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[PATCH] C++: dlsym casts in gdb/linux-thread-db.c and gdb/gdbserver/thread-db.c
- From: Pedro Alves <palves at redhat dot com>
- To: gdb-patches at sourceware dot org
- Date: Mon, 3 Aug 2015 19:49:47 +0100
- Subject: [PATCH] C++: dlsym casts in gdb/linux-thread-db.c and gdb/gdbserver/thread-db.c
- Authentication-results: sourceware.org; auth=none
Implicit void * -> function pointer conversion doesn't work in C++, so
in C++, we need to cast the result of dlsym. This adds a few typedefs
and macros that make this easy. GDBserver's version already had the
CHK macro, so I added it to GDB too.
Tested on x86_64 Fedora 20.
gdb/gdbserver/ChangeLog:
2015-08-03 Pedro Alves <palves@redhat.com>
* thread-db.c (td_ta_new_ftype, td_ta_map_lwp2thr_ftype)
(td_ta_thr_iter_ftype, td_ta_event_addr_ftype)
(td_ta_set_event_ftype, td_ta_clear_event_ftype)
(td_ta_event_getmsg_ftype, td_thr_validate_ftype)
(td_thr_get_info_ftype, td_thr_event_enable_ftype)
(td_thr_tls_get_addr_ftype, td_thr_tlsbase_ftype)
(td_symbol_list_ftype, td_ta_delete_ftype): New typedefs.
(struct thread_db): Use them.
(try_thread_db_load_1): Define local TDB_DLSYM macro and use it in
CHK calls.
(disable_thread_event_reporting): Cast result of dlsym to
destination function pointer type.
(thread_db_mourn): Use td_ta_delete_ftype.
gdb/ChangeLog:
2015-08-03 Pedro Alves <palves@redhat.com>
* linux-thread-db.c (td_init_ftype, td_ta_new_ftype)
(td_ta_map_lwp2thr_ftype, td_ta_thr_iter_ftype)
(td_ta_event_addr_ftype, td_ta_set_event_ftype)
(td_ta_clear_event_ftype, td_ta_event_getmsg_ftype)
(td_thr_validate_ftype, td_thr_get_info_ftype)
(td_thr_event_enable_ftype, td_thr_tls_get_addr_ftype)
(td_thr_tlsbase_ftype): New typedefs.
(struct thread_db_info): Use them.
(try_thread_db_load_1): Define TDB_VERBOSE_DLSYM, TDB_DLSYM , CHK
local macros and use them instead of verbose_dlsym and dlsym
calls.
---
gdb/gdbserver/thread-db.c | 103 +++++++++++++++++++++--------------
gdb/linux-thread-db.c | 135 +++++++++++++++++++++++++++-------------------
2 files changed, 143 insertions(+), 95 deletions(-)
diff --git a/gdb/gdbserver/thread-db.c b/gdb/gdbserver/thread-db.c
index 4288fdb..8ab7277 100644
--- a/gdb/gdbserver/thread-db.c
+++ b/gdb/gdbserver/thread-db.c
@@ -37,6 +37,39 @@ static int thread_db_use_events;
#include <limits.h>
#include <ctype.h>
+typedef td_err_e (td_ta_new_ftype) (struct ps_prochandle * ps,
+ td_thragent_t **ta);
+typedef td_err_e (td_ta_map_lwp2thr_ftype) (const td_thragent_t *ta,
+ lwpid_t lwpid, td_thrhandle_t *th);
+typedef td_err_e (td_ta_thr_iter_ftype) (const td_thragent_t *ta,
+ td_thr_iter_f *callback, void *cbdata_p,
+ td_thr_state_e state, int ti_pri,
+ sigset_t *ti_sigmask_p,
+ unsigned int ti_user_flags);
+typedef td_err_e (td_ta_event_addr_ftype) (const td_thragent_t *ta,
+ td_event_e event, td_notify_t *ptr);
+typedef td_err_e (td_ta_set_event_ftype) (const td_thragent_t *ta,
+ td_thr_events_t *event);
+typedef td_err_e (td_ta_clear_event_ftype) (const td_thragent_t *ta,
+ td_thr_events_t *event);
+typedef td_err_e (td_ta_event_getmsg_ftype) (const td_thragent_t *ta,
+ td_event_msg_t *msg);
+
+typedef td_err_e (td_thr_validate_ftype) (const td_thrhandle_t *th);
+typedef td_err_e (td_thr_get_info_ftype) (const td_thrhandle_t *th,
+ td_thrinfo_t *infop);
+typedef td_err_e (td_thr_event_enable_ftype) (const td_thrhandle_t *th,
+ int event);
+
+typedef td_err_e (td_thr_tls_get_addr_ftype) (const td_thrhandle_t *th,
+ psaddr_t map_address,
+ size_t offset, psaddr_t *address);
+typedef td_err_e (td_thr_tlsbase_ftype) (const td_thrhandle_t *th,
+ unsigned long int modid,
+ psaddr_t *base);
+typedef const char ** (td_symbol_list_ftype) (void);
+typedef td_err_e (td_ta_delete_ftype) (td_thragent_t *);
+
struct thread_db
{
/* Structure that identifies the child process for the
@@ -67,30 +100,17 @@ struct thread_db
struct breakpoint *td_create_bp;
/* Addresses of libthread_db functions. */
- td_err_e (*td_ta_new_p) (struct ps_prochandle * ps, td_thragent_t **ta);
- td_err_e (*td_ta_event_getmsg_p) (const td_thragent_t *ta,
- td_event_msg_t *msg);
- td_err_e (*td_ta_set_event_p) (const td_thragent_t *ta,
- td_thr_events_t *event);
- td_err_e (*td_ta_event_addr_p) (const td_thragent_t *ta,
- td_event_e event, td_notify_t *ptr);
- td_err_e (*td_ta_map_lwp2thr_p) (const td_thragent_t *ta, lwpid_t lwpid,
- td_thrhandle_t *th);
- td_err_e (*td_thr_get_info_p) (const td_thrhandle_t *th,
- td_thrinfo_t *infop);
- td_err_e (*td_thr_event_enable_p) (const td_thrhandle_t *th, int event);
- td_err_e (*td_ta_thr_iter_p) (const td_thragent_t *ta,
- td_thr_iter_f *callback, void *cbdata_p,
- td_thr_state_e state, int ti_pri,
- sigset_t *ti_sigmask_p,
- unsigned int ti_user_flags);
- td_err_e (*td_thr_tls_get_addr_p) (const td_thrhandle_t *th,
- psaddr_t map_address,
- size_t offset, psaddr_t *address);
- td_err_e (*td_thr_tlsbase_p) (const td_thrhandle_t *th,
- unsigned long int modid,
- psaddr_t *base);
- const char ** (*td_symbol_list_p) (void);
+ td_ta_new_ftype *td_ta_new_p;
+ td_ta_event_getmsg_ftype * td_ta_event_getmsg_p;
+ td_ta_set_event_ftype *td_ta_set_event_p;
+ td_ta_event_addr_ftype *td_ta_event_addr_p;
+ td_ta_map_lwp2thr_ftype *td_ta_map_lwp2thr_p;
+ td_thr_get_info_ftype *td_thr_get_info_p;
+ td_thr_event_enable_ftype *td_thr_event_enable_p;
+ td_ta_thr_iter_ftype *td_ta_thr_iter_p;
+ td_thr_tls_get_addr_ftype *td_thr_tls_get_addr_p;
+ td_thr_tlsbase_ftype *td_thr_tlsbase_p;
+ td_symbol_list_ftype *td_symbol_list_p;
};
static char *libthread_db_search_path;
@@ -645,7 +665,10 @@ try_thread_db_load_1 (void *handle)
} \
while (0)
- CHK (1, tdb->td_ta_new_p = dlsym (handle, "td_ta_new"));
+#define TDB_DLSYM(tdb, func) \
+ tdb->func ## _p = (func ## _ftype *) dlsym (tdb->handle, #func)
+
+ CHK (1, TDB_DLSYM (tdb, td_ta_new));
/* Attempt to open a connection to the thread library. */
err = tdb->td_ta_new_p (&tdb->proc_handle, &tdb->thread_agent);
@@ -658,23 +681,23 @@ try_thread_db_load_1 (void *handle)
return 0;
}
- CHK (1, tdb->td_ta_map_lwp2thr_p = dlsym (handle, "td_ta_map_lwp2thr"));
- CHK (1, tdb->td_thr_get_info_p = dlsym (handle, "td_thr_get_info"));
- CHK (1, tdb->td_ta_thr_iter_p = dlsym (handle, "td_ta_thr_iter"));
- CHK (1, tdb->td_symbol_list_p = dlsym (handle, "td_symbol_list"));
+ CHK (1, TDB_DLSYM (tdb, td_ta_map_lwp2thr));
+ CHK (1, TDB_DLSYM (tdb, td_thr_get_info));
+ CHK (1, TDB_DLSYM (tdb, td_ta_thr_iter));
+ CHK (1, TDB_DLSYM (tdb, td_symbol_list));
/* This is required only when thread_db_use_events is on. */
- CHK (thread_db_use_events,
- tdb->td_thr_event_enable_p = dlsym (handle, "td_thr_event_enable"));
+ CHK (thread_db_use_events, TDB_DLSYM (tdb, td_thr_event_enable));
/* These are not essential. */
- CHK (0, tdb->td_ta_event_addr_p = dlsym (handle, "td_ta_event_addr"));
- CHK (0, tdb->td_ta_set_event_p = dlsym (handle, "td_ta_set_event"));
- CHK (0, tdb->td_ta_event_getmsg_p = dlsym (handle, "td_ta_event_getmsg"));
- CHK (0, tdb->td_thr_tls_get_addr_p = dlsym (handle, "td_thr_tls_get_addr"));
- CHK (0, tdb->td_thr_tlsbase_p = dlsym (handle, "td_thr_tlsbase"));
+ CHK (0, TDB_DLSYM (tdb, td_ta_event_addr));
+ CHK (0, TDB_DLSYM (tdb, td_ta_set_event));
+ CHK (0, TDB_DLSYM (tdb, td_ta_event_getmsg));
+ CHK (0, TDB_DLSYM (tdb, td_thr_tls_get_addr));
+ CHK (0, TDB_DLSYM (tdb, td_thr_tlsbase));
#undef CHK
+#undef TDB_DLSYM
return 1;
}
@@ -914,7 +937,9 @@ disable_thread_event_reporting (struct process_info *proc)
td_thr_events_t *event);
#ifndef USE_LIBTHREAD_DB_DIRECTLY
- td_ta_clear_event_p = dlsym (thread_db->handle, "td_ta_clear_event");
+ td_ta_clear_event_p
+ = (td_ta_clear_event_ftype *) dlsym (thread_db->handle,
+ "td_ta_clear_event");
#else
td_ta_clear_event_p = &td_ta_clear_event;
#endif
@@ -974,10 +999,10 @@ thread_db_mourn (struct process_info *proc)
struct thread_db *thread_db = proc->priv->thread_db;
if (thread_db)
{
- td_err_e (*td_ta_delete_p) (td_thragent_t *);
+ td_ta_delete_ftype *td_ta_delete_p;
#ifndef USE_LIBTHREAD_DB_DIRECTLY
- td_ta_delete_p = dlsym (thread_db->handle, "td_ta_delete");
+ td_ta_delete_p = (td_ta_delete_ftype *) dlsym (thread_db->handle, "td_ta_delete");
#else
td_ta_delete_p = &td_ta_delete;
#endif
diff --git a/gdb/linux-thread-db.c b/gdb/linux-thread-db.c
index 26350bb..a076b5e 100644
--- a/gdb/linux-thread-db.c
+++ b/gdb/linux-thread-db.c
@@ -133,6 +133,41 @@ static int thread_signals;
static sigset_t thread_stop_set;
static sigset_t thread_print_set;
+/* Types of the libthread_db functions. */
+
+typedef td_err_e (td_init_ftype) (void);
+
+typedef td_err_e (td_ta_new_ftype) (struct ps_prochandle * ps,
+ td_thragent_t **ta);
+typedef td_err_e (td_ta_map_lwp2thr_ftype) (const td_thragent_t *ta,
+ lwpid_t lwpid, td_thrhandle_t *th);
+typedef td_err_e (td_ta_thr_iter_ftype) (const td_thragent_t *ta,
+ td_thr_iter_f *callback, void *cbdata_p,
+ td_thr_state_e state, int ti_pri,
+ sigset_t *ti_sigmask_p,
+ unsigned int ti_user_flags);
+typedef td_err_e (td_ta_event_addr_ftype) (const td_thragent_t *ta,
+ td_event_e event, td_notify_t *ptr);
+typedef td_err_e (td_ta_set_event_ftype) (const td_thragent_t *ta,
+ td_thr_events_t *event);
+typedef td_err_e (td_ta_clear_event_ftype) (const td_thragent_t *ta,
+ td_thr_events_t *event);
+typedef td_err_e (td_ta_event_getmsg_ftype) (const td_thragent_t *ta,
+ td_event_msg_t *msg);
+
+typedef td_err_e (td_thr_validate_ftype) (const td_thrhandle_t *th);
+typedef td_err_e (td_thr_get_info_ftype) (const td_thrhandle_t *th,
+ td_thrinfo_t *infop);
+typedef td_err_e (td_thr_event_enable_ftype) (const td_thrhandle_t *th,
+ int event);
+
+typedef td_err_e (td_thr_tls_get_addr_ftype) (const td_thrhandle_t *th,
+ psaddr_t map_address,
+ size_t offset, psaddr_t *address);
+typedef td_err_e (td_thr_tlsbase_ftype) (const td_thrhandle_t *th,
+ unsigned long int modid,
+ psaddr_t *base);
+
struct thread_db_info
{
struct thread_db_info *next;
@@ -174,37 +209,19 @@ struct thread_db_info
/* Pointers to the libthread_db functions. */
- td_err_e (*td_init_p) (void);
-
- td_err_e (*td_ta_new_p) (struct ps_prochandle * ps,
- td_thragent_t **ta);
- td_err_e (*td_ta_map_lwp2thr_p) (const td_thragent_t *ta,
- lwpid_t lwpid, td_thrhandle_t *th);
- td_err_e (*td_ta_thr_iter_p) (const td_thragent_t *ta,
- td_thr_iter_f *callback, void *cbdata_p,
- td_thr_state_e state, int ti_pri,
- sigset_t *ti_sigmask_p,
- unsigned int ti_user_flags);
- td_err_e (*td_ta_event_addr_p) (const td_thragent_t *ta,
- td_event_e event, td_notify_t *ptr);
- td_err_e (*td_ta_set_event_p) (const td_thragent_t *ta,
- td_thr_events_t *event);
- td_err_e (*td_ta_clear_event_p) (const td_thragent_t *ta,
- td_thr_events_t *event);
- td_err_e (*td_ta_event_getmsg_p) (const td_thragent_t *ta,
- td_event_msg_t *msg);
-
- td_err_e (*td_thr_get_info_p) (const td_thrhandle_t *th,
- td_thrinfo_t *infop);
- td_err_e (*td_thr_event_enable_p) (const td_thrhandle_t *th,
- int event);
-
- td_err_e (*td_thr_tls_get_addr_p) (const td_thrhandle_t *th,
- psaddr_t map_address,
- size_t offset, psaddr_t *address);
- td_err_e (*td_thr_tlsbase_p) (const td_thrhandle_t *th,
- unsigned long int modid,
- psaddr_t *base);
+ td_init_ftype *td_init_p;
+ td_ta_new_ftype *td_ta_new_p;
+ td_ta_map_lwp2thr_ftype *td_ta_map_lwp2thr_p;
+ td_ta_thr_iter_ftype *td_ta_thr_iter_p;
+ td_ta_event_addr_ftype *td_ta_event_addr_p;
+ td_ta_set_event_ftype *td_ta_set_event_p;
+ td_ta_clear_event_ftype *td_ta_clear_event_p;
+ td_ta_event_getmsg_ftype * td_ta_event_getmsg_p;
+ td_thr_validate_ftype *td_thr_validate_p;
+ td_thr_get_info_ftype *td_thr_get_info_p;
+ td_thr_event_enable_ftype *td_thr_event_enable_p;
+ td_thr_tls_get_addr_ftype *td_thr_tls_get_addr_p;
+ td_thr_tlsbase_ftype *td_thr_tlsbase_p;
};
/* List of known processes using thread_db, and the required
@@ -677,9 +694,20 @@ try_thread_db_load_1 (struct thread_db_info *info)
/* Initialize pointers to the dynamic library functions we will use.
Essential functions first. */
- info->td_init_p = verbose_dlsym (info->handle, "td_init");
- if (info->td_init_p == NULL)
- return 0;
+#define TDB_VERBOSE_DLSYM(info, func) \
+ info->func ## _p = (func ## _ftype *) verbose_dlsym (info->handle, #func)
+
+#define TDB_DLSYM(info, func) \
+ info->func ## _p = (func ## _ftype *) dlsym (info->handle, #func)
+
+#define CHK(a) \
+ do \
+ { \
+ if ((a) == NULL) \
+ return 0; \
+ } while (0)
+
+ CHK (TDB_VERBOSE_DLSYM (info, td_init));
err = info->td_init_p ();
if (err != TD_OK)
@@ -689,9 +717,7 @@ try_thread_db_load_1 (struct thread_db_info *info)
return 0;
}
- info->td_ta_new_p = verbose_dlsym (info->handle, "td_ta_new");
- if (info->td_ta_new_p == NULL)
- return 0;
+ CHK (TDB_VERBOSE_DLSYM (info, td_ta_new));
/* Initialize the structure that identifies the child process. */
info->proc_handle.ptid = inferior_ptid;
@@ -720,27 +746,24 @@ try_thread_db_load_1 (struct thread_db_info *info)
return 0;
}
- info->td_ta_map_lwp2thr_p = verbose_dlsym (info->handle,
- "td_ta_map_lwp2thr");
- if (info->td_ta_map_lwp2thr_p == NULL)
- return 0;
-
- info->td_ta_thr_iter_p = verbose_dlsym (info->handle, "td_ta_thr_iter");
- if (info->td_ta_thr_iter_p == NULL)
- return 0;
-
- info->td_thr_get_info_p = verbose_dlsym (info->handle, "td_thr_get_info");
- if (info->td_thr_get_info_p == NULL)
- return 0;
+ /* These are essential. */
+ CHK (TDB_VERBOSE_DLSYM (info, td_ta_map_lwp2thr));
+ CHK (TDB_VERBOSE_DLSYM (info, td_ta_thr_iter));
+ CHK (TDB_VERBOSE_DLSYM (info, td_thr_validate));
+ CHK (TDB_VERBOSE_DLSYM (info, td_thr_get_info));
/* These are not essential. */
- info->td_ta_event_addr_p = dlsym (info->handle, "td_ta_event_addr");
- info->td_ta_set_event_p = dlsym (info->handle, "td_ta_set_event");
- info->td_ta_clear_event_p = dlsym (info->handle, "td_ta_clear_event");
- info->td_ta_event_getmsg_p = dlsym (info->handle, "td_ta_event_getmsg");
- info->td_thr_event_enable_p = dlsym (info->handle, "td_thr_event_enable");
- info->td_thr_tls_get_addr_p = dlsym (info->handle, "td_thr_tls_get_addr");
- info->td_thr_tlsbase_p = dlsym (info->handle, "td_thr_tlsbase");
+ TDB_DLSYM (info, td_ta_event_addr);
+ TDB_DLSYM (info, td_ta_set_event);
+ TDB_DLSYM (info, td_ta_clear_event);
+ TDB_DLSYM (info, td_ta_event_getmsg);
+ TDB_DLSYM (info, td_thr_event_enable);
+ TDB_DLSYM (info, td_thr_tls_get_addr);
+ TDB_DLSYM (info, td_thr_tlsbase);
+
+#undef TDB_VERBOSE_DLSYM
+#undef TDB_DLSYM
+#undef CHK
/* It's best to avoid td_ta_thr_iter if possible. That walks data
structures in the inferior's address space that may be corrupted,
--
1.9.3