[gdb/testsuite] Reimplement gdb.gdb/complaints.exp as unittest

When building gdb with "-Wall -O2 -g -flto=auto", I run into:
...
(gdb) call clear_complaints()^M
No symbol "clear_complaints" in current context.^M
(gdb) FAIL: gdb.gdb/complaints.exp: clear complaints
...

The problem is that lto has optimized away the clear_complaints function
and consequently the selftest doesn't work.

Fix this by reimplementing the selftest as a unit test.

Factor out two new functions:
- void
  execute_fn_to_ui_file (struct ui_file *file, std::function<void(void)> fn);
- std::string
  execute_fn_to_string (std::function<void(void)> fn, bool term_out);
and use the latter to capture the complaints output.

Tested on x86_64-linux.

1 files changed, 0 insertions, 137 deletions

diff --git a/gdb/testsuite/gdb.gdb/complaints.exp b/gdb/testsuite/gdb.gdb/complaints.exp
deleted file mode 100644
index 2391d66..0000000
--- a/gdb/testsuite/gdb.gdb/complaints.exp
+++ /dev/null
@@ -1,137 +0,0 @@
-# Copyright 2002-2021 Free Software Foundation, Inc.
-
-# This program is free software; you can redistribute it and/or modify
-# it under the terms of the GNU General Public License as published by
-# the Free Software Foundation; either version 3 of the License, or
-# (at your option) any later version.
-#
-# This program is distributed in the hope that it will be useful,
-# but WITHOUT ANY WARRANTY; without even the implied warranty of
-# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-# GNU General Public License for more details.
-#
-# You should have received a copy of the GNU General Public License
-# along with this program.  If not, see <http://www.gnu.org/licenses/>.
-
-# This file was written by Andrew Cagney (cagney at redhat dot com),
-# derived from xfullpath.exp (written by Joel Brobecker), derived from
-# selftest.exp (written by Rob Savoye).
-
-load_lib selftest-support.exp
-
-if [target_info exists gdb,noinferiorio] {
-    verbose "Skipping because of no inferiorio capabilities."
-    return
-}
-
-# Similar to gdb_test_stdio, except no \r\n is expected before
-# $gdb_prompt in the $gdb_spawn_id.
-
-proc test_complaint {test inferior_io_re msg} {
-    global inferior_spawn_id gdb_spawn_id
-    global gdb_prompt
-
-    set inferior_matched 0
-    set gdb_matched 0
-
-    gdb_test_multiple $test $msg {
-	-i $inferior_spawn_id -re "$inferior_io_re" {
-	    set inferior_matched 1
-	    if {!$gdb_matched} {
-		exp_continue
-	    }
-	}
-	-i $gdb_spawn_id -re "$gdb_prompt $" {
-	    set gdb_matched 1
-	    if {!$inferior_matched} {
-		exp_continue
-	    }
-	}
-    }
-
-    verbose -log "inferior_matched=$inferior_matched, gdb_matched=$gdb_matched"
-    gdb_assert {$inferior_matched && $gdb_matched} $msg
-}
-
-proc test_initial_complaints { } {
-    # Unsupress complaints
-    gdb_test "set stop_whining = 2"
-
-    gdb_test_no_output "set var \$cstr = \"Register a complaint\""
-
-    # Prime the system
-    gdb_test_stdio \
-	"call complaint_internal (\$cstr)" \
-	"During symbol reading: Register a complaint"
-
-    # Re-issue the first message #1
-    with_test_prefix "re-issue" {
-	gdb_test_stdio \
-	    "call complaint_internal (\$cstr)" \
-	    "During symbol reading: Register a complaint"
-    }
-
-    # Add a second complaint, expect it
-    gdb_test_stdio \
-	"call complaint_internal (\"Testing! Testing! Testing!\")" \
-	"During symbol reading: Testing. Testing. Testing."
-
-    return 0
-}
-
-# Check that nothing comes out when there haven't been any real
-# complaints.  Note that each test is really checking the previous
-# command.
-
-proc test_empty_complaint { cmd msg } {
-    global gdb_prompt
-    global inferior_spawn_id gdb_spawn_id
-
-    if {$gdb_spawn_id == $inferior_spawn_id} {
-	gdb_test_no_output $cmd $msg
-    } else {
-	set seen_output 0
-	gdb_test_multiple $cmd $msg {
-	    -i $inferior_spawn_id -re "." {
-		set seen_output 1
-		exp_continue
-	    }
-	    -i $gdb_spawn_id "$gdb_prompt $" {
-		gdb_assert !$seen_output $msg
-	    }
-	}
-    }
-}
-
-proc test_empty_complaints { } {
-    global decimal
-
-    set re [multi_line \
-		"All functions matching regular expression \[^:\]*:" \
-		"" \
-		"File \[^\r\n\]*/complaints\\.c:" \
-		"$decimal:\tvoid clear_complaints\\(\\);"]
-
-    set found 0
-    gdb_test_multiple "info function ^clear_complaints()$" "" {
-	-re -wrap $re {
-	    set found 1
-	}
-	-re -wrap "" {
-	}
-    }
-    if { ! $found } {
-	untested "Cannot find clear_complaints, skipping test"
-	return 0
-    }
-
-    test_empty_complaint "call clear_complaints()" \
-	    "clear complaints"
-
-    return 0
-}
-
-do_self_tests captured_command_loop {
-    test_initial_complaints
-    test_empty_complaints
-}