[PATCH v2 1/9] gdb/ctf: add debug logging in ctfread.c

simon.marchi
2026-02-17T19:55:34Z

Add some debug statements, to be able to visualize what is happening
when loading CTF debug info. Add a new "set debug ctf" command, with
the usual logging macros.

Here's an example of the result, when reading the binary from test
gdb.ctf/cruss-tu-cyclic:

[ctf] elfctf_build_psymtabs: start: building psymtabs for /home/simark/build/binutils-gdb/gdb/testsuite/outputs/gdb.ctf/cross-tu-cyclic/cross-tu-cyclic
[ctf] scan_partial_symbols: start: fname='.ctf'
[ctf] scan_partial_symbols: is parent, using fname='/home/simark/build/binutils-gdb/gdb/testsuite/outputs/gdb.ctf/cross-tu-cyclic/cross-tu-cyclic'
[ctf] ctf_psymtab_type_cb: adding type tid=0x1 kind=INTEGER name='int'
[ctf] ctf_psymtab_type_cb: adding type tid=0x2 kind=INTEGER name='long int'
[ctf] ctf_psymtab_type_cb: adding type tid=0x3 kind=FORWARD name='B'
[ctf] ctf_psymtab_type_cb: adding type tid=0x5 kind=FORWARD name='A'
[ctf] ctf_psymtab_type_cb: adding type tid=0x8 kind=STRUCT name='C'
[ctf] ctf_psymtab_add_stt_entries: adding function psym 'main' tid=0x7 kind=FUNCTION
[ctf] scan_partial_symbols: end: fname='.ctf'
[ctf] scan_partial_symbols: start: fname='/home/simark/src/binutils-gdb/gdb/testsuite/gdb.ctf/cross-tu-cyclic-1.c'
[ctf] ctf_psymtab_type_cb: adding type tid=0x80000001 kind=STRUCT name='B'
[ctf] ctf_psymtab_type_cb: adding type tid=0x80000002 kind=STRUCT name='A'
[ctf] scan_partial_symbols: end: fname='/home/simark/src/binutils-gdb/gdb/testsuite/gdb.ctf/cross-tu-cyclic-1.c'
[ctf] scan_partial_symbols: start: fname='/home/simark/src/binutils-gdb/gdb/testsuite/gdb.ctf/cross-tu-cyclic-2.c'
[ctf] ctf_psymtab_type_cb: adding type tid=0x80000001 kind=STRUCT name='A'
[ctf] scan_partial_symbols: end: fname='/home/simark/src/binutils-gdb/gdb/testsuite/gdb.ctf/cross-tu-cyclic-2.c'
[ctf] scan_partial_symbols: start: fname='/home/simark/src/binutils-gdb/gdb/testsuite/gdb.ctf/cross-tu-cyclic-3.c'
[ctf] ctf_psymtab_type_cb: adding type tid=0x80000001 kind=STRUCT name='A'
[ctf] scan_partial_symbols: end: fname='/home/simark/src/binutils-gdb/gdb/testsuite/gdb.ctf/cross-tu-cyclic-3.c'
[ctf] scan_partial_symbols: start: fname='/home/simark/src/binutils-gdb/gdb/testsuite/gdb.ctf/cross-tu-cyclic-4.c'
[ctf] ctf_psymtab_type_cb: adding type tid=0x80000001 kind=STRUCT name='A'
[ctf] ctf_psymtab_type_cb: adding type tid=0x80000002 kind=STRUCT name='B'
[ctf] scan_partial_symbols: end: fname='/home/simark/src/binutils-gdb/gdb/testsuite/gdb.ctf/cross-tu-cyclic-4.c'
[ctf] elfctf_build_psymtabs: end: building psymtabs for /home/simark/build/binutils-gdb/gdb/testsuite/outputs/gdb.ctf/cross-tu-cyclic/cross-tu-cyclic

Change-Id: If3800d14dd965ccefa67a24ef5c4481aef70ffa4
Reviewed-By: Eli Zaretskii <eliz@gnu.org>
---
gdb/NEWS | 4 ++
gdb/ctfread.c | 95 ++++++++++++++++++++++++++++++++++++++++++++-
gdb/doc/gdb.texinfo | 7 ++++
3 files changed, 104 insertions(+), 2 deletions(-)

diff --git a/gdb/NEWS b/gdb/NEWS
index 1957e63eae44..7e5594bd81cc 100644
--- a/gdb/NEWS
+++ b/gdb/NEWS
@@ -89,6 +89,10 @@ set debug gnu-ifunc on|off
show debug gnu-ifunc
Turn on or off debug messages related to GNU ifunc resolution.

+set debug ctf on|off
+show debug ctf
+ Turn on or off debug messages about CTF reading.
+
set progress-bars enabled on|off
show progress-bars enabled
Allows the progress bars, used when debuginfod is downloading
diff --git a/gdb/ctfread.c b/gdb/ctfread.c
index e24d0ef60d02..141f51f621b0 100644
--- a/gdb/ctfread.c
+++ b/gdb/ctfread.c
@@ -80,12 +80,49 @@
#include "block.h"
#include "ctfread.h"
#include "psymtab.h"
+#include "cli/cli-cmds.h"
+
+/* When true, print debug messages related to CTF reading. */
+static bool debug_ctf = false;
+
+/* Print a "ctf" debug statement. */
+
+#define ctf_debug_printf(fmt, ...) \
+ debug_prefixed_printf_cond (debug_ctf, "ctf", fmt, ##__VA_ARGS__)
+
+#define CTF_SCOPED_DEBUG_START_END(fmt, ...) \
+ scoped_debug_start_end (debug_ctf, "ctf", fmt, ##__VA_ARGS__)

#if ENABLE_LIBCTF

#include "ctf.h"
#include "ctf-api.h"

+/* Return a string representation of a CTF type kind. */
+
+static const char *
+ctf_kind_str (uint32_t kind)
+{
+ switch (kind)
+ {
+ case CTF_K_UNKNOWN: return "UNKNOWN";
+ case CTF_K_INTEGER: return "INTEGER";
+ case CTF_K_FLOAT: return "FLOAT";
+ case CTF_K_POINTER: return "POINTER";
+ case CTF_K_ARRAY: return "ARRAY";
+ case CTF_K_FUNCTION: return "FUNCTION";
+ case CTF_K_STRUCT: return "STRUCT";
+ case CTF_K_UNION: return "UNION";
+ case CTF_K_ENUM: return "ENUM";
+ case CTF_K_FORWARD: return "FORWARD";
+ case CTF_K_TYPEDEF: return "TYPEDEF";
+ case CTF_K_VOLATILE: return "VOLATILE";
+ case CTF_K_CONST: return "CONST";
+ case CTF_K_RESTRICT: return "RESTRICT";
+ default: return "???";
+ }
+}
+
using ctf_type_map = gdb::unordered_map<ctf_id_t, struct type *>;

struct ctf_dict_info
@@ -992,10 +1029,18 @@ ctf_add_type_cb (ctf_id_t tid, void *arg)
/* Check if tid's type has already been defined. */
type = get_tid_type (ccp->of, tid);
if (type != nullptr)
- return 0;
+ {
+ ctf_debug_printf ("tid=%ld already defined, skipping", tid);
+ return 0;
+ }

ctf_id_t btid = ctf_type_reference (ccp->dict, tid);
kind = ctf_type_kind (ccp->dict, tid);
+
+ ctf_debug_printf ("processing tid=%ld kind=%s name='%s' btid=%ld",
+ tid, ctf_kind_str (kind),
+ ctf_type_name_raw (ccp->dict, tid) ? : "(null)", btid);
+
switch (kind)
{
case CTF_K_STRUCT:
@@ -1059,6 +1104,9 @@ ctf_add_var_cb (const char *name, ctf_id_t id, void *arg)

kind = ctf_type_kind (ccp->dict, id);

+ ctf_debug_printf ("adding variable name='%s' tid=%ld kind=%s",
+ name, id, ctf_kind_str (kind));
+
if (type == nullptr)
{
complaint (_("ctf_add_var_cb: %s has NO type (%ld)"), name, id);
@@ -1101,7 +1149,15 @@ add_stt_entries (struct ctf_context *ccp, int functions)
{
type = get_tid_type (ccp->of, tid);
if (type == nullptr)
- continue;
+ {
+ ctf_debug_printf ("skipping '%s' tid=0x%lx (no type found)",
+ tname, tid);
+ continue;
+ }
+
+ ctf_debug_printf ("adding %s '%s' tid=0x%lx",
+ functions ? "function" : "object", tname, tid);
+
sym = new (&ccp->of->objfile_obstack) symbol;
OBJSTAT (ccp->of, n_syms++);
sym->set_type (type);
@@ -1186,6 +1242,10 @@ ctf_psymtab_add_stt_entries (ctf_dict_t *dict, ctf_psymtab *pst,
else
loc_class = LOC_STATIC;

+ ctf_debug_printf ("adding %s psym '%s' tid=0x%lx kind=%s",
+ functions ? "function" : "object", tname, tid,
+ ctf_kind_str (kind));
+
pst->add_psymbol (tname, true,
tdomain, loc_class, -1,
psymbol_placement::GLOBAL,
@@ -1219,6 +1279,8 @@ ctf_psymtab::expand_psymtab (struct objfile *objfile)
{
struct ctf_context *ccp;

+ CTF_SCOPED_DEBUG_START_END ("expanding psymtab");
+
gdb_assert (!readin);

ccp = &context;
@@ -1247,6 +1309,8 @@ ctf_psymtab::expand_psymtab (struct objfile *objfile)
void
ctf_psymtab::read_symtab (struct objfile *objfile)
{
+ CTF_SCOPED_DEBUG_START_END ("reading symtab for '%s'", filename);
+
if (readin)
warning (_("bug: psymtab for %s is already read in."), filename);
else
@@ -1263,6 +1327,9 @@ ctf_psymtab::read_symtab (struct objfile *objfile)

offset = get_objfile_text_range (objfile, &tsize);

+ ctf_debug_printf ("starting buildsym for '%s', offset=%s, tsize=%zu",
+ filename, hex_string (offset), tsize);
+
buildsym_compunit builder (objfile, this->filename, nullptr,
language_c, offset);
builder.record_debugformat ("ctf");
@@ -1360,6 +1427,9 @@ ctf_psymtab_type_cb (ctf_id_t tid, void *arg)
if (name == nullptr || *name == '\0')
return 0;

+ ctf_debug_printf ("adding type tid=0x%lx kind=%s name='%s'",
+ tid, ctf_kind_str (kind), name);
+
ccp->pst->add_psymbol (name, false,
domain, loc_class, section,
psymbol_placement::GLOBAL,
@@ -1377,6 +1447,10 @@ ctf_psymtab_var_cb (const char *name, ctf_id_t id, void *arg)
struct ctf_context *ccp = (struct ctf_context *) arg;

uint32_t kind = ctf_type_kind (ccp->dict, id);
+
+ ctf_debug_printf ("adding variable name='%s' tid=0x%lx kind=%s",
+ name, id, ctf_kind_str (kind));
+
ccp->pst->add_psymbol (name, true,
kind == CTF_K_FUNCTION
? FUNCTION_DOMAIN
@@ -1398,10 +1472,13 @@ scan_partial_symbols (ctf_dict_t *dict, psymtab_storage *partial_symtabs,
struct objfile *of = tup->of;
bool isparent = false;

+ CTF_SCOPED_DEBUG_START_END ("fname='%s'", fname);
+
if (strcmp (fname, ".ctf") == 0)
{
fname = bfd_get_filename (of->obfd.get ());
isparent = true;
+ ctf_debug_printf ("is parent, using fname='%s'", fname);
}

ctf_psymtab *pst = create_partial_symtab (fname, tup->arc, dict,
@@ -1462,6 +1539,9 @@ elfctf_build_psymtabs (struct objfile *of)
bfd *abfd = of->obfd.get ();
int err;

+ CTF_SCOPED_DEBUG_START_END ("building psymtabs for %s",
+ bfd_get_filename (abfd));
+
ctf_archive_t *arc = ctf_bfdopen (abfd, &err);
if (arc == nullptr)
error (_("ctf_bfdopen failed on %s - %s"),
@@ -1495,3 +1575,14 @@ elfctf_build_psymtabs (struct objfile *of)
}

#endif /* ENABLE_LIBCTF */
+
+INIT_GDB_FILE (_initialize_ctfread)
+{
+ add_setshow_boolean_cmd ("ctf", no_class, &debug_ctf,
+ _("Set CTF reading debugging."),
+ _("Show CTF reading debugging."),
+ _("When true, print debug messages related to "
+ "CTF reading."),
+ nullptr, nullptr,
+ &setdebuglist, &showdebuglist);
+}
diff --git a/gdb/doc/gdb.texinfo b/gdb/doc/gdb.texinfo
index 103549ece778..0745cf20b130 100644
--- a/gdb/doc/gdb.texinfo
+++ b/gdb/doc/gdb.texinfo
@@ -29252,6 +29252,13 @@ exported symbols. The default is off.
Displays the current state of displaying debugging messages related to
reading of COFF/PE exported symbols.

+@cindex CTF debug messages
+@item set debug ctf
+Turns on or off display of debugging messages related to reading CTF
+debug info. The default is off.
+@item show debug ctf
+Displays the current state of CTF debug info reading messages.
+
@item set debug dwarf-die
@cindex DWARF DIEs
Dump DWARF DIEs after they are read in.
--
2.53.0