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libctf, next: introduce new class of easier-to-use iterators

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The libctf machinery currently only provides one way to iterate over its
data structures: ctf_*_iter functions that take a callback and an arg
and repeatedly call it.

This *works*, but if you are doing a lot of iteration it is really quite
inconvenient: you have to package up your local variables into
structures over and over again and spawn lots of little functions even
if it would be clearer in a single run of code.  Look at ctf-string.c
for an extreme example of how unreadable this can get, with
three-line-long functions proliferating wildly.

The deduplicator takes this to the Nth level. It iterates over a whole
bunch of things: if we'd had to use _iter-class iterators for all of
them there would be twenty additional functions in the deduplicator
alone, for no other reason than that the iterator API requires it.

Let's do something better. strtok_r gives us half the design: generators
in a number of other languages give us the other half.

The *_next API allows you to iterate over CTF-like entities in a single
function using a normal while loop. e.g. here we are iterating over all
the types in a dict:

ctf_next_t *i = NULL;
int *hidden;
ctf_id_t id;

while ((id = ctf_type_next (fp, &i, &hidden, 1)) != CTF_ERR)
  {
    /* do something with 'hidden' and 'id' */
  }
if (ctf_errno (fp) != ECTF_NEXT_END)
    /* iteration error */

Here we are walking through the members of a struct with CTF ID
'struct_type':

ctf_next_t *i = NULL;
ssize_t offset;
const char *name;
ctf_id_t membtype;

while ((offset = ctf_member_next (fp, struct_type, &i, &name,
                                  &membtype)) >= 0
  {
    /* do something with offset, name, and membtype */
  }
if (ctf_errno (fp) != ECTF_NEXT_END)
    /* iteration error */

Like every other while loop, this means you have access to all the local
variables outside the loop while inside it, with no need to tiresomely
package things up in structures, move the body of the loop into a
separate function, etc, as you would with an iterator taking a callback.

ctf_*_next allocates 'i' for you on first entry (when it must be NULL),
and frees and NULLs it and returns a _next-dependent flag value when the
iteration is over: the fp errno is set to ECTF_NEXT_END when the
iteartion ends normally.  If you want to exit early, call
ctf_next_destroy on the iterator.  You can copy iterators using
ctf_next_copy, which copies their current iteration position so you can
remember loop positions and go back to them later (or ctf_next_destroy
them if you don't need them after all).

Each _next function returns an always-likely-to-be-useful property of
the thing being iterated over, and takes pointers to parameters for the
others: with very few exceptions all those parameters can be NULLs if
you're not interested in them, so e.g. you can iterate over only the
offsets of members of a structure this way:

while ((offset = ctf_member_next (fp, struct_id, &i, NULL, NULL)) >= 0)

If you pass an iterator in use by one iteration function to another one,
you get the new error ECTF_NEXT_WRONGFUN back; if you try to change
ctf_file_t in mid-iteration, you get ECTF_NEXT_WRONGFP back.

Internally the ctf_next_t remembers the iteration function in use,
various sizes and increments useful for almost all iterations, then
uses unions to overlap the actual entities being iterated over to keep
ctf_next_t size down.

Iterators available in the public API so far (all tested in actual use
in the deduplicator):

/* Iterate over the members of a STRUCT or UNION, returning each member's
   offset and optionally name and member type in turn.  On end-of-iteration,
   returns -1.  */
ssize_t
ctf_member_next (ctf_file_t *fp, ctf_id_t type, ctf_next_t **it,
                 const char **name, ctf_id_t *membtype);

/* Iterate over the members of an enum TYPE, returning each enumerand's
   NAME or NULL at end of iteration or error, and optionally passing
   back the enumerand's integer VALue.  */
const char *
ctf_enum_next (ctf_file_t *fp, ctf_id_t type, ctf_next_t **it,
              int *val);

/* Iterate over every type in the given CTF container (not including
   parents), optionally including non-user-visible types, returning
   each type ID and optionally the hidden flag in turn. Returns CTF_ERR
   on end of iteration or error.  */
ctf_id_t
ctf_type_next (ctf_file_t *fp, ctf_next_t **it, int *flag,
               int want_hidden);

/* Iterate over every variable in the given CTF container, in arbitrary
   order, returning the name and type of each variable in turn.  The
   NAME argument is not optional.  Returns CTF_ERR on end of iteration
   or error.  */
ctf_id_t
ctf_variable_next (ctf_file_t *fp, ctf_next_t **it, const char **name);

/* Iterate over all CTF files in an archive, returning each dict in turn as a
   ctf_file_t, and NULL on error or end of iteration.  It is the caller's
   responsibility to close it.  Parent dicts may be skipped.  Regardless of
   whether they are skipped or not, the caller must ctf_import the parent if
   need be.  */
ctf_file_t *
ctf_archive_next (const ctf_archive_t *wrapper, ctf_next_t **it,
                  const char **name, int skip_parent, int *errp);

ctf_label_next is prototyped but not implemented yet.

include/
	* ctf-api.h (ECTF_NEXT_END): New error.
	(ECTF_NEXT_WRONGFUN): Likewise.
	(ECTF_NEXT_WRONGFP): Likewise.
	(ECTF_NERR): Adjust.
	(ctf_next_t): New.
	(ctf_next_create): New prototype.
	(ctf_next_destroy): Likewise.
	(ctf_next_copy): Likewise.
	(ctf_member_next): Likewise.
	(ctf_enum_next): Likewise.
	(ctf_type_next): Likewise.
	(ctf_label_next): Likewise.
	(ctf_variable_next): Likewise.

libctf/
	* ctf-impl.h (ctf_next): New.
	(ctf_get_dict): New prototype.
	* ctf-lookup.c (ctf_get_dict): New, split out of...
	(ctf_lookup_by_id): ... here.
	* ctf-util.c (ctf_next_create): New.
	(ctf_next_destroy): New.
	(ctf_next_copy): New.
	* ctf-types.c (includes): Add <assert.h>.
	(ctf_member_next): New.
	(ctf_enum_next): New.
	(ctf_type_iter): Document the lack of iteration over parent
	types.
	(ctf_type_next): New.
	(ctf_variable_next): New.
	* ctf-archive.c (ctf_archive_next): New.
	* libctf.ver: Add new public functions.
This commit is contained in:
Nick Alcock 2020-06-03 15:13:24 +01:00
parent 2399827bfa
commit 688d28f621
9 changed files with 606 additions and 10 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

16
include/ChangeLog
View File

@ -1,3 +1,19 @@
2020-07-22 Nick Alcock <nick.alcock@oracle.com>
* ctf-api.h (ECTF_NEXT_END): New error.
(ECTF_NEXT_WRONGFUN): Likewise.
(ECTF_NEXT_WRONGFP): Likewise.
(ECTF_NERR): Adjust.
(ctf_next_t): New.
(ctf_next_create): New prototype.
(ctf_next_destroy): Likewise.
(ctf_next_copy): Likewise.
(ctf_member_next): Likewise.
(ctf_enum_next): Likewise.
(ctf_type_next): Likewise.
(ctf_label_next): Likewise.
(ctf_variable_next): Likewise.
2020-07-22 Nick Alcock <nick.alcock@oracle.com>
* ctf-api.h (ctf_ref): New.

33
include/ctf-api.h
View File

@ -204,10 +204,13 @@ enum
ECTF_DUMPSECTCHANGED, /* Section changed in middle of dump. */
ECTF_NOTYET, /* Feature not yet implemented. */
ECTF_INTERNAL, /* Internal error in link. */
ECTF_NONREPRESENTABLE /* Type not representable in CTF. */
ECTF_NONREPRESENTABLE, /* Type not representable in CTF. */
ECTF_NEXT_END, /* End of iteration. */
ECTF_NEXT_WRONGFUN, /* Wrong iteration function called. */
ECTF_NEXT_WRONGFP /* Iteration entity changed in mid-iterate. */
};
#define ECTF_NERR (ECTF_NONREPRESENTABLE - ECTF_BASE + 1) /* Count of CTF errors. */
#define ECTF_NERR (ECTF_NEXT_WRONGFP - ECTF_BASE + 1) /* Count of CTF errors. */
/* The CTF data model is inferred to be the caller's data model or the data
model of the given object, unless ctf_setmodel() is explicitly called. */
@ -227,8 +230,9 @@ enum
#define CTF_ADD_NONROOT 0 /* Type only visible in nested scope. */
#define CTF_ADD_ROOT 1 /* Type visible at top-level scope. */
/* These typedefs are used to define the signature for callback functions
that can be used with the iteration and visit functions below. */
/* These typedefs are used to define the signature for callback functions that
can be used with the iteration and visit functions below. There is also a
family of iteration functions that do not require callbacks. */
typedef int ctf_visit_f (const char *name, ctf_id_t type, unsigned long offset,
int depth, void *arg);
@ -248,6 +252,15 @@ typedef char *ctf_dump_decorate_f (ctf_sect_names_t sect,
typedef struct ctf_dump_state ctf_dump_state_t;
/* Iteration state for the _next() functions, and allocators/copiers/freers for
it. (None of these are needed for the simple case of iterating to the end:
the _next() function allocate and free the iterators for you.) */
typedef struct ctf_next ctf_next_t;
extern ctf_next_t *ctf_next_create (void);
extern void ctf_next_destroy (ctf_next_t *);
extern ctf_next_t *ctf_next_copy (ctf_next_t *);
/* Opening. These mostly return an abstraction over both CTF files and CTF
archives: so they can be used to open both. CTF files will appear to be an
archive with one member named '.ctf'. The low-level functions
@ -353,13 +366,25 @@ extern int ctf_label_info (ctf_file_t *, const char *, ctf_lblinfo_t *);
extern int ctf_member_count (ctf_file_t *, ctf_id_t);
extern int ctf_member_iter (ctf_file_t *, ctf_id_t, ctf_member_f *, void *);
extern ssize_t ctf_member_next (ctf_file_t *, ctf_id_t, ctf_next_t **,
const char **name, ctf_id_t *membtype);
extern int ctf_enum_iter (ctf_file_t *, ctf_id_t, ctf_enum_f *, void *);
extern const char *ctf_enum_next (ctf_file_t *, ctf_id_t, ctf_next_t **,
int *);
extern int ctf_type_iter (ctf_file_t *, ctf_type_f *, void *);
extern int ctf_type_iter_all (ctf_file_t *, ctf_type_all_f *, void *);
extern ctf_id_t ctf_type_next (ctf_file_t *, ctf_next_t **,
int *flag, int want_hidden);
extern int ctf_label_iter (ctf_file_t *, ctf_label_f *, void *);
extern int ctf_label_next (ctf_file_t *, ctf_next_t **, const char **); /* TBD */
extern int ctf_variable_iter (ctf_file_t *, ctf_variable_f *, void *);
extern ctf_id_t ctf_variable_next (ctf_file_t *, ctf_next_t **,
const char **);
extern int ctf_archive_iter (const ctf_archive_t *, ctf_archive_member_f *,
void *);
extern ctf_file_t *ctf_archive_next (const ctf_archive_t *, ctf_next_t **,
const char **, int skip_parent, int *errp);
/* This function alone does not currently operate on CTF files masquerading
as archives, and returns -EINVAL: the raw data is no longer available. It is
expected to be used only by archiving tools, in any case, which have no need

19
libctf/ChangeLog
View File

@ -1,3 +1,22 @@
2020-07-22 Nick Alcock <nick.alcock@oracle.com>
* ctf-impl.h (ctf_next): New.
(ctf_get_dict): New prototype.
* ctf-lookup.c (ctf_get_dict): New, split out of...
(ctf_lookup_by_id): ... here.
* ctf-util.c (ctf_next_create): New.
(ctf_next_destroy): New.
(ctf_next_copy): New.
* ctf-types.c (includes): Add <assert.h>.
(ctf_member_next): New.
(ctf_enum_next): New.
(ctf_type_iter): Document the lack of iteration over parent
types.
(ctf_type_next): New.
(ctf_variable_next): New.
* ctf-archive.c (ctf_archive_next): New.
* libctf.ver: Add new public functions.
2020-07-22 Nick Alcock <nick.alcock@oracle.com>
* libctf.ver (ctf_ref): New.

107
libctf/ctf-archive.c
View File

@ -732,6 +732,113 @@ ctf_archive_iter (const ctf_archive_t *arc, ctf_archive_member_f *func,
return func (arc->ctfi_file, _CTF_SECTION, data);
}
/* Iterate over all CTF files in an archive, returning each dict in turn as a
ctf_file_t, and NULL on error or end of iteration. It is the caller's
responsibility to close it. Parent dicts may be skipped. Regardless of
whether they are skipped or not, the caller must ctf_import the parent if
need be.
We identify parents by name rather than by flag value: for now, with the
linker only emitting parents named _CTF_SECTION, this works well enough. */
ctf_file_t *
ctf_archive_next (const ctf_archive_t *wrapper, ctf_next_t **it, const char **name,
int skip_parent, int *errp)
{
ctf_file_t *f;
ctf_next_t *i = *it;
struct ctf_archive *arc;
struct ctf_archive_modent *modent;
const char *nametbl;
const char *name_;
if (!i)
{
if ((i = ctf_next_create()) == NULL)
{
if (errp)
*errp = ENOMEM;
return NULL;
}
i->cu.ctn_arc = wrapper;
i->ctn_iter_fun = (void (*) (void)) ctf_archive_next;
*it = i;
}
if ((void (*) (void)) ctf_archive_next != i->ctn_iter_fun)
{
if (errp)
*errp = ECTF_NEXT_WRONGFUN;
return NULL;
}
if (wrapper != i->cu.ctn_arc)
{
if (errp)
*errp = ECTF_NEXT_WRONGFP;
return NULL;
}
/* Iteration is made a bit more complex by the need to handle ctf_file_t's
transparently wrapped in a single-member archive. These are parents: if
skip_parent is on, they are skipped and the iterator terminates
immediately. */
if (!wrapper->ctfi_is_archive && i->ctn_n == 0)
{
i->ctn_n++;
if (!skip_parent)
{
wrapper->ctfi_file->ctf_refcnt++;
return wrapper->ctfi_file;
}
}
arc = wrapper->ctfi_archive;
/* The loop keeps going when skip_parent is on as long as the member we find
is the parent (i.e. at most two iterations, but possibly an early return if
*all* we have is a parent). */
const ctf_sect_t *symsect;
const ctf_sect_t *strsect;
do
{
if ((!wrapper->ctfi_is_archive) || (i->ctn_n >= le64toh (arc->ctfa_nfiles)))
{
ctf_next_destroy (i);
*it = NULL;
if (errp)
*errp = ECTF_NEXT_END;
return NULL;
}
symsect = &wrapper->ctfi_symsect;
strsect = &wrapper->ctfi_strsect;
if (symsect->cts_name == NULL)
symsect = NULL;
if (strsect->cts_name == NULL)
strsect = NULL;
modent = (ctf_archive_modent_t *) ((char *) arc
+ sizeof (struct ctf_archive));
nametbl = (((const char *) arc) + le64toh (arc->ctfa_names));
name_ = &nametbl[le64toh (modent[i->ctn_n].name_offset)];
i->ctn_n++;
} while (skip_parent && strcmp (name_, _CTF_SECTION) == 0);
if (name)
*name = name_;
f = ctf_arc_open_by_name_internal (arc, symsect, strsect,
name_, errp);
f->ctf_archive = (ctf_archive_t *) wrapper;
return f;
}
#ifdef HAVE_MMAP
/* Map the header in. Only used on new, empty files. */
static void *arc_mmap_header (int fd, size_t headersz)

32
libctf/ctf-impl.h
View File

@ -326,6 +326,36 @@ struct ctf_archive_internal
void (*ctfi_bfd_close) (struct ctf_archive_internal *);
};
/* Iterator state for the *_next() functions. */
struct ctf_next
{
void (*ctn_iter_fun) (void);
ctf_id_t ctn_type;
ssize_t ctn_size;
ssize_t ctn_increment;
uint32_t ctn_n;
/* We can save space on this side of things by noting that a container is
either dynamic or not, as a whole, and a given iterator can only iterate
over one kind of thing at once: so we can overlap the DTD and non-DTD
members, and the structure, variable and enum members, etc. */
union
{
const ctf_member_t *ctn_mp;
const ctf_lmember_t *ctn_lmp;
const ctf_dmdef_t *ctn_dmd;
const ctf_enum_t *ctn_en;
const ctf_dvdef_t *ctn_dvd;
} u;
/* This union is of various sorts of container we can iterate over:
currently dictionaries and archives. */
union
{
const ctf_file_t *ctn_fp;
const ctf_archive_t *ctn_arc;
} cu;
};
/* Return x rounded up to an alignment boundary.
eg, P2ROUNDUP(0x1234, 0x100) == 0x1300 (0x13*align)
eg, P2ROUNDUP(0x5600, 0x100) == 0x5600 (0x56*align) */
@ -362,6 +392,8 @@ extern ctf_id_t ctf_lookup_by_rawname (ctf_file_t *, int, const char *);
extern ctf_id_t ctf_lookup_by_rawhash (ctf_file_t *, ctf_names_t *, const char *);
extern void ctf_set_ctl_hashes (ctf_file_t *);
extern ctf_file_t *ctf_get_dict (ctf_file_t *fp, ctf_id_t type);
typedef unsigned int (*ctf_hash_fun) (const void *ptr);
extern unsigned int ctf_hash_integer (const void *ptr);
extern unsigned int ctf_hash_string (const void *ptr);

19
libctf/ctf-lookup.c
View File

@ -305,6 +305,18 @@ ctf_lookup_by_symbol (ctf_file_t *fp, unsigned long symidx)
return type;
}
/* Return the native dict of a given type: if called on a child and the
type is in the parent, return the parent. Needed if you plan to access
the type directly, without using the API. */
ctf_file_t *
ctf_get_dict (ctf_file_t *fp, ctf_id_t type)
{
if ((fp->ctf_flags & LCTF_CHILD) && LCTF_TYPE_ISPARENT (fp, type))
return fp->ctf_parent;
return fp;
}
/* Return the pointer to the internal CTF type data corresponding to the
given type ID. If the ID is invalid, the function returns NULL.
This function is not exported outside of the library. */
@ -312,17 +324,16 @@ ctf_lookup_by_symbol (ctf_file_t *fp, unsigned long symidx)
const ctf_type_t *
ctf_lookup_by_id (ctf_file_t **fpp, ctf_id_t type)
{
ctf_file_t *fp = *fpp; /* Caller passes in starting CTF container. */
ctf_file_t *fp = *fpp; /* Caller passes in starting CTF dict. */
ctf_id_t idx;
if ((fp->ctf_flags & LCTF_CHILD) && LCTF_TYPE_ISPARENT (fp, type)
&& (fp = fp->ctf_parent) == NULL)
if ((fp = ctf_get_dict (fp, type)) == NULL)
{
(void) ctf_set_errno (*fpp, ECTF_NOPARENT);
return NULL;
}
/* If this container is writable, check for a dynamic type. */
/* If this dict is writable, check for a dynamic type. */
if (fp->ctf_flags & LCTF_RDWR)
{

352
libctf/ctf-types.c
View File

@ -18,6 +18,7 @@
<http://www.gnu.org/licenses/>. */
#include <ctf-impl.h>
#include <assert.h>
#include <string.h>
/* Determine whether a type is a parent or a child. */
@ -103,6 +104,125 @@ ctf_member_iter (ctf_file_t *fp, ctf_id_t type, ctf_member_f *func, void *arg)
return 0;
}
/* Iterate over the members of a STRUCT or UNION, returning each member's
offset and optionally name and member type in turn. On end-of-iteration,
returns -1. */
ssize_t
ctf_member_next (ctf_file_t *fp, ctf_id_t type, ctf_next_t **it,
const char **name, ctf_id_t *membtype)
{
ctf_file_t *ofp = fp;
uint32_t kind;
ssize_t offset;
ctf_next_t *i = *it;
if (!i)
{
const ctf_type_t *tp;
ctf_dtdef_t *dtd;
if ((type = ctf_type_resolve (fp, type)) == CTF_ERR)
return -1; /* errno is set for us. */
if ((tp = ctf_lookup_by_id (&fp, type)) == NULL)
return -1; /* errno is set for us. */
if ((i = ctf_next_create ()) == NULL)
return ctf_set_errno (ofp, ENOMEM);
i->cu.ctn_fp = ofp;
(void) ctf_get_ctt_size (fp, tp, &i->ctn_size,
&i->ctn_increment);
kind = LCTF_INFO_KIND (fp, tp->ctt_info);
if (kind != CTF_K_STRUCT && kind != CTF_K_UNION)
{
ctf_next_destroy (i);
return (ctf_set_errno (ofp, ECTF_NOTSOU));
}
dtd = ctf_dynamic_type (fp, type);
i->ctn_iter_fun = (void (*) (void)) ctf_member_next;
/* We depend below on the RDWR state indicating whether the DTD-related
fields or the DMD-related fields have been initialized. */
assert ((dtd && (fp->ctf_flags & LCTF_RDWR))
|| (!dtd && (!(fp->ctf_flags & LCTF_RDWR))));
if (dtd == NULL)
{
i->ctn_n = LCTF_INFO_VLEN (fp, tp->ctt_info);
if (i->ctn_size < CTF_LSTRUCT_THRESH)
i->u.ctn_mp = (const ctf_member_t *) ((uintptr_t) tp +
i->ctn_increment);
else
i->u.ctn_lmp = (const ctf_lmember_t *) ((uintptr_t) tp +
i->ctn_increment);
}
else
i->u.ctn_dmd = ctf_list_next (&dtd->dtd_u.dtu_members);
*it = i;
}
if ((void (*) (void)) ctf_member_next != i->ctn_iter_fun)
return (ctf_set_errno (ofp, ECTF_NEXT_WRONGFUN));
if (ofp != i->cu.ctn_fp)
return (ctf_set_errno (ofp, ECTF_NEXT_WRONGFP));
/* Resolve to the native dict of this type. */
if ((fp = ctf_get_dict (ofp, type)) == NULL)
return (ctf_set_errno (ofp, ECTF_NOPARENT));
if (!(fp->ctf_flags & LCTF_RDWR))
{
if (i->ctn_n == 0)
goto end_iter;
if (i->ctn_size < CTF_LSTRUCT_THRESH)
{
if (name)
*name = ctf_strptr (fp, i->u.ctn_mp->ctm_name);
if (membtype)
*membtype = i->u.ctn_mp->ctm_type;
offset = i->u.ctn_mp->ctm_offset;
i->u.ctn_mp++;
}
else
{
if (name)
*name = ctf_strptr (fp, i->u.ctn_lmp->ctlm_name);
if (membtype)
*membtype = i->u.ctn_lmp->ctlm_type;
offset = (unsigned long) CTF_LMEM_OFFSET (i->u.ctn_lmp);
i->u.ctn_lmp++;
}
i->ctn_n--;
}
else
{
if (i->u.ctn_dmd == NULL)
goto end_iter;
if (name)
*name = i->u.ctn_dmd->dmd_name;
if (membtype)
*membtype = i->u.ctn_dmd->dmd_type;
offset = i->u.ctn_dmd->dmd_offset;
i->u.ctn_dmd = ctf_list_next (i->u.ctn_dmd);
}
return offset;
end_iter:
ctf_next_destroy (i);
*it = NULL;
return ctf_set_errno (ofp, ECTF_NEXT_END);
}
/* Iterate over the members of an ENUM. We pass the string name and associated
integer value of each enum element to the specified callback function. */
@ -154,8 +274,126 @@ ctf_enum_iter (ctf_file_t *fp, ctf_id_t type, ctf_enum_f *func, void *arg)
return 0;
}
/* Iterate over the members of an enum TYPE, returning each enumerand's NAME or
NULL at end of iteration or error, and optionally passing back the
enumerand's integer VALue. */
const char *
ctf_enum_next (ctf_file_t *fp, ctf_id_t type, ctf_next_t **it,
int *val)
{
ctf_file_t *ofp = fp;
uint32_t kind;
const char *name;
ctf_next_t *i = *it;
if (!i)
{
const ctf_type_t *tp;
ctf_dtdef_t *dtd;
if ((type = ctf_type_resolve_unsliced (fp, type)) == CTF_ERR)
return NULL; /* errno is set for us. */
if ((tp = ctf_lookup_by_id (&fp, type)) == NULL)
return NULL; /* errno is set for us. */
if ((i = ctf_next_create ()) == NULL)
{
ctf_set_errno (ofp, ENOMEM);
return NULL;
}
i->cu.ctn_fp = ofp;
(void) ctf_get_ctt_size (fp, tp, NULL,
&i->ctn_increment);
kind = LCTF_INFO_KIND (fp, tp->ctt_info);
if (kind != CTF_K_ENUM)
{
ctf_next_destroy (i);
ctf_set_errno (ofp, ECTF_NOTENUM);
return NULL;
}
dtd = ctf_dynamic_type (fp, type);
i->ctn_iter_fun = (void (*) (void)) ctf_enum_next;
/* We depend below on the RDWR state indicating whether the DTD-related
fields or the DMD-related fields have been initialized. */
assert ((dtd && (fp->ctf_flags & LCTF_RDWR))
|| (!dtd && (!(fp->ctf_flags & LCTF_RDWR))));
if (dtd == NULL)
{
i->ctn_n = LCTF_INFO_VLEN (fp, tp->ctt_info);
i->u.ctn_en = (const ctf_enum_t *) ((uintptr_t) tp +
i->ctn_increment);
}
else
i->u.ctn_dmd = ctf_list_next (&dtd->dtd_u.dtu_members);
*it = i;
}
if ((void (*) (void)) ctf_enum_next != i->ctn_iter_fun)
{
ctf_set_errno (ofp, ECTF_NEXT_WRONGFUN);
return NULL;
}
if (ofp != i->cu.ctn_fp)
{
ctf_set_errno (ofp, ECTF_NEXT_WRONGFP);
return NULL;
}
/* Resolve to the native dict of this type. */
if ((fp = ctf_get_dict (ofp, type)) == NULL)
{
ctf_set_errno (ofp, ECTF_NOPARENT);
return NULL;
}
if (!(fp->ctf_flags & LCTF_RDWR))
{
if (i->ctn_n == 0)
goto end_iter;
name = ctf_strptr (fp, i->u.ctn_en->cte_name);
if (val)
*val = i->u.ctn_en->cte_value;
i->u.ctn_en++;
i->ctn_n--;
}
else
{
if (i->u.ctn_dmd == NULL)
goto end_iter;
name = i->u.ctn_dmd->dmd_name;
if (val)
*val = i->u.ctn_dmd->dmd_value;
i->u.ctn_dmd = ctf_list_next (i->u.ctn_dmd);
}
return name;
end_iter:
ctf_next_destroy (i);
*it = NULL;
ctf_set_errno (ofp, ECTF_NEXT_END);
return NULL;
}
/* Iterate over every root (user-visible) type in the given CTF container.
We pass the type ID of each type to the specified callback function. */
We pass the type ID of each type to the specified callback function.
Does not traverse parent types: you have to do that explicitly. This is by
design, to avoid traversing them more than once if traversing many children
of a single parent. */
int
ctf_type_iter (ctf_file_t *fp, ctf_type_f *func, void *arg)
@ -175,7 +413,11 @@ ctf_type_iter (ctf_file_t *fp, ctf_type_f *func, void *arg)
}
/* Iterate over every type in the given CTF container, user-visible or not.
We pass the type ID of each type to the specified callback function. */
We pass the type ID of each type to the specified callback function.
Does not traverse parent types: you have to do that explicitly. This is by
design, to avoid traversing them more than once if traversing many children
of a single parent. */
int
ctf_type_iter_all (ctf_file_t *fp, ctf_type_all_f *func, void *arg)
@ -195,6 +437,55 @@ ctf_type_iter_all (ctf_file_t *fp, ctf_type_all_f *func, void *arg)
return 0;
}
/* Iterate over every type in the given CTF container, optionally including
non-user-visible types, returning each type ID and hidden flag in turn.
Returns CTF_ERR on end of iteration or error.
Does not traverse parent types: you have to do that explicitly. This is by
design, to avoid traversing them more than once if traversing many children
of a single parent. */
ctf_id_t
ctf_type_next (ctf_file_t *fp, ctf_next_t **it, int *flag, int want_hidden)
{
ctf_next_t *i = *it;
if (!i)
{
if ((i = ctf_next_create ()) == NULL)
return ctf_set_errno (fp, ENOMEM);
i->cu.ctn_fp = fp;
i->ctn_type = 1;
i->ctn_iter_fun = (void (*) (void)) ctf_type_next;
*it = i;
}
if ((void (*) (void)) ctf_type_next != i->ctn_iter_fun)
return (ctf_set_errno (fp, ECTF_NEXT_WRONGFUN));
if (fp != i->cu.ctn_fp)
return (ctf_set_errno (fp, ECTF_NEXT_WRONGFP));
while (i->ctn_type <= fp->ctf_typemax)
{
const ctf_type_t *tp = LCTF_INDEX_TO_TYPEPTR (fp, i->ctn_type);
if ((!want_hidden) && (!LCTF_INFO_ISROOT (fp, tp->ctt_info)))
{
i->ctn_type++;
continue;
}
if (flag)
*flag = LCTF_INFO_ISROOT (fp, tp->ctt_info);
return LCTF_INDEX_TO_TYPE (fp, i->ctn_type++, fp->ctf_flags & LCTF_CHILD);
}
ctf_next_destroy (i);
*it = NULL;
return ctf_set_errno (fp, ECTF_NEXT_END);
}
/* Iterate over every variable in the given CTF container, in arbitrary order.
We pass the name of each variable to the specified callback function. */
@ -229,6 +520,63 @@ ctf_variable_iter (ctf_file_t *fp, ctf_variable_f *func, void *arg)
return 0;
}
/* Iterate over every variable in the given CTF container, in arbitrary order,
returning the name and type of each variable in turn. The name argument is
not optional. Returns CTF_ERR on end of iteration or error. */
ctf_id_t
ctf_variable_next (ctf_file_t *fp, ctf_next_t **it, const char **name)
{
ctf_next_t *i = *it;
if ((fp->ctf_flags & LCTF_CHILD) && (fp->ctf_parent == NULL))
return (ctf_set_errno (fp, ECTF_NOPARENT));
if (!i)
{
if ((i = ctf_next_create ()) == NULL)
return ctf_set_errno (fp, ENOMEM);
i->cu.ctn_fp = fp;
i->ctn_iter_fun = (void (*) (void)) ctf_variable_next;
if (fp->ctf_flags & LCTF_RDWR)
i->u.ctn_dvd = ctf_list_next (&fp->ctf_dvdefs);
*it = i;
}
if ((void (*) (void)) ctf_variable_next != i->ctn_iter_fun)
return (ctf_set_errno (fp, ECTF_NEXT_WRONGFUN));
if (fp != i->cu.ctn_fp)
return (ctf_set_errno (fp, ECTF_NEXT_WRONGFP));
if (!(fp->ctf_flags & LCTF_RDWR))
{
if (i->ctn_n >= fp->ctf_nvars)
goto end_iter;
*name = ctf_strptr (fp, fp->ctf_vars[i->ctn_n].ctv_name);
return fp->ctf_vars[i->ctn_n++].ctv_type;
}
else
{
ctf_id_t id;
if (i->u.ctn_dvd == NULL)
goto end_iter;
*name = i->u.ctn_dvd->dvd_name;
id = i->u.ctn_dvd->dvd_type;
i->u.ctn_dvd = ctf_list_next (i->u.ctn_dvd);
return id;
}
end_iter:
ctf_next_destroy (i);
*it = NULL;
return ctf_set_errno (fp, ECTF_NEXT_END);
}
/* Follow a given type through the graph for TYPEDEF, VOLATILE, CONST, and
RESTRICT nodes until we reach a "base" type node. This is useful when
we want to follow a type ID to a node that has members or a size. To guard

29
libctf/ctf-util.c
View File

@ -173,3 +173,32 @@ ctf_set_errno (ctf_file_t * fp, int err)
fp->ctf_errno = err;
return CTF_ERR;
}
/* Create a ctf_next_t. */
ctf_next_t *
ctf_next_create (void)
{
return calloc (1, sizeof (struct ctf_next));
}
/* Destroy a ctf_next_t, for early exit from iterators. */
void
ctf_next_destroy (ctf_next_t *i)
{
free (i);
}
/* Copy a ctf_next_t. */
ctf_next_t *
ctf_next_copy (ctf_next_t *i)
{
ctf_next_t *i2;
if ((i2 = ctf_next_create()) == NULL)
return NULL;
memcpy (i2, i, sizeof (struct ctf_next));
return i2;
}

9
libctf/libctf.ver
View File

@ -73,6 +73,7 @@ LIBCTF_1.0 {
ctf_type_compat;
ctf_member_info;
ctf_member_next;
ctf_array_info;
ctf_member_count;
@ -87,10 +88,17 @@ LIBCTF_1.0 {
ctf_member_iter;
ctf_enum_iter;
ctf_enum_next;
ctf_type_iter;
ctf_type_next;
ctf_type_iter_all;
ctf_label_iter;
ctf_variable_iter;
ctf_variable_next;
ctf_next_create;
ctf_next_destroy;
ctf_next_copy;
ctf_add_array;
ctf_add_const;
@ -138,6 +146,7 @@ LIBCTF_1.0 {
ctf_arc_open_by_name_sections;
ctf_archive_count;
ctf_archive_iter;
ctf_archive_next;
ctf_archive_raw_iter;
ctf_get_arc;