Commit Graph

86 Commits

Author SHA1 Message Date
Rui Ueyama afb87d8336 [WebAssembly] Remove dead code.
llvm-svn: 326018
2018-02-24 02:43:31 +00:00
Sam Clegg 9310297438 [WebAssembly] Add explicit symbol table
This change modified lld to in response the llvm change which
moved to a more explicit symbol table in the object format.

Based on patches by Nicholas Wilson:
 1. https://reviews.llvm.org/D41955
 2. https://reviews.llvm.org/D42585

The primary difference that we see in the test output is that
for relocatable (-r) output we now have symbol table which
replaces exports/imports and globals.

See: https://github.com/WebAssembly/tool-conventions/issues/38
Differential Revision: https://reviews.llvm.org/D43264

llvm-svn: 325861
2018-02-23 05:08:53 +00:00
Sam Clegg 00245539b6 [WebAssembly] Rename GlobalSymbol types. NFC.
Purely a rename in preparation for adding new global symbol type.

We want to use GlobalSymbol to represent real wasm globals and
DataSymbol for pointers to things in linear memory (what ELF would
call STT_OBJECT).

This reduces the size the patch to add the explicit symbol table
which is coming soon!

Differential Revision: https://reviews.llvm.org/D43476

llvm-svn: 325645
2018-02-20 23:38:27 +00:00
Sam Clegg 4f61714fd6 [WebAssembly] Remove InputChunk from Symbol baseclass
Instead include InputFuction and InputSegment directly
in the subclasses that use them (DefinedFunction and
DefinedGlobal).

Differential Revision: https://reviews.llvm.org/D43493

llvm-svn: 325603
2018-02-20 17:45:38 +00:00
Sam Clegg caca8d5db3 [WebAssembly] Remove unneeded classifer methods from Symbol class. NFC.
We already have isa<> for this, and these methods were simply
duplicating those redundantly.

Differential Revision: https://reviews.llvm.org/D43422

llvm-svn: 325418
2018-02-17 00:44:21 +00:00
Sam Clegg 3f8db98807 [WebAssembly] Simplify FunctionSymbol::get/set/hasFunctionType. NFC.
Differential Revision: https://reviews.llvm.org/D43416

llvm-svn: 325415
2018-02-16 23:50:23 +00:00
Sam Clegg b2f6e1c2f2 [WebAssebmly] Remove unneeded cast. NFC.
llvm-svn: 325382
2018-02-16 20:26:15 +00:00
Sam Clegg fe78ccf1a1 [WebAssembly] Fix bug is function signature checking
This bug effected undefined symbols that were resolved by
existing defined symbols.  We were skipping the signature
check in this case.

Differential Revision: https://reviews.llvm.org/D43399

llvm-svn: 325376
2018-02-16 19:45:41 +00:00
Sam Clegg c484ee0a9c [WebAssebmly] Remove use of Optional to fix assertion in gcc
This was causing GCC builds with fail with:
Symbols.h:240:3: error: static assertion failed: Symbol types must be
trivially destructible
  static_assert(std::is_trivially_destructible<T>(

The reason this is a gcc-only failure is that OptionalStorage has
as specialization for POD types that isn't built under GCC.

Differential Revision: https://reviews.llvm.org/D43317

llvm-svn: 325185
2018-02-14 22:55:38 +00:00
Rui Ueyama 38781a59f6 Revert r325158: Convert an assert to a static_assert. NFC.
This reverts commit r325158 because it broke GCC builds.

llvm-svn: 325183
2018-02-14 22:43:43 +00:00
Rui Ueyama de8140066a Remove a failing static_assert.
This static_assert is legitimate, but it is failing on some build environments.
I'm removing it until it's fixed to unbreak the bots.

llvm-svn: 325181
2018-02-14 22:26:23 +00:00
Sam Clegg ab31b7759d Convert an assert to a static_assert. NFC.
Differential Revision: https://reviews.llvm.org/D43305

llvm-svn: 325158
2018-02-14 19:28:46 +00:00
Sam Clegg dfb0b2c78f [WebAssembly] Use a Symbol class heirarchy. NFC.
This brings wasm into line with ELF and COFF in terms of
symbol types are represented.

Differential Revision: https://reviews.llvm.org/D43112

llvm-svn: 325150
2018-02-14 18:27:59 +00:00
Sam Clegg 37a4a8a4b1 [WebAssembly] Add __data_end link-sythentic symbol.
This is similar to _end (See https://linux.die.net/man/3/edata for more)
but using our own unique name since our use cases will most likely be
different and we want to keep our options open WRT to memory layout.

This change will allow is to remove the DataSize from the linking
metadata section which is currently being used by emscripten to derive
the end of the data.

Differential Revision: https://reviews.llvm.org/D42867

llvm-svn: 324443
2018-02-07 03:04:53 +00:00
Sam Clegg f0d433d0c6 [WebAssembly] Refactor linker-generated symbols. NFC.
Group all synthetic symbols in the in single struct to match
the ELF linker.

This change is part of a larger change to add more linker
symbols such as `_end` and `_edata`.

Differential Revision: https://reviews.llvm.org/D42866

llvm-svn: 324157
2018-02-02 22:59:56 +00:00
Sam Clegg fc50c62311 clang format
llvm-svn: 323622
2018-01-28 19:57:02 +00:00
Sam Clegg 24b3dcd4bf [WebAssemly] Associate symbol with InputChunk in which they are defined. NFC.
Summary:
Rather than explicit Function or InputSegment points store a
pointer to the base class (InputChunk) and use llvm dynamic
casts when we need a subtype.

This change is useful for add the upcoming gc-section support
wants to deal with all input chunks.

Subscribers: aheejin, llvm-commits

Differential Revision: https://reviews.llvm.org/D42625

llvm-svn: 323621
2018-01-28 19:57:01 +00:00
Sam Clegg 67abf53961 [WebAssembly] Don't duplicate functions in table output
Previously, we were ensuring that the "output index" for
InputFunctions was unique across all symbols that referenced
a function body, but allowing the same function body to have
multiple table indexes.

Now, we use the same mechanism for table indexes as we already
do for output indexes, ensuring that each InputFunction is only
placed in the table once.

This makes the LLD output table denser and smaller, but should
not change the behaviour.

Note that we still need the `Symbol::TableIndex` member, to
store the table index for function Symbols that don't have an
InputFunction, i.e. for address-taken imports.

Patch by Nicholas Wilson!

Differential Revision: https://reviews.llvm.org/D42476

llvm-svn: 323379
2018-01-24 21:45:25 +00:00
Sam Clegg 1963d71cb8 [WebAssembly] Simplify generation of "names" section
Simplify generation of "names" section by simply iterating
over the DefinedFunctions array.

This even fixes some bugs, judging by the test changes required.
Some tests are asserting that functions are named multiple times,
other tests are asserting that the "names" section contains the
function's alias rather than its original name

Patch by Nicholas Wilson!

Differential Revision: https://reviews.llvm.org/D42076

llvm-svn: 322751
2018-01-17 20:19:04 +00:00
Sam Clegg 4e07ecb5ab [WebAssembly] Remove unused member variable. NFC.
Patch by Nicholas Wilson!

llvm-svn: 322731
2018-01-17 18:58:50 +00:00
Sam Clegg 2a06afae16 [WebAssembly] Add --export flag to force a symbol to be exported
This is useful for emscripten or other tools that want to
selectively exports symbols without necessarily changing the
source code.

Differential Revision: https://reviews.llvm.org/D42003

llvm-svn: 322408
2018-01-12 22:10:35 +00:00
Sam Clegg 408064ef1e [WebAssembly] Don't allow functions to be named more than once
Even though a function can have multiple names in the
linking standards (i.e. due to aliases), there can only
be one name for a given function in the NAME section.

Differential Revision: https://reviews.llvm.org/D41975

llvm-svn: 322383
2018-01-12 17:56:15 +00:00
Sam Clegg 20db381b90 [WebAssembly] Refactor symbol and symbol table to remove WasmSymbol references
This WasmSymbol types comes directly from the input objects
but we want to be able to represent synthetic symbols too.

This is more in line with how the ELF linker represents symbols.

This change also removes the logic from Symbol::getVirtualAddress
for finding the global address and instead has the InputFile
provide this.

Differential Revision: https://reviews.llvm.org/D41426

llvm-svn: 322145
2018-01-10 00:52:20 +00:00
Sam Clegg 8d146bbc0c [WebAssembly] Output functions individually
The code section is now written out one function
at a time rather than all the functions in a given
objects being serialized at once.

This change lays the groundwork for supporting
--gc-sections.

Differential Revision: https://reviews.llvm.org/D41315

llvm-svn: 322138
2018-01-09 23:56:44 +00:00
Sam Clegg 87e61923a4 [WebAssembly] Write out undefined symbol addresses as zero
The addresses of undefined symbols that make it into the final
executable (i.e. weak references to non-existent symbols) should
resolve to zero.

Also, make sure to not include function in the indirect function
table if they are not included in the output.

Differential Revision: https://reviews.llvm.org/D41839

llvm-svn: 322045
2018-01-08 23:39:11 +00:00
Sam Clegg 574d7ce954 [WebAssembly] Base imports on Symtab. NFC.
Since imports are undefined symbols we know we can
find all of them my looking at the symbol table alone.
(i.e. imports cannot be have local binding).

This will be strictly faster and also allows us
to to remove a method from Symbol class

Differential Revision: https://reviews.llvm.org/D41304

llvm-svn: 320847
2017-12-15 19:23:49 +00:00
Sam Clegg fc1a912b9b [WebAssembly] De-dup indirect function table.
Create the indirect function table based on symbols rather
than just duplicating the input entries.  This has the
effect of de-duplicating the table.

This is a followup to the equivalent change made for globals:
  https://reviews.llvm.org/D40859

Partially based on a patch by Nicholas Wilson:
  https://reviews.llvm.org/D40845

Differential Revision: https://reviews.llvm.org/D40989

llvm-svn: 320428
2017-12-11 22:00:56 +00:00
Sam Clegg 31de2f0ccf [WebAssembly] Add -u/--undefined argument handling
Adds a new argument to wasm-lld, `--undefined`, with
similar semantics to the ELF linker. It pulls in symbols
from files contained within a `.a` archive, forcing them
to be included even if the translation unit would not
otherwise be pulled in.

Patch by Nicholas Wilson

Differential Revision: https://reviews.llvm.org/D40724

llvm-svn: 320004
2017-12-07 03:19:53 +00:00
Sam Clegg 4eedcfc946 [WebAssembly] Improve support linker synthetic symbols
This is part of larger change to add synthetic symbols
for section start/end points and init/fini_array:
  https://reviews.llvm.org/D40760

Allows synthetic global symbols to have an explicitly set
virtual address.

Differential Revision: https://reviews.llvm.org/D40843

llvm-svn: 319813
2017-12-05 19:05:45 +00:00
Sam Clegg 7e7566323d toString function take a const refs where possible
Differential Revision: https://reviews.llvm.org/D40824

llvm-svn: 319787
2017-12-05 16:50:46 +00:00
Sam Clegg 4b27c0554c Reland "[WebAssembly] Add support for visibility flag""
Subscribers: jfb, dschuff, jgravelle-google, aheejin, sunfish

Differential Revision: https://reviews.llvm.org/D40773

llvm-svn: 319627
2017-12-03 02:38:04 +00:00
Heejin Ahn 675147b54d [WebAssembly] Revert r319592 "Add support for visibility flag"
r319488 reportedly broke one of LLVM bots (ubuntu-gcc7.1-werror), and this patch
depends on that patch.
See http://lab.llvm.org:8011/builders/ubuntu-gcc7.1-werror/builds/3369 for
details.

llvm-svn: 319603
2017-12-02 02:05:50 +00:00
Sam Clegg e7487e4c92 [WebAssembly] Add support for visibility flag
Patch by Nicholas Wilson

Differential Revision: https://reviews.llvm.org/D40690

llvm-svn: 319592
2017-12-01 22:37:25 +00:00
Rui Ueyama 69989bdbf2 clang-format.
llvm-svn: 319512
2017-12-01 02:11:29 +00:00
Sam Clegg b862159683 [WebAssembly] Allow function signature checking at link time
This change allows checking of function signatures but
does not yes enable it by default.  In this mode, linking
two objects that were compiled with a different signatures
for the same function will produce a link error.

New options for enabling and disabling this feature have been
added: (--check-signatures/--no-check-signatures).

Differential Revision: https://reviews.llvm.org/D40371

llvm-svn: 319396
2017-11-30 01:40:08 +00:00
Sam Clegg c94d393ad5 [WebAssembly] Initial wasm linker implementation
This linker backend is still a work in progress but is
enough to link simple programs including linking against
library archives.

Differential Revision: https://reviews.llvm.org/D34851

llvm-svn: 318539
2017-11-17 18:14:09 +00:00