[PATCH] MIPS/GAS: Correct file option settings with `.insn'

["Maciej W. Rozycki" <macro at codesourcery dot com>]

Hi,

 Noticed in fixing some GDB DWARF-2 tests for the MIPS target -- if the 
`.insn' directive is used at the beginning of a source file before any 
instructions have been produced, then any symbols it affects will have the 
MIPS16 flag set.  This is because we don't call `file_mips_check_options' 
from `s_insn' and as a result the initial value of -1 of 
`mips_opts.mips16' is taken as true because all the checks throughout GAS 
merely compare it against zero, e.g. `HAVE_CODE_COMPRESSION'.  The result 
is seen in the dump below, where `foo' has the 0xf0 aka `STO_MIPS16' flag 
set.

 In fixing this bug additionally I noticed the `EF_MIPS_ARCH_ASE_M16' or 
`EF_MIPS_ARCH_ASE_MICROMIPS' flag isn't set as appropriate if only `.insn' 
directives have been used to produce code, typically from handcoded 
instruction words.  This is because `file_ase_mips16' and 
`file_ase_micromips' are only set in `append_insn'.  They need to be set 
as appropriate in `s_insn', because `.insn' is meant as an assembly 
instruction equivalent and any data that follows is supposed to be 
interpreted as machine code for the ISA mode currently selected.  The 
problem is seen in the dump below where disassembly of `bar' shows the 
standard MIPS ISA hexadecimal instruction encoding.

 This is fixed with the change below and a corresponding test case is 
provided the source of which has been used to produce this incorrect dump 
too:

insn-opts.o:     file format elf32-tradbigmips

SYMBOL TABLE:
00000000 l    d  .text	00000000 .text
00000000 g     F .text	00000004 0xf0 foo
00000004 g     F .text	00000004 0x80 bar
00000008 g     O .text	00000004 baz

Disassembly of section .text:
00000000 <foo> 0000      	addiu	s0,sp,0
00000002 <foo+0x2> 0000      	addiu	s0,sp,0
00000004 <bar> 00000000 	nop
00000008 <baz> 00000000 00000000                       ........

Regression-tested against the usual MIPS targets.  OK to apply?

2014-10-12  Maciej W. Rozycki  <macro@codesourcery.com>

	gas/
	* config/tc-mips.c (s_insn): Set file options.

	gas/testsuite/
	* gas/mips/insn-opts.d: New test.
	* gas/mips/insn-opts.s: New test source.
	* gas/mips/mips.exp: Run the new test.

  Maciej

binutils-gas-mips-insn-check-options.diff
Index: binutils-fsf-trunk-quilt/gas/config/tc-mips.c
===================================================================
--- binutils-fsf-trunk-quilt.orig/gas/config/tc-mips.c	2014-08-21 13:05:39.000000000 +0100
+++ binutils-fsf-trunk-quilt/gas/config/tc-mips.c	2014-10-11 23:15:09.817805607 +0100
@@ -16003,6 +16003,10 @@ s_cpadd (int ignore ATTRIBUTE_UNUSED)
 static void
 s_insn (int ignore ATTRIBUTE_UNUSED)
 {
+  file_mips_check_options ();
+  file_ase_mips16 |= mips_opts.mips16;
+  file_ase_micromips |= mips_opts.micromips;
+
   mips_mark_labels ();
 
   demand_empty_rest_of_line ();
Index: binutils-fsf-trunk-quilt/gas/testsuite/gas/mips/insn-opts.d
===================================================================
--- /dev/null	1970-01-01 00:00:00.000000000 +0000
+++ binutils-fsf-trunk-quilt/gas/testsuite/gas/mips/insn-opts.d	2014-10-12 00:07:31.157624404 +0100
@@ -0,0 +1,18 @@
+#objdump: -dtz -j .text --prefix-addresses --show-raw-insn
+#name: MIPS .insn default file options
+
+# Check that .insn at the beginning of assembly sees default file options
+# such as the ISA mode right.
+
+.*: +file format .*mips.*
+
+SYMBOL TABLE:
+0+000000 l    d  \.text	0+000000 \.text
+0+000000 g     F \.text	0+000004 foo
+0+000004 g     F \.text	0+000004 0x80 bar
+0+000008 g     O \.text	0+000004 baz
+
+Disassembly of section \.text:
+0+000000 <foo> 00000000 	nop
+0+000004 <bar> 0000 0000 	nop
+0+000008 <baz> .*
Index: binutils-fsf-trunk-quilt/gas/testsuite/gas/mips/insn-opts.s
===================================================================
--- /dev/null	1970-01-01 00:00:00.000000000 +0000
+++ binutils-fsf-trunk-quilt/gas/testsuite/gas/mips/insn-opts.s	2014-10-11 22:49:24.147986735 +0100
@@ -0,0 +1,23 @@
+	.text
+
+	.globl	foo
+	.type	foo, @function
+foo:
+	.insn
+	.dc.l	0
+	.size	foo, . - foo
+
+	.set	micromips
+
+	.globl	bar
+	.type	bar, @function
+bar:
+	.insn
+	.dc.l	0
+	.size	bar, . - bar
+
+	.globl	baz
+	.type	baz, @object
+baz:
+	.dc.l	0
+	.size	baz, . - baz
Index: binutils-fsf-trunk-quilt/gas/testsuite/gas/mips/mips.exp
===================================================================
--- binutils-fsf-trunk-quilt.orig/gas/testsuite/gas/mips/mips.exp	2014-08-21 13:00:22.000000000 +0100
+++ binutils-fsf-trunk-quilt/gas/testsuite/gas/mips/mips.exp	2014-10-11 23:02:15.228926461 +0100
@@ -1097,6 +1097,7 @@ if { [istarget mips*-*-vxworks*] } {
     run_dump_test "align3"
     run_dump_test "odd-float"
     run_dump_test "ehword"
+    run_dump_test "insn-opts"
 
     run_list_test_arches "mips-macro-ill-sfp" "-32 -msingle-float" \
 					[mips_arch_list_matching mips2]