Re: x32 ABI Support (was Re: Three weeks to branching (gdb 7.5 release))

["H.J. Lu" <hjl dot tools at gmail dot com>]

On Sun, Jun 10, 2012 at 2:51 PM, Mark Kettenis <mark.kettenis@xs4all.nl> wrote:
>> Date: Thu, 31 May 2012 11:18:02 -0700
>> From: "H.J. Lu" <hjl.tools@gmail.com>
>>
>> > I think this is the wrong approach for x32 support. We should
>> > break amd64_x32_init_abi into 2 parts:
>> >
>> > 1. OS specific part. ?It should be private to amd64-tdep.c.
>
> There is no OS specific code in amd64-tdep.c. ?Only code that
> implements the generic OS-agnistic low-level ABI.
>
>> > 2. Generic part. ?It should be exported from amd64-tdep.c and can
>> > be used by all x32 OSes.
>
> Yes, and that entry point should be amd64_x32_init_abi(). ?That is the
> pattern that has been established, and I see no reason to deviate from
> it. ?So here is the diff I suggested before again with one change: it
> moves most of the amd64 Linux support bits into its own function and
> calls that from both amd64_linux_init_abi() and
> amd64_x32_linux_init_abi(). ?I'm sure some of those bits are wrong for
> x32, but if you want to fix things up from that end, it is fine with
> me. ?The important bit that I care about is getting the inheritance
> structure right.
>
>
> Index: amd64-linux-tdep.c
> ===================================================================
> RCS file: /cvs/src/src/gdb/amd64-linux-tdep.c,v
> retrieving revision 1.50
> diff -u -p -r1.50 amd64-linux-tdep.c
> --- amd64-linux-tdep.c ?12 May 2012 08:54:03 -0000 ? ? ?1.50
> +++ amd64-linux-tdep.c ?10 Jun 2012 21:39:08 -0000
> @@ -1288,41 +1288,12 @@ amd64_linux_core_read_description (struc
> ?}
>
> ?static void
> -amd64_linux_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
> +amd64_linux_init_abi_common(struct gdbarch_info info, struct gdbarch *gdbarch)
> ?{
> ? struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
> - ?const struct target_desc *tdesc = info.target_desc;
> - ?struct tdesc_arch_data *tdesc_data = (void *) info.tdep_info;
> - ?const struct tdesc_feature *feature;
> - ?int valid_p;
> -
> - ?gdb_assert (tdesc_data);
>
> ? linux_init_abi (info, gdbarch);
>
> - ?tdep->gregset_reg_offset = amd64_linux_gregset_reg_offset;
> - ?tdep->gregset_num_regs = ARRAY_SIZE (amd64_linux_gregset_reg_offset);
> - ?tdep->sizeof_gregset = 27 * 8;
> -
> - ?amd64_init_abi (info, gdbarch);
> -
> - ?/* Reserve a number for orig_rax. ?*/
> - ?set_gdbarch_num_regs (gdbarch, AMD64_LINUX_NUM_REGS);
> -
> - ?if (! tdesc_has_registers (tdesc))
> - ? ?tdesc = tdesc_amd64_linux;
> - ?tdep->tdesc = tdesc;
> -
> - ?feature = tdesc_find_feature (tdesc, "org.gnu.gdb.i386.linux");
> - ?if (feature == NULL)
> - ? ?return;
> -
> - ?valid_p = tdesc_numbered_register (feature, tdesc_data,
> - ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?AMD64_LINUX_ORIG_RAX_REGNUM,
> - ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?"orig_rax");
> - ?if (!valid_p)
> - ? ?return;
> -
> ? tdep->sigtramp_p = amd64_linux_sigtramp_p;
> ? tdep->sigcontext_addr = amd64_linux_sigcontext_addr;
> ? tdep->sc_reg_offset = amd64_linux_sc_reg_offset;
> @@ -1330,10 +1301,6 @@ amd64_linux_init_abi (struct gdbarch_inf
>
> ? tdep->xsave_xcr0_offset = I386_LINUX_XSAVE_XCR0_OFFSET;
>
> - ?/* GNU/Linux uses SVR4-style shared libraries. ?*/
> - ?set_solib_svr4_fetch_link_map_offsets
> - ? ?(gdbarch, svr4_lp64_fetch_link_map_offsets);
> -
> ? /* Add the %orig_rax register used for syscall restarting. ?*/
> ? set_gdbarch_write_pc (gdbarch, amd64_linux_write_pc);
>
> @@ -1543,6 +1510,88 @@ amd64_linux_init_abi (struct gdbarch_inf
>
> ? tdep->i386_syscall_record = amd64_linux_syscall_record;
> ?}
> +
> +static void
> +amd64_linux_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
> +{
> + ?struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
> + ?const struct target_desc *tdesc = info.target_desc;
> + ?struct tdesc_arch_data *tdesc_data = (void *) info.tdep_info;
> + ?const struct tdesc_feature *feature;
> + ?int valid_p;
> +
> + ?gdb_assert (tdesc_data);
> +
> + ?tdep->gregset_reg_offset = amd64_linux_gregset_reg_offset;
> + ?tdep->gregset_num_regs = ARRAY_SIZE (amd64_linux_gregset_reg_offset);
> + ?tdep->sizeof_gregset = 27 * 8;
> +
> + ?amd64_init_abi (info, gdbarch);
> +
> + ?/* Reserve a number for orig_rax. ?*/
> + ?set_gdbarch_num_regs (gdbarch, AMD64_LINUX_NUM_REGS);
> +
> + ?if (! tdesc_has_registers (tdesc))
> + ? ?tdesc = tdesc_amd64_linux;
> + ?tdep->tdesc = tdesc;
> +
> + ?feature = tdesc_find_feature (tdesc, "org.gnu.gdb.i386.linux");
> + ?if (feature == NULL)
> + ? ?return;
> +
> + ?valid_p = tdesc_numbered_register (feature, tdesc_data,
> + ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?AMD64_LINUX_ORIG_RAX_REGNUM,
> + ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?"orig_rax");
> + ?if (!valid_p)
> + ? ?return;
> +
> + ?amd64_linux_init_abi_common (info, gdbarch);
> +
> + ?/* GNU/Linux uses SVR4-style shared libraries. ?*/
> + ?set_solib_svr4_fetch_link_map_offsets
> + ? ?(gdbarch, svr4_lp64_fetch_link_map_offsets);
> +}
> +
> +static void
> +amd64_x32_linux_init_abi(struct gdbarch_info info, struct gdbarch *gdbarch)
> +{
> + ?struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
> + ?const struct target_desc *tdesc = info.target_desc;
> + ?struct tdesc_arch_data *tdesc_data = (void *) info.tdep_info;
> + ?const struct tdesc_feature *feature;
> + ?int valid_p;
> +
> + ?gdb_assert (tdesc_data);
> +
> + ?tdep->gregset_reg_offset = amd64_linux_gregset_reg_offset;
> + ?tdep->gregset_num_regs = ARRAY_SIZE (amd64_linux_gregset_reg_offset);
> + ?tdep->sizeof_gregset = 27 * 8;
> +
> + ?amd64_x32_init_abi (info, gdbarch);
> +
> + ?/* Reserve a number for orig_rax. ?*/
> + ?set_gdbarch_num_regs (gdbarch, AMD64_LINUX_NUM_REGS);
> +
> + ?if (! tdesc_has_registers (tdesc))
> + ? ?tdesc = tdesc_x32_linux;
> + ?tdep->tdesc = tdesc;
> +
> + ?feature = tdesc_find_feature (tdesc, "org.gnu.gdb.i386.linux");
> + ?if (feature == NULL)
> + ? ?return;
> +
> + ?valid_p = tdesc_numbered_register (feature, tdesc_data,
> + ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?AMD64_LINUX_ORIG_RAX_REGNUM,
> + ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?"orig_rax");
> + ?if (!valid_p)
> + ? ?return;
> +
> + ?amd64_linux_init_abi_common (info, gdbarch);
> +
> + ?/* GNU/Linux uses SVR4-style shared libraries. ?*/
> + ?set_solib_svr4_fetch_link_map_offsets
> + ? ?(gdbarch, svr4_ilp32_fetch_link_map_offsets);
> +}
>
>
> ?/* Provide a prototype to silence -Wmissing-prototypes. ?*/
> @@ -1553,6 +1602,8 @@ _initialize_amd64_linux_tdep (void)
> ?{
> ? gdbarch_register_osabi (bfd_arch_i386, bfd_mach_x86_64,
> ? ? ? ? ? ? ? ? ? ? ? ? ?GDB_OSABI_LINUX, amd64_linux_init_abi);
> + ?gdbarch_register_osabi (bfd_arch_i386, bfd_mach_x64_32,
> + ? ? ? ? ? ? ? ? ? ? ? ? GDB_OSABI_LINUX, amd64_x32_linux_init_abi);
>
> ? /* Initialize the Linux target description. ?*/
> ? initialize_tdesc_amd64_linux ();
> Index: amd64-tdep.c
> ===================================================================
> RCS file: /cvs/src/src/gdb/amd64-tdep.c,v
> retrieving revision 1.104
> diff -u -p -r1.104 amd64-tdep.c
> --- amd64-tdep.c ? ? ? ?14 May 2012 18:56:40 -0000 ? ? ?1.104
> +++ amd64-tdep.c ? ? ? ?10 Jun 2012 21:39:09 -0000
> @@ -258,7 +258,8 @@ static const char *amd64_word_names[] =
> ?static const char *amd64_dword_names[] =
> ?{
> ? "eax", "ebx", "ecx", "edx", "esi", "edi", "ebp", "esp",
> - ?"r8d", "r9d", "r10d", "r11d", "r12d", "r13d", "r14d", "r15d"
> + ?"r8d", "r9d", "r10d", "r11d", "r12d", "r13d", "r14d", "r15d",
> + ?"eip"
> ?};
>
> ?/* Return the name of register REGNUM. ?*/
> @@ -2729,6 +2730,43 @@ amd64_init_abi (struct gdbarch_info info
> ? set_gdbarch_stap_parse_special_token (gdbarch,
> ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?i386_stap_parse_special_token);
> ?}
> +
> +
> +static struct type *
> +amd64_x32_pseudo_register_type (struct gdbarch *gdbarch, int regnum)
> +{
> + ?struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
> +
> + ?switch (regnum - tdep->eax_regnum)
> + ? ?{
> + ? ?case AMD64_RBP_REGNUM: ? ? /* %ebp */
> + ? ?case AMD64_RSP_REGNUM: ? ? /* %esp */
> + ? ? ?return builtin_type (gdbarch)->builtin_data_ptr;
> + ? ?case AMD64_RIP_REGNUM: ? ? /* %eip */
> + ? ? ?return builtin_type (gdbarch)->builtin_func_ptr;
> + ? ?}
> +
> + ?return i386_pseudo_register_type (gdbarch, regnum);
> +}
> +
> +void
> +amd64_x32_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
> +{
> + ?struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
> + ?const struct target_desc *tdesc = info.target_desc;
> +
> + ?amd64_init_abi (info, gdbarch);
> +
> + ?if (! tdesc_has_registers (tdesc))
> + ? ?tdesc = tdesc_x32;
> + ?tdep->tdesc = tdesc;
> +
> + ?tdep->num_dword_regs = 17;
> + ?set_tdesc_pseudo_register_type (gdbarch, amd64_x32_pseudo_register_type);
> +
> + ?set_gdbarch_long_bit (gdbarch, 32);
> + ?set_gdbarch_ptr_bit (gdbarch, 32);
> +}
>
> ?/* Provide a prototype to silence -Wmissing-prototypes. ?*/
> ?void _initialize_amd64_tdep (void);
> Index: amd64-tdep.h
> ===================================================================
> RCS file: /cvs/src/src/gdb/amd64-tdep.h,v
> retrieving revision 1.21
> diff -u -p -r1.21 amd64-tdep.h
> --- amd64-tdep.h ? ? ? ?4 Jan 2012 08:16:56 -0000 ? ? ? 1.21
> +++ amd64-tdep.h ? ? ? ?10 Jun 2012 21:39:09 -0000
> @@ -80,6 +80,8 @@ extern void amd64_displaced_step_fixup (
> ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?struct regcache *regs);
>
> ?extern void amd64_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch);
> +extern void amd64_x32_init_abi (struct gdbarch_info info,
> + ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? struct gdbarch *gdbarch);
>
> ?/* Fill register REGNUM in REGCACHE with the appropriate
> ? ?floating-point or SSE register value from *FXSAVE. ?If REGNUM is
>
>

It works with the following patch.  Can you check it in?

Thanks.

-- 
H.J.
---
diff --git a/gdb/i386-tdep.c b/gdb/i386-tdep.c
index 5b04505..9cc2e30 100644
--- a/gdb/i386-tdep.c
+++ b/gdb/i386-tdep.c
@@ -2780,7 +2780,7 @@ i386_mmx_type (struct gdbarch *gdbarch)
 /* Return the GDB type object for the "standard" data type of data in
    register REGNUM.  */

-static struct type *
+struct type *
 i386_pseudo_register_type (struct gdbarch *gdbarch, int regnum)
 {
   if (i386_mmx_regnum_p (gdbarch, regnum))
diff --git a/gdb/i386-tdep.h b/gdb/i386-tdep.h
index f297ae7..e1f7c44 100644
--- a/gdb/i386-tdep.h
+++ b/gdb/i386-tdep.h
@@ -307,6 +315,7 @@ extern int i386_dword_regnum_p (struct gdbarch
*gdbarch, int regnum);
 extern int i386_xmm_regnum_p (struct gdbarch *gdbarch, int regnum);
 extern int i386_ymm_regnum_p (struct gdbarch *gdbarch, int regnum);

+extern struct type *i386_pseudo_register_type (struct gdbarch *, int);
 extern const char *i386_pseudo_register_name (struct gdbarch *gdbarch,
 					      int regnum);