Partial fix for PR breakpoints/10737: Make syscall info be per-arch instead of global

This patch intends to partially fix PR breakpoints/10737, which is
about making the syscall information (for the "catch syscall" command)
be per-arch, instead of global.  This is not a full fix because of the
other issues pointed by Pedro here:

  <https://sourceware.org/bugzilla/show_bug.cgi?id=10737#c5>

However, I consider it a good step towards the real fix.  It will also
help me fix <https://sourceware.org/bugzilla/show_bug.cgi?id=17402>.

What this patch does, basically, is move the "syscalls_info"
struct to gdbarch.  Currently, the syscall information is stored in a
global variable inside gdb/xml-syscall.c, which means that there is no
easy way to correlate this info with the current target or
architecture being used, for example.  This causes strange behaviors,
because the syscall info is not re-read when the arch changes.  For
example, if you put a syscall catchpoint in syscall 5 on i386 (syscall
open), and then load a x86_64 program on GDB and put the same syscall
5 there (fstat on x86_64), you will still see that GDB tells you that
it is catching "open", even though it is not.  With this patch, GDB
correctly says that it will be catching fstat syscalls.

  (gdb) set architecture i386
  The target architecture is assumed to be i386
  (gdb) catch syscall 5
  Catchpoint 1 (syscall 'open' [5])
  (gdb) set architecture i386:x86-64
  The target architecture is assumed to be i386:x86-64
  (gdb) catch syscall 5
  Catchpoint 2 (syscall 'open' [5])

But with the patch:

  (gdb) set architecture i386
  The target architecture is assumed to be i386
  (gdb) catch syscall 5
  Catchpoint 1 (syscall 'open' [5])
  (gdb) set architecture i386:x86-64
  The target architecture is assumed to be i386:x86-64
  (gdb) catch syscall 5
  Catchpoint 2 (syscall 'fstat' [5])

As I said, there are still some problems on the "catch syscall"
mechanism, because (for example) the user should be able to "catch
syscall open" on i386, and then expect "open" to be caught also on
x86_64.  Currently, it doesn't work.  I intend to work on this later.

gdb/
2014-11-20  Sergio Durigan Junior  <sergiodj@redhat.com>

	PR breakpoints/10737
	* amd64-linux-tdep.c (amd64_linux_init_abi_common): Adjust call to
	set_xml_syscall_file_name to provide gdbarch.
	* arm-linux-tdep.c (arm_linux_init_abi): Likewise.
	* bfin-linux-tdep.c (bfin_linux_init_abi): Likewise.
	* breakpoint.c (print_it_catch_syscall): Adjust call to
	get_syscall_by_number to provide gdbarch.
	(print_one_catch_syscall): Likewise.
	(print_mention_catch_syscall): Likewise.
	(print_recreate_catch_syscall): Likewise.
	(catch_syscall_split_args): Adjust calls to get_syscall_by_number
	and get_syscall_by_name to provide gdbarch.
	(catch_syscall_completer): Adjust call to get_syscall_names to
	provide gdbarch.
	* gdbarch.c: Regenerate.
	* gdbarch.h: Likewise.
	* gdbarch.sh: Forward declare "struct syscalls_info".
	(xml_syscall_file): New variable.
	(syscalls_info): Likewise.
	* i386-linux-tdep.c (i386_linux_init_abi): Adjust call to
	set_xml_syscall_file_name to provide gdbarch.
	* mips-linux-tdep.c (mips_linux_init_abi): Likewise.
	* ppc-linux-tdep.c (ppc_linux_init_abi): Likewise.
	* s390-linux-tdep.c (s390_gdbarch_init): Likewise.
	* sparc-linux-tdep.c (sparc32_linux_init_abi): Likewise.
	* sparc64-linux-tdep.c (sparc64_linux_init_abi): Likewise.
	* xml-syscall.c: Include gdbarch.h.
	(set_xml_syscall_file_name): Accept gdbarch parameter.
	(get_syscall_by_number): Likewise.
	(get_syscall_by_name): Likewise.
	(get_syscall_names): Likewise.
	(my_gdb_datadir): Delete global variable.
	(struct syscalls_info) <my_gdb_datadir>: New variable.
	(struct syscalls_info) <sysinfo>: Rename variable to
	"syscalls_info".
	(sysinfo): Delete global variable.
	(have_initialized_sysinfo): Likewise.
	(xml_syscall_file): Likewise.
	(sysinfo_free_syscalls_desc): Rename to...
	(syscalls_info_free_syscalls_desc): ... this.
	(free_syscalls_info): Rename "sysinfo" to "syscalls_info".  Adjust
	code to the new layout of "struct syscalls_info".
	(make_cleanup_free_syscalls_info): Rename parameter "sysinfo" to
	"syscalls_info".
	(syscall_create_syscall_desc): Likewise.
	(syscall_start_syscall): Likewise.
	(syscall_parse_xml): Likewise.
	(xml_init_syscalls_info): Likewise.  Drop "const" from return value.
	(init_sysinfo): Rename to...
	(init_syscalls_info): ...this.  Add gdbarch as a parameter.
	Adjust function to deal with gdbarch.
	(xml_get_syscall_number): Delete parameter sysinfo.  Accept
	gdbarch as a parameter.  Adjust code.
	(xml_get_syscall_name): Likewise.
	(xml_list_of_syscalls): Likewise.
	(set_xml_syscall_file_name): Accept gdbarch as parameter.
	(get_syscall_by_number): Likewise.
	(get_syscall_by_name): Likewise.
	(get_syscall_names): Likewise.
	* xml-syscall.h (set_xml_syscall_file_name): Likewise.
	(get_syscall_by_number): Likewise.
	(get_syscall_by_name): Likewise.
	(get_syscall_names): Likewise.

gdb/testsuite/
2014-11-20  Sergio Durigan Junior  <sergiodj@redhat.com>

	PR breakpoints/10737
	* gdb.base/catch-syscall.exp (do_syscall_tests): Call
	test_catch_syscall_multi_arch.
	(test_catch_syscall_multi_arch): New function.

1 files changed, 13 insertions, 8 deletions

diff --git a/gdb/breakpoint.c b/gdb/breakpoint.c
index b19d198..7b56260 100644
--- a/gdb/breakpoint.c
+++ b/gdb/breakpoint.c
@@ -8607,10 +8607,11 @@ print_it_catch_syscall (bpstat bs)
   ptid_t ptid;
   struct target_waitstatus last;
   struct syscall s;
+  struct gdbarch *gdbarch = bs->bp_location_at->gdbarch;
 
   get_last_target_status (&ptid, &last);
 
-  get_syscall_by_number (last.value.syscall_number, &s);
+  get_syscall_by_number (gdbarch, last.value.syscall_number, &s);
 
   annotate_catchpoint (b->number);
 
@@ -8653,6 +8654,7 @@ print_one_catch_syscall (struct breakpoint *b,
   struct syscall_catchpoint *c = (struct syscall_catchpoint *) b;
   struct value_print_options opts;
   struct ui_out *uiout = current_uiout;
+  struct gdbarch *gdbarch = b->loc->gdbarch;
 
   get_user_print_options (&opts);
   /* Field 4, the address, is omitted (which makes the columns not
@@ -8679,7 +8681,7 @@ print_one_catch_syscall (struct breakpoint *b,
         {
           char *x = text;
           struct syscall s;
-          get_syscall_by_number (iter, &s);
+          get_syscall_by_number (gdbarch, iter, &s);
 
           if (s.name != NULL)
             text = xstrprintf ("%s%s, ", text, s.name);
@@ -8710,6 +8712,7 @@ static void
 print_mention_catch_syscall (struct breakpoint *b)
 {
   struct syscall_catchpoint *c = (struct syscall_catchpoint *) b;
+  struct gdbarch *gdbarch = b->loc->gdbarch;
 
   if (c->syscalls_to_be_caught)
     {
@@ -8725,7 +8728,7 @@ print_mention_catch_syscall (struct breakpoint *b)
            i++)
         {
           struct syscall s;
-          get_syscall_by_number (iter, &s);
+          get_syscall_by_number (gdbarch, iter, &s);
 
           if (s.name)
             printf_filtered (" '%s' [%d]", s.name, s.number);
@@ -8746,6 +8749,7 @@ static void
 print_recreate_catch_syscall (struct breakpoint *b, struct ui_file *fp)
 {
   struct syscall_catchpoint *c = (struct syscall_catchpoint *) b;
+  struct gdbarch *gdbarch = b->loc->gdbarch;
 
   fprintf_unfiltered (fp, "catch syscall");
 
@@ -8759,7 +8763,7 @@ print_recreate_catch_syscall (struct breakpoint *b, struct ui_file *fp)
         {
           struct syscall s;
 
-          get_syscall_by_number (iter, &s);
+          get_syscall_by_number (gdbarch, iter, &s);
           if (s.name)
             fprintf_unfiltered (fp, " %s", s.name);
           else
@@ -12037,6 +12041,7 @@ catch_syscall_split_args (char *arg)
 {
   VEC(int) *result = NULL;
   struct cleanup *cleanup = make_cleanup (VEC_cleanup (int), &result);
+  struct gdbarch *gdbarch = target_gdbarch ();
 
   while (*arg != '\0')
     {
@@ -12056,12 +12061,12 @@ catch_syscall_split_args (char *arg)
       /* Check if the user provided a syscall name or a number.  */
       syscall_number = (int) strtol (cur_name, &endptr, 0);
       if (*endptr == '\0')
-	get_syscall_by_number (syscall_number, &s);
+	get_syscall_by_number (gdbarch, syscall_number, &s);
       else
 	{
 	  /* We have a name.  Let's check if it's valid and convert it
 	     to a number.  */
-	  get_syscall_by_name (cur_name, &s);
+	  get_syscall_by_name (gdbarch, cur_name, &s);
 
 	  if (s.number == UNKNOWN_SYSCALL)
 	    /* Here we have to issue an error instead of a warning,
@@ -12102,7 +12107,7 @@ this architecture yet."));
      to get the syscall XML file loaded or, most important,
      to display a warning to the user if there's no XML file
      for his/her architecture.  */
-  get_syscall_by_number (0, &s);
+  get_syscall_by_number (gdbarch, 0, &s);
 
   /* The allowed syntax is:
      catch syscall
@@ -15345,7 +15350,7 @@ static VEC (char_ptr) *
 catch_syscall_completer (struct cmd_list_element *cmd,
                          const char *text, const char *word)
 {
-  const char **list = get_syscall_names ();
+  const char **list = get_syscall_names (get_current_arch ());
   VEC (char_ptr) *retlist
     = (list == NULL) ? NULL : complete_on_enum (list, word, word);