Commit Graph

86 Commits

Author SHA1 Message Date
Bob Haarman b8a59c8aa5 [lld] unified COFF and ELF error handling on new Common/ErrorHandler
Summary:
The COFF linker and the ELF linker have long had similar but separate
Error.h and Error.cpp files to implement error handling. This change
introduces new error handling code in Common/ErrorHandler.h, changes the
COFF and ELF linkers to use it, and removes the old, separate
implementations.

Reviewers: ruiu

Reviewed By: ruiu

Subscribers: smeenai, jyknight, emaste, sdardis, nemanjai, nhaehnle, mgorny, javed.absar, kbarton, fedor.sergeev, llvm-commits

Differential Revision: https://reviews.llvm.org/D39259

llvm-svn: 316624
2017-10-25 22:28:38 +00:00
George Rimar f22ec9ddf6 [ELF] - Linkerscript: fix issue with SUBALIGN.
This is PR34886.

SUBALIGN command currently triggers failture if result expression
is zero. Patch fixes the issue, treating zero as 1, what is consistent with
other places and ELF spec it seems.

Patch also adds "is power of 2" check for this and other expressions
returning alignment.

Differential revision: https://reviews.llvm.org/D38846

llvm-svn: 316580
2017-10-25 14:50:51 +00:00
Rui Ueyama 4092016b7b Return early if it fails to parse a hex string.
This patch doesn't change the behavior of the program because it
would eventually return None at end of the function. But it is
better to return None early if we know it will eventually happen.

llvm-svn: 315495
2017-10-11 19:30:39 +00:00
Rui Ueyama 722221f5a7 Swap parameters of getSymbolValue.
Usually, a function that does symbol lookup takes symbol name as
its first argument. Also, if a function takes a source location hint,
it is usually the last parameter. So the previous parameter order
was counter-intuitive.

llvm-svn: 315433
2017-10-11 04:34:34 +00:00
Rui Ueyama f0403c601a Rename BytesDataCommand -> ByteCommand.
llvm-svn: 315431
2017-10-11 04:22:09 +00:00
Rui Ueyama 6b394caaf1 Rename Commands -> SectionCommands.
"Commands" was ambiguous because in the linker script, everything is
a command. We used to handle only SECTIONS commands, and at the time,
it might make sense to call them the commands, but it is no longer
the case. We handle not only SECTIONS but also MEMORY, PHDRS, VERSION,
etc., and they are all commands.

llvm-svn: 315409
2017-10-11 01:50:56 +00:00
Rui Ueyama a323e2a722 Rename HasSections -> HasSectionsComand.
HasSections is true if there is at least one SECTIONS linker
script command, and it is not directly related to whether we have
section objects or not. So I think the new name is better.

llvm-svn: 315405
2017-10-11 01:34:51 +00:00
Rui Ueyama ac27de9dc7 Remove ScriptConfiguration class and move the members to LinkerScript class.
ScriptConfiguration was a class to contain parsed results of
linker scripts. LinkerScript is a class to interpret it.

That ditinction was needed because we haven't instantiated
LinkerScript early (because, IIRC, LinkerScript class was a
ELFT template function). So, when we parse linker scripts,
we couldn't directly store the result to a LinkerScript instance.

Now, that limitation is gone. We instantiate LinkerScript
at the very beginning of our main function. We can directly
store parse results to a LinkerScript instance.

llvm-svn: 315403
2017-10-11 01:19:33 +00:00
Rui Ueyama 4fbe351817 Remove a constructor from ExprValue. NFC.
I think three ctors are too many for this simple class.

llvm-svn: 315394
2017-10-11 00:06:27 +00:00
Rui Ueyama 0ae2c24c5d Use llvm::Optional instead of UINT_MAX to represent a null value.
llvm-svn: 315168
2017-10-08 03:45:49 +00:00
Rui Ueyama 617e2f98a0 Make ScriptParser::checkSection a non-member function.
This patch also make its return type to `void` because
it always returns a given value as-is.

llvm-svn: 315165
2017-10-08 02:27:02 +00:00
Rui Ueyama 9b18f50f79 Remove a trivial function.
llvm-svn: 315164
2017-10-08 02:06:03 +00:00
Rafael Espindola 23be5e8d70 Consider ForceAbsolute again in moveAbsRight.
This patch goes back to considering ForceAbsolute in moveAbsRight, but
only if the second argument is not already absolute.

With this we can handle "foo + ABSOLUTE(foo)" and "ABSOLUTE(foo) + foo".

llvm-svn: 313800
2017-09-20 19:24:57 +00:00
Rafael Espindola 01a409520b Consider only A.Sec in moveAbsRight.
The idea of this function is to simplify the implementation of binary
operators like add.

A value might be absolute because of an ABSOLUTE expression, but it
still depends on the value of a section and we might not be able to
evaluate it early. We should keep such values on the LHS, so that we
can delay the evaluation.

We can now handle both "1 + ABSOLUTE(foo)" and "ABSOLUTE(foo) + 1".

llvm-svn: 313794
2017-09-20 18:56:08 +00:00
Rafael Espindola a6acd23c53 Align addresses, not offsets.
This fixes two more cases where we were aligning the offset in a
section, instead of the final address.

llvm-svn: 312983
2017-09-12 00:06:00 +00:00
Rafael Espindola 8016bdfd93 Handle empty dynamic lists.
llvm-svn: 312820
2017-09-08 18:53:43 +00:00
Rafael Espindola d72d97b3be If --dynamic-list is given, only those symbols are preemptible.
This allows combining --dynamic-list and version scripts too. The
version script controls which symbols are visible, and
--dynamic-list controls which of those are preemptible.

Unlike previous versions, undefined symbols are still considered
preemptible, which was the issue breaking the cfi tests.

This fixes pr34053.

llvm-svn: 312806
2017-09-08 18:16:59 +00:00
George Rimar 5f37541c73 [ELF] - Linkerscript: implement REGION_ALIAS.
REGION_ALIAS(alias, region)

Alias names can be added to existing memory regions created with
the MEMORY command. Each name corresponds to at most one
memory region.

Differential revision: https://reviews.llvm.org/D37477

llvm-svn: 312777
2017-09-08 08:23:15 +00:00
Rafael Espindola 0ff545c018 Revert "Revert "Revert r311468: If --dynamic-list is given, only those symbols are preemptible""
This reverts commit r312757.

Evgenii Stepanov reports that it broke some tests.

llvm-svn: 312771
2017-09-08 01:09:52 +00:00
Rafael Espindola b7d0be5896 Revert "Revert r311468: If --dynamic-list is given, only those symbols are preemptible"
If --dynamic-list is given, only those symbols are preemptible.

This allows combining --dynamic-list and version scripts too. The
version script controls which symbols are visible, and --dynamic-list
controls which of those are preemptible.

This fixes pr34053.

llvm-svn: 312757
2017-09-07 23:19:09 +00:00
Rui Ueyama 0440be4a42 Detect linker script INCLUDE cycles.
Differential Revision: https://reviews.llvm.org/D37524

llvm-svn: 312656
2017-09-06 18:14:08 +00:00
Rui Ueyama fd06b02558 Add a comment.
llvm-svn: 312655
2017-09-06 18:09:06 +00:00
Rui Ueyama e158f7c329 Revert r311468: If --dynamic-list is given, only those symbols are preemptible
This reverts commit r311468 because it broke some CFI bots.

llvm-svn: 311497
2017-08-22 21:54:58 +00:00
Rui Ueyama 9cbbacb910 If --dynamic-list is given, only those symbols are preemptible
Patch by Rafael Espíndola.

This is PR34053.

The implementation is a bit of a hack, given the precise location where
IsPreemtible is set, it cannot be used from
SymbolTable::handleAnonymousVersion.

I could add another method to SymbolTable if you think that would be
better.

Differential Revision: https://reviews.llvm.org/D36499

llvm-svn: 311468
2017-08-22 16:31:47 +00:00
Hafiz Abid Qadeer 6f1d954ef4 [ELF, LinkerScript] Support ! operator in linker script.
Summary: This small patch adds the support for ! operator in linker scripts. 

Reviewers: ruiu, rafael

Reviewed By: ruiu

Subscribers: meadori, grimar, emaste, llvm-commits

Differential Revision: https://reviews.llvm.org/D36451

llvm-svn: 310607
2017-08-10 15:25:47 +00:00
George Rimar ce6080819c [ELF] - Remove ScriptLexer::Error field and check ErrorCount instead.
D35945 introduces change when there is useless to check Error flag
in few places, but ErrorCount must be checked instead.

But then we probably can just check ErrorCount always. That should simplify
things. Patch do that.

Differential revision: https://reviews.llvm.org/D36266

llvm-svn: 310046
2017-08-04 10:34:14 +00:00
George Rimar 5fb17128f7 [ELF] - Do not segfault if linkerscript tries to access Target too early.
Following possible scripts triggered accessing to Target when it was not yet
initialized (was nullptr).

MEMORY { name : ORIGIN = DATA_SEGMENT_RELRO_END; }
MEMORY { name : ORIGIN = CONSTANT(COMMONPAGESIZE); }

Patch errors out instead.

Differential revision: https://reviews.llvm.org/D36140

llvm-svn: 309953
2017-08-03 16:05:08 +00:00
George Rimar 60833f6e22 [ELF] - Do not crash when ALIGN/DATA_SEGMENT_ALIGN expression used with zero value.
Previously we would crash when tried to ALIGN(0).
Patch uses value 1 instead in this case, that
looks to be consistent with GNU linkers
and reasonable and simple behavior itself.

Differential revision: https://reviews.llvm.org/D35942

llvm-svn: 309372
2017-07-28 09:27:49 +00:00
Rafael Espindola 8c022ca783 Merge OutputSectionCommand and OutputSection.
This is a bit of a hack, but it is *so* convenient.

Now that we create synthetic linker scripts when none is provided, we
always have to handle paired OutputSection and OutputsectionCommand and
keep a mapping from one to the other.

This patch simplifies things by merging them and creating what used to
be OutputSectionCommands really early.

llvm-svn: 309311
2017-07-27 19:22:43 +00:00
Meador Inge b0e6229742 [ELF, LinkerScript] Memory region name parsing fix
This patch fixes a small issue with respect to how memory region names
are parsed on output section descriptions.  For example, consider:

  .text : { *(.text) } > rom

That can also be written like:

  .text : { *(.text) } >rom

The latter form is accepted by GNU LD and is fairly common.

Differential Revision: https://reviews.llvm.org/D35920

llvm-svn: 309191
2017-07-26 21:51:09 +00:00
Petr Hosek 039fb8c296 [ELF] Align the value if needed when computing the expression
Also add the test cases for the addition and subtraction both for
the relative and absolute case.

Differential Revision: https://reviews.llvm.org/D35346

llvm-svn: 308692
2017-07-20 23:11:47 +00:00
Rui Ueyama 875ae82b0b Add the --chroot option for --reproduce.
Summary:
If the linker is invoked with `--chroot /foo` and `/bar/baz.o`, it
tries to read the file from `/foo/bar/baz.o`. This feature is useful
when you are dealing with files created by the --reproduce option.

Reviewers: grimar

Subscribers: llvm-commits, emaste

Differential Revision: https://reviews.llvm.org/D35517

llvm-svn: 308646
2017-07-20 18:17:55 +00:00
Rui Ueyama 1e77ad1456 Move feature-specific functions out of Strings.cpp.
Functions declared in Strings.h should provide generic string operations
for the linker, but some of them are too specific to some features. This
patch moves them to the location where they are used.

llvm-svn: 307949
2017-07-13 20:30:35 +00:00
Peter Smith 906e9a1898 [ELF] Extract temporary state used in assignAddresses()
The assignAddresses() function accumulates state in the LinkerScript that
prevents it from being called multiple times. This change moves the state
into a separate structure AddressState that is created at the start of the
function and disposed of at the end.

CurAddressState is used rather than passing a reference to the state as a
parameter to the functions used by assignAddresses(). This is because the
getSymbolValue function needs to be executed in the context of AddressState
but it is stored in ScriptParser when AddressState is not available.

The AddressState is also used in a limited context by processCommands()

Differential Revision: https://reviews.llvm.org/D34345

llvm-svn: 307367
2017-07-07 09:11:27 +00:00
Rui Ueyama 3271d3704a Fix a bug in output section directive.
Previously, it couldn't parse

  SECTIONS .text (0x1000) : { *(.text) }

because "(" was interpreted as the begining of the "(NOLOAD)" directive.

llvm-svn: 305006
2017-06-08 19:47:16 +00:00
George Rimar fbb0463f39 [ELF] - Linkerscript: implement NOLOAD section type.
This is PR32351

Each output section may have a type. The type is a keyword in parentheses.
(https://sourceware.org/binutils/docs/ld/Output-Section-Type.html#Output-Section-Type)
This patch support only one type, it is NOLOAD.
If output section has such type, we force it to be SHT_NOBITS. 

More details are available on a review page.

Differential revision: https://reviews.llvm.org/D33647

llvm-svn: 304925
2017-06-07 16:31:08 +00:00
George Rimar 41c7ab4a3d [ELF] - Linkerscript: improved error reporting.
When linking linux kernel LLD currently reports next errors:

ld: error: unable to evaluate expression: input section .head.text has no output section assigned
ld: error: At least one side of the expression must be absolute
ld: error: At least one side of the expression must be absolute

That does not provide file/line information and overall looks unclear. 
Patch adds location information to ExprValue and that allows
to provide more clear error messages.

Differential revision: https://reviews.llvm.org/D33943

llvm-svn: 304881
2017-06-07 08:54:43 +00:00
Zachary Turner 264b5d9e88 Move Object format code to lib/BinaryFormat.
This creates a new library called BinaryFormat that has all of
the headers from llvm/Support containing structure and layout
definitions for various types of binary formats like dwarf, coff,
elf, etc as well as the code for identifying a file from its
magic.

Differential Revision: https://reviews.llvm.org/D33843

llvm-svn: 304864
2017-06-07 03:48:56 +00:00
Rafael Espindola 05c4f67cf3 Move name lookup to script parsing time.
We were looking up sections by name during expression evaluation. By
keeping track of forward declarations we can do the lookup during
script parsing.

Doing the lookup earlier will be more efficient when assignAddresses
is run twice and removes two uses of OutputSections.

llvm-svn: 304381
2017-06-01 01:16:50 +00:00
Petr Hosek 3c6de1a66c [ELF] Use late evaluation for ALIGN in expression
While the following expression is handled fine:

  PROVIDE_HIDDEN(newsym = oldsym + address);

The following expression triggers an error because the expression
is evaluated as absolute:

  PROVIDE_HIDDEN(newsym = ALIGN(oldsym, CONSTANT(MAXPAGESIZE)) + address);

To avoid this error, we use late evaluation for ALIGN by making the
alignment an attribute of the expression itself.

Differential Revision: https://reviews.llvm.org/D33629

llvm-svn: 304185
2017-05-30 03:18:28 +00:00
George Rimar ab94768cc1 [ELF] - Use llvm::to_integer() instead of StringRef::getAsInteger().
Switch to llvm::to_integer() everywhere in LLD instead of 
StringRef::getAsInteger() because API of latter is confusing. 
It returns true on error and false otherwise what makes reading 
the code incomfortable.

Differential revision: https://reviews.llvm.org/D33187

llvm-svn: 303149
2017-05-16 08:19:25 +00:00
Rui Ueyama 91b95b61f8 Add memory ORIGIN and LENGTH expression support
Adds support for the ORIGIN and LENGTH linker script built in functions.

  ORIGIN(memory) Return the origin of the memory region
  LENGTH(memory) Return the length of the memory region

Redo of D29775 for refactored linker script parsing.

Patch by Robert Clarke

Differential Revision: https://reviews.llvm.org/D32934

llvm-svn: 302564
2017-05-09 18:24:38 +00:00
Rui Ueyama 8acbf1cca9 Rename readOutputSectionFiller parseFill.
"read" is used as a prefix for functions that read tokens from input
streams. This function doesn't really read anything, but just parses
a given string as an integer, so rename.

llvm-svn: 300281
2017-04-13 23:40:19 +00:00
Rui Ueyama 15732b718b Fix FILL linker script command.
FILL command doesn't need a semicolon.
Fixes https://bugs.llvm.org/show_bug.cgi?id=32657

llvm-svn: 300280
2017-04-13 23:40:00 +00:00
Rui Ueyama 040af7deab Allow expressions in MEMORY command.
Previously, we allowed only integers in this context. Now you can
write expressions there. LLD is now able to handle the following
linker, for example.

  MEMORY { rom (rx) : ORIGIN = (1024 * 1024) }

llvm-svn: 300131
2017-04-12 23:16:52 +00:00
Evgeniy Stepanov a76349bffe [lld] Keep full library path in DT_NEEDED.
Fixes PR32572.

When
    (a) a library has no soname
and (b) library is given on the command line with path (and not through -L/-l flags)
DT_NEEDED entry for such library keeps the path as given.

This behavior is consistent with gold and bfd, and is used in compiler-rt test suite.

This is a second attempt after r300007 got reverted. This time relro-omagic test is
changed in a way to avoid hardcoding the path to the test directory in the objdump'd
binary.

llvm-svn: 300011
2017-04-12 00:13:48 +00:00
Evgeniy Stepanov d512afe3da Revert "[lld] Keep full library path in DT_NEEDED."
This reverts commit r300007. Reason: breaks all the bots.

llvm-svn: 300008
2017-04-12 00:01:21 +00:00
Evgeniy Stepanov 2c2dcae13c [lld] Keep full library path in DT_NEEDED.
Fixes PR32572.

When
    (a) a library has no soname
and (b) library is given on the command line with path (and not through -L/-l flags)
DT_NEEDED entry for such library keeps the path as given.

This behavior is consistent with gold and bfd, and is used in compiler-rt test suite.

llvm-svn: 300007
2017-04-11 23:46:58 +00:00
Rui Ueyama b58079d4e2 Remove big-endianness from =<fillexp> code.
llvm-svn: 300005
2017-04-11 22:45:57 +00:00
Rui Ueyama 5c65088fd4 Return Optional<uint64_t> from readInteger instead of returning just success/failure.
llvm-svn: 299600
2017-04-05 23:22:11 +00:00