[OBV] Clean up gdb.trace/entry-values.exp

[Yao Qi]

This patch is to clean up gdb.trace/entry-values.exp as a preparation
of the next patch.  It updates the comments to reflect the code.

One DIE generated in dwarf assembler is

 		GNU_call_site {
		    {low_pc "$bar_start + $bar_call_foo" addr}
 		    {abstract_origin :$foo_label}

the DW_AT_low_pc attribute is the return address after the call, so I
rename variable bar_call_foo to returned_from_foo.

It is obvious, and I've pushed it in.

gdb/testsuite:

2014-12-29  Yao Qi  <yao@codesourcery.com>

	* gdb.trace/entry-values.exp: Update comments.  Rename variable
	bar_call_foo to returned_from_foo.
---
 gdb/testsuite/ChangeLog                  |  5 +++++
 gdb/testsuite/gdb.trace/entry-values.exp | 18 +++++++++---------
 2 files changed, 14 insertions(+), 9 deletions(-)

diff --git a/gdb/testsuite/ChangeLog b/gdb/testsuite/ChangeLog
index 1f08d80..b8cfe33 100644
--- a/gdb/testsuite/ChangeLog
+++ b/gdb/testsuite/ChangeLog
@@ -1,3 +1,8 @@
+2014-12-29  Yao Qi  <yao@codesourcery.com>
+
+	* gdb.trace/entry-values.exp: Update comments.  Rename variable
+	bar_call_foo to returned_from_foo.
+
 2014-12-20  Mihail-Marian Nistor  <mihail.nistor@freescale.com>
 
 	PR gdb/17394
diff --git a/gdb/testsuite/gdb.trace/entry-values.exp b/gdb/testsuite/gdb.trace/entry-values.exp
index 1b4d5cd..6bb0514 100644
--- a/gdb/testsuite/gdb.trace/entry-values.exp
+++ b/gdb/testsuite/gdb.trace/entry-values.exp
@@ -26,16 +26,16 @@ if  {[gdb_compile ${srcdir}/${subdir}/${srcfile} ${binfile}1.o \
     return -1
 }
 
-# Start GDB and load object file, compute the function length and
-# the offset of branch instruction in function.  They are needed
-# in the Dwarf Assembler below.
+# Start GDB and load object file, compute the offset of the
+# instruction in bar returned from foo.  It is needed in the Dwarf
+# Assembler.
 
 gdb_exit
 gdb_start
 gdb_reinitialize_dir $srcdir/$subdir
 gdb_load ${binfile}1.o
 
-set bar_call_foo ""
+set returned_from_foo ""
 
 if { [istarget "arm*-*-*"] || [istarget "aarch64*-*-*"] } {
     set call_insn "bl"
@@ -47,18 +47,18 @@ if { [istarget "arm*-*-*"] || [istarget "aarch64*-*-*"] } {
     set call_insn "call"
 }
 
-# Calculate the offset of the instruction bar calls foo.
+# Calculate the offset of the instruction in bar returned from foo.
 set test "disassemble bar"
 gdb_test_multiple $test $test {
     -re ".*$hex <\\+$decimal>:\[ \t\]+$call_insn\[^\r\n\]+\r\n\[ \]+$hex <\\+($decimal)>:.*$gdb_prompt $" {
-	set bar_call_foo $expect_out(1,string)
+	set returned_from_foo $expect_out(1,string)
     }
     -re ".*$gdb_prompt $" {
 	fail $test
     }
 }
 
-if { [string equal $bar_call_foo ""] } {
+if { [string equal $returned_from_foo ""] } {
     fail "Find the call or branch instruction offset in bar"
     # The following test makes no sense if the offset is unknown.  We need
     # to update the pattern above to match call or branch instruction for
@@ -72,7 +72,7 @@ gdb_exit
 set asm_file [standard_output_file $srcfile2]
 Dwarf::assemble $asm_file {
     declare_labels int_label foo_label
-    global bar_call_foo
+    global returned_from_foo
     global srcdir subdir srcfile
 
     set bar_result [function_range bar ${srcdir}/${subdir}/${srcfile}]
@@ -116,7 +116,7 @@ Dwarf::assemble $asm_file {
 		}
 
 		GNU_call_site {
-		    {low_pc "$bar_start + $bar_call_foo" addr}
+		    {low_pc "$bar_start + $returned_from_foo" addr}
 		    {abstract_origin :$foo_label}
 		} {
 		    # Faked entry values are reference to variables 'global1'
-- 
1.9.3