gdb/testsuite: extend special '^' handling to gdb_test_multiple

The commit:

  commit 08ec06d6440745ef9204d39197aa1e732df41056
  Date:   Wed Mar 29 10:41:07 2023 +0100

      gdb/testsuite: special case '^' in gdb_test pattern

Added some special handling of '^' to gdb_test -- a leading '^' will
cause the command regexp to automatically be included in the expected
output pattern.

It was pointed out that the '-wrap' flag of gdb_test_multiple is
supposed to work in the same way as gdb_test, and that the recent
changes for '^' had not been replicated for gdb_test_multiple.  This
patch addresses this issue.

So, after this commit, the following two constructs should have the
same meaning:

  gdb_test "command" "^output" "test name"

  gdb_test_multiple "command" "test name" {
    -re -wrap "^output" {
      pass $gdb_test_name
    }
  }

In both cases the '^' will case gdb.exp to inject a regexp that
matches 'command' after the '^' and before the 'output', this is in
addition to adding the $gdb_prompt pattern after 'output' in the
normal way.

The special '^' handling is only applied when '-wrap' is used, as this
is the only mode that aims to mimic gdb_test.

While working on this patch I realised that I could actually improve
the logic for the special '^' handling in the case where the expected
output pattern is empty.  I replicated these updates for both gdb_test
and gdb_test_multiple in order to keep these two paths in sync.

There were a small number of tests that needed adjustment after this
change, mostly just removing command regexps that are now added
automatically, but the gdb.base/settings.exp case was a little weird
as it turns out trying to match a single blank line is probably harder
now than it used to be -- still, I suspect this is a pretty rare case,
so I think the benefits (improved anchoring) outweigh this small
downside (IMHO).

4 files changed, 6 insertions, 13 deletions

diff --git a/gdb/testsuite/gdb.base/bitshift.exp b/gdb/testsuite/gdb.base/bitshift.exp
index adc5996d736..5ea0cd870ed 100644
--- a/gdb/testsuite/gdb.base/bitshift.exp
+++ b/gdb/testsuite/gdb.base/bitshift.exp
@@ -24,19 +24,17 @@ clean_restart
 # expected error.  If WARNING_OR_ERROR is empty, it is expected that
 # GDB prints no text other than the print result.
 proc test_shift {lang cmd result_re {warning_or_error ""}} {
-    set cmd_re [string_to_regexp $cmd]
-
     if {$lang == "go"} {
 	if {$warning_or_error != ""} {
 	    set error_re "[string_to_regexp $warning_or_error]"
 	    gdb_test_multiple $cmd "" {
-		-re -wrap "^$cmd_re\r\n$error_re" {
+		-re -wrap "^$error_re" {
 		    pass $gdb_test_name
 		}
 	    }
 	} else {
 	    gdb_test_multiple $cmd "" {
-		-re -wrap "^$cmd_re\r\n\\$$::decimal$result_re" {
+		-re -wrap "^\\$$::decimal$result_re" {
 		    pass $gdb_test_name
 		}
 	    }
@@ -49,7 +47,7 @@ proc test_shift {lang cmd result_re {warning_or_error ""}} {
 	}
 
 	gdb_test_multiple $cmd "" {
-	    -re -wrap "^$cmd_re\r\n$warning_re\\$$::decimal$result_re" {
+	    -re -wrap "^$warning_re\\$$::decimal$result_re" {
 		pass $gdb_test_name
 	    }
 	}
diff --git a/gdb/testsuite/gdb.base/maint-print-frame-id.exp b/gdb/testsuite/gdb.base/maint-print-frame-id.exp
index 2ad9b6ddfd7..9e88f37205f 100644
--- a/gdb/testsuite/gdb.base/maint-print-frame-id.exp
+++ b/gdb/testsuite/gdb.base/maint-print-frame-id.exp
@@ -33,10 +33,6 @@ proc get_frame_id { level } {
     set id "**unknown**"
 
     gdb_test_multiple "maint print frame-id ${level}" "" {
-	-re "^maint print frame-id\[^\r\n\]+\r\n" {
-	    exp_continue
-	}
-
 	-wrap -re "^frame-id for frame #\[0-9\]+: (\[^\r\n\]+)" {
 	    set id $expect_out(1,string)
 	    pass $gdb_test_name
diff --git a/gdb/testsuite/gdb.base/settings.exp b/gdb/testsuite/gdb.base/settings.exp
index 6248ba3e495..ac885d838a1 100644
--- a/gdb/testsuite/gdb.base/settings.exp
+++ b/gdb/testsuite/gdb.base/settings.exp
@@ -542,7 +542,7 @@ proc test-string {variant} {
     if {$variant != "filename"} {
 	# This odd expected output here is because we expect GDB to
 	# emit a single blank line as a result of this command.
-	gdb_test "$show_cmd" "^" "$show_cmd: show default"
+	gdb_test -nonl "$show_cmd" "^\r\n" "$show_cmd: show default"
     } else {
 	gdb_test "$show_cmd" "/foo/bar" "$show_cmd: show default"
     }
@@ -574,7 +574,7 @@ proc test-string {variant} {
 	    gdb_test_no_output "$set_cmd"
 	    # This odd expected output here is because we expect GDB to
 	    # emit a single blank line as a result of this command.
-	    gdb_test "$show_cmd" "^" "$show_cmd: empty second time"
+	    gdb_test -nonl "$show_cmd" "^\r\n" "$show_cmd: empty second time"
 	}
     }
 
diff --git a/gdb/testsuite/gdb.base/wrap-line.exp b/gdb/testsuite/gdb.base/wrap-line.exp
index 03d94720c9c..81c1514cfb4 100644
--- a/gdb/testsuite/gdb.base/wrap-line.exp
+++ b/gdb/testsuite/gdb.base/wrap-line.exp
@@ -57,8 +57,7 @@ proc get_screen_width { } {
     set cmd "maint info screen"
     set re \
 	[multi_line \
-	     ^$cmd \
-	     $re1 \
+	     ^$re1 \
 	     $re2 \
 	     "(?:$re3" \
 	     ")?$re4" \