From a933405894161c8b15f675c48d077b7f7d6aabf2 Mon Sep 17 00:00:00 2001 From: Simon Marchi Date: Mon, 11 Dec 2017 21:05:30 -0500 Subject: [PATCH] remote: Return NULL extra_info/name if they are empty Commit remote: C++ify thread_item and threads_listing_context 21fe1c752e254167d953fa8c846280f63a3a5290 broke the test gdb.threads/names.exp. The problem is that since we now use an std::string to hold the extra_info, an empty string is returned by target_extra_thread_info to print_thread_info_1 when the remote stub didn't send any extra info, instead of NULL before. Because of that, print_thread_info_1 prints the extra info between parentheses, which results in some spurious empty parentheses. Expected: * 1 Thread 22752.22752 "main" all_threads_ready () at ... Actual : * 1 Thread 22752.22752 "main" () all_threads_ready () a ... Since the bug was introduced by a behavior change in the remote target, I chose to fix it on the remote target side by making it return NULL when the extra string is empty. This will avoid possibly changing the behavior of the common code and affecting other targets. The name field has the same problem. If a remote stub returns no thread names, remote_thread_name will return an empty string instead of NULL, so print_thread_info_1 will show empty quotes ("") instead of nothing. gdb/ChangeLog: PR gdb/22556 * remote.c (remote_thread_name): Return NULL if name is empty. (remote_threads_extra_info): Return NULL if extra info is empty. --- gdb/ChangeLog | 6 ++++++ gdb/remote.c | 10 ++++++++-- 2 files changed, 14 insertions(+), 2 deletions(-) diff --git a/gdb/ChangeLog b/gdb/ChangeLog index 78fd713f91f..6416c12a494 100644 --- a/gdb/ChangeLog +++ b/gdb/ChangeLog @@ -1,3 +1,9 @@ +2017-12-11 Simon Marchi + + PR gdb/22556 + * remote.c (remote_thread_name): Return NULL if name is empty. + (remote_threads_extra_info): Return NULL if extra info is empty. + 2017-12-11 Pedro Alves * defs.h (elf_sym_fns_lazy_psyms, elf_sym_fns_gdb_index) diff --git a/gdb/remote.c b/gdb/remote.c index fe2771316cb..852fdef4903 100644 --- a/gdb/remote.c +++ b/gdb/remote.c @@ -2268,7 +2268,10 @@ static const char * remote_thread_name (struct target_ops *ops, struct thread_info *info) { if (info->priv != NULL) - return get_remote_thread_info (info)->name.c_str (); + { + const std::string &name = get_remote_thread_info (info)->name; + return !name.empty () ? name.c_str () : NULL; + } return NULL; } @@ -3319,7 +3322,10 @@ remote_threads_extra_info (struct target_ops *self, struct thread_info *tp) struct thread_info *info = find_thread_ptid (tp->ptid); if (info != NULL && info->priv != NULL) - return get_remote_thread_info (info)->extra.c_str (); + { + const std::string &extra = get_remote_thread_info (info)->extra; + return !extra.empty () ? extra.c_str () : NULL; + } else return NULL; } -- 2.30.2