Add support for using the ADR alias in Thumb mode against nearby symbols.

	PR gas/18541
gas	* config/tc-arm.c (md_apply_fix): Add support for ADR in thumb
	mode against a nearby symbol.

tests	* gas/arm/thumb.s: Add test of ADR against a nearby symbol.
	* gas/arm/thumb.d: Update expected output.
	* gas/arm/thumb-eabi.d: Likewise.

6 files changed, 72 insertions, 0 deletions

diff --git a/gas/ChangeLog b/gas/ChangeLog
index 00305e9..0a1326e 100644
--- a/gas/ChangeLog
+++ b/gas/ChangeLog
@@ -1,5 +1,11 @@
 2015-06-18  Nick Clifton  <nickc@redhat.com>
 
+	PR gas/18541
+	* config/tc-arm.c (md_apply_fix): Add support for ADR in thumb
+	mode against a nearby symbol.
+
+2015-06-18  Nick Clifton  <nickc@redhat.com>
+
 	PR gas/18481
 	* config/tc-arm.c (tc_gen_reloc): Include BFD_RELOC_ARM_TLS_LE32
 	in the same case as BFD_RELOC_ARM_TLS_IS32.
diff --git a/gas/config/tc-arm.c b/gas/config/tc-arm.c
index 9ccee40..1793965 100644
--- a/gas/config/tc-arm.c
+++ b/gas/config/tc-arm.c
@@ -23158,6 +23158,45 @@ md_apply_fix (fixS *	fixP,
 	  }
 	else if (rs == REG_PC || rs == REG_SP)
 	  {
+	    /* PR gas/18541.  If the addition is for a defined symbol
+	       within range of an ADR instruction then accept it.  */
+	    if (subtract
+		&& value == 4
+		&& fixP->fx_addsy != NULL)
+	      {
+		subtract = 0;
+
+		if (! S_IS_DEFINED (fixP->fx_addsy)
+		    || S_GET_SEGMENT (fixP->fx_addsy) != seg
+		    || S_IS_WEAK (fixP->fx_addsy))
+		  {
+		    as_bad_where (fixP->fx_file, fixP->fx_line,
+				  _("address calculation needs a strongly defined nearby symbol"));
+		  }
+		else
+		  {
+		    offsetT v = fixP->fx_where + fixP->fx_frag->fr_address;
+
+		    /* Round up to the next 4-byte boundary.  */
+		    if (v & 3)
+		      v = (v + 3) & ~ 3;
+		    else
+		      v += 4;
+		    v = S_GET_VALUE (fixP->fx_addsy) - v;
+
+		    if (v & ~0x3fc)
+		      {
+			as_bad_where (fixP->fx_file, fixP->fx_line,
+				      _("symbol too far away"));
+		      }
+		    else
+		      {
+			fixP->fx_done = 1;
+			value = v;
+		      }
+		  }
+	      }
+
 	    if (subtract || value & ~0x3fc)
 	      as_bad_where (fixP->fx_file, fixP->fx_line,
 			    _("invalid immediate for address calculation (value = 0x%08lX)"),
diff --git a/gas/testsuite/ChangeLog b/gas/testsuite/ChangeLog
index d929e68..64e8cd7 100644
--- a/gas/testsuite/ChangeLog
+++ b/gas/testsuite/ChangeLog
@@ -1,5 +1,12 @@
 2015-06-18  Nick Clifton  <nickc@redhat.com>
 
+	PR gas/18541
+	* gas/arm/thumb.s: Add test of ADR against a nearby symbol.
+	* gas/arm/thumb.d: Update expected output.
+	* gas/arm/thumb-eabi.d: Likewise.
+
+2015-06-18  Nick Clifton  <nickc@redhat.com>
+
 	PR gas/18481
 	* gas/arm/tls.s: Add tests of the tpoff pseudo with a local
 	symbol.
diff --git a/gas/testsuite/gas/arm/thumb-eabi.d b/gas/testsuite/gas/arm/thumb-eabi.d
index 19fc797..afe076b 100644
--- a/gas/testsuite/gas/arm/thumb-eabi.d
+++ b/gas/testsuite/gas/arm/thumb-eabi.d
@@ -163,3 +163,8 @@ Disassembly of section \.text:
 0+942 <[^>]+> 4801      	ldr	r0, \[pc, #4\]	; \(0+948 <[^>]+>\)
 0+944 <[^>]+> 1c08      	adds	r0, r1, #0
 0+946 <[^>]+> 46c0      	nop			; \(mov r8, r8\)
+0+948 <[^>]+> a001      	add	r0, pc, #4	; \(adr r0, 00000950 <[^>]+>\)
+0+94a <[^>]+> a001      	add	r0, pc, #4	; \(adr r0, 00000950 <[^>]+>\)
+0+94c <[^>]+> a000      	add	r0, pc, #0	; \(adr r0, 00000950 <[^>]+>\)
+0+94e <[^>]+> 46c0      	nop			; \(mov r8, r8\)
+#pass
diff --git a/gas/testsuite/gas/arm/thumb.d b/gas/testsuite/gas/arm/thumb.d
index c928aaf..65d007a 100644
--- a/gas/testsuite/gas/arm/thumb.d
+++ b/gas/testsuite/gas/arm/thumb.d
@@ -163,3 +163,8 @@ Disassembly of section \.text:
 0+942 <[^>]+> 4801      	ldr	r0, \[pc, #4\]	; \(0+948 <[^>]+>\)
 0+944 <[^>]+> 1c08      	adds	r0, r1, #0
 0+946 <[^>]+> 46c0      	nop			; \(mov r8, r8\)
+0+948 <[^>]+> a001      	add	r0, pc, #4	; \(adr r0, 00000950 <[^>]+>\)
+0+94a <[^>]+> a001      	add	r0, pc, #4	; \(adr r0, 00000950 <[^>]+>\)
+0+94c <[^>]+> a000      	add	r0, pc, #0	; \(adr r0, 00000950 <[^>]+>\)
+0+94e <[^>]+> 46c0      	nop			; \(mov r8, r8\)
+#pass
diff --git a/gas/testsuite/gas/arm/thumb.s b/gas/testsuite/gas/arm/thumb.s
index a044bdf..3c759b3 100644
--- a/gas/testsuite/gas/arm/thumb.s
+++ b/gas/testsuite/gas/arm/thumb.s
@@ -201,3 +201,13 @@ forwardonly:
 baz:
 	mov	r0, r1
 	nop
+
+	adr	r0, pr18541
+	adr	r0, pr18541
+	adr	r0, pr18541
+	nop
+	.align
+	.global pr18541
+pr18541:
+	.long	0
+