When loading the debug info package
libLLVM.so.10-10.0.1-lp152.30.4.x86_64.debug from openSUSE Leap 15.2, we
run into a dwarf error:
...
$ gdb -q -batch libLLVM.so.10-10.0.1-lp152.30.4.x86_64.debug
Dwarf Error: Cannot not find DIE at 0x18a936e7 \
[from module libLLVM.so.10-10.0.1-lp152.30.4.x86_64.debug]
...
The DIE @ 0x18a936e7 does in fact exist, and is part of a CU @ 0x18a23e52.
No error message is printed when using -readnow.
What happens is the following:
- a dwarf2_per_cu_data P is created for the CU.
- a dwarf2_cu A is created for the same CU.
- another dwarf2_cu B is created for the same CU.
- the dwarf2_cu B is set in per_objfile->m_dwarf2_cus, such that
per_objfile->get_cu (P) returns B.
- P->load_all_dies is set to 1.
- all dies are read into the A->partial_dies htab
- dwarf2_cu A is destroyed.
- we try to find the partial_die for the DIE @ 0x18a936e7 in B->partial_dies.
We can't find it, but do not try to load all dies, because P->load_all_dies
is already set to 1.
- an error message is generated.
The question is why we're creating dwarf2_cu A and B for the same CU.
The dwarf2_cu A is created here:
...
(gdb) bt
#0 dwarf2_cu::dwarf2_cu (this=0x79a9660, per_cu=0x23c0b30,
per_objfile=0x1ad01b0) at dwarf2/cu.c:38
#1 0x0000000000675799 in cutu_reader::cutu_reader (this=0x7fffffffd040,
this_cu=0x23c0b30, per_objfile=0x1ad01b0, abbrev_table=0x0,
existing_cu=0x0, skip_partial=false) at dwarf2/read.c:6487
#2 0x0000000000676eb3 in process_psymtab_comp_unit (this_cu=0x23c0b30,
per_objfile=0x1ad01b0, want_partial_unit=false,
pretend_language=language_minimal) at dwarf2/read.c:7028
...
And the dwarf2_cu B is created here:
...
(gdb) bt
#0 dwarf2_cu::dwarf2_cu (this=0x885e8c0, per_cu=0x23c0b30,
per_objfile=0x1ad01b0) at dwarf2/cu.c:38
#1 0x0000000000675799 in cutu_reader::cutu_reader (this=0x7fffffffcc50,
this_cu=0x23c0b30, per_objfile=0x1ad01b0, abbrev_table=0x0,
existing_cu=0x0, skip_partial=false) at dwarf2/read.c:6487
#2 0x0000000000678118 in load_partial_comp_unit (this_cu=0x23c0b30,
per_objfile=0x1ad01b0, existing_cu=0x0) at dwarf2/read.c:7436
#3 0x000000000069721d in find_partial_die (sect_off=(unknown: 0x18a55054),
offset_in_dwz=0, cu=0x0) at dwarf2/read.c:19391
#4 0x000000000069755b in partial_die_info::fixup (this=0x9096900,
cu=0xa6a85f0) at dwarf2/read.c:19512
#5 0x0000000000697586 in partial_die_info::fixup (this=0x8629bb0,
cu=0xa6a85f0) at dwarf2/read.c:19516
#6 0x00000000006787b1 in scan_partial_symbols (first_die=0x8629b40,
lowpc=0x7fffffffcf58, highpc=0x7fffffffcf50, set_addrmap=0, cu=0x79a9660)
at dwarf2/read.c:7563
#7 0x0000000000678878 in scan_partial_symbols (first_die=0x796ebf0,
lowpc=0x7fffffffcf58, highpc=0x7fffffffcf50, set_addrmap=0, cu=0x79a9660)
at dwarf2/read.c:7580
#8 0x0000000000676b82 in process_psymtab_comp_unit_reader
(reader=0x7fffffffd040, info_ptr=0x7fffc1b3f29b, comp_unit_die=0x6ea90f0,
pretend_language=language_minimal) at dwarf2/read.c:6954
#9 0x0000000000676ffd in process_psymtab_comp_unit (this_cu=0x23c0b30,
per_objfile=0x1ad01b0, want_partial_unit=false,
pretend_language=language_minimal) at dwarf2/read.c:7057
...
So in frame #9, a cutu_reader is created with dwarf2_cu A. Then a fixup takes
us to the following CU @ 0x18aa33d6, in frame #5. And a similar fixup in
frame #4 takes us back to CU @ 0x18a23e52. At that point, there's no
information available that we're already trying to read that CU, and we end up
creating another cutu_reader with dwarf2_cu B.
It seems that there are two related problems:
- creating two dwarf2_cu's is not optimal
- the unoptimal case is not handled correctly
This patch addresses the last problem, by moving the load_all_dies flag from
dwarf2_per_cu_data to dwarf2_cu, such that it is paired with the partial_dies
field, which ensures that the two can be kept in sync.
Tested on x86_64-linux.
gdb/ChangeLog:
2021-05-27 Tom de Vries <tdevries@suse.de>
PR symtab/27898
* dwarf2/cu.c (dwarf2_cu::dwarf2_cu): Add load_all_dies init.
* dwarf2/cu.h (dwarf2_cu): Add load_all_dies field.
* dwarf2/read.c (load_partial_dies, find_partial_die): Update.
* dwarf2/read.h (dwarf2_per_cu_data::dwarf2_per_cu_data): Remove
load_all_dies init.
(dwarf2_per_cu_data): Remove load_all_dies field.
+2021-05-27 Tom de Vries <tdevries@suse.de>
+
+ PR symtab/27898
+ * dwarf2/cu.c (dwarf2_cu::dwarf2_cu): Add load_all_dies init.
+ * dwarf2/cu.h (dwarf2_cu): Add load_all_dies field.
+ * dwarf2/read.c (load_partial_dies, find_partial_die): Update.
+ * dwarf2/read.h (dwarf2_per_cu_data::dwarf2_per_cu_data): Remove
+ load_all_dies init.
+ (dwarf2_per_cu_data): Remove load_all_dies field.
+
2021-05-26 Simon Marchi <simon.marchi@efficios.com>
* regcache.c (reg_buffer::reg_buffer): Default-initialize
producer_is_icc (false),
producer_is_icc_lt_14 (false),
producer_is_codewarrior (false),
- processing_has_namespace_info (false)
+ processing_has_namespace_info (false),
+ load_all_dies (false)
{
}
bool processing_has_namespace_info : 1;
+ /* This flag will be set when reading partial DIEs if we need to load
+ absolutely all DIEs for this compilation unit, instead of just the ones
+ we think are interesting. It gets set if we look for a DIE in the
+ hash table and don't find it. */
+ bool load_all_dies : 1;
+
struct partial_die_info *find_partial_die (sect_offset sect_off);
/* If this CU was inherited by another CU (via specification,
last_die = NULL;
gdb_assert (cu->per_cu != NULL);
- if (cu->per_cu->load_all_dies)
+ if (cu->load_all_dies)
load_all = 1;
cu->partial_dies
/* If we didn't find it, and not all dies have been loaded,
load them all and try again. */
- if (pd == NULL && cu->per_cu->load_all_dies == 0)
+ if (pd == NULL && cu->load_all_dies == 0)
{
- cu->per_cu->load_all_dies = 1;
+ cu->load_all_dies = 1;
/* This is nasty. When we reread the DIEs, somewhere up the call chain
THIS_CU->cu may already be in use. So we can't just free it and
{
dwarf2_per_cu_data ()
: queued (false),
- load_all_dies (false),
is_debug_types (false),
is_dwz (false),
reading_dwo_directly (false),
any of the current compilation units are processed. */
unsigned int queued : 1;
- /* This flag will be set when reading partial DIEs if we need to load
- absolutely all DIEs for this compilation unit, instead of just the ones
- we think are interesting. It gets set if we look for a DIE in the
- hash table and don't find it. */
- unsigned int load_all_dies : 1;
-
/* Non-zero if this CU is from .debug_types.
Struct dwarf2_per_cu_data is contained in struct signatured_type iff
this is non-zero. */
projects / binutils-gdb.git / commitdiff