[binutils-gdb] Introduce procedure use_gdb_stub

[Simon Marchi <simark at sourceware dot org>]

https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;h=8929ad8bbca9a8b036eba0397992d6f3b4d1966b

commit 8929ad8bbca9a8b036eba0397992d6f3b4d1966b
Author: Simon Marchi <simon.marchi@ericsson.com>
Date:   Wed May 4 09:27:19 2016 -0400

    Introduce procedure use_gdb_stub
    
    This patch introduces the use_gdb_stub procedure, which allows getting
    the right value of the use_gdb_stub variable/property in any all
    situations.
    
    When calling it before the $use_gdb_stub global variable has been set,
    it will return the value of the use_gdb_stub property from the board
    file.  This happens when tests want to bail out early (even before gdb
    has been started) when the current test setup is a stub.
    
    Otherwise, it returns the value of the $use_gdb_stub global.
    
    It's possible for these two to differ when a test file overrides the
    value of the global.
    
    gdb/testsuite/ChangeLog:
    
    	* lib/gdb.exp (use_gdb_stub): New procedure.

Diff:
---
 gdb/testsuite/ChangeLog   |  4 ++++
 gdb/testsuite/lib/gdb.exp | 20 ++++++++++++++++++++
 2 files changed, 24 insertions(+)

diff --git a/gdb/testsuite/ChangeLog b/gdb/testsuite/ChangeLog
index bbb5262..e3830b6 100644
--- a/gdb/testsuite/ChangeLog
+++ b/gdb/testsuite/ChangeLog
@@ -1,3 +1,7 @@
+2016-05-04  Simon Marchi  <simon.marchi@ericsson.com>
+
+	* lib/gdb.exp (use_gdb_stub): New procedure.
+
 2016-05-03  Yunlian Jiang <yunlian@google.com>
 	    Doug Evans  <dje@google.com>
 
diff --git a/gdb/testsuite/lib/gdb.exp b/gdb/testsuite/lib/gdb.exp
index 5a5a8fb..6d25b0c 100644
--- a/gdb/testsuite/lib/gdb.exp
+++ b/gdb/testsuite/lib/gdb.exp
@@ -3053,6 +3053,26 @@ proc gdb_is_target_remote {} {
     return [gdb_is_target_remote_prompt "$gdb_prompt $"]
 }
 
+# Return the effective value of use_gdb_stub.
+#
+# If the use_gdb_stub global has been set (it is set when the gdb process is
+# spawned), return that.  Otherwise, return the value of the use_gdb_stub
+# property from the board file.
+#
+# This is the preferred way of checking use_gdb_stub, since it allows to check
+# the value before the gdb has been spawned and it will return the correct value
+# even when it was overriden by the test.
+
+proc use_gdb_stub {} {
+  global use_gdb_stub
+
+  if [info exists use_gdb_stub] {
+     return $use_gdb_stub
+  }
+
+  return [target_info exists use_gdb_stub]
+}
+
 # Return 1 if the current remote target is an instance of our GDBserver, 0
 # otherwise.  Return -1 if there was an error and we can't tell.