[PATCH] [gdb/tui] Show regs when switching to regs layout

[Tom de Vries <tdevries@suse.de>]

When starting gdb in CLI mode, running to main and switching into the TUI regs
layout:
...
$ gdb -q a.out -ex start -ex "layout regs"
...
we get:
...
+---------------------------------+
|                                 |
| [ Register Values Unavailable ] |
|                                 |
+---------------------------------+
...

Fix this by updating the TUI_DATA_WIN in tui_apply_current_layout.

Tested on x86_64-linux.

PR tui/28600
Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=28600
---
 gdb/testsuite/gdb.tui/regs.exp | 10 ++++++----
 gdb/tui/tui-layout.c           |  6 ++++++
 2 files changed, 12 insertions(+), 4 deletions(-)

diff --git a/gdb/testsuite/gdb.tui/regs.exp b/gdb/testsuite/gdb.tui/regs.exp
index 520f6ddba96..0be99625b9f 100644
--- a/gdb/testsuite/gdb.tui/regs.exp
+++ b/gdb/testsuite/gdb.tui/regs.exp
@@ -41,10 +41,12 @@ Term::command "layout regs"
 Term::check_box "register box" 0 0 80 8
 Term::check_box "source box in regs layout" 0 7 80 8
 
-set text [Term::get_line 1]
-# Just check for any register window content at all.
-Term::check_contents "any register contents" "\\|.*\[^ \].*\\|"
-
+# The current frame is main, check that registers are available.
+set re_reg_vals_unavailable \
+    [string_to_regexp {[ Register Values Unavailable ]}]
+gdb_assert \
+    { ![Term::check_region_contents_p 0 0 80 8 $re_reg_vals_unavailable] } \
+    "Register values available"
 
 # Check that we can successfully cause the register window to appear
 # using the 'tui reg next' and 'tui reg prev' commands.
diff --git a/gdb/tui/tui-layout.c b/gdb/tui/tui-layout.c
index 85f4991c769..813f8f93b57 100644
--- a/gdb/tui/tui-layout.c
+++ b/gdb/tui/tui-layout.c
@@ -112,6 +112,12 @@ tui_apply_current_layout (bool preserve_cmd_win_size_p)
   if (gdbarch == nullptr && TUI_DISASM_WIN != nullptr)
     tui_get_begin_asm_address (&gdbarch, &addr);
   tui_update_source_windows_with_addr (gdbarch, addr);
+
+  if (TUI_DATA_WIN != nullptr && has_stack_frames ())
+    {
+      frame_info_ptr fi = get_selected_frame (NULL);
+      TUI_DATA_WIN->check_register_values (fi);
+    }
 }
 
 /* See tui-layout.  */

base-commit: 2ec31e54dff83130fbde8d2f674469078ee203d5
-- 
2.35.3