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, 11 insertions, 0 deletions

diff --git a/gdb/gdbarch.h b/gdb/gdbarch.h
index 5cd4197..0bd1d56 100644
--- a/gdb/gdbarch.h
+++ b/gdb/gdbarch.h
@@ -60,6 +60,7 @@ struct stap_parse_info;
 struct ravenscar_arch_ops;
 struct elf_internal_linux_prpsinfo;
 struct mem_range;
+struct syscalls_info;
 
 /* The architecture associated with the inferior through the
    connection to the target.
@@ -1056,6 +1057,16 @@ typedef LONGEST (gdbarch_get_syscall_number_ftype) (struct gdbarch *gdbarch, pti
 extern LONGEST gdbarch_get_syscall_number (struct gdbarch *gdbarch, ptid_t ptid);
 extern void set_gdbarch_get_syscall_number (struct gdbarch *gdbarch, gdbarch_get_syscall_number_ftype *get_syscall_number);
 
+/* The filename of the XML syscall for this architecture. */
+
+extern const char * gdbarch_xml_syscall_file (struct gdbarch *gdbarch);
+extern void set_gdbarch_xml_syscall_file (struct gdbarch *gdbarch, const char * xml_syscall_file);
+
+/* Information about system calls from this architecture */
+
+extern struct syscalls_info * gdbarch_syscalls_info (struct gdbarch *gdbarch);
+extern void set_gdbarch_syscalls_info (struct gdbarch *gdbarch, struct syscalls_info * syscalls_info);
+
 /* SystemTap related fields and functions.
    A NULL-terminated array of prefixes used to mark an integer constant
    on the architecture's assembly.