Commit Graph

491 Commits

Author SHA1 Message Date
Alan Modra
7dba9362c1 Rewrite __start and __stop symbol handling
This arranges for __start and __stop symbols to be defined before
garbage collection, for all target formats.  That should allow the
COFF and PE --gc-sections to keep a singleton orphan input section,
a feature lost by 2017-06-13 commit cbd0eecf26.  The fancier ELF
treatment of keeping all input sections associated with a __start or
__stop symbol, from 2015-10-23 commit 1cce69b9dc, is retained.

.startof. and .sizeof. symbols are deliberately not defined before
garbage collection, so these won't affect garbage collection of
sections.

The patch also ensures __start, __stop, .startof. and .sizeof. symbols
are defined before target size_dynamic_sections is called, albeit
with a preliminary value, so that target code doesn't need to cope
with a symbol changing from undefined at size_dynamic_sections to
defined at relocate_section.

Also, a number of problems with the testcases have been fixed.

	PR ld/20022
	PR ld/21557
	PR ld/21562
	PR ld/21571
include/
	* bfdlink.h (struct bfd_link_hash_entry): Delete undef.section.
bfd/
	* targets.c (struct bfd_target): Add _bfd_define_start_stop.
	(BFD_JUMP_TABLE_LINK): Likewise.
	* elf-bfd.h (bfd_elf_define_start_stop): Declare.
	* elflink.c (_bfd_elf_gc_mark_rsec): Update comment.
	(bfd_elf_define_start_stop): New function.
	* linker.c (bfd_generic_define_start_stop): New function.
	* coff64-rs6000.c (rs6000_xcoff64_vec, rs6000_xcoff64_aix_vec): Init
	new field.
	* aout-adobe.c (aout_32_bfd_define_start_stop): Define.
	* aout-target.h (MY_bfd_define_start_stop): Define.
	* aout-tic30.c (MY_bfd_define_start_stop): Define.
	* binary.c (binary_bfd_define_start_stop): Define.
	* bout.c (b_out_bfd_define_start_stop): Define.
	* coff-alpha.c (_bfd_ecoff_bfd_define_start_stop): Define.
	* coff-mips.c (_bfd_ecoff_bfd_define_start_stop): Define.
	* coff-rs6000.c (_bfd_xcoff_bfd_define_start_stop): Define.
	* coffcode.h (coff_bfd_define_start_stop): Define.
	* elfxx-target.h (bfd_elfNN_bfd_define_start_stop): Define.
	* i386msdos.c (msdos_bfd_define_start_stop): Define.
	* i386os9k.c (os9k_bfd_define_start_stop): Define.
	* ieee.c (ieee_bfd_define_start_stop): Define.
	* ihex.c (ihex_bfd_define_start_stop): Define.
	* libbfd-in.h (_bfd_nolink_bfd_define_start_stop): Define.
	* mach-o-target.c (bfd_mach_o_bfd_define_start_stop): Define.
	* mmo.c (mmo_bfd_define_start_stop): Define.
	* nlm-target.h (nlm_bfd_define_start_stop): Define.
	* oasys.c (oasys_bfd_define_start_stop): Define.
	* pef.c (bfd_pef_bfd_define_start_stop): Define.
	* plugin.c (bfd_plugin_bfd_define_start_stop): Define.
	* ppcboot.c (ppcboot_bfd_define_start_stop): Define.
	* som.c (som_bfd_define_start_stop): Define.
	* srec.c (srec_bfd_define_start_stop): Define.
	* tekhex.c (tekhex_bfd_define_start_stop): Define.
	* versados.c (versados_bfd_define_start_stop): Define.
	* vms-alpha.c (vms_bfd_define_start_stop): Define.
	(alpha_vms_bfd_define_start_stop): Define.
	* xsym.c (bfd_sym_bfd_define_start_stop): Define.
	* bfd-in2.h: Regenerate.
	* libbfd.h: Regenerate.
ld/
	* emultempl/elf32.em (gld${EMULATION_NAME}_after_open): Don't set
	__start/__stop syms here.
	* ldlang.c (lang_set_startof): Delete.
	(start_stop_syms, start_stop_count, start_stop_alloc): New vars.
	(lang_define_start_stop, lang_init_start_stop, foreach_start_stop,
	undef_start_stop, lang_undef_start_stop, lang_init_startof_sizeof,
	set_start_stop, lang_finalize_start_stop): New functions.
	(lang_process): Call _start_stop functions.
	* testsuite/ld-elf/pr21562a.d: Use xfail rather than notarget.
	Correct typos and list of xfail targets.
	* testsuite/ld-elf/pr21562b.d: Likewise.
	* testsuite/ld-elf/pr21562c.d: Likewise.
	* testsuite/ld-elf/pr21562d.d: Likewise.
	* testsuite/ld-elf/pr21562e.d: Likewise.
	* testsuite/ld-elf/pr21562f.d: Likewise.
	* testsuite/ld-elf/pr21562g.d: Likewise.
	* testsuite/ld-elf/pr21562h.d: Likewise.
	* testsuite/ld-elf/pr21562i.d: Likewise.
	* testsuite/ld-elf/pr21562j.d: Likewise.
	* testsuite/ld-elf/pr21562k.d: Likewise.
	* testsuite/ld-elf/pr21562l.d: Likewise.
	* testsuite/ld-elf/pr21562m.d: Likewise.
	* testsuite/ld-elf/pr21562n.d: Likewise.
	* testsuite/ld-elf/sizeofa.d: Likewise.  Adjust to pass for generic ELF.
	* testsuite/ld-elf/sizeofb.d: Likewise.
	* testsuite/ld-elf/startofa.d: Likewise.
	* testsuite/ld-elf/startofb.d: Likewise.
2017-06-16 23:38:28 +09:30
H.J. Lu
b27685f201 ld: Don't define __start_SECNAME/__stop_SECNAME for -r
__start_SECNAME and __stop_SECNAME shouldn't be defined for "ld -r".

	* ldlang.c (lang_set_startof): Skip if config.build_constructors
	is FALSE.
	* testsuite/ld-elf/sizeofc.d: New file.
	* testsuite/ld-elf/startofc.d: Likewise.
2017-06-13 13:04:56 -07:00
H.J. Lu
cbd0eecf26 Always define referenced __start_SECNAME/__stop_SECNAME
Currently, linker will define __start_SECNAME and __stop_SECNAME symbols
only for orphaned sections.

However, during garbage collection, ELF linker marks all sections with
references to __start_SECNAME and __stop_SECNAME symbols as used even
when section SECNAME isn't an orphaned section and linker won't define
__start_SECNAME nor __stop_SECNAME.  And ELF linker stores the first
input section whose name matches __start_SECNAME or __stop_SECNAME in
u.undef.section for garbage collection.  If these symbols are provided
in linker script, u.undef.section is set to the section where they will
defined by linker script, which leads to the incorrect output.

This patch changes linker to always define referenced __start_SECNAME and
__stop_SECNAME if the input section name is the same as the output section
name, which is always true for orphaned sections, and SECNAME is a C
identifier.  Also __start_SECNAME and __stop_SECNAME symbols are marked
as hidden by ELF linker so that __start_SECNAME and __stop_SECNAME symbols
for section SECNAME in different modules are unique.  For garbage
collection, ELF linker stores the first matched input section in the
unused vtable field.

bfd/

	PR ld/20022
	PR ld/21557
	PR ld/21562
	PR ld/21571
	* elf-bfd.h (elf_link_hash_entry): Add start_stop.  Change the
	vtable field to a union.
	(_bfd_elf_is_start_stop): Removed.
	* elf32-i386.c (elf_i386_convert_load_reloc): Also check for
	__start_SECNAME and __stop_SECNAME symbols.
	* elf64-x86-64.c (elf_x86_64_convert_load_reloc): Likewise.
	* elflink.c (_bfd_elf_is_start_stop): Removed.
	(_bfd_elf_gc_mark_rsec): Check start_stop instead of calling
	_bfd_elf_is_start_stop.
	(elf_gc_propagate_vtable_entries_used): Skip __start_SECNAME and
	__stop_SECNAME symbols.  Updated.
	(elf_gc_smash_unused_vtentry_relocs): Likewise.
	(bfd_elf_gc_record_vtinherit): Likewise.
	(bfd_elf_gc_record_vtentry): Likewise.

ld/

	PR ld/20022
	PR ld/21557
	PR ld/21562
	PR ld/21571
	* ld.texinfo: Update __start_SECNAME/__stop_SECNAME symbols.
	* ldlang.c (lang_insert_orphan): Move handling of __start_SECNAME
	and __stop_SECNAME symbols to ...
	(lang_set_startof): Here.  Also define __start_SECNAME and
	__stop_SECNAME for -Ur.
	* emultempl/elf32.em (gld${EMULATION_NAME}_after_open): Mark
	referenced __start_SECNAME and __stop_SECNAME symbols as hidden
	and set start_stop for garbage collection.
	* testsuite/ld-elf/pr21562a.d: New file.
	* testsuite/ld-elf/pr21562a.s: Likewise.
	* testsuite/ld-elf/pr21562a.t: Likewise.
	* testsuite/ld-elf/pr21562b.d: Likewise.
	* testsuite/ld-elf/pr21562b.s: Likewise.
	* testsuite/ld-elf/pr21562b.t: Likewise.
	* testsuite/ld-elf/pr21562c.d: Likewise.
	* testsuite/ld-elf/pr21562c.t: Likewise.
	* testsuite/ld-elf/pr21562d.d: Likewise.
	* testsuite/ld-elf/pr21562d.t: Likewise.
	* testsuite/ld-elf/pr21562e.d: Likewise.
	* testsuite/ld-elf/pr21562f.d: Likewise.
	* testsuite/ld-elf/pr21562g.d: Likewise.
	* testsuite/ld-elf/pr21562h.d: Likewise.
	* testsuite/ld-elf/pr21562i.d: Likewise.
	* testsuite/ld-elf/pr21562j.d: Likewise.
	* testsuite/ld-elf/pr21562k.d: Likewise.
	* testsuite/ld-elf/pr21562l.d: Likewise.
	* testsuite/ld-elf/pr21562m.d: Likewise.
	* testsuite/ld-elf/pr21562n.d: Likewise.
	* testsuite/ld-gc/pr20022.d: Likewise.
	* testsuite/ld-gc/pr20022a.s: Likewise.
	* testsuite/ld-gc/pr20022b.s: Likewise.
	* testsuite/ld-gc/gc.exp: Run PR ld/20022 tests.
	* testsuite/ld-gc/pr19161.d: Also accept local __start_SECNAME
	symbol.
	* testsuite/ld-gc/start.d: Likewise.
	* testsuite/ld-x86-64/lea1a.d: Updated.
	* testsuite/ld-x86-64/lea1b.d: Updated.
	* testsuite/ld-x86-64/lea1d.d: Updated.
	* testsuite/ld-x86-64/lea1e.d: Likewise.
2017-06-13 08:53:22 -07:00
Andrew Burgess
7bdf4127c3 ld: Allow section groups to be resolved as part of a relocatable link
This commit adds a new linker feature: the ability to resolve section
groups as part of a relocatable link.

Currently section groups are automatically resolved when performing a
final link, and are carried through when performing a relocatable link.
By carried through this means that one copy of each section group (from
all the copies that might be found in all the input files) is placed
into the output file.  Sections that are part of a section group will
not match input section specifiers within a linker script and are
forcibly kept as separate sections.

There is a slight resemblance between section groups and common
section.  Like section groups, common sections are carried through when
performing a relocatable link, and resolved (allocated actual space)
only at final link time.

However, with common sections there is an ability to force the linker to
allocate space for the common sections when performing a relocatable
link, there's currently no such ability for section groups.

This commit adds such a mechanism.  This new facility can be accessed in
two ways, first there's a command line switch --force-group-allocation,
second, there's a new linker script command FORCE_GROUP_ALLOCATION.  If
one of these is used when performing a relocatable link then the linker
will resolve the section groups as though it were performing a final
link, the section group will be deleted, and the members of the group
will be placed like normal input sections.  If there are multiple copies
of the group (from multiple input files) then only one copy of the group
members will be placed, the duplicate copies will be discarded.

Unlike common sections that have the --no-define-common command line
flag, and INHIBIT_COMMON_ALLOCATION linker script command there is no
way to prevent group resolution during a final link, this is because the
ELF gABI specifically prohibits the presence of SHT_GROUP sections in a
fully linked executable.  However, the code as written should make
adding such a feature trivial, setting the new resolve_section_groups
flag to false during a final link should work as you'd expect.

bfd/ChangeLog:

	* elf.c (_bfd_elf_make_section_from_shdr): Don't initially mark
	SEC_GROUP sections as SEC_EXCLUDE.
	(bfd_elf_set_group_contents): Replace use of abort with an assert.
	(assign_section_numbers): Use resolve_section_groups flag instead
	of relocatable link type.
	(_bfd_elf_init_private_section_data): Use resolve_section_groups
	flag instead of checking the final_link flag for part of the
	checks in here.  Fix white space as a result.
	* elflink.c (elf_link_input_bfd): Use resolve_section_groups flag
	instead of relocatable link type.
	(bfd_elf_final_link): Likewise.

include/ChangeLog:

	* bfdlink.h (struct bfd_link_info): Add new resolve_section_groups
	flag.

ld/ChangeLog:

	* ld.h (struct args_type): Add force_group_allocation field.
	* ldgram.y: Add support for FORCE_GROUP_ALLOCATION.
	* ldlex.h: Likewise.
	* ldlex.l: Likewise.
	* lexsup.c: Likewise.
	* ldlang.c (unique_section_p): Check resolve_section_groups flag
	not the relaxable link flag.
	(lang_add_section): Discard section groups when we're resolving
	groups.  Clear the SEC_LINK_ONCE flag if we're resolving section
	groups.
	* ldmain.c (main): Initialise resolve_section_groups flag in
	link_info based on command line flags.
	* testsuite/ld-elf/group11.d: New file.
	* testsuite/ld-elf/group12.d: New file.
	* testsuite/ld-elf/group12.ld: New file.
	* NEWS: Mention new features.
	* ld.texinfo (Options): Document --force-group-allocation.
	(Miscellaneous Commands): Document FORCE_GROUP_ALLOCATION.
2017-06-06 09:53:38 +01:00
Nick Clifton
3aa2d05a72 Treat a prefix of "$SYSROOT" in the same way as "=" when parsing linker search paths.
PR ld/21251
	* ldfile.c (ldfile_add_library_path): If the path starts with
	$SYSROOT then use the sysroot as the real prefix.
	* ldlang.c (lang_add_input_file): Treat $SYSROOT in the same
	way as =.
	* ldlex.l: Add $SYSROOT as allow prefix for a filename.
	* ld.texinfo (-L): Document that $SYSROOT acts like = when
	prefixing a library search path.
	(INPUT): Likewise.
	* testsuite/ld-scripts/sysroot-prefix.exp: Add $SYSROOT prefix
	tests.
2017-05-18 15:07:59 +01:00
Maciej W. Rozycki
80070c0d34 PR ld/21233: Avoid sweeping forced-undefined symbols in section GC
Complement commit 902e9fc76a ("PR ld/20828: Move symbol version
processing ahead of GC symbol sweep"), commit b531344c34 ("PR
ld/20828: Reorder the symbol sweep stage of section GC") and commit
81ff47b3a5 ("PR ld/20828: Fix linker script symbols wrongly forced
local with section GC"), and prevent symbols forcibly entered in the
output file with the use of the `--undefined=' or `--require-defined='
linker command line options or the EXTERN linker script command from
being swept in section garbage collection and consequently recorded in
the dynamic symbol table as local entries.  This happens in certain
circumstances, where a symbol reference also exists in one of the static
input files, however only in a section which is garbage-collected and
does not make it to the output file, and the symbol is defined in a
dynamic object present in the link.

For example with the `i386-linux' target and the `pr21233.s' and
`pr21233-l.s' sources, and the `pr21233.ld' linker script included with
this change we get:

$ as -o pr21233-l.o pr21233-l.s
$ ld -shared -T pr21233.ld -o libpr21233.so pr21233-l.o
$ as -o pr21233.o pr21233.s
$ ld --gc-sections -e foo --require-defined=bar -T pr21233.ld -o pr21233 pr21233.o libpr21233.so
$ readelf --dyn-syms pr21233

Symbol table '.dynsym' contains 2 entries:
   Num:    Value  Size Type    Bind   Vis      Ndx Name
     0: 00000000     0 NOTYPE  LOCAL  DEFAULT  UND
     1: 00000000     0 OBJECT  LOCAL  DEFAULT  UND bar
$

which makes the run-time `bar' dependency of the `pr21233' executable
different from its corresponding link-time dependency, i.e. the presence
of `libpr21233.so' and its `bar' symbol is required at the link time,
however at the run time a copy of `libpr21233.so' without `bar' will do.
Similarly with `--undefined=' and EXTERN which do not actually require
the reference to the symbol requested to be satisfied with a definition
at the link time, however once the definition has been pulled at the
link time, so it should at the dynamic load time.

Additionally with the `mips-linux' target we get:

$ ld --gc-sections -e foo --require-defined=bar -T pr21233.ld -o pr21233 pr21233.o libpr21233.so
ld: BFD (GNU Binutils) 2.28.51.20170324 assertion fail .../bfd/elfxx-mips.c:3861
$

as the target is not prepared to handle such a local dynamic symbol.

With this change in effect we get:

$ readelf --dyn-syms pr21233

Symbol table '.dynsym' contains 2 entries:
   Num:    Value  Size Type    Bind   Vis      Ndx Name
     0: 00000000     0 NOTYPE  LOCAL  DEFAULT  UND
     1: 00000000     0 OBJECT  GLOBAL DEFAULT  UND bar
$

instead, for both targets.

	ld/
	PR ld/21233
	* ldlang.c (insert_undefined): Set `mark' for ELF symbols.
	* testsuite/ld-elf/pr21233.sd: New test.
	* testsuite/ld-elf/pr21233-l.sd: New test.
	* testsuite/ld-elf/pr21233.ld: New test linker script.
	* testsuite/ld-elf/pr21233-e.ld: New test linker script.
	* testsuite/ld-elf/pr21233.s: New test source.
	* testsuite/ld-elf/pr21233-l.s: New test source.
	* testsuite/ld-elf/shared.exp: Run the new tests.
2017-04-04 23:21:44 +01:00
Tristan Gingold
2170171889 ld: check overflow only for allocated sections.
* ldlang.c (lang_check_section_addresses): Check only for
	allocated sections.
2017-03-21 12:00:30 +01:00
H.J. Lu
9216a6f335 Use addr_mask to check VMA and LMA
Since BFD64 may be used on 32-bit address, we need to apply addr_mask
to check VMA and LMA.

	* ldlang.c (lang_check_section_addresses): Use addr_mask to
	check VMA and LMA.
2017-03-14 09:09:54 -07:00
Tristan Gingold
d40e34db39 ld: add an error in case of address space overflow.
ld/
	* ldlang.c (lang_check_section_addresses): Check for address space
	overflow.
	* testsuite/ld-checks/checks.exp (overflow_check): New procedure
	* testsuite/ld-checks/over.s: New test source.
	* testsuite/ld-checks/over.d: New test.
	* testsuite/ld-checks/over2.s: New test source.
	* testsuite/ld-checks/over2.d: New test.
2017-03-13 10:41:22 +01:00
Andrew Burgess
14ea2c1b23 ld: Track changes to default region LMA even for empty sections
Given a linker script fragment like this:

   SECTIONS {
     . = 0x1000;
     .text   : AT(0x100) { *(.text)   }
     .data   : AT(0x200) { *(.data)   }
     .rodata : AT(0x300) { *(.rodata) }
   }

and an input file containing sections, '.text', '.data.1', and
'.rodata', then we'd expect the linker to place '.text' and '.rodata' in
the obvious way, and the '.data.1' orphan section would be located after
the '.data' section (assuming similar section properties).

Further, I believe that the expectation would be that the LMA for the
orphan '.data.1' section would start from 0x200 (as there is no '.data'
content).

However, right now, the LMA for '.data.1' would be 0x101, following on
from the '.text' section, this is because the change in LMA for the
'.data' section is not noticed by the linker, if there's no content in
the '.data' section.

What can be even more confusing to a user (though the cause is obvious
once you understand what's going on) is that adding some content to
'.data' will cause the orphan '.data.1' to switch to an LMA based off of
0x200.

This commit changes the behaviour so that an empty section that is in
the default lma region, and sets its lma, will adjust the lma of the
default region, this change will then be reflected in following sections
within the default lma memory region.

There's a new test to cover this issue that passes on a range of
targets, however, some targets generate additional sections, or have
stricter memory region size requirements that make it harder to come
up with a generic pass pattern, that still tests the required
features.  For now I've set the test to ignore these targets.

ld/ChangeLog:

	* ldlang.c (lang_size_sections_1): Shortcut loop only after
	tracking changes to the default regions LMA.
	* testsuite/ld-elf/orphan-9.ld: Extend header comment.
	* testsuite/ld-elf/orphan-10.d: New file.
	* testsuite/ld-elf/orphan-10.s: New file.
	* NEWS: Mention change in behaviour.
2017-03-09 21:11:06 +00:00
Andrew Burgess
77f5e65ecf ld: better handling of lma region for orphan sections
When picking an lma_region for an orphan section we currently create a
new lang_output_section_statement_type and then populate this with the
orphan section.

The problem is that the lang_output_section_statement_type has a prev
pointer that links back to the previous output section.  For non-orphan
output sections, that are created in linker script order, the prev
pointer will point to the output section that appears previous in linker
script order, as you'd probably expect.

The problem is that orphan sections are placed after processing the
linker script, and so, in the case of an output section created for an
orphan input section, the prev pointer actually points to the last
output section created.

This causes some unexpected behaviour when the orphan section is not
placed after the last non-orphan section that was created.

For example, consider this linker script:

  MEMORY {
    TEXT   : ORIGIN = 0x200,  LENGTH = 0x10
    RODATA : ORIGIN = 0x400,  LENGTH = 0x10
  }

  SECTIONS {
    .text   :           {*(.text)    } AT>TEXT
    .data   : AT(0x300) { *(.data)   }
    .rodata :           { *(.rodata) } AT>RODATA
  }

If we are processing an orphan section '.data.1' and decide to place
this after '.data', then the output section created will have a prev
pointer that references the '.rodata' output section.  The result of
this is that '.data.1' will actually be assigned to the RODATA lma
region, which is probably not the expected behaviour.

The reason why '.data.1' is placed into the lma region of the '.rodata'
section is that lma region propagation is done at the time we create the
output section, based on the previous output section pointer, which is
really just a last-output-section-created pointer at that point in time,
though the prev point is fixed up later to reflect the true order of the
output sections.

The solution I propose in this commit is to move the propagation of lma
regions into a separate pass of the linker, rather than performing this
as part of the enter/exit of output sections during linker script
parsing.

During this later phase we have all of the output sections to hand, and
the prev/next points have been fixed up by this point to reflect the
actual placement ordering.

There's a new test to cover this issue that passes on a range of
targets, however, some targets generate additional sections, or have
stricter memory region size requirements that make it harder to come
up with a generic pass pattern, that still tests the required
features.  For now I've set the test to ignore these targets.

ld/ChangeLog:

	* ldlang.c (lang_leave_output_section_statement): Move lma_region
	logic to...
	(lang_propagate_lma_regions): ...this new function.
	(lang_process): Call new function.
	* testsuite/ld-elf/orphan-9.d: New file.
	* testsuite/ld-elf/orphan-9.ld: New file.
	* testsuite/ld-elf/orphan-9.s: New file.
	* NEWS: Mention change in behaviour.
2017-03-09 21:11:05 +00:00
Alan Modra
d933941d6c Fix ld uninitialized read of script ASSERT data structure
lang_assignment_statement serves both assignments and asserts.

	* ldlang.c (open_input_bfds): Check that lang_assignment_statement
	is not an assert before referencing defsym.
2017-03-07 12:33:28 +10:30
Nick Clifton
1273da0414 Fix buffer overflows in ld when printing translated strings.
ld	* ldmain.c (add_archive_element): Eliminate string buffer.
	* ldlang.c (lang_print_asneeded): Likewise.
2017-01-31 12:07:04 +00:00
Alan Modra
2571583aed Update year range in copyright notice of all files. 2017-01-02 14:08:56 +10:30
Igor Kudrin
9ef7906f20 Do not add padding if an output section is marked as ignored
* ldlang.c (size_input_section): Avoid calling insert_pad
	if output_section_statement->ignored is set.
2016-12-22 00:12:36 +10:30
Ambrogino Modigliani
370dfff4c4 Fix spelling in comments in C source files (ld)
* deffile.h: Fix spelling in comments.
	* ld.h: Fix spelling in comments.
	* ldlang.c: Fix spelling in comments.
	* ldmisc.c: Fix spelling in comments.
	* pe-dll.c: Fix spelling in comments.
2016-11-27 15:04:38 +10:30
Andrew Burgess
8f1732fc2a ld: Allow EXCLUDE_FILE to be used outside of the section list
Currently the EXCLUDE_FILE linker script construct can only be used
within the input section list, and applied only to the section pattern
immediately following the EXCLUDE_FILE.  For example:

    *.o (EXCLUDE_FILE (a.o) .text .rodata)

In this case all sections matching '.text' are included from all files
matching '*.o' but not from the file 'a.o'.  All sections matching
'.rodata' are also included from all files matching '*.o' (incluing from
'a.o').

If the user wants to restrict the inclusion of section '.rodata' so that
this too is not taken from the file 'a.o' then the above example must be
extended like this:

    *.o (EXCLUDE_FILE (a.o) .text EXCLUDE_FILE (a.o) .rodata)

However, due to the internal grammar of the linker script language the
snippet 'EXCLUDE_FILE (a.o) .text' is parsed by a pattern called
'wildcard_spec'.  The same 'wildcard_spec' pattern is also used to parse
the input file name snippet '*.o' in the above examples.  As a result of
this pattern reuse within the linker script grammar then the following
is also a valid linker script construct:

    EXCLUDE_FILE (a.o) *.o (.text .rodata)

However, though the linker accepts this without complaint the
EXCLUDE_FILE part is silently ignored and has no effect.

This commit takes this last example and makes it a useful, valid,
construct.  The last example now means to include sections '.text' and
'.rodata' from all files matching '*.o' except for the file 'a.o'.

If the list of input sections is long, and the user knows that the file
exclusion applies across the list then the second form might be a
clearer alternative to replicating the EXCLUDE_FILE construct.

I've added a set of tests for EXCLUDE_FILE to the linker, including
tests for the new functionality.

ld/ChangeLog:

	* ldlang.h (struct lang_wild_statement_struct): Add
	exclude_name_list field.
	* ldlang.c (walk_wild_file_in_exclude_list): New function.
	(walk_wild_consider_section): Use new
	walk_wild_file_in_exclude_list function.
	(walk_wild_file): Add call to walk_wild_file_in_exclude_list.
	(print_wild_statement): Print new exclude_name_list field.
	(lang_add_wild): Initialise new exclude_name_list field.
	* testsuite/ld-scripts/exclude-file-1.d: New file.
	* testsuite/ld-scripts/exclude-file-1.map: New file.
	* testsuite/ld-scripts/exclude-file-1.t: New file.
	* testsuite/ld-scripts/exclude-file-2.d: New file.
	* testsuite/ld-scripts/exclude-file-2.map: New file.
	* testsuite/ld-scripts/exclude-file-2.t: New file.
	* testsuite/ld-scripts/exclude-file-3.d: New file.
	* testsuite/ld-scripts/exclude-file-3.map: New file.
	* testsuite/ld-scripts/exclude-file-3.t: New file.
	* testsuite/ld-scripts/exclude-file-4.d: New file.
	* testsuite/ld-scripts/exclude-file-4.map: New file.
	* testsuite/ld-scripts/exclude-file-4.t: New file.
	* testsuite/ld-scripts/exclude-file-a.s: New file.
	* testsuite/ld-scripts/exclude-file-b.s: New file.
	* testsuite/ld-scripts/exclude-file.exp: New file.
	* ld.texinfo (Input Section Basics): Update description of
	EXCLUDE_FILE to cover the new features.
	* NEWS: Mention new EXCLUDE_FILE usage.
2016-11-04 12:04:11 +00:00
Alan Modra
f02cb05882 Always descend into output section statements in lang_do_assignments
See https://sourceware.org/ml/binutils/2016-07/msg00091.html
This patch stop --gc-sections elf_gc_sweep_symbol localizing symbols
that ought to remain global.

The difficulty with always descending into output section statements
is that symbols defined by the script in such statements don't have
a bfd section when lang_do_assignments runs early in the link process.
There are two approaches to curing this problem.  Either we can
create the bfd section early, or we can use a special section.  This
patch takes the latter approach and uses bfd_und_section.  (Creating
bfd sections early results in changed output section order, and thus
lots of testsuite failures.  You can't create all output sections
early to ensure proper ordering as KEEP then stops empty sections
from being stripped.)

The wrinkle with this approach is that some code that runs at
gc-sections time needs to be made aware of the odd defined symbols
using bfd_und_section.

bfd/
	* elf64-x86-64.c (elf_x86_64_convert_load_reloc): Handle symbols
	defined temporarily with bfd_und_section.
	* elflink.c (_bfd_elf_gc_keep): Don't set SEC_KEEP for bfd_und_section.
	* elfxx-mips.c (mips_elf_local_pic_function_p): Exclude defined
	symbols with bfd_und_section.
ld/
	* ldlang.c (lang_do_assignments_1): Descend into output section
	statements that do not yet have bfd sections.  Set symbol section
	temporarily for symbols defined in such statements to the undefined
	section.  Don't error on data or reloc statements until final phase.
	* ldexp.c (exp_fold_tree_1 <etree_assign>): Handle bfd_und_section
	in expld.section.
	* testsuite/ld-mmix/bpo-10.d: Adjust.
	* testsuite/ld-mmix/bpo-11.d: Adjust.
2016-10-11 18:13:04 +10:30
Alan Modra
50e03d47b7 Pass link_info to _bfd_merge_private_bfd_data
Most BFD linker functions take a bfd_link_info param, which reinforces
the fact that they are linker functions and allow access to linker
callbacks, eg. einfo for printing errors.  I was going to use einfo
for --fatal-warnings support before I decided a better way was the
patch commit 4519d071.

bfd/
	* targets.c (bfd_target <_bfd_merge_private_bfd_data>): Replace
	obfd param with struct bfd_link_info param.  Update all callers.
	* linker.c (bfd_merge_private_bfd_data): Likewise.
	(_bfd_generic_verify_endian_match): Likewise.
	* aoutf1.h (sunos_merge_private_bfd_data): Likewise.
	* coff-arm.c (coff_arm_merge_private_bfd_data): Likewise.
	* elf-attrs.c (_bfd_elf_merge_object_attributes): Likewise.
	* elf-bfd.h (_bfd_elf_ppc_merge_fp_attributes): Likewise.
	(_bfd_elf_merge_object_attributes): Likewise.
	* elf-m10300.c (_bfd_mn10300_elf_merge_private_bfd_data): Likewise.
	* elf-s390-common.c (elf_s390_merge_obj_attributes): Likewise.
	* elf32-arc.c (arc_elf_merge_private_bfd_data): Likewise.
	* elf32-arm.c (elf32_arm_merge_eabi_attributes): Likewise.
	(elf32_arm_merge_private_bfd_data): Likewise.
	* elf32-bfin.c (elf32_bfin_merge_private_bfd_data): Likewise.
	* elf32-cr16.c (_bfd_cr16_elf_merge_private_bfd_data): Likewise.
	* elf32-cris.c (cris_elf_merge_private_bfd_data): Likewise.
	* elf32-frv.c (frv_elf_merge_private_bfd_data): Likewise.
	* elf32-h8300.c (elf32_h8_merge_private_bfd_data): Likewise.
	* elf32-i370.c (i370_elf_merge_private_bfd_data): Likewise.
	* elf32-iq2000.c (iq2000_elf_merge_private_bfd_data): Likewise.
	* elf32-m32c.c (m32c_elf_merge_private_bfd_data): Likewise.
	* elf32-m32r.c (m32r_elf_merge_private_bfd_data): Likewise.
	* elf32-m68hc1x.c (_bfd_m68hc11_elf_merge_private_bfd_data): Likewise.
	* elf32-m68hc1x.h (_bfd_m68hc11_elf_merge_private_bfd_data): Likewise.
	* elf32-m68k.c (elf32_m68k_merge_private_bfd_data): Likewise.
	* elf32-mcore.c (mcore_elf_merge_private_bfd_data): Likewise.
	* elf32-mep.c (mep_elf_merge_private_bfd_data): Likewise.
	* elf32-msp430.c (elf32_msp430_merge_mspabi_attributes): Likewise.
	(elf32_msp430_merge_private_bfd_data): Likewise.
	* elf32-mt.c (mt_elf_merge_private_bfd_data): Likewise.
	* elf32-nds32.c (nds32_elf_merge_private_bfd_data): Likewise.
	* elf32-nios2.c (nios2_elf32_merge_private_bfd_data): Likewise.
	* elf32-or1k.c (elf32_or1k_merge_private_bfd_data): Likewise.
	* elf32-ppc.c (_bfd_elf_ppc_merge_fp_attributes): Likewise.
	(ppc_elf_merge_obj_attributes): Likewise.
	(ppc_elf_merge_private_bfd_data): Likewise.
	* elf32-rl78.c (rl78_elf_merge_private_bfd_data): Likewise.
	* elf32-rx.c (rx_elf_merge_private_bfd_data): Likewise.
	* elf32-s390.c (elf32_s390_merge_private_bfd_data): Likewise.
	* elf32-score.c (s3_elf32_score_merge_private_bfd_data): Likewise.
	(elf32_score_merge_private_bfd_data): Likewise.
	* elf32-score.h (s7_elf32_score_merge_private_bfd_data): Likewise.
	* elf32-score7.c (s7_elf32_score_merge_private_bfd_data): Likewise.
	* elf32-sh.c (sh_merge_bfd_arch, sh_elf_merge_private_data): Likewise.
	* elf32-sh64.c (sh64_elf_merge_private_data): Likewise.
	* elf32-sparc.c (elf32_sparc_merge_private_bfd_data): Likewise.
	* elf32-tic6x.c (elf32_tic6x_merge_attributes): Likewise.
	(elf32_tic6x_merge_private_bfd_data): Likewise.
	* elf32-v850.c (v850_elf_merge_private_bfd_data): Likewise.
	* elf32-vax.c (elf32_vax_merge_private_bfd_data): Likewise.
	* elf32-visium.c (visium_elf_merge_private_bfd_data): Likewise.
	* elf32-xtensa.c (elf_xtensa_merge_private_bfd_data): Likewise.
	* elf64-ia64-vms.c (elf64_ia64_merge_private_bfd_data): Likewise.
	* elf64-ppc.c (ppc64_elf_merge_private_bfd_data): Likewise.
	* elf64-s390.c (elf64_s390_merge_private_bfd_data): Likewise.
	* elf64-sh64.c (sh_elf64_merge_private_data): Likewise.
	* elf64-sparc.c (elf64_sparc_merge_private_bfd_data): Likewise.
	* elfnn-aarch64.c (elfNN_aarch64_merge_private_bfd_data): Likewise.
	* elfnn-ia64.c (elfNN_ia64_merge_private_bfd_data): Likewise.
	* elfxx-mips.c (mips_elf_merge_obj_e_flags): Likewise.
	(mips_elf_merge_obj_attributes): Likewise.
	(_bfd_mips_elf_merge_private_bfd_data): Likewise.
	* elfxx-mips.h (_bfd_mips_elf_merge_private_bfd_data): Likewise.
	* elfxx-sparc.c (_bfd_sparc_elf_merge_private_bfd_data): Likewise.
	* elfxx-sparc.h (_bfd_sparc_elf_merge_private_bfd_data): Likewise.
	* elfxx-target.h (bfd_elfNN_bfd_merge_private_bfd_data): Likewise.
	* elfxx-tilegx.c (_bfd_tilegx_elf_merge_private_bfd_data): Likewise.
	* elfxx-tilegx.h (_bfd_tilegx_elf_merge_private_bfd_data): Likewise.
	* libbfd-in.h (_bfd_generic_bfd_merge_private_bfd_data): Likewise.
	* bfd-in2.h: Regenerate.
	* libbfd.h: Regenerate.
ld/
	* ldlang.c (lang_check): Update bfd_merge_private_bfd_data call.
2016-10-07 11:24:41 +10:30
Alan Modra
52d45da3f2 Make bfd_error_handler_type like vprintf
It was like printf, which means you can't use bfd_set_error_handler to
hook in a function to do something and then call the original handler.

The patch also deletes some unused functions and makes pointers local.

bfd/
	* bfd-in.h: Include stdarg.h.
	* bfd.c (bfd_error_handler_type): Make like vprintf.
	(_bfd_error_internal): Rename from _bfd_error_handler.  Make static.
	(error_handler_internal): New function, split out from..
	(_bfd_default_error_handler): ..here.  Rename to _bfd_error_handler.
	(bfd_set_error_handler): Update.
	(bfd_get_error_handler, bfd_get_assert_handler): Delete.
	(_bfd_assert_handler): Make static.
	* coffgen.c (null_error_handler): Update params.
	* elf-bfd.h (struct elf_backend_data <link_order_error_handler>):
	Don't use bfd_error_handler_type.
	* elf64-mmix.c (mmix_dump_bpo_gregs): Likewise.
	* elfxx-target.h (elf_backend_link_order_error_handler): Default
	to _bfd_error_handler.
	* libbfd-in.h (_bfd_default_error_handler): Don't declare.
	(bfd_assert_handler_type): Likewise.
	(_bfd_error_handler): Update.
	* bfd-in2.h: Regenerate.
	* libbfd.h: Regenerate.
ld/
	* ldlang.c (ignore_bfd_errors): Update params.
2016-09-30 11:38:39 +09:30
Alan Modra
2e84f9c1b5 Ignore symbols defined in SHF_EXCLUDE sections
PR 20513
	* ldlang.c (section_already_linked): Deal with SHF_EXCLUDE sections.
2016-08-31 19:22:43 +09:30
Alan Modra
4212b42d79 Don't include libbfd.h outside of bfd, part 4
Not much to see here, just renaming a function.

bfd/
	* targets.c (bfd_seach_for_target): Rename to..
	(bfd_iterate_over_targets): ..this.  Rewrite doc.
	* bfd-in2.h: Regenerate.
ld/
	* ldlang.c (open_output): Replace bfd_search_for_target with
	bfd_iterate_over_targets.  Localize vars.
2016-07-16 13:29:35 +09:30
Alan Modra
76e7a75123 Don't include libbfd.h outside of bfd, part 1
Make BFD_ALIGN available to objcopy.  Fix assertions.  Don't use
bfd_log2 in ppc32elf.em or bfd_malloc in xtensaelf.em and bucomm.c.

bfd/
	* libbfd-in.h (BFD_ALIGN): Move to..
	* bfd-in.h: ..here.
	* elf32-ppc.h (struct ppc_elf_params): Add pagesize.
	* elf32-ppc.c (default_params): Adjust init.
	(ppc_elf_link_params): Set pagesize_p2.
	* libbfd.h: Regenerate.
	* bfd-in2.h: Regenerate.
binutils/
	* ar.c: Don't include libbfd.h.
	* objcopy.c: Likewise.
	* bucomm.c (bfd_get_archive_filename): Use xmalloc rather than
	bfd_malloc.
gas/
	* config/bfin-parse.y: Don't include libbfd.h.
	* config/tc-bfin.c: Likewise.
	* config/tc-rl78.c: Likewise.
	* config/tc-rx.c: Likewise.
	* config/tc-metag.c: Likewise.
	(create_dspreg_htabs, create_scond_htab): Use gas_assert not BFD_ASSERT.
	* Makefile.am: Update dependencies.
	* Makefile.in: Regenerate.
ld/
	* ldlang.c: Don't include libbfd.h.
	* emultempl/nds32elf.em: Likewise.
	* emultempl/ppc64elf.em: Likewise.
	* emultempl/ppc32elf.em: Likewise.
	(pagesize): Delete.
	(params): Update init.
	(ppc_after_open_output): Use params.pagesize.  Don't call bfd_log2.
	(PARSE_AND_LIST_ARGS_CASES): Use params.pagesize.
	* emultempl/sh64elf.em: Don't include libbfd.h.
	(after_allocation): Use ASSERT, not BFD_ASSERT.
	* emultempl/xtensaelf.em: Don't include libbfd.h.
	(replace_insn_sec_with_prop_sec): Use xmalloc, not bfd_malloc.
	* Makefile.am: Update dependencies.
	* Makefile.in: Regenerate.
2016-07-16 13:25:11 +09:30
Alan Modra
0aa7f5862e Formatting fixes.
* ldbuildid.c: Formatting.
	* ldcref.c: Formatting.
	* ldctor.c: Formatting.
	* ldemul.c: Formatting.
	* ldexp.c: Formatting.
	* ldfile.c: Formatting.
	* ldlang.c: Formatting.
	* ldmain.c: Formatting.
	* ldwrite.c: Formatting.
2016-06-14 13:25:21 +09:30
Alan Modra
3860d2b4b7 Delete bfd_my_archive macro
Many more places use abfd->my_archive rather than bfd_my_archive (abfd),
so let's make the code consistently use the first idiom.

bfd/
	* bfd-in.h (bfd_my_archive): Delete.
	* bfd-in2.h: Regenerate.
binutils/
	* ar.c: Expand uses of bfd_my_archive.
	* size.c: Likewise.
ld/
	* ldlang.c: Expand uses of bfd_my_archive.
	* ldmain.c: Likewise.
	* ldmisc.c: Likewise.
	* plugin.c: Likewise.
2016-06-14 13:24:37 +09:30
H.J. Lu
d4758f96f7 Pass %E to einfo when bfd_section == NULL
Report BFD error When bfd_section == NULL in init_os.

	* ldlang.c (init_os): Pass %E to einfo when bfd_section == NULL.
2016-05-04 19:41:34 -07:00
Nick Clifton
4f3b23b390 Add support for non-ELF targets to check their relocs.
bfd	* aout-adobe.c: Use _bfd_generic_link_check_relocs.
	* aout-target.h: Likewise.
	* aout-tic30.c: Likewise.
	* binary.c: Likewise.
	* bout.c: Likewise.
	* coff-alpha.c: Likewise.
	* coff-rs6000.c: Likewise.
	* coff64-rs6000.c: Likewise.
	* coffcode.h: Likewise.
	* i386msdos.c: Likewise.
	* i386os9k.c: Likewise.
	* ieee.c: Likewise.
	* ihex.c: Likewise.
	* libbfd-in.h: Likewise.
	* libecoff.h: Likewise.
	* mach-o-target.c: Likewise.
	* mmo.c: Likewise.
	* nlm-target.h: Likewise.
	* oasys.c: Likewise.
	* pef.c: Likewise.
	* plugin.c: Likewise.
	* ppcboot.c: Likewise.
	* som.c: Likewise.
	* srec.c: Likewise.
	* tekhex.c: Likewise.
	* versados.c: Likewise.
	* vms-alpha.c: Likewise.
	* xsym.c: Likewise.
	* elfxx-target.h: Use _bfd_elf_link_check_relocs.
	* linker.c (bfd_link_check_relocs): New function.
	(_bfd_generic_link_check_relocs): New function.
	* targets.c (BFD_JUMP_TABLE_LINK): Add initialization of
	_bfd_link_check_relocs field.
	(struct bfd_target)L Add _bfd_link_check_relocs field.
	* bfd-in2.h: Regenerate.
	* libbfd.h: Regenerate.

ld	* ldlang.c (lang_check_relocs): Use bfd_link_check_relocs in
	prefernce to _bfd_elf_link_check_relocs.  Drop test for ELF
	targets.  Do not stop the checks when problems are encountered.

include	* bfdlink.h: Add prototype for bfd_link_check_relocs.
2016-04-21 15:43:00 +01:00
H.J. Lu
fbf05aa70d Move ELF relocation check after lang_gc_sections
Move ELF relocation check after lang_gc_sections so that all the
reference counting code for plt and got relocs can be removed.  This
only affects ELF targets which check relocations after opening all
input file.

	* ldlang.c (lang_check_relocs): New function.
	(lang_process): Call lang_check_relocs after lang_gc_sections.
	* emultempl/elf32.em (gld${EMULATION_NAME}_before_parse): Don't
	call _bfd_elf_link_check_relocs here.
2016-04-20 17:08:55 -07:00
Matthew Fortune
cdf969539c Add new NOCROSSREFS_TO linker script command
NOCROSSREFS_TO is similar to the existing NOCROSSREFS command but only
checks one direction of cross referencing.

ld/ChangeLog

	* ld.texinfo: Document NOCROSSREFS_TO script command.
	* ldlang.h (struct lang_nocrossrefs): Add onlyfirst field.
	(lang_add_nocrossref_to): New prototype.
	* ldcref.c (check_local_sym_xref): Use onlyfirst to only look for
	symbols defined in the first section.
	(check_nocrossref): Likewise.
	* ldgram.y (NOCROSSREFS_TO): New script command.
	* ldlang.c (lang_add_nocrossref): Set onlyfirst to FALSE.
	(lang_add_nocrossref_to): New function.
	* ldlex.l (NOCROSSREFS_TO): New token.
	* NEWS: Mention NOCROSSREFS_TO.
	* testsuite/ld-scripts/cross4.t: New file.
	* testsuite/ld-scripts/cross5.t: Likewise.
	* testsuite/ld-scripts/cross6.t: Likewise.
	* testsuite/ld-scripts/cross7.t: Likewise.
	* testsuite/ld-scripts/crossref.exp: Run 4 new NOCROSSREFS_TO
	tests.
2016-04-18 12:45:46 +01:00
Alan Modra
136a43b762 PR18452, ld allows overlapping sections
PR 18452
	* ldlang.c (maybe_overlays): Delete.
	(lang_size_sections_1): Remove code setting maybe_overlays.
	(lang_check_section_addresses): Instead detect overlays by
	exact match of section VMAs here.  Fix memory leak.
2016-04-08 23:41:44 +09:30
Dan Gisselquist
953dd97e56 Show sizes in linker map in target machine address units
* ldlang.c (print_output_section_statement): Show minfo size
	in target machine address units.
	(print_reloc_statement): Likewise.
	(print_padding_statement): Likewise.
	(print_data_statement): Likewise.  Ensure minimum print_dot
	increment of one address unit.
2016-04-08 14:33:02 +09:30
Alan Modra
fc90c28021 More cases of missing TO_ADDR in ldlang.c
and one extraneous occurrence.

	* ldlang.c (TO_ADDR, TO_SIZE, opb_shift): Move earlier in file.
	(lang_insert_orphan): Use TO_ADDR in __stop sym calculation.
	(print_input_section): Don't use TO_ADDR when printing section
	size.
	(lang_size_sections_1): Use TO_ADDR in overlay lma calculation.
	(lang_size_sections): Use TO_ADDR in relro end calculation.
2016-03-31 19:35:33 +10:30
Alan Modra
a87dd97a20 PR18452, ld allows overlapping sections
PR 18452
	* ldlang.c (maybe_overlays): New static var.
	(lang_size_sections_1): Set it here.
	(struct check_sec): New.
	(sort_sections_by_lma): Adjust for array of structs.
	(sort_sections_by_vma): New function.
	(lang_check_section_addresses): Check both LMA and VMA for overlap.
	* testsuite/ld-scripts/rgn-over7.d: Adjust.
2016-03-30 17:50:03 +10:30
Alan Modra
ca62bc4a86 Missing TO_ADDR
* ldlang.c (lang_size_sections_1): Correct code detecting a
	backward non-overlapping move.
2016-03-30 17:50:03 +10:30
Alan Modra
2e4a7aea70 Use consistent test for .tbss sections in ldlang.c
Some places tested SEC_LOAD, others SEC_HAS_CONTENTS.

	* ldlang.c (IS_TBSS): New macro, extracted from..
	(IGNORE_SECTION): ..here.
	(lang_size_sections_1): Use IS_TBSS and IGNORE_SECTION.
	(lang_size_sections, lang_do_assignments_1): Use IS_TBSS.
2016-03-30 17:50:03 +10:30
Nick Clifton
4153b6dbb0 Improve COFF/PE linker garbage collection by preventing the removal of sections containing exported symbols.
PR ld/19803
	* ldlang.c (lang_add_gc_name): New function.  Adds the provided
	symbol name to the list of gc symbols.
	(lang_process): Call lang_add_gc_name with entry_symbol_default if
	entry_symbol.name is NULL.  Use lang_add_gc_name to add the init
	and fini function names.
	* pe-dll.c (process_def_file_and_drectve): Add exported names to
	the gc symbol list.
	* testsuite/ld-pe/pr19803.s: Do not export _testval symbol.
	* testsuite/ld-pe/pr19803.d: Tweak expected output.
2016-03-22 12:25:08 +00:00
Senthil Kumar Selvaraj
41f46ed9fe Fix possible failure in the AVR linker tests.
* ld-avr/gc-section-debugline.d: Relax regex check for CU.
2016-03-18 09:51:47 +00:00
Alan Modra
6f2750feaf Copyright update for binutils 2016-01-01 23:00:01 +10:30
Alan Modra
b39910205f Account for .tbss alignment when adjusting start of relro
Another option might be to not bump "dot" for .tbss alignment in the
main section sizing loop, but that could leak some of the following
section into the TLS segment.  Leakage shouldn't matter since it will
be to bytes past the end of .tdata, but for now this is a safer
option.

	PR ld/19264
	* ldlang.c (lang_size_sections): Don't ignore .tbss when
	adjusting start of relro region.
2015-11-19 16:22:25 +10:30
Alan Modra
936384714f Re: Orphan output section with multiple input sections
The last patch missed handling the case where the ideal place to put
an orphan was after a non-existent output section statement, as can
happen when not using the builtin linker scripts.  This patch uses the
updated flags for that case too, and extends the support to mmo and pe.

	PR ld/19162
	* emultempl/elf32.em (gld${EMULATION_NAME}_place_orphan): Pass
	updated flags to lang_output_section_find_by_flags.
	* emultempl/mmo.em (mmo_place_orphan): Merge flags for any
	other input sections that might match a new output section to
	decide placement.
	* emultempl/pe.em (gld_${EMULATION_NAME}_place_orphan): Likewise.
	* emultempl/pep.em (gld_${EMULATION_NAME}_place_orphan): Likewise.
	* ldlang.c (lang_output_section_find_by_flags): Add sec_flags param.
	* ldlang.h (lang_output_section_find_by_flags): Update prototype.
2015-10-29 19:42:50 +10:30
Alan Modra
321df0656c Evaluate __start_* and __stop_* symbol PROVIDE expressions early
Makes these symbols defined before bfd_elf_size_dynamic_sections, to
avoid horrible hacks elsewhere.  The exp_fold_tree undefweak change
is necessary to define undefweak symbols early too.  The comment was
wrong.  PROVIDE in fact defines undefweak symbols, via
bfd_elf_record_link_assignment.

	PR ld/19175
	* ldlang.c (lang_insert_orphan): Evaluate __start_* and __stop_*
	symbol PROVIDE expressions.
	* ldexp.c (exp_fold_tree_1 <etree_provide>): Define undefweak
	references.
2015-10-27 12:54:59 +10:30
Alan Modra
975f8a9e31 Delay converting linker script defined symbols from absolute
Giving linker script symbols defined outside of output sections a
section-relative value early, leads to them being used in expressions
as if they were defined inside an output section.  This can mean loss
of the section VMA, and wrong results.

ld/
	PR ld/18963
	* ldexp.h (struct ldexp_control): Add rel_from_abs.
	(ldexp_finalize_syms): Declare.
	* ldexp.c (new_rel_from_abs): Keep absolute for expressions
	outside of output section statements.  Set rel_from_abs.
	(make_abs, exp_fold_tree, exp_fold_tree_no_dot): Clear rel_from_abs.
	(struct definedness_hash_entry): Add final_sec, and comment.
	(update_definedness): Set final_sec.
	(set_sym_sections, ldexp_finalize_syms): New functions.
	* ldlang.c (lang_process): Call ldexp_finalize_syms.
ld/testsuite
	PR ld/18963
	* ld-scripts/pr18963.d,
	* ld-scripts/pr18963.t: New test.
	* ld-scripts/expr.exp: Run it.
	* ld-elf/provide-hidden-2.ld: Explicitly make "dot" absolute.
	* ld-mips-elf/gp-hidden.sd: Don't care about _gp section.
	* ld-mips-elf/no-shared-1-n32.d: Don't care about symbol shown at
	start of .data section.
	* ld-mips-elf/no-shared-1-n64.d: Likewise.
	* ld-mips-elf/no-shared-1-o32.d: Likewise.
2015-09-18 12:39:16 +09:30
Andrew Burgess
c005eb9e34 ld: Extend options for altering orphan handling behaviour.
Replace the options --warn-orphan and --no-warn-orphan with a single
option --orphan-handling=MODE, where mode can be place, warn, error, and
discard.

Mode 'place' is the default, and is the current behaviour, placing the
orphan section into a suitable output section.

Mode 'warn' is the same as '--warn-orphan'.  The orphan is also placed
using the same algorithm as for 'place'.

Mode 'error' is the same as '--warn-orphan' and '--fatal-warnings'.

Mode 'discard' assigns all output sections to the /DISCARD/ section.

ld/ChangeLog:

	* ld.h (enum orphan_handling_enum): New.
	(ld_config_type): Remove warn_orphan, add orphan_handling.
	* ldemul.c (ldemul_place_orphan): Remove warning about orphan
	sections.
	* ldlang.c (ldlang_place_orphan): New function.
	(lang_place_orphans): Call ldlang_place_orphan.
	* ldlex.h (enum option_values): Remove OPTION_WARN_ORPHAN and
	OPTION_NO_WARN_ORPHAN, add OPTION_ORPHAN_HANDLING.
	* lexsup.c (ld_options): Remove 'warn-orphan' and
	'no-warn-orphan', add 'orphan-handling'.
	(parse_args): Remove handling for OPTION_WARN_ORPHAN and
	OPTION_NO_WARN_ORPHAN, add handling for OPTION_ORPHAN_HANDLING.
	* NEWS: Replace text about --warn-orphan with --orphan-handling.
	* ld.texinfo (Options): Remove --warn-orphan entry and add
	entry on --orphan-handling.
	(Orphan Sections): Add reference to relevant command line options.

ld/testsuite/ChangeLog:

	* ld-elf/elf.exp: Switch to rely on run_dump_test.
	* ld-elf/orphan-5.l: Update expected output.
	* ld-elf/orphan-5.d: New file.
	* ld-elf/orphan-6.d: New file.
	* ld-elf/orphan-6.l: New file.
	* ld-elf/orphan-7.d: New file.
	* ld-elf/orphan-7.map: New file.
	* ld-elf/orphan-8.d: New file.
	* ld-elf/orphan-8.map: New file.
2015-09-04 22:30:55 +01:00
H.J. Lu
0e1862bb40 Add output_type to bfd_link_info
The "shared" field in bfd_link_info is set for both DSO and and PIE.
There are separate fields for executable and relocatable outputs.  This
patch adds an "output_type" field:

enum output_type
{
  type_unknown = 0,
  type_executable,
  type_dll,
  type_relocatable
};

and a "pic" field to bfd_link_info to replace shared, executable and
relocatable fields so that we can use the "output_type" field to check
for output type and the "pic" field check if output is PIC.  Macros,
bfd_link_executable, bfd_link_dll, bfd_link_relocatable, bfd_link_pic
and bfd_link_pie, are provided to check for output features.

bfd/

	* bfd/aoutx.h: Replace shared, executable, relocatable and pie
	fields with bfd_link_executable, bfd_link_dll,
	bfd_link_relocatable, bfd_link_pic and bfd_link_pie.
	* bfd/bout.c: Likewise.
	* bfd/coff-alpha.c: Likewise.
	* bfd/coff-arm.c: Likewise.
	* bfd/coff-i386.c: Likewise.
	* bfd/coff-i960.c: Likewise.
	* bfd/coff-m68k.c: Likewise.
	* bfd/coff-mcore.c: Likewise.
	* bfd/coff-mips.c: Likewise.
	* bfd/coff-ppc.c: Likewise.
	* bfd/coff-rs6000.c: Likewise.
	* bfd/coff-sh.c: Likewise.
	* bfd/coff-tic80.c: Likewise.
	* bfd/coff-x86_64.c: Likewise.
	* bfd/coff64-rs6000.c: Likewise.
	* bfd/coffgen.c: Likewise.
	* bfd/cofflink.c: Likewise.
	* bfd/ecoff.c: Likewise.
	* bfd/ecofflink.c: Likewise.
	* bfd/elf-bfd.h: Likewise.
	* bfd/elf-eh-frame.c: Likewise.
	* bfd/elf-ifunc.c: Likewise.
	* bfd/elf-m10200.c: Likewise.
	* bfd/elf-m10300.c: Likewise.
	* bfd/elf-s390-common.c: Likewise.
	* bfd/elf-vxworks.c: Likewise.
	* bfd/elf.c: Likewise.
	* bfd/elf32-arm.c: Likewise.
	* bfd/elf32-avr.c: Likewise.
	* bfd/elf32-bfin.c: Likewise.
	* bfd/elf32-cr16.c: Likewise.
	* bfd/elf32-cr16c.c: Likewise.
	* bfd/elf32-cris.c: Likewise.
	* bfd/elf32-crx.c: Likewise.
	* bfd/elf32-d10v.c: Likewise.
	* bfd/elf32-dlx.c: Likewise.
	* bfd/elf32-epiphany.c: Likewise.
	* bfd/elf32-fr30.c: Likewise.
	* bfd/elf32-frv.c: Likewise.
	* bfd/elf32-ft32.c: Likewise.
	* bfd/elf32-h8300.c: Likewise.
	* bfd/elf32-hppa.c: Likewise.
	* bfd/elf32-i370.c: Likewise.
	* bfd/elf32-i386.c: Likewise.
	* bfd/elf32-i860.c: Likewise.
	* bfd/elf32-ip2k.c: Likewise.
	* bfd/elf32-iq2000.c: Likewise.
	* bfd/elf32-lm32.c: Likewise.
	* bfd/elf32-m32c.c: Likewise.
	* bfd/elf32-m32r.c: Likewise.
	* bfd/elf32-m68hc11.c: Likewise.
	* bfd/elf32-m68hc1x.c: Likewise.
	* bfd/elf32-m68k.c: Likewise.
	* bfd/elf32-mcore.c: Likewise.
	* bfd/elf32-mep.c: Likewise.
	* bfd/elf32-metag.c: Likewise.
	* bfd/elf32-microblaze.c: Likewise.
	* bfd/elf32-moxie.c: Likewise.
	* bfd/elf32-msp430.c: Likewise.
	* bfd/elf32-mt.c: Likewise.
	* bfd/elf32-nds32.c: Likewise.
	* bfd/elf32-nios2.c: Likewise.
	* bfd/elf32-or1k.c: Likewise.
	* bfd/elf32-ppc.c: Likewise.
	* bfd/elf32-rl78.c: Likewise.
	* bfd/elf32-rx.c: Likewise.
	* bfd/elf32-s390.c: Likewise.
	* bfd/elf32-score.c: Likewise.
	* bfd/elf32-score7.c: Likewise.
	* bfd/elf32-sh-symbian.c: Likewise.
	* bfd/elf32-sh.c: Likewise.
	* bfd/elf32-sh64.c: Likewise.
	* bfd/elf32-spu.c: Likewise.
	* bfd/elf32-tic6x.c: Likewise.
	* bfd/elf32-tilepro.c: Likewise.
	* bfd/elf32-v850.c: Likewise.
	* bfd/elf32-vax.c: Likewise.
	* bfd/elf32-visium.c: Likewise.
	* bfd/elf32-xc16x.c: Likewise.
	* bfd/elf32-xstormy16.c: Likewise.
	* bfd/elf32-xtensa.c: Likewise.
	* bfd/elf64-alpha.c: Likewise.
	* bfd/elf64-hppa.c: Likewise.
	* bfd/elf64-ia64-vms.c: Likewise.
	* bfd/elf64-mmix.c: Likewise.
	* bfd/elf64-ppc.c: Likewise.
	* bfd/elf64-s390.c: Likewise.
	* bfd/elf64-sh64.c: Likewise.
	* bfd/elf64-x86-64.c: Likewise.
	* bfd/elflink.c: Likewise.
	* bfd/elfnn-aarch64.c: Likewise.
	* bfd/elfnn-ia64.c: Likewise.
	* bfd/elfxx-mips.c: Likewise.
	* bfd/elfxx-sparc.c: Likewise.
	* bfd/elfxx-tilegx.c: Likewise.
	* bfd/i386linux.c: Likewise.
	* bfd/linker.c: Likewise.
	* bfd/m68klinux.c: Likewise.
	* bfd/pdp11.c: Likewise.
	* bfd/pe-mips.c: Likewise.
	* bfd/peXXigen.c: Likewise.
	* bfd/reloc.c: Likewise.
	* bfd/reloc16.c: Likewise.
	* bfd/sparclinux.c: Likewise.
	* bfd/sunos.c: Likewise.
	* bfd/vms-alpha.c: Likewise.
	* bfd/xcofflink.c: Likewise.

include/

	* include/bfdlink.h (output_type): New enum.
	(bfd_link_executable): New macro.
	(bfd_link_dll): Likewise.
	(bfd_link_relocatable): Likewise.
	(bfd_link_pic): Likewise.
	(bfd_link_pie): Likewise.
	(bfd_link_info): Remove shared, executable, pie and relocatable.
	Add output_type and pic.

ld/

	* ld/ldctor.c: Replace shared, executable, relocatable and pie
	fields with bfd_link_executable, bfd_link_dll,
	bfd_link_relocatable, bfd_link_pic and bfd_link_pie.
	* ld/ldemul.c: Likewise.
	* ld/ldfile.c: Likewise.
	* ld/ldlang.c: Likewise.
	* ld/ldmain.c: Likewise.
	* ld/ldwrite.c: Likewise.
	* ld/lexsup.c: Likewise.
	* ld/pe-dll.c: Likewise.
	* ld/plugin.c: Likewise.
	* ld/emultempl/aarch64elf.em: Likewise.
	* ld/emultempl/aix.em: Likewise.
	* ld/emultempl/alphaelf.em: Likewise.
	* ld/emultempl/armcoff.em: Likewise.
	* ld/emultempl/armelf.em: Likewise.
	* ld/emultempl/avrelf.em: Likewise.
	* ld/emultempl/beos.em: Likewise.
	* ld/emultempl/cr16elf.em: Likewise.
	* ld/emultempl/elf-generic.em: Likewise.
	* ld/emultempl/elf32.em: Likewise.
	* ld/emultempl/genelf.em: Likewise.
	* ld/emultempl/generic.em: Likewise.
	* ld/emultempl/gld960.em: Likewise.
	* ld/emultempl/gld960c.em: Likewise.
	* ld/emultempl/hppaelf.em: Likewise.
	* ld/emultempl/irix.em: Likewise.
	* ld/emultempl/linux.em: Likewise.
	* ld/emultempl/lnk960.em: Likewise.
	* ld/emultempl/m68hc1xelf.em: Likewise.
	* ld/emultempl/m68kcoff.em: Likewise.
	* ld/emultempl/m68kelf.em: Likewise.
	* ld/emultempl/metagelf.em: Likewise.
	* ld/emultempl/mipself.em: Likewise.
	* ld/emultempl/mmo.em: Likewise.
	* ld/emultempl/msp430.em: Likewise.
	* ld/emultempl/nds32elf.em: Likewise.
	* ld/emultempl/needrelax.em: Likewise.
	* ld/emultempl/nios2elf.em: Likewise.
	* ld/emultempl/pe.em: Likewise.
	* ld/emultempl/pep.em: Likewise.
	* ld/emultempl/ppc32elf.em: Likewise.
	* ld/emultempl/ppc64elf.em: Likewise.
	* ld/emultempl/sh64elf.em: Likewise.
	* ld/emultempl/solaris2.em: Likewise.
	* ld/emultempl/spuelf.em: Likewise.
	* ld/emultempl/sunos.em: Likewise.
	* ld/emultempl/tic6xdsbt.em: Likewise.
	* ld/emultempl/ticoff.em: Likewise.
	* ld/emultempl/v850elf.em: Likewise.
	* ld/emultempl/vms.em: Likewise.
	* ld/emultempl/vxworks.em: Likewise.
2015-08-18 05:51:19 -07:00
Andrew Burgess
0a61824343 ld: Add '--require-defined' command line option.
Add a new command line option '--require-defined' to the linker.  This
option operates identically to the '--undefined' option, except that if
the symbol is not defined in the final output file then the linker will
exit with an error.

When making use of --gc-section, or just when trying to pull in parts of
a library, it is not uncommon for a user to use the '--undefined'
command line option to specify a symbol that the user then expects to be
defined by one of the object files supplied to the link.

However, if for any reason the symbol is not satisfied by an object
provided to the link the user will be left with an undefined symbol in
the output file, instead of a defined symbol.

In some cases the above behaviour is what the user wants, in other cases
though we can do better.  The '--require-defined' option tries to fill
this gap.  The symbol passed to the '--require-defined' option is
treated exactly as if the symbol was passed to '--undefined', however,
before the linker exits a check is made that all symbols passed to
'--require-defined' are actually defined, if any are not then the link
will fail with an error.

ld/ChangeLog:

	* ld.texinfo (Options): Document --require-defined option.
	* ldlang.c (struct require_defined_symbol): New structure.
	(require_defined_symbol_list): New variable.
	(ldlang_add_require_defined): New function.
	(ldlang_check_require_defined_symbols): New function.
	(lang_process): Check required symbols are defined.
	* ldlang.h (ldlang_add_require_defined): Declare.
	* ldlex.h (enum option_values): Add OPTION_REQUIRE_DEFINED_SYMBOL.
	* lexsup.c (ld_options): Add '--require-defined' entry.
	(parse_args): Handle '--require-defined' entry.
	* NEWS: Mention new '--require-defined' option.

ld/testsuite/ChangeLog:

	* ld-undefined/require-defined-1.d: New file.
	* ld-undefined/require-defined-2.d: New file.
	* ld-undefined/require-defined-3.d: New file.
	* ld-undefined/require-defined-4.d: New file.
	* ld-undefined/require-defined-5.d: New file.
	* ld-undefined/require-defined.exp: New file.
	* ld-undefined/require-defined.s: New file.
2015-08-04 10:00:05 +01:00
Tristan Gingold
3604cb1f8c Add new ld option: --print-memory-usage
ld/
	* NEWS: Mention new option.
	* lexsup.c (parse_args): Handle --print-memory-usage.
	(ld_options): Add --print-memory-usage.
	* ldmain.c (main): Call lang_print_memory_usage.
	* ldlex.h (enum option_values): Add OPTION_PRINT_MEMORY_USAGE.
	* ldlang.h: Add prototype of lang_print_memory_usage.
	* ldlang.c (lang_print_memory_size, lang_print_memory_usage): New
	functions.
	* ld.texinfo (Options): Document --print-memory-usage.
	* ld.h (args_type): Add print_memory_usage field.

ld/testsuite/
	* ld-scripts/print-memory-usage-1.t,
	* ld-scripts/print-memory-usage-1.s,
	* ld-scripts/print-memory-usage-1.l,
	* ld-scripts/print-memory-usage-2.t,
	* ld-scripts/print-memory-usage-2.l,
	* ld-scripts/print-memory-usage-3.s,
	* ld-scripts/print-memory-usage-3.t,
	* ld-scripts/print-memory-usage-3.l,
	* ld-scripts/print-memory-usage.t: New tests.
	* ld-scripts/print-memory-usage.exp: Run them.
2015-06-12 11:24:36 +02:00
Alan Modra
0e5fabeb2c Rewrite relro adjusting code
The linker tries to put the end of the last section in the relro
segment exactly on a page boundary, because the relro segment itself
must end on a page boundary.  If for any reason this can't be done,
padding is inserted.  Since the end of the relro segment is typically
between .got and .got.plt, padding effectively increases the size of
the GOT.  This isn't nice for targets and code models with limited GOT
addressing.

The problem with the current code is that it doesn't cope very well
with aligned sections in the relro segment.  When making .got aligned
to a 256 byte boundary for PowerPC64, I found that often the initial
alignment attempt failed and the fallback attempt to be less than
adequate.  This is a particular problem for PowerPC64 since the
distance between .got and .plt affects the size of plt call stubs,
leading to "stubs don't match calculated size" errors.

So this rewrite takes a direct approach to calculating a new relro
base.  Starting from the last section in the segment, we calculate
where it must start to position its end on the boundary, or as near as
possible considering alignment requirements.  The new start then
becomes the goal for the previous section to end, and so on for all
sections.  This of course ignores the possibility that user scripts
will place . = ALIGN(xxx); in the relro segment, or provide section
address expressions.  In those cases we might fail, but the old code
probably did too, and a fallback is provided.

ld/
	* ldexp.h (struct ldexp_control): Delete dataseg.min_base.  Add
	data_seg.relro_offset.
	* ldexp.c (fold_binary <DATA_SEGMENT_ALIGN>): Don't set min_base.
	(fold_binary <DATA_SEGMENT_RELRO_END>): Do set relro_offset.
	* ldlang.c (lang_size_sections): Rewrite code adjusting relro
	segment base to line up last section on page boundary.
ld/testsuite/
	* ld-x86-64/pr18176.d: Update.
2015-04-22 23:19:59 +09:30
Alan Modra
6166ed9330 Mark _init and _fini for --gc-sections
gold marks _init and _fini via symbol, ld marks them via section
(default scripts set .init and .fini section KEEP).  This makes it
possible for people to write their own _init and not bother to put the
function into the right section.

	PR ld/18223
	* ldlang.c (lang_process): Add _init and _fini to gc_sym_list.
2015-04-10 10:27:03 +09:30
Alan Modra
0fad6e4b94 Cast shift expression
PR ld/18176
	* ldlang.c (lang_size_sections): Cast shift expression.
2015-04-07 23:21:42 +09:30
Alan Modra
6c1aca3e2d Start of relro segment adjustment
Adjusting the start of the relro segment in order to make it end
exactly on a page boundary runs into difficulties when sections in the
relro segment are aligned;  Adjusting the start by (next_page - end)
sometimes results in more than that adjustment occurring at the end,
overrunning the page boundary.  So when that occurs we try a new lower
start position by masking the adjusted start with the maximum section
alignment.  However, we didn't consider that this masked start address
may in fact be before the initial relro base, which is silly since
that can only increase padding at the relro end.

I've also moved some calculations closer to where they are used, and
comments closer to the relevant statements.

	* ldlang.c (lang_size_sections): When alignment of sections
	results in relro base adjustment being too large, don't go lower
	than the initial value.
	* ldexp.c (fold_binary <DATA_SEGMENT_RELRO_END>): Comment.
	* scripttempl/elf.sc (DATA_SEGMENT_ALIGN): Omit SEGMENT_SIZE
	alignment when SEGMENT_SIZE is the same as MAXPAGESIZE.
2015-04-01 19:37:58 +10:30