov <jcmvbkbc at gmail dot com>]

Despite the documentation and the comment in xtensa_move_literals, in
the presence of --text-section-literals and --auto-litpools literals are
moved from the separate literal sections into .init and .fini, because
the check in the xtensa_move_literals is incorrect.

This moving was broken with introduction of auto litpools: some literals
now may be lost. This happens because literal frags emitted from .init
and .fini are not closed when new .literal_position marks new literal
pool. Then frag_align(2, 0, 0) changes type of the last literal frag to
rs_align. rs_align frags are skipped in the xtensa_move_literals. As a
result fixups against such literals are not moved out of .init.literal/
.fini.literal sections producing the following assembler error:

  test.S: Warning: fixes not all moved from .init.literal
  test.S: Internal error!

Fix check for .init.literal/.fini.literal in the xtensa_move_literals
and don't let it move literals from there in the presence of
--text-section-literals or --auto-litpools.

2016-02-17  Max Filippov  <jcmvbkbc@gmail.com>
gas/
	* config/tc-xtensa.c (xtensa_move_literals): Fix check for
	.init.literal/.fini.literal section name.
	* testsuite/gas/xtensa/all.exp: Add init-fini-literals to the
	list of xtensa tests.
	* testsuite/gas/xtensa/init-fini-literals.d: New file:
	init-fini-literals test result patterns.
	* testsuite/gas/xtensa/init-fini-literals.s: New file:
	init-fini-literals test.
---
 gas/config/tc-xtensa.c                        | 12 ++++++++++--
 gas/testsuite/gas/xtensa/all.exp              |  1 +
 gas/testsuite/gas/xtensa/init-fini-literals.d | 24 ++++++++++++++++++++++++
 gas/testsuite/gas/xtensa/init-fini-literals.s | 19 +++++++++++++++++++
 4 files changed, 54 insertions(+), 2 deletions(-)
 create mode 100644 gas/testsuite/gas/xtensa/init-fini-literals.d
 create mode 100644 gas/testsuite/gas/xtensa/init-fini-literals.s

diff --git a/gas/config/tc-xtensa.c b/gas/config/tc-xtensa.c
index 36a06cc..5773634 100644
--- a/gas/config/tc-xtensa.c
+++ b/gas/config/tc-xtensa.c
@@ -11061,6 +11061,10 @@ xtensa_move_literals (void)
   fixS *fix, *next_fix, **fix_splice;
   sym_list *lit;
   struct litpool_seg *lps;
+  const char *init_name = INIT_SECTION_NAME;
+  const char *fini_name = FINI_SECTION_NAME;
+  int init_name_len = strlen(init_name);
+  int fini_name_len = strlen(fini_name);
 
   mark_literal_frags (literal_head->next);
 
@@ -11171,9 +11175,13 @@ xtensa_move_literals (void)
 
   for (segment = literal_head->next; segment; segment = segment->next)
     {
+      const char *seg_name = segment_name (segment->seg);
+
       /* Keep the literals for .init and .fini in separate sections.  */
-      if (!strcmp (segment_name (segment->seg), INIT_SECTION_NAME)
-	  || !strcmp (segment_name (segment->seg), FINI_SECTION_NAME))
+      if ((!memcmp (seg_name, init_name, init_name_len) &&
+	   !strcmp (seg_name + init_name_len, ".literal")) ||
+	  (!memcmp (seg_name, fini_name, fini_name_len) &&
+	   !strcmp (seg_name + fini_name_len, ".literal")))
 	continue;
 
       frchain_from = seg_info (segment->seg)->frchainP;
diff --git a/gas/testsuite/gas/xtensa/all.exp b/gas/testsuite/gas/xtensa/all.exp
index 7ff7bd7..6b67320 100644
--- a/gas/testsuite/gas/xtensa/all.exp
+++ b/gas/testsuite/gas/xtensa/all.exp
@@ -102,6 +102,7 @@ if [istarget xtensa*-*-*] then {
     run_dump_test "first_frag_align"
     run_dump_test "auto-litpools"
     run_dump_test "loc"
+    run_dump_test "init-fini-literals"
 }
 
 if [info exists errorInfo] then {
diff --git a/gas/testsuite/gas/xtensa/init-fini-literals.d b/gas/testsuite/gas/xtensa/init-fini-literals.d
new file mode 100644
index 0000000..19ed121
--- /dev/null
+++ b/gas/testsuite/gas/xtensa/init-fini-literals.d
@@ -0,0 +1,24 @@
+#as: --text-section-literals
+#objdump: -r
+#name: check that literals for .init and .fini always go to separate sections
+
+.*: +file format .*xtensa.*
+#...
+RELOCATION RECORDS FOR \[\.init\.literal\]:
+#...
+00000000 R_XTENSA_PLT      init
+#...
+RELOCATION RECORDS FOR \[\.fini\.literal\]:
+#...
+00000000 R_XTENSA_PLT      fini
+#...
+RELOCATION RECORDS FOR \[\.init\]:
+#...
+.* R_XTENSA_SLOT0_OP  \.init\.literal
+.* R_XTENSA_SLOT0_OP  \.init\.literal\+0x00000004
+#...
+RELOCATION RECORDS FOR \[\.fini\]:
+#...
+.* R_XTENSA_SLOT0_OP  \.fini\.literal
+.* R_XTENSA_SLOT0_OP  \.fini\.literal\+0x00000004
+#...
diff --git a/gas/testsuite/gas/xtensa/init-fini-literals.s b/gas/testsuite/gas/xtensa/init-fini-literals.s
new file mode 100644
index 0000000..7c9ec17
--- /dev/null
+++ b/gas/testsuite/gas/xtensa/init-fini-literals.s
@@ -0,0 +1,19 @@
+	.section	.init,"ax",@progbits
+	.literal_position
+	.literal .LC0, init@PLT
+	.literal_position
+	.literal .LC1, 1
+	.align	4
+
+	l32r	a2, .LC0
+	l32r	a2, .LC1
+
+	.section	.fini,"ax",@progbits
+	.literal_position
+	.literal .LC2, fini@PLT
+	.literal_position
+	.literal .LC3, 1
+	.align	4
+
+	l32r	a2, .LC2
+	l32r	a2, .LC3
-- 
2.1.4