gdb: Fix DUPLICATE and PATH regressions throughout

The previous patch to add -prompt/-lbl to gdb_test introduced a
regression: Before, you could specify an explicit empty message to
indicate you didn't want to PASS, like so:

  gdb_test COMMAND PATTERN ""

After said patch, gdb_test no longer distinguishes
no-message-specified vs empty-message, so tests that previously would
be silent on PASS, now started emitting PASS messages based on
COMMAND.  This in turn introduced a number of PATH/DUPLICATE
violations in the testsuite.

This commit fixes all the regressions I could see.

This patch uses the new -nopass feature introduced in the previous
commit, but tries to avoid it if possible.  Most of the patch fixes
DUPLICATE issues the usual way, of using with_test_prefix or explicit
unique messages.

See previous commit's log for more info.

In addition to looking for DUPLICATEs, I also looked for cases where
we would now end up with an empty message in gdb.sum, due to a
gdb_test being passed both no message and empty command.  E.g., this
in gdb.ada/bp_reset.exp:

 gdb_run_cmd
 gdb_test "" "Breakpoint $decimal, foo\\.nested_sub \\(\\).*"

was resulting in this in gdb.sum:

 PASS: gdb.ada/bp_reset.exp:

I fixed such cases by passing an explicit message.  We may want to
make such cases error out.

Tested on x86_64 GNU/Linux, native and native-extended-gdbserver.  I
see zero PATH cases now.  I get zero DUPLICATEs with native testing
now.  I still see some DUPLICATEs with native-extended-gdbserver, but
those were preexisting, unrelated to the gdb_test change.

Change-Id: I5375f23f073493e0672190a0ec2e847938a580b2

1 files changed, 25 insertions, 27 deletions

diff --git a/gdb/testsuite/gdb.trace/passc-dyn.exp b/gdb/testsuite/gdb.trace/passc-dyn.exp
index 32fcecf..747e420 100644
--- a/gdb/testsuite/gdb.trace/passc-dyn.exp
+++ b/gdb/testsuite/gdb.trace/passc-dyn.exp
@@ -31,8 +31,6 @@ if { [gdb_compile "$srcdir/$subdir/$srcfile" $binfile \
     return -1
 }
 gdb_load $binfile
-gdb_test "tstop"       ".*" ""
-gdb_test "tfind none"  ".*" ""
 runto_main
 gdb_reinitialize_dir $srcdir/$subdir
 
@@ -96,40 +94,40 @@ gdb_test "continue" \
     "run trace experiment"
 gdb_test "tstop" ".*" ""
 
-gdb_test "tfind none" ".*" ""
-if [gdb_test "printf \"x \%d x\\n\", \$trace_frame" "x -1 x" ""] {
-    untested "skipping further tests due to print failure"
-    return -1
+with_test_prefix "trace_frame -1" {
+    gdb_test "tfind none" ".*"
+    gdb_test "printf \"x \%d x\\n\", \$trace_frame" "x -1 x" \
+	"print \$trace_frame"
 }
 
-gdb_test "tfind tracepoint $tdp2" ".*" ""
-if [gdb_test "printf \"x \%d x\\n\", \$trace_frame" "x 0 x" ""] {
-    untested "skipping further tests due to print failure"
-    return -1
+with_test_prefix "trace_frame 0" {
+    gdb_test "tfind tracepoint $tdp2" ".*"
+    gdb_test "printf \"x \%d x\\n\", \$trace_frame" "x 0 x" \
+	"print \$trace_frame"
 }
 
-gdb_test "tfind tracepoint $tdp3" ".*" ""
-if [gdb_test "printf \"x \%d x\\n\", \$trace_frame" "x 1 x" ""] {
-    untested "skipping further tests due to print failure"
-    return -1
+with_test_prefix "trace_frame 1" {
+    gdb_test "tfind tracepoint $tdp3" ".*"
+    gdb_test "printf \"x \%d x\\n\", \$trace_frame" "x 1 x" \
+	"print \$trace_frame"
 }
 
-gdb_test "tfind tracepoint $tdp4" ".*" ""
-if [gdb_test "printf \"x \%d x\\n\", \$trace_frame" "x 2 x" ""] {
-    untested "skipping further tests due to print failure"
-    return -1
+with_test_prefix "trace_frame 2" {
+    gdb_test "tfind tracepoint $tdp4" ".*"
+    gdb_test "printf \"x \%d x\\n\", \$trace_frame" "x 2 x" \
+	"print \$trace_frame"
 }
 
-gdb_test "tfind tracepoint $tdp2" ".*" ""
-if [gdb_test "printf \"x \%d x\\n\", \$trace_frame" "x 3 x" ""] {
-    untested "skipping further tests due to print failure"
-    return -1
+with_test_prefix "trace_frame 3" {
+    gdb_test "tfind tracepoint $tdp2" ".*"
+    gdb_test "printf \"x \%d x\\n\", \$trace_frame" "x 3 x" \
+	"print \$trace_frame"
 }
 
-gdb_test "tfind tracepoint $tdp3" ".*" ""
-if [gdb_test "printf \"x \%d x\\n\", \$trace_frame" "x 4 x" ""] {
-    untested "skipping further tests due to print failure"
-    return -1
+with_test_prefix "trace_frame 4" {
+    gdb_test "tfind tracepoint $tdp3" ".*"
+    gdb_test "printf \"x \%d x\\n\", \$trace_frame" "x 4 x" \
+	"print \$trace_frame"
 }
 
 ## We should now be at the last frame, because this frame's passcount
@@ -139,5 +137,5 @@ if [gdb_test "printf \"x \%d x\\n\", \$trace_frame" "x 4 x" ""] {
 gdb_test "tfind" "failed to find.*" "4.5: dynamic passcount test"
 
 # Finished!
-gdb_test "tfind none" ".*" ""
+gdb_test "tfind none" ".*"