[PATCH v2 08/42] Add dwarf2_per_objfile field to dwarf2_cu

Simon Marchi
2020-05-12T21:09:19Z

Subsequent patches will make dwarf2_per_cu_data objfile-independent.
This means that the dwarf2_per_cu_data::dwarf2_per_objfile field must
go.

The code using a dwarf2_cu structure currently accesses the current
dwarf2_per_objfile object through dwarf2_cu->per_cu->dwarf2_per_objfile.
Since it's ok for the dwarf2_cu to know about the current objfile (a
dwarf2_cu is always used in the context of a particular objfile), add a
dwarf2_per_objfile field to dwarf2_cu. Upcoming patches will gradually
remove uses of dwarf2_per_cu_data::dwarf2_per_objfile in favor of
dwarf2_cu::dwarf2_per_objfile, until the former can be removed.

gdb/ChangeLog:

* dwarf2/read.c (struct dwarf2_cu) <dwarf2_cu>: Add parameter.
<per_objfile>: New member.
(class cutu_reader) <init_tu_and_read_dwo_dies>: Add parameter.
(cutu_reader::init_tu_and_read_dwo_dies): Add parameter, update
call to dwarf2_cu.
(cutu_reader::cutu_reader): Update.
(dwarf2_cu::dwarf2_cu): Add parameter, initialize per_objfile.
---
gdb/dwarf2/read.c | 28 ++++++++++++++++++----------
1 file changed, 18 insertions(+), 10 deletions(-)

diff --git a/gdb/dwarf2/read.c b/gdb/dwarf2/read.c
index c9617293284..096002219a3 100644
--- a/gdb/dwarf2/read.c
+++ b/gdb/dwarf2/read.c
@@ -399,7 +399,8 @@ struct delayed_method_info
/* Internal state when decoding a particular compilation unit. */
struct dwarf2_cu
{
- explicit dwarf2_cu (struct dwarf2_per_cu_data *per_cu);
+ explicit dwarf2_cu (dwarf2_per_cu_data *per_cu,
+ dwarf2_per_objfile *per_objfile);
~dwarf2_cu ();

DISABLE_COPY_AND_ASSIGN (dwarf2_cu);
@@ -466,6 +467,9 @@ struct dwarf2_cu
/* Backlink to our per_cu entry. */
struct dwarf2_per_cu_data *per_cu;

+ /* The dwarf2_per_objfile that owns this. */
+ struct dwarf2_per_objfile *per_objfile;
+
/* How many compilation units ago was this CU last referenced? */
int last_used = 0;

@@ -928,7 +932,8 @@ class cutu_reader : public die_reader_specs
void keep ();

private:
- void init_tu_and_read_dwo_dies (struct dwarf2_per_cu_data *this_cu,
+ void init_tu_and_read_dwo_dies (dwarf2_per_cu_data *this_cu,
+ dwarf2_per_objfile *per_objfile,
int use_existing_cu);

struct dwarf2_per_cu_data *m_this_cu;
@@ -6852,7 +6857,8 @@ lookup_dwo_unit (struct dwarf2_per_cu_data *this_cu,
Read a TU directly from a DWO file, bypassing the stub. */

void
-cutu_reader::init_tu_and_read_dwo_dies (struct dwarf2_per_cu_data *this_cu,
+cutu_reader::init_tu_and_read_dwo_dies (dwarf2_per_cu_data *this_cu,
+ dwarf2_per_objfile *per_objfile,
int use_existing_cu)
{
struct signatured_type *sig_type;
@@ -6873,7 +6879,7 @@ cutu_reader::init_tu_and_read_dwo_dies (struct dwarf2_per_cu_data *this_cu,
{
/* If !use_existing_cu, this_cu->cu must be NULL. */
gdb_assert (this_cu->cu == NULL);
- m_new_cu.reset (new dwarf2_cu (this_cu));
+ m_new_cu.reset (new dwarf2_cu (this_cu, per_objfile));
}

/* A future optimization, if needed, would be to use an existing
@@ -6934,7 +6940,7 @@ cutu_reader::cutu_reader (struct dwarf2_per_cu_data *this_cu,
/* Narrow down the scope of possibilities to have to understand. */
gdb_assert (this_cu->is_debug_types);
gdb_assert (abbrev_table == NULL);
- init_tu_and_read_dwo_dies (this_cu, use_existing_cu);
+ init_tu_and_read_dwo_dies (this_cu, dwarf2_per_objfile, use_existing_cu);
return;
}

@@ -6961,7 +6967,7 @@ cutu_reader::cutu_reader (struct dwarf2_per_cu_data *this_cu,
{
/* If !use_existing_cu, this_cu->cu must be NULL. */
gdb_assert (this_cu->cu == NULL);
- m_new_cu.reset (new dwarf2_cu (this_cu));
+ m_new_cu.reset (new dwarf2_cu (this_cu, dwarf2_per_objfile));
cu = m_new_cu.get ();
}

@@ -7153,7 +7159,7 @@ cutu_reader::cutu_reader (struct dwarf2_per_cu_data *this_cu,
/* This is cheap if the section is already read in. */
section->read (objfile);

- m_new_cu.reset (new dwarf2_cu (this_cu));
+ m_new_cu.reset (new dwarf2_cu (this_cu, dwarf2_per_objfile));

begin_info_ptr = info_ptr = section->buffer + to_underlying (this_cu->sect_off);
info_ptr = read_and_check_comp_unit_head (dwarf2_per_objfile,
@@ -23477,10 +23483,12 @@ run_test ()

#endif /* GDB_SELF_TEST */

-/* Initialize dwarf2_cu CU, owned by PER_CU. */
+/* Initialize dwarf2_cu to read PER_CU, in the context of PER_OBJFILE. */

-dwarf2_cu::dwarf2_cu (struct dwarf2_per_cu_data *per_cu_)
- : per_cu (per_cu_),
+dwarf2_cu::dwarf2_cu (dwarf2_per_cu_data *per_cu,
+ dwarf2_per_objfile *per_objfile)
+ : per_cu (per_cu),
+ per_objfile (per_objfile),
mark (false),
has_loclist (false),
checked_producer (false),
--
2.26.2