Fix spurious FAILs with examine-backward.exp

The test case examine-backward.exp issues the command "x/-s" after the end
of the first string in TestStrings, but without making sure that this
string is preceded by a string terminator.  Thus GDB may spuriously print
some random characters from before that string, and then the test fails.

This patch assures that TestStrings is preceded by a string terminator.

gdb/testsuite/ChangeLog:

	* gdb.base/examine-backward.c (Barrier): New character array
	constant, to ensure that TestStrings is preceded by a string
	terminator.

diff --git a/gdb/testsuite/ChangeLog b/gdb/testsuite/ChangeLog
index 018104c219903842233c975e378a122c6f5da0fa..2386c0a18103c8f551f23bc5384d51eefe07b122 100644 (file)
--- a/gdb/testsuite/ChangeLog
+++ b/gdb/testsuite/ChangeLog
@@ -1,3 +1,9 @@
+2017-03-20  Andreas Arnez  <arnez@linux.vnet.ibm.com>
+
+       * gdb.base/examine-backward.c (Barrier): New character array
+       constant, to ensure that TestStrings is preceded by a string
+       terminator.
+
 2017-03-16  Andreas Arnez  <arnez@linux.vnet.ibm.com>
 
        * lib/dwarf.exp: Add support for DW_OP_implicit_pointer.

diff --git a/gdb/testsuite/gdb.base/examine-backward.c b/gdb/testsuite/gdb.base/examine-backward.c
index 5e9162a293afa20d1f9ca8bd18acfb2c924d28be..462089d14e1327f2ee2064e9faf304b0a262a485 100644 (file)
--- a/gdb/testsuite/gdb.base/examine-backward.c
+++ b/gdb/testsuite/gdb.base/examine-backward.c
@@ -32,6 +32,14 @@ literals.  The content of each array is the same as followings:
   };
 */
 
+/* This is here just to ensure we have a null character before
+   TestStrings, to avoid showing garbage when we look for strings
+   backwards from TestStrings.  */
+
+const char Barrier[] = {
+  0x00,
+};
+
 const char TestStrings[] = {
   0x41, 0x42, 0x43, 0x44, 0x45, 0x46, 0x47, 0x48,
   0x49, 0x4a, 0x4b, 0x4c, 0x4d, 0x4e, 0x4f, 0x50,