[RFC PATCH 4/4] gdb/riscv : Add rv64 ilp32 support in gdb

[Liao Shihua <shihua@iscas.ac.cn>]

This patch supports rv64 ilp32 in gdb. I know should send it
to gdb maillist, but due to its close correlation with the 
previous patch, it is temporarily placed here.
It add a new gdb features abi_xlen.


ChangeLog:

        * gdb/arch/riscv.h (struct riscv_gdbarch_features):Add abi_xlen .
        * gdb/riscv-tdep.c (riscv_abi_xlen):Likewise
        (riscv_features_from_bfd):Likewise
        (riscv_gdbarch_init):change long_bit by abi_xlen.
---
 gdb/arch/riscv.h | 10 +++++++++-
 gdb/riscv-tdep.c | 20 ++++++++++++++++----
 2 files changed, 25 insertions(+), 5 deletions(-)

diff --git a/gdb/arch/riscv.h b/gdb/arch/riscv.h
index 54610ed6c16..a41faba1168 100644
--- a/gdb/arch/riscv.h
+++ b/gdb/arch/riscv.h
@@ -41,6 +41,12 @@ struct riscv_gdbarch_features
      uninitialised.  */
   int xlen = 0;
 
+  /* The size of the pointer_size in bytes.  This is either 4 (ILP32), 8
+     (LP64).  No other value is valid.  Initialise to the
+     invalid 0 value so we can spot if one of these is used
+     uninitialised.  */
+  int abi_xlen = 0;
+
   /* The size of the f-registers in bytes.  This is either 4 (RV32), 8
      (RV64), or 16 (RV128).  This can also hold the value 0 to indicate
      that there are no f-registers.  No other value is valid.  */
@@ -68,6 +74,7 @@ struct riscv_gdbarch_features
   bool operator== (const struct riscv_gdbarch_features &rhs) const
   {
     return (xlen == rhs.xlen && flen == rhs.flen
+	    && abi_xlen == rhs.abi_xlen
 	    && embedded == rhs.embedded && vlen == rhs.vlen
 	    && has_fflags_reg == rhs.has_fflags_reg
 	    && has_frm_reg == rhs.has_frm_reg
@@ -88,8 +95,9 @@ struct riscv_gdbarch_features
 		       | (has_frm_reg ? 1 : 0) << 12
 		       | (has_fcsr_reg ? 1 : 0) << 13
 		       | (xlen & 0x1f) << 5
+		       | (abi_xlen & 0x1f) << 14
 		       | (flen & 0x1f) << 0
-		       | (vlen & 0xfff) << 14);
+		       | (vlen & 0xfff) << 19);
     return val;
   }
 };
diff --git a/gdb/riscv-tdep.c b/gdb/riscv-tdep.c
index 500279e1ae9..d4531896cc1 100644
--- a/gdb/riscv-tdep.c
+++ b/gdb/riscv-tdep.c
@@ -774,7 +774,7 @@ int
 riscv_abi_xlen (struct gdbarch *gdbarch)
 {
   riscv_gdbarch_tdep *tdep = gdbarch_tdep<riscv_gdbarch_tdep> (gdbarch);
-  return tdep->abi_features.xlen;
+  return tdep->abi_features.abi_xlen;
 }
 
 /* See riscv-tdep.h.  */
@@ -3835,9 +3835,15 @@ riscv_features_from_bfd (const bfd *abfd)
       int e_flags = elf_elfheader (abfd)->e_flags;
 
       if (eclass == ELFCLASS32)
-	features.xlen = 4;
+	{
+	  features.xlen == 4;
+    features.abi_xlen = 4;
+	}
       else if (eclass == ELFCLASS64)
-	features.xlen = 8;
+	{
+	  features.xlen == 8;
+    features.abi_xlen = 8;
+	}
       else
 	internal_error (_("unknown ELF header class %d"), eclass);
 
@@ -3846,6 +3852,12 @@ riscv_features_from_bfd (const bfd *abfd)
       else if (e_flags & EF_RISCV_FLOAT_ABI_SINGLE)
 	features.flen = 4;
 
+      if (e_flags & EF_RISCV_X32)
+	{
+	  features.xlen == 8;
+    features.abi_xlen = 4;
+	}
+
       if (e_flags & EF_RISCV_RVE)
 	{
 	  if (features.xlen == 8)
@@ -4175,7 +4187,7 @@ riscv_gdbarch_init (struct gdbarch_info info,
   /* Target data types.  */
   set_gdbarch_short_bit (gdbarch, 16);
   set_gdbarch_int_bit (gdbarch, 32);
-  set_gdbarch_long_bit (gdbarch, riscv_isa_xlen (gdbarch) * 8);
+  set_gdbarch_long_bit (gdbarch, riscv_abi_xlen (gdbarch) * 8);
   set_gdbarch_long_long_bit (gdbarch, 64);
   set_gdbarch_float_bit (gdbarch, 32);
   set_gdbarch_double_bit (gdbarch, 64);
-- 
2.38.1.windows.1