llvm-svn: 198812

paired LO16 relocation.

llvm-svn: 198790

Add basic emulation mapping for NetBSD/amd64, so that clang -m32 works
as expected.

llvm-svn: 198337

Currently LLD always print a warning message if the same symbol is specified
more than once for /export option. It's a bit annoying because specifying the
same symbol with compatible options is actually safe and considered as a
normal use case. This patch makes LLD to warn only when incompatible export
options are given.

llvm-svn: 198104

No functionality change.

llvm-svn: 198075

llvm-svn: 198074

Currently .drectve section contents are parsed after other sections are parsed.
That order may result in wrong results if other sections depend on command line
options in the directive section.

For example, if a weak symbol is defined using /alternatename option in the
directive section, we have to read it first and then read the text section
contents. Otherwise the weak symbol won't be defined.

This patch changes the order to fix the issue.

llvm-svn: 198071

There was a bug that the linker does not report an error if symbols specified
by -u (or /include on Windows) are not resolved. This patch fixes it by adding
such symbols to the dead strip root.

llvm-svn: 198041

llvm-svn: 198033

Subsystem field in the PE/COFF file header has no meanining for the DLL.
It looks like MSVC link.exe sets the default subsystem (Windows GUI) to
the field if no /subsystem option is specified.

llvm-svn: 198015

Makes the tests pass (rather, not run) on release builds.

llvm-svn: 197838

The main changes are in:
  include/lld/Core/Reference.h
  include/lld/ReaderWriter/Reader.h
Everything else is details to support the main change.

1) Registration based Readers
Previously, lld had a tangled interdependency with all the Readers.  It would
have been impossible to make a streamlined linker (say for a JIT) which
just supported one file format and one architecture (no yaml, no archives, etc).
The old model also required a LinkingContext to read an object file, which
would have made .o inspection tools awkward.

The new model is that there is a global Registry object. You programmatically 
register the Readers you want with the registry object. Whenever you need to 
read/parse a file, you ask the registry to do it, and the registry tries each 
registered reader.

For ease of use with the existing lld code base, there is one Registry
object inside the LinkingContext object. 


2) Changing kind value to be a tuple
Beside Readers, the registry also keeps track of the mapping for Reference
Kind values to and from strings.  Along with that, this patch also fixes
an ambiguity with the previous Reference::Kind values.  The problem was that
we wanted to reuse existing relocation type values as Reference::Kind values.
But then how can the YAML write know how to convert a value to a string? The
fix is to change the 32-bit Reference::Kind into a tuple with an 8-bit namespace
(e.g. ELF, COFFF, etc), an 8-bit architecture (e.g. x86_64, PowerPC, etc), and
a 16-bit value.  This tuple system allows conversion to and from strings with 
no ambiguities.

llvm-svn: 197727

Executable files do not use a string table, so section names longer than 8
characters are not permitted. Long section names should just be truncated.

llvm-svn: 197470

If NONAME option is given for an export, that symbol will be exported only by
its ordinal. LLD will not emit the symbol name to the export table.

llvm-svn: 197371

OrdinalBase is an addend to the ordinals. We used to always set 1 to the field.
Although it produced a valid a DLL export table, it'd be a waste if the first
ordinal does not start with 1 -- we had to have NULL fields at the beginning of
the export address table. By setting the ordinal base, we can eliminate the
NULL fields.

llvm-svn: 197367

You can specify exported function's ordinal by /export:func,@<number> command
line option, but LLD ignored the option until now. This patch implements the
feature.

Ordinal is basically the index into the exported function address table. So,
for example, if /export:foo,@42 is specified, the linker writes foo's address
to 42th entry in the address table. Windows supports import-by-ordinal; you
can not only import a function by name, but by its ordinal. If you want to
allow your DLL users to import your functions by their ordinals, you need to
make sure that your functions are always exported with the same ordinals.
This is the feature for that situation.

llvm-svn: 197364

The following are the most significant peculiarities of MIPS target:
- MIPS ABI requires some special tags in the dynamic table.
- GOT consists of two parts local and global. The local part contains
  entries refer locally visible symbols. The global part contains entries
  refer global symbols.
- Entries in the .dynsym section which have corresponded entries in the
  GOT should be:
  * Emitted at the end of .dynsym section
  * Sorted accordingly to theirs GOT counterparts
- There are "paired" relocations. One or more R_MIPS_HI16 and R_MIPS_GOT16
  relocations should be followed by R_MIPS_LO16 relocation. To calculate
  result of R_MIPS_HI16 and R_MIPS_GOT16 relocations we need to combine
  addends from these relocations and paired R_MIPS_LO16 relocation.

The patch reviewed by Michael Spencer, Shankar Easwaran, Rui Ueyama.
http://llvm-reviews.chandlerc.com/D2156

llvm-svn: 197342

Symbol names exported from a DLL should be undecorated, not prefixed by
an underscore ones.

llvm-svn: 197307

llvm-svn: 197306

The only data in .edata whose length varies is the string. This patch moves
all the strings to the end of the section, so that 16-bit or 32-bit integers
are aligned on correct boundaries.

llvm-svn: 197213

This is the first patch to emit data for the DLL export table. The DLL export
table is the data used by the Windows loader to find the address of exported
function from DLL. With this patch, LLD is able to emit a valid DLL export
table which the Windows loader can interpret and load.

The data structure of the DLL export table is described in the Microsoft
PE/COFF Specification, section 5.3.

DLL support is not complete yet; the linker needs to emit an import library
for a DLL, otherwise the linker cannot link against the DLL. We also do not
support export-only-by-ordinal yet.

llvm-svn: 197212

If section size is not multiple of 512, the writer added NULL bytes at the end
of it to make it so. That is not required by the PE/COFF spec, and the MSVC's
linker does not do that too. So we don't need to do that, too.

llvm-svn: 197002

llvm-svn: 196756

llvm-svn: 196754

GroupedSectionsPass was a complicated pass. That pass's job was to reorder
atoms by section name, so that the atoms with the same section prefix will be
emitted consecutively to the executable. The pass added layout edges to atoms,
and let the layout pass to actually reorder them.

This patch simplifies the design by making GroupedSectionPass to directly
reorder atoms, rather than adding layout edges. This resembles ELF's
ArrayOrderPass.

This patch improves the performance of LLD; it used to take 7.1 seconds to
link LLD with LLD on my Macbook Pro, but it now takes 6.1 seconds.

llvm-svn: 196628

Emitting idata atoms to their own section would make debugging easier.
The Windows loader do not really care about whether the DLL import table is
in .rdata or its own .idata section, so there is no change in functionality.

llvm-svn: 196458

llvm-svn: 196332

These relocations are used in .debug section.

llvm-svn: 196262

This reverts commit r195852 because LLD seems to create broken executables
with that patch when compiled with MSVC 2013.

llvm-svn: 196078

llvm-svn: 196056

llvm-svn: 196054

No change in functionality.

llvm-svn: 196053

This is a patch to let the PECOFF writer to use the information passed
by the parser for /section option. The implementation of /section should
now be complete.

llvm-svn: 195893

/MERGE:foo=bar command line option merges section foo to section bar. If
section bar does not exist, foo is just renamed as bar.

llvm-svn: 195856

llvm-svn: 195854

llvm-svn: 195853

Atom ordinals are the indeces in a file. Currently the PECOFF reader assigns
ordinals for each section, so it's (incorrectly) assigning duplicate ordinals.

llvm-svn: 195852

Instead of having multiple SectionChunks for each section (.text, .data,
.rdata and .bss), we could have one chunk writer that can emit any sections.
This patch does that -- removing all section-sepcific chunk writers and
replace them with one "generic" writer.

This change should simplify the code because it eliminates similar-but-
slightly-different classes.

It also fixes an issue in the previous design. Before this patch, we could
emit only limited set of sections (i.e. .text, .data, .rdata and .bss). With
this patch, we can emit any sections.

llvm-svn: 195797

This reverts accidental commit r195794.

llvm-svn: 195795

llvm-svn: 195794