[binutils-gdb] libctf, dump: fix slice dumping
Nick Alcock
nix@sourceware.org
Wed Jul 22 17:10:41 GMT 2020
https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;h=70447401740235d828c4b7b87e398eeae4801094
commit 70447401740235d828c4b7b87e398eeae4801094
Author: Nick Alcock <nick.alcock@oracle.com>
Date: Mon May 11 18:18:50 2020 +0100
libctf, dump: fix slice dumping
Now that we can have slices of anything terminating in an int, we must
dump things accordingly, or slices of typedefs appear as
c5b: __u8 -> 16c: __u8 -> 78: short unsigned int (size 0x2)
which is unhelpful. If things *are* printed as slices, the name is
missing:
a15: [slice 0x8:0x4]-> 16c: __u8 -> 78: short unsigned int (size 0x2)
And struct members give no clue they're a slice at all, which is a shame
since bitfields are the major use of this type kind:
[0x8] (ID 0xa15) (kind 10) __u8 dst_reg
Fix things so that everything slicelike or integral gets its encoding
printed, and everything with a name gets the name printed:
a15: __u8 [slice 0x8:0x4] (size 0x1) -> 1ff: __u8 (size 0x1) -> 37: unsigned char [0x0:0x8] (size 0x1)
[0x0] (ID 0xa15) (kind 10) __u8:4 (aligned at 0x1, format 0x2, offset:bits 0x8:0x4)
Bitfield struct members get a technically redundant but much
easier-to-understand dumping now:
[0x0] (ID 0x80000005) (kind 6) struct bpf_insn (aligned at 0x1)
[0x0] (ID 0x222) (kind 10) __u8 code (aligned at 0x1)
[0x8] (ID 0x1e9e) (kind 10) __u8 dst_reg:4 (aligned at 0x1, format 0x2, offset:bits 0x8:0x4)
[0xc] (ID 0x1e46) (kind 10) __u8 src_reg:4 (aligned at 0x1, format 0x2, offset:bits 0xc:0x4)
[0x10] (ID 0xf35) (kind 10) __s16 off (aligned at 0x2)
[0x20] (ID 0x1718) (kind 10) __s32 imm (aligned at 0x4)
This also fixes one place where a failure to format a type would be
erroneously considered an out-of-memory condition.
libctf/
* ctf-dump.c (ctf_is_slice): Delete, unnecessary.
(ctf_dump_format_type): improve slice formatting. Always print
the type size, even of slices.
(ctf_dump_member): Print slices (-> bitfields) differently from
non-slices. Failure to format a type is not an OOM.
Diff:
---
libctf/ChangeLog | 8 +++++
libctf/ctf-dump.c | 92 ++++++++++++++++++++++++++++++++++---------------------
2 files changed, 65 insertions(+), 35 deletions(-)
diff --git a/libctf/ChangeLog b/libctf/ChangeLog
index b13c51c88e6..841f1462f29 100644
--- a/libctf/ChangeLog
+++ b/libctf/ChangeLog
@@ -1,3 +1,11 @@
+2020-07-22 Nick Alcock <nick.alcock@oracle.com>
+
+ * ctf-dump.c (ctf_is_slice): Delete, unnecessary.
+ (ctf_dump_format_type): improve slice formatting. Always print
+ the type size, even of slices.
+ (ctf_dump_member): Print slices (-> bitfields) differently from
+ non-slices. Failure to format a type is not an OOM.
+
2020-07-22 Nick Alcock <nick.alcock@oracle.com>
* ctf-dump.c (ctf_dump_format_type): Emit a warning.
diff --git a/libctf/ctf-dump.c b/libctf/ctf-dump.c
index 55aa496e8b7..94d6bc6f018 100644
--- a/libctf/ctf-dump.c
+++ b/libctf/ctf-dump.c
@@ -79,20 +79,6 @@ ctf_dump_free (ctf_dump_state_t *state)
}
}
-/* Slices need special handling to distinguish them from their referenced
- type. */
-
-static int
-ctf_is_slice (ctf_file_t *fp, ctf_id_t id, ctf_encoding_t *enc)
-{
- int kind = ctf_type_kind (fp, id);
-
- return (((kind == CTF_K_INTEGER) || (kind == CTF_K_ENUM)
- || (kind == CTF_K_FLOAT))
- && ctf_type_reference (fp, id) != CTF_ERR
- && ctf_type_encoding (fp, id, enc) == 0);
-}
-
/* Return a dump for a single type, without member info: but do show the
type's references. */
@@ -129,26 +115,45 @@ ctf_dump_format_type (ctf_file_t *fp, ctf_id_t id, int flag)
goto err;
}
- /* Slices get a different print representation. */
+ if (asprintf (&bit, " %s%lx: ", nonroot_leader, id) < 0)
+ goto oom;
+ str = str_append (str, bit);
+ free (bit);
+ bit = NULL;
+
+ if (buf[0] != '\0')
+ {
+ str = str_append (str, buf);
+ str = str_append (str, " ");
+ }
+
+ free (buf);
+ buf = NULL;
- if (ctf_is_slice (fp, id, &enc))
+ /* Slices get a different print representation. */
+ if (ctf_type_kind_unsliced (fp, id) == CTF_K_SLICE)
{
ctf_type_encoding (fp, id, &enc);
- if (asprintf (&bit, " %s%lx: [slice 0x%x:0x%x]%s",
- nonroot_leader, id, enc.cte_offset, enc.cte_bits,
- nonroot_trailer) < 0)
+ if (asprintf (&bit, "[slice 0x%x:0x%x] ",
+ enc.cte_offset, enc.cte_bits) < 0)
goto oom;
}
- else
+ else if (ctf_type_kind (fp, id) == CTF_K_INTEGER)
{
- if (asprintf (&bit, " %s%lx: %s (size 0x%lx)%s", nonroot_leader,
- id, buf[0] == '\0' ? "(nameless)" : buf,
- (unsigned long) ctf_type_size (fp, id),
- nonroot_trailer) < 0)
+ ctf_type_encoding (fp, id, &enc);
+ if (asprintf (&bit, "[0x%x:0x%x] ",
+ enc.cte_offset, enc.cte_bits) < 0)
goto oom;
}
- free (buf);
- buf = NULL;
+ str = str_append (str, bit);
+ free (bit);
+ bit = NULL;
+
+ if (asprintf (&bit, "(size 0x%lx)%s",
+ (unsigned long) ctf_type_size (fp, id),
+ nonroot_trailer) < 0)
+ goto oom;
+
str = str_append (str, bit);
free (bit);
bit = NULL;
@@ -516,6 +521,7 @@ ctf_dump_member (const char *name, ctf_id_t id, unsigned long offset,
char *typestr = NULL;
char *bit = NULL;
ctf_encoding_t ep;
+ int has_encoding = 0;
ssize_t i;
for (i = 0; i < depth; i++)
@@ -535,24 +541,40 @@ ctf_dump_member (const char *name, ctf_id_t id, unsigned long offset,
return 0;
}
- goto oom;
+ return -1; /* errno is set for us. */
+ }
+
+ if (ctf_type_encoding (state->cdm_fp, id, &ep) == 0)
+ {
+ has_encoding = 1;
+ ctf_type_encoding (state->cdm_fp, id, &ep);
+
+ if (asprintf (&bit, " [0x%lx] (ID 0x%lx) (kind %i) %s%s%s:%i "
+ "(aligned at 0x%lx", offset, id,
+ ctf_type_kind (state->cdm_fp, id), typestr,
+ (name[0] != 0 && typestr[0] != 0) ? " " : "", name,
+ ep.cte_bits, (unsigned long) ctf_type_align (state->cdm_fp,
+ id)) < 0)
+ goto oom;
+ }
+ else
+ {
+ if (asprintf (&bit, " [0x%lx] (ID 0x%lx) (kind %i) %s%s%s "
+ "(aligned at 0x%lx", offset, id,
+ ctf_type_kind (state->cdm_fp, id), typestr,
+ (name[0] != 0 && typestr[0] != 0) ? " " : "", name,
+ (unsigned long) ctf_type_align (state->cdm_fp, id)) < 0)
+ goto oom;
}
- if (asprintf (&bit, " [0x%lx] (ID 0x%lx) (kind %i) %s %s (aligned at 0x%lx",
- offset, id, ctf_type_kind (state->cdm_fp, id), typestr, name,
- (unsigned long) ctf_type_align (state->cdm_fp, id)) < 0)
- goto oom;
*state->cdm_str = str_append (*state->cdm_str, bit);
free (typestr);
free (bit);
typestr = NULL;
bit = NULL;
- if ((ctf_type_kind (state->cdm_fp, id) == CTF_K_INTEGER)
- || (ctf_type_kind (state->cdm_fp, id) == CTF_K_FLOAT)
- || (ctf_is_slice (state->cdm_fp, id, &ep) == CTF_K_ENUM))
+ if (has_encoding)
{
- ctf_type_encoding (state->cdm_fp, id, &ep);
if (asprintf (&bit, ", format 0x%x, offset:bits 0x%x:0x%x", ep.cte_format,
ep.cte_offset, ep.cte_bits) < 0)
goto oom;
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