[PATCHv4 09/14] gdb: implement readline rl_directory_rewrite_hook callback

Andrew Burgess
2024-07-04T14:23:49Z

Implement the readline rl_directory_rewrite_hook callback function,
this is used when readline needs to offer completions from within a
directory. The important thing is that this function should remove
any escaping, this allows GDB to correctly offer completions in
situations like this:

(gdb) file /tmp/directory\ with\ spaces/<TAB><TAB>

Note the escaping in 'directory\ with\ spaces'. Without the
rl_directory_rewrite_hook callback readline will try to open a
directory literally called '/tmp/directory\ with\ spaces' which
obviously doesn't exist.

There are tests added to cover this new functionality.
---
gdb/completer.c | 21 +++++++++++++++++++
.../gdb.base/filename-completion.exp | 12 +++++++++++
2 files changed, 33 insertions(+)

diff --git a/gdb/completer.c b/gdb/completer.c
index b0e999ef514..b80649c5260 100644
--- a/gdb/completer.c
+++ b/gdb/completer.c
@@ -321,6 +321,26 @@ gdb_completer_file_name_dequote (char *filename, int quote_char)
return strdup (tmp.c_str ());
}

+/* Implement readline's rl_directory_rewrite_hook. Remove any quoting from
+ the string *DIRNAME,update *DIRNAME, and return non-zero. If *DIRNAME
+ doesn't need updating then return zero. See readline docs for more
+ information. */
+
+static int
+gdb_completer_directory_rewrite (char **dirname)
+{
+ if (!rl_completion_found_quote)
+ return 0;
+
+ int quote_char = rl_completion_quote_character;
+ char *new_dirname
+ = gdb_completer_file_name_dequote (*dirname, quote_char);
+ free (*dirname);
+ *dirname = new_dirname;
+
+ return 1;
+}
+
/* Apply character escaping to the filename in TEXT and return a newly
allocated buffer containing the possibly updated filename.

@@ -3416,6 +3436,7 @@ _initialize_completer ()
rl_filename_quote_characters = " \t\n\\\"'";
rl_filename_dequoting_function = gdb_completer_file_name_dequote;
rl_filename_quoting_function = gdb_completer_file_name_quote;
+ rl_directory_rewrite_hook = gdb_completer_directory_rewrite;

add_setshow_zuinteger_unlimited_cmd ("max-completions", no_class,
&max_completions, _("\
diff --git a/gdb/testsuite/gdb.base/filename-completion.exp b/gdb/testsuite/gdb.base/filename-completion.exp
index a4b411c1c67..cf00d007ca7 100644
--- a/gdb/testsuite/gdb.base/filename-completion.exp
+++ b/gdb/testsuite/gdb.base/filename-completion.exp
@@ -170,6 +170,11 @@ proc run_quoting_and_escaping_tests { root } {
set dq "\\\""
}

+ test_gdb_complete_unique "${cmd} ${qc}${root}/bb2/dir${sp}1/" \
+ "${cmd} ${qc}${root}/bb2/dir${sp}1/unique${sp}file${qc}" " " \
+ false \
+ "expand a unique file name in a directory containing a space"
+
test_gdb_complete_filename_multiple "$cmd ${qc}${root}/bb2/" \
"d" "ir${sp}" {
"dir 1/"
@@ -177,6 +182,13 @@ proc run_quoting_and_escaping_tests { root } {
} "" "${qc}" false \
"expand multiple directory names containing spaces"

+ test_gdb_complete_filename_multiple "${cmd} ${qc}${root}/bb2/dir${sp}2/" \
+ "f" "ile${sp}" {
+ "file 1"
+ "file 2"
+ } "" "${qc}" false \
+ "expand contents of a directory containing a space"
+
test_gdb_complete_filename_multiple "$cmd ${qc}${root}/aaa/" \
"a" "a${sp}" {
"aa bb"
--
2.25.4