2012-02-21 Pedro Alves <palves@redhat.com>

	    Tom Tromey  <tromey@redhat.com>

	* lib/gdb.exp: Add description of test prefixes.
	(with_test_prefix): New procedure.
	* gdb.arch/altivec-abi.exp: Use with_test_prefix.
	* gdb.base/attach-pie-misread.exp: Use with_test_prefix.
	* gdb.base/break-interp.exp: Use with_test_prefix.  Use append
	instead of lappend to append to pf_prefix.
	* gdb.base/catch-load.exp: Use with_test_prefix.
	* gdb.base/disp-step-syscall.exp: Use with_test_prefix.
	* gdb.base/jit-so.exp: Use with_test_prefix.
	* gdb.base/jit.exp: Use with_test_prefix.
	* gdb.base/return-nodebug.exp (do_test): Use append instead of
	lappend to append to pf_prefix.
	* gdb.base/sepdebug.exp: Use with_test_prefix.
	* gdb.base/solib-display.exp: Use with_test_prefix.
	* gdb.base/solib-overlap.exp: Use with_test_prefix.
	* gdb.base/watch-cond-infcall.exp: Use with_test_prefix.
	* gdb.base/watchpoint.exp: Use with_test_prefix.
	* gdb.dwarf2/dw2-noloc.exp: Use with_test_prefix.
	* gdb.mi/mi-watch.exp: Use with_test_prefix.
	* gdb.mi/mi2-watch.exp: Use with_test_prefix.
	* gdb.threads/non-ldr-exc-1.exp: Use with_test_prefix.
	* gdb.threads/non-ldr-exc-2.exp: Use with_test_prefix.
	* gdb.threads/non-ldr-exc-3.exp: Use with_test_prefix.
	* gdb.threads/non-ldr-exc-4.exp: Use with_test_prefix.
	* gdb.threads/watchpoint-fork.exp: Use with_test_prefix.  Use
	append instead of lappend to append to pf_prefix.
	* gdb.threads/watchthreads-reorder.exp: Use with_test_prefix.
	* gdb.trace/change-loc.exp: Use with_test_prefix.
	* gdb.trace/pending.exp: Use with_test_prefix.
	* gdb.trace/status-stop.exp: Use with_test_prefix.
	* gdb.trace/strace.exp: Use with_test_prefix.
	* gdb.trace/trace-break.exp: Use with_test_prefix.
	* gdb.trace/unavailable.exp: Use with_test_prefix.  Use append
	instead of lappend to append to pf_prefix.

1 files changed, 86 insertions, 0 deletions

diff --git a/gdb/testsuite/lib/gdb.exp b/gdb/testsuite/lib/gdb.exp
index 00fe71c..3a43f95 100644
--- a/gdb/testsuite/lib/gdb.exp
+++ b/gdb/testsuite/lib/gdb.exp
@@ -1481,6 +1481,92 @@ proc skip_shlib_tests {} {
     return 1
 }
 
+# Test files shall make sure all the test result lines in gdb.sum are
+# unique in a test run, so that comparing the gdb.sum files of two
+# test runs gives correct results.  Test files that exercise
+# variations of the same tests more than once, shall prefix the
+# different test invocations with different identifying strings in
+# order to make them unique.
+#
+# About test prefixes:
+#
+# $pf_prefix is the string that dejagnu prints after the result (FAIL,
+# PASS, etc.), and before the test message/name in gdb.sum.  E.g., the
+# underlined substring in
+#
+#  PASS: gdb.base/mytest.exp: some test
+#        ^^^^^^^^^^^^^^^^^^^^
+#
+# is $pf_prefix.
+#
+# The easiest way to adjust the test prefix is to append a test
+# variation prefix to the $pf_prefix, using the with_test_prefix
+# procedure.  E.g.,
+#
+# proc do_tests {} {
+#   gdb_test ... ... "test foo"
+#   gdb_test ... ... "test bar"
+#
+#   with_test_prefix " subvariation a:" {
+#     gdb_test ... ... "test x"
+#   }
+#
+#   with_test_prefix " subvariation b:" {
+#     gdb_test ... ... "test x"
+#   }
+# }
+#
+# with_test_prefix " variation1:" {
+#   ...do setup for variation 1...
+#   do_tests
+# }
+#
+# with_test_prefix " variation2:" {
+#   ...do setup for variation 2...
+#   do_tests
+# }
+#
+# Results in:
+#
+#  PASS: gdb.base/mytest.exp: variation1: test foo
+#  PASS: gdb.base/mytest.exp: variation1: test bar
+#  PASS: gdb.base/mytest.exp: variation1: subvariation a: test x
+#  PASS: gdb.base/mytest.exp: variation1: subvariation b: test x
+#  PASS: gdb.base/mytest.exp: variation2: test foo
+#  PASS: gdb.base/mytest.exp: variation2: test bar
+#  PASS: gdb.base/mytest.exp: variation2: subvariation a: test x
+#  PASS: gdb.base/mytest.exp: variation2: subvariation b: test x
+#
+# If for some reason more flexibility is necessary, one can also
+# manipulate the pf_prefix global directly, treating it as a string.
+# E.g.,
+#
+#   global pf_prefix
+#   set saved_pf_prefix
+#   append pf_prefix "${foo} bar"
+#   ... actual tests ...
+#   set pf_prefix $saved_pf_prefix
+#
+
+# Run BODY in the context of the caller, with the current test prefix
+# (pf_prefix) appended with PREFIX.  Returns the result of BODY.
+#
+proc with_test_prefix { prefix body } {
+  global pf_prefix
+
+  set saved $pf_prefix
+  append pf_prefix $prefix
+  set code [catch {uplevel 1 $body} result]
+  set pf_prefix $saved
+
+  if {$code == 1} {
+      global errorInfo errorCode
+      return -code $code -errorinfo $errorInfo -errorcode $errorCode $result
+  } else {
+      return -code $code $result
+  }
+}
+
 # Return 1 if _Complex types are supported, otherwise, return 0.
 
 proc support_complex_tests {} {