[PATCH] [gdb/cli] Add maintenance ignore-probes

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

There's a command "disable probes", but SystemTap probes, for instance
libc:longjmp cannot be disabled:
...
$ gdb -q -batch a.out -ex start -ex "disable probes libc ^longjmp$"
  ...
Probe libc:longjmp cannot be disabled.
Probe libc:longjmp cannot be disabled.
Probe libc:longjmp cannot be disabled.
...

Add a command "maintenance ignore-probes" that ignores probes during
get_probes, such that we can easily pretend to use a libc without the
libc:longjmp probe:
...
(gdb) maint ignore-probes -verbose libc ^longjmp$
ignore-probes filter has been set to:
PROVIDER: 'libc'
PROBE_NAME: '^longjmp$'
OBJNAME: ''
(gdb) start ^M
  ...
Ignoring SystemTap probe libc longjmp in /lib64/libc.so.6.^M
Ignoring SystemTap probe libc longjmp in /lib64/libc.so.6.^M
Ignoring SystemTap probe libc longjmp in /lib64/libc.so.6.^M
...

The "Ignoring ..." messages can be suppressed by not using -verbose.

Note that as with "disable probes", running simply "maint ignore-probes"
ignores all probes.

The ignore-probes filter can be reset by using:
...
(gdb) maint ignore-probes -reset
ignore-probes filter has been reset
...

For now, the command is only supported for SystemTap probes.

PR cli/27159
Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=27159
---
 gdb/doc/gdb.texinfo |  22 +++++++++
 gdb/probe.c         | 115 ++++++++++++++++++++++++++++++++++++++++++++
 gdb/probe.h         |   5 ++
 gdb/stap-probe.c    |   3 ++
 4 files changed, 145 insertions(+)

diff --git a/gdb/doc/gdb.texinfo b/gdb/doc/gdb.texinfo
index 755fbf72a7c..5ea248a87fd 100644
--- a/gdb/doc/gdb.texinfo
+++ b/gdb/doc/gdb.texinfo
@@ -6114,6 +6114,7 @@ disabled, but @code{SystemTap} probes cannot be disabled.
 You can enable (or disable) one or more probes using the following
 commands, with optional arguments:
 
+@anchor{enable probes}
 @table @code
 @kindex enable probes
 @item enable probes @r{[}@var{provider} @r{[}@var{name} @r{[}@var{objfile}@r{]}@r{]}@r{]}
@@ -40900,6 +40901,27 @@ Like the @code{with} command, but works with @code{maintenance set}
 variables.  This is used by the testsuite to exercise the @code{with}
 command's infrastructure.
 
+@kindex maint ignore-probes
+@item maint ignore-probes [@var{-v}|@var{-verbose}] [@var{provider} [@var{name} [@var{objfile}]]]
+@itemx maint ignore-probes @var{-reset}
+Set or reset the ignore-probes filter.  The @var{provider}, @var{name}
+and @var{objfile} arguments are as in @code{enable probes} and
+@code{disable probes} (@pxref{enable probes}).  Only supported for
+SystemTap probes.
+
+Here's an example of using @code{maint ignore-probes}:
+@smallexample
+(gdb) maint ignore-probes -verbose libc ^longjmp$
+    ignore-probes filter has been set to:
+    PROVIDER: 'libc'
+    PROBE_NAME: '^longjmp$'
+    OBJNAME: ''
+(gdb) start
+<... more output ...>
+Ignoring SystemTap probe libc longjmp in /lib64/libc.so.6.^M
+Ignoring SystemTap probe libc longjmp in /lib64/libc.so.6.^M
+Ignoring SystemTap probe libc longjmp in /lib64/libc.so.6.^M
+@end smallexample
 @end table
 
 The following command is useful for non-interactive invocations of
diff --git a/gdb/probe.c b/gdb/probe.c
index 4193f9f936b..10e51df6dae 100644
--- a/gdb/probe.c
+++ b/gdb/probe.c
@@ -680,6 +680,109 @@ disable_probes_command (const char *arg, int from_tty)
     }
 }
 
+static bool ignore_probes_p = false;
+static bool ignore_probes_idx = 0;
+static bool ignore_probes_verbose_p;
+static gdb::optional<compiled_regex> ignore_probes_prov_pat[2];
+static gdb::optional<compiled_regex> ignore_probes_name_pat[2];
+static gdb::optional<compiled_regex> ignore_probes_obj_pat[2];
+
+/* See comments in probe.h.  */
+
+bool
+ignore_probe_p (const char *provider, const char *name,
+		const char *objfile_name, const char *type)
+{
+  if (!ignore_probes_p)
+    return false;
+
+  gdb::optional<compiled_regex> &re_prov
+    = ignore_probes_prov_pat[ignore_probes_idx];
+  gdb::optional<compiled_regex> &re_name
+    = ignore_probes_name_pat[ignore_probes_idx];
+  gdb::optional<compiled_regex> &re_obj
+    = ignore_probes_obj_pat[ignore_probes_idx];
+
+  bool res
+    = ((!re_prov
+	|| re_prov->exec (provider, 0, NULL, 0) == 0)
+       && (!re_name
+	   || re_name->exec (name, 0, NULL, 0) == 0)
+       && (!re_obj
+	   || re_obj->exec (objfile_name, 0, NULL, 0) == 0));
+
+  if (res && ignore_probes_verbose_p)
+    gdb_printf (gdb_stdlog, _("Ignoring %s probe %s %s in %s.\n"),
+		type, provider, name, objfile_name);
+
+  return res;
+}
+
+/* Implementation of the `maintenance ignore-probes' command.  */
+
+static void
+ignore_probes_command (const char *arg, int from_tty)
+{
+  std::string ignore_provider, ignore_probe_name, ignore_objname;
+
+  bool verbose_p = false;
+  if (arg != nullptr)
+    {
+      const char *idx = arg;
+      std::string s = extract_arg (&idx);
+
+      if (strcmp (s.c_str (), "-reset") == 0)
+	{
+	  if (*idx != '\0')
+	    error (_("-reset: no arguments allowed"));
+
+	  ignore_probes_p = false;
+	  gdb_printf (gdb_stdout, _("ignore-probes filter has been reset\n"));
+	  return;
+	}
+
+      if (strcmp (s.c_str (), "-verbose") == 0
+	  || strcmp (s.c_str (), "-v") == 0)
+	{
+	  verbose_p = true;
+	  arg = idx;
+	}
+    }
+
+  parse_probe_linespec (arg, &ignore_provider, &ignore_probe_name,
+			&ignore_objname);
+
+  /* Parse the regular expressions, making sure that the old regular
+     expressions are still valid if an exception is throw.  */
+  int new_ignore_probes_idx = 1 - ignore_probes_idx;
+  gdb::optional<compiled_regex> &re_prov
+    = ignore_probes_prov_pat[new_ignore_probes_idx];
+  gdb::optional<compiled_regex> &re_name
+    = ignore_probes_name_pat[new_ignore_probes_idx];
+  gdb::optional<compiled_regex> &re_obj
+    = ignore_probes_obj_pat[new_ignore_probes_idx];
+  re_prov.reset ();
+  re_name.reset ();
+  re_obj.reset ();
+  if (!ignore_provider.empty ())
+    re_prov.emplace (ignore_provider.c_str (), REG_NOSUB,
+		     _("Invalid provider regexp"));
+  if (!ignore_probe_name.empty ())
+    re_name.emplace (ignore_probe_name.c_str (), REG_NOSUB,
+		     _("Invalid probe regexp"));
+  if (!ignore_objname.empty ())
+    re_obj.emplace (ignore_objname.c_str (), REG_NOSUB,
+		    _("Invalid object file regexp"));
+  ignore_probes_idx = new_ignore_probes_idx;
+
+  ignore_probes_p = true;
+  ignore_probes_verbose_p = verbose_p;
+  gdb_printf (gdb_stdout, _("ignore-probes filter has been set to:\n"));
+  gdb_printf (gdb_stdout, _("PROVIDER: '%s'\n"), ignore_provider.c_str ());
+  gdb_printf (gdb_stdout, _("PROBE_NAME: '%s'\n"), ignore_probe_name.c_str ());
+  gdb_printf (gdb_stdout, _("OBJNAME: '%s'\n"), ignore_objname.c_str ());
+}
+
 /* See comments in probe.h.  */
 
 struct value *
@@ -931,4 +1034,16 @@ If you do not specify any argument then the command will disable\n\
 all defined probes."),
 	   &disablelist);
 
+  add_cmd ("ignore-probes", class_maintenance, ignore_probes_command, _("\
+Ignore probes.\n\
+Usage: maintenance ignore-probes [-v|-verbose] [PROVIDER [NAME [OBJECT]]]\n\
+       maintenance ignore-probes -reset\n\
+Each argument is a regular expression, used to select probes.\n\
+PROVIDER matches probe provider names.\n\
+NAME matches the probe names.\n\
+OBJECT matches the executable or shared library name.\n\
+If you do not specify any argument then the command will ignore\n\
+all defined probes.  To reset the ignore-probes filter, use the -reset form.\n\
+Only supported for SystemTap probes."),
+	   &maintenancelist);
 }
diff --git a/gdb/probe.h b/gdb/probe.h
index 598f43a238e..a6001769cbd 100644
--- a/gdb/probe.h
+++ b/gdb/probe.h
@@ -304,4 +304,9 @@ extern struct cmd_list_element **info_probes_cmdlist_get (void);
 extern struct value *probe_safe_evaluate_at_pc (frame_info_ptr frame,
 						unsigned n);
 
+/* Return true if the PROVIDER/NAME probe from OBJFILE_NAME needs to be
+   ignored.  */
+
+bool ignore_probe_p (const char *provider, const char *name,
+		     const char *objfile_name, const char *TYPE);
 #endif /* !defined (PROBE_H) */
diff --git a/gdb/stap-probe.c b/gdb/stap-probe.c
index 6f91d87846a..f119e2c02ff 100644
--- a/gdb/stap-probe.c
+++ b/gdb/stap-probe.c
@@ -1619,6 +1619,9 @@ handle_stap_probe (struct objfile *objfile, struct sdt_note *el,
       return;
     }
 
+  if (ignore_probe_p (provider, name, objfile_name (objfile), "SystemTap"))
+    return;
+
   stap_probe *ret = new stap_probe (std::string (name), std::string (provider),
 				    address, gdbarch, sem_addr, probe_args);
 

base-commit: 5d80df4a109e7b648e324423a5fbc3c1ba02e816
-- 
2.35.3