Fix PR gas/26001 (pdp11-*-*)

PR gas/26001
* gas/config/tc-pdp11.c (parse_reg): Distinguish register names from
symbols that begin with a register name.
* gas/testsuite/gas/pdp11/pdp11.exp: Add test of such symbols.
* gas/testsuite/gas/pdp11/pr26001.s: Likewise.
* gas/testsuite/gas/pdp11/pr26001.d: Likewise.

5 files changed, 41 insertions, 1 deletions

diff --git a/gas/ChangeLog b/gas/ChangeLog
index 0d1565f..c0b3dc8 100644
--- a/gas/ChangeLog
+++ b/gas/ChangeLog
@@ -1,3 +1,12 @@
+2020-05-27  Stephen Casner  <casner@acm.org>
+
+	PR gas/26001
+	* config/tc-pdp11.c (parse_reg): Distinguish register names from
+	symbols that begin with a register name.
+	* testsuite/gas/pdp11/pdp11.exp: Add test of such symbols.
+	* testsuite/gas/pdp11/pr26001.s: Likewise.
+	* testsuite/gas/pdp11/pr26001.d: Likewise.
+
 2020-05-27  Simon Cook  <simon.cook@embecosm.com>
 
         * config/tc-riscv.c (riscv_init_csr_hash): NULL initilize next
diff --git a/gas/config/tc-pdp11.c b/gas/config/tc-pdp11.c
index d38a3cd..57daa0f 100644
--- a/gas/config/tc-pdp11.c
+++ b/gas/config/tc-pdp11.c
@@ -358,8 +358,17 @@ parse_reg (char *str, struct pdp11_code *operand)
       str += 2;
     }
   else
-    operand->error = _("Bad register name");
+    {
+      operand->error = _("Bad register name");
+      return str;
+    }
 
+  if (ISALNUM (*str) || *str == '_' || *str == '.')
+    {
+      operand->error = _("Bad register name");
+      str -= 2;
+    }
+  
   return str;
 }
 
diff --git a/gas/testsuite/gas/pdp11/pdp11.exp b/gas/testsuite/gas/pdp11/pdp11.exp
index e27dd05..65c6a05 100644
--- a/gas/testsuite/gas/pdp11/pdp11.exp
+++ b/gas/testsuite/gas/pdp11/pdp11.exp
@@ -23,4 +23,5 @@ if [expr [istarget "pdp11-*-*"]]  then {
     run_dump_test "absreloc"
     run_dump_test "pr14480"
     run_dump_test "pr23481"
+    run_dump_test "pr26001"
 }
diff --git a/gas/testsuite/gas/pdp11/pr26001.d b/gas/testsuite/gas/pdp11/pr26001.d
new file mode 100644
index 0000000..a6ccdef
--- /dev/null
+++ b/gas/testsuite/gas/pdp11/pr26001.d
@@ -0,0 +1,12 @@
+#name: PR 26001 - distinguish register names from symbols
+#objdump: -dw
+
+.*: +file format .*
+
+Disassembly of section .text:
+
+0+00 <start>:
+[ 	]+0:[ 	]+09f7 fffc[ 	]+jsr[ 	]+pc, 0 <start>
+[ 	]+4:[ 	]+1037 0004[ 	]+mov[ 	]+r0, \$c <space>
+[ 	]+8:[ 	]+1dc1 0002[ 	]+mov[ 	]+\$e <r00f>, r1
+#pass
diff --git a/gas/testsuite/gas/pdp11/pr26001.s b/gas/testsuite/gas/pdp11/pr26001.s
new file mode 100644
index 0000000..44faa14
--- /dev/null
+++ b/gas/testsuite/gas/pdp11/pr26001.s
@@ -0,0 +1,9 @@
+	.text
+	.globl	sprintf
+start:	jsr	pc,sprintf
+	mov	r0,space
+	mov	r00f,r1
+	.data
+space:	.word	0
+r00f:	.word	0
+	.end