[PATCH] gdb:csky using csky_gdbarch_tdep in csky_gdbarch_init

[Jiangshuai Li <jiangshuai_li@c-sky.com>]

add three points:
1. add vars to csky_gdbarch_tdep
2. save mach, fpu_abi, vdsp_verion and fpu_hardfp from info.abfd
3. find a pre-declared gdbarch via point 2

fpu_abi and vdsp_verion will be used by gdbarch_return_value
and gdbarch_push_dummy_call later.

gdb/
	*csky-tdep.h: add vars to csky_gdbarch_tdep
	*csky-tdep.c: save msgs from info.abfd and use them
	to find a pre-declared gdbarch
---
 gdb/csky-tdep.c | 87 +++++++++++++++++++++++++++++++++++++++++++++++--
 gdb/csky-tdep.h | 17 +++++++++-
 2 files changed, 100 insertions(+), 4 deletions(-)

diff --git a/gdb/csky-tdep.c b/gdb/csky-tdep.c
index cba0065fa53..44c2b56fba4 100644
--- a/gdb/csky-tdep.c
+++ b/gdb/csky-tdep.c
@@ -2157,16 +2157,97 @@ static struct gdbarch *
 csky_gdbarch_init (struct gdbarch_info info, struct gdbarch_list *arches)
 {
   struct gdbarch *gdbarch;
+  /* Analysis info.abfd.  */
+  unsigned int mach;
+  int mach_find = 0;
+  unsigned long abfd_e_flags;
+  unsigned int fpu_abi = 0;
+  unsigned int vdsp_version = 0;
+  unsigned int fpu_hardfp = 0;
+  static bfd_arch_info_type bfd_csky_arch_t;
+
+  /* When the type of bfd file is srec(or any files are not elf),
+     the E_FLAGS will be not credible.  */
+  if (info.abfd && bfd_get_flavour (info.abfd) == bfd_target_elf_flavour)
+    {
+      /*  Get e_flags form abfd.  */
+      abfd_e_flags = elf_elfheader (info.abfd)->e_flags;
+      if (IS_CSKY_V2 (abfd_e_flags))
+        {
+          switch (abfd_e_flags & CSKY_ARCH_MASK)
+            {
+            case CSKY_ARCH_801:
+            case CSKY_ARCH_802:
+            case CSKY_ARCH_803:
+            case CSKY_ARCH_807:
+            case CSKY_ARCH_810:
+            case CSKY_ARCH_860:
+              mach = abfd_e_flags & CSKY_ARCH_MASK;
+              mach_find = 1;
+              break;
+            default:
+              mach = CSKY_ARCH_810;
+              break;
+            }
+        }
+      else
+        {
+          mach = CSKY_ARCH_810;
+        }
+
+      /* Get FPU, VDSP build options.  */
+      fpu_abi = bfd_elf_get_obj_attr_int (info.abfd,
+                                          OBJ_ATTR_PROC,
+                                          Tag_CSKY_FPU_ABI);
+      vdsp_version = bfd_elf_get_obj_attr_int (info.abfd,
+                                               OBJ_ATTR_PROC,
+                                               Tag_CSKY_VDSP_VERSION);
+      fpu_hardfp = bfd_elf_get_obj_attr_int (info.abfd,
+                                             OBJ_ATTR_PROC,
+                                             Tag_CSKY_FPU_HARDFP);
+    }
+  else
+    {
+      mach = CSKY_ARCH_810;
+    }
+
+  /* Set info.bfd_arch_info.  */
+  memcpy (&bfd_csky_arch_t, info.bfd_arch_info, sizeof (bfd_csky_arch_t));
+  if (mach_find)
+    bfd_csky_arch_t.mach = abfd_e_flags;
+  else
+    bfd_csky_arch_t.mach = mach | CSKY_ABI_V2;
+  info.bfd_arch_info = &bfd_csky_arch_t;
 
   /* Find a candidate among the list of pre-declared architectures.  */
-  arches = gdbarch_list_lookup_by_info (arches, &info);
-  if (arches != NULL)
-    return arches->gdbarch;
+  for (arches = gdbarch_list_lookup_by_info (arches, &info);
+       arches != NULL;
+       arches = gdbarch_list_lookup_by_info (arches->next, &info))
+    {
+      csky_gdbarch_tdep *tdep
+        = (csky_gdbarch_tdep *) gdbarch_tdep (arches->gdbarch);
+      if (mach != tdep->mach)
+        continue;
+      if (fpu_abi != tdep->fpu_abi)
+        continue;
+      if (vdsp_version != tdep->vdsp_version)
+        continue;
+      if (fpu_hardfp != tdep->fpu_hardfp)
+        continue;
+
+      /* Found a match.  */
+      return arches->gdbarch;
+    }
 
   /* None found, create a new architecture from the information
      provided.  */
   csky_gdbarch_tdep *tdep = new csky_gdbarch_tdep;
   gdbarch = gdbarch_alloc (&info, tdep);
+  tdep->mach = mach;
+  tdep->return_reg = CSKY_RET_REGNUM;
+  tdep->fpu_abi = fpu_abi;
+  tdep->vdsp_version = vdsp_version;
+  tdep->fpu_hardfp = fpu_hardfp;
 
   /* Target data types.  */
   set_gdbarch_ptr_bit (gdbarch, 32);
diff --git a/gdb/csky-tdep.h b/gdb/csky-tdep.h
index 7898e0d325b..3dbbb13bfbb 100644
--- a/gdb/csky-tdep.h
+++ b/gdb/csky-tdep.h
@@ -33,7 +33,22 @@ enum lr_type_t
 /* Target-dependent structure in gdbarch.  */
 struct csky_gdbarch_tdep : gdbarch_tdep
 {
-  /* This is Unused.  */
+  /* Save abfd_e_flags.  */
+  unsigned int mach;
+
+  /* The selected register will form a list, which will be update, when
+   conducting -data-list-register-changed command.  */
+  char * selected_registers;
+  unsigned int return_reg;
+
+  /* Save fv_pseudo_registers_count.  */
+  unsigned int has_vr0;
+  unsigned int fv_pseudo_registers_count;
+
+  /* Save FPU ABI.  */
+  unsigned int fpu_abi;
+  unsigned int vdsp_version;
+  unsigned int fpu_hardfp;
 };
 
 /* Instruction sizes.  */
-- 
2.17.1