[PATCH 5/6] gdb: Fix scrolling in TUI

Andrew Burgess
2020-01-07T11:52:35Z

From: Tom Tromey <tom@tromey.com>

Hannes Domani pointed out that my previous patch to fix the "list"
command in the TUI instead broke vertical scrolling. While looking at
this, I found that do_scroll_vertical calls print_source_lines, which
seems like a very roundabout way to change the source window. This
patch removes this oddity and fixes the bug at the same time.

I've added a new test case. This is somewhat tricky, because the
obvious approach of sending a dummy command after the scroll did not
work -- due to how the TUI works, sennding a command causes the scroll
to take effect.

gdb/ChangeLog
2019-12-22 Tom Tromey <tom@tromey.com>

PR tui/18932:
* tui/tui-source.c (tui_source_window::do_scroll_vertical): Call
update_source_window, not print_source_lines.

gdb/testsuite/ChangeLog
2019-12-22 Tom Tromey <tom@tromey.com>

PR tui/18932:
* lib/tuiterm.exp (Term::wait_for): Rename from _accept. Return a
meangingful value.
(Term::command, Term::resize): Update.
* gdb.tui/basic.exp: Add scrolling test.

Change-Id: I9636a7c8a8cade37431c6165ee996a9d556ef1c8
---
gdb/ChangeLog | 6 ++++++
gdb/testsuite/ChangeLog | 8 ++++++++
gdb/testsuite/gdb.tui/basic.exp | 13 +++++++++++++
gdb/testsuite/lib/tuiterm.exp | 16 ++++++++++------
gdb/tui/tui-source.c | 23 +++++++++++++----------
5 files changed, 50 insertions(+), 16 deletions(-)

diff --git a/gdb/testsuite/gdb.tui/basic.exp b/gdb/testsuite/gdb.tui/basic.exp
index c3a3fdd4f5e..be822f8a915 100644
--- a/gdb/testsuite/gdb.tui/basic.exp
+++ b/gdb/testsuite/gdb.tui/basic.exp
@@ -35,6 +35,19 @@ gdb_assert {![string match "No Source Available" $text]} \
Term::command "list main"
Term::check_contents "list main" "21 *return 0"

+# Get the first source line.
+set line [Term::get_line 1]
+# Send an up arrow.
+send_gdb "\033\[A"
+# Wait for a redraw and check that the first line changed.
+if {[Term::wait_for [string_to_regexp $line]] \
+ && [Term::get_line 1] != $line\
+ && [Term::get_line 2] == $line} {
+ pass "scroll up"
+} else {
+ fail "scroll up"
+}
+
Term::check_box "source box" 0 0 80 15

Term::command "layout asm"
diff --git a/gdb/testsuite/lib/tuiterm.exp b/gdb/testsuite/lib/tuiterm.exp
index 0307745d879..7adaf1b71ab 100644
--- a/gdb/testsuite/lib/tuiterm.exp
+++ b/gdb/testsuite/lib/tuiterm.exp
@@ -388,8 +388,10 @@ namespace eval Term {
_clear_lines 0 $_rows
}

- # Accept some output from gdb and update the screen.
- proc _accept {wait_for} {
+ # Accept some output from gdb and update the screen. WAIT_FOR is
+ # a regexp matching the line to wait for. Return 0 on timeout, 1
+ # on success.
+ proc wait_for {wait_for} {
global expect_out
global gdb_prompt
variable _cur_x
@@ -424,7 +426,7 @@ namespace eval Term {
timeout {
# Assume a timeout means we somehow missed the
# expected result, and carry on.
- return
+ return 0
}
}

@@ -443,6 +445,8 @@ namespace eval Term {
set wait_for $prompt_wait_for
}
}
+
+ return 1
}

# Like ::clean_restart, but ensures that gdb starts in an
@@ -490,7 +494,7 @@ namespace eval Term {
# be supplied by this function.
proc command {cmd} {
send_gdb "$cmd\n"
- _accept [string_to_regexp $cmd]
+ wait_for [string_to_regexp $cmd]
}

# Return the text of screen line N, without attributes. Lines are
@@ -682,14 +686,14 @@ namespace eval Term {
# Due to the strange column resizing behavior, and because we
# don't care about this intermediate resize, we don't check
# the size here.
- _accept "@@ resize done $_resize_count"
+ wait_for "@@ resize done $_resize_count"
incr _resize_count
# Somehow the number of columns transmitted to gdb is one less
# than what we request from expect. We hide this weird
# details from the caller.
_do_resize $_rows $cols
stty columns [expr {$_cols + 1}] < $gdb_spawn_name
- _accept "@@ resize done $_resize_count, size = ${_cols}x${rows}"
+ wait_for "@@ resize done $_resize_count, size = ${_cols}x${rows}"
incr _resize_count
}
}
diff --git a/gdb/tui/tui-source.c b/gdb/tui/tui-source.c
index 1503cd4c636..13f2dc7cfe1 100644
--- a/gdb/tui/tui-source.c
+++ b/gdb/tui/tui-source.c
@@ -136,26 +136,29 @@ tui_source_window::do_scroll_vertical (int num_to_scroll)
{
if (!content.empty ())
{
- struct tui_line_or_address l;
struct symtab *s;
struct symtab_and_line cursal = get_current_source_symtab_and_line ();
+ struct gdbarch *arch = gdbarch;

if (cursal.symtab == NULL)
- s = find_pc_line_symtab (get_frame_pc (get_selected_frame (NULL)));
+ {
+ struct frame_info *fi = get_selected_frame (NULL);
+ s = find_pc_line_symtab (get_frame_pc (fi));
+ arch = get_frame_arch (fi);
+ }
else
s = cursal.symtab;

- l.loa = LOA_LINE;
- l.u.line_no = start_line_or_addr.u.line_no
- + num_to_scroll;
+ int line_no = start_line_or_addr.u.line_no + num_to_scroll;
const std::vector<off_t> *offsets;
if (g_source_cache.get_line_charpos (s, &offsets)
- && l.u.line_no > offsets->size ())
- l.u.line_no = start_line_or_addr.u.line_no;
- if (l.u.line_no <= 0)
- l.u.line_no = 1;
+ && line_no > offsets->size ())
+ line_no = start_line_or_addr.u.line_no;
+ if (line_no <= 0)
+ line_no = 1;

- print_source_lines (s, l.u.line_no, l.u.line_no + 1, 0);
+ cursal.line = line_no;
+ update_source_window (arch, cursal);
}
}

--
2.14.5