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.
Implement the '.nop SIZE[, CONTROL]' assembler directive, which emits
SIZE bytes filled with no-op instructions. SIZE is absolute expression.
The optional CONTROL byte controls how no-op instructions should be
generated. If the comma and @var{control} are omitted, CONTROL is
assumed to be zero.
For Intel 80386 and AMD x86-64 targets, CONTROL byte specifies the size
limit of a single no-op instruction. The valid values of CONTROL byte
are between 0 and 8 for 16-bit mode, between 0 and 10 for 32-bit mode,
between 0 and 11 for 64-bit mode. When 0 is used, the no-op size limit
is set to the maximum supported size.
2 new relax states, rs_space_nop and rs_fill_nop, are added to enum
_relax_state, which are similar to rs_space and rs_fill, respectively,
but they fill with no-op instructions, instead of a single byte. A
target backend must override the default md_generate_nops to generate
proper no-op instructions. Otherwise, an error of unimplemented .nop
directive will be issued whenever .nop directive is used.
* NEWS: Mention .nop directive.
* as.h (_relax_state): Add rs_space_nop and rs_fill_nop.
* read.c (potable): Add .nop.
(s_nop): New function.
* read.h (s_nop): New prototype.
* write.c (cvt_frag_to_fill): Handle rs_space_nop and
rs_fill_nop.
(md_generate_nops): New function.
(relax_segment): Likewise.
(write_contents): Use md_generate_nops for rs_fill_nop.
* config/tc-i386.c (alt64_11): New.
(alt64_patt): Likewise.
(md_convert_frag): Handle rs_space_nop.
(i386_output_nops): New function.
(i386_generate_nops): Likewise.
(i386_align_code): Call i386_output_nops.
* config/tc-i386.h (i386_generate_nops): New.
(md_generate_nops): Likewise.
* doc/as.texinfo: Document .nop directive.
* testsuite/gas/i386/i386.exp: Run .nop directive tests.
* testsuite/gas/i386/nop-1.d: New file.
* testsuite/gas/i386/nop-1.s: Likewise.
* testsuite/gas/i386/nop-2.d: Likewise.
* testsuite/gas/i386/nop-2.s: Likewise.
* testsuite/gas/i386/nop-3.d: Likewise.
* testsuite/gas/i386/nop-3.s: Likewise.
* testsuite/gas/i386/nop-4.d: Likewise.
* testsuite/gas/i386/nop-4.s: Likewise.
* testsuite/gas/i386/nop-5.d: Likewise.
* testsuite/gas/i386/nop-5.s: Likewise.
* testsuite/gas/i386/nop-6.d: Likewise.
* testsuite/gas/i386/nop-6.s: Likewise.
* testsuite/gas/i386/nop-bad-1.l: Likewise.
* testsuite/gas/i386/nop-bad-1.s: Likewise.
* testsuite/gas/i386/x86-64-nop-1.d: Likewise.
* testsuite/gas/i386/x86-64-nop-2.d: Likewise.
* testsuite/gas/i386/x86-64-nop-3.d: Likewise.
* testsuite/gas/i386/x86-64-nop-4.d: Likewise.
* testsuite/gas/i386/x86-64-nop-5.d: Likewise.
* testsuite/gas/i386/x86-64-nop-6.d: Likewise.
* as.c: Include write.h.
(common_emul_init): Use FAKE_LABEL_NAME.
* ecoff.c (add_file, ecoff_directive_end, ecoff_directive_loc):
Likewise.
(ecoff_build_symbols): Use FAKE_LABEL_CHAR.
* expr.c (get_symbol_name): Use FAKE_LABEL_CHAR. Accept only if
input_from_string is TRUE.
* read.c (input_from_string): New.
(read_symbol_name): Use FAKE_LABEL_CHAR. Accept only if
input_from_string is TRUE.
(temp_ilp): Set input_from_string to TRUE.
(restore_ilp): Set input_from_string to FALSE.
* read.h (input_from_string): Declare.
* symbols.c: Include write.h
(S_IS_LOCAL): Check for FAKE_LABEL_CHAR.
(symbol_relc_make_sym): Fix comment refering to default fake label
string.
* write.h (FAKE_LABEL_CHAR): New.
* config/tc-riscv.h (FAKE_LABEL_CHAR): Define.
* testsuite/gas/all/err-fakelabel.s: New.
I'd edited these thinking that there might be cases where the counts
were one, but on further investigation it appears not. What's left
here are some minor tweaks.
* read.c (assemble_one, s_bundle_unlock): Formatting.
Consistently add comma and "bytes" to error message.
* testsuite/gas/i386/bundle-bad.l: Adjust to suit.
PR 22324
* read.c (s_rept): Use size_t type for count parameter.
(do_repeat): Change type of count parameter to size_t.
Issue an error is the count parameter is negative.
(do_repeat_with_expression): Likewise.
* read.h: Update prototypes for do_repeat and
do_repeat_with_expression.
* doc/as.texinfo (Rept): Document that a zero count is allowed but
negative counts are not.
* config/tc-rx.c (rx_rept): Use size_t type for count parameter.
* config/tc-tic54x.c (tic54x_loop): Cast count parameter to size_t
type.
* testsuite/gas/macros/end.s: Add a test using a negative repeat
count.
* testsuite/gas/macros/end.l: Add expected error message.
We can't create alias of common symbol. Local alias of common symbol has
been disallowed. But global alias of common symbol is disallowed when the
common symbol is seen first and silently dropped otherwise. This patch
disallows alias of common symbol in all cases.
gas/
PR gas/21667
* read.c (pseudo_set): Update error message for alias of common
symbol.
* write.c (write_object_file): Disallow both local and global
aliases of common symbol.
* testsuite/gas/elf/common5a.d: New file.
* testsuite/gas/elf/common5a.l: Likewise.
* testsuite/gas/elf/common5a.s: Likewise.
* testsuite/gas/elf/common5b.d: Likewise.
* testsuite/gas/elf/common5b.l: Likewise.
* testsuite/gas/elf/common5b.s: Likewise.
* testsuite/gas/elf/common5c.d: Likewise.
* testsuite/gas/elf/common5c.s: Likewise.
* testsuite/gas/elf/common5d.d: Likewise.
* testsuite/gas/elf/common5d.s: Likewise.
* testsuite/gas/elf/elf.exp: Run common5a, common5b, common5c
and common5d.
* read.c (temp_ilp): New function. Installs a temporary input
line pointer.
(restore_ilp): New function. Restores the original input line
pointer.
* read.h (temp_ilp): Prototype.
(restore_ilp): Prototype.
* stabs.c (dot_func_p): Use bfd_boolean type.
(generate_asm_file): Use temp_ilp and restore_ilp.
(stabs_generate_asm_lineno): Likewise.
(stabs_generate_asm_endfunc): Likewise.
gas/
* read.c (emit_leb128_expr): Extended unsigned big number for
sleb128.
* testsuite/gas/all/gas.exp (test_cond): Add sleb128-8 test.
* testsuite/gas/all/sleb128.d: New test.
* testsuite/gas/all/sleb128.s: New test source.
This increases consistancy of how we allocate memory, and always casting the
result to the proper type. It also helps make sure we get any use of sizeof on
the result type correct.
gas/ChangeLog:
2016-03-22 Trevor Saunders <tbsaunde+binutils@tbsaunde.org>
* listing.c (listing_message): Use XNEW style allocation macros.
* read.c (read_a_source_file): Likewise.
(read_symbol_name): Likewise.
(s_mri_common): Likewise.
(assign_symbol): Likewise.
(s_reloc): Likewise.
(emit_expr_with_reloc): Likewise.
(s_incbin): Likewise.
(s_include): Likewise.
* sb.c (sb_build): Likewise.
(sb_check): Likewise.
* read.c (emit_expr_with_reloc): Add code check a bignum with
nbytes == 1.
* config/rx/rx-parse.y (rx_intop): Accept bignum values for sizes
other than 32-bits.
* testsuite/gas/elf/bignum.s: New test source file.
* testsuite/gas/elf/bignum.d: New test driver file.
* testsuite/gas/elf/elf.exp: Run the new test.
* symbols.c (decode_local_label_name): Make type a const char *.
* listing.c (print_source): Make type of p const char *.
(print_line): Make type of string const char *.
(buffer_line): Return const char *.
(title): Make type const char *.
(subtitle): Likewise.
(listing_listing): Make type of p const char *.
* messages.c (as_internal_value_out_of_range): Make type of prefix
const char *.
* stabs.c (s_stab_generic): make type of stab_secname, stabstr_secname
and string const char *.
* read.c (_bfd_rel): Make type of name const char *.
* app.c (out_string): Change type to const char *.
(struct app_save::out_string): Likewise.
gas * read.c (finish_bundle): Avoid recording a negative alignment.
(do_align): Use unsigned values for n, len and max. Only create
a frag if the alignment requirement is greater than the minimum
byte alignment. Avoid recording a negative alignment.
(s_align): Use unsigned values where appropriate.
(bss_alloc): Use an unsigned value for the alignment.
(sizeof_sleb128): Add a comment noting that we encode one octet
per byte, regardless of the value of OCTETS_PER_BYTE_POWER.
(emit_leb129_expr): Abort if the emitted encoding was longer than
expected.
* read.h (output_leb128): Update prototype.
(sizeof_leb128): Update prototype.
(bss_alloc): Update prototype.
* write.c (record_alignment): Use an unsigned value for the
alignment. Do not record alignments less than the minimum
alignment for a byte.
* write.h (record_alignment): Update prototype.
While not allowed, this certainly shouldn't result in confusing the
programmer (by skipping lines in unexpected ways): Without returning,
demand_empty_rest_of_line() (at the end of the function) will demand
the _next_ line to be empty, and without the conditional we would
ignore the next line.
Some of the TC_START_LABEL implementations need to adjust the end of
the symbol, when a colon doesn't mean a label definition. That means
they need access to nul_char both the restore the NUL location (it may
be a quote rather than a colon) and to store the new nul_char. Others
need adjusting to step over a potential trailing quote.
PR gas/18581
* config/tc-aarch64.h (TC_START_LABEL): Redefine.
* config/tc-arm.c (tc_start_label_without_colon): Delete params.
Use input_line_pointer directly.
* config/tc-arm.h (TC_START_LABEL): Redefine.
(TC_START_LABEL_WITHOUT_COLON): Redefine.
(tc_start_label_without_colon): Update prototype.
* config/tc-bfin.c (bfin_start_label): Delete ptr param. Check
for NUL instead.
* config/tc-bfin.h (bfin_start_label): Update prototype.
(TC_START_LABEL): Redefine.
* config/tc-d30v.h (TC_START_LABEL): Redefine.
* config/tc-fr30.c (restore_colon): Rewrite.
(fr30_is_colon_insn): Add nul_char param. Return int. Bump
i_l_p over quote. Update restore_colon calls.
* config/tc-fr30.h (TC_START_LABEL): Redefine.
(fr30_is_colon_insn): Update prototype.
* config/tc-m32c.c (restore_colon, m32c_is_colon_insn): As above.
* config/tc-m32c.h (TC_START_LABEL): Redefine.
(m32c_is_colon_insn): Update prototype.
* config/tc-m32r.h (TC_START_LABEL): Redefine.
* config/tc-mep.h (TC_START_LABEL): Redefine.
* config/tc-nds32.h (TC_START_LABEL): Redefine.
* config/tc-tic54x.c (tic54x_start_label): Replace params with
nul_char and next_char. Step over trailing quote.
* config/tc-tic54x.h (TC_START_LABEL_WITHOUT_COLON): Redefine.
(tic54x_start_label): Update prototype.
* read.c (TC_START_LABEL): Redefine. Update invocation.
(TC_START_LABEL_WITHOUT_COLON): Update invocation.
* config/tc-nios2.c (s_nios2_set): Save initial input_line_pointer
and restore if calling s_set. Don't restore delim again.
Tests that bfd_perform_reloc doesn't freak over a NONE reloc at end
of section.
gas/
* read.c (s_reloc): Match BFD_RELOC_NONE, BFD_RELOC{8,16,32,64}.
* write.c (get_frag_for_reloc): Allow match just past end of frag.
gas/testsuite/
* gas/all/none.s,
* gas/all/none.d: New test.
* gas/all/gas.exp: Run it.
When runtime patching code (like e.g. done by the Linux kernel) there
may be cases where the set of stack frame alterations differs between
unpatched and patched code. Consequently the corresponding unwind data
needs patching too. Locating the right places within an FDE, however,
is rather cumbersome without a way to insert labels in the resulting
section. Hence this patch introduces a new directive, .cfi_label. Note
that with the way CFI data gets emitted currently (at the end of the
assembly process) this can't support local FB- and dollar-labels.
gas/
2015-01-12 Jan Beulich <jbeulich@suse.com>
* gas/dw2gencfi.c (cfi_add_label, dot_cfi_label): New.
(cfi_pseudo_table): Add "cfi_label".
(output_cfi_insn): Handle CFI_label.
(select_cie_for_fde): Als terminate CIE when encountering
CFI_label.
* dw2gencfi.h (cfi_add_label): Declare.
(struct cfi_insn_data): New member "sym_name".
(CFI_label): New.
* read.c (read_symbol_name): Drop "static".
* read.h (read_symbol_name): Declare.
gas/testsuite/
2015-01-12 Jan Beulich <jbeulich@suse.com>
gas/cfi/cfi-label.d, gas/cfi/cfi-label.s: New.
gas/cfi/cfi.exp: Run new tests.
The C standard doesn't guarantee a function pointer can be cast to
void* and vice versa.
binutils/
* prdbg.c (print_debugging_info): Don't use void* for function
pointer param.
* budbg.h (print_debugging_info): Update prototype.
gas/
* read.c (s_altmacro, s_reloc): Make definition static.
The construct being added to the cond.s test case otherwise triggered
both the "missing closing ..." and the "stray ..." (twice) warnings in
_find_end_of_line(). As that code fragments suggests, this is needed to
support (include) files that can be used for both assembler .include
and compiler #include directives.
Wu Heng
Alan Modra
Andreas Schwab
H.J. Lu
Jim Wilson
Nick Clifton
Andreas Krebbel
Alexandre Oliva
Tristan Gingold
Ambrogino Modigliani
Trevor Saunders
Trevor Saunders
Dan Gisselquist
Jan Beulich
Dominik Vogt