Re: Three weeks to branching (gdb 7.5 release)

[Mark Kettenis <mark.kettenis@xs4all.nl>]

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> Date: Sun, 20 May 2012 08:40:26 -0700
> From: "H.J. Lu" <hjl.tools@gmail.com>
> 
> On Fri, May 11, 2012 at 11:43 AM, H.J. Lu <hjl.tools@gmail.com> wrote:
> > On Fri, May 11, 2012 at 11:17 AM, Joel Brobecker <brobecker@adacore.com> wrote:
> >> Hello,
> >>
> >> Just a quick heads up: The current tentative date for branching
> >> GDB (7.5 release) is Mon Jun 4th, which is a little over three weeks
> >> away.
> >>
> >> I've created a wiki page for known issues that need to be fixed
> >> before then:
> >>
> >>    http://sourceware.org/gdb/wiki/GDB_7.5_Release
> >>
> >> When you add an issue, please make sure you add a name so we know
> >> who is coordinating the effort.  If you don't know who can work
> >> on it, please just post the issue here, and we'll try to find some
> >> help.
> >>
> >> I only know of one issue, which is a noticeable performance degradation
> >> that was reported a while ago:
> >>
> >
> > I'd like to merge x32 into GDB 7.5.  My x32 change is on hjl/x32/master
> > branch at
> >
> > http://sourceware.org/git/?p=gdb.git;a=summary
> >
> > The current diff only has 864 lines.  One patch:
> >
> > http://sourceware.org/ml/gdb-patches/2012-05/msg00097.html
> >
> > isn't reviewed yet.  I will open a meta bug for x32 integration.
> >
> 
> I opened:
> 
> http://sourceware.org/bugzilla/show_bug.cgi?id=14099
> 
> Thanks for help from everyone.  The full GDBserver x32 support
> as well as partial GDB x32 support have been checked in.  The
> remaining patches are:
> 
> http://sourceware.org/ml/gdb-patches/2012-04/msg00195.html
> http://sourceware.org/ml/gdb-patches/2012-04/msg00191.html
> http://sourceware.org/ml/gdb-patches/2012-05/msg00744.html
> http://sourceware.org/ml/gdb-patches/2012-05/msg00531.html
> http://sourceware.org/ml/gdb-patches/2012-05/msg00533.html
> http://sourceware.org/ml/gdb-patches/2012-05/msg00489.html
> http://sourceware.org/ml/gdb-patches/2012-05/msg00438.html
> http://sourceware.org/ml/gdb-patches/2012-05/msg00097.html
> 
> I would appreciate help to get them reviewed and approved.

As I wrote before, I don't think adding lots if if-statements is the
proper way to add a new ABI to GDB.  The proper way is to do it like
the diff below.  In that diff, I'm not entirely confident that calling
amd64_linux_init_abi() from amd64_x32_linux_init_abi() makes all that
much sense.  For example the amd64_linux_record_tdep stuff probably
isn't right for the x32 ABI.  But at least this will give us a
starting point where we won't end up adding 

  if (gdbarch_ptr_bit (gdbarch) == 32)
    {
      ...
    }
  else
    {
    }

blocks all over the place.



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	20 May 2012 20:31:53 -0000
@@ -1543,6 +1543,24 @@ amd64_linux_init_abi (struct gdbarch_inf
 
   tdep->i386_syscall_record = amd64_linux_syscall_record;
 }
+
+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;
+
+  amd64_linux_init_abi (info, gdbarch);
+  amd64_x32_init_abi (info, gdbarch);
+
+  if (! tdesc_has_registers (tdesc))
+    tdesc = tdesc_amd64_linux;
+  tdep->tdesc = tdesc;
+
+  /* GNU/Linux uses SVR4-style shared libraries.  */
+  set_solib_svr4_fetch_link_map_offsets
+    (gdbarch, svr4_ilp32_fetch_link_map_offsets);
+}
 \f
 
 /* Provide a prototype to silence -Wmissing-prototypes.  */
@@ -1553,6 +1571,8 @@ _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	20 May 2012 20:31:54 -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);
 }
+\f
+
+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	20 May 2012 20:31:54 -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
Index: i386-tdep.h
===================================================================
RCS file: /cvs/src/src/gdb/i386-tdep.h,v
retrieving revision 1.78
diff -u -p -r1.78 i386-tdep.h
--- i386-tdep.h	27 Apr 2012 20:47:54 -0000	1.78
+++ i386-tdep.h	20 May 2012 20:31:57 -0000
@@ -309,6 +309,8 @@ extern int i386_ymm_regnum_p (struct gdb
 
 extern const char *i386_pseudo_register_name (struct gdbarch *gdbarch,
 					      int regnum);
+extern struct type *i386_pseudo_register_type (struct gdbarch *gdbarch,
+					       int regnum);
 
 extern void i386_pseudo_register_read_into_value (struct gdbarch *gdbarch,
 						  struct regcache *regcache,