x86: Update segment register check in Intel syntax

https://sourceware.org/ml/binutils/2009-04/msg00223.html

introduced a new Intel syntax parser which accepts

	mov	eax, fs:gs:[eax]

It ignores anything between ':'s after fs and treats

	mov	eax, DWORD PTR fs:foobar:16
	mov	eax, DWORD PTR fs:foobar:barfoo:16
	mov	eax, DWORD PTR fs:ds:16
	mov	eax, DWORD PTR fs:ds:cs:16

as

	mov	eax, DWORD PTR fs:16

This patch updates segment register check and only allows a single ':'.

	PR gas/21874
	* config/tc-i386-intel.c (i386_intel_operand): Update segment
	register check.
	* testsuite/gas/i386/intelok.s: Replace "fs:gs:[eax]" with
	"fs:[eax]".
	* testsuite/gas/i386/inval-seg.s: Add tests for invalid segment
	register.
	* testsuite/gas/i386/x86-64-inval-seg.s: Likewise.
	* testsuite/gas/i386/inval-seg.l: Updated.
	* testsuite/gas/i386/x86-64-inval-seg.l: Likewise.

7 files changed, 57 insertions, 18 deletions

diff --git a/gas/ChangeLog b/gas/ChangeLog
index 1a3439d9e12..81ce3f7f70f 100644
--- a/gas/ChangeLog
+++ b/gas/ChangeLog
@@ -1,3 +1,16 @@
+2017-08-01  H.J. Lu  <hongjiu.lu@intel.com>
+
+	PR gas/21874
+	* config/tc-i386-intel.c (i386_intel_operand): Update segment
+	register check.
+	* testsuite/gas/i386/intelok.s: Replace "fs:gs:[eax]" with
+	"fs:[eax]".
+	* testsuite/gas/i386/inval-seg.s: Add tests for invalid segment
+	register.
+	* testsuite/gas/i386/x86-64-inval-seg.s: Likewise.
+	* testsuite/gas/i386/inval-seg.l: Updated.
+	* testsuite/gas/i386/x86-64-inval-seg.l: Likewise.
+
 2017-07-31  John David Anglin  <danglin@gcc.gnu.org>
 
 	* config/tc-hppa.c (pa_ip): Clear `d' bit in branch on bit instructions
diff --git a/gas/config/tc-i386-intel.c b/gas/config/tc-i386-intel.c
index 92ed98ee6b7..9e8135e3bac 100644
--- a/gas/config/tc-i386-intel.c
+++ b/gas/config/tc-i386-intel.c
@@ -932,13 +932,7 @@ i386_intel_operand (char *operand_string, int got_a_float)
 
       if (intel_state.seg)
 	{
-	  for (;;)
-	    {
-	      expP = symbol_get_value_expression (intel_state.seg);
-	      if (expP->X_op != O_full_ptr)
-		break;
-	      intel_state.seg = expP->X_add_symbol;
-	    }
+	  expP = symbol_get_value_expression (intel_state.seg);
 	  if (expP->X_op != O_register)
 	    {
 	      as_bad (_("segment register name expected"));
diff --git a/gas/testsuite/gas/i386/intelok.s b/gas/testsuite/gas/i386/intelok.s
index eae9c2d5092..4c16613e54d 100644
--- a/gas/testsuite/gas/i386/intelok.s
+++ b/gas/testsuite/gas/i386/intelok.s
@@ -150,7 +150,7 @@ start:
 	mov	eax, [eax[ecx]]
 	mov	eax, [[eax][ecx]]
 	mov	eax, es:[eax]
-	mov	eax, fs:gs:[eax]
+	mov	eax, fs:[eax]
 
 	# expressions
 
diff --git a/gas/testsuite/gas/i386/inval-seg.l b/gas/testsuite/gas/i386/inval-seg.l
index efe190e9998..c1bbef93ab1 100644
--- a/gas/testsuite/gas/i386/inval-seg.l
+++ b/gas/testsuite/gas/i386/inval-seg.l
@@ -1,10 +1,20 @@
 .*: Assembler messages:
 .*:3: Error: .*
 .*:4: Error: .*
+.*:7: Error: .*
+.*:8: Error: .*
+.*:9: Error: .*
+.*:10: Error: .*
 GAS LISTING .*
 
 
-   1 [ 	]*	.text
-   2 [ 	]*# All the following should be illegal
-   3 [ 	]*	movl	%ds,\(%eax\)
-   4 [ 	]*	movl	\(%eax\),%ds
+[ 	]*1[ 	]+\.text
+[ 	]*2[ 	]+\# All the following should be illegal
+[ 	]*3[ 	]+movl	%ds,\(%eax\)
+[ 	]*4[ 	]+movl	\(%eax\),%ds
+[ 	]*5[ 	]+
+[ 	]*6[ 	]+\.intel_syntax noprefix
+[ 	]*7[ 	]+mov	eax, DWORD PTR fs:foobar:16
+[ 	]*8[ 	]+mov	eax, DWORD PTR fs:foobar:barfoo:16
+[ 	]*9[ 	]+mov	eax, DWORD PTR fs:ds:16
+[ 	]*10[ 	]+mov	eax, DWORD PTR fs:ds:cs:16
diff --git a/gas/testsuite/gas/i386/inval-seg.s b/gas/testsuite/gas/i386/inval-seg.s
index 4cc222145e8..b23d87de33e 100644
--- a/gas/testsuite/gas/i386/inval-seg.s
+++ b/gas/testsuite/gas/i386/inval-seg.s
@@ -2,3 +2,9 @@
 # All the following should be illegal
 	movl	%ds,(%eax)
 	movl	(%eax),%ds
+
+	.intel_syntax noprefix
+	mov	eax, DWORD PTR fs:foobar:16
+	mov	eax, DWORD PTR fs:foobar:barfoo:16
+	mov	eax, DWORD PTR fs:ds:16
+	mov	eax, DWORD PTR fs:ds:cs:16
diff --git a/gas/testsuite/gas/i386/x86-64-inval-seg.l b/gas/testsuite/gas/i386/x86-64-inval-seg.l
index adef5d41d44..51deb15e55f 100644
--- a/gas/testsuite/gas/i386/x86-64-inval-seg.l
+++ b/gas/testsuite/gas/i386/x86-64-inval-seg.l
@@ -3,12 +3,22 @@
 .*:4: Error: .*
 .*:5: Error: .*
 .*:6: Error: .*
+.*:9: Error: .*
+.*:10: Error: .*
+.*:11: Error: .*
+.*:12: Error: .*
 GAS LISTING .*
 
 
-   1 [ 	]*	.text
-   2 [ 	]*# All the following should be illegal
-   3 [ 	]*	movq	%ds,\(%rax\)
-   4 [ 	]*	movl	%ds,\(%rax\)
-   5 [ 	]*	movq	\(%rax\),%ds
-   6 [ 	]*	movl	\(%rax\),%ds
+[ 	]*1[ 	]+\.text
+[ 	]*2[ 	]+\# All the following should be illegal
+[ 	]*3[ 	]+movq	%ds,\(%rax\)
+[ 	]*4[ 	]+movl	%ds,\(%rax\)
+[ 	]*5[ 	]+movq	\(%rax\),%ds
+[ 	]*6[ 	]+movl	\(%rax\),%ds
+[ 	]*7[ 	]+
+[ 	]*8[ 	]+\.intel_syntax noprefix
+[ 	]*9[ 	]+mov	eax, DWORD PTR fs:foobar:16
+[ 	]*10[ 	]+mov	eax, DWORD PTR fs:foobar:barfoo:16
+[ 	]*11[ 	]+mov	eax, DWORD PTR fs:ds:16
+[ 	]*12[ 	]+mov	eax, DWORD PTR fs:ds:cs:16
diff --git a/gas/testsuite/gas/i386/x86-64-inval-seg.s b/gas/testsuite/gas/i386/x86-64-inval-seg.s
index bb547422364..cfe46cf639f 100644
--- a/gas/testsuite/gas/i386/x86-64-inval-seg.s
+++ b/gas/testsuite/gas/i386/x86-64-inval-seg.s
@@ -4,3 +4,9 @@
 	movl	%ds,(%rax)
 	movq	(%rax),%ds
 	movl	(%rax),%ds
+
+	.intel_syntax noprefix
+	mov	eax, DWORD PTR fs:foobar:16
+	mov	eax, DWORD PTR fs:foobar:barfoo:16
+	mov	eax, DWORD PTR fs:ds:16
+	mov	eax, DWORD PTR fs:ds:cs:16