The flag controlling the default DWARF CIE version to produce now
starts with the value -1. This can be modified with the command line
flag as before, but after command line flag processing, in
md_after_parse_args targets can, if the global still has the value -1,
override this value. This gives a target specific default.
If a CIE version is not select either by command line flag, or a
target specific default, then some new code in dwarf2_init now select
a global default. This remains as version 1 to match previous
behaviour.
This RISC-V has a target specific default of version provided, this
make the return column uleb128, which means we can use all DWARF
registers include CSRs.
I chose to switch to version 3 rather than version 4 as this is most
similar to the global default (version 1). Switching to version 4
adds additional columns to the CIE header.
gas/ChangeLog:
* as.c (flag_dwarf_cie_version): Change initial value to -1, and
update comment.
* config/tc-riscv.c (riscv_after_parse_args): Set
flag_dwarf_cie_version if it has not already been set.
* dwarf2dbg.c (dwarf2_init): Initialise flag_dwarf_cie_version if
needed.
* testsuite/gas/riscv/default-cie-version.d: New file.
* testsuite/gas/riscv/default-cie-version.s: New file.
ld/ChangeLog:
* testsuite/ld-elf/eh5.d: Accept version 3 DWARF CIE.
Change-Id: Ibbfe8f0979fba480bf0a359978b09d2b3055555e
All symbols, sizes and relocations in this section are octets instead of
bytes. Required for DWARF debug sections as DWARF information is
organized in octets, not bytes.
bfd/
* section.c (struct bfd_section): New flag SEC_ELF_OCTETS.
* archures.c (bfd_octets_per_byte): New parameter sec.
If section is not NULL and SEC_ELF_OCTETS is set, one octet es
returned [ELF targets only].
* bfd.c (bfd_get_section_limit): Provide section parameter to
bfd_octets_per_byte.
* bfd-in2.h: regenerate.
* binary.c (binary_set_section_contents): Move call to
bfd_octets_per_byte into section loop. Provide section parameter
to bfd_octets_per_byte.
* coff-arm.c (coff_arm_reloc): Provide section parameter
to bfd_octets_per_byte.
* coff-i386.c (coff_i386_reloc): likewise.
* coff-mips.c (mips_reflo_reloc): likewise.
* coff-x86_64.c (coff_amd64_reloc): likewise.
* cofflink.c (_bfd_coff_link_input_bfd): likewise.
(_bfd_coff_reloc_link_order): likewise.
* elf.c (_bfd_elf_section_offset): likewise.
(_bfd_elf_make_section_from_shdr): likewise.
Set SEC_ELF_OCTETS for sections with names .gnu.build.attributes,
.debug*, .zdebug* and .note.gnu*.
* elf32-msp430.c (rl78_sym_diff_handler): Provide section parameter
to bfd_octets_per_byte.
* elf32-nds.c (nds32_elf_get_relocated_section_contents): likewise.
* elf32-ppc.c (ppc_elf_addr16_ha_reloc): likewise.
* elf32-pru.c (pru_elf32_do_ldi32_relocate): likewise.
* elf32-s12z.c (opru18_reloc): likewise.
* elf32-sh.c (sh_elf_reloc): likewise.
* elf32-spu.c (spu_elf_rel9): likewise.
* elf32-xtensa.c (bfd_elf_xtensa_reloc): likewise
* elf64-ppc.c (ppc64_elf_brtaken_reloc): likewise.
(ppc64_elf_addr16_ha_reloc): likewise.
(ppc64_elf_toc64_reloc): likewise.
* elflink.c (bfd_elf_final_link): likewise.
(bfd_elf_perform_complex_relocation): likewise.
(elf_fixup_link_order): likewise.
(elf_link_input_bfd): likewise.
(elf_link_sort_relocs): likewise.
(elf_reloc_link_order): likewise.
(resolve_section): likewise.
* linker.c (_bfd_generic_reloc_link_order): likewise.
(bfd_generic_define_common_symbol): likewise.
(default_data_link_order): likewise.
(default_indirect_link_order): likewise.
* srec.c (srec_set_section_contents): likewise.
(srec_write_section): likewise.
* syms.c (_bfd_stab_section_find_nearest_line): likewise.
* reloc.c (_bfd_final_link_relocate): likewise.
(bfd_generic_get_relocated_section_contents): likewise.
(bfd_install_relocation): likewise.
For section which have SEC_ELF_OCTETS set, multiply output_base
and output_offset with bfd_octets_per_byte.
(bfd_perform_relocation): likewise.
include/
* coff/ti.h (GET_SCNHDR_SIZE, PUT_SCNHDR_SIZE, GET_SCN_SCNLEN),
(PUT_SCN_SCNLEN): Adjust bfd_octets_per_byte calls.
binutils/
* objdump.c (disassemble_data): Provide section parameter to
bfd_octets_per_byte.
(dump_section): likewise
(dump_section_header): likewise. Show SEC_ELF_OCTETS flag if set.
gas/
* as.h: Define SEC_OCTETS as SEC_ELF_OCTETS if OBJ_ELF.
* dwarf2dbg.c: (dwarf2_finish): Set section flag SEC_OCTETS for
.debug_line, .debug_info, .debug_abbrev, .debug_aranges, .debug_str
and .debug_ranges sections.
* write.c (maybe_generate_build_notes): Set section flag
SEC_OCTETS for .gnu.build.attributes section.
* frags.c (frag_now_fix): Don't divide by OCTETS_PER_BYTE if
SEC_OCTETS is set.
* symbols.c (resolve_symbol_value): Likewise.
ld/
* ldexp.c (fold_name): Provide section parameter to
bfd_octets_per_byte.
* ldlang (init_opb): New argument s. Set opb_shift to 0 if
SEC_ELF_OCTETS for the current section is set.
(print_input_section): Pass current section to init_opb.
(print_data_statement,print_reloc_statement,
print_padding_statement): Likewise.
(lang_check_section_addresses): Call init_opb for each
section.
(lang_size_sections_1,lang_size_sections_1,
lang_do_assignments_1): Likewise.
(lang_process): Pass NULL to init_opb.
This adds another test for file numbers given in .file directives,
checking that the value can be represented as an unsigned int and that
a memory allocation expression doesn't overflow. I removed a test
added recently since an earlier test (num < 1) already covers the
(num < 0) case.
* dwarf2dbg.c: Whitespace fixes.
(get_filenum): Don't strdup "file". Adjust error message.
(dwarf2_directive_filename): Use an unsigned type for "num".
Catch truncation of file number and overflow of get_filenum
XRESIZEVEC multiplication. Delete dead code.
PR 24538
gas * macro.c (get_any_string): Increase size of buffer used to hold
decimal value of expression result.
* dw2gencfi.c (get_debugseg_name): Handle an empty name.
* dwarf2dbg.c (get_filenum): Catch integer wraparound when
extending allocate file array.
(dwarf2_directive_filename): Add extra checks of the computed file
number.
* config/tc-arm.c (arm_tc_equal_in_insn): Insert copy of name into
warning hash table.
(s_arm_eabi_attribute): Check for obj_elf_vendor_attribute
returning -1.
* config/tc-i386.c (i386_output_nops): Catch an attempt to
generate nops of negative lengths.
* as.h (MAX_LITTLENUMS): Move definition to here from...
* config/atof-ieee.c: ...here.
* config/tc-aarch64.c: ...here.
* config/tc-arc.c: ...here.
* config/tc-arm.c: ...here.
* config/tc-epiphany.c: ...here.
* config/tc-i386.c: ...here.
* config/tc-ia64.c: ...here. (And correct the value).
* config/tc-m32c.c: ...here.
* config/tc-m32r.c: ...here.
* config/tc-metag.c: ...here.
* config/tc-microblaze.c: ...here.
* config/tc-nds32.c: ...here.
* config/tc-or1k.c: ...here.
* config/tc-score.c: ...here.
* config/tc-score7.c: ...here.
* config/tc-tic4x.c: ...here.
* config/tc-tilegx.c: ...here.
* config/tc-tilepro.c: ...here.
* config/tc-visium.c: ...here.
* config/tc-sh.c (md_assemble): Add check for an instruction with
no opcodes.
* config/tc-mips.c (mips_lookup_insn): Add check for very short
instruction name.
* config/tc-tic54x.c: Use unsigned chars to access is_end_of_line
array.
(tic54x_start_line_hook): Check for an empty line.
(next_line_shows_parallel): Do not walk off the end of the string.
(tic54x_macro_start): Check for too much macro nesting.
(tic54x_start_label): Add label_start parameter. Use this
parameter to check the first character of the label.
* config/tc-tic54x.h (TC_START_LABEL_WITHOUT_COLON): Pass
line_start variable to tic54x_start_label.
PR 24538
opcodes * ia64-opc.c (ia64_find_matching_opcode): Check for reaching the
end of the table prematurely.
Location views at borders between subsegments/subsections in the same
segment/section are computed as if each new subsegment/subsection
started with a forced view reset to zero, but the line number program
does not introduce resets that are not explicitly requested, so if a
subsegment ends at the same address another starts, the line number
program will have a continuity of views at the border address, whereas
the initial view number label in the latter subsegment will be
miscomputed as zero.
This patch delays the assignment of view expressions at subsegment
heads to the time of chaining the frags of subsegments into a single
segment, so that they are set based on the view at the end of the
previous subsegment in the same segment.
The line number program created for the test program had an
unnecessary DW_LNS_advance_pc at the end. This patch also arranges
for us not to emit it.
for gas/ChangeLog
* dwarf2dbg.c (set_or_check_view): Skip heads when assigning
views of prior locs.
(dwarf2_gen_line_info_1): Skip heads.
(size_inc_line_addr, emit_inc_line_addr): Drop
DW_LNS_advance_pc for zero addr delta.
(dwarf2_finish): Assign views for heads of segments.
* testsuite/gas/elf/dwarf2-19.d: New.
* testsuite/gas/elf/dwarf2-19.s: New.
* testsuite/gas/elf/elf.exp: Test it.
All relocations specify a byte address. As dwarf debug information is
organized in octets, some relocations may not be aligned. While it
might be possible to define special relocations that operate at an
octet offset from their address, it's easier to ensure the relocations
are aligned by padding with "nop" statements.
In most dwarf sections this requirement is already fulfilled, only
relocations for symbol address within the .debug_line section can be
misaligned.
* dwarf2dbg.c (out_set_addr): Align relocation within .debug_line.
As all dwarf debug information is organized in octets, the size of all
dwarf sections must be aligned to OCTETS_PER_BYTE. Most DWARF sections
meet this requirement, only the .debug_line section can reach an
arbitrary octet size.
In order to align the size to a multiple of OCTETS_PER_BYTE, the section
is padded with "nop" statements at the end.
* dwarf2dbg.c (out_debug_line): Pad size of .debug_line section.
Like other dwarf2 offsets, also the string offsets in the .debug_info
section which points into the .debug_str section must be expressed in
octets instead of bytes.
* dwarf2dbg.c (out_debug_str): Use octets for .debug_string pointers.
Like the u32 size field at the beginning of the section, also the
prologue size must be expressed in octets.
* dwarf2dbg.c (out_debug_line): Use octets for .debug_line prologue.
The content of the dwarf2 sections .debug_line, .debug_aranges and
.debug_info starts with an u32 containing the the size of the remaining
data. According to the dwarf2 specification this value must be expressed
in octets instead of bytes.
* dwarf2dbg.c (out_debug_line): Use octets for dwarf2 headers.
(out_debug_aranges, out_debug_info): Likewise.
The units of the value returned by "frag_now_fix()" and "size" do not
match. "frag_now_fix()" returns bytes (can be 8, 16 or 32 bit), while
"size" is octets (exactly 8 bit).
* dwarf2dbg.c (dwarf2_emit_insn): Fix calculation of line info offset.
What a trip down a rabbit hole this bug has been.
First observation: You can't use deferred_expression in s_leb128.
deferred_expression implements the semantics of .eqv or '==', saving
an expression with minimal simplification for assignment to a symbol
so that the expression is evaluated at uses of the symbol. In
particular, the value of "dot" is not evaluated at the .eqv symbol
assignment, but later. When s_leb128 uses deferred_expression,
"later" is at the end of assembly, giving entirely the wrong value of
"dot". There is no way to fix this for the s_leb128 use without
breaking .equ (which incidentally was already somewhat broken, see
commit e4c2619ad1). So, don't use deferred_expression in s_leb128.
But that leads to the gas test elf/dwarf2-17 failing, because view
symbols are calculated with a chain of expression symbols. In the
dwarf2-17 .L1 case there is a "temp_sym_1 > temp_sym_2" expression,
with temp_sym_1 and temp_sym_2 on either side of a ".balign". Since
".balign" and many other directives moving "dot" are not calculated on
the first (and only) pass over source, .L1 cannot be calculated until
final addresses are assigned to frags. However, ".uleb128 .L1" *is*
calculated immediately, resulting in the wrong value.
The reason why .L1 is calculated immediately is that code in
expr.c:operand after the comment
/* If we have an absolute symbol or a reg, then we know its
value now. */
does as it says and fixes the value of .L1, because .L1 is assigned
to absolute_section in dwarf2dbg.c:set_or_check_view. So, correct
that to expr_section.
Unfortunately that fix leads to failure of the elf/dwarf2-5 test with
../gas/elf/dwarf2-5.s: Error: attempt to get value of unresolved symbol `.L5'
../gas/elf/dwarf2-5.s: Error: attempt to get value of unresolved symbol `.L11'
../gas/elf/dwarf2-5.s: Error: attempt to get value of unresolved symbol `.L12'
So why is that? Well, it turns out that .L5 is defined in terms of
.L4, and apparently .L4 is undefined. But .L4 clearly is defined,
otherwise we would hit an error when trying to use .L4 a little
earlier. There are two copies of .L4! So, symbols are cloned when
that should not happen.
Symbol cloning is a technique used by gas to support saving the value
of symbols that change between uses, but that isn't the case with
.L4. Only one value is set and used for .L4, but indeed .L4 was being
cloned by symbol_clone_if_forward_ref. This despite no forward refs
being present. Also, .L4 is a local symbol and a cursory glance at
symbol_clone_if_forward_ref "if (symbolP && !LOCAL_SYMBOL_CHECK (symbolP))"
would seem to prevent cloning of local symbols. All is not as it
seems though, a curse of using macros. LOCAL_SYMBOL_CHECK modifies
its argument if a "struct local_symbol" is converted to the larger
"struct symbol", as happens when assigning a view symbol value.
That fact results in the recursive call to symbol_clone_if_forward_ref
returning a different address for "add_symbol". This problem could
have been fixed by using symbol_same_p rather than comparing symbol
pointers, but I thought it better to use the real symbol throughout.
Note that symbol_find_exact also returns the real symbol for a
converted local symbol.
Finally, this patch does expose lack of support for forward symbol
definitions in various targets. For example:
alpha-linux +ERROR: ../ld/testsuite/ld-elf/pr11138-2.c: compilation failed
This is caused by view symbol uses. On alpha-linux-gcc (GCC) 8.1.1
20180502 they happen to occur in .byte directives so were silently
broken in cases like elf/dwarf2-17 anyway.
/tmp/ccvtsMfU.s: Assembler messages:
/tmp/ccvtsMfU.s: Fatal error: unhandled relocation type BFD_RELOC_8
/tmp/ccvtsMfU.s: Fatal error: unhandled relocation type BFD_RELOC_8
md_apply_fix on those targets needs to handle fixups that resolve down
to a constant.
PR 23040
* symbols.c (get_real_sym): New function.
(symbol_same_p): Use get_real_sym.
(symbol_clone_if_forward_ref): Save real original add_symbol and
op_symbol for comparison against that returned from lookup or
recursive calls.
* dwarf2dbg.c (set_or_check_view): Use expr_section for
expression symbols, not absolute_section.
(dwarf2_directive_loc): Check symbol_equated_p and tidy cloning
of view symbols.
* read.c (s_leb128): Don't use deferred_expression.
Fix locviews on ia64. If we do not drop the view after copying line
info to slots in the bundle, we may attempt to compute the view more
than once and get very confused.
for gas/ChangeLog
* dwarf2dbg.c (dwarf2_consume_line_info): Drop view.
Trying to build (for mmix-knuth-mmixware but I don't think that
matters) yields the following (repeatable on e.g. CompileFarm gcc20
sporting gcc-4.7.2 as default):
gcc -DHAVE_CONFIG_H -I. -I/home/hp/binutils/src/gas -I. -I/home/hp/binutils/src/gas -I../bfd -I/home/hp/binutils/src/gas/config -I/home/hp/binutils/src/gas/../include -I/home/hp/binutils/src/gas/.. -I/home/hp/binutils/src/gas/../bfd -DLOCALEDIR="\"/usr/local/share/locale\"" -W -Wall -Wstrict-prototypes -Wmissing-prototypes -Wshadow -Werror -Wwrite-strings -I/home/hp/binutils/src/gas/../zlib -g -O2 -MT dwarf2dbg.o -MD -MP -MF .deps/dwarf2dbg.Tpo -c -o dwarf2dbg.o /home/hp/binutils/src/gas/dwarf2dbg.c
cc1: warnings being treated as errors
/home/hp/binutils/src/gas/dwarf2dbg.c: In function 'dwarf2dbg_final_check':
/home/hp/binutils/src/gas/dwarf2dbg.c:2246: error: declaration of 'expr' shadows a global declaration
/home/hp/binutils/src/gas/expr.h:180: error: shadowed declaration is here
make[4]: *** [dwarf2dbg.o] Error 1
IIRC this is a false namespace clash and the warning is not observable
with a new-enough gcc. Committed as obvious.
brgds, H-P
PS. Idea: -Wcompiler; warn about constructs problematic with e.g. old gcc. 1/2 ;-)
Putting the name, comp_dir and producer strings in the .debug_str section
makes it possible to share them across CUs. This saves a small amount of
space (about ~20K on a glibc libc.so.6 build with debuginfo). And makes
it easier for tools like rpm debugedit to adjust the source paths when
generating separate debuginfo files.
gas/
* dwarf2dbg.c (out_debug_abbrev): Use DW_FORM_strp instead of
DW_FORM_string for DW_AT_name, DW_AT_comp_dir and DW_AT_producer.
(out_debug_info): Accept symbols to name, comp_dir and producer
in the .debug_str section and emit those offsets not full strings.
(out_debug_str): New function that outputs the strings for name,
comp_dir and producer in .debug_str and generates symbols to
those strings.
(out_debug_line): Create a .debug_str section if necessary and
call out_debug_str before calling out_debug_info.
* testsuite/gas/aarch64/dwarf.d: Add extra section symbol to
expected output.
out_debug_aranges uses frag_align to make sure the addresses start
out aligned. Using frag_align will call frag_var[_init], which will
end up calling TC_FRAG_INIT. On arm and aarch64 TC_FRAG_INIT will
generate a $d mapping symbol for the .debug_aranges to show that at
that point a sequence of data items starts.
Such a symbol pointing into a non-allocated debug section will confuse
eu-strip -g. And it seems inefficient and wrong in general to have
additional mapping symbols for debug sections, which won't contain
actual code in the first place.
Just keep track of the aranges header size and use plain padding to
align the addresses which avoids generating any mapping symbols on
aarch64 and arm.
Includes a testcase for aarch64 that PASS with this patch and shows
the extra $d mapping symbol in .debug_aranges before.
gas/ChangeLog
* dwarf2dbg.c (out_header): Document EXPR->X_add_number value,
out_debug_aranges depends on it.
(out_debug_aranges): Track size of header to properly pad header
for address alignment.
gas/testsuite/ChangeLog
* gas/aarch64/dwarf.d: New.
* gas/aarch64/dwarf.s: New.
PR 17940
* dwarf2dbg.c (out_header): When generating dwarf sections use
real symbols not temps for the start and end symbols.
* config/tc-msp430.h (TC_FORCE_RELOCATION_SUB_SAME): Also prevent
adjustments to relocations in debug sections.
(TC_LINKRELAX_FIXUP): Likewise.
* elf32-msp430.c (msp430_elf_relax_delete_bytes): Adjust debug
symbols at end of sections. Adjust function sizes.
Hash lookup is silly when we can attach the line table info directly
to sections instead. Worse, hash lookup fails when we have multiple
sections with the same name.
gas/
* dwarf2dbg.c (all_segs_hash): Delete.
(get_line_subseg): Delete last_seg, last_subseg, last_line_subseg.
Retrieve line_seg for section via seg_info.
* subsegs.h (segment_info_typet): Add dwarf2_line_seg.
gas/testsuite/
* gas/elf/group2.d, * gas/elf/group2.s: New test.
* gas/elf/elf.exp: Run it.
Don't be clever, calculate the length directly as the difference of
two symbols.
* dwarf2dbg.c (out_debug_line): Correct .debug_line header_length
field for 64-bit dwarf.
2012-08-01 James Lemke <jwlemke@codesourcery.com>
* gas/dwarf2dbg.c (out_set_addr): Allow for non-constant value of
DWARF2_LINE_MIN_INSN_LENGTH
* gas/config/tc-ppc.c (ppc_dwarf2_line_min_insn_length): Declare
and initialize.
(md_apply_fix): Branch addr can be a multiple of 2 or 4.
* gas/config/tc-ppc.h (DWARF2_LINE_MIN_INSN_LENGTH): Now a
variable reference.
gas/testsuite/ChangeLog:
2012-08-01 James Lemke <jwlemke@codesourcery.com>
* gas/cfi/cfi-ppc-1.d: Allow for code alignment of 2 or 4.
ld/ChangeLog:
2012-08-01 James Lemke <jwlemke@codesourcery.com>
* ld/testsuite/ld-gc/pr13683.d: XFAIL for powerpc*-*-eabivle.
linker relaxation.
(dwarf2_gen_line_info): Generate real, local, labels for line
numbers.
(dwarf2dbg_convert_frag): Do not finalize the computation of the
frag's symbol value when linker relaxation is enabled.
(ADDR_DELTA_LIMIT): Define.
(size_fixed_inc_line_addr): Use ADDR_DELTA_LIMIT.
(emit_fixed_inc_line_addr): Likewise.
* write.c (fixup_segment): If the subtraction of two symbols
cannot be resolved but is valid, then prevent bogus range warnings
by pre-biasing add_number.
* config/tc-h8300.h (DWARF2_USE_FIXED_ADVANCE_PC): Define to 0.
* gas/lns/lns.exp: Use alternate lns-common test for targets
enabling linker relaxation.
* gas/lns/lns-big-delta.d: Allow for output from architectures
with 32-bit addresses.
* dwarf2dbg.c (DWARF2_ARANGES_VERSION): New define to 2.
(DWARF2_LINE_VERSION): Likewise.
(out_debug_line): Use DWARF2_LINE_VERSION not DWARF2_VERSION.
(out_debug_aranges): Use DWARF2_ARANGES_VERSION not DWARF2_VERSION.
(out_debug_abbrev): Use DW_FORM_data for DW_AT_high_pc when
DWARF2_VERSION >= 4.
(out_debug_info): Use difference between start and end as data
value for DW_AT_high_pc when DWARF2_VERSION >= 4.
* config/tc-ia64.h (DWARF2_LINE_VERSION): Override it.
