lib/completion-support.exp: Add test_gdb_completion_offers_commands

This adds a procedure to the collection of completion-testing
routines, that allows checking whether completion offers all commands
as completion candidates.  This will be used for testing completing
"frame apply all [TAB]", "thread apply all [TAB]", etc.

gdb/testsuite/ChangeLog:
2019-06-13  Pedro Alves  <palves@redhat.com>

        * lib/completion-support.exp (test_gdb_complete_tab_multiple)
	(test_gdb_complete_cmd_multiple, test_gdb_complete_multiple): Add
	'max_completions' parameter and handle it.
	(test_gdb_completion_offers_commands): New.

1 files changed, 57 insertions, 9 deletions

diff --git a/gdb/testsuite/lib/completion-support.exp b/gdb/testsuite/lib/completion-support.exp
index 3e498d3..97fed18 100644
--- a/gdb/testsuite/lib/completion-support.exp
+++ b/gdb/testsuite/lib/completion-support.exp
@@ -119,10 +119,11 @@ proc test_gdb_complete_tab_unique { input_line complete_line_re append_char_re }
 
 # Test that completing INPUT_LINE with TAB completes to "INPUT_LINE +
 # ADD_COMPLETED_LINE" and that it displays the completion matches in
-# COMPLETION_LIST.
+# COMPLETION_LIST.  If MAX_COMPLETIONS then we expect the completion
+# to hit the max-completions limit.
 
 proc test_gdb_complete_tab_multiple { input_line add_completed_line \
-					  completion_list } {
+					  completion_list {max_completions 0}} {
     global gdb_prompt
 
     set input_line_re [string_to_regexp $input_line]
@@ -130,6 +131,12 @@ proc test_gdb_complete_tab_multiple { input_line add_completed_line \
 
     set expected_re [make_tab_completion_list_re $completion_list]
 
+    if {$max_completions} {
+	append expected_re "\r\n"
+	append expected_re \
+	    "\\*\\*\\* List may be truncated, max-completions reached\\. \\*\\*\\*"
+    }
+
     set test "tab complete \"$input_line\""
     send_gdb "$input_line\t"
     gdb_test_multiple "" "$test (first tab)" {
@@ -179,12 +186,20 @@ proc test_gdb_complete_cmd_unique { input_line complete_line_re } {
 
 # Test that completing "CMD_PREFIX + COMPLETION_WORD" with the
 # complete command displays the COMPLETION_LIST completion list.  Each
-# entry in the list should be prefixed by CMD_PREFIX.
+# entry in the list should be prefixed by CMD_PREFIX.  If
+# MAX_COMPLETIONS then we expect the completion to hit the
+# max-completions limit.
 
-proc test_gdb_complete_cmd_multiple { cmd_prefix completion_word completion_list {start_quote_char ""} {end_quote_char ""} } {
+proc test_gdb_complete_cmd_multiple { cmd_prefix completion_word completion_list {start_quote_char ""} {end_quote_char ""} {max_completions 0}} {
     global gdb_prompt
 
     set expected_re [make_cmd_completion_list_re $cmd_prefix $completion_list $start_quote_char $end_quote_char]
+
+    if {$max_completions} {
+	append expected_re \
+	    "$cmd_prefix \\*\\*\\* List may be truncated, max-completions reached\\. \\*\\*\\*.*\r\n"
+    }
+
     set cmd_re [string_to_regexp "complete $cmd_prefix$completion_word"]
     set test "cmd complete \"$cmd_prefix$completion_word\""
     gdb_test_multiple "complete $cmd_prefix$completion_word" $test {
@@ -255,11 +270,15 @@ proc test_gdb_complete_unique { input_line complete_line {append_char " "} {max_
 # Test that completing "CMD_PREFIX + COMPLETION_WORD" adds
 # ADD_COMPLETED_LINE to the input line, and that it displays
 # COMPLETION_LIST as completion match list.  COMPLETION_WORD is the
-# completion word.
-
-proc test_gdb_complete_multiple { cmd_prefix completion_word add_completed_line completion_list {start_quote_char ""} {end_quote_char ""}} {
-    test_gdb_complete_tab_multiple "$cmd_prefix$completion_word" $add_completed_line $completion_list
-    test_gdb_complete_cmd_multiple $cmd_prefix $completion_word $completion_list $start_quote_char $end_quote_char
+# completion word.  If MAX_COMPLETIONS then we expect the completion
+# to hit the max-completions limit.
+
+proc test_gdb_complete_multiple {
+  cmd_prefix completion_word add_completed_line completion_list
+  {start_quote_char ""} {end_quote_char ""} {max_completions 0}
+} {
+    test_gdb_complete_tab_multiple "$cmd_prefix$completion_word" $add_completed_line $completion_list $max_completions
+    test_gdb_complete_cmd_multiple $cmd_prefix $completion_word $completion_list $start_quote_char $end_quote_char $max_completions
 }
 
 # Test that all the substring prefixes of INPUT from [0..START) to
@@ -481,3 +500,32 @@ proc foreach_location_labels { sources functions labels body_linespec body_expli
 	    }
 	}
 }
+
+# Check that completion of INPUT_LINE results in GDB completing on all
+# command names.
+proc test_gdb_completion_offers_commands {input_line} {
+    global gdb_prompt
+
+    # There are two many commands to usefully check here.  So we force
+    # max-completions to 2, and check if those 2 come out.
+
+    # Save current max-completions.
+    set max_completions 0
+    set test "show max-completions"
+    gdb_test_multiple $test $test {
+	-re "Maximum number of completion candidates is (.*)\\.\r\n$gdb_prompt $" {
+	    set max_completions $expect_out(1,string)
+	}
+    }
+
+    # Force showing two commands.
+    gdb_test_no_output "set max-completions 2" ""
+
+    test_gdb_complete_multiple $input_line "" "" {
+	"!"
+	"+"
+    } "" "" 1
+
+    # Restore.
+    gdb_test_no_output "set max-completions $max_completions" ""
+}