Add support for extracting thread names from cores.

Add a new gdbarch method to extract a thread name from a core for a
given thread.  Use this new method in core_thread_name to implement the
to_thread_name target op.

gdb/ChangeLog:

	* corelow.c (core_thread_name): New function.
	(init_core_ops): Use "core_thread_name" for the "to_thread_name"
	target op.
	* gdbarch.sh (core_thread_name): New gdbarch callback.
	* gdbarch.h: Re-generate.
	* gdbarch.c: Re-generate.

5 files changed, 64 insertions, 0 deletions

diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index 40b5deb..b54ac3f 100644
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,3 +1,12 @@
+2016-01-19  John Baldwin  <jhb@FreeBSD.org>
+
+	* corelow.c (core_thread_name): New function.
+	(init_core_ops): Use "core_thread_name" for the "to_thread_name"
+	target op.
+	* gdbarch.sh (core_thread_name): New gdbarch callback.
+	* gdbarch.h: Re-generate.
+	* gdbarch.c: Re-generate.
+
 2016-01-19  Simon Marchi  <simon.marchi@polymtl.ca>
 
 	* python/lib/gdb/printing.py (_EnumInstance.to_string): Explicitly
diff --git a/gdb/corelow.c b/gdb/corelow.c
index 90e3d56..224719e 100644
--- a/gdb/corelow.c
+++ b/gdb/corelow.c
@@ -986,6 +986,15 @@ core_pid_to_str (struct target_ops *ops, ptid_t ptid)
   return buf;
 }
 
+static const char *
+core_thread_name (struct target_ops *self, struct thread_info *thr)
+{
+  if (core_gdbarch
+      && gdbarch_core_thread_name_p (core_gdbarch))
+    return gdbarch_core_thread_name (core_gdbarch, thr);
+  return NULL;
+}
+
 static int
 core_has_memory (struct target_ops *ops)
 {
@@ -1038,6 +1047,7 @@ init_core_ops (void)
   core_ops.to_thread_alive = core_thread_alive;
   core_ops.to_read_description = core_read_description;
   core_ops.to_pid_to_str = core_pid_to_str;
+  core_ops.to_thread_name = core_thread_name;
   core_ops.to_stratum = process_stratum;
   core_ops.to_has_memory = core_has_memory;
   core_ops.to_has_stack = core_has_stack;
diff --git a/gdb/gdbarch.c b/gdb/gdbarch.c
index d45af1a..4143744 100644
--- a/gdb/gdbarch.c
+++ b/gdb/gdbarch.c
@@ -269,6 +269,7 @@ struct gdbarch
   gdbarch_core_xfer_shared_libraries_ftype *core_xfer_shared_libraries;
   gdbarch_core_xfer_shared_libraries_aix_ftype *core_xfer_shared_libraries_aix;
   gdbarch_core_pid_to_str_ftype *core_pid_to_str;
+  gdbarch_core_thread_name_ftype *core_thread_name;
   const char * gcore_bfd_target;
   int vtable_function_descriptors;
   int vbit_in_delta;
@@ -612,6 +613,7 @@ verify_gdbarch (struct gdbarch *gdbarch)
   /* Skip verify of core_xfer_shared_libraries, has predicate.  */
   /* Skip verify of core_xfer_shared_libraries_aix, has predicate.  */
   /* Skip verify of core_pid_to_str, has predicate.  */
+  /* Skip verify of core_thread_name, has predicate.  */
   /* Skip verify of gcore_bfd_target, has predicate.  */
   /* Skip verify of vtable_function_descriptors, invalid_p == 0 */
   /* Skip verify of vbit_in_delta, invalid_p == 0 */
@@ -824,6 +826,12 @@ gdbarch_dump (struct gdbarch *gdbarch, struct ui_file *file)
                       "gdbarch_dump: core_read_description = <%s>\n",
                       host_address_to_string (gdbarch->core_read_description));
   fprintf_unfiltered (file,
+                      "gdbarch_dump: gdbarch_core_thread_name_p() = %d\n",
+                      gdbarch_core_thread_name_p (gdbarch));
+  fprintf_unfiltered (file,
+                      "gdbarch_dump: core_thread_name = <%s>\n",
+                      host_address_to_string (gdbarch->core_thread_name));
+  fprintf_unfiltered (file,
                       "gdbarch_dump: gdbarch_core_xfer_shared_libraries_p() = %d\n",
                       gdbarch_core_xfer_shared_libraries_p (gdbarch));
   fprintf_unfiltered (file,
@@ -3554,6 +3562,30 @@ set_gdbarch_core_pid_to_str (struct gdbarch *gdbarch,
 }
 
 int
+gdbarch_core_thread_name_p (struct gdbarch *gdbarch)
+{
+  gdb_assert (gdbarch != NULL);
+  return gdbarch->core_thread_name != NULL;
+}
+
+const char *
+gdbarch_core_thread_name (struct gdbarch *gdbarch, struct thread_info *thr)
+{
+  gdb_assert (gdbarch != NULL);
+  gdb_assert (gdbarch->core_thread_name != NULL);
+  if (gdbarch_debug >= 2)
+    fprintf_unfiltered (gdb_stdlog, "gdbarch_core_thread_name called\n");
+  return gdbarch->core_thread_name (gdbarch, thr);
+}
+
+void
+set_gdbarch_core_thread_name (struct gdbarch *gdbarch,
+                              gdbarch_core_thread_name_ftype core_thread_name)
+{
+  gdbarch->core_thread_name = core_thread_name;
+}
+
+int
 gdbarch_gcore_bfd_target_p (struct gdbarch *gdbarch)
 {
   gdb_assert (gdbarch != NULL);
diff --git a/gdb/gdbarch.h b/gdb/gdbarch.h
index 3c16af2..3fadcd1 100644
--- a/gdb/gdbarch.h
+++ b/gdb/gdbarch.h
@@ -63,6 +63,7 @@ struct ravenscar_arch_ops;
 struct elf_internal_linux_prpsinfo;
 struct mem_range;
 struct syscalls_info;
+struct thread_info;
 
 #include "regcache.h"
 
@@ -866,6 +867,14 @@ typedef char * (gdbarch_core_pid_to_str_ftype) (struct gdbarch *gdbarch, ptid_t
 extern char * gdbarch_core_pid_to_str (struct gdbarch *gdbarch, ptid_t ptid);
 extern void set_gdbarch_core_pid_to_str (struct gdbarch *gdbarch, gdbarch_core_pid_to_str_ftype *core_pid_to_str);
 
+/* How the core target extracts the name of a thread from a core file. */
+
+extern int gdbarch_core_thread_name_p (struct gdbarch *gdbarch);
+
+typedef const char * (gdbarch_core_thread_name_ftype) (struct gdbarch *gdbarch, struct thread_info *thr);
+extern const char * gdbarch_core_thread_name (struct gdbarch *gdbarch, struct thread_info *thr);
+extern void set_gdbarch_core_thread_name (struct gdbarch *gdbarch, gdbarch_core_thread_name_ftype *core_thread_name);
+
 /* BFD target to use when generating a core file. */
 
 extern int gdbarch_gcore_bfd_target_p (struct gdbarch *gdbarch);
diff --git a/gdb/gdbarch.sh b/gdb/gdbarch.sh
index f80cd51..4ac6b90 100755
--- a/gdb/gdbarch.sh
+++ b/gdb/gdbarch.sh
@@ -721,6 +721,9 @@ M:ULONGEST:core_xfer_shared_libraries_aix:gdb_byte *readbuf, ULONGEST offset, UL
 # How the core target converts a PTID from a core file to a string.
 M:char *:core_pid_to_str:ptid_t ptid:ptid
 
+# How the core target extracts the name of a thread from a core file.
+M:const char *:core_thread_name:struct thread_info *thr:thr
+
 # BFD target to use when generating a core file.
 V:const char *:gcore_bfd_target:::0:0:::pstring (gdbarch->gcore_bfd_target)
 
@@ -1247,6 +1250,7 @@ struct ravenscar_arch_ops;
 struct elf_internal_linux_prpsinfo;
 struct mem_range;
 struct syscalls_info;
+struct thread_info;
 
 #include "regcache.h"