This commit is the result of running the gdb/copyright.py script,
which automated the update of the copyright year range for all
source files managed by the GDB project to be updated to include
year 2023.
Clang up to version 15 (current) adds macros that were defined in the
command line or by "other means", according to the Dwarf specification,
after the last DW_MACRO_end_file, instead of before the first
DW_MACRO_start_file, as the specification dictates. When GDB reads the
macros after the last file is closed, the macros never end up "in scope"
and so we can't print them. This has been submitted as a bug to Clang
developers (https://github.com/llvm/llvm-project/issues/54506), and PR
macros/29034 was opened for GDB to keep track of this.
Seeing as there is no expected date for it to be fixed, add a workaround
for all current versions of Clang. The workaround detects when
the main file would be closed and if the producer is Clang, and turns
that operation into a noop, so we keep a reference to the current_file
as those macros are read.
A test case was added to confirm the functionality, and the KFAIL for
running gdb.base/macro-source-path when using clang.
Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=29034
Approved-By: Simon Marchi <simon.marchi@efficios.com>
This commit brings all the changes made by running gdb/copyright.py
as per GDB's Start of New Year Procedure.
For the avoidance of doubt, all changes in this commits were
performed by the script.
Since 4d7188abfd ("gdbsupport: add debug assertions in
gdb::optional::get"), some macro-related tests fail on Ubuntu 20.04 with
the system gcc 9.3.0 compiler when building with _GLIBCXX_DEBUG. For
example, gdb.base/info-macros.exp results in:
(gdb) break -qualified main
/home/smarchi/src/binutils-gdb/gdb/../gdbsupport/gdb_optional.h:206: internal-error: T& gdb::optional<T>::get() [with T = long unsigned int]: Assertion `this->has_value ()' failed.
The binary contains DWARF 4 debug info and includes a pre-standard
(pre-DWARF 5) .debug_macro section. The CU doesn't have a
DW_AT_str_offsets_base attribute (which doesn't exist in DWARF 4). The
field dwarf2_cu::str_offsets_base is therefore empty. At
dwarf2/read.c:24138, we unconditionally read the value in the optional,
which triggers the assertion shown above.
The same thing happens when building the test program with DWARF 5 with
the same gcc compiler, as that version of gcc doesn't use indirect
string forms, even with DWARF 5. So it still doesn't add a
DW_AT_str_offsets_base attribute on the CU.
Fix that by propagating down a gdb::optional<ULONGEST> for the str
offsets base instead of ULONGEST. That value is only used in
dwarf_decode_macro_bytes, when encountering an "strx" macro operation
(DW_MACRO_define_strx or DW_MACRO_undef_strx). Add a check there that
we indeed have a value in the optional before reading it. This is
unlikely to happen, but could happen in theory with an erroneous file
that uses DW_MACRO_define_strx but does not provide a
DW_AT_str_offsets_base (in practice, some things would probably have
failed before and stopped processing of debug info). I tested the
complaint by inverting the condition and using a clang-compiled binary,
which uses the strx operators. This is the result:
During symbol reading: use of DW_MACRO_define_strx with unknown string offsets base [in module /home/simark/build/binutils-gdb/gdb/testsuite/outputs/gdb.base/info-macros/info-macros]
The test now passes cleanly with the setup mentioned above, and the
testsuite looks on par with how it was before 4d7188abfd.
Change-Id: I7ebd2724beb7b9b4178872374c2a177aea696e77
This commits the result of running gdb/copyright.py as per our Start
of New Year procedure...
gdb/ChangeLog
Update copyright year range in copyright header of all GDB files.
GDB complaints "During symbol reading: unrecognized DW_MACFINO
opcode 0xb" with the testcase given below. Clang is emitting
DW_MACRO_define_strx and DW_MACRO_undef_strx entries in .debug_macro
section which are not supported in GDB. This patch handles them.
DW_MACRO_define_strx and DW_MACRO_undef_strx are added in DWARFv5.
They have two operands. The first operand encodes the line number of
the #define or #undef macro directive. The second operand identifies
a string; it is represented using an unsigned LEB128 encoded value,
which is interpreted as a zero-based index into an array of offsets
in the .debug_str_offsets section. This is as per the section 6.3.2.1
of Dwarf Debugging Information Format Version 5.
Test case used:
#define MAX_SIZE 10
int main(void)
{
int size = 0;
size = size + MAX_SIZE;
printf("\n The value of size is [%d]\n",size);
return 0;
}
clang -gdwarf-5 -fdebug-macro macro.c -o macro.out
Before the patch:
gdb/new_gdb/binutils-gdb/build/bin/gdb -q macro.out -ex "set complaints 1" -ex "start"
Reading symbols from macro.out...
During symbol reading: unrecognized DW_MACFINO opcode 0xb
Temporary breakpoint 1 at 0x4004df: file macro.c, line 7.
Starting program: /home/nitika/workspace/macro.out
Temporary breakpoint 1, main () at macro.c:7
7 int size = 0;
(gdb)
Tested by running the testsuite before and after the patch with
-gdwarf-5 and there is no increase in the number of test cases
that fails. Used clang 11.0.0.
gdb/ChangeLog:
* dwarf2/macro.c (dwarf_decode_macro_bytes): Handle DW_MACRO_define_strx
and DW_MACRO_undef_strx.
(dwarf_decode_macros): Likewise
* dwarf2/read.c (dwarf_decode_macros): Pass str_offsets_base in the parameters
which is the value of DW_AT_str_offsets_base.
* dwarf2/macro.h (dwarf_decode_macros): Modify the definition to include
str_offsets_base.
While doing the psymtab-sharing patchset, I avoided renaming variables
unnecessarily to avoid adding noise to patches, but I'd like to do it
now. Basically, we have these dwarf2 per-something structures:
- dwarf2_per_objfile
- dwarf2_per_bfd
- dwarf2_per_cu_data
I named the instances of dwarf2_per_bfd `per_bfd` and most of instances
of dwarf2_per_cu_data are called `per_cu`. Most pre-existing instances
of dwarf2_per_objfile are named `dwarf2_per_objfile`. For consistency
with the other type, I'd like to rename them to just `per_objfile`. The
`dwarf2_` prefix is superfluous, since it's already clear we are in
dwarf2 code. It also helps reducing the line wrapping by saving 7
precious columns.
gdb/ChangeLog:
* dwarf2/comp-unit.c, dwarf2/comp-unit.h, dwarf2/index-cache.c,
dwarf2/index-cache.h, dwarf2/index-write.c,
dwarf2/index-write.h, dwarf2/line-header.c,
dwarf2/line-header.h, dwarf2/macro.c, dwarf2/macro.h,
dwarf2/read.c, dwarf2/read.h: Rename struct dwarf2_per_objfile
variables and fields from `dwarf2_per_objfile` to just
`per_objfile` throughout.
Change-Id: I3c45cdcc561265e90df82cbd36b4b4ef2fa73aef
This changes the DWARF macro reader to use a const dwarf2_section_info.
gdb/ChangeLog
2020-03-26 Tom Tromey <tom@tromey.com>
* dwarf2/macro.h (dwarf_decode_macros): Make section parameter
const.
* dwarf2/macro.c (skip_form_bytes, skip_unknown_opcode)
(dwarf_decode_macro_bytes, dwarf_decode_macros): Make section
parameter const.
This moves some more code out of dwarf2/read.c, introducing new files
dwarf2/macro.c and dwarf2/macro.h.
gdb/ChangeLog
2020-03-26 Tom Tromey <tom@tromey.com>
* dwarf2/read.c (dwarf2_macro_malformed_definition_complaint)
(macro_start_file, consume_improper_spaces)
(parse_macro_definition, skip_form_bytes, skip_unknown_opcode)
(dwarf_parse_macro_header, dwarf_decode_macro_bytes)
(dwarf_decode_macros): Move to macro.c.
* dwarf2/macro.c: New file.
* dwarf2/macro.h: New file.
* Makefile.in (COMMON_SFILES): Add dwarf2/macro.c.
