[PATCH 4/7] gdbarch: add memory_byte_size method

Simon Marchi
2015-04-08T19:56:35Z

Add a new gdbarch method to get the length of a memory byte for a given
architecture. The default implementation returns 1.

gdb/ChangeLog:

* arch-utils.h (default_memory_byte_size): New.
* arch-utils.c (default_memory_byte_size): New.
* gdbarch.sh (memory_byte_size): New.
* gdbarch.h: Re-generated.
* gdbarch.c: Re-generated.
---
gdb/arch-utils.c | 9 +++++++++
gdb/arch-utils.h | 1 +
gdb/gdbarch.c | 23 +++++++++++++++++++++++
gdb/gdbarch.h | 6 ++++++
gdb/gdbarch.sh | 4 ++++
5 files changed, 43 insertions(+)

diff --git a/gdb/arch-utils.c b/gdb/arch-utils.c
index e1c8ab0..4f3cb7b 100644
--- a/gdb/arch-utils.c
+++ b/gdb/arch-utils.c
@@ -882,6 +882,15 @@ default_gnu_triplet_regexp (struct gdbarch *gdbarch)
return gdbarch_bfd_arch_info (gdbarch)->arch_name;
}

+/* Default method for gdbarch_memory_byte_size. By default, a memory byte has
+ a size of 1 octet. */
+
+int
+default_memory_byte_size (struct gdbarch *gdbarch)
+{
+ return 1;
+}
+
/* -Wmissing-prototypes */
extern initialize_file_ftype _initialize_gdbarch_utils;

diff --git a/gdb/arch-utils.h b/gdb/arch-utils.h
index ed3bec9..ecf5e0d 100644
--- a/gdb/arch-utils.h
+++ b/gdb/arch-utils.h
@@ -202,5 +202,6 @@ extern void default_skip_permanent_breakpoint (struct regcache *regcache);
extern CORE_ADDR default_infcall_mmap (CORE_ADDR size, unsigned prot);
extern char *default_gcc_target_options (struct gdbarch *gdbarch);
extern const char *default_gnu_triplet_regexp (struct gdbarch *gdbarch);
+extern int default_memory_byte_size (struct gdbarch *gdbarch);

#endif
diff --git a/gdb/gdbarch.c b/gdb/gdbarch.c
index 97874c9..58b9630 100644
--- a/gdb/gdbarch.c
+++ b/gdb/gdbarch.c
@@ -328,6 +328,7 @@ struct gdbarch
gdbarch_infcall_mmap_ftype *infcall_mmap;
gdbarch_gcc_target_options_ftype *gcc_target_options;
gdbarch_gnu_triplet_regexp_ftype *gnu_triplet_regexp;
+ gdbarch_memory_byte_size_ftype *memory_byte_size;
};

/* Create a new ``struct gdbarch'' based on information provided by
@@ -428,6 +429,7 @@ gdbarch_alloc (const struct gdbarch_info *info,
gdbarch->infcall_mmap = default_infcall_mmap;
gdbarch->gcc_target_options = default_gcc_target_options;
gdbarch->gnu_triplet_regexp = default_gnu_triplet_regexp;
+ gdbarch->memory_byte_size = default_memory_byte_size;
/* gdbarch_alloc() */

return gdbarch;
@@ -660,6 +662,7 @@ verify_gdbarch (struct gdbarch *gdbarch)
/* Skip verify of infcall_mmap, invalid_p == 0 */
/* Skip verify of gcc_target_options, invalid_p == 0 */
/* Skip verify of gnu_triplet_regexp, invalid_p == 0 */
+ /* Skip verify of memory_byte_size, invalid_p == 0 */
buf = ui_file_xstrdup (log, &length);
make_cleanup (xfree, buf);
if (length > 0)
@@ -1095,6 +1098,9 @@ gdbarch_dump (struct gdbarch *gdbarch, struct ui_file *file)
"gdbarch_dump: max_insn_length = %s\n",
plongest (gdbarch->max_insn_length));
fprintf_unfiltered (file,
+ "gdbarch_dump: memory_byte_size = <%s>\n",
+ host_address_to_string (gdbarch->memory_byte_size));
+ fprintf_unfiltered (file,
"gdbarch_dump: memory_insert_breakpoint = <%s>\n",
host_address_to_string (gdbarch->memory_insert_breakpoint));
fprintf_unfiltered (file,
@@ -4707,6 +4713,23 @@ set_gdbarch_gnu_triplet_regexp (struct gdbarch *gdbarch,
gdbarch->gnu_triplet_regexp = gnu_triplet_regexp;
}

+int
+gdbarch_memory_byte_size (struct gdbarch *gdbarch)
+{
+ gdb_assert (gdbarch != NULL);
+ gdb_assert (gdbarch->memory_byte_size != NULL);
+ if (gdbarch_debug >= 2)
+ fprintf_unfiltered (gdb_stdlog, "gdbarch_memory_byte_size called\n");
+ return gdbarch->memory_byte_size (gdbarch);
+}
+
+void
+set_gdbarch_memory_byte_size (struct gdbarch *gdbarch,
+ gdbarch_memory_byte_size_ftype memory_byte_size)
+{
+ gdbarch->memory_byte_size = memory_byte_size;
+}
+

/* Keep a registry of per-architecture data-pointers required by GDB
modules. */
diff --git a/gdb/gdbarch.h b/gdb/gdbarch.h
index c94c19c..169f752 100644
--- a/gdb/gdbarch.h
+++ b/gdb/gdbarch.h
@@ -1459,6 +1459,12 @@ typedef const char * (gdbarch_gnu_triplet_regexp_ftype) (struct gdbarch *gdbarch
extern const char * gdbarch_gnu_triplet_regexp (struct gdbarch *gdbarch);
extern void set_gdbarch_gnu_triplet_regexp (struct gdbarch *gdbarch, gdbarch_gnu_triplet_regexp_ftype *gnu_triplet_regexp);

+/* Return the length in octets of a memory byte on this architecture. */
+
+typedef int (gdbarch_memory_byte_size_ftype) (struct gdbarch *gdbarch);
+extern int gdbarch_memory_byte_size (struct gdbarch *gdbarch);
+extern void set_gdbarch_memory_byte_size (struct gdbarch *gdbarch, gdbarch_memory_byte_size_ftype *memory_byte_size);
+
/* Definition for an unknown syscall, used basically in error-cases. */
#define UNKNOWN_SYSCALL (-1)

diff --git a/gdb/gdbarch.sh b/gdb/gdbarch.sh
index 0f303a4..607caa1 100755
--- a/gdb/gdbarch.sh
+++ b/gdb/gdbarch.sh
@@ -1109,6 +1109,10 @@ m:char *:gcc_target_options:void:::default_gcc_target_options::0
# returns the BFD architecture name, which is correct in nearly every
# case.
m:const char *:gnu_triplet_regexp:void:::default_gnu_triplet_regexp::0
+
+# Return the length in octets of a memory byte on this architecture.
+m:int:memory_byte_size:void:::default_memory_byte_size::0
+
EOF
}

--
2.1.4