gdbarch: Use an anonymous union for target data in `gdbarch_info'

As an update to commit ede5f15146ae ("gdbarch.h: Change
gdbarch_info::tdep_info's type to void *") replace the definition of the
`tdep_info' member in `struct gdbarch_info' with an anonymous union,
comprising the original member, with its type reverted to `struct
gdbarch_tdep_info *', a `tdesc_data' member of a `struct tdesc_arch_data
*' type and an `id' member of an `int *' type.  Remove now unnecessary
casts throughout use places then, making code easier to read an less
prone to errors, which may happen with casting.

	gdb/
	* gdbarch.sh (gdbarch_info): Replace the `tdep_info' member with
	a union of `tdep_info', `tdesc_data' and `id'.
	* aarch64-tdep.c (aarch64_gdbarch_init): Use `info.tdesc_data'
	rather than `info.tdep_info'.
	* amd64-linux-tdep.c (amd64_linux_init_abi): Likewise.
	* i386-linux-tdep.c (i386_linux_init_abi): Likewise.
	* i386-tdep.c (i386_gdbarch_init): Likewise.
	* mips-linux-tdep.c (mips_linux_init_abi): Likewise.
	* mips-tdep.c (mips_gdbarch_init): Likewise.
	* nds32-tdep.c (nds32_gdbarch_init): Likewise.
	* rs6000-tdep.c (rs6000_gdbarch_init): Likewise.
	* ppc-linux-tdep.c (ppu2spu_sniffer): Use `info.id' rather than
	`info.tdep_info'.
	(ppc_linux_init_abi): Use `info.tdesc_data' rather than
	`info.tdep_info'.
	* sparc-tdep.c (sparc32_gdbarch_init): Likewise.
	* spu-multiarch.c (spu_gdbarch): Use `info.id' rather than
	`info.tdep_info'.
	* spu-tdep.c (spu_gdbarch_init): Likewise.
	* gdbarch.h: Regenerate.

15 files changed, 68 insertions, 22 deletions

diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index affff94..818f438 100644
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,3 +1,26 @@
+2017-08-07  Maciej W. Rozycki  <macro@imgtec.com>
+
+	* gdbarch.sh (gdbarch_info): Replace the `tdep_info' member with
+	a union of `tdep_info', `tdesc_data' and `id'.
+	* aarch64-tdep.c (aarch64_gdbarch_init): Use `info.tdesc_data'
+	rather than `info.tdep_info'.
+	* amd64-linux-tdep.c (amd64_linux_init_abi): Likewise.
+	* i386-linux-tdep.c (i386_linux_init_abi): Likewise.
+	* i386-tdep.c (i386_gdbarch_init): Likewise.
+	* mips-linux-tdep.c (mips_linux_init_abi): Likewise.
+	* mips-tdep.c (mips_gdbarch_init): Likewise.
+	* nds32-tdep.c (nds32_gdbarch_init): Likewise.
+	* rs6000-tdep.c (rs6000_gdbarch_init): Likewise.
+	* ppc-linux-tdep.c (ppu2spu_sniffer): Use `info.id' rather than
+	`info.tdep_info'.
+	(ppc_linux_init_abi): Use `info.tdesc_data' rather than
+	`info.tdep_info'.
+	* sparc-tdep.c (sparc32_gdbarch_init): Likewise.
+	* spu-multiarch.c (spu_gdbarch): Use `info.id' rather than
+	`info.tdep_info'.
+	* spu-tdep.c (spu_gdbarch_init): Likewise.
+	* gdbarch.h: Regenerate.
+
 2017-08-07  Leszek Swirski  <leszeks@google.com>
 
 	* dwarf2read.c (dwarf2_string_attr): Allow DW_FORM_GNU_strp_alt.
diff --git a/gdb/aarch64-tdep.c b/gdb/aarch64-tdep.c
index 75bb00f..7816281 100644
--- a/gdb/aarch64-tdep.c
+++ b/gdb/aarch64-tdep.c
@@ -2997,7 +2997,7 @@ aarch64_gdbarch_init (struct gdbarch_info info, struct gdbarch_list *arches)
 
   /* Hook in the ABI-specific overrides, if they have been registered.  */
   info.target_desc = tdesc;
-  info.tdep_info = (void *) tdesc_data;
+  info.tdesc_data = tdesc_data;
   gdbarch_init_osabi (info, gdbarch);
 
   dwarf2_frame_set_init_reg (gdbarch, aarch64_dwarf2_frame_init_reg);
diff --git a/gdb/amd64-linux-tdep.c b/gdb/amd64-linux-tdep.c
index cf24789..31d2b16 100644
--- a/gdb/amd64-linux-tdep.c
+++ b/gdb/amd64-linux-tdep.c
@@ -1863,8 +1863,7 @@ static void
 amd64_linux_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
 {
   struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
-  struct tdesc_arch_data *tdesc_data
-    = (struct tdesc_arch_data *) info.tdep_info;
+  struct tdesc_arch_data *tdesc_data = info.tdesc_data;
   const struct tdesc_feature *feature;
   int valid_p;
 
@@ -2077,8 +2076,7 @@ static void
 amd64_x32_linux_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
 {
   struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
-  struct tdesc_arch_data *tdesc_data
-    = (struct tdesc_arch_data *) info.tdep_info;
+  struct tdesc_arch_data *tdesc_data = info.tdesc_data;
   const struct tdesc_feature *feature;
   int valid_p;
 
diff --git a/gdb/gdbarch.h b/gdb/gdbarch.h
index 1c95301..ceb867f 100644
--- a/gdb/gdbarch.h
+++ b/gdb/gdbarch.h
@@ -1647,7 +1647,21 @@ struct gdbarch_info
   bfd *abfd;
 
   /* Use default: NULL (ZERO).  */
-  void *tdep_info;
+  union
+    {
+      /* Architecture-specific information.  The generic form for targets
+	 that have extra requirements.  */
+      struct gdbarch_tdep_info *tdep_info;
+
+      /* Architecture-specific target description data.  Numerous targets
+	 need only this, so give them an easy way to hold it.  */
+      struct tdesc_arch_data *tdesc_data;
+
+      /* SPU file system ID.  This is a single integer, so using the
+	 generic form would only complicate code.  Other targets may
+	 reuse this member if suitable.  */
+      int *id;
+    };
 
   /* Use default: GDB_OSABI_UNINITIALIZED (-1).  */
   enum gdb_osabi osabi;
diff --git a/gdb/gdbarch.sh b/gdb/gdbarch.sh
index 3aab17f..36451b1 100755
--- a/gdb/gdbarch.sh
+++ b/gdb/gdbarch.sh
@@ -1474,7 +1474,21 @@ struct gdbarch_info
   bfd *abfd;
 
   /* Use default: NULL (ZERO).  */
-  void *tdep_info;
+  union
+    {
+      /* Architecture-specific information.  The generic form for targets
+	 that have extra requirements.  */
+      struct gdbarch_tdep_info *tdep_info;
+
+      /* Architecture-specific target description data.  Numerous targets
+	 need only this, so give them an easy way to hold it.  */
+      struct tdesc_arch_data *tdesc_data;
+
+      /* SPU file system ID.  This is a single integer, so using the
+	 generic form would only complicate code.  Other targets may
+	 reuse this member if suitable.  */
+      int *id;
+    };
 
   /* Use default: GDB_OSABI_UNINITIALIZED (-1).  */
   enum gdb_osabi osabi;
diff --git a/gdb/i386-linux-tdep.c b/gdb/i386-linux-tdep.c
index 708de97..dd21b70 100644
--- a/gdb/i386-linux-tdep.c
+++ b/gdb/i386-linux-tdep.c
@@ -855,8 +855,7 @@ i386_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
-    = (struct tdesc_arch_data *) info.tdep_info;
+  struct tdesc_arch_data *tdesc_data = info.tdesc_data;
   const struct tdesc_feature *feature;
   int valid_p;
 
diff --git a/gdb/i386-tdep.c b/gdb/i386-tdep.c
index bd728f0..b1e5afd 100644
--- a/gdb/i386-tdep.c
+++ b/gdb/i386-tdep.c
@@ -8604,7 +8604,7 @@ i386_gdbarch_init (struct gdbarch_info info, struct gdbarch_list *arches)
   /* Hook in ABI-specific overrides, if they have been registered.
      Note: If INFO specifies a 64 bit arch, this is where we turn
      a 32-bit i386 into a 64-bit amd64.  */
-  info.tdep_info = tdesc_data;
+  info.tdesc_data = tdesc_data;
   gdbarch_init_osabi (info, gdbarch);
 
   if (!i386_validate_tdesc_p (tdep, tdesc_data))
diff --git a/gdb/mips-linux-tdep.c b/gdb/mips-linux-tdep.c
index f144a2e..001fd40 100644
--- a/gdb/mips-linux-tdep.c
+++ b/gdb/mips-linux-tdep.c
@@ -1616,8 +1616,7 @@ mips_linux_init_abi (struct gdbarch_info info,
 {
   struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
   enum mips_abi abi = mips_abi (gdbarch);
-  struct tdesc_arch_data *tdesc_data
-    = (struct tdesc_arch_data *) info.tdep_info;
+  struct tdesc_arch_data *tdesc_data = info.tdesc_data;
 
   linux_init_abi (info, gdbarch);
 
diff --git a/gdb/mips-tdep.c b/gdb/mips-tdep.c
index 8bd11ee..75e45ef 100644
--- a/gdb/mips-tdep.c
+++ b/gdb/mips-tdep.c
@@ -8785,7 +8785,7 @@ mips_gdbarch_init (struct gdbarch_info info, struct gdbarch_list *arches)
   mips_register_g_packet_guesses (gdbarch);
 
   /* Hook in OS ABI-specific overrides, if they have been registered.  */
-  info.tdep_info = tdesc_data;
+  info.tdesc_data = tdesc_data;
   gdbarch_init_osabi (info, gdbarch);
 
   /* The hook may have adjusted num_regs, fetch the final value and
diff --git a/gdb/nds32-tdep.c b/gdb/nds32-tdep.c
index ae84567..7725248 100644
--- a/gdb/nds32-tdep.c
+++ b/gdb/nds32-tdep.c
@@ -2134,7 +2134,7 @@ nds32_gdbarch_init (struct gdbarch_info info, struct gdbarch_list *arches)
   nds32_add_reggroups (gdbarch);
 
   /* Hook in ABI-specific overrides, if they have been registered.  */
-  info.tdep_info = (void *) tdesc_data;
+  info.tdesc_data = tdesc_data;
   gdbarch_init_osabi (info, gdbarch);
 
   /* Override tdesc_register callbacks for system registers.  */
diff --git a/gdb/ppc-linux-tdep.c b/gdb/ppc-linux-tdep.c
index 5b86e15..324b29d 100644
--- a/gdb/ppc-linux-tdep.c
+++ b/gdb/ppc-linux-tdep.c
@@ -1350,7 +1350,7 @@ ppu2spu_sniffer (const struct frame_unwind *self,
       info.bfd_arch_info = bfd_lookup_arch (bfd_arch_spu, bfd_mach_spu);
       info.byte_order = BFD_ENDIAN_BIG;
       info.osabi = GDB_OSABI_LINUX;
-      info.tdep_info = &data.id;
+      info.id = &data.id;
       data.gdbarch = gdbarch_find_by_info (info);
       if (!data.gdbarch)
 	return 0;
@@ -1650,8 +1650,7 @@ ppc_linux_init_abi (struct gdbarch_info info,
                     struct gdbarch *gdbarch)
 {
   struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
-  struct tdesc_arch_data *tdesc_data
-    = (struct tdesc_arch_data *) info.tdep_info;
+  struct tdesc_arch_data *tdesc_data = info.tdesc_data;
   static const char *const stap_integer_prefixes[] = { "i", NULL };
   static const char *const stap_register_indirection_prefixes[] = { "(",
 								    NULL };
diff --git a/gdb/rs6000-tdep.c b/gdb/rs6000-tdep.c
index 97a975e..59d6896 100644
--- a/gdb/rs6000-tdep.c
+++ b/gdb/rs6000-tdep.c
@@ -6529,7 +6529,7 @@ rs6000_gdbarch_init (struct gdbarch_info info, struct gdbarch_list *arches)
 
   /* Hook in ABI-specific overrides, if they have been registered.  */
   info.target_desc = tdesc;
-  info.tdep_info = tdesc_data;
+  info.tdesc_data = tdesc_data;
   gdbarch_init_osabi (info, gdbarch);
 
   switch (info.osabi)
diff --git a/gdb/sparc-tdep.c b/gdb/sparc-tdep.c
index dce8527..6135e0b 100644
--- a/gdb/sparc-tdep.c
+++ b/gdb/sparc-tdep.c
@@ -1906,7 +1906,7 @@ sparc32_gdbarch_init (struct gdbarch_info info, struct gdbarch_list *arches)
         }
 
       /* Target description may have changed. */
-      info.tdep_info = tdesc_data;
+      info.tdesc_data = tdesc_data;
       tdesc_use_registers (gdbarch, tdesc, tdesc_data);
     }
 
diff --git a/gdb/spu-multiarch.c b/gdb/spu-multiarch.c
index abc4653..3da502c 100644
--- a/gdb/spu-multiarch.c
+++ b/gdb/spu-multiarch.c
@@ -107,7 +107,7 @@ spu_gdbarch (int spufs_fd)
   info.bfd_arch_info = bfd_lookup_arch (bfd_arch_spu, bfd_mach_spu);
   info.byte_order = BFD_ENDIAN_BIG;
   info.osabi = GDB_OSABI_LINUX;
-  info.tdep_info = &spufs_fd;
+  info.id = &spufs_fd;
   return gdbarch_find_by_info (info);
 }
 
diff --git a/gdb/spu-tdep.c b/gdb/spu-tdep.c
index 1ab9a9c..ca1a3fc 100644
--- a/gdb/spu-tdep.c
+++ b/gdb/spu-tdep.c
@@ -2668,8 +2668,8 @@ spu_gdbarch_init (struct gdbarch_info info, struct gdbarch_list *arches)
   int id = -1;
 
   /* Which spufs ID was requested as address space?  */
-  if (info.tdep_info)
-    id = *(int *)info.tdep_info;
+  if (info.id)
+    id = *info.id;
   /* For objfile architectures of SPU solibs, decode the ID from the name.
      This assumes the filename convention employed by solib-spu.c.  */
   else if (info.abfd)