Fix PR gas/33175 sframe: --gsframe=no does not disable when .cfi_sections directive with .sframe
--gsframe=no should also disable generation of SFrame section when explicit CFI directive: .cfi_sections .sframe is specified in the input.
This means we need to track whether SFrame generation was explicitly disabled by the user.
Introduce a new enum to facilitate disambiguation between GEN_SFRAME_DEFAULT_NONE and GEN_SFRAME_DISABLED.
While fixing the bug by adding the enum, keep the upcoming requirement in mind: we will also need to disambiguate between --enable-default-sframe and user-specified --gsframe/--gsframe=yes.
The intent is to not display SFrame related warnings or errors like: as_bad (_(".sframe not supported for target")); for unsupported targets if --enable-default-sframe is in effect.
This implies we need to have a four state enum ( GEN_SFRAME_DEFAULT_NONE, GEN_SFRAME_CONFIG_ENABLED, GEN_SFRAME_DISABLED, GEN_SFRAME_ENABLED) gas
I omitted documentation in 8aad677a12 in
error. Rectify that with:
1) changing ---help to mention bare `--gsframe` too, as we're not
getting rid of that;
2) adding the new --gsframe=[no|yes] form to as.texi.
PR gas/33125
* gas/as.c (parse_args): Tweak --gsframe= help text.
* gas/doc/as.texi: Document --gsframe=[no|yes].
(cherry picked from commit 50c1c57426)
Being able to explicitly disable SFrames on the command line is useful,
especially when looking at a gas that enables SFrames by default. The
binutils testsuite will benefit from this as there's testcases that don't
expect their presence.
In summary:
* Nothing is passed => no SFrames (no change from before)
* --gsframe is passed => SFrames (no change from before)
* --gsframe=yes is passed => SFrames (previously rejected)
* --gsframe-no is passed => no SFrames (previously rejected)
PR gas/33125
* gas/as.c (parse_args): Accept --gsframe=no, --gsframe=yes.
(cherry picked from commit 8aad677a12)
This removes many unnecessary NULL casts. I'm also adding a few arg
casts in concat calls, to make the code consistent. Advice from quite
a few years ago was that it's better to use the exact type for args
corresponding to function ellipses, in case NULL is defined as plain
0. (I think that happened with some early 64-bit systems. Plain NULL
ought to be OK nowadays.)
It has been more than once that I would have wanted to have a way to
know the gas version in assembly sources, perhaps for use with .if. Add
such a pre-defined symbol, introducing the common pattern GAS(<symbol>)
for any such symbols. The use of parentheses is to keep the risk of
collisions with users' symbols as low as possible. (Possible future
arch-specific symbols may want to use GAS(<arch>:<symbol>).)
Similarly permit determining whether the assembler is a released
version. The exact value probably isn't of much use, it's more the
defined-ness that one might care about. Yet the symbol needs to have
some value anyway.
While by default pre-defined symbols won't be emitted to the symbol
table, introduce -emit-local-absolute to allow requesting this. Re-
purpose flag_strip_local_absolute to become tristate, with a negative
value indicating to also emit pre-defined symbols.
Presumably since no target enables this and there's also no configure
control, builds with NO_LISTING defined didn't really work anymore.
Convert fallback functions to macros and add #ifndef in a few places.
(Behavior is different for affected command line options vs directives:
The former are rejected as unrecognized, while the latter are silently
ignored. I think that's fair enough.)
gas currently emits informational messages for context information along warnings.
In the context of system register tests in AArch64 backend, these messages
pollute the tests when checking for error message patterns in stderr output.
This patch aims at providing two new flags while preserving the existing
behavior if none of the options is provided.
* --info, similar to the existing --warn flag to enable diagnostic
informational messages (default behavior).
* --no-info, similar to the existing --no-warn flag to disable diagnostic
informational messages.
It also adds the flags to the existing documentation, and command manual.
In commit f592407e4d I deleted gas' obj_sec_set_private_data, and
instead put the gas modification of bfd's *ABS* and *UND* sections in
bfd_make_section_old_way. More recently in commit 8b5a212495 I made
tekhex symbol creation use bfd_make_section_old_way for symbol
sections. After that we saw numerous non-repeatable oss-fuzz reports
of accesses to freed memory involving relocation symbols. I think
what is happening is:
A tekhex testcase with an absolute symbol is run through the tool,
modifying bfd_abs_section.symbol to point to a symbol on the bfd's
objalloc memory. On closing that bfd bfd_abs_section.symbol points to
freed memory.
A second testcase is run through the tool with some access to the
*ABS* symbol. This triggers the invalid memory access.
The same thing could happen if a user runs objdump or nm with two
files on the command line, the first being a tekhex file with absolute
symbols, or if ld is given tekhex input among other files. Clearly,
it's a bad idea to modify the *ABS* or *UND* sections for input files.
bfd/
* section.c (bfd_make_section_old_way): Don't call
_new_section_hook for standard abs, com, und and ind sections.
gas/
* as.c (bfd_std_section_init): New function.
(perform_an_assembly_pass): Move section initialisation to..
(gas_init): ..here. Use bfd_std_section_init.
First of all make the declarations globally visible, such that producer
and consumer actually share them.
For the latter two simply add const (as PPC already had it,), while for
the former achieve the effect by converting to an array: There's no need
for the extra level of indirection.
The individual struct emulation instances shouldn't be declared in a .c
file; it and the producers of the symbols want to both see the
declarations, so declarations and definitions don't go out of sync. Move
these declarations to emul.h.
While there also adjust the conditional around this_format: That symbol
is never #define-d anywhere, and it's needed only when USE_EMULATIONS is
defined. (Really, when obj-multi isn't in use, it also is effectively
only ever written to.)
The only time 'v' was overridden, allowing for an optional value, was
when OBJ_VMS support still existed (until a little less than 20 years
ago). Drop the respective leftovers.
With that OPTION_VERBOSE also becomes redundant and hence is being
dropped.
Printing optc with %c makes sense only when optc is actually a
character. Add logic to also deal with unrecognized long options,
rejected by md_parse_option() rather than get_opt_long_only(). Also
quote the reproduced strings, such that possible included whitespace
can be recognized.
- help message: add a comma between the short and long option
- as doc:
- brief summary of how to invoke gas: separate [-w] [-x] on a new line as those
two options have nothing to do with the warning options.
- reordering of the warning options to have the same order as the listing.
- no-warn option description: change an "and" to a "or", as it is either the short
or long option to use, but not both at the same time.
- remove trailing whitespaces.
This patch adds support in GAS to create generic GAS instructions
(a.k.a., the ginsn) for the x86 backend (AMD64 ABI only at this time).
Using this ginsn infrastructure, GAS can then synthesize CFI for
hand-written asm for x86_64.
A ginsn is a target-independent representation of the machine
instructions. One machine instruction may need one or more ginsn.
This patch also adds skeleton support for printing ginsn in the listing
output for debugging purposes.
Since the current use-case of ginsn is to synthesize CFI, the x86 target
needs to generate ginsns necessary for the following machine
instructions only:
- All change of flow instructions, including all conditional and
unconditional branches, call and return from functions.
- All register saves and unsaves to the stack.
- All instructions affecting the two registers that could potentially
be used as the base register for CFA tracking. For SCFI, the base
register for CFA tracking is limited to REG_SP and REG_FP only for
now.
The representation of ginsn is kept simple:
- GAS instruction has GINSN_NUM_SRC_OPNDS (defined to be 2 at this time)
number of source operands and one destination operand at this time.
- GAS instruction uses DWARF register numbers in its representation and
does not track register size.
- GAS instructions carry location information (file name and line
number).
- GAS instructions are ID's with a natural number in order of their
addtion to the list. This can be used as a proxy for the static
program order of the corresponding machine instructions.
Note that, GAS instruction (ginsn) format does not support
GINSN_TYPE_PUSH and GINSN_TYPE_POP. Some architectures, like aarch64,
do not have push and pop instructions, but rather STP/LDP/STR/LDR etc.
instructions. Further these instructions have a variety of addressing
modes, like offset, pre-indexing and post-indexing etc. Among other
things, one of differences in these addressing modes is _when_ the addr
register is updated with the result of the address calculation: before
or after the memory operation. To best support such needs, the generic
instructions like GINSN_TYPE_LOAD, GINSN_TYPE_STORE together with
GINSN_TYPE_ADD, and GINSN_TYPE_SUB may be used.
The functionality provided in ginsn.c and scfi.c is compiled in when a
target defines TARGET_USE_SCFI and TARGET_USE_GINSN. This can be
revisited later when there are other use-cases of creating ginsn's in
GAS, apart from the current use-case of synthesizing CFI for
hand-written asm.
Support is added only for System V AMD64 ABI for ELF at this time. If
the user enables SCFI with --32, GAS issues an error:
"Fatal error: SCFI is not supported for this ABI"
For synthesizing (DWARF) CFI, the SCFI machinery requires the programmer
to adhere to some pre-requisites for their asm:
- Hand-written asm block must begin with a .type foo, @function
It is highly recommended to, additionally, also ensure that:
- Hand-written asm block ends with a .size foo, .-foo
The SCFI machinery encodes some rules which align with the standard
calling convention specified by the ABI. Apart from the rules, the SCFI
machinery employs some heuristics. For example:
- The base register for CFA tracking may be either REG_SP or REG_FP.
- If the base register for CFA tracking is REG_SP, the precise amount of
stack usage (and hence, the value of REG_SP) must be known at all times.
- If using dynamic stack allocation, the function must switch to
FP-based CFA. This means using instructions like the following (in
AMD64) in prologue:
pushq %rbp
movq %rsp, %rbp
and analogous instructions in epilogue.
- Save and Restore of callee-saved registers must be symmetrical.
However, the SCFI machinery at this time only warns if any such
asymmetry is seen.
These heuristics/rules are architecture-independent and are meant to
employed for all architectures/ABIs using SCFI in the future.
gas/
* Makefile.am: Add new files.
* Makefile.in: Regenerated.
* as.c (defined): Handle documentation and listing option for
ginsns and SCFI.
* config/obj-elf.c (obj_elf_size): Invoke ginsn_data_end.
(obj_elf_type): Invoke ginsn_data_begin.
* config/tc-i386.c (x86_scfi_callee_saved_p): New function.
(ginsn_prefix_66H_p): Likewise.
(ginsn_dw2_regnum): Likewise.
(x86_ginsn_addsub_reg_mem): Likewise.
(x86_ginsn_addsub_mem_reg): Likewise.
(x86_ginsn_alu_imm): Likewise.
(x86_ginsn_move): Likewise.
(x86_ginsn_lea): Likewise.
(x86_ginsn_jump): Likewise.
(x86_ginsn_jump_cond): Likewise.
(x86_ginsn_enter): Likewise.
(x86_ginsn_safe_to_skip): Likewise.
(x86_ginsn_unhandled): Likewise.
(x86_ginsn_new): New functionality to generate ginsns.
(md_assemble): Invoke x86_ginsn_new.
(s_insn): Likewise.
(i386_target_format): Add hard error for usage of SCFI with non AMD64 ABIs.
* config/tc-i386.h (TARGET_USE_GINSN): New definition.
(TARGET_USE_SCFI): Likewise.
(SCFI_MAX_REG_ID): Likewise.
(REG_FP): Likewise.
(REG_SP): Likewise.
(SCFI_INIT_CFA_OFFSET): Likewise.
(SCFI_CALLEE_SAVED_REG_P): Likewise.
(x86_scfi_callee_saved_p): Likewise.
* gas/listing.h (LISTING_GINSN_SCFI): New define for ginsn and
SCFI.
* gas/read.c (read_a_source_file): Close SCFI processing at end
of file read.
* gas/scfidw2gen.c (scfi_process_cfi_label): Add implementation.
(scfi_process_cfi_signal_frame): Likewise.
* subsegs.h (struct frch_ginsn_data): New forward declaration.
(struct frchain): New member for ginsn data.
* gas/subsegs.c (subseg_set_rest): Initialize the new member.
* symbols.c (colon): Invoke ginsn_frob_label to convey
user-defined labels to ginsn infrastructure.
* ginsn.c: New file.
* ginsn.h: New file.
* scfi.c: New file.
* scfi.h: New file.
When the command line option --scfi=experimenta is passed to the GNU
assembler, it will synthesize DWARF call frame information (CFI) for the
input assembly.
The option --scfi=experimental will also ignore most of the existing
.cfi_* directives, if already contained in the provided input file.
Only the following CFI directives will not be ignored:
- .cfi_sections,
- .cfi_label,
- .cfi_signal_frame
To use SCFI, a target will need to:
- define TARGET_USE_SCFI and TARGET_USE_GINSN, and other necessary
definitions,
- provide means to help GAS understand the target specific instruction
semantics by creating ginsns.
The upcoming support for SCFI is inteded to be experimental, hence the
option --scfi=experimental. The --scfi= may see more options like
--scfi=[all,none] added in future, once the SCFI support in GAS is
mature and robust. The offering may also see for example, an
--scfi=inline option for dealing with inline asm may be added in the
future. In --scfi=inline option, the GNU assembler may consume (and not
ignore) the compiler generated CFI for the code surrounding the inline
asm.
Also document the option.
gas/
* as.c (show_usage): Add support for --scfi=experimental.
(parse_args): Likewise.
* as.h (enum synth_cfi_type): Define new type.
* doc/as.texi: Document the new option.
Adds two new external authors to etc/update-copyright.py to cover
bfd/ax_tls.m4, and adds gprofng to dirs handled automatically, then
updates copyright messages as follows:
1) Update cgen/utils.scm emitted copyrights.
2) Run "etc/update-copyright.py --this-year" with an extra external
author I haven't committed, 'Kalray SA.', to cover gas testsuite
files (which should have their copyright message removed).
3) Build with --enable-maintainer-mode --enable-cgen-maint=yes.
4) Check out */po/*.pot which we don't update frequently.
Yet again with the removal of gasp about 20 years ago this extra level
of indirection isn't necessary anymore either. Drop macro.c's local
variable and make as.c's global.
While doing the conversion, switch the variable to "bool".
Again with the removal of gasp about 20 years ago the extra level of
indirection isn't necessary anymore. Drop macro.c's local variable and
use the global flag directly.
This removes a leftover from i960 support; with that nothing is left
which would set macro_strip_at to non-zero, so the variable is converted
to a #define (retaining the logic in case a new user would appear) and
macro_init()'s respective parameter is dropped.
With the removal of gasp (about 20 years ago) the need for this kind-
of-hook has disappeared. Go a step beyond merely moving the to be called
function: Inline its contents right at the sole call site.
This fixes a bug in .include and .incbin where given an absolute path
the -I dirs would be searched for the path.
* read.c (include_dir_count, include_dir_maxlen): Make them size_t.
(search_and_open): New function.
(s_incbin, s_include): Use search_and_open.
(init_include_dir): New function.
(add_include_dir): Don't set initial "." dir here.
* read.h (include_dir_count, include_dir_maxlen): Update.
(init_include_dir, search_and_open): Declare.
* as.c (gas_early_init): Call init_include_dir.
* config/tc-rx.c (rx_include): Avoid warning by using size_t.
* config/tc-tic54x.c (tic54x_set_default_include): Simplify and
use notes for include path.
(tic54x_mlib): Use search_and_open.
Fix another case of oss-fuzz tripping over gas static state,
ie. starting over testing another input file with rubbish left
uncleared in bss. size_end_sym pointed at garbage.
* ehopt.c (get_cie_info): Delete forward declaration.
(struct frame_data): Move to file scope.
(frame): New static, packaged..
(check_eh_frame): ..eh_frame_data and debug_frame_data.
(eh_begin): New function.
* as.c (gas_init): Call eh_begin.
* as.h (eh_begin): Declare.
While commit b0c295e1b8 ("add --enable-default-compressed-debug-
sections-algorithm configure option") adjusted flag_compress_debug's
initializer, it didn't alter the default used when the command line
option was specified with an (optional!) argument. This rendered help
text inconsistent with actual behavior in certain configurations.
As to help text - the default reported there clearly shouldn't be
affected by a possible earlier --compress-debug-sections= option, so
flag_compress_debug can't be used when emitting usage information.
I don't see much point in cluttering the source with the PROGRESS
macros, which of course do nothing at all with the definitions in
progress.h. progress.h is unchanged apart from the copyright comment
since commit d4d4c53c68 in 1994.
binutils/
* ar.c: Don't include progress.h, or invoke PROGRESS macros.
* nm.c: Likewise.
* objcopy.c: Likewise.
* objdump.c: Likewise.
gas/
* as.h: Don't include progress.h.
* as.c: Don't invoke PROGRESS macros.
* write.c: Likewise.
include/
* progress.h: Delete.
ld/
* ldmain.c: Don't include progress.h, or invoke PROGRESS macros.
Rename gas_late_init to plain gas_init, to reinforce the idea that
this is where the bulk of gas initialisation belongs. Also reorder
some initialisation.
* as.c (gas_init): Rename from gas_late_init. Open output
file and arrange for dump_statistics to be called here rather
than in main. Create .gasversion. local symbol earlier,
because we can.
The newer update-copyright.py fixes file encoding too, removing cr/lf
on binutils/bfdtest2.c and ld/testsuite/ld-cygwin/exe-export.exp, and
embedded cr in binutils/testsuite/binutils-all/ar.exp string match.
When --gsframe is specified, the assembler will generate a .sframe
section from the CFI directives in the assembly.
ChangeLog:
* gas/as.c (parse_args): Parse args and set flag_gen_sframe.
* gas/as.h: Introduce skeleton for --gsframe.
* gas/doc/as.texi: document --gsframe.
bfd/ChangeLog:
* bfd-in.h (bfd_hash_set_default_size): Add COMPRESS_UNKNOWN
enum value.
(struct compressed_type_tuple): New.
* bfd-in2.h (bfd_hash_set_default_size): Regenerate.
(struct compressed_type_tuple): Likewise.
* libbfd.c (ARRAY_SIZE): New macro.
(bfd_get_compression_algorithm): New function.
(bfd_get_compression_algorithm_name): Likewise.
gas/ChangeLog:
* as.c: Do not special-case, use the new functions.
ld/ChangeLog:
* emultempl/elf.em: Do not special-case, use the new functions.
* lexsup.c (elf_static_list_options): Likewise.
PR29397 PR29563: Add new configure option --with-zstd which defaults to
auto. If pkgconfig/libzstd.pc is found, define HAVE_ZSTD and support
zstd compressed debug sections for most tools.
* bfd: for addr2line, objdump --dwarf, gdb, etc
* gas: support --compress-debug-sections=zstd
* ld: support ELFCOMPRESS_ZSTD input and --compress-debug-sections=zstd
* objcopy: support ELFCOMPRESS_ZSTD input for
--decompress-debug-sections and --compress-debug-sections=zstd
* gdb: support ELFCOMPRESS_ZSTD input. The bfd change references zstd
symbols, so gdb has to link against -lzstd in this patch.
If zstd is not supported, ELFCOMPRESS_ZSTD input triggers an error. We
can avoid HAVE_ZSTD if binutils-gdb imports zstd/ like zlib/, but this
is too heavyweight, so don't do it for now.
```
% ld/ld-new a.o
ld/ld-new: a.o: section .debug_abbrev is compressed with zstd, but BFD is not built with zstd support
...
% ld/ld-new a.o --compress-debug-sections=zstd
ld/ld-new: --compress-debug-sections=zstd: ld is not built with zstd support
% binutils/objcopy --compress-debug-sections=zstd a.o b.o
binutils/objcopy: --compress-debug-sections=zstd: binutils is not built with zstd support
% binutils/objcopy b.o --decompress-debug-sections
binutils/objcopy: zstd.o: section .debug_abbrev is compressed with zstd, but BFD is not built with zstd support
...
```
Currently md_end is typically used for some final actions rather than
freeing memory like other *_end functions. Rename it to md_finish,
and rename target implementation. The renaming of target functions
makes it possible to find them all with "grep md_finish",
eg. md_mips_end is renamed to mips_md_finish, not md_mips_finish.
This patch leaves a number of md_end functions unchanged, those that
either do nothing or deallocate memory, and calls them late.
The idea here is that target maintainers implement md_end functions to
tidy memory, if anyone cares. Freeing persistent memory in gas is
not at all important, except that it can hide more important memory
leaks, those that happen once per some frequent gas operation, amongst
these unimportant memory leaks.
* as.c (main): Rename md_end to md_finish.
* config/tc-alpha.c, * config/tc-alpha.h,
* config/tc-arc.c, * config/tc-arc.h,
* config/tc-arm.c, * config/tc-arm.h,
* config/tc-csky.c, * config/tc-csky.h,
* config/tc-ia64.c, * config/tc-ia64.h,
* config/tc-mcore.c, * config/tc-mcore.h,
* config/tc-mips.c, * config/tc-mips.h,
* config/tc-mmix.c, * config/tc-mmix.h,
* config/tc-msp430.c, * config/tc-msp430.h,
* config/tc-nds32.c, * config/tc-nds32.h,
* config/tc-ppc.c, * config/tc-ppc.h,
* config/tc-pru.c, * config/tc-pru.h,
* config/tc-riscv.c, * config/tc-riscv.h,
* config/tc-s390.c, * config/tc-s390.h,
* config/tc-sparc.c, * config/tc-sparc.h,
* config/tc-tic4x.c, * config/tc-tic4x.h,
* config/tc-tic6x.c, * config/tc-tic6x.h,
* config/tc-v850.c, * config/tc-v850.h,
* config/tc-xtensa.c, * config/tc-xtensa.h,
* config/tc-z80.c, * config/tc-z80.h: Similarly.
* output-file.c (output_file_close): Call md_end.
So that the notes obstack can be used for persistent storage in
parse_args.
* as.c (parse_args): Use notes_alloc and notes_strdup.
(free_notes): New function.
(main): Init notes obstack, and arrange to be freed on exit.
* read.c (read_begin): Don't init notes obstack.
(read_end): Free cond_obstack.
* subsegs.c (subsegs_end): Don't free cond_obstack or notes.
itbl_files seems to be debug code. Get rid of it.
* as.c (struct itbl_file_list): Delete.
(itbl_files): Delete.
(parse_args): Don't keep itbl_files list.
This is mostly a tidy with the aim of being able to free
out_file_name, but it does fix a possible attempt to unlink the output
file twice (not that that matters).
* as.h (keep_it): New global.
* as.c (keep_it): Delete.
(close_output_file): Delete, merged into..
* output-file.c (output_file_close): ..here. Delete parameter.
* output-file.h (output_file_close): Update prototype.
The result of running etc/update-copyright.py --this-year, fixing all
the files whose mode is changed by the script, plus a build with
--enable-maintainer-mode --enable-cgen-maint=yes, then checking
out */po/*.pot which we don't update frequently.
The copy of cgen was with commit d1dd5fcc38ead reverted as that commit
breaks building of bfp opcodes files.
* as.c (parse_args): Add support for --multibyte-handling.
* as.h (multibyte_handling): Declare.
* app.c (scan_for_multibyte_characters): New function.
(do_scrub_chars): Call the new function if multibyte warning is
enabled.
* input-scrub,c (input_scrub_next_buffer): Call the multibyte
scanning function if multibyte warnings are enabled.
* symbols.c (struct symbol_flags): Add multibyte_warned bit.
(symbol_init): Call the multibyte scanning function if multibyte
symbol warnings are enabled.
(S_SET_SEGMENT): Likewise.
* NEWS: Mention the new feature.
* doc/as.texi: Document the new feature.
* testsuite/gas/all/multibyte.s: New test source file.
* testsuite/gas/all/multibyte1.d: New test driver file.
* testsuite/gas/all/multibyte1.l: New test expected output.
* testsuite/gas/all/multibyte2.d: New test driver file.
* testsuite/gas/all/multibyte2.l: New test expected output.
* testsuite/gas/all/gas.exp: Run the new tests.
