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Re: [patch] Fix readelf display of 8-byte values
I seem to have accidentally dropped binutils from the cc list, and
Nick's reply went only to me. Revised patch below...
-cary
On Tue, Feb 14, 2012 at 1:05 AM, nick clifton <nickc@redhat.com> wrote:
> Hi Cary,
>
>> Done.
>
>
> One small point:
>
>
>> +/* Return the high-order 32-bits and the low-order 32-bits
>> + ? of a large value separately. ?*/
>> +
>> +void
>> +byte_get_64 (unsigned char *field, int size, elf_vma *high, elf_vma *low)
>> +{
>> + ?if (size<= 4)
>> + ? ?{
>> + ? ? ?*high = 0;
>> + ? ? ?*low = byte_get (field, size);
>> + ? ?}
>
>
> What is the purpose of the 'size' parameter ? ?Currently size is always 8,
> which matches the purpose implied by the function's name. ?Do you envisage a
> future use where the function might be used to get either 4 byte or 8 byte
> values ? ?If so then this ought to be mentioned in the comment at the start
> of the function. ?Or if you have no such future use in mind, then the
> parameter ought to be dropped.
>
> Cheers
> ?Nick
2012-02-14 Cary Coutant <ccoutant@google.com>
* dwarf.c (dwarf_vmatoa64): New function.
(read_and_display_attr_value): Print 8-byte forms as single hex
numbers.
(process_debug_info): Print type signatures as single hex numbers.
* elfcomm.c (byte_get_64): New function.
* elfcomm.h (byte_get_64): New function.
commit 7716cd59d3136dea27787e94b68d9b0e3a303a79
Author: Cary Coutant <ccoutant@google.com>
Date: Wed Feb 8 18:08:20 2012 -0800
Print data8 and ref_sig8 forms with proper byte order.
diff --git a/binutils/dwarf.c b/binutils/dwarf.c
index 2258c67..5ad9b93 100644
--- a/binutils/dwarf.c
+++ b/binutils/dwarf.c
@@ -169,6 +169,27 @@ dwarf_vmatoa (const char *fmtch, dwarf_vma value)
return ret;
}
+/* Format a 64-bit value, given as two 32-bit values, in hex.
+ For reentrancy, this uses a buffer provided by the caller. */
+
+static const char *
+dwarf_vmatoa64 (dwarf_vma hvalue, dwarf_vma lvalue, char *buf,
+ unsigned int buf_len)
+{
+ int len = 0;
+
+ if (hvalue == 0)
+ snprintf (buf, buf_len, "%" DWARF_VMA_FMT "x", lvalue);
+ else
+ {
+ len = snprintf (buf, buf_len, "%" DWARF_VMA_FMT "x", hvalue);
+ snprintf (buf + len, buf_len - len,
+ "%08" DWARF_VMA_FMT "x", lvalue);
+ }
+
+ return buf;
+}
+
dwarf_vma
read_leb128 (unsigned char *data, unsigned int *length_return, int sign)
{
@@ -1381,9 +1402,12 @@ read_and_display_attr_value (unsigned long attribute,
case DW_FORM_data8:
if (!do_loc)
{
- uvalue = byte_get (data, 4);
- printf (" 0x%s", dwarf_vmatoa ("x", uvalue));
- printf (" 0x%lx", (unsigned long) byte_get (data + 4, 4));
+ dwarf_vma high_bits;
+ char buf[64];
+
+ byte_get_64 (data, &high_bits, &uvalue);
+ printf (" 0x%s",
+ dwarf_vmatoa64 (high_bits, uvalue, buf, sizeof (buf)));
}
if ((do_loc || do_debug_loc || do_debug_ranges)
&& num_debug_info_entries == 0)
@@ -1453,16 +1477,14 @@ read_and_display_attr_value (unsigned long attribute,
case DW_FORM_ref_sig8:
if (!do_loc)
{
- int i;
- printf (" signature: ");
- for (i = 0; i < 8; i++)
- {
- printf ("%02x", (unsigned) byte_get (data, 1));
- data += 1;
- }
+ dwarf_vma high_bits;
+ char buf[64];
+
+ byte_get_64 (data, &high_bits, &uvalue);
+ printf (" signature: 0x%s",
+ dwarf_vmatoa64 (high_bits, uvalue, buf, sizeof (buf)));
}
- else
- data += 8;
+ data += 8;
break;
default:
@@ -2113,7 +2135,8 @@ process_debug_info (struct dwarf_section *section,
dwarf_vma cu_offset;
int offset_size;
int initial_length_size;
- unsigned char signature[8] = { 0 };
+ dwarf_vma signature_high = 0;
+ dwarf_vma signature_low = 0;
dwarf_vma type_offset = 0;
hdrptr = start;
@@ -2147,14 +2170,8 @@ process_debug_info (struct dwarf_section *section,
if (do_types)
{
- int i;
-
- for (i = 0; i < 8; i++)
- {
- signature[i] = byte_get (hdrptr, 1);
- hdrptr += 1;
- }
-
+ byte_get_64 (hdrptr, &signature_high, &signature_low);
+ hdrptr += 8;
type_offset = byte_get (hdrptr, offset_size);
hdrptr += offset_size;
}
@@ -2191,13 +2208,13 @@ process_debug_info (struct dwarf_section *section,
printf (_(" Pointer Size: %d\n"), compunit.cu_pointer_size);
if (do_types)
{
- int i;
- printf (_(" Signature: "));
- for (i = 0; i < 8; i++)
- printf ("%02x", signature[i]);
- printf ("\n");
- printf (_(" Type Offset: 0x%s\n"),
- dwarf_vmatoa ("x", type_offset));
+ char buf[64];
+
+ printf (_(" Signature: 0x%s\n"),
+ dwarf_vmatoa64 (signature_high, signature_low,
+ buf, sizeof (buf)));
+ printf (_(" Type Offset: 0x%s\n"),
+ dwarf_vmatoa ("x", type_offset));
}
}
diff --git a/binutils/elfcomm.c b/binutils/elfcomm.c
index e44dee8..4224f82 100644
--- a/binutils/elfcomm.c
+++ b/binutils/elfcomm.c
@@ -238,6 +238,25 @@ byte_get_signed (unsigned char *field, int size)
}
}
+/* Return the high-order 32-bits and the low-order 32-bits
+ of an 8-byte value separately. */
+
+void
+byte_get_64 (unsigned char *field, elf_vma *high, elf_vma *low)
+{
+ if (byte_get == byte_get_big_endian)
+ {
+ *high = byte_get_big_endian (field, 4);
+ *low = byte_get_big_endian (field + 4, 4);
+ }
+ else
+ {
+ *high = byte_get_little_endian (field + 4, 4);
+ *low = byte_get_little_endian (field, 4);
+ }
+ return;
+}
+
/* Return the path name for a proxy entry in a thin archive, adjusted
relative to the path name of the thin archive itself if necessary.
Always returns a pointer to malloc'ed memory. */
diff --git a/binutils/elfcomm.h b/binutils/elfcomm.h
index 3f9727e..2a3c913 100644
--- a/binutils/elfcomm.h
+++ b/binutils/elfcomm.h
@@ -47,6 +47,7 @@ extern elf_vma (*byte_get) (unsigned char *, int);
extern elf_vma byte_get_signed (unsigned char *, int);
extern elf_vma byte_get_little_endian (unsigned char *, int);
extern elf_vma byte_get_big_endian (unsigned char *, int);
+extern void byte_get_64 (unsigned char *, elf_vma *, elf_vma *);
#define BYTE_PUT(field, val) byte_put (field, val, sizeof (field))
#define BYTE_GET(field) byte_get (field, sizeof (field))