We have but ELF binutils tests in the MIPS subset, and non-ELF MIPS/GAS
ports are gone, making a future addition of any non-ELF tests unlikely.
Bail out right away then if non-ELF, consuming one level of indentation
across the actual tests run.
binutils/
* testsuite/binutils-all/mips/mips.exp: Bail out right away if
non-ELF.
Verify MIPS16e2 ASE instruction assembly, disassembly and object file
flags.
binutils/
* testsuite/binutils-all/mips/mips16-undecoded.d: Add `-mips3'
to `as' flags.
* testsuite/binutils-all/mips/mips16e2-undecoded.d: New test.
* testsuite/binutils-all/mips/mips16e2-extend-insn.d: New test.
* testsuite/binutils-all/mips/mips16-undecoded.s: Remove
`.module mips3'.
* testsuite/binutils-all/mips/mips.exp: Run the new tests.
gas/
* testsuite/gas/mips/mips16e2.d: New test.
* testsuite/gas/mips/mips16e2-mt.d: New test.
* testsuite/gas/mips/mips16e2-sub.d: New test.
* testsuite/gas/mips/mips16e2@mips16e2-sub.d: New test.
* testsuite/gas/mips/mips16e2-mt-sub.d: New test.
* testsuite/gas/mips/mips16e2@mips16e2-mt-sub.d: New test.
* testsuite/gas/mips/mips16e2-hilo.d: New test.
* testsuite/gas/mips/mips16e2-hilo-n32.d: New test.
* testsuite/gas/mips/mips16e2-reloc-error.d: New test.
* testsuite/gas/mips/mips16e2-imm-error.d: New test.
* testsuite/gas/mips/elf_ase_mips16e2.d: New test.
* testsuite/gas/mips/elf_ase_mips16e2-2.d: New test.
* testsuite/gas/mips/elf-rel9-mips16e2.d: New test.
* testsuite/gas/mips/mips16e2-lui.d: New test.
* testsuite/gas/mips/mips16e2@mips32r2-sync.d: New test.
* testsuite/gas/mips/mips16e2@mips32r2-sync-1.d: New test.
* testsuite/gas/mips/mips16e2@lui-2.d: New test.
* testsuite/gas/mips/mips16e2-reloc-error.l: New stderr output.
* testsuite/gas/mips/mips16e2-imm-error.l: New stderr output.
* testsuite/gas/mips/mips16e2@lui-2.l: New stderr output.
* testsuite/gas/mips/mips16e2.s: New test source.
* testsuite/gas/mips/mips16e2-mt.s: New test source.
* testsuite/gas/mips/mips16e2-sub.s: New test source.
* testsuite/gas/mips/mips16e2-mt-sub.s: New test source.
* testsuite/gas/mips/mips16e2-hilo.s: New test source.
* testsuite/gas/mips/mips16e2-reloc-error.s: New test source.
* testsuite/gas/mips/mips16e2-imm-error.s: New test source.
* testsuite/gas/mips/elf-rel9-mips16e2.s: New test source.
* testsuite/gas/mips/mips16e2-lui.s: New test source.
* testsuite/gas/mips/mips.exp: Expand `mips32r2-sync',
`mips32r2-sync-1', `lui-1' and `lui-2' tests across MIPS16e2
architectures. Run the new tests.
Add MIPS16e2 ASE support as per the architecture specification[1],
including in particular:
1. A new ELF ASE flag to mark MIPS16e2 binaries.
2. MIPS16e2 instruction assembly support, including a relaxation update
to use LUI rather than an LI/SLL instruction pair for loading the
high part of 32-bit addresses.
3. MIPS16e2 instruction disassembly support, including updated rules for
extended forms of instructions that are now subdecoded and therefore
do not alias to the original MIPS16 ISA revision instructions even
for encodings that are not valid in the MIPS16e2 instruction set.
Add `-mmips16e2' and `-mno-mips16e2' GAS command-line options and their
corresponding `mips16e2' and `no-mips16e2' settings for the `.set' and
`.module' pseudo-ops. Control the availability of the MT ASE subset of
the MIPS16e2 instruction set with a combination of these controls and
the preexisting MT ASE controls.
Parts of this change by Matthew Fortune and Andrew Bennett.
References:
[1] "MIPS32 Architecture for Programmers: MIPS16e2 Application-Specific
Extension Technical Reference Manual", Imagination Technologies
Ltd., Document Number: MD01172, Revision 01.00, April 26, 2016
include/
* elf/mips.h (AFL_ASE_MIPS16E2): New macro.
(AFL_ASE_MASK): Adjust accordingly.
* opcode/mips.h: Document new operand codes defined.
(mips_operand_type): Add OP_REG28 enum value.
(INSN2_SHORT_ONLY): Update description.
(ASE_MIPS16E2, ASE_MIPS16E2_MT): New macros.
bfd/
* elfxx-mips.c (print_mips_ases): Handle MIPS16e2 ASE.
opcodes/
* mips-dis.c (mips_arch_choices): Add ASE_MIPS16E2 and
ASE_MIPS16E2_MT flags to the unnamed MIPS16 entry.
(mips_convert_abiflags_ases): Handle the AFL_ASE_MIPS16E2 flag.
(print_insn_arg) <OP_REG28>: Add handler.
(validate_insn_args) <OP_REG28>: Handle.
(print_mips16_insn_arg): Handle MIPS16 instructions that require
32-bit encoding and 9-bit immediates.
(print_insn_mips16): Handle MIPS16 instructions that require
32-bit encoding and MFC0/MTC0 operand decoding.
* mips16-opc.c (decode_mips16_operand) <'>', '9', 'G', 'N', 'O'>
<'Q', 'T', 'b', 'c', 'd', 'r', 'u'>: Add handlers.
(RD_C0, WR_C0, E2, E2MT): New macros.
(mips16_opcodes): Add entries for MIPS16e2 instructions:
GP-relative "addiu" and its "addu" spelling, "andi", "cache",
"di", "ehb", "ei", "ext", "ins", GP-relative "lb", "lbu", "lh",
"lhu", and "lw" instructions, "ll", "lui", "lwl", "lwr", "mfc0",
"movn", "movtn", "movtz", "movz", "mtc0", "ori", "pause",
"pref", "rdhwr", "sc", GP-relative "sb", "sh" and "sw"
instructions, "swl", "swr", "sync" and its "sync_acquire",
"sync_mb", "sync_release", "sync_rmb" and "sync_wmb" aliases,
"xori", "dmt", "dvpe", "emt" and "evpe". Add split
regular/extended entries for original MIPS16 ISA revision
instructions whose extended forms are subdecoded in the MIPS16e2
ISA revision: "li", "sll" and "srl".
binutils/
* readelf.c (print_mips_ases): Handle MIPS16e2 ASE.
* NEWS: Mention MIPS16e2 ASE support.
gas/
* config/tc-mips.c (RELAX_MIPS16_ENCODE): Add `e2' flag.
(RELAX_MIPS16_E2): New macro.
(RELAX_MIPS16_PIC, RELAX_MIPS16_SYM32, RELAX_MIPS16_NOMACRO)
(RELAX_MIPS16_USER_SMALL, RELAX_MIPS16_USER_EXT)
(RELAX_MIPS16_DSLOT, RELAX_MIPS16_JAL_DSLOT)
(RELAX_MIPS16_EXTENDED, RELAX_MIPS16_MARK_EXTENDED)
(RELAX_MIPS16_CLEAR_EXTENDED, RELAX_MIPS16_ALWAYS_EXTENDED)
(RELAX_MIPS16_MARK_ALWAYS_EXTENDED)
(RELAX_MIPS16_CLEAR_ALWAYS_EXTENDED, RELAX_MIPS16_MACRO)
(RELAX_MIPS16_MARK_MACRO, RELAX_MIPS16_CLEAR_MACRO): Shift bits.
(mips16_immed_extend): New prototype.
(options): Add OPTION_MIPS16E2 and OPTION_NO_MIPS16E2 enum
values.
(md_longopts): Add "mmips16e2" and "mno-mips16e2" options.
(mips_ases): Add "mips16e2" entry.
(mips_set_ase): Handle MIPS16e2 ASE.
(insn_insert_operand): Explicitly handle immediates with MIPS16
instructions that require 32-bit encoding.
(is_opcode_valid_16): Pass enabled ASE bitmask on to
`opcode_is_member'.
(validate_mips_insn): Explicitly handle immediates with MIPS16
instructions that require 32-bit encoding.
(operand_reg_mask) <OP_REG28>: Add handler.
(match_reg28_operand): New function.
(match_operand) <OP_REG28>: Add handler.
(append_insn): Pass ASE_MIPS16E2 setting to RELAX_MIPS16_ENCODE.
(match_mips16_insn): Handle MIPS16 instructions that require
32-bit encoding and `V' and `u' operand codes.
(mips16_ip): Allow any characters except from `.' in opcodes.
(mips16_immed_extend): Handle 9-bit immediates. Do not shuffle
immediates whose width is not one of these listed.
(md_estimate_size_before_relax): Handle MIPS16e2 relaxation.
(mips_relax_frag): Likewise.
(md_convert_frag): Likewise.
(mips_convert_ase_flags): Handle MIPS16e2 ASE.
* doc/as.texinfo (Target MIPS options): Add `-mmips16e2' and
`-mno-mips16e2' options.
(-mmips16e2, -mno-mips16e2): New options.
* doc/c-mips.texi (MIPS Options): Add `-mmips16e2' and
`-mno-mips16e2' options.
(MIPS ASE Instruction Generation Overrides): Add `.set mips16e2'
and `.set nomips16e2'.
Disassemble the MIPS16 BREAK and SDBBP instruction's immediate operand
in the hexadecimal rather than decimal numeral system and add respective
operandless variants with an implicit 0 operand, making our handling of
these instructions consistent with how we have processed their regular
MIPS and microMIPS counterparts since forever.
opcodes/
* mips16-opc.c (decode_mips16_operand) <'6'>: Switch the operand
type to hexadecimal.
(mips16_opcodes): Add operandless "break" and "sdbbp" entries.
binutils/
* testsuite/binutils-all/mips/mips16-extend-insn.d: Adjust BREAK
and SDBBP disassembly.
gas/
* testsuite/gas/mips/mips16.d: Adjust BREAK disassembly.
* testsuite/gas/mips/mips16-64@mips16.d: Likewise.
* testsuite/gas/mips/mips16-64.d: Likewise.
* testsuite/gas/mips/mips16-64@mips16-64.d: Likewise.
* testsuite/gas/mips/mips16-macro.d: Likewise.
* testsuite/gas/mips/mips16-64@mips16-macro.d: Likewise.
* testsuite/gas/mips/mips16-sub.d: Likewise.
* testsuite/gas/mips/mips16-32@mips16-sub.d: Likewise.
Define `tempfile' and `copyfile' in `mips.exp' so that standalone script
execution via `RUNTESTFLAGS=mips.exp' works rather than producing:
Running .../binutils/testsuite/binutils-all/mips/mips.exp ...
ERROR: tcl error sourcing
.../binutils/testsuite/binutils-all/mips/mips.exp.
ERROR: can't read "tempfile": no such variable
while executing
"binutils_assemble_flags ${srcfile} $tempfile $opts(as)"
(procedure "run_dump_test" line 207)
invoked from within
"run_dump_test "mips-ase-1""
invoked from within
"if [is_elf_format] {
run_dump_test "mips-ase-1"
run_dump_test "mips-ase-2"
run_dump_test "mips-ase-3"
run_dump_test "mixed-mips16"
..."
(file ".../binutils/testsuite/binutils-all/mips/mips.exp" line 22)
invoked from within
"source .../binutils/testsuite/binutils-all/mips/mips.exp"
("uplevel" body line 1)
invoked from within
"uplevel #0 source .../binutils/testsuite/binutils-all/mips/mips.exp"
invoked from within
"catch "uplevel #0 source $test_file_name""
testcase .../binutils/testsuite/binutils-all/mips/mips.exp completed in 0 seconds
binutils/
* testsuite/binutils-all/mips/mips.exp: Define `tempfile' and
`copyfile' variables.
The type of relcount is long and the type of sec->reloc_count is
unsigned int. On 32-bit hosts, GCC issues an error:
objcopy.c:2144:20: error: comparison between signed and unsigned integer expressions [-Werror=sign-compare]
if (relcount > sec->reloc_count)
Cast relcount to unsigned long to silence GCC.
* objcopy.c (merge_gnu_build_notes): Cast relcount to unsigned
long when comparing with sec->reloc_count.
Correct the disassembly of the PC-relative immediate argument of the
MIPS16 synthetic LA, LW, DLA and LD instructions and do not mask the
LSB, which in this case is a part of the data address rather than the
ISA bit and has to be fully presented.
opcodes/
* mips-dis.c (print_insn_arg): Only clear the ISA bit for jumps
and branches and not synthetic data instructions.
binutils/
* testsuite/binutils-all/mips/mips16-undecoded.d: Adjust the
disassembly of PC-relative LA and LW synthetic instructions.
PR binutils/21438
* dwarf.c (process_extended_line_op): Do not assume that the
string extracted from the section is NUL terminated.
(fetch_indirect_string): If the string retrieved from the section
is not NUL terminated, return an error message.
(fetch_indirect_line_string): Likewise.
(fetch_indexed_string): Likewise.
PR binutils/21407
* bucomm.c (get_file_size): Return -1 if file_name is NULL.
* ar.c (main): Fail with usage() invocation if no file names are
provided.
* readelf.c (process_section_headers): Warn about overlarge
sections.
(print_gnu_build_attribute_name): Print the number of unrecognised
note types. Fix formatting in the presence of errors.
(testsuite/binutils-all/note-2-32.s): Fix encoding of numeric notes.
(testsuite/binutils-all/note-2-64.s): Likewise.
A static, non-relocated global offset table will be embedded in static
binaries produced from objects containing any kind of GOT relocations,
generally PIC code. All symbols will have been resolved in static link
in such binaries making all GOT entries local and their values final as
there is no run-time load processing further performed.
Dump such GOT with `readelf -A' like already done with regular GOT, to
make it easier to examine static code that uses accesses via the GOT
pointer. There will be no dynamic segment or section in a static binary
to get the GOT pointer (DT_PLTGOT) from, so use section headers to find
a `.got' section instead.
binutils/
* readelf.c (process_mips_specific): Add static GOT support.
Unavailable data is handled gracefully in MIPS GOT processing done by
`print_mips_got_entry', so all that is needed in special GOT[1] handling
is to verify whether data can be retrieved for the purpose of the GNU
marker check done with `byte_get'. Remove the extra error reporting
code then, introduced with commit 75ec1fdbb7 ("Fix runtime seg-fault
in readelf when parsing a corrupt MIPS binary.") in the course of
addressing PR binutils/21344, and defer the error case to regular local
GOT entry processing.
binutils/
* readelf.c (process_mips_specific): Remove error reporting from
GOT[1] processing.
Null data is handled gracefully throughout in MIPS GOT processing, with
addresses printed normally and unavailable data shown as `<unknown>' by
`print_mips_got_entry', and special processing code for GOT[1] doing an
explicit check. Remove an unwanted null GOT data check then, introduced
with commit 592458412f in the course of addressing PR binutils/12855.
binutils/
* readelf.c (process_mips_specific): Remove null GOT data check.
Complement commit 986e18a5a9 ("Add a second 'pinfo' member to
mips_opcode to extend number of available bits"),
<https://sourceware.org/ml/binutils/2005-01/msg00261.html>, and annotate
MIPS16 NOP, LA, DLA and the synthetic forms of LD and LW instructions as
aliases. These correspond to MOVE, and the PC-relative ADDIU, DADDIU,
LD and LW hardware instructions respectively.
binutils/
* testsuite/binutils-all/mips/mips16-alias.d: New test.
* testsuite/binutils-all/mips/mips16-noalias.d: New test.
* testsuite/binutils-all/mips/mips16-alias.s: New test source.
* testsuite/binutils-all/mips/mips.exp: Run the new tests.
opcodes/
* mips16-opc.c (AL): New macro.
(mips16_opcodes): Mark "nop", "la", "dla", and synthetic forms
of "ld" and "lw" as aliases.
PR binutils/21379
* readelf.c (process_dynamic_section): Detect over large section
offsets in the DT_SYMTAB entry.
PR binutils/21345
* readelf.c (process_mips_specific): Catch an unfeasible memory
allocation before it happens and print a suitable error message.
* objcopy.c: Add --no-merge-notes option to disable note merging.
Add --[no-]merge-notes option to strip, and enable it by default.
(num_bytes): New function.
(merge_gnu_build_notes): Add code to merge stack size notes.
* binutils.texi: Update strip and objcopy documentation.
* readelf.c (print_gnu_build_attribute_name): Use defined
constants for note types.
objcopy/
* objcopy.c (struct redefine_node): Delete the field "next".
(redefine_sym_list): Deleted.
(redefine_specific_htab): New hash table.
(redefine_specific_reverse_htab): Likewise.
(eq_string_redefnode): New function.
(htab_hash_redefnode): Likewise.
(create_symbol2redef_htab): Likewise.
(add_specific_symbol_node): Likewise.
(create_symbol_htabs): Create redefine_specific_htab and
redefine_specific_reverse_htab.
(lookup_sym_redefinition): Use hash table instead of list.
(redefine_list_append): Likewise, and rename to add_redefine_and_check.
(copy_main): Use redefine_specific_htab instead of redefine_sym_list.
Update comments.
Mark an ALLOC section, which should be placed in special memory area,
with SHF_GNU_MBIND. Its sh_info field indicates the special memory
type. GNU_MBIND section names start with ".mbind" so that they are
placed as orphan sections by linker. All input GNU_MBIND sections
with the same sh_type, sh_flags and sh_info are placed in one output
GNU_MBIND section. In executable and shared object, create a
GNU_MBIND segment for each GNU_MBIND section and its segment type is
PT_GNU_MBIND_LO plus the sh_info value. Each GNU_MBIND segment is
aligned at page boundary.
The assembler syntax:
.section .mbind.foo,"adx",%progbits
^ 0: Special memory type.
|
'd' for SHF_GNU_MBIND.
.section .mbind.foo,"adx",%progbits,0x1
^ 1: Special memory type.
|
'd' for SHF_GNU_MBIND.
.section .mbind.bar,"adG",%progbits,.foo_group,comdat,0x2
^ 2: Special memory type.
|
'd' for SHF_GNU_MBIND.
bfd/
* elf.c (get_program_header_size): Add a GNU_MBIND segment for
each GNU_MBIND section and align GNU_MBIND section to page size.
(_bfd_elf_map_sections_to_segments): Create a GNU_MBIND
segment for each GNU_MBIND section.
(_bfd_elf_init_private_section_data): Copy sh_info from input
for GNU_MBIND section.
binutils/
* NEWS: Mention support for ELF SHF_GNU_MBIND and
PT_GNU_MBIND_XXX.
* readelf.c (get_segment_type): Handle PT_GNU_MBIND_XXX.
(get_elf_section_flags): Handle SHF_GNU_MBIND.
(process_section_headers): Likewise.
* testsuite/binutils-all/mbind1.s: New file.
* testsuite/binutils-all/objcopy.exp: Run readelf test on
mbind1.s.
gas/
* NEWS: Mention support for ELF SHF_GNU_MBIND.
* config/obj-elf.c (section_match): New.
(get_section): Match both sh_info and group name.
(obj_elf_change_section): Add argument for sh_info. Pass both
sh_info and group name to get_section. Issue an error for
SHF_GNU_MBIND section without SHF_ALLOC. Set sh_info.
(obj_elf_parse_section_letters): Set SHF_GNU_MBIND for 'd'.
(obj_elf_section): Support SHF_GNU_MBIND section info.
* config/obj-elf.h (obj_elf_change_section): Add argument for
sh_info.
* config/tc-arm.c (start_unwind_section): Pass 0 as sh_info to
obj_elf_change_section.
* config/tc-ia64.c (obj_elf_vms_common): Likewise.
* config/tc-microblaze.c (microblaze_s_data): Likewise.
(microblaze_s_sdata): Likewise.
(microblaze_s_rdata): Likewise.
(microblaze_s_bss): Likewise.
* config/tc-mips.c (s_change_section): Likewise.
* config/tc-msp430.c (msp430_profiler): Likewise.
* config/tc-rx.c (parse_rx_section): Likewise.
* config/tc-tic6x.c (tic6x_start_unwind_section): Likewise.
* doc/as.texinfo: Document 'd' for SHF_GNU_MBIND.
* testsuite/gas/elf/elf.exp: Run section12a, section12b and
section13.
* testsuite/gas/elf/section10.d: Updated.
* testsuite/gas/elf/section10.s: Likewise.
* testsuite/gas/elf/section12.s: New file.
* testsuite/gas/elf/section12a.d: Likewise.
* testsuite/gas/elf/section12b.d: Likewise.
* testsuite/gas/elf/section13.l: Likewise.
* testsuite/gas/elf/section13.d: Likewise.
* testsuite/gas/elf/section13.s: Likewise.
include/
* elf/common.h (PT_GNU_MBIND_NUM): New.
(PT_GNU_MBIND_LO): Likewise.
(PT_GNU_MBIND_HI): Likewise.
(SHF_GNU_MBIND): Likewise.
ld/
* NEWS: Mention support for ELF SHF_GNU_MBIND and
PT_GNU_MBIND_XXX.
* emultempl/elf32.em (gld${EMULATION_NAME}_place_orphan): Place
input GNU_MBIND sections with the same type, attributes and
sh_info field into a single output GNU_MBIND section.
* testsuite/ld-elf/elf.exp: Run mbind2a and mbind2b.
* testsuite/ld-elf/mbind1.s: New file.
* testsuite/ld-elf/mbind1a.d: Likewise.
* testsuite/ld-elf/mbind1b.d: Likewise.
* testsuite/ld-elf/mbind1c.d: Likewise.
* testsuite/ld-elf/mbind2a.s: Likewise.
* testsuite/ld-elf/mbind2b.c: Likewise.
This adds -Mraw for PowerPC objdump, a disassembler option to display
the underlying machine instruction rather than aliases. For example,
"rlwinm" always rather than "rotlwi" when the instruction is
performing a simple rotate.
binutils/
* doc/binutils.texi (objdump): Document PowerPC -M options.
gas/
* config/tc-ppc.c (md_parse_option): Reject -mraw.
include/
* opcode/ppc.h (PPC_OPCODE_RAW): Define.
(PPC_OPCODE_*): Make them all unsigned long long constants.
opcodes/
* ppc-dis.c (ppc_opts): Set PPC_OPCODE_PPC for "any" flags. Add
"raw" option.
(lookup_powerpc): Don't special case -1 dialect. Handle
PPC_OPCODE_RAW.
(print_insn_powerpc): Mask out PPC_OPCODE_ANY on first
lookup_powerpc call, pass it on second.
* readelf.c (print_gnu_build_attribute_name): Allow stack
protection notes to contain numeric values. Use a colon rather
than a space to separate a string name from its values. Decode
the numeric value of a stack protection note.
* objcopy.c (merge_gnu_build_notes): Allow version notes to
contain extra text after the protocol version number.
The fix for PR binutils/17512 added a check for the dynamic segment being
inside the actual ELF file. If not an error message would be produced:
readelf: Error: the dynamic segment offset + size exceeds the size of the file
Unfortunately for separate debuginfo files it is common for the dynamic
segment not being inside the file because the .dynamic section is NOBITS.
Since the check is done unconditionally in process_program_headers and
process_program_headers is always called (to setup dynamic_addr in case
it is needed). The error is produced on any operations done on any .debug
file (even if no program headers or the dynamic segment is used).
If there are section headers then a cross check is done to see if the
.dynamic section is NOBITS in which case dynamic_addr is set to zero
without a warning or error (which is then checked first before any
operation on the dynamic segement is done).
Move the check for the dynamic segment being inside the actual ELF file
after the cross check with the section headers to suppress the error for
.debug files.
binutils/ChangeLog:
* readelf.c (process_program_headers): Move dynamic_addr check
after .dynamic section cross check.
include * elf/common.h (GNU_BUILD_ATTRIBUTE_SHORT_ENUM): New GNU BUILD
note type.
binutils * readelf.c (print_gnu_build_attribute_name): Add support for
GNU_BUILD_ATTRIBUTE_SHORT_ENUM.
* readelf.c (print_gnu_build_attribute_description): Move symbol
printing code to...
(print_symbol_for_build_attribute): New function. ...here.
Add to find the best symbol to associate with an OPEN note.
Add code to cache the symbol table and string table, so that they
are not loaded every time a note is displayed.
* testsuite/binutils-all/note-2-32.s: Add a function symbol.
* testsuite/binutils-all/note-2-64.s: Likewise.
* testsuite/binutils-all/note-2-32.d: Update expected note output.
* testsuite/binutils-all/note-2-64.d: Likewise.
If the source file is more recent than the object file, line number
information in the object may no longer match the source. So print a
warning message.
* objdump.c (update_source_path): Add abfd param. Add struct
stat vars. Pass to try_print_file_open. Warn if source is more
recent than object.
(try_print_file_open, slurp_file): Add struct stat param to
return fstat.
(show_line): Call update_source_path with bfd.