[ The test-case requires commit c1a66c0629 "[gdb] Expand symbolless symtabs
using maint expand-symtabs". ]
Consider the debug info for the test-case included in this patch. It consists
of a PU:
...
<0><d2>: Abbrev Number: 2 (DW_TAG_partial_unit)
<1><d3>: Abbrev Number: 0
...
imported by a CU:
...
<0><df>: Abbrev Number: 2 (DW_TAG_compile_unit)
<e0> DW_AT_language : 2 (non-ANSI C)
<e1> DW_AT_stmt_list : 0xe9
<1><e5>: Abbrev Number: 3 (DW_TAG_imported_unit)
<e6> DW_AT_import : <0xd2> [Abbrev Number: 2]
<1><ea>: Abbrev Number: 0
...
and the CU has a dw2-symtab-includes.h file in the .debug_line file name
table:
...
The Directory Table (offset 0x101):
1 /data/gdb_versions/devel/src/gdb/testsuite/gdb.dwarf2
The File Name Table (offset 0x138):
Entry Dir Time Size Name
1 1 0 0 dw2-symtab-includes.h
...
After expanding all symtabs, we can see the CU listed in the user field of the
PU, and vice-versa the PU listed in the includes of the CU:
...
$ gdb.sh -batch \
-iex "set language c" \
outputs/gdb.dwarf2/dw2-symtab-includes/dw2-symtab-includes \
-ex "maint expand-symtabs" \
-ex "maint info symtabs"
...
{ ((struct compunit_symtab *) 0x394dd60)
debugformat DWARF 2
producer (null)
dirname (null)
blockvector ((struct blockvector *) 0x394dea0)
user ((struct compunit_symtab *) 0x394dba0)
}
{ ((struct compunit_symtab *) 0x394dba0)
debugformat DWARF 2
producer (null)
dirname (null)
blockvector ((struct blockvector *) 0x394dd10)
user ((struct compunit_symtab *) (null))
( includes
((struct compunit_symtab *) 0x394dd60)
)
}
...
But if we instead only expand the symtab for the dw2-symtab-includes.h file,
the includes and user links are gone:
...
$ gdb -batch \
-iex "set language c" \
outputs/gdb.dwarf2/dw2-symtab-includes/dw2-symtab-includes \
-ex "maint expand-symtabs dw2-symtab-includes.h" \
-ex "maint info symtabs"
...
{ ((struct compunit_symtab *) 0x2728210)
debugformat DWARF 2
producer (null)
dirname (null)
blockvector ((struct blockvector *) 0x2728350)
user ((struct compunit_symtab *) (null))
}
{ ((struct compunit_symtab *) 0x2728050)
debugformat DWARF 2
producer (null)
dirname (null)
blockvector ((struct blockvector *) 0x27281c0)
user ((struct compunit_symtab *) (null))
}
...
The includes are calculated by process_cu_includes in gdb/dwarf2/read.c.
In the case of expanding all symtabs:
- the CU partial symtab is expanded using psymtab_to_symtab
- psymtab_to_symtab calls dwarf2_psymtab::read_symtab
- dwarf2_psymtab::read_symtab calls dwarf2_psymtab::expand_psymtab
- dwarf2_psymtab::read_symtab calls process_cu_includes, and we have the
includes
In the case of expanding the symtab for dw2-symtab-includes.h:
- the dw2-symtab-includes.h partial symtab is expanded using psymtab_to_symtab
- psymtab_to_symtab calls dwarf2_include_psymtab::read_symtab
- dwarf2_include_psymtab::read_symtab calls
dwarf2_include_psymtab::expand_psymtab
- dwarf2_include_psymtab::expand_psymtab calls
partial_symtab::expand_dependencies
- partial_symtab::expand_dependencies calls dwarf2_psymtab::expand_psymtab
for the CU partial symtab
- the CU partial symtab is expanded using dwarf2_psymtab::expand_psymtab
- process_cu_includes is never called
Fix this by making sure in dwarf2_include_psymtab::read_symtab that
read_symtab is called for the CU partial symtab.
Tested on x86_64-linux, with native, and target board cc-with-dwz and
cc-with-dwz-m.
In addition, tested test-case with target boards cc-with-gdb-index.exp,
cc-with-debug-names.exp and readnow.exp.
gdb/ChangeLog:
2020-04-14 Simon Marchi <simon.marchi@polymtl.ca>
Tom de Vries <tdevries@suse.de>
PR symtab/25718
* psympriv.h (struct partial_symtab::read_symtab)
(struct partial_symtab::expand_psymtab)
(struct partial_symtab::read_dependencies): Update comments.
* dwarf2/read.c (struct dwarf2_include_psymtab::read_symtab): Call
read_symtab for includer.
(struct dwarf2_include_psymtab::expand_psymtab): Assert false.
(struct dwarf2_include_psymtab::readin_p): Call readin_p () for includer.
(struct dwarf2_include_psymtab::m_readin): Remove.
(struct dwarf2_include_psymtab::includer): New member function.
(dwarf2_psymtab::expand_psymtab): Assert !readin.
gdb/testsuite/ChangeLog:
2020-04-14 Tom de Vries <tdevries@suse.de>
PR symtab/25718
* gdb.dwarf2/dw2-symtab-includes.exp: New file.
