[binutils-gdb] Fix ARm assembler so that it rejects invalid immediate values for the Thumb ORR instruction.

[Nick Clifton <nickc at sourceware dot org>]

https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;h=db7bf1058d28b2b5e931c60435a13f6db15df6af

commit db7bf1058d28b2b5e931c60435a13f6db15df6af
Author: Nick Clifton <nickc@redhat.com>
Date:   Tue Feb 13 16:50:04 2018 +0000

    Fix ARm assembler so that it rejects invalid immediate values for the Thumb ORR instruction.
    
    	PR 22773
    	* config/tc-arm.c (md_apply_fix): Test Rn field of Thumb ORR
    	instruction before assuming that it is a MOV instruction.
    	* testsuite/gas/arm/pr22773.s: New test.
    	* testsuite/gas/arm/pr22773.d: New test driver.
    	* testsuite/gas/arm/pr22773.l: New expected output.

Diff:
---
 gas/ChangeLog                   | 9 +++++++++
 gas/config/tc-arm.c             | 8 +++++---
 gas/testsuite/gas/arm/pr22773.d | 2 ++
 gas/testsuite/gas/arm/pr22773.l | 3 +++
 gas/testsuite/gas/arm/pr22773.s | 9 +++++++++
 5 files changed, 28 insertions(+), 3 deletions(-)

diff --git a/gas/ChangeLog b/gas/ChangeLog
index e66e8ce..adf4569 100644
--- a/gas/ChangeLog
+++ b/gas/ChangeLog
@@ -1,3 +1,12 @@
+2018-02-13  Nick Clifton  <nickc@redhat.com>
+
+	PR 22773
+	* config/tc-arm.c (md_apply_fix): Test Rn field of Thumb ORR
+	instruction before assuming that it is a MOV instruction.
+	* testsuite/gas/arm/pr22773.s: New test.
+	* testsuite/gas/arm/pr22773.d: New test driver.
+	* testsuite/gas/arm/pr22773.l: New expected output.
+
 2018-02-13  H.J. Lu  <hongjiu.lu@intel.com>
 
 	PR gas/22791
diff --git a/gas/config/tc-arm.c b/gas/config/tc-arm.c
index 9786f14..7a5c02b 100644
--- a/gas/config/tc-arm.c
+++ b/gas/config/tc-arm.c
@@ -23596,12 +23596,14 @@ md_apply_fix (fixS *	fixP,
 	      /* MOV accepts both Thumb2 modified immediate (T2 encoding) and
 		 UINT16 (T3 encoding), MOVW only accepts UINT16.  When
 		 disassembling, MOV is preferred when there is no encoding
-		 overlap.
-		 NOTE: MOV is using ORR opcode under Thumb 2 mode.  */
+		 overlap.  */
 	      if (((newval >> T2_DATA_OP_SHIFT) & 0xf) == T2_OPCODE_ORR
+		  /* NOTE: MOV uses the ORR opcode in Thumb 2 mode
+		     but with the Rn field [19:16] set to 1111.  */
+		  && (((newval >> 16) & 0xf) == 0xf)
 		  && ARM_CPU_HAS_FEATURE (cpu_variant, arm_ext_v6t2_v8m)
 		  && !((newval >> T2_SBIT_SHIFT) & 0x1)
-		  && value >= 0 && value <=0xffff)
+		  && value >= 0 && value <= 0xffff)
 		{
 		  /* Toggle bit[25] to change encoding from T2 to T3.  */
 		  newval ^= 1 << 25;
diff --git a/gas/testsuite/gas/arm/pr22773.d b/gas/testsuite/gas/arm/pr22773.d
new file mode 100644
index 0000000..adb9681
--- /dev/null
+++ b/gas/testsuite/gas/arm/pr22773.d
@@ -0,0 +1,2 @@
+# name: PR 22773: Invalid immediate constants produce incorrect instruction
+# error-output: pr22773.l
diff --git a/gas/testsuite/gas/arm/pr22773.l b/gas/testsuite/gas/arm/pr22773.l
new file mode 100644
index 0000000..587c8a8
--- /dev/null
+++ b/gas/testsuite/gas/arm/pr22773.l
@@ -0,0 +1,3 @@
+[^:]*: Assembler messages:
+[^:]*:8: Error: invalid constant \(3201\) after fixup
+#pass
diff --git a/gas/testsuite/gas/arm/pr22773.s b/gas/testsuite/gas/arm/pr22773.s
new file mode 100644
index 0000000..011ecfd
--- /dev/null
+++ b/gas/testsuite/gas/arm/pr22773.s
@@ -0,0 +1,9 @@
+	.syntax unified
+	.cpu cortex-m4
+	.thumb
+
+	.section  .text
+
+	orr r1, #12800	 	/* This is OK.  */
+	orr r1, #12801		/* This cannot be encoded in Thumb mode.  */
+	/* GAS used to accept it though, and produce a MOV instruction instead.  */